Slide 1

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 2

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 3

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 4

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 5

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 6

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 7

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 8

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 9

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 10

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 11

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 12

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 13

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 14

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 15

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 16

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 17

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 18

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 19

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 20

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 21

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 22

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 23

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 24

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 25

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 26

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 27

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 28

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 29

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 30

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 31

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 32

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 33

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 34

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 35

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 36

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 37

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 38

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 39

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 40

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 41

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 42

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 43

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 44

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 45

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 46

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 47

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 48

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 49

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 50

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 51

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 52

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 53

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 54

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 55

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 56

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 57

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 58

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 59

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 60

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 61

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 62

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 63

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 64

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 65

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 66

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 67

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 68

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 69

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 70

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 71

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 72

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 73

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 74

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 75

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 76

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 77

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78


Slide 78

CONFOCAL MICROSCOPY
IN A NEW LIGHT

Introduction to Confocal Microscopy

Title: Introduction to Confocal Microscopy
Presented by: Dr. Andrew Dixon
Date: May 2009

An Introduction to Confocal Microscopy
•
•
•
•
•
•
•

3

What is the problem?
Marvin Minsky’s idea
The confocal principle
The power of confocal imaging
Increasing imaging speed
Imaging in 3-D
Summary of key points

What is the Problem?
Optical microscope images contain both in-focus and out-of-focus detail
How can one produce an image which only includes the in-focus detail?

4

All-in-Focus

True color information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

5

Marvin Minsky’s Idea
Instead of collecting the complete
image at one time, Minsky
proposed to build up the image
‘point by point’.
In this way one can introduce
additional optical components in
the light collection path to block the
out-of-focus light from contributing
to the image.

6

Marvin Minsky
Inventor of the confocal
microscope
Harvard (1955)

US Patent 3,013,467

The Confocal Principle
The sample is illuminated with a focused spot of
light.
detector
Confocal aperture

Light from the sample is re-focused at the confocal
aperture.
Only in-focus signal reaches the detector

illumination

X
X/Y Image

Y
Focus Cone

sample

7

Specimen

The Optical Section

optical section - micron

18
16
14
12
10
8
6
4
2
0
0

0.5

1

1.5

lateral resolution - micron

Optical section ‘thickness’ depends on
objective lens NA. Lateral and axial
resolution are related.

8

The Power of Confocal Imaging
Conventional image

In the mid 80’s mirror scanning
systems were developed that
adapted a conventional microscope
for confocal imaging.

(Dr. W.B. Amos,
MRC Cambridge)

Confocal image

Scientists became very excited by
the images they could obtain,
without having to prepare very thin
section samples.
Bio-Rad MRC-500

Example images show tubulin
structure in fertilized sea urchin egg
immuno-labelled for fluorescence
contrast. (scale bar 50 micron)

9

Increasing Imaging Speed
Scanning a focused illumination spot,
point by point is relatively slow.
Several alternative schemes have
been developed to increase imaging
speed.

One approach is to illuminate the
sample simultaneously with multiple
spots of light.
Another approach is to illuminate
the sample with a focused line of
light. This is the system used in the
Axio CSM 700 from Carl Zeiss.

10

From Optical Section to 3-D image
A series of optical section images can be combined
into a single ‘all in focus’ image, or manipulated to
provide quantitative information about surface
profile, surface roughness etc.

11

…A World of Possibilities

Biological Research
Neurons in a Brainbow transgenic
mouse, labeled with multiple hues
of fluorescent proteins. Extended
focus image

(Dr. J. Livet Harvard University)

12

Material Sciences
True color information in 3D topography
Surface profiling. Surface roughness

In Conclusion…

•

Exceptional contrast optical section images

•

Non-contact probing and profiling

•

Not restricted to single color imaging

•

Imaging at high speed

•

Qualitative and quantitative 3-D characterization

•

High resolution surface profiling

Confocal microscopy delivers…

13

End

14

Advanced Confocal Microscopy:
Axio CSM 700

Title: Advanced Confocal Microscopy: Axio CSM 700
Presented by: Dr. Franz Reischer
Date: May 2009

Axio CSM 700 – System Overview

Xe illuminator, conf. microscope, controller, user PC
16

Innovative Confocal Method
1

1

Xe illuminator

2

Multi slit grid for scanning
instead of scan mirrors

3

Beam splitter

4

Sample / focal plane

5

Digital detector which also

2

5

3

provides digital confocal
apertures

17

4

3D Image Acquisition
3D topographies, height maps, profilometry,
and roughness analysis are all based on the
acquisition of Z stacks.

Axio CSM 700 always measures the current
position of the stage using a laser linear scale

with 10 nm increments and 24 bit.

18

Advantages
•

High acquisition speed (up to > 100 fps)

•

True colour confocal microscopy

•

High resolution

 Optical 3D profilometer

19

Optical resolution: XY
I

No resolution
No contrast

20

x,y

Optical resolution: XY
I

No resolution
No contrast

21

x,y

Cut-off distance reached,
but contrast is equal to zero

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61
Maximum resolution
Rayleigh criterium

22

Strictly
confocal

Classical

Optical resolution: XY
I

x,y

No resolution
No contrast

Cut-off distance reached,
but contrast is equal to zero

d(x,y) ~ f * l / NA
f= 0.37 … 0.61

Maximum resolution
Rayleigh criterium

23

Strictly
confocal

Classical

Resolution
Maximum contrast

Lateral Resolution Limit: Grid
Sample:
Nanoscale critical dimension standards (supracon AG Jena)
Colour channel: blue
Objective:
Epiplan-APOCHROMAT 150x/0.95
200 nm L&S

24

Resolution limit

150 nm L&S

Axial Detection Limit
Test Sample:
Validated depth measurement
sample with 80 nm steps
Objective:
EC Epiplan-APOCHROMAT 100x/0.95

True height:
Measured height:
Difference:

25

80 nm
87 nm
7 nm

High Range of Samples
•

Surfaces with low as well as high reflectivity, incl. polished metals &
totally smooth glass.

26

•

Top surface of coatings and substrates under transparent layers.

•

Film thickness measurement of transparent layers starting at ~ 1 µm

Comparison of confocal microscopy
Typical light
microscope

Without
preparation
High resolved
viewing with
large depth of
field
Display in true
colour
3D measurements
in submicrometer
range

27

Scanning electron
microscope

Tactile instruments
for roughness
measurement

True colour
confocal
microscope

Axio CSM 700 …
… opening up
new worlds of microanalysis.

28

Applications for Topographic Measurements in Materials Engineering

Title: Applications for Topographic Measurements in Materials
Engineering
Presented by: Ralf Loeffler
Date: May 2009

Application Examples
•
•
•

30

Geometry inspection on cutting plate.
Failure analysis on turbine blade.
Tribology on high performance steel.

Geometry Inspection – Cutting Plate

31

•

Turning and milling are the most important machining steps in
metal processing / machining

•

Cutting plates consist of coated (TiCN) hard-metal (WC)

•

Important factors on wear behaviour: plate material and geometry
of cutting edge, but also material of workpiece

•

Empirical approach to improve wear properties of cutting plates
 mostly qualitative characterization of tool wear

•

Quantitative characterization enables accurate measurement of
important parameters influencing tool performance
(roughness and geometry of cutting edge, e.g. honing and erosion)

•

Goal: high tool life / endurance at high feed rates

Geometry Inspection – Cutting Plate
top view

3D-µCT surface rendering

side view

resolution: 10 µm/vx
Functional parameters influencing performance: angle and radius of cutting edge

32

Geometry Inspection – Cutting Plate
Definition of functional parameters

rake
honing 1 (r1)
chamfer
honing 1 (r1)
honing 2 (r2)

honing 2 (r2)
tool flank

33

Geometry Inspection – Cutting Plate

r1
r2

focus image

rake angle

34

Geometry Inspection – Cutting Plate

only one cutting edge radius (honing) 
approx 200 µm
wear groove
height: approx. 11 µm
width approx. 49 µm

35

Geometry Inspection – Cutting Plate
Quantitative Measurement: new plate
Roughness - along cutting edge

36

Rz = 2.2 µm

Ra=0.3 µm

Geometry Inspection – Cutting Plate
Quantitative Measurement: worn plate
Roughness - along cutting edge

37

Rz = 10.9 µm

Ra=1.0 µm

Geometry Inspection – Cutting Plate
New cutting plate
Roughness (Ra)
(along cutting edge)

•

0.3 µm

•

1.0 µm

Roughness (RZ)
(along cutting edge)

•

2.2 µm

•

10.9 µm

rake angle

•

18 deg

•

19 deg

cutting edge radius

•

•

not determined

•

47 µm
100 µm

•

no wear

•

mechanism:
adhesive wear

Features

38

Worn cutting plate

Geometry Inspection – Cutting Plate
Conclusion
• Complex sample geometry limits accessibility
 positioning of sample essential
•

Standard methods limited to qualitative evaluation
 Confocal Axio CSM 700 allows qualitative and quantitative
analysis

•

Wear can be quantified by means of roughness, flattening
(erosion) and angle widening

39

Failure Analysis – Turbine Blade

40

•

Sample:
blade of compressor unit (turbine)

•

Status:
failed, surface wear detected

•

Material:
austenitic steel

•

Manufacturing:
milling in one piece, blades not welded
on ring

•

Environment:
rotation speed approx. 300 m/s in
hot vapour atmosphere

Failure Analysis – Turbine Blade
Top view: sections with distinct surface wear
no wear

high wear

intermediate wear

section 1

section 2

section 3

section 1

41

section 2

section 3

Failure Analysis – Turbine Blade
no wear

Roughness Measurement
Note milling marks

area measurement

Ra = 0.7 µm

Rz = 27.3 µm
topography profile

42

Failure Analysis – Turbine Blade
intermediate wear

Roughness Measurement
area measurement

Ra = 1.4 µm

43

Rz = 21.7µm

Note wear and milling marks

topography profile

Failure Analysis – Turbine Blade
high wear

R1= 630 µm
Depth = 65 µm

Note deep wear marks
Roughness Measurement
area measurement
Ra = 2.7 µm

44

Rz = 109.4 µm

Failure Analysis – Turbine Blade
1

2

R1 = 530 µm
Depth = 65 µm

1

3

4

5

high wear

R1 = 550 µm

1

Depth = 65 µm

3

4

3

2

4

5

5

Note aligned wear marks
Roughness Measurement
area measurement
Ra = 4.0 µm

45

Rz = 45.4 µm

2

3

4

5

Failure Analysis – Turbine Blade
high wear

R1 = 450 µm
Depth = 70 µm

2D topography profile

Image acquisition: 50x

46

Failure Analysis – Turbine Blade
Section 1
No wear

Section 3
Intermediate wear

Roughness (Ra)

•

0.7 µm

•

4.0 µm

•

1.4 µm

Roughness (RZ)

•

27.3 µm

•

45.4 µm

•

21.7 µm

Features

•

Milling marks
dominate
No wear marks

•

Deep, round
wear marks
Milling marks
barley visible

•

Small, rather
round wear
marks
Milling marks
clearly visible

•

47

Section 2
High wear

•

•

Failure Analysis – Turbine Blade
Conclusion
•
•

•

48

Wear can be quantified by means of Ra-value
Due to large spherical defects Rz-value increases in areas with
“coarse” defect structure
Shape of defect may be linked to prevailing mechanism, either
erosion or cavitation

Tribology – Maraging Steel Composites
•

Tribology testing of new, exceptionally hard
Metal-Matrix-Composites  fuel injection systems

•

Wear depth < 2 µm  white light interferometer

•

Need: reliable, accurate and fast measurement system with high precision
and visual presentation of the data

Pin on disc testing by 1500 MPa

need for materials with
excellent wear properties
49

Tribology – Maraging Steel Composites
Wear mark virtually absent (depth < 2 µm)  limited analytical methods available

Note: only ceramic exhibits
signs of wear and tear outs

SEM micrograph of a steel-ceramic
composite before testing

50

SEM micrograph of a steel-ceramic
composite after testing

Tribology – Maraging Steel Composites
Wear mark on a steel-ceramic composite  excellent graphical representation

LOM (bright field) micrograph of a wear 3D visualization of a wear mark on a
mark on a steel-ceramic composite
steel-ceramic composite using the
Axio CSM 700

51

Tribology – Maraging Steel Composites
Axio CSM 700 analysis with all-focus image
•

Excellent visualization

•

Wear mechanism: only by
leveling ceramic particles

•

Axio CSM 700 data in accordance
with SEM micrograph observation

•

Scanning of entire wear mark
at high magnification

width = 300 µm

height ≤ 1 µm

52

Tribology – Maraging Steel Composites
Axio CSM 700 vs. White Light Interferometer
Identical results to the WLI analysis method
Advantages of the Axio CSM 700 are its speed and visual representation of
data as all-in-one snapshots with height, focus and true color images

WLI 2D-profile
Axio CSM 700 (20x)

53

End

54

Exotic Applications in Confocal Microscopy

Title: Exotic Applications in Confocal Microscopy
Presented by: Dr. Steve Metcalfe
Date: May 2009

Example Applications
•
•

•
•
•
•
•
•
•
•
•
•

56

Foam
Paper
CCD array
Polymer Film on Metal Substrate
Electronics PCB
Electronics sub assemblies
Solar Cell (Photo Voltaic Materials)
SiC Wafers
Light Guide
MicroLens Arraay
Fresnel lens
Precision Assembly STFC

Foam

Dynamic processes like foam can be accessed, (as long as they stay still long enough to
collect the images) The high speed frame mode can help here.
The structures of foam are very important for a number of disciplines.

57

Paper & Fabrics
These days all materials come
under scrutiny and fibrous
materials like Paper and Fabrics
cannot escape the quest for
knowledge in the development of
new materials.

For example, ink penetration is used to examine ink quality as well as counterfeit material
compared to original writings.
Fabrics can also be examined for penetration of spray on coatings and surface
contamination
Examination of filters for particles and particle volume are also examples

58

Ink on Paper

Pigment ink keeps on the surface and dye ink penetrates into the paper.
SEM also can detect the same phenomenon but the SEM could not
visualize colour information.

59

CCD with Bayer Mask Sensor

Objects which are arrays can be inspected.
Image analysis measurements can be made by thresholding out based on colour. It is then
possible to measure individual features, Counting sizing and volume data are all available.
Out of interest, note that there are more green pixels than read or blue.
This is due to the colour response of the human eye

60

Polymer Film on Metal Substrate

61

•

Laminate. Using advanced techniques both surfaces or a laminate can be inspected.

•

2 individual scans are completed one for the top surface and one for the lower.

•

Both of these scans can then be superimposed and viewed on the 3D display.

•

Layer thickness can then be ascertained.

PCB Track - Conductive strip

It is easy to see the 3D topography of this sample.

62

Rendered PCB Track

The surface image can be rendered with a true colour image as above or
colour coded in height.
A combination of these display techniques help to reveal the surface structures in their true
form.

63

Measurements

Data relating to the angle and radius can be obtained. Also distance and height at the
same time.
Compared to tactile methods we can see both the small and large surfaces.

64

Solder Bumps

No noise but true colour information in 3D topography
Bump dimension: 13.8 µm height and 79 µm width

65

TFT Spacer – Touch Panel Spacer

Measurements and images are presented for these common electronic spacers.
A touchscreen is a display which can detect the presence and location of a touch within
the display area. The term generally refers to touch or contact to the display of the
device by a finger or hand. (Wikipedia)
Now a common place technology used on games, mobile phones and many other
electronic devices.

66

Photo Voltaic

Advanced thin-film photovoltaic cells are multi layer structures.
Surface topography, roughness and form are all important to the performance of the material

67

Laser Scribes on Thin Film Solar Cells
Reports and data are assembled from
all the data sources.
Namely topographical data from the
Z scan.
Rendered data in full colour.
A horizontal scan across the laser
scribe is overlaid and the
corresponding with measurements
presented.
The entire length of the scribe can be
measured and resulting data for
average, min, max and Standard
Deviation can be found.

68

Photo Voltaic at 100 x Objective

Full colour data is available at high magnifications

69

Pattern on SiC wafer

Grooved pattern on SiC coated with
SiO2.
In normal reflection mode distances
are measured too short because of the
SiO2 coating.
New first peak method and knowledge
of refraction index gives correct
distances between SiC top surface and

grooves.

70

Metal Mold for Light Guide Panel

These complex surfaces can be visualised readily with confocal techniques.

71

Micro Lens Array

Microlenses are small lenses, generally with diameters less than a millimetre (mm) and often as small as
10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical
quality but sometimes unwanted effects arise due to optical diffraction at the small features.
Microoptics in nature. Examples of microoptics are to be found in nature ranging from simple structures
to gather light for photosynthesis in leaves to compound eyes in insects. As methods of forming
microlenses and detector arrays are further developed then the ability to mimic optical designs found in
nature will lead to new compact optical systems

72

Fresnel lens

A Fresnel lens is a type of lens invented by French physicist Augustin-Jean Fresnel.
Originally developed for lighthouses.
Measurements of surface properties are easily achieved.

73

Topography of cosmetics materials

3D image of human skin,
silicone replica

Lipstick

Collected images can be used to
measure skin replica
blending condition of lipstick,
manicure and foundation.
3D image of human hair

74

Precision Assembly & Manufacture

STFC have extensive expertise in the process of micro-fabrication at the
sub-mm level and an understanding of the problems that this poses

75

Precision Assembly & Manufacture

Laser targets assembled under a microscope.
Some items are conical in shape.
Roughness of curved surfaces will be measured.
A difficult task for other instruments due to the conical shape of the part.

76

Acknowledgements

77

•

Wikipedia for historic information.

•

Chris Spindloe STFC Rutherford for his help with the Laser Target images.
Last 2 slides

End
Questions and Answers

78