Slide 1

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 2

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 3

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 4

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 5

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 6

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 7

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 8

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 9

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 10

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 11

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 12

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 13

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 14

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 15

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 16

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 17

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 18

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 19

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 20

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 21

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 22

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 23

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 24

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 25

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 26

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 27

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 28

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 29

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 30

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 31

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 32

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 33

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 34

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 35

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 36

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com


Slide 37

Conformal Coatings
Enhanced protection for enhanced PCB performance

Introduction
Why Coat?

CONFORMAL COATINGS



A newly manufactured printed circuit board will generally perform
well but performance will quickly deteriorate.



Common causes of deterioration and PCB failure include:
o Atmospheric moisture
o Contamination of the surface with airborne ionic material
o Electrostatic attraction of dust to the surface
o Corrosive environments, such as salt fog



Conformal coatings can be applied to a PCB giving protection
against the environment, extending the life of the board and
therefore can be used in a vast array of electronic applications.

CONFORMAL COATINGS


Conformal coatings are thin coatings, typically 25-75 microns, which
‘conform’ to the contours of a PCB.



The ideal conformal coating will have performance requirements that
include:
o Good electrical properties
o Low moisture permeability
o Good mechanical durability
o Excellent adhesion properties
o Good thermal resistance



Additional properties such as flame retardance or chemical resistance
may also be required.

CONFORMAL COATING TERMINOLOGY
Different chemistries utilised in conformal coating technology require different types of
cure. It is important to understand the terms used in conformal coating in under to
understand cure schedules:
‘Tack Free’ – this is the time at which the coating is no longer tacky but slight indentations
may be left in the coating when pressed firmly
‘Touch Dry’ – this is the time at which the coating is dry enough to touch without leaving
any fingerprints on the surface of the coating
It is important to note that some coatings are very soft and can feel tacky even when fully
cured. The touch dry time in these cases is more a reference to when you can move the
board without affecting the coating

‘Cure Time’ – this is the time at which the coating is fully cured and will offer protection
It is also important to note that most coatings actually reach their optimum cure level after
around 7 days but they will provide protection prior to this

CONFORMAL COATING APPLICATION
Conformal coatings can be brushed, dipped or sprayed depending on the
requirements. Customers often specify their desired application method.

Brushing:

Advantages

Disadvantages

Cost effective

Uneven coating

Ideal for small scale
production

Difficult to get under
components

Selective coating

Only one side at a time can
be coated

CONFORMAL COATING APPLICATION
Dip Coating:

Advantages

Disadvantages

Ideal for medium scale
production

Initial capital outlay

Uniform coating thickness

Masking essential for
connectors

Easy to operate machinery

Special extraction may be
required

Both sides can be coated
at the same time

Suitable for higher
viscosity materials

Coating can penetrate under
components

Operator training required
but not difficult

CONFORMAL COATING APPLICATION
Spraying – aerosol or manual spray gun:

Advantages

Disadvantages

Cost effective

Overspray can occur

Ideal for bench top work and
repair

Difficult to get under
components

Ideal for small to medium
scale production

Special extraction may be
required

Convenient

Only one side at a time can
be coated

SPRAYING

CONFORMAL COATING APPLICATION
Selective Spraying:

Advantages

Disadvantages

No masking required

Initial capital outlay

Uniform thickness

Low under component
penetration – requires good
flow properties with the coating

Automated process – good for
Special extraction may be
inline procedures
required – but can be linked to
the machine easily

Ideal for all scales of
production

Requires a trained operator to
set the software

SELECTIVE COATING

SELECTIVE COATING

Application Conditions
• Temperature – Affects viscosity and evaporation rate
• Humidity – Contaminates dip coat tanks, blooming in hand spray
and affects curing / pot life.
• Ventilation – Affects operators

Product Choice
Coating Options

Considerations for Choice
As there are many different applications for conformal coatings, there are also a
number of elements that must be considered as part of the selection process:

Coating properties
•
•
•
•
•
•
•
•

Adhesion
Flexibility
Temperature range
Mechanical durability
Electrical performance
Environmental performance
Flame retardance
Mould resistance

Application
•
•
•
•
•
•
•
•

Viscosity/application
Touch dry time
Full cure time
Curing conditions
Is re-work required?
Cost
Quality
Approvals required?

CONFORMAL COATING TYPES
Conformal coatings are available in a number of different chemistry types
and also cure via different mechanisms.
The different types of conformal coating include:
o Solvent-based – Evaporation Cure
o Solvent-based – Heat Cure
o Low VOC/Water-based – Evaporation/Heat Cure
o Non-VOC – Moisture Cure
o UV Cure – Dual Cure: Moisture/Heat
Common conformal coating chemistries include:
o Acrylic
o Polyurethane
o Silicone
o Modified-silicone

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a flexible, transparent & unique modified silicone conformal
coating specifically designed for the protection of electronic circuitry.
Key Features:
o Resistant to most solvents, lubricants and chemicals associated
with most aerospace and automotive applications.
o Excellent adhesion under various climatic conditions to a variety of
substrates, including high altitude/decompression
o Fluoresces under UV light for ease of inspection.
o Extreme operating temperature range (-70˚C to +200˚C)
o Excellent electrical properties

DCA (SCC3) MODIFIED SILICONE COATING
DCA is a solvent based coating and can be sprayed, dipped or brushed.
For optimum properties, DCA should be heat cured (2hrs at RT, 2hrs @ 90˚C
advised). If RT cured then the solvent resistance will be significantly reduced.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals
o

Def-Stan 59/47 – Standard now obsolete

o

UL746 – File Number E138403

DCA (SCC3) MODIFIED SILICONE COATING
The DCA (SCC3) Range includes:
o
o
o
o
o
o

DCA-FD – Fast-dry version
DCA-HT – With improved high temperature performance
DCR – Opaque red version
DCB – Opaque black version
DCRT – Opaque red, high viscosity version
DCE – Thixotropic gel version (dam and fill applications)





Unique range of products based on a silicone modified alkyd
Avoids issues associated with silicone migration
Easier processing than standard silicones
Performance compares with many silicone conformal coatings

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a flexible and transparent acrylic conformal coating for the protection of
electronic circuitry.
It has been formulated to meet many of today’s commercial applications, meeting
both Military and IPC standards.
Key Features:
o Toluene free product.
o Fluoresces under UV light for ease of inspection.
o Wide operating temperature range (-65˚C to +125˚C)
o Excellent Dielectric properties
o Clear coating with excellent resistance to yellowing when exposed
to UV light

TFA – TOLUENE FREE ACRYLIC COATING
TFA is a solvent based coating and can be sprayed, dipped or brushed.
Should be used with DCT thinners and removed with CCRG – Electrolube
Conformal Coating Remover Gel
Approvals

o

UL746 Approved
IPC-CC-830 approved
Automatically meets MIL-46058-C



Also available: AFA – Aromatic Free Acrylic

o
o

VOCs or Volatile Organic Compounds are carbon based
compounds which vaporise easily under ambient
conditions
VOCs contribute towards the formation of ground level
ozone
Such pollution can have many detrimental effects on the
environment, damaging forests and vegetation
In addition, some materials classed as VOCs can act as
irritants and over exposure can lead to a variety of health
problems

VOC DEFINITION

EU Solvents Emissions Directive
“Any organic compound having at 20˚C a vapour
pressure of 0.01kPa or more, or having
corresponding volatility under the particular
conditions of use”

UVCL - UV Cure
• Extremely rapid initial cure schedule
• Ideal for high volume production
• In-line process, curing equipment required

• Very high level of protection; highly cross-linked coating
• Excellent chemical and solvent resistance

• Using a dual cure system can ensure that in shadowed areas under
components the coating still cures and protects the PCB
• Moisture
• Heat

• UV cure coatings are available as 100% solids materials
• Non-VOC options

WBPS – WATER-BASED COATING
WBPs is a water-based conformal coating, based on polymeric
materials which has been specifically formulated for the protection of
electronic circuitry.
It offers an excellent blend of both physical and electrical properties in a
more environmentally and user friendly package when compared to
conventional solvent based conformal coatings.
Non-flammable and contains very low levels of VOC’s.
WBP is for dipping/brushing applications whilst WBPS (Sprayable) has
been specifically formulated for use in selective film coater equipment.

WBPS – WATER-BASED COATING
Key Features:
o

o
o
o
o
o
o

Environmentally friendly and eliminates hazards associated with
solvent based conformal coatings
Excellent solvent resistance.
Very low VOC content
NMP (N-Methyl pyrrolidone) free.
Fluoresces under UV light for ease of inspection.
Excellent adhesion on a wide variety of substrates.
Excellent Dielectric properties and resistant to mould growth.

PUC – POLYURETHANE COATING
PUC is a tough, flexible, modified polyurethane conformal coating and is
specifically designed for the protection of electronic circuitry, particularly in harsh
conditions.
Key Features
o Excellent adhesion to a wide variety of substrates.
o Fluoresces under UV light for ease of inspection.
o Good resistance to a wide variety of chemicals including acids and
alkalis.
o Wide operating temperature range.
o Excellent mechanical properties including abrasion resistance
o Solvent-based, can be sprayed, dipped or brushed
o Should be used with PTH thinners and removed with CCRG

OTHER COATINGS
Modified Silicone – LFCC, FSC (Modified with acrylic; up to 125˚C)
Acrylic – HPA (MIL Approved), APL, AFA, APLSP (Sprayable version), TRV
Water-Based – WBP (Dipping Version)
Polyester – CPL
Surface Modifier – TFCF (Fluorinated)

CHOOSING THE RIGHT PRODUCT
 High Temperature – DCA (SCC3) Range
 Excellent Clarity – TFA or an Acrylic Coating
 Chemical Resistance – PUC or DCA (SCC3) Range
 Cosmetic Appearance – CPL (no UV trace)
 Low Solvent Content – WBP or WBPs
 Reworkable – Acrylic Coatings or FSC
 UL Approved – DCA and TFA
 UV Cure - UVCL

Polyester

Modified Silicone
DCA
FSCP
FSC

CPL

UV Cure
UVCL

Polyurethane
PUC
PUCAF

Opaque
DCRT
DCR

Acrylic

DCB
HPA

TFA
Water-Based

APL
AFA

WBP

WBPs

Electrolube Conformal Coating Selector Chart
YES

UVCL
WBP(s)

Is low/non VOC required?

DCA (UL746)
UVCL (IPC-CC-830)
WBP(s)
PUC
PUCAF

NO

HPA (MIL-I-46058C)
TFA (IPC-CC-830/UL746)
AFA (UL746)
FSC (IEC61086)
YES

YES

NO

Is optical clarity required?
YES

Is chemical resistance
required?

YES

Is an approval
required?

NO

NO

Is an approval
required?

NO

YES

YES

Is a fast touch dry
time required?

YES

Is the operating temperature
below -55°C?

DCA/WBP(s)

NO
NO

APL

YES

Is easy removal for
re-work required?
NO

Is the operating temperature
above 130°C?

DCA

Conformal Coatings
Potential Problems

Adhesion Loss


Incorrect curing could cause adhesion loss. This could be due to
insufficient curing, i.e. the coating has not finished cross-linking.



It could also be a problem with removing masking material – ideally
this should be done when the coating is still soft.

Conformal Coatings
Rework Considerations

Coating Removal Products
• For acrylics, a solvent based product like Electrolube ULS is ideal
for quick and clean removal of the coating.

• For coatings with a higher chemical resistance, a product such as
Electrolube RRS will be required.
• For localised rework, a remover gel like Electrolube CCRG is ideal.

OTHER PRODUCTS
In order for conformal coatings to be applied correctly some complimentary
products are required:

• Thinners – where applicable conformal coatings are diluted to the required viscosity,
Electrolube have a range of thinners suitable for this process
• Masking – PCM and PCS are coating masks suitable for covering connectors during
the coating process

Thank You
For further information please visit www.electrolube.com