Transcript Toner Transfer Method for PCBs

Toner Transfer
Method for PCBs
One ham’s first attempts
to make PCBs at home
Jim Larsen, AL7FS
907-345-3190
[email protected]
QRP
Ver 1.0 3/22/06
By Jim Larsen, AL7FS
Page 1
Overview of Toner Transfer PCBs
•
•
•
•
•
•
•
•
•
•
QRP
First attempts at Printed Circuit Boards
What is toner transfer method?
My approach to toner transfer
Drawing the Schematic
Converting to a PCB layout
Preparing the Board, Laying down the Toner
Removing the Paper; Leaving the Toner
Etching the Board, cleanup and solder coat
Drilling, shearing and building
Comments and Suggestions
Page 2
First Attempts at PCBs
• Early years – sticky labels cut with a sharp
blade
• Sharpie permanent ink pens for resist
• Results worked but were pretty simple and
crude
QRP
Page 3
PCBs via Toner Transfer (TT)
Why even build my own boards?
Seemed like fun.
Cost can be low.
For over 40 years complex Boards stopped me.
Manhattan Style building is good but I never
seem to get started.
Front-end load the hard work; finish with fun.
So What is Toner Transfer
Method??
QRP
Page 4
Toner Transfer Method
• A method of creating a printed circuit board
(PCB) using a copy machine or a laser printer
to make apply the etchant resist pattern
• Software now available to create schematic
and PCB layout
• No expensive equipment is required but can
be helpful in the home
• A simple process once the basics are mastered
QRP
Page 5
AL7FS Approach
Equipment in the Toner Transfer Process
• A computer
• Free Demo Software – Up to 250 pins
• Laser Printer or Copier
• Various dishes for soaking or etching
• A household iron or a laminator
• Tarn-X, soap, scrubber, Acetone cleaner,
surgical gloves,
• Drill Press
• Carbide drill bits
• Shear or other method for cutting PCB
QRP
Page 6
AL7FS Approach
Equipment in the Toner Transfer Process
• A computer – Already had a computer
• Free Demo Software – DipTrace demo version
• Laser Printer or Copier – Decided to Buy Printer
• Various dishes - Already had on hand
• A household iron or a laminator – Laminator-eBay
• Tarn-X, soap, scrubber, Acetone cleaner, surgical
gloves – Had all but the scrubber
• Drill Press – Decided to buy a small one
• Carbide drill bits – Bought via eBay
• Shear or other method for cutting PCB – Will use a
friend’s shear
QRP
Page 7
Lets build a simple circuit:
•Zapper circuit schematic.
• From Dr. Clark's book
"The Cure For All
Diseases“
•Only the schematic is
provided from web source
• What to do……??
QRP
•http://www.members.aol.com/mas1911/index.html
Page 8
Dip Trace
–
Draw
the
Schematic
http://www.diptrace.com/
Diptrace has a Free Version: Freeware edition does not support
export to DXF, Gerber and N/C Drill, max. number of pins — 250.
QRP
Page 9
Zapper Schematic
QRP
Page 10
Diptrace Convert to PCB –Step 1
Next Step is to move the components
to the layout you would like.
QRP
Page 11
Run AutoRouter
Scale 400%
QRP
Page 12
Print to Transfer Paper
• Tried Inkjet Photo Paper with zero success
• Plain Costco bulk white paper worked
QRP
Page 13
Clean PCB Board
• Tarn-X First
• Board was old with
fingerprints
• Dishsoap and hot water
• Scrub down with
rough green scrub pad
from Carrs
• Don’t touch surface
from here to the end
QRP
Page 14
Transfer Toner to Board
QRP
Or Use a Clothes Iron
Page 15
Remove Paper from Toner
Soak 20+ Min. Warm,
Soapy Water
QRP
Page 16
Rub off the Paper
QRP
Page 17
Rub off the paper
QRP
Page 18
Circuit Ready for Etching
QRP
Page 19
Choices at This Point
• Etch all Four circuits
• Need to touch up traces and Pads
QRP
• Cut the best board free of others
• Needs No touchup – 3 good 1 bad
• Uses less toner
• Cut with hack saw, finish w/file
• Find a shear for cleanest cuts
Page 20
Etching the Board
• I used old Etching
Solution – 15 years old
(Not a good idea)
• Temperature of solution
was only about 68 degrees
(Not warm enough)
• Bottle says up to two
hours
• I took 65 minutes –
That’s too long
QRP
Page 21
Etching the Board
QRP
• Used a throw-away brush to gently wipe the
surface and keep fresh solution on the copper
Page 22
Etching the Board
• Copper slowly is eaten away
QRP
• Only the circuit will remain
Page 23
Etching the Board
• The Etching is complete
QRP
• Some circuits are good, others not good
Page 24
Etching the Board
• This one looks pretty good but with
QRP
some pitting
Page 25
Cleaning off the Toner
• Acetone was used to
clean off the Toner
from the circuit
pattern
•Left black smudges
on the board – No
answer for this yet
QRP
Page 26
Cleaning up the Traces
• My etch process
undercut the toner in
places
• I inspected each
circuit with a
magnifying glass
• In places I added a
jumper to assure
continuity
QRP
Page 27
Cleaning up the Traces
Solder Paste rubbed on
circuit
Temp. – 750 F
QRP
Solder Wick = solder
brush
Paint the traces with
Solder
Page 28
Cleaning up the Traces
• Solder on traces protects the copper from
corrosion
QRP
Page 29
Additional Cleanup
• Poor traces repaired with small wire and
soldered into place
QRP
Page 30
Additional Cleanup
• Poor traces repaired with small wire and
soldered into place
QRP
Page 31
Finishing touches
• Small drill press is
a requirement
•Small diameter
drill bits need drill
press
• Drill bits need to
be carbide tip drills
• Don’t breath the
dust from drilling
QRP
Page 32
Final Touches
• May Use toner transfer method again to
add component outlines on the top of the
board. Can use household iron or
laminator to fix the toner
• Solder in the components
• Test the circuit
• Install in a chassis as desired
QRP
Page 33
Final Comments
• This is my first attempt at toner transfer.
• I offer my observations as a learning tool
• I plan to keep trying new techniques
• There are Many variations on this
technique
• Board cleaning methods used by me not
best. (e.g., the acetone black smears)
• My etching technique undercut some traces
(Needs major improvement)
• Great potential with this technique
Give it a try Yourself !!
QRP
Page 34
Links for Toner Transfer
• http://www.diptrace.com/ HomePage for DipTrace
software
• http://groups.yahoo.com/group/diptr/ Mail List for
DipTrace
• http://groups.yahoo.com/group/Homebrew_PCBs Mail List for
homebrew PCBs
• http://max8888.orcon.net.nz/pcbs.htm another step by
step example
• http://www.Google.com/ search on “toner transfer
method”
QRP
Page 35
Alaska QRP Club
• No officers, no directors, no constitution &
No dues.
• Meets the Third Friday of every month - 7:00
PM (Some show for dinner at 6PM)
• Meet at Dennys (in the back room) on
DeBarr near Bragaw.
• Contact is Jim Larsen, AL7FS, 907-345-3190.
[email protected]
• http://www.qsl.net/kl7aqc/
QRP
Page 36
Questions?
QRP
Page 37