Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

HI all here.

I am an Electronic Oldtimer haveing gone thru all sorts of PCB hobby
fabrication. Currently most of my PCB´s are milled
( Home Made Router ..proxxon table..cheap overhead grinder as spindle
drive..0.5 to 1.0 mm endmills used ..turbocnc as software )

Since the size of the x-y table is limited and for more complex
boards the minimum trace distance is limited by the bit size as well
as they are not easy to get for low budget, i needed a second
process.
In the Old days, i used normal photorestist process. As this was
never very constant, doing just a few boards every now and then, i
also looked into Toner Transfer...

First i had unconstant and not good results. I found out a big
mistake was using 3rd Party Toner with my Laserjet 2100. Original
Toner works much better...
Second was to find a way to set the Density of the beast, which is
not really simple. Finally i found a free tool somewhere to set the
density to full. Now even better results.

Second was the Paper , many referrals found in Newsgroups refer to
paper which one cannot find in Germany. The "Reichelt" Catalogue
works well but i hate glueing the small pages to a A4 paper. So i
looked around for some paper that works as good, but in A4 or Letter
Size.

I found the following to work good:

ARP Datacon catalogue, works but is not so easy to dissolve
BCS Catalogue, works very good. Solid paper which dissolves easily,
leaving some Clay on the traces.
Semi Transparent Paper used for Technical Drawings: Works very good,
sometimes just "flys" away fron the board after transfer is done.

Next step was to get rid of the problems with IRONING ( especially
smearing) , i tried a small laminator from "Olympia" for Business
Cards etc. This one did not heat enough and after attaching a
homemade Temperature Control i got it hot enough to transfer, but it
died soon as the gears melted.

Next i tried a cheap A4 Laminator . This one after replacing the
electronics again with my own controller, works brilliantly. Be sure
to remove all the plastic vover and mount it to a wood or otherwise
heat resistant base. I run the Board thru the laminator for 4-6 times
at the normal speed. Pulsar Green TTF works also with lower
temperature setting.
Take care of the 220 Volts ( Ground the Metal parts ! ) and isolated
all wiring.

I will upload a sample picture how it looks.

If anyone wants the Schematics/Layout ( eagle ) for my AVR based
(4433 or Mega 8 , any that has Analogue input and can attach a LCD )
contact me. Program is Bascom. Speed regulation ( on/off ) is already
on the board but not yet programmed. Basically even a Tiny 45 should
do this job well ( without LCD )