On Sat, 27 May 2006 09:39:04 -0700, "RST Engineering"
wrote:

I just got a very good "homebrew" PCB process set up using gloss photo paper
printed in a laser printer ironed onto the board for the resist and muriatic
acid / hydrogen peroxide for the etchant. Is this the way you are making
boards?

Jim

Hello Jim

I use a similar setup to make boards all the time and it works
reasonably well. No 8mil tracks tho. I just discovered some paper and
haven't tried to see how small I can make the traces yet. I've been
pretty sick for a few months and just haven't felt like messing with
it. The one board I did make using it had much sharper defined edges
and the drill guide holes etched nicely also with no residue left on
the board. I never did find any photo paper that didn't leave the
residue that needed cleaned off especially in the 25mil drill guide
holes. The paper is made by Pulsar and is Digi-Key P/N 182-1003-ND. If
you want to try it get the "GreenTRF" film to go with it, P/N
182-1021-ND. The GreenTRF film is just applied over the toner after it
is transfered from the paper and leaves the image on the board
completely sealed with a glossy green finish. I believe the paper was
about $1 per 8.5x11 sheet and I don't remember how much the "GreenTRF"
cost me, but it wasn't much for an 8in by 15ft piece.
I was making enough boards that I got myself a press designed for
making T-shirts. Actually my wife got tired of me complaining about
having to press so hard with the iron and bought it for me. It allows
me to set the temperature and the clamping force precisely and
repeatably, and it works great for transfering the image to the board.
The press was kinda pricey, I think she paid about $300 for it. Now
that's true love!
I've been using ammonium persulfate for etchant and just picked up
some peroxide and acid so I can try making my own etchant.
I have a drill stand for my Dremel Moto-tool that was made by Dremel
that I use for drilling the boards. I use a #10 Opti-Visor and have no
trouble drilling the boards even with my pathetic eyesight. The etched
drill guide holes in the center of the pads really helps hitting the
holes dead center. With just a little care drills will last until they
get dull. As a matter of fact the only time I break one is when I get
careless trying to go too fast.
I'm feeling pretty good this afternoon, so I think I'll try making a
board with a test pattern to see how fine I can get my tracks.
If I can run a track between 0.1" spaced pads and I'll be happy.
I think you'll like with your setup after you get the hang of doing
it.

Mike