gnupic: Re: [gnupic] PCB blues - any suggestions?
Subject:
[gnupic] PCB blues - any suggestions?
From:
"csb" ####@####.####
Date:
31 May 2005 02:57:30 +0100
Message-Id: <STVNV.2472BLM@sympatico.ca>
Oops... sent a PM instead of a post. take 2.
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> I've made at least 12 attempts today, to transfer the artwork onto the
> copper, with no success.
Hmm... I made this board (plus a few others) with the toner-transfer
method: (please excuse the bad focus)
http://rsc-mirror3.netfirms.com/1/elec/board-pics.htm
the exacto marks are there for safety. I found no shorts, but there
were a few specks of copper left in some places.
This is only the my second 2-layer board... that's why the holes aren't
lined up properly. They weren't buffed yet, either. . The 2X13 header
has 0.1" pitch. 99% traces are 16mil (or 12?? can't remember), the others
are 10mil.
> Printer I'm using is an HP 2550L Color Laserjet.
This could be *a* problem.
Here's what I do:
I use a HP LJ 2100, with glossy photo paper (I don't even know what kind
or brand). I print the artwork twice, to have thick lines. Thick enough
so I can feel the traces when I run my fingers over them. I cut out the
artwork, leaving some paper around what I want. I fold the excess paper
around the board so it won't slide when I'm ironing it.
I heat up an old clothes iron (I put it to max for a few minutes) while
I get 2 containers full of ordinary hot water.
I don't know how much time is needed, I just heat up the paper until
its brown everywhere (especially around corners), I normally start to
see some traces through the paper.
Dunk the board in hot water. I let it sit for 10 minutes, and by that
time the paper just peels of. I finish cleaning off the paper in the
second container, using my fingers. Then, I etch the board in warm
ferric chloride. and finally, drill, buff, test, solder, test, etc.
> I'm getting very tempted to give up on artwork transfer entirely, and
> use Eagle to create standardised veroboard (strip board) layouts - an
You might give it a few last tries, just to be sure. It's great to be
able to use 0603, SOIC and SOT packages without having to buy or make
special adapters... plus, a home-made PCB looks a lot better than a
proto-board improvisation!
Good luck!
Christian
