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Subject: Re: [Homebrew_PCBs] Re:etched my first board today -- photos-- considering options....

From: "Stefan Trethan" <stefan_trethan@...>
Date: 2005-07-03

On Sun, 03 Jul 2005 19:45:50 +0200, lcdpublishing
<lcdpublishing@...> wrote:

>
> 1) Chemicals - nasty stuff

Yea, can't etch without ;-). A permanent setup makes it easier tho, and if
you make a clever board holder you don't need to come into contact with
the etchant or clean up much.

> 2) Toner transfer & detail - maybe a hit or miss process. Although,
> it it looks bad, you can remove it and try again with no real loss
> at this point

You will eventually get this to work reliably, well, almost always.

> 3) Chemical etching appears to be a bit tricky, especially in the
> areas where the traces are tight together. It is hard to see if you
> etched away those areas until you get the board out and cleaned.

Using a clear etchant (CuCl or persuphate) and tank helps a lot, with
light from the other side of the tank. Near traces etching is actually
faster - if you removed all the paper residue. ('cause over masked areas
the etchant is not used, so it eats the adjacent areas faster)

> 4) Drilling lot's of tiny holes is very hard on the eyes.

too true. better use your cnc.

> 5) Detailing - cleaning up touching traces. Again, the process is a
> pretty basic mechanical process using: picks, files, and hobby
> knife. Would be pretty easy if I could only see this stuff without
> so much eye strain.

will become redundant as you get better with the above steps.

> 6) Rather slow - step-by-step process. I am sure would get faster
> with time and practice.

right. will get MUCH more efficient over time. A small board is done in
half an hour, and you can use the time while one etches to prepare the
next or drill or...


Milling boards: has it's own set of problems. Do not expect it to solve
them all ;-)
Read the bungard file milling against etching, it is pretty clear as to
what the problems are.
EDM would solve many of those, but i admit not all.

ST