[XCSSA] Printed Circuit Borad Fabrication

[X-otic Computer Systems of San Antonio]

On Fri, Apr 10, 2009 at 11:20 AM, X-otic Computer Systems of San
Antonio <xcssa at xcssa.org> wrote:
> Anton!  Whatcha been up to man?!

I've been insanely busy working on some new sites. Working on a new
RobotEvents.com now, hope to launch it at the VEX World Championships
at the end of the month. I've also got a few robots in the works,
should have an article written about one this weekend.

I've also been writing for Wired's GeekDad blog (geekdad.com). We've
got a booth at Maker Faire in SF at the end of May. I'm trying to
figure out which robots I'm taking and which ones I can get finished
by then.

>> I etch my own boards using Acid Cupric Chloride, it's pretty easy to
>> make and can be regenerated with a cheap fish tank bubbler. (Or just
>> shake in an watertight container)
>>
>> http://members.optusnet.com.au/eseychell/PCB/etching_CuCl/index.html
>>
>> I store it in a plastic bottle and shake it up before etching.
>
> Wow.. interesting stuff there!
> So this stuff emits HCl fumes?  Sounds kinda.. toxic.
> Why this instead of Ferro Chloric acid?  You do much etching?

CuCl can be replenished with air (or peroxide) and can be used over
and over again. It also leaves the copper in a state that is a little
(but not much) safer to dispose of. Pouring Ferro Chloric down the
drain is hard on the waste treatment plants as it kills the bacteria
they use to process waste.

Fumes aren't much of a problem at room temperature. I usually etch in
my garage with the door open and can barely smell it. A bubbler and
larger tank would probably add to the fumes, but not a lot.

I etch a couple boards a month. I don't get a lot of time to play, but
I'm slowly working on a 3/4" cube robot. I'm due to etch a new layout
since the current rev has been patched and jumpered a few times.

> I never had very good luck with it.. it was always too "cracky".. and I would
> have to go over the whole thing with a etchresist pen to keep it clean.  I
> think some XCSSA folks have played with that blue rubber iron on stuff a bit.

The trick with toner transfer is to get the copper very clean. Any
oils or dust will affect the adhesion. I find that Epson high gloss
photo paper and iron set to high works best.  Iron it til the paper
starts to turn brown.  It will start to peel off on it's own when it'd
done. Soak it in water for half an hour before pulling it off, clean
gently with soap and water and if any toner flakes off start over.


>> The small bits must be used in a good drill
>> press or dremil press and even then you'll break a few.
>
> I just use my "dremel press":
>        http://theweeks.org/tmp/SHOW/3_proto_drill4.jpg
>        http://theweeks.org/tmp/SHOW/4_proto_drill5.jpg
>
> works like a charm...

Cool, I have one similar to that and it works well. I've also used my
large drill press with some luck, but it wobbles about 2mm side to
side at the tip of the bit, not so good when drilling 0.3mm holes.

>        Erbium Laser Rod
>        http://www.goldmine-elec-products.com/prodinfo.asp?number=G16735

Nice, I just ordered the laser rod, now to research how to pump it.

Anton
-- 
http://antonolsen.com/
http://geekdad.com/