Newbie PCB ques..

[Harry Bissell]

Try the  TTS "Toner Transfer System"... (Digi-Key carries it...) You
photocopy or lazer print your artwork (mirror image required) and then Iron
it on the bare copper PCB. It works better than resist pen... but still
not perfect. If you get good adhesion to the copper eberything will be OK.
I'd go with 20 mil minimum runs...

IMHO only a "kook" will try to run between DIP pads on a home etch board.
Fix the layout and use a jumper... reliability will be 100% better. Flame
ME if you want... I'm right !!!!

Someone tell me the etchant recovery trick... It sounds great. What do you
use for electrodes ??? Carbon ???   How much current etc... I don't want to
blow up my house !!!   :^) Harry

Toby Paddock wrote:

> I've done a few boards using a resist pen. The hardest part for
> me was getting good coverage of the ink. When you lift the
> pen and then continue, it's easy to get a little bare spot.
> Same thing where the trace meets the pads. Sometimes you
> can tap-tap-tap make little dots to fill the bare spots while not
> letting the wet ink mess up the dry ink.
>
> Sharpie pens seemed to work better than Rub-a-dub pens,
> the only 2 types I tried. This was about 15 years ago.
> Pentel now makes a permanent pen that might be a possibility.
> Color in unused areas to reduce the amount of copper
> removed will make the etchant last longer.
>
> I had a friend who could even sneak traces between DIP pads.
> He also would renew the ferric chloride (?) by passing current
> between electrodes and the copper would come out of solution
> and plate one of the electrodes. Or something like that.
>
> I did one 2 sided board by drilling undersize holes first.
> Undersize because the edges of the holes get etched a little.
> The holes locate the pads on both sides. Drill the correct size
> after etching. Use a container with a roundish bottom.
>
> Note: If you have the bright idea of swinging the pen around
> on a string to get the ink to the tip. Be sure the cap is on tight
> or a Bad Thing can happen. Yes, I do know that for a fact.
>
> No doubt this has been well covered by now, but I'm behind as usual.
>
>  - -- -  Toby Paddock
> http://www.seanet.com/~tpaddock
>
> Paul Perry wrote:
> >you take the artwork drawing, and stick it to the raw PCB.
> >Then get a pointed punch, and ding wherever there is a hole.
> >Then take off the artwork, and use a 'resist' pen to
> >draw in the tracks. You cant go far wrong,
> >as you have the dings to guide you.
> >Then drill the holes & etch the board.
> >WARNING: I havn't tried this. But, for an uncrowded single side board,
> >it looks likely.