On Mon, 04 Jan 2010 07:59:12 -0000, you wrote:
>Hi,
>
>While I'm an experienced design engineer, I've never done a PC board in 40+ years of design. We had a special department to do that. Now retired, I thought I'd try inventing. I find PCBs important to that goal.
Works for me.
>
>In getting together a kit to do this, I had a few thoughts and questions. I hope you more experienced (though not necessarily older) and (presumably) wiser folks :-) can address some of these questions.
I'll give it a try.
>
>1) I've looked into photo paper and "Press-N-Peel" to transfer toner as resist. Do you think laser T-shirt transfer paper, which is probably cheaper, would work, too? Has someone tried this?
>
T shirt transfer paper (at least, the inkjet type) has a film that
goes over the whole page area. You'd be covering the board with
that. You want something that doesn't add a coating to the board,
only transfers the resist. I happen to use the pulsar paper well, but
I've also done photoetching.
>2) Do you think latex gloves, as you'd find in a doctor's office, would be safe for handling boards and etchant? They're cheap at Walgreens and disposable to reduce cleanup effort.
Cheaper at Harbor freight. But I use the nitrile ones, and throw them
away after one use. However, the yellow gloves, perhaps the "chemical
resistant ones" are more resistant to hot etchant and last longer.
They are also more tear resistant, but they will die eventually.
>
>3) If ferric chloride wouldn't destroy them, would kitchen plastic bags (ZipLock-type) work for etching boards? They'd probably save on etchant and, if I don't slop too much, reduce cleanup.
Ferric chloride won't destroy them during one use. I'd try the
freezer style, they're tougher.
Pulsar has some fast etch techniques. Not done them with a lot of
success, but you can speed up the etching if you gently rub some areas
of the board. Etch resist has to be tough, though.
>
>4) How nasty is used ferric chloride? Is it a HazMat material? How do you folks dispose of it in an eco-friendly manner?
>
varies in opinion and locale. Others use a mixture of hydrogen
peroxide and muriatic acid, which seems to be a nicer etchant. I'll
be trying it later.
>5) Would Krylon spray clear coating and/or spray paint work as a solder mask? My thought is to spray the board immediately after etching and touch-up. Then, I would assume, soldering would burn off the paint instantly. Would a second coat be necessary after assembly?
Not a solder mask, but moderately decent for board coating. I put
parts on both sides, so not so useful. I think it would be less heat
resistant than you want, so how to make it a solder mask is a good
question.
>
>Thanks for considering my questions. I'll probably have more later.
Works for me.
Harvey
>
>Jim Barnes
>
>
>
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