Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Hi guys,

I got a chance to do some more experimenting with the dry film photo
process. I did a "step" test doing various exposure times and found
out that the UV lamp I bought for this purpose simply isn't powerful
enough. I have a regular light bulb of the right color range and
tried that with much better results - exposure time through
transparncy of only 3 minutes. I have much more experimenting to do
to get it better, but was able to make my first board all the way
through the etching process.

A couple of questions...

1) When I used to have a black and white dark room, I discovered
that the developer would last a long time and could be reused over
and over again. I realize the developer for negative resist film is
much different than photographic developer, but suspect that the
chemical will stay "active" and as such, I could be reusing it. Has
anyone tried this?

2) While doing the exposure / developer tests, I realized very
quickly just how tough this resist is. I was scrubbing with a
scotch brite pad vigorously without removing the resist. This leads
me to the next question. Should the resist be removed or can it be
left on the copper? If you have to remove it, how do you do it?

Thanks in advance!

Chris