Homebrew PCBs

thinktink.com has a wealth of information, if you can find your way to it.

>1. There is a coating on each side of the resist. A plastic and a
>mylar side. Make sure you remove the plastic side before laminating.
>How do you tell which side is which? I am not sure yet. I just got lucky.

     Use two pieces of tape on a corner of the cut film, one on each side 
(I like slightly used masking tape for this). The side that comes off 
easier is the one that's supposed to come off. Only pull the leading inch 
(2cm) or so, so you can peel it as it feeds into the laminator.

>2. Lamination with my stock GBC H200 laminator works great. I ran it
>through three times and it stuck just fine. It was easier than when I
> do toner transfer.

     I've used a cheap desktop laminator - and I mean $25 cheap - and it 
was fine for thin brass sheet with several passes. I recently tried pcb 
material and it ended up requiring a couple of "tacking" passes, a short 
stay in the oven, and then a few more passes. That came out great, the 
laminator-only attempt had the resist lifting off the board.

>3. Be careful of the resist overlapping the board. After laminating I
>found my pcb stuck to my carrier. No real problem. I just cut it out
>with the knife.

     I tape the leading edge of the resist to a sheet of paper, position 
the substrate, and then pass it into the laminator. I only strip that 
protective sheet a little way so I can pull it as it feeds into the 
laminating rollers. This helps eliminate bubbles, overlaps, etc. I also 
cut the resist oversize, but I have a lot to play with.

>4. Leave the mylar film on until you finish exposing.

     Um, yeah. That's there to protect the resist, and keeps it from 
sticking to the hot laminator rollers. I had no idea that it had anything 
to do with the resist hardening (?)

>5. Make sure you remove all the mylar.

     Yours didn't all come off in a single piece?

>6. I used Arm and Hammer washing soda for developer and it worked just
>fine.

     Perfecto, cheap sodium carbonate. Wish I could find the washing soda 
around here, seems nobody's heard of it. I've been using my photographic 
stuff.

>7. Exposure time under a fluorescent lamp was about 30 minutes.

     Cool, it worked. However, go to the hardware store and spend $10 - 
$20 on a 500 watt halogen work light, if you don't already own one. 
Assemble it and leave out the screw that secures the front cover. Use it 
with the cover open (glass out of the way), try 4 - 5 minutes at 18" 
distance as a starting point. Avoid looking at the light that comes out 
of it (or the bulb itself!), that UV absorbing glass is there for a 
reason.

And, 
     Sunlight as a UV source?

     I've had it be good enough for some things, and sorely inadequate 
for others. Spend a few bucks on the halogen light mentioned above and 
it'll be consistent day/night, winter/summer. You can always move up from 
there.

     ack! gotta go do work...
     -Gary