Homebrew PCBs

Bob,

Dry film photo resist is laminated to the panel using a hot roll 
laminator. The dry film resist that I use is .0015" thick and is 
developed in a 1% sodium carbonate (soda ash) solution. These films 
are negative acting and exposed with a UV light source. My light 
source uses a mercury vapor lamp which exposes the film in about 17 
seconds. If you expose the film using a negative you will have the 
traces and pads left behind on the copper panel for etching. After 
etching the photoresist is stripped from the board using a weak 
sodium hydroxide or lye solution. 

Tom


--- In Homebrew_PCBs@yahoogroups.com, "Bob Fitzgerald <newaag@y...>" 
<newaag@y...> wrote:
> What is the technique with dryfilm resist? It sounds like it is 
> laminated to the boards with heat? I just bought a dry mount press 
so 
> I'm interested. I assume this is better than spraying boads? Is 
this 
> one of those products where it is not sold in small qty?
> thks
> Bob
> 
> --- In Homebrew_PCBs@yahoogroups.com, "twb8899 <twb8899@y...>" 
> <twb8899@y...> wrote:
> > I can help anyone interested in blank boards with dryfilm 
> > photoresist. I have a laminator and plenty of dryfilm resist on 
> hand. 
> > 
> > Also have a photoplotter that makes positive or negative films 
from 
> > Gerber photoplot data. Contact me off list if there is any 
> interest.  
> > 
> > Tom     twb8899@y... 
> >