Homebrew PCBs

Tom - 
Thanks. As you can see, I'm not to savvy about how the pros do it.  I 
would imagine this process needs a very good negative. Do you use a  
laser or inkjet printer? I really marvel at the quality boards one 
can buy for relatively cheap these days, like computer motherboard 
fully stuffed sans processor for 60-90. 
Bob  
 
--- In Homebrew_PCBs@yahoogroups.com, "twb8899 <twb8899@y...>" 
<twb8899@y...> wrote:
> 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... 
> > >