Chris,
Here is a site with a wealth of information that you may find interesting,
http://www.capefearpress.com/puretchpcb.htmlThere was one reference to this site in a posting about 1 year ago relative to sources of dry film resist.
They are selling a high resolution negative Riston at $10.00 for 2 square feet as a sample size. The price drops by 1/2 if you buy 20 square feet $(45.00). I learned a lot by watching their videos. In particular, the explanations of the Stouffer step gauge are excellent.
Baxter
--- In Homebrew_PCBs@yahoogroups.com, Chris Maness <chris@...> wrote:
>
> I made up a board on a CAD transfer program, and printed it off on a
> transparency. I exposed it to my homebrew UV LED array for 1'30" and
> transferred it to a store baught developer. I agitated it in the developer
> at the recommended 10:1 concentration for well over 5 minutes and the light
> sensitive coating showed no sign of coming off. I exposed it again for a
> solid 5 minutes, and again put it in the developer with no sign of any
> action. I have left in the back yard now to see if it will finally come
> off. It does look like some milky looking material is slowly coming off,
> but this is MUCH longer than I expected. I am asuming all the positive
> boards require the same NaOH solution, so I don't think that's the problem,
> but I am not sure.
>
> Any suggestions?
>
> Thanks,
> Chris Maness
>
>
> [Non-text portions of this message have been removed]
>