Re: Printed Circuit Board Supplies

SNTLewis@... wrote:

> From: SNTLewis@...
>
> Err, I have been trying to follow this thread and am hopelessly lost.
> I
> currently use GC-Electronics pre-sensitized boards to make prototypes.
>
> Apparently there is a "dry" system out there. I have tried the
> Toner-Transfer-System from Digikey (or Mouser) and found it lacking in
> boards
> over 3 square inches. I don't make a lot of boards per run or year,
> but the
> "dry film" intrigues me.
>
> Can someone direct to a URL or site that has this information?

Try www.kepro.com. they sell the machinery as well as the materials.
You can buy pre-sensitized boards, chemicals, development machines,
etc. I used the pre-sensitized boards until I got a deal on the
laminating
machine. It is a lot less expensive if you laminate your own boards,
but the
initial investment is pretty steep.

The resist is exposed with UV light, same as the GC. This is a
'negative'
system, the clear area of the master film allows UV through, which
hardens
the resist. You develop the resist with sodium carbonate, a slightly
stronger
relative of baking soda. Although there are dire warnings, I develop
the
board by wiping with my fingertips, it doesn't seem to do any harm.
After etching, the resist is stripped with a lye solution, which I
definitely
don't touch! The results are totally professional, I'm sure if you had
films of sufficient quality, you could do boards with 5 mil lines and
spaces
with no problem.

Jon