Re: Printed Circuit Board Supplies

hansw wrote:

> From: hansw <hansw@...>
>
> Ted,
> A question comes to mind. As you have a laminator to look at, how
> difficult do you think it would be to make one ?

The heated roll it the tricky part. They have a metal roller, coated
with some insulating material, then
resistance wire is wound around it, and then it is covered by silicone
rubber. VERY tricky, I'd
hate to try to make one.

> Then there is the question of cost of dry film. What are the minimum
> these (whoever you use ) will sell for in $... how much
> film would that be ?

I bought a 125' roll, 12" wide, from Kepro. That is the standard size
roll from DuPont.
I could spool some off and sell it. But, the roll is now $126.70 in
their catalog.

> What's the shelf life of the film ? this would be important for me...

DuPont states it is one year. I think the shelf life of the laminated
boards works out
to about 4 years for me. It is beginning to look like the laminating
process may
'rejuvenate' the film somewhat, but I don't know for sure how well you
can get
away with keeping this stuff for a long time.

> One thing I like about positive pre sensitized boards, I simply use
> Red Devil Lye as a developer and it's fast. Exposure for 1
> minute under my UV light source and develop in Lye for about 30-45
> seconds... I make transparencies on my LaserJet, I'm also
> able to consistently get very fine lines <10 mill is not problem,
> anything seems pointless for my kind of work.

The problem with the laser transparencies is you can't do 2-sided work
bigger than about 2" on the longest dimension. Also, you can't use a
CNC drill on the boards, because there is too much wander/squirm
of the paper/transparency feed.

Jon