On Thursday 01 February 2007 18:25, Lez wrote:
> Ok I have had enough tonight of TT
>
>
> I need to get 10 little 2 inch ∗ 2 1/2 inch boards done. (only holds a
> pic and some transistors)
>
> I can buy the developer for £1.20, I can get a 8∗4 board for £1.20, so
> for £3.60 I can get everything, except a source of UV..........
>snip<
30 years or so ago I made a BUNCH prototype boards both at home and at work
using #2 photofloods (IIRC 300W). A sheet of plate glass to hold the film in
contact with the board. IIRC the light was about 6" from board. I'm really
fuzzy here, but exposure was in the order of 5-10 minutes. The #2 was a 3400
degree kelvin incandescent bulb used heavily in photo studios back then.
Quartz halogen was just showing up back then, so I never tired them, but heat
might be a real problem.
--
Keith Bowers - Thomasville, NC