Homebrew PCBs

In article <dtalok+5p6k@...>,
   patroclus04 <patroclus04@...> wrote:

> "and put the board and transparency on the glass. I then put a heavy
> book on top of the board to ensure it is pressed down. "

> I can't see what you say... Sorry. as this may sound stupid.. but..I put
> the PCB on top of glass?? the glass on top?? If you put a heavy book on
> top, how can UV light expose the board??

OK

The tubes and control gear are mounted in box with a glass top. You lay
the transparancy on top of the glass and the PCB on top of that so that
the light shines through the glass and transparancy to expose the board.

The heavy book is laid on top of the PCB to press it firmly down on top of
the transparancy so that you get good contact between PCB and transparancy
to ensure a sharp image.

In my case, my light box has a lid having a layer of foam inside it. When
the lid is shut and fastened down, the foam squeezes down on top of the
board ensuring good contact. This also prevents UV escaping to affect the
eyes

Stuart