> Alan wrote
> Just did a little looking, and sure enough the
> UV LEDs I have are in the correct range for
> exposing a board. Should've thought of that a
> year ago.. Saw off the inbuilt lens, mount the
> LED and a better lens so it's focused onto the
> board, and have an apeture hole near the board to
> block any stray light. Feed the board
> vertically, have a second setup on the other
> side, and do both sides at once. Do 4 or 8 LEDs
> on each side to cut the exposure time too.
> Wouldn't even care if it took hours personally,
> it'd still be great for small test boards and
> pretty simple to build up..
> Of course looks like the inkjet will end up being
> more practical, but heck should've already built
> this a long time ago. Might even do it sometime
> just for fun, should be easy to do a simple
> version on an old printer mechanism.
I think if you search the archive this idea with
solid state UV emitters has been discussed.
I don't remember the exact numbers but I seem to
recall someone saying it would take weeks to expose
a uv sensitve PCB with UV LEDs.