Maybe my google skills aren’t very good, but I can’t see to find a source for these UV reactive PCB boards. Is there a special name for them?

Posted at 10:40 am on Oct 23rd, 2008 by Jack

Yes, Photo Etch Boards, they are recognisable by the black protective film, i have a question too, do UV leds work as well as a UV Flourecent Tube?

Posted at 11:04 am on Oct 23rd, 2008 by Funky Gibbon

Yeah, I was kinda surprised by the idea of using uv leds.. I mean, it makes sense, and is kind of a ‘duh!’ moment for me.
Looking at his finished pcbs (check the posts sidebar) they look pretty good.

Posted at 12:26 pm on Oct 23rd, 2008 by MRE

UV tubes are usually way more efficient than LEDs but you always can increase the exposure time or use more LEDs.

I personally use an old mercury-UV-lamp at appr. 40cm distance.

Posted at 5:33 pm on Oct 23rd, 2008 by Till

Earlier this year I made a similar lightbox using a 12″ record flight case and around 90 UV leds.

(Grainy publicly viewable pic on facebook here: http://www.facebook.com/photo.php?pid=36475041&l=07175&id=61204497 )

This method produces very good results, and mine only needed a gap of around 5cm before the emitted light became even (with the particular leds I used).

In the true style of building something to make something else, I first prototyped this point to point wiring all these leds which had been affixed in a 12″ square piece of wood. They then exposed the boards that now form the actual light box :)

I went down to the local glass supplier to get two panes of 12″ square glass cut to sandwich the mask and board.

There is also a 128×64 graphics LCD cut into the top that gives a nice display, and a rotary encoder switch (with button press) to give all of the input required.

All this was run off a 5v 2A (but not using all 2 amps!) wall mounted transformer.

-Andy

Posted at 1:56 am on Oct 24th, 2008 by Andy Taylor

interesting idea. Get 100 or so ultra cheap UV 3mm LED’s off ebay, sand down using a jig sideways to 2mm and then glue them together side on and solder to the PCB. In theory you could expose an entire line in one go and the drive circuitry is as simple as a few 4017’s with a varying constant current on the power line.

You could probably also use SMD UV but this would be limiting.
-A

Posted at 11:40 am on Mar 13th, 2009 by andre