I made a box using a 125W HID globe like the one on the right:
http://www.specialtyoptical.com/catalog/160wsb_e24-bl_2712682.htmThe blue glass is "woods glass" and blocks all the bad short-wave UV
and longer wave white light.
I have it in a cylindrical parabolic reflector and is 60cm from the
glass. It exposes negative resist in 30secs, but i do 90secs to make
sure. Because of the distance, i get sharp traces regardless of which
side of the printout film i place against the pcb.
It take 2mins to warm up. If you switch it off, it won't switch on
for another few minutes.
There's a ton of blacklights:
http://unblinkingeye.com/Articles/Light/light.htmlhttp://www.specialtyoptical.com/catalog/blacklights_264645_products.htmhttp://www.lightbulbsdirect.com/page/001/CTGY/Blacklightshttp://www.thelightbulbcompany.co.uk/product/prod161.htmlhttp://www.topbulb.com/find/prod_list.asp?intSubCategory=557http://www.google.com.au/search?hl=en&q=%22blacklight+blue%22+uv+hid&btnG=Search&meta=Norman Stewart wrote:
> I built one years ago, using a high intensity industrial
> hi-bay lamp and suitable ballast/transformer. The glass
> envelope containing the fluorescent material around the
> quartz uv source must be broken off (carefully!) leaving
> only the quartz tube. This gives a high intensity UV lamp
> that is very long lived. Mine was built in the mid 1960's
> and the original tube is still going strong. The lamps are
> designed to run 24/7 for several years at a time. The only
> drawback is that it requires a relatively long
> turn-on/warmup time - like about 5 minutes for full
> brightness. You need a mechanical shutter - a sheet of
> plywood, aluminum, etc., to block the light between
> exposures. And VERY good eye protection.
>
> Norm
>
> Terry Mickelson wrote:
>
>>I'd like to build a UV box to do positive resist exposure. The
>>presensitized boards are 5 by 7 inches, so the box and lamps need not
>>be too large. Also not too hot as this box is only open on the bottom.
>>LED's are under consideration but so far a pre-made PC board to hold
>>400 or so is too expensive. The board is nothing more than etched
>>parallel lines with drilled holes every .1 inch. UV lamps are a second
>>choice but they tend to fade and burn out over time.
>>What are your recommendations?
>>Terry M