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Re: [Homebrew_PCBs] UV lamps?

2005-01-21 by Russell Shaw

I made a box using a 125W HID globe like the one on the right:

   http://www.specialtyoptical.com/catalog/160wsb_e24-bl_2712682.htm

The 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.html
http://www.specialtyoptical.com/catalog/blacklights_264645_products.htm
http://www.lightbulbsdirect.com/page/001/CTGY/Blacklights
http://www.thelightbulbcompany.co.uk/product/prod161.html
http://www.topbulb.com/find/prod_list.asp?intSubCategory=557

http://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

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