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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Re: [Homebrew_PCBs] UV lamps?
2005-01-21 by Russell Shaw
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