Homebrew PCBs

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
> 
> 
> 
> 
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs 
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
> 
> 
> 


-- 
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 265.6.13 - Release Date: 1/16/2005