Homebrew PCBs

Hi Jeff,

I use a metal halide HQI 11' aquarium fixture with a double ended, 150W, 10,000K bulb.  The parabolic holder has a special high UV reflector. I got it last year on closeout sale for about $150 including the bulb and ballast. I just set it atop a DIY 1/2" PVC pipe frame with adjustable legs. It puts out a lot of UV (my measurements with a UV meter from bottom);

3 1/2" --> 32 mw/cm**2 (no UV protective glass), 22 mw/cm**2 (with glass protector)
6 1/4" --> 14 mw/cm**2                           10 mw/cm**2

A much cheaper alternative is the Damar 25 Watt Compact Fluorescent Blacklight ($14),

http://www.blacklight.com/items/DH25SLBLB

Just use it with a cheap parabolic shop light reflector. My measurements for this are,

edge of reflector to center --> 1 mw/cm**2 to 3mw/cm**2 at 4" from bottom of reflector.

The Damar site has specs for this bulb which shows a fairly narrow spectrum that peaks at 352 nm which is nearly ideal for photoresists. The collimation isn't all that great, however.

Baxter

--- In Homebrew_PCBs@yahoogroups.com, "Jeff" <jeff.heiss@...> wrote:
>
> I see that some here are using HID mercury lamps for mask/photoresist exposure.  Where can HID mercury lamps be obtained?  Do they give better results than black lights or the yellow-housing halogen work lights found in home centers?