Re: Flourescent tubes (350 nm...

GSnowman@aol.com
Thu, 18 Aug 94 17:04:15 EDT

> 1. Printed circuit board exposure units. The Ultra-lite max manufactured
> by Logical Devices of Ft Lauderdale has 4 UV elements, a tray size of
> 9" x 13" and is supposed to put out 1500 micro watts per square centimetre.
> I'm not sure of the wavelength or how it compares to normal BL tubes.
> Price here is Aust $450. EPROM erasers are much cheaper but wouldn't
> have much coverage.

Jameco Electronics carries something they call "Photo Etch Light Bulb Set".
This consists of a 3400K white light bulb and a 4800K UV bulb. The UV bulb
is intended for use with PCB photo resist. I don't know anything about the
power output, and I've never used it. However, it only costs US $16.95 for
the set (US$ 14.95 each for 10 or more.) Is anyone tempted to give it a go?
(Part Number is Jameco 70471, and Jameco is at 1800-831-4242 or
+415-592-8097. They are in the Pacific time zone).

I have no affiliation with anyone who sells this product.

This raises a question I've been meaning to ask here for some time. Printed
circuit
manufacturers make a transparency at the size of the board, then expose a
board covered in photo resist through the transparency. The resist exposed to
light disappears. They then dunk the board in etchant, which removes copper
from the board. This gives rise to, effectively, a contact print made out of
copper. I have been thinking about experimenting with
artistic uses of this process for a while. Has anyone ever done anything with
this? Although
I don't expect to get any tonality, I bet I could copy a kodalith negative
quite accurately.

Geoff Snowman
gsnowman@aol.com