Homebrew PCBs

> Richard wrote:
>
> <SNIP>
> This unit was a simple wood enclosure,
> with the bottom lined with aluminum
> foil, then eight 20w germicidal-UV
> lamps (these are the clear glass ones);
> and a piece of 1/4" plate glass on top;
> about an inch above the bulbs.  Not at
> all a collimated source; but with 10
> bulbs mounted right next to each other
> all the way up the box; it faked
> 'collimated' quite well...lol.
> 
> Note:  it is WELL worth the trouble to
> find and buy the germicidal lamps.
> They burn an image far faster than
> 'black light' bulbs.
> <SNIP>

Data sheets for most of the positive
resist I have seen would indicate that
black light (long wave UV) bulbs are
faster at exposing than germicidal bulbs
(short wavelength).

Is the negative resist different to the
positive stuff ?

I know that _some_ gemicidal lamps have
much higher wattage ratings per unit
length that common black light ones (10's
of watts 100mmm as opposed to 18W in
600mm).