Homebrew PCBs

[snip]
 > If you don't mind language that you do not understand, please visit
 > http://zastos.blogspot.com photos are worth more than thousand
 > words.

Unfortunately I in fact don't understand the language :) but - nice work!

 >
 > UV LEDs can be found much cheaper at eBay, but the UV lamps are much
 > cheaper :)

Hmmm, be VERY carefull. I just was reading a post from a guy in a german 
PCB forum who used such e-bay LEDs just to find out they did not worked 
as expected!

I had a UV lamp based unit already, and switched to the LED variant 
mostly for two reasons:

a) with the UV lamp, I had undercuts due to the way the unit was 
constructed (tubes were fairly close at the PCB) and the truly non 
paralell nature of such lamps.

b) the unit used four lamps which are fairly strong. Exposure time was 
only 10 seconds! The fact that the lamps were not going on absolutely 
synchronousely was leading to a non even exposure across the PCB which 
was almost uncontrollable.

With the LEDs you have an opening angle of only 20 degrees. One could 
even use a 10 mm LED pattern and put them into tubes to further narrow 
this and/or also increase the distance to the PCB. But again, it turned 
out very well. I'm sure though that one could also build an exposure 
unit with tubes or lamps that works equally well. It just apeared to me 
to be a very simple way for me to get consistant exposure with very 
repeateable results.

Markus