Homebrew PCBs

>>Hmmm, I have a picture online of my exposing unit which is a Scanner
>>housing with UV tubes built in. The picture showes the opened unit and
>>there you can see that the tubes are relatively close too....
>
>Similar to mine, except you have *lots* more tubes and mine is made 
>(crudely) from MDF. 8-)
>
>My tubes (I only have 2) are about 13.5 cms from the glass and about 10 cms 
>apart. Exposure is 13 minutes. I keep meaning to add a third tube in the 
>middle and use curved reflectors and a sort of grid for collimation.

The picture maybe does not show it clearly, but the tubes there are
farily close to the glass. I'm not at home at the moment to measure,
but out of my memory I'd say it's around 4 cm. Exposure time with the
precoated material (I asume something similar to what you use) is 90
seconds.

I could get the scanner housing for cheap from a loca dealer (was a
scanner where the software and docs got lost). The tubes are from a
Braun face browner unit.

Since I soon will have my plating trhough station ready I will switch
to photo resist ( I have it already ) and I was told that by using it
exposure time dropps significantly and becomes much less critical also
- well, let's see...

Markus