Homebrew PCBs

I'm new here but find this list very interesting. A good UV lighting 
system is the plain old mercury vapor lamps. These are commonly used 
for dusk-to-dawn lighting. The bulbs are available in several 
wattages such as 175, 400 and 1000 watts. One of these bulbs and a 
reflector makes a great UV exposure system. Visit any large warehouse 
and check out the lighting system since these are very commonly used 
in larger buildings.

I have a commercial exposure system that uses this type of bulb. It 
is a Colight Model DMVL-930 with 1000 watt bulbs on the top and 
bottom. The exposure time when using 1.5 mil dry film photoresist is 
17 seconds. If there is any interest in this I can photograph the 
"guts" of this machine next time I clean the reflectors and post the 
photographs in the photo section of this list.

It really would not be hard to make this exposure unit. Polished 
aluminum sheeting or aluminmum foil could be used to make the 
reflector system. I have helped several of my ham buddys set this 
type of unit up and they have all been amazed at how fast this can 
expose the photo resist. You can also make silk screens with this 
setup.

I made my first hobby circuit board in 1966 and owned a commercial 
printed circuit business for 23 years. We closed that plant last year 
due to foreign competition and rising costs. I did keep the best 
"small" equipment for my own home shop. This still allows me to make 
boards for the instruments I make as well as my ham radio projects. 

We gave away the plating operation because it was really a drag 
putting up with the evironmental issues etc. I kept one smaller 
photoplotter, several semi-automatic drilling machines, silk 
screening equipment and all of the tooling and setup stuff. The big 
Excellon CNC drilling and routing equipment was all sold off. 

I started my company on the kitchen table in the late 1970's and it 
looks like I've gone full circle but this time ended up in the 
basement!  It's much more fun this way I might add. We made boards up 
to ten layers back then but it was just way to much work and the 
headaches just kept getting worse. Too much work, too many hours, too 
little pay and no more fun !!  

I do enjoy the hobby side of this technology and would be willing to 
help out with ideas and maybe some equipment projects that could be 
posted on this list. If there is any interest let me know. Sorry 
about the long post... sometimes I get going and don't know when to 
stop!!! Hope I can help out.

Tom