On 15/06/2011 14:22, John wrote:
>
>
>>
>> Here is my homemade unit:
>>
>> http://www.leonheller.com/Photos/UV%20unit.jpg
>>
>> It works very well and was cheap to make.
>>
>> Leon
>> --
>> Leon Heller
>> G1HSM
>>
> Please tell me more details. I would like to give this method a test. I know there is a wealth of information with Google but imitating yours would likely save both time& money!
I bought a couple of standard 12" fluorescent units, disassembled them,
and substituted UV tubes for the standard ones.
The box was made from MDF and square wood strip, glued and screwed
together. I had a sheet of ordinary window glass cut to size, which
rests on the upper wood strips.
I use an exposure time of 11 minutes for positive resist pre-coated
board material, timed with a kitchen timer app on my Dell Streak. I
could make a timer to switch it on and off, but it isn't worth the effort.
I get 8/8 mil tracks and can do TQFP parts with 0.5 mm lead spacing
without any problems, with transparencies produced on my cheap HP 5940
inkjet printer.
Leon
--
Leon Heller
G1HSM