Homebrew PCBs

90 secs is good. I believe pre-warming of the lamp will take about 3 
minutes. You can incorporate a simple vacuum pump so that the film will 
contact the PCB better.

----- Original Message ----- 
From: "Russell Shaw" <rjshaw@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, December 09, 2005 8:31 AM
Subject: Re: [Homebrew_PCBs] Presensitised PCB



> I made a UV lightbox with 125Watt HID lamp 24" from the glass, and in
> a cylindrical parabolic reflector (lamp lays horizontal). 90%+ exposure
> happens in 30secs, and i found a good optimum to use is 90secs for
> pre-coated negative pcb. The pcb is held against the glass by the lid
> that has a layer of sponge.
>