On Sun, 12 Jan 2003, Olin Lathrop wrote:

*>> On an aside, would it be possible to expose sensitized PCBs with a
*>> photographic enlarger? I know it would likely be impractical, as you'd
*>> have to get the sizing and focus perfectly right, which means it would
*>> likely be easier to just use a contact layout to shield the board. Plus,
*>> I don't have an enlarger :)
*>
*>I experimented with that a very long time ago (mid 1970s).  It can be done,
*>but requires exposures measured in numbers of half hours with ordinary
*>enlarger lamps.

Try a quartz street lamp like Dwayne uses. I also use a variant of this
(but not streetlamp), with 150W for most board and erasure work. You can
use an old enlarger where there is room to put the arc lamp in.

Peter

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