Very interesting. Assuming your limiting factor is the beam width,
can you focus the laser to a smaller width? On ebay I see CO2 lasers
for engraving at $1600 with shipping that might do.
Mark
At 09:00 AM 12/29/2010, you wrote:
>We've been using the paint method to do boards for a few months now,
>and it's been working pretty well. If you need top-notch detail,
>then you need to go with a photoresist solution. 10mil/10mil is
>pretty easy to do repeatably.
>
>The key thing to remember that the laser is about 8mil wide. This
>will affect the width of the traces and isolation that you lay out,
>because you'd end up with less and more, respectively.
>
>We have noticed the re-adhesion behavior mentioned below, but if you
>reduce the paint to the minimum needed for coverage, the amount of
>airborne burnt-off paint will be correspondingly reduced. Burning
>from the far side of the board probably couldn't hurt. We clean
>lasered boards gently with IPA and a cotton ball before etching.
>
>We've gone from bare copper clad board to etched-undrilled in about
>30 minutes with fresh etchant (FeCl). Assuming that you have access
>to a laser printer, the ease+cost can't be beat (you might be able
>to do cheaper by hand-drawing or plotting with a resist pen
>though). But you won't be running two traces in between
>0.1"-centered holes either, so there's still a place for photoresist
>in the world.
>
>We haven't done any soldermasking, but if you find something that
>works well for you, let us all know.
>
>-eric
>
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