Re: [CAD_CAM_EDM_DRO] Laser specs ?

Hi Dave

I know that the glass-epoxy board material can be cut with a CO2 laser, having done it myself. Using a small CO2 laser, ~15 watts pulsed running at ~25%, it was a slow and smokey process. After trying this once, I set up a slitting saw on the horizontal mill for the rest of the cuts. A more powerful laser would probably help a lot.

As far as cutting the copper goes, copper is a very good reflector of IR, especially at CO2 laser wavelength. Perhaps if the copper were coated with something or the surface was chemically altered--but then you might as well just etch the board. An excimer laser emitting UV with very high pulse energies would probably have no problem with the copper. A YAG laser might be another possibility. If you look at the absorbtion spectra of the material in question, that will tell you what wavelengths are absorbed and thus what wavelengths would be good for cutting.

Bob

----- Original Message -----
From: turbulatordude
To: CAD_CAM_EDM_DRO@yahoogroups.com
Sent: Saturday, December 23, 2006 12:52 PM
Subject: [CAD_CAM_EDM_DRO] Laser specs ?


Hi all,

Can anyone advise how one can figure just what laser wavelenghts are
needed to cut different things ?

I seem to remember someone saying that one type of laser would not cut
glass, but another would.

I am interested in what it would take to cut copper on a PCB, and not
cut the fiberglass. if that is possible.

Thanks,

Dave





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