Re: [CAD_CAM_EDM_DRO] Laser "route" Printed Circuit Boards

Roland Jollivet wrote:

> Hi alan
>
> Knee jerk response is; If you want to use a CO2 laser, the power would have
> to be a bit higher than if the substrate was a wafer of steel. Shiny copper
> is THE best surface for reflecting CO2 laser beams and laser mirrors are
> made of this for that reason. But maybe that means using 50W instead of 20W
> ??
>
> What would the effect be of the burn on the fibreglass substrate? A thin
> burnt surface between tracks is going to be conductive, maybe not at DC
> levels, but definately at RF.
>
> Notwithstanding, those teeeny vias you see on PC cards are laser drilled.
>

If they are actually laser drilled, they are drilled by a really high
power pulsed laser,
YAG I think. The explosive vaporization of the epoxy leaves a fairly
clean hole.
Burning a gap with a CW laser would not do anywhere as clean a job, I
don't think.
The lasers are such expensive gear, and so easily damaged, that I think
a lot of
really fine holes are still mechanically drilled.

Jon