There's a guy on eBay selling 1 watt fiber optic coupled diodes that
might do the job. The fiber is very small diameter (can't quite
remember) so it can be used without a lens to cut lines <5 mil if
the fiber is placed very close to the pcb. I was going to use a cnc
router to control the laser path. It seems very workable, but I have
gotten sidetracked with other techniques for making pcbs. I may get back to it.
Mark
At 11:08 AM 4/14/2011, you wrote:
>Sorry for shotting down an otherwise great idea, but having played with
>these laser diodes quite a bit, specifically in terms of cutting with
>the beam <http://elabz.com/category/laser-cutting/> , I would have to
>say that there is just not enough energy in the beam of a regular,
>off-the-shelf DVD or even Bluray burner to evaporate paint off a
>copper-clad FR (or any other solid material for that matter). Copper
>transfers heat away from the laser ablation point too well, in fact just
>about any non-porous material does. That's why most of the stuff you'll
>see cut with these laser diodes is foam.
>
>Additionally, as others pointed out, the optics of the drive are
>designed to be focused at a point in a middle of the CD's thickness and
>even though the lens do adjust floating on the electromagnetic mount,
>the adjustment would most likely be not enough to focus on the surface
>(plus the pain layer thickness) instead.
>
>
>But I do like the idea in principal and I am planning on upping the
>energy quite a bit by installing a 1W laser diode (IR or blue) and
>trying paint evaporation again. It may just work on a thinnest (0.7
>mil's the thinnest?) PCB I can find...
>
>
>--- In Homebrew_PCBs@yahoogroups.com, "Boman33" <boman33@...> wrote:
> >
> > Here is a crazy idea that might just work:
> >
> > A first requirement is being able to cut out a PCB the to look just
>like a
> > CD. It needs to be accurate and typically a lathe would be used.
>Apply a
> > layer of paint or other protective coating over the copper.
> >
> >
> >
> > Pop it into a CD burner that has the Light Scribe or whatever it is
>called
> > feature to mark CDs. Take the layout and convert it to a JPG and use
>the
> > marking software to place it on the CD. Several small SMT PCBs will
>fit on
> > a CD. "Write" the picture to the "CD" and hopefully it will vaporize
>the
> > paint. Afterwards etch the boards as usual.
> >
> > If the power is controllable, it might also be used to expose a
>photoresist
> > as an alternative.
> >
> > Bertho
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>[Non-text portions of this message have been removed]
>
>
>
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