Homebrew PCBs

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]
>



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