--- In
Homebrew_PCBs@yahoogroups.com, "Juan EA7FNJ" <ea7fnj@...> wrote:
>
> Hi guys!
>
> I''ve seen this: http://c4r0.skrzynka.org/_hv/index.php?page=lasers/cnc2
>
> I was thinking: why don't use this kind of laser to burn the
> photoresist board. After you develop it and ready for the etch. I
> knoww the CO2 laser but it's more expensive than a simple burn laser
> from a DVD burner.
>
> Any idea?
>
> Bye!
>
Hi guys interesting thread,
For my 2c I use a 40W CO2 Laser (Chinese Engraving one)(2nd Hand
off ebay) to burn of matt black spray paint off brass to make stencils
(ie solder and screen print) and gobos for Theatre lighting bonus of
using spray paint is its not delicate like some of the other coatings
I've tried on brass and copper, you can really scrub the residue off
then hit it with Acid/H2O2 etchant.
The thing is the cheap (less than $3000AU) Laser engravers are
Raster devices so to burn the "resist" off a complete board would mean
scanning the entire board too remove the "resist" and experience has
shown me that you need to do it twice to get the best removal, this is
a down side as the laser tubes have a finite life in the low thousands
of hours and are expensive and anything that scans a raster image 1
dot/line at a time is sloooow (I offset the projected cost by making
engraved name tags when I'm not indulging in the hobby)
On the subject of using CO2 Lasers to "cut" copper as I understand
it the actual mirrors in a CO2 Laser are coated polished copper as the
radiation is in the infrared range so anything strong enough to cut
copper would also burn the mirrors up in the process. I believe that
to cut copper you need to use a YAG Laser and a air/gas jet to blow
the cut material out of the cut.
I hope this helps
Regards
Stephen