Homebrew PCBs

Juan 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.

A laser from a DVD burner should be quite adequate to expose photoresist.

I played around with large argon lasers and scanners as a means of resist 
exposure rather a long time ago.

It was difficult to keep things square, the right size and in focus but the 
results were still rather acceptable.

A x-y plotter rig like those used with CO2 laser engravers would be a much 
better option and a great deal cheaper.

You'd probably want to use a considerably longer focal length lense.

X-Y CO2 laser engravers usually have the collimated laser statically mounted 
and shining along one axis hitting a travelling 45 degree mirror which 
redirects the beam up the other axis to another travelling 45 degree mirror 
which in turn directs the beam down onto the work through a focusing optic.


DVD laser diodes are probably best mounted on the gantry aimed directly at the 
work.