Homebrew PCBs

On May 18, 2006, at 4:39 PM, thomascouey wrote:

>  It might be hard to implement, but if
> you could get a thin masking material and laser etch your pattern
> through it so that it becomes something like an eraser shield (if
> anyone's familiar with the old pencil and paper drafting days), then
> use it as a mask and spray on a resist (hair spray?).
>
> Is there a material out there that would melt away at very low
> temperature, but be robust enough to handle?

I like the idea... there's a new transfer paper the HTFDP folks are  
talking about called MiraCool.

You heat-press it and then the backer practically falls off by  
itself.   (By comparison with 'hot-peel' transfer paper that you have  
to peel when very hot or it sticks).

That would leave a layer of polymer on the PCB.   A quick scan with a  
laser engraver would burn the "positive" areas and then you'd just  
drop the board in the etchant.

The poly coat would help protect the PCB traces while the copper in  
the unwanted areas dissolved.

Take the board out of solution, and use a heat gun to take off the poly.