Hi Curt,
If it scrubs off, fine! Do you think it cut a single pad? I think that
might be the worse case. Or possibly the small text sometimes written
on a board. Not absolutely necessary for the hobbyist.
A pencil lead you say? perhaps use a mechanical pencil to advance it
(it gets used up, does it?). And you'd have to lower and raise the Z
axis continuously to maintain the arc? sounds like a lot of work! Are
you working on it? ;>)
This is a little different, but how about "rolling on" a silver plate,
and using that for a resist? If I remember correctly, Ferric Cloride
will not etch silver. This would be especially useful after putting in
eyelet's for via's.
There is a product called "coolAMP", that might be of use here. Then
we'd be "rolling on" the actual traces, and perhaps "blotting" on the
pads, somewhat similar to what a photo plotter would do...? I know
other "resists" can be applied this way, but as I have a need for SILVER
plate on a small round PCB (.93"), with three "contact" areas (yes I
have plans for a digitizer probe), and a long "probe" to attach to it's
middle, I thought this might be a viable means of generating traces and
pads on a PCB.
Alan KM6VV
curt_rxr wrote:
>
> --- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Curt,
> >
> > Interesting idea, but I'd be concerned about the contamination of
> the
> > board with the arc eroding of the isolation cuts.
> >
> > Alan KM6VV
>
> Hi Alan,
>
> The effluvium would be colloidal copper in water. It should
> clean up when you scrub the board prior to plating ( I think!? )
>
> I was thinking using water pumped through a grounding sleeve,
> which would make certain of return path for the spark and also
> constantly flush the eroded copper from the board. Since the
> electrode would be a mechanical pencil lead, the sleeve would small
> and the dielectric flow would be limited.
>
> The software would have to cut the isolated areas first (
> i.e. inputs in guard rings and drill center pips in pads ).
>
> CWR