Homebrew PCBs

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