Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
> On Sat, 16 Apr 2005 13:39:18 -0700, Tobias Gogolin <usertogo@g...>  
> wrote:
> 
> >
> > Hi folks
> > I am wondering has anone ever tried to disconnect the fuser (the hot
> > chamber the paper runns trough to fuse the toner to the paper?
> > I have notices that when there was a paper jam the section printed but
> > not fused has the toner very loosly on the paper, which if it can be
> > handled without disturbing the pattern may result in a more complete
> > transfer of toner ?
> > cheers
> > Tobias
> > P.S>: It would be cool if sombody could figure out how to increse the
> > precission of the print offset (margin) so well that one could print 2
> > or more layers of toner?
> 
> 
> i do not think the loose toner would be practical, alignment and all.
> I remember one time it got stuck and i manged to rescue the printout
by  
> running it through the fuser i use for transfer.
> I do not see what the advantage would be of keeping the toner loose,
how  
> would you get it on the PCB without simultaneously fusing it to the
paper  
> anyway?
> Do try the silicone paper if you have trouble with release. I will
do more  
> experimenting soon, with neutral-curing silicone i got a few days
ago so  
> there are no acetic acid concerns.
> 
> i don't think you can print twice with a laser, inkjets are better
with  
> alignment.
> 
> ST

I pulled the fuser out of my HP4L.  Tried printing on various
media.  One problem was repulsion of like-charged particles tended
to fuzz out the trace.  Putting aluminum foil between the backing
sheet and media being printed helped that a lot.
but I still had a lot of trouble keeping it from spreading due to
handling shock.

Tried electrostatic transfer to the board.  Sorta worked, but had
too many voids in the 8 mil traces.

Tell  us more about the neutral-curing silicone.  Brand, cost?

mike