Homebrew PCBs

Interesting question.  I think its pretty much an insulator since it 
gets picked up via static electricity prior to fusing.  I think a 
conductor would have problems.   but I just tried a quick test with 
my multimeter and got nothing.  maybe its an issue but i haven't seen 
any problems, yet.

--- In Homebrew_PCBs@yahoogroups.com, "ballendo" <ballendo@y...> 
wrote:
> Phil,
> 
> Thank you for a really detailed useful post!
> 
> One question: Do you worry about the conductivity of the 
> toner "screen print"? Seems that it could be an issue...
> 
> Ballendo
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> 
wrote:
> > After trying lots of paper and making a few boards with magazine 
> > paper, I found just the right paper and a good technique.  I'm 
very 
> > pleased with the results for both 1 and 2 sided boards.  Up until 
> > now, I was pretty dissapointed with the quality of what i was 
> making -
> >  lots of trace blooming and areas of poor resist adhesion..  I 
know 
> > others have different techniques that work but this is getting 
darn 
> > near fool proof for me.
> > 
> > The paper is general purpose good quality inkjet paper - less 
than 
> $5 
> > for 500.  I use a canon personal copier to get toner onto the 
paper 
> > and crank the darkness up quite a bit.  The toner goes on thick, 
> the 
> > paper absorbs the excess toner nicely and I get very very little 
> > blooming of my traces anymore. 
> > 
> > Copper substrate prep is pretty standard except I use emery cloth 
> at 
> > 220 grit to significanly increase the surface area to improve 
toner 
> > bonding. I'm going to try something finer than that. wash, 
degrease 
> > and dry in oven.
> > 
> > I put the iron on just a touch back from the hottest setting 
> > (cotton).  I also use children's construction paper between the 
> iron 
> > and the toner paper as a pad to even out the pressure which I 
apply 
> > quite liberally.  I iron both sides for a minute at what my 
> bathroom 
> > scale says is 30 lbs of pressure.  Finally, I leave the iron on 
top 
> > of the board/paper assembly and turn it off to let it cool down.  
> > This is an important step as it keeps the melted toner in strong 
> > contact with the copper substrate to ensure good bonding.  Once 
> cool 
> > enough to handle, it goes into the water for a standard soak and 
> > rub.  The paper falls apart very quickly and the toner doesn't 
> flake 
> > off at all so I can scrub pretty hard.
> > 
> > Also, I am getting good results with legend printing (some times 
> > called silk screen).  I use the above technique with 2 changes.  
> > First one is that after one minute of ironing, I use the edge of 
> the 
> > iron to "burnish" the toner paper into the board.  This ensures 
> good 
> > contact of the hot toner to all surfaces including next to 
traces.  
> > The second one is that I do a hot peel of the toner paper.  
Enough 
> > toner stays on the board to be very legable but more importantly, 
> no 
> > soak-n-rub cycle and thus I can go right to drilling with no more 
> > than a 5 minute delay.
> > 
> > some pix taken with a 10X microscope 
> > http://www.geocities.com/phil1960us/pcb/
> > 
> > Phil