Homebrew PCBs

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