Homebrew PCBs

Mike,

The Staples Picture paper comes off easily. I let it soak in hot 
soapy water for about 10 minutes.  This paper is NOT like a film 
that peels off, rather it almost dissolves in water, then is rubbed 
or brushed off. Doesn't take long at all.

I usually run half sheets of paper thru the laserjet. Just cheap I 
guess.

The pcb was normal thickness, nothing special. It took me some 
experimenting to get the right number of passes thru the laminator 
for good adhesion. The GBC laminators are designed to laminate a 
paper in  one pass. Laminiating a "heavy weight' pcb in a single 
pass is beyond the capacity of the heater. The GBC has a handy red 
temperature light. After the first pass, it takes a few seconds to 
get back up to temp. By running multiple passes, you can reach the 
fusing temp. I generally run a dozen passes, some face up, some face 
down to even out the heat. The thickness (mass) of the paper and of 
the pcb is significant. Remember it is the temperature at the 
toner / copper interface that is critical. 

I use the release paper from the back of labels as a substrate for 
printing legends. It is extremely thin and worksd great. Fewer 
passes are needed and it peels off easily. I don't use it for the 
copper side because the toner is barely held on to the paper. I had 
had problems with the toner flaking off in the past. Though with a 
little effort, it would probably work very well.

Good luck with your Laserjet III. Compared to today's laserjets, it 
is built and runs like a locomotive. I occasionally consider buying 
a new one, but ithe LJIII just keeps chugging along.

Myc

--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
> How did you exactly remove that heavy paper off the PCB?
> My try with that paper was using Lexmark Optra laser printer. 
> However, I conveniently picked up, God knows why, a Laser III the 
> other day...What was the thickness of your PCB?
> 
> Mike
> 
> --- In Homebrew_PCBs@yahoogroups.com, "mycroft2152" 
> <mycroft2152@y...> wrote:
> > After reading the write up on Staples Picture paper SKU # 471861 
> for 
> > toner transfer, I decided to give it a try on my next boards. 
> > 
> > I've had success with a GBC 4" laminator, clay coated inkjet 
paper 
> > and a Laserjet III+. I also use label release paper for the 
legends 
> > on the front of the board. The boards were done on Eagle and 
were 
> > relativey simple with wide-ish traces. There were traces going 
> > between pads.
> > 
> > The final boards were comparable to my regular setup. 
> > 
> > What I liked: The heavier paper was easier to handle and went 
thru 
> > my antique laser jet smoothly. After removing the paper, 
transfer 
> > was sharp and black. There was no white clay film in the toner 
and 
> > the holes in the pads cleaned out easily.
> > 
> > What I didn't like: The heavier paper required more passes thru 
the 
> > laminator to get the same results. This was expected. Removal 
was a 
> > little slower than the clay coated paper, but did completely 
come 
> > off. The cost was about 3x (30 sheets for $10 vs 100 sheets for 
> $10).
> > 
> > Overall, I thought the Staples picture paper was pretty good, 
> > reasonably cost effective and easy to use. The only 
consideration 
> > during changeover was allowing for the extra thickness of the 
paper 
> > in processing.
> > 
> > Myc