Homebrew PCBs

In a continuing search for a better and cheaper toner transfer 
method, 
I've tried a number of different papers. Photo papers, magazine 
pages, 
inkjet papers, label backing and even the parchment baking paper.

The parchment paper worked well with no soaking needed. But 
unfortunately the 'grain' or the texture of the paper occasionnally 
created hairline breaks in the traces. I tried pre treating the 
paper 
by running it though the Laserjet IIIP+ which I've been using. But 
still had some problems.

It appears that a silicone release coating (as seen in the coated 
paper trials) is the key to waterless 
removal. Recently the ladies at the Reynold's kitchens have been 
talking about a new coated non stick foil. I thought it was worth a 
shot.

Boy was I surprised! I attached a small piece of the non-stick foil 
to a regular sheet of paper and ran it through my laserjet IIIP+, 
printing on the non stick side. The printing was sharp and clear. 
Even the board outlines as drawn in EAGLE were clean.

With fingers crossed, I attached it to a clean piece of copper clad 
and ran it through my off-the-shelf laminator. I let it cool.

The foil peeled easily away from the copperclad, leaving all of the 
toner firmly attached to the copperclad and the foil clean.

It looks like the silicone coating on the foil acts as an insulator 
to keep the charge and allow the toner to transfer and then acts as 
a release agent.

The foil transfers the heat easier than paper which acts as an 
insulator.

Anyways, it works. The cost is trivial, about $3 US for 35 square 
feet.

So. during your next trip to the grocery store pick up some 
Reynolds "Release" non=stick aluminum foil. It's probably in the 
same aisle as the chicken grills. :)

Myc