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Subject: Toner Transfer Failures

From: "John" <jferrell13@...>
Date: 2012-03-05

This has become a humpling experience!
You folks have made this sound too easy, or maybe senility has set in on my part.

First try: Printed a sample from some packages example, magazine paper, HP P1102W Laser printer. Not too bad, did not fuse well to board though.
I used really thin double sided board, Electronic Goldmine vendor , I think.
Second try:This time I ordered paper from DigiKey. Made a board with DesignSpark PCB package. It is pretty simple, just cross over from an Arduino to a prototype board with SIP's & some RJ-45 Female connectors to SIP's to stick on a Prototype Board. All on about a 3X5 paper. I used a Double sided board that I had in my junk. Washed in Lacquer thinner, polished with scotch brite pad. Toner did not transfer well and that is where I disvovered I had not properly scaled the paper. The pin spacing was 9 to the inch instead of ten. OK, so I washed the toner off with Lacquer thinner and went to my giant Chinese milling machine to check out drilling the board. I set the 800 pound machine up to run at max spindle speed knowing it would not be fast enough. How about that! The 1 mm drill with the bigger shank did jus fine with it!
after drilling 40 pins for a DIP chip I realized computer control was going to be essential. Project under planning... The chip fit fine but I wonder about the drill size. It may be too big to leave enough copper for pads. IS 1 mm THE RIGHT SIZE FOR PC BOARDS GENERAL USE?

Third try: I got the scaling right and tried again with some single sided board that I had in my treasure collection. I figured that I needed more heat so I cranked up the heat on the iron to Linen. I did not move it around much but I did push down pretty hard. After about 3 or 4 minutes I heard a "pop" sound and figured I had broke something in the iron. As the paper cooled down it turned kind of brittle. The board bowed away a bit and the stiff paper raised up in spots. I put the paper in a soak bucket and did something else for a bit. When the paper separated not only had the fusing failed to transfer well but the PC board had copper blisters large and all over! I blame the board this time. It was likely over 30 years old.

Fourth try: I ordered some fresh, modern board from Jameco. It did not blister, but did not transfer as well as expected. I think the single side board is going to bow any way I do it I am thinking I need to just use double sided and etch the excess away. Maybe I need to try some different paper too.

Comments, criticism and laughter invited...

John Ferrell W8CCW