Hi!
Using a iron to do toner transfer successfully takes some experimentation!
You did not indicate the size of the board you are trying to make,But it is easier to do small boards
with a iron..
I used a DRY iron ( No holes in the sole plate!) I found one in a discount housewares store for $10.
It worked better than my wife's iron.But you are really better off buying a laminator.
Check the website for laminator section and look at the user ratings..There are units that work ok for less than $60.
I found a High quality laminator on Ebay cheap by carefully scanning the listings and pouncing when the real
good deal shows up..I got a $400 laminator for $75 plus shipping.. It can laminate boards over .065 inch.Thick.,
Use 1/32" board if you can the Epoxy glass dissipates heat too fast..Phenolic paper boards are ideal..
I get almost perfect transfers every time the boards look like I photo etched them..
OK anyway ,With a iron it is hard to get enough pressure on the board.
I found on the web that if you put a short wooden dowel under the board to present a pressure point.
When you iron the board Roley-poly fashion you get better pressure!
Use good oven Mitts when you do this to keep the board under control.
Most important the board must be absolutely clean! I use Bar Keepers Friend or Oxalic acid powder.
I use Scotch Brite pads. But they come in different grits I get fine gray ones at Auto Paint stores.You may find this at
also at Pep Boys or Auto Zone also. The ones in the Super market are too coarse.
then I use Acetone to clean the board then rinse with water.. If the water lays like a sheet on the board ,you are good to go..
Don't touch the boards with your bare fingers wear plastic gloves.
Regard
Mike
________________________________
From: John <
jferrell13@...>
To:
Homebrew_PCBs@yahoogroups.com Sent: Monday, March 5, 2012 8:24 PM
Subject: [Homebrew_PCBs] Toner Transfer Failures
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
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