PCB using toner transfert method, another try

by Sébastien Lelong — posted at 2008-04-22 07:54 last modified 2008-04-22 07:54

I've just build another board, using toner-transfert-system (TTS). Last try required lots of trials/errors, still leaving unanswered questions... This time, the first try was perfect. Here's my ultimate recipe:

I use glossy photo paper for laser printer (135g/m²)

wash your PCB board with soap, then with window cleaner (or detergent with alcohol).
sandpaper your board with ultra thin paper (600, one used for body car)
wash again the board with soap, then with window cleaner. It must absolutely be dry.
preheat the board, with your iron (max temperature, mine doesn't heat a lot)
place the paper on the board. Be careful, it'll instantly stick to the board.
iron the paper. Apply a lot of pressure, all over the board, for ~15min (yes a long time, but it may depend on your iron)
continue with the iron tip, and redraw all the circuit (black tracks will appear through the paper), for ~5min.
Ironing time: ~20min
then place the board on hot water, no soap. Soak it for 30min.
peel-off the paper. Most can easily be removed, only the last layer, where the toner sticks, will mostly remain on the board.
soak it again for 1h
peel-off again the paper. You may need to remove very small portion of paper, between the tracks. Leave the paper on the tracks, it won't bother while etching since tracks remain accurate. This can be time-consuming, but be precise. Also don't be paranoid, the toner really stick well to the board and won't be removed easily
once done, dry the board. Check if you've missed some paper.
clean the board with window cleaner. While it won't remove toner, it'll help to remove paper residue and get an accurate board.
you're done. You'll then need to etch the board. Once done, remove the toner using acetone (nail polish remover works well)

Here's some pictures:


Once all paper has been peeled-off, here's the global result: tracks are still covered with paper, but the whole seems accurate.	Zooming shows tracks are perfectly accurate, even holes in pads. Text is too fuzzy won't be rendered well if left as is. Using window cleaner can help removing extra paper residue.

Paper on tracks is clearly visible here. Important is the way limit between tracks and copper is clean, accurate.	After etching, here the result. Everything looks nice. There are two pen traces which I've added. The big trace on top of the board isn't consistent at all. Using a PCB pen is definitively not reliable...

Once cleaned... Great...	Even text is readable :)