Discussion in 'Electronics & Electrics' started by Goth, Jan 29, 2004.
Beats a guillotine
It's like the best of both worlds
I've found that press n peel can withstand a lot more heat than I thought. The technique I've been using for a while hasn't failed me yet.
1. Wear some surgical gloves to stop getting fingerprints and they'll absorb some of the heat when you touch the copper plate.
2. Scrub copper with steel wool, I just use a green scotch brite seems to work fine, make sure all the edges are well scratched too.
3. Dry it off with a cloth that doesn't produce fiber if you can, and a dash of acetone. I just use tissue paper but it can leave fibers that might interfere with small tracks.
4. Put you iron on medium heat, the low heat just doesn't work well. Now put the iron onto the copper plate to heat it up for 30seconds
5. Take iron off, align your press n peel and put it onto the copper, best to start laying a corner and pushing it down from there to avoid an air bubble as the copper is hot and the film will stick to it, use your nails to press it down so you don't burn yourself.
6. Get the iron and "iron" the pcb, that is get the tip of the iron and shimmy it all over the pcb film so all the film is stuck down. You can kinda see when the film hasn't stuck to the copper because it will be a different colour to the rest. In the end you should have scratch marks all over the plastic side of the film. Put the iron flat on the whole pcb for 30sec - whole procedure here takes about 2min for a pcb as big as the iron.
7. Take off the iron, turn the tap on, pick up the super hot pcb and rush to the tap, cover it in water and wait till it's cool to the touch. Slowly pull back the plastic, starting with one edge, as you pull it back if you see any parts that didn't stick and are still on the film stop peeling film off, and put hot iron on that part "scratching" the back plastic. Repeat until you can pull back a perfect pcb transfer.
Anyone tried it using a hacked laminator?
See here : http://www.ultrakeet.com.au/index.php?id=article&name=makepcbs
Great results he's getting with the film he uses, though you need to use a thin pcb.
Using the press n peel stuff and similar products I get best results using a modded laminator.
I found using the iron on method too inconsistent.
Are you using thin PCB? I've been considering trying the modded laminator method given the highly variable results I've had with an iron, but I get the impression that apart from the thickness of standard PCB, the extra copper sucks too much heat out of the laminator?
Pre-heating the board or slowing the feed rate would probably improve the results.
No, I don't use the thin stuff. I use the standard thickness for double sided boards.
The best part with the laminator is that I can imprint onto both sides of the PCB at the same time, eliminating problems with alignment.
Another hint to getting good results: Have large areas of copper on the print. This gives the press n peel more area to stick to. That way when you peel it away, you don't end up peeling away the tracks too.
I normally have a 0.5cm thick border around my circuits, this protects the outer most tracks from peeling away. After the etching is done, I just cut the border area away. The other good thing about keep lots of copper areas is that there will be less to etch. This means less time in the etchant bath, which means less room for error.