Just found this article.. Ive never thought of this before, but its not new. Anyway.. it leaves the question, how do you get a complex PCB design onto a pcb in such a way that the tracks are all electically insulated.. maybe existing etch resist methods will work? http://overhauledpc.com/guides.php?guide=5&page=0 Also, thesolution starts as water + salt solution. What will it be after copper is disolved into it - if it changes?
I don't think this will work, because if one of the print wires is etched away, it doesn't let current flow anymore and so not the whole print will be etched away, I think the residu will be CuCl2 or something like that, but that is easily dissolved, so there will be no residu, the copper will just dissolve. So there will be some copper in the solution
Hmmm...I don't think the inks would make good insulators against the electricity. I can imagine conduction occuring through the ink unless you put it on pretty thick. Try it out and let is know how it works.
Exactly (well, near enough) the same process can be used in x-ray crystallography to study metal structures at the atomic level. A sheet is etched away until a hole forms, electrolysis is faster than just using an acid. The metal round the edges of the hole may be only a few atoms thick. Got the T-shirt. Problem with pcbs is preferential attack at the copper/laquer interface (same mechanism as crevice corrosion) giving under-cutting, but it could cut down on the amount of ferric chloride needed.
Im going to try it some time.. Any idea how to work out the required current/ resistance for doing some thing like this? - dontreally want to burn out my spare psu's and I have the question, wont the psu just cut out as its near enough to a short to ground?
i would be very scared of trying something like this, in my books its up there with the do it yourself annodizing, not my kind of thing right now, but its a real good idea
You need a very strong warm salt solution; sodium sulphate (Glauber's salt) would perhaps be better than sodium chloride (cooking salt) if you can find it, as there's no chance of chlorine gas coming off. You can use a series resistor to limit psu current to about 10A (0.47R 50W on the 5V line), but variable control to get a minimum amount of gassing at the copper side would be better. Or just move the pcb and the cathode plate further apart to reduce current. Faraday's Law of Electrolysis says 2 Faradays (2 x 96,500 amp.seconds) are needed to move 250g copper (Cu++).
96.5kA/s (27A/h) sounds like a LOT of power to move a small mount of copper.. Suppose its about right.. I will just have to expose very small amounts of cooper at a time to get the resistance right.. dont wanna blow my psu or make resistors explode Wouldnt sodium sulphate give off sulphar gas which is also poisonous? While were on this topic.. I have some silver-chloride which I made to electroless plate some copper, but it didnt work too well... But could I electoplate using this? What would happen if this was used as the salt? would the chlorine form gas and leave the silver behind, but in what form? and what will happen to the copper which is moved? Also do I need to use differnt metals for the cathode/anode?
250g of copper will be about the amount on a 3ft x 3ft board... Silver chloride is almost insoluble in water. Silver nitrate is soluble, but deposits silver on copper like copper sulphate deposits copper on steel, just by dipping the metal in it. A thin loose dirty film. To plate with silver you usually use a cyanide solution.
