Conductive Ink... anyone try?

[jsleep]

I hate to spoil the party (if I have), but you can't solder to conductive pen ink.  If you did manage to get a solder joint on to it, it would be, at best, very "dodgy" (as they say in UK).  This stuff is really for trace repair only.

There is an actual copper trace set copper traces and pads with one side sticky that you can use for repairs.  You stick it down on the board and then you can drill thru it, solder to it, etc.  As you can imagine, IMHO making a full circuit board from scratch with this would be much more difficult than etching.  Again the intended purpose is for board repairs.

JD

[Triffid]

Well, that is some what contradictory to what the manufacturer said.  They did say that sodering at high temps could make things ugly, but sodering at low temps would be just fine.   It probably depends on how good your soder technique is.  I guess I assumed that to mean... 15 watts = OK, 30 watts = ugly  Of course, I am not really going to know until I try.

[javacody]

OK, here's an idea.

*Print out the circuit board design.
*Glue it to carboard.
*Trace the circuit with the pen.
*Punch your holes.
*Solder in components

All done. It may be a worthy experiment.

[Triffid]

Also... Even if you can't soder the conductive ink, what is preventing you from sodering the components in place first, then tracing your curcuit.  This may take a little more planning, but it would still beat that darn etch process in my opinion.

[petemoore]

That supposedly was conductive material that dries' ... I remem trying to work with it a little bit...It didn't do very well IIRC...Dunno if it's the same type stuuf tho.

[aaronkessman]

I thought about doing this a while back. I got a sample of the conductive ink pen and tried soldering to it. the iron temp was high (not sure how high, but it was up there) and it made things messy. the ink melted or something and balled up with the solder. lower temp might be better. best would be to trace out the interconnects AFTER soldering. immediately after to assure a good bond between solder and ink.

i was worried about resistance of the ink itself. as long as the traces i drew were solid, resistance seemed minimal. i'd make the following suggestions:

1. keep traces as short as possible
2. use pad-per-hole board so that you're always going over a pad - keeps actual ink parts of the trace length down
3. use at least two layers of the ink.

the stuff dries very quickly. you can bake it to make it go even faster. I'm going to try it when i get the chance.

Aaron

[Paul Perry (Frostwave)]

I doubt you could ever solder to any conductive ink. But, all you would have to do is, put a metal tag in, and paint over the end of the tag & solder to the other end of the tag.

[aaronkessman]

tried soldering to the conductive ink pen stuff today. i used the lowest temperature on the iron and it barely melted the solder. it DID stick to the ink, but not very well,  and didn't make the ink just ball up and get absorbed into the solder or peel off the substrate. this worked as long as i didn't keep the iron on it long. Prolonged exposure even at low temperature always makes the ink desintegrate.

i still wouldn't solder to the ink though since the ink is kind of crumbly to begin with. you wouldn't want to mess with trying to get solder to stick to it.

Aaron

[Triffid]

Have you tried sodering, then inking?  Do you have contact problems that way?

[aaronkessman]

no. doesn't look like there's an adhesion issue with ink on the solder. however, after soldering, i'd make sure there wasn't any flux residue or whatever on the board. best to clean with alcohol, possibly scrub a little with a scotchbrite pad just to get the surface as clean as possible.

[aaronkessman]

update to this:

Im going to build my tremulus lune with a conductive pen. Here's my plan

1) draw a layout on perfboard using the PCB layout from commonsound
2) using a sharp blade, scratch that pattern into the pad side of the perfboard in order to show me where to draw and also improve adhesion
3) solder my components
4) draw the circuit in
5) bake it in an oven to improve adhesion of the ink

I did a test of baking and was able to get the resistance of the ink to about 0.15 ohms in the length between two *holes*. I did not have actual perfboard, which has large pads, so the actual resistance from pad to pad will be even less than 0.1 Ohms. negligible. Cant wait to get started on this. the layout is almost an exact fit already.

adhesion to both copper, solder, and board looks quite strong with a bake of >100ºC for a few minutes.

[puretube]

milli-Ohms can contribute to ground (-loop) problems...

[aaronkessman]

a solution would then be to use an actual wire for the ground bus like you normally would on perf.

[puretube]

don`t know if it`s possible to "paste" a heap of solder on top of the ink,
but if so, that may help a lot;
in fact, I love to "thicken up" my ground ( & supply-) traces on real PCBs that way...

[aaronkessman]

yes! it is!

i just tried it using the soldering iron at low temp - not conrolled, but just before it had heated up all the way. adhesion to conductive ink was way better than what i reported last time, not sure why. but you could definitely overlay important traces, like the ground bus and V+ with solder after the fact. Actually, once you've bridged all components with solder, adhesion of the solder to the ink and the ink to board is irrelevent.

in other words, it willwork great. just need low low temp soldering.

[puretube]

good to hear;
thanx for checking that out
- would really be an interesting alternative for experimental/proto circuits - ...

[aaronkessman]

the stuff seems to come off with a little acetone scrubbing. may work with other not-evil solvents too. but it seems like it's rigorous enough to put in a stomp box. at least one for myself. i'd never *sell* one or make on for someone else with this stuff though.

[marc]

i had something similiar a while back. i thought it would help with a circuit i was trying to debug. my only concern was the one i used had warnings on it that said inhaling the fumes could be fatal! i haven't used it since and i made sure it's in a place where my kid would never find it.

i'm not convinced the tehnique suggested in this thread would be simpler than etching and drilling a board though.

[aaronkessman]

well, everything is fatal if its in the correct dose. you DO know about dihydrogen monoxide dont you?

http://www.dhmo.org

fact is, there is so little solvent in the amount you put down when youre drawing, that its next to nothing. soldering is much worse for you.

seems to me like it *is* easier because i dont need a PCB kit - which has its own hazardous chemicals which are worse for my home than the solvents in the pen, and I dont need a drill press. just a layout that works. which you'd need anyway.

wouldnt do it for somehing like a EH electric mistress, but for something the size of the tremulus lune.....

heh

[col]

There used to be a product in the UK from Hornby Railways called solder paint for their digital Zero 1 control system. It was used to re-join tracks on the chips after they had been cut to assign a number to them. I don't know if it or something similar is still available. It was useful for joining thin sheet together as you could paint one side, press them together end then heat them with an iron, joining them together. Whether or not you could trace on a board with it I do not know. It was expensive for a small tube and the one I bought dried up very quickly once it had been opened.