Conductive Ink Pen - how to apply without bridging when there are multiple traces?

[Almighty1]

I was wondering if anyone here has any experience using conductive ink pens as it seems the motherboard I am recapping has some broken traces. The problem is the traces are next to each other and I am trying to avoid bridging the traces together but what's the best method to do it as I've tried:

1) using 3M Scotch Magic tape outlining the trace but the ink still seems to bleed to the other trace.

2) just apply to the entire area and let it dry but after it dries, using the tip of a paring knife to draw the lines between the trace, it will basically take all the conductive ink off.

Is there another way to apply it so it will just be a hairline instead of spreading and creating a short?

[Goldieoldie]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

Hi,
Rather than using conductive ink,I've repaired traces by using thin copper wire ( single strand from hook up wire ) then a drop of glue to hold the wires in place
Pete

[Almighty1]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

Never thought about that method but wouldn't the glue prevent conductivity as the wire has to be secured tight to the traces and I thought glues were non-conductive.

[stj]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

yes, wire and if it's long you tack it down with glue afterwards.
i'v had nothing but trouble with silver paint.

btw, dont use cyanocrylate (superglue / crazy glue) ever on pcb's
use UHU all purpose adhesive.
it sticks real well, dry's clear and can be ripped off later.
it wont vaporize into your eyes if you go near it later with a soldering iron like cyanocrylate.

[stj]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

Never thought about that method but wouldn't the glue prevent conductivity as the wire has to be secured tight to the traces and I thought glues were non-conductive.

he meant solder the wire & use the glue to hold it down.

[Almighty1]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

Only problem is the traces are fairly close as the gap is about 2-3 hairs apart so soldering would basically cause a short.

[stj]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

no it wouldnt, i'v done it before.
single-strand copper wire can be placed on tracks like that.

post a foto of the problem area.

[Almighty1]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

Hard to get a picture in focus so I've borrowed one basically showing something in a similar manner, there is like 6-7 traces which all are broken that I'm trying to fix. I can see how single-strand copper wire can be placed but how will you get the solder to be hair thin so it doesn't touch the other traces. I even heard some people use a 0.5mm pencil to fix traces but it just won't be long lasting as that's how some people defeated the AMD CPU frequency lock.

[chozo4]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

In such cases what I would do is clear off a small section of soldermask further up on each trace so you don't risk bridging it with others adjacent to it. Just alternate the locations on the traces accordingly to avoid any scraped traces right next to each other.

[stj]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

yep,
strip & tin the tracks,
tin the wire,
then they will solder together fine.

[rievax_60]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

In such cases what I would do is clear off a small section of soldermask further up on each trace so you don't risk bridging it with others adjacent to it. Just alternate the locations on the traces accordingly to avoid any scraped traces right next to each other.

That is what I do also, works well.
If the tracks are very fine and I need many attempts at getting the wire soldered in the right place, I use candle wax as flux. It doesn't need to be reapplied often like other flux types do.

[Almighty1]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

Good point so basically I can join any two parts of the trace as long as it's the same trace? Also, where would I get the wire for this? What's a good way to clear off a small section of the soldermask without damaging the trace beneath it?

[budm]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

I use fiberglass pen, something like this: great for corroded joints and pins.
http://www.frys.com/product/2581741?...FcI7Mgod3FgApw

[stj]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

for wire just strip some stranded wire and use a strand.
when i want really thin wire i unwind an old transformer or speaker coil.

remember that transformer / coil wire is insulated with laquer.

[rievax_60]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

It is important to not scrape soldermask from adjacent tracks if you want to avoid solder bridges. I use a stainless steel rod sharped like a small flat screwdriver point, but slightly rounded.
The fine wire from small mains transformers can usually be tinned easily at normal soldering temperatures.

[Almighty1]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

I have a few of the pens budm mentioned and the problem is it will scrape the soldermask off from more than one track which is what I'm trying to avoid. I don't have any old transformers or speaker coils which is why getting the wire is not exactly that easy. I'm wondering what kind of trouble people actually have with the conductive ink from the conductive ink pens since I know it works except the question is how to draw fine thin lines with it since we're talking about 11 traces within a 5mm width.

[mmartell]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

You can get fine wire from a piece of solder braid.

[eccerr0r]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

When I can, I just use 30 ga Kynar wire wrap wire, but it's just because I have plenty of it (have a bit over 1000ft)
But it seems as nobody wire wraps anymore, the price of this stuff has gone up a bit since I last checked, it used to be $4 or so for 100ft...

[Uniballer]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

+1 on the Kynar insulated wire.

[stj]

Re: Conductive Ink Pen - how to apply without bridging when there are multiple traces

i love kynar, but it takes practice to strip it nicely.