Best way (if any) to reattach a copper trace that has lifted?

[skiraly017]

I've come across a few vintage pedals where the traces are starting to lift. Is there a safe way to fix this? Thanks.

[aron]

Glue???

[Paul Perry (Frostwave)]

For a 'vintage' pedal there are two considerations - appearance AND reliability.

Personally, if a trace is lifting, for reliability I would definitely run a wire along the trace, from start to finish, joining the components, so you aren't relying on the trace at all.
But how to do this with minimal change to the appearance...??

[frank_p]

There is a reply that RG made some times ago.  It involve making a knot with a wire around the leg of a component and then passing it trough the hole (if I remember well.  Can't find it with the search function... 

I even saw a tutorial on the net but don't remember where it is...

[frank_p]

Ah Ah ! Found it:

http://www.diystompboxes.com/smfforum/index.php?topic=67381.msg536700#msg536700

A tutorial is there also:
http://home.comcast.net/~machrone/bjr/mistakes.htm

[aron]

>I would definitely run a wire along the trace

I've done that to fix a broken trace. Would crazy glue not work :-)?

[CGDARK]

A bare wire over the broken trace from point to point is the best to go. A little difficult to keep the wire in place while you solder but worth the effort.

CG

[Paul Perry (Frostwave)]

I don't have any objection to just gluing the damn thing down, but traces aren't all that strong. By all means glue it, seeing as it isn't part of a $400M Mars project!
I had a midito CV converter returned to me for repair, and someone had connected an output to the mains (!) One chip had fried, and an eight inch trace was blown off the board & curled up like a watchspring. New chip plus a piece of wire where the trace was - good as new. If only it was always that easy..

What is REALLY ugly, is when stuff with plated through holes goes bad through butchery with overheated irons. Then you really do have problems.

[aron]

WOW Paul.... incredible. In the past I have soldered a wire over a trace to fix things.... It's worked for me.

[petemoore]

  Look where everything that goes somewhere goes, try to find a better place than where you'll ruin more of the board fiddlin' with the liftrace to do the patch.
  If you can't find that on the board, try to find another way to get a solid core lead [like resistor lead] solidly attached and bent just right to pin the trace [that you cleaned up by ?using a fingernail sanding stick?] down. hopefully the fix stix.
  Then follow the map' [use schematic] and see how it did.
  Maybe you can drill a dinky hole for the resistor leads to poke through from where they can be solidly attached above the board to other component leads, patch above board? of course.
  This may help keep the wire in place for making the trace connection, get solder to hold on both trace and lead surfaces, use brief heat, try to get the 'tack on' point to work quickly.
  Put the solder on the tip right before pressing it to the trace, then grab the pliers to pin the new wire and trace against each other, sandwiched against the board, right after the solder and trace get hot enough.
  Trace gets heated through the wire unless you can get the tip angle to hit both just right real quick.

[PerroGrande]

I have some thin, copper "tape" (adhesive on one side) that is used in making stained glass windows.  I have found it to be a great way to repair traces that have been completely destroyed due to age or overly aggressive soldering.  The cool thing about this stuff is that it is made for soldering.  If better contact between the board and the tape is needed, a drop of super glue does the trick.

I helped a friend with some boards that had been damaged from solder overheating.  Here is an example of the tape being used as a total replacement for a destroyed trace/solder pad:



The local electronics store has essentially the same stuff, but for a substantially higher price than it can be obtained from a stained-glass hobby supplier.   

On an related note -- the stained glass suppliers have adhesive copper sheets that make AWESOME shielding for plastic boxes, etc.

[Marcos - Munky]

I just use a jumper/wire soldered to the trace. But if it's an vintage effect, I think a little glue plus some solder flux and a layer of solder (to make a kind of solder mask) will do the job.

[CodeMonk]

>I would definitely run a wire along the trace

I've done that to fix a broken trace. Would crazy glue not work :-)?

Wire is good.
I used to work in electronics (Assembler, tech, do whatever). So heres the opinion of a professional (sort of, I haven't worked in that industry for about 10 years).
Many times traces lifted due to to much soldering (re-working boards etc.). Quite often we just used some super glue to hold down the traces and pads as well. Worked pretty good.

[96ecss]

I've never used a conductive ink pen, but I wonder how well it would work. Has anyone here ever tried one?

http://hmcelectronics.com/cgi-bin/scripts/query.cgi?query=cw2200stp

Dave

[skiraly017]

I'm sorry, I should have been more specific with my question. I've done the wire strand methond (and these were all excellent suggestions) but what I was trying to ask is if there was a way to repair a lifted trace without changing the cosmetics. Let's say you had an uber rare vintage pedal in mint condition but one of the traces was lifting and you didn't want to do the wire strand repiar. Is there an adhesive that you could use to glue the trace back down. I would be hesitant to use Crazy Glue becuase it seems to eat through things.

[R.G.]

The thing about glues is that it's always a race between the soldering heat and the glue decomposing. Epoxies get soft with heat. They vary with exact composition. Machinists use super glue (cyanoacrylates) to fix parts in place knowing they can release them by heating the parts.

I'm sorry, I should have been more specific with my question. I've done the wire strand methond (and these were all excellent suggestions) but what I was trying to ask is if there was a way to repair a lifted trace without changing the cosmetics. Let's say you had an uber rare vintage pedal in mint condition but one of the traces was lifting and you didn't want to do the wire strand repiar. Is there an adhesive that you could use to glue the trace back down. I would be hesitant to use Crazy Glue becuase it seems to eat through things.

It eats through things because it contains acetone as a solvent. The amount of acetone in enough super glue to glue down a trace will not harm the PCB or the trace before it evaporates. But epoxy is what glues copper foil to PCB substrate. And that's why too much heat for too long lifts traces - it softens the epoxy layer.

[Mark Hammer]

And this is why I often use software to make traces thicker on PCB layouts; just to make sure that heat will not displace them under my watch.

HOW to make them thicker?  I use an older version of Paint Shop Pro, though I imagne the same thing could be accomplished with other packages.

First, if the image is in black and white, I convert to 8-bit greyscale.  Once in greyscale, I use a "soften" filter.  That will effectively smudge the image outwards.  Next, I apply a highlight/shadow adjustment which makes those light greys around the perimeter of the original black areas darker, and simultaneously lightens the very light grey just outside that area.  I try not to do it in one pass.  Rather I'll alternate between using the highlight/shadow tool, and a brighten/contrast tool.  One, then the other, until I get a suitable extension of the original traces in a nice thick, black.  Sometimes, to do a good job, you need to increase the size of the original image (e.g., a 600 x 600 original might need to have resoltuion increased to 2000 x 2000 to do a good job).

Once the thickening is completed, I do any touchup needed (sometimes you needed to unshort adjacent traces or pads that have been thickened a little too much).  Very often, the white dots that were in the middle of pads at the start, get filled up and need to be re-instated, but that's a simple job.  The thicker traces are not only more resistant to lifting off under "novice" soldering practices, but use less etchant as well; a nice perk.

Of course, this is only useful information for those wanting to prevent lift-off, and pose no panacea whatsoever for those attempting to repair an existing PCB where a trace has lifted and possibly fractured.

[frank_p]

I build Manhattan style with crazy glue and it's working, it's not super strong but it's holding. So perhaps you could use a clad sheet and glue it with minor visual effect.  Epoxies are sensible to heat as RG said.  To un-glue an epoxied piece of wood on guitars (ex: fretboard from a neck) I run a big iron on the wood that I want to remove and can "pop" it out with chisels and scrapers. So obviously, the heated epoxy is weaker than a hardwood part.

[reverbie]

Sort of a tangent, but along the lines of what Mark H said...whenever etching your own boards or even having them pass produced, it's a good idea to have FAT traces when possible and even extra holes drilled in vulnerable parts of the circuitry...that way you can re-drill a new hole if a trace lifts or just wire right into your "backup" hole. I have seen this on multiple tube amp boards.

[frank_p]

And this is why I often use software to make traces thicker on PCB layouts; just to make sure that heat will not displace them under my watch.
HOW to make them thicker?  I use an older version of Paint Shop Pro, though I imagne the same thing could be accomplished with other packages.
First, if the image is in black and white, I convert to 8-bit greyscale.  Once in greyscale, ...etc

Oh ! OK Mark ! You do this to an existing layout that you take from the web, book, etc..  At first read I toughed you were doing that when doing your own design...  I must be tired...