How to fix broken PCB board?

[Script]

A friend of mine just brought in a piece of gear that has a severely broken PCB cause it fell of a table, so that several traces are broken (a total of 16 at least). Unfortunately the board is SMD and traces are really thin. I'm not sure how to fix this, and whether it is possible at all. Looks like I could bridge some traces by adding cables, but that doesn't seem possible everywhere. Anyone has experiences and suggestions? I'd be grateful for any hints or advice.

Cheers,
S

 

[Apache5]

Normally bridging them with wire wrap is how I solve broken traces... You must find a bias or component where to solder ends or you can try to scratch de varnish to solder de wire wrap directly to trace, but you say they are very thin and maybe its not an option. Then, usually, I fix the wire wrap position with some contact glue points. sure I will not say anything new to you... but is what I do. 
good luck!

Arnau

 

[Script]

Wire wrap, yeah that's what I was thinking too. Traces are half a millimetre or so. Tiny tiny.
How do I stabilize the board itself? I was thinking superglue and a piece of plastic or wood glued to the side. Good idea?

 

[amorris]

green nail polish

 

[Script]

Green nail polish, great idea! I haven't thought of that. Love it: "Baby, I like your style!" 8)

I'll try supergluing tiny pieces of hard plastic to the side for stabilizing and from the underside (luckily, no traces there). The unit fell flat on a pot (soldered onto the PCB board) and the impact crashed the PCB with more than hair cracks. Ouch, ouch!

I know there's "liquid metal" trace fix that comes in tubes. Can't remember what it's called though. Aynone remembers?

Otherwise I'll go for wiring as described in this Guide (page 132 following).
http://www.intertronics.co.uk/resource/guide1.pdf
Some nice illustrations in there. Equipment is definitely too pro for me though.

At least 16 traces on a SMD PCB -- feels a bit like performing micro-surgery on the heart using kitchen knives, haha ;D

 

[Apache5]

for "stabilize" the board sometimes I use fiberglass remains (without copper) glued with bicomponent epoxy glue. Usually I dont like superglue because the one I have broke with blows, is too hard ("fragile"). It depends on whether the gear will be subjected to vibration and movement.
Cool link which you put, I'll have to study it 

Arnau

 

[JohnRoberts]

First is only a 1 sided or 2 sided board? If there are internal layers you are pretty much finished before your start.

Second, are all the broken traces accessible? If traces go to BGA parts with pads under the IC or even some very dense ICs it will be difficult to tack wires on.

The discrete SMD parts themselves will generally have relatively large pads (except for dense multi-pin ICs, so you can connect pad to pad.

You generally don't need very heavy wire, so perhaps single stands unwound from some stranded wire.

PCB are made from epoxy, so can be repaired with epoxy.

This is very fine difficult work... Is it worth the trouble?

Good luck.

JR

 

[gemini86]

I often find that jumping from pad to pad is way easier than trying to "fix" broken traces, so +1 on what John has said.