PCB repairs

[HDT_aero]

anyone know any way to repair a crack in a clusters flexible pcb without making the part brittle??

cheers
Adam

[hakhawk]

strip about 5mm of the lacquer back from either side of the crack, lightly get some solder on the track, get some wire, join the 2 parts, use least amount of heat and time as possible

[michaelw]

I would use conductive varnish. It is a suspention of silver particles in an expoxy binder. You can get it as a pen dispenser (pain in the arse to work with) or just in a pot (you can use a tooth pick as a paint brush) reseal the the tracks with clear varnish (cheap nail polish does the trick, the expensive ones don't seem to have the solvents that are good for electronics and bad for nails)

www.Jaycar.com.au has the silver varnish part number NS3030.

Mike

[HDT_aero]

thanks guys that conductive varnish shounds tops

[michaelw]

Oh, one thing I forgot. Use the varnish to stick down a few strands of copper wire across the break. That was if there is too much fles the copper wire will still create the path, the varnish then acts as a glue for the wire.

Mike