Circuit board trace repair...

[Carlos E Murillo-Sanchez]

Chuck Guzis via cctalk wrote:
> On 8/13/20 9:58 PM, dwight via cctalk wrote:
>> How much current is ir suppose to carry? I'd just replace it with a piece of wire wrap wire if it is less than an amp.
>> Of course, I assume you've fixed what ever failed to cause it to blow.
>> Gold wire is expensive.
>> Dwight
> According to my tables, AWG 30 copper wire has a resistance of 0.107 ohm
> per foot or about 9 milliohm per inch.  I suspect that it would work
> under almost all PCB repair conditions.  I've repaired power traces on
> CPU boards using WW wire with no ill effects.
>
> --Chuck
>
>
Of course, it is not just about the resistance, but the resulting 
thermal cycling at the endpoints... About 25 years ago, I learned the 
hard way about keeping each amp across at least two DB-whatever pins in 
experimental hybrid-electric vehicles.  Nowadays we routinely x-ray 
crimps for safety-critical things such as ABS harnesses.   Ampacity 
calculations differ wildly accross applications.

carlos.