I am currently designing a PCB layout for my team's high current, high voltage project and am having trouble with choosing my trace width.
The circuit is composed of 12 inductors placed in series with short traces connecting them together (about 5mm max length). We are feeding 10μs pulses at ~300A/1000V at a maximum rate of 10 pulses per second by discharching capacitor banks into the coils. The capacitors are recharged by an external source.
I have looked for resources on the subject, but nothing I could find applies to the level of current and voltage we are applying.
Is there a rule for determining trace width for very high current pulses?
Answer
It's not the current that matters, it is heat. The current will heat up your copper on top of the FR4.
The heat generated is current squared time resistance of (trace + solder joints + component leads). The square in there is what makes the high currents so scary, even ath the 1:10k duty cycle you have on the positive side of the balance sheet.
So I agree with Dans answer very much: a trace suitable for a 10A continous current should do the trick. "Suitable" menas that the heat does not increase your PCB temperature more than your specifications allow for. Which as usul depends on many factors like type of PCB, overall heat sources on it, hos the heat is dissipated to the environment etc.
hase
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