Hello everyone.

Obviously when designing a high voltage PCB, we must make sure that the areas of copper, that have high voltage differences, must have an adequate clearance. However, what about the clearance, for example, between a trace on the top layer and a component on the top layer. For example, lets say I have a trace running in between the two pads of a big high voltage TH capacitor. Even if the trace is sufficiently distant from the pads of the capacitor, should I be worried about the clearance betwwen the trace and the actual body of the capacitor? Also lets say for example, that I have two or more TH resistors in parallel, like in the picture (R25, R26, R27). They all connect 300V (a high voltage) to GND. Should i be worried about the clearance between the resistor bodies? Beacuse the voltage is distributed down each resistor, and probably not evenly so, so there migh be a high voltage difference in between two adjacent resistors that migh cause problems if the two resistors are too close.

 

I would not worry about this as there will be a solder resist coating in place followed by an air gap. I have a PCB with upwards of 400V on it passing under large polypropylene film capacitors.

 

It may be over kill but; I often use silk screen under HV parts. (white filled rectangle) It adds insulation and helps me remember "HV" here.

 

With what, if any, government or industry safety standards does your assembly need to comply? That question is rhetorical.