If I have traces connecting a relay to an terminal block (10A relay, 6A terminal, 5A expected maximum load) and I double the traces up on both sides of the board (mirror the traces on the top and the bottom) to double the current capacity of the traces (effectively turn 1oz copper into 2oz), is it best to leave them as they are or to stitch the traces together with vias?
The longest trace is just under 1".
Would the stitching adversely affect the current capacity of the traces and defeat the objective? Or would it allow for better heat management and thus actually increase the current capacity?
Or would it have no effect whatsoever?
And what of the effect of 50/60Hz through the two traces with FR4 dielectric between them? Would doubling, with or without stitching, have an effect?