46A on a PCB could be at a 150um board. I never remember the convertion from OZ to um so I can not tell that number. But i have a 18 channel dimmer rack running 3 phase 400V 32A on 105um boards, and it is still running and is almost 35 years old now . I would beleive You could run 46A at 105 - 150 um without damage, and even some short spikes at higher current.