Hi,
The following via calculator...
https://circuitcalculator.com/wordpress/2006/03/12/pcb-via-calculator/...shows a power dissipation of 30mW when carrying 12 Amps (for a via as follows..
drill = 1.5mm diam
Board thickness = 1.6mm
1 ounce copper
......so why does it calculate that "Ampacity" is only 7.48 Amps?
***Also, i am certain that a 4 layer board with 1 ounce copper , does not have 1 ounce copper in the via side walls, unless they are plated up with an extra process, which is very expensive.....do you concur?
A standard 1 ounce copper board, would only have half ounce copper in the via walls...(unless plated up with the extra expensive plating process)