I have a board on an aluminum plate manufactured by PCBCart. Apparently, the "board" is less than 1 mil thick (because it is actually Kapton film?) while the aluminum plate to which it is firmly attached is a bit less than 32 mils.
My question is why does the Saturn app show less current carrying capacity in 10 mil traces than with a standard PCB? It gives .77A capability (with the default parameters) if I use 1 mil PCB thickness and 1 mil distance to the plane. But, if I change the PCB thickness to32 mils, the current carrying capacity is ~1.3A.
With a heat sink that close to the traces, this seems intuitively wrong.