PCB copper coin embedded is a perfect option to transmit the heat of the circuit board,but limited manufacturing capaiblity as below:
Copper coin thickness: 0.8mm(min), 3.0mm(max), can be more thicker than 3.0mm.
Copper coin size: 3.0 X 3.0mm (min), 400.00 X 300.00mm(max);
Spacing copper coin to holes: 1.0mm;
Spacing copper coin to track: 1.0mm(min).