R-IN32M4-CL3 User's Manual: Board design edition
8. Thermal Design
R18UZ0074EJ0100
Page 29 of 61
Dec 24, 2019
(5) Residual Copper Ratio of Cu Layers
Increasing the residual copper ratio in all layers of the board layers increases the breadth of the paths for heat transfer.
(6) Cu Thickness
Designing all Cu layers of the board to be thick increases the volume of paths for heat dissipation. Since thinner Cu
layers reduce the effectiveness of heat dissipation, care is required on this point. We recommend that the power supply
and GND layers be at least 35-um thick.