This talk will highlight how PCB design parameters (number of layers, copper weight and PCB thickness) affect the thermal resistance of the PCB hence the package ampacity of the power module. For PCB-soldered power modules, the PCB is the main heat drain for the power module terminals. Therefore, the thermal performance of the PCB is critical for the thermal performance of the module terminals (package ampacity). The goal is to help designers understand the correlation between PCB design parameters and thermal performance of the PCB, so they take the thermal performance of the PCB into consideration early in their design stage.