Abstract: The power semiconductor module includes a power semiconductor assembly and a heat transfer member. The power semiconductor assembly includes a circuit board and a case. The circuit board includes an insulating substrate. The second attachment surface to which the heat transfer member is attached is recessed from the first attachment surface to which the heat sink is attached. The maximum recessed distance of the second attachment surface from the first attachment surface is smaller than the original thickness of the heat transfer member, and is greater than the lower limit thickness of the heat transfer member.

Abstract: A technique disclosed in the specification of the present application is a technique for increasing a degree of freedom of an IGBT in a device, and as a result, achieving downsizing of the device. A semiconductor device relating to a technique disclosed in the specification of the present application includes a plurality of IGBTs connected in series on a power source line in which bus current flows and a MOSFET connected to the plurality of IGBTs in series. The bus current flows via a drain terminal and a source terminal of the MOSFET.

Abstract: The power semiconductor module includes a power semiconductor assembly and a heat transfer member. The power semiconductor assembly includes a circuit board and a case. The circuit board includes an insulating substrate. The second attachment surface to which the heat transfer member is attached is recessed from the first attachment surface to which the heat sink is attached. The maximum recessed distance of the second attachment surface from the first attachment surface is smaller than the original thickness of the heat transfer member, and is greater than the lower limit thickness of the heat transfer member.