Abstract: An improvement in the manufacturing efficiency of a circuit substrate and a semiconductor module where a semiconductor device including electrodes on a front and a back surface is mounted. [Solution] A semiconductor module includes a wiring substrate where a via and a interconnecting pattern are formed, a semiconductor device disposed on a first surface side of the wiring substrate, and a bonding portion including a first bonding layer disposed on the wiring substrate side and a second bonding layer disposed on the semiconductor device side.

Abstract: A semiconductor power module (10) includes a ceramic multilayer substrate (100), a bonding layer (110), a diffusion layer (120) and a semiconductor device (130). The bonding layer is placed on a first surface (105) of the ceramic multilayer substrate and is provided as a planar thin film layer including conductive bonding parts (111) configured to electrically connect the semiconductor device with the ceramic multilayer substrate and insulating bonding parts (112) configured to isolate the semiconductor device from the ceramic multilayer substrate. Also disclosed is a production method of the semiconductor power module.