Abstract: A first conductor layer is provided on a first surface of an insulating plate, and has a first volume. A second conductor layer is provided on a second surface of the insulating plate, and has a second volume. A third conductor layer is provided on a second surface of the insulating plate, and has a second volume. The third conductor layer has a mounting region thicker than the second conductor layer. The sum of the second and third volumes is greater than or equal to 70% and smaller than or equal to 130% of the first volume. A semiconductor chip is provided on the mounting region. A sealing part is formed of an insulator, and seals the semiconductor chip within a case.

Abstract: A first conductor layer is provided on a first surface of an insulating plate, and has a first volume. A second conductor layer is provided on a second surface of the insulating plate, and has a second volume. A third conductor layer is provided on a second surface of the insulating plate, and has a second volume. The third conductor layer has a mounting region thicker than the second conductor layer. The sum of the second and third volumes is greater than or equal to 70% and smaller than or equal to 130% of the first volume. A semiconductor chip is provided on the mounting region. A sealing part is formed of an insulator, and seals the semiconductor chip within a case.

Abstract: An insulating substrate includes a base portion that is made of metal and serves as a radiating surface, an insulating layer, and a circuit pattern. The insulating substrate has convex warpage in the radiating surface at ambient temperature. A power semiconductor element is mounted on the circuit pattern. A sealing material has a thickness greater than a thickness of the insulating substrate. The sealing material has a linear expansion coefficient greater than a linear expansion coefficient of the insulating substrate in an in-plane direction of a mounting surface of the insulating substrate. A heat conduction layer is located on the radiating surface of the base portion and is solid at ambient temperature and is liquid at a temperature higher than or equal to a phase-change temperature higher than ambient temperature.

Abstract: A base plate has a mounting surface on which a semiconductor element is mounted and a heat-radiation surface for radiating heat to a cooler. The cover has a portion that seals the semiconductor element on the mounting surface of the base plate. The cover has a projecting portion arranged outside the heat-radiation surface and projecting from a level of the heat-radiation surface in a thickness direction. The intermediate layer is arranged on the heat-radiation surface of the base plate, projects from the level of the projecting portion of the cover in a thickness direction, and is made of a thermoplastic material in a solid-phase state.

Abstract: A base plate has a mounting surface on which a semiconductor element is mounted and a heat-radiation surface for radiating heat to a cooler. The cover has a portion that seals the semiconductor element on the mounting surface of the base plate. The cover has a projecting portion arranged outside the heat-radiation surface and projecting from a level of the heat-radiation surface in a thickness direction. The intermediate layer is arranged on the heat-radiation surface of the base plate, projects from the level of the projecting portion of the cover in a thickness direction, and is made of a thermoplastic material in a solid-phase state.