Patent ID: 8648461

Claim:
A semiconductor device comprising: a wiring substrate; a semiconductor element mounted on the wiring substrate; a first radiator member arranged on the semiconductor element and thermally coupled to the semiconductor element; and a second radiator member arranged on the first radiator member and thermally coupled to the first radiator member; wherein the second radiator member includes a plurality of projections which project out toward the first radiator member, the plurality of projections being formed on a circumference of a concentric circle with respect to a center point of the second radiator member when the second radiator member is viewed from above; the first radiator member includes a plurality of grooves in which the plurality of projections are movable, the plurality of grooves being formed on a circumference of a concentric circle with respect to a center point of the first radiator member when the first radiator member is viewed from above, each of the plurality of grooves including a terminating end; and each of the plurality of projections is fitted to the terminating end of a corresponding one of the plurality of grooves with the center point of the first radiator member and the center point of the second radiator member coincided.