Patent ID: 8643171

Claim:
A power semiconductor device comprising: a mold unit that includes a power semiconductor element, a base plate, and a mold resin, the power semiconductor element being mounted on one surface of the base plate, a convex portion being formed on an other surface of the base plate, the convex portion including a plurality of grooves, the power semiconductor element being sealed with the mold resin in such a manner as to expose the convex portion; a plurality of radiation fins inserted into the grooves, respectively, and fixedly attached to the base plate by swaging; and a metal plate that includes a cut-off portion into which the convex portion is inserted, the metal plate being arranged between the mold unit and the radiation fins with the convex portion inserted into the cut-off portion, wherein the metal plate includes a protrusion that protrudes from an edge of the cut-off portion and that digs into a side surface of the convex portion when the convex portion is inserted into the cut-off portion.