SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To improve heat radiation performance in a semiconductor device including at least one pair of an upper arm and a lower arm.SOLUTION: In a semiconductor device, each of heat sinks (40, 44, 50, 54) is subject to cutting together with an encapsulation resin body (70) and heat radiation faces (40a, 44a, 50a, 54a) are exposed from the encapsulation resin body; and a first connection part (47) of a first relay part (46) and a second connection part (57) of a second relay part (56) are connected in an alignment direction of a first heat sink (40) and a third heat sink and in a region (71) between a second heat sink and the third heat sink. In the first connection part and the second connection part, surfaces which are orthogonal to own plate thickness directions and to which a solder (60) is connected are defined as connection surfaces (47a, 57a), respectively, and respective connection surfaces are perpendicular to respective one surfaces (11a, 21a) of semiconductor elements (11, 21).