A semiconductor device comprising a first switching element, as a switching element forming an upper arm, having electrodes on upper and lower surfaces and a second switching element, as a switching element forming a lower arm, having electrodes on upper and lower surfaces, the first switching element and the second switching element being disposed in parallel and controlled in such a manner that when a short circuit occurs between the electrodes of one of the first switching element and the second switching element, the other one of the first switching element and the second switching element is restricted from being turned on, the semiconductor device further comprising:
- a plurality of heat sinks electrically connected to the switching elements, including,
- a first heat sink electrically connected to the electrode on the lower surface of the first switching element,
- a second heat sink electrically connected to the electrode on the upper surface of the first switching element,
- a third heat sink electrically connected to the electrode on the lower surface of the second switching element, and
- a fourth heat sink electrically connected to the electrode on the upper surface of the second switching element,
- a joint portion provided to at least one of the second heat sink and the third heat sink to electrically join the second heat sink and the third heat sink;
- an encapsulation resin body in which the first and second switching elements, the first through fourth heat sinks, and the joint portion are integrally encapsulated;
- a first power-supply terminal extending from the first heat sink in a direction orthogonal to both of an alignment direction in which the first switching element and the second switching element are aligned and a thickness direction of the first switching element and exposed to an outside of the encapsulation resin body;
- an external connection output terminal extending from the third heat sink in a same direction as the first power-supply terminal extends and exposed to the outside of the encapsulation resin body;
- and
- a second power-supply terminal having an encapsulated portion electrically connected to an extended portion of the fourth heat sink and encapsulated in the encapsulation resin body and an exposed portion extending from the encapsulated portion in a same direction as the first power-supply terminal extends and exposed to the outside of the resin encapsulation body, the second power-supply terminal being connected to a power supply together with the first power-supply terminal, the extended portion of the fourth heat sink extending from a main body portion of the fourth heat sink in the alignment direction toward the first switching element and encapsulated in the encapsulated resin body, wherein:
- the second power-supply terminal is disposed in the alignment direction in a region between the first power-supply terminal and the output terminal and between the second heat sink and the third heat sink;
- in the encapsulation resin body, a portion having a same potential as the first power-supply terminal is referred to a first potential portion, a portion having a same potential as the second power-supply terminal is referred to a second potential portion, and a portion having a same potential as the output terminal is referred to as a third potential portion, at least one of a shortest distance between the first potential portion and the third potential portion and a shortest distance between the second potential portion and the third potential portion is shorter than a shortest distance between the first potential portion and the second potential portion;
- the joint portion and a connecting portion between the encapsulated portion of the second power supply terminal and the extended portion of the fourth heat sink are disposed in another region extending between the second heat sink and the third heat sink in the alignment direction and between edges of opposite ends of the second and third heat sinks in the direction orthogonal to both of the alignment direction and the thickness direction of the first switching element.