COOLING DEVICE OF SEMICONDUCTOR ELEMENT

PURPOSE:To attach a semiconductor element to one cooling member only, to bring its whole surface into complete contact with a heat-conducting contact face, to make a cooling heat capacity shouldered by cooling members identical and to eliminate an imbalance by a method wherein a plurality of semiconductor elements are attached to individual cooling members without being spread over both cooling members. CONSTITUTION:Out of transistors 1 to 6, a transistor 1 of a phase on one end side of a positive pole, i.e., a U phase, and transistors 4, 5 of a phase on one end side of a negative pole, i.e., the U phase, of a V phase and adjacent to it are attached to a cooling member 10 on one side; all the transistors are not spread over a cooling member 11 on the other side. Remaining transistors 2, 3 and 6 are attached to the cooling member 11 on the other side and are not spread over the cooling member 10 on the one side. Individual terminal of the transistors 1, 2, 3 and the transistors 4, 5, 6 are connected while each positive pole and a negative pole are short-circuited respectively by using a conductor bar 7 on the collector side and a conductor bar 9 on the emitter side; an emitter and a collector at an upper arm and a lower arm of each phase are short-circuited at each phase on the output side by using a conductor bar 81. Accordingly, the conductor bar 81 on the output side is inclined.