| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device capable of reducing the difference in cooling efficiency between bus bars.SOLUTION: A three-phase inverter device 10 comprises: a ceramic substrate 21; metal plates 22 to 25 provided on a surface of the ceramic substrate 21; semiconductor elements 41 to 46 provided on surfaces of the metal plates 22 to 25; and a cooler 11 thermally joined to a rear surface of the ceramic substrate 21. A bus bar 34 for a cathode is joined to the fourth metal plate 25. A bus bar 29 for an anode is joined to the semiconductor elements 42, 44, and 46. In the bus bar 29 for the anode, a ratio of an area of an unjoined surface to an area of a joining surface 29a is larger than a ratio of an area of an unjoined surface to a joining surface 34a of the bus bar 34 for the cathode. A resistance value of the bus bar 29 for the anode is smaller than a resistance value of the bus bar 34 for the cathode. |
