| 摘要 |
PROBLEM TO BE SOLVED: To reduce dimensions as a whole, improve heat radiation efficiency, and reduce electrical resistances of circuit board wirings. SOLUTION: Switching devices 24a-24c and 25a-25c are grouped into high- potential side devices and low potential side devices. The high-potential side switching devices 24a-24c, and the low-potential side switching devices 25a-25c are arranged, so as to face each other and, further, the high-potential side and low-potential side switching devices 24a-24c and 25a-25c are attached to a common heat-radiating member 23. With such a constitution, the switching devices 24a-24c and 25a-25c are arranged, not only in one direction but also in a direction perpendicular to it, so that the dimensions can be reduced as a whole. In addition, according to the construction, the heat-radiating member 23 has an approximately square shape, and its heat radiation area will be increased. Moreover, wiring patterns of a printed wiring board 21 can be shortened and simplified. |
