Mounting structure of a switching element at a heat sink

摘要

The control unit has a driving circuit driving a motor. A heat sink (27) is provided at a substrate of the control unit. One switching unit is equipped to the circuit and is switched on and off at a relatively high speed by the circuit. Another switching unit is equipped to the circuit and is switched on and off at a relatively low speed by the circuit. The switching units are alternately arranged and fixed to the heat sink.