Patent ID: 7445081

Claim:
An electric power steering apparatus including an electric motor for outputting assist torque to a steering wheel of a vehicle, and a control unit for controlling the driving of said electric motor, said control unit comprising: a power main body including a bridge circuit composed of a plurality of semiconductor switching elements for switching a current supplied to said electric motor in accordance with torque assisting said steering wheel; a control main body that generates a drive signal to control said bridge circuit based on the steering torque of said steering wheel; a metal substrate that is composed of a plurality of insulating layers and a plurality of conductor layers having wiring patterns respectively formed thereon, said insulating layers and said conductor layers being laminated on a metal plate; connector terminals that are made of an electrically conductive material and are arranged in a peripheral portion of said metal substrate; and metal elements that have one end portions welded to said conductor layers of said metal substrate on which said power main body is mounted, and the other end portions welded to said connector terminals.