| 摘要 |
Conducting layers 11 and resin-made insulating layers 12 are alternately laminated to form a laminated circuit portion 13, and a metal substrate 14 is installed so as to be in contact with an insulating layer 12, which is the lowermost layer. The conducting layers 11, the insulating layers 12, and the metal substrate 14 are thermal compression bonded. In order to connect the uppermost conducting layer 11 on which electronic component 31 is placed with the lowermost insulating layer 12, a conducting layer 22 is formed on the inner surface by copper plating to install a heat dissipating via 21 into which a resin 23 is filled. A conducting layer 11, which is the uppermost layer, is subjected to gold plating 15, with nickel plating undercoated. An electronic component for driving a motor 31 is placed on the uppermost conducting layer 11, by which the metal substrate 14 can be used as a motor drive circuit substrate for an electric power steering system. |
