| 摘要 |
PROBLEM TO BE SOLVED: To attain both a cost reduction and a certain ground connection by attaching low cost parts simply to a case. SOLUTION: A PC board 3 is mounted on a case 2 made of an aluminum die cast, and an earth contact of the printed circuit board and the case 2 are bonded with an earth wire 10. A ground of the case side is connected with a bolt 12 for ground connection to the case 2, and by giving nickel plating on a head upper surface 12a1 of the bolt, it is managed to a predetermined surface coarseness, and a wire bonding by ultrasonic crimping is carried out by making an upper surface of the bolt-head section into a putt surface. |
