| 摘要 |
PURPOSE:To reduce thermal resistance between a transistor and a printed board by installing the transistor in a cavity on a heat emitting fin and soldering the rear side of the heat emitting fin in the cavity with the printed board. CONSTITUTION:The rear side of a dented portion 4a of a heat emitting fin 4 located under a transistor 9 is soldered with a conductor section of a printed board 12, which conducts the heat generated in the transistor 9 to the printed board 12 immediately by way of the dented portion of the heat emitting fin 4, which results in the reduction of thermal resistance. Since the upper part transistor 9 in the portion where the heat emitting fin 4 is soldered with the printed board 12, is soldered with high melting point solder, there will be no fusion. This construction makes it possible to protect chip capacitors or leads from breakdown and reduce thermal resistance between the transistor 9 and the printed board 12. |
