| 摘要 |
<p>PURPOSE:To realize a semiconductor device free of characteristics deterioration attributable to moisture infiltrating through the interface between a metal supporting board and a cast resin by a method wherein a coating of a polyimide-based resin is positioned between at least the metal supporting board near a semiconductor element and a cast resin. CONSTITUTION:In a design wherein a semiconductor element 1 is fixed to a metal supporting board 2 and both semiconductor element 1 and metal supporting 2 are covered with a cast resin 8, a coating 7 is positioned between, at least, the metal supporting board 2 near the semiconductor element 1 and the cast resin 8. For example, electrodes on the lower surface of a transistor chip 1 is soldered to a metal supporting board 2 made, for example, of a nickel- plated copper plate. A mount 21 is provided on one end of the metal supporting board 2 and a collector terminal 3 is formed on the other end. An emitter electrode on the upper surface of the transistor chip 1 is connected to an emitter electrode 4, and a base electrode to a base electrode 5, with bonding wires 6. After this, a polyimide-based resin 7 is applied to surround the transistor chip 1 and a resin 8 is cast.</p> |
