| 摘要 |
PURPOSE:To equalize the current distribution of a transistor and improve the strength of a safety operation region by directly mounting the emitter of the transistor at heat dissipating substrate side. CONSTITUTION:A collector electrode is disposed upside and base and emitter electrodes are opposed with the main surface of a heat dissipating plate 2. A nickel film is formed on the entire surface of an emitter electrode E to form a thick solder layer 6 and connect is directly to the plate 2. A base electrode is coated with a protective film 7 and isolated from an electrode E to be partially opened. A wire layer 8 formed through a thin insulating film 9 on the heat dissipating plate surface is passed through the opening and connected to the base electrode with solder 10, a wire 11 is mounted at the wire layer 8, and a wire 12 is mounted also at the collector electrode C. According to this configuration, the temperature distribution on the emitter electrode surface becomes uniform and the electrode thickness is thick to equalize the current distribution. Therefore, it can improve the strength of the safety operation region. |
