| 摘要 |
PURPOSE:To prevent a locally generating abnormal etching by a method wherein an insulating layer is provided on the circumferential part of the thermal reinforcement plate of a chip in such a manner that it is overlapped with the circumferential part of a cathode electrode, thereby enabling to protect the circumferential parts of the cathode electrode and the upper thermal reinforcement plate of the chip. CONSTITUTION:A P-base 2 and a P-emitter 3 are formed by thermally diffusing acceptor impurities from both sides of an N type Si single crystal substrate 1. Then, a N type emitter 4 is formed by selectively diffusing donor impurities from the side of the P-base 2. At this time, a number of P-base exposed parts 5 are formed in the N type emitter 4. Then, an insulating layer 6 is formed on the circumferential part of said thyristor chip, an anode electrode 7, a cathode electrode 8, and a gate electrode 9 are provided, the gate electrode 9 is soldered between a pair of reinforcement plates 10 and 11 having equal thermal expansion coefficient, and they are formed into a sandwich structure. |
