| 摘要 |
992,702. Silicon rectifiers. STANDARD TELEPHONES & CABLES Ltd. Sept. 1, 1961 [Sept. 2, 1960], No. 31550/61. Heading H1K. A rectifier is made by diffusing acceptor and donor materials respectively preferably boron and phosphorus into opposite faces of a weakly P-type silicon wafer in a protective atmosphere to form a P + PN + zone structure in which the central P zone is about 200 Á thick. The atmosphere, preferably nitrogen, is purified by passing it over a copper catalyst and through a liquid air trap. The resulting wafer may be heated in inert gas between a lead wafer on its P side and the lead coated enlarged solid end of a stranded copper, silver or silver coated copper wire on its N side in a mould to form an integral assembly. The lead wafer and coating may contain 5% by weight silver. After etching the assembly is placed on the tinned central boss 14 (Fig. 5) of a copper or silver casing 12 and attached thereto by heating to below the melting point of lead. The stranded wire 2 is then threaded through metal tube 8 in insulating block 7 and its strands pinched together outside the casing by squeezing the tube. After bending back the loose ends over the outside of the tube cable shoe 10 is forced over them. Sealing of the housing is completed by means of solder or thermoplastic resin at points 11. |
