GB1111028A - A semiconductor device incorporating a pressure multiple electrical contact assembly - Google Patents

Abstract

1,111,028. Semi-conductor devices. WESTINGHOUSE ELECTRIC CORPORATION. 9 March, 1967 [8 June, 1966], No. 11125/67. Heading H1K. A spring loaded contact assembly in a semiconductor device includes a deformable insulating disc 12 of P.T.F.E. or P.T.F.C.E. which forces contact members 30, 36 against contact areas or regions 61, 62 of a semiconductor body. The contact members (which consist of Cu, Ag, Ni, Au, In, Sn, or basealloys thereof) have portions passing through holes extending from face to face of the de formable member 12, and have silver wires 34, 38 attached thereto. The deformable member under the action of spring washers 74, 76 is forced to adopt the surface contour defined by the special shaped end zone 61 and zone 62 of the semi-conductor body. As described the complete device has a threaded contact stud 42 of Cu, Ag, Al, of base alloys of these (e.g. brass), or of ferrous-base alloys to which is brazed a cylindrical housing which may be of ferrous-base alloy. On the stud is a layer 58 of a soft metal (Au, Ag, Sn, In, Pb, or Al) to compensate for surface irregularities between the stud and a (gold-plated) disc of Mo, W, Ta or of base alloys thereof. A solder layer 68 (Ag/Pb/Sb) lies between this and the semiconductor body comprising layers 61, 62, 63 with PN junction between adjacent layers. The spring washers 76 act between metal thrust washers 74, 78 the lower of which acts on an insulating washer 72 of ceramic, mica, glass, quartz, or fluorocarbon. The upper thrust washer is retained in the assembly by a snap ring 80 fitting a groove in the housing wall. An apertured insulating disc stops excessive lateral movement of the silver wires 34, 38 to prevent them from damage. Lying on the disc is a moisture getter formed by a ring 88 of a molecular sieve. The cover 94, 96 is projection welded on to the casing. The silver lead 34 is swaged or rolled within its surrounding sleeve to form a seal and the other lead 28 is terminated with a blind sleeve from which a further lead 108 extends.