METHOD FOR EFFECTING SUPERCONDUCTIVE CONNECTIONS

• Main Author: GEORGE J. KAHAN
• Format: Patent
• Language: English
• Published: 21.02.1967
• Subjects: BASIC ELECTRIC ELEMENTS; CURRENT COLLECTORS; ELECTRICITY; INFORMATION STORAGE; LINE CONNECTORS; PHYSICS; STATIC STORES

991,824. Jointing, welding by pressure. INTERNATIONAL BUSINESS MACHINES CORPORATION. Jan. 30, 1963 [Jan. 31, 1962], No. 3798/63. Headings B3R and B3V. [Also in Division H1] A method of forming electrical connections between metallic surfaces comprises subjecting the surfaces to the action of an acid and resin solution, said acid being reactive with any oxide coating formed on said surfaces, to expose clean metallic surfaces, and contacting said exposed surfaces. A superconductive connection between a wire 17, conductive strip 19 or foil of, for example, lead and a " land " structure 5 also of lead of a cryotron is made by applying as by syringeing a quantity of an acid-solventresin solution to the surfaces to be joined and applying sufficient pressure to cause the surfaces to contact. The solution may comprise 2 grams polyvinyl butyral, 20 mls. of methyl alcohol and 0.75 mls. of glacial acetic acid. At least 4 hours is required for the joint to. form; this may be reduced by applying slight heat or in a reduced atmosphere. Lead powders may be added to the above solution and the resultant paste applied to and between the surfaces to be joined to form a conductive joint 16. Alternative resins may be polyvinyl acetate and polyvinyl pyrrolidone. When the members to be joined are made from tin a solution containing oxalic acid is used in lieu of acetic acid. A known type of cryotron comprises an aluminium substrate 1, an insulating layer 3 of aluminium oxide on which are arranged " land " structures 5, of hard superconductive material, insulating layers 9, 13 of silicon monoxide between which is positioned a strip 11 of soft superconductive material, a control conductor layer 15 connected to the structure 5 and an insulating layer 14.