GB1004020A — Improvements in or relating to the mounting of electrical components

USPTO Abstract

1,004,020. Rectifier mountings. STANDARD TELEPHONES & CABLES Ltd. April 24, 1964, No. 17027/64. Heading H1K. A composite disc comprising a uniform layer 6 of one material and a slotted layer 7 of another material is designed for use in the attachment of an electrical component such as a solid state rectifier to a mounting of markedly different thermal expansion coefficient. When the component is a silicon semi-conductor and the mounting of copper, layer 6 is preferably of molybdenum and will be soft soldered to the component and layer 6 of copper which will be similarly soldered to the mounting. The composite disc itself may be prepared by hard soldering copper and molybdenum discs together and subsequently cutting the slots 13 to extend as deep as the solder: it may also be formed by casting or powder metallurgy. Fig. 1 (not shown) depicts a P-N junction rectifier mounted between a pair of the composite discs. The rectifier is produced by coating the surface of an intrinsic silicon wafer with doping impurities, soldering the discs to the wafer and subsequently alloying in the impurities. The solder itself may serve as a source of impurity material. Several alternative semi-conductor body materials, impurity elements and materials for use in the composite disc are mentioned in the Specification.