GB1386967A - Making electrical connections to semi-conductor devices - Google Patents

Abstract

1386967 Semi-conductor devices; component assemblies DEFENCE SECRETARY OF STATE FOR 15 May 1972 [17 May 1971] 15306/71 Headings H1K and H1R A method of making electrical connection to a semi-conductor device comprises depositing a layer of glass on a conductive plate 13, heating the layer to convert it to a glass-ceramic material, etching the layer to leave a post 12, mounting the device 11 on the plate adjacent the post, and bonding a connection 14 between the top of the post and an electrode on the device. A ring 17 (Fig. 5), may also be formed by etching from the layer, and a cap 18 may be fixed to the ring, and contact the post top, to form one contact of the assembly. The structure and materials of the encapsulation are said to reduce capacitance at GHz frequencies. A plurality of devices 11, 11a may be present each associated with a separate post 12, 12a, or a plurality of devices may be associated with a single post, in series or parallel relationship. The assembly may be incorporated in a wave guide, or form a travelling wave tube arrangement. The semi-conductor devices may be avalanche or PIN diodes, high frequency transistors, varactors or Gunn effect devices. The glass ceramic may be a mixture of oxides, predominantly of silicon, zinc and lithium. The plate 13 which forms a contact of the assembly may be of copper or diamond, the connection 14 being of gold.