| 摘要 |
<p>775,191. Welding by pressure. GENERAL ELECTRIC CO., Ltd. Aug. 19, 1955 [Aug. 23, 1954], No. 24500/54. Class 83 (4). [Also in Group XXXVI] In the manufacture of a semi-conductor device in a sealed envelope, at least one seal is made by cold pressure welding, after the operative part of the device is mounted in the envelope. Fig. 1 shows a PN junction rectifier comprising a germanium wafer 3 on an oxygen-free high conductivity copper base I and having an alloy electrode comprising a bead of indium 5 and lead wire 7. The assembly is completed by placing a copper cover-plate 8 on to base 1 and cold welding the flanges 11 and 12. The lead wire 7 which may be of nickel, passes through, and is cold welded to, nickel tube 10 which is insulated from cover 8 by a glass region 9. In Fig. 2, which shows the apparatus for the cold welding, steel punches 15 and 16 sliding in tube 13, compress the flanges 11 and 12 together. A groove 12 in the base 1 accommodates the flow of metal. Wire 7 is welded to tube 10 by means of a pair of hand cutters (Fig. 3, not shown). The sealing operations are preferably carried out in an atmosphere of dry nitrogen. The use of cold welding avoids risk of damage to the rectifier due to thermal or chemical action. Specification 784,939 is referred to.</p> |
