| 摘要 |
<p>1277201 Semi-conductor devices ENGLISH ELECTRIC CO Ltd 12 Aug 1969 [24 May 1968] 24902/68 Heading H1K A semi-conductor wafer is sandwiched between two massive thermally conductive members by means of a cap secured to one member and embracing and applying spring pressure to the other member, the two members being joined by a hermetically sealed insulating envelope and the two members having cross-sections not substantially less than that of the wafer throughout their extent within the sealed envelope. As shown, Fig. 1, an SCR comprises a wafer 1 resting on a copper cathode contact member 2 and having its upper face contacted by a second copper contact member 3 having a bore for an insulated gate contact electrode 4. The members 2, 3 are urged towards one another by means of belleville-type spring washers 8 and a metal cap 11 which screws on to a ring 12 brazed to member 2. The cap 11 is insulated by means of ceramic caps 9, 13. The envelope comprises a ceramic ring 15 joined to the members 2, 3 by discs 17, 18; 6, 16 which are soldered to respective members and ring as appropriate and then joined by welding at 19 and 20. Large area heat sinks 22 may be soldered or shrunk on to the members 2, 3. In a modification, Figs. 2 and 3 (not shown), the spring washers are omitted and the metal cap (23) has circumferential slots to increase its resilience so that it forms a spring. The semi-conductor device may be a diode instead of an SCR and the metal cap may be crimped on to the lower body. The contact members 2, 3 may be provided with rims or pips to locate the semi-conductor wafer. Reference has been directed by the Comptroller to Specification 992,472.</p> |
