Semi-conducteur en boîtier ou capsule

摘要

929,967. Semi-conductor devices. PHILCO CORPORATION. Dec. 23, 1959 [Dec. 24, 1958], No. 43674/59. Class 37. [Also in Group XXIII] In an hermetically enclosed semi-conductor device such as a transistor triode, the electrical leads to the device are relatively 'flat and are sealed, in a substantially coplanar arrangement, in a member of insulating material. The semi-conductor device comprises a flanged top shield 11, Fig. 3, an apertured sealing dish 12 and a glass-surfaced lower shield 13, these members jointly serving to hermetically enclose the transistor assembly 14, the leads 151 to which are stamped out of a metal plate 26. In assembling the device, the leads 151 are encased between the lower glass surfaced face 28 of dish 12 and glass surface 27 of the lower shield 13. The glass faces which may be of potash, soda-lead glass are fused in an oven at 800-850‹ C. so that the adjacent glass faces coalesce and enclose the leads 151 between them. To facilitate sealing the leads, which may be of copper, they may be oxidized on their outer surfaces which may then be coated with a layer of glass by spraying or painting an alcohol and glass mixture on to the surface, or by dusting the surface when heated with powdered glass. In order to provide a path of low thermal impedance from the primary heat source, normally the collector junction, to an appropriate heat sink, a stud 20 is provided to afford intimate thermal coupling between the collector contact and its lead-in electrode. The stud 20, Fig. 2, and the collector contact or pellet of the transistor blank are joined by soldering. To facilitate attachment to the emitter and base elements of the transistor assembly 14, these elements are, respectively, provided with short U-shaped taps 22, 23, the upstanding terminal portions of which are joined preferably by cold welding to respective vertical lead portions 24. The leads are preferably formed from 2 mil. copper foil, the depth of penetration of the foil layer in the glass seal 27, 28 is preferably 10 mils. and the completed assembly is 30 mil. thick. Specification 926,021 is referred to.