Electric semi-conducting devices

Abstract

Abstract 914,592. Semi-conductor devices. STANDARD TELEPHONES & CABLES Ltd. April 17, 1959 [April 23, 1958], No. 13142/59. Class 37. [Also in Group XXII] A semi-conductor element is mounted in a casing comprising a metal part including a rim fitting into a channel in another metal part of different hardness. After assembling the parts with the rim in the channel, the housing is sealed by plastic deformation in the cold of one of the parts. In one embodiment the softer part is a threaded copper bolt 4 with an annular channel 3. Sealing is effected by deforming the edges of the channel over the flanged edge of steel cylinder 6. External connection to the upper face of the semi-conductor element is provided by a stranded copper or silver wire (Fig. 4) with a conical solid end engaging the element. The wire leaves the housing through a metal tubule 8 in a sintered glass bead 7. The wire, which is deformed and solid where it passes through the tubule, is pinch sealed therein in vacuo or in an inert atmosphere, the abutting surfaces of the wire and tube being coated with a low-melting metal, e.g., tin, to facilitate sealing. In an alternative arrangement, the wire consists of a solid-headed part 11b of silver and an upper part 11a of tinned copper, the abutting solid ends 13a, 13b having the cross-sections shown to facilitate evacuation of the housing prior to sealing. During the pinch sealing process, the two parts of the wire are joined and sealed within the tube. In a modification of the above device, the copper base is internally threaded for mounting on a cooling block and silverplated to allow etching of the mounted semiconductor element without copper contamination of the etchant. A transistor is also described, comprising two sub-assemblies 5, 6, 7, 8 of the construction shown in Fig. 1, sealed in annular grooves on opposite faces of an apertured plate carrying the semi-conductor element. In another arrangement (Fig. 3) comprising copper base-plate 4 and steel cap 2, connections are sealed through the base-plate by glass-metal seals, as shown in Fig. 3a, the edges of apertures 10 being deformed in the cold state to fix the seals.

Inventors

• 👤 Wolfson Henry
• 👤 Shepard Stanley Carden

Bibliographic Details