| 摘要 |
<p>934,185. Semi-conductor devices. STANDARD TELEPHONES & CABLES Ltd. Jan. 8, 1960 [Jan. 14, 1959], No. 766/60. Class 37. In a method of mounting a semi-conductor element on a metallic base-plate possessing good heat-conducting properties, the element is connected during processing to a small metallic plate of good heat-conducting properties which acts as one electrode connection and which, after the completion of the said processing and the provision of a second connection, is connected to the base-plate by partial deformation of the material of the base-plate in the cold state. In the rectifier shown, a wafer 1 of germanium or silicon comprising a PN junction is soldered to a lead 5 made of copper or silver wire, preferably gilded silver wire, the ends of which are welded to form a solid part 6, and is also soldered to a small conical or, as shown, stepped plate 4 preferably of silver with a coating of gold; the device is then etched. The solder may contain significant impurities to produce the PN junction. The small plate 4 is inserted in a central recess in a base-plate 7 of, e.g. soft copper, the recess having a convex bottom and fitting closely to the wider part of plate 4, which may be grooved or roughened. Concentric with the central recess is an annular groove in the base-plate 7. The upstanding copper between the recess and the groove is deformed over the step in plate 4 by two concentric cylindrical stamps (not shown), the outer one being located in the groove, while the inner one is forced down on to the copper. A cap comprising a steel tube 12, to one end of which is fused a glass bead 13 through which is sealed a small tube 14, is fitted into the groove and the copper around the groove is deformed over a flange at the bottom of tube 12. Finally, the small tube 14 is deformed around the lead 5 at 15. The base-plate 7 has a threaded shank 16 which serves to mount it on a chassis. Semiconductor devices other than diodes may be mounted in this way, and several devices may be mounted on a single base-plate. Specifications 838,167 and 914,592 are referred to.</p> |
