GB1099874A - Semi-conductor devices for high currents - Google Patents

Abstract

1,099,874. Mounting semi-conductor devices' ALLM€NNA SVENSKA ELEKTRISKA A.B. April 14, 1965 [April 20, 19641, No. 15970/65. Heading H1K. A semi-conductor system comprises a hermetically sealed box comprising bottom, lid and insulating rings therebetween, the bottom and the lid being in contact with a semiconductor device, e.g. transistor, thyristor or diode, a cooling system in contact with the box and wherein the insulating rings have metal flanges attached thereto and joined to each other outside the rings. A thyristor incorporates a PNP silicon disc 1 having an Al layer soldered on the under side thereof and supported on a plate 2 of Mo, and overlayed with an Au-Sb layer 3. The system is hermetically sealed in a box formed by lid 5, bottom 4, rings 6 and 7 and flanges 8 and 9. The lid, bottom and flanges may be made of Cu, Mo, W, Fe/Ni or Fe/Co/Ni whilst the rings may be of porcelain or ceramic, each of the two parts of the box 5, 7 and 9, and 4, 6 and 8 being joined up by silver soldering whilst the flanges may be joined by cold-welding, soldering or high-frequency welding according to the proximity of the semi-conductor system. Cooling bodies 13 and 14, e.g. of Cu or Al are joined to the lid and the bottom by soldering or pressure contacts. Parts of a clamping device, items 19 to 27, for making the pressure contact are shown in the Figure (also Fig. 2, not shown). Electrical connections to the device are made through studs 28 and 29 whilst the gate electrode is connected by conductor 12, flanges 8 and 9 and contact 10.