300 ampere, 1000 volt hermetic Darlington transistor

Abstract

A hermetic package designed for high performance in hostile environments and military applications has been developed to replace the plastic, nonhermetic, industry-standard 300 A KS62 Darlington transistor. the hermetic package uses a flat copper bus for the collector and emitter terminals, which are isolated from the metal package with oblong ceramic insulators. The collector and emitter terminals are terminated on the top of the hermetic package and are isolated from the package body with a plastic cover. The hermetic package with this plastic cover has the same footprint and dimensions as, and is interchangeable with, the 300 A plastic Darlington transistor. The designer therefore has a choice of selecting either the hermetic or nonhermetic package at any time during design or even changing to the hermetic package during production or as a field retrofit. Another unique feature is the use of a relatively heavy 0.030 inch thick lid that is TIG- (tungsten-inert-gas-) welded to complete the hermetic sealing of the package body. The hermetic package is desirable for high-current Darlington transistors and MOSFETs or other high-current semiconductors used in military and other hostile ambient applications. >