Transistor Museum Early Germanium Power Transistor History by Joe Knight Westinghouse Page 4

A SURVEY OF EARLY POWER TRANSISTORS

by Joe A. Knight

WESTINGHOUSE 1950s/60s GERMANIUM

POWER TRANSISTORS

As no doubt Westinghouse was aware of what other companies were doing in silicon semiconductor development they had embarked on a major product development that was truly unique. By early 1958 they had developed a High Power Silicon Power Transistor unlike any other. Westinghouse had developed a high purity silicon 'fusion' (not diffusion) process power transistor capable of dissipating 150 watts and working at a temperature of up to 150 degrees Centigrade. Germanium power transistors were unable to come close to these numbers.

ABOVE, L-to-R: The first two items are like the one shown in a paper Westinghouse presented in early-1958 on their Silicon Power Transistor development. By mid-1958 they had developed prototype versions called the npn fused 2-amp "WX1015" (1015A - 1015F) series and the npn fused 5-amp "WX1016" (1016A - 1016F) series. Both series were housed in welded stainless steel hermetically sealed cases with a bottom threaded stud for external heat sink mounting. Prices varied from $76 to $155 for 2 amp/300 volt versions and from $97 up to $250 for 5 amp/300 volt versions. These were not inexpensive devices. The last two items above (intact and cut-open) are early pre-production versions of a JEDEC registered "2N1015C" type. These use the normal inter-digitized element design (fingers with-in fingers) and so are likely from Siliconix, a second source for this new series. By early 1959 Westinghouse began advertising production availability for their new 2-amp "2N1015" series and the new 5-amp "2N1016" series. Ratings were now limited from 30 to 200 volts at 150 watts dissipation. Both new series were designed for amplifying and switching service.

ABOVE, L-to-R: The first two items show a 1961 production "2N1015C" type, top and interior. The interior shot shows how Westinghouse used the 'concentric annuli' design for construction of their junction elements. This ring with-in ring design allowed for a compact base and emitter configuration. The third device shows a

1961 production "2N1016C" 5-amp Power Transistor. The last item shows the threaded stud bottom connection.

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Joe A. Knight Early Power Transistor History – WESTINGHOUSE Page 4