1,244,023. Semi-conductor devices. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 29 Aug., 1968 [30 Aug., 1967], No. 41335/68. Heading H1K. The lead structure of. a high frequency transistor is designed to compensate the effects of lead inductance and capacitance over a broad band; one terminal is a metallic basplate and the others are strips which extend parallel to the plane of the base-plate and which differ from one another in width and/or in their spacing from the base-plate. Formulµ are given by which the width/spacing ratio for given strips may be determined. For the common emitter arrangement shown the emitter terminal 1 is silver-plated molybdenum and bears a beryllia block 2 having three gilded areas 3, 4, 5. The semi-conductor body 9 is soldered to one of these, 3, through its collector region and the collector lead is also attached. Wires from the emitter regions are bonded to the central area 4 from which electrical connection is continued to the base-plate by the side gilding 6. The (large) base lead 8 is soldered to the third area 5 and has attached to it a metal block 12 so that the base wires 10 may be carried clear of the emitter wires. In variants different spacing of the strip for the base-plate may be obtained by using a (beryllia) block 2 with ends of different thickness or by bending a lead into a parallel plane. The transistor is completed by cast or moulded insulation (11, not shown) of ceramic, glass or plastics which covers only the central part of the base-plate, enclosing the transistor, block 2, and the inner ends of the leads 7 and 8.
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