Abstract: The subassembly of the present invention includes three pairs of aligned steering diodes and a single thyristor situated between spaced apart conductive heat sink plates. The subassembly is configured to fit into a standard 3-lead transistor outline package by arrangement of the semiconductors and shaping of the conductive plates. In one embodiment, the plates are square, and the components are arranged such that the diode pairs and thyristor are proximate the corners of the plates. In another embodiment, a "T" arrangement is utilized for the components which are situated between "H" shaped plates.

Abstract: Sets of six steering diodes and an ungated Thyristor are simultaneously formed into surge protection circuit modules by mass production techniques. An extended lead frame is provided with three spaced parallel leads for each module. The leads are connected at one end by a bridge. The sets of components are arranged along the lead frame in a fixture. By heating, each lead is soldered between a pair of steering diodes and the steering diodes on each side of the lead frame are soldered to different conductive plates. A thyristor is soldered between the plates. The partially formed modules are removed as a unit from the fixture and may be encased simultaneously. The bridge is removed to separate the modules and the leads trimmed and bent as required.