IE34521L - Series connection of semiconductor elements - Google Patents

Abstract

1320412 Semi-conductor devices GENERAL ELECTRIC CO 25 Sept 1970 [2 Oct 1969] 45895/70 Heading H1K A subassembly consisting of a stack of semiconductor junction elements bonded together in series between a pair of junctionless low resistivity semi-conductor connectors is mounted with the connectors making low-resistance connection with the formed ends of conductors projecting up from a substrate into which they are moulded or stuck, or with conductors extending on to lands projecting from the surface of a substrate and on to which the connectors also extend, the low-resistance connections in either case being made by a mass of curable plastics containing conductive particles. The curing temperature of the plastics is below the softening temperature of the stack bonding material. In all cases the stack has a passivating coating and is encapsulated in a fabricated housing or in moulded plastics. The elements are etched and rinsed and the passivation applied after attaching the stack to the conductors. In assembling the Fig. 1 arrangement notched conductors 106 are forced apart to permit insertion of the stack between them. The conductive bonding material supplements the resulting pressure contact or, Fig. 2 (not shown), may replace it entirely. A cold setting resin loaded with silver, gold, or aluminium particles may be used but to avoid thermal stress in operation it is preferred to use a resin which is cured at a temperature above those occurring in operation. Suitable passivants are resins, glass and silicon oxide or nitride over oxide but silicone varnish with an overcoat of cold setting silicone resin is preferred. The moulded encapsulation is preferably of epoxy, silicone or phenolic resin. As shown the junction elements are of PN type, but use of PIN, PNP, NPN, and NPNP elements is also suggested. [GB1320412A]