Specifications for integrated circuits in telecommunications equipment

The demand for reliable semiconductor components in telecommunications systems has stimulated the preparation of two specification schemes, one for bipolar digital integrated circuits of the widely used standard-scale type and the other for MOS custom components representing large-scale integration. While sharing many reliability requirements with other applications, the telecommunications field is distinguished by the need for a long service life, often of several decades. Both schemes accordingly involve accelerated tests, particularly those employing elevated ambient temperatures. Other requirements are also common, as for encapsulation, but the main approaches differ. For bipolar circuits, the traditional component sampling procedure is adopted, details being given of the basis and background of some of the more important clauses. The MOS specification is based on design and process control, of which only the latter is presently developed featuring the use of a specially designed test component. Many years must elapse before the impact of the specifications can be judged objectively, but an encouraging impression has been obtained from early experience of their application.