Abstract:

Production of microelectronic devices encapsulated in solid, molded plastic packages has rapidly increased since the early 1980s. Today, millions of plastic-encapsulated devices are produced daily. On the other hand, only a few million hermetic (cavity) packages (Figure 1) are produced per year. Reasons for the increased use of plastic-encapsulated packages include cost, availability, size, weight, quality, and reliability. Markets taking advantage of this technology range from computers and telecommunications to automotive uses. Yet, several industries, the military in particular, will not accept such devices. One reason for this reluctance to use the best available commercial parts is a perceived risk of poor reliability, derived from antiquated military specifications, standards, and handbooks; other common justifications cite differing environments; inadequate screens inadequate test data, and required government audits of suppliers' processes.

This paper describes failure mechanisms associated with plastic encapsulation and their elimination. It provides data indicating the relative reliability of cavity and solid-encapsulated packaging, and presents possible approaches to assuring quality and reliability in the procuring and applying this successful commercial technology.