INVESTIGATION OF LOW GLASS TRANSITION TEMPERATURE ON COTS PEM'S RELIABILITY FOR SPACE APPLICATIONS

摘要

Microcircuit manufacturers of Plastic Encapsulated Microcircuits (PEM's) have made changes in epoxy molding compound materials and chemistry, which lower Glass Transition Temperature (Tg). PEM users in harsh environments have concerns if either the part in its application, or in evaluation or assembly, is used close to, or above, the Tg. Various Tg measurement techniques are discussed and test results from one of them presented on a variety of commonly available PEM's. The implications of the results on usage of these parts in space applications will be presented. Reliability test results of sample low Tg PEM's will be presented. The experiments include bum-in (short life testing) under different temperatures. Different low temperature Tg microcircuits were tested. Assessment of final electrical test measurements and yield are shown.