Thermomechanical Effects in Packaging: Matching CTE or Not?

Abstract

Development of effective packages for microelectronics, MEMS, as well as for other microsystems and advanced modern devices, is usually based on minimization of thermomechanical effects and maximization of the useful life of a package. Such extremization-analysis depends on the effects that coefficients of thermal expansion (CTEs) have on the design of packages. This paper examines thermomechanics of a package and evaluates the effects that matching (or not) of CTEs may have on a package and its life. This examination is illustrated with representative examples.