ABSTRACT

Temperature and relative humidity affect electrical, chemical, mechanical. and thermo-mechanical properties of microelectronic packages. Attention has been focused on the environmental effects that results in various physical failures. The scanning electron microscope is a useful tool for visually characterizing these failures, but its use is restricted because the specimens examined must be coated. The environmental scanning electron microscope functions like a traditional high-quality scanning electron microscope, and also allows the researcher to examine unprepared, uncoated specimens. This makes it possible to view wet or moist specimens in their natural states. In this paper. several experimental efforts using the E-SEM technique are discussed. The first was a study of thermal effects on L-band microwave monolithic integrated circuits. The second investigation concentrated on ad/absorptive effects on multilayer thin film polyimides. The third study focused on thermal and humidity cycling effects on the interfacial bonding characteristics of resin-fiber interfaces near plated-through-holes in printed wiring boards.