Overview of multilayered thin film theories for MEMS and electronic packaging applications

Interfacial stresses due to thermal mismatch in layered structures are one of the major causes of mechanical failures in electronic packages and Micro-Electro-Mechanical System (MEMS) structures. Applying analytical solutions to predict the magnitude and the distribution of interfacial stresses in thermostat-like multilayer structures has been widely adopted by many electronic packaging and MEMS researchers. This investigation is based on multilayer theory models. To discuss and distinguish their characteristics, finite element analysis numerical solutions and multilayer theory analytical solutions are compared and analyzed. This encompasses the theories´ application spectrum as well as their prediction ability. This work not only discusses the property and the workability of theories but also fabricates a multilayer structure made on a silicon substrate to demonstrate the feasibility of finite element method (FEM) and multilayer theories experimentally. Experimental results demonstrate that the finite element method is a feasible approach to predict the mechanical behavior of multilayer structures.