Modeling the mechanical behavior of underfill resins and predicting their performance in flip-chip assemblies

A number of analytical models exist that can predict the effect of filler content on the mechanical behavior of filled epoxy resins. Such models can predict increases in viscosity, strength, fracture toughness, and modulus as well as the decrease in the coefficient of thermal expansion with increasing filler content. In this paper we will couple these analytical models that predict the mechanical behavior of filled epoxy resins with our FEM analyses of the thermal cycling behavior for flip-chip assemblies. Such an exercise should identify the effect of filler content on flip-chip performance.