Investigation on effect of coupling agents in epoxy based underfill material for flip chip application

Underfill material is used in flip chip assembly to improve the solder joint fatigue lifetime. The adhesion between underfill material and passivation layer on integrated circuit chip as well as substrate is critical to the reliability of flip chip assembly. In order to improve the adhesion property of the underfill, the coupling agents are widely used. In this study, three different silane coupling agents, two titanate coupling agents, and one zirconate coupling agents were added into an epoxy underfill material, and their effects on the various properties of underfill were investigated.