Influence of titanate and zirconate coupling agents in epoxy underfill material

This paper presents an investigation of the effects of five titanate and zirconate coupling agents (CA) with different functional groups on various properties of epoxy underfill materials, including viscosity, curing, thermo-mechanical properties, and adhesion to SiO/sub 2/ passivation. CA-A, CA-C, and CA-E increased the viscosity of underfill. Addition of the coupling agents led to decrease in the curing onset temperature of epoxy underfill formulations. All of the coupling agents investigated in this study also brought a slight decrease in glass transition temperature (T/sub g/) of epoxy underfill. The die shear test of underfill on SiO/sub 2/ passivation showed that the adhesion was not changed significantly with the addition of the titanate and zirconate coupling agents, except for CA-E. The influence of coupling agent CA-E concentration in underfill materials was further investigated. CA-E has potential for use in epoxy underfill to improve adhesion.