PROJECT TITLE :

Effect of Nano-Particles on Heterogeneous Void Nucleation in No-Flow Underfill Materials

ABSTRACT:

The massive variety of voids induced by the thermal impact from solder reflow method is one of the technical challenges for flip chip package techniques typically with no-flow underfills. The underfill voids might extensively reduce the life cycle in thermal cyclic check. This paper reviewed classical heterogeneous bubble nucleation theories to model voids nucleation occurring on the part boundary of solid solder and liquidus underfill to regulate the nucleation during flip chip assembly process using no-flow underfill materials. On the heterogeneous voids nucleation, the properties of nucleation sites (like density and surface tension) that determine void formation were explored using nano-sized fillers. So, this experiment investigated the result of nano-sized fillers, which are potential nucleation sites in the no-flow underfill material, on the void formation by changing the nano-sized filler kind and concentration. Eventually, we tend to proposed a formulation guideline of no-flow underfill materials using nano-sized fillers to effectively forestall the underfill voiding during flip chip assembly process.