Flux/underfill Compatibility Study for Flip-chip Assembly Process

Abstract

The rapid uptake of flip-chip technology within the electronics industry due to their better thermal performance, smaller size, lower profile, light weight, and higher input/output density, the solder joints together with underfill in flip chip package serve as a mechanical mechanism for resisting the thermal deformation induced by the coefficient of thermal expansion (CTE) mismatch between silicon die and substrate. underfill materials are employed in flip-chip assemblies to enhance solder joint reliability performance. The adhesion of underfills with solders is important to the integrity of the flip-chip structure. The effect of temperature and humidity aging as well as flux residue on adhesion strength was also investigated.