Reliability Analysis of Lead-free Flip Chip Solder Joint

Abstract

The purpose of this paper is to study effect of thermal cycle condition on the reliability of lead-free flip chip solder joint. Flip chip assembly was subjected to thermal cycle (MIT-STD-883) condition. Two dimensional finite element analysis (FEA) has been carried out using ANSYS commercial software. There are two types of lead-free solder (Sn96.5-Ag3.5 and Sn95.5-Ag3.8-Cu0.7). They used flip chip solder joints have been evaluated. For each lead-free flip chip solder joint, thermal stress and strain have been studied. The plastic strain is mainly effect on thermal fatigue of solder joint, so two types of lead-free solder joint compare with Sn63-Pb37 solder joint in equivalent plastic strain, and thermal fatigue life of these three types of solder joint has been analyzed and assessed.