Thermal Fatigue Analysis of PBGA Solder Joints With the Consideration of Damage Evolution

Abstract

This paper presents a computational thermal fatigue analysis for the life prediction of solder joints in a plastic ball grid array-printed circuit board (PBGA-PCB) assembly. The PBGA has a full grid array of 256 solder balls with 1.0 mm ball pitch. The PCB is a 4-layer FR-4 laminate with a thickness of 1.57 mm (62 mils). The assembly is subjected to −40∼125°C thermal cycling (one-hour cycle). Finite element analysis is performed to obtain the creep hysteresis loops. Based on a previously developed model, the evolution of damage is considered in the life prediction of solder joints. Besides, PCBs with various thicknesses (40 mils and 20 mils) are investigated. The results from different cases are compared and discussed.