Finite element comparative study on creep and random vibrations of solder joints in BGA package

• Our investigation of thermal stress and strain accumulated in BGA joints made from the five solder alloys found that SAC396 and SAC405 alloys possess outstanding resistance to failure induced by thermal stress. • The bottom interface between the BGA ball and the copper pad on the substrate is the critical site for failure, experiencing the highest deformation and stress under thermal and vibration loadings. • Lead-free solder alloys, particularly SAC405, demonstrated superior thermo-mechanical and random vibration reliability compared to the lead-based Sn63Pb37 solder joints. • Among the lead-free alloys studied, SAC405 is highlighted as the most robust option, showing the least thermal strain and strain energy dissipation. As the demand for increasing miniaturisation and functionality of electronic devices soars, understanding the creep and random vibration of solder joints (SJs) in BGA packages in devices is critical to achieving high device reliability. This research employs Finite Element Analysis (FEA) to evaluate the response of four lead-free and one eutectic (Sn63Pb37) solder joints in BGA packages to failure induced by creep and random vibration. Results show deformation and stress damage distributions on the solder joints. The bottom of the solder joint in the BGA assembly is critical to deformation and stress failure induced by thermal and vibration loadings—the stress magnitude of the lead-based solder joint and more than any of the lead-free joints. SAC305 demonstrates the accumulation of the largest volumetric strain energy density (SED) dissipation per cycle loading, while SAC405 accumulates the least SED. The solder joints of SAC387 and SAC405 are observed to amass the highest and least thermal strain, respectively. Stress magnitude in Sn63Pb37 solder joints is highest while that in SAC405 SJs is lowest. Furthermore, SAC405 and Eutectic Sn63Pb37 depict the largest and smallest deformation, respectively. A resilience response of SAC405 to thermal cycle loading is observed. However, the detected susceptibility to deformation-induced failure under random vibration challenges the solder's reliability performance. The findings provide new knowledge that guides the selection of solder alloys for BGA components in electronic devices operating across various sectors that demand higher reliability.