Study on the Board Level Reliability of Lead-free PBGA Packages

In this paper, a finite element modeling of lead and lead-free soldered PBGA package was performed. The inelastic stress and strain of the solder joints in the PBGA package under thermal cycling has been analyzed. The Garofalo-Arrheninus model was applied to describe the steady-state creep for the solders at high temperatures. The high-low temperatures extreme point, plastic strain, creep strain were analyzed in thermal cycling simulations. Various solder joint fatigue life was calculated by modified Coffin-Masson fatigue life prediction model. Finally, the fatigue life of three different solders in PBGA is compared