Effect of Creep, Fatigue and Random Vibration on the Integrity of Solder Joints in BGA Package

Abstract

This study employs Finite Element Analysis (FEA) to investigate the effects of creep, fatigue, and random vibration on the integrity of solder joints in BGA packages in electronic modules. Evaluating the response of lead-based Sn63Pb37 and lead-free SnAgCu alloy solders (SAC305, SAC387, SAC396, and SAC405) to induced loads - stress, strain, strain energy density, and displacement in the joints is obtained and studied better to understand the mechanism of the joints' degradation. SAC305 and SAC405 are modelled with linear stress-temperature relationships σ = 3.152T–68.167 and σ = 1.543T–34.983, respectively. The magnitude of the strain energy density in the joints is a key failure driver. SAC387 and SAC396 solder joints display lower values of strain energy density and thus have higher durability. Displacement analysis indicates that SAC305 and Sn63Pb37 are prone to deformation-induced failure. SAC387 exhibits the highest fatigue yield stress at 58 MPa, while SAC405 displays the lowest stress at 22 MPa. Analysis of the results of random vibration shows that Sn63Pb37 developed the highest stress at 34.62 MPa and is thus susceptible to stress-induced failure. The robust stress, strain, and strain energy responses of SAC405 and SAC396 provide key insights into improving the mechanical reliability of future electronic devices towards better sustainability.