Finite Element Analysis of Solder Joint Fatigue Failure in SiP Under Random Vibration Loading

To investigate the failure modes and failure life of the internal structure of System-in-Package (SiP) under random vibration environments, a specific model of RF SiP was selected as the research object. The random vibration was conducted by using SolidWorks software to establish a 3D simplified model and ANSYS Workbench finite element simulation software. Based on the GJB 150.16A standard, acceleration power spectral density was set by using a generic device selection spectrum, followed by modal and random vibration analyses. The equivalent stress, strain, and deformation cloud maps of various parts of the RF SiP was analyzed based on the simulation results. By applying CoffinManson's equation, Miner's rule, Steinberg's model, and the three-band method to the finite element analysis results, the fatigue life prediction was performed. This indicated a fatigue life of 4, 5 8 5 cycles for the ball grid array (BGA) of the RF SiP. This study presents a finite element simulation methodology for assessing the vibration-induced fatigue life of RF SiP. The methodology provides reference data for predicting the operational lifetime of this specific SiP model, which apply to actual service conditions.