Theoretical calculation and Simulation of BGA package stress under temperature cycling load

Under temperature cycling load, solder joints are the most vulnerable locations for faults in electronic equipment. Damage and failure of solder joints are important factors causing faults in electronic equipment. In order to solve the problem of solder joint damage and failure caused by cycling thermal stress in instruments and equipment under temperature load, the BGA packaging circuit board of ceramic chip is taken as the research object, and the maximum shear stress of solder joint is calculated theoretically and simulated based on engineering algorithm and finite element simulation respectively. Based on engineering algorithm and finite element simulation, the maximum shear stress of solder joints is calculated and simulated respectively. An engineering algorithm for maximum shear stress at solder joints of BGA encapsulated circuit boards is presented based on the geometric relationship of each part of the model and the theory of material mechanics. To explore the effects of different constitutive models on the simulation results of weld creep characteristics, Anand viscoplastic constitutive model and Wiese two-power constitutive model are introduced into the simulation software to simulate. The results show that the two models have similar results, which indicates that the two constitutive models are both suitable for describing the creep properties of weld joints. The method presented in this paper has good engineering application value and can be used to analyze the stress level of BGA encapsulated circuit board under temperature cycling load.