![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
ABSTRACT
This study explores Coffin-Manson equation and its feasibility for tin-silver-copper (Sn/3.0Ag/0.5Cu) solder. Most of the Sn/Ag/Cu solder studies were performed by experiment or the finite element method. In this study, MARC, a finite element analysis package, is applied for simulation. In the simulation, the material properties are temperature-dependent and the boundary conditions are time-dependent. Complying with JEDEC standard, the derivation of fatigue life formula for solder is built from experimental data. Using the experimental results of the BGA ball shear test, the amplitude of equivalent plastic shear strain at 1/4 cycle is obtained by finite element method. Meanwhile, substituting the CSP thermal cycle test results into Weibull life distribution, the amplitude of equivalent plastic shear strain at 3085 cycle is solved. The numerical results of the equivalent plastic shear strain amplitude are used to derive the Coffin-Manson equation proposed. To verify the feasibility and reliability of the formula derived, the result of an isothermal low cycle fatigue test is analyzed by the finite element method. It is observed that the proposed equation has a good agreement with the experimental data.