Reliability life assessment and prediction for high density FOWLP package using finite element analysis and statistical approach

A Finite Element Analysis (FEA) modelling study on solder joint fatigue life assessment under thermal cycling conditions for two High Density (HD) Fan Out Wafer Level Packaging (FOWLP) packages is presented in this paper. Package designs and material properties of FOWLP packaging materials such as photo-dielectric and epoxy molding compound are studied. Unlike the conventional numerical parametric study, this study adopts both Ansys Mechanical and the statistical analysis tool Minitab to analyze the modelling results. Facilitated by the statistical tool, the solder joint Thermal Cycling on Board (TCoB) fatigue life prediction formulas have been derived. For any parameters within the data ranges prescribed in Design-of-Experiment (DOE) table, solder joint fatigue life can be quickly calculated by using the derived prediction equations. Furthermore, critical factors that significantly affect solder joint fatigue life are identified by the statistical tool. Hence, the novel numerical methodology presented in this paper, which integrates the FEA modelling tool and the statistical tool, is able to enhance the efficiency of the Design Technology Co-Optimization (DTCO) process for solder joint TCoB fatigue life assessment.