Modelling and prediction on process dependent wafer warpage for FOWLP technology using finite element analysis and statistical approach

Abstract

A Finite Element Analysis (FEA) modelling on process dependent wafer warpage for Fan Out Wafer Level Packaging (FOWLP) technology is presented in this paper. Instead of using conventional Design-of-Experiment (DOE) approach, the numerical parametric study is performed based on the DOE table generated by statistical data analysis tool. By analyzing the modelling results, the statistical tool is able to derive the wafer warpage prediction equations for each process steps. For any parameters within the data ranges prescribed in DOE table, wafer warpage can be quickly calculated by using the prediction equations. Case study on wafer warpage for two high density package designs for different FOWLP process steps is presented. Critical parameters that impact wafer warpage significantly are identified for each process step by the statistical tool. This established methodology is able to predict wafer level warpage for FOWLP processes efficiently so that the design and process parameters could be co-optimized to address the wafer warpage issues.