Theoretical Prediction of Flow- and Thermo-mechanical-induced Die Shift in Fan-out Wafer-Level Packaging

This paper attempts to conduct a comprehensive investigation of the die shift of fan-out wafer level packaging (FOWLP) during the fan-out (FO) fabrication process. Both the flow and the thermo-mechanical effects on the die shift are considered through flow-structural analysis and process-dependent thermal-mechanical analysis, respectively. The temperature-or/and time-dependent mateiral properties of the liquid type of molding compound are first characterized experimentall, and their cure kinetics and temperature- and conversion-dependent viscosity are established through theoretical and experimental methods. The predicted results are compared against the on-line measurement data. At last, the effects of some process, geometry and material parameters on the flow-induced and thermo-mechanically induced die shift are addressed.