Die shift prediction of fan out panel level packages considering both warpage and flow induced mechanisms with temperature dependent properties.

Abstract

Fan-out panel-level packaging is a leading technology in advanced semiconductor manufacturing, yet the phenomenon of die shift during the compression molding process remains a significant challenge to yield and reliability. This study presents a comprehensive investigation into the mechanisms of die shift, categorizing them into warpage-induced and fluid-flow-induced effects. By integrating material characterization, advanced finite element modeling, and nanoindentation analysis, we evaluate the thermal softening behavior of heat release tape and its contribution to die shift. It is found that the Young's modulus of heat release tape (HRT) decreases by a factor of 2 to 3 at elevated temperatures, substantially increasing fluid-induced die shift. Simulations incorporating this high-temperature behavior improve agreement with experimental measurements by up to 48%. Moreover, results show that warpage effects dominate die shift in peripheral die locations, while fluid-flow effects intensify with local die density. This work establishes a validated multiphysics framework for accurate die shift prediction, highlighting the critical role of temperature-dependent mechanical properties in modeling real-world packaging scenarios.