Prediction methodology of die shift for advanced panel level packaging

ABSTRACT This study has been focused on die shift mechanism in die-first manufacture process, with a specific focus on the process-induced challenges associated with large area substrate size. The critical process parameters and package stacking geometry factors are considered to estimate the influence on die position. Finite element analysis is utilized to simulate warpage behaviors based on coefficient thermal expansion mismatch between various packaging materials involving substrate, epoxy molding compound (EMC) and die. In addition, computational fluid dynamics has been applied to realize the physical mechanism during compression molding flow process. In addition, EMC material characteristics have been influenced by temperature especially in the modification of volume amount. Consequently, pressure, volume difference, temperature and degree of cure are considered in the measurement of EMC material. In addition, temperature factor has been divided into two conditions involving controlled 150°C temperature and varying temperate range between 50 and 250 °C. The die pattern of a package unit involving multi-dies is simulated and validated with non-contact optical tool. The preliminary result shows that die shift is increased rapidly with the location factor. The amount of die shift is measured smaller than 45 μm. In addition, the deviation of die shifting between the simulation and measurements is <13%. The design of mold cavities is not included in this research. This study provides a method to estimate die shift under various compression molding process of EMC for advanced packaging structures featuring diverse die-first panel level packaging development.