Characterization of FOWLP Process using Temporary Bonding Materials on Carrier with Very Low Die Shift

Abstract

This study aims to link several epoxy mold compound (EMC) material properties to warpage and die-shift that are typically present in a fanout wafer level packaging process flow with RDL last process conditions. Two EMC compounds with different CTE, Tg, and modulus are evaluated and compared for warpage and die-shift performance on a next generation temporary bonding material (TBM). A low CTE and high Tg seem to be very beneficial to achieve low warpage on blanket mold on TBM wafers. When dies are embedded, the modulus plays a major role in order to mitigate thermal stresses that occur due to the Si-mold CTE mismatch during molding.