Warpage Assessment of System in Wafer-level Package Technology with RDL Process through Theoretical Approach and Experimental Validation

Thermal warpage would appear during the redistribution layer (RDL) fabrication process of the system in wafer-level package technology, which may result in challenges in subsequent procedures. Thus, finite element analysis (FEA) with element birth and death techniques was performed to predict the process-induced warpage during the RDL process, and effective material property technique were used to simplify the complex RDL structure. To identify the optimal factorial combinations on design parameters, Taguchi methods with adequate orthogonal array were applied to warpage simulations. It is concluded from the results that the warpage value can be reduced by 32 % if the optimized experimental parameters were used for the RDL fabrication process.