Advanced FOPoP technology in heterogeneous integration: Finite element analysis with element birth and death technique

Abstract

This research investigates the advanced applications of Fan-Out Package-on-Package (FOPoP) technology within heterogeneous integration, highlighting its critical role in artificial intelligence (AI), big data analytics, and 5 G communication systems. Heterogeneous integration technology, which merges diverse components and technologies into a single package, is essential for addressing the increasing demands of modern electronic systems. However, wafer warpage during the FOPoP manufacturing process poses a significant challenge, impacting yield, chip alignment, and handling. We employ Finite Element Analysis (FEA) to tackle this issue using the element birth and death technique for process-oriented simulations. Our method innovatively utilizes both the backside and frontside Redistribution Layer (RDL) to create vertical interconnections within the FOPoP structure. The simulation process includes 11 stages: backside RDL electroplating, Polyimide (PI) curing, Molding Compound (MC) curing, frontside RDL electroplating, and PI curing. Comparing the simulated FOPoP wafer warpage values at each stage with experimental data, we consistently found discrepancies under 10 %, validating the accuracy of our simulations. Additionally, we identify effective strategies to reduce FOPoP wafer warpage through parameter analysis, such as lowering copper trace density in the RDL and increasing the die area ratio, thereby improving manufacturing yield. This research advances the understanding of FOPoP technology in heterogeneous integration and provides a robust framework for its application in next-generation electronic systems.