Polymer-Based wafer-Level Warpage Prediction and Regulation for the Advanced Packaging

Controlling warpage is of key importance for realizing reliable and cost-efficient advanced packaging. However, warpage effects can occur during the manufacturing process, caused by a combination of different processing temperatures, different materials, and the changing properties of the materials (e.g. polymerization and related cure shrinkage). One approach to controlling warpage could be realized by assessing a numerical simulation workflow of the advanced packaging process chain and prefabricate back-side film, in which the relevant material properties and geometry are used as input. Polymers are easy to prepare, compatible with advanced packaging processes, and can achieve a wide range of stress transformation. In this paper, a warpage control method by prefabricating backside polymer film and a Multi-physics finite element model was proposed. The results show that the polymers can achieve wafer-level warpage control in the curvature range of 0.003~0.041 on a 4-inch Si wafer.