Improving Warpage Characterization of Large Wafers in Fan-Out Packaging Technology

During the production of Fan-Out Wafer/Panel Level Packages (FOWLP/ FOPLP), one of the key challenges is to keep the warpage low. Many production steps are needed and a multitude of materials are used which influence the deformation shape of a wafer or panel during production. To keep the warpage at a level that is sufficiently small, it is necessary to know how materials and manufacturing steps like molding, post-mold-cure, dicing and reflow soldering influence the internal strain. In this work, a simplified FO-wafer is created and modeled by means of numerical simulation models. For these numerical simulations, the inputs of material data and defined measurement conditions are essential. To achieve defined conditions of warpage measurement, this paper focuses on an analysis of the measurement set-up for large wafer by using a specified 3-point support. This 3-point support provides a controlled contact support of the wafer and reduces the effect of gravity, which especially may occur during heating due to the softening of the layers. The results show a good agreement between the measurement and the numerical simulations.