Numerical Approach to Predict Silicon Wafer Grinding Warpage

As electronic packaging is becoming thinner and lighter, it is necessary to address the grinding process issues in the silicon wafer. In this context, the self-rotating grinding method is usually employed to mitigate the backside grinding in thin wafers, due to its high effectiveness. However, as the residual stress cannot be completely eliminated from the grinding process, it will cause warpage and lead to die damage. This phenomenon has been investigated by applying the finite element method (FEM) when modeling the grinding process. In the present investigation, a simulation model of the grinding process was developed for analyzing the warpage process and the residual stress. To validate the simulation model, experimental testing was conducted, whereby Scanning Electron Microscope (SEM) was used to observe the wafer depth, and crystal lattice breakage was observed through Raman Analyzer. The experimental data were used to validate the simulation model of the grinding process, which was subsequently applied to analyze the warpage and the residual stress in the wafer grinding.