Study of Simulation of Micro-Cutting Process of Alternatively-Arranged Resin and Metal

Abstract

For the planarization process of LSI wafers, metal bumps covered with a certain kind of resin are machined with a diamond tool before its stacking. In this study, the deformation process and temperature field in this process are analytically simulated with FEM. In order to analyze the cutting process for resin which has a viscosity, the cutting simulator first has to treat the visco-elastic-plastic material property. Secondly, to analyze the cutting at the micro-meter level depth of cut, the analysis model was scaled down. Finally, to simulate the cutting process of a LSI wafer, PVC and 70%Cu-30%Zn brass were assigned a resin and a metal part, respectively. As a result, it was clarified that the machining temperature during a resin cutting remains high even if the depth of cut is a micro-meter scale because of its poor thermal conductivity. In addition, the chip forming process showed very discriminative deformation at the boundary between the metal bump and a resin.