Analysis of ultrafast laser ablation of fused silica filled epoxy molding compound (EMC) using an improved two temperature model: The effect of the processing parameters and the particle size

Abstract

Ultrafast laser-based dicing of fused silica-filled Epoxy Molding Compound (EMC) is a more efficient, effective, and flexible alternative to the conventional blade saw dicing method. However, the experimental study on the ultrafast laser ablation of fused silica-filled EMC is limited and presented limitations. In this study, an improved 3D Two Temperature Model (improved 3D-TTM) is developed for the ultrafast laser ablation of fused silica-filled EMC to study the ablation behavior. A level-set equation is added to the improved 3D-TTM to capture the ablation front. In the meantime, the method of modeling the fused silica particle embedded in the EMC in the improved 3D-TTM is also described. The improved 3D-TTM showed good agreement with the experimental results and was further used to explore the effect of processing parameters on ablation efficiency and material removal rate. Three ablation ranges at different laser powers were identified. The differences in ablation mechanisms behind those ranges are discussed. It was found that direct ejection can significantly improve the material removal rate. The effect of the filler size on the ablation efficiency is also discussed. It was found that larger filler size EMC will have a smaller ablation efficiency under the same processing conditions. The power thresholds for initiating the direct ejection material removal for different filler sizes were determined by the improved 3D-TTM.