研究目的
Investigation on the crack fracture mode and edge quality in laser dicing of glass-anisotropic silicon double-layer wafer.
研究成果
The anisotropy of silicon layer and the dicing direction should be taken great care of during laser dicing to obtain good crack edge quality with low surface roughness. The crack induced by thermal-stress within the silicon layer tends to propagates along its main cleavage planes with lower surface energy. The application of inappropriate dicing direction results in the deviation of crack propagation path.
研究不足
1. The crack propagation behaviors in micro-scale are analyzed by FEM based on the classical linear elastic Griffith fracture theory in the two-dimensional form and static seam-type crack model. But the actual crack propagates in the three-dimensional way, which exhibits a much more complex stress distribution and propagation behavior. 2. The bonding layer is not considered in the numerical simulation, which may play an unnegligible role during the crack propagation. 3. The thermal defects at the leading and ending edges cannot be eliminated completely.