Modeling and experimental investigation of monocrystalline silicon wafer cut by diamond wire saw

Diamond wire sawing is one of the key technologies in solar cell manufacturing process and semiconductor chip manufacturing process. The thinned of silicon wafer has become a development trend of semiconductor industry, and the reduction of silicon wafer thickness can improve the material utilization and reduce the manufacturing cost. Therefore, the minimum thickness analytical model of diamond wire saw cutting monocrystalline silicon wafer is proposed in this paper to study the processing mechanism of minimum thickness of monocrystalline silicon wafer. Firstly, based on the Kirchhoff's thin plate theory, the theoretical equation of the maximum internal stress of single silicon wafer and the sawing thickness of the silicon wafer is derived from the sawing force model. Combined with the Mohr's strength theory, the analytical model of minimum sawing thickness of monocrystalline silicon wafer is established. Then, the analytical model is verified by the finite element simulation. The average error between the simulation results and the calculation results of the analytical model about the minimum sawing thickness of silicon wafer is 9%. Finally, the monocrystalline silicon sawing verification experiments are conducted under some groups of processing conditions. The experimental results show that the minimum sawing thickness of the silicon wafer decreases with the increasing axial speed of the wire saw, increases with the increase of the feed rate of the wire saw, and decreases first and then increases with workpiece speed becoming large. The average error of the experimental results and the calculation results of the analytical model of the wafer minimum sawing thickness is 7.4%, which verifies corrections of the analytical model.