Simulation and experimental research on water-jet guided laser cutting silicon wafer

Silicon wafer cutting is a key process in wafer manufacturing. Traditional cutting methods can not do this work well, but water-jet guided laser processing which is based on the principle of full reflection can do it perfectly. A new simulation model of water-jet guided laser cutting silicon wafer was set up. The model treated the uniform energy input of water-jet guided laser, the cooling effect of the water jet, and the melting and removal of the silicon. The simulation results revealed that the effect of water jet cooling on wafer temperature field is very distinct. Machining silicon wafer, stainless steel1Cr18Ni9Ti and 65 Mn were simulated. The results showed silicon wafer had the least heat affected zone of all. Experiments were done using the new water-jet guided laser micromachining system. The results showed that the energy intensity distributed over the water jet cross section nearly homogeneous and the energy decreased little in long working distance. Applying optimized machining parameters to cut silicon wafer, nearly no burrs, no cracks, no heat affected zone were formed, the cutting results were better than diamond saw and gas (Ar) assisted laser cutting.