厚硅片的高速激光切片研究

基于激光切片原理的分析,给出了厚硅片的高速激光切片方法,采用平凸腔补偿工作物质的热透镜效应,利用Nd∶YAG棒本身的自孔径选模作用,获得了光束质量因子M²等于4.19的50 W 1.064 μm激光输出。选取合适的扩束倍数、重复频率和出气孔直径,当切割0.75 mm厚的硅片时,切片速度达400 mm/min;当切割两层叠放的0.75 mm厚的硅片时,切片速度达到100 mm/min。切片的切口光滑,切缝较窄,重复精度高,切片质量好,达到用传统方法难以达到的切片效果。

Study on LD-pumped Nd:YAG laser cutter for silicon wafer

By analysizing the theory of laser cutter,a rapid laser cutter method is given for cutting thick silicon wafer.Considering laser medium thermal lens effect and thermal focal length changing with the pumping power,using plano-convex high reflectivity mirror as the back cavity mirror to compensate the heat lens influence,utilizing the Nd∶YAG self-aperture effect also,more than 50 W average power 1.064 μm laser output is obtained with beam quality factor M2 of 4.19.Choosing suitable beam expander factor,appropriate aperture diameter of exit beam and repetition rate,when the cutting velocity is 400 mm/min,a silicon wafer of 0.75 mm thickness can be penetrated;when the cutting velocity is 100 mm/min,a silicon wafer of double-layer 0.75 mm thickness can be penetrated.Experimental results show that the cross section is fine in narrow groove and excellent repeatability precision,it is more better than that of other conventional cutting methods.