摘要
利用绿光皮秒激光器结合空间光调制器和GS反馈算法,实现对硅片的并行切割工艺研究,分析多光束之间相邻光束的光斑重叠率、光束离焦量、离焦光束单脉冲能量对切缝深度和切缝底部平坦程度的影响。研究结果表明,多光束中相邻光束之间的重叠率应控制在70%~80%之间,可以使次切割深度最大且切割槽底部平坦。对阵列光束进行正离焦,有利于提升切割槽底部平坦程度。离焦量由聚焦光束瑞利长度和光束像差共同决定,试验条件下离焦量控制在1~2倍的瑞利长度可获得最佳效果。多光束离焦后切割深度降低,在一定范围内,可以通过提高多光束中离焦光束的单脉冲能量有效提升切割深度,且不影响切割槽底部的平坦程度。
This research investigates the parallel cutting process of silicon wafer using a green picosecond laser,spatial light modulator,and GS feedback algorithm.It examines the influence of several factors such as the overlap ratio of adjacent beams in multiple beams,defocus magnitude of beams,and the energy of single pulses from defocused beams on the depth and flatness of slits.The results show that the laser overlap ratio should be controlled between 70%~80%,which can maximize the single cutting depth and make the bottom of the cutting groove flat.The positive defocus of the array beam is helpful to improve the flatness of the bottom of the cutting groove.The defocus amount is determined by the Rayleigh length of the focused beam and the beam aberration.Under these experimental conditions,optimal results are yielded when the defocus quantity is maintained at 1 to 2 times the Rayleigh length.After the multi-beam is defocused,the cutting depth is reduced.In a certain range,the cutting depth can be effectively improved by increasing the single pulse energy of the defocused beam in the multi beam without affecting the flatness of the bottom of the cutting groove.
作者
汪于涛
Wang Yutao(Shanghai Keylab of Laser Beam Micro Processing,Shanghai Institute of Laser Technology,Shanghai 200233,China)
出处
《应用激光》
CSCD
北大核心
2023年第11期108-115,共8页
Applied Laser
基金
上海市科委项目(19511130400)。
关键词
皮秒激光
多光束
硅片切割
切割深度
picosecond laser
multi-beam
silicon wafer cutting
cutting depth
