利用飞秒激光在铝箔上按设定好的轮廓程序重复扫描直至切透得到所需轮廓的微型器件, 研究了飞秒激光加工参数对切缝边缘坡度的影响规律。实验结果表明, 透镜焦距、扫描速度和飞秒激光能量密度与切缝坡度密切相关。切缝坡度随着扫描速度的增大而增大, 随着能量密度和聚焦透镜焦距的增大而逐渐减小。实验中飞秒激光切透大块铝箔材料即微型器件脱落时停止出光, 切缝未能继续发育, 坡度主要由材料上表面切割缝宽决定, 与飞秒激光高斯能量分布特征和去除材料的阈值密切相关。

Utilizing the femtosecond laser to scan the aluminium foils repeatedly until to cut through according to the set profile program, get the profile-required microminiature devices. The law of the influence that femtosecond laser machining parameters have on the kerf slope has been studied through the entire process. The experiment results show that the focal length, the scanning speed and the energy fluence of the femtosecond laser are closely related to the kerf slope: the kerf slope grows with the scanning speed increasing; it reduces gradually with the energyfluence and the focal length of the focusing lens increasing. The kerf keeps growing during the experiment. When the aluminium foils are cut through, that is exactly when the microminiature devices fall apart, the femtosecond laser stops simultaneously and then the kerf couldn′t continue growing. The slope is mainly decided by the kerf width of the material upper surface, which is closely related with Gaussian Energy′s distribution characteristics of the femtosecond laser and the threshold value of the material reduction.