飞秒激光加工玻璃微结构的机理与工艺参数研究

【作者】 杨雪；

【导师】 孙会来；

【作者基本信息】 天津工业大学 ， 机械工程， 2021， 硕士

【摘要】 德国肖特公司生产的BOROFLOAT?33(BF33)是一种高品质的硼硅玻璃材料,具有透光率高、热膨胀系数低、耐热性强、化学稳定性好等优点,被广泛应用于航空航天、电工电子、MEMS器件封装、生物医疗及光学等领域。然而,现阶段实现玻璃等硬脆性材料的微结构加工还存在很大困难,传统的机械加工方法无法满足玻璃精细加工的要求。目前飞秒激光作为一种新兴的加工方式极具应用前景,因其脉宽极短、单脉冲能量极高的特性,对硬脆性和高熔点材料的高精度微纳加工具有显著优势。因此本文利用飞秒激光技术进行BF33硼硅玻璃的微结构加工,通过分析飞秒激光烧蚀透明电介质的机理,建立物理模型,模拟得到理论烧蚀阈值;通过飞秒激光多脉冲累积烧蚀实验,求解得到实验烧蚀阈值;通过单因素实验和正交实验进行激光参数优化,得到微透镜阵列结构的最优激光加工参数,最后进行氢氟酸腐蚀实验得到了光滑的微透镜阵列。主要研究内容如下:(1)根据透明电介质材料电子密度随时间的变化关系方程和雪崩电离、多光子电离理论,建立了飞秒激光烧蚀BF33硼硅玻璃的物理模型,通过MATLAB软件对BF33硼硅玻璃的烧蚀阈值进行编程计算,得到理论数值;(2)开展不同重复频率下的多脉冲累积烧蚀实验,根据超景深显微镜图及数学模型,求解BF33硼硅玻璃的烧蚀阈值,得到实验数值,并分析了多脉冲作用下材料烧蚀阈值的变化特点;(3)通过单因素飞秒激光烧蚀实验,得到了激光功率、重复频率、扫描速度和扫描次数对BF33硼硅玻璃烧蚀质量的影响规律,通过多因子正交实验得到了最优的激光加工参数,并进行实验验证对比了优化前后的激光加工形貌;(4)以优化后的实验参数为依据,进一步探究了激光参数对微透镜圆度、直径和深度的影响规律,综合分析得到最佳的微透镜加工参数,利用该激光参数制备得到深度为15μm、直径为33.4μm(深径比约为1:2)的微透镜及其阵列结构,并探究了微透镜直径和表面形貌随氢氟酸腐蚀时间的变化规律,最后对微透镜阵列的光学性能进行了检测。更多还原

【Abstract】 BOROFLOAT?33(BF33)produced by German SCHOTT is a high-quality borosilicate glass material,which has the advantages of high light transmittance,low thermal expansion coefficient,strong heat resistance,and good chemical stability.It is widely used in aeronautics and astronautics,electrical and electronic,MEMS device packaging,biomedical and optical fields.However,at this stage,there are still great difficulties in realizing the microstructure processing of hard and brittle materials such as glass,and traditional mechanical processing methods cannot meet the requirements of fine glass processing.At present,femtosecond laser as an emerging processing method has great application prospects.Because of its extremely short pulse width and extremely high single pulse energy,it has significant advantages for high-precision micro-nano processing of hard,brittle and high melting point materials.Therefore,this paper uses femtosecond laser technology to process the microstructure of BF33 borosilicate glass.By analyzing the mechanism of femtosecond laser ablation of transparent dielectrics,a physical model is established,and the theoretical ablation threshold is simulated.Through femtosecond laser multi-pulse cumulative ablation experiment,solve the experimental ablation threshold.Through single factor experiment and orthogonal experiment to optimize the laser parameters,get the optimal laser processing parameters of the microlens array structure,and finally carry out the hydrofluoric acid corrosion experiment to get the smooth microlens array.The main research contents are as follows:(1)According to the relationship equation of the electron density of transparent dielectric materials with time and the theory of avalanche ionization and multiphoton ionization,a physical model of femtosecond laser ablation of BF33 borosilicate glass was established,and BF33 borosilicate glass was ablated by MATLAB the threshold value is programmed and calculated,and the theoretical value is obtained.(2)Carry out multi-pulse cumulative ablation experiments under different repetition frequencies,and calculate the ablation threshold of BF33 borosilicate glass according to the super-depth microscope image and mathematical model,obtain the experimental value,and analyze the material ablation threshold under the action of multiple pulses change characteristics.(3)Through single-factor femtosecond laser ablation experiments,the influence of laser power,repetition frequency,scanning speed and scanning times on the ablation quality of BF33 borosilicate glass was obtained,and the optimal laser was obtained through multi-factor orthogonal experiments.The processing parameters were verified by experiments to compare the laser processing morphology before and after optimization.(4)Based on the optimized experimental parameters,the influence of laser parameters on the roundness,diameter and depth of the microlens is further explored,and the best microlens processing parameters are obtained through comprehensive analysis.The depth of 15μm is obtained by using the laser parameters.Microlens with a diameter of 33.4μm(depth-to-diameter ratio is about 1:2)and its array structure,and the changes of the microlens diameter and surface morphology with the hydrofluoric acid etching time are explored,and finally the optics of the microlens array Performance was tested.更多还原