基于微电铸overplating的微透镜制造技术研究

发布时间：2018-01-14 23:07

本文关键词：基于微电铸overplating的微透镜制造技术研究　出处：《中国科学技术大学》2016年博士论文　论文类型：学位论文

【摘要】：作为一种重要的微光学元件,微透镜及其阵列凭借其汇聚、准直以及成像的能力,在诸多领域得到了广泛的应用；相应的微透镜制造方法也是层出不穷,成为微光学领域的研究热点。本文利用微孔电沉积在其过电铸overplating阶段形成的球凸结构作为母型,结合翻模复制工艺,提出了一种全新的微透镜制造方法。从数值仿真以及实验的角度深入研究了overplating结构的面形演变机理。在工艺参数优化研究的基础上,建立兼容性良好的集成工艺,实现了参数可控的大数值孔径微透镜以及填充比可达100%的微透镜阵列的制造,并对其几何参数及光学性能进行了测量评价。主要工作从以下几个方面展开：从电沉积过程的基本电化学原理出发,建立了微孔电沉积过程的数值计算模型。该模型通过对流场分布、反应离子的物质输运以及电化学反应动力学的耦合,结合移动网格技术,实现了阴极沉积面形的动态仿真。在此基础上利用有限元方法分析了对流搅拌对微孔电沉积过程的影响,并与实验结果相对比,为后续的电铸实验条件选择提供理论依据。对微孔电沉积在overplating阶段的成形规律开展了深入的研究。利用本文构建的数值计算模型,分析了电极的结构尺寸以及电沉积速度等因素对overplating阶段沉积面形演变的影响。通过自行搭建的电铸实验系统,开展overplating沉积过程的实验研究：探索微孔孔径、结构的深宽比,以及电流密度等条件对overplating沉积过程的影响。数值计算以及实验研究的结果均表明,微孔孔径以及电沉积速度越小,则越倾向于形成球凸形的overplating结构；而微孔孔径以及电沉积速度越大,则越倾向于形成中间低而四周高的火山口形overplating结构。后续的测量结果表明了该工艺过程的良好稳定性和重复性。本方法的整个工艺流程主要包含光刻、微电铸以及软光刻翻模几个阶段,在分析各个阶段工艺参数影响机理的基础上,对相关工艺参数的优化进行了研究,建立了兼容性良好的集成工艺,实现了微透镜及其阵列的制造。本文通过改进光刻工艺参数,获得了满足后续电铸处理需求的稳定性良好的光刻胶掩膜结构。优化微电铸的电参数,改善沉积面的粗糙度,保证微透镜的表面精度满足基本的光学应用需求。改善软光刻翻模工艺,实现光固化胶对透镜凹模的良好填充,获得高精度无气泡缺陷的复制透镜及其阵列。对翻模所得微透镜及其阵列的几何参数和光学性能进行测量和评价。本文利用显微成像结合图像处理技术,通过轮廓的提取及拟合实现了透镜几何参数的测量。在此基础上,分析了透镜面形的演化规律,根据透镜几何参数与电铸时间的关系评价了工艺的可控性。结果表明通过控制电铸时间可以获得参数可变的大数值孔径微透镜。搭建光学测量平台,对透镜的焦距进行测量；并对不同填充比透镜阵列的光学特性进行测量,结果表明该方法所获得的透镜阵列具有良好的光学参数一致性。
[Abstract]:As an important optical element, micro lens and lens array with its convergence, and collimation imaging, has been widely used in many fields; the corresponding micro lens manufacturing method is also emerge in an endless stream, become a hot research field of micro optics. The micro hole is formed in the stage of the electrodeposition of overplating over plating ball as a parent with convex structure, mold replication process, puts forward a new micro lens manufacturing method. From the numerical simulation and experimental study of the surface structure of overplating evolution mechanism. Based on the parameter optimization process, the establishment of the integrated process of good compatibility, achieve high numerical aperture parameters controllable micro lens manufacturing and filling ratio up to 100% micro lens array, and the geometrical parameters and optical properties were measured. The main work as following Aspects: starting from the basic principle of electrochemical deposition, we present a numerical simulation model of microporous electrodeposition process. The model of the flow field distribution, reactive ion mass transport and electrochemical reaction coupling dynamics, the combination of mobile grid technology, realized the dynamic simulation of the cathode deposition surface. On the basis of the use of Co. element analysis of convective mixing effects on micro electro deposition process, and compared with the experimental results, and provide a theoretical basis for selection of experimental conditions. The subsequent electroforming forming regularity in phase overplating microporous electrodeposition has been studied in detail. By using the numerical calculation model is established in this paper, analyzed the influence factors of the structure size of the electrode and the deposition speed etc. on the evolution of overplating phase deposition surface. By electroforming experiment system was set up, carry out overplating deposition Experimental study on the process of exploration: pore size, depth width ratio of the structure, and the influence of current density conditions on overplating deposition process. Numerical calculation and experimental study results show that the pore size and the deposition velocity is small, the structure of overplating is more inclined to form a ball convex; and pore size and electrodeposition the greater the speed, is more inclined to form an intermediate low volcano overplating structure around. The measurement results show good stability of the subsequent process and repeatability. The method of the whole process include lithography, soft lithography and micro electroforming mold several stages, based on analyzing the influence mechanism of technology the parameters of each stage, studied the optimization of the process parameters, established the integrated process of good compatibility, the fabrication of micro lens and lens array. The change In lithography process parameters, satisfying the photoresist processing needs good stability following electroforming mask structure. Optimization of electrical parameters of micro electroforming deposition, improve the surface roughness, meet the surface precision of micro lens basic optical applications. The improvement of the soft lithography molding process, to achieve light curing adhesive on the lens die good filling, copying lens and lens array to obtain high precision without bubble defects. Through the measurement and evaluation of geometric parameters and optical properties of the mold of the micro lens and lens array. The micro imaging combined with image processing technology, through extracting and fitting contour measuring lens geometry parameters. On this basis, analysis evolution of the lens surface, the controllability of the process evaluation according to the relationship between lens geometry parameters and electroforming time. The results show that the time can be obtained by controlling the electroforming parameters A large numerical aperture microlens is built. Optical measurement platform is built to measure the focal length of lens. The optical properties of lens array with different fill ratios are measured. The results show that the lens array obtained by this method has good optical parameter consistency.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ153.4;TH74

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