基于辉光放电二维模型数值模拟及实验的玻璃清洗研究

发布时间：2018-04-18 02:30

本文选题：玻璃清洗 + 等离子体　；参考：《东北大学》2014年硕士论文

【摘要】：真空玻璃的优点很多,但至今仍未实现普及,这与玻璃表面的气体吸附与放气密不可分。传统的加热方法不能满足对大面积玻璃清洗的要求,采用在真空环境中用等离子体对玻璃表面进行轰击清洗的方法,可以得到干净、含气量少的玻璃表面,提高了真空玻璃的质量和寿命,因此该方法具有很好的研究和应用前景。现阶段关于等离子体清洗的研究局限于微电子、平板电脑显示器等行业,对大面积的建材玻璃清洗的研究几乎空白。本文从玻璃清洗设备放电结构的设计出发,利用COMSOL Multiphysics软件,建立数学模型和几何模型,以相对简单的放电清洗结构为基础,用一种经过修正的流体模型,针对放电电极带电的正负、工作电压、工作气压等工艺参数进行了模拟,分析了等离子体的特性对玻璃清洗的影响。通过模拟得到等离子体密度分布云图、电子温度云图、离子流密度曲线等结果。比较模拟结果发现：放电电极带负电清洗效果要好于电极带正电,其原因是电极带负电时可以充分利用玻璃的悬浮电位,电子和正离子同时完成清洗且清洗过程可连续；随着放电电压的增加,荷电粒子的能量增加,但是由于电场变强,电极对正离子的吸引力增大,导致离子流密度不均匀,综合考虑后选出最优工作电压为-1000V；随着工作气压的增加等离子体离化率增加,但由于碰撞增多导致荷电粒子能量降低,综合比较后选择最优工作气压为8Pa。本文中,还对玻璃清洗的结构参数进行了模拟分析,包括电极的截面形状,电极与玻璃之间的距离h、工作室宽度H、电极之间的距离L、电极的排列形式等。其中对清洗设备结构的尺寸参数的优化设计基于正交试验,通过按照正交表进行的模拟得到一组最优的参数组合,即：h=12.5mm,H=35mm、L=25mm,理论分析其原因为这组参数工作室宽度比其余组小,在四个角落被电离的氩离子距最外侧的电极较近,受外侧电极的引力距离短,氩离子依靠初速度会冲过外侧电极吸引到达玻璃中间区域,因此玻璃的清洗效果会更好。这组参数对玻璃清洗设备的设计与真空玻璃生产线的设计具有重要的指导的意义。通过模拟发现电极截面形状为圆形的清洗效果要好于电极截面形状为方形时；电极双排排列清洗效果要好于电极单排排列。这些结果都将对清洗设备的改进起到促进作用。本文在优化得到的结果的基础上,进行了相似设备的实验验证。实验结果表明清洗工作电压为-1000V时,清洗过的玻璃表面十分干净平整；工作电压为-1500V时,清洗过的表面也很干净,但会导致玻璃表面产生溅射凹坑使得玻璃表面不平整,不利于下道工序镀膜的进行。后又在计算机中针对实验设备的结构进行建模模拟,模拟结果为电压为-1500V时电子能量为50eV,大于玻璃的溅射阈能,导致玻璃表面轻微溅射。通过实验及实验模型的模拟验证了本文方法和结果的正确性,完全可以用于指导玻璃清洗设备的改进优化和工艺参数优化。本文结果对玻璃清洗设备的工艺参数优化、结构设计和对现有设备的改进具有实际的指导作用和参考价值。
[Abstract]:Many of the advantages of vacuum glass, but has not yet achieved popularity, it is inseparable with the adsorption and gas gas glass surface. The traditional heating method can not meet the requirements of large area glass cleaning, used in vacuum environment on glass surface by plasma bombardment cleaning method for washing, can get clean, containing less gas of glass surface and improve the quality and service life of the vacuum glass, so this method has good research and application prospects. At the present stage of research on plasma cleaning limited in microelectronics, flat-panel computer monitors and other industries, research on building glass cleaning large area is almost blank. This article from the design of glass cleaning equipment discharge structure of the use of COMSOL Multiphysics software, established the mathematical model and the geometric model, in order to discharge cleaning a relatively simple structure based on a modified model of fluid after The discharge electrode, positive and negative charged working voltage, working pressure and other parameters were simulated, analyzed the influence of plasma characteristics of glass cleaning. The plasma density distribution is obtained by simulation, electron temperature nephogram, ion current density curve results. The simulation results show that the discharge electrode with better cleaning effect in the negative the reason is that the positively charged electrode, electrode with negative charge can make full use of the floating potential of glass, electrons and positive ions at the same time to complete the cleaning and the cleaning process can be continuous; with the increase of discharge voltage, the charged particle energy increases, but due to strong electric field, attractive electrode on the positive ion increases, the ion current density does not lead to even after considering the optimum operating voltage is -1000V; with the increase of pressure plasma ionization rate increase, but due to the collision resulted from the increase in load The electric energy of particles is reduced, after comprehensive comparison to select the optimal working pressure is 8Pa. this paper, the structure parameters of glass cleaning are analyzed, including the section shape of the electrode, the distance between the electrode and the glass studio h, width of H, the distance between the electrodes L, electrode arrangement. The optimum design parameters the structure of cleaning equipment based on orthogonal test, get a set of optimal parameters through simulation according to the orthogonal table: h=12.5mm, H=35mm, L=25mm, theoretical analysis of the reasons for this set of parameters is higher than that of the other group studio width is small, in the four corners by electrode argon ionization from the outside is near by the gravity of the outer electrode, short distance, initial velocity will depend on argon ion across the outer electrode to attract the glass in the middle area, so the cleaning effect of the glass will be better. This set of parameters on glass cleaning equipment Has the important guiding design of vacuum glass production line significance. According to the simulation of electrode section shape for the better cleaning effect on circular electrode section is in the shape of a square; the double electrode arrangement of cleaning effect is better than single row electrode. These results will be improved for cleaning equipment based plays a promoting role. In the optimized results, verified similar equipment. The experimental results show that the cleaning working voltage is -1000V, the glass surface washed very clean and smooth; the working voltage is -1500V, the surface cleaning is very clean, but will lead to the glass surface sputtering pit so that the glass surface is not flat, not for the next step. After coating and in the computer structure according to the experimental equipment of modeling and simulation, the simulation results for the voltage of -1500V electron energy is 50eV, The sputtering threshold is greater than that of the glass can lead to slight surface sputtering. Through simulation experiments and experimental model to verify the correctness of the method and the results, can be used for guiding glass cleaning equipment improvement and optimization of process parameters. The process parameters on the glass cleaning equipment optimization, structure design and improvement of the existing equipment with practical guidance and reference value.

【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TQ171.7;TB490

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