荫罩母板精密自动对准系统的研究

发布时间：2018-01-14 17:26

本文关键词：荫罩母板精密自动对准系统的研究　出处：《南京师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以荫罩母板自动对准过程中位置偏差检测及整个系统控制技术的研究与实现为论题,建立了光束经透射式双光栅衍射后产生的各次叠栅光强与光栅位移的数学模型,并通过MATLAB对光栅模型进行了仿真实验,得出其变化规律。仿真结果表明,衍射叠栅光强信号可以直接反应出位移的变化,信号强度随两片光栅的相对微位移呈周期性变化,因而叠栅信号可用于荫罩母板微位移测量。建立了荫罩母板复合式双驱动对准系统,为实现大行程高精度对准奠定了基础。本课题设计的复合式双驱动对准系统是由宏对准与微对准两部分结合而成的。宏对准是依靠步进电机带动精密滚珠丝杠组成的宏动台,根据粗光栅检测获得的位移信号,来发出相应的脉冲指令驱动宏动台,使下动板移动到既定的对准范围内,完成宏对准,对准精度可达到±220μm,工作行程为1000mn。宏对准结束后,计算机再根据细光栅检测信号的大小,发出相应的驱动电压,驱动压电陶瓷产生相应的动力,带动柔性铰链发生相应的形变,完成微小位移的对准,系统最终实现了±100nm荫罩母板对准精度,兼顾了工作行程和对准精度两方面的要求。针对压电陶瓷存在非线性,精确数学模型难于建立的缺陷,提出了荫罩母板精密对准的自适应模糊控制,并给出了相应控制流程。实验结果表明,设计的控制方案缓解了压电陶瓷及对准系统本身存在的非线性问题,实现了系统控制的快速响应和高稳定性,有效提高了对准速度和对准精度。
[Abstract]:In this paper, the research and realization of the position deviation detection and the control technology of the whole system in the automatic alignment process of shadow mask motherboard are discussed. The mathematical model of the intensity and displacement of the superimposed grating produced by the transmission double grating diffraction is established, and the simulation experiment of the grating model is carried out by MATLAB. The simulation results show that the light intensity signal of the diffracted grating can directly reflect the change of the displacement, and the signal intensity varies periodically with the relative micro-displacement of the two gratings. Therefore, the stacked grid signal can be used to measure the micro-displacement of the shadow mask motherboard, and a compound dual-drive alignment system for the shadow mask motherboard is established. The compound double drive alignment system designed in this paper is composed of macro alignment and micro alignment. Macro alignment is a precision ball screw set driven by step motor. Into a macro platform. According to the displacement signal obtained by the coarse grating detection, the corresponding pulse instruction is issued to drive the macro moving table, so that the lower moving plate moves to the established alignment range, and the macro alignment is completed, and the alignment accuracy can reach 卤220 渭 m. The working stroke is 1000mn.After the macro alignment is finished, the computer sends out the corresponding driving voltage according to the size of the detection signal of the fine grating, and drives the piezoelectric ceramics to produce the corresponding power. The deformation of flexure hinge is driven to achieve the alignment of small displacement. Finally, the alignment accuracy of 卤100nm shadow mask motherboard is achieved. Considering the requirements of working stroke and alignment accuracy, an adaptive fuzzy control for precision alignment of shadow mask motherboard is proposed to solve the problem of nonlinear and difficult to establish accurate mathematical model of piezoelectric ceramics. The experimental results show that the proposed control scheme alleviates the nonlinear problem of the piezoelectric ceramics and the alignment system, and realizes the fast response and high stability of the control system. The alignment speed and precision are improved effectively.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN141.32

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