Development of a surface encoder for next generation three-axis precision stages

本研究发展一种由正弦角栅及二维斜率感测器所组成之面形编码器，以应用于多自由度平面运动之量测。角网格具有三维微结构表面，其是X方向和Y方向上的周期性正弦波的叠加。基于激光的斜率传感器用于读取网格表面的局部斜率轮廓。X和Y位置以及围绕X、Y和Z轴的倾斜运动可以通过使用最大速度为550 mm/s的多个传感器来检测。一种用于XY平面内纳米级位置测量的双通道表面编码器。通过使用双通光学布局，传感器的灵敏度变为单通表面编码器的灵敏度的两倍。采用快速伺服金刚石车削的方法制作了角栅，并对角栅的加工精度进行了测试。所构造的快速刀具伺服系统采用压电陶瓷管作动器驱动刀具， ...更多信息 TE的金刚石工具和作为反馈传感器的电容探头，被证实具有约4 kHz的带宽和在闭环模式下的几个纳米的工具位移精度。基于干涉显微图像的二维离散傅里叶变换（DFT）的评价技术已被开发，以有效地评价制造的网格表面。φ150 mm网格面的加工结果表明了该系统的有效性。制作的角栅最小间距为10 μm。采用UV滚筒复制技术在大面积薄膜上制作角栅，并将表面编码器应用于表面电机驱动的工作台，实现五自由度的精密定位。表面电机由放置在同一表面上的成对线性电机组成。直线电机的磁性阵列和定子绕组分别安装在台板（移动元件）和载物台底座上。表面编码器的角栅安装在由空气轴承悬浮的载物台的台板上。倾斜传感器和空气轴承垫固定在载物台底座上，使得压板的运动不受电子电缆和空气软管的影响。表面编码器也已应用于索耶电机驱动的阶段。少

This research has developed a surface encoder consisting of a sinusoidal angle grid and a two-dimensional slope sensor for multi-degree-of-freedom planar motion measurement. The angle grid has a three dimensional micro-structured surface, which is a superposition of periodic sinusoidal waves in the X-and Y-directions. The laser-based slope sensor is used to read local slope profiles of the grid surface. The X-and Y-positions together with tilt motions about the X-, Y-and Z-axes can be detected by using multiple sensors with a maximum speed of 550mm/s. a double pass surface encoder for nanometer position measurement in the XY plane. By using a double pass optical layout, the sensitivity of the sensor becomes twice as much as that of the single pass surface encoder. A resolution of 2 nm has been realized.Diamond turning with a fast tool servo has been chosen as the fabrication method for the angle grid. The constructed fast tool servo, which employs a piezoelectric tube actuator to actua … More te the diamond tool and a capacitance probe as the feedback sensor, was confirmed to have a bandwidth of approximately 4 kHz and a tool displacement accuracy of several nanometers in the closed-loop mode. An evaluation technique based on the two-dimensional discrete Fourier transform (DFT) of interference microscope images has been developed to evaluate the fabricated grid surface effectively. The fabrication result of a grid surface over an area of φ150 mm has indicated the effectiveness of the fabrication system. The fabricated minimum pitch of the angle grid is 10 μm. A UV roller replication technique has also been developed to fabricate the angle grid on large area films.The surface encoder has been applied for surface motor-driven stages for five degree-of-freedom precision positioning. The surface motor consists of pairs of linear motors placed on the same surface. The magnetic array and the stator winding of the linear motor are mounted on the platen (the moving element) and the stage base, respectively. The angle grid of the surface encoder is mounted on the platen of the stage which is levitated by air-bearings. The slope sensors and the air-bearing pads are fixed on the stage base so that the motion of the platen is not affected by the electronic cables and air hoses. The surface encoder has also been applied to Sawyer motor driven stages. Less