In planar optics machining, surface flatness is a critical requirement for making high-quality optical devices. Chemical mechanical polishing (CMP) is an important process of smoothing surfaces for hard and brittle planar optics. Thus, there are growing interests in developing high-precision flatness on-machine measurement system for tin plate CMP process. However, the traditional evaluation measurement cannot meet the measurement accuracy requirement of approximate 2 μm. In this study, we propose an effective on-machine measuring system for the large-caliber optical tin plate, which consists of linear guideway, rotary table, and measuring sensor. In the system, the straightness error of the guideway and the axial runout error of the rotary table are compensated using a spiral method and the Keyence LK-G5000 measuring sensor. First, the spiral measuring path is formed by the movement of the line guideway and rotary table, which can prevent from multiple calibration. Then, the 3D flatness error of the dressing process is measured by linear movement of the LK-G5000 and the rotation of the tin plate. After the primary measurement process, the obtained 3D flatness error is compensated for straightness and axial runout error in sequence. To verify the accuracy of the flatness measurement, the tin plate is dressed by the natural diamond tool according to the measured 3D flatness error. After the dressing process, the peak-valley value of the remeasured flatness error can achieve 2.12 μm through a single-step dressing. The experimental results provide the accuracy and reliability of the high-precision on-machine flatness measurement system for the large-caliber tin plate.

中文翻译：

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大口径镀锡板化学机械抛光工艺平整度在机测量系统

在平面光学加工中，表面平整度是制造高质量光学器件的关键要求。化学机械抛光 (CMP) 是平滑硬脆平面光学元件表面的重要工艺。因此，开发用于马口铁 CMP 工艺的高精度平面度在机测量系统越来越受到关注。然而，传统的评估测量无法满足大约2μm的测量精度要求。在本研究中，我们提出了一种有效的大口径光学镀锡板在机测量系统，该系统由直线导轨、转台和测量传感器组成。在系统中，使用螺旋法和 Keyence LK-G5000 测量传感器补偿导轨的直线度误差和转台的轴向跳动误差。第一的，由直线导轨和转台的运动形成螺旋测量路径，可防止多次校准。然后，通过LK-G5000的直线运动和镀锡板的旋转来测量修整过程的3D平面度误差。在初步测量过程之后，获得的3D平面度误差依次补偿直线度和轴向跳动误差。为验证平整度测量的准确性，根据测得的3D平整度误差，用天然金刚石工具对镀锡板进行修整。修整后，通过单步修整，重新测量平整度误差的峰谷值可达到2.12 μm。实验结果为大口径镀锡板高精度在机平整度测量系统的准确性和可靠性提供了依据。