A novel conditioning method for pad profile accuracy in full aperture polishing

Abstract

Full aperture polishing (FAP) is widely used as the final finishing process of large optical flats to obtain super smooth surface. The polishing pad is an important part in the FAP system, and its conditioning accuracy has a great influence on the polishing flatness of the component. However, the traditional full-aperture conditioning method (FCM) has been unable to meet the current use requirements, especially for large-size polishing plate. In this paper, we propose a subaperture fixed connection conditioning method (SFCCM), which reduces the size of conditioner and adds its movement. Based on the theory of multi-system kinematics and coordinate transformation, the formation mechanism of the surface profile error of pad is studied, the conditioning error transfer model is established, and the main error factors that affect the conditioning accuracy are pointed out. Through error compensation, the conditioning accuracy is improved. Experimental results showed that SFCCM has a better surface profile modification effect than FCM. Furthermore, the surface accuracy of the optical component of SFCCM is higher than that of FCM in the same FAP process.