Optics and Precision Engineering, Volume. 23, Issue 8, 2220(2015)
Motion-precision control in bonnet-polishing
To meet the ultra-high precision manufacture demands of spherical surfaces and aspherical surfaces in an optical system of Deep Ultra Violet (DUV) and Extreme Ultra Violet (EUV), a series of motion-precision control methods in bonnet-polishing were proposed. Firstly, the temperatures of main operation units were finely controlled to allow the motion-precision of polishing to be to 50 μm. Then, the coordinates transmitting method was used to guarantee the two-dimension unity between measured data and operating data to be 0.30 -0.70 mm. Furthermore, the convergence efficiency of surface-error in fine polishing was improved by bonnet removal estimation method and feedback correction method. Finally, the vertical position accuracy between bonnet and work piece was improved to 10 μm by probing-correction method. The experiment results on a actual polishing by using motion-precision control methods indicate that the surface machining accuracy is 0.8 nm(RMS) in polishing a flat with a diameter of 280 mm , and that is 1.1 nm(RMS) in polishing a concave with a diameter of 160 mm. The proposed methods realize ultra-high precision polishing for spherical surfaces and aspherical surfaces, and they are also suitable for other contact small tool computer controlled polishing.
Get Citation
Copy Citation Text
WANG Fei, ZHANG Jian, PENG Li-rong, WANG Gao-wen, SUI Yong-xin. Motion-precision control in bonnet-polishing[J]. Optics and Precision Engineering, 2015, 23(8): 2220
Received: Aug. 25, 2014
Accepted: --
Published Online: Oct. 22, 2015
The Author Email: Fei WANG (wangf@sklao.ac.cn)