| 摘要 |
PURPOSE:To reliably detect the ideal state of flatness of a polishing surface by a method wherein, during polishing of a work, vibration in the vicinity of the inner and outer peripheries of an upper surface plate is detected and through comparison between vibration signals for the vicinity of the inner periphery and the vicinity of the outer periphery, abnormality of of flatness of the polishing surfaces of upper and lower surface plates is detected. CONSTITUTION:When a work W is polished, the work W is inserted through the holding hole 4a of a planetary gear 4, an upper surface plate 3 is placed thereon, and pressurization is applied at a constant pressure. By rotating a solar gear 2a by a motor 1, the upper and under surfaces of the work W held by the planetary gear 4 are polished through the medium of slurry-like grinding grains by upper and lower surface plates 3 and 5. In this case, vibration in the vicinity of the inner and outer peripheries of the upper surface plate 3 is detected by vibration detecting means 9 and 10. After each detecting signal is amplified at 11, and the signal is fed to an analyzing 12 to analyze the degree of vibration. The degrees of vibration in the vicinity of the inner and the outer peripheries are compared with each other by a comparing means 13. When a difference in the degree of vibration or a quotient attains a reference value, it is decided that the degrees of flatness of the polishing surfaces of the surface plates 3 and 5 are abnormal and operation of a polishing device body A is stopped. |
