| 摘要 |
PROBLEM TO BE SOLVED: To prevent vibration of bearing and to eliminate the mechanical adjusting thereof by forming at least one supporting face, on which a fluid flows, between a fluid source and a discharge pipe and supporting a polishing pad assembly by a fluid flowing on the supporting face. SOLUTION: One fluid bearing 34 is larger than other four bearings and located in the center. Four remaining fluid bearings 34 are located symmetrically around the central fluid bearing. Each fluid bearing has a central fluid inlet 36 to be coupled with a pressurized fluid source, and an annular fluid outlet 38 extending around the fluid inlet 36. Each fluid outlet 38 can be coupled with a fluid discharge pipe having lower pressure than the fluid source. A recess region 26 between the fluid inlet 36 and the fluid outlet 38 forms a supporting face 40. In the operation, a fluid is pumped up through the fluid inlet 36 and discharged from the fluid outlet 38 through the supporting face 40. Consequently, a fluid film is formed on the supporting face 40 and the hemispheric face 30 of a platen 28 is supported through the fluid film. |
