| 摘要 |
PROBLEM TO BE SOLVED: To provide a polishing device with an internal gear, a sun gear, a lower surface plate and an upper surface plate smoothly rotated by using a frictional type of power transmission instead of a gear. SOLUTION: For a polishing device, an internal gear 30 and an sun gear 40 are provided to be engaged with a gear formed on the outer periphery of a carrier 65, in which a wafer is stored, so that the carrier 65 can be held between a lower surface plate 20 and an upper surface plate 50. With the rotational center C of the internal gear 30, the sun gear 40, a lower surface plate 20 and an upper surface plate 50, respective driving motors 21, 31, 41, 51 are symmetrically arranged. Driving pulleys 23, 33, 43, 53 fixed to the output shafts of the driving moors 21, 31, 41, 51 are put in frictional contact with the respective power transmission parts 35, 45, 25, 55 of the internal gear 30, the sun gear 40, the lower surface plate 20 and the upper surface plate 50 to rotate the internal gear 30, the sum gear 40, the lower surface plate 20 and the upper surface plate 50. As heating sources including the driving motors 21, 31, 41, 51 are symmetrically arranged, the possibility of great local heat enough for thermal deformation is eliminated. |
