| 摘要 |
PURPOSE:To turn a chuck roughly and finely by a method wherein a wafer chuck is supported on a supporter using balls, both ends of V type link are fixed to the central part of the chuck and peripheral part through the intermediary of elastic fulcrums and an electrostrictive element is provided also through the intermediary of the elastic fulcrums. CONSTITUTION:A roller 19 is shifted by a motor 22 through a cam 21 to turn a wafer chuck 32 centered on balls 2 and the chuck 32 supported on the supporter by the balls 2 is located by the rapid calculation of the rough turning angle by the cam 21. The minutely turning position of the chuck 32 may be also located by elongation and contraction due to voltage fluctuation of the current distortion element 18 bending each fulcrum in respective direction and turning the chuck 32 centered on the balls 2, because a V type link 20 and an electrostrictive element 18 are supported respectively by the fulcrums 15, 16 and 16, 17 between the parts 12 and 13 of the chuck 32. Besides, the original turning point of the cam 21 is detected by a dog 27 and a senser 26 while the abutment of the chuck 32 against a stopper 7 is detected by sensers 28, 29 and dogs 30, 31. Through this constitution, the chucked wafer 32 may be aligned with a specified mask rapidly and accurately. |
