| 摘要 |
PROBLEM TO BE SOLVED: To provide a positioning device for preventing the bearing surface of a static pressure air bearing provided on the bottom surface of a mobile unit from coming into contact with a surface plate surface, by suppressing deformation by the dead weight of a stage surface plate and the weight of the mobile unit placed above. SOLUTION: The support on the rear surface of the stage surface plate 11 is provided at each of two locations, namely at one location in which a fixed guide 15 is attached, and another location at the opposite side (where the mobile unit most approaches the end face). Large chamfering is made to a corner at the side of the fixed guide to reduce the dead weight, thus extremely suppressing the deformation of the stage surface plate 11. The rear surface of the stage surface plate 11 is in a rib structure for reducing weight, so that supports at three locations are arranged at a position in which a rib crosses. Further, the center of a pre-load magnet unit is arranged near a place above a circle passing through the center of the static pressure air bearing provided on the bottom surface of an XY slider 14, thus also suppressing the deformation of the stage surface plate 11 by the difference between the repulsion of static pressure air and the operation of pre-load suction force. COPYRIGHT: (C)2005,JPO&NCIPI |
