| 摘要 |
<p>PURPOSE:To enable a wafer to be positioned accurately even if it is slightly eccentric by allowing an optical sensor to be supported to a movable member which is positioned at a fixed position near an outer periphery of the wafer and by allowing the wafer to be rotated while a plurality of rollers which are provided at the movable member are in contact with a peripheral edge of the wafer. CONSTITUTION:A rear edge of an arm 20 is mounted on a bracket 9 so that it can rotate freely by a vertical spindle 19 and then a rocking member 22 which rotates around a vertical spindle 21 is attached to a tip of this arm 20. An optical sensor A consists of a photoelectric element 23 and a light source 24 and the photoelectric element 23 is fixed to a supporting piece 25 at a front lower side of the rocking member 22 and the light source 24 is fixed to a support piece 26 at a front upper side of the member 22. A roller 32 is fitted to a protruding part of both sides at a front of the rocking member 22 by a vertical spindle and is allowed to contact an outer periphery of the wafer 6 with it as a contact part. When detecting a detection part such as an orientation flat or a notch which are provided at a peripheral edge of the wafer by the optical sensor, the optical sensor always detects a part which is away from the peripheral edge of the wafer by a fixed distance, thus enabling the orientation flat or notch of the wafer to be detected accurately.</p> |
