| 摘要 |
<p>PURPOSE:To make possible a high-precision positioning of a wafer by a method wherein the wafer is supported by at least 3 pieces or more of rotatably supporting balls to support the rear of the wafer and at the same time, rotationally driving means, which come into contact to the peripheral surface of the wafer and rotate the wafer, are provided and the orientation flat of the wafer is positioned. CONSTITUTION:A wafer is supported its rear by 4 pieces of supporting balls 7 being provided rotatably on a supporting board 4 and at the same time, the peripheral surface on the side of the lower part of the wafer is supported by a pair of driving rollers 8 and 8 and a plurality of guide rollers 9. If a motor 12 is made to drive and the rollers 8 and 8 are rotated in a prescribed direction interlocking to the drive of the motor 12, the wafer is rotated by the frictional contact of the peripheral surface of it itself with each roller 8. Moreover, the wafer is also rotated with the rotation of each roller 8 and the orientation flat of the wafer comes into contact to the rollers 8 and 8 in a state to run parallel to the rollers 8 and 8. Whereupon, at this point of time, a laser beam detecting means 15 detects accurately the central position of the orientation flat and at the same time, as the rotation of the rollers 8 is stopped, the wafer results in being positioned on the board 4.</p> |
