| 摘要 |
PROBLEM TO BE SOLVED: To provide a sub chuck table which allows displacement of a plate-like object to be appropriately detected.SOLUTION: A sub chuck table (16) is arranged in the vicinity of a chuck table (14) and has on an upper face thereof a rectangular holding face (16a) that suctions and holds a plate-like object (11). On the holding face is formed a latticed suction groove (48) which includes a plurality of vertical grooves (48a) and a plurality of lateral grooves (48b) and connects to suction paths (50) communicated with the suction means. At outer edges of the holding face corresponding to two adjacent sides are arranged abutting walls (52a and 52b), which are smaller in height than a thickness of the plate-like object, and to which a side face (11c) of the plate-like object is abutted when placing the plate-like object. The vertical grooves and the lateral grooves positioned at outermost edges of the holding face respectively have end parts (48c) extended from intersection points between the vertical grooves and the lateral grooves toward the abutting walls.SELECTED DRAWING: Figure 3 |
