WORKPIECE HOLDER AND METHOD USING SAME FOR DETECTING LATERAL DISPLACEMENT OF WORKPIECE

摘要

Provided are a workpiece holding apparatus capable of detecting lateral displacement of a workpiece (w) in a planar direction, and a method of detecting lateral displacement of a workpiece (w) with use of the workpiece holding apparatus. The workpiece holding apparatus, which is configured to hold the workpiece (w), with an adhesive pad (2) mounted on a support plate, includes: a capacitance measuring device (5) including an electrode pair formed of first and second electrodes (3a, 3b) and arranged at least at a part of a position corresponding to a peripheral edge portion of the workpiece (w), the capacitance measuring device (5) being configured to measure capacitance of the electrode pair; and a comparator circuit (6) configured to compare the measured capacitance with a predetermined reference value, to thereby detect lateral displacement of the workpiece (w) in a planar direction of the support plate (1). Further, the method of detecting lateral displacement of a workpiece (w) includes comparing the capacitance input to the comparator circuit (6) with a predetermined reference value, to thereby detect the lateral displacement of the workpiece (w).

主权项

1. A workpiece holding apparatus, which is configured to hold a workpiece with an adhesive pad mounted on a support plate, the workpiece holding apparatus comprising:
a capacitance measuring device comprising an electrode pair formed of first and second electrodes and arranged at least at a part of a position corresponding to a peripheral edge portion of the workpiece, the capacitance measuring device being configured to measure capacitance of the electrode pair; and a comparator circuit configured to compare the measured capacitance with a predetermined reference value, to thereby detect lateral displacement of the workpiece in a planar direction of the support plate.