| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for detecting the overlap of a workpiece and a carrier in double-sided polishing device. <P>SOLUTION: At least two eddy current sensors 22 are provided in an empty space formed in an upper platen 11 of the double-sided polishing device. After the workpiece 16 is loaded in a workpiece-holding hole of the carrier 15 and the upper platen is lowered, when a distance to an upper surface of the carrier is detected by the eddy current sensors, it is determined that the workpiece and the carrier are superposed in the case where a value larger than a preset reference value is detected by at least one of the eddy current sensors, or in the case where a difference between the values respectively detected by the two eddy current sensors is larger than the preset value. When the overlap of the workpiece and the carrier is detected, an alarm is given to an operator to load the workpiece again. <P>COPYRIGHT: (C)2008,JPO&INPIT |
