| 摘要 |
PROBLEM TO BE SOLVED: To measure the worn amount of a grinding wheel or polishing cloth accurately without the drop of the efficiency of the grinding work of a wafer. SOLUTION: As the worn amount of cup type grinding wheels 54, 64 is measured by a non-contact type worn amount measuring instrument 68 consisting of a floodlight 70 and optical receiver 72, the worn amount measuring instrument 68 can be fixingly arranged to the position in which the polish of the wafer 26 by the cup type grinding wheels 56, 64 is not disturbed. As it is unnecessary that the worn amount measuring instrument 68 is moved to a measuring position at every measurement like the worn amount measuring instrument of a contact type like a limit switch and after finishing the measurement the worn amount measuring instrument 68 is moved to an original position, a polishing efficiency can be measured so as not to drop. |
