| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to detect occurrence of an uneven wear in an abrasive pad and to detect a proper replacement timing for the abrasive pad.SOLUTION: A value of number of revolutions or a value of a rotational torque of a table drive shaft for rotationally driving a polishing table or a dresser drive shaft for driving a dresser, or a value of an oscillation torque of a dresser oscillation shaft for oscillating the dresser is detected at every predetermined times, an amount of change is calculated on the basis of detected value of number of revolutions, detected value of the rotational torque or detected value of the oscillation torque, and whether or not the amount of change exceeds a predetermined value is judged. When it is judged predetermined times that the amount of change exceeds the predetermined value, a warning is given to a user. |
