A dressing method comprises the steps of rotating a rotary dresser at a high speed for dressing a surface of the grindstone, previous to contact of the rotary dresser with the surface of the grindstone, and detecting a rotational vibration caused by a bearing adapted to support the rotary dresser in rotation, by use of a vibration sensor for detecting a contact vibration having a specific frequency band generated when the rotary dresser in rotation comes into contact with the grindstone. Providing that the rotational vibration has been detected, an output signal from the vibration sensor is judged to be active, allowing the grindstone to be dressed. Prior to the execution of the dressing, failures in the vibration sensor and other deficiencies are detected.
A chemical-mechanical polishing apparatus includes a polishing pad, a polishing table, a wafer holder, a dresser for setting the polishing pad each time after a specified number of wafers are chemically and mechanically polished; and a conditioning controller for controlling the conditions of setting the polishing pad based on a polishing rate and a required length of polishing time. The chemical-mechanical polishing apparatus can suitably correct, after every polishing of the specified number of wafers, the setting conditions of the polishing pad and can properly conduct the subsequent polishing.
A movable frame assembly to move a device for dressing a grinding wheel for the sharpening an ice skate blade. The device uses a housing surrounding a grinding wheel and movable frame with a swing arm. A dressing tool is mounted in the dresser swing arm and the dresser swing arm is rotatable between a storage position and an operating position. The movable frame assembly slides along rails to allow positioning of the dressing tool into the grinding wheel. Horizontally and vertically disposed bearings are positioned beside and under a rail with resiliently biased bearings are held against the top of the rail. The bearings help the rails of the movable frame move smoothly. The rails are spaced apart by yokes on the arm or a bar across the top of the dresser to prevent binding as the movable frame is slid for dressing the wheel. Adjustment of the rails is also provided for by adjustment slots at the back of the rails.
