| 摘要 |
PROBLEM TO BE SOLVED: To provide a grinding wheel which prevents a ground portion from remaining in a ring-shape between an outer peripheral end of a bottom surface of a circular recessed portion and a lower end of an inner peripheral surface of a ring-shaped reinforcing portion.SOLUTION: A grinding wheel 22 grinds a back surface of a wafer to form a circular recessed portion and a ring-shaped projecting portion surrounding the circular recessed portion on an outer periphery of the wafer. The grinding wheel 22 is equipped with a plurality of grinding wheel 54 arranged in a ring-shape, which passes through a center of the wafer and has an outer diameter smaller than a radial of the wafer, when the wafer is positioned at a ground position; and a wheel base stand 46 for supporting the plurality of grinding wheel 54 arranged in the ring-shape. Each of the grinding wheel 54 is formed from a sintered grinding wheel 56 made by sintering abrasive grains with a bonding material, and an electrocasting grindstone 58 made by fixing the abrasive grains coated on the outside of the sintered grinding wheel 56 with plating. |
