Patent ID: 7439162

Claim:
A wafer dividing method for dividing into individual devices a wafer whose front surface is divided into a device area in which a plurality of devices are divided by streets and formed and a peripheral margin area surrounding the device area, the wafer dividing method comprising: a recessed portion forming step of affixing a protective member to the front surface of the wafer, grinding a rear surface side of said device area to form a recessed portion, and forming an annular reinforcement part that includes a peripheral margin area on an outer periphery of said recessed portion; a uniform thickness processing step of removing said annular reinforcement part by grinding a rear surface of said annular reinforcement part or cutting away said annular reinforcement part so as to give said wafer a uniform thickness; a street position location step of locating positions of said streets formed on the front surface of the wafer by infrared imaging from the rear surface side of said wafer; a division step of cutting along the streets located in said street position location step from the rear surface side of the wafer and dividing the wafer into individual devices; and a dicing frame support step of affixing dicing tape to the rear side of the wafer divided into devices, supporting the wafer with a dicing frame, and peeling said protective member off the front surface of said wafer.