Patent ID: 8927395
Filing Date: 2015-01-06
Classification: B23K,H01L

Abstract:
1. A wafer processing method to divide a wafer on which a plurality of planned dividing lines are formed in a lattice manner on a front surface and devices are formed in a plurality of areas partitioned by the plurality of planned dividing lines, into individual devices along the planned dividing lines, the wafer processing method comprising: a modified layer forming step of forming a modified layer inside the wafer along the planned dividing lines by irradiating the wafer with a laser beam with such a wavelength as to be transmitted through the wafer from a back surface side of the wafer along the planned dividing lines, and a dividing step of dividing the wafer into the individual devices along the planned dividing lines along which the modified layer is formed by applying an external force to the wafer after said modified layer forming step, wherein said modified layer forming step includes