Patent ID: 7682858
Filing Date: 2010-03-23
Classification: B23K,B28D,H01L

Abstract:
1. A wafer processing method for dividing a wafer having function elements in areas sectioned by dividing lines formed on the front surface in a lattice pattern, into individual chips along the dividing lines, comprising: a deteriorated layer forming step for forming a deteriorated layer on the back surface of the wafer at a distance corresponding to the final thickness of the chip from the front surface of the wafer by applying a laser beam capable of passing through the wafer along the dividing lines from the back surface of the wafer; a dividing step for dividing the wafer into individual chips along the dividing lines by applying external force to the wafer in which the deteriorated layer has been formed along the dividing lines; and a back surface grinding step for grinding the back surface of the wafer divided into individual chips to remove the entire deteriorated layer and to form the wafer to the final thickness of the chip; wherein a protective tape affixing step for affixing a protective tape to the front surface of the wafer is carried out before the deteriorated layer forming step; and after the protective tape affixing step, a polish-processing step for polishing the back surface of the wafer is carried out before the deteriorated layer forming step.