Patent ID: 7446022
Filing Date: 2008-11-04
Classification: B23K

Abstract:
1. A laser processing method for forming a groove in a wafer with a protecting film thereon, along a predetermined dividing line, said wafer including a substrate having a processing surface on which is formed said protecting film, said method comprising the steps of: applying to the protecting film, along the dividing line, a first pulse laser beam that is set to a first output which can process the protecting film but cannot process the substrate under the protecting film, to form a first groove in the protective film along the dividing line; applying along the dividing line a second pulse laser beam that is set to a second output which is higher than the first output and which can process the substrate, to form a second groove in the substrate along the dividing line; wherein the first pulse laser bean and the second pulse laser beam are applied by a common laser beam application means; and removing the protective film and dividing the wafer by mechanical breaking along the dividing line.