Patent ID: 7772092
Filing Date: 2010-08-10
Classification: B23K,H01L

Abstract:
1. A method of processing a wafer having a plurality of devices which are composed of a laminate consisting of an insulating film and a functional film on the front surface of a substrate, along streets for sectioning the plurality of devices by using a laser beam processing machine that comprises a chuck table for holding a workpiece, which is arranged in such a manner that it can move in a processing-feed direction, a first laser beam application means having a first condenser for applying a laser beam to the workpiece held on the chuck table, a second laser beam application means having a second condenser for applying a laser beam to the workpiece held on the chuck table, which is spaced at a predetermined distance in the processing-feed direction from the first condenser, a processing-feed means for moving the chuck table in the processing-feed direction, an indexing-feed means for moving the chuck table in an indexing-feed direction perpendicular to the processing-feed direction, and a condenser position adjustment means for adjusting the relative positions in the indexing-feed direction of the first condenser and the second condenser, the method comprising: a first blocking groove forming step for forming a first blocking groove in the laminate from one end toward the other end in a one-side portion in the width direction of a street of the wafer by positioning the one-side portion in the width direction at one end of the street of the wafer held on the chuck table at the application position of a laser beam to be applied from the first condenser of the first laser beam application means and activating the first laser beam application means to apply a laser beam having an output capable of dividing the laminate while moving the chuck table in a first processing-feed direction; and a second blocking groove and a dividing groove forming step for forming a second blocking groove in the laminate from the other end toward the one end in the other-side portion in the width direction of the street of the wafer by positioning the other-side portion in the width direction at the other end of the street which has undergone the first blocking groove forming step at the application position of a laser beam to be applied from the first condenser of the first laser beam application means and activating the first laser beam application means to apply a laser beam having an output capable of dividing the laminate while moving the chuck table in a second processing-feed direction and at the same time, forming a dividing groove in the laminate and the substrate from the other end toward the one end along an intermediate portion between the first blocking groove and the second blocking groove formed in the street of the wafer by positioning the application position of a laser beam to be applied from the second condenser of the second laser beam application means at a position corresponding to the center portion in the width direction of the street which has undergone the first blocking groove forming step on a downstream side in the second processing-feed direction of the application position of a laser beam to be applied from the first condenser and activating the second laser beam application means to apply a laser beam having an output capable of forming the dividing groove in the laminate and the substrate.