Patent ID: 8685839

Claim:
A workpiece dividing method for dividing a workpiece having a plurality of division lines formed on a front side of said workpiece for partitioning a plurality of regions where a plurality of devices are respectively formed, wherein an adhesive tape having an adhesive surface and a pear-skin surface opposite the adhesive surface as an exposed surface is attached to the back side of said workpiece on said adhesive surface, said workpiece dividing method comprising: a planarizing step of applying a liquid resin to said exposed surface of said adhesive tape and then curing said liquid resin to thereby planarize said exposed surface of said adhesive tape; a modified layer forming step of applying a laser beam having a transmission wavelength to said cured resin, said adhesive tape, and said workpiece from the side of said exposed surface of said adhesive tape to said workpiece in the condition where the focal point of said laser beam is set at a predetermined depth in said workpiece after performing said planarizing step, thereby forming a plurality of modified layers in said workpiece along said division lines; and a dividing step of applying an external force to said workpiece after performing said modified layer forming step, thereby dividing said workpiece along said division lines as starting from said modified layers formed in said workpiece as a break start point.