US Patent 7648850 Method for producing semiconductor chip

A method for producing many semiconductor chips, each having a semiconductor circuit disposed on the face thereof and a die bonding film stuck to the back thereof, from a semiconductor wafer in which many rectangular regions are defined on its face by streets arranged in a lattice pattern, and the semiconductor circuit is disposed in each of the rectangular regions. The method comprises: a groove formation step of forming grooves of a predetermined depth along the streets on the face of the semiconductor wafer; a protective film sticking step of sticking a protective film to the face of the semiconductor wafer, where the grooves have been formed; a division step of grinding the back of the semiconductor wafer to render the thickness of the semiconductor wafer equal to or smaller than the depth of the groove, thereby dividing the rectangular regions individually; a die bonding film/holding film sticking step of sticking a die bonding film and a holding film, in this order, to the ground back of the semiconductor wafer; a protective film peeling step of peeling the protective film from the face of the semiconductor wafer; a spacing increasing step of stretching the holding film to increase spacing between the individually divided rectangular regions; and a die bonding film cutting step of irradiating the die bonding film with a laser beam from the face side of the semiconductor wafer through the clearance between the rectangular regions to cut the die bonding film along the clearance between the rectangular regions.