| 摘要 |
PROBLEM TO BE SOLVED: To provide a processing method in which a wafer is irradiated with a laser beam along a predetermined division line to form a modified layer, a rear face is then ground into finished thickness, and at the time of division into devices, the devices are prevented from being damaged by rubbing corners of the devices with each other.SOLUTION: A processing method of a wafer for dividing the wafer on which devices 22 are formed, along a predetermined division line includes: a process of irradiating the wafer with a laser beam while matching a convergent point with the inside of the wafer and forming a modified layer which becomes a fracture origin; and a rear face grinding process of grinding a rear face of the wafer to form the wafer with predetermined thickness and dividing the wafer into devices 22 along the predetermined division line. Before implementing grinding, a protection member 4 cooled to a temperature which is lower than the temperature at the time of implementing grinding is affixed to a front face of the wafer, and a gap S is formed between the divided devices 22 and 22 by thermally expanding the protection member 4 by temperature rise when implementing the rear face grinding process, thereby preventing neighboring devices 22 from contacting. |
