METHOD OF DIVIDING SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a method of dividing a substrate which improves productivity in dividing the substrate having a reinforcement layer on a surface in which compression stress is generated using a laser beam.SOLUTION: The method of dividing a substrate includes the steps of: irradiating, by a laser beam oscillation unit 21, with a laser beam of a wavelength of 355 nm or greater and 1064 nm or less having transmissivity to a reinforced glass substrate W that has a reinforcement layer on a surface in which compression stress is generated, so that the laser beam focuses at a position in the substrate of about 20% or greater and 80% or less of a substrate thickness from a bottom; and repeating for a plurality of times to scan the laser beam along a line to be divided until the substrate W is divided, while the laser beam focus is kept at the same depth.