| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the extension of a crack from the adjacent initial cracks of a wafer narrow in dividing interval. SOLUTION: A plurality of initial cracks 12, 13-1 are formed to one side 11a of an almost square wafer 11 composed of a fragile material and the wafer 11 is irradiated with laser beam to be heated in the vicinity of the initial cracks 12, 13-1 and the initial cracks 12, 13-1 are advanced by heat stress to divide the wafer 11. In this method, a plurality of the initial cracks 12, 13-l are made different in length between the adjacent initial cracks. The vicinity of the long initial crack 13 among the adjacent initial cracks 12, 13-1 is prefentially heated by the irradiation with laser beam to advance a crack from the initial cracks 12, 13-1.</p> |
