To improve working precision and moreover to reduce thermal effect to devices such as a LSI in the case of working a semiconductor wafer or the like.
In this working method, a crack formed in the working start point of a material is guided along a predetermined splitting line with thermal stress by irradiation generating with the application of the heat source of a laser beam or the like. In this case, the material is irradiated with such a band shaped heat source B that the diameter in the direction along the predetermined splitting line L becomes long while the diameter in the rectangular direction becomes short. Whereby, the temperature distribution having a steep grade in the vicinity of the crack end is formed without rising the power density of the heat source.
OKIYAMA TOSHIHIRO
SHIRAHAMA HIDEYUKI
OONITA EISHIN
SUENAGA TOMOHIRO
KINOSHITA KOICHI
MAEKAWA SHUNICHI
MORITA HIDEKI
NAGASAKI PREFECTURE
JAPAN RES DEV CORP
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