| 摘要 |
A method of cleaving a strip by tensile stress applied by a pulse laser point heat source by shifting a pulse-heating position of the pulse laser point heat source on the basis of both an optimum distance "D" of a center position of a pulse beam spot of the pulse laser point heat source irradiated on the strip from a tip of a crack of the strip and an optimum pulse time "t" of the pulse laser point heat source, wherein the optimum distance "D" is determined by the steps of: selecting "t" to find a value of 4 kappa t/W2 where " kappa " is a thermal diffusivity of the strip, "W" is a width defined as a distance between a cleaving-intended line and a side edge of the strip; and finding an optimum value of D/W from the value of 4 kappa t/W2 with reference to a previously obtained relationship between the optimum value of D/W and the value of 4 kappa t/W2 thereby to find the optimum distance "D". The optimum distance "D" is found so that if the value of 4 kappa t/W2 is in the range of 0.0001-0.05, then the optimum value of D/W is 0.1, if the value of 4 kappa t/W2 is in the range of 0.05-1.0, then the optimum value of D/W is 0.2, and if the value of 4 kappa t/W2 is not less than 1.0, then the optimum value of D/W is 0.4.
|
