| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a laser beam machining method which is capable of cutting an object for machining without the occurrence of melting and a crack deviating from a planned cutting line on the surface of the object for machining. SOLUTION: This laser beam machining device 100 has a laser beam source 101 which emits a laser beam L below 1μs in pulse width, a condenser lens 105 which condenses the laser beam in such a manner that the peak power density of the condensing point P of the laser beam attains >=1×10<8> (W/cm<2> ), numerical aperture adjusting means 405 which adjusts the numerical aperture of an optical system including the condenser lens, means 113 which aligns the condensing point to the inside of the object 1 for machining, means 109 and 111 which move the condensing point along the planned cutting line 5 and means 127 which previously stores the correlativity between the numerical aperture and the size of the reforming spot and selects the numerical aperture capable of forming the reforming spot to the inputted size. The numerical aperture adjusting means adjusts the numerical aperture in such a manner that the selected numerical aperture is attained.</p> |
