Laser machining device and laser machining method
AssigneeTokyo Seimitsu Co., Ltd.
InventorTakao Shionoya
Life of this patent
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Abstract
Provided are a laser machining device and a laser machining method capable of stably operating an autofocus function without causing an unfavorable state such as an overshoot etc. A laser machining device and a laser machining method of the present invention performs a normal AF (autofocus) control when a scan position of the machining laser light and the detecting laser light is located in a work central portion, and performs a slow-tracking AF (autofocus) control with a trackability to a displacement of a main surface of a work reduced to be lower than a trackability of the normal AF control when the scan position of the machining laser light and the detecting laser light is located in a work end portion.
Claims20
A laser machining device which condenses a machining laser light inside a work to form a modified region inside the work along a planned dividing line, the laser machining device comprising:
- a condensing lens configured to condense the machining laser light and a detecting laser light toward the work;
- a scanner configured to relatively move the condensing lens and the work in a direction orthogonal to an optical axis direction of the condensing lens, to scan the machining laser light and the detecting laser light over the work;
- an adjuster configured to adjust a distance between the condensing lens and the work;
- a detector configured to detect a reflected light to output a detection signal according to a height of a main surface of the work, the reflected light being the detecting laser light reflected on the main surface of the work;
- a first controller configured to control, based on the detection signal output by the detector;
- the adjuster so as to cause a light condensing point of the detecting laser light to track a displacement of the main surface of the work, in case where a scan position of the machining laser light and the detecting laser light is in a central portion of the work;
- and
- a second controller configured to control;
- based on the detection signal output by the detector, the adjuster so as to cause the light condensing point of the detecting laser light to track the displacement of the main surface of the work with a trackability to the displacement of the main surface of the work reduced to be lower than a trackability of the first controller, in a case where the scan position of the machining laser light and the detecting laser light is in an end portion of the work.
A laser machining method of condensing a machining laser light inside a work to form a modified region inside the work along a planned dividing line, using a laser machining device including:
- a condensing lens configured to condense the machining laser light and a detecting laser light toward the work;
- a scanner configured to relatively move the condensing lens and the work in a direction orthogonal to an optical axis direction of the condensing lens to scan the machining laser light and the detecting laser light over the work;
- an adjuster configured to adjust a distance between the condensing lens and the work;
- and
- a detector configured to detect a reflected light to output a detection signal according to a height of a main surface of the work, the reflected light being the detecting laser light reflected on the main surface of the work,
- the laser machining method comprising:
- a first control step of controlling, based on the detection signal output from the detector, the adjuster so as to cause a light condensing point of the detecting laser light to track a displacement of the main surface of the work, in a case where a scan position of the machining laser light and the detecting laser light is in a central portion of the work;
- and
- a second control step of controlling, based on the detection signal output from the detector, the adjuster so as to cause the light condensing point of the detecting laser light to track the displacement of the main surface of the work, with a trackability to the displacement of the main surface of the work reduced to be lower than a trackability in the first control step, in a case where the scan position of the machining laser light and the detecting laser light is in an end portion of the work.
Dependencies are inferred from the claim text.