JP2004337881A - Laser beam machining method and laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus with which the laser beam machining can be performed with high efficiency. <P>SOLUTION: This laser beam machining apparatus 100 is provided with: a pulsed laser beam oscillator 3 for oscillating the pulsed laser beam; a continuous oscillation laser beam oscillator 4 for oscillating the continuously oscillating laser beam having an oscillating wavelength different from that of the pulse laser beam; a dichroic mirror 1 for generating a mixed laser beam by optically mixing the pulsed laser beam and the continuously oscillating laser beam; and a condensing lens 2 for condensing the mixed laser beam for machining a workpiece to the workpiece. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser processing method and a laser processing apparatus that perform laser welding, laser cutting, laser drilling, and the like by mixing two or more types of laser beams.
[0002]
[Prior art]
Lasers are roughly classified into two types depending on the oscillation mode. That is, a continuous oscillation (hereinafter referred to as “CW”) laser that emits a laser beam continuously with respect to time and a pulse laser that emits a laser beam intermittently with respect to time.
[0003]
For example, in laser welding, a CW laser emits a laser beam continuously, so that the bead on the welding surface becomes smooth, but the penetration depth becomes shallow because the peak power is low. On the other hand, since the pulse laser has a high peak power, the penetration depth becomes deep, but since it is an intermittent laser beam, the weld surface state is not smooth. Therefore, the CW laser is used for thin plate welding, and the pulse laser is used for welding high reflectivity materials such as aluminum.
[0004]
In order to compensate for the characteristics of these two types of lasers, hybrid laser oscillators in which a CW laser and a pulse laser are superposed have begun to be studied. For example, in JP-A-8-162702 (Patent Document 1), one YAG rod is provided with an excitation lamp for pulse oscillation and an excitation lamp for CW oscillation around it. Has proposed a laser apparatus capable of irradiating two types of laser beams with the laser oscillator.
[0005]
In Japanese Patent Laid-Open No. 10-137965 (Patent Document 2), laser beams emitted from two or more types of laser oscillators are guided into one optical fiber by a laser beam combiner and emitted from the optical fiber. A YAG laser synthesizing method and apparatus for focusing and processing a composite laser beam that has been collected by an outgoing optical lens system have been proposed.
[0006]
For example, FIG. 29 shows an outline of the configuration disclosed in Japanese Patent Laid-Open No. Hei 8-162702 (Patent Document 1). Around the YAG rod 91, an excitation lamp 92 for pulse laser oscillation and an excitation lamp 93 for CW laser oscillation are installed. A pulse power supply 94 for pulse laser oscillation and a CW laser oscillation are provided for each of them. A CW power source 95 is connected.
[0007]
Therefore, the pulse laser and the CW laser can be simultaneously oscillated by one laser oscillator. The laser beam emitted from this laser oscillator is guided to the optical fiber 97 by the condensing optical system 96. The laser beam that has passed through the optical fiber 97 is condensed by the processing condensing optical system 98. The condensing spot 99 at this time has a substantially circular shape, and both the pulse laser and the CW laser have the same spot diameter.
[0008]
FIG. 30 shows an outline of the configuration disclosed in Japanese Patent Laid-Open No. 10-137965 (Patent Document 2). The pulse laser beam emitted from the pulse laser oscillator 80 is transmitted through the optical fiber 82. Further, the CW laser beam emitted from the CW laser oscillator 81 is transmitted through the optical fiber 83. The laser beams respectively passing through the two optical fibers 82 and 83 are combined by the laser beam combiner 84 and further incident on the optical fiber 85. The mixed laser beam that has passed through the optical fiber 85 is condensed by the processing condensing optical system 86. At this time, the focused spot 87 has a substantially circular shape, and both the pulse laser and the CW laser have the same spot diameter.
[0009]
In both cases, a plurality of laser beams are optically mixed in an optical fiber, and the laser beam emitted from the optical fiber is condensed by a condensing optical system. Are substantially equivalent, and the beam intensity distribution state is also substantially equivalent.
[0010]
[Patent Document 1]
JP-A-8-162702
[0011]
[Patent Document 2]
JP-A-10-137965
[0012]
[Problems to be solved by the invention]
The pulse laser has a beam spot diameter and a beam intensity distribution state suitable for taking advantage of the features. The same applies to the CW laser. Therefore, more efficient laser processing can be performed by setting the beam spot diameter and beam intensity distribution state utilizing the features of each laser beam.
[0013]
However, in the conventional hybrid laser as described above with reference to FIGS. 29 and 30, both the pulse laser and the CW laser have the same spot diameter. Therefore, the beam spot diameter utilizing the respective features of the pulse laser and the CW laser. It can not be. Therefore, there is a problem that highly efficient laser processing cannot be performed.
[0014]
An object of the present invention is to provide a laser processing method and a laser processing apparatus capable of performing laser processing with high efficiency.
[0015]
[Means for Solving the Problems]
The laser processing method according to the present invention includes a step of oscillating a pulse beam laser and oscillating a continuous wave laser with an oscillation wavelength different from the oscillation wavelength of the pulse beam laser, and optically combining the pulse beam laser and the continuous wave laser. A mixed laser beam to generate a mixed laser beam and a step of focusing the mixed laser beam on the workpiece to process the workpiece.
[0016]
A laser processing apparatus according to the present invention includes a pulse beam laser oscillator that oscillates a pulse beam laser, a continuous wave laser oscillator that oscillates a continuous wave laser with an oscillation wavelength different from the oscillation wavelength of the pulse beam laser, and the pulse beam laser. A dichroic mirror that generates a mixed laser beam optically mixed with the continuous wave laser; and a condensing lens that focuses the mixed laser beam on the workpiece in order to process the workpiece. It is characterized by.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0018]
(Embodiment 1)
FIG. 1 is a perspective view showing the appearance of the laser processing apparatus 100 according to the first embodiment, and FIG. 2 is a schematic diagram showing the configuration of the laser processing apparatus 100.
[0019]
The laser processing apparatus 100 includes a jig 32 for placing a workpiece 31 on which two plates are abutted. The laser processing apparatus 100 is provided with a uniaxial stage 33 for moving the jig 32 along the direction indicated by the arrow.
[0020]
The laser processing apparatus 100 includes a YAG pulse beam laser oscillator 3 that oscillates a pulse beam laser having an oscillation wavelength of 1064 nanometers (nm). The pulse beam laser oscillated by the pulse beam laser oscillator 3 passes through the collimating optical system 24 provided in the processing condensing optical system 29 through the pulse optical fiber 22 having a core diameter of 0.6 millimeter (mm). Then, it enters the dichroic mirror 1.
[0021]
The laser processing apparatus 100 includes a continuous wave laser oscillator 4 that oscillates a continuous wave laser having an oscillation wavelength of 808 nanometers (nm). The continuous wave laser oscillator 4 is constituted by a high-power semiconductor laser oscillator. The continuous wave laser oscillated in the high-power semiconductor laser oscillator 4 enters the dichroic mirror 1.
[0022]
The dichroic mirror 1 mixes the pulse beam laser that has passed through the collimating optical system 24 and the continuous wave laser oscillated in the high-power semiconductor laser oscillator 4 and applies the mixed laser beam to the condenser lens 2. The condensing lens 2 condenses the pulse beam laser and continuous wave laser mixed by the dichroic mirror 1 onto the workpiece 31.
[0023]
Next, the diameter of the condensed spot when each laser beam is condensed by the condenser lens 2 will be described. In Embodiment 1, since the focal length of the collimating optical system 24 is 50 millimeters (mm) and the focal length of the condenser lens 2 is also 50 millimeters (mm), the imaging magnification is 1: 1. Yes.
[0024]
The end surface of the core of the pulse laser beam emitted from the pulse optical fiber 22 is condensed at an imaging position where the collimating optical system 24 and the condenser lens 2 form an image. Therefore, the condensing spot 10 of the pulse laser beam has a circular shape similar to the core shape, and the spot diameter is about 0.6 millimeters (mm).
[0025]
On the other hand, the condensing spot diameter of the semiconductor laser beam is not generally a circular shape but a line shape. The reason is as follows.
[0026]
A high-power semiconductor laser generally used for processing will be described with reference to FIGS. The one-dimensional array of semiconductor laser array bars 51 constituting the continuous wave laser oscillator 4 has a form as shown in FIG. 3 and is mainly composed of a semiconductor laser array chip 52 and a heat sink 53.
[0027]
In the semiconductor laser array chip 52, a plurality of semiconductor laser emitters 54 are arranged in a straight line at a constant pitch. For example, the thickness (active layer direction) of the semiconductor laser emitter 54 is as narrow as about 1 micrometer (μm), and conversely, its width (in the direction parallel to the active layer) is as wide as about 100 micrometers (μm). It has become. Further, about 50 semiconductor laser emitters 54 are arranged in the width direction with a pitch of about 200 micrometers (μm). Therefore, the width dimension of the semiconductor laser array chip 52 is about 10 millimeters (mm). When the laser output from the semiconductor laser emitter 54 is 1 watt (W), if there are 50 semiconductor laser emitters 54, the laser output is 50 W.
[0028]
The divergence angle of the laser beam emitted from the semiconductor laser emitter 54 is about 40 degrees with respect to the perpendicular direction (thickness direction) and about 10 degrees with respect to the parallel direction (width direction). Since the laser beam diameter at the laser oscillation exit corresponds to the active layer size of the semiconductor laser emitter 54, the perpendicular direction is 1 micrometer (μm) and the parallel direction is 100 micrometers (μm).
[0029]
In the semiconductor laser array chip 52 in which a plurality of semiconductor laser emitters 54 are combined, since the plurality of semiconductor laser emitters 54 are aligned in the width direction, the divergence angle of the laser beam is determined for each semiconductor. This is the same as the case of the laser emitter 54, which is about 40 degrees with respect to the perpendicular direction and about 10 degrees with respect to the parallel direction. However, the laser beam diameter at the exit is 1 micrometer (μm) in the perpendicular direction, but 10 millimeters (mm) in the parallel direction.
[0030]
In order to directly use such a one-dimensional array of semiconductor laser array spars 51 for laser processing, it is necessary to narrow the laser beam emitted from the one-dimensional array of semiconductor laser array bars 51 to a minute spot. For this purpose, it is necessary to improve the spread angle of the laser beam. In general, for the semiconductor laser emitter 54, the optical axis in the thickness direction (active layer direction) is called FASTAXIS, and conversely, the optical axis in the width direction (parallel to the active layer) is called SLOWAXIS. In the FASTAXIS direction, as shown in FIG. 4, the divergence angle of the laser beam 55 is as large as about 35 degrees. Therefore, as shown in FIG. 5, a collimating lens 56 is attached in front of the semiconductor laser array chip 52 on a straight line, and the divergence angle of the FASTAX1S laser beam is about 35 degrees to 0.24 degrees (4 mrad). It has been improved.
[0031]
On the other hand, in the SLOWAXIS direction, the laser beam emission source is basically a line having a width of 10 millimeters (mm), so the beam divergence angle cannot be easily reduced. A beam divergence of about 10 degrees (175 mrad). In other words, the divergence angle of the laser beam emitted from the semiconductor laser array bar 51 with the collimating lens 56 is unbalanced at 4 mrad for FASTAX1S and 175 mrad for SLOWAX1S.
[0032]
In order to increase the total output of the semiconductor laser beam, actually, as shown in FIGS. 6 and 7, the one-dimensional array of semiconductor laser array bars 51 is shaped to be easily stacked in the thickness direction. A semiconductor laser array stack 57 shown in FIG. 8 is formed by stacking the one-dimensional array of semiconductor laser array bars 51. For example, if five one-dimensionally arranged semiconductor laser array bars 51 are stacked, a laser output of about 250 W can be obtained (50 W × 5). At that time, the laser beam diameter (laser emission surface) from the semiconductor laser array stack 57 is 10 millimeters (mm) in the thickness direction (the thickness of the one-dimensionally arranged semiconductor laser array bar 51 is 2 mm × 5), and is 10 in the width direction. Millimeter (mm). The divergence angle of the laser beam is 4 mrad for FASTAX1S and 175 mrad for SLOWAX1S, as in the case of the semiconductor laser array bar 51 with the collimating lens 56.
[0033]
Therefore, as shown in FIGS. 9 and 10, when the light is condensed by a normal spherical lens 58, the spot diameter at the condensing lens 58 is proportional to the value of the divergence angle of the laser beam. For example, the spot diameter when focused by a condenser lens with a focal length of 50 millimeters (mm) is 0.2 millimeters (mm) (50 millimeters (mm) × 4 mrad) for FASTAXIS, and about 8.8 millimeters for SLOWAXIS ( mm) (50 millimeters (mm) × 175 mrad).
[0034]
That is, the focal spot diameter of the semiconductor laser beam is 50 millimeters (mm) in the first embodiment, and therefore, as described above, 0.2 millimeters (mm) × 8.8 millimeters (mm). It becomes a line shape (spot 11 in FIG. 2). By taking advantage of the characteristics of the high-power semiconductor laser beam in this way, a linear spot shape can be efficiently formed instead of a circular spot. The first embodiment is based on such characteristics.
[0035]
When the condensing spot shape of the laser processing apparatus in Embodiment 1 is enlarged, a spot shape as shown in FIG. 11 is obtained. FIG. 11 shows a spot shape 10 of a circular pulse laser beam and a spot shape 11 of a CW laser having a line shape.
[0036]
Further, the power density in the section AA direction and the power density in the section BB direction shown in FIG. 11 have the spatial distribution shapes as shown in FIGS. 12 and 13, respectively. From FIG. 12, in the direction of the section AA, the spot diameter of the CW laser (semiconductor laser) is as long as 8.8 millimeters (mm) with respect to the pulse spot diameter φ0.6 millimeters (mm). Therefore, in the cross-sectional AA direction, the overlapping effect of the pulse laser and the CW laser can be expected, and the region not irradiated with the pulse laser is also irradiated with the CW laser. The effect of the CW laser such as preheating / postheating / annealing can also be expected in surrounding regions other than the region irradiated with the pulse laser.
[0037]
On the other hand, from FIG. 13, in the cross-section BB direction, the spot diameter of the semiconductor laser (CW laser) is as small as 0.2 millimeter (mm) with respect to the pulse spot diameter of φ0.6 millimeter (mm). Therefore, in the direction of the cross section BB, the effect of superimposition can be expected in the region where the central portion of the pulse laser (0.2 mm range) and the CW laser overlap. Further, since the CW laser is not irradiated except for the central portion (0.2 mm range) of the pulse laser, unnecessary thermal influence can be prevented in that region.
[0038]
Next, the temporal change of superposition processing will be described. FIG. 14 is a graph showing temporal changes in the laser output of the pulse laser beam when pulse laser oscillation is performed at a constant interval and energy. FIG. 15 is a graph showing temporal changes in the output of the CW laser when the CW laser is oscillated at a constant power. When these two types of laser beams are superimposed, as shown in FIG. 16, a pulse laser is added on a constant CW laser output. That is, a constant CW laser is emitted even when the pulse laser is not irradiated.
[0039]
Next, a laser processing method using the laser processing apparatus according to Embodiment 1 will be described. As one example of laser processing, butt seam welding will be described with reference to FIG. The composite laser beam 30 emitted from the processing condensing optical system 29 is applied to the butting portion 34 of the workpiece 31. The direction of the spot shape at that time is set so that the major axis direction of the spot 11 of the CW laser becomes a direction along the abutting portion 34 as shown in FIG. Usually, the spot 10 of the pulse laser is set at the center in the major axis direction of the spot 11 of the CW laser.
[0040]
However, when the effect of the preheating of the CW laser is desired to be remarkable, as shown in FIG. 18, the center of the major axis direction of the spot 11 of the CW laser with respect to the moving direction of the uniaxial stage 33 (the arrow direction in FIG. 1). Further, a spot 10 of the pulse laser is set on the rear side.
[0041]
On the other hand, when the effect of the post-heating of the CW laser is desired to be noticeable, the pulse laser is moved in front of the center in the major axis direction of the spot 11 of the CW laser with respect to the moving direction of the uniaxial stage 33 (the arrow direction in FIG. Spot 10 is set.
[0042]
Since the moving direction of the uniaxial stage 33 (in the direction of the arrow in FIG. 1) and the longitudinal direction of the abutting portion 34 of the workpiece 31 are set parallel to each other, the composite laser beam 30 is irradiated with the movement of the uniaxial stage 33. Then, butt seam welding can be performed.
[0043]
The butt seam welding capability at this time will be described. This time, as one of the welding capacities, the evaluation is based on the penetration depth obtained when the same energy is input. The result at that time is shown in FIG. The penetration depth is evaluated when the pulse energy is 2J and 4J. In the case of only the pulse laser (in the figure, ● mark), in the case where the CW laser (50 W) having the same spot shape as the pulse laser is superimposed on the pulse laser (in the figure, circle mark), Comparison is made with a case where a CW laser (50 W) having a line-shaped spot shape is superimposed (indicated by a triangle mark in the figure). As is apparent from FIG. 20, the penetration is deepest when a CW laser having a line-like spot shape is superimposed on the pulse laser. That is, since the line-shaped spot shape of the CW pulse laser coincides with the butt welding line, the laser energy efficiency is the best in welding, and as a result, the penetration depth is deepened.
[0044]
In this manner, the pulse laser beam emitted from the pulse laser oscillator is guided to the optical fiber, and the pulse laser beam emitted from the optical fiber is roughly collimated by the collimating optical system. On the other hand, a semiconductor laser emitted from a semiconductor laser oscillator having an oscillation wavelength different from the oscillation wavelength of a pulse laser oscillator and a pulse laser beam emitted from a collimating optical system are optically mixed by a dichroic mirror, and the mixing is performed. The laser beam is condensed by a condensing optical system and laser processing is performed. At that time, the condensing spot diameter at the condensing point of the pulse laser beam is made approximately circular, while the condensing spot diameter at the condensing point of the semiconductor laser beam is formed into an ellipse, an ellipse, or a line shape. By making the major axis larger than the focused spot diameter of the pulse laser beam and moving the processing stage or the focusing optical system in the major axis direction, highly efficient laser processing can be performed.
[0045]
As described above, according to the first embodiment, the step of optically mixing the pulse beam laser and the continuous wave laser to generate the mixed laser beam, and the processing of the mixed laser beam to process the workpiece And a process of condensing the object. For this reason, the shape of the spot of the pulse beam laser included in the mixed laser beam and the shape of the spot of the continuous wave laser included in the mixed laser beam can be made to take advantage of the characteristics of each laser. As a result, the efficiency of laser processing can be increased.
[0046]
(Embodiment 2)
FIG. 21 is a schematic diagram showing a configuration of a laser processing apparatus 100A according to the second embodiment. The same components as those of the laser processing apparatus 100 according to Embodiment 1 described above with reference to FIG. 2 are denoted by the same reference numerals. Therefore, detailed description of these components is omitted.
[0047]
The pulse laser emitted from the YAG pulse beam laser oscillator 3 is transmitted through the pulse optical fiber 6. Similarly, the semiconductor laser beam emitted from the continuous wave laser oscillator 4 constituting the high output semiconductor laser is also transmitted through the optical fiber 7 for high output semiconductor laser.
[0048]
The dichroic mirror 1 has a characteristic that it is transmissive to the oscillation wavelength of 1064 nanometers (nm) of the YAG pulse laser beam and conversely reflects to the oscillation wavelength of 808 nanometers (nm) of the high-power semiconductor laser beam. Have. Therefore, the transmitted pulse laser beam passes through the dichroic mirror 1 as it is. On the other hand, the high-power semiconductor semiconductor laser beam is reflected by the dichroic mirror 1. That is, the pulsed laser beam and the semiconductor laser beam are mixed by the dichroic mirror 1 and roughly collimated by the collimating optical system 24. Further, the collimated mixed laser beam is condensed by the condenser lens 2.
[0049]
Next, the diameter of the condensed spot when each laser beam is condensed by the condenser lens 2 will be described. In the second embodiment, an optical fiber having a core diameter of 0.6 millimeters (mm) is used as the pulse optical fiber 6, the focal length of the collimating optical system 24 is 50 millimeters (mm), and the condenser lens 2 is used. Is also 50 millimeters (mm), and its imaging magnification is 1: 1.
[0050]
Therefore, the condensing spot shape is circular (spot 10 in FIG. 21) like the core shape, and the spot diameter is about 0.6 millimeter (mm). Conversely, since the core diameter of the optical fiber 7 for high-power semiconductor lasers is 0.3 mm (mm), the condensing spot shape is circular (the spot in FIG. 21 is the same as the core shape). 11A), and the spot diameter is about 0.3 millimeter (mm).
[0051]
An enlarged view of the spot shape is shown in FIG. FIG. 22B shows the power density distribution of the cross section AA (and cross section BB) of the spot. As can be seen from FIG. 22A and FIG. 22B, the spot 11A by the CW laser beam enters the highest portion in the center of the spot 10 by the pulse beam.
[0052]
In FIG. 23, when a workpiece 41 is irradiated with a pulse laser 42, a keyhole 44 is formed at a substantially central portion of the melted portion 43 at the spot diameter. The diameter of the melting part 43 differs depending on the energy of the pulse laser 42 but is slightly larger than the spot diameter. The keyhole 44 is about 1/5 to 1/2 of the melt spot diameter.
[0053]
Referring to FIG. 24, in the superposition processing of the pulse laser and the CW laser, the CW laser 45 having a spot diameter smaller than the spot diameter of the pulse laser 42 with respect to the keyhole 44 formed for the pulse laser 42. Is inserted. For this reason, the energy of the CW laser is effectively used in the keyhole 44. Therefore, the penetration depth becomes deeper.
[0054]
On the other hand, when welding is performed while moving the condensing optical system (or processing stage) for processing as in seam welding, the pulse spot of the work piece 41 is caused by the temperature distribution of the workpiece 41 as shown in FIG. In particular, the keyhole 44 moves in the traveling direction of the processing condensing optical system. At that time, it is effective to shift the position of the spot 11A of the CW laser toward the moving direction of the processing condensing optical system with respect to the center of the spot 10 of the pulse laser (FIG. 22A).
[0055]
Conversely, by making the core diameter of the optical fiber 7 for a high-power semiconductor laser larger than the core diameter of the optical fiber 6 for pulses, the surroundings can be protected against distortion and thermal stress on the member caused by the pulse laser. The CW laser can perform metallurgical heat treatment such as preheating / postheating / annealing.
[0056]
An enlarged view of the spot shape at that time is shown in FIG. FIG. 27B shows the power density distribution of the cross section AA (and cross section BB) of the spot.
[0057]
(Embodiment 3)
Next, Embodiment 3 of the present invention will be described with reference to FIG. The same components as those of the laser processing apparatus 100A according to Embodiment 2 described above with reference to FIG. 2 are denoted by the same reference numerals. Therefore, detailed description of these components is omitted.
[0058]
The pulse laser emitted from the YAG pulse laser oscillator 3 is transmitted through the pulse optical fiber 6B. Similarly, the semiconductor laser beam emitted from the continuous wave laser oscillator 4 constituting the high output semiconductor laser is also transmitted through the optical fiber 7B for high output semiconductor laser. The core diameter of the pulse optical fiber 6B and the core diameter of the high-power semiconductor laser optical fiber 7B are the same.
[0059]
The pulse laser beam transmitted through the pulse optical fiber 6B is roughly collimated by the pulse laser collimating optical system 8. Similarly, the high-power semiconductor laser beam is roughly collimated by the high-power semiconductor laser collimating optical system 9. At this time, the collimating optical systems 8 and 9 have different focal lengths. Thereafter, the collimated laser beams are mixed by the dichroic mirror 1 and condensed by the condenser lens 2.
[0060]
Next, the diameter of the condensed spot when each laser beam is condensed by the condenser lens 2 will be described. In Embodiment 3, the core diameters of the optical fibers 6B and 7B are 0.6 millimeters (mm). The focal length of the pulse laser collimating optical system 8 is 50 millimeters (mm). That is, in the pulse laser, the imaging magnification is 1: 1.
[0061]
On the other hand, in the semiconductor laser, the imaging magnification is 3: 5. Therefore, the focused spot shape of the pulse beam is about 0.6 millimeter (mm). On the other hand, the focused spot shape of the high-power semiconductor laser is about 1 millimeter (mm) (0.6 millimeter (mm) × 5/3). That is, even when the same optical fiber is used, the same spot shape as that in the example shown in the second embodiment can be obtained by changing the focal length of the collimating lens for processing.
[0062]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a laser processing method and a laser processing apparatus capable of performing laser processing with high efficiency.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external appearance of a laser processing apparatus according to a first embodiment.
FIG. 2 is a schematic diagram showing a configuration of a laser processing apparatus according to the first embodiment.
3 is a perspective view showing an external appearance of a continuous wave laser oscillator provided in the laser processing apparatus according to Embodiment 1. FIG.
4 is a front view showing a configuration of a continuous wave laser oscillator provided in the laser processing apparatus according to Embodiment 1. FIG.
5 is a front view showing another configuration of the continuous wave laser oscillator provided in the laser processing apparatus according to Embodiment 1. FIG.
6 is a plan view showing another configuration of the continuous wave laser oscillator provided in the laser processing apparatus according to Embodiment 1. FIG.
7 is a front view showing still another configuration of the continuous wave laser oscillator provided in the laser machining apparatus according to Embodiment 1. FIG.
FIG. 8 is a front view showing still another configuration of the continuous wave laser oscillator provided in the laser processing apparatus according to the first embodiment.
FIG. 9 is a front view showing still another configuration of the continuous wave laser oscillator provided in the laser processing apparatus according to the first embodiment.
10 is a plan view showing still another configuration of the continuous wave laser oscillator provided in the laser machining apparatus according to Embodiment 1. FIG.
11 is a diagram showing laser spots irradiated by the laser processing apparatus according to Embodiment 1. FIG.
12 is a graph showing power density along the cross section AA shown in FIG.
13 is a graph showing power density along a cross section BB shown in FIG.
14 is a graph showing temporal changes in the output of the pulse laser irradiated by the laser processing apparatus according to Embodiment 1. FIG.
15 is a graph showing temporal changes in the output of the CW laser irradiated by the laser processing apparatus according to Embodiment 1. FIG.
16 is a graph showing a temporal change in the sum of the output of the pulse laser and the output of the CW laser irradiated by the laser processing apparatus according to Embodiment 1. FIG.
FIG. 17 is a plan view showing relative movement between a laser spot irradiated by the laser processing apparatus according to Embodiment 1 and a workpiece;
FIG. 18 is a plan view showing relative movement between another laser spot irradiated by the laser processing apparatus according to Embodiment 1 and the workpiece.
FIG. 19 is a plan view showing relative movement between another laser spot irradiated by the laser processing apparatus according to Embodiment 1 and the workpiece.
20 is a graph showing the relationship between the pulse energy of the laser irradiated by the laser processing apparatus according to Embodiment 1 and the penetration depth of the workpiece. FIG.
FIG. 21 is a schematic diagram showing a configuration of a laser processing apparatus according to the second embodiment.
FIG. 22 (a) is a plan view showing laser spots irradiated by the laser processing apparatus according to the second embodiment;
(B) is a graph which shows the power density along the cross section AA and the cross section BB shown to (a).
FIG. 23 is a cross-sectional view for explaining a method of processing a workpiece by the laser processing apparatus according to the second embodiment.
24 is a cross-sectional view for explaining a method of processing a workpiece by the laser processing apparatus according to Embodiment 2. FIG.
25 is a cross-sectional view for explaining a method of processing a workpiece by the laser processing apparatus according to Embodiment 2. FIG.
FIG. 26 is a plan view showing another laser spot irradiated by the laser processing apparatus according to the second embodiment.
FIG. 27A is a plan view showing still another laser spot irradiated by the laser machining apparatus according to Embodiment 2. FIG.
(B) is a graph which shows the power density along the cross section AA and the cross section BB shown to (a).
FIG. 28 is a schematic diagram showing a configuration of a laser processing apparatus according to the third embodiment.
FIG. 29 is a schematic diagram showing a configuration of a conventional laser processing apparatus.
FIG. 30 is a schematic diagram showing the configuration of another conventional laser processing apparatus.
[Explanation of symbols]
1 Dichroic mirror
2 Condensing lens
3 Pulse beam laser oscillator
4 Continuous oscillation laser oscillator
5 Relative movement device
6,7 optical fiber
8,9 collimating optics
10, 11 Focusing spot
13 Semiconductor laser array bar
100 Laser processing equipment

Claims (15)

Oscillating a pulse beam laser and oscillating a continuous wave laser with an oscillation wavelength different from the oscillation wavelength of the pulse beam laser;
Optically mixing the pulse beam laser and the continuous wave laser to generate a mixed laser beam;
And condensing the mixed laser beam onto the workpiece to process the workpiece. The shape of the focused spot on the workpiece of the pulse beam laser is substantially circular,
The shape of the focused spot on the workpiece of the continuous wave laser is one of an ellipse, an ellipse, and a line shape, and
2. The laser processing method according to claim 1, wherein a major axis of the focused spot of the continuous wave laser is longer than a diameter of the focused spot of the pulse beam laser. The laser processing according to claim 2, further comprising a step of relatively moving the workpiece and the mixed laser beam focused on the workpiece along a major axis direction of a focused spot of the continuous wave laser. Method. Guiding the pulsed beam laser to a pulsed laser optical fiber, and further guiding the oscillated continuous wave laser to a continuous wave laser optical fiber having a core diameter different from the core diameter of the pulsed laser optical fiber,
The step of generating the mixed laser beam optically mixes the pulsed beam laser guided by the pulsed laser optical fiber and the continuous wave laser guided by the continuous wave laser optical fiber. Laser processing method. Guiding the pulsed beam laser to a pulsed laser optical fiber and further guiding the oscillated continuous wave laser to a continuous wave laser optical fiber having the same core diameter as the pulsed laser optical fiber;
The pulse beam laser guided by the pulse laser optical fiber is collimated by a first collimating optical system, and the continuous wave laser guided by the continuous wave laser optical fiber is different from the focal length of the first collimating optical system. Further comprising collimating with a second collimating optical system having a focal length;
The step of generating the mixed laser beam optically mixes the pulse beam laser collimated by the first collimating optical system and the continuous wave laser collimated by the second collimating optical system. The laser processing method as described. The shape of the focused spot on the workpiece of the pulse beam laser is substantially circular,
The laser processing method according to claim 1, wherein a shape of a focused spot in the workpiece of the continuous wave laser is a substantially circular shape smaller than a focused spot of the pulse beam laser. The center of the focused spot of the continuous wave laser is the center of the focused spot of the pulse beam laser along the direction in which the workpiece and the mixed laser beam focused on the workpiece are relatively moved. The laser processing method according to claim 6, wherein the laser processing method is offset. A pulse beam laser oscillator for oscillating a pulse beam laser; and
A continuous wave laser oscillator that oscillates a continuous wave laser with an oscillation wavelength different from the oscillation wavelength of the pulse beam laser;
A dichroic mirror that generates a mixed laser beam obtained by optically mixing the pulse beam laser and the continuous wave laser;
A laser processing apparatus comprising: a condensing lens for condensing the mixed laser beam on the workpiece in order to process the workpiece. The shape of the focused spot on the workpiece of the pulsed beam laser included in the mixed beam laser is substantially circular,
The shape of the focused spot on the workpiece of the continuous wave laser included in the mixed beam laser is one of an ellipse, an ellipse, and a line shape,
The laser processing apparatus according to claim 8, wherein a major axis of the focused spot of the continuous wave laser is longer than a diameter of the focused spot of the pulse beam laser. 10. The apparatus according to claim 9, further comprising a relative movement device that relatively moves the workpiece and the mixed laser beam focused on the workpiece along a major axis direction of a focused spot of the continuous wave laser. Laser processing equipment. A pulsed laser optical fiber provided to guide the pulsed beam laser;
A continuous-wave laser optical fiber having a core diameter different from the core diameter of the pulsed laser optical fiber for guiding the oscillated continuous-wave laser;
The laser processing apparatus according to claim 8, wherein the dichroic mirror optically mixes the pulse beam laser guided by the pulse laser optical fiber and the continuous wave laser guided by the continuous wave laser optical fiber. A pulsed laser optical fiber provided to guide the pulsed beam laser;
A continuous wave laser optical fiber having a core diameter substantially the same as the core diameter of the pulsed laser optical fiber to guide the oscillated continuous wave laser;
A first collimating optical system for collimating the pulsed beam laser guided by the pulsed laser optical fiber;
A second collimating optical system having a focal length different from the focal length of the first collimating optical system for collimating the continuous wave laser guided by the continuous wave laser optical fiber;
The laser processing apparatus according to claim 8, wherein the dichroic mirror optically mixes the pulse beam laser collimated by the first collimating optical system and the continuous wave laser collimated by the second collimating optical system. . The shape of the focused spot on the workpiece of the pulsed beam laser included in the mixed beam laser is substantially circular,
The laser processing apparatus according to claim 8, wherein a shape of a condensing spot in the workpiece of the continuous wave laser included in the mixed beam laser is a substantially circular shape smaller than a condensing spot of the pulse beam laser. . The center of the focused spot of the continuous wave laser is the center of the focused spot of the pulse beam laser along the direction in which the workpiece and the mixed laser beam focused on the workpiece are relatively moved. The laser processing apparatus of Claim 13 which has shifted | deviated with respect to. The continuous wave laser oscillator has a two-dimensional array of semiconductor laser array bars formed by laminating one to a plurality of one-dimensional array of semiconductor laser array bars along its thickness direction. Laser processing equipment.

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