JPH09323184A - Laser beam machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make beam condensing positions of both a laser beam for machining and laser beam for alignment coincide and to improve positioning precision of alignment of an object to be machined. SOLUTION: The laser beam machine has a laser beam generating means LS1 to generate a laser beam 21 of wave length of λ1 , a laser beam generating means LS1 to generate a laser beam 22 of wave length of λ2 and a beam condensing optical system including a diffraction optical element 23. A focus position under the highest degree number m1 , of diffraction of diffraction efficiency of diffraction optical element 23 for the beam of wave length λ1 and a focus position under the highest degree number m2 (m2 ≠m1 ) of diffraction of diffraction efficiency of diffraction optical element 23 for the beam of wave length λ2 (λ2 ≠λ1 ) are roughly coincided. Both laser beams are condensed on the object 5 to be machined at the same focal distance and with aberration-free. The laser beam machine, in which condensing positions of the laser beam for machining and laser beam for alignment are made to coincide and the positioning precision of alignment of object to be machined is improved, is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus, and more specifically, a laser having an optical system for converging a processing laser beam and light having a wavelength different from that of the laser beam. The present invention relates to a processing device.

[0002]

2. Description of the Related Art As an apparatus for irradiating a workpiece with a laser beam to perform processing, for example, an apparatus having a schematic configuration shown in FIG. 7 is known. As shown in FIG. 7, the laser processing apparatus according to this conventional technique includes a laser light source 1 for irradiating a workpiece 5 placed on a stage 6 with a laser beam 3 through a dichroic mirror 12 and a condenser lens 11. , Mirror system 1
A visible light laser 2 for irradiating a workpiece 5 with visible light 4 through an optical system similar to the laser light source 1 is provided.
A part of the visible light 4 reflected by the surface of the workpiece 5 is again transmitted through the condenser lens 11, and a part is further transmitted through the dichroic mirror 12 and is incident on the light receiving element 14 through the alignment optical system 13. .

As a result, it is possible to observe the condensing position of the processing light in the invisible region with visible light, and further the visible light 4 separated by using the dichroic mirror 12 is CCD.
By monitoring with the light receiving element 14 such as a camera, it can be used for confirming the processing state of the workpiece 5 and positioning.

FIG. 8 shows an example in which a light source other than laser light such as a mercury lamp is used as a light source for alignment. In this case, the basic configuration is almost the same as that of the example shown in FIG. 7, and the mercury lamp 41 is used instead of the visible light laser, and the luminous flux from the mercury lamp 41 is elliptical mirror 42, lens system 43, and switching mirror. The laser light source 1 and the lens system 43 ′ adjust the light beam through the optical axis 44 so as to be coaxial with the optical axis 2 of the processing laser light, and the dichroic mirror 12 and the condensing optical system 11 irradiate the workpiece 5. The light beam reflected on the surface of the work piece 5 can be used for confirmation of the working state of the work piece 5, positioning, etc. by monitoring with the light receiving element 14 as in the example of FIG. It will be possible.

[0005]

In the conventional structure shown in FIG. 7, since the processing laser beam and the alignment laser beam are applied to the workpiece by the same focusing optical system,
If the optical system has chromatic aberration, the two laser beams have different focus positions, which leads to a reduction in the alignment accuracy of the workpiece.

When a light source other than the laser light source is used as in the example of FIG. 8, in order to obtain a light amount necessary for alignment, a light source with a very large light amount, such as a mercury lamp, and the light source are used. A complex optical system is needed to efficiently collect light and efficiently illuminate a small aperture.
The device becomes complicated and expensive. In addition, the alignment light in this case has properties that are essentially different from the laser light in terms of wavelength distribution, polarization state, and coherence length. For this reason, it is difficult to obtain a light spot equivalent to the original laser light for processing on the surface to be processed, and as a result, the alignment accuracy is lowered.

Further, considering these from the following viewpoints, it can be said that there is room for further improvement in the following aspects. That is, according to the conventional technique, since the processing laser beam and the alignment light are applied to the workpiece by the same focusing optical system, when the optical system has chromatic aberration, the focusing positions of the processing laser beam and the alignment light are different. In addition to the reduction in the positional accuracy of the alignment of the workpiece, in addition to the processing laser device, a light source such as an alignment laser device (in the case of FIG. 7) or a mercury lamp (in the case of FIG. 8) is used. It is required separately. Further, the optical system for adjusting the optical axes of the processing laser light and the alignment light to be exactly aligned with each other and the beam shape (beam diameter, etc.) of the processing laser light and the alignment light are shaped to be substantially the same. Optical system is required. Especially when invisible light such as infrared light or ultraviolet light is used for the processing laser,
It becomes difficult to adjust the optical axis alignment with the alignment light.

In the present invention, focusing on the above-mentioned points, the disadvantages as described above can be solved, and the converging positions of the processing laser light and the alignment laser light are equal to each other, so that the alignment of the workpiece can be improved. An object of the present invention is to provide a laser processing device capable of improving position accuracy. Also,
Another purpose is that the laser light for processing and the alignment light have the same focusing position, which improves the positional accuracy of the alignment of the workpiece, and in addition to this, it is composed of a single laser system for processing and alignment. An object of the present invention is to provide an improved laser processing apparatus which is capable of adjusting the optical axes of the processing laser light and the alignment light and easily adjusting the shaping of the beam shape.

[0009]

A laser processing apparatus of the present invention generates a first laser beam generating means for generating a laser beam having a _first wavelength λ _{1 and} a laser beam having a second wavelength λ _2. The second laser beam generation means and the condensing optical system including the diffractive optical element are provided, and the focal position by the diffraction order m ₁ having the highest diffraction efficiency of the diffractive optical element for the light of the wavelength λ _1
2 (where λ ₂ ≠ λ ₁ ) is characterized in that the focal positions of the diffraction order m ₂ (where m ₂ ≠ m ₁ ) having the highest diffraction efficiency of the diffractive optical element are substantially the same. .

According to the present invention, there is provided a laser processing apparatus in which the processing laser light and the alignment laser light have the same converging position and the positional accuracy of the alignment of the workpiece is improved. In the present specification, the term “laser light” is used to include light generated by laser oscillation and coherent light whose wavelength is converted from the light by using a nonlinear optical effect or the like.

FIG. 1 shows the basic principle of a diffractive optical element according to the present invention, and with reference to FIG.
First wavelength λ ₁ from the first and second laser light generating means
Light flux (21) of the second wavelength λ _{2 and} the light flux (22) of the second wavelength λ ₂ are respectively processed by the diffractive optical element (23).
When the diffractive optical element (23) acts as a lens, the relief pattern (24) on the diffractive surface of the diffractive optical element (23) has the highest diffraction efficiency for the first wavelength λ ₁ . When having a groove depth d optimized to be high, the groove depth d is d = (m ₁ λ ₁ ) / using the wavelength λ ₁ and the refractive index n of the substrate forming the relief pattern. (N-1) ..., When the groove depth d is set in this way, a diffraction efficiency of almost 100% can be obtained for a thin relief grating. At this time, m ₁ is a diffraction order and is an integer other than 0.

Further, the first wavelength λ₁And the second wavelength λ
_TwoIs the diffraction order m₁And diffraction order m_TwoAbout
m_Two: M₁To be an integer ratio of₁λ₁
= M_Twoλ_TwoWhen setting to satisfy the relational expression of
The groove depth d of the surf pattern is d = (m_Twoλ_Two) / (N−1) ... which can be expressed as Lerri with the same groove depth d.
Wavelength pattern λ _TwoWith respect to the diffraction order m_TwoUp to
It is equivalent to being optimized. That is, the wavelength λ₁And wavelength λ
_TwoOf the diffractive optical element (23) at two different wavelengths of
It is possible to make the diffraction efficiency almost 100%.

On the other hand, the condition that the diffractive optical element (23) converges the light beam of wavelength λ with the diffraction order m and the aberration at the focal length f is the radius of the p-th relief grating from the center of the relief pattern (24). the When ^{_{r p, (r p 2 +}} f 2) is ^1/2 -f = pmλ ^{····, _{therefore, f = {r p 2 -}} (pmλ) 2} be represented as / 2 pmλ ··· It is possible, and when mλ is constant, the focal length f is also constant.

Therefore, the first wavelength λ₁And the second wavelength λ_TwoTo
As for the relational expression m₁λ₁= M_Twoλ _TwoFrom the wavelength λ₁To
Even with the wavelength λ_TwoAlso have the same focal length
With the same relief pattern (24), the wavelength λ₁And waves
Long λ_TwoDiffractive optical element (2
It is possible to match the condensing position by 3),
Can also be focused without aberration for both wavelengths
You.

Thus, according to the laser processing apparatus of the first aspect of the present invention, the laser light of the first wavelength λ _{1 and} the laser light of the second wavelength λ ₂ having a different wavelength are basically used. It is possible to focus light at the same focal length and with no aberration, and when the optical system has chromatic aberration, the focus positions of the two laser beams are different and the alignment accuracy of the workpiece is degraded. It is possible to prevent such things as
Further, since the diffractive optical element used has substantially no thickness, it is possible to easily make the optical system compact.

Further, in the above, preferably, the diffraction focal length f ₁ at the wavelength lambda ₁ of the optical element (23), and the focal length f ₂ at the wavelength _{λ 2, | f 1 -f 2} | It is characterized in that the condition of <f ₁ × 0.05 is satisfied.

In this way, the diffractive optical element (23)
By using the focal length f ₂ of the focal length f ₁ and wavelength lambda ₂ of the light wavelength lambda ₁ of the _{light, | f 1 -f 2 | <} f 1 ×
If 0.05 is satisfied, it can be considered that the two converging positions are substantially coincident with each other, so that the alignment accuracy of the workpiece 5 can be maintained, and similarly, the converging laser light and the alignment laser light are condensed. It is possible to realize a laser processing apparatus in which the positions are substantially the same and the position accuracy of alignment of a workpiece can be improved. More preferably, by setting the condition of | f ₁ −f ₂ | <f ₁ × 0.01, higher alignment accuracy can be realized.

Further, the laser processing apparatus of the present invention includes a laser light source, a nonlinear optical element which is arranged in the optical path of the laser light emitted from the laser light source, and which generates a higher harmonic wave of the laser light. It has a condensing optical system including a diffractive optical element, and the condensing optical system condenses the laser light and the harmonics at substantially equal positions.

According to the second aspect of the present invention, the converging positions of the processing laser light and the alignment light are the same, the positional accuracy of the alignment of the workpiece is improved, and one laser for processing and alignment is used. There is provided a laser processing apparatus configured by a system and capable of easily adjusting the optical axes of the processing laser light and the alignment light and adjusting the shaping of the beam shape.

In the present invention, a nonlinear optical element for generating a higher harmonics of the wavelength lambda ₂ to the laser light source optical path of the emitted and the wavelength lambda ₁ of the laser beam was placed, the wavelength lambda ₁ from a laser light source High-order harmonics are generated coaxially with the optical axis of the light flux. The diffractive optical element arranged in the condensing optical system condenses the fundamental wave of the wavelength λ ₁ from the laser light source and the higher harmonic of the wavelength λ ₂ at substantially equal positions.

Therefore, it is possible to obtain the same operational effect as in the case of the first aspect, and further,
Higher harmonics converted from wavelength lambda ₁ has a wavelength lambda ₁ of the light spot shape substantially coincides with the light spot shape, the wavelength lambda
Since it is generated on the optical axis equal to ₁ , no alignment is required to align the optical axes of the two light fluxes. Therefore, it is possible to configure a compact system without requiring a different laser system, and it is possible to more easily
The optical axes of the two laser beams can be aligned. Thus, the laser processing apparatus according to the second aspect of the present invention makes it possible to realize a more improved laser processing apparatus.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 4 show a first embodiment of the laser processing apparatus of the present invention. The embodiment of the present invention is configured as follows. As shown in FIG. 2, the laser processing apparatus 100 in this example includes a first laser light generating unit LS1 that generates a laser light having a _first wavelength λ _{1, and} a second laser light having a wavelength different from the _first wavelength λ ₁ . A second laser beam generating means LS2 for generating a laser beam of wavelength λ _{2 and} a focusing optical system including a diffractive optical element 23.

The above-mentioned principle of the diffractive optical element 23 is shown in FIG.
Relief pattern 2 consisting of a number of concentric rings shown
4 is a diffractive optical element, and here, the wave
Long λ ₁The light of the diffraction efficiency of the diffractive optical element 23
Highest diffraction order m₁Focus position by and wavelength λ_TwoLight of
The diffraction efficiency of this diffractive optical element 23 is the highest.
Fold order m_Two(However, m_Two≠ m₁), The focus position is
The configuration is set to match.

The laser processing apparatus 100 is based on such a configuration, and the principle and contents of a preferred example will be described in detail below with reference to FIG. 1 as well.
The basic principle of the diffractive optical element according to the present invention is
All of the following embodiments are applicable. In FIG. 1 or 2, a light flux 21 (laser light) having a _first wavelength λ _{1 and} a light flux 22 (laser light) having a second wavelength λ ₂ are respectively
The diffractive optical element 23 arranged in the condensing optical system irradiates the processed surface 5a of the processed object 5. At this time, the diffractive optical element 23 acts as a lens.

The relief pattern 24 on the diffractive surface of the diffractive optical element 23 has a groove depth d optimized so that the diffraction efficiency is highest for the first wavelength λ ₁ . That is, the groove depth d is calculated by the following formula (1) using the wavelength λ ₁ and the refractive index n of the base material forming the relief pattern.

[Equation 1] Becomes At this time, m ₁ is a diffraction order and is an integer other than 0. By setting the groove depth d in this way, it is possible to obtain a diffraction efficiency of almost 100% for a thin relief grating.

In addition, the first wavelength λ ₁ and the second wavelength λ _1
2 is set to be an integer ratio of m ₂ : m ₁ . That is, the wavelength λ ₁ and the wavelength λ ₂ are set so as to satisfy the relational expression of the following expression (2).

[Equation 2] However, even if the conditional expression (2) is not strictly satisfied, substantially the same action can be obtained if the first wavelength λ ₁ and the second wavelength λ ₂ satisfy the following conditional expression (inequality). become.

(Equation 3)

At this time, the groove depth d of the relief pattern 24 can be expressed by the following equation (3) from the equations (1) and (2).

(Equation 4) This is the relief pattern 24 having the same groove depth d.
, Which is equivalent to being optimized in the diffraction order m ₂ with respect to the wavelength λ ₂ . That is, if the wavelength λ ₁ and the wavelength λ ₂ are different,
The diffraction efficiency of the diffractive optical element 23 is about 1 at both wavelengths.
It is possible to set it to 00%.

On the other hand, as shown in FIG. 1, the relief pattern 24 is formed under the condition that the light beam having the wavelength λ is diffracted by the diffractive optical element 23 and is focused at the focal length f as shown in FIG. , R _p is the radius of the p-th relief grating from the center,

(Equation 5) Becomes From this, the focal length f is calculated by the following equation (5),

(Equation 6) It can be seen that if mλ is constant, the focal length f is also constant.

Here, the first wavelength λ ₁ and the second wavelength λ ₂
, The relational expression m ₁ λ ₁ = m in the above expression (2) is considered.
_{From 2} λ ₂ , it is possible to have the same focal length for both wavelength λ ₁ and wavelength λ ₂ . That is, with the same relief pattern 24, it is possible to make the converging positions of the diffractive optical element 23 coincident with each other for two different wavelengths λ ₁ and λ ₂ . Moreover, it is possible to focus light on both wavelengths without aberration. In addition, since the diffractive optical element 23 has substantially no thickness,
It is also possible to make the optical system compact.

Therefore, according to the above construction, laser light can be used for both processing and alignment, and
While avoiding a decrease in the alignment accuracy of the workpiece due to the difference in the converging positions of the two laser beams due to chromatic aberration, the converging positions of the processing laser beam and the alignment laser beam are equal, The positional accuracy of alignment of the workpiece 5 can be improved.

FIG. 2 specifically embodies this as follows. In FIG. 2, the LS1 uses a processing YAG laser as a first laser light generating means, and the laser generates and emits a laser light 21 having a _first wavelength λ ₁ of 1064 nm. On the other hand, the LS2 is an alignment light source as a second laser light generating means, and here, it is assumed that the laser light 22 having a _second wavelength λ ₂ of 532 nm is generated and emitted. The second laser light 22 is YA
It is generated as the second harmonic of the G laser light.

The laser light 21 is shaped into a predetermined beam by an optical system 16 (optical system 16 on the LS1 side in the figure) such as a beam expander, reflected by a dichroic mirror 12 ', and the optical path thereof is bent. afterwards,
Furthermore, the optical path is bent by the mirror 17 (right side in the figure),
The light enters the diffractive optical element 23 and is focused on the workpiece 5 on the stage 6.

The laser beam 22 is shaped into a predetermined beam by an optical system 16 (optical system 16 on the LS2 side in the figure) such as a beam expander, and its optical path is bent by a mirror 17 (left side in the figure). In this case, the light passes through the dichroic mirror 12 ′, follows the same path as the processing laser light 21, and is condensed at the same position as the processing laser light 21 by the diffractive optical element 23.

As shown in FIG. 1, the diffractive optical element 23 is composed of a large number of concentric rings, has a relief pattern 24 having a blazed cross section, and acts as a diffractive lens (r ₁ , r _2). , r ₃ , ..., R _p ··· are the radii of the relief lattice). Here, the groove depth d of the relief pattern 24 is, for example, BK for the substrate forming the relief surface.
7. If the refractive index n is set to 1.52, when optimized with respect to the primary light (m = 1) of the processing YAG laser (λ ₁ = 1064 nm), according to the above-described formula (1),
The following formula,

(Equation 7) Therefore, d = 2.05 μm.

The groove depth d is equal to the second harmonic (λ) of the YAG laser, as described in the explanation of the above principle.
_{The same} is true for secondary light (m = 2) of ₂ = 532 nm. That is, if the groove depth is d = 2.05 μm,
The other laser light 22 having the wavelength λ ₂ = 532 nm selected as the alignment laser light is also optimized (equations (2) and (3)).

Further, the relief pattern 2 selected to have such a groove depth d (d = 2.05 μm in the above example).
The laser beam processing apparatus 100 in which the diffractive optical element 23 having the number 4 is provided in the condensing optical system as shown in FIG. 2 is described above with reference to FIG. 1 and the respective equations (1) to (5). As described in the operational effects relating to optimization, diffraction efficiency, and aberration-free condensing, the diffractive optical element 23 can basically condense both laser beams 21 and 22 with the same focal length and without aberration. Possible, two laser lights 21,2
The light beams 2 will be condensed at the same position on the workpiece 5. Therefore, it is possible to perform processing while observing the focus position and the shape of the light spot on the processing target surface 5a of the processing YAG laser light 21 that is invisible light by the second harmonic that is visible light.

As described above, according to the first embodiment, the two converging positions of the processing laser light (21) and the alignment laser light (22) can be effectively matched,
It is possible to improve the positional accuracy of the alignment of the workpiece 5. According to this, it is possible to prevent the position accuracy of the alignment of the work piece from being deteriorated due to different condensing positions of the two laser beams when the optical system has chromatic aberration as in the conventional case. In addition, in the case of using an alignment light source other than the laser light source, a complicated optical system is required for efficient illumination, and the device becomes complicated and expensive, and alignment light other than the laser light is used. It is difficult to obtain a light spot equivalent to the original processing laser light on the surface to be processed because it has properties that are essentially different from the laser light, which causes a decrease in alignment position accuracy. The laser processing apparatus 100 without any disadvantage can be realized, and the diffractive optical element 23 to be used need not have a substantial thickness. Therefore, the optical system can be easily made compact, and in this respect as well. It is effective.

Here, some of the preferred embodiments are as follows. [ First Embodiment of First Embodiment ] In the above apparatus, the focal length f ₁ of the diffractive optical element 23 at the wavelength λ _{1 and} the focal length f ₂ of the wavelength λ ₂ are | f ₁ −f ₂ It is also possible to configure and implement so as to satisfy the condition of | <f ₁ × 0.05.

[0039] Thus, by using the diffractive optical element 23, the focal length of the wavelength lambda ₁ of the light f ₁ and wavelength lambda
The focal length f ₂ of the _second light, the above condition, i.e., |
When f ₁ −f ₂ | <f ₁ × 0.05 is satisfied, it can be considered that the two converging positions are substantially coincident with each other, so that the operation accuracy such as the positioning accuracy of the workpiece 5 can be maintained. To be In this example, it is possible to realize the laser processing apparatus 100 capable of improving the positional accuracy of the alignment of the workpiece 5 because the focusing positions of the processing laser light and the alignment laser light are substantially the same. Note that, more effectively, by using the following conditional expression instead of the above, that is, | f ₁ −f ₂ | <f ₁ × 0.01, higher alignment accuracy can be realized.

[ Second Embodiment of First Embodiment ]
Like ] Further, preferably, the first laser light generation means and the second laser light generation means may be implemented as configurations having different laser systems. Again,
It is possible to provide the laser processing apparatus 100 having the same operation and effect as described above, and further, by using different laser systems as means for generating the first and second laser beams, different oscillation modes for both laser beams can be obtained. Laser light of can be used. Thus, for example, the first
Even when the pulsed light is used as the laser light 22 for processing, the position of the workpiece 5 is aligned by using the laser light generation means that emits continuous wave light for alignment as the second laser light 21. It is also possible to obtain the operational effects such as easy operation.

[ Third Embodiment of First Embodiment ]
Also like], preferably, the second wavelength lambda _2, it is preferable to carried out selecting the wavelength corresponding to the harmonics of the first order wavelength lambda _1. In this case as well, it is possible to provide the laser processing apparatus 100 having the same action and effect as described above, and further obtain the following action and effect.

The wavelength of the jth harmonic of the laser light of wavelength λ ₁ can be expressed by λ ₁ / j. The wavelength lambda ₂ of the second laser beam, using the j-order harmonic of the wavelength lambda _1, the ratio of the wavelength lambda ₁ and wavelength lambda ₂ is j: becomes one integer ratio, be represented by the following formula (6) You can

(Equation 8)

Groove depth d on the relief surface of the diffractive optical element 23
Is set so that the diffraction efficiency of the first-order light of the wavelength λ ₁ is maximized, the groove depth d is expressed by the following equation (7).

[Equation 9]

At this time, from the above equations (6) and (7), the groove depth d of the relief pattern 24 is calculated by the following equation (8) using the jth harmonic of the wavelength λ ₁ (wavelength λ ₂ ). Can be expressed as

(Equation 10)

This is equivalent to the fact that the relief pattern 24 having the same groove depth d is optimized for the jth harmonic of the wavelength λ _{1 in} the diffraction order j. In addition, in the description of the function and effect relating to the first embodiment described with reference to FIGS. 1 and 2 and the respective equations (1) to (5), m ₁ =
1, and m ₂ = j, then in this case also m
₁ λ ₁ = m ₂ λ ₂ .

That is, as wavelength λ ₂ , j of wavelength λ ₁
When the next harmonic is used, the ratio between the wavelength λ ₂ and the wavelength λ ₁ is automatically an integer ratio, so that the same operation as that described in the first embodiment described above is performed. Therefore, the same effect as the effect described in the first embodiment can be obtained. Further, since higher-order harmonics can be generated by using a nonlinear crystal such as an LBO crystal or a BBO crystal, a wavelength λ ₂ that satisfies the conditional expression (2) with respect to the wavelength λ ₁
It is not necessary to select a laser which oscillates the same wavelength lambda ₁
With the laser having, the wavelength satisfying the condition (2) can be easily obtained. In this way, it is possible to realize the laser processing apparatus 100 in which the processing laser light and the alignment laser light have the same focus position and the alignment accuracy of the workpiece 5 is improved.

[ Fourth Embodiment of First Embodiment ]
Also like], preferably, the second wavelength lambda ₂ is a wavelength corresponding to a harmonic of the first-order wavelengths lambda _1, either the first or second laser beam, visible light It can also be configured and implemented as follows. In this case, the following operational effects are further exhibited. That is, when the second wavelength λ ₂ is a wavelength corresponding to a higher harmonic of the first wavelength λ ₁ and is in the visible range, the first laser light (wavelength λ ₁ ) is used for processing. Used for the second laser light (wavelength λ ₂ )
Is used for alignment. At this time, the same effect as the above [third embodiment] is obtained, and at the same time, even if the first laser light (wavelength λ ₁ ) is invisible light, Since irradiation is performed with visible light of λ ₂ (second laser light), the position of processing by the first laser light (wavelength λ ₁ ) and the shape of the light spot on the surface to be processed can be accurately observed.

[0048] Conversely, the second wavelength lambda ₂ is a wavelength corresponding to higher-order harmonics of the first wavelength lambda _1, when the first wavelength lambda ₁ is in the visible range, the second Is used for processing, and the first laser light is used for alignment. At this time, the same effect as [Third Embodiment] is obtained, and at the same time, even if the second laser light is invisible light, the work surface 5 is processed.
Since a is irradiated with visible light (first laser light) having a wavelength λ ₁ , it is possible to accurately observe the processing position by the second laser light and the shape of the light spot on the surface to be processed.

As described above, it is possible to realize the laser processing apparatus 100 which can perform alignment with visible light, has the same focusing positions of the processing laser light and the alignment laser light, and has improved the positional accuracy of the alignment of the workpiece 5. You can also The configuration of the embodiment of the present invention can be variously modified and changed, including the examples described so far, and the modifications specifically exemplified below are all examples. Is true.

For example, the relief pattern 24 of the diffractive optical element 23 is ideally a relief grating having a continuous blazed shape as shown in FIG. The same effect can be obtained with a binary diffractive optical element. In this case, although the diffraction efficiency is slightly lowered, the same problem can be achieved. Therefore, the present invention does not preclude such implementations.

Further, as the second laser light 22, a semiconductor laser or the like which emits wavelengths which are substantially coincident with each other may be used instead of using the second harmonic of the YAG laser. At this time, since the semiconductor laser is used for alignment of the workpiece 5, it is desirable to use a continuous wave laser.

Further, according to the above [second embodiment], when short pulse light is used as the processing laser light used in this embodiment, for example, a Q switch is inserted in the processing laser oscillator to operate the oscillator. It can be generated in a controlled manner and can therefore be used for processes such as seam welding, cutting, spot welding, drilling, etc. by utilizing pulsed light having a high peak value. In this case, it is necessary to appropriately select the output of the pulsed light used for processing, the pulse width, and the pulse repetition according to each application, and thus it is preferable to carry out such a method.

When continuous wave light is used as the processing laser light, a high power laser light obtained by arranging a plurality of laser medium rods in series is used to obtain a power density of about 10 ⁶ / cm ^2. Therefore, in this case, the application can also be used for processing such as welding of metals that require output of optical power density, soldering, brazing, trimming, and marking. In addition,
In the embodiment, the processing laser light and the second laser light are the same as those described in the first embodiment, regardless of their oscillation forms (short pulse light, continuous wave light, etc.). The effect of can be obtained.

Further, when infrared light having a wavelength of about 800 to 1500 nm is used for the processing laser, since the second harmonic becomes visible light, laser light of the same wavelength as the processing laser light is used as the second laser light. By using the second harmonic, the same effect as when the YAG laser (wavelength 1064 nm) is used as the processing laser can be obtained. When infrared light on the longer wavelength side is used as the processing laser light, 2
The same effect can be obtained by using, as the second laser light, light in the visible region with higher harmonics than the next.

The wavelength of the first laser light is from 400 to 400 nm.
If a visible laser light in the range of 800 nm is used for alignment and the second harmonic of the laser light having the same wavelength as the second laser light is used for processing, the wavelength of 20
Processing using light in the ultraviolet range of 0 to 400 nm is possible.

The two laser beams used in the present invention are not limited to the fundamental wave and its higher harmonics. For example, when ultraviolet light is used as the processing laser, it may be converted to an appropriate wavelength so as to satisfy the condition of the formula (2) by the nonlinear optical effect such as optical parametric conversion or Raman conversion. Moreover, you may use the several laser system which oscillates the wavelength which satisfy | fills the conditions of Formula (2).

Next, with reference to FIGS. 3 and 4, as a modified example of the first embodiment of the present invention, a function for observing the processing state and positioning of the workpiece 5 is added. An example of the laser processing apparatus 100 having the configuration will be described. In this embodiment,
In the basic configuration shown in FIG. 2 (FIG. 2), each laser light 21 emitted from both laser light generation means LS1 and LS2,
Since the configuration 22 is the same as the configuration shown in FIG. 2 until it enters the same path through the dichroic mirror 12 '(FIG. 2), FIG. 3 shows the subsequent configuration parts.

In the laser processing apparatus 100 shown in FIG. 3, the laser beam 21 is reflected by the illustrated dichroic mirror 12 to have its optical path bent, enters the diffractive optical element 23, and is focused on the workpiece 5 as described above. To be done. The laser light 22 is partially reflected by the dichroic mirror 12, enters the diffractive optical element 23, and is focused on the workpiece 5. Here, in the dichroic mirror 12,
The laser light 21 has such characteristics that it reflects almost 100% and partially transmits the laser light 22.

Of the irradiated laser light 22, the light reflected on the surface 5a to be processed is incident on the diffractive optical element 23 again, and a part of the light is transmitted through the dichroic mirror 12, and is passed through the alignment optical system 13. Then, the light enters the light receiving element 14 such as a photoelectric conversion type image pickup element.

Further, in this example, the irradiation light source 41 is installed as shown in FIG. The light flux emitted from the illumination light source 41 passes through the elliptical mirror 42 and the half mirror 45 and is processed 5
Is irradiated. Of the irradiated illumination light, the illumination light reflected by the surface 5 a to be processed is partially transferred to the light receiving element 14 via the diffractive optical element 23, the dichroic mirror 12, and the alignment optical system 13 as with the laser light 22. Incident. From the signal from the optical element 14, the state of the surface 5a to be processed can be displayed on the monitor 46. Therefore, the monitor 46
It can be used for confirming the processing state and positioning the converging position of the laser light while observing. The illumination light source is
If the illumination light intensity is sufficient to illuminate the workpiece 5, the epi-illumination as shown is not necessary. The present invention may be implemented in this manner.

In the above modification, when the processing laser light 21 and the alignment laser light 22 are separated,
Similar effects can be obtained by using, for example, a polarization beam splitter (FIG. 4) instead of the dichroic mirror 12. The basic configuration in this case is almost the same as the configuration shown in FIG. 3 as shown in FIG. 4, but in the laser processing apparatus 100 of this example, the polarization beam splitter 20 is arranged instead of the dichroic mirror 12. The λ / 2 plate 18 is arranged so as to be able to advance and retreat in the optical path before the incidence of the beam splitter 20, and its optical axis direction is inclined by about 45 ° with respect to the polarization direction of the laser beam. 20 in the optical path between the workpiece 20 and the workpiece 5
The difference is that the plate 19 is arranged so that it can move back and forth.

The polarization of the processing laser beam 21 and the alignment laser beam 22 is linearly polarized so that the polarization directions of the laser beam 21 are parallel to the plane of the paper in FIG. The polarization direction of the laser beam 22 is set to be perpendicular to the plane of the paper in FIG. 4, and at this time, the polarization beam splitter 20 is approximately 1 with respect to the p polarization component.
00% reflection and about 100% transmission for the s-polarized light component.

In the above-mentioned structure, at the time of alignment, the λ / 2 plate 18 and the λ / 4 plate 19 are inserted in the optical path as shown by the solid line in FIG. 4, and the polarization directions of both laser beams 21 and 22 are 90 °. Rotate. At this time, the processing laser beam 21
Is incident on the polarized beam slitter 20 as s-polarized light, the polarized beam splitter 20
Almost transparent.

On the other hand, the alignment laser beam 22
Is incident on the polarization beam splitter 20 as p-polarized light, the polarization beam splitter 2
Since it is almost reflected by 0, the laser light 21 and the alignment light 22 are separated. Further, the alignment laser light 22 has a wavelength of λ /
After passing through the four plates 19, it is irradiated as circularly polarized light on the surface 5a to be processed. Further, the light reflected on the surface to be processed 5a passes through the λ / 4 plate 19 again and becomes polarized light perpendicular to the paper surface in FIG. Therefore, most of the components of the reflected light pass through the polarization beam splitter 20 and enter the light receiving element 14.

When processing, λ inserted in the optical path
The / 2 plate 18 and the λ / 4 plate 19 are withdrawn as indicated by the broken line in FIG. Since the processing laser light 21 is incident on the polarization beam splitter 20 as p-polarized light, it is almost reflected by the polarization beam splitter 20 and is irradiated onto the processed surface 5a. On the contrary, the alignment laser beam 22 is emitted from the polarization beam splitter 20.
Since it will be incident as s-polarized light, it is almost transmitted by the polarization beam splitter 20.

With this structure, in the case of this example, the light amount loss due to the polarization beam splitter 20 is suppressed,
The effect that the light amount of the alignment light 22 can be effectively used at the time of alignment is further obtained.
In this case, a drive mechanism (not shown) is required to drive (advance and retreat) the λ / 2 plate 18 and the λ / 4 plate 19, but even when such a drive mechanism is provided, another optical system can be used. Unlike the case of driving, even if the position or the angle with respect to the optical axis varies a little, the direction of the optical axis of the transmitted light is hardly affected, so that a precise driving mechanism is not required as the driving mechanism.

Even if the λ / 4 plate 19 is installed in the optical path at the time of processing (the solid line in FIG. 4 does not move forward or backward), the action of the processing laser light 21 is essentially Does not change, so it may be always inserted in the optical path. Therefore, in this case, the number of drive mechanisms can be reduced (omitted) accordingly. However, it should be noted that the output of the processing laser light may be slightly decreased, and the surface of the λ / 4 plate may be damaged by the processing laser light.

In all of the above-mentioned embodiments, since different light sources are used for the processing laser light and the alignment light, respectively, the processing laser light 21 is a pulsed light and the alignment laser light 22 is a continuous wave light. It is possible to use a form of laser light.

For example, when processing a semiconductor wafer (workpiece 5) with the structure shown in FIG. 4, the alignment laser beam 22 is irradiated onto the alignment mark formed on the work surface, and the stage is processed. By monitoring the reflected light from the alignment mark of the alignment laser light 22 when the laser beam 6 is moved, the light receiving element 14 performs the reference alignment during processing.

Here, a pulsed laser is used for processing, but it is desirable to use continuous wave light as the alignment laser. In particular, when continuous wave light is used as the alignment laser, the resolution of scattered light and reflected light from the alignment mark can be improved, and the positioning accuracy of the target workpiece is improved. At this time, since the reflected light intensity of the alignment laser light 22 is measured, the illumination light source 41 and the monitor 46 are not necessary,
Can be omitted. Further, the light receiving element 14 need not be an image pickup element, but may be a photodiode, a photocell,
A photomultiplier or the like can be used.

Next, a second embodiment of the laser processing apparatus of the present invention will be described with reference to FIG. In the present embodiment, the converging positions of the processing laser light and the alignment light are equal to each other, the positional accuracy of the alignment of the workpiece is improved, and one laser system is used for the processing and the alignment. The purpose of the present invention is to realize a laser processing device in which it is easy to adjust the optical axes of the processing laser light and the alignment light and adjust the shaping of the beam shape.

Laser processing apparatus 110 according to the embodiment of the present invention is configured as follows. As shown in FIG. 5, the laser processing apparatus 110 in the present example includes a laser light source LS, a non-linear optical element 25 disposed in the optical path of the laser light of the laser light source, and generating high-order harmonics of the laser light. And a configuration having a condensing optical system including the diffractive optical element 23.

As the laser light source LS, here, a laser light source that emits YAG laser light is used as a processing laser light source, and the wavelength 106 emitted from the laser light source is used.
The laser light (YAG laser light) 31 of 4 nm (λ ₁ ) is
After being shaped into a predetermined beam shape by the optical system 16 similar to that shown in FIG. 2, it is reflected by the mirror 17 and is incident on the nonlinear optical element 25 arranged in the optical path of the laser beam 31. The laser light 31 coaxially generates a second harmonic wave 32 having a wavelength of 532 nm (λ ₂ ) in the nonlinear optical element 25.
The laser light 31 is reflected by the dichroic mirror 12, has its optical path bent, enters the diffractive optical element 23, and is focused on the workpiece 5.

Second generated by nonlinear optical element 25
Since the harmonic 32 is generated on the optical axis that coincides with the laser light 31 that is the fundamental wave, it follows a path coaxial with the laser light 31, and is partially reflected by the dichroic mirror 12 and processed by the diffractive optical element 23. The laser light 31 is focused at the same position. Here, the dichroic mirror 12
Has a characteristic that about 100% of the laser light 31 is reflected and part of the second harmonic 32 is transmitted.

The diffractive optical element 23 functions as a diffractive lens to focus the two laser beams 31 and 32 at the same position on the workpiece 5 as in the first embodiment. . In this way, the wavelength 5 is emitted in the optical path of the laser light 31 having the wavelength of 1064 nm emitted from the laser light source LS.
Nonlinear optical element 2 for generating second harmonic wave 32 of 32 nm
5, the second harmonic 32 can be generated coaxially with the optical axis of the laser light 31 of the fundamental wave, and the fundamental wave and the higher harmonics can be equalized by the diffractive optical element 23. It is focused on the position. Also, the processed surface 5a
Is irradiated with the light flux from the illumination light source 41.

In this example, the second harmonic wave 32 is used for alignment, and is reflected by the surface 5a to be processed as shown in FIG. 5 in the same manner as described in the first embodiment. The second harmonic 32 can be observed by the light-receiving element 14, and the image displayed on the monitor 46 can be used to confirm the processing state of the surface 5a to be processed and to position the converging position of the laser light 31. Also, in the case of this example, as described in the first embodiment, the dichroic mirror 12 is used.
The same effect can be obtained by using a polarization beam splitter (20; FIG. 4) instead of. In this case, when linearly polarized light is used as the processing laser light, the polarization direction of the second harmonic generated by the non-linear optical crystal is orthogonal to the polarization direction of the fundamental wave, so that it can be easily implemented.

In this example, by adopting such a configuration, although the means different from the first embodiment can be obtained, the same function and effect as in that case can be obtained, and a different laser system is not required, and the apparatus is compact. It is possible to configure various systems. In this second embodiment of the invention, the wavelength λ ₁ emitted from the first laser light source LS
A non-linear optical element 25 that generates a higher-order harmonic wave (here, the second harmonic wave 32 having a wavelength of 532 nm) of the wavelength λ ₂ is arranged in the optical path of the laser light (here, the YAG laser light 31 having a wavelength of 1064 nm). Then, higher harmonics are generated coaxially with the optical axis of the light flux of wavelength λ _{1. In} this case, the diffractive optical element 23 arranged in the condensing optical system is the same as the one described in the first embodiment. 3rd embodiment of the above], the fundamental wave of the wavelength λ ₁ and the higher harmonics of the wavelength λ ₂ can be condensed at substantially the same positions by the same operation as described above.

As described above, the same effect as the effect described in the first embodiment can be obtained, the converging positions of the processing laser beam and the alignment light are equal, and the alignment accuracy of the workpiece 5 is accurate. Is improved. Furthermore, the wavelength λ ₁
Higher harmonics converted from has a wavelength lambda ₁ of the light spot shape substantially coincides with the light spot shape, because they are produced on the optical axis is equal to the wavelength lambda _1, align the optical axes of the two light beams Does not need alignment for. According to this,
In addition to the processing laser device, it is not necessary to separately provide a light source such as a laser device for alignment, and a single laser system can be used for processing and alignment. Moreover, the conventional type requires an optical system for adjusting the optical axes of the processing laser light and the alignment light so that they are exactly the same, and when the processing laser is invisible light such as infrared light or ultraviolet light. Although adjustment of the optical axis alignment with the alignment light is not easy, such a point can be improved satisfactorily, and the optical axis alignment of the processing laser light and the alignment light and the adjustment of the beam shape can be easily adjusted. Therefore, because of the above, different laser systems are not required,
A more improved laser processing apparatus 11 capable of configuring a compact system and further easily aligning the optical axes of two laser beams.
0 can be realized.

The second embodiment of the present invention can also be modified and changed in various ways. Below, with respect to the configuration of the main part, what is shown by way of example in FIG. 6 is an example of such a modification. Particularly, in the prior art, this is an optical system for adjusting so that the optical axes of the processing laser light and the alignment light are exactly the same as mentioned above, and further, the alignment optical system. Requires an optical system for shaping so as to substantially match the beam shape (beam system, etc.) of the processing laser. Especially, when invisible light such as infrared light or ultraviolet light is used for the processing laser, Focusing on the difficulty of adjusting the optical axis alignment with the alignment light,
In the laser processing apparatus 110, the nonlinear optical element to be applied has an even number of nonlinear optical crystals of substantially the same shape, and the same number of nonlinear optical crystals are arranged so as to be symmetric with respect to a plane perpendicular to the optical axis. By arranging them and providing them with a structure that allows them to move back and forth, it is intended to realize even more effective improvements.

That is, in the laser processing apparatus 110 according to the second embodiment, as shown in FIG. 6, the nonlinear optical element 25 includes, for example, two nonlinear crystals 30 having the same shape, each having a phase matching condition. May be provided so as to be symmetrical with respect to the plane F perpendicular to the optical axis.

This embodiment has the following unique effects. That is, when arranged in this way, FIG.
As shown in FIG. 6A, the optical axis of the processing laser beam 31 before incident on the nonlinear crystal 30 and the optical axis on the exit side coincide with each other, so that the two nonlinear crystals 30 as shown in FIG. The optical axis of the processing laser light 31 does not change even if the laser beam is exited. Further, the second harmonic 32 is the processing laser beam 3
Since it has a beam shape that is substantially the same as that of 1 and is generated in the coaxial optical path, it is possible to easily perform the optical axis alignment of two laser beams without requiring an optical member for aligning the two optical axes. is there. Therefore, when performing alignment or the like, the nonlinear crystal 30 is inserted into the optical path of the processing laser light 31 to generate the second harmonic wave 32, and when processing, the nonlinear crystal 30 is exited and the processing laser light is emitted. It is possible to irradiate the processed surface 5a with all the energy of 31.

As described above, according to this modification, an even number of nonlinear crystals (here, two nonlinear crystals 30) having substantially the same shape as the optical axis of the laser light emitted from the laser light source LS (FIG. 5) are formed. Is arranged symmetrically with respect to the plane perpendicular to the phase optical axis, the optical axis does not change before and after passing through the nonlinear optical element. Further, the optical axis of the higher-order harmonic wave (here, the second harmonic wave) generated by the nonlinear optical crystal substantially coincides with the optical axis of the transmitted laser light. Further, the shape of the light spot of the higher harmonic wave is substantially the same as the shape of the light spot of the transmitted laser light.

As described above, by using the non-linear optical element having the above-mentioned configuration for the non-linear optical element 25 in the laser processing apparatus of the present embodiment, laser light having a desired beam shape with the optical axes aligned with each other is generated. be able to. Therefore, further improvement is added, and as in the case of FIG. 5, it is composed of one laser system,
Further, it is possible to realize the improved laser processing apparatus 110 in which the optical axes of the processing laser light and the alignment light are easily adjusted and the beam shape is easily adjusted.

In the above description using FIG. 6, the second
Although an example in which two nonlinear optical crystals used to generate the higher harmonic wave are arranged is shown, the present invention is not limited to this, and it is also possible to use an even number of four or six or more. Such increase to 4 or 6 or more also increases the second harmonic intensity by increasing the number of nonlinear optical crystals arranged in the optical path.
In this respect, stable alignment becomes possible. Then, at this time, a plurality of pairs of two nonlinear crystals having the same shape are used to satisfy the phase matching conditions,
By arranging so as to be symmetrical with respect to the plane perpendicular to the optical axis, the same effect as when using two nonlinear optical crystals (FIG. 6) can be obtained. Therefore, you may implement in this way.

When the output of the processing laser light 31 is larger than the damage threshold of the nonlinear optical crystal 30, it is preferable to limit the incident light intensity of the processing laser light 31 with a filter or the like during alignment. . Further, when it is not desired to irradiate the processing surface 5a with the processing laser light during the alignment, a colored glass filter 33 (FIG. 5) or the like is inserted in the optical path between the nonlinear optical element 25 and the processing surface 5a for processing. The second harmonic 32 for alignment, which shields the laser 31
It is advisable to irradiate only the workpiece 5 with the workpiece. The present invention may be embodied in such a manner.

The contents described above can be grasped as the following inventions. [1] Includes first laser light generating means for generating laser light of the first wavelength λ ₁ , second laser light generating means for generating laser light of the second wavelength λ ₂ , and diffractive optical element. A focusing position having a condensing optical system and having a diffraction order m ₁ having the highest diffraction efficiency of the diffractive optical element for light having a wavelength λ ₁ and light having a wavelength λ ₂ (where λ ₂ ≠ λ ₁ ) A laser processing apparatus characterized in that the focal positions according to the diffraction order m ₂ (where m ₂ ≠ m ₁ ) having the highest diffraction efficiency of the element are substantially coincident with each other.

[2] Focal length f ₁ at wavelength λ ₁ of the diffractive optical element and focal length f at wavelength λ _2
2 satisfies the condition of | f ₁ −f ₂ | <f ₁ × 0.05. [3] The laser processing apparatus according to the above-mentioned additional item [1] or [2], wherein the first laser light generating means and the second laser light generating means have different laser systems, respectively.

[4] The second wavelength λ ₂ is a wavelength corresponding to a higher harmonic of the first wavelength λ ₁ , and the additional items [1] to [3] above. The laser processing apparatus according to any one of claims. [5] The second wavelength λ ₂ is a wavelength corresponding to a higher harmonic of the first wavelength λ ₁ , and is the first or second wavelength.
Any one of the laser beams in 1 above is visible light, the laser processing apparatus according to the above-mentioned additional items [1] to [3]. [6] A condensing optical system including a laser light source, a nonlinear optical element arranged in the optical path of the laser light emitted from the laser light source to generate higher harmonics of the laser light, and a diffractive optical element. A laser processing apparatus having the condensing optical system for condensing the laser light and the harmonic at substantially equal positions. [7] Each of the non-linear optical elements has an even number of non-linear optical crystals of substantially the same shape, and the same number of non-linear optical crystals are arranged so as to be symmetric with respect to a plane perpendicular to the optical axis. The laser processing apparatus according to the above-mentioned additional item [6].

[0089]

According to the first aspect of the present invention, the laser light having the first wavelength λ ₁ and the second wavelength λ ₂ having a different wavelength from the laser light having the first wavelength λ ₁
It is possible to focus these laser lights with basically the same focal length and without aberration, and the processing laser light and the alignment laser light have the same focus position.
It is possible to realize a laser processing apparatus capable of improving the positional accuracy of alignment of a work piece, and when the optical system has chromatic aberration, the two laser light converging positions are different and the positional accuracy of alignment of the work piece deteriorates. In addition, the diffractive optical element to be used does not need to have a thickness, and the optical system can be easily made compact.

[0090] Further, the focal length f ₂ of the focal length f _1, and the wavelength lambda ₂ at a wavelength lambda ₁ of the diffractive optical element, | f ₁ -f ₂ | <When satisfy the condition construction of f ₁ × 0.05 Since it can be considered that the two converging positions are substantially coincident with each other, it is possible to further maintain the alignment accuracy of the workpiece and appropriately secure the alignment accuracy.

Further, according to the laser processing apparatus according to the second aspect of the present invention, the converging positions of the processing laser light and the alignment light are equal, the positional accuracy of alignment of the workpiece is improved, and in addition to this, Can be configured from one laser system for processing and alignment, and further, the optical axis alignment of the processing laser light and the alignment light,
The beam shape can be easily adjusted, different laser systems are not required, and a compact system can be configured. Further, the optical axes of the two laser beams can be easily aligned. It is possible to realize a more improved laser processing device such as.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a diagram showing a configuration of an embodiment (first embodiment) of a laser processing apparatus of the present invention.

FIG. 3 is a diagram showing a configuration of a modified example of the same embodiment and is a diagram showing a main part thereof.

FIG. 4 is also a diagram showing the configuration of another modification,
It is a figure which shows the principal part.

FIG. 5 is a diagram showing a configuration of another embodiment (second embodiment) of the laser processing apparatus of the present invention.

FIG. 6 is a diagram showing a configuration of a modified example of the same embodiment and is a diagram showing a main part thereof.

FIG. 7 is a diagram showing a schematic configuration of a conventional laser processing apparatus.

FIG. 8 is a diagram showing another example of a conventional laser processing apparatus.

[Explanation of symbols]

 5 Workpiece 5a Worked Surface 6 Stage 12 Dichroic Mirror 12 'Dichroic Mirror 13 Alignment Optical System 14 Photoreceptor 16 Optical System 17 Mirror 18 1 / 2λ Plate 19 1 / 4λ Plate 20 Polarized Beam Splitter 21 Laser Light 22 Laser Light 23 Diffractive optical element 24 Relief pattern 25 Nonlinear optical element 30 Nonlinear crystal 31 Laser light 32 Second harmonic 33 Color glass filter 41 Illumination light source 42 Elliptical mirror 45 Half mirror 46 Monitor 100 Laser processing device 110 Laser processing device LS Laser light source LS1 For processing Laser light source LS2 Alignment light source

Claims (3)

[Claims] 1. A first laser light generating means for generating a laser light of a _first wavelength λ ₁ , a second laser light generating means for generating a laser light of a _second wavelength λ ₂ , and a diffractive optical element. A focusing position by a diffraction order m ₁ having the highest diffraction efficiency of the diffractive optical element for light of wavelength λ ₁ and light of wavelength λ ₂ (where λ ₂ ≠ λ ₁ ). The diffraction order m ₂ (where m ₂ ≠
A laser processing device characterized in that the focal positions according to m ₁ ) are substantially the same. Wherein the focal length f ₁ at the wavelength lambda ₁ of the diffractive optical element, and the focal length f ₂ at the wavelength lambda _2, | f ₁ -f ₂ | <satisfies the condition of f ₁ × 0.05 The laser processing apparatus according to claim 1, which is characterized in that. 3. A laser light source, and a laser light source disposed in the optical path of the laser light emitted from the laser light source,
A nonlinear optical element that generates higher harmonics of the laser light and a condensing optical system including a diffractive optical element are provided, and the condensing optical system collects the laser light and the harmonic at substantially equal positions. A laser processing device that emits light.