KR20220005983A - Beam shaping optical device and method for modifying roundness - Google Patents

Abstract

Provided is a beam shaping optical device capable of bringing a beam cross-section close to a perfect circle. A correction optical element including a cylindrical mirror or a cylindrical lens is disposed on a path of a laser beam. A light-collecting optical element comprising a convex lens or a concave mirror is disposed on the path of the laser beam which has passed through the correction optical element. A support mechanism supports the correction optical element and supports the correction optical element so as to be movable in a direction in which an optical path length of the laser beam between the correction optical element and the condensing optical element changes. Accordingly, by changing the optical path length between the correction optical element and the condensing optical element, the amount of change in a diffusion angle can be adjusted.

Description

BEAM SHAPING OPTICAL DEVICE AND METHOD FOR MODIFYING ROUNDNESS

This application claims priority based on Japanese Patent Application No. 2020-117103 filed on July 7, 2020. The entire contents of the application are incorporated herein by reference.

The present invention relates to a beam shaping optical device and a method for adjusting roundness.

A conventional laser processing apparatus for performing punching processing on an object to be processed such as a substrate will be described. The laser beam output from the laser oscillator is guided to a concave mirror, and condensed to a predetermined size at a transfer source position of the beam expander. The beam expander transfers the beam cross-section at the transfer source position to the aperture position. A laser beam whose outer shape of the beam cross-section has become substantially circular due to the aperture is incident on the surface of the object to be processed through the galvanoscanner and the fθ lens.

In order to form a circular hole in the object to be processed, it is preferable to increase the roundness of the cross section of the beam on the surface of the object to be processed. Circularity refers to the size of an error from a geometrically correct circle of a circular body. For example, when a circular body is sandwiched between two concentric geometric circles, it can be expressed as a difference between the radii of the two circles when the distance between the two concentric circles becomes the minimum. The smaller the difference in radii, the closer the circular shape is to a perfect circle. Patent Document 1 below discloses a laser oscillator in which the roundness of the beam mode is improved by disposing mirrors having different radii of curvature in two orthogonal directions in the optical resonator of the laser beam.

Patent Document 1: Japanese Patent Application Laid-Open No. 2017-34055

In the conventional apparatus, the shape of the cross-section of the beam becomes circular due to the aperture, but the shape of the cross-section of the beam on the surface of the object to be processed may collapse from the circular shape. This is because the beam profile and the beam spread angle at the position where the aperture is arranged are different in the longitudinal direction and the transverse direction.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a beam shaping optical apparatus capable of making a beam cross-section close to a perfect circle and a method for adjusting the roundness.

According to one aspect of the present invention,

a correction optical component disposed in the path of the laser beam and comprising a cylindrical mirror or a cylindrical lens;

a condensing optical part disposed in the path of the laser beam passing through the correction optical part, and comprising a convex lens or a concave mirror;

A beam shaping optical apparatus having a support mechanism for movably supporting the correction optical part in a direction for changing the optical path length of the laser beam between the correction optical part and the condensing optical part is provided.

According to another aspect of the present invention,

Condensing the laser beam to a reference position via a correction optical component including a cylindrical mirror or a cylindrical lens, and a condensing optical component including a convex lens or a concave mirror;

There is provided a roundness adjustment method for changing the optical path length of the laser beam between the correction optical component and the condensing optical component to bring the cross section of the laser beam at the reference position close to a perfect circle.

When the correction optical component is arranged, one of the beam diffusion angles in two directions orthogonal to the optical axis of the laser beam is fixed and the other is changed. By changing the optical path length between the correction optical component and the condensing optical component, the amount of change in the diffusion angle can be adjusted. Thereby, the beam cross-section can be made close to a perfect circle.

Fig. 1 is a schematic diagram of a laser processing apparatus on which a beam shaping optical apparatus according to the present embodiment is mounted.
2 is a cross-sectional view including an optical axis of the laser oscillator.
3 is a cross-sectional view perpendicular to the optical axis of the laser oscillator according to the embodiment.
Fig. 4 is a schematic diagram of a beam shaping optical apparatus according to an embodiment.
5A to 5C are schematic diagrams showing the divergence and convergence of the laser beam when it is assumed that the laser beam goes straight without considering the bending of the path due to the reflection of the laser beam.
6A is a perspective view of a cylindrical concave mirror, an optical axis of an incident laser beam, and an optical axis of a reflected laser beam of a beam shaping optical device according to another embodiment, and FIG. 6B is a cylindrical concave mirror It is a diagram showing the change in the shape of the beam cross-section when the correction optical component is moved when the bus line is parallel to the x-axis. It is a diagram showing the change in the shape of the cross-section of the beam when it is lost.

A beam shaping optical apparatus according to an embodiment will be described with reference to 5C of FIGS. 1 to 5 .

1 is a schematic diagram of a laser processing apparatus in which a beam shaping optical apparatus 50 according to the present embodiment is mounted. The laser processing apparatus includes a laser oscillator 12 , a processing apparatus 80 , and a control apparatus 70 .

The laser oscillator 12 is supported on a mount 11 , and the mount 11 is fixed to a common base 100 . The processing apparatus 80 includes a beam shaping optical apparatus 50 , a beam scanner 81 , an fθ lens 82 , and a stage 85 . The object 90 is supported on the stage 85 . The beam shaping optical device 50 , the beam scanner 81 , the f? lens 82 , and the stage 85 are supported on a common base 100 . The common base 100 is, for example, a floor.

The laser oscillator 12 outputs a pulsed laser beam. As the laser oscillator 12, for example, a carbon dioxide laser oscillator is used. The pulsed laser beam output from the laser oscillator 12 has a beam profile shaped by the beam shaping optical device 50, and is incident on the object to be processed 90 via the beam scanner 81 and the fθ lens 82. . The beam scanner 81 scans a laser beam in two directions. The stage 85 moves the object 90 in two directions parallel to its surface. The control device 70 controls the beam shaping optical device 50 to make the shape of the beam cross-section close to a perfect circle.

The beam scanner 81 scans the laser beam in two directions and makes the pulsed laser beam incident on a desired position of the object 90, whereby punching is performed. When the scannable range of the pulsed laser beam does not cover the entire surface of the object 90 , by moving the object 90 by the stage 85 , approximately the entire surface of the object 90 is moved. can be processed.

FIG. 2 is a cross-sectional view including the optical axis of the laser oscillator 12 . The laser oscillator 12 includes a chamber 15 for accommodating the laser medium gas and the optical resonator 20 . A laser medium gas is accommodated in the chamber 15 . The inner space of the chamber 15 is divided into an optical chamber 16 positioned on the upper side and a blower chamber 17 positioned on the lower side. The optical chamber 16 and the blower chamber 17 are partitioned by an upper and lower partition plate 18 . However, the upper and lower partition plate 18 is provided with an opening through which the laser medium gas flows between the optical chamber 16 and the blower chamber 17 . The bottom plate 19 of the optical chamber 16 extends from the side wall of the blower chamber 17 in the direction of the optical axis 20A of the optical resonator 20, and the length of the optical chamber 16 in the optical axis direction is , is longer than the length of the blower chamber 17 in the optical axis direction.

The bottom plate 19 of the chamber 15 is supported by the mount 11 (FIG. 1) at the four support points 45. As shown in FIG. The four support points 45 are arrange|positioned in the position corresponding to the four vertices of a rectangle in planar view.

In the optical chamber 16, a pair of discharge electrodes 21 and a pair of resonator mirrors 25 are arranged. A pair of discharge electrodes 21 is fixed to the electrode box 22, respectively. The pair of electrode boxes 22 are supported on the bottom plate 19 through a plurality of electrode support members 23 . The pair of discharge electrodes 21 are arranged at intervals in the vertical direction, and a discharge region 24 is defined therebetween. The discharge electrode 21 generates a discharge in the discharge region 24 to excite the laser medium gas. A pair of resonator mirrors 25 constitute an optical resonator 20 having an optical axis 20A passing through the discharge region 24 . As will be described later with reference to FIG. 3 , the laser medium gas flows through the discharge region 24 in a direction perpendicular to the paper surface of FIG. 2 .

A pair of resonator mirrors 25 are fixed to a common resonator base 26 arranged in the optical chamber 16 . The resonator base 26 is a plate-shaped member elongated in the direction of the optical axis 20A, and is supported by the base plate 19 via a plurality of optical resonator support members 27 .

A light transmission window 28 for transmitting a laser beam is provided at the intersection of the extension line extending the optical axis 20A of the optical resonator 20 in one direction (left direction in FIG. 1) and the wall surface of the optical chamber 16. is fitted The laser beam excited in the optical resonator 20 passes through the light transmission window 28 and is radiated to the outside.

A blower 29 is arranged in the blower chamber 17 . The blower 29 circulates the laser medium gas between the optical chamber 16 and the blower chamber 17 .

Fig. 3 is a cross-sectional view perpendicular to the optical axis 20A (Fig. 2) of the laser oscillator 12 according to the embodiment. As described with reference to FIG. 2 , the inner space of the chamber 15 is divided into an upper optical chamber 16 and a lower blower chamber 17 by the upper and lower partition plates 18 . In the optical chamber 16, a pair of discharge electrodes 21 and a resonator base 26 are arranged. A pair of discharge electrodes 21 is fixed to the electrode box 22, respectively. The electrode box 22 is supported on the bottom plate 19 ( FIG. 2 ) of the chamber 15 by a plurality of electrode support members 23 . A discharge region 24 is defined between the pair of discharge electrodes 21 . The resonator base 26 is supported on the bottom plate 19 (FIG. 2) of the chamber 15 by a plurality of optical resonator support members 27. As shown in FIG. Since the electrode support member 23 and the optical resonator support member 27 are disposed at positions deviated from the cross section shown in FIG. 3, the electrode support member 23 and the optical resonator support member 27 are indicated by broken lines in FIG. is indicated as

A partition plate 40 is arranged in the optical chamber 16 . The partition plate 40 includes a first gas flow path 41 from the opening 18A provided in the upper and lower partition plate 18 to the discharge region 24 , and another provided in the upper and lower partition plate 18 from the discharge region 24 . A second gas flow path 42 up to the opening 18B is defined. The laser medium gas flows through the discharge region 24 in a direction perpendicular to the optical axis 20A (FIG. 2). The discharge direction is orthogonal to both the direction in which the laser medium gas flows and the optical axis 20A. A circulation path in which the laser medium gas circulates is formed by the blower chamber 17 , the first gas flow path 41 , the discharge region 24 , and the second gas flow path 42 . The blower 29 generates a flow of laser medium gas indicated by an arrow so that the laser medium gas circulates through this circuit.

The heat exchanger 43 is accommodated in the circulation path in the blower chamber 17 . The laser medium gas heated in the discharge region 24 is cooled by passing through the heat exchanger 43 , and the cooled laser medium gas is re-supplied to the discharge region 24 .

Next, with reference to FIG. 4, the beam shaping optical apparatus 50 according to this embodiment will be described.

4 is a schematic diagram of a beam shaping optical device 50 according to an embodiment. The beam shaping optical device 50 includes a correction optical component 51 , a condensing optical component 55 , a plane mirror 56 , a beam expander 60 , an aperture 61 , a plane mirror 62 , and a support mechanism ( 65 ), and a detector 66 . The correction optical component 51 includes a cylindrical concave mirror 52 and a plane mirror 53 . The condensing optical component 55 is a concave mirror having a spherical or parabolic reflective surface.

The laser beam output from the laser oscillator 12 is reflected by the cylindrical concave mirror 52 and is reflected by the plane mirror 53 to be incident on the condensing optical component 55 . The laser beam reflected by the condensing optical component 55 is reflected by the plane mirror 56 and is incident on the beam expander 60 . The beam expander 60 transfers the beam cross-section at the reference position 63 between the plane mirror 56 and the beam expander 60 by enlarging or reducing the beam diameter at the position of the aperture 61 . The reference position 63 is sometimes referred to as a full-on position. With respect to the beam expander 60, the reference position 63 and the position of the aperture 61 are in a conjugate relationship.

The aperture 61 shields the peripheral portion of the laser beam to shape the beam cross-section into a circular shape. The laser beam passing through the aperture 61 is reflected by the plane mirror 62 and is incident on the beam scanner 81 . For the beam scanner 81, for example, a galvanoscanner is used. The beam scanner 81 scans a laser beam in two directions. The fθ lens 82 condenses the laser beam scanned by the beam scanner 81 on the surface of the object 90 to be processed. For example, the fθ lens 82 forms an image of the aperture 61 on the surface of the object 90 to be processed.

The support mechanism 65 movably supports the correction optical component 51 along the optical axis of the laser beam between the correction optical component 51 and the condensing optical component 55 . The correction optical component 51 translates as indicated by the double arrows in FIG. 4 . The correction optical component 51 after movement is indicated by a broken line. The optical axis of the laser beam incident on the correction optical component 51 and the optical axis of the laser beam directed from the correction optical component 51 toward the condensing optical component 55 are parallel. The support mechanism (65) moves the correction optical component (51) while maintaining the relative positional relationship between the cylindrical concave mirror (52) and the plane mirror (53). For this reason, even if the correction optical component 51 is moved, the optical path length of the laser beam from the laser oscillator 12 to the condensing optical component 55 remains unchanged.

The detector 66 is movable between the reference position 63 on the path of the laser beam and the position deviated from the path of the laser beam, as indicated by the double arrows. In Fig. 4, the detector 66 located at the reference position 63 on the path of the laser beam is indicated by a broken line, and the detector 66 at a position deviated from the path of the laser beam is indicated by a solid line. The detector 66 detects the shape of the beam cross section of the incident laser beam. As the detector 66, for example, a beam profiler can be used.

The detection result by the detector 66 is input to the control device 70 . The control device (70) controls the support mechanism (65) based on the detection result of the detector (66) to move the correction optical component (51). Details of the control of the support mechanism 65 will be described later.

Next, the divergence and convergence of the laser beam in the beam shaping optical device 50 and the shape of the beam cross section will be described with reference to 5A to 5C of FIG. 5 .

5A to 5C are schematic diagrams showing the divergence and convergence of the laser beam when it is assumed that the laser beam goes straight without considering the bending of the path due to the reflection of the laser beam. xyz orthogonal with the direction parallel to the bus bar of the cylindrical surface of the cylindrical concave mirror 52 (FIG. 4) being the x direction, the plane perpendicular to the bus bar being the y direction, and the traveling direction of the laser beam being the z direction Define the coordinate system. For example, the x-direction corresponds to the direction (discharge direction) in which the pair of discharge electrodes 21 (FIG. 2) are spaced apart, and the y-direction corresponds to the laser medium gas in the discharge region 24 (FIG. 3). corresponds to the direction of flow.

5A and 5B in Fig. 5 show the divergence and convergence of the laser beam in the yz plane. 5A and 5B in Fig. 5 are different from each other in the position of the cylindrical concave mirror 52. As shown in Figs. In 5B of FIG. 5, the state similar to the state shown in FIG. 5A is shown by the broken line. 5C in Fig. 5 shows the divergence and convergence of the laser beam in the zx plane. In Figs. 5A to 5C, the optical axis 30 of the laser beam 31 output from the laser oscillator 12 is indicated by a double-dashed line. Here, the "optical axis of the laser beam" is a straight line connecting the centers of the beam cross-sections, and corresponds to a straight line extending the optical axis 20A of the optical resonator 20 in the laser oscillator 12 .

The laser beam 31 output from the laser oscillator 12 is guided to the reference position 63 via the cylindrical concave mirror 52 and the condensing optical component 55 . In this embodiment, at the exit of the laser oscillator 12, the beam cross section 32 of the laser beam 31 is an ellipse long in the x direction. Further, the diffusion angle θy of the laser beam 31 in the yz plane (5A, 5B in Fig. 5) is larger than the diffusion angle θx (5C in Fig. 5) of the laser beam 31 in the zx plane.

The cylindrical concave mirror 52 converges the laser beam 31 in the yz plane as shown in Figs. 5A and 5B. In the zx plane, the cylindrical concave mirror 52 functions as a plane mirror, and does not affect the convergence and divergence of the laser beam 31 .

The broken line shown in 5A of FIG. 5 shows the state of divergence and convergence of the laser beam 31 when a flat mirror is disposed instead of the cylindrical concave mirror 52. As shown in FIG. Since the diffusion angle θy of the laser beam 31 in the yz plane is larger than the diffusion angle θx of the laser beam 31 in the zx plane, the beam cross section 33 at the reference position 63 is shown in FIG. As shown by the broken line in 5A, it becomes an ellipse long in the y direction.

When the cylindrical concave mirror 52 is arranged, the laser beam 31 converges in the yz plane, and the divergence and convergence of the laser beam 31 are not affected in the zx plane. For this reason, the dimension of the beam cross-section 33 in the reference position 63 is reduced in the y direction. In the state shown in FIG. 5A, the amount of reduction in the y-direction of the beam cross-section 33 becomes excessively large, and the beam cross-section 33 becomes an ellipse long in the x-direction as indicated by a solid line.

As shown in Fig. 5B, when the cylindrical concave mirror 52 is moved toward the condensing optical component 55, the convergence force of the laser beam 31 in the yz plane is weakened. In the zx plane, even if the cylindrical concave mirror 52 is moved, the divergence and convergence of the laser beam 31 are not affected. As a result, the beam cross-section 33 at the reference position 63 extends in the y-direction from the beam cross-section 33 shown by the solid line in 5A of FIG. 5 . As shown to 5B and 5C of FIG. 5, the beam cross section 33 changes from the shape shown by the broken line to the shape shown by the solid line, and approaches a perfect circle.

Next, the function of the control device 70 (FIG. 4) will be described.

The control device 70 acquires the detection result from the detector 66 and detects the shape of the beam cross-section. Further, by controlling the support mechanism 65, the correction optical component 51 is moved in a direction in which the shape of the beam cross-section approaches a perfect circle. When the difference between the shape of the current beam cross-section and the roundness is within the allowable range, the control device 70 stops the correction optical component 51 .

Next, the excellent effect of this embodiment is demonstrated.

According to the evaluation experiment by the inventors of the present application, if the beam cross-section at the reference position 63 (FIG. 4), which is the transfer source of the beam expander 60, deviates from the perfect circle, the beam cross-section is set to the true circle by the aperture 61. Even when shaping, it became clear that the shape of the processed hole shifted|deviated from a perfect circle. This is because, even if only the outer shape of the beam cross-section at the position of the aperture 61 is formed into a perfect circle, the beam profile in the beam cross-section and the diffusion angle of the laser beam are different in the vertical direction and the horizontal direction orthogonal to the optical axis. . When the cross section of the beam at the reference position 63 was made close to a perfect circle, it was found that the processed hole became close to a perfect circle.

In this embodiment, the beam cross section at the reference position 63 can be made close to a perfect circle by adjusting the position of the correction optical component 51 (FIG. 4). When the cross-section of the beam at the reference position 63 approaches a perfect circle, the cross-section of the beam on the surface of the object 90 also approaches a perfect circle, making it possible to form a circular hole.

Further, in this embodiment, even if the correction optical component 51 (FIG. 4) is moved, the optical path length of the laser beam from the laser oscillator 12 to the condensing optical component 55 does not change. For this reason, when the movement of the correction optical component 51 affects the propagation state of the laser beam other than the divergence and convergence of the laser beam in the yz plane (5A, 5B in Fig. 5), none. Thereby, the number of parameters to be adjusted in order to make the beam cross-section close to a perfect circle is suppressed, and adjustment can be performed easily.

Next, a modified example of the above embodiment will be described.

Although the cylindrical concave mirror 52 (FIG. 4) is used for the correction optical component 51 in the above embodiment, a cylindrical concave mirror 52 may be used instead of the cylindrical concave mirror 52. That is, the correction optical component 51 may include a cylindrical mirror. Alternatively, instead of the cylindrical concave mirror 52, a cylindrical convex lens or a cylindrical concave lens may be used. When a cylindrical lens is used, the plane mirror 53 (FIG. 4) is unnecessary. As described above, as the correction optical component 51, an optical component having a cylindrical reflective surface or a refracting surface may be used. Incidentally, although a concave mirror is used as the condensing optical component 55 in the above embodiment, a convex lens may be used instead of the concave mirror.

In the above embodiment, the beam shaping optical apparatus 50 (FIG. 1) is mounted on a laser processing apparatus for performing punching, but may be mounted on other laser processing apparatuses. In particular, a great effect is obtained by mounting the beam in a laser processing apparatus which is required to process the beam cross-section close to a perfect circle. Incidentally, although a carbon dioxide laser is used as the laser oscillator 12, the beam shaping optical device 50 according to the above embodiment may be combined with various other laser oscillators.

In the above embodiment, the laser beam is incident on the plane mirror 53 after being reflected by the cylindrical concave mirror 52 (FIG. 4), but the positions of both may be exchanged. That is, the laser beam output from the laser oscillator 12 may be reflected by the plane mirror 53 and the reflected light may be incident on the cylindrical concave mirror 52 .

In the above embodiment, the control device 70 controls the support mechanism 65 to move the correction optical component 51 , but the user manually adjusts the support mechanism 65 to move the correction optical component 51 . you can do it

In the above embodiment, the correcting optical component 51 is disposed in the path of the laser beam between the laser oscillator 12 and the condensing optical component 55, but between the correcting optical component 51 and the condensing optical component 55 You may change the positional relationship. That is, the condensing optical component 55 may be disposed in the path of the laser beam between the laser oscillator 12 and the correction optical component 51 . Also in this case, by changing the optical path length of the laser beam between the correction optical component 51 and the condensing optical component 55, the beam cross section at the reference position 63 can be made close to the perfect circle.

Next, a beam shaping optical apparatus according to another embodiment will be described with reference to 6A to 6C of FIG. 6 . Hereinafter, a description of the configuration common to the beam shaping optical apparatus according to the embodiment shown in 5C of FIGS. 1 to 5 will be omitted.

6A of FIG. 6 is a cylindrical concave mirror 52 of the beam shaping optical device according to the present embodiment, an optical axis 30A of a laser beam incident on the cylindrical concave mirror 52, and an optical axis of a reflected laser beam ( 30B) is a perspective view. The beam shaping optical device 50 according to the present embodiment includes a posture adjustment mechanism 67 . The posture adjustment mechanism 67 bisects the angle formed by the optical axis 30A of the laser beam incident on the cylindrical concave mirror 52 and the optical axis 30B of the laser beam reflected from the cylindrical concave mirror 52 . As the rotational center (35), the posture of the cylindrical concave mirror (52) in the rotational direction is changed. The rotation center 35 is perpendicular to the reflective surface of the cylindrical concave mirror 52 .

Next, with reference to 6B and 6C of FIG. 6, the excellent effect of this embodiment is demonstrated.

6B is a diagram showing a change in the shape of the beam cross-section 33 when the correction optical component 51 is moved when the bus bar of the cylindrical concave mirror 52 is parallel to the x-axis. Since the bus bar of the cylindrical concave mirror 52 is parallel to the x-axis, when the correction optical component 51 is moved, the beam cross-section 33 is extended and reduced in the y-direction. When the long axis of the cross section of the beam indicated by the broken line before roundness adjustment is inclined with respect to the y direction, the cross section of the beam 33 does not become a perfect circle even if the cross section of the beam 33 is extended and reduced in the y direction.

When the posture in the rotational direction of the cylindrical concave mirror 52 is changed, the direction in which the beam end face 33 is expanded and contracted by moving the correction optical component 51 is inclined with respect to the y direction.

6C of FIG. 6 is a figure which shows the change of the shape of the beam cross-section 33 when the direction which expands and contracts the beam cross-section 33 is inclined with respect to the y direction. The posture in the rotational direction of the cylindrical concave mirror 52 is adjusted so that the direction of expansion and contraction coincides with the major axis direction of the beam cross section indicated by the broken line. For this reason, by disposing the cylindrical concave mirror 52, the beam cross-section 33 is reduced in the longitudinal direction of the beam cross-section indicated by the broken line. By moving the correction optical component 51 to adjust the reduction amount of the beam cross-section 33, the beam cross-section 33 can be made close to a perfect circle.

Each of the above-described embodiments is an example, and it goes without saying that partial substitutions or combinations of configurations shown in other embodiments are possible. The same operation and effect due to the same configuration of the plurality of embodiments will not be separately mentioned for each embodiment. In addition, the present invention is not limited to the above-described embodiment. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like are possible.

11 trestle
12 laser oscillator
15 chamber
16 Optical Room
17 blower room
18 upper and lower partition plate
18A, 18B openings
19 base plate
20 optical resonators
20A optical axis
21 discharge electrode
22 electrode box
23 Electrode support member
24 discharge area
25 resonator mirror
26 resonator base
27 Optical resonator support member
28 light transmission window
29 blower
Optical axis of 30, 30A, 30B laser beam
31 laser beam
32 Beam cross-section at the exit of the laser oscillator
33 Beam cross-section at the reference position
35 center of rotation
40 partition plate
41 first gas flow path
42 second gas flow path
43 heat exchanger
45 support
50 Beam Orthopedic Optical Device
51 Correction Optical Components
52 Cylindrical concave mirror
53 flat mirror
55 Condensing Optical Components
56 flat mirror
60 Beam Expander
61 aperture
62 flat mirror
63 reference position
65 support mechanism
66 detector
67 Posture adjustment mechanism
70 control
80 processing equipment
81 Beam Syringe
82 fθ lens
85 stage
90 Processing object
100 common base

Claims (7)

a correction optical component disposed in the path of the laser beam and comprising a cylindrical mirror or a cylindrical lens;
a condensing optical part disposed in the path of the laser beam passing through the correction optical part, and comprising a convex lens or a concave mirror;
and a support mechanism for movably supporting the correction optical component in a direction for changing an optical path length of a laser beam between the correction optical component and the condensing optical component. According to claim 1,
The correction optical component includes a cylindrical concave mirror and a plane mirror,
The optical axis of the laser beam on the entrance side of the correction optical component and the optical axis of the laser beam on the exit side are parallel to each other,
The support mechanism is a beam shaping for supporting the correction optical component so as to be movable in a direction parallel to the optical axis of the laser beam at the entrance and the exit side while maintaining the relative positional relationship between the cylindrical concave mirror and the plane mirror. optics. 3. The method of claim 2,
Changing the posture of the rotational direction of the cylindrical concave mirror with the bisector of an angle between the optical axis of the laser beam incident on the cylindrical concave mirror and the optical axis of the laser beam reflected from the cylindrical concave mirror as the center of rotation A beam shaping optical device further having a posture adjustment mechanism. 4. The method according to any one of claims 1 to 3,
a detector for detecting a shape of a beam cross section at a reference position of a path of a laser beam passing through the correction optical part and the condensing optical part;
and a control device for moving the correction optical part by operating the support mechanism so that the shape of the cross-section of the beam detected by the detector is close to a perfect circle. 5. The method of claim 4,
a beam expander disposed in the path of the laser beam passing through the reference position;
Further having an aperture disposed in the path of the laser beam through the beam expander,
The beam expander is a beam shaping optical device for transferring the cross section of the laser beam at the reference position to the position of the aperture. Condensing the laser beam to a reference position via a correction optical component including a cylindrical mirror or a cylindrical lens, and a condensing optical component including a convex lens or a concave mirror;
A method of adjusting the roundness of the laser beam at the reference position by changing the optical path length of the laser beam between the correction optical part and the condensing optical part to approximate a perfect circle. 7. The method of claim 6,
The correction optical component includes a cylindrical concave mirror,
In addition, with the bisector of the angle between the optical axis of the laser beam incident on the cylindrical concave mirror and the optical axis of the laser beam reflected from the cylindrical concave mirror as the rotational center, the posture in the rotational direction of the cylindrical concave mirror is A method of adjusting the roundness of the laser beam at the reference position by changing it to approximate a perfect circle.

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