Optical apparatus, processing method, and method for manufacturing articles

Abstract

To improve accuracy in laser processing.SOLUTION: An optical device processes an object by irradiating the object with a laser beam. The optical device comprises: a focus position adjustment mechanism that adjusts a focus position of a laser beam; and a converging-angle changing mechanism that changes a converging angle of a laser beam made which is made incident to the object, by varying a beam diameter of a laser beam that is made incident to the focus position adjustment mechanism so that the diameter becomes smaller, as the focus position moves in an advancing direction of the laser beam from a laser incident surface side of the object.SELECTED DRAWING: Figure 5

Description

Technical Field

[0003] , , , , , ,

[0001] The present invention relates to an optical device, a processing method, and a method for manufacturing an article.

Background Art

[0002] An optical scanning device in a laser processing apparatus or the like may include a translation optical system, a condenser optical system, and a deflection optical system so as to condense and irradiate light from an orientation (θx, θy) at a position (x, y, z) on an object. The translation optical system is an optical system that translates (parallel-shifts) the light incident on the condenser optical system described later in order to change the orientation (Patent Document 1). The condenser optical system is an optical system that changes the focal position (z) of light in order to condense it on the object. The deflection optical system (also referred to as a scanning optical system) includes, for example, a deflection optical element such as a mirror, and is an optical system that changes the irradiation position (x, y) of light. Among these optical systems, the translation optical system of Patent Document 1 includes a rotatable reflecting member having a first reflecting surface and a second reflecting surface. Further, it includes an optical system that sequentially reflects the light reflected by the first reflecting surface by a plurality of reflecting surfaces and makes it incident on the second reflecting surface. Furthermore, it includes an adjustment unit that adjusts the optical path of the light reflected by the second reflecting surface and emitted from the reflecting member by changing the rotation angle of the reflecting member. With such a configuration, translation (parallel shift) of the light emitted from the reflecting member is realized. Further, by arranging two sets of the translation optical systems, light can be translated in two axial directions. When the light emitted from the reflecting member is incident on the condenser optical system (condenser lens) in a parallel eccentric manner, convergent light inclined at an inclination angle determined by the amount of eccentricity and the focal length of the condenser optical system is emitted from the condenser optical system. The convergent light can be, for example, irradiated onto an object in an optical processing apparatus and used for processing the object such as drilling by thermal or wave effects.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] In optical processing equipment using the optical scanning device described above, when drilling holes, the laser beam is scanned in the in-plane direction (x and y directions) of the object, and the focal point is lowered from the surface (laser incident side) to the back surface (laser emission side) of the object to perform the processing.

[0005] However, when the focal point is lowered to the back surface of the object, the beam at the surface height of the object has a large diameter, which means the beam overlaps with the edges of the surface, preventing it from reaching deep enough to drill a deep hole.

[0006] The present invention aims to solve the above-mentioned problems and to improve the accuracy of laser processing. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides an optical apparatus for processing an object by irradiating it with laser light, comprising: a focal position adjustment mechanism for adjusting the focal position of the laser light; and a focusing angle changing mechanism for changing the focusing angle of the laser light incident on the object by reducing the beam diameter of the laser light incident on the focal position adjustment mechanism as the focal position moves from the laser incident surface side of the object toward the direction of propagation of the laser light, wherein the focusing angle changing mechanism is Based on the processing time of the hole to be processed in the object, the beam diameter of the laser light incident on the focal position adjustment mechanism is changed. The method is characterized by changing the focusing angle such that the beam diameter of the laser light at the surface position of the object becomes smaller than the diameter or side of the hole formed at the surface position of the object, based on the diameter or side of the hole formed at the surface position of the object, the distance from the surface position of the object to the focal position, and the angle of incidence of the laser light incident on the object. [Effects of the Invention]

[0008] According to the present invention, the above-mentioned problems can be solved and the accuracy of laser processing can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows a partial configuration example of the optical device according to this embodiment. [Figure 2] This figure shows an example configuration of a drive unit that changes the angle of a reflective member. [Figure 3] This figure shows another example of a configuration of an optical device. [Figure 4] This figure shows an example configuration of a laser processing apparatus including a translation optical system. [Figure 5] This figure shows an example configuration of a laser processing apparatus according to this embodiment. [Figure 6] This is a schematic diagram illustrating an example of the hole-drilling process using a laser processing machine. [Figure 7] This diagram shows the shape of the drilled hole and the beam focusing process during the drilling process. [Figure 8] This figure shows numerical examples of processing when the beam focusing angle is changed. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the attached drawings. Throughout the drawings illustrating the embodiments, the same reference numerals will be used for identical components, etc., unless otherwise specified, and repeated descriptions will be omitted.

[0011] [Embodiment of a processing apparatus] Figure 1 shows an example of a part of the configuration of an optical device according to this embodiment. The optical device in this embodiment can control the path of the emitted light (optical path), and for example, it can translate (parallel shift) the light ray. The optical ray parallel shift mechanism (translational optical system) of this embodiment includes a mirror member 2 (also called a reflecting member) that reflects the light ray 51 from the laser light source 50. In the following description, each reflecting surface can be considered as a plane, and examples are given for the case in which the optical path is translated. The mirror member 2 is made of glass, for example, and has a first reflecting surface 2a that receives the light ray 51 from the laser light source 50 and a second reflecting surface 2b on the opposite side. The first reflecting surface 2a and the second reflecting surface 2b are each coated with a coating having high reflectivity. The mirror member 2 may be configured in a prism shape, or the first reflecting surface 2a and the second reflecting surface 2b may be configured independently.

[0012] Furthermore, the mirror member 2 is configured to be angle-variable so that the optical path of the light emitted from the optical device can be controlled (changed). Here, Figure 2 is a diagram showing an example of the configuration of the drive unit (1) for changing the angle of the reflective member (2). As shown in the figure, the mirror member 2 is pivotally supported on the output shaft 1a of the (galvano) motor 1 (drive unit). The control unit 60 outputs a drive signal to the motor 1, and the motor 1 rotates the mirror member 2 via the output shaft 1a by a drive amount corresponding to the drive signal. In this way, the mirror member 2 is configured to be rotatable (angle-variable). Here, the mirror member 2 is tilted at approximately 45 degrees with respect to the light ray 51 from the laser light source 50. In this specification, such a mirror member is called a galvano mirror optical system. Note that the mirror member 2 only needs to be configured so that it can control the optical path of the light emitted from the optical device, and is not limited to this configuration.

[0013] Returning to Figure 1, the translational optical system has an optical system 80 that sequentially reflects the light reflected by the mirror member 2 at multiple reflective surfaces and causes it to enter the mirror member 2. The optical system 80 includes, for example, four mirrors 3, 4, 5, 6 (reflective surfaces) that are fixedly arranged so as to be symmetrical with respect to the light ray 51. The light reflected by the first reflective surface 2a of the mirror member 2 is sequentially reflected by these mirrors 3, 4, 5, 6 and guided to the second reflective surface 2b of the mirror member 2. The light that is finally reflected by the second reflective surface 2b and emitted from the mirror member 2 has a direction of propagation that is substantially the same (substantially parallel) to the direction of propagation of the light ray 51.

[0014] The angle (direction of travel) of the emitted light does not change even if the rotation angle of the mirror member 2 is changed. Therefore, by controlling the rotation angle of the mirror member 2 with the control unit 60, the path of the light reflected by the second reflective surface 2b and emitted from the mirror member 2 can be adjusted (translation or parallel shift).

[0015] Figure 3 shows another example of a configuration of a part of the optical device. This configuration is a combination of the configuration shown in Figure 1 and includes a first translational optical system 61 that receives light rays 51 from a laser light source 50 and a second translational optical system 62 that receives light emitted from the first translational optical system 61. The first translational optical system 61 has angle-adjustable mirror members 13 that reflect the light rays 51 from the laser light source 50. The first translational optical system 61 also has mirrors 14-1, 14-2, 14-3, and 14-4. The second translational optical system 62 has angle-adjustable mirror members 15 that reflect the light rays emitted from the first translational optical system. The second translational optical system 62 also has mirrors 16-1, 16-2, 16-3, and 16-4. The rotation axis 63 of the mirror member 13 of the first translational optical system 61 and the rotation axis 64 of the mirror member 15 of the second translational optical system 62 are arranged to be non-parallel, for example, orthogonal.

[0016] In the first translation optical system 61, the incident light reflected by the first reflection surface of the mirror member 13 is sequentially reflected by the mirrors 14-1, 14-2, 14-3, 14-4 and guided to the second reflection surface on the side opposite to the first reflection surface of the mirror member 13. The light reflected by the second reflection surface and emitted from the mirror member 13 enters the mirror member 15 of the second translation optical system 62. In the second translation optical system 62, the incident light reflected by the first reflection surface of the mirror member 15 is sequentially reflected by the mirrors 16-1, 16-2, 16-3, 16-4 and guided to the second reflection surface on the side opposite to the first reflection surface of the mirror member 15. Finally, the light reflected by the second reflection surface of the mirror member 15 and emitted from the mirror member 15 has a traveling direction substantially the same as (substantially parallel to) the traveling direction of the light beam 51. As shown in FIG. 3, an arrangement may be adopted in which the plane formed by the optical path formed by reflection by each mirror of the first translation optical system 61 intersects the plane formed by the optical path formed by reflection by each mirror of the second translation optical system 62. By arranging the two translation optical systems to intersect in this way, miniaturization of the optical device can be achieved.

[0017] Here, a processing apparatus including the translation optical system described above and an optical system for guiding (irradiating) the light emitted from the translation optical system to an object (target object) will be described. FIG. 4 is a diagram showing a configuration example of a laser processing apparatus including a translation optical system. The laser processing apparatus shown in FIG. 4 includes the translation optical system 17 described with reference to FIG. 3 on the rear side (the subsequent stage) of the laser light source 71. On its rear side, it includes an enlarging optical system, which enlarges the diameter of the light beam by a required amount. The enlarging optical system includes a lens 18 and a collimating lens 19. Further, on the rear side of the enlarging optical system, it includes a condensing optical system (condensing lens 22), which condenses and irradiates the laser light onto the object 23 arranged on its focal plane. Also, between the enlarging optical system and the condensing optical system, (galvano) mirrors 20, 21 (deflection optical system) are included, and by adjusting the rotation angle thereof, light is irradiated onto the target incident position (x, y) on the object 23. That is, it can be said that the (galvano) mirrors 20, 21 are an incident position adjustment mechanism for adjusting the incident position of light. The (galvano) mirrors 20, 21 adjust the incident position where the laser light enters the object 23 in a direction perpendicular to the focal direction of the laser light.

[0018] According to the above configuration, the light rays incident on the condensing optical system can be translated and decentered by the translation optical system 17, and the angle (incident angle) of the light rays emitted from the condensing optical system and incident on the object 23 can be changed (or adjusted). That is to say, the translation optical system 17 can be said to be an angle adjustment mechanism. Also, by adjusting the relative distance between the lens 18 and the collimating lens 19 in the magnifying optical system, the position of the focal plane irradiated on the object 23 can be changed. As a result, it is possible to form a tapered hole or perform a cut having an inclined cross section on the object.

[0019] Here, the laser processing apparatus 100 as the optical apparatus according to the present embodiment will be described. FIG. 5 is a diagram showing a configuration example of the laser processing apparatus 100 according to the present embodiment. As shown in FIG. 5, the laser processing apparatus 100 is configured to perform laser processing by irradiating an object with light rays from the laser light source 71 through an optical apparatus including the above-described translation optical system, magnifying optical system, deflection optical system, and condensing optical system. As this laser light source 71, for example, a femtosecond solid-state laser having an oscillation wavelength of 1030 nm, a frequency of 100 kHz, a pulse width of 350 fs (femtosecond), and an output of 100 μJ / pulse can be used. As the object 23, for example, a stainless steel plate (SUS304) or the like can be used.

[0020] Also, the lens 18 included in the magnifying optical system is fixed on the linear stage 34. The control unit 60 outputs a drive signal to the linear stage 34, and the linear stage 34 moves the lens 18 in the optical axis direction by a driving amount corresponding to the drive signal. Thereby, the position of the focal plane irradiated on the object 23 can be changed. That is to say, the linear stage 34 functions as a focal position adjustment mechanism. Also, as the focal position adjustment mechanism, a mechanism for moving the condensing lens 22 included in the condensing optical system in the optical axis direction may be used.

[0021] Furthermore, the laser processing apparatus 100 includes a reduction optical system between the laser light source 71 and the translation optical system 17, thereby reducing the diameter of the light ray to the required amount. The reduction optical system includes a lens 24 and a collimating lens 25. The lens 24 is fixed on a linear stage 31. The control unit 60 outputs a drive signal to the linear stage 31, and the linear stage 31 moves the lens 24 in the optical axis direction by a drive amount corresponding to the drive signal. This reduces the diameter of the light ray. Alternatively, a beam expander that can adjust the diameter of the light ray to the required amount may be used as the reduction optical system. Furthermore, an aperture diaphragm that can adjust the diameter of the light ray to the required amount may be used as the reduction optical system. The light ray emitted from the laser light source 71 is irradiated onto the object 23 via an optical device including the reduction optical system, translation optical system, magnification optical system, deflection optical system, and focusing optical system.

[0022] The object 23 is fixed and supported by a vacuum chuck 33 on an XY stage 32 that is movable in a plane perpendicular to the optical axis of the focusing optical system. The XY stage 32 has an XY plane perpendicular to the optical axis of the focusing optical system, and a Z axis parallel to the optical axis of the focusing optical system. The XY stage 32 is controlled by a computer device 35 via a stage controller 36.

[0023] Here, we will explain the procedure for drilling holes in object 23 using the laser processing apparatus 100 described above. The laser beam (light ray) emitted from the laser light source 71 is scanned in the in-plane direction (in this case, the XY direction) of the surface of object 23, and the focal position is lowered from the surface (laser incident side) to the back side (laser emission side) of object 23 to perform the processing. When the laser beam is irradiated onto object 23, a part of object 23 near the focal position is locally heated and removed. This type of drilling method is generally called trepanning.

[0024] Figure 6 is a schematic diagram illustrating an example of the drilling process of the laser processing apparatus 100. Figure 6(A) shows an example of the trajectory of the focal position of the laser beam during drilling. As shown in the figure, the laser processing apparatus 100 sequentially removes a portion of the object 23 locally near the focal position with the laser beam, for example, while drawing a circular trajectory. First, the focal position is aligned with the surface of the object 23, and the laser beam is scanned in the in-plane direction, thereby removing a portion of the object 23 in the scanned plane near the surface. Next, the focal position is lowered slightly from the surface to the back of the object, and the laser beam is scanned in the in-plane direction in the same way, thereby removing a portion of the object 23 in the scanned plane. Figure 6(B) shows the state when the focal position is lowered from the surface to the back of the object. At this time, a portion of the object 23 is removed in the depth direction by the amount by which the focal position has been lowered. By repeating this sequentially, drilling is performed while removing the object 23 in the depth direction.

[0025] However, when the focal point is lowered to near the back surface of object 23, the beam spreads out at the surface height of object 23, causing the beam to hit (irradiate) the edge portion 231 of the surface, resulting in the beam not reaching deep enough to drill a deep hole. Figure 6(C) shows the state when the focal point is lowered to near the back surface of object 23.

[0026] Figure 7 shows the shape of the processed hole and the beam focusing during drilling. Here, the processed hole refers to the hole drilled in the object 23. Figure 7(A) shows the shape of the processed hole and the beam focusing when the beam focusing angle is relatively large. As shown in Figure 7(A), when the focal position is lowered to near the back surface during the process of drilling into the object 23, the beam at the surface position 232 of the object 23 becomes defocused, and the beam diameter becomes wider than the focused spot diameter at the focal position. As shown in this figure, this widened beam hits the edge portion 231 of the surface of the processed hole, and a portion of the beam is cut off. Consequently, some of the energy of the laser beam does not reach the focal position, the removal capability at the focal position decreases, and it becomes impossible to drill further into the object 23.

[0027] Conversely, if the beam focusing angle is reduced to avoid beam contact, the diameter of the focused spot at the focal point becomes larger, which presents a problem as it prevents fine machining. Figure 7(B) shows the shape of the machined hole and the beam focusing when the beam focusing angle is smaller than that in Figure 7(A). As shown in Figure 7(B), when the beam focusing angle is reduced, the beam diameter at the surface height of the object 23 becomes smaller compared to Figure 7(A). Therefore, the beam does not come into contact with the edge portion 231 of the surface, but the diameter of the focused spot at the focal point becomes larger. When the laser beam is irradiated onto the object 23 in this state, a part of the object 23 is locally heated and removed near the focal point, but the volume of this removal becomes larger. In hole drilling using a pulsed laser, if the volume of removal per pulse during laser beam irradiation becomes large, the machining resolution deteriorates, and fine machining becomes impossible.

[0028] Therefore, in this embodiment, the beam focusing angle is changed by changing the diameter of the laser beam incident on the focusing optical system as the focal position of the laser beam moves from the front to the back of the object 23, that is, in the direction of laser light propagation. In other words, the beam focusing angle is changed by changing the diameter of the laser beam incident on the focusing optical system as the processing depth of the object 23 by the laser beam increases. That is, the beam focusing angle is made different when processing the vicinity of the front surface of the object 23 and when processing the vicinity of the back surface. Specifically, when processing the vicinity of the front surface of the object 23, the position of the lens 24 of the reduction optical system is adjusted to increase the diameter of the laser beam incident on the focusing optical system, thereby increasing the beam focusing angle at the focal position and performing processing. Then, the focal position is gradually moved from the front to the back surface. When processing the vicinity of the back surface of the object 23, the position of the lens 24 of the reduction optical system is adjusted to decrease the diameter of the laser beam incident on the focusing optical system, thereby decreasing the beam focusing angle at the focal position and performing processing. In other words, the reduction optical system also functions as a focusing angle changing mechanism that alters the beam focusing angle of the laser light incident on object 23.

[0029] The reduction optical system changes the laser beam diameter based on the diameter D of the hole (machined hole) to be machined in object 23, the machining depth of the machined hole, and the incident angle (beam incident angle) at which the laser beam enters object 23. Specifically, the laser beam diameter incident on the focal position adjustment mechanism is changed so that the laser beam diameter 90 at the surface position 232 of object 23 on the incident side of the laser beam does not overlap with the edge portion 231 of the surface of the machined hole. In other words, the laser beam diameter incident on the focal position adjustment mechanism is changed so that the laser beam diameter 90 at the surface position 232 of object 23 on the incident side of the laser beam is smaller than the diameter D of the hole to be machined in object 23.

[0030] Here, if D is the diameter of the processed hole, θ is the beam incidence angle, and ΔZ is the distance from the surface of object 23 to the focal point, it is preferable to perform the processing by changing the beam focusing angle φ so as to satisfy the following equation.

number

[0031] Figure 8 shows numerical examples when processing by changing the beam focusing angle. This figure shows an example of the beam focusing angle φ calculated using the above formula when the diameter D of the processed hole is 100 μm and the beam incidence angle θ is 3°. Figure 8(A) shows an example of the beam focusing angle φ when the distance ΔZ from the surface of object 23 to the focal point is 300 μm. Figure 8(B) shows an example of the beam focusing angle φ when the distance ΔZ from the surface of object 23 on the laser beam incidence side to the focal point is 1000 μm. For example, when the distance ΔZ from the surface of object 23 to the focal point is 300 μm, the beam focusing angle φ is 3.76° in half-angle. Similarly, when the distance ΔZ from the surface of object 23 to the focal point is 1000 μm, the beam focusing angle φ is 1.88° in half-angle.

[0032] Therefore, the beam focusing angle φ is calculated according to the distance ΔZ from the surface of the object 23 to the focal position, and the position of the lens 24 of the reduction optical system is adjusted so as not to exceed this beam focusing angle φ. Then, the diameter of the laser beam incident on the focusing lens 22 included in the focusing optical system is reduced, and laser processing is performed. In this embodiment, since the beam focusing angle is changed from 3.76° to 1.88° in half-angles, and the focal length of the focusing lens 22 is 60 mm, the diameter of the laser beam incident on the focusing lens 22 should be changed from 8 mm to 4 mm.

[0033] In this case, the diameter of the focused spot at the focal position changes from 10 μm to 20 μm. As the diameter of the focused spot increases, the processing resolution deteriorates, as described above. However, in drilling, when the distance ΔZ from the surface of object 23 to the focal position is large, that is, when processing near the back surface of object 23, the processing resolution does not deteriorate even if the diameter of the focused spot increases. This is because the laser beam undergoes multiple reflections inside object 23, which reduces the effective diameter of the focused spot.

[0034] Furthermore, in order to further reduce the deterioration of processing resolution, the laser light intensity of the laser light source 71 may be changed according to the focusing angle of the laser beam. For example, the control unit 60 increases the laser light intensity of the laser light source 71 as the focusing angle of the laser beam decreases. This makes it possible to further reduce the deterioration of processing resolution.

[0035] Therefore, when processing the vicinity of the surface of object 23, the beam focusing angle is increased and the focusing spot diameter is decreased to prevent deterioration of the processing resolution, and when processing the vicinity of the back surface of object 23, the beam focusing angle is decreased so that the beam does not fall on the edges of the surface.

[0036] The distance ΔZ from the surface of object 23 to the focal point may be replaced with the machining depth of the machined hole. Here, machining depth refers to the depth of the machined hole at the time of machining. For example, it is possible to obtain the machining depth in advance according to the machining time. Also, the incident angle (beam incident angle θ) at which the laser beam enters object 23 can be determined in advance, for example, according to the material of object 23. Then, for example, the computer device 35 can determine in advance the beam focusing angle φ according to the elapsed machining time. Thus, the computer device 35 can determine in advance the laser beam diameter incident on the focusing optical system according to the elapsed machining time. For example, the computer device 35 outputs the laser beam diameter incident on the focusing optical system according to the elapsed machining time to the control unit 60. The control unit 60 may then output a drive signal to the linear stage 31 so that the laser beam diameter becomes the input laser beam diameter according to the machining time, and the linear stage 31 may move the lens 24 in the optical axis direction. The control unit 60 may change the laser beam diameter incident on the focusing optical system in steps or discretely.

[0037] Furthermore, although this embodiment describes the case of machining a cylindrical hole in object 23, the machined hole may also be rectangular, for example. If the machined hole is rectangular, the diameter D of the machined hole is replaced with the side of the machined hole. Also, when machining a tapered (conical) hole in object 23, the laser beam diameter is changed based on the diameter of the machined hole at the surface position of object 23 and the machining depth of the machined hole.

[0038] As described above, the processing apparatus according to this embodiment solves the aforementioned problems, improves the accuracy of laser processing, and enables drilling with a high aspect ratio.

[0039] [Embodiments relating to the method of manufacturing articles] The processing apparatus according to the embodiment described above can be used in a method for manufacturing articles. This method for manufacturing articles may include a step of processing an object (target) using the processing apparatus, and a step of processing the object processed in the first step. This processing may include, for example, at least one of the following: processing other than the processing, transport, inspection, sorting, assembly, and packaging. The method for manufacturing articles according to this embodiment is advantageous over conventional methods in at least one of the following: performance, quality, productivity, and production cost of the articles.

[0040] [Other Embodiments] Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. In the embodiments described above, the control unit 60 and the computer device 35 are separate units, but the control unit 60 may implement the functions of the computer device 35, or the computer device 35 may implement the functions of the control unit 60.

[0041] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0042] 17 Translation optical system 20,21 (Galvano) Mirror 23 Object 24 lenses 31 Linear Stage 35 Computer equipment 50,71 Laser light source 60 Control Unit 100 Laser Processing Equipment

Claims

1. An optical device for processing an object by irradiating it with laser light, A focal position adjustment mechanism for adjusting the focal position of the laser beam, The system includes a focusing angle changing mechanism that changes the focusing angle of the laser beam incident on the object by reducing the beam diameter of the laser beam incident on the focusing position adjustment mechanism as the focal position moves from the laser incident surface side of the object in the direction of propagation of the laser beam, The aforementioned focusing angle changing mechanism is Based on the processing time of the hole to be processed in the object, the beam diameter of the laser light incident on the focal position adjustment mechanism is changed. An optical device characterized by changing the focusing angle such that the beam diameter of the laser light at the surface position of the object becomes smaller than the diameter or side of the hole formed at the surface position of the object, based on the diameter or side of the hole formed at the surface position of the object, the distance from the surface position of the object to the focal position, and the angle of incidence of the laser light incident on the object.

2. The optical apparatus according to claim 1, further comprising an angle adjustment mechanism for adjusting the angle of incidence at which the laser light is incident on the object.

3. The optical apparatus according to claim 2, characterized in that the angle adjustment mechanism includes a galvanometer mirror optical system.

4. The optical apparatus according to any one of claims 1 to 3, characterized in that the focusing angle changing mechanism changes the beam diameter of the laser light incident on the focusing position adjustment mechanism based on the processing depth of the hole processed in the object.

5. The optical apparatus according to claim 4, characterized in that the focusing angle changing mechanism changes the focusing angle φ based on the following formula, where D is the diameter or side of the hole formed on the surface of the object, ΔZ is the distance from the surface of the object to the focal point, and θ is the angle of incidence at which the laser light enters the object. [Math 1]

6. The optical apparatus according to any one of claims 1 to 5, characterized in that the focusing angle changing mechanism changes the beam diameter of the laser light incident on the focus position adjustment mechanism based on the material of the object.

7. The optical apparatus according to any one of claims 1 to 6, characterized in that the focusing angle changing mechanism includes a beam expander.

8. The optical apparatus according to any one of claims 1 to 7, characterized in that the light-gathering angle changing mechanism includes an aperture diaphragm.

9. The optical apparatus according to any one of claims 1 to 8, further comprising an incident position adjustment mechanism for adjusting the incident position in which the laser beam is incident on the object in a direction perpendicular to the focal direction of the laser beam.

10. The optical apparatus according to claim 9, characterized in that the incident position adjustment mechanism includes a galvanometer mirror optical system.

11. The optical apparatus according to claim 9 or 10, characterized in that the incident position adjustment mechanism includes a stage for moving the object.

12. The optical apparatus according to any one of claims 1 to 11, characterized in that the focus position adjustment mechanism includes a stage for moving the object.

13. The optical apparatus according to any one of claims 1 to 12, characterized in that the amount of laser light is changed according to the focusing angle of the laser light.

14. A processing method for processing an object by irradiating it with laser light, The process includes adjusting the focal position of the laser beam while processing the object, The process for processing the object is characterized by changing the beam diameter of the laser light incident on the focal position adjustment mechanism based on the processing time of the hole to be processed in the object, and changing the focusing angle of the laser light incident on the object so that the beam diameter of the laser light at the surface position of the object becomes smaller than the diameter or side of the hole formed at the surface position of the object, the distance from the surface position of the object to the focal position, and the angle of incidence of the laser light incident on the object.

15. A step of processing an object using an optical apparatus according to any one of claims 1 to 13, A method for manufacturing an article, characterized by including a step of processing the object that has undergone the processing in the above step.

16. The method for manufacturing an article according to claim 15, characterized in that the processing is a trepanning process in which a hole is drilled while scanning the laser beam.

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