Laser processing apparatus

Abstract

The present invention comprises: a laser module which generates laser beams; a laser beam delivery guide which guides the laser beams, generated by the laser module, along a predetermined path and causes the laser beams to overlap; and a first imaging lens which is disposed between the laser module and the laser beam delivery guide and adjusts the focus of the laser beams emitted from the laser module towards the laser beam delivery guide. Accordingly, the present invention can ensure a uniform energy distribution of laser beams having a predetermined intensity or higher.

Description

Laser processing device

[0001] The present invention relates to a laser processing device, and more particularly, to a laser processing device that homogenizes the energy distribution of a laser beam.

[0002] Laser processing devices can process objects with high precision using laser beams. However, these laser beams have a Gaussian beam profile with a bell-shaped energy distribution, making it difficult to process the processing area uniformly. To address this issue, conventional laser processing devices have employed a number of methods that utilize the straightness and diffraction properties of the laser beam to transform the Gaussian distribution into a flat, homogeneous energy distribution.

[0003]

[0004] However, conventional methods still suffer from physical limitations in performing precise processing of objects with fine linewidths and thin films due to insufficient energy distribution homogeneity. Furthermore, even when utilizing specially designed optical systems, conventional methods present significant challenges in mass production and lack practicality.

[0005]

[0006] In addition, when looking at prior art, there are problems such as individual design required to correspond to the specific wavelength of the laser beam, and in the case of a laser processing device using a slit, the processing effect for the laser beam irradiated to the actual processing area is low.

[0007] An embodiment of the present invention aims to provide a laser processing device that implements a laser beam having an energy intensity of a predetermined level or higher and a homogenized energy distribution.

[0008] In order to achieve the above-described purpose, a laser processing device according to an embodiment of the present invention is characterized by including a laser module for generating a laser beam, a laser beam transmission guide for guiding the laser beam generated from the laser module along a predetermined path and overlapping the laser beams, and a first focusing lens disposed between the laser module and the laser beam transmission guide for adjusting the focus of the laser beam emitted from the laser module to the laser beam transmission guide.

[0009]

[0010] In addition, it is characterized by further including a beam distribution control module that controls the energy distribution of the laser beam by adjusting the diffusion angle of the laser beam emitted from the laser beam transmission guide.

[0011]

[0012] In addition, the laser beam transmission guide is characterized by having a line shape extended along a predetermined path and a circular shape in cross-section.

[0013]

[0014] In addition, the first imaging lens is characterized in that it has a lens center axis that passes through the first imaging lens, and the lens center axis is arranged at an angle with respect to the optical axis of the laser beam.

[0015]

[0016] In addition, the first focusing lens has a first point and a second point that are symmetrical with respect to the lens center axis, and the first travel distance of the laser beam emitted from the first point and the second travel distance of the laser beam emitted from the second point are different from each other.

[0017]

[0018] In addition, the beam distribution control module is characterized by including a beam diffusion angle control element that diffusions a laser beam at a preset angle, and a rotation unit that rotates the beam diffusion angle control element around the optical axis of the laser beam.

[0019]

[0020] In addition, the beam distribution control module is characterized in that it further includes a polarization variable element that is arranged on the optical path of the laser beam and controls the polarization characteristics of the laser beam.

[0021]

[0022] In addition, it is characterized by further including a second focusing lens for adjusting the focus of a laser beam emitted from a beam distribution control module, a slit arranged corresponding to the focus of the second focusing lens, and an objective lens for adjusting the focus of a laser beam emitted from the slit toward a workpiece.

[0023] According to the present invention, the energy distribution of a laser beam with respect to a beam spot can be homogenized.

[0024]

[0025] In addition, the energy intensity of the laser beam for the beam spot can be improved to a predetermined level or higher compared to the conventional technology.

[0026]

[0027] Additionally, the energy intensity of the laser beam for the beam spot can be secured as an upward convex curve that is high in the center and gradually decreases toward the edge.

[0028] FIG. 1 is a schematic drawing of a laser processing device according to an embodiment of the present invention.

[0029] FIG. 2 is a schematic drawing of the laser beam transmission guide and the first focusing lens illustrated in FIG. 1.

[0030] FIG. 3 is a schematic drawing illustrating one embodiment of the laser beam transmission guide illustrated in FIG. 1.

[0031] Figure 4 is a drawing for explaining the function of the laser beam transmission guide illustrated in Figure 3.

[0032] FIG. 5 is a schematic diagram illustrating one embodiment of the beam distribution control module illustrated in FIG. 1.

[0033] Figure 6 is a drawing for explaining the function of the beam distribution control module illustrated in Figure 5.

[0034] Throughout the specification, identical reference numbers refer to substantially identical components. In the following description, detailed descriptions of components and functions not related to the core components of the present invention and those known in the art may be omitted. The meanings of terms used in this specification should be understood as follows.

[0035] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the scope of the claims.

[0036] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative and are not limited to the details depicted. Like reference numerals designate like elements throughout the specification. Furthermore, in describing the present invention, detailed descriptions of related known technologies will be omitted if they are deemed to unnecessarily obscure the gist of the present invention.

[0037] In this specification, when the terms "includes," "has," and "consists of," are used, other parts may be added, unless "only" is used. When a component is expressed in the singular, it includes the plural unless otherwise explicitly stated.

[0038] When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description.

[0039] When describing a positional relationship, for example, when the positional relationship between two parts is described as 'on top of', 'upper part of', 'lower part of', 'next to', etc., one or more other parts may be located between the two parts, unless 'right away' or 'directly' is used.

[0040] When describing a temporal relationship, for example, when the temporal continuity is described as 'after', 'following', 'next to', 'before', etc., it can also include cases where it is not continuous, as long as 'right away' or 'directly' is not used.

[0041] While terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, a "first" component referred to below may also be a "second" component within the technical scope of the present invention.

[0042] “X-axis direction”, “Y-axis direction” and “Z-axis direction” should not be interpreted as merely geometric relationships in which the relationship between them is perpendicular to each other, but may mean a wider directionality within the range in which the configuration of the present invention can function functionally.

[0043] The term "at least one" should be understood to include all possible combinations of one or more associated items. For example, "at least one of the first, second, and third items" can mean any combination of items that can be represented by two or more of the first, second, and third items, as well as each of the first, second, and third items.

[0044] The features of each of the various embodiments of the present invention can be partially or wholly combined or combined with each other, and various technical connections and operations are possible, and each embodiment can be implemented independently of each other or implemented together in a related relationship.

[0045]

[0046] Hereinafter, a laser processing device (1) according to an embodiment of the present invention will be described with reference to the drawings.

[0047] FIG. 1 is a schematic drawing of a laser processing device (1) according to one embodiment of the present invention.

[0048] Referring to FIG. 1, a laser processing device (1) according to an embodiment of the present invention includes a laser module (10), a laser beam transmission guide (20), and a first imaging lens (30). The laser module (10) generates a laser beam. The laser beam transmission guide (20) guides the laser beam generated by the laser module (10) along a predetermined path. Thereby, the laser beam transmission guide (20) can overlap the laser beams. The first imaging lens (30) is arranged between the laser module (10) and the laser beam transmission guide (20).

[0049]

[0050] The first focusing lens (30) can adjust the focus of the laser beam emitted from the laser module (10) to the laser beam delivery guide (20). Specifically, the first focusing lens (30) can adjust the focus of the laser beam emitted from the laser module (10) to the inside of the laser beam delivery guide (20). That is, the first focusing lens (30) can position the focus of the laser beam emitted from the laser module (10) on the inside of the incident surface of the laser beam delivery guide (20). As a result, the laser beam delivery guide (20), particularly the incident surface of the laser beam delivery guide (20), can be prevented from being deteriorated.

[0051]

[0052] FIG. 2 is a drawing schematically illustrating the laser beam transmission guide (20) and the first focusing lens (30) illustrated in FIG. 1, FIG. 3 is a drawing schematically illustrating one embodiment of the laser beam transmission guide (20) illustrated in FIG. 1, and FIG. 4 is a drawing for explaining the function of the laser beam transmission guide (20) illustrated in FIG. 3.

[0053] Referring to FIGS. 2 to 4, the laser beam delivery guide (20) may have a line shape extending along a predetermined path. The laser beam delivery guide (20) may have a circular shape in cross-section. The laser beam delivery guide (20) may have a difference in refractive index between an inner member arranged on the inside and an outer member surrounding the inner member. Accordingly, the laser beam may be reflected from the inner surface of the laser beam delivery guide (20) and moved along the length of the laser beam delivery guide (20).

[0054]

[0055] The laser beams emitted from the laser module (10) can overlap each other while moving along the laser beam delivery guide (20). Therefore, the laser beams moving along the laser beam delivery guide (20) can have improved energy uniformity while being emitted from the laser beam delivery guide (20). In particular, since the laser beam delivery guide (20) has a circular cross-section, the overlap of the laser beams can be further induced.

[0056]

[0057] The first imaging lens (30) may have a lens center axis (A). The lens center axis (A) passes through the first imaging lens (30). The lens center axis (A) is arranged at an angle with respect to the optical axis (L) of the laser beam. Accordingly, the paths of the laser beams passing through the first imaging lens (30) can be set to be different from each other. Accordingly, the overlap of the laser beams can be improved, thereby ensuring energy uniformity.

[0058]

[0059] In one embodiment, the first focusing lens (30) has a first point (P1) and a second point (P2). The first point (P1) and the second point (P2) are symmetrical with respect to the lens central axis (A). For example, the first point (P1) may be spaced apart from the lens central axis (A) by a first distance in one direction. In addition, the second point (P2) may be spaced apart from the lens central axis (A) by a first distance in another direction. In this case, the first point (P1) and the second point (P2) may be arranged on a straight line perpendicular to the lens central axis (A).

[0060]

[0061] In addition, the first point (P1) may be spaced apart from the incident surface of the laser beam delivery guide (20) by a second distance. The second point (P2) may be spaced apart from the incident surface of the laser beam delivery guide (20) by a third distance. The second distance may be longer than the third distance. That is, the first point (P1) may be spaced apart from the incident surface of the laser beam delivery guide (20) by a further distance than the second point (P2). Accordingly, the first travel distance (L1) of the laser beam emitted from the first point (P1) and the second travel distance (L2) of the laser beam emitted from the second point (P2) are different from each other. Accordingly, as the laser beams move along the laser beam delivery guide (20), they may further overlap, thereby improving the energy uniformity of the laser beam.

[0062]

[0063] Meanwhile, the first travel distance (L1) may be the distance from the first point (P1) to the first reflection point (R1). In addition, the second travel distance (L2) may be the distance from the second point (P2) to the second reflection point (R2). The first reflection point (R1) and the second reflection point (R2) may be defined as reflection points of the laser beam on the inner surface of the laser beam transmission guide (10).

[0064]

[0065] In the case of the existing Flat Top technology in the Single Mode Laser, the energy is scattered across the flat top surface of the beam, so that the energy intensity at the center and edge of the spot becomes homogeneous with a similar size. However, when such a laser beam is applied to Laser CVD, there is a problem that the energy intensity decreases across the flat top surface, making it difficult to deposit in a desired area (shape). According to one embodiment of the present invention, the energy distribution curve of the laser beam gradually decreases from the center to the edge. That is, the energy distribution curve has an energy distribution in the shape of a loaf of bread, which is high in the center and relatively low at the edge. Therefore, the energy intensity for the energy distribution curve of the laser beam is relatively higher than that of the existing Flat Top technology. Accordingly, when the laser beam is applied to Laser CVD, deposition in a desired area (shape) is possible.

[0066]

[0067] In one embodiment, the laser beam delivery guide (20) may have an extension portion (200) and a bend portion (210). The extension portions (200) and the bend portions (210) may be arranged in plurality. Any one of the plurality of extension portions (200) may extend in one direction from the laser module (10). One end of the bend portion (210) may be connected to an end of the extension portion (200) extended from the laser module (10) so that the extension direction may be bent. Another one of the plurality of extension portions (200) may extend in the other direction from the other end of the bend portion (210). For example, the plurality of extension portions (200) may extend in parallel. Thereby, the path of the laser beam may be set in a desired shape. Therefore, the diffusion control of the laser beam may be easy. That is, the energy uniformity of the laser beam may be controlled within a set range. In addition, since the arrangement of the incident surface and the exit surface of the laser beam transmission guide (20) is free, the optical system configuration and arrangement can be free.

[0068]

[0069] FIG. 5 is a drawing schematically illustrating one embodiment of the beam distribution control module (40) illustrated in FIG. 1, and FIG. 6 is a drawing for explaining the function of the beam distribution control module (40) illustrated in FIG. 5.

[0070] Referring to FIGS. 1, 5, and 6, a laser processing device (1) according to an embodiment of the present invention may further include a beam distribution control module (40). The beam distribution control module (40) may control the energy distribution of the laser beam (B) by adjusting the diffusion angle of the laser beam (B) emitted from the laser beam delivery guide (20). In one embodiment, the beam distribution control module (40) may include a beam diffusion angle control element (400) and a rotation unit (410). The beam diffusion angle control element (400) may diffuse the laser beam (B) at a preset angle. The rotation unit (410) may rotate (rotate) the beam diffusion angle control element (400) about the optical axis (L) of the laser beam (B). The beam distribution control module (40) may further include a polarization variable element (420). The polarization variable element (420) is placed on the optical path of the laser beam (B) and can control the polarization characteristics of the laser beam (B).

[0071]

[0072] As the laser beam passes through the beam diffusion angle control element (400), it is dispersed to various locations in the beam spot. By overlapping the laser beams, the energy distribution in the beam spot becomes homogeneous, and the energy intensity can be improved to a predetermined level or higher. As a result, a bread-shaped energy distribution curve having a predetermined energy intensity can be secured.

[0073]

[0074] Referring to FIG. 1, a laser processing device (1) according to an embodiment of the present invention may include a second focusing lens (50), a slit (60), and an objective lens (70). The second focusing lens (50) may be positioned below a beam distribution control module (40). The second focusing lens (50) may adjust the focus of a laser beam emitted from the beam distribution control module (40).

[0075]

[0076] The slit (60) may be arranged below the second focusing lens (50). The slit (60) is arranged corresponding to the focus of the second focusing lens (50). The slit (60) can adjust the size and shape of the laser beam emitted from the second focusing lens (50). The objective lens (70) can adjust the focus of the laser beam emitted from the slit (60) toward the workpiece (2). The objective lens (70) may include a first focusing lens (700) and a second focusing lens (710). By adjusting the position of at least one of the first focusing lens (700) and the second focusing lens (710), the focus of the laser beam can be adjusted toward the workpiece (2).

[0077]

[0078] Although the invention made by the present inventor has been specifically described according to the above embodiments, the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the invention.

Claims

1. Laser module that generates a laser beam; A laser beam transmission guide that guides a laser beam generated from a laser module along a predetermined path and overlaps the laser beams; and A laser processing device including a first focusing lens, which is positioned between a laser module and a laser beam delivery guide and adjusts the focus of a laser beam emitted from the laser module to the laser beam delivery guide.

2. In paragraph 1, A laser processing device further comprising a beam distribution control module that controls the energy distribution of a laser beam by adjusting the diffusion angle of a laser beam emitted from a laser beam transmission guide.

3. In paragraph 1, The laser beam transmission guide is It has a line shape extended along a predetermined path, A laser processing device having a circular cross-section.

4. In paragraph 1, The first focusing lens is, It has a lens center axis that penetrates the first focusing lens, A laser processing device in which the central axis of the lens is positioned at an angle relative to the optical axis of the laser beam.

5. In paragraph 4, The first focusing lens has a first point and a second point that are symmetrical to each other with respect to the central axis of the lens. A laser processing device in which the first travel distance of a laser beam emitted from a first point and the second travel distance of a laser beam emitted from a second point are different from each other.

6. In paragraph 2, The beam distribution control module is A beam diffusion angle control device that diffusionizes a laser beam to a preset angle; and A laser processing device including a rotation unit that rotates a beam diffusion angle control element around the optical axis of a laser beam.

7. In paragraph 6, The beam distribution control module is A laser processing device further comprising a polarization variable element arranged on an optical path of a laser beam to control polarization characteristics of the laser beam.

8. In paragraph 2, A second focusing lens for adjusting the focus of a laser beam emitted from the beam distribution control module; A slit arranged corresponding to the focus of the second focusing lens; and A laser processing device further comprising an objective lens for adjusting the focus of a laser beam emitted from a slit toward a workpiece.

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