KR102657008B1 - Laser processing device and laser processing method using a curved beam - Google Patents

Abstract

A laser processing device and laser processing method using a curved beam are disclosed. A laser processing device according to one aspect of the present invention includes a first lens unit that controls the optical path of a laser beam and amplifies the amount of aberration to generate a curved beam; a second lens unit that tilts the curved beam emitted from the first lens unit; And it may include a third lens unit that focuses the curved beam emitted from the second lens unit on the target area. According to one embodiment of the present invention, laser processing can be performed by providing a laser beam in the form of a curved beam with bending properties, and as a result, a curved cutting surface can be formed on the processing object.

Description

Laser processing device and laser processing method using curved beam {LASER PROCESSING DEVICE AND LASER PROCESSING METHOD USING A CURVED BEAM}

The present invention relates to laser processing, and specifically to a laser processing device and laser processing method using a curved beam.

When cutting a glass substrate with a laser according to the prior art, a method of forming a focus of the laser beam inside the glass substrate was used. When a glass substrate is cut in this state, cutting begins from the portion of the cross section of the glass substrate where the focus of the laser beam is formed, and cracks are formed in the portion of the cross section of the glass substrate where the focus is not formed. As a result, the quality of the cut surface of the glass substrate is uneven, requiring an additional chamfering process to polish the cut surface smoothly, which causes an increase in unit cost and low yield.

Meanwhile, techniques for performing chamfering according to the prior art include mechanical chamfering, melting chamfering, and thermal chamfering, but each chamfering technique has disadvantages. These include increased maintenance costs due to frequent blade replacement, inability to create a clean environment, separate chamber configuration, generation of steps between the start and end points, inability to continuously process, complex structure requirements due to glass inversion, increased difficulty due to this, and difficulty in securing reproducibility. etc. are included.

Therefore, the present invention was derived to solve the above-mentioned problems, and one aspect of the present invention is to provide a laser processing device and a laser processing method that enable laser processing to be performed using a curved beam that radiates in a curved line. .

Other objects of the present invention will become clearer through the examples described below.

One aspect of the present invention provides a laser processing device using a curved beam. A laser processing device according to one aspect of the present invention includes a first lens unit that controls the optical path of a laser beam and amplifies the amount of aberration to generate a curved beam; a second lens unit that tilts the curved beam emitted from the first lens unit; And it may include a third lens unit that focuses the curved beam emitted from the second lens unit on the target area.

The laser processing device according to the present invention may have one or more of the following embodiments. For example, the laser processing device may further include a collimator that adjusts laser emission at the front end of the first lens unit. The collimator may include a beam expander telescope (BET).

The first lens unit may include a spherical convex lens whose incident surface has a convex shape. The second lens unit may include a biconvex lens and a concave-convex lens, and a certain gap may be formed between the biconvex lens and the concave-convex lens. Meanwhile, the third lens unit may include an aspherical convex lens whose incident surface has a convex shape.

At least one of the first lens unit and the second lens unit may include a shift adjustment device that adjusts a shift displacement with respect to the optical axis.

The third lens unit may use one of a plurality of lenses having different focal lengths, and the distance between the second lens unit and the third lens unit may change depending on the focal length of the selected lens.

Another aspect of the present invention provides a laser processing method using a curved beam. A laser processing method according to one aspect of the present invention includes generating a laser beam; Generating a curved beam by amplifying the amount of aberration of the laser beam; Tilting the curved beam; And it may include the step of concentrating the curved beam on a target area and cutting a portion of the processing object with the concentrated curved beam.

According to the means for solving the problems of the present invention as discussed above, various effects including the following can be expected. However, the present invention does not require all of the following effects to be achieved.

According to one embodiment of the present invention, laser processing can be performed by providing a laser beam in the form of a curved beam with bending properties, and as a result, a curved cutting surface can be formed on the processing object.

1 is a conceptual diagram illustrating a laser processing device according to an embodiment of the present invention.
Figure 2 is a side view illustrating a first lens unit of a laser processing device according to an embodiment of the present invention.
FIG. 3 is a conceptual diagram illustrating the change in beam obtained by changing the shift of the first lens unit of FIG. 2.
Figure 4 is a side view illustrating a second lens unit of a laser processing device according to an embodiment of the present invention.
FIG. 5 is a conceptual diagram illustrating the change in beam obtained by changing the shift of the second lens unit of FIG. 4.
Figure 6 is a side view illustrating a third lens unit of a laser processing device according to an embodiment of the present invention.
Figure 7 is a conceptual diagram illustrating how a laser processing device processes a processing object according to an embodiment of the present invention.
Figure 8 is a flowchart illustrating a laser processing method according to an embodiment of the present invention.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, identical or corresponding components will be assigned the same reference numbers regardless of the reference numerals, and duplicates thereof will be provided. Any necessary explanation will be omitted.

Figure 1 is a conceptual diagram illustrating a laser processing device 1000 according to an embodiment of the present invention. FIG. 2 is a side view exemplarily showing the first lens unit 110 of the laser processing apparatus 1000 according to an embodiment of the present invention, and FIG. 3 is a view showing the shift of the first lens unit 110 of FIG. 2. This is a conceptual diagram illustrating the change in beam obtained according to the command. FIG. 4 is a side view exemplarily showing the second lens unit 120 of the laser processing device 1000 according to an embodiment of the present invention, and FIG. 5 is a view showing the shift of the second lens unit 120 of FIG. 4. This is a conceptual diagram illustrating the change in beam obtained according to the command. Figure 6 is a side view illustrating the third lens unit 130 of the laser processing apparatus 1000 according to an embodiment of the present invention. Figure 7 is a conceptual diagram illustrating the laser processing device 1000 processing the processing object 55 according to an embodiment of the present invention.

The laser processing device 1000 according to an embodiment of the present invention may be configured to form a curved beam such as an Airy beam from a laser beam and use it to process the processing object 55. . 1 to 7, the laser processing apparatus 1000 according to an embodiment of the present invention includes a light source unit 10, a collimator 20, a first lens unit 110, a second lens unit 120, and It may include a third lens unit 130.

The light source unit 10 is a part that generates a laser to be used in laser processing. The light source unit 10 may provide wavelengths for an infrared (IR) laser, an ultraviolet (UV) laser, a green and IR (GR) laser, and a CO2 laser depending on the configuration and arrangement of the lenses therein.

The collimator 20 may be disposed at the rear end of the light source unit 10 and the front end of the first lens unit 110, and may serve to control the divergence of the laser generated in the light source unit 10. The collimator 20 may include, for example, a beam expander telescope (BET). As represented in the conceptual diagram of FIG. 1, as the laser beam of the light source unit 10 passes through the BET, laser divergence, which increases as the distance from the optical axis increases, is controlled.

The first lens unit 110 may be placed at the rear of the collimator 20, and may control the optical path of the laser beam and amplify the amount of aberration to generate a curved beam. For example, an Airy beam is one of the representative non-diffractive beams such as a Bessel beam and a Weber beam, and refers to the fact that the transverse field continues to maintain the Airy field shape while the beam progresses. Airy Beam has the property of free acceleration, which causes the direction of Airy Beam to bend even if no external force is applied. The laser processing device 1000 according to an embodiment of the present invention is intended to process the processing object 55 at a portion where a curved beam such as an airy beam is bent.

Figure 2 depicts the first lens unit 110 of the laser processing apparatus 1000 according to an embodiment of the present invention. As shown, the first lens unit 110 may include a spherical convex lens in which the entrance surface 112 has a convex shape and the exit surface 118 has a flat shape. In the example shown in FIG. 2, the first lens unit 110 has a thickness of about 5 mm, a diameter of about 25 mm, and a focal length of about 135 mm.

The second lens unit 120 may be placed at the rear of the first lens unit 110 and may tilt the curved beam generated by the first lens unit 110. That is, the second lens unit 120 may serve to shape the curved beam by bending the curved beam in a direction perpendicular to the direction of travel.

Figure 4 depicts the second lens unit 120 of the laser processing apparatus 1000 according to an embodiment of the present invention. As shown, the second lens unit 120 may be implemented in the form of a doublet lens including one biconvex lens 121 and one concave-convex lens 125. The biconvex lens 121 may have an entrance surface 122 and an exit surface 124 that have a convex shape, and the concave-convex lens 125 may have an entrance surface 126 that is concave, but the exit surface 128 may have a concave shape. It may have a convex shape. A certain gap may be formed between the exit surface 124 of the biconvex lens 121 and the entrance surface 126 of the concave-convex lens 125. In the second lens unit 120 shown in FIG. 4, the entrance surface 122 of the biconvex lens 121 has a radius of curvature of about 30 to 45 mm, and the exit surface 124 has a radius of curvature of about 65 to 80 mm. , the entrance surface 126 of the concave-convex lens 125 has a radius of curvature of about 40 to 55 mm, and the exit surface 128 has a radius of curvature of about 140 to 160 mm.

The third lens unit 130 may be disposed at the rear of the second lens unit 120 and may focus the curved beam passing through the second lens unit 120 on the target area 50. That is, the third lens unit 130 can perform beam focusing to amplify the light intensity of the curved beam.

FIG. 6 depicts a plurality of third lens units 130 applicable to the laser processing apparatus 1000 according to an embodiment of the present invention. As shown, the third lens unit 130 may basically include an aspherical convex lens in which the entrance surface 132 has a convex shape and the exit surface 138 has a flat shape. The lenses shown in Figures 6 (a) to (e) have focal lengths of approximately 8 mm, 10 mm, 12 mm, 15 mm, and 18 mm, respectively. The lens used in the third lens unit 130 in the laser processing apparatus 1000 according to an embodiment of the present invention may be selected from a plurality of lenses with different characteristics as needed.

If the distance between lenses is not positioned correctly, various problems such as optical coupling, light loss, distortion, focus error, and beam interference may occur. To solve these problems, the correct distance arrangement must be determined by considering the lens focal length, lens refractive power, sample thickness and material, DOF (depth field) of the optical system, spot size, beam size, wavelength, beam shape, energy, etc. do. Additionally, the designed distance layout should be implemented, tested, and verified to ensure accuracy and make any necessary adjustments.

The operation of the laser processing device 1000 according to an embodiment of the present invention will be described in more detail with reference to FIGS. 1 to 7.

As described above, the light source unit 10 and the collimator 20 emit a controlled laser beam to the first lens unit 110. The shift displacement movement of the first lens unit 110 causes a change in the refraction of the laser beam, which may change the angle at which the light beam is refracted when it passes through the lens. This ultimately makes it possible to control the position or direction of the light beam that reaches the final stage. That is, it is possible to control the optical path and adjust the size, position, and direction of the curved beam by applying a shift displacement to the first lens unit 110.

To this end, the laser processing apparatus 1000 according to an embodiment of the present invention may include a first shift adjustment device (not shown) that adjusts the shift displacement of the first lens unit 110. For example, the first shift adjustment device may be configured to increase or decrease the shift displacement of the first lens unit 110 by 1 mm. FIG. 3 shows changes in the path of a curved beam passing through the first lens unit 110 when it has various shift displacements. Figures 3 (a) to (d) show the path of the curved beam emitted when the first lens unit 110 moves 1 mm, 2 mm, 3 mm, and 4 mm below the optical axis, respectively.

The curved beam generated in the first lens unit 110 is incident on the second lens unit 120 as described above. The shift displacement movement of the second lens unit 120 may serve to apply tilting adjustment to the curved beam primarily adjusted through the first lens unit 110. The second lens unit 120 may perform a role of making fine adjustments to the curved beam and may adjust tilting in the vertical direction based on the optical axis. This makes it possible to precisely adjust the curved beam to the desired position and optimize the optical system.

To this end, the laser processing apparatus 1000 according to an embodiment of the present invention may include a second shift adjustment device (not shown) that adjusts the shift displacement of the second lens unit 120. For example, the second shift adjusting device may be configured to increase or decrease the shift displacement of the second lens unit 120 by a value within 1 mm. Figure 5 shows changes in the path of a curved beam passing through the second lens unit 120 when it has various shift displacements. Figures 5 (a) to (d) show the path of the curved beam emitted when the second lens unit 120 moves below the optical axis by 0 μm, 200 μm, 400 μm, and 600 μm, respectively.

The curved beam that is finely adjusted and tilted by the second lens unit 120 is incident on the third lens unit 130 as described above. In the embodiment shown in FIG. 6, the third lens unit 130 can select and use one of the five lenses 130a to 130e according to the focal length. The selection of the lens can be made considering the thickness and material of the sample.

The third lens unit 130 can focus the curved beam formed while passing through the first and second lens units 110 and 120 on one area. To this end, the third lens unit 130 focuses on increasing light intensity as much as possible. The third lens unit 130 may use an aspherical lens to maximize light intensity. Unlike spherical lenses, aspherical lenses have a non-uniform lens surface and can provide the effect of accurately focusing light rays and minimizing aberrations.

Although not shown, the laser processing apparatus 1000 according to an embodiment of the present invention selects the lenses (130a to 130e) to be used in the third lens unit 130 and selects the third lens according to the selected lenses (130a to 130e). It may include a distance adjustment device (not shown) that adjusts the position of the unit 130. The distance adjusting device (not shown) can, for example, place one of the plurality of lenses 130a to 130e on the optical path, and adjusts the output of the second lens unit 120 according to a preset value as shown in Table 1. The distance from the face 128 can be adjusted.

The laser processing device 1000 according to an embodiment of the present invention can emit a laser beam in the form of a curved beam as described above, and can bend the laser in the target area 50 using the characteristics of the curved beam. . As shown in FIG. 7, the curved beam that is focused by the third lens unit 130 and acts as a laser is bent along a designed path and can form a curved cutting surface 57 on the processing object 50. there is.

The curved beam type laser provided by the laser processing device 1000 can be used for various purposes related to cutting the processing object 50, and for example, can be used to chamfer the edges of the processing object 50. It is possible to control the amount of chamfering and the chamfering area by adjusting the distance and/or radius of curvature of the optical system.

Figure 8 is a flowchart illustrating a laser processing method according to an embodiment of the present invention. The laser processing method according to an embodiment of the present invention is a laser processing method using a curved beam, and can be performed using the above-described laser processing device 1000 or other processing devices.

First, a step of generating a laser beam (S1010) may be performed. Here, the laser beam refers to a light beam with a designed wavelength, and does not have to have a light intensity sufficient to cut the processing target 55 from the current stage. The laser beam may have a wavelength for, for example, an infrared (IR) laser, an ultraviolet (UV) laser, a green and IR (GR) laser, a CO2 laser, etc.

Subsequently, a diffusion correction step (S1020) for the generated laser beam may be performed. That is, the laser beam can be collimated toward the first lens unit 110 by controlling the divergence of the laser beam. In some embodiments, the laser beam diffusion correction step (S1020) may be integrated into the laser beam generating step (S1010) or may be omitted.

Next, a step of generating a curved beam (S1030) may be performed. This can be accomplished by amplifying the amount of aberration of the laser beam. When the laser processing device 1000 presented above is used, a curved beam may be formed as the laser beam is incident on the first lens unit 110. If necessary, the step of generating a curved beam (S1030) may include adjusting the shift displacement of the first lens unit 110 of the laser processing apparatus 1000. For this purpose, the first lens unit 110 may include a shift control device (not shown) that adjusts the shift displacement of the lens included in the first lens unit 110, and the shift control device may, for example, adjust the shift displacement of the lens. Displacement can be adjusted in 1mm increments.

Next, a step of tilting the curved beam (S1040) may be performed. This may correspond to fine-tuning the curved beam so that bending of the curved beam occurs at the desired location. When the laser processing device 1000 presented above is used, the curved beam may be tilted as the laser beam is incident on the second lens unit 120. If necessary, the step of tilting the curved beam (S1040) may include adjusting the shift displacement of the second lens unit 120 of the laser processing apparatus 1000. For this purpose, the second lens unit 120 may include a shift control device (not shown) that adjusts the shift displacement of the lens included in the second lens unit 120, and the shift control device may, for example, adjust the shift displacement of the lens. The displacement can be adjusted in units of less than 1 mm, for example, 200 μm.

Next, a step (S1050) of concentrating the curved beam on the target area 50 and cutting a portion of the processing target 55 with the concentrated curved beam may be performed. The curved beam has a bending characteristic, and the steps of tilting and concentrating the curved beam (S1040, S1050) ensure that the position where the curved beam is bent is located on the processing target (55). The cutting surface 57 formed on the processing object 55 may have a curved shape due to bending of the curved beam.

The laser processing device 1000 and the laser processing method according to an embodiment of the present invention provide a laser beam in the form of a curved beam with bending properties to form a curved cutting surface 57 on the processing object 55. You can. This can be particularly advantageous when the cutting surface 57 is formed at the edge of the processing object 55 and is used for chamfering.

The laser processing apparatus 1000 and the laser processing method according to an embodiment of the present invention provide significant advantages over the chamfering method according to the prior art. For example, conventional mechanical chamfering requires replacement costs for blades, etc., and involves the problem of environmental pollution by removing the material being cut using water or other cleaning agents. In the case of conventional melting chamfering, the takt time is low, the yield is low, and it has the inconvenience of having to be carried out under a high temperature environment inside a chamber, etc. In the case of conventional heat chamfering, there is a disadvantage in that the yield is low due to the high difficulty of the process. The method according to an embodiment of the present invention can solve these problems and improve the quality of processed products while increasing yield at low cost.

Although the present invention has been described above with reference to an embodiment of the present invention, those skilled in the art will understand the present invention in various ways without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it can be modified and changed.

This invention was developed as part of the technology innovation development project of the Ministry of SMEs and Startups. [S3257269, Development of modular core element technology and process technology for development of Hybrid Laser Cutting equipment for displays]

1000: Laser processing device (1000)
10: light source unit 20: collimator
110: first lens unit 120: second lens unit
130: Third lens unit

Claims (9)

A first lens unit that controls the optical path of the laser beam and amplifies the amount of aberration to generate a curved beam;
a second lens unit that tilts the curved beam emitted from the first lens unit; and
It includes a third lens unit that focuses the curved beam emitted from the second lens unit on the target area,
The first lens unit includes a spherical convex lens having a convex entrance surface and a flat exit surface,
At least one of the first lens unit and the second lens unit includes a shift adjustment device that adjusts a shift displacement with respect to the optical axis,
The second lens unit includes a biconvex lens and a concave-convex lens, and a constant gap is formed between the biconvex lens and the concave-convex lens,
The third lens unit includes an aspherical convex lens with a convex entrance surface,
In the second lens unit, the entrance surface of the biconvex lens has a radius of curvature of 30 to 45 mm, the exit surface has a radius of curvature of 65 to 80 mm, and the entrance surface of the concave-convex lens has a radius of curvature of 40 to 55 mm. A laser processing device characterized in that the emission surface has a radius of curvature of 140 to 160 mm.
According to claim 1,
A laser processing device further comprising a collimator that adjusts laser divergence at the front end of the first lens unit.
According to claim 2,
A laser processing device, wherein the collimator includes a beam expander telescope (BET).
delete delete delete delete According to claim 1,
The third lens unit selects and uses one of a plurality of lenses with different focal lengths, and the distance between the second lens unit and the third lens unit is characterized in that it changes depending on the focal length of the selected lens. Laser processing equipment.
delete