System and method for circular machining of transparent brittle material using ultrafast laser

Abstract

A laser circular machining system according to the present invention may comprise: a laser unit for emitting a laser beam; an optical unit disposed on the traveling path of the laser beam to modulate the laser beam into a Bessel beam; a scan unit for reflecting the Bessel beam modulated by the optical unit to a workpiece and linearly moving the position of the Bessel beam; a focusing lens for positioning the focus of the Bessel beam reflected from the scan unit on the machining surface of the workpiece; and a micro-machining unit for moving the position of the Bessel beam in the circumferential direction to perform circular machining of the workpiece, whereby it is possible to reduce the total circular machining time.

Description

System and method for circular processing of transparent brittle materials using ultrashort lasers

[0001] The present invention relates to a technology for high-speed precision processing of transparent and brittle materials.

[0002] More specifically, the present invention relates to a high-speed circular processing device and method for transparent and brittle materials using an ultrashort laser.

[0003] Lasers are widely used for processing, such as cutting or forming holes in workpieces (objects to be processed).

[0004] In general, in laser processing, a laser beam is formed into a desired shape suitable for the processing task using an optical element such as a lens, and the formed laser beam is irradiated onto the workpiece.

[0005] In particular, a laser beam can be effectively used to circularly process brittle materials that are difficult to process, such as transparent glass substrates.

[0006] Korean Patent Publication No. 10-2022-0032862 (March 15, 2022, hereinafter, Patent Document 1) discloses a laser processing system and method. Specifically, Patent Document 1 discloses a laser processing system including a laser unit that emits a laser beam, an optical unit that projects the laser beam as a Bessel beam, and a stage on which a workpiece to be processed by the Bessel beam is mounted.

[0007] Figure 1 schematically illustrates a laser processing system according to patent document 1.

[0008] Referring to FIG. 1, the illustrated laser circular processing systems include a laser unit (110) that emits a laser beam, an optical unit (120, 130) that emits the laser beam as a Bessel beam, a scanning unit (140), and a focusing lens (150).

[0009] To create a through hole in a transparent brittle material, a localized area is typically modified or processed with a laser, followed by chemical etching to create the hole. However, if the area being processed by the laser contains particles, brittle material defects, or excessive laser power, it can be difficult to create a hole of the desired size during etching. Modifying or processing a localized area into a circular shape and then etching significantly increases yield by satisfying the minimum hole size requirement.

[0010] Therefore, a method for high-speed circular machining of tens to hundreds of micrometers is needed. Conventional methods utilize scanners to create circular shapes. Due to the thickness and size of the scanner's mirror, it operates at a few Hz, limiting the ability of conventional laser machining systems to rapidly process circular shapes of tens to hundreds of micrometers.

[0011] The problem to be solved by the present invention is to provide a laser processing system capable of high-speed circular precision microprocessing of transparent brittle materials by combining a nonlinear absorption optical system, a scanning unit, and a separate microprocessing unit.

[0012] In addition, the problem to be solved by the present invention is to provide a circular laser processing method for transparent brittle materials using an ultrashort laser.

[0013] The problems to be solved by the present invention are not limited to those mentioned above. Other problems and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the problems and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0014] According to an embodiment of the present invention for solving the above problem, a laser circular processing system for a workpiece is provided, comprising: a laser unit emitting a laser beam; an optical unit disposed in a path of the laser beam and modulating the laser beam into a Bessel beam; a scanning unit reflecting the Bessel beam modulated by the optical unit onto the workpiece and linearly moving the position of the Bessel beam; a focusing lens positioning the focus of the Bessel beam reflected from the scan unit on a processing surface of the workpiece; and a micro-processing unit moving the position of the Bessel beam in a circumferential direction to perform circular processing on the workpiece.

[0015] The above-mentioned workpiece may be a transparent brittle material.

[0016] The above laser unit can emit an ultrashort laser beam having a pulse width of about 50 femtoseconds to about 50 picoseconds.

[0017] The above ultrashort laser beam may have a UV wavelength of about 300 nm to 400 nm, a green wavelength of about 500 nm to 600 nm, or a near-infrared wavelength of about 900 nm to 1100 nm.

[0018] The optical unit may include a first lens that modulates an incident laser beam into an annular Bessel beam; and a second lens that modulates the Bessel beam to be parallel to an optical axis.

[0019] The first lens may include a conical prism, an axicon lens, a Diffractive Optical Element (DOE), or a Spatial Light Modulator (SLM).

[0020] The second lens may include a collimating lens or a collimating lens.

[0021] The above scan unit may include one or more drive shafts and one or more mirrors.

[0022] The above micro-machining unit may include a third lens that modulates the optical axis of an annular Bessel beam parallel to the optical axis; a high-speed system comprising one or more drive shafts and mirrors that reflect the Bessel beam modulated by the third lens and adjust the position of the Bessel beam in two or more directions; and a fourth lens that modulates the Bessel beam reflected from the high-speed system into an annular shape.

[0023] The high-speed system may include a piezoelectric motor and / or a galvanometer.

[0024] The above micro-machining unit may be positioned between the optical unit and the scanning unit and may include a transmission window whose rotation speed and tilt angle are adjustable.

[0025] The above scan unit may include one or more drive shafts and one or more mirrors.

[0026]

[0027] According to an embodiment of the present invention for solving the above problem, a laser circular processing method is provided, which is a method for performing circular processing on a transparent brittle material using a laser circular processing system for a workpiece, the system including: a laser unit for emitting a laser beam; an optical unit disposed in a path of the laser beam and modulating the laser beam into a Bessel beam; a scanning unit for reflecting the Bessel beam modulated by the optical unit onto the workpiece and linearly moving the position of the Bessel beam; a focusing lens for positioning the focus of the Bessel beam reflected from the scan unit on a processing surface of the workpiece; and a micro-processing unit for moving the position of the Bessel beam in a circumferential direction so as to perform circular processing on the workpiece.

[0028] Specifically, a laser circular processing method according to an embodiment of the present invention includes the steps of (a) aligning a laser circular processing system on an upper portion of a workpiece; (b) obtaining a Bessel beam through the laser circular processing system; and (c) sequentially irradiating the Bessel beam onto a plurality of through-hole forming regions of the workpiece to change the properties of the through-hole forming regions of the workpiece to form a plurality of circular processing patterns. At this time, formation of each circular processing pattern is performed by the micrometer processing unit, and positional movement from one through-hole forming region to another through-hole forming region is performed by the scan unit.

[0029] The laser unit can emit an ultrashort laser beam having a pulse width of about 50 femtoseconds to about 50 picoseconds. In addition, the laser unit can emit an ultrashort laser beam having a UV wavelength of about 300 nm to 400 nm, a green wavelength of about 500 nm to 600 nm, or a near-infrared wavelength of about 900 nm to 1100 nm.

[0030] The optical unit may include a first lens that modulates an incident laser beam into an annular Bessel beam; and a second lens that modulates the Bessel beam to be parallel to an optical axis.

[0031] The above micro-machining unit may include a third lens that modulates the optical axis of an annular Bessel beam parallel to the optical axis; a high-speed system comprising one or more drive shafts and mirrors that reflect the Bessel beam modulated by the third lens and adjust the position of the Bessel beam in two or more directions; and a fourth lens that modulates the Bessel beam reflected by the high-speed system into an annular shape.

[0032] The high-speed system comprising one or more drive shafts and mirrors may include a piezoelectric motor and / or a galvanometer.

[0033] The above micro-machining unit may be positioned between the optical unit and the scanning unit and may include a transmission window whose rotation speed and tilt angle are adjustable.

[0034] The above scan unit may include one or more drive shafts and one or more mirrors.

[0035] According to the system and method for circular processing of transparent brittle materials using an ultrashort laser according to the present invention, a scanning unit having a processing speed of several Hz and a micrometer processing unit having a processing speed of several kHz are used, so that each circular processing pattern can be formed by the micrometer processing unit, and positional movement between through holes can be performed by the scanning unit. Through this, the total time required for circular processing of transparent brittle materials can be significantly shortened.

[0036] In addition, according to the system and method for processing a transparent brittle material circularly using an ultrashort laser according to the present invention, it is possible to precisely control the processing position of the workpiece at high speed, so that wet etching can be performed in a state where the internal properties of the workpiece are locally changed or processed to have the same or similar size or shape as the through hole, and thus the etching time can be significantly reduced.

[0037] In addition, according to the transparent brittle material circular processing system and method using an ultrashort laser according to the present invention, laser processing can be performed at a speed 100 times or more faster than a conventional through-hole forming method using only a scan unit by using an ultrashort laser.

[0038] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0039] Figure 1 schematically illustrates a laser circular processing system according to the prior art.

[0040] Figure 2 schematically illustrates a laser circular processing system according to an embodiment of the present invention.

[0041] FIG. 3 schematically illustrates a laser circular processing system according to another embodiment of the present invention.

[0042] Figure 4 shows the relationship between the tilt angle of the window and the micrometer circle size in the laser circle processing system of Figure 3.

[0043] FIG. 5 schematically illustrates an example in which both the formation of a circular processing pattern and the positional movement between through holes are performed by a scan unit when performing laser circular processing using the laser circular processing system according to FIG. 1.

[0044] FIG. 6 schematically illustrates an example in which a circular processing pattern is formed by a micrometer processing unit and positional movement between through holes is performed by a scan unit when performing laser circular processing using a laser circular processing system according to FIG. 2 or FIG. 3.

[0045] Figure 7 schematically illustrates a laser circular processing method according to an embodiment of the present invention.

[0046] <Explanation of symbols>

[0047] 101: Processing surface

[0048] 110 laser units

[0049] 120: First optical unit (first lens)

[0050] 130: Second optical unit (second lens)

[0051] 140: Scan unit (system consisting of one or more drive shafts and mirrors)

[0052] 150: Focusing lens

[0053] 210: Micrometer processing unit

[0054] 310: Third optical unit (third lens)

[0055] 320: A high-speed system consisting of one or more drive axles and mirrors.

[0056] 330: 4th optical unit (4th lens)

[0057] 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 only 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 only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0058] To clearly illustrate the present invention in the drawings, parts irrelevant to the description have been omitted, and the same reference numerals have been used throughout the specification to designate identical or similar components. Furthermore, the size and thickness of each component shown in the drawings have been arbitrarily indicated for convenience of explanation, and therefore the present invention is not necessarily limited to what is shown.

[0059] Throughout the specification, when a part is said to be "connected" to another part, this includes not only "directly connected" but also "indirectly connected" with other elements intervening. Furthermore, when a part is said to "include" a component, this does not exclude other components, but rather includes other components, unless otherwise specifically stated.

[0060] In this specification, “front” and “rear” are named based on the direction of travel of the beam, and the direction approaching the workpiece is defined as “rear.”

[0061] Hereinafter, with reference to the attached drawings, a detailed description will be given of a transparent brittle material circular processing system and method using an ultrashort laser according to a preferred embodiment of the present invention.

[0062]

[0063] Figure 2 schematically illustrates a laser circular processing system according to an embodiment of the present invention.

[0064] Referring to FIG. 2, the illustrated laser circular processing systems include a laser unit (110), optical units (120, 130), a scan unit (140), and a focusing lens (150). Each unit, including the laser unit (110) and the scan unit (140), can have its operation controlled by a control unit. In addition, the micrometer processing unit (210) described below can also have its operation controlled by the control unit.

[0065] In the laser circular processing system, a laser beam emitted from a laser unit (110) is modulated into a Bessel beam form through an optical unit (120, 130), and the Bessel beam is irradiated onto a processing surface (101) of a workpiece fixed to a stage to process the workpiece. The Bessel beam irradiated onto the workpiece can process the workpiece at high speed while scanning a predetermined range of the workpiece.

[0066] The laser unit (110) emits a laser beam for processing a workpiece. The laser unit can generate laser light having a pulse and emit it in the form of a beam. Preferably, the laser unit (110) may be a laser unit that emits an ultrashort laser beam having a pulse width of about 50 femtoseconds to about 50 picoseconds. The ultrashort laser beam may have a UV wavelength of about 300 nm to 400 nm, a green wavelength of about 500 nm to 600 nm, or a near-infrared wavelength of about 900 nm to 1100 nm. In addition, the laser beam may have a circular shape or a Gaussian beam shape when viewed in the direction of propagation.

[0067] The workpiece can be flat and made of a transparent, brittle material, such as a glass substrate. Of course, the workpiece can also be made of a variety of materials, including opaque substrates, metal materials, and semiconductor wafers.

[0068] The optical unit (120, 130) is arranged in the path of the laser beam emitted from the laser unit (110) and is configured to emit the incident laser beam as a Bessel beam. According to an embodiment of the present invention, the optical unit (120, 130) may include a first optical unit (or first lens) (120) and a second optical unit (second lens) (130).

[0069] The first lens (120) modulates the incident laser beam into an annular Bessel beam. The laser beam may be diffracted or refracted while passing through the first lens (120) and modulated into an annular (ring-shaped) Bessel beam (when viewed in the beam propagation direction). The first lens (120) may include a conical prism, an axicon lens, a Diffractive Optical Element (DOE), or a Spatial Light Modulator (SLM).

[0070] The second lens (130) modulates the optical axis of the Bessel beam to be parallel. The second lens (130) is positioned behind the first lens (120). The second lens (130) can limit the expansion of the area of ​​the Bessel beam (BL) so as to be suitable for processing the workpiece. The second lens (130) may include a collimating lens or a collimating lens.

[0071] According to an embodiment of the present invention, the optical properties, arrangement intervals, etc. of the first lens (120) and the second lens (130) can be appropriately selected or adjusted. For example, the diameter of the Bessel beam passing through the second lens (212) can be in the range of about 3 to 50 mm.

[0072] After the optical axis of the Bessel beam is aligned parallel while passing through the second lens (120), it can be incident on the scan unit (140).

[0073] The scan unit (140) reflects the Bessel beam modulated by the optical unit to the workpiece. The scan unit (140) may include one or more drive shafts and one or more mirrors. The mirror of the scan unit (140) may have an adjustable angle. In addition, in the present invention, the scan unit (140) linearly moves the position of the Bessel beam. The Bessel beam incident on the scan unit (140) is reflected by the mirror, and the reflected Bessel beam may have an adjustable reflection angle. For example, the scan unit (221) is a system having at least one drive shaft and a mirror.

[0074] The focusing lens (150) positions the focus of the Bessel beam reflected from the scan unit (140) on the processing surface (101) of the workpiece. The focusing lens (150) may be positioned behind the scan unit (140) and in front of the workpiece. According to an embodiment of the present invention, the focal length of the focusing lens (222) may be configured in a range of about 3 to 300 mm. Accordingly, the workpiece may be processed by being positioned at a distance corresponding to the focal length of the focusing lens (150).

[0075] The scan unit (140) and the focusing lens (150) are for moving the focal line of the Bessel beam on the workpiece. According to an embodiment of the present invention, the focal line of the emitted Bessel beam can be created on the processing surface (101) of the workpiece through the scan unit (140) and the focusing lens (150).

[0076]

[0077] Meanwhile, referring to FIG. 2, the laser circular processing system according to the present invention includes a micrometer processing unit (210). The micrometer processing unit (210) moves the position of the Bessel beam in the circumferential direction to perform circular processing on the workpiece.

[0078] To this end, the micrometer processing unit (210) illustrated in FIG. 2 includes a third optical unit (third lens) (310), a high-speed system (320) composed of one or more drive shafts and mirrors, and a fourth optical unit (fourth lens) (330).

[0079] The third lens (310) modulates the optical axis of the annular Bessel beam to be parallel. Like the second lens (130), the third lens (310) may include a collimating lens or a collimating lens.

[0080] The high-speed system (320) reflects the Bessel beam modulated by the third lens (310). In addition, the high-speed system (320) adjusts the position of the Bessel beam in two or more directions.

[0081] The fourth lens (330) annularly modulates the Bessel beam reflected by a high-speed system comprising one or more drive shafts and mirrors. Like the first lens, the fourth lens may be a conical prism, an axicon lens, a DOE, or an SLM.

[0082] The system illustrated in FIG. 2 is a high-speed system composed of one or more drive shafts and mirrors, which can adjust the angle. The high-speed system composed of one or more drive shafts and mirrors may include a piezoelectric motor and / or a galvanometer. The high-speed system may include a steering mirror. For example, since the high-speed system is driven by a piezoelectric motor, it can move the mirror simultaneously in X / Y at high speed, and since it operates at several kHz in a narrow area, micrometer circular processing is more than 10 times faster than a conventional scanner. At this time, the conventional scan unit, which is a system composed of one or more drive shafts and mirrors, plays a role in quickly moving the processing position. That is, in the existing system composed of one or more drive shafts and mirrors, a circle is drawn and the position is moved to a desired position, but in the case of the present invention, with the addition of a micro-machining unit, the roles are separated into a high-speed circular processing module and a high-speed position movement. In addition, the high-speed system composed of one or more drive shafts and mirrors added in the present invention draws a shape at a mirror angle, making it easier to change the size of a circle and process various shapes, and it becomes possible to process smaller circles that were difficult to implement precise shapes due to the dynamic and structural characteristics of existing scanners more precisely at a much faster speed.

[0083]

[0084] FIG. 3 schematically illustrates a laser circular processing system according to another embodiment of the present invention.

[0085] The embodiment illustrated in FIG. 3 also includes a laser unit (110), an optical unit (120, 130), a mirror unit (140), and a focusing unit (150). Since the description in relation to Embodiment 2 can be applied almost as is to these units, a detailed description thereof will be omitted.

[0086] The micrometer processing unit (210) illustrated in FIG. 3 is placed between the optical unit (120, 130) and the scan unit (140), and includes a transparent window (410) whose rotation speed and tilt angle are adjustable.

[0087] The micrometer circular machining illustrated in Fig. 3 corresponds to a method for machining circular shapes at high speed using an optical system and a rotation axis. The micrometer circular machining unit (210) is in the form of a flat, transparent window (410) that allows transmission, and by rotating it at high speed, it can produce an effect similar to a high-speed system comprised of one or more drive shafts and mirrors.

[0088] It utilizes the phenomenon that a parallel beam shifts due to the refractive index (n) when a transparent flat window is tilted. As shown in the example in Fig. 4, the micrometer circular size (D) can be determined according to the mirror thickness (T), refractive index (n), and tilting angle (θ). The rotational speed of the rotational axis is several kHz, so the example shown in Fig. 3, like the example shown in Fig. 2, allows for high-speed processing.

[0089] At this time, the existing scan unit (140) is changed to a role for high-speed position movement.

[0090]

[0091] Fig. 5 schematically illustrates an example in which both the formation of a circular processing pattern and the positional movement between through holes are performed by a scan unit when performing laser circular processing using the laser circular processing system according to Fig. 1. Fig. 6 schematically illustrates an example in which the formation of a circular processing pattern is performed by a micrometer processing unit and the positional movement between through holes is performed by a scan unit when performing laser circular processing using the laser circular processing system according to Fig. 2 or Fig. 3.

[0092] Each circular processing pattern can be formed by a plurality of dot array structures.

[0093] In the conventional case, both the formation of a circular processing pattern and the position movement were performed by the scan unit (140), as in the example illustrated in Fig. 5. Since the scan unit (140) has a processing speed of several Hz, there is a disadvantage in that the overall processing speed is slow.

[0094] However, in the case of the present invention, by using a micrometer processing unit (210) having a processing speed of several kHz together with a scan unit (140) having a processing speed of several Hz, a circular processing pattern can be formed in each through-hole forming region by the micrometer processing unit (210), and positional movement between through-hole forming regions can be performed by the scan unit (140). Through this, the total time required for circular processing of a transparent brittle material can be shortened.

[0095]

[0096] Figure 7 schematically illustrates a laser circular processing method according to an embodiment of the present invention.

[0097] The laser circular processing method according to the present invention includes a laser circular processing system. As described above, the laser circular processing system includes a laser unit (110) that emits a laser beam; an optical unit (120, 130) that is arranged in a path of the laser beam and modulates the laser beam into a Bessel beam; a scanning unit (140) that reflects the Bessel beam modulated by the optical unit onto a workpiece and linearly moves the position of the Bessel beam; a focusing lens (150) that positions the focus of the Bessel beam reflected from the scan unit on a processing surface of the workpiece; and a micro-processing unit (210) that circumferentially moves the position of the Bessel beam to perform circular processing on the workpiece.

[0098] Referring to FIG. 7, the laser circular processing method according to the present invention includes a laser circular processing system alignment step (S710), a Bessel beam acquisition step (S720), and a circular processing pattern formation step (S730). After the circular processing pattern formation step (S730), an etching step (S740) for forming a through hole may be performed.

[0099] First, in the laser circular processing system alignment step (S710), the laser circular processing system is aligned to the upper portion of the workpiece.

[0100] Next, in the Bessel beam acquisition step (S720), the Bessel beam is acquired through an optical unit including a first lens, a second lens, etc.

[0101] Next, in the circular processing pattern forming step (S730), the Bessel beam is sequentially irradiated to multiple through-hole forming regions of the workpiece to change the properties of the through-hole forming regions of the workpiece to form multiple circular processing patterns.

[0102] At this time, in the case of the present invention, each circular processing pattern is formed by a micrometer processing unit, and a positional movement from one through-hole forming region to another through-hole forming region is performed by a scan unit.

[0103] Next, in the etching step (S740), the workpiece having a plurality of circular processing patterns formed thereon is etched to form a plurality of through holes.

[0104] Each circular processing pattern can be formed by a plurality of dot array structures.

[0105] For example, the dot array may be arranged at regular intervals. For another example, the dot array may be arranged at irregular intervals.

[0106] Additionally, the dot array may be formed, for example, in an array structure in which dots are spaced apart from each other. In another example, the dots may be formed in an array structure in which dots are overlapped with each other.

[0107] Etching can be done by wet etching using a fluorinated etchant, a non-fluorinated etchant, etc., but this is only an example, and any etchant that can etch a glass substrate can be used without limitation.

[0108]

[0109] As described above, according to the system and method for circular processing of a transparent brittle material using an ultrashort laser according to the present invention, a scanning unit having a processing speed of several Hz and a micrometer processing unit having a processing speed of several kHz are used, so that each circular processing pattern can be formed by the micrometer processing unit, and positional movement between through holes can be performed by the scanning unit. Through this, the total time required for circular processing of a transparent brittle material can be shortened.

[0110]

[0111] While the above description focuses on specific embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made. Such modifications and variations, as long as they do not depart from the scope of the technical concept provided by the present invention, are considered to be within the scope of the present invention. Therefore, the scope of the present invention should be determined by the claims set forth below.

Claims

1. As a laser circular processing system for a workpiece, A laser unit that emits a laser beam; An optical unit positioned in the path of the laser beam and modulating the laser beam into a Bessel beam; A scanning unit that reflects the Bessel beam modulated by the optical unit onto a workpiece and linearly moves the position of the Bessel beam; A focusing lens that positions the focus of the Bessel beam reflected from the above scanning unit on the processing surface of the workpiece; and A laser circular processing system including a micro-processing unit that moves the position of a Bessel beam in a circumferential direction to perform circular processing on a workpiece.

2. In paragraph 1, A laser circular processing system wherein the above workpiece is a transparent brittle material.

3. In paragraph 1, The above laser unit is a laser circular processing system that emits an ultrashort laser beam having a UV wavelength of 300 nm to 400 nm, a green wavelength of 500 nm to 600 nm, or a near-infrared wavelength of 900 nm to 1100 nm and a pulse width of 50 femtoseconds to 50 picoseconds.

4. In paragraph 1, The above optical unit A first lens that modulates an incident laser beam into an annular Bessel beam; and A laser circular processing system comprising a second lens that modulates the optical axis of the Bessel beam to be parallel.

5. In paragraph 4, A laser circular processing system, wherein the first lens comprises a conical prism, an axicon lens, a Diffractive Optical Element (DOE), or a Spatial Light Modulator (SLM).

6. In paragraph 4, A laser circular processing system, wherein the second lens comprises a collimating lens or a collimating lens.

7. In paragraph 4, The above micro-machining unit A third lens that modulates the optical axis of the annular Bessel beam to be parallel; A high-speed system comprising one or more drive shafts and mirrors that reflect the Bessel beam modulated by the third lens and adjust the position of the Bessel beam in two or more directions; and A laser circular processing system comprising a fourth lens for annularly modulating a Bessel beam reflected from the high-speed system.

8. In paragraph 4, The above high-speed system is a laser circular processing system including a piezoelectric motor and / or a galvanometer.

9. In paragraph 4, A laser circular processing system, wherein the micro-machining unit is disposed between the optical unit and the scanning unit and includes a transmission window whose rotation speed and tilt angle are adjustable.

10. In paragraph 1, A laser circular processing system, wherein the above scan unit includes one or more drive shafts and one or more mirrors.

11. A method for performing circular processing on a transparent brittle material using a laser circular processing system including a micrometer processing unit and a scanning unit according to Article 1, (a) a step of aligning a laser circular processing system on top of a workpiece; (b) a step of obtaining a Bessel beam through the laser circular processing system; and (c) a step of sequentially irradiating the Bessel beam to a plurality of through-hole forming regions of the workpiece to change the properties of the through-hole forming regions of the workpiece to form a plurality of circular processing patterns, A laser circular processing method in which circular processing pattern formation for each through hole is performed by the above micrometer processing unit, and positional movement from one through hole formation area to another through hole formation area is performed by the above scan unit.

12. In paragraph 11, A laser circular processing method, wherein the above laser unit emits an ultrashort laser beam having a UV wavelength of 300 nm to 400 nm, a green wavelength of 500 nm to 600 nm, or a near-infrared wavelength of 900 nm to 1100 nm and a pulse width of 50 femtoseconds to 50 picoseconds.

13. In paragraph 11, The above optical unit A first lens that modulates an incident laser beam into an annular Bessel beam; and A laser circular processing method comprising a second lens that modulates the optical axis of a Bessel beam to be parallel.

14. In paragraph 13, The above micro-machining unit, A third lens that modulates the optical axis of the annular Bessel beam to be parallel; A high-speed system comprising one or more drive shafts and mirrors that reflect the Bessel beam modulated by the third lens and adjust the position of the Bessel beam in two or more directions; A laser circular processing method comprising a fourth lens that modulates a Bessel beam reflected by the high-speed system into an annular shape.

15. In paragraph 13, A laser circular processing method, wherein the high-speed system comprises a piezoelectric motor and / or a galvanometer.

16. In paragraph 13, A laser circular processing method, wherein the micro-machining unit is disposed between the optical unit and the scanning unit and includes a transmission window whose rotation speed and tilt angle are adjustable.

17. In paragraph 11, A laser circular processing method, wherein the above scan unit comprises a system comprising one or more drive shafts and mirrors.

Images