Laser chamfering apparatus and laser chamfering method

Abstract

A laser chamfering apparatus and a laser chamfering method are disclosed. The disclosed laser chamfering device comprises: a laser oscillator for emitting a laser beam; a beam guide device for guiding, toward a cylinder lens, the laser beam emitted from the laser oscillator; the cylinder lens for forming a line focus by focusing the laser beam introduced from the beam guide device; a lens rotation driving unit for adjusting the angle of the line focus by rotating the cylinder lens; a housing for accommodating and supporting the cylinder lens and the lens rotation driving unit; and a stage for changing the relative position of the cylinder lens with respect to a workpiece by moving the housing.

Description

Laser chamfering device and laser chamfering method

[0001] A laser chamfering device and a laser chamfering method are disclosed. More specifically, a laser chamfering device and a laser chamfering method configured to enable cost reduction and efficient utilization of installation space are disclosed.

[0002] Recently, due to the high integration and ultra-thinness of semiconductor devices, the use of glass substrates as well as silicon substrates is increasing.

[0003] Glass substrates possess transparency and insulation properties, so they are applied in various fields such as displays, sensors, and semiconductor packaging.

[0004] However, it has been reported that micro-chipping occurs during the dicing process of glass substrates, leading to a decrease in the mechanical strength of the substrate. In particular, chipping is concentrated at the edges of the substrate, which leads to crack propagation and substrate breakage in subsequent processes. Previously, edges were processed through grinding or chemical etching processes, but these methods had limitations, such as long processing times, high processing costs, and difficulty in ensuring uniform quality.

[0005] The objective of the present invention is to solve the above problems,

[0006] ● An optical system capable of performing precision chamfering on the dicing edge of a glass substrate using a laser is provided, and

[0007] ● Through this, microchip formation is minimized, and

[0008] ● Improves the mechanical strength and reliability of the substrate, and

[0009] ● It is to enable application to the manufacturing process of glass substrates for semiconductor packaging and displays.

[0010] One aspect of the present invention is,

[0011] A laser oscillator configured to emit a laser beam;

[0012] A beam guidance device configured to guide a laser beam emitted from the above laser oscillator to a cylinder lens;

[0013] A cylinder lens configured to focus a laser beam introduced from the beam guidance device to form a line focus;

[0014] A lens rotation drive unit configured to rotate the cylinder lens to adjust the angle of the line focus;

[0015] A housing configured to accommodate and support the above-mentioned cylinder lens and the above-mentioned lens rotation drive unit; and

[0016] A laser chamfering device is provided that includes a stage configured to change the relative position of the cylinder lens with respect to the workpiece by moving the housing.

[0017] The above cylinder lens may have a convex-planar structure, a convex-convex structure, or a convex-concave structure.

[0018] The laser chamfering device may further include a beam homogenizer between the beam guiding device and the cylinder lens.

[0019] The laser chamfering device may further include a focusing lens configured to focus a laser beam that has passed through the cylinder lens.

[0020] The above cylinder lens may include a first cylinder lens and a second cylinder lens.

[0021] The above lens rotation drive unit may include a first lens rotation drive unit and a second lens rotation drive unit.

[0022] The first lens rotation drive unit is configured to adjust the angle of the first cylinder lens to focus a laser beam into a preheating line focus to preheat a part of the workpiece, and the second lens rotation drive unit may be configured to adjust the angle of the second cylinder lens at the same angle as the first lens rotation drive unit to form a chamfering line focus that overlaps with the preheating line focus.

[0023] The first lens rotation drive unit and the second lens rotation drive unit may be configured to perform a V-cut process having a preset cross-sectional angle on the workpiece by independently adjusting the angles of the first cylinder lens and the second cylinder lens.

[0024] Another aspect of the present invention is,

[0025] A step of moving the cylinder lens relative to the workpiece (S10);

[0026] Step of adjusting the angle of the above cylinder lens (S20);

[0027] Step (S30) of injecting a laser beam into the cylinder lens to form a line focus; and

[0028] A laser chamfering method is provided, comprising the step (S40) of inducing absorption of the above line focus on the workpiece to form a defect line and chamfering the workpiece along the defect line.

[0029] In the above step (S30), the line focus can be separated into a line focus for preheating and a line focus for chamfering and formed sequentially.

[0030] The above-mentioned line focus for preheating and line focus for chamfering are formed to overlap, so that preheating and chamfering can be performed sequentially.

[0031] The above-mentioned preheating line focus can preheat a part of the workpiece, and the above-mentioned chamfering line focus can perform chamfering on the preheated part.

[0032] The above step (S30) may be a step of forming a line focus for V-cut machining at a preset angle on the workpiece.

[0033] The above step (S30) may be a step of forming a first line focus inclined to the left and a second line focus inclined to the right based on a virtual vertical line.

[0034] In one embodiment of the present invention, a laser chamfering device can manufacture a pipe with improved uniformity of pipe wall thickness and can minimize installation space.

[0035] Figure 1 is a diagram schematically illustrating a laser spot focusing method.

[0036] Figure 2 is a diagram schematically illustrating a laser line focus formation method.

[0037] FIG. 3 is a schematic diagram showing a laser chamfering device according to a first embodiment of the present invention.

[0038] Figure 4 is a diagram illustrating the operating mechanism of the laser chamfering device shown in Figure 3.

[0039] FIG. 5 is a drawing for explaining a method of chamfering a workpiece using the laser chamfering device shown in FIG. 3.

[0040] FIG. 6 is a drawing for explaining a method of processing a workpiece at various chamfer angles using the laser chamfering device illustrated in FIG. 3.

[0041] Figure 7 is a diagram illustrating the operating mechanism when a beam homogenizer is added to the laser chamfering device shown in Figure 3.

[0042] FIG. 8 is a diagram illustrating the operating mechanism when a beam homogenizer and a focusing lens are added to the laser chamfering device shown in FIG. 3.

[0043] FIG. 9 is a schematic diagram showing a laser chamfering device according to a second embodiment of the present invention.

[0044] FIG. 10 is a schematic diagram showing a laser chamfering device according to a third embodiment of the present invention.

[0045] Hereinafter, a laser chamfering device according to one embodiment of the present invention will be described in detail with reference to the drawings.

[0046] In this specification, "angle" means the degree of inclination relative to an imaginary vertical line.

[0047] Additionally, in this specification, "workpiece" may be a glass product or a component or article capable of laser processing.

[0048] Figure 1 is a diagram schematically illustrating a laser spot focusing method.

[0049] Referring to FIG. 1, the laser spot focusing method is configured such that a laser beam (LB) is incident on a circular lens (RL) to form a spot focus (SF).

[0050] Figure 2 is a diagram schematically illustrating a laser line focus formation method.

[0051] Referring to FIG. 2, the laser line focus forming method is configured such that a laser beam (LB) is incident on a cylinder lens (CL) to form a line focus (LF).

[0052] FIG. 3 is a schematic diagram showing a laser chamfering device (LCA) according to a first embodiment of the present invention.

[0053] Referring to FIG. 3, a laser chamfering device (LCA) according to one embodiment of the present invention includes a laser oscillator (not shown), a beam guidance device (not shown), a cylinder lens (CL), a lens rotation drive unit (LRD), a housing (HS), and a stage (not shown).

[0054] The laser oscillator described above may be configured to emit a laser beam. Specifically, the laser oscillator may be configured to generate a laser beam of a specific wavelength according to power supply and control signals and output it to an external optical system. Additionally, depending on the type of laser oscillator, it may output a continuous wave (CW) or pulsed laser, which may affect processing precision and efficiency.

[0055] The beam guidance device may be configured to guide a laser beam emitted from the laser oscillator to the cylinder lens. To this end, the beam guidance device may include one or more reflective mirrors, beam splitters, beam expanders, or optical fiber transmission modules, and these components enable optimal focus formation at the cylinder lens (CL) by adjusting the propagation direction, position, and beam diameter of the laser beam.

[0056] The cylinder lens (CL) can be configured to focus the laser beam transmitted from the beam guidance device in only one axial direction to form a line-shaped focal point (LF) rather than a spot-shaped focal point. In this case, the cylinder lens (CL) applies a change in refractive index only in one axial direction of the propagation path of the incident laser beam (LBi), thereby compressing the beam width in a certain direction so that the output laser beam (LBo) has a line-shaped focal point.

[0057] In addition, the cylinder lens (CL) can be selected from a convex-planar structure, a convex-convex structure, or a convex-concave structure depending on the processing purpose or beam characteristics, and each structure directly affects the focal length, beam convergence angle, and the length and width of the line focus (LF). For example, the convex-convex structure provides a shorter focal length and higher focusing power, while the convex-concave structure is advantageous for stably forming a line focus of a certain length while minimizing beam distortion.

[0058] The lens rotation drive unit (LRD) can be configured to precisely control the angle at which the line focus (LF) is formed on the surface of the workpiece by rotating it in a desired direction with respect to the central axis of the cylinder lens (CL).

[0059] Specifically, the rotation of the cylinder lens (CL) directly affects the directionality of the line focus (LF), which is useful when forming a machining pattern of a specific angle, such as a V-cut, an inclined cut, or non-perpendicular machining. For example, when the lens rotation drive (LRD) rotates the cylinder lens (CL) by a predetermined angle, the line focus (LF) also rotates by the same angle, so that an oblique cutting line or an inclined surface can be formed on the workpiece.

[0060] In addition, the lens rotation drive unit (LRD) can be configured to include a rotation axis, an electric motor, a reduction gear, an encoder, etc., to control rotational speed and angle with high precision, and can be designed to enable real-time angle changes during processing by linking with an automatic control system as needed.

[0061] The housing (HS) may be configured to accommodate and support the cylinder lens (CL) and the lens rotation drive (LRD). Specifically, the housing (HS) may include a mounting seat or a fixing bracket to maintain the precise position of the cylinder lens (CL) and the lens rotation drive (LRD) inside, and serves to protect the internal components from external shocks or vibrations.

[0062] Additionally, the housing (HS) may be equipped with precision-machined input and output ports to allow the laser beam to pass through, and may have an anti-reflection coating or light-absorbing treatment applied internally to minimize unwanted scattered or reflected light. If necessary, the housing (HS) may be designed to efficiently dissipate heat generated during the operation of the cylinder lens (CL) and lens rotation drive (LRD) by including a heat sink, cooling water channels, or air / water cooling devices.

[0063] The above stage can be configured to move the housing (HS) in a desired direction to precisely change the relative position of the cylinder lens (CL) with respect to the workpiece. Specifically, the stage may have linear movement functions in the X-axis, Y-axis, and Z-axis directions, and, if necessary, may add a θ-axis (rotation axis) movement function to enable processing at a wider variety of angles and positions.

[0064] In addition, the stage may be driven by an electric motor, a linear motor, or a pneumatic / hydraulic actuator, and may include a ball screw or a linear guide to increase movement precision.

[0065] In addition, the stage may include a linear scale or an optical encoder that detects the position of the stage in real time for high-precision machining.

[0066] This configuration allows for fine adjustment of the position of the housing (HS) even during processing, thereby optimizing the relative focal position between the cylinder lens (CL) and the workpiece and enabling the realization of various processing patterns or shapes. If necessary, the stage may be equipped with a damping structure or a vibration-damping design to suppress vibration, thereby enabling stable position control even during high-power laser processing.

[0067] Figure 4 is a diagram illustrating the operating mechanism of the laser chamfering device (LCA) shown in Figure 3.

[0068] Referring to FIG. 4(a), the cylinder lens (CL) changes the refractive index only in a specific axis direction along the path of the incident laser beam (LB11, LB21, LB31, LB41, LB51, LB61), thereby compressing the beam in that direction. As a result, the exit laser beam (LB12, LB22, LB32, LB42, LB52, LB62) strongly converges in one axis direction while remaining parallel in the other axis direction, thereby forming a narrow and long line focus (LF).

[0069] Referring to FIG. 4(b), when the cylinder lens (CL) is tilted by an angle θc, the line focus (LF) is also tilted by an angle θf, and θc and θf have the same value. Here, θc is the angle between the imaginary vertical line (VL) and the lens axis (LA), and θf is the angle between the imaginary vertical line (VL) and the line focus axis (LA).

[0070] FIG. 5 is a drawing for explaining a method of chamfering a workpiece (GL) using a laser chamfering device (LCA) illustrated in FIG. 3, and FIG. 6 is a drawing for explaining a method of processing a workpiece at various chamfer angles using a laser chamfering device (LCA) illustrated in FIG. 3. FIG. 5 (a) is a side view, and FIG. 5 (b) is a front view.

[0071] Referring to FIGS. 5 and 6, when the cylinder lens (CL) is tilted by a predetermined angle, the incident laser beam (LBi) is refracted along the tilted axis of the lens and focused into the output laser beam (LBo). In this process, the cylinder lens (CL) compresses only the specific axis direction of the beam to form a narrow and long line focus (LF), and the line focus (LF) formed according to the tilt angle of the cylinder lens (CL) is also created in a form tilted by the same angle. That is, the tilt angle of the cylinder lens (CL) and the tilt angle of the line focus (LF) are identical, so as the cylinder lens (CL) rotates, the direction of the line focus (LF) also rotates together and is adjusted to a desired angle.

[0072] FIG. 7 is a diagram illustrating the operating mechanism when a beam homogenizer (BH) is added to the laser chamfering device (LCA) shown in FIG. 3.

[0073] Referring to FIG. 7(a), when a beam homogenizer (BH) is not added, the cylinder lens (CL) changes the refractive index only in a specific axial direction along the path of the incident laser beams (LB11, LB21, LB31, LB41, LB51, LB61) and compresses the beam in that direction. Accordingly, the outgoing laser beams (LB12, LB22, LB32, LB42, LB52, LB62) converge strongly in one axial direction while remaining parallel in the other axial direction, forming a narrow and long line focus (LF1).

[0074] On the other hand, referring to FIG. 7(b), the laser beams (LB10, LB20, LB30, LB40, LB50, LB60) incident on the beam homogenizer (BH) have their output distribution adjusted uniformly as they pass through the beam homogenizer (BH). Subsequently, the laser beams (LB11, LB21, LB31, LB41, LB51, LB61) incident on the cylinder lens (CL) have their refractive index changed in a specific axial direction, thereby compressing the beams. As a result, the emitted laser beams (LB12, LB22, LB32, LB42, LB52, LB62) form a line focus (LF2) having a more uniform output distribution than the line focus (LF1) shown in FIG. 7(a).

[0075] FIG. 8 is a diagram illustrating the operating mechanism when a beam homogenizer (BH) and a focusing lens (FL) are added to the laser chamfering device (LCA) shown in FIG. 3.

[0076] Referring to FIG. 8, the laser beams (LB10, LB20, LB30, LB40, LB50, LB60) are incident on and pass through a beam homogenizer (BH), thereby uniformly adjusting the output distribution. Subsequently, the homogenized laser beams (LB11, LB21, LB31, LB41, LB51, LB61) are incident on a cylinder lens (CL) and compressed by a change in refractive index in a specific axial direction. The resulting laser beams (LB12, LB22, LB32, LB42, LB52, LB62) are incident on a focusing lens (FL), and the laser beams (LB13, LB23, LB33, LB43, LB53, LB63) emitted after passing through the focusing lens (FL) form a line focus (LF3) at the rear end. This line focus (LF3) has improved energy density and focus quality compared to the line focus (LF2) shown in Fig. 7 (b), enabling more precise and efficient laser processing.

[0077] FIG. 9 is a schematic diagram showing a laser chamfering device (LCA) according to a second embodiment of the present invention.

[0078] Referring to FIG. 9, the cylinder lens (CL) includes a first cylinder lens (CL1) and a second cylinder lens (CL2), and each cylinder lens (CL1, CL2) includes a first lens rotation drive unit (LRD1) and a second lens rotation drive unit (not shown) so that the rotation angle can be adjusted independently.

[0079] When the direction of movement of the laser chamfering device (LCA), that is, the direction of movement of the head, corresponds to the forward direction (the direction of protrusion forward) relative to the base plane of FIG. 9, the first lens rotation drive unit (LRD1) can adjust the angle of the first cylinder lens (CL1) to focus the incident laser beam (LBi1) into a preheating line focus (LBo1), thereby enabling a portion of the workpiece to be heated uniformly and effectively in advance. Accordingly, the second lens rotation drive unit (not shown) can rotate the second cylinder lens (CL2) at the same angle as the first lens rotation drive unit (LRD1) to form a chamfering line focus (LF) at a position that exactly overlaps with the preheating line focus.

[0080] FIG. 10 is a schematic diagram showing a laser chamfering device (LCA) according to a third embodiment of the present invention.

[0081] Referring to FIG. 10, the cylinder lens (CL) includes a first cylinder lens (CL1) and a second cylinder lens (CL2), and each cylinder lens (CL1, CL2) is designed to function independently. The lens rotation drive unit (LRD) includes a first lens rotation drive unit (LRD1) and a second lens rotation drive unit (LRD2), and is configured to independently adjust the rotation angles of the first cylinder lens (CL1) and the second cylinder lens (CL2), respectively. The first cylinder lens (CL1) converts an incident laser beam (LBi1) into an output laser beam (LBo1) to form a line focus (LF1), and the second cylinder lens (CL2) converts an incident laser beam (LBi2) into an output laser beam (LBo2) to form a line focus (LF2). The first lens rotation drive unit (LRD1) and the second lens rotation drive unit (LRD2) individually set the angle of each cylinder lens according to processing conditions or the characteristics of the workpiece, thereby combining line focus (LF1) and line focus (LF2) to precisely and efficiently perform V-cut processing with a preset cross-sectional angle. This independent control structure can flexibly respond to workpieces with complex shapes and contributes to improved processing quality and reduced defect rates.

[0082] Hereinafter, a laser chamfering method according to one embodiment of the present invention will be described in detail.

[0083] A laser chamfering method according to one embodiment of the present invention comprises the steps of: moving a cylinder lens relative to a workpiece (S10); adjusting the angle of the cylinder lens (S20); incidenting a laser beam onto the cylinder lens to form a line focus (S30); and causing the line focus to induce absorption in the workpiece to form a defect line, and chamfering the workpiece along the defect line (S40).

[0084] In the above step (S10), the position of the cylinder lens is adjusted to accurately align the target area of ​​the laser processing. It is possible to move the cylinder lens while the workpiece is fixed, or to move the workpiece while the cylinder lens is fixed. Through this, the line focus formed in the subsequent step can be accurately projected along the planned chamfering position of the workpiece.

[0085] In the above step (S20), the cylinder lens is rotated or tilted so that the laser beam is irradiated onto the surface of the workpiece at an optimal angle of incidence. Adjusting the angle of the cylinder lens affects the machining depth, edge bevel angle, laser energy distribution, etc., thereby improving machining quality. If necessary, the angle can be adjusted in real time during machining to increase machining precision.

[0086] In the above step (S30), a focus is created in the form of a line that is elongated in one direction, rather than a point. The cylinder lens converges the beam in one axis direction to form a focus and diverges the beam in the other axis direction to form a line shape. The line focus widens the processing width and uniformly distributes energy, thereby simultaneously improving the chamfering speed and quality.

[0087] For example, in the above step (S30), the line focus is divided into a preheating line focus and a chamfering line focus that perform two roles, and these are formed sequentially to proceed with the machining process step by step. First, the preheating line focus raises the temperature of the material by preheating a part of the workpiece, thereby improving the machinability of the material during the subsequent chamfering process. Next, the chamfering line focus is irradiated onto the preheated area, and this focus performs precise chamfering on the workpiece through concentrated laser energy. The two line focuses are designed to overlap spatially so that preheating and chamfering are performed continuously and efficiently, and this configuration has the effect of improving machining quality, minimizing material damage, and increasing work speed.

[0088] As another example, the above step (S30) is a step of creating a line focus to form a V-shaped cutting cross-section on the surface of a workpiece by adjusting a laser beam through a cylinder lens, and can be optically designed and adjusted according to a predetermined V-cut angle considering the material, thickness, and edge bevel requirements of the workpiece. At this time, the line focus is a focus line that extends in the direction of the machining width, and a first and second line focus are formed on the left and right sides, respectively, with respect to a virtual vertical line. The first line focus is positioned at a certain angle to the left of the virtual vertical line, and the second line focus is positioned at the same angle or, if necessary, at a different angle to the right. These two focuses disperse laser energy to both sides of the edge of the workpiece to create a V-shaped or Χ-shaped cutting cross-section. Precise bevel surface machining is possible by intersecting at the center or removing material by heat near the contact point. This configuration has the effect of increasing machining efficiency and edge shape uniformity compared to unidirectional focus irradiation, and minimizing subsequent polishing and post-processing steps.

[0089] In the above step (S40), when a line focus is irradiated, laser energy is selectively absorbed within the material to form microcracks or weakened defect lines. These defect lines provide a path along which the material can be easily separated or cut, and along this path, the edges are processed into a beveled shape (chamfering). As a result, unnecessary material loss is reduced, a precise and smooth edge shape is achieved, and subsequent polishing or post-processing steps are shortened.

[0090] The present invention has been described with reference to the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

[0091] [Explanation of the symbol]

[0092] RL: Circular lens CL: Cylindrical lens

[0093] LB: Laser beam SF: Spot focus

[0094] LF: Line Focus LCA: Laser Chamfering Device

[0095] HS: Housing LRD: Lens rotation drive unit

[0096] θ c : Lens tilting angle θ f : Focal angle

[0097] VL: Imaginary vertical line LA: Lens axis

[0098] FA: Focus axis GL: Glass element

[0099] BH: Beam Homogenizer FL: Concentrating Lens

Claims

A laser oscillator configured to emit a laser beam; A beam guidance device configured to guide a laser beam emitted from the above laser oscillator to a cylinder lens; A cylinder lens configured to focus a laser beam introduced from the beam guidance device to form a line focus; A lens rotation drive unit configured to rotate the cylinder lens to adjust the angle of the line focus; A housing configured to accommodate and support the above-mentioned cylinder lens and the above-mentioned lens rotation drive unit; and A laser chamfering device comprising a stage configured to change the relative position of the cylinder lens with respect to a workpiece by moving the housing. In paragraph 1, The above-described cylinder lens is a laser chamfering device having a convex-planar structure, a convex-convex structure, or a convex-concave structure. In paragraph 1, A laser chamfering device further comprising a beam homogenizer between the beam guiding device and the cylinder lens. In paragraph 1, A laser chamfering device further comprising a focusing lens configured to focus a laser beam that has passed through the above-mentioned cylinder lens. In paragraph 1, The above cylinder lens is a laser chamfering device comprising a first cylinder lens and a second cylinder lens. In paragraph 5, The above lens rotation drive unit is a laser chamfering device comprising a first lens rotation drive unit and a second lens rotation drive unit. In paragraph 6, A laser chamfering device configured such that the first lens rotation drive unit adjusts the angle of the first cylinder lens to focus a laser beam into a preheating line focus to preheat a part of the workpiece, and the second lens rotation drive unit adjusts the angle of the second cylinder lens at the same angle as the first lens rotation drive unit to form a chamfering line focus that overlaps with the preheating line focus. In paragraph 6, A laser chamfering device configured such that the first lens rotation drive unit and the second lens rotation drive unit independently adjust the angles of the first cylinder lens and the second cylinder lens to perform V-cut processing having a preset cross-sectional angle on the workpiece. A step of moving the cylinder lens relative to the workpiece (S10); Step of adjusting the angle of the above cylinder lens (S20); Step (S30) of injecting a laser beam into the cylinder lens to form a line focus; and A laser chamfering method comprising the step (S40) of inducing absorption of the above line focus on the workpiece to form a defect line and chamfering the workpiece along the defect line. In Paragraph 9, A laser chamfering method in which, in the above step (S30), the line focus is separated into a line focus for preheating and a line focus for chamfering and formed sequentially. In Paragraph 10, A laser chamfering method in which the above-mentioned preheating line focus and chamfering line focus are formed to overlap, so that preheating and chamfering are performed sequentially. In Paragraph 11, A laser chamfering method in which the above-mentioned preheating line focus preheats a part of the workpiece, and the above-mentioned chamfering line focus performs chamfering on the preheated part. In Paragraph 9, The above step (S30) is a laser chamfering method that forms a line focus for V-cut processing at a preset angle on the workpiece. In Paragraph 13, The above step (S30) is a laser chamfering method that forms a first line focus inclined to the left and a second line focus inclined to the right based on a virtual vertical line.

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