Brittle material chamfering machining method and device

Abstract

The invention relates to a brittle material chamfer machining method and device. The brittle material chamfer machining method comprises the steps that a shaping light path is configured, a modified guide line matched with a target chamfer is formed on the subsurface of a workpiece to be machined, scanning movement is conducted along the edge contour of the workpiece, and a continuous modified area is formed; a Bezier cutting head is provided, the brittle material is cut along the modified area, and a target chamfer contour is formed; and the cut workpiece to be machined is split, so that the target chamfering area is separated along the target chamfering contour. By means of the brittle material chamfering machining method and device, the side face roughness can be reduced, the bending resistance strength after chamfering is improved, the etching rate is increased, and the problem that existing CNC chamfering machining is low in yield is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of brittle material processing, and in particular relates to a brittle material chamfering processing method and device. Background Art

[0002] Chamfering is an important step in the processing of brittle materials. Currently, this task is mainly accomplished through traditional CNC chamfering equipment. This involves automatically chamfering glass and other products by controlling the rotation of the corresponding tool according to a preset program and moving it along a specified processing path through the CNC machine tool.

[0003] However, traditional chamfering methods, such as those using CNC milling machines, have numerous drawbacks. For one thing, the processing yield is low, and processing time is long, making it difficult to meet the demands of efficient production. Furthermore, microcracks are likely to form on the sides of brittle materials after processing, which can severely impact the material's strength and result in poor bending resistance after chamfering.

[0004] While existing laser processing technology can improve efficiency, single-use laser processing methods are prone to edge cracking due to uneven energy distribution during the modification and cracking of brittle materials, or low etching rates that affect processing efficiency. Therefore, a method for chamfering brittle materials that balances precision, efficiency, and surface quality is urgently needed. Summary of the Invention

[0005] In view of this, the present invention provides a method and device for chamfering brittle materials to solve the problems of low yield, long processing time and weak bending resistance of brittle materials after chamfering.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the present invention to solve the technical problem is to provide a method for chamfering brittle materials, including: configuring a shaping optical path, forming a modified guide line matching the target chamfer on the sub-surface of the workpiece to be processed, and scanning and moving along the edge contour of the workpiece to form a continuous modified area; providing a Bessel cutting head, cutting the workpiece to be processed along the modified area to form a chamfer contour; and splitting the cut workpiece to be processed so that the chamfer area is separated along the chamfer contour.

[0007] Optionally, the shape of the modified guide line includes an arc segment or a double straight line segment.

[0008] Optionally, the angle between the two line segments of the double straight line splicing segment and the target chamfered oblique line is 0-10°.

[0009] Optionally, forming a modified guide line on the sub-surface of the workpiece to be processed that matches the target chamfer includes: adjusting weight compensation, and using a vertically incident shaping light path to output a light beam to form a modified guide line on the sub-surfaces of the upper and lower planes of the workpiece to be processed that matches the target chamfer.

[0010] Optionally, the light beam output by the shaping light path includes multiple sub-foci, and the multiple sub-foci are arranged in a linear array.

[0011] Optionally, the number of the sub-foci is 14 to 25.

[0012] Optionally, the shaping optical path integrates a DOE shaping module according to the phase diagram obtained by shaping.

[0013] Optionally, the splitting of the cut workpiece includes: The laser heats the chamfered profile or applies external forces to the chamfered profile.

[0014] Optionally, after splitting the cut workpiece, the method further includes: etching the split workpiece to reduce the roughness of the chamfered surface.

[0015] The present invention also provides a brittle material chamfering processing device, including: a modification module, used to configure a shaping optical path, form a modification guide line matching the target chamfer on the sub-surface of the workpiece to be processed, and scan and move along the edge contour of the workpiece to form a continuous modified area; a cutting module, used to provide a Bessel cutting head, cut the workpiece to be processed along the modified area to form a chamfer contour; and a splitting module, used to split the cut workpiece to separate the chamfered area along the chamfer contour.

[0016] Compared with the prior art, the method and device for chamfering brittle materials provided by the present invention have the following beneficial effects: By first modifying the brittle material workpiece and then cutting the modified area, the degree of damage to the cut edge can be effectively reduced, cutting accuracy can be improved, processing efficiency can be increased, the extension of microcracks within the material and the depth of the surface damage layer can be reduced, thereby reducing the side roughness and improving the bending strength after chamfering. In addition, when the etching rate of brittle materials is low due to material reasons, the single chamfer can be etched simultaneously from above and below the cracked single chamfer line to increase the etching rate. Unlike the method of etching and then breaking it apart, the vertical line is partially cracked before etching, and the roughness is significantly optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic flow chart of the steps of a chamfering method for brittle materials provided in the first embodiment of the present invention; Figure 2 A schematic structural diagram of a workpiece in the first embodiment of the present invention; Figure 3 Schematic diagram of the angle at which the output beam of the shaped optical path enters the workpiece; Figure 4 This is a schematic diagram of the principle of forming a modified guide line after the output beam of the shaped optical path enters the workpiece; Figure 5 Schematic diagrams of the shapes of two modified guide lines; Figure 6 Schematic diagram of the subsequent steps of splitting; Description of reference numerals: N, side; M, plane. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0019] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0020] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0021] like Figures 1 and 2 As shown, the first embodiment of the present invention provides a method for chamfering brittle materials, which includes: S100, configuring a shaping optical path, forming a modified guide line matching the target chamfer on the sub-surface of the workpiece to be processed, and scanning and moving along the edge contour of the workpiece to form a continuous modified area; In this embodiment, if Figure 2 As shown, the processing method is used to chamfer the angle between the side surface N and the plane M corresponding to the thickness direction of the brittle material workpiece, and form a modified area on the target chamfer area of ​​the workpiece to be processed through the output of the shaping light path to facilitate subsequent chamfer cutting.

[0022] Specifically, the shaping optical path is configured according to the geometric parameters of the target chamfer of the workpiece to be processed, and a programmable beam shaping method is used to change the phase and / or amplitude of the initial laser beam emitted by the laser, so as to shape the initial laser beam into multiple sub-focuses, and adjust the energy of each sub-focus and the shape of the multiple sub-focuses. After the adjustment is completed, the shaped beam is output to the workpiece to be processed, and a modified guide line matching the target chamfer geometric parameters is formed on the sub-surface of the workpiece. The modified guide line is scanned and moved along the edge contour of the workpiece to be chamfered according to the modified guide line, and the modified guide line is connected into a modified guide surface along the edge contour direction, thereby forming a continuous modified area.

[0023] It can be understood that the energy and component shapes of multiple sub-focuses are adjusted according to the geometric parameters of the target chamfer of the workpiece to be processed. For example, multiple sub-focuses are arranged in a linear array so that when the light beam is projected onto the workpiece to be processed, a modified guide line consistent with the target chamfer oblique line size is formed.

[0024] S200, provides a Bessel cutting head to cut the workpiece along the modified area to form a chamfered contour; Specifically, after the modified area is formed, the modified area of ​​the workpiece to be processed is cut by switching to the Bessel cutting head in an automatic switching spectroscopic manner.

[0025] After the modified area is formed in the above step S100, the position of the vertical line is reserved. When cutting with a Bessel cutting head, the cutting trajectory is planned according to the position of the modified area, wherein the focal depth is 0.5mm~1mm, the incident beam diameter is 5mm~12mm, preferably 10mm, and the energy is adjusted in real time through closed-loop feedback so that the position error between the cutting trajectory and the modified area is less than 5μm, forming a chamfered contour.

[0026] S300, splitting the workpiece to be processed after cutting, so that the chamfered area is separated along the chamfered contour; The fragmentation method includes The chamfered area is separated along the chamfered contour by laser heating (heating temperature 100℃~300℃) or applying external force by a mechanical stress device.

[0027] In this way, by first modifying the workpiece of brittle material and then cutting the modified area, the degree of damage to the cutting edge can be effectively reduced, the cutting accuracy can be improved, the cutting efficiency can be increased, the expansion of microcracks inside the material and the depth of the surface damage layer can be reduced, thereby reducing the side roughness and improving the bending strength after chamfering.

[0028] In the above steps, the following types of initial laser beams and shaper adjustment methods can be selected for the configuration of the shaping optical path: The initial laser beam is a picosecond laser. A programmable beam shaper can control the picosecond laser's formation of uniformly distributed sub-focuses within the material by adjusting the laser beam's phase and amplitude distribution. For example, a preset phase pattern can be used to shape the laser beam into a linear array of straight spot patterns. Picosecond lasers have pulse widths in the picosecond range (typically 1 to 1000 picoseconds), offering extremely short pulse durations and high peak power. This characteristic enables them to concentrate energy release within a very short timeframe when interacting with the material, reducing the heat-affected zone and thus avoiding excessive thermal damage to brittle materials. This makes them particularly suitable for precise material modification, particularly for glass.

[0029] The initial laser beam is a femtosecond laser, which is shaped into a linear or dot-matrix modified spot using a programmable beam shaper. The shaper modulates the phase and amplitude of the laser beam according to the preset processing requirements. By adjusting the optical parameters of the shaper, such as the focal length of the lens and the angle of the reflector, the propagation direction and focusing characteristics of the laser beam can be changed, thereby achieving precise control of the shape and size of the spot. Among them, the pulse width of the femtosecond laser is shorter, and its peak power is extremely high at the femtosecond level (typically 1 to 1000 femtoseconds). It can transfer energy to the material in a shorter time, with almost no heat diffusion and minimal damage to the material. It can achieve ultra-high-precision modified processing and is particularly suitable for brittle materials with extremely high processing precision requirements, and is suitable for materials with high hardness such as sapphire.

[0030] In some examples, such as Figure 3 As shown, the light beam output by the shaping light path is incident from a direction perpendicular to the plane M of the workpiece to be processed, and a modified guide line is formed on the sub-surface of the workpiece to be processed by modulating the beam parameters.

[0031] It is understandable that the beam parameters are determined according to the material and size of the workpiece.

[0032] Taking a specific example, for a workpiece of 0.5mm thick rectangular glass, the original laser beam, after being modulated by the shaping optical path, has the following beam parameters: 14 to 25 sub-foci arranged in a linear array, a wavelength of 1000nm to 1100nm, a pulse width of 100fs to 10ps, a pulse count of 1 to 10 pulses per train, a scanning speed of 50mm to 1000mm / s, and a position range of 1 to 10µm. With multiple sub-foci arranged in a linear array, incident perpendicular to the workpiece plane M, a modified guide line is formed in the target chamfer area of ​​the workpiece to be processed. The projected height of the modified guide line along the thickness of the glass is 0.1mm, and the coordinate error between the two nearest points of the modified guide line projected onto the glass plane is less than 10µm. After the modified guide line is formed, it is scanned along the length and width of the glass to form a continuous modified surface.

[0033] It can be understood that the focusing energy of each sub-focus can be adjusted independently, and the scanning process can be that the glass does not move and the output light beam of the shaping light path is moved around the edge of the glass, or the output light beam of the shaping light path does not move and the glass rotates around its central axis.

[0034] All of this displacement can be achieved through the coordinated operation of a horizontal module, a rotary module, and other driving components. For example, a glass is placed on a horizontal module, and the output beam is projected onto the desired chamfered area to form a modified guide line. The horizontal module then drives the glass to move along its length, creating a modified area along the length of the glass. Similarly, by combining multiple modules, modified areas can be formed simultaneously on all four sides of the glass.

[0035] In some examples, such as Figure 4 As shown, forming a modified guide line that matches the target chamfer on the sub-surface of the workpiece to be processed includes: adjusting the weight compensation, using the vertically incident shaping light path to output the light beam to form a modified guide line that matches the target chamfer on the sub-surfaces of the upper and lower planes M of the workpiece to be processed.

[0036] That is, there are two modified guide lines, the two modified guide lines are respectively located in the angle regions between the two planes M and the side surfaces N of the workpiece to be processed, and the two modified guide lines are symmetrical to each other.

[0037] Specifically, the light beam output by the shaped optical path is incident from a direction perpendicular to the plane M, and forms modified guide lines in the angle area between the upper plane M and the side surface N and the angle area between the lower plane M and the side surface N, respectively. Modified areas on both sides can be formed at the same time, thereby improving the efficiency of chamfering both sides of the workpiece at the same time.

[0038] It can be understood that weight compensation refers to correcting the unevenness caused by material properties, optical path deviation or target accuracy requirements during the processing by adjusting the energy distribution, phase distribution or other parameter weights in different areas of the light beam to achieve more precise material modification.

[0039] In this example, the laser light source can be collimated and then introduced into the focusing lens. The distance between the lens and the material is preliminarily adjusted so that the theoretical focusing position covers the upper and lower shallow areas of the material. The laser is turned on and a test shot is fired at low power. The upper and lower surfaces M of the material are observed under a microscope to see if there are any traces of modification. The power, pulse width and other parameters are gradually adjusted until continuous and uniform modification guide lines are formed on the upper and lower planes M at the same time. The parameters are fixed, and batches of materials are processed. The consistency of the modification effect is ensured through online monitoring (such as real-time observation with an optical microscope). Specifically, in terms of optical path layout, the laser light source can use a picosecond laser with a wavelength of 1000nm~1100nm (such as Coherent's picosecond laser). Its short pulse characteristics (pulse width 100fs~10ps) can reduce thermal diffusion and accurately control the energy deposition position. The collimation can be composed of a collimating lens to adjust the light emitted by the laser light source into parallel light, ensuring that the incident light enters the subsequent focusing link in a regular form. A focusing lens with a large numerical aperture (NA) (such as a customized plano-convex focusing lens) is used. By precisely designing its curvature radius and material refractive index, two high-energy density areas are formed at a specific depth range inside the material after the light beam is focused. The brittle material (such as glass) is fixed horizontally to ensure that the incident light is perpendicular to plane M. The distance between the material and the focusing lens is adjusted by a high-precision translation stage to accurately control the focusing position.

[0040] By leveraging the focal depth of a focusing lens and the diffraction properties of the beam, a beam of light, upon entering a material, generates sufficient energy density simultaneously at the subsurfaces below the upper surface and above the lower surface (e.g., 0.1mm above and below 0.5mm thick glass). By adjusting the lens focal length and the position of the material, the beam forms "energy peaks" in these two regions, inducing material modification.

[0041] Based on the material's absorption characteristics for the laser wavelength (e.g., the absorption coefficient of glass for 1064nm light), an appropriate wavelength is selected so that upon incident light, the upper and lower shallow regions absorb energy and undergo modification. If the material's absorption is weak, the multiphoton absorption effect (achieved through high power density) can be exploited to preferentially modify specific upper and lower regions.

[0042] In some examples, such as Figure 5 As shown, the shape of the modified guide line includes an arc segment or a double straight line segment.

[0043] It's understandable that when the chamfer is a straight line, a 2µm to 20µm bump will appear on the chamfered surface, affecting the appearance of the chamfer. Modifying the guide line with an arc segment or a double straight line segment can avoid this bump, thereby preventing the chamfered surface from being bumped and affecting the appearance.

[0044] It is understandable that the shape of the arc segment and the double straight line segment is achieved by adjusting the position distribution of each focus point in the sub-focus. Preferably, the angle α between the two straight line segments of the double straight line segment and the target chamfer line is 0-10°.

[0045] In some examples, the shaped optical path is integrated with a DOE shaping module according to the phase diagram obtained by shaping.

[0046] It is understandable that when processing the same target chamfer on a single workpiece, the DOE module is customized according to the phase diagram of the programmable beam shaping and integrated into the shaping optical path, which makes the shaping optical path simple to debug and easy to maintain.

[0047] The above-mentioned integration method can be: after customizing the DOE shaping module according to the phase diagram, a collimating lens and a DOE shaping module are arranged in sequence at the output end of the light source, so that the original Gaussian beam is collimated and vertically incident on the surface of the DOE shaping module; the DOE shaping module modulates the beam wavefront through its micro-nano structure (such as a relief phase grating) to shape the single beam into a preset focal array (such as a 14-sub-focal linear array); a high-precision adjustment mechanism (±10μrad angle fine-tuning, ±5μm displacement adjustment) is integrated inside the module to ensure that the DOE shaping module is in the optimal diffraction efficiency position (incident angle deviation ≤±0.1°); the shaped beam is compressed by a subsequent focusing lens to compress the spot size, and then driven by a galvanometer group or a servo platform to be incident on the sub-surface area in a direction perpendicular to the workpiece plane M, thereby realizing precise processing of the modified guide line.

[0048] In some examples, such as Figure 6 As shown, after the workpiece is split, it also includes: S400, etching the workpiece after splitting to reduce the surface roughness of the chamfer; Specifically, the etching method can be wet etching, such as using hydrofluoric acid (HF)-based etching, immersing the edge of the split workpiece in the etching solution, stirring at a constant temperature (25~50℃), and etching for 5~30 minutes to remove edge microcracks or burrs, so that the edge roughness Ra is reduced from 5μm to below 0.5μm.

[0049] A second embodiment of the present invention provides a brittle material chamfering device, comprising: The modification module is used to configure the shaping light path, form a modification guide line that matches the target chamfer on the sub-surface of the workpiece to be processed, and scan and move along the edge contour of the workpiece to form a continuous modification area; A cutting module is used to provide a Bessel cutting head to cut the workpiece to be processed along the modified area to form a chamfer contour; The splitting module is used to split the workpiece to be processed after cutting, so that the chamfered area is separated along the chamfered contour.

[0050] Furthermore, the brittle material chamfering processing device also includes an etching module for etching the workpiece after splitting to reduce the roughness of the chamfered surface.

[0051] Compared with the prior art, the method and device for chamfering brittle materials provided by the present invention have the following advantages: The method of first modifying the workpiece of brittle material and then cutting the modified area can effectively reduce the damage of the cutting edge, improve cutting accuracy, improve processing efficiency, reduce the expansion of microcracks inside the material and the depth of the surface damage layer, thereby reducing the side roughness and improving the bending strength after chamfering.

[0052] Furthermore, when the etching rate of a brittle material is low due to material reasons, etching of a single chamfer can be performed simultaneously from above and below the single chamfer line after the crack, thereby increasing the etching rate.

[0053] Different from the method of etching and then breaking it apart, the vertical line is partially cracked and then etched, which significantly optimizes the roughness.

[0054] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for chamfering brittle materials, characterized in that: include: Configure a shaping optical path to form a modified guide line that matches the target chamfer on the sub-surface of the workpiece to be processed, and scan and move along the edge contour of the workpiece to form a continuous modified area; A Bessel cutting head is provided to cut the workpiece to be processed along the modified area to form a chamfered contour; The workpiece to be processed is split after cutting, so that the chamfered area is separated along the chamfer contour.

2. A method for chamfering brittle materials according to claim 1, characterized in that: The shape of the modified guide line includes an arc segment or a double straight line splicing segment.

3. A method for chamfering brittle materials according to claim 2, characterized in that: The angle between the two line segments of the double straight line splicing segment and the target chamfered oblique line is 0-10°.

4. A method for chamfering brittle materials according to claim 1, characterized in that: The method of forming a modified guide line matching the target chamfer on the sub-surface of the workpiece to be processed comprises: The weight compensation is adjusted, and the output light beam of the vertically incident shaping light path is used to form modified guide lines that match the target chamfer on the sub-surfaces of the upper and lower planes of the workpiece to be processed.

5. A method for chamfering brittle materials according to claim 1, characterized in that: The light beam output by the shaping light path includes a plurality of sub-foci, and the plurality of sub-foci are arranged in a linear array.

6. A method for chamfering brittle materials according to claim 5, characterized in that: The number of the sub-foci is 14 to 25.

7. A method for chamfering brittle materials according to claim 1, characterized in that: The shaping optical path is integrated with a DOE shaping module according to the phase diagram obtained by shaping.

8. A method for chamfering brittle materials according to claim 1, characterized in that: The workpiece split after cutting comprises: pass The laser heats the chamfered profile or applies external forces to the chamfered profile.

9. A method for chamfering brittle materials according to claim 1, characterized in that: The method further comprises the following steps after the workpiece is split after being cut: Etch the workpiece after splitting to reduce the surface roughness of the chamfer.

10. A device for chamfering brittle materials, characterized in that: include: The modification module is used to configure the shaping light path, form a modification guide line that matches the target chamfer on the sub-surface of the workpiece to be processed, and scan and move along the edge contour of the workpiece to form a continuous modification area; A cutting module is used to provide a Bessel cutting head to cut the workpiece to be processed along the modified area to form a chamfer contour; The splitting module is used to split the workpiece to be processed after cutting, so that the chamfered area is separated along the chamfered contour.

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