Cover plate glass, laser drilling and hole chamfering processing method and pretreatment device thereof

Abstract

The invention discloses a cover plate glass, a laser drilling and hole chamfering processing method and a pretreatment device thereof, and the method comprises the following steps: carrying out laser modification treatment on glass by using a laser profiling light beam, and forming a modified contour surface consistent with the shape of a hole and a chamfer thereof in the glass, the material enclosed by the modified contour surface is a waste block needing to be removed; laser grooving treatment is conducted on the waste block through laser, and a drainage groove extending towards the interior of the glass till the drainage groove is close to the modified contour surface is formed; placing the grooved glass in an etching solution, wherein the etching solution permeates into the drainage groove to etch to the modified contour surface and then etches along the modified contour surface; the etched glass is subjected to splitting treatment, and the waste blocks are ejected out, so that the holes and the chamfers of the holes are formed; the device is flexible and controllable, the machining efficiency is improved, the machining precision is improved, and the machining requirements of chamfers of different shapes can be met.

Description

Technical Field

[0001] The present invention relates to the field of glass hole processing, and in particular to a cover glass, a laser drilling and hole chamfering processing method and a preprocessing device thereof. Background Art

[0002] Cover glass is widely used in electronic products such as smartphones, tablets, and touch screens due to its excellent light transmittance, wear resistance, and chemical stability. Holes are usually required to be designed on the cover for considerations such as heat dissipation, audio transmission, sensor functions, connection and charging interfaces, and design aesthetics. At present, the main methods for drilling holes in cover glass and their defects are as follows:

[0003] 1. Mechanical drilling method: Use a drilling tool to perform rotary cutting on the glass to form the required aperture, and then use a special chamfering tool to cut the hole after drilling to form the required chamfer shape, refer to patent CN114701077B. This method is easy for the drill bit to break the glass and easily produce triangular holes; it is suitable for thicker cover glass, with higher drilling accuracy, but the drill bit is easy to wear, and the technical requirements for operators are high, and the operation is complicated; it is easy to produce debris and dust pollution, the drill bit is easy to wear, and debris and dust are generated, and the technical requirements are high (grinding wheel and grinding fluid are consumed).

[0004] 2. Laser drilling method: Use a laser beam to heat process the glass, so that the glass partially melts, evaporates or vaporizes, thereby forming a straight through hole, refer to patent CN115356807B. Most of the existing laser processing technologies are aimed at single drilling or cutting tasks, and lack an integrated solution for simultaneously achieving drilling and hole chamfering. Generally, a straight through hole is formed first and then the laser beam is used to heat the hole mouth after drilling, so that the glass partially melts and flows, thereby forming a chamfer, refer to patent CN110757006B. This method is fast and efficient, and is suitable for cover glass of various thicknesses. Laser drilling has no tool loss and low cost. However, there will be a taper problem in processing through holes, and the shape of the chamfer of the processed hole is limited. Only straight chamfers can be made (such as trapezoidal and V-shaped), and chamfers with arc shapes or multi-segment line combinations are difficult to achieve (such as C-shaped, U-shaped, and broken line shapes), and the through holes and chamfers are distributed, and the quality of the chamfers and through hole overlaps is not good.

[0005] 3. Ultrasonic drilling method: Use the energy generated by ultrasonic vibration to generate tiny cracks on the glass, and then expand the cracks to form holes, refer to patent CN110465985B. This method is suitable for cover glass with complex structure or uneven thickness, but the equipment cost is high, and it will magnify the micro cracks of the cover glass itself, causing broken pieces, scratches, edge collapse and other defects, and the yield rate is not high.

[0006] The above information disclosed in this Background section is included only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is currently known to a person of ordinary skill in the art. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a cover glass, a laser drilling and hole chamfering processing method and a pretreatment device thereof in view of the above-mentioned defects of the prior art.

[0008] The technical solution adopted by the present invention to solve its technical problem is:

[0009] A laser drilling and hole chamfering method is constructed to form a chamfered hole on thin glass that penetrates the thickness of the glass. The method comprises:

[0010] Laser modification step: using a laser profiling beam to perform laser modification on the glass, forming a modified contour surface in the glass that is consistent with the shape of the hole and its chamfer, and the material enclosed by the modified contour surface is the waste block that needs to be removed;

[0011] Laser grooving step: using a laser to perform a laser grooving process on the waste block to form a drainage groove extending into the interior of the glass until it approaches the modified contour surface;

[0012] Etching step: placing the grooved glass in an etching solution, wherein the etching solution penetrates into the drainage groove, etches to the modified contour surface, and then etches along the modified contour surface;

[0013] Splitting step: Splitting the etched glass to eject the waste block to form the hole and its chamfer.

[0014] Furthermore, in the laser drilling and hole chamfering method described in the present invention, the drainage groove includes an annular groove opened on the front side of the glass and surrounding the central axis of the hole, or / and an annular groove opened on the back side of the glass and surrounding the central axis of the hole.

[0015] Furthermore, in the laser drilling and hole chamfering method described in the present invention, the drainage groove is recessed along the thickness direction of the glass; the recessed depth of the drainage groove is equivalent to the corresponding chamfer depth, and the outer diameter of the drainage groove is slightly smaller than the inner diameter of the hole.

[0016] Furthermore, in the laser drilling and hole chamfering processing method of the present invention, the laser grooving step specifically includes:

[0017] The focus of the laser beam is controlled so that the focus is on the back side of the glass. The laser beam passes through the glass to ablate the glass on the back side. The laser beam is rotated and cut along the central axis of the hole for one circle. After moving the focus upward for multiple times, the laser beam is continuously rotated and cut to finally form a circle of annular grooves that meet the depth requirements.

[0018] Or / and, control the focus of the laser beam so that the focus is on the front side of the glass, the laser beam ablates the glass on the front side of the glass, rotates the laser beam along the central axis of the hole to cut a circle, and finally forms a circle of annular grooves that meet the depth requirements by moving the focus downward multiple times and continuing to rotate and cut.

[0019] Furthermore, in the laser drilling and hole chamfering processing method described in the present invention, the laser beam used in laser grooving is a Gaussian beam.

[0020] Furthermore, in the laser drilling and hole chamfering processing method described in the present invention, the laser modification step specifically includes: generating a profiling beam consistent with the longitudinal cross-sectional profile shape of the hole and its chamfer, the profiling beam comprising a plurality of focal points distributed along the longitudinal cross-sectional profile of the hole and its chamfer, with a focal spacing of 1-10um; rotating the profiling beam along the central axis of the hole to obtain the modified profile surface.

[0021] Furthermore, in the laser drilling and hole chamfering method of the present invention, among the multiple foci of the profiling light beam: the energy of the focus located at the chamfered portion is smaller than the energy of the focus located at the straight-through portion of the hole.

[0022] Furthermore, in the laser drilling and hole chamfering processing method of the present invention, the first focus and the last focus of the profiling light beam fall on the front side and the back side of the glass respectively.

[0023] A laser drilling and hole chamfering pretreatment device is constructed for use in the above method, characterized in that the device comprises:

[0024] A dual-optical path system is used to generate two laser beams, the first beam is a profiling beam for laser modification, and the second beam is a beam for laser grooving;

[0025] The rotating moving platform is used to place the glass to be processed, and the glass is placed under the first light beam and the second light beam in sequence for processing.

[0026] A cover glass is constructed, comprising a chamfered hole opened by the above method.

[0027] The cover glass, laser drilling and hole chamfering processing method and pretreatment device of the present invention have the following beneficial effects: the present invention forms a modified contour surface consistent with the shape of the hole and its chamfer through laser modification, forms a drainage groove extending into the interior of the glass until close to the modified contour surface through laser grooving, and then uses the drainage groove to introduce etching liquid into the interior of the glass, accelerates the removal of the modified contour surface through etching, and finally ejects the waste by splitting to obtain the hole. The present invention is flexible and controllable, improves processing efficiency, improves processing accuracy, and can meet the chamfering processing requirements of different shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work:

[0029] Figure 1 It is a flow chart of the laser drilling and hole chamfering processing method of the present invention;

[0030] Figure 2 It is a process principle diagram of the laser drilling and hole chamfering processing method of the present invention;

[0031] Figure 3 This is the schematic diagram of the laser modification process;

[0032] Figure 4 This is the schematic diagram of the laser grooving process;

[0033] Figure 5 It is a schematic diagram of the structure of the pretreatment device;

[0034] Figure 6 is a schematic diagram of energy distribution during laser modification in a specific implementation manner;

[0035] Figure 7 Metallographic image of glass after laser modification;

[0036] Figure 8 This is the metallographic image after the glass is grooved;

[0037] Fig. 9 It is a metallographic image after etching of glass;

[0038] Fig.10 This is a metallographic diagram of the glass after it cracked. DETAILED DESCRIPTION

[0039] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Typical embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, rather than limitations on the technical solutions of the present application. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0040] Embodiment 1

[0041] refer to Figure 1 The laser drilling and hole chamfering method of the present invention is used to form a chamfered hole penetrating the thickness of the glass on thin glass. The method mainly comprises:

[0042] Laser modification step S100: using a laser profiling beam to perform laser modification on the glass, forming a modified contour surface in the glass that is consistent with the shape of the hole and its chamfer, and the material enclosed by the modified contour surface is the waste block that needs to be removed. Figure 2 In the figure, the dotted line 1 represents the modified contour surface.

[0043] Laser grooving step S200: using laser to perform laser grooving on the waste block to form a drainage groove extending into the interior of the glass until it approaches the modified contour surface. Figure 2 In the figure, 2 represents a drainage groove.

[0044] Etching step S300: placing the grooved glass in an etching solution, wherein the etching solution penetrates into the drainage grooves and etches to the modified contour surface and then etches along the modified contour surface. Figure 2 In the figure, 3 represents etching solution, and 4 represents waste blocks after etching.

[0045] The breaking step S400 is to break the etched glass into pieces, and push out the waste block to form the hole and its chamfer. Figure 2 In the figure, 6 represents the ejector pin used for the split, which presses down to eject the waste block. 5 represents the final hole and its chamfer.

[0046] Since the present invention utilizes a profiling beam to modify the hole, it can meet the requirements of holes of various shapes and chamfers of various shapes, and realizes efficient, high-precision, and non-destructive drilling and hole chamfering processing; since the laser is used to make grooves in the hole to approach the modified contour surface, the etching liquid can directly penetrate into the glass through the drainage groove to etch the modified contour surface at a subsequent moment. Since the etching speed is determined by the glass material and the concentration and temperature of the liquid, the present invention can accelerate the etching speed by using the groove method without changing these liquid polishing conditions, and can realize the drilling requirements of glass of different thicknesses; compared with traditional mechanical drilling, , because of the fast processing speed, no need to change tools, and significantly shortened processing cycle, the processing efficiency can be improved, and the entire processing process is non-mechanical contact processing, avoiding cracks and burrs caused by mechanical stress, improving the quality of finished products, and reducing material damage; compared with traditional laser drilling, the dimensional accuracy and shape accuracy of drilling and chamfering of the present invention are improved, and energy consumption and cost can be reduced, because the present invention only uses laser modification and grooving, so laser processing does not require consumables such as coolant, cutting fluid and grinding wheel, low energy consumption, and a high degree of automation in the processing process, reducing labor costs.

[0047] The above steps are described in detail below.

[0048] 1) Laser modification steps:

[0049] In this step, laser grooving is performed on the waste block by laser, forming a drainage groove extending into the interior of the glass until it approaches the modified contour surface. Here, approaching means that the distance between the blind end of the drainage groove and the modified contour surface is very small, so small that when the glass is placed in the etching solution, the etching solution can etch the drainage groove to connect with the modified contour surface in a very short time t. Assuming that the etching time T in the etching step is (T is determined according to experiments), the time t is much smaller than the etching time T, for example, t is less than 0.1T.

[0050] refer to Figure 3 It can be understood that the modified contour surface is a shape that completely imitates the hole and its chamfer (it can be understood as actually the contour of the hole and its chamfer), which is formed by projecting a large number of focal points on the glass. The energy of these focal points is configured to only achieve the modification effect when acting on the glass. These focal points are closely distributed to form a curved surface consistent with the shape of the hole and its chamfer, which can be understood as a modified contour surface. Therefore, according to the requirements of the hole and its chamfer, the corresponding focus distribution (i.e. the position of each focus) and energy distribution (i.e. the energy of each focus) can be designed, so that various shapes of holes and various shapes of chamfers can be met, and efficient, high-precision, and damage-free drilling and hole chamfering processing can be achieved.

[0051] The specific implementation method of the modification is not limited. For example, it can be projected one by one; it can also be projected at all the focuses; it can also be a beam tangent scanning composed of several focuses. Taking the beam tangent scanning composed of several focuses as an example, refer to Figure 3 , first generate a longitudinal section profile of the hole and its chamfer (the longitudinal section can also be understood as a section parallel to the thickness direction of the glass, such as Figure 3 The profiling beam is a profiling beam with a consistent shape (shown by the dashed line 7 in the middle), and the profiling beam includes a plurality of focuses distributed along the longitudinal profile of the hole and its chamfer. More focuses can better control the chamfer shape and form a profile surface closer to the chamfer of the hole. For this reason, the focus spacing in this embodiment is 1-10um; then, the profiling beam is directed along the central axis of the hole (the central axis is shown in FIG. Figure 3 The modified contour surface is obtained by rotating and cutting in one circle (as shown by the middle dotted line 8).

[0052] It should be noted that the rotary circular cutting mentioned in this article can be achieved by fixing the glass product and rotating the light beam, or by fixing the light beam and rotating the glass product to be cut. Generally, the latter is adopted.

[0053] In order to facilitate subsequent accelerated etching and to facilitate splitting, the first focus and the last focus of the shaped light beam fall on the front and back sides of the glass respectively, so that in the subsequent step S300, the etching liquid can be etched synchronously from the front and back sides of the glass along the modified contour surface during etching, and the splitting in the subsequent step S400 will be smoother.

[0054] Theoretically, there is no special requirement for the energy of the multiple focal points of the profiling beam, as long as the purpose of modification can be achieved. In order to improve the processing efficiency and the processing accuracy of the chamfer of the hole, the energy of the focus can be adjusted according to whether the focus is located in the chamfer or the straight-through part. For example, the energy of the focus located in the chamfer part among the multiple focal points of the profiling beam is generally less than the energy of the focus located in the straight-through part of the hole, that is, the energy of the focus of the straight-through part is higher, and the energy of the focus of the straight-through part can be designed to be a level that only a slight etching is needed to split.

[0055] The energy and speed parameters during laser modification need to ensure that the heat generated by the laser on the subsurface is sufficient to melt the glass without damaging the glass subsurface. Use appropriate laser energy and cutting speed so that the heat generated by the laser on the subsurface is sufficient to melt the material and form the required chamfer shape while avoiding excessive heat damage to the surface. In actual implementation, multiple trial cuts are required to determine the best parameter combination. During the laser chamfering process, the real-time monitoring system of the processing equipment is used to observe possible problems during the processing, such as laser focus offset, material deformation, etc., and the processing is immediately suspended for adjustment when necessary. After the hole and hole chamfering processing is completed, the production sample is taken, and the hole and hole chamfer shape and edge quality of the product are observed through slicing and microscopy, and the laser parameters are adjusted according to specific problems. By repeatedly adjusting the laser parameters, the best hole and hole chamfering effect and the minimum thermal impact can be achieved.

[0056] 2) Laser grooving steps:

[0057] The purpose of laser opening drainage grooves is to allow the etching solution to penetrate directly and quickly into the interior of the glass, and the modified contour surface cannot be touched during grooving to avoid damaging the shape of the hole.

[0058] In a specific embodiment, the drainage groove includes an annular groove opened on the front side of the glass and surrounding the central axis of the hole, and an annular groove opened on the back side of the glass and surrounding the central axis of the hole. The annular groove is recessed along the thickness direction of the glass from the front side / back side of the glass, and the recess depth D of the annular groove is equivalent to the depth of the chamfer corresponding to it (the equivalent here means that the depth error of the two is within an acceptable empirical error range), and the outer diameter of the annular groove is slightly smaller than the inner diameter of the hole. It can also be understood that the blind end of the annular groove is near the inflection point between the chamfer and the straight-through part of the hole. Assuming that the etching time of step S300 is T, the difference between the outer diameter of the drainage groove and the inner diameter of the hole is small enough to make the time t required for the etching liquid to etch the drainage groove to the modified contour surface much less than T.

[0059] It can be understood that, with the etching process remaining unchanged, the position, size and depth of the grooves can be adjusted for different aperture sizes, different chamfer shapes and different glass thicknesses. The overall trend of the drainage groove is to extend from the glass surface (front / back) to the inside of the glass to a surface close to the modified contour.

[0060] There is no restriction on the laser grooving method. Figure 4 , the following provides a specific laser grooving method:

[0061] First, the focus of the laser beam (a Gaussian beam is used here) is controlled so that the focus is on the back side of the glass, as shown in FIG. Figure 4The reference numeral 9 indicates the focus. The laser beam passes through the glass to ablate the glass on the back side. The laser beam is rotated and cut along the central axis of the hole. After moving the focus upward for many times, the laser beam is rotated and cut continuously to finally form a ring groove that meets the depth requirement (i.e., the depth is D).

[0062] Then, the focus of the laser beam is controlled so that the focus is on the front side of the glass. The laser beam ablates the glass on the front side of the glass, and the laser beam is rotated and cut along the central axis of the hole in a circle. After moving the focus downward multiple times, the laser beam is continued to rotate and cut in a circle to finally form a circle of annular grooves that meet the depth requirements.

[0063] By adopting the above-mentioned slotting method, the slotting depth D can be flexibly controlled to match different etching schemes. The slotting depth D can also be changed by changing the laser power, frequency, pulse width, and scanning times. The slotting method can also adopt the flat-top light slotting method, that is, adding a flat-top light DOE lens in the optical path.

[0064] 3) Etching step:

[0065] Etching is also called chemical polishing. The chemical liquid used in chemical polishing is either an acidic solution or an alkaline solution, depending on the processing requirements and the chemical composition of the glass. During the etching process, the etching liquid directly penetrates into the interior of the glass through the drainage groove, and the etching liquid also penetrates into the connection position between the modified contour surface and the front and back of the glass. Among them, the blind end of the drainage groove is etched to the connected modified contour surface in a short time, and the etching liquid can be etched in both the upper and lower directions along the modified contour surface, etching the chamfered part of the modified contour surface upwards and etching the straight part of the modified contour surface downwards.

[0066] Liquid polishing parameters include concentration, temperature, and etching time. The etching time needs to be set according to the specific product. This application only needs to determine a reasonable etching time T through experimental observation of the specific product after laser modification and laser grooving to ensure that it will not be over-etched (over-etching means that the waste block will fall off), and at the same time facilitate subsequent splitting (no new defects will be generated due to incomplete liquid polishing during splitting). Etching is a conventional process in this field, so it will not be described in detail. After etching is completed, the waste block will maintain a weak connection stress with the inside of the glass. After splitting, the waste block will fall off the glass, fully revealing the shape of the hole and its chamfer.

[0067] 4) Splitting step

[0068] The split can be made by using a pin to press down from the front side of the glass toward the center of the waste block, so that the waste block can be pushed out, thereby obtaining a hole and its chamfer.

[0069] In the embodiment of the present invention, a hole and a chamfered contour surface are processed in the glass through multiple focal points to obtain a modified contour surface, and then a laser groove is performed on the waste block, and the etching liquid directly penetrates into the interior of the glass through the groove, and finally the hole and the chamfer are revealed through the cracks, and the hole and the chamfer are formed in one step, and the edge is smooth, which shortens the processing time and reduces the processing cost, and avoids the stress concentration and quality control difficulties caused by the traditional hole and chamfer directly on the glass surface, and effectively reduces the risk of cracking; by accurately controlling the laser processing parameters, the micron-level processing accuracy is achieved, and the hole and the chamfer edge are ensured to be smooth and neat, which solves the problem of limited chamfering processing, so that a smooth double-sided chamfer can be made in a small aperture, and the heat generated during the processing is minimized, the heat-affected zone is reduced, and the possibility of glass cracking due to thermal stress is reduced; because the hole and chamfer processing is performed inside the glass, the surface scratches and burrs that may be generated in the traditional method are avoided, which helps to maintain the integrity of the glass surface and reduce the risk of microcracks; the chamfer inside the hole can improve the edge strength of the hole, making it more tough when it is impacted or pressurized, and reducing the possibility of cracking.

[0070] Embodiment 2

[0071] This embodiment provides a laser drilling and hole chamfering preprocessing device, which is used in the drilling and hole chamfering processing method of the present invention. Figure 5 The device includes a dual optical path system and an X / Y / R rotating moving platform.

[0072] The dual-optical path system is used to generate two laser beams, the first beam is a profiling beam for laser modification, and the second beam is a beam for laser grooving. Specifically, the rotating mobile platform includes a laser A1, a 1 / 2 wave plate A2, a beam splitter A3, a first beam expander A4, a 1 / 4 wave plate A5, a DOE (Diffractive optical element) lens A6 (SLM, Spatial Light Modulator, spatial light modulator can also be selected), a focusing lens A7, a reflector A9, a second beam expander A10, and a scanning galvanometer A11.

[0073] Laser A1 emits laser horizontally, 1 / 2 wave plate A2 is arranged on the light-emitting side of laser A1, and beam splitter A3 is located on the light-emitting side of 1 / 2 wave plate A2. The first beam expander A4, 1 / 4 wave plate A5, beam deflector A6 (specifically DOE lens), and focusing objective lens A7 are arranged in sequence below beam splitter A3, and reflector A9 is behind beam splitter A3. The second beam expander A10 and scanning galvanometer A11 are arranged in sequence below reflector A9. Beam splitter A3 splits two laser beams. The first beam is transmitted downward to the first beam expander A4 and output after passing through A5-A7. The second beam continues to be transmitted horizontally backward to reflector A9 and output after passing through A10 and A11. Focusing mirrors, reflectors, beam deflectors, etc. can accurately control the direction, focusing position, and moving path of the laser beam. The rotating moving platform is shown as A8 in the figure, which is used to place the glass A12 to be processed and has a fine-tuning function to ensure processing accuracy. A8 can be rotated to realize the circular cutting function during laser modification and the circular cutting function during laser grooving. A8 can also be moved horizontally, so that the glass A12 is first placed under the first light beam for laser modification and then moved to the second light beam for laser grooving.

[0074] A specific application case based on the present invention is provided below.

[0075] 1) Pretreatment: Clean and position the cover glass to ensure that the processing area is clean and free of impurities.

[0076] 2) Laser parameter setting: According to the material, thickness and processing requirements of the cover glass, set the laser output power, pulse frequency, spot size and other parameters.

[0077] 3) Pre-processing of drilling and chamfering: Use a laser beam to accurately modify the required hole diameter and chamfering on the cover glass; then, control the focusing depth and moving speed of the laser beam to ensure the verticality and accuracy of the drilling, and perform laser grooving.

[0078] Specifically, the laser provides a high-energy, stable laser beam with a wavelength of 1060-1064nm, a maximum output power of 120W, and an adjustable pulse width of 190fs-20ps. Figure 5 The laser optical path is divided into two by using a beam splitter prism. The first optical path is a contoured beam cutting optical path, which is composed of a first beam expander 4, a 1 / 4 wave plate 5, a DOE lens 6, and a focusing objective lens 7; the second optical path is a laser slotting optical path, which is composed of a second beam expander 10, a scanning galvanometer 11 and a number of reflectors 9.

[0079] In the first optical path, the first beam expander 4 expands the laser beam, changes the polarization state of the beam through the 1 / 4 wave plate 5, and then passes through the DOE lens 6 to generate a profiled beam. The profiled beam is focused to the required size by the focusing lens 7 (focusing magnification 20x, 50x, selected according to the glass thickness) and then the glass 12 is chamfered. The processing parameters of the first optical path are laser power 10-30W, cutting speed 50-1000mm / s, dot spacing 1-10um, and frequency 10-150kHz. Figure 6 As shown in the figure, the energy distribution of the profiling beam in this application case is shown. In actual processing, the theoretical effect may be affected by factors such as gravity affecting the etching flow rate. Therefore, the energy of the local focus is generally adjusted according to the actual situation during the experiment. Figure 6 There will be several focal points with slightly different energies in the straight-through section. Figure 7 The figure shows a metallographic image of the glass after laser modification from a top view angle.

[0080] In the second optical path, after the second beam expander 10 expands the laser beam, it is focused into Gaussian light by the scanning galvanometer 11, and the scanning galvanometer 11 is used to control the beam to achieve circular grooving. Because the size of the hole and its chamfer is known in advance, the center axis of the hole can be located through the CCD positioning function, and then the scanning galvanometer can be used to accurately perform laser grooving in the waste block area of ​​the modified shape formed by the first optical path. The processing parameters of the second optical path are: laser power 30-80W, speed 5-500mm / s, frequency 100-500kHz. Figure 8 (a) is a top view of the metallographic image after the grooves are cut on the back of the glass. Figure 8 (b) is a top view metallographic image after grooves are cut on both the back and front of the glass. Figure 8 (c) is a cross-sectional metallographic image after grooves are cut on both the back and front sides of the glass.

[0081] 4) Chemical etching: Liquid-polishing the glass according to the liquid-polishing process. Fig. 9 (a) is a top view metallographic image after glass etching. Fig. 9 (b) is a cross-sectional metallographic image after glass etching.

[0082] 5) Cleaning: Use cleaning fluid to remove residual chemicals and other impurities to improve the quality of the finished product.

[0083] 6) Ejector splits to form the required holes and chamfers. Fig. 9 (a) is a top view metallographic image of the hole and its chamfer after the split. Fig. 9 (b) is a cross-sectional metallographic image of the hole and its chamfer after the split.

[0084] In summary, it can be seen that the present invention hides the holes and chamfered contours inside the glass, and cooperates with the drainage groove to directly introduce the etching liquid into the glass to engrave the contour surface, which greatly improves the processing efficiency and can effectively solve the problems of hole and chamfer processing in traditional thin glass processing, such as limited chamfering processing, difficult quality control, long processing time and high processing cost from multiple aspects. It improves the strength and durability of the hole edge, improves the surface quality, and provides better protection for the safety and aesthetics of glass products.

[0085] It should be noted that the terms "vertical", "horizontal" and similar expressions used herein are for illustrative purposes only. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0086] Terms including ordinal numbers such as "first", "second" and the like used in this specification may be used to describe various constituent elements, but these constituent elements are not limited by these terms. The purpose of using these terms is only to distinguish one constituent element from other constituent elements. For example, without departing from the scope of the present invention, the first constituent element may be named as the second constituent element, and similarly, the second constituent element may also be named as the first constituent element. The term "or / and" used herein includes any and all combinations of one or more related listed items.

[0087] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A laser drilling and hole chamfering method for forming a chamfered hole on thin glass that penetrates the thickness of the glass, characterized in that: The method comprises: Laser modification step: using a laser profiling beam to perform laser modification on the glass, forming a modified contour surface in the glass that is consistent with the shape of the hole and its chamfer, and the material enclosed by the modified contour surface is the waste block that needs to be removed; Laser grooving step: using a laser to perform a laser grooving process on the waste block to form a drainage groove extending into the interior of the glass; Etching step: placing the grooved glass in an etching solution, wherein the etching solution penetrates into the drainage groove, etches to the modified contour surface, and then etches along the modified contour surface; Splitting step: Splitting the etched glass to eject the waste block to form the hole and its chamfer.

2. The laser drilling and hole chamfering method according to claim 1, characterized in that: The drainage groove includes an annular groove opened on the front side of the glass and surrounding the central axis of the hole, or / and an annular groove opened on the back side of the glass and surrounding the central axis of the hole.

3. The laser drilling and hole chamfering method according to claim 1, characterized in that: The drainage groove is sunken along the thickness direction of the glass; the sunken depth of the drainage groove is equivalent to the depth of the corresponding chamfer, and the outer diameter of the drainage groove is slightly smaller than the inner diameter of the hole.

4. The laser drilling and hole chamfering method according to claim 1, characterized in that: The laser grooving step specifically includes: The focus of the laser beam is controlled so that the focus is on the back side of the glass. The laser beam passes through the glass to ablate the glass on the back side. The laser beam is rotated and cut along the central axis of the hole for one circle. After moving the focus upward for multiple times, the laser beam is rotated and cut for one circle to finally form a circle of annular groove that meets the depth requirement. Or / and, control the focus of the laser beam so that the focus is on the front side of the glass, the laser beam ablates the glass on the front side of the glass, and the laser beam is rotated and cut along the central axis of the hole in a circle, and finally a circle of annular groove that meets the depth requirement is formed by moving the focus downward multiple times and then rotating and cutting.

5. The laser drilling and hole chamfering method according to claim 4, characterized in that: The laser beam used in laser grooving is a Gaussian beam.

6. The laser drilling and hole chamfering method according to claim 1, characterized in that: The laser modification step specifically includes: generating a profiling beam consistent with the longitudinal cross-sectional profile shape of the hole and its chamfer, the profiling beam comprising a plurality of focal points distributed along the longitudinal cross-sectional profile of the hole and its chamfer, with a focal spacing of 1-10um; rotating the profiling beam along the central axis of the hole to obtain the modified profile surface.

7. The laser drilling and hole chamfering method according to claim 6, characterized in that: Among the multiple focal points of the shaped light beam, the energy of the focal point located at the chamfered portion is smaller than the energy of the focal point located at the straight-through portion of the hole.

8. The laser drilling and hole chamfering method according to claim 6, characterized in that: The first focus and the last focus of the shaped light beam fall on the front side and the back side of the glass respectively.

9. A laser drilling and hole chamfering pretreatment device, used in the method according to any one of claims 1 to 8, characterized in that: The device comprises: A dual-optical path system is used to generate two laser beams, the first beam is a profiling beam for laser modification, and the second beam is a beam for laser grooving; The rotating moving platform is used to place the glass to be processed, and the glass is placed under the first light beam and the second light beam for processing.

10. A cover glass, characterized in that: It comprises a chamfered hole opened by the method according to any one of claims 1 to 8.

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