Laser micropore machining method and device for transparent workpiece
Through the laser micropore processing method, a multi-focus beam is used to form a modified surface inside the transparent workpiece and etch it, which solves the problems of low efficiency and low yield of traditional micropore processing, and achieves efficient and low-cost micropore molding.
Patent Information
- Application Number
- CN202510778472.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-11
- Publication Date
- 2025-08-26
AI Technical Summary
Traditional micropore processing methods have problems such as low processing efficiency, easy breakage of milling cutters leading to higher costs and low yield.
By shaping the Gaussian laser beam into a multi-focus beam, the beam is controlled to rotate around the micropore axis for one round to form a spatially modified surface inside the workpiece, and the holes and chamfers are formed through etching processing.
Improve processing efficiency, reduce costs, avoid the problems of stress concentration and difficulty in quality control, and improve the yield rate.
Smart Images
Figure CN120533331A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of micro-hole processing, and in particular to a laser micro-hole processing method and device for a transparent workpiece. Background Art
[0002] With the rapid development of consumer electronics, transparent, brittle materials (such as thin glass) have become the preferred material for cover panels of electronic products such as smartphones and wearable devices due to their excellent scratch resistance, high light transmittance, aesthetics, and chemical stability. To meet requirements such as heat dissipation, audio transmission, sensor functionality, interface adaptation, and aesthetic design, high-precision micropore structures, especially those with chamfered corners, are often required in these cover panels.
[0003] Currently, the industry generally uses CNC machine tools to grind microholes, relying on micro-milling cutters with diameters less than 0.3mm. Although this machining method has certain processing capabilities, its contact-based machining characteristics lead to the following significant drawbacks: 1. Low machining efficiency: Single-hole machining is time-consuming, making it difficult to meet the needs of large-scale production; 2. Milling cutter breakage leads to increased costs: Micro-milling cutters are prone to breakage, requiring frequent tool replacement, driving up production costs; 3. Low yield: Brittle materials are prone to microcracks or chipping under mechanical stress, resulting in an overall yield rate typically below 85%.
[0004] Therefore, there is still much room for improvement in traditional micro-hole processing methods in terms of improving processing efficiency, reducing costs, and improving yield rates. Summary of the Invention
[0005] The main purpose of the present invention is to provide a laser micro-hole processing method and device for transparent workpieces, aiming to solve the technical problems of low processing efficiency, easy breakage of milling cutters leading to increased costs and low yield rate in traditional micro-hole processing methods.
[0006] To achieve the above objectives, the present invention provides, on the one hand, a laser micro-hole processing method for a transparent workpiece, wherein the workpiece is transparent to the laser, and the method comprises the following steps: S1: provides Gaussian laser beam; S2: shaping and focusing the Gaussian laser beam to form a multi-focal beam and applying it to the interior of the workpiece, wherein the spatial trajectory of the multi-focal beam includes a main vertical trajectory line extending along the axis of the desired microhole, a chamfer line connecting the main vertical trajectory line and the surface of the workpiece, and an auxiliary line located radially inward of the main vertical trajectory line, wherein one end of the auxiliary line intersects the main vertical trajectory line and the other end extends to the surface of the workpiece; S3: controlling the multi-focus light beam to rotate around the axis of the desired microhole to form a spatially modified surface inside the workpiece to obtain a modified workpiece; S4: Etching the modified workpiece to achieve microporous forming of the workpiece.
[0007] Optionally, in one embodiment, step S4 specifically includes: The modified workpiece includes a sample area, an upper waste area and a lower waste area. The modified workpiece is immersed in an etching solution. After etching is completed, the upper waste area and the lower waste area can fall off from the top and bottom respectively to obtain the sample area, thereby realizing microporous forming of the workpiece.
[0008] Optionally, in one embodiment, when one end of the auxiliary line intersects at the endpoint of the vertical line of the main track, a preset distance is provided between one end of the auxiliary line and the endpoint of the vertical line of the main track, and the preset distance ranges from 1 to 40 μm.
[0009] Optionally, in one embodiment, the angle α between the auxiliary line and the vertical line of the main track can be dynamically adjusted.
[0010] Optionally, in one embodiment, processing parameters are set according to the material properties of the workpiece and the microhole precision requirements, and the processing parameters include: laser power of 20~100W, wavelength of 495nm~570nm or 950nm~1400nm, pulse frequency of 50~1000kHz, single pulse energy of 100~1000uJ, the number of sub-pulses in a pulse train of 1~10, position synchronization output accuracy of 1~5µm, and the moving speed of the multi-focus light beam of 50~500mm / s.
[0011] Optionally, in one embodiment, the axial coverage of the multi-focus light beam is adjusted so that the axial coverage of the multi-focus light beam is greater than the thickness of the workpiece.
[0012] Optionally, in one embodiment, the axial coverage of the multi-focus light beam is 10µm to 100µm larger than the thickness of the workpiece.
[0013] Optionally, in one embodiment, the etching solution is an acidic solution or an alkaline solution, and the etching solution is selected according to the chemical composition of the workpiece. The etching parameters include concentration, temperature, and time.
[0014] Optionally, in one embodiment, the components of the acidic solution include: hydrofluoric acid with a concentration of 3-5%, sulfuric acid with a concentration of 1-2%, ammonium fluoride with a concentration of 1-3%, and a surfactant with a concentration of 0.1-0.3%; the components of the alkaline solution include: sodium hydroxide with a temperature of 120-150°C and a concentration of 30-70%.
[0015] On the other hand, the present invention also provides a laser micro-hole processing device for a transparent workpiece to implement the above method, comprising: a laser for providing a Gaussian laser beam; A beam shaper, configured to shape the Gaussian laser beam into a multi-focus beam; a focusing lens, disposed below the beam shaper, for focusing the multi-focal beam into the interior of a workpiece; The rotary motor and X / Y platform are used to drive the beam shaper.
[0016] In the technical solution provided by the present invention, a Gaussian laser beam is shaped into a multi-focus beam containing a main track vertical line, a chamfer line and an auxiliary line, and then the multi-focus beam is controlled to rotate around the axis of the desired microhole for one circle to form a spatially modified surface inside the workpiece. The modified workpiece is then etched to reveal the hole and chamfer structure, thereby realizing the integrated forming of the hole and chamfer structure. Compared with the traditional contact processing method, this laser non-contact micro-hole processing method effectively improves the processing efficiency, reduces the processing cost, and avoids the stress concentration and difficulty in quality control caused by the traditional contact processing method directly processing the workpiece surface, thereby effectively improving the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.
[0018] Figure 1 A schematic flow chart of an embodiment of a laser micro-hole processing method for a transparent workpiece provided by the present invention; Figure 2 for Figure 1 Schematic diagram of the spatial trajectory of the multi-focus beam; Figure 3 for Figure 1 Schematic diagram of the structure of the mid-space modified surface; Figure 4 for Figure 1 Schematic diagram of the etching process; Figure 5 This is a schematic structural diagram of an embodiment of a laser micro-hole processing device for a transparent workpiece provided by the present invention.
[0019] Among them, 10, multi-focus beam; 11, main track vertical line; 12, chamfer line; 13, auxiliary line; 21, sample area; 22, upper waste area; 23, lower waste area. DETAILED DESCRIPTION
[0020] To facilitate understanding of the present invention, the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly attached to the other element, or one or more elements can be interposed therebetween. When an element is described as being "connected to" another element, it can be directly connected to the other element, or one or more elements can be interposed therebetween. The terms "vertical," "horizontal," "left," "right," "inner," "outer," and similar expressions used in this specification are for illustrative purposes only. In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating relative importance or implicitly specifying the number of technical features indicated. Therefore, unless otherwise specified, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; "plurality" means two or more. The term "comprising" and any variations thereof are intended to be non-exclusive, and one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.
[0021] In addition, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or internal communication between two components. All technical and scientific terms used in this specification have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.
[0022] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0023] The present invention is suitable for processing micro-holes with chamfers on transparent brittle materials (such as glass, sapphire, resin, etc.).
[0024] like Figures 1 to 4 As shown, an embodiment of the present invention provides a laser micro-hole processing method for a transparent workpiece, wherein the workpiece is transparent to the laser, and the method comprises the following steps: S1: provides Gaussian laser beam; S2: Shaping and focusing the Gaussian laser beam to form a multi-focus beam 10 and applying it to the interior of the workpiece. The spatial trajectory of the multi-focus beam 10 includes a main vertical line 11 extending along the axis of the desired microhole, a chamfer line 12 connecting the main vertical line 11 and the workpiece surface, and an auxiliary line 13 located radially inward of the main vertical line 11. One end of the auxiliary line 13 intersects the main vertical line 11, and the other end extends to the surface (upper or lower surface) of the workpiece. S3: Controlling the multi-focus light beam 10 to rotate one circle around the axis of the desired micro-hole to form a spatially modified surface inside the workpiece, thereby obtaining a modified workpiece. The spatially modified surface is a bursting surface composed of a plurality of tiny bursting cracks, and the micro-hole forming of the workpiece is achieved by using the bursting surface as a guide; S4: Etching the modified workpiece to achieve microporous forming of the workpiece.
[0025] By shaping the Gaussian laser beam into a multi-focus beam 10 containing a main track vertical line 11, a chamfer line 12 and an auxiliary line 13, and then controlling the multi-focus beam 10 to rotate around the axis of the desired microhole, a spatial modified surface is formed inside the workpiece, and then the modified workpiece is etched to make the hole and chamfer structure appear, thereby realizing the integrated forming of the hole and chamfer structure. Compared with the traditional contact processing method, this laser non-contact micro-hole processing method effectively improves the processing efficiency and reduces the processing cost, and avoids the stress concentration and difficulty in quality control caused by the traditional contact processing method directly processing the workpiece surface, thereby effectively improving the yield rate.
[0026] Reference Figure 4 In this embodiment, step S4 specifically includes: the modified workpiece includes a sample area 21, an upper waste area 22 and a lower waste area 23, and the modified workpiece is immersed in an etching solution. After etching is completed, the upper waste area 22 and the lower waste area 23 can fall off from the top and bottom respectively to obtain the sample area 21, thereby realizing the micropore forming of the workpiece.
[0027] During the etching process, the etching liquid reacts with the surface of the workpiece to remove tiny scratches, burrs and surface dirt, thereby improving the surface finish; at the same time, the etching liquid penetrates into the interior of the workpiece through the microcracks in the spatially modified surface area. Since the etching rate of the spatially modified surface area is greater than that of the unmodified area, the upper waste area 22 and the lower waste area 23 are gradually separated from the sample area 21, thereby achieving better hole wall roughness while realizing micropore forming of the workpiece.
[0028] In actual applications, through repeated testing, the optimal etching parameters are selected to ensure that subsequent splitting can be performed easily without causing new defects. Etching parameters include concentration, temperature, and time.
[0029] In this embodiment, the etching solution is an acidic solution or an alkaline solution. The specific solution selected depends on the specific processing requirements and the chemical composition of the workpiece.
[0030] The acidic solution consists of 3-5% hydrofluoric acid, 1-2% sulfuric acid, 1-3% ammonium fluoride, and 0.1-0.3% surfactant. Hydrofluoric acid is used for glass etching, sulfuric acid is used to enhance the etching effect of hydrofluoric acid, ammonium fluoride is used as a buffer to control the etching rate, and surfactants are used to ensure uniform etching and control pore structure. The acidic solution is suitable for etching high-silicon-content glass, such as quartz glass, as well as for applications requiring meticulous polishing and oxide layer removal.
[0031] The alkaline solution consists of 30-70% sodium hydroxide at a temperature of 120-150°C. It is suitable for etching aluminosilicate glass, as well as for rough polishing or other applications requiring low cost and high safety.
[0032] Furthermore, after step S4, the workpiece is further cleaned and dried. Specifically, in this embodiment, after the etching process is completed, the workpiece is thoroughly cleaned with anhydrous alcohol to remove residual chemical liquid. After cleaning, the workpiece is placed in a drying device and dried until there is no water stain on the surface and it remains bright.
[0033] Reference Figure 3 , showing the spatial modification surface formed by the multi-focus light beam 10 of three different spatial trajectories a, b, and c. One end of the auxiliary line 13 can intersect at the endpoint or non-endpoint of the main track vertical line 11. Since the two ends of the main track vertical line 11 are each connected to a chamfer line 12, the thermal effect at the endpoint of the main track vertical line 11 is greater than the thermal effect at the non-endpoint. Therefore, when one end of the auxiliary line 13 intersects at the endpoint of the main track vertical line 11, a preset distance is set between one end of the auxiliary line 13 and the endpoint of the main track vertical line 11 to avoid excessive thermal effects at the endpoint causing unnecessary cracks in the workpiece. The preset distance ranges from 1 to 40µm, and the preset distance is dynamically adjusted according to the workpiece material and laser parameters.
[0034] The angle α between the auxiliary line 13 and the vertical line 11 of the main track can be dynamically adjusted to adapt to micro-holes of different diameters.
[0035] According to the material properties of the workpiece and the microhole precision requirements, the processing parameters are set. The processing parameters include: laser power of 20~100W, wavelength of 495nm~570nm or 950nm~1400nm, pulse frequency of 50~1000kHz, single pulse energy of 100~1000uJ, the number of sub-pulses in a pulse train of 1~10, position synchronization output accuracy (PSO distance) of 1~5µm, and the moving speed of the multi-focus beam (10) of 50~500mm / s. Within this processing parameter range, it is possible to take into account processing quality (low thermal damage, high precision), efficiency and process flexibility (adaptation to different materials and hole shape requirements).
[0036] For example, when the workpiece is thin glass (less than 1mm thick) and high microhole precision is required, the processing parameters are set as follows: laser power of 50W, wavelength of 1030nm, pulse frequency of 100kHz, single pulse energy of 640uJ, number of sub-pulses per pulse train of 4, position synchronization output accuracy (PSO distance) of 1µm, and multi-focus beam 10 movement speed of 200mm / s. This parameter combination achieves a balance of "low thermal damage, high precision, and controllable efficiency" in microhole processing of thin glass.
[0037] Furthermore, the axial coverage of the multi-focal beam 10 is adjusted so that the axial coverage of the multi-focal beam 10 is greater than the thickness of the workpiece to meet the incoming material tolerance of the workpiece. Preferably, the axial coverage of the multi-focal beam 10 is 10-100 μm greater than the thickness of the workpiece.
[0038] Reference Figure 5 This embodiment further provides a laser micro-hole processing device for a transparent workpiece to implement the above-mentioned method. The device includes: a laser for providing a Gaussian laser beam; a beam shaper for shaping the Gaussian laser beam to obtain a multi-focus beam 10; a focusing lens disposed below the beam shaper and for focusing the multi-focus beam 10 into the workpiece; a rotary motor for driving the beam shaper; and an X / Y stage for controlling the movement of the multi-focus beam 10.
[0039] In this embodiment, the laser selected is an ultrafast laser suitable for thin glass materials, such as an infrared femtosecond laser or an infrared picosecond laser, to ensure that high-efficiency micro-hole processing can be achieved. In addition, the laser is equipped with necessary auxiliary equipment, such as an automatic loading and unloading system, a cooling system, and a safety protection system. Before processing, check all parts of the device, including the laser, optical path system, cooling system, safety protection system, and power supply, to ensure that the equipment is in good condition, confirm that the safety protection device is working properly, and fix the thin glass to be processed on the workbench to ensure that it is stable and does not move. Vacuum suction can be used to fix the thin glass product.
[0040] In this embodiment, the beam shaper may be a spatial light modulator or a diffractive optical element, and a multi-focus parallel processing strategy is used to achieve one-time processing, improve processing efficiency, and reduce the heat-affected zone.
[0041] There are also solutions in the prior art that use laser drilling and then chamfer the edges of the holes. The principle is to achieve a melting hole effect by continuously rotating the focus to ablate the workpiece. The excess waste falls off due to the ablation effect. After the hole processing is completed, the chamfer is processed through an additional process. This method has the disadvantages of long processing time, large thermal response area, and high energy consumption. In the embodiment of the present invention, the outline of the hole and chamfer is formed inside the workpiece by laser, and then the hole and chamfer are revealed by etching. Compared with the laser ablation solution, it has the advantages of one-time forming, small heat-affected zone, high processing accuracy, low energy consumption, and reduced stress concentration.
[0042] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above. For the sake of simplicity, they are not provided in detail. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that it is still possible to modify the technical solutions described in the above embodiments, or to make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A laser micro-hole processing method for a transparent workpiece, wherein the workpiece is transparent to the laser, characterized in that: The following steps are involved: S1: provides Gaussian laser beam; S2: shaping and focusing the Gaussian laser beam to form a multi-focus beam (10) and applying the multi-focus beam (10) to the interior of the workpiece, wherein the spatial trajectory of the multi-focus beam (10) includes a main trajectory vertical line (11) extending along the axial direction of the desired microhole, a chamfer line (12) connecting the main trajectory vertical line (11) and the surface of the workpiece, and an auxiliary line (13) located radially inside the main trajectory vertical line (11), wherein one end of the auxiliary line (13) intersects with the main trajectory vertical line (11) and the other end extends to the surface of the workpiece; S3: controlling the multi-focus light beam (10) to rotate around the axis of the desired microhole for one circle, thereby forming a spatially modified surface inside the workpiece and obtaining a modified workpiece; S4: Etching the modified workpiece to achieve microporous forming of the workpiece.
2. The laser micro-hole processing method for a transparent workpiece according to claim 1, characterized in that: Step S4 specifically includes: The modified workpiece includes a sample area (21), an upper waste area (22) and a lower waste area (23). The modified workpiece is immersed in an etching solution. After etching is completed, the upper waste area (22) and the lower waste area (23) can be detached from the upper and lower sides respectively to obtain the sample area (21), thereby realizing microporous forming of the workpiece.
3. The laser micro-hole processing method for a transparent workpiece according to claim 1, characterized in that: When one end of the auxiliary line (13) intersects at the endpoint of the main track vertical line (11), a preset distance is provided between one end of the auxiliary line (13) and the endpoint of the main track vertical line (11), and the range of the preset distance is 1 to 40 μm.
4. The laser micro-hole processing method for a transparent workpiece according to claim 1, characterized in that: The angle α between the auxiliary line (13) and the main track vertical line (11) can be dynamically adjusted.
5. The laser micro-hole processing method for a transparent workpiece according to claim 1, characterized in that: The processing parameters are set according to the material properties of the workpiece and the microhole precision requirements. The processing parameters include: laser power of 20~100W, wavelength of 495nm~570nm or 950nm~1400nm, pulse frequency of 50~1000kHz, single pulse energy of 100~1000uJ, the number of sub-pulses in a pulse train of 1~10, position synchronization output accuracy of 1~5µm, and the moving speed of the multi-focus beam (10) of 50~500mm / s.
6. The laser micro-hole processing method for a transparent workpiece according to claim 1, characterized in that: The axial coverage range of the multi-focus light beam (10) is adjusted so that the axial coverage range of the multi-focus light beam (10) is greater than the thickness of the workpiece.
7. The laser micro-hole processing method for a transparent workpiece according to claim 6, characterized in that: The axial coverage of the multi-focus light beam (10) is 10-100 μm greater than the thickness of the workpiece.
8. The laser micro-hole processing method for a transparent workpiece according to claim 2, characterized in that: The etching solution is an acidic solution or an alkaline solution. The etching solution is selected according to the chemical composition of the workpiece. The etching parameters include concentration, temperature and time.
9. The laser micro-hole processing method for a transparent workpiece according to claim 8, characterized in that: The acidic solution comprises: hydrofluoric acid with a concentration of 3-5%, sulfuric acid with a concentration of 1-2%, ammonium fluoride with a concentration of 1-3%, and a surfactant with a concentration of 0.1-0.3%; The alkaline solution comprises sodium hydroxide at a temperature of 120-150° C. and a concentration of 30-70%.
10. A laser micro-hole processing device for a transparent workpiece, for implementing the method according to any one of claims 1 to 9, characterized in that: include: a laser for providing a Gaussian laser beam; a beam shaper for shaping the Gaussian laser beam to obtain a multi-focus beam (10); A focusing mirror, arranged below the beam shaper, for focusing the multi-focal beam (10) into the interior of a workpiece; a rotary motor for driving the beam shaper; An X / Y platform is used to control the movement of the multi-focus light beam (10).