A transparent workpiece surface texture processing device and method based on laser metal sputtering

Abstract

The present invention discloses a device and method for processing the surface texture of a transparent workpiece based on laser metal sputtering; the method is as follows: First, arrange a laser generator, a sputtering substrate, and a transparent workpiece equipped with a transparent mask; Second, the laser generator emits a laser focused on the surface of the sputtering substrate, and uses the sputtered fragments to form a texture on the surface of the transparent workpiece. The present invention realizes the indirect non-contact processing of the transparent workpiece by using the kinetic energy of the debris generated by laser ablation of the underlying metal to impact the surface of the transparent workpiece to form a texture; since the laser energy only acts on the metal substrate, the transparent workpiece does not need to be directly exposed to the focus of the high-energy laser beam, and the material melting, microcracks or thermal stress deformation caused by the thermal effect in the traditional laser direct writing technology can be avoided. Compared with the traditional processing method, the thermal damage rate of the transparent workpiece processing is reduced, and at the same time, the use of coolant or protective gas is avoided, simplifying the process flow.

Description

Technical Field

[0001] The present invention belongs to the technical field of transparent workpiece processing, and particularly relates to a device and method for processing surface textures of transparent workpieces based on laser metal sputtering. Background Art

[0002] Processing micro-nano texture arrays (such as circular, wavy, etc.) on the surface of transparent materials can significantly improve their tribological properties and functional characteristics. For example, processing micro-textures on the surface of photovoltaic glass in the aerospace field can enhance its impact resistance and reduce impact damage caused by dust particles; introducing annular textures on the surface of transparent ceramic tools can improve cutting lubricity and reduce the risk of brittle fracture; in the fields of optical devices and semiconductors, for example, processing specific textures on the surface of transparent conductive oxide (TCO) films can endow them with better optoelectronic properties; processing bionic textures on the surface of transparent polyethylene materials can improve drag reduction.

[0003] The existing processing technologies for preparing textures on transparent materials are mainly two types: chemical etching method and laser direct writing technology.

[0004] However, the chemical etching method relies on etching solutions, has low edge accuracy, and it is difficult to etch some transparent materials, with relatively high costs and long processing times; while the laser direct writing technology needs to directly ablate the surface of the transparent material. Due to the high light transmittance of the material, insufficient energy absorption occurs, and it is necessary to significantly increase the laser power, which may cause thermodynamic damages such as micro-cracks and thermal stress deformation. Moreover, when processing complex textures, it is necessary to mechanically rotate the axis to cooperate with the light beam for scanning in a specific shape, with high requirements for equipment accuracy and low efficiency, making it difficult to meet the industrial batch demand. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and device for processing texture arrays on transparent workpieces to address the current problem of difficult processing of surface textures on transparent workpieces. By covering a hollow mask with the required texture shape below the target material, laser ablation of the metal below generates debris splashing and impact, physically cutting the part not blocked by the mask, and processing the required shape texture on the surface of the transparent workpiece while avoiding thermal damage to the transparent workpiece.

[0006] In the first aspect, the present invention provides a method for processing surface textures of transparent workpieces based on laser metal sputtering, which includes the following steps:

[0007] Step 1: A laser generator and a sputtering substrate made of metal are respectively arranged on both sides of the transparent workpiece to be processed; the transparent workpiece and the sputtering substrate are parallel to each other with a sputtering distance left; the side of the transparent workpiece close to the sputtering substrate is covered with a transparent texture mask; the transparent texture mask is provided with a through groove structure matching the texture shape.

[0008] Step 2: The laser generator emits a laser that is focused on the surface of the sputtering substrate and moves along a preset path; sputtering fragments are formed on the surface of the sputtering substrate under the laser. The sputtering fragments impact the transparent workpiece through the through-hole structure on the transparent texture mask, so that a grooved texture is formed on the surface of the transparent workpiece.

[0009] Preferably, in Step 2, the focal length of the laser generator is set F as follows:

[0010]

[0011] wherein, D is the distance between the laser generator and the sputtering substrate; d is the thickness of the transparent workpiece to be processed; n is the relative refractive index of the transparent workpiece with respect to the processing environmental medium.

[0012] Preferably, the value of the sputtering spacing is 0.5 mm to 1.5 mm.

[0013] Preferably, a plurality of processing points are set on the side surface of the sputtering substrate; the laser generator is aligned with any one of the processing points; during the process of the laser generator emitting laser, the laser generator and the sputtering substrate move synchronously, so that the laser emitted by the laser generator continuously irradiates and ablates the processing points. Whenever the ablation duration of a processing point reaches the maximum cumulative ablation duration, the laser generator temporarily stops working, and the processing point aligned with the laser generator is replaced by moving the sputtering substrate. If all the processing points on all the sputtering substrates have been ablated, the sputtering substrate is replaced; the replaced sputtering substrate is reused after being polished to eliminate the ablation marks.

[0014] Preferably, the processing points on the sputtering substrate are arranged in a matrix; the distance between adjacent two processing points is greater than the ablation horizontal sputtering distance.

[0015] Preferably, every preset ablation processing duration, the laser generator temporarily stops working, and the debris between the sputtering substrate and the transparent workpiece is removed by negative pressure suction.

[0016] In a second aspect, the present invention provides a device for processing the surface texture of a transparent workpiece based on laser metal sputtering, which includes a frame, a laser three-axis moving module, a laser generator, a workpiece clamp, a substrate three-axis moving module, a substrate clamp and a sputtering substrate. The workpiece clamp is used for clamping the transparent workpiece. The substrate clamp is used for clamping the sputtering substrate. The laser three-axis moving module and the substrate three-axis moving module respectively drive the laser generator and the substrate clamp to move. The laser generator, the transparent workpiece to be processed, and the sputtering substrate are arranged in sequence from top to bottom.

[0017] Preferably, both the laser three-axis moving module and the substrate three-axis moving module are mounted on the frame. The laser generator is mounted on the end moving part of the laser three-axis moving module; the substrate fixture is mounted on the end moving part of the substrate three-axis moving module.

[0018] Preferably, the laser three-axis moving module is mounted on the frame. The laser generator and the substrate three-axis moving module are both mounted on the end moving structure of the laser three-axis moving module; the substrate fixture is mounted on the end moving part of the substrate three-axis moving module.

[0019] Preferably, a negative pressure suction machine is further included; the suction port of the negative pressure suction machine faces the area between the sputtering substrate and the transparent plate to be processed, and is used to suck the debris generated by sputtering.

[0020] Advantages of the present invention:

[0021] In the present invention, the kinetic energy of the debris generated by laser ablation of the underlying metal impacts the surface of the transparent workpiece to form a texture, realizing the indirect non-contact processing of the transparent workpiece; since the laser energy only acts on the metal substrate, the transparent workpiece does not need to be directly exposed to the focus of the high-energy laser beam, avoiding material melting, microcracks or thermal stress deformation caused by the thermal effect in the traditional laser direct writing technology. Compared with the traditional processing method, the thermal damage rate of the transparent workpiece processing is reduced, and at the same time, the use of coolant or protective gas is avoided, simplifying the process flow.

[0022] The present invention uses the method of covering a transparent mask with the required texture hollow, and scans the entire lower surface of the transparent material through the sputtering effect excited by the laser to quickly generate a texture on the surface of the transparent workpiece, and the transparent mask can be reused, facilitating batch processing; compared with the traditional method of scanning the femtosecond laser along the texture morphology, the present invention is not limited by the rotation speed and scanning speed during processing; by using the x-y axis adjustment, the sputtering substrate can be efficiently utilized, and high-efficiency production of various micro-textures can be realized.

[0023] The present invention significantly reduces the processing cost by reusing the ablation area of the metal material and using a conventional pulsed laser such as a nanosecond laser to replace the expensive ultrafast laser equipment; in addition, the method of processing the plate by physical impact makes the method have no selectivity for the material of the transparent workpiece, and can be compatible with various materials such as glass, resin, and polyethylene, solving the environmental protection and safety problems existing in the traditional chemical etching method and the problem of being unable to be compatible with various materials. Description of the drawings

[0024] Figure 1 It is a flowchart of Embodiment 1 of the present invention.

[0025] Figure 2 It is a schematic structural diagram of the transparent workpiece surface texture processing device used in Embodiment 1 of the present invention.

[0026] Figure 3 This is a schematic diagram of the processing principle of Embodiment 1 of the present invention.

[0027] Figure 4 This is a topographical map of the surface texture of the transparent workpiece processed in Embodiment 1.

[0028] Reference numerals: 1, laser three-axis movement module; 2, laser generator; 3, workpiece fixture; 4, transparent workpiece; 4-1, texture; 5, substrate three-axis movement module; 6, substrate fixture; 7, sputtering substrate; 8, transparent texture mask; 8-1, through-hole structure; 9, negative pressure suction machine. Detailed implementation manners

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0031] Next, the present invention will be further described in conjunction with the accompanying drawings and specific embodiments, but it is not a limitation of the present invention.

[0032] Embodiment 1

[0033] As shown in Figure 1 、 Figure 2 and 3 A method for processing the surface texture of a transparent workpiece based on laser metal sputtering, and a device for processing the surface texture of a transparent workpiece used, including a frame, a laser three-axis movement module 1, a laser generator 2, a workpiece fixture 3, a substrate three-axis movement module 5, a substrate fixture 6, a sputtering substrate 7, a transparent texture mask 8, and a negative pressure suction machine 9.

[0034] In this embodiment, the transparent workpiece 4 to be processed is a glass sheet.

[0035] The laser three-axis moving module 1 and the substrate three-axis moving module 5 are both installed on the frame. The laser generator 2 is installed on the end moving part of the laser three-axis moving module 1; the laser three-axis moving module 1 is used to drive the laser generator 2 to move with three degrees of freedom. The workpiece fixture 3 is fixed on the frame; the substrate fixture 6 is installed on the end moving part of the substrate three-axis moving module 5. The sputtering substrate 7 is clamped on the substrate fixture 6. The substrate three-axis moving module 5 is used to drive the substrate fixture 6 to move with three degrees of freedom. The laser generator 2, the transparent workpiece to be processed, and the sputtering substrate 7 are arranged in sequence from top to bottom.

[0036] The workpiece fixture 3 is used to clamp the transparent workpiece 4 to be processed. The substrate fixture 6 is used to clamp the sputtering substrate 7 made of metal. The transparent workpiece 4 and the sputtering substrate 7 are parallel to each other and arranged at intervals. In this embodiment, the distance between the transparent workpiece 4 and the sputtering substrate 7 is a preset sputtering distance. In this embodiment, the value of the sputtering distance L is 1 mm. The setting of the sputtering distance L can avoid thermal damage to the transparent workpiece 4 caused by the heated sputtering substrate 7. In other embodiments, the sputtering distance L can also take other values that can ensure the sputtering effect, such as 0.5 mm to 1.5 mm.

[0037] The transparent texture mask 8 is fixedly attached to the side of the transparent workpiece 4 to be processed facing the sputtering substrate 7. The transparent texture mask 8 is provided with a through groove structure 8-1 that matches the shape of the target texture. The transparent texture mask 8 is used to ensure that a texture 4-1 of the required shape is formed on the transparent workpiece 4. In this embodiment, the through groove structure 8-1 on the transparent texture mask 8 is formed by direct laser processing.

[0038] The suction port of the negative pressure suction machine 9 faces the area between the sputtering substrate 7 and the transparent plate to be processed, and is used to suck the debris generated by sputtering.

[0039] As Figure 2 shown, the processing principle of this transparent workpiece surface texture processing device is as follows: Using pulsed laser to penetrate the transparent workpiece 4 and the transparent texture mask 8, and focusing on the sputtering substrate 7 made of metal. Laser ablation will cause the metal on the sputtering substrate 7 to generate sputtering fragments that spread in a ring shape. The ring-shaped sputtering fragments impact the part of the lower surface of the transparent workpiece 4 that is not blocked by the mask, and the sputtering fragments machine micro-scale groove structures on the transparent workpiece 4. As the laser generator 2 moves, a strip-shaped texture 4-1 as Figure 2 shown will be generated.

[0040] The transparent mask material should have sufficient light transmittance and impact resistance; in this embodiment, the material of the transparent texture mask 8 is polycarbonate.

[0041] In this embodiment, the laser three-axis moving module 1 and the substrate three-axis moving module 5 adopt XYZ three-axis linear motor platforms with the same structure; the positioning accuracy of the XYZ three-axis linear motor platform is ±0.5 μm; the maximum speed is 500 mm / s.

[0042] In this embodiment, the workpiece fixture 3 fixes the transparent workpiece 4 by means of vacuum adsorption.

[0043] As Figure 1 and Figure 3 shown, the method for processing the micro-texture of the transparent workpiece using the above transparent workpiece surface texture processing device includes the following steps:

[0044] Step 1: According to the material of the transparent workpiece 4 to be processed and the texture size to be processed, conduct a debris impact experiment to determine the laser ablation processing parameters.

[0045] The specific steps of the debris impact experiment are as follows: With different laser processing parameters and the same sputtering distance, the laser emitted by the laser generator 2 is focused on the sputtering substrate 7, and the sputtering fragments generated on the sputtering substrate 7 are used to process the lower surface of the transparent workpiece 4. The laser processing parameters include laser energy density and scanning time.

[0046] According to the processing results corresponding to different laser processing parameters, determine the sputtering groove depth corresponding to different laser processing parameters; according to the set target groove depth, select the corresponding laser processing parameters as the optimal laser processing parameters.

[0047] Under the condition of the optimal laser processing parameters, conduct a mask impact experiment, and determine the number of times the mask can be reused according to the damage condition of the mask after different processing times.

[0048] According to the optimal laser processing parameters, conduct an ablation experiment on the sputtering substrate 7; observe whether the groove depth processed under different laser processing times meets the texture size requirements, and determine the maximum cumulative ablation duration of a single point on the sputtering substrate 7. In this embodiment, the maximum cumulative ablation duration of a single point on the sputtering substrate 7 is determined to be 20 s; that is, each processing point can only be processed repeatedly for 20 s, otherwise the sputtering processing effect will no longer meet the expectations.

[0049] After testing, the horizontal sputtering range diameter of the sputtering substrate 7 due to laser ablation is about 1 mm. To avoid the mutual influence of adjacent processing points on the sputtering substrate 7, a processing point array arranged in a matrix shape is set with a center distance of 1.5 mm between adjacent points on the sputtering substrate 7.

[0050] Step 2: Fix the transparent texture mask 8 on the surface to be processed of the transparent workpiece 4; clamp the transparent workpiece 4 to be processed on the workpiece fixture 3, so that the surface to be processed of the transparent workpiece 4 faces the sputtering substrate 7 and maintains a sputtering distance L from the sputtering substrate 7. The laser three-axis movement module 1 and the substrate three-axis movement module 5 drive the laser generator 2 and the sputtering substrate 7 to move respectively, so that the laser generator 2, the scanning starting position on the transparent workpiece 4, and a processing point on the sputtering substrate 7 are on the same straight line.

[0051] Adjust the focal length of the laser generator 2 F as follows:

[0052]

[0053] where D is the distance between the laser generator 2 and the sputtering substrate; d is the thickness of the transparent workpiece to be processed; n is the relative refractive index of the transparent workpiece with respect to the processing ambient medium. In this embodiment, the processing environment is air; therefore n is the relative refractive index of the transparent workpiece with respect to air.

[0054] Step 3: Perform sputtering processing by laser scanning: Use the maximum cumulative ablation duration determined in Step 1 as a processing cycle; within one processing cycle, the laser generator 2 drives by the laser three-axis movement module 1 and performs full-coverage scanning on the transparent workpiece 4 according to the optimal laser processing parameters obtained in Step 1. At the same time, the sputtering substrate 7 drives by the substrate three-axis movement module and moves synchronously with the laser generator 2, so that the laser emitted by the laser generator 2 irradiates at the same position on the sputtering substrate 7 (i.e., a fixed processing point), and the fragments sputtered from the same processing point on the sputtering substrate 7 impact the lower surface of the transparent workpiece 4 as the laser scans. After completing one processing cycle, enter Step 4 to replace the processing point on the sputtering substrate 7.

[0055] Step 4: Replace the processing point: The laser generator 2 stops emitting laser and moving; the substrate three-axis movement module 5 drives the sputtering substrate 7 to move, so that an unablated processing point moves to a position aligned with the laser generator 2; if all the processing points on all the sputtering substrates 7 have been ablated, replace the sputtering substrate 7; the replaced sputtering substrate 7 is reused after being polished to eliminate the ablation marks. Then, enter the next processing cycle.

[0056] Step 5: Repeat Step 3 and Step 4 until the processing of the texture 4-1 on the transparent workpiece 4 is completed. Replace the processed transparent workpiece 4 and re-execute Step 3 to Step 5. After the processing of the transparent workpiece 4 is completed, clean the transparent workpiece 4 using an ultrasonic cleaning machine, and measure the width, depth, and surface roughness of the texture 4-1 using a white light interferometer or a laser confocal microscope.

[0057] In Step 3 and Step 4, after each cycle of ablation for a preset duration, the ablation processing cycle stops, and the negative pressure suction machine 9 is started to clean the debris remaining on the surface of the metal sheet and the impact debris on the glass sheet and the mask, preventing secondary attachment and contamination of the sheet. In this embodiment, the value of the preset duration is 150 s to 200 s.

[0058] In this embodiment, the processing results of six different-shaped textures 4-1 are as Figure 4 shown, Figure 4 The (a), (b), (c), (d), (e), and (f) parts of Figure 4 correspond to the textures of circular array, square grid, straight queue, rhombic grid, wave queue, and honeycomb respectively. There is only the light and shadow naturally generated by the illumination at the edge of the texture on the groove texture of

[0059] Example 2

[0060] A method for processing the surface texture of a transparent workpiece based on laser metal sputtering. The difference between this embodiment and Embodiment 1 is that the processed transparent workpiece is different; in this embodiment, the material of the processed transparent workpiece is transparent ceramic.

[0061] Example 3

[0062] A method for processing the surface texture of a transparent workpiece based on laser metal sputtering. The difference between this embodiment and Embodiment 1 is that the processed transparent workpiece is different; in this embodiment, the material of the processed transparent workpiece is transparent resin.

[0063] Example 4

[0064] A method for processing the surface texture of a transparent workpiece based on laser metal sputtering. The difference between this embodiment and Embodiment 1 is that the processing device is different.

[0065] In this embodiment, the substrate three-axis moving module 5 is installed on the end moving structure of the laser three-axis moving module 1; the laser three-axis moving module 1 can drive the laser generator 2 and the sputtering substrate 7 to move synchronously; only when the sputtering substrate 7 needs to change the working position, the substrate three-axis moving module 5 drives the sputtering substrate 7 to move alone.

[0066] Since in this embodiment, the laser three-axis moving module 1 can drive the laser generator 2 and the sputtering substrate 7 to move simultaneously, it helps to provide the consistency of the movement of the laser generator 2 and the sputtering substrate 7 during processing, ensures that the position of the laser beam irradiating on the sputtering substrate 7 remains unchanged, and improves the processing accuracy.

[0067] Embodiment 5

[0068] A method for processing the surface texture of a transparent workpiece based on laser metal sputtering. The difference between this embodiment and Embodiment 1 is that the sputtering substrate and the laser generator do not move synchronously; in this embodiment, the sputtering substrate remains stationary, and the laser generator scans different positions of the sputtering substrate, and the sputtering fragments formed by ablation impact different positions on the lower surface of the transparent workpiece to form a groove-type texture.

[0069] Although the present invention has been described in the above embodiments with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed, as long as they do not deviate from the spirit and scope of the present invention defined by the appended claims. It should be understood that the different dependent claims and the features described herein can be combined in a manner different from that described in the original claims. It should also be understood that the features described in connection with a single embodiment can be used in other described embodiments.

Claims

1. A method for processing the surface texture of a transparent workpiece based on laser metal sputtering; characterized in that: Including the following steps: Step 1: A laser generator (2) and a sputtering substrate (7) made of metal are respectively arranged on both sides of the transparent workpiece (4) to be processed; the transparent workpiece (4) and the sputtering substrate (7) are parallel to each other with a sputtering distance left; the side of the transparent workpiece (4) close to the sputtering substrate (7) is covered with a transparent texture mask (8); the transparent texture mask (8) is provided with a through-hole structure matching the texture shape. Step 2: The laser generator (2) emits a laser focused on the surface of the sputtering substrate (7) and moves along a preset path; sputtered fragments are formed on the surface of the sputtering substrate (7) under the laser; the sputtered fragments impact the transparent workpiece (4) through the through-hole structure on the transparent texture mask (8), so that a texture is formed on the surface of the transparent workpiece (4).

2. The method for processing the surface texture of a transparent workpiece based on laser metal sputtering according to claim 1, characterized in that: In step two, set the focal length of the laser generator (2) F as follows: ； Wherein, D is the distance between the laser generator (2) and the sputtering substrate; d is the thickness of the transparent workpiece to be processed; n is the relative refractive index of the transparent workpiece with respect to the processing ambient medium.

3. The method for machining the surface texture of a transparent workpiece according to claim 1, wherein: The value of the sputtering distance is 0.5 mm to 1.5 mm.

4. The method for processing the surface texture of a transparent workpiece according to claim 1, wherein: A plurality of processing points are set on the side of the sputtering substrate (7); the laser generator (2) is aligned with any one of the processing points; during the process of the laser generator (2) emitting laser, the laser generator (2) and the sputtering substrate (7) move synchronously, so that the laser emitted by the laser generator (2) continuously irradiates and ablates the processing points; whenever the ablation time of a processing point reaches the maximum cumulative ablation time, the laser generator (2) temporarily stops working, and the processing point aligned with the laser generator (2) is replaced by moving the sputtering substrate (7).

5. The method for processing the surface texture of a transparent workpiece according to claim 4, characterized in that: The processing points on the sputtering substrate (7) are arranged in a matrix; the distance between adjacent two processing points is greater than the ablation horizontal sputtering distance.

6. The method for processing the surface texture of a transparent workpiece according to claim 1, characterized in that: Every preset ablation processing duration, the laser generator (2) temporarily stops working, and the debris between the sputtering substrate (7) and the transparent workpiece (4) is removed by negative pressure suction.

7. A transparent workpiece surface texture processing device based on laser metal sputtering, characterized in that: A device for performing the transparent workpiece surface texture processing method as claimed in claim 1; the transparent workpiece surface texture processing device includes a frame, a laser three-axis moving module (1), a laser generator (2), a workpiece fixture (3), a substrate three-axis moving module (5), a substrate fixture (6) and a sputtering substrate (7); the workpiece fixture (3) is used for clamping the transparent workpiece; the substrate fixture (6) is used for clamping the sputtering substrate (7); the laser three-axis moving module (1) and the substrate three-axis moving module (5) respectively drive the laser generator (2) and the substrate fixture (6) to move; the laser generator (2), the transparent workpiece to be processed, and the sputtering substrate (7) are arranged in sequence from top to bottom.

8. The transparent workpiece surface texture processing device according to claim 7, characterized in that: The laser three-axis moving module (1) and the substrate three-axis moving module (5) are both installed on the frame; the laser generator (2) is installed on the end moving part of the laser three-axis moving module (1); the substrate fixture (6) is installed on the end moving part of the substrate three-axis moving module (5).

9. The transparent workpiece surface texture processing device according to claim 7, wherein: The laser three-axis moving module (1) is installed on the frame; the laser generator (2) and the substrate three-axis moving module (5) are both installed on the end moving structure of the laser three-axis moving module (1); the substrate fixture (6) is installed on the end moving part of the substrate three-axis moving module (5).

10. The transparent workpiece surface texture processing device according to claim 7, wherein: It further includes a negative pressure suction machine (9); the suction port of the negative pressure suction machine (9) faces the area between the sputtering substrate (7) and the transparent plate to be processed, and is used to suck up the debris generated by sputtering.

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