Method for processing groove in glass surface and preparation method of unequal-thickness flexible glass

Abstract

The invention discloses a method for processing a groove in a glass surface and a preparation method of unequal-thickness flexible glass, and the method comprises the following steps: S1, carrying out primary modification on a target groove area of the glass through ultrafast laser, and forming a microcrystalline layer at a specific depth of the target groove area; s2, performing secondary modification on the target groove area through ultrafast laser to form a latent image layer; s3, performing laser etching on the edge of the target groove; s4, forming a groove in the laser processing surface through chemical etching; the depth of the microcrystalline layer is 1 / 4-1 / 2 of the depth of the target groove, and the depth of the latent image layer is the target depth of the target groove. According to the method, the damage risk in the flexible glass processing process can be effectively reduced, meanwhile, the shape of the groove area can be accurately controlled, the thickness uniformity is greatly improved, and the product appearance and performance are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of flexible glass, and in particular relates to a method for machining grooves on a glass surface and a method for preparing flexible glass of unequal thickness. Background Art

[0002] Flexible glass usually refers to ultra-thin glass with a thickness of less than 0.1mm. It has excellent bending performance and high light transmittance, so it is widely used in display materials such as foldable electronic products. However, too thin thickness also leads to poor strength and impact resistance of flexible glass, and it is easy to break during use.

[0003] In order to better balance the performance requirements of flexible glass, the current stage mainly uses grooves formed in the folding area to enable the folding area to obtain the required bending performance, while ensuring that the non-folding area has good strength and impact resistance. The current methods for processing grooves on the surface of flexible glass mainly include CNC, chemical etching, and hot pressing, but the above methods are prone to glass breakage defects, uneven thickness, and uncontrollable groove shape. These methods greatly affect the appearance and performance of unequal thickness flexible glass, limiting its large-scale application in the field of flexible display materials.

[0004] Compared with unmodified glass, ultrafast laser-modified glass has a very fast etching rate, which makes it possible to prepare flexible glass of different thicknesses by combining laser modification with chemical etching. However, the scattering of laser inside the glass will cause deviations in the selection of modified areas, and the laser energy is prone to attenuation, resulting in the finished product morphology not being consistent with the designed morphology, affecting the appearance and performance of the product. Summary of the invention

[0005] Based on the above technical problems, the present invention provides a method for preparing flexible glass of unequal thickness by ultrafast laser secondary modification, which can effectively reduce the risk of breakage during the processing of flexible glass, and at the same time can accurately control the shape of the groove area, greatly improve the thickness uniformity, and significantly improve the product appearance and performance.

[0006] The specific scheme of the present invention is as follows:

[0007] One of the purposes of the present invention is to provide a method for machining a groove on a glass surface, comprising:

[0008] S1. Modify the target groove area of ​​the glass once by ultrafast laser to form a microcrystalline layer at a specific depth of the target groove area; S2. Modify the target groove area twice by ultrafast laser to form a latent image layer; S3. Laser etch the edge of the target groove; S4. Form a groove on the laser processed surface by chemical etching;

[0009] The depth of the microcrystalline layer is 1 / 4 to 1 / 2 of the target groove depth, and the depth of the latent image layer is the target depth of the target groove.

[0010] The present invention adopts a method combining ultrafast laser and chemical etching. First, two ultrafast laser modifications are used to form a latent image layer at the bottom of the target groove, and then the edge of the target groove is laser etched, thereby forming microchannels on both sides and the bottom of the groove, so that the chemical etching solution can etch the glass through the microchannel, directly peel off the target groove area, and obtain the target groove.

[0011] Furthermore, when ultrafast laser is used for primary modification to directly form a latent image layer at the bottom of the target groove, the scattering of the generated laser inside the glass causes deviations in the selection of the modified area, and the laser energy is prone to attenuation, resulting in the morphology of the finished product not being consistent with the designed morphology, affecting the appearance and performance of the product. The present invention divides the ultrafast laser modification into two steps. First, the modification is performed at 1 / 4 to 1 / 2 of the depth of the target groove to obtain a microcrystalline layer, which can reduce the scattering of the secondary laser inside the glass and improve the optical path stability and energy concentration. On this basis, the laser is focused to the bottom of the target groove for secondary modification, and a latent image layer with a uniform etching degree can be obtained.

[0012] The depth of the target groove of the present invention refers to the vertical height of the bottom of the groove from the glass processing surface. The depth of the microcrystalline layer refers to the vertical height of the microcrystalline layer from the glass processing surface. The depth of the latent image layer refers to the vertical height of the latent image layer from the glass processing surface. Preferably, the glass is flexible glass.

[0013] Preferably, in S1, the ultrafast laser is a femtosecond pulse laser; the femtosecond pulse laser has a wavelength of 750 to 850 nm, a pulse width of 100 to 200 fs, a power of 80 to 120 W, and a scanning speed of 40 to 60 mm / s.

[0014] Preferably, in S1, the microcrystalline particles of the microcrystalline layer have a particle size of 0.2-1.0 μm and a particle spacing of 1-3 μm. The particle spacing of the present invention refers to the distance between microcrystalline particles.

[0015] Preferably, S1 specifically comprises: using a femtosecond pulse laser to perform ultrafast laser modification on the target groove area starting from the edge of the target groove area in a U-shaped or S-shaped route to form a microcrystalline layer; more preferably, in S1, the target groove area is ultrafast laser modified in a U-shaped route.

[0016] Preferably, in S2, the ultrafast laser is a femtosecond pulse laser; the femtosecond pulse laser has a wavelength of 900 to 1200 nm, a pulse width of 300 to 500 fs, a power of 30 to 50 W, and a scanning speed of 180 to 230 mm / s. More preferably, in S2, the femtosecond pulse laser beam is incident at a vertical angle through the microcrystalline layer.

[0017] The incident angle and focal length are adjusted by feedback information from a beam verticality detector to achieve vertical incidence of the light beam passing through the microcrystalline layer.

[0018] Preferably, S2 specifically comprises: using a femtosecond pulse laser to perform ultrafast laser modification on the target groove area starting from the edge of the target groove in a U-shaped or S-shaped route to form a latent image layer; more preferably, in S2, the target groove area is subjected to ultrafast laser modification in an S-shaped route.

[0019] Preferably, in S3, the laser for laser etching is a picosecond laser; more preferably, an infrared picosecond laser; and particularly preferably, a single-light-source infrared picosecond laser.

[0020] Preferably, in S3, the laser power of laser etching is 60-90W, and the etching speed is 40-60mm / s. During laser etching, the etching track maintains linear motion in a fixed direction, and the laser intensity distribution is kept uniform.

[0021] Preferably, S4 specifically includes: coating a UV pyrolytic acid-resistant film on the non-groove area of ​​the laser processed surface and the other side of the glass, and placing the entire glass into an etching solution after curing to form a groove of a target shape.

[0022] The second object of the present invention is to provide a method for preparing flexible glass of unequal thickness, comprising: obtaining a groove on the glass processing surface by any of the above methods; and then chemically thinning the other side of the glass to a target thickness to obtain flexible glass of unequal thickness.

[0023] Preferably, a UV pyrolytic acid-resistant film is coated on the entire groove surface, and a spraying process is used to chemically thin the other side of the glass to a target thickness.

[0024] Preferably, the method further comprises tempering the thinned glass.

[0025] Preferably, the glass is any one of high-aluminum silicate glass, soda-lime silicate glass and borate glass.

[0026] Preferably, the thickness of the arc-shaped groove part of the unequal thickness glass is smaller than the thickness of other parts; the distance from the bottom of the groove to the side away from the groove is <0.1mm; preferably, the distance from the bottom of the groove to the side away from the groove is 0.03±0.005mm.

[0027] The beneficial effects of the present invention are:

[0028] (1) The present invention uses secondary ultrafast laser modification to form a latent image area in a designated area inside the glass. Compared with the method of directly forming the latent image area by one laser modification, the present invention can significantly improve the stability of the laser optical path and the energy concentration, optimize the uniformity of laser modification, greatly reduce the risk of uneven defects in the latent image area, and improve the appearance yield and performance reliability of finished glass products of unequal thickness. Further combined with chemical etching, the shape of the groove can be precisely controlled, effectively improving the appearance quality and thickness uniformity.

[0029] (2) The method of the present invention can obtain a microchannel, directly etch the latent image layer completely, and directly peel off the target groove area without etching the entire groove area, which can greatly shorten the etching time and improve production efficiency.

[0030] (3) The present invention mainly uses laser technology to perform unequal thickness forming, which can be highly combined with computer numerical control technology to achieve full-process automated processing and industrialized mass production, and has the advantages of high efficiency, low cost, and no pollution. Compared with unequal thickness forming methods such as CNC and hot pressing, ultrafast laser modification is used to prepare unequal thickness flexible glass. No mechanical stress is generated on the glass during the processing, which can greatly reduce the risk of glass breakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of forming a microcrystalline layer by laser modification in step S1 in Example 1;

[0032] Figure 2 This is a schematic diagram of forming a latent image layer by laser modification in step S2 of Example 1;

[0033] Figure 3 This is a schematic diagram of the cutting area formed by laser etching in step S3 of Example 1;

[0034] Figure 4 This is a schematic diagram of forming grooves by chemical etching in step S4 of Example 1. DETAILED DESCRIPTION

[0035] The technical solutions of the present invention are described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustration only and are not to be construed as limiting the scope of the present invention.

[0036] In the following examples and comparative examples, the glass used is high aluminosilicate glass with a thickness of 0.25 mm.

[0037] Example 1

[0038] A flexible glass of unequal thickness, wherein the thickness of the groove portion of the glass is smaller than the thickness of other portions, the distance from the bottom of the groove to the side away from the groove is 0.03 mm, and the thickness of other portions is 0.1 mm; the height of the groove is 70 μm. It is prepared according to the following process:

[0039] S1. Fix the glass to be processed on the laser workbench, adjust the wavelength of the femtosecond pulse laser to 760nm, the pulse width to 120fs, the power to 110W, and the scanning speed to 40mm / s, and perform ultrafast laser modification on the designated area with a depth of 25μm inside the glass in a U-shaped route starting from the edge of the target groove to form a microcrystalline layer with a microcrystalline particle size of 0.8μm and a particle spacing of 2.5μm, such as Figure 1 As shown;

[0040] S2. Adjust the wavelength of the femtosecond pulse laser to 1000nm, the pulse width to 350fs, the power to 46W, and the scanning speed to 190mm / s. Adjust the laser incident angle and focal length through the feedback information of the beam verticality monitor so that the beam passing through the microcrystalline layer is incident at a vertical angle. Perform ultrafast laser secondary modification on the designated area with a depth of 70μm inside the glass starting from the edge of the target groove along an S-shaped route to form Figure 2 The latent image layer shown;

[0041] S3, adjust the power of the single light source infrared picosecond laser to 80w, the etching speed to 50mm / s, and during laser etching, the etching track maintains a fixed direction of linear motion to maintain a uniform laser intensity distribution. Laser etching is performed on the edges of both sides of the target groove to form two laser cutting areas with a depth of 70μm, such as Figure 3 As shown;

[0042] S4, apply UV pyrolytic acid-resistant film on the non-groove area of ​​the laser processing surface and the other side of the glass, and put the entire glass into the etching solution after curing to form Figure 4 The groove shown;

[0043] S5, coating the entire groove surface with a pyrolytic acid-resistant film, and chemically thinning the other side of the glass to a target thickness using a spraying process;

[0044] S6. Cut and chemically toughen the chemically thinned glass to obtain flexible glass of varying thicknesses.

[0045] Example 2

[0046] A flexible glass of unequal thickness, wherein the thickness of the groove portion of the glass is smaller than the thickness of other portions, the distance from the bottom of the groove to the side away from the groove is 0.03 mm, and the thickness of other portions is 0.09 mm; the height of the groove is 60 μm. It is prepared according to the following process:

[0047] S1. Fix the glass to be processed on the laser workbench, adjust the wavelength of the femtosecond pulse laser to 800nm, the pulse width to 150fs, the power to 100W, and the scanning speed to 50mm / s, and perform ultrafast laser modification on the designated area with a depth of 20μm inside the glass in a U-shaped route starting from the edge of the target groove to form a microcrystalline layer with a particle size of 0.6μm and a particle spacing of 2μm;

[0048] S2. The wavelength of the femtosecond pulse laser is adjusted to 1080nm, the pulse width is 400fs, the power is 40W, and the scanning speed is 200mm / s. The laser incident angle and focal length are adjusted by feedback information from the beam verticality monitor so that the beam passing through the microcrystalline layer is incident at a vertical angle. Starting from the edge of the target groove, the designated area with a depth of 60μm in the glass is subjected to ultrafast laser secondary modification along an S-shaped route to form a latent image layer.

[0049] S3. Adjust the power of the single-light source infrared picosecond laser to 74w and the etching speed to 50mm / s. During laser etching, the etching track maintains a fixed direction of linear motion and maintains a uniform laser intensity distribution. Laser etching is performed on the edges of both sides of the target groove to form two laser cutting areas with a depth of 60μm;

[0050] Steps S4, S5 and S6 are the same as those in Example 1.

[0051] Example 3

[0052] A flexible glass of unequal thickness, wherein the thickness of the groove portion of the glass is smaller than the thickness of other portions, the distance from the bottom of the groove to the side away from the groove is 0.03 mm, and the thickness of other portions is 0.08 mm; the height of the groove is 50 μm. It is prepared according to the following process:

[0053] S1. Fix the glass to be processed on the laser workbench, adjust the wavelength of the femtosecond pulse laser to 840nm, the pulse width to 180fs, the power to 90W, and the scanning speed to 60mm / s. Perform ultrafast laser modification on the designated area with a depth of 15μm inside the glass starting from the edge of the target groove in a U-shaped route to form Figure 1 The microcrystalline layer shown has a particle size of 0.4 μm and a particle spacing of 1.5 μm;

[0054] S2. The wavelength of the femtosecond pulse laser is adjusted to 1160nm, the pulse width is 450fs, the power is 34W, and the scanning speed is 210mm / s. The laser incident angle and focal length are adjusted by feedback from the beam verticality monitor so that the beam passing through the microcrystalline layer is incident at a vertical angle. Starting from the edge of the target groove, the designated area with a depth of 50μm inside the glass is subjected to ultrafast laser secondary modification along an S-shaped route to form a latent image layer.

[0055] S3. Adjust the power of the single-light source infrared picosecond laser to 68w and the etching speed to 50mm / s. During laser etching, the etching track maintains a fixed direction of linear motion and maintains a uniform laser intensity distribution. Laser etching is performed on the edges of both sides of the target groove to form two laser cutting areas with a depth of 50μm;

[0056] Steps S4, S5 and S6 are the same as those in Example 1.

[0057] Comparative Example 1

[0058] A flexible glass of unequal thickness, wherein the thickness of the groove portion of the glass is smaller than the thickness of other portions, the distance from the bottom of the groove to the side away from the groove is 0.03 mm, and the thickness of other portions is 0.1 mm; the height of the groove is 70 μm. It is prepared according to the following process:

[0059] S1. Fix the glass to be processed on the laser workbench, adjust the wavelength of the femtosecond pulse laser to 1000nm, the pulse width to 350fs, the power to 46W, and the scanning speed to 190mm / s, and perform ultrafast laser modification on the designated area with a depth of 70μm inside the glass in an S-shaped route starting from the edge of the target groove to form Figure 2 The latent image layer shown;

[0060] Steps S2, S3, S4, and S5 are the same as steps S3, S4, S5, and S6 in Example 1.

[0061] Comparative Example 2

[0062] A flexible glass of unequal thickness, wherein the thickness of the groove portion of the glass is smaller than the thickness of other portions, the distance from the bottom of the groove to the side away from the groove is 0.03 mm, and the thickness of other portions is 0.1 mm; the height of the groove is 70 μm. It is prepared according to the following process:

[0063] S1. Use CNC precision engraving to form a groove with a width of 20 mm and a height of 70 μm on the glass surface;

[0064] S2, coating a UV pyrolytic acid-resistant film on the non-folding area of ​​the groove surface, and polishing the folding area with a chemical polishing liquid after curing;

[0065] S3. UV pyrolysis acid-resistant film is applied to the entire groove surface, and the other side of the glass is chemically thinned by spraying process. The thickness of the other parts outside the groove is 0.1mm, and the distance from the bottom of the groove to the side away from the arc groove is 0.03mm;

[0066] S4. Cutting and chemically toughening the chemically thinned glass to obtain flexible glass of varying thicknesses.

[0067] Comparative Example 3

[0068] A flexible glass of unequal thickness, wherein the thickness of the groove portion of the glass is smaller than the thickness of other portions, the distance from the bottom of the groove to the side away from the groove is 0.03 mm, and the thickness of other portions is 0.1 mm; the height of the groove is 70 μm. It is prepared according to the following process:

[0069] S1. Forming grooves using chemical etching process: UV thermal adhesive is applied to the non-folding area for acid-resistant protection, and a groove with a width of 20 mm and a height of 70 μm is formed on the glass surface using etching liquid;

[0070] Steps S2, S3 and S4 are the same as those in Comparative Example 1.

[0071] Comparative Example 4

[0072] A flexible glass of unequal thickness, wherein the thickness of the groove portion of the glass is smaller than the thickness of other portions, the distance from the bottom of the groove to the side away from the groove is 0.03 mm, and the thickness of other portions is 0.1 mm; the height of the groove is 70 μm. It is prepared according to the following process:

[0073] S1. Forming the groove by hot pressing process: heating the glass to above the softening point, processing the female mold and the male mold according to the target size, and hot pressing to obtain a groove with a width of 20 mm and a height of 70 μm;

[0074] Steps S2, S3 and S4 are the same as those in Comparative Example 1.

[0075] Comparative Example 5

[0076] A uniform thickness flexible glass, wherein the thickness of each part of the glass is 0.03 mm, is obtained by chemically thinning high-aluminum silicate glass and then chemically tempering it.

[0077] The bending performance and impact resistance of the flexible glass obtained in the above embodiments and comparative examples were tested by the following test methods:

[0078] (1) Bending performance: The bending performance is characterized by the number of bending times. The non-bending part of the flexible glass is fixed to the surface of the bending instrument with tape. The glass is bent into a book-like shape using the bending instrument. The bending angle is switched from the two panels fitting together to 180°. The bending frequency is 30 times / min, and the number of times the glass is broken is recorded.

[0079] (2) Impact resistance: The performance is characterized by the pen drop height. 50 μm OCA and 50 μm PET (elastic modulus of about 3 to 4 GPa) are attached to the upper and lower surfaces of the flexible glass. The test table is made of marble. A pen with a mass of 12 g and a diameter of 0.5 mm is dropped freely from a certain height. The height of the broken glass is recorded, which is the pen drop height.

[0080] The test results of the flexible glass performance obtained in the above examples and comparative examples are shown in Table 1:

[0081] Table 1 Flexible glass performance test results

[0082]

[0083]

[0084] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for machining a groove on a glass surface, characterized in that: include: S1. Performing a primary modification on the target groove area of ​​the glass by ultrafast laser to form a microcrystalline layer at a specific depth of the target groove area; S2. Performing a secondary modification on the target groove area by ultrafast laser to form a latent image layer; S3. Performing laser etching on the edge of the target groove; S4, forming a groove on the laser processed surface by chemical etching; The depth of the microcrystalline layer is 1 / 4 to 1 / 2 of the target groove depth, and the depth of the latent image layer is the target depth of the target groove.

2. The method for machining a groove on a glass surface according to claim 1, characterized in that: In S1, the ultrafast laser is a femtosecond pulse laser; the femtosecond pulse laser has a wavelength of 750 to 850 nm, a pulse width of 100 to 200 fs, a power of 80 to 120 W, and a scanning speed of 40 to 60 mm / s.

3. The method for machining a groove on a glass surface according to claim 1 or 2, characterized in that: In S1, the microcrystalline particles of the microcrystalline layer have a particle size of 0.2 to 1.0 μm and a particle spacing of 1 to 3 μm; preferably, in S1, a femtosecond pulse laser is used to perform ultrafast laser modification on the target groove area starting from the edge of the target groove area in a U-shaped or S-shaped route to form a microcrystalline layer.

4. The method for machining a groove on a glass surface according to any one of claims 1 to 3, characterized in that: In S2, the ultrafast laser is a femtosecond pulse laser; the femtosecond pulse laser has a wavelength of 900 to 1200 nm, a pulse width of 300 to 500 fs, a power of 30 to 50 W, and a scanning speed of 180 to 230 mm / s.

5. The method for machining a groove on a glass surface according to any one of claims 1 to 4, characterized in that: In S2, a femtosecond pulse laser is used to perform ultrafast laser modification on the target groove area starting from the edge of the target groove in a U-shaped or S-shaped route to form a latent image layer.

6. The method for machining a groove on a glass surface according to any one of claims 1 to 5, characterized in that: In S3, the laser for laser etching is a picosecond laser; preferably a single-light-source infrared picosecond laser.

7. The method for machining a groove on a glass surface according to any one of claims 1 to 6, characterized in that: In S3, the laser power of the laser etching is 60 to 90 W, and the etching speed is 40 to 60 mm / s.

8. The method for machining a groove on a glass surface according to any one of claims 1 to 7, characterized in that: S4 specifically includes: coating a UV pyrolytic acid-resistant film on the non-groove area of ​​the laser processed surface and the other side of the glass, and after curing, placing the entire glass into an etching solution to form a groove of a target shape.

9. A method for preparing flexible glass of unequal thickness, characterized in that: include: A groove is obtained on a glass processing surface by using any method of claims 1 to 8; and then the other side of the glass is chemically thinned to a target thickness to obtain flexible glass of unequal thickness.

10. The method for preparing flexible glass of unequal thickness according to claim 9, characterized in that: A UV pyrolytic acid-resistant film is coated on the entire groove surface, and the other side of the glass is chemically thinned to a target thickness using a spraying process; preferably, the thinned glass is tempered.

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