Tempered glass and electronic device

Abstract

The present application provides tempered glass and an electronic device. The tempered glass comprises: a substrate, comprising a first surface and a second surface which are opposite to each other; a first compressive stress layer, arranged on the first surface, wherein the first compressive stress layer comprises a microcrystalline layer, and the microcrystalline layer is located on the side of the first compressive stress layer facing away from the substrate; and a second compressive stress layer, arranged on the second surface, wherein in a thickness direction, i.e., the direction from the first surface to the second surface, the uniformity of the thickness of the first compressive stress layer is greater than the uniformity of the thickness of the second compressive stress layer. By enabling the tempered glass and the electronic device to have the structure, the first compressive stress layer comprising the microcrystalline layer and the second compressive stress layer hinder the expansion of micro-cracks inside the glass, thereby facilitating ensuring mechanical properties of the glass.

Description

Tempered glass and electronic devices

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 26, 2023, with application number 202321630815.9 and application name “Tempered Glass and Electronic Devices,” the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of glass technology, and in particular to a tempered glass and an electronic device. Background Art

[0003] There are a large number of microcracks inside the glass substrate itself, which can easily expand under the influence of external forces or environmental media. In the process of being processed into glass products with a certain appearance and shape, the glass substrate needs to go through production processes such as cutting, engraving, hot bending, and polishing. These production processes will cause a certain degree of damage to the glass substrate during the processing, causing the microcracks inside the glass substrate to expand or generate new microcracks. These microcracks are difficult to detect and reduce the mechanical properties of the glass products.

[0004] Summary of the Invention

[0005] The purpose of this application is to provide a strengthened glass and an electronic device to solve the problem that microcracks inside the glass are easy to expand and affect the mechanical properties of the glass.

[0006] To achieve the purpose of this application, this application provides the following technical solutions:

[0007] In a first aspect, the present application provides a tempered glass comprising: a substrate comprising a first surface and a second surface opposite to each other; a first compressive stress layer disposed on the first surface, wherein the first compressive stress layer comprises a microcrystalline layer, and the microcrystalline layer is located on a side of the first compressive stress layer opposite to the substrate; and a second compressive stress layer disposed on the second surface, wherein the thickness direction is from the first surface to the second surface, and the thickness uniformity of the first compressive stress layer is greater than the thickness uniformity of the second compressive stress layer.

[0008] In one embodiment, the microcrystalline layer, the first compressive stress layer, the substrate, and the second compressive stress layer are an integrated structure.

[0009] In one embodiment, the microcrystalline layer and the tempered glass satisfy the relationship: 0.001≤L1 / L≤0.2; wherein L1 is the thickness of the microcrystalline layer, and L is the overall thickness of the tempered glass.

[0010] In one embodiment, an area of ​​an orthographic projection of the microcrystalline layer on the substrate is smaller than or equal to an area of ​​an orthographic projection of the first compressive stress layer on the substrate.

[0011] In one embodiment, a surface of the first compressive stress layer facing away from the microcrystalline layer is perpendicular to the thickness direction, and a surface of the second compressive stress layer facing the first compressive stress layer is wavy, having a plurality of wave crests and a plurality of wave troughs that are alternately distributed.

[0012] In one embodiment, in the thickness direction, there is a distance between the surface of the first compressive stress layer facing the second compressive stress layer and the extreme point of the second compressive stress layer at the wave crest.

[0013] In one embodiment, the thickness of the second compressive stress layer at the plurality of wave crests is equal, and the thickness of the second compressive stress layer at the plurality of wave troughs is equal.

[0014] In one embodiment, the second compressive stress layer satisfies the relationship: 0.2≤L2 / L3≤0.8; wherein L2 is the thickness of the second compressive stress layer at the trough, and L3 is the thickness of the second compressive stress layer at the peak.

[0015] In one embodiment, the second compressive stress layer and the strengthened glass satisfy the relationship: 0.1≤L3 / L≤0.4; wherein L3 is the thickness of the second compressive stress layer at the wave peak, and L is the overall thickness of the strengthened glass.

[0016] In one embodiment, the first compressive stress layer and the strengthened glass satisfy the relationship: 0.1≤L4 / L≤0.4; wherein L4 is the thickness of the first compressive stress layer, and L is the overall thickness of the strengthened glass.

[0017] In one embodiment, the size of the crystal phase of the microcrystalline layer is 5 nm to 150 nm.

[0018] In one embodiment, the strengthened glass further includes a third compressive stress layer and a fourth compressive stress layer. The third compressive stress layer is located on a side of the microcrystalline layer facing away from the first compressive stress layer, and the fourth compressive stress layer is located on a side of the second compressive stress layer facing away from the substrate.

[0019] In a second aspect, the present application also provides an electronic device, comprising the tempered glass described in any embodiment of the first aspect, wherein the surface of the microcrystalline layer of the tempered glass facing away from the second compressive stress layer faces the external space of the electronic device, and the surface of the second compressive stress layer of the tempered glass facing away from the microcrystalline layer faces the internal space of the electronic device.

[0020] The tempered glass provided in the present application includes a substrate, a first compressive stress layer, and a second compressive stress layer. The first compressive stress layer includes a microcrystalline layer. A first compressive stress layer including a microcrystalline layer is provided on one surface of the substrate, and a second compressive stress layer is provided on the other opposite surface. This allows the tempered glass to be provided with compressive stress layers on both opposite sides of the substrate. This helps the first and second compressive stress layers to hinder the expansion of microcracks and improve the mechanical properties of the tempered glass. The microcrystalline layer is provided on at least a portion of the surface of the first compressive stress layer facing away from the substrate, which helps further improve the surface hardness of the tempered glass and further hinder the expansion of microcracks. At the same time, the thickness uniformity of the second compressive stress layer is less than that of the first compressive stress layer, so that the second compressive stress layer forms an uneven surface on the side facing the substrate, which can generate compressive stress that resists impact forces from more directions, improve the second compressive stress layer's ability to resist external impact, and make the tempered glass have better drop resistance and impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the implementation methods or the description of the prior art. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] FIG1 is a cross-sectional view of a tempered glass according to an embodiment;

[0023] FIG2 is a cross-sectional view of another embodiment of a tempered glass;

[0024] FIG3 is a flow chart of preparing strengthened glass according to an embodiment;

[0025] FIG4 is a cross-sectional view of an electronic device according to an embodiment.

[0026] Explanation of reference numerals: 10 - substrate, 20 - first compressive stress layer, 30 - microcrystalline layer, 40 - second compressive stress layer, 50 - third compressive stress layer, 60 - fourth compressive stress layer, 1 - strengthened glass, 2 - electronic device, 200 - internal space. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be an intermediate component. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or there may be an intermediate component.

[0029] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used in this application includes any and all combinations of one or more of the relevant listed items.

[0030] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features of the embodiments may be combined with each other.

[0031] An embodiment of the present application provides a strengthened glass 1. Referring to FIG. 1 , the strengthened glass 1 includes a substrate 10, a first compressive stress layer 20, and a second compressive stress layer 40. The first compressive stress layer 20 includes a microcrystalline layer 30, which is located on the side of the first compressive stress layer 20 facing away from the substrate 10. The substrate 10 includes a first surface and a second surface facing away from each other. The first compressive stress layer 20 is disposed on the first surface, and the second compressive stress layer 40 is disposed on the second surface. This provides compressive stress layers on both opposing sides of the strengthened glass 1, thereby enhancing the mechanical strength of the two opposing surfaces of the strengthened glass 1.

[0032] In ordinary glass, the microcracks' propagation paths are unimpeded, and further expansion of the microcracks can easily lead to a decrease in the mechanical properties of the ordinary glass. The crystalline phase in the microcrystalline layer 30 not only increases the surface hardness of the strengthened glass 1, but also passivates the microcracks, slowing or even hindering their propagation, thereby improving the mechanical properties of the strengthened glass 1.

[0033] The first compressive stress layer 20 and the second compressive stress layer 40 can generate compressive stress to offset the external impact force when the tempered glass 1 is subjected to the external impact force, so that the two opposite sides of the tempered glass 1 can better resist the external impact and improve the drop resistance and impact resistance of the tempered glass 1.

[0034] Usually, molten salt for chemical strengthening is coated on the surface of the glass, and ion exchange occurs between the molten salt and the glass to form a stress layer on the surface of the glass.

[0035] Taking the direction from the first surface toward the second surface as the thickness direction, the thickness of the first compressive stress layer 20 is uniformly distributed, while the thickness of the second compressive stress layer 40 is non-uniformly distributed, such that the thickness uniformity of the first compressive stress layer 20 is greater than the thickness uniformity of the second compressive stress layer 40. Optionally, the difference between the maximum thickness and the minimum thickness of the first compressive stress layer 20 is less than the difference between the maximum thickness and the minimum thickness of the second compressive stress layer 40. Optionally, the surface of the first compressive stress layer 20 facing the substrate 10 is a flat surface, while the surface of the second compressive stress layer 40 facing the substrate 10 is an uneven surface. The surface of the second compressive stress layer 40 facing the substrate 10 has multiple surfaces arranged at different angles, which can generate compressive stress to resist impact forces in multiple directions and hinder the propagation of microcracks in multiple directions.

[0036] By providing a first compressive stress layer 20 including a microcrystalline layer 30 on one surface of the substrate 10 of the strengthened glass 1 and providing a second compressive stress layer 40 on the other opposite surface, compressive stress layers are provided on both opposite sides of the strengthened glass 1. This facilitates the first compressive stress layer 20 and the second compressive stress layer 40 to inhibit the growth of microcracks, thereby improving the mechanical properties of the strengthened glass 1. The microcrystalline layer 30 is provided on at least a portion of the surface of the first compressive stress layer 20 facing away from the substrate 10, which facilitates further increasing the surface hardness of the strengthened glass 1 and further inhibiting the growth of microcracks.

[0037] The thickness uniformity of the second compressive stress layer 40 is less than that of the first compressive stress layer 20 , which helps ensure the overall strength of the tempered glass 1 . Furthermore, the second compressive stress layer 40 can generate compressive stress to resist impact forces in more directions, thereby improving the second compressive stress layer 40's ability to resist external impacts and hindering the propagation of microcracks in more directions. This provides the tempered glass 1 with better drop and impact resistance.

[0038] In one embodiment, referring to FIG1 , the microcrystalline layer 30, the first compressive stress layer 20, the substrate 10, and the second compressive stress layer 40 form an integrated structure. The first compressive stress layer 20, including the microcrystalline layer 30, is formed on one side of the glass, while the second compressive stress layer 40 is formed on the opposite side, thereby modifying the glass to form the strengthened glass 1. The unmodified portion of glass between the first compressive stress layer 20 and the second compressive stress layer 40 serves as the substrate 10.

[0039] In one embodiment, the substrate 10 is the main body of the tempered glass 1 , and the main body of the tempered glass 1 is lithium aluminosilicate glass, calcium aluminosilicate glass, or magnesium aluminosilicate glass.

[0040] A crystal nucleating agent is introduced into the surface layer of processed ordinary glass, and heat treatment is performed to induce the crystal nucleating agent to promote surface crystallization of the glass, thereby obtaining a strengthened glass 1 having a microcrystalline layer 30 on the surface.

[0041] The crystal nucleating agent can be any of metal crystal nucleating agents, oxide crystal nucleating agents, and fluoride crystal nucleating agents. Metal crystal nucleating agents include Ag, Cu, Pt, etc.; oxide crystal nucleating agents include TiO2, ZrO2, etc.; and fluoride crystal nucleating agents include CaF2, MgF2, etc. When a metal is used as a crystal nucleating agent, it is usually introduced into the glass in the form of a metal compound, such as metal chloride, metal oxide, metal nitrate, or metal sulfate. Under certain temperature conditions, the metal enters the surface layer of the glass in the form of ions, inducing crystal precipitation in the glass, thereby achieving microcrystallization of the glass surface.

[0042] The crystal phase of the microcrystalline layer 30 is any one of lithium disilicate, cristobalite, β-spodumene, spinel, β-wollastonite, mullite, and cordierite.

[0043] In one embodiment, the size of the crystal phase of the microcrystalline layer 30 is 5 nm to 150 nm.

[0044] By ensuring that the size of the crystal phases of the microcrystalline layer 30 falls within the aforementioned range, the light transmittance of the microcrystalline layer 30 is improved, enabling the tempered glass 1 to be used as a display screen for an electronic device 2. Within the aforementioned range of crystal phase sizes, the smaller the crystal phase size, the higher the light transmittance of the microcrystalline layer 30. This allows the microcrystalline layer 30 to achieve high light transmittance even when it is thick.

[0045] In one embodiment, referring to FIG. 1 , the microcrystalline layer 30 and the tempered glass 1 satisfy the relationship: 0.001≤L1 / L≤0.2; wherein L1 is the thickness of the microcrystalline layer 30 , and L is the overall thickness of the tempered glass 1 .

[0046] By ensuring that the thickness of the microcrystalline layer 30 and the overall thickness of the tempered glass 1 satisfy the above relationship, the thickness of the microcrystalline layer 30 can be reasonably set, thereby ensuring the overall strength of the tempered glass 1 and effectively improving the surface hardness of the tempered glass 1. When the tempered glass 1 is subjected to external forces, the microcrystalline layer 30 can effectively hinder the expansion of microcracks within the tempered glass 1, thereby improving the mechanical properties of the tempered glass 1 and providing the tempered glass 1 with better drop resistance and impact resistance.

[0047] In one embodiment, referring to FIG. 1 , the area of ​​the orthographic projection of the microcrystalline layer 30 on the substrate 10 is less than or equal to the area of ​​the orthographic projection of the first compressive stress layer 20 on the substrate 10 . The microcrystalline layer 30 is formed on the side of the first compressive stress layer 20 facing away from the substrate 10 , such that the surface of the microcrystalline layer 30 facing the substrate 10 is connected to the rest of the first compressive stress layer 20 . The first compressive stress layer 20 provided with the microcrystalline layer 30 is advantageously provided with an increased surface hardness of the strengthened glass 1 , thereby improving the mechanical properties of the strengthened glass 1 .

[0048] In one embodiment, referring to FIG. 1 , the surface of the first compressive stress layer 20 facing away from the microcrystalline layer 30 is perpendicular to the thickness direction, and the surface of the second compressive stress layer 40 facing the first compressive stress layer 20 is wavy with multiple crests and multiple troughs alternately distributed.

[0049] Optionally, in the second compressive stress layer 40, the plurality of wave crests are equidistant from the surface of the second compressive stress layer 40 facing away from the substrate 10. The plurality of wave troughs are equidistant from the surface of the second compressive stress layer 40 facing away from the substrate 10. The plurality of wave crests have equidistant inclination angles relative to the thickness direction.

[0050] Optionally, the thickness of the second compressive stress layer 40 at the crest and the trough is greater than the thickness of the first compressive stress layer 20 , so as to improve the mechanical strength of the tempered glass 1 on the side where the second compressive stress layer 40 is provided.

[0051] When the second compressive stress layer 40 is generated on one side of the strengthened glass 1, in order to form a wavy surface of the second compressive stress layer 40, the surface of the strengthened glass 1 facing away from the microcrystalline layer 30 is partially shielded before strengthening, so that the surface of the strengthened glass 1 is covered with a coating. This coating can block ion exchange between the glass and the molten salt, so that the second compressive stress layer 40 forms troughs in the areas covered by the coating and forms peaks in the areas not covered by the coating.

[0052] The shielding area of ​​the coating on the surface of the strengthened glass 1 facing away from the microcrystalline layer 30 is 10% to 50% of the area of ​​the surface of the strengthened glass 1 facing away from the microcrystalline layer 30 .

[0053] By making the surface of the first compressive stress layer 20 facing away from the microcrystalline layer 30 perpendicular to the thickness direction, and the surface of the second compressive stress layer 40 facing the first compressive stress layer 20 being wavy with multiple crests and troughs alternately distributed, the first compressive stress layer 20 and the second compressive stress layer 40 are asymmetrically arranged, that is, the two opposite sides of the tempered glass 1 are asymmetrically arranged.

[0054] When the tempered glass 1 is impacted from the side having the microcrystalline layer 30 and the first compressive stress layer 20, the side having the second compressive stress layer 40 is subjected to a greater impact force, resulting in a greater deformation of the side having the second compressive stress layer 40. This causes the surface of the second compressive stress layer 40 facing the first compressive stress layer 20 to be wavy. This helps the second compressive stress layer 40 to generate compressive stress in both the thickness direction and the direction perpendicular to the thickness to resist the impact force, thereby improving the resistance of the second compressive stress layer 40 to impact forces in different directions, thereby improving the mechanical properties of the tempered glass 1, and making the tempered glass 1 have better drop resistance and impact resistance.

[0055] In one embodiment, referring to FIG. 1 , a distance is provided in the thickness direction between the surface of the first compressive stress layer 20 facing the second compressive stress layer 40 and the extreme point of the wave crest of the second compressive stress layer 40. This ensures a spacing between the first and second surfaces of the substrate 10, thereby ensuring the thickness of the substrate 10, preventing complete modification of the glass, and maintaining the overall strength of the strengthened glass 1.

[0056] In one embodiment, referring to FIG. 1 , the thickness of the second compressive stress layer 40 at multiple wave crests is equal, and the thickness of the second compressive stress layer 40 at multiple wave troughs is equal, so that the thickness of the second compressive stress layer 40 is regularly and evenly alternating, ensuring that the second compressive stress layer 40 has a comparable ability to hinder further expansion of microcracks at multiple wave crests, and has a comparable ability to hinder further expansion of microcracks at multiple wave troughs.

[0057] In one embodiment, referring to FIG. 1 , the second compressive stress layer 40 satisfies the relationship: 0.2 ≤ L2 / L3 ≤ 0.8, where L2 is the thickness of the second compressive stress layer 40 at the trough, and L3 is the thickness of the second compressive stress layer 40 at the peak. Preferably, the thickness of the second compressive stress layer 40 at the trough is 50 μm-160 μm, and the thickness of the second compressive stress layer 40 at the peak is 100 μm-200 μm.

[0058] By ensuring that the second compressive stress layer 40 satisfies the above relationship, the difference between the thickness of the second compressive stress layer 40 at the trough and the thickness of the second compressive stress layer 40 at the peak can be reasonably set. This helps the second compressive stress layer 40 generate compressive stress that resists impact forces in both the thickness direction and the direction perpendicular to the thickness, thereby improving the resistance of the second compressive stress layer 40 to impact forces in different directions, thereby improving the mechanical properties of the tempered glass 1, and making the tempered glass 1 have better drop resistance and impact resistance.

[0059] In one embodiment, referring to FIG. 1 , the second compressive stress layer 40 and the strengthened glass 1 satisfy the relationship: 0.1 ≤ L3 / L ≤ 0.4, where L3 is the thickness of the second compressive stress layer 40 at the wave crest, and L is the overall thickness of the strengthened glass 1. Preferably, the overall thickness of the strengthened glass 1 is 0.3 mm to 3 mm.

[0060] By ensuring that the second compressive stress layer 40 and the tempered glass 1 satisfy the aforementioned relationship, the thickness of the second compressive stress layer 40 at the wave crest is appropriately set, thereby preventing the second compressive stress layer 40 from being too thick and ensuring the overall strength of the tempered glass 1. The second compressive stress layer 40 can effectively hinder the expansion of microcracks within the tempered glass 1, thereby improving the mechanical properties of the tempered glass 1 and providing the tempered glass 1 with better drop resistance and impact resistance.

[0061] In one embodiment, referring to FIG1 , the first compressive stress layer 20 and the strengthened glass 1 satisfy the relationship: 0.1 ≤ L4 / L ≤ 0.4, where L4 is the thickness of the first compressive stress layer 20 and L is the overall thickness of the strengthened glass 1. Preferably, the thickness of the first compressive stress layer 20 is 100 μm to 200 μm.

[0062] By ensuring that the first compressive stress layer 20 and the tempered glass 1 satisfy the above relationship, the thickness of the first compressive stress layer 20 can be reasonably set, thereby preventing the first compressive stress layer 20 from being too thick and ensuring the overall strength of the tempered glass 1. The first compressive stress layer 20 can effectively hinder the expansion of microcracks within the tempered glass 1, thereby improving the mechanical properties of the tempered glass 1 and providing the tempered glass 1 with better drop resistance and impact resistance.

[0063] In one embodiment, referring to FIG. 2 , the tempered glass 1 further includes a third compressive stress layer 50 and a fourth compressive stress layer 60. The third compressive stress layer 50 is located on the side of the microcrystalline layer 30 facing away from the first compressive stress layer 20, and the fourth compressive stress layer 60 is located on the side of the second compressive stress layer 40 facing away from the substrate 10. The third and fourth compressive stress layers 50, 60 further hinder the propagation of microcracks within the tempered glass 1, thereby improving the mechanical properties of the tempered glass 1 and imparting enhanced drop and impact resistance.

[0064] In one embodiment, the hardness of the microcrystalline layer 30 is greater than the hardness of other portions of the first compressive stress layer 20 .

[0065] The present application also provides an electronic device 2, refer to Figure 1, including the tempered glass 1 described in any of the above embodiments, wherein the surface of the microcrystalline layer 30 of the tempered glass 1 facing away from the second compressive stress layer 40 faces the external space of the electronic device 2, and the surface of the second compressive stress layer 40 of the tempered glass 1 facing away from the microcrystalline layer 30 faces the internal space 200 of the electronic device 2.

[0066] The surface of the tempered glass 1 provided with the microcrystalline layer 30 serves as the direct contact surface between the electronic device 2 and the external environment. The microcrystalline layer 30 increases the surface hardness of the direct contact surface between the tempered glass 1 and the external environment. The surface of the tempered glass 1 provided with the second pressure layer serves as the surface located inside the electronic device 2. When subjected to an external impact, the surface of the tempered glass 1 facing the inside of the electronic device 2 undergoes the greatest deformation. The second pressure layer helps to improve the impact resistance of the surface of the tempered glass 1 located inside the electronic device 2.

[0067] In one embodiment, referring to FIG. 4 , the present application further provides an electronic device 2. The electronic device 2 includes the tempered glass 1 shown in FIG. The surface of the third compressive stress layer 50 of the tempered glass 1 facing away from the fourth compressive stress layer 60 faces the exterior of the electronic device 2, while the surface of the fourth compressive stress layer 60 of the tempered glass 1 facing away from the third compressive stress layer 50 faces the interior space 200 of the electronic device 2. This allows the surface of the tempered glass 1 provided with the third compressive stress layer 50 to serve as the direct contact surface between the electronic device 2 and the external environment. The third compressive stress layer 50 increases the surface hardness of the surface of the tempered glass 1 in direct contact with the external environment. The surface of the tempered glass 1 provided with the fourth compressive stress layer 60 serves as the surface located within the interior of the electronic device 2. When subjected to an external impact, the surface of the tempered glass 1 facing the interior of the electronic device 2 experiences the greatest deformation. The fourth compressive stress layer 60 helps improve the impact resistance of the surface of the tempered glass 1 located within the interior of the electronic device 2.

[0068] It can be understood that the electronic device 2 in this embodiment includes the tempered glass 1 in the above-mentioned embodiment. Therefore, the electronic device 2 in this embodiment has all the technical effects of the tempered glass 1 in the above-mentioned embodiment. Since the technical effects of the tempered glass 1 have been fully described in the above-mentioned embodiment, they will not be repeated here.

[0069] The present application also provides a method for preparing a tempered glass 1. Referring to FIG. 3 , the method for preparing the tempered glass 1 includes:

[0070] Step S10: Cutting, engraving, hot bending, polishing and other processes are performed on the glass to form a flat or curved glass with a certain shape;

[0071] Step S20: spreading a layer of CuCl on the surface of the processed glass to diffuse copper ions into the surface layer of the glass, then cleaning the glass and heat-treating the glass to precipitate crystals on the surface layer of the glass, thereby obtaining glass including a microcrystalline layer 30;

[0072] Step S30: partially covering the surface of the glass facing away from the microcrystalline layer 30 with a coating to perform a first strengthening, thereby obtaining a strengthened glass 1 including a first compressive stress layer 20 and a second compressive stress layer 40 on both sides;

[0073] Step S40 : removing the coating on the surface of the strengthened glass 1 and performing a second strengthening process to obtain the strengthened glass 1 including the third compressive stress layer 50 and the fourth compressive stress layer 60 on both sides.

[0074] Wherein, in step S20, the reaction temperature of CuCl and glass is 500°C-700°C, and the reaction time is 0.1h-5h; the reaction temperature of heat treatment of the cleaned glass is 600°C-800°C, and the reaction time is 0.5h-5h.

[0075] In step S30, the glass is immersed in a first molten salt for a first strengthening. The first molten salt contains sodium ions. The sodium ions of the first molten salt are exchanged with the lithium ions of the glass, forming a first compressive stress layer 20 and a second compressive stress layer 40 on opposite sides of the glass, respectively. Since the surface of the glass facing away from the microcrystalline layer 30 is partially covered with a coating, the coating hinders the exchange of sodium ions and lithium ions, resulting in an uneven thickness distribution of the second compressive stress layer 40, and the surface of the second compressive stress layer 40 facing the first compressive stress layer 20 is wavy.

[0076] In step S40, the tempered glass 1 is immersed in a second molten salt for a second strengthening. The second molten salt contains potassium ions. The potassium ions of the second molten salt are exchanged with the sodium ions and lithium ions of the tempered glass 1, forming a shallow third compressive stress layer 50 and a shallow fourth compressive stress layer 60 on opposite sides of the tempered glass 1, respectively. The third compressive stress layer 50 is located on the side of the microcrystalline layer 30 facing away from the first compressive stress layer 20, and the fourth compressive stress layer 60 is located on the side of the second compressive stress layer 40 facing away from the substrate 10.

[0077] It should be understood that during the first strengthening, large-sized ions (eg, sodium ions) diffuse into the interior of the glass, and the diffusion depth of the large ions is equal to the thickness of the stress layer. Optionally, the diffusion depth of the large-sized ions is greater than the thickness of the microcrystalline layer 30.

[0078] The technical solution of this application is described in detail below through specific implementation methods.

[0079] Implementation Method 1

[0080] This embodiment provides a tempered glass 1 and a preparation method thereof, comprising the following steps:

[0081] (1) Lithium aluminum silicate glass is processed into curved glass with a size of 155mm*70mm*0.5mm through CNC, hot bending, polishing and other processes;

[0082] (2) spreading a layer of CuCl on the surface of the processed glass at a reaction temperature of 600° C. for 1 hour to diffuse copper ions into the surface layer of the glass, then cleaning the glass and heat-treating the glass at a heat treatment temperature of 700° C. for 1 hour to precipitate crystals on the surface layer of the glass, thereby obtaining glass including a microcrystalline layer 30;

[0083] (3) partially covering the surface of the glass facing away from the microcrystalline layer 30 with a coating, where the area of ​​the coating is 20% of the area of ​​the surface of the glass facing away from the microcrystalline layer 30, and performing a first strengthening to obtain a strengthened glass 1 including a first compressive stress layer 20 and a second compressive stress layer 40;

[0084] (4) The coating on the surface of the strengthened glass 1 is removed, and the strengthened glass 1 is strengthened for the second time to obtain the strengthened glass 1 including the third compressive stress layer 50 and the fourth compressive stress layer 60 .

[0085] Implementation Method 2

[0086] This embodiment provides a tempered glass 1 and a preparation method thereof. The difference from embodiment 1 is that the reaction time of CuCl and glass in step (2) is 2 hours, and the area of ​​the coating in step (3) is 30% of the surface area of ​​the glass facing away from the microcrystalline layer 30.

[0087] Comparative Example 1 provides a tempered glass 1 and a preparation method thereof. The difference between Comparative Example 1 and Implementation Example 1 is that step (2) and step (3) are not included.

[0088] To illustrate the mechanical properties of the tempered glass 1 provided in Embodiment 1, the following tests were performed:

[0089] Sandpaper drop test: Using a mobile phone as an example, this test simulates a drop of the entire device onto sandpaper. The glass is placed on a protective middle frame with a 200g counterweight. Using a directional drop tester, the glass is subjected to free fall from various heights. The glass, with the surface of the microcrystalline layer 30, touches the marble floor lined with 180-grit sandpaper. The height at which the glass breaks is recorded.

[0090] Drop ball impact test: The glass is placed on a profiling jig and a steel ball is used to hit the surface of the glass with the microcrystalline layer 30 from different heights. The impact energy of the glass is calculated. The glass is subjected to a four-point bending drop ball impact test. The test results are shown in Table 1 below:

[0091] Table 1

[0092] From the analysis of Table 1, it can be seen that the impact resistance of the tempered glass 1 in Embodiment 1 and Embodiment 2 is significantly improved.

[0093] In the description of the implementation methods of the present application, it should be noted that the orientation or position relationship of terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", and "outside" are based on the orientation or position relationship of the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or original referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0094] The above disclosure is only a preferred embodiment of the present application, and it is certainly not intended to limit the scope of the rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present application are still within the scope covered by the present application.

Claims

1. A tempered glass (1), characterized in that: include: A substrate (10) comprising a first surface and a second surface opposite to each other; A first compressive stress layer (20) is disposed on the first surface, wherein the first compressive stress layer (20) comprises a microcrystalline layer (30), and the microcrystalline layer (30) is located on a side of the first compressive stress layer (20) facing away from the substrate (10); as well as A second compressive stress layer (40) is arranged on the second surface, with the direction from the first surface to the second surface being the thickness direction, and the thickness uniformity of the first compressive stress layer (20) is greater than the thickness uniformity of the second compressive stress layer (40).

2. The tempered glass (1) according to claim 1, characterized in that: The microcrystalline layer (30), the first compressive stress layer (20), the substrate (10), and the second compressive stress layer (40) are an integrated structure.

3. The tempered glass (1) according to claim 1 or 2, characterized in that: The microcrystalline layer (30) and the strengthened glass (1) satisfy the relationship: 0.001≤L1 / L≤0.2; wherein L1 is the thickness of the microcrystalline layer (30), and L is the overall thickness of the strengthened glass (1).

4. The tempered glass (1) according to any one of claims 1 to 3, characterized in that: The area of ​​the orthographic projection of the microcrystalline layer (30) on the substrate (10) is smaller than or equal to the area of ​​the orthographic projection of the first compressive stress layer (20) on the substrate (10).

5. The tempered glass (1) according to any one of claims 1 to 4, characterized in that: The surface of the first compressive stress layer (20) facing away from the microcrystalline layer (30) is perpendicular to the thickness direction, and the surface of the second compressive stress layer (40) facing the first compressive stress layer (20) is wavy and has a plurality of wave crests and a plurality of wave troughs that are alternately distributed.

6. The tempered glass (1) according to claim 5, characterized in that: In the thickness direction, there is a distance between the surface of the first compressive stress layer (20) facing the second compressive stress layer (40) and the extreme point of the second compressive stress layer (40) at the wave crest.

7. The tempered glass (1) according to claim 5 or 6, characterized in that: The thickness of the second compressive stress layer (40) at the plurality of wave crests is equal, and the thickness of the second compressive stress layer (40) at the plurality of wave troughs is equal.

8. The tempered glass (1) according to any one of claims 5 to 7, characterized in that: The second compressive stress layer (40) satisfies the relationship: 0.2≤L2 / L3≤0.8; wherein L2 is the thickness of the second compressive stress layer (40) at the wave valley, and L3 is the thickness of the second compressive stress layer (40) at the wave peak.

9. The tempered glass (1) according to any one of claims 5 to 7, characterized in that: The second compressive stress layer (40) and the strengthened glass (1) satisfy the relationship: 0.1≤L3 / L≤0.4; wherein L3 is the thickness of the second compressive stress layer (40) at the wave crest, and L is the overall thickness of the strengthened glass (1).

10. The tempered glass (1) according to any one of claims 1 to 9, characterized in that: The first compressive stress layer (20) and the strengthened glass (1) satisfy the relationship: 0.1≤L4 / L≤0.4; wherein L4 is the thickness of the first compressive stress layer (20), and L is the overall thickness of the strengthened glass (1).

11. The tempered glass (1) according to any one of claims 1 to 10, characterized in that: The size of the crystal phase of the microcrystalline layer (30) is 5nm-150nm.

12. The tempered glass (1) according to any one of claims 1 to 11, characterized in that: The strengthened glass (1) further comprises a third compressive stress layer (50) and a fourth compressive stress layer (60), wherein the third compressive stress layer (50) is located on a side of the microcrystalline layer (30) facing away from the first compressive stress layer (20), and the fourth compressive stress layer (60) is located on a side of the second compressive stress layer (40) facing away from the substrate (10).

13. The tempered glass (1) according to any one of claims 1 to 12, characterized in that: The hardness of the microcrystalline layer (30) is greater than the hardness of other parts of the first compressive stress layer (20).

14. The tempered glass (1) according to any one of claims 1 to 13, characterized in that: The difference between the maximum thickness and the minimum thickness of the first compressive stress layer (20) is smaller than the difference between the maximum thickness and the minimum thickness of the second compressive stress layer (40).

15. An electronic device (2), characterized in that: The tempered glass (1) comprises the tempered glass (1) as claimed in any one of claims 1 to 14, wherein the surface of the microcrystalline layer (30) of the tempered glass (1) facing away from the second compressive stress layer (40) faces the external space of the electronic device (2), and the surface of the second compressive stress layer (40) of the tempered glass (1) facing away from the microcrystalline layer (30) faces the internal space (200) of the electronic device (2).

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