Display panel, cover plate and method for preparing cover plate

Abstract

The present application provides a display panel, a cover plate and a method for preparing the cover plate, wherein the cover plate includes a main body, and the material of the main body includes transparent aluminum oxynitride ceramic, and the crystal phase structure of the transparent aluminum oxynitride ceramic includes a spinel crystal phase, thereby achieving 3D hot bending forming of the cover plate while ensuring hardness and mechanical properties.

Description

Technical Field

[0001] The present application relates to the field of display, and in particular to a display panel, a cover plate, and a method for preparing the cover plate. Background Art

[0002] The cover plate is mainly used as the outermost layer of the display panel of electronic consumer products to protect other structural layers in the display panel. It is also called optical glass, glass window, etc. The main material of the cover plate is ultra-thin flat glass. After processing, it can have functions such as impact resistance, scratch resistance, oil resistance, anti-fingerprint, and enhanced light transmittance.

[0003] At present, the mainstream cover materials are mainly aluminosilicate glass and lithium-based glass. The internal structure of these two types of glass is usually a short-range disordered molecular structure, which has limitations on the mechanical properties of the cover glass. In order to improve the hardness and mechanical properties of the product, sapphire glass with a highly dense interior has gradually become the mainstream choice of cover materials. However, since the interior of sapphire glass is an extremely dense hexagonal cubic crystal of aluminum oxide, the existing process cannot meet the 3D hot bending of sapphire glass, so the cover using sapphire glass as the main material has great limitations.

[0004] Therefore, there is an urgent need to find a new cover material that can achieve 3D hot bending of the cover while ensuring hardness and mechanical properties. Summary of the invention

[0005] The display panel, cover plate and method for preparing the cover plate provided in the present application can solve the problem that the existing cover plate cannot achieve 3D hot bending forming of the cover plate while having both hardness and mechanical properties.

[0006] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a cover plate, applied to the display panel, the cover plate includes a main body, the material of the main body includes transparent aluminum oxynitride ceramic, and the crystal phase structure of the transparent aluminum oxynitride ceramic includes a spinel crystal phase.

[0007] In one embodiment, the thickness of the cover plate is 0.2 mm-0.8 mm.

[0008] In one embodiment, the crystallinity of the spinel crystal phase in the aluminum oxynitride transparent ceramic of the spinel crystal phase type is 70%-85%.

[0009] In one embodiment, the crystal size of the spinel crystal phase in the aluminum oxynitride transparent ceramic is 15nm-50nm.

[0010] In one embodiment, the volume density of the cover plate is 2.85 g / cm 3 -4.0g / cm 3 .

[0011] In one embodiment, the hardness of the cover plate is 170 Gpa-200 Gpa.

[0012] In one embodiment, the cover plate further comprises an optical layer, and the optical layer is located on the surface of the main body; wherein the optical transmittance of the main body is greater than 85%; and the optical transmittance of the cover plate is greater than 90.5%.

[0013] In order to solve the above technical problems, another technical solution adopted in the present application is: providing a display panel, including a cover plate and a screen body, the cover plate is the cover plate described in any of the above items; the screen body includes a substrate and a light-emitting layer arranged on the substrate, and the cover plate is arranged on the side of the light-emitting layer away from the substrate.

[0014] To solve the above technical problems, another technical solution adopted in the present application is: to provide a method for preparing a cover plate, comprising: sintering a combined powder containing aluminum oxide, nitrogen and a first auxiliary agent in a sintering furnace according to a first preset condition to obtain a first embryonic body, wherein the first embryonic body contains single-phase aluminum oxynitride transparent ceramic particles; after the first embryonic body is formed, introducing a second auxiliary agent into the sintering furnace and sintering in the sintering furnace according to a second preset condition to obtain a second embryonic body, wherein the second embryonic body contains aluminum oxynitride transparent ceramic particles in a spinel crystal phase; sintering the second embryonic body according to a third preset condition, and then grinding and polishing.

[0015] In one embodiment, the first preset condition includes a first sintering heating rate, a first sintering temperature and a first sintering time, the first sintering heating rate is 600°C / min-900°C / min, the first sintering temperature is 740°C-780°C, and the first sintering time is 0.4h-0.6h; the second preset condition includes a second sintering heating rate, a second sintering temperature and a second sintering time, the second sintering heating rate is 300°C / min-400°C / min, the second sintering temperature is 850°C-900°C, and the second sintering time is 0.8h-1.2h; the third preset condition includes a third sintering temperature and a third sintering time, the third sintering temperature is 1 00℃-120℃, the third sintering time is 1.5h-2.5h; the combined powder comprises: 30%-40% by mass of SiO2, 22%-32% by mass of Al2O3, 18%-26% by mass of CaO, 7%-12% by mass of MgO, 0.2%-5% by mass of Fe2O3, 0.1%-3% by mass of Cr2O3, 7%-13% by mass of TiO2, 5%-10% by mass of P2O5, and 2.2%-4.5% by mass of ZnO; the first auxiliary agent comprises hydrogen, carbon, ammonia and aluminum powder; the second auxiliary agent comprises at least one of SiC, GeO2, PbO and CdO.

[0016] Different from the prior art, the display panel, cover plate and method for preparing the cover plate provided in the present application, the cover plate includes a main body, and the material of the main body includes transparent aluminum oxynitride ceramic, and the crystal phase structure of the transparent aluminum oxynitride ceramic includes a spinel crystal phase, thereby achieving 3D hot bending forming of the cover plate while ensuring hardness and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of an embodiment of a display panel provided by the present application;

[0018] Figure 2 Yes Figure 1 A partial cross-sectional view of the display panel along line AA is shown;

[0019] Figure 3 It is a schematic flow chart of an embodiment of a method for preparing a cover plate provided in the present application;

[0020] Figure 4 It is a partial cross-sectional view along line AA of another embodiment of the display panel provided in the present application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] The terms "first", "second", "third" in this application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", "third" can expressly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the embodiments of this application, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the steps or units listed, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0023] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] The present application is described in detail below with reference to the accompanying drawings and embodiments.

[0025] See also Figure 1 and Figure 2 , Figure 1 is a schematic structural diagram of an embodiment of a display panel provided by the present application; Figure 2 Yes Figure 1 The shown figure is a partial cross-sectional view of the display panel along line AA.

[0026] The display panel 100 provided in the present application is a multi-layer stacked structure, including a cover plate 10 and a screen body 20. The screen body 20 includes a substrate 21, a light-emitting layer 22 disposed on the substrate 21, and the cover plate 10 is disposed on the side of the light-emitting layer 22 away from the substrate 21, and is used to increase the surface hardness and wear resistance of the display panel 100, so that it has functions such as anti-impact, scratch-resistant, oil-resistant, and anti-fingerprint. The cover plate 10 has a high optical transmittance, allowing the light emitted from the light-emitting layer 22 to pass through the cover plate 10, thereby bringing a visual experience to the user.

[0027] Among them, other film layers (not shown) may be further arranged between the cover plate 10 and the screen body 20, for example, a packaging layer, which may be a rigid packaging or a flexible packaging, to prevent air, moisture, etc. from penetrating into the screen body 20, thereby avoiding damage to components and circuits in the display panel 100.

[0028] Among them, the cover plate 10 provided by the present application includes a main body 11, and the material of the main body 11 includes aluminum oxynitride (AlON) transparent ceramic, which is a transparent polycrystalline ceramic, and its strength and hardness are second only to single crystal sapphire, and it has good optical transmittance from near ultraviolet (0.2μm) to mid-infrared (6.0μm), which can meet the requirements of the cover plate 10 for hardness, mechanical properties and optical transmittance. And the crystal phase structure of aluminum oxynitride transparent ceramic includes spinel crystal phase (γ-AlON). Specifically, in the crystal phase system, aluminum oxynitride transparent ceramics belong to the AlN-Al2O3 binary system, and generally have a wurtzite structure and a spinel structure in structure. The γ-AlON polycrystalline phase is usually a spinel phase, which has excellent optical, mechanical and thermophysical properties. Therefore, using aluminum oxynitride transparent ceramics with spinel crystal phase as the cover plate 10, 3D hot bending of the cover plate 10 can be achieved, so that the display panel 100 can form a curved screen, a full screen, a folding screen, etc., to adapt to the development trend of the display panel 100.

[0029] Among them, the chemical formula of aluminum oxynitride transparent ceramic is Al (64+x) / 3 O (32-x) N x , x=[2,25]. Specifically, the value of x is strongly related to the structural characteristics of the aluminum oxynitride transparent ceramic. Under the condition of meeting the dual requirements of the cover plate 10 for optics and mechanics, according to the above chemical formula, when the value of x is larger, the content of Al and N elements is higher, the content of O element is lower, and the mechanical properties of the aluminum oxynitride transparent ceramic are better; when the value of x is smaller, the content of Al and N elements is lower, the content of O element is higher, and the optical properties of the aluminum oxynitride transparent ceramic are better. The value of x needs to be adjusted within the allowable range.

[0030] Among them, due to the limitation of crystal size, the transparent cover plate 10 made of the existing spinel crystal phase aluminum oxynitride transparent ceramic is relatively thick, and its thickness is generally more than ten millimeters or even dozens of millimeters. However, the thickness of the cover plate 10 in the display panel 100 is generally required to be less than 0.7 mm. The existing spinel crystal phase aluminum oxynitride transparent ceramic cannot meet the requirements of the cover plate 10.

[0031] Therefore, see Figure 3 , Figure 3 1 is a flow chart of an embodiment of a method for preparing a cover plate provided in the present application. The present application provides a method for preparing a cover plate 10, comprising:

[0032] Step S1: sintering a composite powder containing aluminum oxide, nitrogen and a first auxiliary agent in a sintering furnace according to first preset conditions to obtain a first embryonic body.

[0033] Specifically, the first auxiliary agent includes hydrogen, carbon, ammonia and aluminum powder; the combined powders forming the aluminum oxynitride transparent ceramic include SiO2, Al2O3, CaO, MgO, Fe2O3, Cr2O3, TiO2, P2O5 and ZnO, and 30% to 40% by mass of SiO2, 22% to 32% by mass of Al2O3, 18% to 26% by mass of CnO are added according to the molar ratio of the binary phase diagram of the spinel crystal phase of the aluminum oxynitride transparent ceramic. aO, 7%-12% by mass of MgO, 0.2%-5% by mass of Fe2O3, 0.1%-3% by mass of Cr2O3, 7%-13% by mass of TiO2, 5%-10% by mass of P2O5 and 2.2%-4.5% by mass of ZnO are mixed, and carbon and aluminum powder are added and dry pressed into shape, and then put into a sintering furnace and hydrogen, nitrogen and ammonia are introduced under the first preset conditions for high-temperature sintering to obtain a first embryo body. The first embryo body contains single-phase aluminum oxynitride transparent ceramic particles.

[0034] Among them, the first preset condition includes a first sintering heating rate, a first sintering temperature and a first sintering time, the first sintering heating rate is 600℃ / min-900℃ / min, the first sintering temperature is 740℃-780℃, and the first sintering time is 0.4h-0.6h. In this application, the sintering furnace is a silicon-molybdenum rod resistance furnace, and the first sintering heating rate is set to 700℃ / min, the first sintering temperature is 760℃, and the first sintering time is 0.5h.

[0035] Among them, SiO2 is an essential component of the skeleton of the cover plate 10. It can improve the network connection degree of the cover plate 10, the chemical resistance and mechanical strength of the cover plate 10. If the content is too high, the high-temperature viscosity of the cover plate 10 material will be increased, making it difficult to melt the cover plate 10 material. Therefore, the suitable SiO2 content in this application is 30%-40% by mass of SiO2.

[0036] Among them, Al2O3 is an intermediate of the cover plate 10. Within a certain content range, Al2O3 and SiO2 together form the main body of the network of the cover plate 10, greatly improving the mechanical strength and chemical stability of the cover plate 10. It also plays a very important role in ion exchange, making the network of the cover plate 10 more compact. However, if the content is too high, the cover plate 10 is difficult to melt. Therefore, the appropriate Al2O3 content of the present application is 22%-32% by mass of Al2O3.

[0037] Among them, CaO can improve the chemical stability and mechanical strength of the cover plate 10, has the effect of reducing high temperature viscosity and increasing low temperature viscosity, and makes it easier to melt the material of the cover plate 10. Therefore, the suitable CaO content of the present application is 18%-26% by mass of CaO.

[0038] Among them, MgO can reduce high temperature viscosity without reducing the strain point, making the cover plate 10 material easy to melt, which is beneficial to the melting of the cover plate 10 material and can improve the stability of the cover plate 10 material. Therefore, the suitable MgO content of the present application is 7%-12% by mass of MgO.

[0039] Among them, Fe2O3 can improve the melting efficiency of the cover plate 10. Fe2O3 will dissociate at a temperature of 1300°C, increasing the oxygen atmosphere in the melting process and improving the melting efficiency of the cover plate 10. However, too much iron will affect the hue of the glass. Therefore, the suitable Fe2O3 content in this application is 0.2%-5% by mass of Fe2O3.

[0040] Among them, Cr2O3 is the acceptor of valence electrons, which causes the local capacity in the structure of the cover plate 10 to change and cause self-nucleation, thereby promoting the microscopic nucleation inside the cover plate 10 material. Therefore, the suitable Cr2O3 content in this application is 0.1%-3% by mass of Cr2O3.

[0041] Among them, TiO2 is the main nucleation traction agent, which promotes the formation of metastable nucleation of materials in the initial nucleation stage and reduces the thermal expansion coefficient of the cover plate 10 material. Therefore, the suitable TiO2 content in this application is 7%-13% by mass of TiO2.

[0042] Among them, P2O5 can promote the change from needle-shaped crystals to rod-shaped crystals, improve the polarization properties of the material, generate internal stress inside the material, and increase the mechanical properties of the material; inhibit the coloring effect of iron ions in the cover plate 10, so the suitable P2O5 content in this application is 5%-10% by mass of P2O5.

[0043] The zinc element is located in the middle of the network space, and accumulates the surrounding silicon-oxygen tetrahedrons, improves the Young's modulus of the cover plate 10, improves the stability of the cover plate 10, and increases the ion exchange speed and depth. Therefore, the suitable ZnO content of the present application is 2.2%-4.5% by mass of ZnO.

[0044] Step S2: After the first embryonic body is formed, a second auxiliary agent is introduced into the sintering furnace and sintered in the sintering furnace according to second preset conditions to obtain a second embryonic body.

[0045] Specifically, the second additive includes at least one of SiC, GeO2, PbO and CdO. The second additive is used to strengthen the crystallization of the single-phase aluminum oxynitride transparent ceramic particles toward the composite phase, so that the second embryo formed after sintering the first embryo contains aluminum oxynitride transparent ceramic particles of spinel crystal phase.

[0046] The second preset condition includes a second sintering heating rate, a second sintering temperature and a second sintering time, the second sintering heating rate is 300°C / min-400°C / min, the second sintering temperature is 850°C-900°C, and the second sintering time is 0.8h-1.2h. In the present application, the second sintering heating rate is 350°C / h, the second sintering temperature is 850°C, and the second sintering time is 1h.

[0047] Step S3: sintering the second embryonic body according to the third preset condition, and then grinding and polishing.

[0048] Specifically, after the second embryo is formed, the second embryo is further sintered according to the third preset condition, and the sintered structure is densified by particle rearrangement and pore filling to ensure its optical transmittance. The third preset condition includes a third sintering temperature and a third sintering time, the third sintering temperature is 100°C-120°C, and the third sintering time is 1.5h-2.5h. In the present application, the third sintering temperature is 112°C, and the third sintering time is 2h.

[0049] Then, the aluminum oxynitride transparent ceramic containing the spinel crystal phase formed after sintering is subjected to grinding and polishing and other processes to obtain a cover substrate, and further, an optical layer can be coated to obtain the cover 10 of the present application.

[0050] Among them, during the whole sintering process, the pressure in the sintering furnace is 45Kpa-78Kpa, which can be determined according to the type of sintering furnace.

[0051] Specifically, through the preparation method of the cover plate 10 provided in the present application, the crystallinity of the spinel crystal phase in the obtained aluminum oxynitride transparent ceramic is 70%-85%, so that the aluminum oxynitride transparent ceramic cover plate 10 has excellent thermal physical properties, and thus the cover plate 10 can achieve 3D hot bending forming.

[0052] Specifically, through the preparation method of the cover plate 10 provided in the present application, the crystal size of the spinel crystal phase in the aluminum oxynitride transparent ceramic is 15nm-50nm. Specifically, the crystal size is strongly related to the optical transmittance of the material. The optical transmittance of the cover plate 10 material must meet the requirements, so the crystal size in the aluminum oxynitride transparent ceramic is required to be much smaller than the visible wavelength (340nm), and the more stable the crystal ball size, the better the optical transmittance of the cover plate 10. In addition, the crystal size is related to the crystallinity. To ensure that the crystallinity of the aluminum oxynitride transparent ceramic is within the specification value range, the crystal size is required to be no more than 50nm. Further, the crystal size is related to the mechanical properties and chemical stability of the material. As the outermost layer of the display panel 100, the cover plate 10 is particularly important for impact resistance. In order to ensure the macroscopic mechanical properties of the cover plate 10, the crystal size is required to be not less than 15nm. Therefore, the preferred crystal size of the spinel crystal phase in the aluminum oxynitride transparent ceramic is 20nm-30nm, so as to better meet the requirements of the crystallinity of the aluminum oxynitride transparent ceramic and the mechanical properties of the cover plate 10.

[0053] Specifically, through the preparation method of the cover plate 10 provided in the present application, the thickness of the cover plate 10 can be made as thin as 0.2mm-0.8mm, and the optical transmittance of the transparent aluminum oxynitride ceramic substrate is greater than 85%. By further coating an optical layer on the transparent aluminum oxynitride ceramic substrate, the optical transmittance of the cover plate 10 is greater than 90.5%, which can meet the requirements of the thickness and optical transmittance of the cover plate 10 in the display panel 100.

[0054] Specifically, through the preparation method of the cover plate 10 provided in the present application, the volume density of the cover plate 10 is 2.85 g / cm 3 -4.0g / cm 3 Specifically, the density of the cover plate 10 generally depends on its total composition. During the sintering process, the density of the cover plate 10 varies greatly. In order to stabilize the internal structure and macroscopic performance of the cover plate 10, the density of the cover plate 10 is set at 2.85 g / cm 3 -4.0g / cm 3 There is a small fluctuation between the values, but the most preferred density value is 3.6. At this density value, the processing cost of 3D hot bending of the cover plate 10 is the lowest.

[0055] Specifically, through the preparation method of the cover plate 10 provided in the present application, the hardness of the cover plate 10 is 170Gpa-200Gpa. Specifically, hardness is an inherent property of the material, which is related to its structure and component addition. The hardness of the cover plate 10 is required to be not less than 5H (pencil hardness). Because the cover plate 10 needs to undergo a strengthening process, the hardness requirement of the cover plate 10 material only needs to be not less than 170Gpa. However, considering the 3D hot bending process, the maximum hardness is set to be no greater than 200Gpa, so as to facilitate the 3D hot bending of the cover plate 10 and reduce the processing cost.

[0056] Specifically, through the preparation method of the cover plate 10 provided in the present application, the dielectric constant of the cover plate 10 is 9.0-9.6, so it has good insulation ability.

[0057] Specifically, through the preparation method of the cover plate 10 provided in the present application, the dielectric loss allowable value of the cover plate 10 is 0.001-0.002. Specifically, the smaller the dielectric loss, the better the quality of the cover plate 10 and the better the insulation performance. If the dielectric loss is too large, the temperature of the cover plate 10 will rise too high when the display panel 100 is working, which will accelerate the thermal decomposition and aging of the cover plate 10 and affect the product life.

[0058] Specifically, the preparation method of the cover plate 10 provided in the present application limits the specific components and content range of the combined powder, and controls the sintering temperature, sintering time and sintering pressure, so that the cover plate 10 prepared by the method can achieve 3D hot bending forming of the cover plate 10 while having both hardness and mechanical properties.

[0059] In one embodiment, see Figure 4 , Figure 4 : is a partial cross-sectional view along line AA of another embodiment of the display panel provided by the present application. The cover plate 10 includes a main body 11 and an optical layer 12 disposed on the surface of the main body 11. Among them, the material of the main body 11 includes transparent ceramics of aluminum oxynitride, and the optical transmittance of the main body 11 is greater than 85%, while the optical transmittance of the general cover plate 10 is required to be greater than 90.5%. The present application arranges the optical layer 12 on the surface of the main body 11, so that the optical transmittance of the cover plate 10 is greater than 90.5%. In this embodiment, the optical layer 12 is arranged on the surface of the main body 11 away from the screen body 20, and the optical layer can be an AR coating. Specifically, the AR coating is a multi-layer anti-reflection (AR) coating technology on the glass surface, which has the functions of reducing reflected light and anti-glare. By matching the refractive index and thickness of the AR coating, the light wave generates multi-beam interference in the AR coating, for example, destructive interference on the upper surface and constructive interference on the lower surface, which increases the emission of useful light, reduces the reflection of interference light, and increases the contrast, thereby making the optical transmittance of the cover plate 10 greater than 90.5%.

[0060] In the application, the optical layer 12 is a single-sided AR coating, which is disposed on the surface of the main body 11 facing away from the screen body 20, and the optical layer 12 is a single-sided three-layer AR coating (eg, ITO+SiO2+TiO2) to increase the optical transmittance of the cover plate 10.

[0061] Different from the prior art, the display panel 100, the cover plate 10 and the preparation method of the cover plate 10 provided in the present application, the cover plate 10 includes a main body 11, and the material of the main body 11 includes transparent aluminum oxynitride ceramic, and the crystal phase structure of the transparent aluminum oxynitride ceramic includes a spinel crystal phase, thereby achieving 3D hot bending forming of the cover plate 10 while ensuring hardness and mechanical properties.

[0062] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing a cover plate, characterized in that: include: Sintering a composite powder containing aluminum oxide, nitrogen and a first auxiliary agent in a sintering furnace according to first preset conditions to obtain a first embryonic body, wherein the first embryonic body comprises single-phase aluminum oxynitride transparent ceramic particles; After the first embryonic body is formed, a second auxiliary agent is introduced into the sintering furnace and sintered in the sintering furnace according to second preset conditions to obtain a second embryonic body, wherein the second embryonic body comprises transparent ceramic particles of aluminum oxynitride in a spinel crystal phase; sintering the second embryonic body according to a third preset condition, and then grinding and polishing the second embryonic body; Wherein, the first preset condition includes a first sintering heating rate, a first sintering temperature and a first sintering time, the first sintering heating rate is 600°C / min-900°C / min, the first sintering temperature is 740°C-780°C, and the first sintering time is 0.4h-0.6h; The second preset conditions include a second sintering heating rate, a second sintering temperature and a second sintering time, the second sintering heating rate is 300° C. / min-400° C. / min, the second sintering temperature is 850° C.-900° C., and the second sintering time is 0.8h-1.2h; The third preset condition includes a third sintering temperature and a third sintering time, the third sintering temperature is 100° C.-120° C., and the third sintering time is 1.5 h-2.5 h; The composite powder comprises: 30%-40% by mass of SiO2, 22%-32% by mass of Al2O3, 18%-26% by mass of CaO, 7%-12% by mass of MgO, 0.2%-5% by mass of Fe2O3, 0.1%-3% by mass of Cr2O3, 7%-13% by mass of TiO2, 5%-10% by mass of P2O5, and 2.2%-4.5% by mass of ZnO; The first auxiliary agent includes hydrogen, carbon, ammonia and aluminum powder; The second auxiliary agent includes at least one of SiC, GeO2, PbO and CdO.

2. A cover plate, applied to a display panel, characterized in that: The cover plate is prepared by the preparation method described in claim 1 above; The cover plate includes a main body, the material of the main body includes aluminum oxynitride transparent ceramic, and the crystal phase structure of the aluminum oxynitride transparent ceramic includes a spinel crystal phase.

3. The cover plate according to claim 2, characterized in that: The thickness of the cover plate is 0.2 mm-0.8 mm.

4. The cover plate according to claim 2, characterized in that: The crystallinity of the spinel crystal phase in the aluminum oxynitride transparent ceramic of the spinel crystal phase type is 70%-85%.

5. The cover plate according to claim 2, characterized in that: The crystal size of the spinel crystal phase in the aluminum oxynitride transparent ceramic is 15nm-50nm.

6. The cover plate according to claim 2, characterized in that: The volume density of the cover plate is 2.85 g / cm 3 -4.0g / cm 3 .

7. The cover plate according to claim 2, characterized in that: The hardness of the cover plate is 170Gpa-200Gpa.

8. The cover plate according to claim 2, characterized in that: The cover plate also includes: An optical layer, located on the surface of the main body; Among them, the optical transmittance of the main body is greater than 85%; the optical transmittance of the cover is greater than 90.5%.

9. A display panel, characterized in that: include: A cover plate, wherein the cover plate is the cover plate according to any one of claims 2 to 8; The screen body comprises a substrate and a light-emitting layer arranged on the substrate, and the cover plate is arranged on a side of the light-emitting layer away from the substrate.

Images