Qualitative analysis method for warping, coated glass, preparation method and electronic equipment

Abstract

The invention provides a qualitative analysis method for warping of a laminated structure, coated glass, a preparation method and electronic equipment. The laminated structure comprises multiple film layers which are sequentially laminated, the multiple film layers comprise n tensile stress layers and m compressive stress layers, the laminated structure has a neutral axis, the n tensile stress layers are sequentially laminated on the same side of the neutral axis, and the m compressive stress layers are sequentially laminated on the other side of the neutral axis. The surface, away from the neutral axis, of the pressure stress layer farthest from the neutral axis is a preset surface, and the qualitative analysis method comprises the steps that the warping radius 1 / rho of the laminated structure is calculated according to a relational expression (1), the relational expression (1) is # imgabs0 #, and the warping degree of the laminated structure is predicted according to the warping radius of the laminated structure. The embodiment of the invention provides a qualitative analysis method for warping of a laminated structure, which can predict the warping degree of the laminated structure and has high accuracy.

Description

Technical Field

[0001] The present application relates to the field of electronics, and in particular to a qualitative analysis method for warping of a laminated structure, coated glass and a preparation method thereof, and electronic equipment. Background Art

[0002] The coating process on glass is to form a functional thin film on the surface of the glass by means of physical deposition. This thin film can change the optical properties of the glass, such as enhancing reflection and improving light transmittance, so as to achieve the purpose of beautification, heat insulation, sun protection and other functions. During the coating process, due to the influence of various factors such as materials, processes and environment, the coating layer often warps. Warping not only reduces the functionality and aesthetics of the coated product, but may also cause structural failure and affect the product life. However, in the related art, it is impossible to evaluate the warping risk of glass coating before coating. Summary of the invention

[0003] The embodiment of the present application provides a qualitative analysis method for the warping of a laminated structure, which can predict the degree of warping of the laminated structure with a high accuracy.

[0004] In a first aspect, an embodiment of the present application provides a qualitative analysis method for warping of a laminated structure, wherein the laminated structure comprises a plurality of film layers stacked in sequence, wherein the plurality of film layers comprises n tensile stress layers and m compressive stress layers, wherein the laminated structure has a neutral axis, wherein the n tensile stress layers are stacked in sequence on the same side of the neutral axis, wherein the m compressive stress layers are stacked in sequence on the other side of the neutral axis, wherein the surface of the compressive stress layer farthest from the neutral axis and away from the neutral axis is a preset surface, wherein the qualitative analysis method comprises:

[0005] The warping radius 1 / ρ of the stacked structure is calculated according to the relation (1), which is:

[0006]

[0007] Where, ρ is the curvature of the neutral axis, ε u is the uniform strain of the laminate structure, ΔT is the difference between the processing temperature and the room temperature of the laminate structure; i ranges from 1 to n; E i is the elastic modulus of the tensile stress layer in the direction from the compressive stress layer to the tensile stress layer; α i is the thermal expansion coefficient of the i-th tensile stress layer in the direction from the compressive stress layer to the tensile stress layer; z i is the distance from the surface of the i-th tensile stress layer facing the neutral axis to the preset surface; i+1 is the distance from the surface of the i-th tensile stress layer away from the neutral axis to the preset surface; j is 1 to m, E jα is the elastic modulus of the j-th compressive stress layer in the direction from the compressive stress layer to the tensile stress layer; j is the thermal expansion coefficient of the jth compressive stress layer in the direction from the compressive stress layer to the tensile stress layer; z j is the distance from the surface of the j-th tensile stress layer facing the neutral axis to the preset surface; j+1 is the distance from the surface of the j-th tensile stress layer away from the neutral axis to the preset surface; and

[0008] The warping degree of the stacked structure is predicted according to the warping radius of the stacked structure.

[0009] A second aspect of the present application provides a method for preparing coated glass. Before the coated glass is prepared, the degree of warping of the coated glass is predicted using the qualitative analysis method for warping of the laminated structure described in the embodiment of the present application.

[0010] A third aspect of the present application provides a coated glass, wherein the coated glass comprises a glass layer and a coating layer which are stacked, and the coated glass is prepared by the method for preparing coated glass described in the embodiment of the present application.

[0011] A fourth aspect of the present application provides an electronic device, comprising:

[0012] Display screen;

[0013] The coated glass described in the embodiment of the present application; and

[0014] A processor is electrically connected to the display screen and is used to control the display screen to display.

[0015] In the qualitative analysis method of the warping of the laminated structure of the application embodiment, the relationship (1) is used to calculate the warping radius 1 / ρ of the laminated structure. According to the size of the warping radius 1 / ρ of the laminated structure, the warping condition of the laminated structure can be predicted according to the material of each film layer of the laminated structure and the preparation process of the laminated structure, thereby providing a better improvement direction for the preparation and design of the laminated structure. In addition, the relationship (1) of the present application has been verified to be able to accurately predict the degree of warping of the laminated structure, with high calculation accuracy and short analysis cycle, which can greatly improve the preparation efficiency of the laminated structure and reduce the preparation cost of the laminated structure. Furthermore, the qualitative analysis method of the warping of the laminated structure of the present application does not require a large amount of experimental equipment and personnel investment, and can significantly reduce costs compared to experimental methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a schematic flow chart of a qualitative analysis method for warping of a stacked structure according to an embodiment of the present application.

[0018] Figure 2 It is a schematic structural diagram of a stacked structure according to an embodiment of the present application.

[0019] Figure 3 It is a schematic flow chart of a qualitative analysis method of warpage of a laminated structure according to another embodiment of the present application.

[0020] Figure 4 It is a schematic diagram of a flow chart of obtaining the relational expression (1) according to an embodiment of the present application.

[0021] Figure 5 Schematic diagram of the internal stress of the laminated structure according to an embodiment of the present application.

[0022] Figure 6 It is a schematic structural diagram of a laminated structure that is bent or warped in one embodiment of the present application.

[0023] Figure 7 It is a schematic diagram of a flow chart of obtaining the relational expression (2) according to an embodiment of the present application.

[0024] Figure 8 It is a schematic structural diagram of coated glass according to an embodiment of the present application.

[0025] Fig. 9 It is a schematic structural diagram of coated glass according to another embodiment of the present application.

[0026] Fig.10 It is a schematic diagram of the structure of an electronic device according to an embodiment of the present application.

[0027] Fig.11 It is a schematic diagram of a partial exploded structure of an electronic device according to an embodiment of the present application.

[0028] Fig.12 It is a circuit block diagram of an electronic device according to an embodiment of the present application.

[0029] Description of reference numerals:

[0030] 100-laminated structure, 10-film layer, 10a-tensile stress layer, 10b-compressive stress layer, 11-neutral axis, 12-preset surface, 200-coated glass, 210-glass layer, 220-coating layer, 300-electronic device, 310-display screen, 320-middle frame, 330-processor, 340-housing, 350-memory, 370-camera module, 341-light-transmitting part. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings 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.

[0032] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0033] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0034] It should be noted that, for the convenience of explanation, in the embodiments of the present application, the same figure marks represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0035] The coating process on glass is to form a functional thin film on the glass surface by means of physical deposition. This thin film can change the optical properties of the glass, such as enhancing reflection and improving light transmittance, so as to achieve the purpose of beautification, heat insulation, sun protection and other functions. The main coating processes include chemical vapor deposition (CVD), physical vapor deposition (PVD), sputtering coating and magnetron coating.

[0036] During the coating process, the coating layer often warps due to the influence of various factors such as materials, processes and environment. Warping not only reduces the functionality and aesthetics of the coated product, but may also cause structural failure and affect the product life. Specifically, coating warping is a relatively common quality defect, and its manifestations include but are not limited to the following: 1) partial or overall bulging or depression of the coating layer; 2) the coating layer detaches from the glass substrate; 3) uneven stress distribution of the coating layer, resulting in glass deformation.

[0037] Thermal stress is one of the main causes of warping. Different materials have different thermal expansion coefficients. The mismatch in thermal expansion coefficients between the coating material and the glass substrate will cause stress during the cooling process. If this stress is not effectively released, it will cause warping or cracking. The relevant technology is difficult to accurately control and fully understand the distribution and impact of this thermal stress, resulting in insufficient product consistency and stability. In addition, the type of substrate glass (such as float glass, high borosilicate glass, etc.) and surface treatment process (such as chemical strengthening, thermal strengthening, etc.) will also affect the adhesion and warping of the coating layer.

[0038] In the related technology, the phenomenon of coating warping is mainly improved from the perspective of process, and the risk of glass coating warping cannot be evaluated before coating. To understand the stress distribution and warping of glass after coating, it can only be obtained through testing after coating. However, this method is not only costly but also time-consuming.

[0039] See also Figure 1 and Figure 2 The embodiment of the present application provides a qualitative analysis method for warping of a laminated structure 100, wherein the laminated structure 100 includes a plurality of film layers 10 stacked in sequence, wherein the plurality of film layers 10 include n tensile stress layers 10a and m compressive stress layers 10b, and the laminated structure 100 has a neutral axis 11, wherein the n tensile stress layers 10a are stacked in sequence on the same side of the neutral axis 11, and the m compressive stress layers 10b are stacked in sequence on the other side of the neutral axis 11, and the surface of the compressive stress layer 10b farthest from the neutral axis 11 and facing away from the neutral axis 11 is a preset surface 12, and the qualitative analysis method includes:

[0040] S1, calculating the warping radius 1 / ρ of the stacked structure 100 according to equation (1); and

[0041] The relation (1) is:

[0042]

[0043] Wherein, ρ is the curvature of the neutral axis 11, ε uis the uniform strain of the laminated structure 100, ΔT is the difference between the processing temperature and the room temperature of the laminated structure 100; i is a value from 1 to n, and n is an integer greater than or equal to 1; E i α is the elastic modulus of the i-th tensile stress layer 10a in the direction from the compressive stress layer 10b to the tensile stress layer 10a; i is the thermal expansion coefficient of the i-th tensile stress layer 10a in the direction from the compressive stress layer 10b to the tensile stress layer 10a; z i is the distance from the surface of the i-th tensile stress layer 10a facing the neutral axis 11 to the preset surface 12; i+1 is the distance from the surface of the i-th tensile stress layer 10a away from the neutral axis 11 to the preset surface 12; j is 1 to m, m is an integer greater than or equal to 1, E j α is the elastic modulus of the j-th compressive stress layer 10b in the direction from the compressive stress layer 10b to the tensile stress layer 10a; j is the thermal expansion coefficient of the jth compressive stress layer 10b in the direction from the compressive stress layer 10b to the tensile stress layer 10a; z j is the distance from the surface of the j-th tensile stress layer 10a facing the neutral axis 11 to the preset surface 12; j+1 is the distance from the surface of the j-th tensile stress layer 10a away from the neutral axis 11 to the preset surface 12;

[0044] S2 , predicting a warping degree of the stacked structure 100 according to the warping radius of the stacked structure 100 .

[0045] It should be noted that the multi-layer film layers 10 are stacked and connected in sequence.

[0046] Optionally, the laminated structure 100 may be a coated glass (i.e., a laminated structure 100 in which a glass layer and a coating layer are laminated), or a display screen assembly having a plurality of film layers 10 bonded together. In other embodiments, the laminated structure 100 may also be other products, as long as a plurality of film layers 10 are sequentially laminated and connected. In the embodiments of the application, the laminated structure 100 is illustrated and described using coated glass as an example, which should not be construed as a limitation on the laminated structure 100 of the embodiments of the present application, nor should it be construed as a limitation on the qualitative analysis method of the warpage of the laminated structure 100 of the present application.

[0047] It can be understood that when the laminated structure 100 is a coated glass, the processing temperature of the laminated structure 100 is the coating temperature when coating is performed on the glass layer to form a coating layer.

[0048] It should be noted that the uniform strains of the multiple film layers 10 are all equal, so the uniform strain of each film layer 10 of the stacked structure 100 is represented by a unified symbol εu Since the curvature difference of different film layers 10 on the laminated structure 100 is small and can be ignored, in the quantitative analysis method of the present application, the curvature of different film layers 10 is represented by the curvature ρ of the neutral axis 11 .

[0049] It should be noted that ε u Refers to the average strain of the laminated structure 100 under the external load. The external load includes temperature load and pressure load.

[0050] It should be noted that the tensile stress layer 10a is a film layer 10 subjected to tensile stress among the multiple film layers 10, the compressive stress layer 10b is a film layer 10 subjected to compressive stress among the multiple film layers 10, and the neutral axis 11 refers to a plane composed of positions that are neither subjected to tensile stress nor to compressive stress in the laminated structure 100. It can be understood that the n-layer tensile stress layer 10a and the m-layer compressive stress layer 10b are respectively arranged on opposite sides of the neutral axis 11. The preset surface 12 is the surface of the m-layer compressive stress layer 10b that is farthest from the neutral axis 11.

[0051] It should be noted that the larger 1 / ρ is, the smaller the warping degree of the laminated structure 100 is, the smaller the risk of warping is, and the better the product performance of the laminated structure 100 is; conversely, the smaller 1 / ρ is, the greater the warping degree of the laminated structure 100 is, and the greater the risk of warping is.

[0052] In the qualitative analysis method of the warpage of the laminated structure 100 of the embodiment of the application, the relationship (1) is used to calculate the warpage radius 1 / ρ of the laminated structure 100. According to the size of the warpage radius 1 / ρ of the laminated structure 100, the warpage of the laminated structure 100 can be predicted according to the material of each film layer 10 of the laminated structure 100 and the preparation process of the laminated structure 100, so as to better provide improvement directions for the preparation and design of the laminated structure 100. In addition, the relationship (1) of the present application has been verified to be able to accurately predict the warpage degree of the laminated structure 100, with high calculation accuracy and short analysis cycle, which can greatly improve the preparation efficiency of the laminated structure 100 and reduce the preparation cost of the laminated structure 100. Furthermore, the qualitative analysis method of the warpage of the laminated structure 100 of the present application does not require a large amount of experimental equipment and personnel investment, and can significantly reduce costs compared with experimental methods.

[0053] In some embodiments, there are multiple stacked structures 100, and calculating the warping radius of the stacked structures 100 according to equation (1) includes: calculating the warping radii of the multiple stacked structures 100 respectively according to equation (1).

[0054] The qualitative analysis method further includes: performing normalization processing on the warping radii of the plurality of stacked structures 100 to obtain normalized results of the warping radii of the plurality of stacked structures 100 .

[0055] Predicting the warping degree of the stacked structure 100 according to the warping radius of the stacked structure 100 includes: predicting the warping degrees of the plurality of stacked structures 100 according to normalized results of the warping radii of the plurality of stacked structures 100 , and guiding the design of the stacked structure 100 according to the warping degrees.

[0056] It should be noted that, the larger the value of the normalized result of the warping radius of the stacked structure 100 is, the smaller the risk of warping of the stacked structure 100 is, and the smaller the degree of warping of the stacked structure 100 is.

[0057] See also Figure 3 It can be understood that the qualitative analysis method of the warpage of the laminated structure 100 of this embodiment includes:

[0058] S3, calculating the warping radii of the plurality of stacked structures 100 respectively according to equation (1);

[0059] S4, normalizing the warping radii of the plurality of stacked structures 100 to obtain normalized results of the warping radii of the plurality of stacked structures 100; and

[0060] S5, predicting the warping degrees of the plurality of stacked structures 100 according to the normalized results of the warping radii of the plurality of stacked structures 100, and guiding the design of the stacked structures 100 according to the warping degrees.

[0061] In this embodiment, after normalizing the warping degrees of multiple stacked structures 100, the warping degrees of the stacked structures 100 can be well judged according to the normalized results; in addition, by changing parameters such as the material or processing temperature of a certain film layer 10 in the stacked structure 100, the warping degrees of the multiple stacked structures 100 are calculated respectively, so that according to the normalized results of the warping radii of the multiple stacked structures 100, the influence of parameters such as the material or processing temperature of the film layer 10 on the warping radius of the stacked structure 100 can be understood, so that the stacked structure 100 can be better designed, thereby reducing the trial and error cost in the preparation process of the stacked structure 100, improving the production efficiency of the stacked structure 100, and reducing the preparation cost of the stacked structure 100.

[0062] See also Figure 4 In some embodiments, the relationship (1) is obtained by the following steps:

[0063] S11, according to the fact that the sum of the internal stresses of the laminated structure 100 caused by temperature changes is 0, equation (2) is obtained;

[0064] Wherein, the relation (2) is: Among them, t i is the thickness of the i-th tensile stress layer 10a in the direction from the compressive stress layer 10b to the tensile stress layer 10a; t j is the thickness of the j-th compressive stress layer 10b in the direction from the compressive stress layer 10b to the tensile stress layer 10a;

[0065] The schematic diagram of the internal stress of the laminated structure 100 is shown in FIG. Figure 5 shown.

[0066] S12, according to the fact that the sum of the internal stresses caused by the bending deformation of the laminated structure 100 is 0, equation (3) is obtained;

[0067] Wherein, the relation (3) is:

[0068] S13, according to the relationship between stress and strain, the internal stress σ of the tensile stress layer 10a of the i-th layer is obtained. i The relationship (4) and the internal stress σ of the j-th compressive stress layer 10b are j The relationship (5)

[0069] Wherein, the internal stress σ of the i-th tensile stress layer 10a is i The relationship (4) is: The internal stress σ of the j-th compressive stress layer 10b is j The relationship (5) is: Wherein, z1 is the distance from a point on the i-th tensile stress layer 10a to the preset surface 12; z2 is the distance from a point on the j-th tensile stress layer 10a to the preset surface 12; b is the distance from the neutral axis 11 to the preset surface 12;

[0070] S14, according to the sum of the internal bending moments generated by the internal stress of the laminated structure 100 being 0, equation (6) is obtained; and

[0071] Among them, the relationship (6) is:

[0072] It should be noted that the internal stress of the laminated structure 100 will cause the multiple film layers 10 to have internal bending moments, and the internal stress is away from the neutral axis 11, that is, the internal bending moment of the tensile stress layer 10a of the i-th layer is: σ i (z1-z b ); The internal bending moment of the j-th compressive stress layer 10b is: σ j (z2-z b ).

[0073] The schematic diagram of the structure of the laminated structure 100 that is bent or warped is shown in FIG. Figure 6 shown.

[0074] S15, substitute the relational expressions (2), (3), (4) and (5) into the relational expression (6) to obtain the relational expression (1).

[0075] In this embodiment, by disassembling the physical model of the laminated structure 100 and analyzing the stress condition of the laminated structure 100 through mechanical theory, the relationship (1) is calculated based on the following conditions: the sum of the internal stresses of the laminated structure 100 caused by temperature change is 0, the sum of the internal stresses of the laminated structure 100 caused by bending deformation is 0, and the sum of the internal bending moments caused by the internal stresses of the laminated structure 100 is 0. The relationship (1) can be used to accurately predict the degree of warping of the laminated structure 100, which can greatly improve the preparation efficiency of the laminated structure 100 and reduce the preparation cost of the laminated structure 100.

[0076] Optionally, by substituting equation (2) and equation (3) into equation (4), the equation of internal stress of each tensile stress layer 10a can be obtained, thereby obtaining the distribution of internal stress of each tensile stress layer 10a; by substituting equation (2) and equation (3) into equation (5), the equation of internal stress of each compressive stress layer 10b can be obtained, thereby obtaining the distribution of internal stress of each compressive stress layer 10b. In this way, the stress distribution of each film layer 10 of the multilayer film layer 10 can be analyzed, thereby qualitatively analyzing the risk of stress generation of the laminated structure 100, and providing a reference for the preparation and design of the laminated structure 100.

[0077] See also Figure 7 In some embodiments, the relationship (2) is obtained by the following steps:

[0078] S111, when the stacked structure 100 is cooled from the processing temperature to room temperature (such as 25°C), the thermal strain of the i-th tensile stress layer 10a caused by the temperature change The relationship (21) is Thermal strain of the j-th compressive stress layer 10b caused by temperature change The relationship (22) is

[0079] Optionally, when the laminated structure 100 is a coated glass, the surface of the glass layer is in a high temperature state when the coated layer is uniformly vacuum coated, and the temperature is T1. As time goes by, both the glass layer and the coated layer will drop to normal temperature T2, and the temperature change of the coated glass ΔT=T1-T2.

[0080] S112, according to equations (21) and (22), the total strain of the i-th tensile stress layer 10a caused by temperature change is obtained as equation (23): The total strain of the jth compressive stress layer 10b caused by temperature change is expressed as equation (24):

[0081] S113, according to the fact that the sum of the internal stresses of the laminated structure 100 caused by temperature change is 0, relation (23), relation (24), relation (25) is obtained:

[0082] S114, equation (26) is obtained from equation (25), equation (21) and equation (22): as well as

[0083] It can be understood that, under the temperature load of the laminated structure 100, the i-th tensile stress layer 10a is stretched relative to the uniform strain, then the sum of the stress values ​​of the n-th tensile stress layer 10a is: When the stacked structure 100 is subjected to temperature load, the j-th compressive stress layer 10b is compressed relative to the uniform strain. Then, the sum of the stress values ​​of the m-th compressive stress layer 10b is:

[0084]

[0085] S115, equation (2) is obtained from equation (26).

[0086] In this embodiment, the sum of the internal stresses caused by temperature changes is zero, and the stress is equal to the elastic modulus multiplied by the strain, so that the relationship (2) can be obtained. This embodiment fully considers the influence of temperature changes on stress, so that the final relationship (1) can more accurately predict the warping radius of the laminated structure 100, thereby better guiding the design of materials and process conditions of the laminated structure 100.

[0087] In some embodiments, the relationship (3) is obtained by the following steps:

[0088] S121, according to the laminated structure 100, which is still in a balanced state under the action of internal stress, the internal stress of the tensile stress layer 10a of the i-th layer under bending deformation is: The internal stress of the j-th compressive stress layer 10b under bending deformation is: as well as

[0089] S122, according to the fact that the sum of the internal stresses caused by the bending deformation of the laminated structure 100 is 0, the relationship is obtained: After conversion, we get the relation (3).

[0090] In this embodiment, the relationship (3) is obtained based on the fact that the laminated structure 100 is still in a state of equilibrium under the action of internal stress. This embodiment fully considers the influence of stress changes on the warping of the laminated structure 100, so that the finally obtained relationship (1) can more accurately predict the warping radius of the laminated structure 100, thereby better guiding the design of materials and process conditions of the laminated structure 100.

[0091] In some embodiments, the relationship (4) is obtained by the following steps:

[0092] S131, according to the relationship between the bending strain and the curvature of the stacked structure 100, the bending strain of the i-th tensile stress layer 10a is obtained. The relationship (41):

[0093] S132, according to the total strain of the film layer 10 when it is bent is equal to the uniform strain of the film layer 10 and the bending strain of the film layer 10, and the relationship (41), the total strain ε of the i-th tensile stress layer 10a is obtained: i The relationship (42) is: as well as

[0094] S133, according to the relationship between stress and strain and relation (42), relation (4) is obtained:

[0095]

[0096] In some embodiments, the relationship (5) is obtained by the following steps:

[0097] S134, according to the relationship between the bending strain and the curvature of the stacked structure 100, the bending strain of the j-th compressive stress layer 10b is obtained. The relationship (51):

[0098] S135, according to the total strain of the film layer 10 when it is bent is equal to the uniform strain of the film layer 10 and the bending strain of the film layer 10, and the relationship (51), the total strain ε of the j-th compressive stress layer 10b is obtained: j The relationship (52) is: as well as

[0099] S136, according to the relationship between stress and strain and relation (52), relation (5) is obtained:

[0100]

[0101] In this embodiment, the influence of uniform strain and bending strain on the bending of the laminated structure 100 is taken into consideration, so that the stress inside each tensile stress layer 10a and each compressive stress layer 10b can be analyzed more accurately, and the finally obtained relationship (1) can more accurately predict the warping radius of the laminated structure 100, thereby better guiding the design of the material and process conditions of the laminated structure 100.

[0102] In some embodiments, when the tensile stress layer 10a is one layer and the compressive stress layer 10b is one layer, the calculation of the warping radius 1 / ρ of the stacked structure 100 according to the relation (1) includes: calculating the warping radius 1 / ρ of the stacked structure 100 according to the relation (7), and the relation (7) is:

[0103]

[0104] Wherein, ρ is the curvature of the neutral axis 11, ε u is the uniform strain of the laminated structure 100, ΔT is the difference between the processing temperature and the room temperature of the laminated structure 100, E g is the elastic modulus of the tensile stress layer 10a, α g is the thermal expansion coefficient of the tensile stress layer 10a, t g is the thickness of the tensile stress layer 10a, E f is the elastic modulus of the compressive stress layer 10b, α f is the thermal expansion coefficient of the compressive stress layer 10b, t f is the thickness of the compressive stress layer 10b.

[0105] It can be seen from equations (1) and (7) that the warping degree of the laminated structure 100 is related to the thickness, elastic modulus, thermal expansion coefficient, and temperature change of each film layer 10 in the laminated structure 100. According to equations (1) and (7), the warping degree of the laminated structure 100 can be well predicted, providing a qualitative analysis and reference for the stress risk of the laminated structure 100.

[0106] In this embodiment, by simplifying the number of layers of the laminated structure 100, the warping radius of the laminated structure 100 with a two-layer structure can be more accurately predicted. In particular, when applied to glass coating, it can provide better reference and guidance for the design of glass coating. The warping radius 1 / ρ of the laminated structure 100 is calculated using the relationship (7) of the embodiment of the present application. According to the size of the warping radius 1 / ρ of the laminated structure 100, the warping condition of the laminated structure 100 can be predicted according to the material of each film layer 10 of the laminated structure 100 and the preparation process of the laminated structure 100, thereby providing a better improvement direction for the preparation and design of the laminated structure 100. In addition, the relationship (7) of the present application has been verified to be able to accurately predict the degree of warping of the laminated structure 100, with high calculation accuracy and short analysis cycle, which can greatly improve the preparation efficiency of the laminated structure 100 and reduce the preparation cost of the laminated structure 100. Furthermore, the qualitative analysis method of the warpage of the laminated structure 100 of the present application does not require a large amount of experimental equipment and personnel investment, and can significantly reduce costs compared to experimental methods.

[0107] In some embodiments, the relationship (7) is obtained by the following steps:

[0108] S11', according to the fact that the sum of the internal stresses of the laminated structure 100 caused by temperature change is 0, the relationship E is obtained. g (ε u -α g ΔT)t g +E f (ε u -α f ΔT)t f =0, and the conversion yields the relation (71):

[0109] Optionally, when the laminate structure 100 is cooled from the processing temperature to room temperature (eg, 25° C.), the thermal strain of the tensile stress layer 10a caused by the temperature change The relationship is Thermal strain of the j-th compressive stress layer 10b caused by temperature change The relationship is The total strain of the tensile stress layer 10a caused by temperature change is expressed as The total strain of the compressive stress layer 10b caused by temperature change is expressed as According to the sum of the internal stresses of the laminated structure 100 caused by temperature changes being 0 and the above relationship, E g (ε u -α g ΔT)t g +E f (ε u -α fΔT)t f =0, after conversion, we get the above relational equation (71).

[0110] S12', according to the fact that the sum of the internal stresses caused by the bending deformation of the laminated structure 100 is 0, the relationship is obtained: After conversion, we get the relationship (72):

[0111]

[0112] S13', according to the relationship between stress and strain, the internal stress σ of the tensile stress layer 10a is obtained. g Satisfies the relationship (73) And the internal stress σ of the compressive stress layer 10b f Relationship (74) Wherein, z1 is the distance from a point on the tensile stress layer 10a to the preset surface 12; z2 is the distance from a point on the tensile stress layer 10a to the preset surface 12; b is the distance from the neutral axis 11 to the preset surface 12;

[0113] S14', according to the sum of the internal bending moments generated by the internal stress of the laminated structure 100 being 0, the relationship (75) is obtained:

[0114]

[0115] S15', substitute the relational expressions (71), (72), (73) and (74) into the relational expression (75) to obtain the relational expression (7).

[0116] In this embodiment, by simplifying the laminated structure 100 and disassembling the physical model of the laminated structure 100, the stress condition of the laminated structure 100 is analyzed through mechanical theory, and the sum of the internal stresses caused by temperature changes in the laminated structure 100 is 0, the sum of the internal stresses caused by bending deformation of the laminated structure 100 is 0, and the sum of the internal bending moments caused by the internal stresses of the laminated structure 100 is 0, thereby calculating the relationship (7). The relationship (7) can be used to accurately predict the degree of warping of the laminated structure 100, which can greatly improve the preparation efficiency of the laminated structure 100 and reduce the preparation cost of the laminated structure 100.

[0117] The embodiment of the present application further provides a method for preparing coated glass. Before the coated glass is prepared, the warping degree of the coated glass is predicted using the qualitative analysis method for the warping of the laminated structure 100 described in the embodiment of the present application.

[0118] For the qualitative analysis method of the warping of the stacked structure 100 , please refer to the description of the corresponding part of the above embodiment, which will not be repeated here.

[0119] The method for preparing coated glass of the embodiment of the present application uses the qualitative analysis method of the warping of the laminated structure 100 described in the embodiment of the present application to predict the degree of warping of the coated glass before coating; the qualitative analysis method of the warping of the laminated structure 100 uses the relationship (1) of the embodiment of the present application to calculate the warping radius 1 / ρ of the coated glass, and according to the size of the warping radius 1 / ρ of the coated glass, the warping of the coated glass can be predicted according to the material of each film layer 10 of the coated glass and the preparation process of the coated glass, so as to better provide improvement directions for the preparation and design of the coated glass. In addition, the relationship (1) of the present application has been verified to be able to accurately predict the degree of warping of the coated glass, with high calculation accuracy and short analysis cycle, which can greatly improve the preparation efficiency of the coated glass and reduce the preparation cost of the coated glass. Furthermore, the qualitative analysis method of the warping of the coated glass of the present application does not require a large amount of experimental equipment and personnel investment, and can significantly reduce costs compared with experimental methods.

[0120] See also Figure 8 and Fig. 9 The embodiment of the present application further provides a coated glass 200, wherein the coated glass 200 includes a glass layer 210 and a coating layer 220 which are stacked, and the coated glass 200 is prepared by the method for preparing the coated glass 200 described in the embodiment of the present application.

[0121] It can be understood that before coating, the warping of the coated glass 200 is predicted by using the qualitative analysis method of the warping of the laminated structure 100 according to the embodiment of the present application.

[0122] For detailed description of other aspects of the method for preparing the coated glass 200, please refer to the description of the corresponding part of the above embodiment, which will not be repeated here.

[0123] Optionally, the coating layer 220 may be coated by at least one of chemical vapor deposition (CVD), physical vapor deposition (PVD), sputtering coating, magnetron coating, and the like.

[0124] The coated glass 200 of the present application includes a stacked glass layer 210 and a coating layer 220, and the coated glass 200 is prepared by the method for preparing the coated glass 200 described in the embodiment of the present application. Before coating, the method for preparing the coated glass 200 uses the qualitative analysis method for the warping of the laminated structure 100 described in the embodiment of the present application to predict the warping degree of the coated glass 200; the qualitative analysis method for the warping of the laminated structure 100 uses the relationship (1) of the embodiment of the present application to calculate the warping radius 1 / ρ of the coated glass 200, and according to the size of the warping radius 1 / ρ of the coated glass 200, the warping of the coated glass 200 can be predicted according to the material of each film layer 10 of the coated glass 200 and the preparation process of the coated glass 200, so as to better provide improvement directions for the preparation and design of the coated glass 200. In addition, the relational expression (1) of the present application has been verified to be able to accurately predict the degree of warping of the coated glass 200, with high calculation accuracy and short analysis cycle, which can greatly improve the preparation efficiency of the coated glass 200 and reduce the preparation cost of the coated glass 200. Furthermore, the qualitative analysis method of the warping of the coated glass 200 of the present application does not require a large amount of experimental equipment and personnel investment, and can significantly reduce costs compared to experimental methods.

[0125] The following provides a further description of the qualitative analysis method of the warpage of the laminated structure 100 of the application through a specific embodiment.

[0126] Example 1 to Example 4

[0127] The laminated structure 100 of each embodiment is a coated glass 200, wherein the coated glass 200 comprises a laminated glass layer 210 and a coating layer 220, wherein the glass layer 210 is 2301 glass, and the thickness of the glass layer 210 is t g is 0.6 mm, the elastic modulus Eg of the glass layer 210 is 77 GPa, and the thermal expansion coefficient α of the glass layer 210 is g =5.99×10 -6 / ℃, the coating layer 220 includes SiO2 and SiN, and the thermal expansion coefficient of the coating layer 220 is α f =1.8×10 -6 The thickness and elastic modulus of the coating layer 220 of each embodiment are shown in Table 1 below.

[0128] The coated glass 200 of each embodiment adopts the qualitative analysis method of the warpage of the laminated structure 100 of this embodiment to calculate its warpage radius, and the warpage radius of each embodiment is normalized by the calculation result of embodiment 1. After the coated glass 200 of each embodiment is tested, its warpage radius is measured and normalized by the measurement result of embodiment 1. The calculation results and experimental results of each embodiment are shown in Table 1 below.

[0129] Table 1 Theoretical calculation results and experimental results of the coated glass 200 of each embodiment

[0130]

[0131] It can be seen from the test results of Examples 1 to 4 that when the qualitative analysis method of the warping of the laminated structure 100 of the present application is applied to the qualitative analysis of the warping degree of the coated glass 200, the theoretical calculation and the actual measurement have a high degree of consistency, and the error is less than or equal to 5%, and the warping degree of the coated glass 200 can be accurately predicted.

[0132] See also Figures 10 to 12 The embodiment of the present application also provides an electronic device 300, which includes a display screen 310, the coated glass 200 described in the embodiment of the present application; and a processor 330, wherein the processor 330 is electrically connected to the display screen 310 and is used to control the display screen 310 to display.

[0133] For detailed description of other aspects of the coated glass 200 , please refer to the description of the corresponding parts of the above embodiment, which will not be repeated here.

[0134] Optionally, the coated glass 200 can be used as a front cover of the electronic device 300 to protect the display screen 310 , or can be used as a back cover of the electronic device 300 , such as a battery back cover.

[0135] The electronic device 300 of the embodiment of the present application may be, but is not limited to, a portable electronic device 300 such as a mobile phone, a tablet computer, a laptop computer, a desktop computer, a smart bracelet, a smart watch, an e-reader, a game console, etc.

[0136] Optionally, the display screen 310 may be, but is not limited to, one or more of a liquid crystal display screen, a light emitting diode display screen (LED display screen), a micro light emitting diode display screen (Micro LED display screen), a sub-millimeter light emitting diode display screen (Mini LED display screen), an organic light emitting diode display screen (OLED display screen), etc.

[0137] Optionally, the processor 330 includes one or more general-purpose processors, wherein the general-purpose processor can be any type of device capable of processing electronic instructions, including a central processing unit (CPU), a microprocessor, a microcontroller, a main processor, a controller, and an ASIC, etc. The processor 330 is used to execute various types of digital storage instructions, such as software or firmware programs stored in a memory, which enables the computing device to provide a wide variety of services.

[0138] Optionally, the electronic device 300 of the present application further includes a memory 350. The memory 350 is electrically connected to the processor 330 and is used to store program codes required for the processor 330 to run, program codes required for controlling the display screen 310, display content of the display screen 310, and the like.

[0139] Optionally, the memory 350 may include a volatile memory (Volatile Memory), such as a random access memory (Random Access Memory, RAM); the memory 350 may also include a non-volatile memory (NVM), such as a read-only memory (Read-Only Memory, ROM), a flash memory (Flash Memory, FM), a hard disk drive (Hard Disk Drive, HDD) or a solid-state drive (SSD). The memory 350 may also include a combination of the above-mentioned types of memory.

[0140] In some embodiments, the coated glass 200 is used as a protective cover of the display screen. The electronic device 300 of the embodiment of the present application further includes a middle frame 320 and a camera module 370. The middle frame 320 is disposed between the display screen 310 and the housing 340, and the side of the middle frame 320 is exposed to the housing 340 and the display screen 310. The middle frame 320 and the housing 340 enclose a housing space (not shown), and the housing space is used to accommodate the processor 330, the memory 350 and the camera module 370. The camera module 370 is electrically connected to the processor 330 for shooting under the control of the processor 330.

[0141] Optionally, the housing 340 has a light-transmitting portion 341, and the camera module 370 can shoot through the light-transmitting portion 341 on the housing 340, that is, the camera module 370 in this embodiment is a rear camera module. It can be understood that in other embodiments, the light-transmitting portion 341 can be set on the display screen 310, that is, the camera module 370 is a front camera module 370. In the schematic diagram of this embodiment, the light-transmitting portion 341 is illustrated as an opening. In other embodiments, the light-transmitting portion 341 may not be an opening, but a light-transmitting material, such as plastic, glass, etc.

[0142] It can be understood that the electronic device 300 described in this embodiment is merely a form of electronic device 300 to which the coated glass 200 is applied, and should not be understood as a limitation on the electronic device 300 provided in the present application, nor should it be understood as a limitation on the coated glass 200 provided in each embodiment of the present application.

[0143] Mentioning "embodiment" and "implementation method" in this application means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrases 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 in this application can be combined with other embodiments. In addition, it should also be understood that the features, structures or characteristics described in the various embodiments of the present application can be arbitrarily combined to form another embodiment that does not deviate from the spirit and scope of the technical solution of the present application, if there is no contradiction between them.

[0144] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the above preferred implementation modes, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A qualitative analysis method for warping of a laminated structure, characterized in that: The laminated structure comprises a plurality of film layers stacked in sequence, the plurality of film layers comprising n tensile stress layers and m compressive stress layers, the laminated structure has a neutral axis, the n tensile stress layers are stacked in sequence on the same side of the neutral axis, the m compressive stress layers are stacked in sequence on the other side of the neutral axis, the surface of the compressive stress layer farthest from the neutral axis that is away from the neutral axis is a preset surface, and the qualitative analysis method comprises: The warping radius 1 / ρ of the stacked structure is calculated according to the relation (1), which is: Where, ρ is the curvature of the neutral axis, ε u is the uniform strain of the laminate structure, ΔT is the difference between the processing temperature and the room temperature of the laminate structure; i ranges from 1 to n; E i is the elastic modulus of the tensile stress layer in the direction from the compressive stress layer to the tensile stress layer; α i is the thermal expansion coefficient of the i-th tensile stress layer in the direction from the compressive stress layer to the tensile stress layer; z i is the distance from the surface of the i-th tensile stress layer facing the neutral axis to the preset surface; i+1 is the distance from the surface of the i-th tensile stress layer away from the neutral axis to the preset surface; j is 1 to m, E j α is the elastic modulus of the j-th compressive stress layer in the direction from the compressive stress layer to the tensile stress layer; j is the thermal expansion coefficient of the jth compressive stress layer in the direction from the compressive stress layer to the tensile stress layer; z j is the distance from the surface of the j-th tensile stress layer facing the neutral axis to the preset surface; j+1 is the distance from the surface of the j-th tensile stress layer away from the neutral axis to the preset surface; and The warping degree of the stacked structure is predicted according to the warping radius of the stacked structure.

2. The method for qualitative analysis of warpage of a laminated structure according to claim 1, characterized in that: The number of the stacked structures is multiple, and the warping radius of the stacked structures is calculated according to the relationship (1), including: calculating the warping radius of the multiple stacked structures respectively according to the relationship (1); The qualitative analysis method further comprises: normalizing the warping radii of the plurality of stacked structures to obtain normalized results of the warping radii of the plurality of stacked structures; Predicting the warping degree of the stacked structure according to the warping radius of the stacked structure includes: predicting the warping degrees of the plurality of stacked structures according to normalized results of the warping radii of the plurality of stacked structures, and guiding the design of the stacked structure according to the warping degrees.

3. The qualitative analysis method of warpage of a laminated structure according to claim 1, characterized in that: The relationship (1) is obtained by the following steps: According to the fact that the sum of the internal stresses caused by temperature changes in the laminated structure is 0, the relationship (2) is obtained: Among them, t i is the thickness of the i-th tensile stress layer in the direction from the compressive stress layer to the tensile stress layer; t j is the thickness of the jth compressive stress layer in the direction from the compressive stress layer to the tensile stress layer; According to the fact that the sum of the internal stresses caused by bending deformation in the laminated structure is 0, the relationship (3) is obtained: According to the relationship between stress and strain, the internal stress σ of the tensile stress layer of the i-th layer is obtained: i Satisfying the relationship (4) And the internal stress σ of the jth compressive stress layer j Relation (5) Wherein, z1 is the distance from a point on the tensile stress layer of the i-th layer to the preset surface; z2 is the distance from a point on the tensile stress layer of the j-th layer to the preset surface; b is the distance from the neutral axis to the preset surface; According to the sum of the internal bending moments generated by the internal stress of the laminated structure is 0, the relationship (6) is obtained: as well as Substituting the equations (2), (3), (4) and (5) into the equation (6) yields the equation (1).

4. The qualitative analysis method of warpage of a laminated structure according to claim 3, characterized in that: The relationship (2) is obtained by the following steps: When the laminated structure is cooled from processing temperature to room temperature, the thermal strain of the i-th tensile stress layer caused by temperature change The relationship (21) is Thermal strain of the jth compressive stress layer caused by temperature change The relationship (22) is According to equations (21) and (22), the total strain of the i-th tensile stress layer caused by temperature change is obtained as equation (23): The total strain of the jth compressive stress layer caused by temperature change is expressed as (24) According to the fact that the sum of the internal stresses of the laminated structure caused by temperature changes is 0, equation (23) and equation (24), equation (25) is obtained: From equation (25), equation (21) and equation (22), we get equation (26): From equation (26), we get equation (2).

5. The qualitative analysis method of warpage of a laminated structure according to claim 3, characterized in that: The relationship (3) is obtained by the following steps: According to the fact that the laminated structure is still in a balanced state under the action of internal stress, the internal stress of the tensile stress layer of the i-th layer under bending deformation is: The internal stress of the jth compressive stress layer under bending deformation is as well as According to the fact that the sum of the internal stresses caused by bending deformation in the laminated structure is 0, we can get the relationship: After conversion, we get the relation (3).

6. The qualitative analysis method of warpage of a laminated structure according to claim 3, characterized in that: The relationship (4) is obtained by the following steps: According to the relationship between the bending strain and the curvature of the laminated structure, the bending strain of the i-th tensile stress layer is obtained: The relationship (41): According to the total strain of the film layer when it is bent, which is equal to the uniform strain of the film layer and the bending strain of the film layer, and the relationship (41), the total strain ε of the i-th tensile stress layer is obtained: i The relationship (42) is: as well as According to the relationship between stress and strain and equation (42), equation (4) is obtained: The relationship (5) is obtained by the following steps: According to the relationship between the bending strain and the curvature of the laminated structure, the bending strain of the j-th compressive stress layer is obtained: The relationship (51): According to the total strain of the film layer when it is bent, which is equal to the uniform strain of the film layer and the bending strain of the film layer, and the relationship (51), the total strain ε of the j-th compressive stress layer is obtained: j The relationship (52) is: as well as According to the relationship between stress and strain and equation (52), equation (5) is obtained:

7. The qualitative analysis method of warpage of a laminated structure according to claim 1, characterized in that: When the tensile stress layer is one layer and the compressive stress layer is one layer, the warping radius 1 / ρ of the laminated structure is calculated according to the relation (1), comprising: calculating the warping radius 1 / ρ of the laminated structure according to the relation (7), wherein the relation (7) is: Where, ρ is the curvature of the neutral axis, ε u is the uniform strain of the laminate structure, △T is the difference between the processing temperature and the room temperature of the laminate structure, E g is the elastic modulus of the tensile stress layer, α g is the thermal expansion coefficient of the tensile stress layer, t g is the thickness of the tensile stress layer, E f is the elastic modulus of the compressive stress layer, α f is the thermal expansion coefficient of the compressive stress layer, t f is the thickness of the compressive stress layer.

8. The qualitative analysis method of warpage of a laminated structure according to claim 7, characterized in that: The relationship (7) is obtained by the following steps: According to the fact that the sum of the internal stresses caused by temperature changes in the laminated structure is 0, the relationship E is obtained: g (ε u -α g ΔT)t g +E f (ε u -α f ΔT)t f =0, and the conversion yields the relation (71): According to the fact that the sum of the internal stresses caused by bending deformation in the laminated structure is 0, we can get the relationship: After conversion, we get the relationship (72): According to the relationship between stress and strain, the internal stress σ of the tensile stress layer is obtained: g Satisfies the relationship (73) And the internal stress σ of the compressive stress layer f Relationship (74) Wherein, z1 is the distance from a point on the tensile stress layer to the preset surface; z2 is the distance from a point on the tensile stress layer to the preset surface; b is the distance from the neutral axis to the preset surface; According to the fact that the sum of the internal bending moments generated by the internal stress of the laminated structure is 0, the relationship (75) is obtained: Substituting the equations (71), (72), (73) and (74) into the equation (75) yields the equation (7).

9. A method for preparing coated glass, characterized in that: Before the coated glass is prepared, the warping degree of the coated glass is predicted by using the qualitative analysis method for warping of the laminated structure according to any one of claims 1 to 8.

10. A coated glass, characterized in that: The coated glass comprises a glass layer and a coating layer which are stacked, and the coated glass is prepared by the method for preparing coated glass according to claim 9.

11. An electronic device, characterized in that: include: Display screen; The coated glass according to claim 10; as well as A processor is electrically connected to the display screen and is used to control the display screen to display.

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