Shell structure, display module, and electronic device

Abstract

The embodiments of the present application relate to the technical field of electronic devices. Provided are a shell structure, a display module, and an electronic device. The shell structure can improve the scratch resistance of cover plate glass, and when the shell structure is applied to a 3D curved display panel, there is no color difference in the appearance of a 3D curved display area, such that the electronic device has a better appearance. The shell structure comprises a substrate and a scratch-resistant layer, which is located on one side of the substrate, wherein the scratch-resistant layer comprises at least two materials, which comprise at least one high-refractive-index material and at least one low-refractive-index material; and the thickness of the scratch-resistant layer is greater than or equal to 300 nm and is less than or equal to 5000 nm. The refractive index of the low-refractive-index material is less than or equal to the refractive index of the substrate, and the refractive index of the high-refractive-index material is greater than 1.6.

Description

Housing structure, display module and electronic equipment

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on March 15, 2023, with application number 202310278159.9 and application name “Casing structure, display module and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of electronic equipment, and in particular to a housing structure, a display module and an electronic device. Background Art

[0003] The display panel is a component that enables the display function of electronic devices such as mobile phones and tablets. To enhance the mechanical strength and wear resistance of the display panel, the outer side of the display panel is usually covered with a protective glass cover.

[0004] However, with the use of electronic devices such as mobile phones and tablets, the contact between glass cover plates and hard objects will cause more and more visible scratches to appear on the surface of the glass cover plates, affecting the appearance of electronic devices. Scratches may also destroy the stress balance of the cover glass, resulting in a decrease in the impact resistance of the glass cover plates.

[0005] Summary of the Invention

[0006] To address the above technical issues, the present application provides a housing structure, a display module, and an electronic device. These structures can enhance the scratch resistance of the cover glass. Furthermore, when the housing structure is applied to a 3D curved display panel, the 3D curved display area will not exhibit color differences, resulting in a superior appearance for the electronic device.

[0007] In a first aspect, an embodiment of the present application provides a shell structure, comprising: a substrate and an anti-scratch layer located on one side of the substrate; the anti-scratch layer comprises at least two materials, and the at least two materials include at least one high-refractive index material and at least one low-refractive index material; the thickness of the anti-scratch layer is greater than or equal to 300 nm and less than or equal to 5000 nm; wherein the refractive index of the low-refractive index material is less than or equal to the refractive index of the substrate, and the refractive index of the high-refractive index material is greater than 1.6.

[0008] By mixing at least one high-refractive index material and at least one low-refractive index material to form an anti-scratch layer, the refractive index of the anti-scratch layer is made equal to or close to that of the substrate. This ensures that the protective structure has no effect on the substrate's transmittance and reflectivity, and furthermore, the appearance color is not affected by the thin thickness of the edge of the protective structure. In addition, because the anti-scratch layer includes a high-refractive index material, the high-refractive index material is relatively dense, and its thickness is between 300-5000nm. This gives the anti-scratch layer strong scratch resistance. In summary, the shell structure provided by the embodiments of the present application has both good appearance and optical properties and strong scratch resistance.

[0009] According to the first aspect, the shell structure also includes a first base layer, located between the substrate and the anti-scratch layer, which is used to improve the adhesion between the substrate and the anti-scratch layer, prevent the film layer from falling off and causing poor appearance, and improve the yield of the hard coating process.

[0010] According to the first aspect, or any implementation of the first aspect above, the material of the first primer layer is the same as the material element of the substrate; or, is in the same group or adjacent to the material element of the substrate (in the periodic table).

[0011] For example, when the substrate is inorganic glass, the first primer layer may be made of silicon dioxide, as inorganic glass contains silicon dioxide. When the substrate is sapphire, the first primer layer may be made of aluminum oxide, as sapphire contains aluminum oxide. This allows for better bonding between the substrate and the first primer layer.

[0012] According to the first aspect, or any implementation of the first aspect above, the thickness of the first primer layer is greater than or equal to 5 nm and less than or equal to 200 nm. In this manner, the first primer layer will not be too thin to achieve the desired effect of increasing adhesion between the substrate and the anti-scratch layer, nor will the first primer layer be too thick to exhibit its inherent properties.

[0013] According to the first aspect, or any implementation of the first aspect above, the shell structure also includes an optical adjustment layer, which is located on the side of the anti-scratch layer away from the substrate, and is used to adjust the appearance color of the shell structure so that the optical performance of the substrate is corrected to meet the optical performance requirements.

[0014] According to the first aspect, or any implementation of the first aspect above, the thickness of the optical adjustment layer is less than or equal to 300 nm. In some embodiments, the thickness of the optical adjustment layer is greater than or equal to 60 nm and less than or equal to 80 nm. Exemplarily, the thickness H3 of the optical adjustment layer is 60 nm, 65 nm, 70 nm, 75 nm, or 80 nm, etc.

[0015] According to the first aspect, or any implementation of the first aspect above, the material of the optical adjustment layer includes at least one of silicon dioxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, etc. The embodiment of the present application does not limit the material of the optical adjustment layer, and those skilled in the art can select it according to actual needs.

[0016] Exemplarily, the material of the optical adjustment layer includes one of silicon dioxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, etc.; or, the material of the optical adjustment layer includes at least two of silicon dioxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, etc.

[0017] According to the first aspect, or any implementation of the first aspect above, the shell structure also includes a friction-reducing layer, which is located on the side of the anti-scratch layer facing away from the substrate. The anti-fingerprint layer has an anti-fingerprint (AF) function, and when the user touches the display module, the user has a smooth touch, which is beneficial to the user experience.

[0018] According to the first aspect, or any implementation of the first aspect above, the dynamic friction coefficient of the friction-reducing layer is greater than or equal to 0.01 and less than or equal to 0.1, and the water drop angle is greater than 100°. In this way, the friction between the finger and the shell structure is small, reducing damage to the various film layers of the shell structure.

[0019] According to the first aspect, or any implementation of the first aspect above, the thickness of the anti-friction layer is greater than or equal to 3 nm and less than or equal to 50 nm.

[0020] Exemplarily, the thickness of the anti-friction layer includes 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm, etc.

[0021] According to the first aspect, or any implementation of the first aspect, the friction-reducing layer is composed of an organic material and an inorganic material with low surface energy.

[0022] Exemplarily, the material of the friction-reducing layer includes perfluoropolyethers (PFPE).

[0023] According to the first aspect, or any implementation of the first aspect above, the shell structure also includes a second base layer, located between the anti-friction layer and the anti-scratch layer, for improving the adhesion of the anti-friction layer, preventing the film layer from falling off and causing poor appearance, and improving the yield of the hard coating process.

[0024] According to the first aspect, or any implementation of the first aspect above, the second primer layer includes a first primer sublayer and a second primer sublayer, and the second primer sublayer is located on a side of the first primer sublayer away from the anti-scratch layer. Of course, the second primer layer can also include only one film layer.

[0025] According to the first aspect, or any implementation of the first aspect above, the thickness of the first base sublayer is less than or equal to 200 nm; the thickness of the second base sublayer is less than or equal to 50 nm.

[0026] In this way, the second primer layer will not fail to increase the adhesion between the substrate and the anti-scratch layer due to its thinness, nor will it fail to exhibit its own performance due to its thickness.

[0027] According to the first aspect, or any implementation method of the above first aspect, the material of the second base sub-layer includes silicon monoxide, silicon dioxide or silicon dioxide-doped materials, etc.; the material of the first base sub-layer includes diamond-like carbon, diamond or carbon nitride, etc. The embodiment of the present application does not limit the materials of the first base sub-layer and the second base sub-layer, and those skilled in the art can make a choice according to actual needs.

[0028] According to the first aspect, or any implementation of the first aspect above, the refractive index of the anti-scratch layer satisfies the following formula: R0≤100%-R1-T1

[0029] Among them, R0 is the reflectivity of the anti-scratch layer; R1 is the reflectivity of the substrate; T1 is the transmittance of the shell structure; n0 is the refractive index of air 1; n1 is the refractive index of the anti-scratch layer; and n2 is the refractive index of the substrate.

[0030] In this way, the transmittance of the shell structure can be guaranteed to be above a preset value (required transmittance, such as above 90.5%), so that the film layer has no effect on the transmittance and reflectance of the substrate.

[0031] According to the first aspect, or any implementation of the first aspect above, the mass fractions of the high refractive index material and the low refractive index material satisfy:

[0032] Among them, a i =(n i 2 +2) -1 ,ρ i is the material density, C i is the material mass fraction, n i is the material refractive index.

[0033] According to the formula, a high refractive index material and a low refractive index material are mixed to obtain an anti-scratch layer with a refractive index below 1.56, so that the anti-scratch layer has no effect on the transmittance and reflectivity of the substrate.

[0034] According to the first aspect, or any implementation of the first aspect above, the anti-scratch layer is formed by mixing aluminum oxide and silicon dioxide, the mass fraction of aluminum oxide is less than or equal to 80%, and the refractive index of the anti-scratch layer is less than or equal to 1.7.

[0035] According to the first aspect, or any implementation of the first aspect above, the anti-scratch layer is formed by mixing silicon nitride and silicon dioxide, the mass fraction of silicon nitride is less than or equal to 60%, and the refractive index of the anti-scratch layer is less than or equal to 1.7.

[0036] According to the first aspect, or any implementation of the first aspect above, the above-mentioned film layers are formed by a deposition process. For example, the anti-scratch layer is formed by a deposition process. Even if the anti-scratch layer formed by coating using the deposition process has different thicknesses on the large surface and the 3D curved surface, there will be no problem of inconsistent appearance color.

[0037] In a second aspect, embodiments of the present application provide a display module comprising the housing structure of the first aspect and any one of its implementations. The second aspect corresponds to the first aspect and any one of its implementations. The technical effects corresponding to the second aspect can be found in the technical effects corresponding to the first aspect and any one of its implementations, and are not further elaborated here.

[0038] In a third aspect, embodiments of the present application provide an electronic device, including the housing structure of the first aspect and any one of its implementations. The third aspect corresponds to the first aspect and any one of its implementations. The technical effects corresponding to the third aspect can be found in the technical effects corresponding to the first aspect and any one of its implementations, and are not further elaborated here.

[0039] According to a third aspect, the electronic device includes a display module, the display module includes a display panel and a cover plate located on one side of the display panel, and the housing structure is a cover plate of the electronic device.

[0040] According to a third aspect, the electronic device includes a back cover, and the housing structure is the back cover of the electronic device. Exemplarily, the back cover is a battery cover of a mobile phone or a tablet. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is a schematic structural diagram of an electronic device provided in an embodiment of the present application;

[0042] FIG2 is an exploded view of the electronic device shown in FIG1 ;

[0043] FIG3 is a schematic structural diagram of another electronic device provided in an embodiment of the present application;

[0044] FIG4 is a schematic structural diagram of another electronic device provided in an embodiment of the present application;

[0045] FIG5 is a schematic cross-sectional view of a cover plate of the electronic device shown in FIG4 along the AA′ direction according to an embodiment of the present application;

[0046] FIG6 is a schematic cross-sectional view of another cover plate of the electronic device shown in FIG4 along the AA′ direction according to an embodiment of the present application;

[0047] FIG7 is a schematic cross-sectional view of a housing structure of the electronic device shown in FIG4 along the AA′ direction according to an embodiment of the present application;

[0048] FIG8 is a schematic diagram of optical reflection of the anti-scratch layer;

[0049] FIG9 is a schematic cross-sectional view of another housing structure of the electronic device shown in FIG4 along the AA′ direction according to an embodiment of the present application;

[0050] FIG10 is a schematic cross-sectional view of another housing structure of the electronic device shown in FIG4 along the AA′ direction according to an embodiment of the present application;

[0051] FIG11 is a schematic cross-sectional view of another housing structure of the electronic device shown in FIG4 along the AA′ direction according to an embodiment of the present application;

[0052] FIG12 is a comparative test diagram of the housing structure provided in an embodiment of the present application;

[0053] FIG13 is a flow chart of a method for preparing a shell structure provided in an embodiment of the present application;

[0054] FIG14 is a flow chart of another method for preparing a shell structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0056] The term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0057] In the description and claims of the embodiments of this application, the terms "first" and "second" are used to distinguish different objects, rather than to describe a specific order of objects. For example, the terms "first target object" and "second target object" are used to distinguish different objects, rather than to describe a specific order of objects.

[0058] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0059] In the description of the embodiments of this application, unless otherwise specified, "multiple" means two or more. For example, "multiple processing units" means two or more processing units; "multiple systems" means two or more systems.

[0060] The embodiments of the present application provide an electronic device. The electronic device provided in the embodiments of the present application can be a mobile phone, a laptop computer, a tablet computer, a personal digital assistant (PDA), an in-car computer, a television, a smart wearable device (such as a smart watch, a smart bracelet, a smart head-mounted display, smart glasses), a smart home device, etc. The embodiments of the present application do not specifically limit the specific form of the above electronic devices. For the sake of convenience, the following description takes the electronic device as an example.

[0061] To facilitate the clear description of the subsequent structural features and their positional relationships, the positional relationships of the various structures within the phone are defined using the X-axis, Y-axis, and Z-axis directions. The X-axis represents the width of the phone, the Y-axis represents the length, and the Z-axis represents the thickness.

[0062] Referring to Figure 1 , which is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application, the electronic device is, for example, a mobile phone. As shown in Figure 1 , the mobile phone 100 includes a display module 10 , a back cover (also called a battery cover) 20 , and a middle frame 30 .

[0063] It is understood that in FIG1 , the mobile phone 100 is in the shape of a rectangular flat plate. In other optional embodiments, the shape of the electronic device may also be a square flat plate, a circular flat plate, an oval flat plate, etc. Of course, the electronic device may also be a foldable electronic device (such as a foldable mobile phone).

[0064] Refer to Figure 2, which is an exploded view of the electronic device shown in Figure 1. As shown in Figure 2, along the Z-axis direction, the display module 10 includes a cover plate 11 and a display panel 12 that are stacked, and the cover plate 11 is bonded to the display panel 12 through a transparent adhesive layer (not shown in the figure). The transparent adhesive layer is, for example, an optically clear adhesive (OCA) or the like. The display panel 12 includes, for example, an organic light emitting diode (OLED) display panel, a liquid crystal display panel (LCD) and an LED display panel, among which the LED display panel includes, for example, a Micro-LED display panel, a Mini-LED display panel, etc. The embodiment of the present application does not specifically limit the type of the display panel 12.

[0065] It should be noted that the display panel 12 is not limited to the 2D (Dimensions) display panel shown in Figures 1 and 2, but may also be a 2.5D curved display panel (not shown in the figures) or a 3D curved display panel (see Figure 3). When the display panel 12 is a 2.5D curved display panel or a 3D curved display panel, it may be a dual-curved display panel or a quad-curved display panel. Referring to Figure 3, when the display panel 12 is a dual-curved display panel, the display panel 12 includes not only a main display portion 121, but also includes a first curved display portion 122 located on opposite sides of the main display portion 121 along the X-axis direction. Referring to Figure 4, when the display panel 12 is a quad-curved display panel, the display panel 12 includes not only a main display portion 121, and a first curved display portion 122 located on opposite sides of the main display portion 121 along the X-axis direction, but also includes a second curved display portion 123 located on opposite sides of the main display portion 121 along the Y-axis direction.

[0066] It is understandable that in order to clearly illustrate the structure of the display panel 12 , the cover of the mobile phone 100 is not shown in FIG. 3 and FIG. 4 .

[0067] Correspondingly, when the display panel 12 is a 2.5D curved display panel or a 3D curved display panel, the cover plate 11 is also a 2.5D curved cover plate or a 3D curved cover plate. In other words, the cover plate is conformal to the display panel. For example, corresponding to FIG3 , when the display panel 12 includes a main display portion 121 and two first curved display portions 122, the cover plate 11 includes a straight portion opposite to the main display portion 121 and two first curved portions opposite to the first curved display portion 122. Corresponding to FIG4 , when the display panel 12 includes a main display portion 121, two first curved display portions 122, and two second curved display portions 123, the cover plate 11 includes a straight portion opposite to the main display portion 121, two first curved portions opposite to the first curved display portion 122, and two second curved portions opposite to the second curved display portion 123.

[0068] It should be noted that the main display portion 121 may be positioned relative to the straight portion such that the projection of the main display portion 121 on the plane formed by the X-axis and the Y-axis coincides with the projection of the straight portion on the plane formed by the X-axis and the Y-axis. The first curved display portion 122 may be positioned relative to the first curved portion such that the projection of the first curved display portion 122 on the plane formed by the X-axis and the Y-axis coincides with the projection of the first curved portion on the plane formed by the X-axis and the Y-axis, or the projection of the first curved display portion 122 on the plane formed by the X-axis and the Y-axis lies within the projection of the first curved portion on the plane formed by the X-axis and the Y-axis. The second curved display portion 123 may be positioned relative to the second curved portion such that the projection of the second curved display portion 123 on the plane formed by the X-axis and the Y-axis coincides with the projection of the second curved portion on the plane formed by the X-axis and the Y-axis, or the projection of the second curved display portion 123 on the plane formed by the X-axis and the Y-axis lies within the projection of the second curved portion on the plane formed by the X-axis and the Y-axis.

[0069] The following examples are all described by taking the display panel 10 as a 3D curved display panel and the cover plate 11 as a 3D curved cover plate as an example.

[0070] Continuing with Figures 1 and 2 , the back cover 20 is located on the side of the display panel 12 facing away from the cover plate 11 . The back cover 20 can be made of, for example, opaque materials such as plastic, plain leather, or fiberglass; or can be made of translucent materials such as glass. The present embodiment does not limit the material of the back cover 20 .

[0071] The middle frame 30 is located between the cover plate 11 and the back cover 20. The middle frame 30 includes an annular appearance part 31 and a support part 32 located inside the annular appearance part 31 and between the display panel 12 and the back cover 20. The cover plate 11, the annular appearance part 31 and the back cover 20 can enclose a housing cavity. The housing cavity is provided with the display panel 12, the printed circuit board (PCB) 40, the flexible printed circuit (FPC) 50, the battery 60, the speaker module 70, and the system on chip (SoC) and application processor (AP) arranged on the PCB 40 (not shown in the figure), and the structure in the housing cavity is supported by the support part 32 of the middle frame 30. For example, the display module 10 is provided on the support part 32 by means of adhesive, and the display module 10 is supported by the support part 32.

[0072] The cover plate 11 is, for example, a glass substrate. While the provision of a glass substrate can enhance the mechanical strength and wear resistance of the display panel 12, with the use of electronic devices such as mobile phones and tablets, the glass substrate comes into contact with hard objects, resulting in an increasing number of visible scratches on the surface of the glass cover plate, affecting the aesthetics of the electronic device. Furthermore, scratches may disrupt the stress balance of the cover plate 11, resulting in a decrease in the impact resistance of the cover plate 11.

[0073] Therefore, in order to improve the scratch resistance, the cover plate 11 further includes a protective structure. The protective structure is located on the side of the glass substrate facing away from the display panel 12 (ie, the side exposed to the outside) to improve the scratch resistance of the cover plate 11 .

[0074] For example, refer to Figure 5, which is a schematic diagram of the cross-sectional structure of a cover plate of the electronic device shown in Figure 4 of the embodiment of the present application along the AA' direction. As shown in Figure 5, the cover plate 11 includes a glass substrate 111 and a protective structure 112 located on one side of the glass substrate. The protective structure 112 is composed of three parts: a lower optical layer 1121, an anti-scratch layer 1122, and an upper optical layer 1123. Among them, the lower optical layer 1121 and the upper optical layer 1123 are composed of high-refractive index materials and low-refractive index materials alternately stacked to modulate the reflectivity of the protective structure 112 to visible light and improve the optical performance. The anti-scratch layer 1122 is composed of a high-refractive index material with high hardness, which can improve the scratch resistance of the cover plate 11.

[0075] According to the interference phenomenon caused by the diffraction principle of the optical film layer on light of different wavelengths, the thickness of the optical film determines the appearance color of the cover. The above-mentioned optical film layers (i.e., the lower optical layer 1121, the anti-scratch layer 1122, and the upper optical layer 1123) are all formed by coating using a deposition process. During coating, the cover is installed in such a way that when the normal of the large surface (straight portion 111) and the incident angle of the coating particles are 0°, the maximum deposition rate is obtained, and the normal of the 3D curved surface (the first curved portion and / or the second curved portion) and the incident angle of the coating particles are at a certain angle α. The film thickness and α are in a cosα variation relationship, that is, the thickness at the straight portion of the cover 11 is different from the thickness of the protective structure corresponding to the first curved portion and / or the second curved portion of the cover 11, resulting in the large surface and the 3D curved surface appearing inconsistent in color, affecting the appearance of the mobile phone.

[0076] For example, see Figure 6, which is a schematic diagram of another cover structure of the electronic device shown in Figure 4 according to an embodiment of the present application, taken along the AA' direction. As shown in Figure 6, the cover 11 includes a glass substrate 111 and a protective structure 112 located on one side of the glass substrate 111. The protective structure 112 is, for example, a single layer of diamond-like carbon (DLC) film. The DLC film has a high hardness, which can improve the scratch resistance of the cover 11.

[0077] While the DLC film layer doesn't cause color inconsistencies between the large and 3D curved surfaces, it does contain black graphite molecules, which have a strong light-absorbing ability and can affect the optical performance of the cover. Furthermore, due to its thinness (no more than 50nm), the DLC film is easily punctured, thus not significantly improving the cover's scratch resistance.

[0078] That is to say, the above-mentioned cover plate (including the glass substrate and the protective structure on the glass substrate) cannot simultaneously take into account the characteristics of good appearance and optical performance as well as strong scratch resistance.

[0079] Based on this, an embodiment of the present application provides a shell structure, which includes a substrate and a protective structure located on one side of the substrate, wherein the protective structure includes an anti-scratch layer, and the anti-scratch layer is formed by mixing at least two materials, and the at least two materials include at least one high refractive index material and at least one low refractive index material. The refractive index of this anti-scratch layer formed by mixing at least one high refractive index material and at least one low refractive index material is the same as or close to the refractive index of the substrate. In this way, the protective structure has no effect on the transmittance and reflectivity of the substrate, thereby avoiding inconsistent color of the cover plate caused by the thin edge area of ​​the protective structure. In addition, since the high refractive index material included in the anti-scratch layer is relatively dense and its thickness is between 300-5000nm, the anti-scratch layer has strong scratch resistance. In summary, the shell structure provided by the embodiment of the present application has both good appearance and optical properties and strong scratch resistance.

[0080] It should be noted that the housing structure can be the cover plate 11 in the display module 10, or the back cover 20 of a mobile phone, tablet computer, etc. Of course, the application scenarios of the housing structure are not limited to this. As long as the structure is used to improve the scratch resistance and optical performance of electronic devices, it is within the scope of protection of this application.

[0081] The specific structure of the housing structure and its preparation process are described in detail below. In order to more conveniently and clearly describe the subsequent solutions, the following examples are described using the housing structure as the cover plate 11 of the mobile phone 100 as an example, and the following content does not constitute a limitation of this application.

[0082] It can be understood that when the shell structure is the back cover 20 mentioned above, the specific structure of the back cover 20 and the effect produced are the same as the examples below where the shell structure is the cover plate 11. The specific structure and effect when the shell structure is the back cover 20 will not be repeated below.

[0083] First, the specific structure of the housing structure will be described.

[0084] Referring to Figure 7 , Figure 7 is a schematic cross-sectional view of a housing structure of the electronic device shown in Figure 4 according to an embodiment of the present application, taken along the AA' direction. As shown in Figure 7 , the housing structure 11 includes a substrate 111 and a protective structure 112 located on the side of the substrate 111 facing away from the display panel 12. The protective structure 112 includes a first base layer 1124 and an anti-scratch layer 1125. The first base layer 1124 is located between the substrate 111 and the anti-scratch layer 1125 to increase adhesion between the substrate 111 and the anti-scratch layer 1125, preventing film shedding and resulting in poor appearance, and improving the yield rate of the hard coating process.

[0085] The substrate 111 may include an inorganic glass system substrate such as microcrystalline glass, soda-lime glass, aluminosilicate glass, etc.; it may also include an organic substrate such as polymethyl methacrylate (PMMA) and polycarbonate (PC); it may also include a ceramic substrate.

[0086] Accordingly, the material of the first bottom layer 1124 includes silicon dioxide, aluminum oxide, zirconium dioxide, and other materials that are homogeneous with the material of the substrate 111 (the same material element as the substrate 111) or similar (the same family or adjacent to the material element of the substrate 111). For example, when the material of the substrate 111 is inorganic glass, since inorganic glass contains silicon dioxide, the material of the first bottom layer 1124 can be silicon dioxide, for example. When the material of the substrate 111 is sapphire, since sapphire contains aluminum oxide, the material of the first bottom layer 1124 can be aluminum oxide, for example. In this way, the substrate 111 and the first bottom layer 1124 can be better bonded.

[0087] In this case, the thickness H1 of the first bottom layer 1124 can be, for example, greater than or equal to 5 nm and less than or equal to 200 nm. This ensures that the first bottom layer 1124 is neither too thin, thereby preventing the adhesion between the substrate 111 and the anti-scratch layer 1125 from being increased, nor too thick, thereby preventing the first bottom layer 1124 from exhibiting its inherent properties. For example, if the first bottom layer 1124 is too thick, it may become brittle, impairing the scratch resistance. In the following examples, the thickness of the second bottom layer is the same, and these examples will not be repeated.

[0088] In some embodiments, the thickness H1 of the first bottom layer 1124 may be greater than or equal to 30 nm and less than or equal to 60 nm. For example, the thickness H1 of the first bottom layer 1124 may be 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm.

[0089] The anti-scratch layer 1125 is a film layer formed by mixing at least two materials, including at least one high-refractive-index material and at least one low-refractive-index material. In this application, the refractive index of the high-refractive-index material is generally defined as greater than 1.6, while the refractive index of the low-refractive-index material is generally less than or equal to 1.52. The high-refractive-index material in the anti-scratch layer 1125 can make the anti-scratch layer 1125 harder, improving its scratch resistance. The low-refractive-index material in the anti-scratch layer 1125 can make the overall refractive index of the anti-scratch layer 1125 the same as or similar to that of the substrate 111. When the overall refractive index of the anti-scratch layer 1125 is the same as or similar to that of the substrate 111, the effect is equivalent to simply increasing the thickness of the substrate 111, with little impact on the light transmittance and reflectivity of the substrate 111. Therefore, even if a first base layer 1124 and an anti-scratch layer 1125 are provided on the substrate 111, and the total thickness of the large surface corresponding to the first base layer 1124 and the anti-scratch layer 1125 is different from the thickness of the 3D curved surface corresponding to the first base layer 1124 and the anti-scratch layer 1125, it will not cause a difference in appearance color.

[0090] In addition, the thickness H2 of the anti-scratch layer 1125 can be greater than or equal to 300 nm and less than or equal to 5000 nm. In this way, the problem of easy puncture of the film layer due to the thin anti-scratch layer 1125 can be avoided, and the scratch resistance of the anti-scratch layer is further improved.

[0091] The high-refractive-index material may include, for example, silicon nitride, aluminum oxide, titanium nitride, tantalum oxide, or zirconium oxide, and the low-refractive-index material may include, for example, silicon dioxide, magnesium fluoride, or calcium fluoride. Of course, the high-refractive-index material and the low-refractive-index material are not limited to the types listed above, and those skilled in the art may select them based on actual circumstances. As long as the anti-scratch layer 1125 includes at least two materials, and the at least two materials include at least one high-refractive-index material and at least one low-refractive-index material, the material is within the scope of protection of this application.

[0092] In some embodiments, the refractive index of the anti-scratch layer 1125 satisfies the following formula: R0≤100%-R1-T1 (1)

[0093] Combined with Figure 8, Figure 8 is a schematic diagram of the optical reflection of the anti-scratch layer. As shown in Figure 8, R0 is the reflectivity of the anti-scratch layer; R1 is the reflectivity of the substrate; T1 is the transmittance of the shell structure; n0 is the refractive index of air 1; n1 is the refractive index of the anti-scratch layer; and n2 is the refractive index of the substrate.

[0094] This is because the sum of the transmittance and reflectance of the shell structure 11 is 100%, wherein the transmittance of the mobile phone cover needs to meet certain requirements, for example, the transmittance of the mobile phone cover is required to be ≥90.5%, and the reflectance is determined by the reflectance of the substrate and the reflectance of the anti-scratch layer. When the material of the substrate is determined, the reflectance of the substrate is also determined. For example, if the substrate is a glass substrate, the reflectance of the glass substrate is 4.2%. Therefore, the reflectance of the anti-scratch layer 1125 must meet the above formula (1), that is, the reflectance R0 of the anti-scratch layer can be determined according to formula (1). When the reflectance of the anti-scratch layer is known, the refractive index value of the anti-scratch layer can be determined according to formula (2).

[0095] For example, the substrate 111 is a glass substrate, the reflectivity R1 of the glass substrate is 4.2%, the refractive index n2 of the glass substrate is 1.52, and the transmittance T1 of the mobile phone cover is required to be ≥90.5%, n0 is 1, and by substituting the above formulas (1) and (2), it can be obtained that the refractive index of the anti-scratch layer n1≤1.56.

[0096] When the refractive index n1 of the anti-scratch layer is ≤1.56, the transmittance of the shell structure can be guaranteed to be above 90%, so that the film layer has no effect on the transmittance and reflectivity of the substrate 111 .

[0097] In this case, according to the Lorentz-Lorentz dispersion theory formula of the refractive index and component ratio of the multi-material mixture of the film, the refractive index n1 of the anti-scratch layer after the multi-material mixture satisfies the following formula:

[0098] Among them, a i =(n i 2 +2) -1 ,ρ i is the material density, C i is the material percentage concentration (i.e. mass fraction), n i is the refractive index of the material. The mass fraction of the high refractive index and the mass fraction of the low refractive index can be determined according to formula (3). In other words, by mixing the high refractive index material and the low refractive index material whose mass fractions are determined according to formula (3), a scratch-resistant layer having a refractive index below 1.56 can be obtained, thereby ensuring that the scratch-resistant layer 1125 has no effect on the transmittance and reflectivity of the substrate 111.

[0099] For example, the anti-scratch layer 1125 is formed by mixing two materials, namely, aluminum oxide (Al2O3) with a high refractive index material and silicon dioxide (SiO2) with a low refractive index material, or the anti-scratch layer 1125 is formed by mixing two materials, namely, silicon nitride (Si3N4) with a high refractive index material and silicon dioxide (SiO2) with a low refractive index material, wherein the weight concentration of the high refractive index material is C H , the density is ρ H, the refractive index is n H ; The percentage concentration of low refractive index material is C L , the density is ρ L , the refractive index is n L The percentage concentration of high refractive index material is C H , the density is ρ H , the refractive index is n H ; The percentage concentration of low refractive index material is C L (C L =1-C H ), the density is ρ L , the refractive index is n L Substitute it into formula (3), and then simplify formula (3) to obtain:

[0100] The calculation results are shown in Table 1 below:

[0101] Table 1 shows the relationship between the mass fraction of high refractive index material, the refractive index of the anti-scratch layer and the transmittance of the shell structure.

[0102] As shown in Table 1, when the anti-scratch layer 1125 is formed by mixing a high-refractive-index material, aluminum oxide (Al2O3), and a low-refractive-index material, silicon dioxide (SiO2), and the mass fraction of the high-refractive-index material, aluminum oxide (Al2O3), is less than or equal to 60%, the refractive index of the anti-scratch layer is less than or equal to 1.56. When the anti-scratch layer 1125 is formed by mixing a high-refractive-index material, silicon nitride (Si3N4), and a low-refractive-index material, silicon dioxide (SiO2), and the mass fraction of the high-refractive-index material, silicon nitride (Si3N4), is less than or equal to 30%, the refractive index of the anti-scratch layer is less than or equal to 1.56.

[0103] Furthermore, to prevent excessive Young's modulus of the anti-scratch layer 1125 from causing excessive stress in the film, which could lead to deformation of the substrate (baseboard 111) and decreased adhesion of the film (anti-scratch layer 1125), the Young's modulus of the anti-scratch layer 1125 must be greater than that of the substrate 111, and the relationship between the two must be 1 ≤ E1 / E3 ≤ 3, where E1 is the Young's modulus of the anti-scratch layer 1125 and E3 is the Young's modulus of the substrate 111. In other words, the Young's modulus of the anti-scratch layer 1125 should be 1-3 times that of the substrate 111.

[0104] To further adjust the exterior color of the housing structure, see Figure 9, which illustrates a film layer diagram of another housing structure provided in an embodiment of the present application. As shown in Figure 9, the protective structure 112 also includes an optical adjustment layer 1126, located on the side of the anti-scratch layer 1125 facing away from the first primer layer 1124, to adjust the optical performance and exterior color of the housing structure.

[0105] Regarding the material of the optical adjustment layer 1126, the embodiments of the present application do not limit the material of the optical adjustment layer 1126, and those skilled in the art can select the material according to actual circumstances. The optical adjustment layer 1126 can be composed of a single material or multiple materials. For example, when the optical adjustment layer 1126 is composed of a single material, the material of the optical adjustment layer 1126 can be, for example, one of silicon dioxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, etc.; when the optical adjustment layer 1126 is composed of multiple materials, the material of the optical adjustment layer 1126 can be, for example, at least two of silicon dioxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, etc.

[0106] As for the thickness of the optical adjustment layer 1126, those skilled in the art can design it based on the thickness of the anti-scratch layer 1125, the refractive index of the anti-scratch layer 1125, the refractive index of the optical adjustment layer 1126, and the color requirements of the optical adjustment layer 1126 (such as the color requirement of the optical adjustment layer 1126 is that the a and b values ​​are both ±1), and based on optical design software (such as optical thin film design software TFC, optical thin film analysis software Macleod, etc.).

[0107] Among them, the a and b values ​​are the a and b values ​​in the Lab colorimetry system, where the L component in the Lab colorimetry system is used to represent the brightness of the pixel, and its value range is [0, 100], representing from pure black to pure white; a represents the range from red to green, and its value range is [127, -128]; b represents the range from yellow to blue, and its value range is [127, -128].

[0108] For example, the thickness H3 of the optical adjustment layer 1126 may be less than or equal to 300 nm. In some embodiments, the thickness H3 of the optical adjustment layer 1126 may be greater than or equal to 60 nm and less than or equal to 80 nm. For example, the thickness H3 of the optical adjustment layer 1126 may be 60 nm, 65 nm, 70 nm, 75 nm, or 80 nm, etc.

[0109] To reduce damage to the housing structure caused by external friction with hard objects, see Figure 10, which is a schematic cross-sectional view of another housing structure along the AA' direction of the electronic device shown in Figure 4 of the embodiment of this application. As shown in Figure 10, the protective structure 112 also includes a second base layer 1127 and an anti-friction layer 1128. The second base layer 1127 is located between the optical adjustment layer 1126 and the anti-friction layer 1128 to increase the adhesion between the anti-friction layer 1128 and the optical adjustment layer 1126, while also improving the anti-friction layer 1128's resistance to alkali sweat.

[0110] For example, the second primer layer 1127 may include two layers, namely a first primer sublayer 11271 and a second primer sublayer 11272. The second primer sublayer 11272 is located on the side of the first primer sublayer 11271 facing away from the optical adjustment layer 1126. The second primer sublayer 11272 may be composed of, for example, SiO2, SiO, or a doped SiO2 material. The thickness of the second primer sublayer 11272 (along the Z-axis direction) is generally less than or equal to 50 nm. For example, the thickness of the second primer sublayer 11272 may be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, or 50 nm. The first primer sublayer 11271 may be composed of one or more materials having a Mohs hardness greater than 7. Materials having a Mohs hardness greater than 7 may include, for example, diamond-like carbon, diamond, carbon nitride, etc. The thickness (along the Z-axis direction) of the first primer sublayer 11271 may be less than or equal to 200 nm, that is, the thickness H4 of the second primer layer 1127 may be less than or equal to 250 nm. For example, the thickness of the first primer sublayer 11271 may be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, or 200 nm.

[0111] Of course, the second base layer 1127 is not limited to including two film layers. Referring to FIG. 11 , the second base layer 1127 may also include one film layer.

[0112] The coefficient of kinetic friction of the anti-friction layer 1128 can be, for example, greater than or equal to 0.01 and less than or equal to 0.1, and the water drop angle can be greater than, for example, 100°. Furthermore, due to the low friction, the surface is smoother to the touch and less likely to leave marks. Therefore, the anti-friction layer 1128 also has an anti-fingerprint (AF) function.

[0113] This is because when the user's finger touches the display module 10, friction will be generated between the finger and the cover plate, and the friction will damage the film layers of the cover plate. According to the friction formula: f = μ × Fn,

[0114] Among them, f is the friction force, Fn is the normal pressure, and μ is the friction coefficient.

[0115] Therefore, since the dynamic friction coefficient of the anti-friction layer 1128 in the embodiment of the present application is between 0.01 and 0.1, when the user touches the display module 10, the user can feel a smooth touch, thereby improving the user experience.

[0116] The present embodiment of the present application does not limit the material of the anti-friction layer 1128, as long as it meets the above-mentioned friction coefficient requirements. For example, the anti-friction layer 1128 may include an organic or inorganic material with low surface energy. Exemplarily, the material of the anti-friction layer 1128 may be perfluoropolyether (PFPE).

[0117] The present embodiment does not limit the thickness of the anti-friction layer 1128, and those skilled in the art can set it according to actual conditions. For example, the thickness H5 of the anti-friction layer 1128 can be greater than or equal to 3 nm and less than or equal to 50 nm.

[0118] In summary, the shell structure provided by the embodiment of the present application has a refractive index of 1.46-1.75 because the anti-scratch layer 1125 is composed of a mixture of high and low refractive index materials. This coating layer has no effect on the transmittance and reflectivity of the substrate 111. Thus, after coating, the film layer has high transmittance and low reflectivity, and even if the thickness of the large surface is different from that of the 3D curved surface, there will be no difference in appearance color. Furthermore, after coating, the shell structure has a Mohs hardness of 7 or above, and the film layer has enhanced puncture resistance. The provision of the optical adjustment layer 1126 modifies the optical properties of the substrate to meet optical performance requirements. By providing a first base layer 1124 between the substrate 111 and the anti-scratch layer 1125, and a second base layer 1127 between the anti-friction layer 1128 and the optical adjustment layer 1126, the film layer can be prevented from shedding and causing poor appearance, significantly improving the yield rate of the hard coating process. That is to say, the shell structure provided in the embodiment of the present application has strong anti-puncture ability, high transmittance and good tactile appearance.

[0119] In order to illustrate in detail the above-mentioned effects produced by the shell structure provided by the present application, the shell structure provided by the embodiment of the present application was tested, wherein the description is made by testing the shell structure shown in FIG. 10 .

[0120] Specifically: The adhesion of each film layer in the shell structure shown in FIG10 was measured using a micrometer scratch tester and was improved by 20-50%. For example, see FIG12, which is a comparative test diagram of the shell structure provided in the embodiment of the present application, wherein FIG12(1) is a test result diagram when the shell structure 11 provided in the embodiment of the present application does not include the first bottom layer 1124 and the second bottom layer 1127, and FIG12(2) is a test result diagram when the shell structure 11 provided in the embodiment of the present application includes the first bottom layer 1124 and the second bottom layer 1127. By comparison, it can be seen that when the shell structure 11 not including the first bottom layer 1124 and the second bottom layer 1127 is loaded with a force of 0.65N, there is a problem of falling off between the film layers of the shell structure 11; when the shell structure 11 including the first bottom layer 1124 and the second bottom layer 1127 is loaded with a force of 0.96N, there is no falling off between the film layers of the shell structure 11, that is, the adhesion between the film layers of the shell structure 11 provided in the embodiment of the present application is significantly improved.

[0121] The hardness of the shell structure shown in Figure 10 was measured using a nanoindenter. For example, the Vickers hardness was 1000-2600 HV and the Young's modulus was 80-170 GPa. The hardness test was performed using a Vickers indenter. The indentation depth of less than or equal to about 100 nm was measured on the surface of the hard film system, and the hardness was greater than or equal to about 1100 HV. The surface hardness of each of the above-mentioned film layers (the first base layer 1124, the anti-scratch layer 1125, the optical adjustment layer 1126, the second base layer 1127 and the anti-friction layer 1128) was set on the substrate 111 using a Mohs hardness pen. The Mohs hardness pen was loaded with a weight of 500 grams. The Mohs hardness was measured to be above 7. That is, the shell structure 11 provided in the embodiment of the present application has a large hardness and the film layer has a strong anti-puncture ability.

[0122] The optical performance of the housing structure 11 was tested using a spectrophotometer, and the results showed that the reflectivity of the housing structure in the wavelength range of 380-780nm was less than 15%, and the transmittance was greater than 85%. This means that the housing structure 11 provided in this embodiment of the application has good optical performance.

[0123] According to the International Commission on Illumination, under normal incidence conditions, in the (L*, a*, b*) colorimeter system, the reflected color values ​​a and b are ±1, and the transmitted color values ​​a and b are ±1. This means that the external light color of the housing structure 11 provided in this embodiment of the application is good.

[0124] In summary, after testing, it can be seen that the shell structure provided in the embodiment of the present application has not only greater hardness and strong anti-puncture ability, but also higher transmittance and better appearance, and can greatly improve the yield of the hard coating process.

[0125] It should be noted that the above tests were conducted using one housing structure (the housing structure shown in FIG10 ) as an example, and are intended to demonstrate that the housing structure 11 provided herein has greater hardness, stronger puncture resistance, higher transmittance, and better appearance, while significantly improving the yield rate of the hard coating process. In practice, the Vickers hardness, transmittance, and other results obtained when testing different housing structures 11 are not limited to the above example.

[0126] The above describes the specific structure of the housing structure 11. The following describes the process for preparing the housing structure in conjunction with the housing structure shown in FIG11. Since the method for preparing this housing structure can be used, for example, to prepare the aforementioned housing structure, it has the same beneficial effects as the aforementioned housing structure. For details not fully described in this embodiment, reference can be made to the aforementioned embodiment of the housing structure.

[0127] Referring to FIG. 13 , FIG. 13 is a flow chart of a method for preparing a shell structure provided in an embodiment of the present application. As shown in FIG. 13 , the steps of the method for preparing a shell structure provided in an embodiment of the present application specifically include:

[0128] S131 , cleaning the substrate 111 .

[0129] For example, the substrate is a glass substrate, and the glass substrate is placed in a magnetron sputtering machine and cleaned with argon ions.

[0130] Among them, the background vacuum degree is 1×10 -3 During the experiment, Ar gas was first introduced to 0.5 Pa, and a capacitively coupled plasma source was used to generate Ar+ plasma to clean the sample surface for 10 min to remove surface pollutants and adsorbed gases.

[0131] S132 , depositing a film on one side of the substrate 111 to form a first bottom layer 1124 .

[0132] Specifically, the designed thickness is input into the coating machine, and then the process parameters are set: for example, the background vacuum is 5.0×10 -4 Pa, the temperature is set to: 80 degrees Celsius; specific parameters: ion source (RadicalSource): 4500W; Ar flow: 200sccm; O2 flow: 120sccm; N2 flow: 0sccm; coating time Time: 240s, to obtain the first bottom layer SiO2, and its thickness is 40-80nm.

[0133] S133 , depositing a film on the side of the first base layer 1124 facing away from the substrate 111 to form an anti-scratch layer 1125 .

[0134] The scratch-resistant layer 1125 is, for example, composed of SiO2 (a low-refractive-index material) and Si3N4 (a high-refractive-index material). According to Table 1, the scratch-resistant layer is designed to have a refractive index of 1.6 and a thickness of 2000 nm.

[0135] Set process parameters: For example, background vacuum 5.0×10 -4 Pa, in order to obtain the above designed SiON (SiO2-Si3N4), the coating parameters are set as follows: sputtering power of silicon target: 7500W; Ar flow: 120sccm; N2 flow: 80sccm; Oxygen flow: 30sccm; RadicalSource power: 4500W, and the equipment input requirement thickness is 2000nm.

[0136] S134 , depositing a film on the side of the anti-scratch layer 1125 facing away from the first base layer 1124 to form an optical adjustment layer 1126 .

[0137] S135 , a deposition method is used to coat the side of the optical adjustment layer 1126 away from the anti-scratch layer 1125 to form a second base layer 1127 .

[0138] For example, the second bottom layer is a SiO2 bottom layer. To obtain the SiO2 bottom layer, the coating parameters set are: silicon target sputtering power: 8 kW; Ar flow rate: 200 sccm; O2 flow rate: 120 sccm; coating time: 6-10 minutes, resulting in a silicon dioxide film with a thickness of 40-80 nm.

[0139] S136 , depositing a film on the side of the second base layer 1127 away from the optical adjustment layer 1126 to form an anti-friction layer 1128 .

[0140] The process parameters are set as follows: for example, the background vacuum of the anti-friction layer is 5.0×10 -3 Pa; Specific parameters: Power: 1-5KW; Coating pressure 5.0×10 -2 Pa, coating time: 6min.

[0141] Optionally, in order to enhance the adhesion between the film layers, the second base layer 1127 is subjected to an anodic plasma treatment before the anti-friction layer 1128 is plated.

[0142] The shell structure shown in Figure 11 can be obtained through the above steps. Then, the shell structure formed by this method is tested to obtain the following optical properties: 91.1% transmittance and 8.4% reflectivity in the 380-780nm band. Vickers indenter hardness test, the indentation depth of less than or equal to about 100nm was measured on the hard AR surface, and the hardness was 1280HV; the Mohs hardness test reached 500g force, greater than 7, the transmittance color A value was 0.73, the B value was -0.87, the reflectance color A value was -0.34, and the B value was 0.68, that is, the shell structure provided in the embodiment of the present application has greater hardness, stronger anti-puncture ability, higher transmittance and better appearance.

[0143] The preparation process of the shell structure is not limited thereto. The preparation process of the shell structure will be described below with reference to the shell structure shown in FIG. 10 .

[0144] Referring to FIG. 14 , FIG. 14 is a flow chart of another method for preparing a shell structure provided in an embodiment of the present application. As shown in FIG. 14 , the steps of the method for preparing a shell structure provided in an embodiment of the present application specifically include:

[0145] S141 , cleaning the substrate 111 .

[0146] For example, the substrate is a glass substrate, and the glass substrate is placed in a magnetron sputtering machine and cleaned with argon ions.

[0147] Among them, the background vacuum degree is 1×10 -3 During the experiment, Ar gas was first introduced to 0.5 Pa, and a capacitively coupled plasma source was used to generate Ar+ plasma to clean the sample surface for 10 min to remove surface pollutants and adsorbed gases.

[0148] S142 , depositing a film on one side of the substrate 111 to form a first bottom layer 1124 .

[0149] Specifically, the designed thickness is input into the coating machine, and then the process parameters are set: for example, the background vacuum is 5.0×10 -4 Pa, the temperature is set to: 80 degrees Celsius; specific parameters: ion source (RadicalSource): 4500W; Ar flow: 200sccm; O2 flow: 120sccm; N2 flow: 0sccm; coating time Time: 240s, to obtain the first bottom layer SiO2, and its thickness is 40-80nm.

[0150] S143 , depositing a film on the side of the first base layer 1124 facing away from the substrate 111 to form an anti-scratch layer 1125 .

[0151] The scratch-resistant layer 1125 is, for example, composed of SiO2 (a low-refractive-index material) and Si3N4 (a high-refractive-index material). According to Table 1, the scratch-resistant layer is designed to have a refractive index of 1.75 and a thickness of 1500 nm.

[0152] Set process parameters: For example, background vacuum 5.0×10 -4 Pa, in order to obtain the above designed SiON (SiO2-Si3N4), the coating parameters are set as follows: sputtering power of silicon target: 7500W; Ar flow: 120sccm; N2 flow: 80sccm; Oxygen flow: 20sccm; RadicalSource power: 4500W, and the equipment input requirement thickness is 1500nm.

[0153] S144 , depositing a film on the side of the anti-scratch layer 1125 facing away from the first base layer 1124 to form an optical adjustment layer 1126 .

[0154] The optical adjustment layer 1126 is made of silicon dioxide, for example. To obtain the optical adjustment layer SiO2, the coating parameters were set as follows: silicon target sputtering power: 8 kW, Ar flow rate: 200 sccm, O2 flow rate: 120 sccm, and coating time: 6-10 minutes, resulting in a 40-80 nm thick silicon dioxide film.

[0155] S145 , a deposition method is used to coat the side of the optical adjustment layer 1126 away from the anti-scratch layer to form a first primer sub-layer 11271 .

[0156] For example, in order to obtain a bottom hard film CN, the coating parameters are set as follows: sputtering power of C target: 8KW, Ar flow rate: 250sccm, N2 flow rate: 120sccm, coating time 5min, and a CN film layer with a thickness of 5-20nm is obtained.

[0157] S146: Deposition is performed on the side of the first priming sub-layer 11271 facing away from the optical adjustment layer 1126 to form a second priming sub-layer 11272. For example, to obtain a priming SiO2 film, the following deposition parameters are set: silicon target sputtering power: 8 kW, Ar flow rate: 200 sccm, O2 flow rate: 120 sccm, and deposition time: 2 minutes, resulting in a 3-20 nm thick silicon dioxide film.

[0158] S147 , coating the second base sub-layer 11272 on a side facing away from the optical adjustment layer by a deposition method to form an anti-friction layer 1128 .

[0159] The process parameters are set as follows: for example, the background vacuum of the anti-friction layer is 5.0×10-3 Pa; Specific parameters: Power: 1-5KW; Coating pressure 5.0×10 -2 Pa, coating time: 6min.

[0160] Optionally, in order to enhance the adhesion between the film layers, the second base layer 1127 is subjected to an anodic plasma treatment before the anti-friction layer 1128 is plated.

[0161] The shell structure shown in Figure 10 can be obtained through the above steps. Then, the shell structure formed by this method is tested to obtain the following optical properties: 92.4% transmittance and 7.4% reflectivity in the 380-780nm band. Vickers indenter hardness test, the indentation depth of less than or equal to about 100nm was measured on the hard AR surface, and the hardness was 1580HV; the Mohs hardness test reached 1500g force, greater than 7, the transmittance color A value was 0.02, the B value was -0.07, the reflectance color A value was 0.43, and the B value was 0.57, that is, the shell structure provided in the embodiment of the present application has greater hardness, stronger anti-puncture ability, higher transmittance and better appearance.

[0162] It should be noted that various deposition methods can be used in the above-mentioned film coating production methods. For example, vacuum deposition techniques, such as chemical vapor deposition (such as plasma-enhanced chemical vapor deposition (PECVD), low-pressure chemical vapor deposition, atmospheric pressure chemical vapor deposition, and plasma-enhanced atmospheric pressure chemical vapor deposition), physical vapor deposition (for example, reactive or non-reactive sputtering or laser ablation), thermal or electron beam evaporation, or atomic layer deposition, can be used to form each film layer. Liquid-based methods such as spray coating, dip coating, spin coating, or slot coating (for example, using sol-gel materials) can also be used.

[0163] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A shell structure, It is characterized in that include: A substrate and an anti-scratch layer located on one side of the substrate; The anti-scratch layer comprises at least two materials, wherein the at least two materials comprise at least one high refractive index material and at least one low refractive index material; The thickness of the anti-scratch layer is greater than or equal to 300 nm and less than or equal to 5000 nm; The refractive index of the low-refractive-index material is less than or equal to the refractive index of the substrate, and the refractive index of the high-refractive-index material is greater than 1.

6.

2. The housing structure according to claim 1, It is characterized in that The shell structure further includes a first coating layer located between the substrate and the anti-scratch layer, and used for improving the adhesion between the substrate and the anti-scratch layer.

3. The housing structure according to claim 2, It is characterized in that The material of the first primer layer is the same as the material element of the substrate; or, is of the same family or adjacent to the material element of the substrate.

4. The housing structure according to claim 2, It is characterized in that The thickness of the first primer layer is greater than or equal to 5 nm and less than or equal to 200 nm.

5. The housing structure according to any one of claims 1 to 4, It is characterized in that The shell structure further includes an optical adjustment layer, which is located on a side of the anti-scratch layer away from the substrate and is used to adjust the appearance color of the shell structure.

6. The housing structure according to claim 5, It is characterized in that The thickness of the optical adjustment layer is less than or equal to 300 nm.

7. The housing structure according to claim 5, It is characterized in that The material of the optical adjustment layer includes at least one of silicon dioxide, titanium dioxide, tantalum pentoxide and niobium pentoxide.

8. The housing structure according to any one of claims 1 to 7, It is characterized in that The housing structure further comprises a friction reducing layer located on a side of the anti-scratch layer facing away from the substrate.

9. The housing structure according to claim 8, It is characterized in that The dynamic friction coefficient of the anti-friction layer is greater than or equal to 0.01 and less than or equal to 0.1, and the water drop angle is greater than 100°.

10. The housing structure according to claim 8, It is characterized in that The thickness of the anti-friction layer is greater than or equal to 3 nm and less than or equal to 50 nm.

11. The housing structure according to claim 8, It is characterized in that The anti-friction layer is composed of organic materials and inorganic materials with low surface energy.

12. The housing structure according to claim 8, It is characterized in that The shell structure further includes a second primer layer, which is located between the anti-friction layer and the anti-scratch layer and is used to improve the adhesion of the anti-friction layer.

13. The housing structure according to claim 12, It is characterized in that The second primer layer includes a first primer sublayer and a second primer sublayer, wherein the second primer sublayer is located on a side of the first primer sublayer away from the anti-scratch layer.

14. The housing structure according to claim 13, It is characterized in that The thickness of the first primer sublayer is less than or equal to 200 nm; the thickness of the second primer sublayer is less than or equal to 50 nm.

15. The housing structure according to claim 13, It is characterized in that The material of the second primer sublayer includes silicon monoxide, silicon dioxide or a material doped with silicon dioxide; the material of the first primer sublayer includes diamond-like carbon, diamond or carbon nitride.

16. The housing structure according to claim 1, It is characterized in that The refractive index of the anti-scratch layer satisfies the following formula: R0≤100%-R1-T1 Among them, R0 is the reflectivity of the anti-scratch layer; R1 is the reflectivity of the substrate; T1 is the transmittance of the shell structure; n0 is the refractive index of air 1; n1 is the refractive index of the anti-scratch layer; n2 is the refractive index of the substrate.

17. The housing structure according to claim 16, It is characterized in that The mass fractions of the high refractive index material and the low refractive index material satisfy: Among them, a i =(n i 2 +2) -1 , ρ i is the material density, C i is the material mass fraction, n i is the material refractive index.

18. The housing structure according to claim 17, It is characterized in that The anti-scratch layer is formed by mixing two materials, aluminum oxide and silicon dioxide, the mass fraction of the aluminum oxide is less than or equal to 80%, and the refractive index of the anti-scratch layer is less than or equal to 1.

7.

19. The housing structure according to claim 17, It is characterized in that The anti-scratch layer is formed by mixing silicon nitride and silicon dioxide, the mass fraction of silicon nitride is less than or equal to 60%, and the refractive index of the anti-scratch layer is less than or equal to 1.

7.

20. The housing structure according to claim 1, It is characterized in that The anti-scratch layer is formed by a deposition process.

21. A display module, It is characterized in that The invention comprises a shell structure as described in any one of claims 1 to 20.

22. An electronic device, It is characterized in that The invention comprises a shell structure as described in any one of claims 1 to 20.

23. The electronic device according to claim 22, It is characterized in that The electronic device comprises a display module, the display module comprises a display panel and a cover plate located at one side of the display panel, and the housing structure is the cover plate of the electronic device.

24. The electronic device according to claim 22, It is characterized in that The electronic device comprises a back cover, and the housing structure is the back cover of the electronic device.

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