Electronic equipment, rear cover and preparation method of rear cover

Abstract

The invention relates to electronic equipment, a rear cover and a preparation method of the rear cover. The rear cover comprises two organic synthetic fiber layers and at least one first inorganic fiber layer, and the at least one first inorganic fiber layer is stacked between the two organic synthetic fiber layers. According to the rear cover, the composite material formed by the organic synthetic fiber material and the first inorganic fiber material is adopted, the organic synthetic fibers on the surface layer are good in toughness and appearance attribute texture and can provide strength and rigidity in the X direction and the Y direction, the first inorganic fibers in the middle can provide strength and rigidity in the Z direction, and the organic synthetic fibers and the first inorganic fibers are organically compounded; therefore, the rear cover with high strength and rigidity in three-dimensional directions is formed. Moreover, a sandwich structure is adopted, stress can be balanced, and damage caused by difference of thermal expansion coefficients is avoided.

Description

Technical Field

[0001] The present disclosure relates to the technical field of housing design, and in particular to an electronic device, a back cover and a preparation method thereof. Background Art

[0002] With the growing demand for thinner and lighter consumer electronic products, thinner back cover technology solutions have become a research focus. Traditional back covers are divided into four types of materials: second inorganic, plastic, first inorganic, and composite panels. Due to process technology barriers and material mechanical properties limitations, these four types of materials have reached the lower limit of thinness. In order to further break through the lower limit, composite materials that can achieve ultra-thin molding and high specific strength in terms of process have become the focus of development. Summary of the invention

[0003] The present disclosure provides an electronic device, a back cover and a method for manufacturing the same to address deficiencies in the related art.

[0004] In a first aspect, an embodiment of the present disclosure provides a back cover, comprising: two layers of organic synthetic fiber layers and at least one layer of first inorganic fiber layer, wherein the at least one layer of first inorganic fiber layer is stacked between the two layers of the organic synthetic fiber layers.

[0005] Optionally, the first inorganic fiber layer is a single layer, and the back cover further includes at least one second inorganic fiber layer, wherein the second inorganic fiber layer is disposed between at least one of the two organic synthetic fiber layers and the first inorganic fiber layer.

[0006] Optionally, at least one resin layer is further included, and the resin layer is arranged between the first inorganic fiber layer and the second inorganic fiber layer and between the organic synthetic fiber layer and the second inorganic fiber layer.

[0007] Optionally, the first inorganic fiber layer is at least two layers, and the back cover further includes at least one second inorganic fiber layer, which is arranged at least between the first inorganic fiber layer and the organic synthetic fiber layer and between two adjacent first inorganic fiber layers.

[0008] Optionally, at least one resin layer is further included, and the resin layer is arranged between the first inorganic fiber layer and the second inorganic fiber layer, between the organic synthetic fiber layer and the second inorganic fiber layer, and between two adjacent first inorganic fiber layers.

[0009] Optionally, it further comprises at least one resin layer, wherein the resin layer is disposed between the organic synthetic fiber layer and the first inorganic fiber layer and between two adjacent first inorganic fiber layers; and / or

[0010] The organic synthetic fiber layer comprises an aramid fiber layer; and / or

[0011] The first inorganic fiber layer includes a ceramic fiber layer.

[0012] Optionally, the second inorganic fiber layer includes a glass fiber layer.

[0013] In a second aspect, an embodiment of the present disclosure provides a method for preparing a back cover, comprising:

[0014] stacking at least one first inorganic fiber layer on the first organic synthetic fiber layer, and stacking a second organic synthetic fiber layer on the at least one first inorganic fiber layer to form a composite material body;

[0015] The composite body is hot-pressed into shape.

[0016] Optionally, at least one first inorganic fiber layer is stacked on the first organic synthetic fiber layer, and a second organic synthetic fiber layer is stacked on the at least one first inorganic fiber layer, comprising:

[0017] The second inorganic fiber layer is stacked at least between the first organic synthetic fiber layer and the adjacent first inorganic fiber layer, between two adjacent first inorganic fiber layers, and between the second organic synthetic fiber layer and the adjacent first inorganic fiber layer.

[0018] Optionally, the second inorganic fiber layer includes a glass fiber layer.

[0019] Optionally, a second inorganic fiber layer is stacked at least one of between a first organic synthetic fiber layer and an adjacent first inorganic fiber layer, between two adjacent first inorganic fiber layers, and between a second organic synthetic fiber layer and an adjacent first inorganic fiber layer, comprising:

[0020] A resin layer is stacked between the first organic synthetic fiber layer and the adjacent second inorganic fiber layer, between the first inorganic fiber layer and the adjacent second inorganic fiber layer, and between the second organic synthetic fiber layer and the adjacent second inorganic fiber layer.

[0021] Optionally, at least one first inorganic fiber layer is stacked on the first organic synthetic fiber layer, and a second organic synthetic fiber layer is stacked on the at least one first inorganic fiber layer, comprising:

[0022] A resin layer is stacked between the first organic synthetic fiber layer and the adjacent first inorganic fiber layer, between two adjacent first inorganic fiber layers, and between the second organic synthetic fiber layer and the adjacent first inorganic fiber layer.

[0023] Optionally, after the composite material body is hot-pressed, the method further comprises:

[0024] The composite material body formed by hot pressing is laser processed and cut according to a set shape.

[0025] Optionally, before stacking at least one first inorganic fiber layer on the first organic synthetic fiber layer and stacking a second organic synthetic fiber layer on the at least one first inorganic fiber layer to form the composite material body, the method further comprises:

[0026] The organic synthetic fiber layer and the first inorganic fiber layer are cut according to set sizes.

[0027] Optionally, hot pressing the composite body comprises:

[0028] Thermoforming temperature is higher than 150°C and lower than 200°C; and / or

[0029] Thermoforming time is less than 15 minutes; and / or

[0030] The hot pressing pressure is not less than 15MPa.

[0031] Optionally, the organic synthetic fiber layer comprises an aramid fiber layer; and / or

[0032] The first inorganic fiber layer includes a ceramic fiber layer.

[0033] In a third aspect, an embodiment of the present disclosure provides an electronic device, comprising a back cover as described in the first aspect.

[0034] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0035] From the above embodiments, it can be seen that the back cover of the present disclosure is a composite material formed by an organic synthetic fiber material and a first inorganic fiber material. The organic synthetic fiber on the surface has good toughness and good appearance and texture, and can provide strength and rigidity in the XY direction. The first inorganic fiber in the middle can provide strength and rigidity in the Z direction. The two are organically composited to form a back cover with high strength and rigidity in three directions. In addition, the sandwich structure can balance stress and avoid damage caused by differences in thermal expansion coefficients.

[0036] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0038] Figure 1is a schematic structural diagram of a back cover according to an exemplary embodiment.

[0039] Figure 2 is a schematic structural diagram of a back cover according to another exemplary embodiment.

[0040] Figure 3 is a schematic structural diagram of a back cover according to yet another exemplary embodiment.

[0041] Figure 4 It is a schematic flow chart of a method for preparing a back cover according to an exemplary embodiment. DETAILED DESCRIPTION

[0042] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0043] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0044] In order to facilitate understanding of the technical solution of the present disclosure, the electronic device, the back cover and the manufacturing method thereof are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0045] See also Figure 1As shown, the embodiment of the present disclosure provides a back cover, which can be applied to electronic devices, and can also be expanded to structural appearance parts in other fields, such as consumer electronic products, automobile interiors, home accessories, etc. It includes: two layers of organic synthetic fiber layers 10 and at least one first inorganic fiber layer 20, and the at least one first inorganic fiber layer 20 is laminated between the two layers of organic synthetic fiber layers 10. Optionally, the organic synthetic fiber layer 10 may include an aramid fiber layer, and the aramid fiber may include models such as Kevlar 29, Kevlar49, and Kevlar 119. The first inorganic fiber layer 20 may include a ceramic fiber layer, and the ceramic fiber may include models such as Nextel 312, Nextel 440, Nextel 610, and Nextel 720. It should be noted that the number of layers of the first inorganic fiber layer 20 can be set according to actual needs, and the present disclosure does not limit this.

[0046] It can be seen from the above embodiments that the back cover of the present invention is a composite material formed by an organic synthetic fiber material and a first inorganic fiber material. The organic synthetic fiber on the surface has good toughness and good appearance and texture, and can provide strength and rigidity in the XY direction. The first inorganic fiber in the middle can provide strength and rigidity in the Z direction. The two are organically compounded to form a back cover with high strength and rigidity in all three directions. In addition, the sandwich structure can balance stress and avoid damage caused by differences in thermal expansion coefficients. In this way, through material design, aramid fiber composite materials and ceramic fiber composite materials are used for compounding. The modulus of ceramic fiber can be as high as 370GPa, which can provide higher strength and rigidity. Aramid fiber, as a special fiber used in bulletproof clothing, can provide better toughness, so that the back cover has both high strength and impact resistance. The composite material after compounding is an ultra-high performance composite back cover with both strength and toughness, which can form a composite back cover with ultra-high strength. By improving the strength of the back cover material, compared with the current smallest back cover of 0.7mm thickness on the market, the back cover can be thinned to 0.55mm thickness.

[0047] In some optional embodiments, the back cover may further include at least one resin layer, which is disposed between the organic synthetic fiber layer 10 and the first inorganic fiber layer 20 and between two adjacent first inorganic fiber layers 20. After being hot-pressed, the resin layer can connect the organic synthetic fiber layers 10 and the first inorganic fiber layers 20 to each other.

[0048] See also Figure 2As shown, in some optional embodiments, the first inorganic fiber layer 20 is a single layer, and the back cover may further include at least one second inorganic fiber layer 30, and the second inorganic fiber layer 30 is disposed between at least one of the two organic synthetic fiber layers 10 and the first inorganic fiber layer 20. In this embodiment, the second inorganic fiber layer 30 is disposed between the two organic synthetic fiber layers 10 and the first inorganic fiber layer 20. Optionally, the second inorganic fiber layer 30 may include a glass fiber layer, and the glass fiber may limit the ceramic fiber.

[0049] Furthermore, the back cover may further include at least one resin layer, which is disposed between the first inorganic fiber layer 20 and the second inorganic fiber layer 30 and between the organic synthetic fiber layer 10 and the second inorganic fiber layer 30. After being hot-pressed, the resin layer can connect the fiber layers to each other.

[0050] See also Figure 3 As shown, in some optional embodiments, the first inorganic fiber layer 20 is at least two layers, and the back cover may further include at least one second inorganic fiber layer 30, and the second inorganic fiber layer 30 is disposed between the first inorganic fiber layer 20 and the organic synthetic fiber layer 10 and between two adjacent first inorganic fiber layers 20. In this embodiment, the first inorganic fiber layer 20 is two layers, and the second inorganic fiber layer 30 is disposed between the two first inorganic fiber layers 20. Optionally, the second inorganic fiber layer 30 may include a glass fiber layer, and the glass fiber may limit the ceramic fiber.

[0051] Furthermore, the back cover may also include at least one resin layer, which is disposed between the first inorganic fiber layer 20 and the second inorganic fiber layer 30, between the organic synthetic fiber layer 10 and the second inorganic fiber layer 30, and between two adjacent first inorganic fiber layers 20. After being hot-pressed, the resin layer can connect the fiber layers to each other.

[0052] It is understandable that during the hot pressing process, due to the fluidity of the resin, the ceramic fibers will be spread out, resulting in unevenness, uneven appearance and other undesirable conditions. Therefore, by adding a glass fiber layer, the reverse limit control of the ceramic fibers can be achieved, which plays a certain limiting role to reduce the occurrence of the above-mentioned undesirable conditions, solve the pain point problem of the molding of unidirectional tape fibers and woven cloth composite materials of ceramic fibers, and solve the problems of poor flatness and product warping deformation during the molding of different types of composite materials. It should be noted that the number of layers of the first inorganic fiber layer 20 and the second inorganic fiber layer 30 can be set according to actual needs, and the present disclosure does not limit this.

[0053] The disclosed embodiment also provides an electronic device, which may be a consumer electronic product such as a mobile phone or a tablet computer. The electronic device includes the back cover described in the above embodiment and implementation method.

[0054] It can be seen from the above embodiments that the electronic device disclosed in the present invention has a back cover made of a composite material formed by an organic synthetic fiber material and a first inorganic fiber material. The organic synthetic fiber on the surface has good toughness and good appearance and texture, and can provide strength and rigidity in the XY direction. The first inorganic fiber in the middle can provide strength and rigidity in the Z direction. The two are organically compounded to form a back cover with high strength and rigidity in all three directions. In addition, a sandwich structure is adopted to balance stress and avoid damage caused by differences in thermal expansion coefficients. In this way, through material design, aramid fiber composite materials and ceramic fiber composite materials are used for compounding. The modulus of ceramic fiber can be as high as 370GPa, which can provide higher strength and rigidity. Aramid fiber, as a special fiber used in bulletproof clothing, can provide better toughness. The composite material after compounding is an ultra-high performance composite back cover with both strength and toughness, which can form a composite back cover with ultra-high strength. By improving the strength of the back cover material, compared with the current smallest back cover of 0.7mm thickness on the market, the back cover can be thinned to 0.55mm thickness, realizing the design requirements of lightweight and miniaturized products.

[0055] See also Figure 4 Combined with Figure 1 As shown, the embodiment of the present disclosure also provides a method for preparing a back cover, comprising the following steps S11-S112:

[0056] Step S11: stacking at least one first inorganic fiber layer 20 on the first organic synthetic fiber layer 10, and stacking a second organic synthetic fiber layer 10 on at least one first inorganic fiber layer 20, to form a composite material body. Optionally, the organic synthetic fiber layer 10 may include an aramid fiber layer, and the aramid fiber may include models such as Kevlar29, Kevlar49, and Kevlar 119. The first inorganic fiber layer 20 may include a ceramic fiber layer, and the ceramic fiber may include models such as Nextel 312, Nextel 440, Nextel 610, and Nextel 720. It should be noted that the number of layers of the first inorganic fiber layer 20 can be set according to actual needs, and the present disclosure does not limit this.

[0057] Step S12: hot press molding the composite material body. Optionally, hot press molding the composite material body may further include the following parameter setting requirements: hot press molding temperature is higher than 150° C. and lower than 200° C. Hot press molding time is lower than 15 min. Hot press molding pressure is not less than 15 MPa.

[0058] It can be seen from the above embodiments that the preparation method of the back cover disclosed in the present invention adopts a composite material formed by an organic synthetic fiber material and a first inorganic fiber material. The organic synthetic fiber on the surface has good toughness and good appearance and texture, and can provide strength and rigidity in the XY direction. The first inorganic fiber in the middle can provide strength and rigidity in the Z direction. The two are organically compounded to form a back cover with high strength and rigidity in all three directions. In addition, the sandwich structure can balance stress and avoid damage caused by differences in thermal expansion coefficients. In this way, through material design, aramid fiber composite materials and ceramic fiber composite materials are used for compounding. The modulus of ceramic fiber can be as high as 370GPa, which can provide higher strength and rigidity. Aramid fiber, as a special fiber used in bulletproof clothing, can provide better toughness. The composite material after compounding is an ultra-high performance composite back cover with both strength and toughness, which can form a composite back cover with ultra-high strength. By improving the strength of the back cover material, compared with the current smallest back cover of 0.7mm thickness on the market, the back cover can be thinned to 0.55mm thickness.

[0059] In some optional embodiments, in the above step S11, stacking at least one first inorganic fiber layer 20 on the first organic synthetic fiber layer 10, and stacking the second organic synthetic fiber layer 10 on at least one first inorganic fiber layer 20, may further include: stacking a resin layer between the first organic synthetic fiber layer 10 and the adjacent first inorganic fiber layer 20, between two adjacent first inorganic fiber layers 20, and between the second organic synthetic fiber layer 10 and the adjacent first inorganic fiber layer 20. After the resin layer is hot-pressed, it can play a role in connecting the fiber layers to each other.

[0060] Combination Figure 2 and Figure 3 As shown, in some optional embodiments, in the above step S11, at least one first inorganic fiber layer 20 is stacked on the first organic synthetic fiber layer 10, and the second organic synthetic fiber layer 10 is stacked on the at least one first inorganic fiber layer 20, which may further include: stacking a second inorganic fiber layer 30 at least one of between the first organic synthetic fiber layer 10 and the adjacent first inorganic fiber layer 20, between two adjacent first inorganic fiber layers 20, and between the second organic synthetic fiber layer 10 and the adjacent first inorganic fiber layer 20. Optionally, the second inorganic fiber layer 30 may include a glass fiber layer, and the glass fiber may limit the ceramic fiber.

[0061] Furthermore, stacking the second inorganic fiber layer 30 at least one of between the first organic synthetic fiber layer 10 and the adjacent first inorganic fiber layer 20, between two adjacent first inorganic fiber layers 20, and between the second organic synthetic fiber layer 10 and the adjacent first inorganic fiber layer 20 may further include stacking a resin layer between the first organic synthetic fiber layer 10 and the adjacent second inorganic fiber layer 30, between the first inorganic fiber layer 20 and the adjacent second inorganic fiber layer 30, and between the second organic synthetic fiber layer 10 and the adjacent second inorganic fiber layer 30. After the resin layer is thermoformed, it can play a role in connecting the fiber layers to each other.

[0062] It is understandable that during the hot pressing process, due to the fluidity of the resin, the ceramic fibers will be spread out, resulting in unevenness, uneven appearance and other undesirable conditions. Therefore, by adding a glass fiber layer, the reverse limit control of the ceramic fibers can be achieved, which plays a certain limiting role to reduce the occurrence of the above-mentioned undesirable conditions, solve the pain point problem of the molding of unidirectional tape fibers and woven cloth composite materials of ceramic fibers, and solve the problems of poor flatness and product warping deformation during the molding of different types of composite materials. It should be noted that the number of layers of the first inorganic fiber layer 20 and the second inorganic fiber layer 30 can be set according to actual needs, and the present disclosure does not limit this.

[0063] In some optional embodiments, after hot-pressing the composite body, the above step S12 may also include: laser processing and cutting the hot-pressed composite body according to the set shape, thereby realizing the scheme of first forming and then laser processing. Optionally, five-axis laser processing can be used to process the appearance and realize the processing of the curvature of the surface. This solves the problem of flatness warping caused by the need to first process the appearance and then form the aramid fiber-containing structural parts on the market. Furthermore, after laser processing, the cut surface of the back cover product can be simply wiped to remove impurities, etc.

[0064] In some optional embodiments, the above step S11, before stacking at least one first inorganic fiber layer 20 on the first organic synthetic fiber layer 10 and stacking the second organic synthetic fiber layer 10 on at least one first inorganic fiber layer 20 to form a composite material body, may also include: cutting the organic synthetic fiber layer 10 and the first inorganic fiber layer 20 according to a set size. It is understandable that the raw material of the composite material can be cut into a designed size according to the size of the back cover product, and the raw material can include epoxy ceramic board, epoxy glass fiber board, epoxy aramid fiber board, etc.

[0065] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0066] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A back cover, characterized in that: include: Two organic synthetic fiber layers and at least one first inorganic fiber layer, wherein the at least one first inorganic fiber layer is stacked between the two organic synthetic fiber layers.

2. The back cover according to claim 1, characterized in that: The first inorganic fiber layer is a single layer, and the back cover further includes at least one second inorganic fiber layer, wherein the second inorganic fiber layer is disposed between at least one of the two organic synthetic fiber layers and the first inorganic fiber layer.

3. The back cover according to claim 2, characterized in that: The invention also includes at least one resin layer, wherein the resin layer is disposed between the first inorganic fiber layer and the second inorganic fiber layer and between the organic synthetic fiber layer and the second inorganic fiber layer.

4. The back cover according to claim 1, characterized in that: The first inorganic fiber layer has at least two layers, and the back cover also includes at least one second inorganic fiber layer, which is arranged at least between the first inorganic fiber layer and the organic synthetic fiber layer and between two adjacent first inorganic fiber layers.

5. The back cover according to claim 4, characterized in that: It also includes at least one resin layer, which is arranged between the first inorganic fiber layer and the second inorganic fiber layer, between the organic synthetic fiber layer and the second inorganic fiber layer, and between two adjacent first inorganic fiber layers.

6. The back cover according to claim 1, characterized in that: It also includes at least one resin layer, wherein the resin layer is disposed between the organic synthetic fiber layer and the first inorganic fiber layer and between two adjacent first inorganic fiber layers; and / or The organic synthetic fiber layer comprises an aramid fiber layer; and / or The first inorganic fiber layer includes a ceramic fiber layer.

7. The back cover according to claim 2 or 4, characterized in that: The second inorganic fiber layer includes a glass fiber layer.

8. A method for preparing a back cover, characterized in that: include: stacking at least one first inorganic fiber layer on the first organic synthetic fiber layer, and stacking a second organic synthetic fiber layer on the at least one first inorganic fiber layer to form a composite material body; The composite body is hot-pressed into shape.

9. The preparation method according to claim 8, characterized in that: At least one first inorganic fiber layer is stacked on the first organic synthetic fiber layer, and a second organic synthetic fiber layer is stacked on the at least one first inorganic fiber layer, comprising: The second inorganic fiber layer is stacked at least between the first organic synthetic fiber layer and the adjacent first inorganic fiber layer, between two adjacent first inorganic fiber layers, and between the second organic synthetic fiber layer and the adjacent first inorganic fiber layer.

10. The preparation method according to claim 9, characterized in that: The second inorganic fiber layer includes a glass fiber layer.

11. The preparation method according to claim 8, characterized in that: The second inorganic fiber layer is stacked at least one of between the first organic synthetic fiber layer and the adjacent first inorganic fiber layer, between two adjacent first inorganic fiber layers, and between the second organic synthetic fiber layer and the adjacent first inorganic fiber layer, comprising: A resin layer is stacked between the first organic synthetic fiber layer and the adjacent second inorganic fiber layer, between the first inorganic fiber layer and the adjacent second inorganic fiber layer, and between the second organic synthetic fiber layer and the adjacent second inorganic fiber layer.

12. The preparation method according to claim 8, characterized in that: At least one first inorganic fiber layer is stacked on the first organic synthetic fiber layer, and a second organic synthetic fiber layer is stacked on the at least one first inorganic fiber layer, comprising: A resin layer is stacked between the first organic synthetic fiber layer and the adjacent first inorganic fiber layer, between two adjacent first inorganic fiber layers, and between the second organic synthetic fiber layer and the adjacent first inorganic fiber layer.

13. The preparation method according to claim 8, characterized in that: After the composite material body is hot-pressed, the method further comprises: The composite material body formed by hot pressing is laser processed and cut according to a set shape.

14. The preparation method according to claim 8, characterized in that: Before forming the composite material body, at least one first inorganic fiber layer is stacked on the first organic synthetic fiber layer, and a second organic synthetic fiber layer is stacked on the at least one first inorganic fiber layer, the method further comprises: The organic synthetic fiber layer and the first inorganic fiber layer are cut according to set sizes.

15. The preparation method according to claim 8, characterized in that: The composite material body is hot pressed into shape, comprising: Thermoforming temperature is higher than 150°C and lower than 200°C; and / or Thermoforming time is less than 15 minutes; and / or The hot pressing pressure is not less than 15MPa.

16. The preparation method according to claim 8, characterized in that: The organic synthetic fiber layer comprises an aramid fiber layer; and / or The first inorganic fiber layer includes a ceramic fiber layer.

17. An electronic device, characterized in that: Comprising the back cover as described in any one of claims 1-7.

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