CN117135848B

CN117135848B - Back cover, processing method thereof and electronic equipment

Info

Publication number: CN117135848B
Application number: CN202310230218.5A
Authority: CN
Inventors: 王晓光; 霍国亮; 别永超; 臧永强
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2023-02-28
Filing date: 2023-02-28
Publication date: 2024-05-14
Anticipated expiration: 2043-02-28
Also published as: CN117135848A

Abstract

The application discloses a back cover, a processing method thereof and electronic equipment, relates to the technical field of electronic equipment, and aims to reduce the thickness of the back cover while guaranteeing the puncture resistance of the back cover. Wherein, the back of the body lid is used for electronic equipment, and electronic equipment is inside to be equipped with battery and antenna radiator, and the back of the body lid includes the composite sheet, and the composite sheet includes: the first substrate and the reinforcing plate are provided with mounting grooves, and the first substrate is an insulating piece; the reinforcing plate is fixedly connected in the mounting groove, the reinforcing plate is a metal plate or a carbon fiber plate, the orthographic projection of the reinforcing plate on the reference plane is a first projection, the orthographic projection of the battery on the reference plane is a second projection, the orthographic projection of the antenna radiator on the reference plane is a third projection, the first projection and the second projection are overlapped, and the first projection and the third projection are not overlapped; wherein, the reference plane is perpendicular to the thickness direction of the back cover.

Description

Back cover, processing method thereof and electronic equipment

Technical Field

The application relates to the technical field of electronic equipment, in particular to a back cover, a processing method thereof and electronic equipment.

Background

Electronic devices such as smartphones and tablet computers have become an indispensable part of people's daily lives. With the continuous pursuit of consumers for the thinning of electronic devices, the thickness of the back cover of the electronic device is continuously reduced. As the thickness of the back cover is reduced, the puncture resistance of the back cover is reduced, and the protection requirement of the back cover on electronic devices (such as a battery, a main board and the like) in the electronic equipment cannot be met, so that the electronic devices face safety risks. Therefore, how to reduce the thickness of the back cover and improve the puncture resistance of the back cover is a technical problem to be solved at present.

Disclosure of Invention

The embodiment of the application provides a back cover, a processing method thereof and electronic equipment, which are used for reducing the thickness of the back cover while ensuring the puncture resistance of the back cover.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical scheme:

in a first aspect, the present application provides a back cover for an electronic device, the electronic device having a battery and an antenna radiator disposed therein, the back cover comprising a composite board, the composite board comprising: the first substrate and the reinforcing plate are provided with mounting grooves, and the first substrate is an insulating piece; the reinforcing plate is fixedly connected in the mounting groove, the reinforcing plate is a metal plate or a carbon fiber plate, the orthographic projection of the reinforcing plate on the reference plane is a first projection, the orthographic projection of the battery on the reference plane is a second projection, the orthographic projection of the antenna radiator on the reference plane is a third projection, the first projection and the second projection are overlapped, and the first projection and the third projection are not overlapped; wherein, the reference plane is perpendicular to the thickness direction of the back cover.

According to the back cover provided by the embodiment of the application, the mounting groove is formed in the first substrate, the reinforcing plate is arranged in the mounting groove, meanwhile, the front projection (namely the first projection) of the reinforcing plate on the reference plane is overlapped with the front projection (namely the second projection) of the battery on the reference plane, and the front projection (namely the first projection) of the reinforcing plate on the reference plane is not overlapped with the front projection (namely the third projection) of the antenna radiator on the reference plane. Therefore, on one hand, at least part of the area of the battery can be covered by the reinforcing plate, so that the battery is prevented from being pierced by external sharp objects, and the safety performance of the battery can be improved; on the other hand, the antenna radiator can be prevented from being covered by the reinforcing plate, the influence of the reinforcing plate on the antenna signal of the electronic equipment can be avoided, the clearance space of the antenna can be increased, the antenna radiation performance of the electronic equipment can be improved, the communication signal quality of the electronic equipment can be improved, and the requirements of electronic equipment such as a 5G mobile phone on the communication signal quality can be met.

In a possible implementation manner of the first aspect, the outer contour of the second projection coincides with the outer contour of the first projection, or the outer contour of the second projection is located within the outer contour of the first projection. Therefore, the whole battery can be ensured to be covered by the reinforcing plate, the protection effect of the back cover on the battery can be improved, the battery is prevented from being punctured by an external sharp object, and the safety performance of the battery is ensured.

In a possible implementation manner of the first aspect, the first substrate includes a first surface and a second surface opposite to each other; the mounting groove comprises a first notch and a groove side wall, the first notch penetrates through the first surface, and the groove side wall is arranged around the first notch; the stiffening plate comprises a first end face and a first peripheral wall, the orientation of the first end face is the same as that of the first surface, the first peripheral wall is arranged around the first end face, and the first peripheral wall is fixedly connected to the side wall of the groove. Simple structure, processing is convenient, and is convenient for the assembly between stiffening plate and the first base plate.

In a possible implementation manner of the first aspect, the first peripheral wall is adhesively connected to the groove side wall by an adhesive, and a first concave groove is provided on the first peripheral wall. Like this, can increase the bonding area between first periphery wall and the groove lateral wall, can increase the quantity of gluing agent between first periphery wall and the groove lateral wall, and then can promote the joint strength between stiffening plate and the first base plate.

In a possible implementation manner of the first aspect, the first peripheral wall is provided with a first concave groove. Thus, the connection area between the first peripheral wall and the groove side wall can be increased, the amount of the connection medium between the first peripheral wall and the groove side wall can be increased, and the connection strength between the reinforcing plate and the first substrate can be improved.

In a possible implementation manner of the first aspect, the first surface faces the battery, and the back cover further includes: the first insulating layer is arranged on the first end face of the reinforcing plate. Therefore, the reinforcing plate and the battery can be separated through the first insulating layer, so that the reinforcing plate can be prevented from directly contacting the battery, electrode short circuit caused by sharp protrusions formed on the reinforcing plate can be avoided, secondary damage to the battery caused by the sharp protrusions can be effectively avoided, the protective capability of the back cover is greatly improved, and the safety performance of the battery is improved.

In a possible implementation manner of the first aspect, the first insulating layer includes: the first part is arranged on the first end face of the reinforcing plate, and the second part is arranged on the first surface of the first substrate. Therefore, the thickness of the back cover in the area where the first substrate is located can be increased on the basis that the whole thickness of the back cover is not increased, so that the structural strength and the puncture resistance of the area where the first substrate is located are improved, and the whole puncture resistance of the back cover can be improved.

In one possible implementation of the first aspect, the first portion and the second portion are integrally formed. In this way, the first part and the second part can be integrally assembled on the surface of the composite board facing the battery, or the first part and the second part can be formed on the surface of the composite board facing the battery in the same processing procedure, so that the assembling process of the back cover can be simplified, and the processing cost can be reduced.

In one possible implementation manner of the first aspect, the material of the first insulating layer includes at least one of acrylic, glass fiber, aramid fiber, and polyethylene terephthalate. The materials have good insulating property, high structural strength and large Young modulus, and can further improve the puncture resistance of the back cover.

In one possible implementation manner of the first aspect, the thickness of the first insulating layer is greater than or equal to 0.01mm and less than or equal to 0.15mm. Therefore, the design of lightening and thinning the back cover can be realized while the protective performance of the back cover is improved.

In a possible implementation manner of the first aspect, the first insulating layer is formed on the surface of the reinforcing plate by a chemical vapor deposition method, a physical vapor deposition method, spraying or coating. Like this, first insulating layer can direct connection in the surface of composite sheet to can omit the connection medium that is used for connecting composite sheet and first insulating layer, on the one hand can improve the joint strength between first insulating layer and the composite sheet, on the other hand is favorable to reducing the whole thickness of back of the body lid, can realize the frivolous design of back of the body lid when guaranteeing the puncture resistance performance of back of the body lid.

In one possible implementation manner of the first aspect, the first insulating layer is attached to the surface of the composite board by injection molding. In this way, the connection medium for connecting the composite plate and the first insulating layer can be omitted as well, and the connection strength between the first insulating layer and the composite plate can be ensured.

In a possible implementation manner of the first aspect, the first insulating layer is integrally formed with the first substrate. In this way, the assembling process between the first insulating layer and the first substrate can be omitted, and the connection strength between the first insulating layer and the first substrate can be improved.

In a possible implementation manner of the first aspect, the first insulating layer may be further adhered to a surface of the composite board by an adhesive. Simple process and convenient assembly.

In one possible implementation manner of the first aspect, the thickness of the first substrate is greater than or equal to 0.03mm. In this way, the structural strength of the first substrate can be ensured. Further, the thickness of the first substrate is less than or equal to 0.3mm. In this way, the overall thickness of the back cover can be reduced while ensuring the structural strength of the first substrate.

In a possible implementation manner of the first aspect, the back cover further includes a second insulating layer, and the second insulating layer is disposed on a side of the composite board facing away from the battery. Thus, through setting up the second insulating layer, on the one hand can improve the roughness and the outward appearance uniformity of the one side surface of deviating from the battery of composite sheet, can simplify the shaping degree of difficulty of outward appearance layer, can promote the outward appearance aesthetic measure of back of the body lid simultaneously, on the other hand, can further promote the overall structure intensity of back of the body lid, and then can further improve the puncture resistance performance of back of the body lid.

In a possible implementation manner of the first aspect, the first substrate includes a first surface and a second surface opposite to each other, and the first surface faces the battery; the mounting groove comprises a second notch, the second notch penetrates through the second surface, the reinforcing plate comprises a second end face, and the second end face is oriented in the same direction as the second surface; the second insulating layer covers the second end face of the reinforcing plate and the second surface of the first substrate. A specific arrangement mode of the second insulating layer is provided.

In a possible implementation manner of the first aspect, the material of the second insulating layer includes at least one of acrylic, glass fiber, aramid fiber, and polyethylene terephthalate. The materials have good insulating property, high structural strength and large Young modulus, and can further improve the puncture resistance of the back cover.

In one possible implementation manner of the first aspect, the thickness of the second insulating layer is greater than or equal to 0.01mm and less than or equal to 0.15mm. Thus, the puncture resistance of the back cover can be further improved, and the light and thin design of the back cover can be realized.

In a possible implementation manner of the first aspect, the second insulating layer is formed on the surface of the composite board by a chemical vapor deposition method, a physical vapor deposition method, spraying or coating; or the second insulating layer is attached to the surface of the composite board through injection molding, or the second insulating layer and the first substrate are integrally formed. In this way, the assembling process between the second insulating layer and the first substrate can be omitted, and the connection strength between the second insulating layer and the first substrate can be improved.

In a possible implementation manner of the first aspect, the second insulating layer may be further adhered to a surface of the composite board by an adhesive. Simple process and convenient assembly.

In one possible implementation manner of the first aspect, the first substrate is a glass fiber board, an aramid fiber board, an acryl board or a polycarbonate board. The material has higher mechanical property and good insulating property, can reduce the thickness of the back cover on the basis of ensuring the puncture resistance and the anti-drop property of the back cover, and can avoid the influence of the first substrate on the antenna signal of the electronic equipment, thereby being beneficial to improving the radiation property of the antenna of the electronic equipment, improving the communication signal quality of the electronic equipment and meeting the requirements of the electronic equipment such as a 5G mobile phone and the like on the communication signal quality.

In one possible implementation manner of the first aspect, the thickness of the stiffening plate is greater than or equal to 0.03mm and less than or equal to 0.15mm. Therefore, the thickness and the weight of the back cover can be reduced while the puncture resistance of the back cover is ensured, and the light and thin design of the back cover is realized.

In a possible implementation manner of the first aspect, a minimum distance between an outer contour of the first projection and an outer contour of the third projection is greater than or equal to 0.3mm. Therefore, the clearance space of the antenna can be ensured, the radiation performance of the antenna can be improved, and the communication quality of the electronic equipment can be further improved.

In a possible implementation manner of the first aspect, the first substrate includes a first surface and a second surface opposite to each other, and the first surface faces the battery; the back cover further comprises an appearance layer, and the appearance layer is positioned on the side, facing the second surface, of the back cover. Thus, the appearance expressive force of the back cover can be improved.

In one possible implementation of the first aspect, the thickness of the appearance layer is greater than or equal to 30 microns and less than or equal to 50 microns. Thus, the overall thickness of the back cover can be reduced while the appearance effect of the back cover is ensured.

In one possible implementation manner of the first aspect, the thickness of the back cover is greater than or equal to 0.25mm and less than or equal to 0.5mm. Thus, the puncture resistance of the back cover can be improved while the thickness of the back cover is reduced.

In one possible implementation manner of the first aspect, the puncture resistance force average value of the back cover is greater than or equal to 100N. Illustratively, the puncture resistance of the back cover may be 100N, 110N, 115N, 120N, 125N, 130N, 135N, 140N, 145N, 150N, 155N, 160N, 165N, 170N, 180N, etc. In this way, the puncture resistance of the back cover can be ensured.

In a second aspect, the present application provides a method for processing a back cover, including: providing a first prepreg, wherein the first prepreg comprises first fiber cloth and a thermosetting adhesive, the first fiber cloth is glass fiber cloth or aramid fiber cloth, and the number of layers of the first fiber cloth is one or more; performing semi-curing treatment on the first prepreg to obtain a first semi-cured material; processing the first semi-cured material to form a mounting groove on the first semi-cured material; placing the reinforcing plate into the mounting groove to obtain a composite plate blank; and carrying out hot pressing treatment on the composite board.

The processing method of the back cover is simple in process and easy to implement, and the back cover processed by the processing method can reduce the thickness of the back cover while guaranteeing puncture resistance, realize the light and thin design of the back cover, and improve the connection strength between the reinforcing plate and the first substrate, so that the structural stability of the back cover can be improved.

In a possible implementation manner of the second aspect, before the hot pressing treatment of the composite board, the method further includes: providing a second prepreg, wherein the second prepreg comprises second fiber cloth and a thermosetting adhesive, the second fiber cloth is glass fiber cloth or aramid fiber cloth, and the number of layers of the second fiber cloth is one or more; performing semi-curing treatment on the second prepreg to obtain a second semi-cured material; a second prepreg layer stack is disposed on at least one side of the composite panel blank.

In a possible implementation manner of the second aspect, the processing method further includes: and forming an appearance layer on the side facing the outer surface of the composite board blank after the hot pressing treatment.

In a third aspect, the present application provides an electronic device, including a back cover according to any one of the above-mentioned embodiments, and/or including a back cover processed by any one of the above-mentioned processing methods.

In a possible implementation manner of the third aspect, the electronic device further includes: the middle frame comprises a middle plate and a frame, the middle plate is fixed on the inner surface of the frame, and the battery is arranged on the middle plate; the medium plate is the metalwork, and the outward flange of medium plate is equipped with a plurality of breaks, breaks and divides out a plurality of antenna radiators with the outward flange of medium plate. Therefore, the radiation frequency band of the antenna can be increased on the basis of reducing the occupied space of the antenna radiator, the radiation performance of the antenna can be improved, the communication signal quality of the electronic equipment can be improved, and the 5G communication function of the electronic equipment can be realized.

In a possible implementation manner of the third aspect, the electronic device includes a circuit board, the circuit board is disposed on the middle board, and an orthographic projection of the stiffening plate on the reference plane overlaps with an orthographic projection of the circuit board on the reference plane. Therefore, the reinforcing plate can cover at least part of the area of the circuit board, so that the circuit board can be protected through the reinforcing plate, and the safety performance of the circuit board and electronic components on the circuit board can be improved.

In a possible implementation manner of the third aspect, the plurality of reinforcing plates are arranged at intervals, the plurality of mounting grooves are arranged at intervals, and the plurality of mounting grooves are in one-to-one correspondence with the plurality of reinforcing plates. Therefore, the plurality of reinforcing plates can respectively cover a plurality of areas inside the electronic equipment, the weight of the reinforcing plates can be reduced while the safety of devices inside the electronic equipment is further improved, and the light and thin design of the electronic equipment is facilitated.

The technical effects caused by any one of the design manners in the third aspect may be referred to the technical effects caused by the different design manners in the first aspect, which are not described herein.

Drawings

Fig. 1 is a perspective view of an electronic device provided in some embodiments of the present application;

FIG. 2 is an exploded view of the electronic device shown in FIG. 1;

FIG. 3 is a cross-sectional view of the electronic device of FIG. 1 taken along line A-A;

FIG. 4 is a schematic view of a partial structure of a middle plate of the electronic device shown in FIG. 2;

FIG. 5 is a schematic view of a laminated structure of a back cover according to the prior art;

FIG. 6 is a partial cross-sectional view of a back cover provided in some embodiments of the application;

FIG. 7 is a cross-sectional view of the first substrate in the back cover of FIG. 6;

FIG. 8 is a top view of the back cover of FIG. 6;

FIG. 9 is a perspective view of the stiffening plate in the back cover shown in FIG. 8;

FIG. 10 is a partial cross-sectional view of a back cover provided by other embodiments of the present application;

FIG. 11 is a partial cross-sectional view of a back cover provided by further embodiments of the present application;

FIG. 12 is a schematic view of the back cover and battery assembly of FIG. 11;

FIG. 13 is a partial cross-sectional view of a back cover provided by further embodiments of the present application;

Fig. 14 is a flowchart of a method for processing a back cover according to some embodiments of the present application;

FIG. 15 is a flowchart of a method for manufacturing a back cover according to other embodiments of the present application;

Fig. 16 is a flowchart of a method for processing a back cover according to some embodiments of the present application.

Reference numerals:

100. An electronic device;

10. a screen; 11. a light-transmitting cover plate; 12. a display screen;

20. A middle frame; 21. a frame; 22. a middle plate; 221. an assembly groove; 222. breaking the seam; 223. an antenna radiator;

30. A circuit board; 31. a main circuit board; 32. a secondary circuit board;

40. A battery;

50. A back cover; 501. a substrate; 502. an appearance layer;

51. A composite board; 511. a first substrate; 511a, mounting slots; 511a1, a first notch; 511a2, a second notch; 511a3, groove sidewalls; 5111. a first surface; 5112. a second surface; 512. a reinforcing plate; 5121. a first end face; 5122. a second end face; 5123. a first peripheral wall; 5123a, a first concave groove;

52. a first insulating layer; 521. a first portion; 522. a second portion;

53. A second insulating layer;

50a, a first fiber cloth; 50b, a thermosetting adhesive; 50c, a first prepreg; 50d, a first semi-cured material; 50e, a composite board blank; 50f, a second semi-cured material;

Detailed Description

In embodiments of the present application, the terms "exemplary" or "such as" and the like are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g." in an embodiment should not be taken as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

In embodiments of the present application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

In the description of embodiments of the application, the term "at least one" means one or more, and "a plurality" means two or more. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b, or c may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or plural.

In the description of the embodiment of the present application, "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

In describing embodiments of the present application, it should be noted that, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" should be construed broadly, and for example, "connected" may be either detachably connected or non-detachably connected; may be directly connected or indirectly connected through an intermediate medium. Wherein, "fixedly connected" means that the relative positional relationship is unchanged after being connected with each other. "rotationally coupled" means coupled to each other and capable of relative rotation after coupling. "slidingly coupled" means coupled to each other and capable of sliding relative to each other after being coupled.

References to directional terms in the embodiments of the present application, such as "inner", "outer", "upper", "lower", "front", "rear", "left", "right", etc., are merely with reference to the directions of the drawings, and thus are used for better, more clear explanation and understanding of the embodiments of the present application, rather than to indicate or imply that the apparatus or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the embodiments of the present application.

In the description of embodiments of the present application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

As used herein, "parallel", "perpendicular", "equal" includes the stated case as well as the case that approximates the stated case, the range of which is within an acceptable deviation range as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., limitations of the measurement system). For example, "parallel" includes absolute parallel and approximately parallel, where the acceptable deviation range for approximately parallel may be, for example, a deviation within 5 °; "vertical" includes absolute vertical and near vertical, where the acceptable deviation range for near vertical may also be deviations within 5 °, for example. "equal" includes absolute equal and approximately equal, where the difference between the two, which may be equal, for example, is less than or equal to 5% of either of them within an acceptable deviation of approximately equal.

In order to facilitate the description of the technical scheme of the present application, before the back cover, the processing method thereof and the electronic device in the embodiment of the present application are described in detail, some concepts related to the present application are first described.

Puncture resistance: resistance to penetration by a piercing needle. Puncture resistance is generally expressed in terms of puncture resistance, puncture strength or puncture elongation. Puncture resistance can be measured by referring to GB/T37841-2019 test method for puncture resistance of Plastic film and sheet.

Puncture resistance: the maximum force required to penetrate the sample vertically by the lancet. The greater the puncture resistance, the better the puncture resistance.

Glass fiber board: glass fiber boards, also known as fiberglass boards, fiberglass insulation boards, fiberglass composite boards, and the like, are synthesized from fiberglass materials and high heat resistant composite materials.

Carbon fiber plate: the carbon fiber plate is formed by impregnating and hardening carbon fibers arranged in the same direction with resin.

Thermosetting adhesive: the thermosetting adhesive is liquid at normal temperature (25 ℃), and is solid after being heated.

Metal insert injection molding (outserr mou ld ing): metal insert injection molding is a method of fixing a metal insert in place in a mold in advance and then injecting plastic for molding.

Chemical vapor deposition (chemica l vapor depos it ion, CVD): chemical vapor deposition is a process in which a gaseous or vapor phase of a substance is reacted at a gas-phase or gas-solid interface to produce a solid deposit.

Physical vapor deposition (phys ica l vapor depos it ion, PVD): physical vapor deposition is a method of vaporizing a coating material by physical means (e.g., evaporation, sputtering, etc.), and depositing a film on the surface of a substrate.

The application provides an electronic device. The electronic devices include, but are not limited to, mobile phones, tablet computers (tab let persona lcomputer), laptop computers (l aptop computer), personal Digital Assistants (PDAs) L D IGITA L ASS I STANT), personal computers, notebook computers, vehicle-mounted devices, and wearable devices. Among them, wearable devices include, but are not limited to, watches, bracelets, and the like.

Referring to fig. 1-2, fig. 1 is a perspective view of an electronic device 100 according to some embodiments of the present application, and fig. 2 is an exploded view of the electronic device 100 shown in fig. 1. The electronic device 100 in this embodiment is described by taking a tablet phone as an example. It will be appreciated that in other embodiments, the electronic device 100 may also be a foldable cellular phone. Referring to fig. 1-2, in this example, an electronic device 100 includes a screen 10, a center 20, a circuit board 30 (not shown in fig. 1), a battery 40 (not shown in fig. 1), and a back cover 50 (which may also be referred to as a battery cover).

It is to be understood that fig. 1 and 2 and the related figures below only schematically illustrate some of the components comprised by the electronic device 100, the actual shape, actual size, actual position and actual configuration of which are not limited by fig. 1 and 2 and the figures below. In addition, when the electronic device 100 is some other form of device, the electronic device 100 may not include the screen 10.

In the embodiment shown in fig. 1, the electronic device 100 has a rectangular flat plate shape. For convenience of description of the embodiments below, an XYZ coordinate system is established. Specifically, the width direction of the electronic device 100 is defined as the X-axis direction, the length direction of the electronic device 100 is defined as the Y-axis direction, and the thickness direction of the electronic device 100 is defined as the Z-axis direction. It is to be understood that the coordinate system of the electronic device 100 may be flexibly set according to actual needs, which is not specifically limited herein. In other embodiments, the shape of the electronic device 100 may also be square planar, circular planar, oval planar, etc.

The screen 10 is used to display images, videos, and the like. Referring to fig. 2, a screen 10 includes a light-transmitting cover plate 11 and a display screen 12. The light-transmitting cover plate 11 is laminated with the display screen 12. The light-transmitting cover plate 11 is mainly used for protecting and preventing dust of the display screen 12. The display 12 may be a flexible display or a rigid display. For example, the display 12 may be an organic light emitting diode (organ ic l ight-EMITT ING D iode, OLED) display, a liquid crystal display (l iqu ID CRYSTA L D I SP L AY, LCD), or the like.

The middle frame 20 serves as a supporting skeleton of the electronic apparatus 100 for mounting electronic devices such as the screen 10, the circuit board 30, the battery 40, and the like. Referring to fig. 2 in combination with fig. 3, fig. 3 is a cross-sectional view of the electronic device 100 shown in fig. 1 at line A-A. The middle frame 20 includes a rim 21 and a middle plate 22. The frame 21 is annular, and the middle plate 22 is fixed to the inner surface of the frame 21. The rim 21 may surround the outer edge of the middle plate 22. The screen 10 may be fixed to the bezel 21 or the middle plate 22 by means of the light-transmitting cover plate 11.

In some embodiments, midplane 22 is a metal piece. Specifically, the middle plate 22 may be made of a metal material with greater structural strength and hardness, so that the middle plate 22 has greater structural strength, and thus the middle plate 22 can play a role in stable support. On the basis of this, the antenna radiator 223 of the electronic device 100 may be formed on the middle plate 22.

Referring to fig. 4, fig. 4 is a schematic partial structure of the middle plate 22 of the electronic device 100 shown in fig. 2. The outer edge of the middle plate 22 is provided with a plurality of slits 222, which slits 222 divide the outer edge of the middle plate 22 into at least one antenna radiator 223. The break 222 is filled with an insulating material (not shown). Wherein, the term "plurality" as used herein refers to two or more. In this way, the radiation frequency band of the antenna can be increased on the basis of reducing the occupied space of the antenna radiator 223, so that the radiation performance of the antenna can be improved, the communication signal quality of the electronic device 100 can be improved, and the 5G communication function of the electronic device 100 can be realized.

In some embodiments, bezel 21 may be formed on the outer edge of midplane 22 by an injection molding process. Specifically, the frame 21 is a plastic member. In this way, the connection strength between the frame 21 and the middle plate 22 can be improved, and the part of the frame 21 can be filled in the break joint 222, and the frame 21 is used to form the insulating material, so that the processing technology of the middle frame 20 can be simplified, the processing efficiency can be improved, and the processing cost can be reduced.

Of course, it is understood that in other embodiments, the antenna radiator 223 may not be disposed on the midplane 22. For example, the antenna radiator 223 may also be integrated on the circuit board 30.

With continued reference to fig. 2, the circuit board 30 includes a main circuit board 31 and a sub circuit board 32. The main circuit board 31 and the sub circuit board 32 are fixedly connected to a side surface of the middle plate 22 facing away from the screen 10, and the main circuit board 31 and the sub circuit board 32 are disposed at a distance. Illustratively, the primary circuit board 31 and the secondary circuit board 32 are disposed spaced apart in the Y-axis direction.

The main circuit board 31 is used for integrating control chips, which may be, for example, an application processor (app l icat ion processor, AP), a double data rate synchronous dynamic random access memory (doub LE DATA RATE, DDR), a universal memory (UFS), and the like.

The secondary circuit board 32 is used to integrate electronics such as an antenna (e.g., a 5G antenna) rf front end, a universal serial bus (un IVERSA L SER IA lbus, USB) device, a vibrator, etc. The frame 21 may be provided with a socket corresponding to the USB device, and accessories such as a charger, an earphone, a data line, etc. may be electrically connected to the USB device through the socket, so as to realize transmission of power, signals and data. The secondary circuit board 32 is electrically connected with the primary circuit board 31 to realize data and signal transmission between the primary circuit board 31 and the secondary circuit board 32. It will be appreciated that in other embodiments, the circuit board 30 may include only the main circuit board 31, and not the sub-circuit board 32.

The battery 40 is used to provide power to the display 12, motherboard, etc. Referring to fig. 2 and 3, the battery 40 may be fixedly attached to a side surface of the middle plate 22 facing away from the screen 10. For example, the battery 40 may be disposed between the main circuit board 31 and the sub circuit board 32. The surface of the middle plate 22 on the side facing away from the screen 10 is provided with a fitting groove 221, and the battery 40 can be mounted in the fitting groove 221. In this way, the stacking dimension of the battery 40 and the middle plate 22 in the Z-axis direction is advantageously reduced, and the overall thickness of the electronic device 100 is advantageously reduced.

The back cover 50 forms a part of a housing of the electronic apparatus 100, and protects electronic devices such as the circuit board 30, the battery 40, and the like inside the electronic apparatus 100. With continued reference to fig. 2 and 3, the back cover 50 is located on a side of the middle plate 22 away from the screen 10, and the back cover 50 is fixed to the middle frame 20. The back cover 50 and the middle frame 20 enclose a receiving chamber for receiving the main circuit board 31, the sub circuit board 32, the battery 40, and the like. Alternatively, the back cover 50 may be a 2D back cover, a 2.5D back cover, or a 3D back cover.

Referring to fig. 5, fig. 5 is a schematic diagram of a laminated structure of a back cover 50 in the prior art. The back cover 50 includes a substrate 501 and an exterior layer 502 disposed on an outer surface of the substrate 501. The substrate 501 generally includes an acryl (po LYMETHY LMETHACRY L ATE, PMMA) plate, a polycarbonate (po lycarbonate, PC) plate, a composite plate formed by stacking an acryl plate, a polycarbonate plate, a glass fiber plate, and the like. In order to ensure the puncture resistance of the back cover 50 to improve the safety of electronic devices such as the battery 40 in the electronic device 100, the thickness of the back cover 50 needs to be more than 0.5mm, which is not beneficial to further thinning the thickness of the back cover 50, and thus the puncture resistance and the light and thin design of the back cover 50 and the electronic device 100 cannot be achieved.

In order to reduce the thickness of the back cover 50 and ensure the puncture resistance of the back cover 50, refer to fig. 6, wherein fig. 6 is a partial cross-sectional view of the back cover 50 according to some embodiments of the present application. The back cover 50 includes a composite plate 51, and the composite plate 51 includes a first substrate 511 and a reinforcing plate 512. The first substrate 511 is provided with a mounting groove 511a, and the reinforcing plate 512 is fixedly connected to the mounting groove 511a.

Specifically, the first substrate 511 is an insulating member, and the reinforcing plate 512 is a metal plate. The front projection of the reinforcing plate 512 on the reference plane is a first projection, the front projection of the battery 40 on the reference plane is a second projection, the front projection of the antenna radiator 223 on the reference plane is a third projection, the first projection and the second projection overlap, and the first projection and the third projection do not overlap. Wherein the reference plane is perpendicular to the thickness direction of the back cover 50. That is, the reference plane is perpendicular to the Z-axis direction. In this way, when the back cover 50 is applied to the electronic device 100, at least a partial area of the battery 40 may be covered by the reinforcing plate 512, and the antenna radiator 223 may not be covered by the reinforcing plate 512.

Because the metal plate has high structural strength and high hardness and Young's modulus, the penetration resistance of the reinforcing plate 512 can be ensured, but the metal material has a shielding effect on antenna signals. In the back cover 50 according to the embodiment of the present application, the mounting groove 511a is formed on the first substrate 511, and the stiffening plate 512 is disposed in the mounting groove 511a, so that the front projection (i.e. the first projection) of the stiffening plate 512 on the reference plane overlaps with the front projection (i.e. the second projection) of the battery 40 on the reference plane, and the front projection (i.e. the first projection) of the stiffening plate 512 on the reference plane does not overlap with the front projection (i.e. the third projection) of the antenna radiator 223 on the reference plane.

In this way, on one hand, at least part of the area of the battery 40 is covered by the reinforcing plate 512, which is beneficial to avoiding the battery 40 from being pierced by an external sharp object, and improving the safety performance of the battery 40; on the other hand, the antenna radiator 223 can be prevented from being covered by the reinforcing plate 512, the influence of the reinforcing plate 512 on the antenna signal of the electronic device 100 can be avoided, the clearance space of the antenna can be increased, the antenna radiation performance of the electronic device 100 can be improved, the communication signal quality of the electronic device 100 can be improved, and the requirement of the electronic device 100 such as a 5G mobile phone on the communication signal quality can be met.

In some embodiments, to further enhance the safety performance of the battery 40, the second projected outer contour coincides with the first projected outer contour, or the second projected outer contour is within the first projected outer contour. In this way, the whole battery 40 can be covered by the reinforcing plate 512, so that the protection effect of the back cover 50 on the battery 40 can be improved, the battery 40 is prevented from being pierced by an external sharp object, and the safety performance of the battery 40 is ensured.

Specifically, in some embodiments, the material of the stiffener 512 may include at least one of stainless steel, aluminum alloy, magnesium alloy, and copper oxide. Illustratively, the reinforcing plate 512 may be a stainless steel plate, an aluminum alloy plate, a magnesium alloy plate, or a copper-clad plate. The materials have high structural strength, high hardness and Young's modulus, can ensure the puncture resistance of the reinforcing plate 512, are easy to obtain and process, and are beneficial to reducing the cost of the back cover 50.

In other embodiments, the stiffening plate 512 may also be a carbon fiber plate. That is, the material of the reinforcing plate 512 is carbon fiber. The carbon fiber plate has high structural strength, large Young's modulus, good impact resistance and puncture resistance, and small density, and can reduce the weight of the back cover 50 while improving the puncture resistance of the back cover 50, thereby realizing the light and thin design of the back cover 50 and the electronic equipment 100.

In some embodiments, the first substrate 511 is a glass fiber board. The glass fiber board has higher mechanical property and good insulating property, can reduce the thickness of the back cover 50 on the basis of ensuring the puncture resistance and the drop resistance of the back cover 50, and can avoid the influence of the first substrate 511 on the antenna signal of the electronic device 100, thereby being beneficial to improving the antenna radiation performance of the electronic device 100, improving the communication signal quality of the electronic device 100 and meeting the requirements of the electronic device 100 such as a 5G mobile phone and the like on the communication signal quality.

It is understood that in other embodiments, the first substrate 511 may also be an aramid fiber board, an acryl board, a PC board, etc. The material also has higher mechanical property and good insulating property.

Referring to fig. 6, the thickness t1 of the first substrate 511 may be greater than or equal to 0.03mm. In this way, the structural strength of the first substrate 511 can be ensured. Further, the thickness t1 of the first substrate 511 may be less than or equal to 0.3mm. In this way, the entire thickness of the back cover 50 can be reduced while ensuring the structural strength of the first substrate 511.

Illustratively, the first substrate 511 may have a thickness 0.03mm、0.04mm、0.05mm、0.06,mm、0.07mm、0.08mm、0.09mm、0.1mm、0.11mm、0.12mm、0.13mm、0.14mm、0.15mm、0.16mm、0.17mm、0.18mm、0.19mm、0.2mm、0.21mm、0.22mm、0.23mm、0.24mm、0.25mm、0.26mm、0.27mm、0.28mm、0.29mm、0.3mm a or the like. The specific thickness of the first substrate 511 may be adjusted according to the specific structure of the back cover 50.

In some embodiments, the thickness of the stiffener 512 is greater than or equal to 0.03mm and less than or equal to 0.15mm. By way of example, the thickness of the stiffening plate 512 may be 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, and the like. Thus, the thickness and weight of the back cover 50 can be reduced while ensuring the puncture resistance of the back cover 50, and the light and thin design of the back cover 50 can be realized.

In some embodiments, referring to fig. 7, fig. 7 is a cross-sectional view of the first substrate 511 in the back cover 50 shown in fig. 6. The first substrate 511 includes a first surface 5111 and a second surface 5112 opposite to each other, and the mounting groove 511a penetrates the first surface 5111 and the second surface 5112. That is, the mounting groove 511a is formed as a through groove in the present embodiment. Specifically, the mounting groove 511a includes a first notch 511a1, a second notch 511a2, and a groove side wall 511a3. The first notch 511a1 extends through the first surface 5111 and the second notch 511a2 extends through the second surface 5112, with the slot sidewall 511a3 disposed about the first notch 511a 1. Specifically, the groove sidewall 511a3 is located between the first notch 511a1 and the second notch 511a 2. Simple structure, processing is convenient, and is convenient for the assembly between stiffening plate 512 and the first base plate 511.

It will be appreciated that in other embodiments, the mounting groove 511a may extend through only the first surface 5111 and not through the second surface 5112, in which case the mounting groove 511a may include only the first notch 511a1 and not the second notch 511a2. Or the mounting groove 511a may extend through only the second surface 5112 and not through the first surface 5111, in which case the mounting groove 511a may include only the second notch 511a2 and not the first notch 511a1. So long as the mounting groove 511a penetrates at least one of the first surface 5111 and the second surface 5112.

With continued reference to fig. 6, the stiffening plate 512 includes opposite first and second end faces 5121 and 5122. The first end face 5121 is oriented in the same direction as the first face 5111 and the second end face 5122 is oriented in the same direction as the second face 5112. In some embodiments, the plane of the first end surface 5121 is coplanar with the plane of the first surface 5111, and the plane of the second end surface 5122 is coplanar with the plane of the second surface 5112. In this way, the thickness of the reinforcing plate 512 can be made the same as the depth of the mounting groove 511a, and the thickness of the reinforcing plate 512 can be increased as much as possible without increasing the overall thickness of the back cover 50, so that the thickness of the back cover 50 and the puncture resistance of the back cover 50 can be both achieved.

In some embodiments, the first substrate 511 is adhesively connected to the stiffener 512. Specifically, referring to fig. 6, the reinforcing plate 512 includes a first peripheral wall 5123, and the first peripheral wall 5123 is disposed around the first end face 5121. Specifically, the first peripheral wall 5123 can be connected between the first end face 5121 and the second end face 5122. The reinforcing plate 512 may be fixedly coupled to the mounting groove 511a by means of the first outer circumferential wall 5123.

Illustratively, the first substrate 511 and the stiffener 512 are adhesively connected by a thermosetting adhesive. Optionally, the thermosetting adhesive comprises at least one of epoxy resin, benzoxazine resin, phenolic resin and the like. That is, the thermosetting adhesive may be an epoxy resin, a benzoxazine resin, a phenolic resin, or a blend resin of two or more of epoxy resin, benzoxazine resin, phenolic resin, and the like.

Because the thermosetting adhesive is liquid at normal temperature, the thermosetting adhesive has fluidity, and in the assembly process, the thermosetting adhesive can flow into the gap between the groove side wall 511a3 of the mounting groove 511a and the reinforcing plate 512, thereby being beneficial to increasing the contact area between the reinforcing plate 512 and the groove side wall 511a3 of the mounting groove 511a, and improving the connection strength between the reinforcing plate 512 and the mounting groove 511 a.

Of course, the connection between the first substrate 511 and the reinforcing plate 512 is not limited thereto. In other embodiments, the first substrate 511 and the stiffener 512 may be bonded by a thermoplastic adhesive. Or in still other embodiments, the first substrate 511 and the reinforcing plate 512 may be further connected by welding, in which case a layer of a weldable coating may be provided on the groove side wall 511a3 of the mounting groove 511 a. The solderable coating may be formed on the slot sidewall 511a3 of the mounting slot 511a by physical vapor deposition, chemical vapor deposition, or the like.

On this basis, in order to improve the connection strength between the first substrate 511 and the stiffener 512, please refer to fig. 8, fig. 8 is a top view of the back cover 50 shown in fig. 6. The top view shown in fig. 8 is a schematic view from the first surface 5111 of the first substrate 511 to the second surface 5112 of the first substrate 511. The first peripheral wall 5123 is provided with a first concave groove 5123a. The first recess groove 5123a may be recessed from the first outer peripheral wall 5123 toward the center of the reinforcing plate 512. Wherein, "center of the stiffening plate 512" refers to the geometric center of the stiffening plate 512. The first recess 5123a can be used to accommodate a connection medium such as an adhesive, solder, or the like. In this way, the connection area between the first outer peripheral wall 5123 and the groove side wall 511a3 can be increased, the amount of the connection medium between the first outer peripheral wall 5123 and the groove side wall 511a3 can be increased, and the connection strength between the reinforcing plate 512 and the first base plate 511 can be further improved.

In some embodiments, referring to fig. 9, fig. 9 is a perspective view of the stiffener 512 in the back cover 50 shown in fig. 8. The first recess groove 5123a may be formed as a penetration groove. Specifically, both ends of the first recess 5123a penetrate the first end face 5121 and the second end face 5122, respectively. In this way, the air pressure in the first recess 5123a is reduced, so that the connection medium such as adhesive and solder can flow in the first recess 5123a, and the connection medium such as adhesive and solder can be ensured to fill the first recess 5123a, so that the quantity of the connection medium such as adhesive and solder between the first peripheral wall 5123 and the groove side wall 511a3 can be further increased, and the structure is simple, and the processing is convenient.

In this embodiment, the first recess groove 5123a has a rectangular cross-sectional shape. It is understood that in other embodiments, the cross-sectional shape of the first concave groove 5123a can also be triangular, trapezoidal, semicircular, irregular, etc. Here, the "cross section of the first concave groove 5123 a" refers to a cross section obtained by cutting the first concave groove 5123a with a plane perpendicular to the Z-axis direction.

It will be appreciated that in other embodiments, the first base plate 511 and the reinforcing plate 512 may be integrally connected by metal insert injection molding. Metal insert injection molding (outserr mou ld ing) is a method of pre-fixing a metal insert in place in a mold for an insert mold, and then injecting plastic for molding.

In some embodiments, to further avoid the effect of the stiffening plate 512 on the antenna signal, the minimum distance d between the orthographic projection (i.e., the first projection) of the stiffening plate 512 on the reference plane and the orthographic projection (i.e., the third projection) of the antenna radiator 223 on the reference plane is greater than or equal to 0.3mm. Specifically, a minimum distance d between the outer contour of the first projection and the outer contour of the third projection is greater than or equal to 0.3mm. Illustratively, the minimum spacing may be 0.3mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 2mm, etc. Thus, the headroom of the antenna can be ensured, the radiation performance of the antenna can be improved, and the communication quality of the electronic device 100 can be improved.

With reference to fig. 10, fig. 10 is a partial cross-sectional view of a back cover 50 according to another embodiment of the present application. The back cover 50 in the present embodiment is different from the back cover 50 in the embodiment shown in fig. 6 in that the back cover 50 in the present embodiment includes an exterior layer 502 in addition to the composite plate 51. The appearance layer 502 is used for improving the appearance texture and appearance expressive force of the back cover 50. The appearance layer 502 is disposed on a side of the composite plate 51 facing away from the cell 40. Illustratively, the appearance layer 502 may be disposed on a side of the substrate 501 toward which the second surface 5112 faces.

The material of the appearance layer 502 may include, but is not limited to, leather, polyurethane (po lyurethane, PU), thermoplastic polyurethane elastomer (thermop l ast ic po lyurethane, TPU), etc., so that the back cover 50 may exhibit a leather or leather-like appearance effect and feel.

Of course, in some embodiments, some colored or gradient patterns may also be implemented on the appearance layer 502 to enrich the appearance effect of the back cover 50. In addition, the appearance layer 502 may be made of other materials such as polyethylene terephthalate (po LYETHY LENE glyco L TEREPHTHA L ATE, PET), polycarbonate (po lycarbonate, PC), and the like, and a texture pattern or a color pattern may be formed on the appearance layer 502 by transfer printing, silk screen printing, or the like, so as to further enhance the appearance expressive force of the back cover 50.

In this embodiment, the appearance layer 502 is formed on a surface of the composite plate 51 on a side facing away from the battery 40. For example, the exterior layer 502 may be formed on the surface of the composite plate 51 by screen printing, spray coating, chemical vapor deposition, physical vapor deposition, or the like. Or the appearance layer 502 may be attached to the surface of the composite plate 51 by adhesive bonding.

In some embodiments, referring to fig. 10, the thickness t2 of the appearance layer 502 is greater than or equal to 30 micrometers (μm) and less than or equal to 50 micrometers. Illustratively, the thickness of the appearance layer 502 may be 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. In this way, the overall thickness of the back cover 50 can be reduced while ensuring the appearance effect of the back cover 50.

It is understood that the appearance layer 502 of this embodiment may be combined with the back cover 50 of any of the embodiments of the present application. In other embodiments, when the back cover 50 further includes other layers, the exterior layer 502 may be formed on the other layers between the composite plate 51 and the exterior layer 502.

Since the external sharp object impacts the reinforcing plate 512, a sharp protrusion may be formed on the surface of the reinforcing plate 512 facing the battery 40, in order to avoid the sharp protrusion contacting the battery 40 to cause an electrode short circuit, refer to fig. 11-12, fig. 11 is a partial cross-sectional view of the back cover 50 according to still other embodiments of the present application, and fig. 12 is an assembly schematic diagram of the back cover 50 and the battery 40 shown in fig. 11. The back cover 50 in this embodiment includes a first insulating layer 52 in addition to the composite plate 51.

Specifically, referring to fig. 12, the first insulating layer 52 is disposed on a surface of the reinforcing plate 512 facing the battery 40. In this embodiment, the first end 5121 of the reinforcing plate 512 faces the battery 40, and the first insulating layer 52 may be disposed on the first end 5121. In this way, the reinforcing plate 512 can be separated from the battery 40 by the first insulating layer 52, so that the reinforcing plate 512 can be prevented from directly contacting the battery 40, and further, electrode short circuit caused by sharp protrusions formed on the reinforcing plate 512 can be avoided, secondary damage to the battery 40 caused by the sharp protrusions can be effectively avoided, the protection capability of the back cover 50 is greatly improved, and the safety performance of the battery 40 is improved.

The material of the first insulating layer 52 includes acryl, glass fiber, aramid fiber, polyethylene terephthalate (po LYETHY LENE G lyco L TEREPHTHA L ATE, PET, which may also be called a mylar sheet), and the like. These materials have good insulating properties, high structural strength, and high young's modulus, and can further improve the puncture resistance of the back cover 50.

In some embodiments, the thickness t3 of the first insulating layer 52 is greater than or equal to 0.01mm and less than or equal to 0.15mm. Illustratively, the first insulating layer 52 may have a thickness 0.01mm、0.02mm、0.03mm、0.04mm、0.05mm、0.06mm、0.07mm、0.08mm、0.09mm、0.1mm、0.11mm、0.12mm、0.13mm、0.14mm、0.15mm a or the like. Thus, the design of the back cover 50 can be made thinner while improving the protective performance of the back cover 50.

On this basis, in order to further improve the overall puncture resistance of the back cover 50, referring to fig. 11 to 12, the first insulating layer 52 includes a first portion 521 and a second portion 522, the first portion 521 is disposed on the surface of the reinforcing plate 512 facing the battery 40, and the second portion 522 is disposed on the surface of the first substrate 511 facing the battery 40. Specifically, the first portion 521 is disposed on the first end surface 5121 of the reinforcing plate 512, and the second portion 522 is disposed on the first surface 5111 of the first substrate 511. In this way, the thickness of the back cover 50 in the area where the first substrate 511 is located can be increased without increasing the overall thickness of the back cover 50, so that the structural strength and the puncture resistance of the area where the first substrate 511 is located can be advantageously improved, and the overall puncture resistance of the back cover 50 can be further improved.

In some embodiments, first portion 521 and second portion 522 are integrally formed pieces. In this way, the first portion 521 and the second portion 522 can be integrally assembled on the surface of the composite plate 51 facing the battery 40, or the first portion 521 and the second portion 522 can be formed on the surface of the composite plate 51 facing the battery 40 in the same processing step, so that the assembling process of the back cover 50 can be simplified, and the processing cost can be reduced. Of course, it will be appreciated that in other embodiments, the first portion 521 and the second portion 522 may be separate pieces, or the first insulating layer 52 may not include the second portion 522.

In some embodiments, the first insulating layer 52 may be formed on the surface of the stiffener 512 by chemical vapor deposition, physical vapor deposition, spraying, coating, or the like. In this way, the first insulating layer 52 may be directly connected to the surface of the composite board 51, so that a connection medium for connecting the composite board 51 and the first insulating layer 52 may be omitted, on one hand, the connection strength between the first insulating layer 52 and the composite board 51 may be improved, on the other hand, the overall thickness of the back cover 50 may be reduced, and the light and thin design of the back cover 50 may be realized while the puncture resistance performance of the back cover 50 is ensured.

In other embodiments, the first insulating layer 52 may also be attached to the surface of the composite plate 51 by injection molding. In this case, the composite plate 51 may be processed first, and then the surface of the composite plate 51 may be injection-molded by the first insulating layer 52. In this way, the connection medium for connecting the composite plate 51 and the first insulating layer 52 can be omitted as well, and the connection strength between the first insulating layer 52 and the composite plate 51 can be ensured. In addition, when the first insulating layer 52 includes the first portion 521 and the second portion 522, since the first substrate 511 and the reinforcing plate 512 of the composite board 51 are both connected to the first insulating layer 52, the structural stability of the composite board 51 is improved, and the reinforcing plate 512 is prevented from slipping out of the mounting groove 511a, so that the overall structural stability of the back cover 50 can be further improved.

In still other embodiments, when first insulating layer 52 includes first portion 521 and second portion 522, first insulating layer 52 may also be integrally formed with first substrate 511. In this embodiment, the first insulating layer 52 may be regarded as a part of the first substrate 511. Illustratively, the first insulating layer 52 and the first substrate 511 may be integrally injection molded. In this case, the whole of the structural member including the first substrate 511 and the first insulating layer 52 may be processed first, and then the reinforcing plate 512 may be fitted into the mounting groove 511a on the first substrate 511. Alternatively, the first substrate 511 and the first insulating layer 52 may be connected to the reinforcing plate 512 by a metal insert injection molding process. In this way, the assembling process between the first insulating layer 52 and the first substrate 511 can be omitted, and the connection strength between the first insulating layer 52 and the first substrate 511 can be improved.

In still other embodiments, the first insulating layer 52 may also be adhered to the surface of the composite plate 51 by an adhesive. The adhesive can be a thermosetting adhesive or a thermoplastic adhesive.

For example, when the materials of the first insulation layer 52 and the first substrate 511 are both glass fibers or aramid fibers, the first insulation layer 52 and the composite plate 51 may be bonded by a thermosetting adhesive. Specifically, in the actual processing process, a glass fiber material or an aramid fiber material may be first prepared into a fiber cloth, then the fiber cloth is immersed in a liquid thermosetting adhesive to form an adhesive on gaps, surfaces and the like in the fiber cloth, so as to obtain prepregs, then the number of stacked prepregs is designed according to the thickness of the first substrate 511 and the first insulating layer 52, after a certain number of prepregs are stacked, a prepreg is subjected to a prepreg curing process, so as to obtain a first substrate semi-cured material and a first insulating layer semi-cured material, then the first substrate semi-cured material is subjected to a treatment, so as to form a mounting groove 511a on the first substrate semi-cured material, then the reinforcing plate 512 is placed in the mounting groove 511a to form a composite plate blank, and finally the composite plate blank and the first insulating layer 52 semi-cured material are subjected to a hot pressing process, so as to obtain the back cover 50 including the composite plate 51 and the first insulating layer 52.

The term "prepreg" refers to a single-layer sheet material having a certain strength obtained by subjecting a prepreg to a low-temperature (e.g., 40 to 80 ℃) curing treatment. At this time, the structural strength of the semi-cured material obtained after the semi-curing treatment is relatively low, and the semi-cured material is basically used for maintaining the basic state of solids, and is relatively soft correspondingly, so that the semi-cured material is convenient to store and transport. The temperature of the hot pressing treatment can be 90-180 ℃.

With reference to fig. 13, fig. 13 is a partial cross-sectional view of a back cover 50 according to still other embodiments of the present application. The back cover 50 in this embodiment includes a second insulating layer 53 in addition to the composite plate 51 and the first insulating layer 52.

Specifically, referring to fig. 13, the second insulating layer 53 is disposed on a surface of the composite plate 51 facing away from the battery 40. Specifically, the second insulating layer 53 covers the second end face 5122 of the reinforcing plate 512 and the second surface 5112 of the first substrate 511. In this way, by providing the second insulating layer 53, on the one hand, the flatness and the appearance consistency of the surface of the composite board 51, which is far away from the battery 40, can be improved, the molding difficulty of the appearance layer 502 can be simplified, and on the other hand, the appearance aesthetic degree of the back cover 50 can be improved, and on the other hand, the overall structural strength of the back cover 50 can be further improved, and the penetration resistance of the back cover 50 can be further improved.

In some embodiments, the material of the second insulating layer 53 includes acryl, glass fiber, aramid fiber, polyethylene terephthalate (po LYETHY LENE glyco L TEREPHTHA L ATE, PET, which may also be referred to as a mylar sheet), and the like. These materials have good insulating properties, high structural strength, and high young's modulus, and can further improve the puncture resistance of the back cover 50.

In some embodiments, referring to fig. 13, the thickness t4 of the second insulating layer 53 is greater than or equal to 0.01mm and less than or equal to 0.15mm. The thickness of the second insulating layer 53 may be 0.01mm、0.02mm、0.03mm、0.04mm、0.05mm、0.06mm、0.07mm、0.08mm、0.09mm、0.1mm、0.11mm、0.12mm、0.13mm、0.14mm、0.15mm a or the like, for example. Thus, the puncture resistance of the back cover 50 can be further improved, and the back cover 50 can be designed to be thin and lightweight.

The processing method of the second insulating layer 53 can be designed with reference to the first insulating layer 52. The material and processing method of the second insulating layer 53 may be the same as or different from those of the first insulating layer 52.

For example, in some embodiments, the material of the second insulating layer 53 includes glass fiber or aramid fiber, and the material of the first insulating layer 52 includes glass fiber or aramid fiber, during the processing, the composite material may be first prepared, and the blank, the first insulating layer prepreg, and the second insulating layer prepreg may be first prepared, and then the laminated first insulating layer 52 prepreg, the composite board blank 50e, and the second insulating layer 53 prepreg may be subjected to a hot pressing process to obtain the back cover 50 including the composite board 51, the first insulating layer 52, and the second insulating layer 53.

In some embodiments, the first insulating layer 52 and the second insulating layer 53 may be symmetrically disposed on opposite sides of the composite plate 51. In this way, the structural symmetry of the back cover 50 can be improved, which is beneficial to improving the overall structural strength of the back cover 50, and the warping phenomenon of the first insulating layer 52, the second insulating layer 53 or the first substrate 511 caused by different shrinkage stresses can be avoided when the first insulating layer semi-cured material, the composite board blank and the second insulating layer semi-cured material are subjected to hot pressing treatment in the processing process, which is beneficial to improving the production yield of the back cover 50.

The reinforcing plate 512 in the above embodiment is disposed corresponding to the battery 40 of the electronic device 100, and it is understood that in other embodiments, the reinforcing plate 512 may be disposed corresponding to the circuit board 30. Specifically, the front projection of the stiffening plate 512 on the reference plane overlaps with the front projection of the circuit board 30 on the reference plane. In this way, the reinforcing plate 512 can cover at least part of the area of the circuit board 30, so that the circuit board 30 can be protected by the reinforcing plate 512, and the safety performance of the circuit board 30 and the electronic components on the circuit board 30 can be improved.

In this case, the front projection of the reinforcing plate 512 on the reference plane may or may not overlap with the front projection of the battery 40 on the reference plane. When the front projection of the reinforcing plate 512 on the reference plane overlaps with the front projection of the battery 40 on the reference plane, the number of reinforcing plates 512 may be one or more.

In some embodiments, the number of the reinforcing plates 512 is plural, the plurality of reinforcing plates 512 are arranged at intervals, the number of the mounting grooves 511a is plural, and the plurality of mounting grooves 511a are in one-to-one correspondence with the plurality of reinforcing plates 512. In this way, the plurality of reinforcing plates 512 can cover a plurality of areas inside the electronic device 100, so that the weight of the reinforcing plates 512 can be reduced while the safety of the internal devices of the electronic device 100 is further improved, and the light and thin design of the electronic device 100 is facilitated.

In some embodiments, the back cover 50 has a thickness greater than or equal to 0.25mm and less than or equal to 0.5mm. Wherein, the thickness of the back cover 50 refers to the interval between the inner surface and the outer surface of the back cover 50. The outer surface of the back cover 50 refers to the surface of the back cover 50 facing away from the interior of the electronic device 100, and the inner surface of the back cover 50 refers to the surface of the back cover 50 facing toward the interior of the electronic device 100. Illustratively, the back cover 50 may have a thickness 0.25mm、0.26mm、0.27mm、0.28mm、0.29mm、0.3mm、0.31mm、0.32mm、0.33mm、0.34m、0.35mm、0.36mm、0.37mm、0.38mm、0.39mm、0.4mm、0.41mm、0.42mm、0.43mm、0.44m、0.45mm、0.46mm、0.47mm、0.48mm、0.49mm、0.5mm a or the like. In this way, the puncture resistance of the back cover 50 can be improved while the thickness of the back cover 50 is reduced.

The following describes a method of processing the back cover 50 in an embodiment of the present application.

Referring to fig. 14, fig. 14 is a flowchart illustrating a method for manufacturing a back cover 50 according to some embodiments of the application. The processing method of the back cover 50 comprises the following steps:

step S100: providing a first prepreg, wherein the first prepreg comprises first fiber cloth and a thermosetting adhesive, the first fiber cloth is glass fiber cloth or aramid fiber cloth, and the number of layers of the first fiber cloth is one or more;

specifically, when the first prepreg includes a plurality of layers of the first fiber cloth, step S100: providing the first prepreg may include:

Step S101: providing a first fibrous cloth;

Step S102: immersing the first fiber cloth into a liquid thermosetting adhesive;

Step S103: and stacking a plurality of first fiber cloth layers comprising thermosetting adhesives to obtain the first prepreg.

It will be appreciated that when the first prepreg comprises a layer of first fibre cloth, step S100 may comprise only steps S101 and S102, and not step S103 described above.

Step S200: performing semi-curing treatment on the first prepreg to obtain a first semi-cured material;

specifically, the prepreg may be subjected to a low-temperature (e.g., 40 ℃ C. To 80 ℃ C.) curing treatment to obtain a first semi-cured material.

The thickness of the first semi-cured material may be greater than or equal to 0.05mm and less than or equal to 0.15mm. Illustratively, the thickness of the first semi-cured material may be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, and the like. Thus, the thickness of the first substrate can be controlled to be between 0.08mm and 0.12mm, and the whole thickness of the back cover can be reduced while the puncture resistance of the first substrate is ensured.

Step S300: processing the first semi-cured material to form a mounting groove on the first semi-cured material;

Specifically, a computer numerical control machine (computer numer ica l contro l, CNC) may be used to process the first semi-solidified material to form the mounting slots. The mounting slot may be a through slot. The process is simple and the processing is convenient.

Step S400: placing the reinforcing plate into the mounting groove to obtain a composite plate blank;

Step S500: and carrying out hot pressing treatment on the composite board blank.

Specifically, when the composite board blank is subjected to hot pressing treatment, the composite board blank can be placed in a corresponding mold to obtain a back cover in a 2D, 2.5D or 3D form. In some embodiments, the autoclave temperature may be from 90 ℃ to 180 ℃. And (5) after the hot pressing treatment in the step (S500), the thermosetting adhesive in the composite board blank is completely cured, and the composite board is obtained.

Referring to fig. 15, fig. 15 is a flowchart illustrating a method for processing a back cover according to another embodiment of the application. The processing method in this embodiment is different from the processing method shown in fig. 14 in that the processing method of the back cover in this embodiment is performed in step S500: before the hot pressing treatment of the composite board, the method further comprises the following steps:

Step S600: providing a second prepreg, wherein the second prepreg comprises second fiber cloth and a thermosetting adhesive, the second fiber cloth is glass fiber cloth or aramid fiber cloth, and the number of layers of the second fiber cloth is one or more;

the specific processing method of step S600 in this embodiment may be the same as that of step S100, and will not be described in detail here.

Step S700: performing semi-curing treatment on the second prepreg to obtain a second semi-cured material;

The specific processing method of step S700 in this embodiment may be the same as that of step S200, and will not be described in detail here.

After the second semi-cured material is subjected to hot pressing treatment, the second semi-cured material may be formed into the first insulating layer and/or the second insulating layer. The thickness of the second semi-cured material may be greater than or equal to 0.05mm and less than or equal to 0.15mm. Illustratively, the thickness of the second semi-cured material may be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, and the like. Thus, the thickness of the first insulating layer and the second insulating layer can be controlled between 0.05mm and 0.15mm, and the whole thickness of the back cover can be reduced while the puncture resistance of the back cover is ensured.

Step S800: a second prepreg layer stack is disposed on at least one side of the composite panel blank.

Specifically, in some embodiments, step S800 includes: and the second semi-cured material layer is arranged on one side of the composite board blank. On this basis, step S500: the hot pressing treatment of the composite board blank comprises the following steps: and carrying out hot pressing treatment on the second semi-cured material and the composite board blank. After the hot pressing treatment in the step S500, the second semi-cured material is formed into a first insulating layer or a second insulating layer, and the composite board blank forms a composite board. Therefore, the puncture resistance performance can be ensured, the thickness of the back cover is reduced, the light and thin design of the back cover is realized, the connection strength between the reinforcing plate and the first substrate and the connection strength between the composite plate and the first insulating layer or the second insulating layer can be improved, and the structural stability of the back cover can be further improved.

In other embodiments, step S800 includes: and stacking the second semi-cured material on two sides of the composite board blank. On this basis, step S500: the hot pressing treatment of the composite board blank comprises the following steps: and carrying out hot pressing treatment on the second semi-cured materials and the composite board blank, which are laminated on two sides of the composite board blank. After the hot pressing treatment in the step S500, the second semi-cured material laminated on one side of the composite board blank is formed into the first insulating layer, the second semi-cured material laminated on the other side of the composite board blank is formed into the second insulating layer, and the composite board blank forms the composite board.

Like this, can reduce the thickness of back of body lid when guaranteeing puncture resistance performance, realize the frivolous design of back of body lid, and can improve the joint strength between stiffening plate and the first base plate, joint strength between composite sheet and first insulating layer, the second insulating layer, and then can improve the structural stability of back of body lid. In addition, the second semi-cured materials are arranged on two sides of the composite board blank in the embodiment, the symmetry of the laminated structure is good, the second semi-cured materials or the composite board blank which are caused by different shrinkage stresses can be effectively prevented from warping in the hot pressing treatment process, and the production yield of the back cover is improved.

On the basis of any of the above embodiments, in step S500: after the hot pressing treatment is carried out on the composite board blank, the processing method further comprises the following steps:

step S900: and forming an appearance layer on the side facing the outer surface of the composite board blank after the hot pressing treatment.

The appearance layer may be formed by coating, spraying, chemical vapor deposition, physical vapor deposition, or the like. The thickness of the appearance layer is 50 nm-100 nm, and the material of the appearance layer can include but is not limited to leather, polyurethane (po lyurethane, PU), thermoplastic polyurethane elastomer (thermop l ast ic po lyurethane, TPU) and the like.

The following describes the method for processing the back cover in detail with reference to specific embodiments. In this embodiment, a case where the first prepreg includes a single layer of the first fiber cloth and the second prepreg includes a single layer of the second fiber cloth will be described.

Referring to fig. 16, fig. 16 is a flowchart illustrating a method for manufacturing a back cover 50 according to some embodiments of the application. The processing method in this embodiment may be used to process the back cover 50 in the embodiment shown in fig. 13. Specifically, the processing method of the back cover 50 includes:

providing a first fibrous cloth 50a; the first fiber cloth 50a is a glass fiber cloth.

Immersing the first fiber cloth 50a into a liquid thermosetting adhesive 50b to obtain a first prepreg 50c;

Performing semi-curing treatment on the first prepreg 50c to obtain a first semi-cured material 50d, and then performing treatment on the first semi-cured material 50d to form mounting grooves 511a on the first semi-cured material 50 d;

placing the reinforcing plate 512 into the installation groove 511a to obtain a composite plate blank 50e;

Providing a second prepreg, performing semi-curing treatment on the second prepreg to obtain a second semi-cured material 50f, and stacking the second semi-cured material 50f on two sides of the composite board blank 50 e;

Performing hot pressing treatment on the second semi-cured materials 50f and the composite board blank 50e which are stacked on two sides of the composite board blank 50e to obtain a back cover 50 blank;

an appearance layer 502 is formed on the outer surface of the back cover 50 blank to provide the back cover 50.

In order to objectively evaluate the puncture resistance of the back cover 50 in the examples of the present application, the present application will be exemplified in detail by comparative examples (comparative example 1 and comparative example 2) and experimental examples (experimental examples 1 to 3).

In the comparative example and the experimental example, the materials, thicknesses, and puncture resistance performance characterization data of the back cover 50 of each laminate structure in the back cover 50 are shown in table 1 below. The laminated structure of the back cover 50 in table 1 is a laminated structure when the appearance layer 502 is not provided on the back cover 50. This laminate structure may also be referred to as a substrate for the back cover 50.

TABLE 1

The puncture resistance in the application can be measured by referring to GB/T37841-2019 puncture resistance test method for plastic films and sheets. Specifically, the puncture resistance test process may be: the sample is flattened in the clamp and clamped with the outer surface of the sample facing the needle. The puncture resistance was tested using a selected puncture speed, wherein the puncture speed was (200.+ -.5) mm/min. The outer surface of the sample is a surface of the sample facing away from the inside of the electronic device 100 when the sample is applied to the electronic device 100.

The puncture resistance average value refers to an average value of puncture resistance of a plurality of samples having the same structure. Specifically, the calculation formula of the average puncture resistance force in the application is as follows: puncture resistance average = (puncture resistance of sample 1+ puncture resistance of sample 2+ puncture resistance of sample 3 + puncture resistance of sample 4 + puncture resistance of sample 5)/5.

As can be seen from table 1, the back cover 50 in each of examples 1 to 3 has excellent puncture resistance, and is specifically expressed as follows: the back cover 50 of example 1 had a puncture resistance average value of 122.65N when the thickness reached 0.25 mm; the back cover 50 of example 2 had a puncture resistance average value of 146.48N when the thickness reached 0.26 mm; the average puncture resistance of the back cover 50 of example 3 was 162.84N when the thickness reached 0.28 mm.

That is, the back cover 50 in this embodiment has a puncture resistance average value of 122.65N to 162.84N when the thickness is 0.25mm to 0.28 mm. Compared to the back cover 50 in comparative example 1, in the case of 50% thickness reduction, the puncture resistance was improved by 74.4%; with a thickness reduction of 48%, the puncture resistance is improved by 108.2%; with a thickness reduction of 44%, the puncture resistance is improved by 131.4%.

In addition, as can be seen from table 1, the puncture resistance force of the back cover 50 increases with the thickness of the back cover 50, and when the thickness of the back cover 50 reaches 0.25mm, the puncture resistance force of the back cover 50 can reach more than 100N. Therefore, when the thickness of the back cover 50 in the embodiment of the present application is 0.25mm to 0.5mm, the average puncture resistance is 100N or more. Further, when the thickness of the back cover 50 in the embodiment of the application is 0.25mm to 0.5mm, the average puncture resistance is 120N or more.

Therefore, the back cover 50 according to the embodiment of the application can improve the puncture resistance of the back cover 50 while reducing the thickness of the back cover 50. Therefore, when the back cover 50 in the embodiment of the application is applied to the electronic device 100, when the back cover 50 is impacted by an external sharp object, the sharp object can be prevented from damaging devices such as the battery 40 in the electronic device 100, and the safety performance of the components such as the battery 40 can be improved while the light and thin design of the back cover 50 and the electronic device 100 is realized.

In the description of the present specification, a particular feature, structure, material, or characteristic may be combined in any suitable manner in one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. The utility model provides a back of body lid, its characterized in that is used for electronic equipment, electronic equipment is inside to be equipped with battery and antenna radiator, the back of body lid includes the composite sheet, the composite sheet includes:

the first substrate is provided with a mounting groove and is an insulating piece; and

The reinforcing plate is fixedly connected in the mounting groove, the reinforcing plate is a metal plate or a carbon fiber plate, the orthographic projection of the reinforcing plate on a reference plane is a first projection, the orthographic projection of the battery on the reference plane is a second projection, the orthographic projection of the antenna radiator on the reference plane is a third projection, the first projection and the second projection are overlapped, and the first projection and the third projection are not overlapped;

wherein, the reference plane is perpendicular to the thickness direction of the back cover.

2. The back cover of claim 1, wherein the second projected outer contour coincides with the first projected outer contour or the second projected outer contour is within the first projected outer contour.

3. The back cover of claim 1, wherein the first substrate comprises first and second opposing surfaces;

The mounting groove comprises a first notch and a groove side wall, the first notch penetrates through the first surface, and the groove side wall is arranged around the first notch;

the stiffening plate comprises a first end face and a first peripheral wall, the orientation of the first end face is the same as that of the first surface, the first peripheral wall is arranged around the first end face, and the first peripheral wall is fixedly connected to the side wall of the groove.

4. A back cover according to claim 3, wherein the first peripheral wall is provided with a first recess.

5. The back cover of claim 3, wherein the first surface faces the battery, the back cover further comprising:

the first insulating layer is arranged on the first end face of the reinforcing plate.

6. The back cover of claim 5, wherein the first insulating layer comprises: the first part is arranged on the first end face of the reinforcing plate, and the second part is arranged on the first surface of the first substrate.

7. The back cover of claim 6, wherein the first portion and the second portion are an integral piece.

8. The back cover of claim 5, wherein the material of the first insulating layer comprises at least one of acrylic, fiberglass, aramid, polyethylene terephthalate.

9. The back cover of claim 5, wherein the thickness of the first insulating layer is greater than or equal to 0.01mm and less than or equal to 0.15mm.

10. The back cover of any of claims 1-9, further comprising a second insulating layer disposed on a side of the composite plate facing away from the battery.

11. The back cover of claim 10, wherein the first substrate comprises opposing first and second surfaces, the first surface facing the battery;

The mounting groove comprises a second notch, the second notch penetrates through the second surface, the reinforcing plate comprises a second end face, and the second end face is oriented in the same direction as the second surface;

the second insulating layer covers the second end face of the reinforcing plate and the second surface of the first substrate.

12. The back cover of claim 10, wherein the material of the second insulating layer comprises at least one of acrylic, fiberglass, aramid, polyethylene terephthalate.

13. The back cover of claim 10, wherein the thickness of the second insulating layer is greater than or equal to 0.01mm and less than or equal to 0.15mm.

14. The back cover of any of claims 1-9, wherein the first substrate is a fiberglass board, an aramid fiber board, an acrylic board, or a polycarbonate board.

15. The back cover according to any one of claims 1-9, wherein the thickness of the stiffening plate is greater than or equal to 0.03mm and less than or equal to 0.15mm.

16. The back cover of any of claims 1-9, wherein a minimum spacing between an outer contour of the first projection and an outer contour of the third projection is greater than or equal to 0.3mm.

17. The back cover of any of claims 1-9, wherein the first substrate comprises opposing first and second surfaces, the first surface facing the battery;

the back cover further comprises an appearance layer, and the appearance layer is positioned on the side, facing the second surface, of the back cover.

18. The back cover of any of claims 1-9, wherein the back cover has a thickness greater than or equal to 0.25mm and less than or equal to 0.5mm.

19. The back cover according to any one of claims 1-9, wherein the back cover has a puncture resistance force average value of greater than or equal to 100N.

20. A method of manufacturing a back cover according to any one of claims 1-19, comprising:

Providing a first prepreg, wherein the first prepreg comprises first fiber cloth and a thermosetting adhesive, the first fiber cloth is glass fiber cloth or aramid fiber cloth, and the number of layers of the first fiber cloth is one or more;

performing semi-curing treatment on the first prepreg to obtain a first semi-cured material;

processing the first semi-cured material to form a mounting groove on the first semi-cured material;

placing the reinforcing plate into the mounting groove to obtain a composite plate blank;

And carrying out hot pressing treatment on the composite board.

21. The method of processing according to claim 20, further comprising, prior to subjecting the composite panel to the autoclave process:

providing a second prepreg, wherein the second prepreg comprises second fiber cloth and a thermosetting adhesive, the second fiber cloth is glass fiber cloth or aramid fiber cloth, and the number of layers of the second fiber cloth is one or more;

performing semi-curing treatment on the second prepreg to obtain a second semi-cured material;

And stacking the second semi-cured material on at least one side of the composite board blank.

22. An electronic device comprising a back cover according to any one of claims 1-19 and/or a back cover processed by a processing method according to claim 20 or 21.

23. The electronic device of claim 22, further comprising:

the middle frame comprises a middle plate and a frame, wherein the middle plate is fixed on the inner surface of the frame, and the battery is arranged on the middle plate;

the middle plate is a metal piece, a plurality of fractures are arranged at the outer edge of the middle plate, and the fractures divide the outer edge of the middle plate into a plurality of antenna radiators.