Battery rear cover, terminal shell and terminal

Abstract

The invention relates to the technical field of terminals, and provides a battery rear cover, a terminal shell and a terminal, which are used for realizing how to increase the battery volume in a limited space to improve the cruising ability of the terminal on the premise of not increasing the thickness of the terminal and the thickness of the whole machine, the battery rear cover comprises a rear cover body, the rear cover body is made of a non-metal material, the first surface of the rear cover body is concave inwards to form a first accommodating area; and the FPC flat cable and / or the wireless charging coil are / is integrated in the first accommodating area, and the main body material of the FPC flat cable and / or the wireless charging coil is the same as the material of the rear cover body. The FPC flat cable is used for connecting the circuit main board of the terminal and the circuit auxiliary board of the terminal. The wireless charging coil is provided with a signal transmission end, and the signal transmission end is used for being connected with the circuit mainboard so as to achieve communication between the wireless charging coil and the circuit mainboard.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of terminals, in particular to a battery back cover, a terminal shell and a terminal. BACKGROUND

[0002] The endurance capability of a terminal product (such as a mobile phone) depends on the battery capacity of the terminal product, and the battery capacity is determined by the battery energy density and the battery volume. Due to the limitation of lithium ion battery material technology, the technology for improving the battery energy density has not yet broken through, so at present the endurance capability of the terminal product can be improved by increasing the battery volume.

[0003] The pursuit of lightness, thinness and beauty of a mobile phone severely limits its three-dimensional size (length, width and thickness), so that the space left for the battery in the mobile phone is extremely limited. Under the traditional mobile phone design scheme, the battery volume is difficult to significantly increase, especially after implanting strong computing power and high power consumption functions such as artificial intelligence (AI) large models in the mobile phone in the future, the requirement for battery capacity is further improved. Improving the battery capacity and the endurance capability has become the key to the competitiveness of future flagship mobile phones. Since the technology for improving the battery energy density of the underlying battery material is limited, how to increase the battery volume in the limited space to improve the endurance capability of the terminal product based on the existing small mobile phone architecture is a technical problem to be solved. SUMMARY

[0004] The present application provides a battery back cover, a terminal shell and a terminal to solve the problem of how to increase the battery volume in the limited space to improve the endurance capability of the terminal without increasing the thickness of the terminal and the overall thickness of the machine.

[0005] To solve the above technical problems, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, the embodiments of the present application provide a battery back cover for a terminal, which comprises: a back cover body made of a non-metallic material, a first face of the back cover body being concave to form a first accommodating area; a flexible printed circuit (FPC) cable and / or a wireless charging coil integrated in the first accommodating area, the main material of the FPC cable and / or the wireless charging coil being the same as the material of the back cover body. The FPC cable is used to connect the main circuit board of the terminal and the auxiliary circuit board of the terminal. The wireless charging coil has a signal transmission end used to connect the main circuit board to realize the communication between the wireless charging coil and the main circuit board.

[0007] The application provides a battery back cover and a terminal adopting the battery back cover. In the application, the wireless charging coil and / or the FPC flat cable are integrated on the battery back cover, and the wireless charging coil and / or the FPC flat cable are integrated in the first accommodating area of the surface of the battery back cover facing the terminal. When the terminal adopts the battery back cover, the wireless charging coil integrated on the battery back cover is used to provide wireless charging for the terminal, and / or the FPC flat cable integrated on the battery back cover is used to realize the communication between the main circuit board and the auxiliary circuit board of the terminal. In the application, the wireless charging coil and / or the FPC flat cable do not need to be additionally arranged in the terminal, so that the internal space of the terminal occupied by the wireless charging coil and / or the FPC flat cable in the Z direction can be reduced. In the application, the wireless charging coil and / or the FPC flat cable do not need to be additionally arranged in the terminal, so that the overall thickness of the terminal can be avoided to be increased. In addition, the thickness of the wireless charging coil and / or the FPC flat cable is absorbed by the Z direction space of the battery back cover, so that the thickness of the terminal and the overall thickness of the terminal are not increased. In the application, the wireless charging coil and / or the FPC flat cable do not need to be additionally arranged in the terminal, so that the Z direction space of the terminal can be used to increase the thickness of the battery to achieve the purpose of increasing the volume of the battery, thereby effectively improving the battery capacity.

[0008] In a possible implementation manner of the application, the flexible circuit board FPC flat cable or the wireless charging coil comprises: a first substrate, a second substrate and a substrate layer which are sequentially stacked from top to bottom, and the second substrate is used as the main material of the wireless charging coil or the wireless charging coil. The first substrate comprises: a first substrate layer and a first metal layer formed on the upper surface of the first substrate layer, and the surface of the first metal layer has a signal transmission end; the second substrate comprises: a second substrate layer and a second metal layer formed on one side or both sides of the second substrate layer, and the second metal layer has a conductive pattern of the flexible circuit board FPC flat cable or the wireless charging coil; the second substrate layer is provided with a first through hole, and the second metal layers on both sides of the second substrate layer are connected through the through hole; the first substrate is provided with a second through hole, and the signal line of the conductive pattern on the second metal layer on both sides of the second substrate layer passes through the first substrate through the second through hole and is connected with the signal transmission end.

[0009] In a possible implementation manner of the application, when the second substrate is used as the main material of the wireless charging coil, the first substrate layer and the upper surface of the second substrate layer, and the substrate layer and the lower surface of the second substrate layer further have a resin layer, and the resin layer is filled with resin-coated copper foil or ultra-thin cloth PP. In this way, the gap between the patterns can be fully filled with resin, and the reliability defects such as the internal cavity of the PCB sub-board can be avoided.

[0010] In one possible implementation of this application, when the second substrate is used as the main material of the wireless charging coil, the first substrate has a groove region filled with nanocrystals.

[0011] In one possible implementation of this application, when the FPC cable and the wireless charging coil are formed on different second substrates, the thickness of the second metal layer is greater when the second substrate is used as the main material of the wireless charging coil than when the second substrate is used as the main material of the FPC cable. By forming second metal layers of different thicknesses, the second substrate can be used as the main material of either the flexible circuit board FPC cable or the wireless charging coil.

[0012] In one possible implementation of this application, the FPC cable and the wireless charging coil are formed on the same second substrate. The thickness of the second metal layer in the first region of the second substrate layer is greater than the thickness of the second metal layer in the second region of the second substrate layer. The second metal layer in the first region is used to form the conductive pattern of the wireless charging coil, and the second metal layer in the second region is used to form the conductive pattern of the FPC cable. This solution allows for the separate fabrication of the FPC cable and the wireless charging coil on the same second substrate.

[0013] In one possible implementation of this application, when the second substrate is used as the main material of the wireless charging coil, the thickness of the second metal layer is determined by the power required for wireless charging, and the line width and spacing of the conductive patterns on the second metal layer on both sides of the second substrate layer meet the preset requirements.

[0014] In one possible implementation of this application, when the second substrate is used as the main material of the flexible printed circuit board (FPC) cable, the dielectric constant Dk of the second substrate layer is ≤4.0, and the dielectric loss Df of the second substrate layer is ≤0.02. This can meet the requirements of high-speed signal transmission such as USB.

[0015] In one possible implementation of this application, the first metal layer and the second metal layer are copper foil layers.

[0016] In one possible implementation of this application, the flexible circuit board (FPC) cable and / or wireless charging coil are integrally formed in the first receiving groove by thermoforming.

[0017] In one possible implementation of this application, the back cover body further has a second receiving groove, within which one or more of the following components are integrated: all or some components of the circuit sub-board, all or some components of the circuit main board, one or more sensors, and a radio frequency antenna. By integrating more components in the terminal onto the back cover body, the occupancy in the XY direction of the terminal is reduced, thereby freeing up more space to increase the size of the battery in the XY direction, thus further increasing the battery volume and achieving the goal of increasing the battery capacity of the terminal.

[0018] In one possible implementation of this application, the material of the back cover body includes one or more of the following: prepreg, glass, and ceramic.

[0019] In one possible implementation of this application, the prepreg is formed from resin and fiberglass cloth.

[0020] In one possible implementation of this application, the resin is BT resin.

[0021] Secondly, embodiments of this application provide a terminal housing, which includes a battery back cover as described in the first aspect or various possible implementations of the first aspect. This terminal housing is used to be fixedly connected to the terminal's display screen to form a receiving space. For example, the terminal's battery, PCB motherboard, PCB sub-board, etc., can be located within this receiving space.

[0022] Thirdly, embodiments of this application provide a terminal, which includes a battery and a terminal housing described in the second aspect or various possible implementations of the second aspect. The battery is located within a receiving space formed by the fixed connection between the terminal housing and the terminal's display screen.

[0023] In one possible implementation of this application, the terminal is a mobile phone, a tablet computer, or a wearable device. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the internal layout of a terminal in the prior art;

[0025] Figure 2 This is a schematic diagram of the internal structure of a smartphone from one perspective in existing technology.

[0026] Figure 3 It is the proportion of space occupied by each component inside the mobile phone in the existing technology;

[0027] Figure 4 This is a schematic diagram of the structure of a battery back cover provided in an embodiment of this application;

[0028] Figures 5 to 12The process diagrams for fabricating wireless charging coils and / or FPC cables provided in the embodiments of this application are as follows;

[0029] Figure 13 A process diagram for manufacturing the back cover of a glass battery. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; "and / or" in this text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0031] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this embodiment, unless otherwise stated, "a plurality of" means two or more.

[0032] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0033] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0034] It should be understood that in this application, "at least one (item)" means one or more. "More than one" means two or more. "At least two (items)" means two or three or more. "And / or" is used to describe the relationship between related objects, indicating that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural.

[0035] The character " / " generally indicates that the preceding and following objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any single or multiple items. For example, "at least one of a, b, or c" can be expressed as: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0036] Both "...when" and "if" indicate that a corresponding action will be taken under certain objective circumstances. They are not time limits, nor do they require a judgment action to be taken when the action is taken, nor do they imply any other limitations.

[0037] This application provides a terminal, including but not limited to mobile or fixed terminals with frames or shells such as mobile phones, tablets, laptops, ultra-mobile personal computers (UMPCs), handheld computers, walkie-talkies, netbooks, POS machines, personal digital assistants (PDAs), dashcams, wearable devices, virtual reality devices, wireless USB flash drives, Bluetooth speakers / headphones, or in-vehicle pre-installed devices.

[0038] like Figure 1 As shown, Figure 1 This diagram illustrates the internal component layout of a mobile phone. The terminal typically contains a main circuit board (such as a printed circuit board, PCB) and secondary circuit boards (such as a secondary PCB), as well as a battery. The main and secondary PCBs are usually positioned opposite each other on either side of the battery. They are connected via FPC cables. The main circuit board typically integrates the processor, memory, flash memory, camera, various sensors, and SIM card slots. The secondary PCB usually houses components such as speakers, Universal Serial Bus (USB), and SIM card slots.

[0039] for example, Figure 1 In the terminal structure shown in (a), it is assumed that the dimensions of the internal space of the mobile phone are represented by length and width. Specifically, the width of the internal space is represented as W1, W1 = 79 mm. The total length of the internal space, L1, is 163.65 mm. The width of the battery is denoted as W2, W2 = 70.96 mm. The length reserved for the PCB motherboard in this internal space, L2, is 63.37 mm, and the length reserved for the battery, L3, is 80.48 mm. Assuming... Figure 1 As shown in (b) of the diagram, the dimensions of the PCB motherboard are width (W3) = 73.77 mm and length L5 = 59.72 mm.Figure 1 It can be seen that the PCB motherboard and PCB sub-board occupy most of the internal space of the terminal. For example, the PCB motherboard may occupy 34% of the internal space of the terminal, and the PCB sub-board may occupy 22% of the internal space of the terminal, together accounting for about 56% of the internal space of the terminal.

[0040] Since the battery life of a terminal product directly depends on the battery capacity, which is calculated as battery capacity = battery energy density * battery volume, the battery capacity can currently be increased by reducing the area of ​​the PCB motherboard and / or PCB sub-board, thus freeing up more space inside the terminal to increase the battery volume.

[0041] However, current PCB motherboards already employ a sandwich-stacked compact structure, meaning they are stacked layer by layer. Furthermore, the circuit integration density of PCB motherboards and sub-boards is already very high. In recent years, the industry has been making breakthroughs in high-density miniaturization technology for PCBAs. Further shrinking the size of PCB motherboards or sub-boards would increase the difficulty and cost of hardware design, manufacturing, and overall heat dissipation, posing a significant challenge. While reducing the size of internal components (such as PCB motherboards and sub-boards) can free up space for a larger battery, thus increasing battery capacity, the increase is minimal. For example, assuming a 1.6mm reduction in the XY direction of the PCB motherboard would only increase battery capacity by 100mAh, this would not only significantly increase technical difficulty and cost but also result in a negligible increase in battery capacity. Therefore, reducing the lateral dimensions of the PCB is not the preferred solution.

[0042] like Figure 2 As shown, Figure 2 A schematic diagram of the internal structure of a current-technology smartphone from one perspective, such as... Figure 2 As shown in (a), a battery 40, an FPC cable 30, a wireless charging coil 60, a main circuit board 20, and a secondary circuit board 10 are sequentially arranged between the phone's display screen (not shown) and the battery back cover 50. The FPC cable 30 connects the main circuit board 20 and the secondary circuit board 10. To fully utilize the internal space of the phone, the FPC cable 30 is located below the battery 40 to connect the main circuit board 20 and the secondary circuit board 10. The wireless charging coil 60 is also located below the battery and connected to the main circuit board 20. "Above the battery" refers to the side of the battery facing the battery back cover. Figure 2 Figure (a) shows that both the FPC cable and the wireless charging coil are positioned along the thickness of the phone, inevitably increasing the overall thickness of the phone. The existing battery back cover structure is as follows: Figure 2 As shown in Figure (b) of the document.

[0043] As mentioned above, given the limited benefits of reducing the battery capacity by mm-level dimensions in the XY direction at a high cost, we can consider high-density hardware technology innovation in the Z direction. Assuming that high-density hardware technology provides an additional 0.1mm of space in the Z direction of the battery, the battery capacity can be increased by 100mAh, which is quite significant. Therefore, increasing the spatial height of the battery in the Z direction through high-density hardware is a better path to improve battery capacity.

[0044] Although it is currently possible to increase battery capacity by directly increasing the height of the battery in the Z direction (i.e., the thickness of the battery), it is difficult to effectively increase the battery thickness due to the limitations of other structural components in the Z direction.

[0045] like Figure 3 As shown, Figure 3 Considering the spatial distribution of various components within a mobile phone, and keeping the overall thickness of the phone constant, the optimization of the battery's Z-axis space is significantly affected by structural components. Analysis of the battery's Z-axis thickness reveals that the fixed constraints of the overall structure, such as the VC heat dissipation plate, battery expansion space, tolerances, and heat dissipation gaps, limit optimization measures. The battery back cover, as a protective structural component, is also constrained by strength and cannot be thinned. The wireless charging coil and FPC cable function as the phone's signal connectors and are already designed to be ultra-thin, limiting optimization space and making them unavoidable in the design. Therefore, directly increasing the battery thickness while maintaining the existing independent component architecture of the mobile phone is highly impractical.

[0046] Based on this, embodiments of this application provide a battery back cover and a terminal using the battery back cover. Since the wireless charging coil and / or FPC cable circuitry are integrated on the battery back cover, and the wireless charging coil and / or FPC cable circuitry are integrated in a first receiving groove on the side of the battery back cover facing the terminal, there is no need to additionally arrange the wireless charging coil and / or FPC cable inside the terminal. This reduces the internal space occupied by the wireless charging coil and / or FPC cable circuitry in the Z-direction of the terminal, thus avoiding an increase in the overall thickness of the terminal due to the presence of the wireless charging coil and / or FPC cable circuitry. By absorbing the thickness of the wireless charging coil and / or FPC cable circuitry in the Z-direction space of the battery back cover, the overall thickness of the phone and the entire device are not increased. Since this solution does not require additional wireless charging coil and / or FPC cable inside the terminal, the Z-direction space of the terminal can be used to increase the battery volume, thereby effectively increasing the battery capacity.

[0047] like Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of a battery back cover provided in an embodiment of this application, as shown below. Figure 4As shown, the battery back cover includes a back cover body 101, a flexible printed circuit (FPC) cable 102, and / or a wireless charging coil 103. The back cover body 101 is made of a non-metallic material.

[0048] The back cover body 101 has a first recessed area formed on its first surface. An FPC cable 102 and / or a wireless charging coil 103 are integrated within this first recessed area. The main body material of the FPC cable 102 and / or the wireless charging coil 103 is the same as that of the back cover body. The FPC cable 102 is used to connect the main circuit board and the secondary circuit board of the terminal. The wireless charging coil 103 has a signal transmission end for connecting to the main circuit board.

[0049] This application provides a battery back cover and a terminal using the battery back cover. Because the solution integrates the wireless charging coil and / or FPC cable circuit on the battery back cover, and the wireless charging coil and / or FPC cable circuit is integrated in a first receiving groove on the side of the battery back cover facing the terminal, wireless charging and / or the connection between the main circuit board and the secondary circuit board can be achieved by means of the wireless charging coil and / or FPC cable integrated on the battery back cover. Since this solution does not require additional arrangement of the wireless charging coil and / or FPC cable inside the terminal, the internal space occupied by the wireless charging coil and / or FPC cable circuit in the Z-direction of the terminal can be reduced, thereby avoiding an increase in the overall thickness of the terminal due to the presence of the wireless charging coil and / or FPC cable circuit. By absorbing the thickness of the wireless charging coil and / or FPC cable circuit using the Z-direction space of the battery back cover, without increasing the overall thickness of the phone or the entire device, and since this solution does not require additional wireless charging coil and / or FPC cable inside the terminal, the Z-direction space of the terminal can be used to increase the battery volume, thereby effectively increasing the battery capacity.

[0050] As an example, the connection between the FPC cable and the PCB motherboard or PCB sub-board is achieved by installing a connector on the PCB motherboard or PCB sub-board and connecting it to the FPC cable to achieve signal transmission.

[0051] The FPC cable in this embodiment can also be an FFC (Flexible Flat Cable) cable.

[0052] As another example, the FPC cable can also have metal springs / probes, and the PCB motherboard and / or PCB sub-board can also have metal springs / probes, so that when the battery back cover is fastened to the terminal, the metal springs / probes on the FPC cable can be aligned with the metal springs / probes on the PCB motherboard and / or PCB sub-board, thereby realizing signal transmission.

[0053] like Figure 5 As shown, Figure 5 This is a schematic diagram of the functional structure of the back cover circuit of a fiberglass battery. For example, PCB processing technology can be used to etch the circuit on the inner core board with copper foil layers on both the top and bottom to obtain the wireless charging coil and / or FPC cable lines. Then, first-order HDI technology is used to press PP boards on the top and bottom of the inner core board to prepare a first-order HDI stacked structure. Optionally, the HDI circuit board can also be painted and film-coated.

[0054] As an example, the modulus of the copper foil in the copper foil layer is 40–50 GPa.

[0055] As an example, such as Figure 8 As shown, Figure 8 A schematic diagram of the design of the wireless charging coil integrated on the first surface of the back cover body 101.

[0056] As an example, the first side of the back cover body 101 may refer to the side of the back cover body 101 facing the terminal's display screen when the battery back cover is fastened to the terminal.

[0057] As an example, the first receiving area may be a first receiving groove formed on the first surface of the back cover body 101. This first receiving groove may be integrally formed on the first surface of the back cover body 101 during the manufacturing process of the battery back cover.

[0058] As an example, the material of the back cover body 101 may include one or more of the following:

[0059] Prepreg, glass materials, ceramic materials.

[0060] As an example, ceramic materials include zirconium oxide, silicon carbide, silicon nitride, aluminum nitride, or alumina ceramics.

[0061] As an example, prepreg is formed from resin and reinforcing materials. For instance, the reinforcing material can be fiberglass cloth, paper-based materials, composite materials, etc. Fiberglass cloth is commonly used as the reinforcing material in the manufacture of multilayer boards.

[0062] As an example, the resin is BT resin.

[0063] In the embodiments of this application, the main material of the FPC cable 102 and / or the wireless charging coil 103 may refer to the material of the substrate included in the PCB that makes the FPC cable and / or the wireless charging coil.

[0064] For example, if the battery back cover is made of prepreg, then prepreg can be used as the material for the inner core board of FPC cables and / or wireless charging coils.

[0065] As an example, the first receiving groove can integrate the FPC cable 102, while the wireless charging coil 103 remains inside the terminal. When the terminal is fastened to the battery back cover, the first signal transmission end of the FPC cable 102 can be electrically connected to the main circuit board, and the second signal transmission end of the FPC cable 102 can be electrically connected to the secondary circuit board, thus enabling communication between the main circuit board and the secondary circuit board via the FPC cable. This solution utilizes the Z-axis space of the battery back cover to absorb the thickness of the FPC cable 102, thereby avoiding the additional Z-axis space occupied by the flexible circuit board FPC cable inside the terminal, thus freeing up Z-axis space inside the terminal to increase the battery volume.

[0066] As an example, the positions of the first and second signal transmission terminals on the back cover body 101 correspond to the positions of the signal transmission terminals on the main circuit board and the sub-circuit board, respectively. Thus, when the terminal and the battery back cover are fastened together, the first signal transmission terminal of the flexible circuit board (FPC) cable 102 can be connected to the signal transmission terminal on the main circuit board to achieve electrical connection. The second signal transmission terminal of the flexible circuit board (FPC) cable 102 can be connected to the signal transmission terminal on the sub-circuit board to achieve electrical connection.

[0067] As another example, a wireless charging coil 103 can be integrated within the first receiving recess, while the flexible circuit board (FPC) cable 102 is located inside the terminal and connects the main circuit board and the secondary circuit board. This solution can utilize the Z-axis space of the battery back cover to absorb the thickness of the wireless charging coil. Since there is no need to additionally arrange the wireless charging coil and / or FPC cable inside the terminal, the freed-up Z-axis space inside the terminal can be used to increase the thickness of the battery, thereby increasing the battery volume.

[0068] Understandably, when the wireless charging coil 103 is integrated within the first receiving groove, but the flexible circuit board (FPC) cable 102 is not integrated, in order to reduce the number of FPC cables and increase the battery volume, the FPC cable can be placed in other locations within the terminal to reduce the Z-axis space occupied by the FPC cable inside the terminal. For example, the FPC cable can be placed on one side of the mid-frame 30 to reduce the Z-axis space occupied by the FPC cable inside the terminal.

[0069] As another example, a wireless charging coil 103 and a flexible circuit board (FPC) cable 202 can be integrated within the first receiving groove. This solution allows for the simultaneous integration of the wireless charging coil 103 and the FPC cable 102 onto the back cover body 101. By utilizing the Z-axis space of the battery back cover to absorb the thickness of the wireless charging coil and the flexible circuit board (FPC) cable, and since there is no need to additionally arrange the wireless charging coil and FPC cable inside the terminal, the Z-axis space freed up inside the terminal can be used to increase the thickness of the battery, thereby increasing the battery volume.

[0070] Understandably, the battery back cover body 101 also has one or more through holes, and the first receiving groove is disposed on the back cover body 101, bypassing one or more through holes. For example, the one or more through holes may include a camera through hole corresponding to a camera, and / or a flash through hole corresponding to a flash.

[0071] The wireless charging coil 103 can be a multi-turn coil. Optionally, the wireless charging coil 103 can be a single-layer coil, or it can include multiple layers of coils perpendicular to the battery back cover, with each layer being a multi-turn coil. In this embodiment, the number of layers and turns of the wireless charging coil in the battery back cover is not limited.

[0072] As another example, the first receiving recess may include receiving recess 1 and receiving recess 2, wherein receiving recess 1 is used to receive the flexible printed circuit board (FPC) cable, and receiving recess 2 is used to receive the wireless charging coil. Integrating the FPC cable and the wireless charging coil into different receiving recesses can reduce signal interference between them.

[0073] The FPC cable 102 and / or wireless charging coil 103 in this application can be integrally formed with the battery back cover. For example, the main body material of the FPC cable 102 and / or wireless charging coil 103 is the same as that of the battery back cover, such as plastic, glass or ceramic. During the battery back cover forming process, the FPC cable 102 and / or wireless charging coil 103 are integrated onto the battery back cover by thermoforming. Alternatively, during the battery back cover manufacturing process, the FPC cable 102 and / or wireless charging coil 103 can be integrally formed and fixed in the first receiving groove of the battery back cover.

[0074] As an example, the FPC cable 102 and / or the wireless charging coil 103 include: a first substrate, a second substrate, and a substrate layer stacked sequentially from top to bottom, wherein the second substrate serves as the main material of the wireless charging coil or the wireless charging coil body.

[0075] The first substrate includes: a first substrate layer and a first metal layer formed on the upper surface of the first substrate layer.

[0076] The second substrate includes a second substrate layer and a second metal layer formed on one or both sides of the second substrate layer. The second metal layer has conductive patterns of an FPC cable 102 and / or a wireless charging coil 103. The material of the second substrate layer is the same as that of the back cover body. A first through-hole is formed on the second substrate layer for connecting the second metal layers formed on both sides of the second substrate layer. The first substrate has a second through-hole, and signal lines of the conductive patterns on the second metal layers on both sides of the second substrate layer pass through the second through-hole on the first substrate and are located on the surface of the first metal layer.

[0077] It is understandable that, in order to connect the second metal layers formed on both sides of the second substrate layer using the first through-hole, the first through-hole is filled with metal, such as copper foil. Similarly, in order to allow signal lines of conductive patterns to pass through the second through-hole on the first substrate to the surface of the first metal layer using the second through-hole, the second through-hole is also filled with metal, such as copper foil.

[0078] For example, the conductive pattern of a flexible printed circuit board (FPC) cable includes the metal lines of the FPC cable, and the conductive pattern of a wireless charging coil includes the metal lines of the wireless charging coil.

[0079] Since a second through hole is provided on the second substrate layer to connect the second metal layers formed on both sides of the second substrate layer, the metal lines between the conductive patterns on the second metal layers on both sides of the second substrate layer can be connected.

[0080] Understandably, a second through-hole is provided on the first substrate so that the TX signal pin of the circuit pattern etched on the inner metal layer of the wireless charging coil and FPC cable can be led out to the surface of the first metal layer.

[0081] As an example, a first substrate layer can be laminated to the upper and lower sides of the second substrate, and then copper foil can be laminated on the first substrate layer located on the upper surface of the second substrate.

[0082] As an example, the material of the second substrate layer is the same as that of the first substrate layer. It is understood that conductive patterns are etched onto the second metal layer on one or both sides of the second substrate layer. It is understood that the second substrate is the main material of the flexible printed circuit board (FPC) cable or wireless charging coil.

[0083] As an example, when the second substrate serves as the main material of the wireless charging coil, a resin layer is further provided between the upper surfaces of the first substrate layer and the second substrate layer, and between the lower surfaces of the first substrate layer and the second substrate layer, the resin layer being filled with resin. For example, resin-coated copper foil or ultra-thin PP cloth.

[0084] It is understood that the resin layer includes at least the resin in the pattern gaps of the conductive patterns in the second metal layer. Optionally, the resin layer further includes: resin between the first substrate layer and the second metal layer located on the upper surface of the second substrate layer, and resin between the substrate layer and the second metal layer located on the lower surface of the second substrate layer.

[0085] Resin is used to fill the gaps between the metal lines of the wireless charging coil. This ensures that the gaps between the circuit patterns etched on the metal layer are fully filled with resin, avoiding reliability defects such as voids inside the PCB sub-board. For example, the resin can be resin-coated copper foil (RCC) or ultra-thin prepreg (PP).

[0086] For example, the thickness of RCC can be 10um, and the thickness of ultra-thin PP fabric can be 50um.

[0087] For example, in the process of manufacturing a wireless charging coil, metal lines can be etched on the second metal layer of the second substrate first, and then 10um thick RCC or 50um thick ultra-thin PP cloth can be pressed with the second substrate with etched metal lines to ensure that the gap between the patterns is fully filled with resin. Then, the first substrate layer is pressed on the upper and lower sides of the second substrate respectively.

[0088] As an example, when the second substrate serves as the main material for the wireless charging coil, a recessed area is formed on the first substrate. This recessed area is filled with nanocrystals. The nanocrystals are embedded into the recessed area on the first substrate according to a cavity structure and then pressed together, ensuring nanocrystal alignment and surface flatness. The embedded cavity structure of the nanocrystal magnetic shielding film achieves a 0.1mm high nanocrystal surface flush, eliminating height differences.

[0089] It is understandable that the groove area opened on the first substrate extends through the first substrate.

[0090] As an example, since the wireless charging coil and the FPC cable have different functions, the thickness of the second metal layer is greater when the second substrate is used as the main material of the wireless charging coil than when the second substrate is used as the main material of the flexible circuit board FPC cable.

[0091] For example, to meet the requirements of high-power wireless charging, when the second substrate is used as the main material of the wireless charging coil, the thickness of the second metal layer can be 80um, while when the second substrate is used as the main material of the FPC cable, the thickness of the second metal layer can be 25um.

[0092] It is understandable that when fabricating the second substrate, a metal layer of a certain thickness can be formed on one or both sides of the second substrate layer first, and then the thickness of the metal layer can be increased to a specified thickness (such as 80um or 25um) by electroplating to obtain the first metal layer.

[0093] The thickness of the second metal layer can be determined by the circuit pattern etched on it. For example, if the etched circuit pattern is that of a wireless charging coil, the thickness of the second metal layer can be 80µm. If the etched circuit pattern is that of an FPC cable, the thickness of the second metal layer can be 25µm.

[0094] As an example, the thickness of the first substrate layer in the FPC cable differs from the thickness of the first substrate layer in the wireless charging coil. For instance, the thickness of the first substrate layer in the wireless charging coil may be less than that in the FPC cable. For example, the thickness of the first substrate layer in the wireless charging coil could be 75µm, while the thickness of the first substrate layer in the FPC cable could be 150µm.

[0095] For example, when fabricating a wireless charging coil, a 35µm thick metal layer can be formed first on one or both sides of the second substrate layer. Then, the thickness of the metal layer can be increased from 35µm to 80µm through electroplating to form a second metal layer on one or both sides of the second substrate layer. The circuit pattern of the wireless charging coil can then be etched onto the second metal layer.

[0096] For example, when manufacturing an FPC cable, a 12µm thick metal layer can be formed first on one or both sides of the second substrate layer. Then, the thickness of the metal layer can be increased from 12µm to 25µm through electroplating to form a second metal layer on one or both sides of the second substrate layer. The circuit pattern for the FPC cable can then be etched onto the second metal layer.

[0097] In one possible implementation of this application, the flexible printed circuit board (FPC) cable and the wireless charging coil can be formed on different substrates; that is, the FPC cable is formed on one second substrate, and the wireless charging coil is formed on another second substrate. Since the FPC cable and the wireless charging coil have different functions, their requirements for the thickness of the second metal layer formed on the second substrate layer are also different. Therefore, fabricating the FPC cable and the wireless charging coil separately allows the fabricated FPC cable and the wireless charging coil to better meet the requirements.

[0098] In one possible implementation of this application, when the second substrate is used as the main material of the flexible circuit board (FPC) cable, the dielectric constant Dk of the second substrate layer is ≤4.0 and the dielectric loss Df of the second substrate layer is ≤0.02.

[0099] In one possible implementation of this application, the flexible printed circuit board (FPC) cable and the wireless charging coil can be formed on the same second substrate. When the FPC cable and the wireless charging coil are formed on the same second substrate, the second metal layer includes a first region and a second region, wherein the thickness of the second metal layer in the first region is greater than the thickness of the second metal layer in the second region. For example, the first region is used to etch the circuit pattern of the wireless charging coil, and the second region is used to etch the circuit pattern of the FPC cable.

[0100] For example, base copper foil can be applied to both the top and bottom sides of the second substrate layer, with a preset thickness (e.g., 35µm). Then, the thickness of the copper foil in the first region is increased to a second preset thickness (e.g., 80µm) through electroplating. Next, the thickness of the copper foil in the second region is thinned to a first preset thickness (e.g., 15µm). Then, the circuit pattern of the wireless charging coil can be etched on the copper foil layer in the first region to form the conductive pattern of the wireless charging coil, and the circuit pattern of the FPC cable can be etched on the copper foil layer in the second region to form the conductive pattern of the FPC cable.

[0101] It is understandable that, in order to prevent the copper foil in the second region from being electroplated thickened when the copper foil in the first region is electroplated thickened, the copper foil in the second region can be protected during the electroplating thickening process.

[0102] It is understandable that, in the specific implementation process, the thickness of the metal layer in the second region on the second substrate layer can be reduced to the first preset thickness first, and then the thickness of the metal layer in the first region on the second substrate layer can be increased by electroplating.

[0103] To enable metal circuitry between conductive patterns on the upper and lower sides of the second metal layer of the second substrate layer, a first through-hole and a second through-hole are formed in the second substrate layer. The position of the first through-hole corresponds to the position of the first region. The position of the second through-hole corresponds to the position of the second region. This allows the metal circuitry between the conductive patterns on the upper and lower sides of the second metal layer of the second substrate layer to be connected via the first through-hole, and vice versa.

[0104] In one possible implementation of this application, when the second substrate is used as the main material of the wireless charging coil, the thickness of the second metal layer is determined by the power required for wireless charging, and the line width and spacing of the conductive patterns on the second metal layer on both sides of the second substrate layer meet the preset requirements.

[0105] For example, to meet the requirements of 80W high-power wireless charging, when the second substrate is used as the main material of the wireless charging coil, the thickness of the second metal layer can be 80µm. For example, the linewidth and spacing of the conductive patterns on the second metal layer on both sides of the second substrate layer must meet the high-density design requirement of linewidth / spacing = 0.25 / 0.10mm. For example, tenting technology can be used to etch lines on the second metal layer to form conductive patterns.

[0106] In one possible implementation of this application, the first metal layer and the second metal layer are copper foil layers, that is, the second metal layer is the copper foil formed on both sides of the second substrate layer. The first metal layer is the copper foil formed on the upper side of the first substrate layer. The lower side of the first substrate layer is the side of the first substrate layer closest to the second substrate.

[0107] In one possible implementation of this application, the flexible circuit board (FPC) cable and / or wireless charging coil are integrally formed in the first receiving groove by thermoforming.

[0108] In one possible implementation of this application, the flexible circuit board (FPC) cable and / or wireless charging coil can be attached to the first receiving groove.

[0109] In one possible implementation of this application, the first receiving groove is integrally formed on the first surface of the back cover body.

[0110] In one possible implementation of this application, the back cover body further has a second receiving groove, and one or more of the following components are integrated in the second receiving groove:

[0111] Radio frequency antenna, one or more components deployed on a circuit sub-board, one or more components deployed on a circuit mainboard, and one or more sensors.

[0112] By integrating all the components in the circuit sub-board onto the back cover body 101, there is no need to arrange the circuit sub-board separately inside the terminal, thus saving the space occupied by the circuit sub-board inside the terminal. Therefore, this space can be used to increase the size of the battery in the XY direction, thereby increasing the battery capacity.

[0113] By integrating some components (such as the USB interface) from the circuit sub-board onto the back cover body 101, the size of the circuit sub-board can be reduced, thus reducing the space occupied by the circuit sub-board inside the terminal. This space can then be used to increase the size of the battery in the XY direction, thereby increasing the battery capacity.

[0114] By integrating all the components in the main circuit board onto the back cover body 101, there is no need to arrange the main circuit board separately inside the terminal, thus saving the space occupied by the main circuit board inside the terminal. Therefore, this space can be used to increase the size of the battery in the XY direction, thereby increasing the battery capacity.

[0115] By integrating some components of the main circuit board onto the back cover body 101, the size of the secondary circuit board can be reduced, thus reducing the space occupied by the main circuit board inside the terminal. This space can then be used to increase the size of the battery in the XY direction, thereby increasing the battery capacity.

[0116] As an example, the sensors inside the terminal can be ambient light sensors, motion sensors, gyroscope sensors, etc.

[0117] It is understandable that the electronic components integrated in the second receiving groove can be components that are already integrated on the PCB motherboard or PCB subboard, or components that need to be integrated on the PCB motherboard or PCB subboard later.

[0118] It is understood that the first receiving groove and the second receiving groove can be the same groove or different grooves, and the embodiments of this application do not limit this.

[0119] In one possible implementation of this application, the 3D molding structure design of the PCB three-dimensional wrapping ensures that the integrated PCB circuitry inside the back cover remains stable and reliable under conditions such as drops, punctures, and vibrations. Furthermore, low-temperature PP thermosetting resin can be used for 3D molding. Under the premise that the 3D molding temperature is lower than the temperature of the PCB circuit material, a temperature difference between the front and rear processes can be achieved, ensuring that the subsequent 3D molding process does not affect the device performance of the finished PCB.

[0120] Taking the battery back cover as an example, which is a composite material made of fiber glass and resin, Figure 6 The process flow for integrating a wireless charging coil into a battery back cover made of a composite material formed from fiberglass cloth and resin is described:

[0121] 1) Provide thin dielectric thick copper clad laminate (CCL), i.e., 2-layer (L) PCB, as the main material for the wireless charging coil. The specific process is as follows:

[0122] like Figure 6 As shown in (a), a thermosetting prepreg (PP) is used as the inner core board (i.e., the second substrate layer). The inner core board has copper foil layers on one or both sides. For example, 35µm copper foil is laminated to one or both sides of the inner core board to form copper foil layers, resulting in a double-sided thick copper CCL. For example, the core board thickness can be 25µm.

[0123] For example, thermosetting prepregs are composite materials made of fiberglass cloth and resin.

[0124] For example, high-strength ultra-thin S-type fiberglass cloth can be used for the fiberglass cloth. High-strength BT resin can be selected, and the two form a composite material to form a dielectric sheet. After curing, the overall modulus of this material is >20 GPa.

[0125] For example, um-level ultra-thin 1017 fiberglass cloth can be composited with BT resin to form thermosetting PP, achieving high strength properties of ultra-thin media.

[0126] For example, the inner core board can undergo an oxidation-reduction reaction in a copper plating bath to form a copper foil layer with a thickness of 35um on both the upper and lower sides of the second substrate layer.

[0127] 2) Electroplating for filling 0.2mm through-hole PCBs:

[0128] like Figure 6 As shown in (b), a first through hole is formed on the inner core board, and the first through hole is filled with metal (such as copper foil) so that the conductive pattern formed on the copper foil layers on the upper and lower sides of the second substrate layer is conductive.

[0129] For example, a first through-hole can be drilled in the inner core board using laser drilling. The first through-hole is then treated with copper plating and electroplating to make it a single unit with the inner core board.

[0130] For example, such as Figure 6 As shown in (c), the circuitry of the wireless charging coil is fabricated on the copper foil layer of the inner core board, such that the copper foil layers formed on the upper and lower sides of the inner core board have conductive patterns of the wireless charging coil. The conductive patterns of the wireless charging coil include the metal circuitry of the wireless charging coil. For ease of description, the circuitry of the wireless charging coil formed in the copper foil layer below the inner core board can be referred to as the "inner layer circuitry." The circuitry of the wireless charging coil formed in the copper foil layer above the inner core board can be referred to as the "second layer circuitry."

[0131] Subsequently, the thickness of the copper foil layer formed on both sides of the inner core board is increased to 80um using a full-board electroplating method to obtain the second metal layer. This meets the requirements for 80W high-power wireless charging.

[0132] For example, circuit patterns can be etched on the copper foil layers formed on the upper and lower sides of the inner core board using tenting technology to obtain conductive patterns with a line width / spacing of 0.25 / 0.10 mm to meet high-density design requirements.

[0133] The above steps can be used to prepare a 2L PCB.

[0134] 3) Thick copper filler bonding:

[0135] like Figure 6 As shown in (d), RCC or PP are laminated on both sides of the 2L PCB to ensure that the gaps between the 80um thick copper patterns are fully filled with resin, thus avoiding reliability defects such as voids inside the PCB sub-board.

[0136] For example, 10um thick RCC or 50um thick ultra-thin PP cloth can be laminated with 2L PCB.

[0137] 4) First-order HDI blind via machining:

[0138] like Figure 6 As shown in (e), PP is laminated on the top and bottom sides of the 2L PCB to form a first outer core board (i.e., a first substrate layer) and a second outer core board (substrate layer) on the top and bottom sides of the 2L PCB, respectively. The upper surface of the first outer core board has a copper foil layer as a first metal layer, constituting a 3L layer circuit diagram. It is understood that the first metal layer on the upper surface of the first outer core board can include a base copper layer and copper plating.

[0139] The top and bottom sides of the 2L PCB can be considered as the first outer core board, or L1, of the multilayer circuit board, and the second outer core board can be considered as the fourth layer, or L4, of the multilayer circuit board. L2 and L3 are the two sides of the inner core board.

[0140] like Figure 6 As shown in (f), blind vias are created on L1 and L2 using laser blind via technology, followed by copper plating and other processes to allow wireless charging signals from the inner and second layer circuits to be routed to the surface of the first layer (i.e., the first metal layer), thus realizing the design of the surface layer signal transmission port. For example, vias can be created on the RCC / PP layer and the first substrate layer, and copper foil can be filled into the vias to allow wireless charging signals from the inner and second layer circuits to be routed to the surface of the first layer (i.e., the first metal layer).

[0141] 5) Local embedding of nanocrystalline soft magnetic materials:

[0142] like Figure 6 As shown in (g), the nanocrystal bonding area is reserved by the Cavity groove through the secondary PP pressing in 4). The nanocrystals are embedded in the groove according to the Cavity structure and pressed to ensure the alignment and surface flatness of the nanocrystals.

[0143] Optionally, in scenes where 3D models exist: such as Figure 7 As shown, low-temperature epoxy resin molding is used to achieve the crater and the curved protrusion of the plate edge, which can be flexibly designed.

[0144] Figure 6The proposed solution integrates a wireless charging coil into the battery back cover, which is a composite material made of fiberglass and resin. The battery back cover with the integrated wireless charging coil is then used in the terminal. This is expected to increase the battery thickness by 0.3 mm and increase the capacity by 300 mAh.

[0145] like Figure 9 As shown, Figure 9 The process flow for integrating FPC cables into the battery back cover of a composite material made of fiberglass cloth and resin:

[0146] 1) Obtaining a 25µm thin dielectric CCL:

[0147] like Figure 9 As shown in Figure (a), a thermosetting PP core board (i.e., the second substrate layer) is formed by using um-level ultra-thin 1017 glass fiber cloth composite BT resin. The material Dk≤4.0 and Df≤0.02 meet the requirements of high-speed signal transmission such as USB.

[0148] A 12µm thick copper foil is laminated to the upper and lower surfaces of the inner substrate to form a second metal layer, thereby obtaining a double-sided thick copper CCL, which serves as the main material for the FPC cable.

[0149] 2) Electroplating for filling 50um through-hole PCBs:

[0150] like Figure 9 As shown in (b), a first through-hole is formed on the inner core board, and the first through-hole is treated with copper plating and electroplating to fill it, so that the second through-hole is filled with a metal layer, realizing the conduction of the upper and lower conductive patterns of the 2L PCB. Figure 9 As shown in (c), circuit patterns are etched on the second metal layers on both the upper and lower sides of the inner core board to fabricate the PFC cable lines on the copper foil layer of the inner core board. The thickness of the second metal layer is increased to 25µm to meet the signal transmission requirements of the FPC.

[0151] 3) First-order HDI blind via machining:

[0152] like Figure 9 As shown in (d), PP is laminated on the top and bottom sides of the 2L PCB to form a first outer core board (i.e., the first substrate) on the top side of the 2L PCB and a second outer core board (i.e., the substrate layer) on the bottom side of the 2L PCB. Copper foil is deposited on the upper surface of the first outer core board to form a 3L layer circuit diagram. The pins of the signal transmission ports of the inner layer circuits and the second layer circuits are brought out to the surface layer of the first layer (i.e., the first metal layer) through laser blind via technology to realize the design of the surface layer signal transmission port.

[0153] Optionally, in scenes where 3D models exist: such as Figure 10As shown, low-temperature epoxy resin molding is used to achieve the crater and the curved protrusion of the plate edge, which can be flexibly designed.

[0154] Figure 11 The solution shown integrates a high-speed FPC cable into the fiberglass back cover. When the terminal hook cover with the integrated high-speed FPC cable is used in the terminal, the battery thickness is expected to increase by 0.15mm, resulting in a gain of 150mAh.

[0155] The following embodiments illustrate the process flow for simultaneously integrating an FPC cable and a wireless charging coil into a battery back cover made of a composite material formed from fiberglass cloth and resin:

[0156] 1) Obtain a 25µm thin dielectric thick copper CCL.

[0157] A thermosetting PP core board (second substrate layer) is formed by combining 1µm ultra-thin 1017 fiberglass cloth with BT resin, achieving high strength characteristics of ultra-thin dielectric. 35µm copper foil is laminated to the top and bottom of the inner core board as copper foil layers, forming a double-sided thick copper CCL (i.e., the second substrate). This double-sided thick copper CCL serves as the main material for the 2L PCB of the wireless charging coil and FPC cable.

[0158] 2) Electroplating for filling 0.2mm through-hole PCBs:

[0159] A first through-hole is formed in the first region of the inner core board. Through-hole electroplating is used to fill the first through-hole with copper foil to achieve conductivity between the inner and second layer circuitry of the wireless charging coil on the 2L PCB. Tenting technology is used to etch the wireless charging coil circuitry into the copper foil layer of the first region of the inner core board. The conductive pattern of the wireless charging coil meets the high-density design requirement of line width / spacing = 0.25 / 0.10mm. The copper foil layer at the FPC cable location is partially protected without electroplating. Figure 11 As shown, a conductive pattern for a wireless charging coil is formed in a copper foil layer in the first region of the inner core board. The thickness of the copper foil layer in the first region of the inner core board can then be increased to 80µm via electroplating to meet the requirements of 80W high-power wireless charging.

[0160] 3) Reduce the thickness of the copper foil layer in the area where the FPC cable is located:

[0161] like Figure 11 As shown, a third through-hole is opened in the second region of the inner core board. Through-hole electroplating is used to fill the third through-hole with copper foil to achieve conductivity between the inner layer and the second layer of the PFC cable on the 2L PCB. The copper foil layer in the second region of the inner core board is subjected to a copper reduction process to achieve a copper layer thickness of 15µm, meeting the copper thickness requirements for the FPC cable surface.

[0162] 4) Thick copper filler bonding: such as Figure 6 As shown in Figure (d), 10µm thick RCC or 50µm thick ultra-thin PP cloth is used to press with 2LPCB to ensure that the gaps between the 80µm thick copper patterns are fully filled with resin, thus avoiding reliability defects such as voids inside the PCB sub-board.

[0163] 5) First-order HDI blind via machining:

[0164] like Figure 6 As shown in (e), PP is laminated to the top and bottom sides of the 2L PCB to form a first outer core board (first substrate layer) and a second outer core board (substrate layer) on the top and bottom sides of the 2L PCB, respectively. Copper foil is deposited on the upper surface of the first outer core board to form a 3L layer circuit diagram. The first outer core board refers to the outer core board located above the inner core board. The second outer core board refers to the outer core board located below the inner core board.

[0165] like Figure 6 As shown in (f), laser blind via technology is used to bring the pins of the signal transmission ports of the inner layer and the second layer to the surface of the first layer (i.e., the first metal layer) to achieve the design of the surface layer signal input port. For example, holes can be made in the RCC / PP layer and the first substrate layer, and copper foil can be filled in the holes to bring the pins of the signal transmission ports of the inner layer and the second layer to the surface of the first layer.

[0166] like Figure 9 As shown in (d), PP is laminated on the top and bottom sides of the 2L PCB, and a first outer core board and a second outer core board are formed on the top and bottom sides of the 2L PCB, respectively. Then, copper foil is applied to the upper surface of the first outer core board to form a 3L layer circuit diagram. Blind holes are opened on the first outer core board and the inner core board through laser blind holes to realize the pins of the signal transmission ports of the inner layer circuit and the second layer circuit to the surface layer of the first layer (i.e., the first metal layer) to realize the design of the surface layer signal input port.

[0167] 6) Local embedding of nanocrystalline soft magnetic materials:

[0168] The nanocrystal bonding area is reserved through the Cavity groove created by secondary PP lamination (4). The nanocrystals are embedded into the groove according to the Cavity structure and then laminated to ensure the alignment and surface flatness of the nanocrystals. The specific process is as follows: Figure 6 As shown in (g) in the diagram.

[0169] 7) 3D modeling, optional. In the 3D modeling scene: low temperature epoxy resin modeling to achieve crater and plate edge curvature protrusion, which can be flexibly designed.

[0170] Figure 11In the process shown, when the wireless charging coil and FPC cable are integrated into the battery back cover made of fiber glass, the battery thickness is expected to increase by 0.45mm and the capacity to gain 450mAh when the battery back cover with the integrated wireless charging coil and FPC cable is used in the terminal.

[0171] like Figure 12 As shown, a glass battery back cover is used as a substrate (carrier), and an RDL-like multilayer circuit process is performed on the glass surface to realize the circuit functionality of the glass back cover, so as to integrate a wireless charging cable coil and / or FPC cable on the glass battery back cover.

[0172] Specific methods are as follows Figure 12 As shown:

[0173] 1) Use a glass cover plate as a substrate. 2) Coat one or more sides of the glass cover plate with UV adhesive / film to form an insulating layer. 3) Perform UV curing treatment on the glass cover plate coated with UV adhesive. 4) Electroplat copper on the insulating layer to form a metal layer. 5) Etch patterns on the metal layer to form the wireless charging coil and / or FPC cable wiring. When multiple layers are required, repeat steps 1) to 5) above to obtain a wireless charging coil and / or FPC cable with glass as the main material. Glass is a common material, such as silicate glass.

[0174] Understandably, to achieve conductivity between the metal layers on both sides of the glass substrate, laser drilling is used between the layers, and then electroplating is performed to make the holes conductive.

[0175] 2D cover plates are typically printed onto a 2D glass substrate using traditional screen printing methods to obtain 2D cover plates with functional holes. For details on how to fabricate 3D or 2D glass cover plates, please refer to existing technology descriptions; they will not be repeated here.

[0176] It requires multiple quality inspection processes. 3D glass inspection needs to be carried out according to process requirements. Generally, it needs to be inspected twice: once for appearance and dimensions before tempering, and again for appearance and warping deformation monitoring after tempering due to stress release and stretching.

[0177] like Figure 13 As shown, Figure 13 The manufacturing process of a glass battery back cover is shown, specifically including: 1) preparing a 3D or 2D glass cover plate; 2) spraying photoresist onto the 3D or 2D glass cover plate and performing pre-curing treatment; 3) exposing the coating using LDI or DNK, followed by development and baking treatment; 4) texturing the glass cover plate; 5) removing the photoresist from the glass substrate; 6) inspecting the appearance of the glass cover plate, and then embedding [such as...] into the glass cover plate.Figure 11 The prepared wireless charging cable coil and / or FPC cable.

[0178] Exposure was performed using a Laser Direct Imaging (LDI) exposure machine.

[0179] The process of integrating a wireless charging coil and / or FPC cable on a ceramic battery back cover can be referenced from the process of making a wireless charging coil and / or FPC cable on a glass battery back cover, and will not be repeated here.

[0180] This application provides a terminal housing, which may include a mid-frame and, as shown in the example, a terminal housing. Figure 4 The battery back cover shown is fixedly connected to the middle frame to form a receiving space. This receiving space is used to house the electronic components of the terminal, such as the PCB motherboard, PCB sub-board, and battery.

[0181] The battery back cover integrating a wireless charging coil and / or FPC cable provided in this application embodiment can be used in mobile terminals as a housing. For example, the battery back cover can be combined with other structures such as a mid-frame to form a housing suitable for a mobile terminal. The terminal housing can be integrally formed with the frame and the aforementioned terminal back cover. For example, the mid-frame and the battery back cover can be made of the same material, such as plastic, glass, or ceramic, and the mid-frame and battery back cover can be thermo-pressed together during the battery back cover molding process. Alternatively, in other embodiments, the mid-frame can be made of a different material than the battery back cover, such as metal, and the mid-frame can also be integrally formed and connected to the battery back cover during the battery back cover molding process, giving the housing better structural strength.

[0182] This application provides a terminal that can employ, for example... Figure 4 The battery back cover shown, or the terminal using the aforementioned terminal housing.

[0183] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery back cover for a terminal, characterized in that, The battery rear cover includes: A back cover body, the back cover body being made of a non-metallic material, and the first surface of the back cover body having a first receiving area; A flexible circuit board (FPC) cable and / or a wireless charging coil are integrated in the first receiving area, and the main material of the flexible circuit board (FPC) cable and / or the wireless charging coil is the same as the material of the back cover body. The FPC cable is used to connect the main circuit board of the terminal and the secondary circuit board of the terminal. The wireless charging coil has a signal transmission end, which is used to connect to the circuit board.

2. The battery back cover according to claim 1, characterized in that, The flexible circuit board (FPC) cable or the wireless charging coil includes: A first substrate, a second substrate, and a substrate layer are stacked sequentially from top to bottom, with the second substrate serving as the main material of the wireless charging coil. The first substrate includes: a first substrate layer and a first metal layer formed on the upper surface of the first substrate layer, wherein the surface of the first metal layer has a signal transmission terminal; The second substrate includes: a second substrate layer and a second metal layer formed on one or both sides of the second substrate layer, wherein the second metal layer has conductive patterns of the flexible circuit board FPC cable or the wireless charging coil; A first through hole is formed on the second substrate layer, and the second metal layers located on both sides of the second substrate layer are connected through the through hole; The first substrate has a second through hole, and the signal lines of the conductive patterns on the second metal layer on both sides of the second substrate layer pass through the second through hole and are connected to the signal transmission terminal through the first substrate.

3. The battery back cover according to claim 2, characterized in that, When the second substrate is used as the main material of the wireless charging coil, a resin layer is further provided between the upper surface of the first substrate layer and the second substrate layer, and between the lower surface of the substrate layer and the second substrate layer, and the resin layer is filled with resin-coated copper foil or ultra-thin PP cloth.

4. The battery back cover according to claim 2 or 3, characterized in that, When the second substrate is used as the main material of the wireless charging coil, the first substrate has a groove region filled with nanocrystals.

5. The battery back cover according to any one of claims 2 to 4, characterized in that, The flexible printed circuit board (FPC) cable and the wireless charging coil are formed on different second substrates. When the second substrate is used as the main material of the wireless charging coil, the thickness of the second metal layer is greater than the thickness of the second metal layer when the second substrate is used as the main material of the flexible circuit board (FPC) cable.

6. The battery back cover according to any one of claims 2 to 4, characterized in that, The flexible circuit board (FPC) cable and the wireless charging coil are formed on the same second substrate. The thickness of the second metal layer in the first region of the second substrate layer is greater than the thickness of the second metal layer in the second region of the second substrate layer. The second metal layer in the first region is used to form the conductive pattern of the wireless charging coil, and the second metal layer in the second region is used to form the conductive pattern of the flexible circuit board (FPC) cable.

7. The battery back cover according to any one of claims 2 to 6, characterized in that, When the second substrate is used as the main material of the wireless charging coil, the thickness of the second metal layer is determined by the power required for wireless charging, and the line width and spacing of the conductive patterns on the second metal layer on both sides of the second substrate layer meet the preset requirements.

8. The battery back cover according to any one of claims 2 to 7, characterized in that, When the second substrate is used as the main material of the flexible circuit board (FPC) cable, the dielectric constant Dk of the second substrate layer is ≤4.0, and the dielectric loss Df of the second substrate layer is ≤0.

02.

9. The battery back cover according to any one of claims 2 to 8, characterized in that, The first metal layer and the second metal layer are copper foil layers.

10. The battery back cover according to any one of claims 1 to 9, characterized in that, The flexible circuit board (FPC) cable and / or wireless charging coil are integrally formed in the first receiving groove by hot pressing.

11. The battery back cover according to any one of claims 1 to 10, characterized in that, The rear cover body also has a second receiving groove, and one or more of the following components are integrated in the second receiving groove: All or some of the components in the circuit sub-board, all or some of the components in the circuit main board, one or more sensors, and radio frequency antennas.

12. The battery back cover according to any one of claims 1 to 11, characterized in that, The material of the rear cover body includes one or more of the following: Prepreg, glass materials, ceramic materials.

13. The battery back cover according to claim 12, characterized in that, The semi-cured sheet is formed from resin and fiberglass cloth.

14. The battery back cover according to claim 13, characterized in that, The resin is BT resin.

15. A terminal housing, characterized in that, The terminal housing includes: a frame and a battery back cover as described in any one of claims 1 to 14, wherein the battery back cover and the frame are fixedly connected to form an accommodating space.

16. A terminal, characterized in that, The terminal includes the terminal housing as described in claim 15, or the battery back cover as described in any one of claims 1 to 14.

17. The terminal according to claim 16, characterized in that, The terminal is a mobile phone or a tablet computer.

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