Coil module, electronic device, and wireless charging system

Abstract

The application provides a coil module, an electronic device and a wireless charging system, and relates to the technical field of wireless charging, and aims to solve the problem that the thickness of the wireless charging coil module is relatively large, which is not conducive to the arrangement of other functional devices in the electronic device. The coil module comprises a coil structure; the coil structure comprises a functional layer; along the thickness direction of the coil structure, the functional layer comprises a first wiring sublayer, a second wiring sublayer and an insulating sublayer located between the first wiring sublayer and the second wiring sublayer; the coil structure further comprises a first end, a second end and a plurality of groups of coils connected in series; the first end and the plurality of groups of coils are arranged on the first wiring sublayer, and the outermost group of coils is connected to the first end; the second end is arranged on the second wiring sublayer; a via hole is arranged on the insulating sublayer, and a connecting structure is arranged in the via hole; the innermost group of coils is connected to the second end through the connecting structure in the insulating sublayer, so that the first end is electrically connected to the second end through the plurality of groups of coils connected in series.

Description

[0001] This application claims priority to the Chinese Patent Application No. 202410047758.4, filed on January 11, 2024, entitled "Coil Module, Electronic Device and Wireless Charging System", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of wireless charging, in particular to a coil module, an electronic device and a wireless charging system. BACKGROUND

[0003] Due to the wireless charging method, it is more secure and reliable than the wired charging method, and it is convenient to use, therefore, more and more electronic devices, such as mobile phones, tablet computers, smart watches, etc., have adopted wireless charging technology. A big core component for realizing wireless charging technology is a wireless charging coil module.

[0004] However, the thickness of the existing wireless charging coil module is relatively thick, which is not conducive to the arrangement of functional devices (such as functional devices corresponding to biometric technology, functional devices corresponding to high-quality images, and functional devices corresponding to artificial intelligence) in electronic devices with increasing functions (such as biometric technology, high-quality images, artificial intelligence, etc.). How to solve the above problems is a problem to be solved at present. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a coil module, an electronic device and a wireless charging system to solve the problem that the thickness of the wireless charging coil module of the prior art is relatively thick, which is not conducive to the arrangement of other functional devices in electronic devices.

[0006] In a first aspect, an embodiment of the present application provides a coil module, which comprises: a coil structure; the coil structure comprises a functional layer, along the thickness direction of the coil structure, the functional layer comprises a first wiring sublayer, a second wiring sublayer and an insulating sublayer located between the first wiring sublayer and the second wiring sublayer; the coil structure further comprises a first end, a second end and a plurality of coil groups connected in series; the first end and the plurality of coil groups are arranged on the first wiring sublayer, and the outermost coil group is connected with the first end; the second end is arranged on the second wiring sublayer; a via hole is formed on the insulating sublayer, and a connecting structure is arranged in the via hole; the innermost coil group is connected with the second end through the connecting structure in the insulating sublayer, so that the first end is electrically connected with the second end through the plurality of coil groups connected in series.

[0007] In the present application, the plurality of coil groups with a larger occupied area are arranged in the first conductive sub-layer, and the second wiring sub-layer only includes the second end with a smaller occupied area. Thus, when the coil module is arranged in the electronic device, other wirings of the electronic device can be arranged on the second wiring sub-layer, thereby avoiding the occupation of the internal space of the electronic device by the other wirings and facilitating the arrangement of other structures. Alternatively, since the second wiring sub-layer only has the second end with a smaller occupied area, the second end with a smaller occupied area can be embedded in other structures of the electronic device, so that the coil module occupies less internal space of the electronic device and facilitates the arrangement of other structures.

[0008] For example, the thickness direction of the coil structure can be the thickness direction of the electronic device or the direction of the central axis passing through the centers of the plurality of coil groups. The thickness direction of the coil structure is perpendicular to the first wiring sub-layer, the second wiring sub-layer and the insulating sub-layer.

[0009] According to the first aspect, the coil module further comprises a magnetic conductive layer. The magnetic conductive layer comprises a hollow portion, and the second end is arranged in the hollow portion.

[0010] The arrangement of the magnetic conductive layer can concentrate the magnetic field, increase the inductance of the coil module, and shield part of the magnetic field to reduce the eddy current loss of the magnetic field on some structures (such as the middle frame, the battery, the printed circuit board, etc.) of the electronic device. In addition, by embedding the second end of the coil structure in the magnetic conductive layer, the occupation of the second end in the thickness direction of the coil module can be avoided, the thickness of the coil module is reduced, and the thickness of the wireless charging coil can be extremely thin, which has great advantages in terms of thickness. For example, the thickness of the coil module is less than 0.2 mm. For example, the thickness of the coil module is only 0.1X mm (wherein X is 1, 2, 3, 4, 5, 6, 7, 8, 9, etc., i.e., the thickness of the coil module is only 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm or 0.19 mm), and of course, the thickness can be less than 0.1 mm.

[0011] According to the first aspect, or any one of the implementation manners of the first aspect, along the thickness direction of the coil structure, the magnetic conductive layer comprises a first protective sub-layer, a second protective sub-layer and a magnetic conductive sub-layer located between the first protective sub-layer and the second protective sub-layer. The magnetic conductive sub-layer comprises a plurality of adhesive layers and nanocrystals located between adjacent two adhesive layers. The first protective sub-layer is arranged adjacent to the coil structure, and the adhesive layer arranged adjacent to the second protective sub-layer is a first adhesive layer. The first protective sub-layer, the adhesive layers other than the first adhesive layer and the film layer where the nanocrystals are located are provided with first openings. The first adhesive layer and the film layer where the second protective sub-layer is located are provided with second openings. The first openings and the second openings form a hollow portion. The projection of the second opening on a reference surface is located within the projection of the first opening on the reference surface. The reference surface is perpendicular to the thickness direction of the coil structure.

[0012] The opening of the first adhesive and the second protective sub-layer is small, that is, the first adhesive and the second protective sub-layer extend to the direction of the hollow part by a part towards the edge of the hollow part, so that the powder of the nanocrystals can be prevented from falling out, and the structure of the coil module is more reliable.

[0013] For example, the reference surface is parallel to the first wiring sub-layer, and other film layers in the coil module are parallel to each other.

[0014] For example, the magnetic conductive sub-layer includes three layers of adhesive and two layers of nanocrystals between the adjacent two layers of adhesive.

[0015] According to the first aspect, or any one of the implementation manners of the first aspect, the coil structure further includes a flexible circuit board unit; the flexible circuit board unit is located in a preset area of the second wiring sub-layer, and the preset area is an area of the second wiring sub-layer in which the second end is not arranged.

[0016] That is, when the coil module is arranged in the electronic device, the flexible circuit board in the electronic device can be arranged on the second wiring sub-layer, that is, the coil module includes not only the wireless charging coil but also the flexible circuit board in the electronic device, so that the occupation of the internal space of the electronic device by other flexible circuit boards is avoided, the arrangement of other structures is facilitated, and the process steps can be reduced.

[0017] According to the first aspect, or any one of the implementation manners of the first aspect, the preset area includes a first sub-area, the first sub-area is a region formed by extending the projection of the outermost coil group on the second wiring sub-layer in each direction by a first preset length; when the line width of the flexible circuit board unit in the first sub-area is greater than a second preset length, the trace of the flexible circuit board unit in the first sub-area is cut into multiple.

[0018] That is, the wider trace of the flexible circuit board unit in the first sub-area is cut into multiple thin lines, so that excessive eddy current loss can be avoided on the wider trace.

[0019] For example, the first preset length can be 5 mm. The second preset length can be 8 mm.

[0020] According to the first aspect, or any one of the implementation manners of the first aspect, the coil module further includes a magnetic conductive layer; along the thickness direction of the coil structure, the magnetic conductive layer is located on the side of the second wiring sub-layer away from the first wiring sub-layer.

[0021] The magnetic conductive layer is arranged on the side of the second wiring sub-layer away from the first wiring sub-layer, that is, the first wiring sub-layer including the coil group is arranged away from the nanocrystals, which is beneficial to improve mutual inductance and wireless charging performance.

[0022] Of course, the magnetic conductive layer can also be located on the side of the first wiring sub-layer away from the second wiring sub-layer.

[0023] According to the first aspect, or any one of the implementations of the first aspect, the number of groups of the coil groups is N, N is less than or equal to 8 and greater than or equal to 7.

[0024] In this way, the coil structure can have both high power and high degree of freedom for wireless charging.

[0025] For example, the number of groups of the coil groups is 7 or 8, and of course can also be 7.5 groups, etc.

[0026] According to the first aspect, or any one of the implementations of the first aspect, the number of groups of the coil groups is 7, the thickness of the first wiring sub-layer is greater than or equal to 25 μm and less than or equal to 40 μm, and each of the coil groups includes M strands of wires, M is greater than or equal to 3.

[0027] In this way, even if the thickness of the coil groups is thick, the large eddy current loss can be avoided on the thick coil groups.

[0028] For example, M is 4.

[0029] According to the first aspect, or any one of the implementations of the first aspect, the number of groups of the coil groups is 7, the thickness of the first wiring sub-layer is less than or equal to 25 μm, and each of the coil groups includes M strands of wires, M is less than or equal to 4.

[0030] Because the M strands of wires are formed by cutting the wires, when M is less than or equal to 4, the waste of wire space can be avoided, and a good current passing effect can also be achieved.

[0031] For example, M is 3.

[0032] According to the first aspect, or any one of the implementations of the first aspect, the number of groups of the coil groups is 8, the thickness of the first wiring sub-layer is greater than or equal to 25 μm and less than or equal to 40 μm, and each of the coil groups includes M strands of wires, M is greater than or equal to 2.

[0033] In this way, even if the thickness of the coil groups is thick, the large eddy current loss can be avoided on the thick coil groups. Moreover, the impedance will not be large due to the increase in the number of coil groups.

[0034] For example, M is 3.

[0035] According to the first aspect, or any one of the implementations of the first aspect, the number of groups of the coil groups is 8, the thickness of the first wiring sub-layer is less than or equal to 25 μm, and each of the coil groups includes M strands of wires, M is less than or equal to 3.

[0036] Because the M-strand wires are formed by cutting the traces, when M is less than or equal to 4, more trace space can be saved, and better current flow effect can be achieved. Moreover, the impedance will not be greatly increased due to the increase in the number of coil groups.

[0037] For example, M is 3.

[0038] According to the first aspect, or any one of the implementations of the first aspect, the width of the plurality of coil groups gradually increases in a direction away from the center of the coil structure. In this way, the current distribution is more uniform.

[0039] For example, the number of coil groups is 8, and the coil groups from the innermost coil group to the outermost coil group are the first coil group, the second coil group, the third coil group, the fourth coil group, the fifth coil group, the sixth coil group, the seventh coil group, and the eighth coil group. The width of the plurality of coil groups gradually increasing can be that the width of the first coil group, the second coil group, the third coil group, the fourth coil group, the fifth coil group, the sixth coil group, the seventh coil group, and the eighth coil group gradually increases. The width of the plurality of coil groups gradually increasing can also be that the width of some adjacent coil groups in the 8 coil groups is the same, and the width of the coil groups with different widths gradually increases in a direction away from the center of the coil structure. For example, the width of the first coil group and the second coil group is the same, the width of the third coil group, the fourth coil group, and the fifth coil group is the same, the width of the sixth coil group, the seventh coil group, and the eighth coil group is the same, and the width of the first coil group, the third coil group, and the sixth coil group gradually increases. For another example, the width of the third coil group, the fourth coil group, and the fifth coil group is the same, the width of the sixth coil group and the seventh coil group is the same, and the width of the first coil group, the second coil group, the third coil group, the sixth coil group, and the eighth coil group gradually increases.

[0040] For example, the number of strands in each coil group can be the same, such as 3 strands or 4 strands.

[0041] According to the first aspect, or any one of the implementations of the first aspect, the number of coil groups is N, the N coil groups include L internal coil groups and (N-L) external coil groups arranged around the L internal coil groups, each coil group includes a plurality of strands, and the number of strands in the external coil groups is greater than the number of strands in the internal coil groups.

[0042] In this way, the current distribution is more uniform.

[0043] Exemplarily, the number of the groups of the coil groups is N groups, and the coil groups from the innermost coil group to the outermost coil group are divided into a first coil group, a second coil group, a third coil group, a fourth coil group, a fifth coil group, a sixth coil group, a seventh coil group and an eighth coil group. The number of the strands of the fifth coil group, the sixth coil group, the seventh coil group and the eighth coil group is the same, the number of the strands of the first coil group, the second coil group, the third coil group and the fourth coil group is the same, and the number of the strands of the eighth coil group is greater than that of the first coil group; or the number of the strands of the second coil group, the third coil group, the fourth coil group, the fifth coil group, the sixth coil group, the seventh coil group and the eighth coil group is the same, and the number of the strands of the eighth coil group is greater than that of the first coil group; or the number of the strands of the sixth coil group, the seventh coil group and the eighth coil group is the same, the number of the strands of the fourth coil group and the fifth coil group is the same, the number of the strands of the first coil group, the second coil group and the third coil group is the same, the number of the strands of the eighth coil group is greater than that of the fifth coil group, and the number of the strands of the fifth coil group is greater than that of the first coil group.

[0044] According to the first aspect, or any one of the implementations of the first aspect, the coil structure is an FPC coil.

[0045] The FPC coil has good flatness and is thin, which is further conducive to the thin design of the device using the coil module.

[0046] In the second aspect, an electronic device is provided, which includes the coil module of the first aspect and any one of the implementations of the first aspect.

[0047] The second aspect corresponds to the first aspect and any one of the implementations of the first aspect. The technical effects corresponding to the second aspect can be referred to the technical effects corresponding to the first aspect and any one of the implementations of the first aspect, which will not be described herein.

[0048] According to the second aspect, the coil structure further includes at least one flexible circuit board unit; the flexible circuit board unit is located in a preset area of the second wiring sublayer, and the preset area is an area of the second wiring sublayer without the second end; and the electronic device further includes a printed circuit board, and the flexible circuit board unit is connected with the printed circuit board.

[0049] The flexible circuit board connected with the printed circuit board in the electronic device can be arranged in the second wiring sublayer, that is, the coil module includes not only the wireless charging coil but also the flexible circuit board in the electronic device, so that the occupation of the internal space of the electronic device by other flexible circuit boards is avoided, the arrangement of other structures is facilitated, and the process steps are reduced.

[0050] Exemplarily, only one flexible circuit board connected with the printed circuit board in the electronic device can be arranged in the second wiring sublayer, two flexible circuit boards connected with the printed circuit board in the electronic device can be arranged in the second wiring sublayer, or a plurality of (for example, three or more) flexible circuit boards connected with the printed circuit board in the electronic device can be arranged in the second wiring sublayer.

[0051] According to the second aspect, or any one of the implementation forms of the second aspect, the printed circuit board comprises a main board and a sub-board, and the main board is connected with the sub-board through the flexible circuit board unit.

[0052] That is, the flexible circuit board connecting the main board and the sub-board is arranged in the second wiring sublayer, which can reduce the occupation of the internal space of the electronic device by the flexible circuit board, and is beneficial to the arrangement of other structures, compared with arranging the flexible circuit board connecting the main board and the sub-board in the accommodation space of the electronic device.

[0053] According to the second aspect, or any one of the implementation forms of the second aspect, the electronic device further comprises a functional device, and the functional device is connected with the printed circuit board through the flexible circuit board unit.

[0054] That is, the flexible circuit board connecting the functional device and the printed circuit board is arranged in the second wiring sublayer, which can reduce the occupation of the internal space of the electronic device by the flexible circuit board, and is beneficial to the arrangement of other structures, compared with arranging the flexible circuit board connecting the functional device and the printed circuit board in the accommodation space of the electronic device.

[0055] Exemplarily, the functional device comprises a loudspeaker or a SIM card. Of course, the functional device is not limited thereto.

[0056] According to the second aspect, or any one of the implementation forms of the second aspect, the flexible circuit board unit is arranged as an NFC coil. That is, the NFC coil is arranged in the second wiring sublayer, which can reduce the occupation of the internal space of the electronic device by the flexible circuit board, and is beneficial to the arrangement of other structures, compared with arranging the NFC coil in the accommodation space of the electronic device.

[0057] According to the second aspect, or any one of the implementation forms of the second aspect, the electronic device comprises a wireless charging receiving device or a wireless charging transmitting device. That is, the receiving coil of the wireless charging receiving device can be the coil module of the first aspect and any one of the implementation forms of the first aspect, and / or the transmitting coil of the wireless charging transmitting device can be the coil module of the first aspect and any one of the implementation forms of the first aspect.

[0058] In a third aspect, an embodiment of the present application provides a wireless charging system, comprising the electronic device of the second aspect and any one of the implementation forms of the second aspect.

[0059] The third aspect corresponds to the second aspect and any implementation thereof. The technical effects of the third aspect and any implementation thereof can be found in the technical effects of the second aspect and any implementation thereof, as described above, and will not be repeated here. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the structure of a wireless charging system provided in an embodiment of this application;

[0061] Figure 2 This is a schematic diagram of the circuit structure of a wireless charging system provided in an embodiment of this application;

[0062] Figure 3 for Figure 1 A schematic diagram of the wireless charging receiver device shown.

[0063] Figure 4 A film layer diagram of a coil module provided in Embodiment 1 of this application;

[0064] Figure 5a A perspective view of a coil module provided in Embodiment 1 of this application;

[0065] Figure 5b for Figure 5a The diagram shows a plan view of the coil module.

[0066] Figure 5c for Figure 5a An exploded view of the coil structure in the coil module shown;

[0067] Figure 5d for Figure 5a An exploded view of the coil module shown;

[0068] Figure 6 An exploded view of yet another coil module provided in Embodiment 1 of this application;

[0069] Figure 7 An exploded view of yet another coil module provided in Embodiment 1 of this application;

[0070] Figure 8 An exploded view of yet another coil module provided in Embodiment 1 of this application;

[0071] Figure 9 A simulation diagram of current density distribution on a coil module provided in Embodiment 1 of this application;

[0072] Figure 10 This is a simulation diagram of the current density distribution on another coil module provided in Embodiment 1 of this application;

[0073] Figure 11A simulation diagram of current density distribution on the coil module provided in Embodiment One of the present application is shown in FIG. 1.

[0074] Figure 12 A film layer diagram of a coil module provided in Embodiment Two of the present application is shown in FIG. 6.

[0075] Figure 13 A plan view of a coil module provided in Embodiment Two of the present application is shown in FIG. 7.

[0076] Figure 14 A Figure 13 An exploded view of the coil module shown in FIG. 8. DETAILED DESCRIPTION

[0077] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0078] The term “and / or” in the present application is merely used to describe an association relationship of associated objects, and means that three relationships can exist, for example, A and / or B can mean that three cases of A alone, A and B together, and B alone exist.

[0079] The terms “first” and “second” and the like in the description and claims of the embodiments of the present application are used to distinguish different objects, and are not used to describe a specific order of the objects. For example, the first target object and the second target object are used to distinguish different target objects, and are not used to describe a specific order of the target objects.

[0080] In the embodiments of the present application, the words “exemplary” or “for example” are used to mean serving as an example, instance, or illustration. Any embodiment or design solution described as “exemplary” or “for example” in the embodiments of the present application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of the words “exemplary” or “for example” is intended to present relevant concepts in a specific manner.

[0081] In the description of the embodiments of the present application, unless otherwise specified, the meaning of “a plurality of” is two or more. For example, a plurality of processing units means two or more processing units; a plurality of systems means two or more systems.

[0082] The connection relationship described in the present application refers to direct or indirect connection. For example, A is connected with B, which can be that A is directly connected with B, or A is indirectly connected with B through one or more other electrical components, for example, A can be directly connected with C, and C is directly connected with B, so that A is connected with B through C. It can also be understood that "A is connected with B" described in the present application can be that A is directly connected with B, or A is indirectly connected with B through one or more other electrical components.

[0083] Firstly, the terms involved in the present application are explained:

[0084] The layer refers to the number of planes of the arrangement of the conductive wires included in the coil provided by the present application. When all the conductive wires included in a coil are wound on the same plane to form a planar coil, the coil is a 1-layer winding coil; when all the conductive wires included in a coil are not arranged on one plane, for example, the first conductive wire is wound on the first plane layer, the second conductive wire is wound on the second plane layer, and the first conductive wire and the second conductive wire are connected through the via in the insulating layer between the first plane layer and the second plane layer, it is explained that the coil is a two-layer winding coil.

[0085] The number of turns refers to the number of turns of the winding in each coil.

[0086] The number of strands refers to the number of parallel conductive wires in each coil during winding.

[0087] Next, the technical scenario involved in the embodiments of the present application is explained.

[0088] The technical solution of the present application is applied to the wireless charging technical scenario. The scenario includes a wireless charging device and a device to be charged. The wireless charging device is used to charge the device to be charged with wireless charging function. For example, the wireless charging device can be a wireless charging mobile power supply, a wireless charging board, a wireless charger, etc., and the device to be charged can be a mobile phone, a tablet computer, a notebook computer, a personal digital assistant (PDA), a vehicle-mounted computer, a smart wearable device (such as a smart watch, a smart bracelet, a headset, etc.), a virtual reality (VR), an augmented reality (AR), etc. The above-mentioned device to be charged can also be a wireless charging electric vehicle, a wireless charging household appliance (such as a sweeping robot, etc.), a drone, etc. electronic products. For another example, the wireless charging device can be a tablet computer, a notebook computer, a mobile phone, etc., and the device to be charged can be a stylus, a magnetic keyboard, etc.

[0089] The wireless charging device can also be referred to as a wireless charging transmitting device, and the device to be charged can also be referred to as a wireless charging receiving device.

[0090] To make the skilled in the art better understand the technical solutions provided by the embodiments of the present application, the principle of wireless charging in the wireless charging technology scenario is briefly introduced below. In the following description, the wireless charging transmitting device is taken as a wireless charger, and the wireless charging receiving device is taken as a mobile phone. In addition, the wireless charging transmitting device is also taken as a wireless charger, and the wireless charging receiving device is also taken as a mobile phone in the following description.

[0091] Referring to Figure 1 , Figure 1 FIG. 1 is a structural schematic diagram of a wireless charging system according to an embodiment of the present application. As shown in Figure 1 , the wireless charging system 01 includes a wireless charging transmitting device 10 and a wireless charging receiving device 20. The wireless charging transmitting device 10 can be a wireless charger, and the wireless charging receiving device 20 can be a mobile phone. The wireless charger can perform wireless charging on the mobile phone.

[0092] It should be noted that Figure 1 the wireless charger has a certain degree of inclination, so that the mobile phone can be closely attached to the wireless charger. Of course, this does not constitute a limitation on the present application. In other optional embodiments of the present application, the wireless charger can also have other forms, for example, the wireless charger is in the form of a flat plate, and the wireless charger supports the mobile phone to be placed horizontally above it.

[0093] Referring to Figure 2 , Figure 2 FIG. 2 is a circuit structural schematic diagram of a wireless charging system according to an embodiment of the present application. As shown in Figure 2 , the wireless charging transmitting device 10 includes a power supply 11 and a wireless transmitting device 12.

[0094] The power supply 11 is configured to provide a direct current voltage. In order to distinguish from other direct current voltages, the direct current voltage provided by the power supply 11 is a first direct current voltage.

[0095] The wireless transmitting device 12 includes a direct current (DC) / alternating current (AC) circuit 122, a resonance capacitor C1, and a transmitting coil L1.

[0096] In some embodiments, the wireless transmitting device 12 further comprises a voltage conversion circuit 121. The voltage conversion circuit 121 is electrically connected with the power supply 11, and is configured to convert the first direct current voltage output by the power supply 11 into a second direct current voltage. For example, the voltage conversion circuit 121 can be a boost circuit (e.g., a boost converter, a step-up transformer, or a power amplifier), which is configured to boost the first direct current voltage output by the power supply 11 and then output the boosted voltage.

[0097] When the voltage conversion circuit 121 is a boost circuit, the potential difference between the wireless charging transmitting device 10 and the wireless charging receiving device 20 can be increased, and the energy transmission capability of the system can be improved, which is beneficial to high-power transmission.

[0098] Of course, the voltage conversion circuit 121 is not limited to a boost circuit, but can also be a step-down circuit, which is configured to step down the first direct current voltage output by the power supply 11 and then output the stepped-down voltage. The voltage conversion circuit 121 can be set according to actual conditions by those skilled in the art.

[0099] The DC / AC circuit 122 is electrically connected with the voltage conversion circuit 121, and is configured to convert the second direct current voltage output by the voltage conversion circuit 121 into an alternating current. For example, the DC / AC circuit 122 can be an inverter bridge, and the circuit structure of the inverter bridge can be a full-bridge circuit or a half-bridge circuit. The DC / AC circuit 122 is also referred to as a transmit (TX) chip.

[0100] The resonance capacitor C1 and the transmit coil L1 are connected in series to form a series resonance network, and the transmit coil L1 is electrically connected with the DC / AC circuit 122 through the resonance capacitor C1. In the process of charging and discharging the resonance capacitor C1 and the transmit coil L1 by the DC / AC circuit 122, the transmit coil L1 can convert the alternating current into an alternating magnetic field.

[0101] In combination with Figure 3 , Figure 3 For Figure 1 the structure of the wireless charging receiving device is shown in FIG. 2. As shown in FIG. 2, the wireless charging receiving device 20 comprises a power supply 21, a voltage conversion circuit 221, a DC / AC circuit 222, a resonance capacitor C2, a receive coil L2, a rectifier circuit 223, a voltage stabilizing circuit 224, and a load 225. Figure 3As shown, the wireless charging receiving device 20, such as a mobile phone, includes a back cover 201, a display screen 202, and a middle frame 203. The display screen 202 and the back cover 201 are respectively located at two sides of the middle frame 203, and the back cover 201, the display screen 202, and the middle frame 203 can enclose a receiving cavity. In the receiving cavity, a printed circuit board (PCB) 204, a battery 205, a speaker (not shown in the figure), a SIM card seat carrying a SIM card, a near field communication (NFC) coil (not shown in the figure), and the like are arranged. In the embodiment of the present application, the PCB 204 includes a main board 2041 and a sub-board 2042, and the main board 2041 and the sub-board 2042 can be connected through a flexible printed circuit (FPC).

[0102] Continuing to refer to Figure 2 and Figure 3 The wireless charging receiving device 20 further includes a wireless receiving device 22 and a load 21. The load 21 is equivalent to a load resistance of a power consumption unit at the back end of the system. The load 21 can be a battery or other devices that need to be charged.

[0103] The wireless receiving device 22 includes a receiving coil L2, a resonance capacitor C2, and an AC / DC circuit 222.

[0104] The receiving coil L2 is located in the receiving cavity, and exemplarily, can be located between the battery 205 and the back cover 201. The receiving coil L2 can be connected with the PCB 204 through an FPC (not shown in the figure).

[0105] The resonance capacitor C2 and the AC / DC circuit 222 are arranged on the PCB 204 (such as the main board 2041), and the receiving coil L2 is connected with the resonance capacitor C2 and the AC / DC circuit 222 through the FPC and the PCB 204 (signal transmission and interaction can be performed). In addition, the AC / DC circuit 222 is also connected with the load 21.

[0106] When the wireless charging transmitting device 10 needs to charge the wireless charging receiving device 20, the receiving coil L2 is close to or adheres to the transmitting coil L1. At this time, the receiving coil L2 in the wireless charging receiving device 20 generates alternating current through electromagnetic induction, the AC / DC circuit 222 converts the alternating current generated by the receiving coil L2 into direct current, and outputs the direct current to the load 21 to supply power to the load 21. Exemplarily, the AC / DC circuit 222 can be a rectifier bridge, and the circuit structure thereof can be a full-bridge circuit or a half-bridge circuit. The AC / DC circuit 222 is also called a receive (RX) chip.

[0107] In some embodiments, when the direct current output by the AC / DC circuit 222 is too large to be directly provided to the load 21, the wireless receiving device 22 can further include a voltage conversion circuit 221. The voltage conversion circuit 221 is electrically connected to the AC / DC circuit 222 and the load 21 respectively, and is configured to reduce the voltage output by the AC / DC circuit 222 to the voltage required by the load 21. For example, the voltage conversion circuit 221 can be a step-down circuit (also referred to as a buck circuit).

[0108] In some embodiments, the voltage conversion circuit 221 can also be a switch capacitor (SC) circuit (not shown in the figure), which can achieve a step-down conversion with a ratio of, for example, 2:1, 4:1, etc. The specific structure of the SC circuit and the principle of achieving step-down conversion can be referred to existing technologies.

[0109] In some embodiments, the wireless charging receiving device 20 can also be charged in a wired manner. When the wireless charging receiving device 20 can be charged in a wired manner, the wireless charging receiving device 20 further includes a USB interface, which is electrically connected to the voltage conversion circuit 221. The charging signal received by the USB interface is transmitted to the voltage conversion circuit 221, so that the voltage conversion circuit 221 reduces the large charging signal to the charging signal required by the load 21 to supply power to the load 21. In some embodiments, an overvoltage protection (OVP) circuit is arranged between the USB interface and the voltage conversion circuit 221. The OVP circuit can include an OVP switch tube, which can be a mos tube. When the OVP circuit detects that the voltage input to the USB interface is too high (exceeds a threshold voltage), the OVP circuit can actively cut off the connection between the voltage conversion circuit 221 and the USB interface to protect the voltage conversion circuit 221.

[0110] The structure of the wireless charging system 01 is introduced above. As can be seen from the above, the wireless charging technology uses the principle of electromagnetic coupling to achieve power transmission, i.e., the alternating current carried by the transmitting coil on the wireless charging sending device side generates a varying magnetic field, and the receiving coil on the wireless charging receiving device side generates an induced current in the varying magnetic field, thereby achieving charging of the wireless charging receiving device side. Therefore, a core component for implementing the wireless charging technology is the wireless charging coil module, i.e., the transmitting coil L1 and / or the receiving coil L2. However, the coil module in the prior art has a relatively large thickness, e.g., the thickness of the existing wireless charging coil module is generally between 0.2 mm and 0.3 mm. This is not conducive to the arrangement of functional devices (e.g., functional devices corresponding to biometric technology, functional devices corresponding to high-quality images, and functional devices corresponding to artificial intelligence) in electronic devices with increasing functions (e.g., biometric technology, high-quality images, and artificial intelligence).

[0111] To solve the above problems, the coil module provided by the present application can be applied to a wireless charging receiving device, that is, the coil module can be a receiving coil in the wireless charging receiving device; or can be applied to a wireless charging transmitting device, that is, the coil module can be a transmitting coil in the wireless charging transmitting device. The structure of the coil module provided by the embodiments of the present application will be described in detail below.

[0112] It should be noted that the coil module provided by the present application is not only suitable for a wireless charging scene, but also suitable for other scenes using the principle of electromagnetic induction.

[0113] Embodiment one

[0114] Referring to Figure 4 , Figure 4 A film layer structure diagram of a coil module provided by the first embodiment of the present application. As Figure 4 shown, the coil module 30 includes a coil structure 31 and a magnetic conductive layer 32, and the coil structure 31 and the magnetic conductive layer 32 are fixed together through a double-sided adhesive layer (such as double-sided adhesive) 33.

[0115] The setting of the magnetic conductive layer 32 can concentrate the magnetic field and improve the inductance of the coil module 30. In addition, as known from the foregoing, the coil module 30 can be provided in a wireless charging receiving device 20, which can include a PCB 204, a battery 205, a middle frame 203 and the like. The PCB 204, the battery 205, the middle frame 203 and the like are generally metal, and the magnetic field will generate eddy current loss on the PCB 204, the battery 205, the middle frame 203 and the like. The setting of the magnetic conductive layer 32 can also shield part of the magnetic field and reduce the eddy current loss generated by the magnetic field on the PCB 204, the battery 205, the middle frame 203 and the like.

[0116] For example, the magnetic conductive layer 32 includes two protective sub-layers 321 and a magnetic conductive sub-layer 322 located between the two protective sub-layers 321, wherein the two protective sub-layers 321 can include a first protective sub-layer and a second protective sub-layer, and the first protective sub-layer is arranged adjacent to the coil structure 31. The protective sub-layer 321 can be a nanocrystalline black film or a polymide (PI). The magnetic conductive sub-layer 322 includes a soft magnetic material, and the soft magnetic material includes ferrite or nanocrystalline and the like. Figure 4 For example, when the soft magnetic material includes nanocrystalline, the magnetic conductive sub-layer 322 includes a plurality of layers of nanocrystalline 3221 and a plurality of layers of adhesive glue 3222 located on both sides of the nanocrystalline 3221 for bonding the nanocrystalline 3221 together, wherein Figure 4 For example, when the magnetic conductive sub-layer 322 includes two layers of nanocrystalline 3221 and three layers of adhesive glue 3222.

[0117] The thickness H21 of the protective sub-layer 321 can be 5 μm, the thickness H22 of the nanocrystal 3221 can be 17 μm, and the thickness H23 of the adhesive 3222 can be 3 μm. In this case, the thickness H2 of the magnetic conductive layer 32 is 53 μm. Of course, the thickness of the protective sub-layer 321, the thickness of the nanocrystal 3221, and / or the thickness of the adhesive 3222 can be adaptively changed to meet different requirements.

[0118] Continuing to refer to Figure 4 , the coil structure 31 can be an FPC coil, and the coil structure 31 includes two protective films 311 and a functional layer 312 between the two protective films 311. The protective film 311 includes a PI layer 3111 and an adhesive 3112 for arranging the PI layer 3111 on the functional layer 312. The functional layer 312 includes two wiring sub-layers 3121 and an insulating sub-layer 3122 between the two wiring sub-layers 3121, and the two wiring sub-layers 3121 include a first wiring sub-layer and a second wiring sub-layer.

[0119] The wiring sub-layer 3121 can be a full-surface metal layer, where the material of the metal layer includes copper, aluminum, nickel, or alloys, etc., and then the coil is formed by etching the metal layer. The specific circuit design of the coil will be described in detail below, and will not be described here.

[0120] In order to realize the electrical connection between the two wiring sub-layers 3121, a via hole is formed on the insulating sub-layer 3122 between the two wiring sub-layers 3121, and a connection structure 3124 for connecting the two wiring sub-layers 3121 is arranged in the via hole. The forming method of the connection structure 3124 is not limited by the embodiments of the present application. For example, continuing to refer to Figure 4 , a full-layer connection layer 3123 can be plated on the wiring sub-layer 3121, and part of the material of the connection layer 3123 will be deposited into the via hole during the plating process to form the connection structure 3124. For another example, the connection structure 3124 is directly formed in the via hole of the insulating sub-layer 3122.

[0121] For example, the thickness H11 of the PI layer 3111 can be 5 μm, the thickness H12 of the adhesive 3112 can be 5 μm, the thickness H13 of the insulator layer 3122 can be 12.5 μm, the thickness H14 of the wiring sublayer 3121 can be 12 μm, and the thickness H15 of the connecting layer 3123 can be 10 μm. In this case, the thickness H1 of the coil structure 31 is 76.5 μm. Alternatively, the thickness H11 of the PI layer 3111 can be 5 μm, the thickness H12 of the adhesive 3112 can be 5 μm, the thickness H13 of the insulator layer 3122 can be 12.5 μm, the thickness H14 of the wiring sublayer 3121 can be 18 μm, and the thickness H15 of the connecting layer 3123 can be 10 μm. In this case, the thickness H1 of the coil structure 31 is 88.5 μm.

[0122] In addition, the double-sided adhesive 33 between the coil structure 31 and the magnetic layer 32 can be 7.5 μm.

[0123] See Figure 5a-5d , Figure 5a This is a perspective view of a coil module provided in Embodiment 1 of this application. Figure 5b for Figure 5a The diagram shown is a plan view of the coil module. Figure 5b (1) is the front view. Figure 5b (2) is the reverse side view. Figure 5c for Figure 5a The exploded view of the coil module shown is as follows. Figure 5d for Figure 5a An exploded view of the coil structure in the coil module shown. Figure 4 , Figure 5a-5d As shown, the coil structure 31 includes a first end D1, a second end D2, and N coil groups 31a connected in series. The first end D1 and the second end D2 are connected by the N coil groups 31a connected in series. Each coil group 31a is one turn (i.e., one loop) of the coil structure 31.

[0124] The N groups of coil groups 31a can be ring-shaped coils, wherein the outer diameter d1 of the coil is less than or equal to 52 mm and greater than or equal to 46 mm; the inner diameter d2 of the coil is less than or equal to 28 mm and less than or equal to 16 mm. For example, the outer diameter d1 of the coil is 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 51 mm or 52 mm; the inner diameter d2 of the coil is 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm or 28 mm. It should be noted that the specific form of the ring-shaped coil is not limited in the embodiments of the present application, and a person skilled in the art can set it according to the actual situation. For example, the ring-shaped coil includes a circular ring-shaped coil, a rectangular ring-shaped coil, a hexagonal ring-shaped coil, an octagonal ring-shaped coil, etc., and the embodiments of the present application are described by taking the circular ring-shaped coil as an example.

[0125] The first end D1 and the N groups of coil groups 31a are formed by etching the first wiring sub-layer and the connecting layer 3123 located on the first wiring sub-layer, and the second end D2 and the N groups of coil groups 31a are formed by etching the second wiring sub-layer and the connecting layer 3123 located on the second wiring sub-layer. The coil group 31a of the outermost coil group in the N groups of coil groups 31a is connected to the first end D1, and the coil group 31a of the innermost coil group in the N groups of coil groups 31a is connected to the second end D2 through the connecting structure 3124 in the via hole in the insulating sub-layer 3122, so that the first end D1 is connected to the second end D2 through the N groups of coil groups 31a connected in series.

[0126] Continuing to refer to Figure 4 , Figure 5a-5d The magnetic conductive layer 32 is provided with a hollow part 32a, and the second end D2 of the coil structure 31 is embedded in the hollow part 32a, so that the second end D2 does not occupy the thickness direction of the coil module 30, and the thickness of the coil module 30 is reduced, for example, the thickness H11+H12+H14+H15=5+5+10+12=32μm can be reduced; or the thickness H11+H12+H14+H15=5+5+10+18=38μm can be reduced.

[0127] In order to further reduce the thickness of the coil module 30, continuing to refer to Figure 4 The part of the protective sub-layer (i.e. the first protective sub-layer) 321 of the magnetic conductive layer 32 in contact with the coil structure 31 is hollow, which can expose the adhesive 3222 between the protective sub-layer 321 and the nanocrystal 3221, and the double-sided adhesive 33 bonding the coil structure 31 and the magnetic conductive layer 32 is located in the hollow part 3211 and contacts the adhesive 3222 between the protective sub-layer 321 and the nanocrystal 3221.

[0128] It can be understood that, in order to ensure the bonding strength of the coil structure 31 and the magnetic conductive layer 32, the thickness of the double-sided adhesive 33 still needs to be kept at 7.5 μm, and therefore the thickness of the protective sub-layer 321 of the magnetic conductive layer 32 in contact with the coil structure 31 and the film layer where the double-sided adhesive 33 is located is 7.5 μm. In this way, the thickness of the coil module 30 can be reduced by 5 μm (the thickness of one protective sub-layer 321).

[0129] Through the above arrangement, the thickness of the coil module 30 can be 100 μm or 106 μm, that is, the thickness of the wireless charging coil module is extremely thin, so that the coil module occupies less space inside the electronic device, which is conducive to the arrangement of other structures.

[0130] In some embodiments, continuing to refer to Figure 4 The adhesive 3222 arranged immediately adjacent to the second protective sub-layer is a first adhesive; the film layer where the first protective sub-layer, the adhesives 3222 other than the first adhesive, and the nanocrystals 3221 are located is provided with a first opening 32a1, and the film layer where the first adhesive and the second protective sub-layer are located is provided with a second opening 32a2, and the first opening and the second opening form a hollow part 32a. The first opening 32a1 is larger than the second opening 32a2, that is, the projection of the second opening 32a2 on the second protective sub-layer is located within the projection of the first opening 32a1 on the second protective sub-layer.

[0131] In this way, the powder of the nanocrystals can be prevented from falling out, and the structure of the coil module is more reliable.

[0132] The film layer structure of the coil module 30 is introduced above, and it can be known from the above content that the thickness of the coil module 30 of the present application can be only 0.1X mm. It can be understood that when the thickness of the coil module is thin, the impedance of the coil module is generally large, and a larger impedance is not conducive to large-power charging of the wireless charging receiving device. In order to realize the effects of large-power charging and thinning of the wireless charging receiving device at the same time, continuing Figure 5a-5d , the number N of the coil groups 31a is less than or equal to 8 and greater than or equal to 7, that is, the number of turns of the coil structure 31 is 7 turns to 8 turns, for example, the number of turns of the coil structure 31 can be 7 turns (as shown in Figure 5c ) or 8 turns (as shown in Figure 6 ). Of course, the number of turns of the coil structure 31 can also be 7.5 turns, and 0.5 turns is half a turn of the wire. For example, 7.5 turns can be formed by winding half a turn on the outermost coil group 31a of the 7 coil groups 31a or by winding half a turn on the innermost coil group 31a of the 7 coil groups 31a.

[0133] The number of turns of the coil structure 31 is 7-8 turns, so that the coil structure 31 has both high power and high degree of freedom of wireless charging, and neither the charging power is affected due to too many turns and large impedance, nor the degree of freedom of the coil structure 31 is low due to too few turns, that is, when the coil module 30 is applied to the wireless charging receiving device 20, the offset distance between the center of the receiving coil and the center of the transmitting coil in the wireless charging transmitting device 10 is small, so that strict alignment is required, and the degree of freedom of the coil structure 31 is low.

[0134] In some embodiments, each coil group 31a includes M strands of wires 311a, M can be less than or equal to 4 and greater than or equal to 2, and examples of M are 2, 3 or 4. Figure 5c and Figure 6 Both are described by taking M as 3 as an example. That is, the coil structure 31 is continuously wound (to form N groups of coil groups 31a connected in series) by the M strands of wires 311a from the first end D1 to the second end D2 connected to the two-layer wiring sublayer 3121, and the current is input from the first end D1, passes through the N groups of coil groups 31a, and is output from the second end D2.

[0135] M is set to be less than or equal to 4 and greater than or equal to 2, so that neither the wiring space is wasted due to too many gaps between adjacent two strands of wires 311a, nor the current transmission is affected due to too few channels for current flow caused by the skin effect due to too few strands of wires 311a.

[0136] The number of strands of each coil group 31a can be determined based on the actual number of turns of the coil structure 31 and the thickness of the wiring sublayer 3121, so that the coil structure 31 has both high power and high degree of freedom of wireless charging.

[0137] In one possible implementation, referring to Figure 7 , Figure 7 is another exploded view of a coil module provided by Embodiment One of the present application. As shown in Figure 7 , the number of coil groups 31a is 7, the thickness of the first wiring sublayer is greater than or equal to 25 μm and less than or equal to 40 μm, each coil group 31a includes M strands of wires 311a, and M is greater than or equal to 3, for example, M is 4.

[0138] In this way, even if the thickness of the coil group 31a is thick, large eddy current loss can also be avoided on the thick coil group 31a.

[0139] It should be noted that in the present application, when the first wiring sublayer is provided with the connecting layer 3123, the thickness of the first wiring sublayer also includes the thickness of the connecting layer 3123.

[0140] In another possible implementation, continuing to refer to Figure 5c , the number of groups of the coil group 31a is 7, the thickness of the first wiring sublayer is less than or equal to 25 μm, and each group of the coil group 31a includes M strands of wires 311a, and M is less than or equal to 4, for example, M is 3.

[0141] Because the M strands of wires 311a are formed by cutting the traces, when M is less than or equal to 4, a large amount of wasted trace space can be avoided, and a large amount of flow-through channels can also be ensured, thus having a good flow-through effect.

[0142] In another possible implementation, continuing to refer to Figure 6 , the number of groups of the coil group is 8, the thickness of the first wiring sublayer is greater than or equal to 25 μm and less than or equal to 40 μm, and each group of the coil group 31a includes M strands of wires 311a, and M is greater than or equal to 2, for example, M is 3.

[0143] In this way, even if the thickness of the coil group 31a is large, large eddy current loss can also be avoided on the thick coil group 31a. Moreover, a large impedance can not be caused due to an increase in the number of coil groups.

[0144] In another possible implementation, referring to Figure 8 , Figure 8 is another exploded view of a coil module provided in Embodiment One of the present application. As shown in Figure 8 , the number of groups of the coil group 31a is 8, the thickness of the first wiring sublayer is less than or equal to 25 μm, and each group of the coil group 31a includes M strands of wires 311a, and M is less than or equal to 3, for example, M is 3.

[0145] Because the M strands of wires 311a are formed by cutting the traces, when M is less than or equal to 3, a large amount of wasted trace space can be avoided, and a good flow-through effect can also be ensured. Moreover, a large impedance can not be caused due to an increase in the number of coil groups.

[0146] In some embodiments, continuing to refer to Figure 5c , the N groups of coil groups 31a include L groups of internal coil groups 31a-I and (N-L) groups of external coil groups 31a-O disposed around the L groups of internal coil groups; each group of the coil group 31a includes a plurality of strands of wires 311a; the number of strands of wires located in the external coil group 31a-O is greater than the number of strands of wires located in the internal coil group 31a-I.

[0147] Since the magnetic field strength inside the coil structure 31 is strong and the magnetic field strength outside is weak, the number of wire strands of the outer coil group 31a-O is greater than that of the inner coil group 31a-I, which can ensure that the outer coil group 31a-O has more current flow channels and improve the uniformity of current distribution.

[0148] The specific value of L is not limited in the embodiments of the present application, and can be set according to actual conditions by those skilled in the art. For example, N is 7 and L is 3: the number of coil groups 31a is 7, and the coil groups from the innermost to the outermost are divided into a first coil group, a second coil group, a third coil group, a fourth coil group, a fifth coil group, a sixth coil group and a seventh coil group. The 7 coil groups 31a include 3 inner coil groups 31a-I and 4 outer coil groups 31a-O arranged around the 3 inner coil groups, i.e., the first coil group, the second coil group and the third coil group are the inner coil groups 31a-I, and the fourth coil group, the fifth coil group, the sixth coil group and the seventh coil group are the outer coil groups 31a-O. The number of wire strands of the fourth coil group, the fifth coil group, the sixth coil group and the seventh coil group is the same, the number of wire strands of the first coil group, the second coil group and the third coil group is the same, and the number of wire strands of the fourth coil group, the fifth coil group, the sixth coil group and the seventh coil group is greater than that of the first coil group, the second coil group and the third coil group.

[0149] In some embodiments, continuing to refer to Figure 6 , the width W0 of the plurality of coil groups 31a gradually increases in the direction away from the center of the coil structure, such as the direction indicated by the arrow XX. Figure 6

[0150] The gradually increasing width of the plurality of coil groups 31a can be that the width of the plurality of coil groups 31a gradually increases in turn in the direction away from the center of the coil structure, such as that the number of coil groups 31a is 8, and the coil groups 31a from the innermost to the outermost are divided into a first coil group, a second coil group, a third coil group, a fourth coil group, a fifth coil group, a sixth coil group, a seventh coil group and an eighth coil group. The width of the first coil group, the second coil group, the third coil group, the fourth coil group, the fifth coil group, the sixth coil group, the seventh coil group and the eighth coil group increases in turn, i.e., the width of the eighth coil group is greater than that of the seventh coil group, the width of the seventh coil group is greater than that of the sixth coil group, the width of the sixth coil group is greater than that of the fifth coil group, the width of the fifth coil group is greater than that of the fourth coil group, the width of the fourth coil group is greater than that of the third coil group, the width of the third coil group is greater than that of the second coil group, and the width of the second coil group is greater than that of the first coil group.

[0151] ​The gradually increasing width of the plurality of groups of coil groups 31a can also be that, along a direction away from the center of the coil structure, the width of some adjacent groups of coil groups 31a is the same, and the width of groups of coil groups 31a with different widths gradually increases. For example, the number of groups of coil groups 31a is 8 groups, and the groups of coil groups 31a from the innermost to the outermost are divided into a first group of coil groups, a second group of coil groups, a third group of coil groups, a fourth group of coil groups, a fifth group of coil groups, a sixth group of coil groups, a seventh group of coil groups, and an eighth group of coil groups. The widths of the first group of coil groups and the second group of coil groups are the same, the widths of the third group of coil groups, the fourth group of coil groups, and the fifth group of coil groups are the same, the widths of the sixth group of coil groups, the seventh group of coil groups, and the eighth group of coil groups are the same, and the widths of the first group of coil groups, the sixth group of coil groups, and the sixth group of coil groups increase in turn.

[0152] Since the magnetic field strength inside the coil structure 31 is strong and the magnetic field strength outside is weak, the width of the innermost group of coil groups 31a, the width of the middle group of coil groups 31a, and the width of the outermost group of coil groups 31a are gradually increased, so that the current-carrying capacity of the innermost group of coil groups 31a, the middle group of coil groups 31a, and the outermost group of coil groups 31a gradually increases, and the uniformity of current distribution is improved.

[0153] It should be noted that when the width W0 of the plurality of groups of coil groups 31a gradually increases along a direction away from the center of the coil structure, the number of strands of the wire 311a of each group of coil groups 31a can be the same, such as 3 strands or 4 strands. Of course, the number of strands of the wire 311a of each group of coil groups 31a can also be different.

[0154] In order to facilitate understanding of the above content, the specific structure of the coil module 30 provided by the embodiment of the application will be introduced in combination with a specific example.

[0155] Example one, continuing to refer to Figure 4 and 7 , the coil inner diameter d1 is 20mm, the coil outer diameter d2 is 48mm, N is 7, and M is 4, that is, in the limited area defined by the coil outer diameter d2 of 48mm and the coil inner diameter d1 of 20mm, the coil structure 31 adopts a 7-turn 4-strand parallel winding scheme; the magnetically permeable sub-layer 322 includes two layers of nanocrystalline 3221 (the thickness of each layer of nanocrystalline 3221 is 17μm), and the material properties of the nanocrystalline satisfy: the saturation magnetic flux density of the nanocrystalline is 1.4T, and the relative magnetic permeability of the nanocrystalline is 3000 times that of air (i.e. μ'3000).

[0156] The electrical parameters in this example are shown in Table 1. In Table 1, L is the inductance of the coil module, Q is the quality factor of the coil module, ARC is the alternating current impedance of the coil module, and DRC is the direct current impedance of the coil module.

[0157] Table 1

[0158]

[0159]

[0160] It can be seen from Table 1 that the inductance L of the coil module also changes at different electromagnetic wave frequencies. And with the increase of frequency, the AC impedance ARC increases, but the AC impedance ARC and the DC impedance DRC are small. In addition, the coil module of the present example has a good quality factor Q. In addition, the self-resonant frequency of the coil module of the present example is 8.9253Mhz, which is far from the working frequency (100KHZ, 130KHZ or 145KHZ, etc.) of the coil module, and will not affect wireless charging. That is, the coil module provided in the present example also has small impedance and appropriate inductance under very small thickness (such as thickness of 0.110mm), which is beneficial to large power wireless charging.

[0161] In addition, the 7 groups of coil groups 31a are divided into first coil group, second coil group, third coil group, fourth coil group, fifth coil group, sixth coil group and seventh coil group from inside to outside. The widths of the third coil group, the fourth coil group and the fifth coil group are the same, the widths of the sixth coil group and the seventh coil group are the same, and the widths of the first coil group, the second coil group, the third coil group and the sixth coil group gradually increase. The line design of the 7 groups of coil groups 31a is shown in Table 2. Among them, the line spacing of the 4 wires 311a of each coil group 31a is 0.06mm. It can be understood that the line spacing is related to the process level, and the smaller the line spacing is, the better.

[0162] Table 2

[0163]

[0164]

[0165] The current density distribution test of the coil module in the present example is carried out, and the test results are shown in Figure 9 , wherein, Figure 9 (1) of the current density distribution of the coil module 30, the color corresponding to each position in the coil module 30 represents the current value, Figure 9 (2) of the color and current value correspondence, that is, the color of each position in Figure 9 (1) is determined according to the color and current value correspondence provided in Figure 9 (2). Figure 9

[0166] Figure 9 ​​As shown, the current density distribution test results revealed that the colors corresponding to each position in coil module 30 are relatively uniform, with minimal color differences between positions, indicating good color consistency. Therefore, using the coil module in this example, current is present at all positions, and the current density distribution is relatively uniform, which is beneficial for high-power wireless charging.

[0167] In summary, the coil module provided in this example enables wireless charging receivers to simultaneously achieve high-power charging and a slim, lightweight design.

[0168] To better illustrate this effect, simulation tests were conducted on the coil module provided in the embodiments of this application. The simulation test results are shown in Table 3. In Table 3, the offset is the offset distance between the center of the transmitting coil and the center of the receiving coil. Positive and negative values ​​can represent the leftward and rightward offset of the center of the receiving coil relative to the center of the transmitting coil, respectively. The target power is the charging efficiency under different loads. The input voltage and input current are the voltage and current provided by the wireless charging transmitting device. The output voltage and output current are the voltage and current generated by the wireless charging receiving device based on the voltage and current provided by the wired charging transmitting device. The input power is the product of the input voltage and input current. The output power is the product of the output voltage and output current. The efficiency is the ratio of the output power to the input power.

[0169] Table 3 Charging efficiency under different offsets

[0170]

[0171]

[0172] As shown in Table 3, the ultra-thin coil module provided in this application embodiment can also support 30W high-power wireless charging.

[0173] Example 2, see below. Figure 4 and 5c The inner diameter d1 of the coil is 20mm, the outer diameter d2 of the coil is 48mm, N is 7, and M is 3. That is, within the limited area defined by the outer diameter d2 of the coil being 48mm and the inner diameter d1 of the coil being 20mm, the coil structure 31 adopts a 7-turn 3-strand parallel winding scheme. The magnetic sublayer 322 includes two layers of nanocrystals 3221 (each layer of nanocrystals 3221 is 17μm thick), and the material properties of the nanocrystals satisfy: the saturation magnetic flux density of the nanocrystals is 1.4T, and the relative permeability of the nanocrystals is 3000 times that of air (i.e., μ'3000).

[0174] The electrical parameters in this example are shown in Table 4. In Table 4, L is the inductance of the coil module, Q is the quality factor of the coil module, ARC is the AC impedance of the coil module, and DRC is the DC impedance of the coil module.

[0175] Table 4

[0176]

[0177] As can be seen from Table 4, the inductance L of the coil module also changes at different electromagnetic wave frequencies. And with the increase of frequency, the AC impedance ARC increases, but both the AC impedance ARC and the DC impedance DRC are small. In addition, the coil module of the present example has a good quality factor Q. Moreover, the self-resonant frequency of the coil module of the present example is 7.8173 Mhz, which is far from the working frequency (100 KHZ, 130 KHZ or 145 KHZ, etc.) of the coil module, and will not affect wireless charging. That is, the coil module provided in the present example also has small impedance and appropriate inductance under very small thickness (e.g., thickness of 0.102 mm).

[0178] The 7 groups of coil groups 31a are divided into first coil group, second coil group, third coil group, fourth coil group, fifth coil group, sixth coil group and seventh coil group from inside to outside. The widths of the first coil group and the second coil group are the same, the widths of the fifth coil group and the sixth coil group are the same, and the widths of the first coil group, the third coil group, the fourth coil group, the fifth coil group and the seventh coil group gradually increase. The line design of the 7 groups of coil groups 31a is shown in Table 5. Among them, the line spacing of the 3 wires 311a of each group of coil groups 31a is 0.06 mm. It can be understood that the line spacing is related to the process level, and the smaller the line spacing is, the better.

[0179] Table 5

[0180]

[0181]

[0182] The current density distribution test is performed on the coil module in the present example, and the test results are shown in Figure 10 , wherein, Figure 10 (1) in the current density distribution of the coil module 30, the color of each position in the coil module 30 represents the current value, Figure 10 (2) in the present example is the correspondence between color and current value, that is, the color of each position in Figure 10 (1) is determined according to the correspondence between color and current value provided in Figure 10 (2). Figure 10

[0183] Figure 10 ​​As shown, it is found by the current density distribution test result that the colors corresponding to the positions in the coil module 30 are relatively uniform, and the difference between the colors corresponding to the positions is relatively small, i.e., the color consistency of the positions is good. It can be known that, by using the coil module in the example, current exists in each position, and the current density is relatively uniform, which is beneficial to high-power wireless charging.

[0184] In summary, the coil module provided in the example can realize that the wireless charging receiving device has the effects of high-power charging and thinning at the same time.

[0185] In order to better illustrate the effect, the coil module provided in the example is simulated and tested, and the simulation test result is shown in Table 6. In Table 6, the offset is the offset distance of the center of the transmitting coil and the center of the receiving coil, and the positive and negative can respectively represent that the center of the receiving coil is offset to the left and right relative to the center of the transmitting coil; the target power is the charging efficiency under different loads; the input voltage and the input current are the voltage and the current provided by the wireless charging sending device side; the output voltage and the output current are the voltage and the current generated by the wireless charging receiving device side based on the voltage and the current provided by the wireless charging sending device side; the input power is the product of the input voltage and the input current; the output power is the product of the output voltage and the output current; and the efficiency is the ratio of the output power to the input power.

[0186] Table 6 Charging efficiency under different offsets

[0187]

[0188]

[0189] It can be known from Table 6 that the ultra-thin coil module provided in the example can also support 30W high-power wireless charging.

[0190] Example Three, continuing to refer to Figure 4 and 6 , the inner diameter d1 of the coil is 20mm, the outer diameter d2 of the coil is 48mm, N is 8, and M is 3, i.e., in the limited area defined by the outer diameter d2 of the coil being 48mm and the inner diameter d1 of the coil being 20mm, the coil structure 31 adopts the 8-turn 3-strand and winding scheme; the magnetically conductive sub-layer 322 includes two layers of nanocrystals 3221 (the thickness of each layer of nanocrystals 3221 is 17μm), and the material properties of the nanocrystals satisfy: the saturation magnetic flux density of the nanocrystals is 1.4T, and the relative magnetic permeability of the nanocrystals is 3000 times that of air (i.e., μ'3000).

[0191] The electrical parameters in the example are shown in Table 7. In Table 7, L is the inductance of the coil module, Q is the quality factor of the coil module, ARC is the alternating current impedance of the coil module, and DRC is the direct current impedance of the coil module.

[0192] Table 7

[0193]

[0194] As can be seen from Table 7, the inductance L of the coil module also changes at different electromagnetic wave frequencies. And with the increase of frequency, the AC impedance ARC increases, but both the AC impedance ARC and the DC impedance DRC are small. In addition, the coil module of the present example has a good quality factor Q. Moreover, the self-resonant frequency of the coil module of the present example is 7.8172Mhz, which is far from the working frequency (100KHZ, 130KHZ or 145KHZ, etc.) of the coil module, and will not affect wireless charging. That is, the coil module provided in the present example also has small impedance and appropriate inductance at a very small thickness (e.g., a thickness of 0.109mm), which is beneficial to large power wireless charging.

[0195] 8 groups of coil groups 31a are divided into first coil group, second coil group, third coil group, fourth coil group, fifth coil group, sixth coil group, seventh coil group and eighth coil group from inside to outside. The widths of the first coil group, the second coil group, the third coil group and the fourth coil group are the same, the widths of the fifth coil group, the sixth coil group and the seventh coil group are the same, and the widths of the first coil group, the fifth coil group and the eighth coil group gradually increase. The line design of the 8 groups of coil groups 31a is shown in Table 8. Among them, the line spacing of the 3 wires 311a of each coil group 31a is 0.06mm. It can be understood that the line spacing is related to the process level, and the smaller the line spacing is, the better.

[0196] Table 8

[0197]

[0198] The current density distribution test of the coil module in the present example is carried out, and the test results are shown in Figure 11 , wherein, Figure 11 (1) in the table is the current density distribution of the coil module 30, and the color corresponding to each position in the coil module 30 represents the current value, Figure 11 (2) in the table is the correspondence between color and current value, that is, the color of each position in Figure 11 (1) is determined according to the correspondence between color and current value provided in Figure 11 (2). Figure 11

[0199] Figure 11 ​​As shown, it is found by the current density distribution test result that the colors corresponding to the positions in the coil module 30 are relatively uniform, and the difference between the colors corresponding to the positions is small, i.e., the color consistency of the positions is good. It can be known that, by using the coil module in the example, current exists in each position, and the current density is relatively uniform, which is beneficial to high-power wireless charging.

[0200] In summary, the coil module provided in the example can realize the effects of high-power charging and thinning of the wireless charging receiving device at the same time.

[0201] In order to better illustrate the effect, the coil module provided in the example is simulated and tested, and the simulation test result is shown in Table 9. In Table 9, the offset is the offset distance of the center of the transmitting coil and the center of the receiving coil, and the positive and negative can respectively represent that the center of the receiving coil is offset to the left and right relative to the center of the transmitting coil. The target power is the charging efficiency under different loads. The input voltage and the input current are the voltage and the current provided by the wireless charging sending device side. The output voltage and the output current are the voltage and the current generated by the wireless charging receiving device side based on the voltage and the current provided by the wireless charging sending device side. The input power is the product of the input voltage and the input current. The output power is the product of the output voltage and the output current. The efficiency is the ratio of the output power to the input power.

[0202] Table 9 Charging efficiency under different offsets

[0203]

[0204] It can be known from Table 9 that the ultra-thin coil module provided in the example can also support 30W high-power wireless charging.

[0205] Example four, continuing to refer to Figure 4 and 8 , the inner diameter d1 of the coil is 20mm, the outer diameter d2 of the coil is 48mm, N is 8, and M is 3, i.e., in the limited area defined by the outer diameter d2 of the coil being 48mm and the inner diameter d1 of the coil being 20mm, the coil structure 31 adopts the 8-turn 3-strand and winding scheme; the magnetically permeable sublayer 322 includes two layers of nanocrystals 3221 (the thickness of each layer of nanocrystals 3221 is 17μm), and the material properties of the nanocrystals satisfy: the saturation magnetic flux density of the nanocrystals is 1.4T, and the relative magnetic permeability of the nanocrystals is 3000 times that of air (i.e., μ'3000). It should be noted that the thicknesses of the wiring sublayers of example one and example three are the same, for example, both are 18μm, the thicknesses of the wiring sublayers of example two and example four are the same, for example, both are 12μm, and the thicknesses of other film layers of example one, example two, example three and example four are the same.

[0206] The electrical parameters in this example are shown in Table 10. In Table 10, L is the inductance of the coil module, Q is the quality factor of the coil module, ARC is the alternating current impedance of the coil module, and DRC is the direct current impedance of the coil module.

[0207] Table 10

[0208]

[0209]

[0210] As can be seen from Table 10, at different electromagnetic wave frequencies, the inductance L of the coil module also changes. And with the increase of frequency, the alternating current impedance ARC increases, but the alternating current impedance ARC and the direct current impedance DRC are both small. In addition, the coil module of this example has a good quality factor Q. Furthermore, the self-resonant frequency of the coil module of this example is 7.8172Mhz, which is far from the working frequency (100KHZ, 130KHZ or 145KHZ, etc.) of the coil module, and will not affect wireless charging. That is, the coil module provided in this example also has a small impedance and a suitable inductance under a very small thickness (e.g., a thickness of 0.109mm), which is conducive to large power wireless charging.

[0211] The 8 groups of coil groups 31a are divided into first coil group, second coil group, third coil group, fourth coil group, fifth coil group, sixth coil group, seventh coil group and eighth coil group from inside to outside. The widths of the first coil group, the second coil group, the third coil group and the fourth coil group are the same, the widths of the fifth coil group, the sixth coil group and the seventh coil group are the same, and the widths of the first coil group, the fifth coil group and the eighth coil group gradually increase. The line design of the 8 groups of coil groups 31a is shown in Table 11. Among them, the line spacing of the 3 wires 311a of each group of coil groups 31a is 0.06mm. It can be understood that the line spacing is related to the process level, and the smaller the line spacing, the better.

[0212] Table 11

[0213]

[0214] In summary, the coil module provided in this example can realize the effect of large power charging and thinning of the wireless charging receiving device at the same time.

[0215] To better illustrate the effect, the coil module provided by the embodiment of the present application is simulated and tested, and the simulation test results are shown in Table 12. In Table 12, the offset is the offset distance of the center of the transmitting coil and the center of the receiving coil, and the positive and negative can respectively represent the left offset and the right offset of the center of the receiving coil relative to the center of the transmitting coil; the target power is the charging efficiency under different loads; the input voltage and the input current are the voltage and the current provided by the wireless charging transmitting device side; the output voltage and the output current are the voltage and the current generated by the wireless charging receiving device side based on the voltage and the current provided by the wireless charging transmitting device side; the input power is the product of the input voltage and the input current; the output power is the product of the output voltage and the output current; and the efficiency is the ratio of the output power to the input power.

[0216] Table 12 Charging efficiency under different offsets

[0217]

[0218] As can be seen from Table 12, the ultra-thin coil module provided by the embodiment of the present application can also support 30W high-power wireless charging.

[0219] As can be seen from the above four examples, the ultra-thin coil module provided by the present application can also support 30W high-power wireless charging.

[0220] Embodiment two

[0221] Referring to Figure 12 , Figure 13 and Figure 14 , Figure 12 is a film layer diagram of a coil module provided by the second embodiment of the present application, Figure 13 is a plan view of a coil module provided by the second embodiment of the present application, Figure 14 is Figure 13 the exploded view of the coil module shown in FIG. 12. As shown in Figure 12 , Figure 13 and Figure 14 , different from the first embodiment, the magnetic conducting layer 32 in the second embodiment is located on one side of the coil structure 31, and the magnetic conducting layer 32 is not provided with a hollow part 32a, and correspondingly, the second wiring sublayer provided with the second end D2 of the coil structure 31 is located between the first wiring sublayer and the magnetic conducting layer 32. In the present embodiment, the coil structure 31 further comprises at least one flexible circuit board unit 31b, and the flexible circuit board unit 31b and the second end D2 of the coil structure 31 are both located in the second wiring sublayer, wherein the flexible circuit board unit 31b is located in a preset area of the second wiring sublayer, and the preset area is an area of the second wiring sublayer without the second end D2.

[0222] It should be noted that, except for special instructions, the specific structure of the coil module 30 in the embodiments of the present application (such as the thickness of each film layer, the number of coil groups 31a, the number of strands, and the width design, etc.) is the same as that of Embodiment One, and can be referred to Embodiment One for details, which will not be repeated here.

[0223] That is, when the coil module is arranged in the electronic device, the flexible circuit board in the electronic device can be arranged on the second wiring sub-layer, that is, the coil module includes not only the wireless charging coil but also the flexible circuit board in the electronic device, so that the occupation of the internal space of the electronic device by other flexible circuit boards is avoided, the arrangement of other structures is facilitated, and the process steps can be reduced.

[0224] As known from the foregoing, the main board 2041 and the auxiliary board 2042 can be connected by the FPC. Therefore, in one example, the FPC unit connecting the main board 2041 and the auxiliary board 2042 can be arranged in the preset area of the second wiring sub-layer, so that the FPC connecting the main board 2041 and the auxiliary board 2042 does not need to be arranged separately in the accommodating cavity of the electronic device, the occupation of the internal space of the electronic device by the FPC is avoided, the arrangement of other structures is facilitated, the FPC is formed at the same time as the second end D2, and the process steps are reduced.

[0225] Since the NFC coil can be wound by the FPC trace, in another example, the NFC coil can be arranged in the preset area of the second wiring sub-layer, so that the NFC coil does not need to be arranged separately in the accommodating cavity of the electronic device, the occupation of the internal space of the electronic device by the NFC coil is avoided, the arrangement of other structures is facilitated, the NFC coil is formed at the same time as the second end D2, and the process steps are reduced.

[0226] In addition, the wireless charging coil (such as the receiving coil L2), the speaker, the SIM card, and other functional devices are connected to the main board 2041 or the auxiliary board 2042 by the FPC. Therefore, in another example, the FPC connecting the functional devices and the main board 2041 or the auxiliary board 2042 can be arranged in the preset area of the second wiring sub-layer, so that the FPC connecting the functional devices and the main board 2041 or the auxiliary board 2042 does not need to be arranged separately in the accommodating cavity of the electronic device, the occupation of the internal space of the electronic device by the FPC is avoided, the arrangement of other structures is facilitated, the FPC is formed at the same time as the second end D2, and the process steps are reduced.

[0227] It should be noted that the above examples are only described by taking the FPC connecting the main board 2041 and the auxiliary board 2042, the NFC coil, or the line of the FPC connecting the functional device (such as the wireless charging coil, the loudspeaker, the SIM card, etc.) and the main board 2041 or the auxiliary board 2042 as an example, but do not constitute a limitation to the present application. In the case of meeting the working requirements of each functional device, other FPCs in the electronic device can be arranged in the preset area of the second wiring sublayer.

[0228] In some embodiments, the preset area includes a first sub-area YY, and the first sub-area YY is a region formed by extending the projection of the outermost coil group on the second wiring sublayer in each direction by a first preset length W1 (that is, the annular region surrounded by the inner annular dashed line and the outer annular dashed line in FIG. 6A). Figure 13 When the line width W2 of the flexible circuit board unit 31b in the first sub-area YY is greater than a second preset length, the traces of the flexible circuit board unit 31b in the first sub-area YY are cut into multiple. That is, the wider traces of the flexible circuit board unit 31b in the first sub-area YY are cut into multiple thin lines, which can avoid excessive eddy current loss on the wider traces.

[0229] For example, the first preset length can be 5 mm. The second preset length can be 8 mm. That is, at least within the range of 5 mm extending from the maximum outer shape of the coil, the line width greater than 8 mm is avoided, and the wider traces within this range can be cut into strands, and the thinner the line width control is, the better.

[0230] From the above two embodiments, it can be seen that the multiple coil groups with larger occupied area are arranged on the first lead sublayer, and the second wiring sublayer only includes the second end with smaller occupied area. Therefore, when the electronic device is provided with the coil module, other traces of the electronic device can be arranged on the second wiring sublayer, which avoids the occupation of the internal space of the electronic device by other traces, and is conducive to the arrangement of other structures, or because the second wiring sublayer only has the second end with smaller occupied area, the second end with smaller occupied area can be embedded in other structures, so that the coil module occupies less space in the electronic device, which is conducive to the arrangement of other structures.

[0231] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A coil module, characterized by The coil structure comprises a first wiring sublayer, an insulating sublayer and a second wiring sublayer along the thickness direction of the coil structure, wherein the insulating sublayer is arranged between the first wiring sublayer and the second wiring sublayer. The coil structure further comprises a first end, a second end and a plurality of coil groups connected in series, the plurality of coil groups are arranged in the first wiring sublayer, and the coil group at the outermost position is connected with the first end. A via hole is arranged on the insulating sublayer, and a connecting structure is arranged in the via hole; the coil group at the innermost position is connected with the second end through the connecting structure, and the first end is electrically connected with the second end through the plurality of coil groups connected in series. The coil module further comprises a magnetic conductive layer, the magnetic conductive layer is provided with a hollow part, and the second end is arranged in the hollow part. Along the thickness direction of the coil structure, the magnetic conductive layer comprises a first protective sublayer, a magnetic conductive sublayer and a second protective sublayer, wherein the magnetic conductive sublayer is located between the first protective sublayer and the second protective sublayer. The magnetic conductive sublayer comprises a plurality of adhesive glue layers and a plurality of nanocrystalline layers, the nanocrystalline layer is located between the two adjacent adhesive glue layers, and the adhesive glue layer closest to the second protective sublayer is the first adhesive glue layer. The first protective sublayer, the adhesive glue layer except the first adhesive glue layer and the film layer where the nanocrystalline layer is located are provided with a first opening; the second protective sublayer and the film layer where the first adhesive glue layer is located are provided with a second opening, and the first opening is larger than the second opening. The first opening and the second opening form the hollow part. The first end is arranged in the first wiring sublayer, and the second end is arranged in the second wiring sublayer.

2. The coil module of claim 1, wherein, The first adhesive glue layer and the second protective sublayer extend to the direction of the hollow part by a part of the edge of the hollow part.

3. The coil module according to claim 1 or 2, characterized in that The first protective sublayer is adjacent to the coil structure.

4. The coil module of claim 1 or 2, wherein The first protective sublayer is adjacent to the coil structure.

5. The coil module of claim 3, wherein, The coil structure and the magnetic conductive layer are fixedly connected through double-sided adhesive tape, and the double-sided adhesive tape is in contact with the adhesive glue layer between the first protective sublayer and the nanocrystalline layer.

6. The coil module of claim 1 or 2, wherein The coil structure and the magnetic conductive layer are fixedly connected through double-sided adhesive tape, and the double-sided adhesive tape is in contact with the adhesive glue layer between the first protective sublayer and the nanocrystalline layer.

7. The coil module of claim 3, wherein, The coil structure and the magnetic conductive layer are fixedly connected through double-sided adhesive tape, and the double-sided adhesive tape is in contact with the adhesive glue layer between the first protective sublayer and the nanocrystalline layer.

8. The coil module of claim 4, wherein, The thickness of the coil module is less than 0.2 mm.

9. The coil module of claim 1 or 2, wherein, The thickness of the coil module is less than 0.2 mm. The number of groups of the coil module is N, N is less than or equal to 8 and greater than or equal to 7.

10. The coil module of claim 3, wherein, The number of groups of the coil module is N, N is less than or equal to 8 and greater than or equal to 7. The number of groups of the coil module is N, N is less than or equal to 8 and greater than or equal to 7.

11. The coil module of any one of claims 1 or 2, wherein, The number of groups of the coil group is 8, and each group of coil groups comprises M strands of wires, M is greater than or equal to 2.

12. The coil module of claim 3, wherein, The coil structure is an FPC coil.

13. The coil module of claim 6, wherein, The coil structure is an FPC coil.

14. The coil module of claim 13, wherein, The coil structure is an FPC coil.

15. The coil module of claim 1 or 2, wherein, The coil structure is an FPC coil.

16. The coil module of claim 3, wherein, ​ 17. The coil module of claim 6, wherein, ​ 18. The coil module of claim 11, wherein, ​ 19. The coil module of claim 12, wherein, The coil structure is an FPC coil.

20. The coil form of claim 1 or 2, wherein, The width of the coil groups gradually increases in a direction away from the center of the coil structure.

21. The coil module of claim 3, wherein, The width of the coil groups gradually increases in a direction away from the center of the coil structure.

22. The coil module of claim 6, wherein, The width of the coil groups gradually increases in a direction away from the center of the coil structure.

23. The coil module of claim 11, wherein, The width of the coil groups gradually increases in a direction away from the center of the coil structure.

24. The coil module of claim 1 or 2, wherein, The coil structure further comprises a flexible circuit board unit; the flexible circuit board unit is located in a preset area of the second wiring sublayer, and the preset area is an area of the second wiring sublayer without the second end.

25. The coil module of claim 3, wherein, The coil structure further comprises a flexible circuit board unit; the flexible circuit board unit is located in a preset area of the second wiring sublayer, and the preset area is an area of the second wiring sublayer without the second end.

26. The coil module of claim 6, wherein, The coil structure further comprises a flexible circuit board unit; the flexible circuit board unit is located in a preset area of the second wiring sublayer, and the preset area is an area of the second wiring sublayer without the second end.

27. The coil module of claim 11, wherein, The coil structure further comprises a flexible circuit board unit; the flexible circuit board unit is located in a preset area of the second wiring sublayer, and the preset area is an area of the second wiring sublayer without the second end.

28. The coil module of claim 24, wherein, The preset area comprises a first sub-area, and the first sub-area is a region formed by extending the projection of the coil group of the outermost coil on the second wiring sublayer in each direction by a first preset length. When the line width of the flexible circuit board unit in the first sub-area is greater than a second preset length, the trace of the flexible circuit board unit in the first sub-area is cut into multiple.

29. An electronic device, comprising: The electronic device comprises a back shell, a display screen, a middle frame, and a coil module as claimed in any one of claims 1-28, the display screen and the back shell are respectively located on both sides of the middle frame, and the back shell, the display screen, and the middle frame enclose a receiving cavity, and the coil module is located in the receiving cavity.

30. The electronic device of claim 29, wherein, The electronic device comprises a wireless charging receiving device or a wireless charging transmitting device.

31. A wireless charging system, comprising: Comprise: The wireless charging transmitting device and the electronic device as claimed in claim 29 or 30.

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