Coil module, wireless charging apparatus and electronic device
By designing the structure of the coil assembly, jumper assembly, and isolation membrane, the problem of large coil thickness was solved, achieving thinner coil modules and efficient power transmission, thus meeting the lightweight requirements of portable devices.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
- Filing Date
- 2025-11-20
- Publication Date
- 2026-06-18
Smart Images
Figure CN2025136437_18062026_PF_FP_ABST
Abstract
Description
Coil modules, wireless charging devices and electronic devices
[0001] This application claims priority to the patent application filed on December 9, 2024, with application number 2024118092340 and title "Coil Module, Wireless Charging Device and Electronic Equipment", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of coils, and more particularly to a coil module, a wireless charging device equipped with the coil module, and an electronic device equipped with the coil module. Background Technology
[0003] Currently, with the development and rapid popularization of new energy and electric vehicles, portable mobile terminal devices such as mobile phones and smart wearable devices are increasingly using wireless charging in real life. This wireless charging technology differs from wired connections in that it transmits electrical energy without contact. Specifically, it transmits wireless power through electromagnetic induction or magnetic resonance between the contactless power receiver and the contactless power transmitter, thereby charging the rechargeable battery of the portable mobile terminal device. The coil is an essential component for contactless power transmission between the contactless power transmitter and receiver. However, existing coils are generally traditional wire-wound coils, which are typically made by winding at least two overlapping and stacked layers. This results in a relatively large thickness, which cannot meet the requirement of reducing coil thickness for high-efficiency wireless power transmission modules at higher power levels. Summary of the Invention
[0004] This application provides a coil module, which includes a coil assembly, a jumper assembly, and an insulating film. The coil assembly includes a first flexible circuit board and a coil bundle disposed on the first flexible circuit board. The coil bundle includes a coil portion, a first connecting end connected to one end of the coil portion, and a second connecting end connected to the other end of the coil portion. The first connecting end is located on the first flexible circuit board, and the second connecting end extends out of the edge of the first flexible circuit board. The jumper assembly includes a second flexible circuit board, a first wire bundle, and a second wire bundle. The first wire bundle and the second wire bundle are disposed on the second flexible circuit board at intervals. One end of the first wire bundle is connected to the first connecting end, and one end of the second wire bundle is connected to the second connecting end. The insulating film is located between the first flexible circuit board and the second flexible circuit board.
[0005] This application also provides a wireless charging device, which includes a coil module, a housing, and a circuit board. The coil module includes a coil assembly, a jumper assembly, and an insulating film. The coil assembly includes a first flexible circuit board and a coil bundle disposed on the first flexible circuit board. The coil bundle includes a coil portion, a first connecting end connected to one end of the coil portion, and a second connecting end connected to the other end of the coil portion. The first connecting end is located on the first flexible circuit board, and the second connecting end extends out of the edge of the first flexible circuit board. The jumper assembly includes a second flexible circuit board, a first wire bundle, and a second wire bundle. The first wire bundle and the second wire bundle are disposed on the second flexible circuit board at intervals. One end of the first wire bundle is connected to the first connecting end, and one end of the second wire bundle is connected to the second connecting end. The insulating film is located between the first flexible circuit board and the second flexible circuit board. The coil module and the circuit board are disposed inside the housing. The coil module is electrically connected to the circuit board. The coil module is used for contactless power transmission.
[0006] This application also provides an electronic device including a coil module, a housing, a battery, and a motherboard. The coil module includes a coil assembly, a jumper assembly, and an insulating film. The coil assembly includes a first flexible circuit board and a coil bundle disposed on the first flexible circuit board. The coil bundle includes a coil portion, a first connecting end connected to one end of the coil portion, and a second connecting end connected to the other end of the coil portion. The first connecting end is located on the first flexible circuit board, and the second connecting end extends out of the edge of the first flexible circuit board. The jumper assembly includes a second flexible circuit board, a first wire bundle, and a second wire bundle. The first wire bundle and the second wire bundle are disposed on the second flexible circuit board at intervals. One end of the first wire bundle is connected to the first connecting end, and one end of the second wire bundle is connected to the second connecting end. The insulating film is located between the first flexible circuit board and the second flexible circuit board. The coil module, the motherboard, and the battery are all disposed within the housing. The coil module is electrically connected to the motherboard. The coil module is used for contactless power reception, and the battery stores the power provided by the coil assembly. Attached Figure Description
[0007] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the implementation will be briefly introduced below. Obviously, the drawings described below are some implementations of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0008] Figure 1 is a three-dimensional structural diagram of the coil module provided in the first embodiment of the present invention.
[0009] Figure 2 is a three-dimensional exploded view of the coil module in Figure 1.
[0010] Figure 3 is a further three-dimensional structural exploded view of the coil module in Figure 2.
[0011] Figure 4 is a further three-dimensional structural exploded view of the coil module in Figure 3.
[0012] Figure 5 is a magnified three-dimensional view of the coil assembly and jumper assembly in Figure 4.
[0013] Figure 6 is an enlarged view of section VI in Figure 5.
[0014] Figure 7 is a magnified three-dimensional view of the coil assembly and jumper assembly in Figure 6 from another perspective.
[0015] Figure 8 is an enlarged view of part VIII in Figure 7.
[0016] Figure 9 is a three-dimensional exploded view of the coil assembly and jumper assembly in Figure 5.
[0017] Figure 10 is a magnified three-dimensional view of the jumper assembly in Figure 9.
[0018] Figure 11 is a three-dimensional exploded view of the jumper assembly in Figure 10.
[0019] Figure 12 is a three-dimensional structural diagram of the jumper assembly in Figure 11 from another perspective.
[0020] Figure 13 is a front structural diagram of the coil assembly and jumper assembly in Figure 5.
[0021] Figure 14 is an enlarged view of section XIV in Figure 13.
[0022] Figure 15 is a cross-sectional view of the coil module in Figure 1.
[0023] Figure 16 is a partial enlarged view of the coil module in Figure 15.
[0024] Figure 17 is a front view of the coil assembly provided in the second embodiment of the present invention.
[0025] Figure 18 is an enlarged view of section XVIII in Figure 17.
[0026] Figure 19 is a front view of the coil assembly provided in the third embodiment of the present invention.
[0027] Figure 20 is an enlarged view of part XX in Figure 19.
[0028] Figure 21 is an exploded three-dimensional structural diagram of the coil module provided in the fourth embodiment of the present invention.
[0029] Figure 22 is a three-dimensional structural diagram of a wireless charging device provided in one embodiment of the present invention.
[0030] Figure 23 is a three-dimensional structural schematic diagram of an electronic device provided in another embodiment of the present invention.
[0031] Figure 24 is a schematic diagram of the wireless charging device in Figure 22 charging the electronic device in Figure 23.
[0032] Main labeling descriptions: 100, Coil module; 30, Coil assembly; 32, First flexible circuit board; 35, Coil bundle; 352, Coil section; 3522, Metal trace; 354, First connection terminal; 356, Second connection terminal; 40, Jumper assembly; 41, Isolating membrane; 42, Second flexible circuit board; 422, First strip sheet; 424, Second strip sheet; 43, Second protective film; 432, First protective sheet; 434, Second protective sheet; 436, Third protective sheet; 44, First wire harness; 442, First solder joint; 443, First solder joint; 445, First electrical contact point; 46, Second wire harness; 462, Second solder joint; 463, Second solder joint; 465, Second electrical contact point. Point; 50, Support layer; 52, First surface; 520, Receiving groove; 522, First receiving section; 524, Second receiving section; 526, Third receiving section; 54, Second surface; 60, First insulating adhesive layer; 62, First clearance groove; 70, First protective film; 72, Clearance hole; 80, Covering film; 82, Second clearance groove; 84, Circular cover; 200, Wireless charging device; 202, Housing; 204, Circuit board; 400, Electronic device; 402, Outer shell; 404, Main board; 406, Battery; 405, Display screen; 91, Second insulating adhesive; 910, Third clearance groove; 912, First clearance section; 914, Second clearance section; 916, Third clearance section; 95, Heat dissipation film. Detailed Implementation
[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0034] Furthermore, the following descriptions of the embodiments are with reference to the accompanying illustrations, used to illustrate specific embodiments in which this application can be implemented. Directional terms used in this application, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying illustrations. Therefore, the use of directional terms is for better and clearer explanation and understanding of this application, and is not intended to indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The term "natural state" refers to the state in which the device or element is not subjected to external forces, such as tension or pressure.
[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," and "set on" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0036] On one hand, this application provides a coil module, which includes:
[0037] A coil assembly includes a first flexible circuit board and a coil bundle disposed on the first flexible circuit board. The coil bundle includes a coil portion, a first connecting end connected to one end of the coil portion, and a second connecting end connected to the other end of the coil portion. The first connecting end is located on the first flexible circuit board, and the second connecting end extends out of the edge of the first flexible circuit board.
[0038] A jumper assembly, the jumper assembly including a second flexible circuit board, a first wire harness and a second wire harness, the first wire harness and the second wire harness being disposed at intervals on the second flexible circuit board, one end of the first wire harness being connected to a first connection terminal, one end of the second wire harness being connected to a second connection terminal, and;
[0039] An isolation membrane is located between the first flexible circuit board and the second flexible circuit board.
[0040] Optionally, one end of the first wire harness is welded to the first connecting end, and one end of the second wire harness is welded to the second connecting end.
[0041] Optionally, one end of the first wire harness is provided with a first solder point, the first connecting end is exposed on both sides of the first flexible circuit board, and the first solder point is soldered to the first connecting end through a first solder part; one end of the second wire harness is provided with a second solder point, the second connecting end extends out of the edge of the first flexible circuit board, and the second solder point is soldered to the second connecting end through a second solder part.
[0042] Optionally, the first wire harness is parallel to the first flexible circuit board, one end of the first wire harness having the first solder point is parallel to and spaced apart from the surface of the first flexible circuit board, and the other end of the first wire harness away from the first solder point extends out of the edge of the first flexible circuit board.
[0043] Optionally, the first wire harness has a first electrical contact at the end opposite to the first welding point, and the second wire harness has a second electrical contact at the end opposite to the second welding point.
[0044] Optionally, the first connection end of the coil bundle is closer to the center line of the first flexible circuit board than the second connection end, the first coil bundle is parallel to the second coil bundle, and the length of the first coil bundle is greater than the length of the second coil bundle.
[0045] Optionally, the second flexible circuit board includes a first strip and a second strip located at opposite ends therefrom, the length of the first strip is greater than the length of the second strip, the width of the second strip is greater than the width of the first strip, the first wire harness is located on the first strip and the second strip, the second wire harness is located on the second strip, and the first strip is attached to the surface of the isolation film away from the first flexible circuit board.
[0046] Optionally, the coil module further includes a support layer, the support layer including a first surface and a second surface disposed opposite to each other, the first flexible circuit board being stacked on the first surface, the first surface being provided with a receiving groove, and the second flexible circuit board being received in the receiving groove.
[0047] Optionally, the receiving groove extends through the second surface, and the isolation membrane is received in the receiving groove.
[0048] Optionally, a first insulating adhesive layer is provided between the first flexible circuit board and the first surface, and the first insulating adhesive layer has a first clearance groove corresponding to the second flexible circuit board, and the isolation film is accommodated in the first clearance groove.
[0049] Optionally, the coil module further includes a first protective film, which covers the surface of the coil portion away from the second flexible circuit board, and the thickness of the insulating film is less than the thickness of the first protective film.
[0050] Optionally, the coil module further includes a cover film covering the surface of the first flexible circuit board away from the second flexible circuit board. The cover film has a second clearance groove facing the coil portion, and the first protective film is accommodated in the second clearance groove.
[0051] Optionally, the coil module further includes a second protective film, which covers the surface of the second flexible circuit board away from the first flexible circuit board, and the thickness of the isolation film is less than the thickness of the second protective film.
[0052] Optionally, the second protective film includes a strip-shaped first protective sheet, a strip-shaped second protective sheet, and a third protective sheet, wherein the first protective sheet is connected between the second protective sheet and the third protective sheet; the shape of the first protective sheet is consistent with the shape of the first strip-shaped sheet, the shape of the second protective sheet is consistent with the shape of the second strip-shaped sheet, and the shape of the third protective sheet is consistent with the shape of the first welding point.
[0053] Optionally, the coil module further includes a second insulating adhesive, which is adhered to the second surface of the support layer. The second insulating adhesive has a third clearance groove facing the second flexible circuit board, and the second protective film is accommodated in the third clearance groove.
[0054] Optionally, the coil module further includes a heat dissipation film, which is attached to the surface of the second insulating adhesive opposite to the support layer.
[0055] Optionally, the support layer is made of nanocrystals.
[0056] Optionally, the coil portion includes multiple turns of metal traces, which are formed by a single metal trace wrapping around one side of the first flexible circuit board from the outside to the inside to form a spiral coil. The multiple turns of metal traces can be wound clockwise or counterclockwise.
[0057] On the other hand, this application also provides a wireless charging device, which includes a coil module, a housing, and a circuit board. The coil module includes a coil assembly, a jumper assembly, and an insulating membrane. The coil assembly includes a first flexible circuit board and a coil bundle disposed on the first flexible circuit board. The coil bundle includes a coil portion, a first connecting end connected to one end of the coil portion, and a second connecting end connected to the other end of the coil portion. The first connecting end is located on the first flexible circuit board, and the second connecting end extends out of the edge of the first flexible circuit board. The jumper assembly includes a second flexible circuit board, a first wire bundle, and a second wire bundle. The first wire bundle and the second wire bundle are disposed on the second flexible circuit board at intervals. One end of the first wire bundle is connected to the first connecting end, and one end of the second wire bundle is connected to the second connecting end. The insulating membrane is located between the first flexible circuit board and the second flexible circuit board. The coil module and the circuit board are disposed inside the housing. The coil module is electrically connected to the circuit board. The coil module is used for contactless power transmission.
[0058] On the other hand, this application also provides an electronic device including a coil module, a housing, a battery, and a motherboard. The coil module includes a coil assembly, a jumper assembly, and an insulating membrane. The coil assembly includes a first flexible circuit board and a coil bundle disposed on the first flexible circuit board. The coil bundle includes a coil portion, a first connecting end connected to one end of the coil portion, and a second connecting end connected to the other end of the coil portion. The first connecting end is located on the first flexible circuit board, and the second connecting end extends out of the edge of the first flexible circuit board. The jumper assembly includes a second flexible circuit board, a first wire bundle, and a second wire bundle. The first wire bundle and the second wire bundle are disposed on the second flexible circuit board at intervals. One end of the first wire bundle is connected to the first connecting end, and one end of the second wire bundle is connected to the second connecting end. The insulating membrane is located between the first flexible circuit board and the second flexible circuit board. The coil module, the motherboard, and the battery are all disposed within the housing. The coil module is electrically connected to the motherboard. The coil module is used for contactless power reception, and the battery stores the power provided by the coil assembly module.
[0059] Please refer to Figures 1 to 4. The coil module 100 provided in the first embodiment of the present invention includes a coil assembly 30, a jumper assembly 40, a support layer 50, a first insulating adhesive layer 60, a first protective film 70, a cover film 80, an isolation film 41, a second protective film 43, a second insulating adhesive 91, and a heat dissipation film 95. The coil assembly 30 includes a first flexible circuit board 32 and a coil bundle 35 disposed on the first flexible circuit board 32. The coil bundle 35 includes a coil portion 352, a first connecting end 354 connected to one end of the coil portion 352, and a second connecting end 354 connected to the other end of the coil portion 352. Two connection terminals 356, the first connection terminal 354 is located on the first flexible circuit board 32, and the second connection terminal 356 extends out of the edge of the first flexible circuit board 32; the jumper assembly 40 includes a second flexible circuit board 42, a first wire harness 44 and a second wire harness 46, the first wire harness 44 and the second wire harness 46 are disposed on the second flexible circuit board 42 at intervals, one end of the first wire harness 44 is connected to the first connection terminal 354, and one end of the second wire harness 46 is connected to the second connection terminal 356 to form a complete circuit; the isolation membrane 41 is located between the first flexible circuit board 32 and the second flexible circuit board.
[0060] Understandably, the coil module 100 can be applied to contactless power receiving devices, which may be, but are not limited to, electronic devices such as mobile phones, smartwatches, tablets, or smart wearables. The coil module 100 can provide power to the battery of the contactless power receiving device. The coil module 100 can also be applied to contactless power transmitting devices, such as wireless charging devices, where the coil module 100 can charge the contactless power receiving device.
[0061] A support layer 50 is stacked on a heat dissipation film 95, and a second insulating adhesive 91 connects the support layer 50 and the heat dissipation film 95; a first flexible circuit board 32 is disposed on the side of the support layer 50 away from the heat dissipation film 95, and a first insulating adhesive layer 60 connects the first flexible circuit board 32 and the support layer 50; a first protective film 70 covers the surface of the coil portion 352 away from the second flexible circuit board 42, and the first protective film 70 is used to protect the surface of the coil assembly 30 from external corrosion, increase the wear resistance and dirt resistance of the coil assembly 30, and improve the reliability and service life of the coil assembly 30; a second protective film 4... The second protective film 43 covers the surface of the second flexible circuit board 42 opposite to the surface of the first flexible circuit board 32. It is used to protect the surfaces of the second flexible circuit board 42, the first wire harness 44, and the second wire harness 46 from external corrosion, increase the wear resistance and dirt resistance of the jumper assembly 40, and improve the reliability and service life of the jumper assembly 40. The cover film 80 covers the surface of the support layer 50 opposite to the surface of the heat dissipation film 95. The cover film 80 is used to protect the surface of the support layer 50 from external corrosion, increase the wear resistance and dirt resistance of the coil module 100, and improve the reliability and service life of the coil module 100.
[0062] In the coil module 100 provided by this invention, the first flexible circuit board 32 and the second flexible circuit board 42 are separated by an isolation film 41. One end of the first wire bundle 44 is connected to the first connection end 354 of the coil section 352, and one end of the second wire bundle 46 is connected to the second connection end 356 of the coil section 352 to form a complete circuit. Compared with the prior art, which uses at least double-layer coil stacking and has a cover film attached to opposite sides of the coil, and then an adhesive layer is attached to the surface of the cover film away from the coil, it can be understood that the winding coil refers to an electromagnetic element formed by winding insulated wires according to a specific pattern using a mechanical device. The coil module 100 provided by this invention uses only the coil bundle 35 disposed on a single-sided first flexible circuit board 32. Compared with the double-layer coil bundle in the prior art, the coil module 100 of this invention reduces the coil bundle by one layer, thereby reducing the thickness of the coil assembly 30 and the overall thickness of the coil module 100. Furthermore, the insulating film 41 of the coil module 100 of this invention replaces the cover film and adhesive layer on the coil side in the prior art, thereby reducing one film layer and further reducing the overall thickness of the coil module 100, in order to meet the trend of thinner electronic devices equipped with the coil module 100. Secondly, the coil assembly 30 adopts a single-sided wiring method, that is, wiring only on the first surface 52, which reduces the thickness of the remaining stacked layers and provides space for increasing the copper thickness of the wiring in the coil section 352, thereby reducing the AC resistance of the coil assembly 30, reducing the temperature of the coil assembly 30 during operation, improving temperature rise, increasing charging efficiency, and reducing losses. Furthermore, only one cover film 80 needs to be provided on one coil section 352, that is, only one cover film 80 is provided on the surface of one coil section 352 facing away from the support layer 50. This eliminates the need to provide a cover film on the surface of the first flexible circuit board 32 facing away from the coil section 352, further reducing the thickness of the coil module 100 and better meeting the needs of lightweight portable devices for contactless power transmission. This thickness refers to the dimensions of each component of the coil module 100 in the stacking direction.
[0063] As shown in Figures 5-12, one end of the first wire harness 44 is welded to the first connecting end 354, and one end of the second wire harness 46 is welded to the second connecting end 356. Specifically, one end of the first wire harness 44 is provided with a first welding point 442, and the first connecting end 354 is exposed on both sides of the first flexible circuit board 32. The first welding point 442 is welded to the first connecting end 354 through a first welding part 443. One end of the second wire harness 46 is provided with a second welding point 462, and the second connecting end 356 extends out of the edge of the first flexible circuit board 32. The second welding point 462 is welded to the second connecting end 356 through a second welding part 463, so as to realize that the coil bundle 35 and the first wire harness 44 and the second wire harness 46 of the second flexible circuit board 42 form a circuit.
[0064] Optionally, the first connection end 354 of the coil bundle 35 is closer to the center line L of the first flexible circuit board 32 than the second connection end 356. The first wire bundle 44 is parallel to the second wire bundle 46, and the length of the first wire bundle 44 is greater than the length of the second wire bundle 46. The first wire bundle 44 and the second wire bundle 46 are two jumpers of the coil module 100, respectively. The first wire bundle 44 is parallel to the first flexible circuit board 32. One end of the first wire bundle 44 with a first solder point 442 is parallel to and spaced apart from the surface of the first flexible circuit board 32, and the other end of the first wire bundle 44 away from the first solder point 442 extends out of the edge of the first flexible circuit board 32. Setting the first wire bundle 44 and the second wire bundle 46 to be parallel and spaced apart not only facilitates processing but also facilitates connection to the circuit system of the contactless charging device / device to be charged.
[0065] The coil section 352 includes multiple turns of metal trace 3522. Each turn of metal trace 3522 is formed by a single metal trace winding around one side of the first flexible circuit board 32 from the outside in to form a spiral coil. The multiple turns of metal trace 3522 can be wound clockwise or counterclockwise. Because the multiple turns of metal trace 3522 can be wound clockwise or counterclockwise to form the spiral coil section 352, the routing of the metal trace 3522 is not limited, and the coil section 352 can be manufactured according to actual needs. In this embodiment, the multiple turns of metal trace 3522 can be wound clockwise. The multiple turns of metal trace 3522 are spaced apart from each other, and the shape formed by each turn of metal trace 3522 is approximately circular. The multiple turns of metal trace 3522 are coaxial. The multiple turns of metal trace 3522 can be exposed on opposite surfaces of the first flexible circuit board 32. The first connecting end 354 is located inside the coil portion 352, and the second connecting end 356 is located on the outer edge of the coil portion 352, with one end of the second connecting end 356 extending away from the metal trace 3522. In this embodiment, the cross-section of the metal trace 3522 is rectangular, which improves the heat dissipation performance, current carrying capacity, and space utilization of the metal trace 3522. In other embodiments, the shape formed by each turn of the metal trace 3522 can also be rectangular, polygonal, or elliptical. Since the metal trace 3522 can be circular, rectangular, polygonal, or elliptical, the coil portion 352 can be designed as a spiral coil of various shapes according to implementation needs.
[0066] In this embodiment, the insulating film 41 is a strip-shaped insulating sheet, which is aligned with the surface of the second flexible circuit board 42 facing the first flexible circuit board 32, so that the first flexible circuit board 32 and the second flexible circuit board 42 are completely insulated. The insulating film 41 may be, but is not limited to, an organic fiber sheet, a polymer insulating sheet, or a composite insulating sheet.
[0067] As shown in Figures 9-12, the second flexible circuit board 42 includes a first strip 422 and a second strip 424 located at opposite ends thereon. The length of the first strip 422 is greater than the length of the second strip 424, and the width of the second strip 424 is greater than the width of the first strip 422. A first wire harness 44 is disposed on one side of the second flexible circuit board 42 and is located on the first strip 422 and the second strip 424. A second wire harness 46 is disposed on the other side of the second flexible circuit board 42 and is located on the second strip 424. The first strip 422 is attached to the surface of the isolation film 41 facing away from the surface of the first flexible circuit board 32. Because the width of the first strip 422 of the second flexible circuit board 42 is smaller than the width of the second strip 424, and the second wire harness 46 is only disposed on the second strip 424, the area of the second flexible circuit board 42 is smaller. This not only reduces the volume occupied by the second flexible circuit board 42 in the coil module 100, which is beneficial to the miniaturization and thinning of the coil module 100, but also saves the materials required to manufacture the second flexible circuit board 42. The first solder point 442 is located at the end of the first strip 422 away from the second strip 424, and the second solder point 462 is located at the end of the second wire harness 46 closer to the first strip 422. The first wire harness 44 has a first electrical contact 445 at one end away from the first solder point 442, and the first electrical contact 445 is exposed on the outer peripheral surface of the support layer 50; the second wire harness 46 has a second electrical contact 465 at one end away from the second solder point 462, and the second electrical contact 465 is exposed on the outer peripheral surface of the support layer 50; the first electrical contact 445 and the second electrical contact 465 are used to connect to the circuit system of the contactless charging device.
[0068] In this embodiment, the first flexible circuit board 32 is circular, and the length direction of the second flexible circuit board 42 is parallel to the radial direction of the first flexible circuit board 32. One end of the second flexible circuit board 42, away from the center line of the first flexible circuit board 32, extends beyond the outer periphery of the first flexible circuit board 32. Since the second flexible circuit board 42 extends radially along the first flexible circuit board 32, and both the first wire harness 44 and the second wire harness 46 extend radially along the first flexible circuit board 32, the lengths of the second flexible circuit board 42, the first wire harness 44, and the second wire harness 46 are all relatively short, which not only saves manufacturing materials but also improves charging efficiency. In this embodiment, the cross-section of the first wire harness 44 is rectangular. In other embodiments, the cross-section of the first wire harness 44 can be, but is not limited to, circular, polygonal, or oblong. In other embodiments, the first flexible circuit board 32 can be, but is not limited to, rectangular, elliptical, polygonal, or irregular in shape.
[0069] The second protective film 43 covers the surface of the second flexible circuit board 42 facing away from the first flexible circuit board 32. The thickness of the isolation film 41 is less than or equal to the thickness of the second protective film 43, thereby further reducing the overall thickness of the coil module 100. The second protective film 43 is strip-shaped and includes a strip-shaped first protective sheet 432, a strip-shaped second protective sheet 434, and a third protective sheet 436. The first protective sheet 432 is connected between the second protective sheet 434 and the third protective sheet 436. The shape of the second protective film 43 is consistent with the shape of the second flexible circuit board 42. Specifically, the shape of the first protective sheet 432 is consistent with the shape of the first strip 422, the shape of the second protective sheet 434 is consistent with the shape of the second strip 424, and the shape of the third protective sheet 436 is consistent with the shape of the first solder joint 442. When the second protective film 43 covers the second flexible circuit board 42, the first protective sheet 432 covers the first strip 422, the second protective sheet 434 covers the second strip 424, and the third protective sheet 436 covers the first solder joint 442. The second protective film 43 can be, but is not limited to, an ultra-thin black cover film, a polyimide film, or an FPC cover film, and the thickness of the second protective film 43 is between 3 μm and 7.5 μm.
[0070] As shown in Figures 9 and 13-14, the coil portion 352 is formed by multiple clockwise turns of a metal trace on the first flexible circuit board 32. The current flows out from the first electrical contact point 445 through the second wire harness 46, the second solder point 462, the second solder part 463, the second connection end 356, and then along the multiple turns of the metal trace 3522, the first connection end 354, the first solder part 443, the first solder point 442, and the first wire harness 44.
[0071] As shown in Figure 4, the coil module 100 also includes a support layer 50, which includes a first surface 52 and a second surface 54 disposed opposite to each other. A first flexible circuit board 32 is stacked on the first surface 52, and a receiving groove 520 is provided on the first surface 52. The second flexible circuit board 42 is received in the receiving groove 520. The receiving groove 520 is a strip-shaped groove corresponding to the second flexible circuit board 42. One end of the receiving groove 520 passes through the outer side of the support layer 50, and the other end of the receiving groove 520 is close to the center of the first surface 52. The width of the receiving groove 520 is greater than or equal to the width of the second flexible circuit board 42. The receiving groove 520 passes through the second surface 54 of the support layer 50 so that the second flexible circuit board 42 can be completely received in the receiving groove 520. That is, when the coil assembly 30 is placed on the support layer 50, the second flexible circuit board 42 is received in the receiving groove 520, and the first surface 52 is supported by the first flexible circuit board 32, thereby reducing the thickness of the coil module 100. The shape of the support layer 50 may be the same as or different from the shape of the first flexible circuit board 32. In this embodiment, the support layer 50 is a rectangular nanocrystal. The support layer 50 may be, but is not limited to, a circular nanocrystal, a polygonal nanocrystal, an elliptical nanocrystal, or an irregularly shaped nanocrystal. The area of the first surface 52 is greater than or equal to the area of the first flexible circuit board 32, so that the first flexible circuit board 32 can fall entirely within the area of the first surface 52. The support layer 50 can absorb energy from the electromagnetic field and convert this energy into electrical energy and transmit it to the receiving end to improve the power transmission efficiency; secondly, it can realize the transmission of electrical energy over a longer distance to expand the application scenarios of wireless power transmission; in addition, the support layer 50 helps the coil module 100 dissipate heat, further improving the power transmission speed and efficiency; the support layer 50 has a high saturation magnetic flux density and relative permeability, which can significantly reduce the volume and mass of the magnetic energy coupling mechanism while ensuring the shielding effect, making it suitable for the wireless charging environment of portable electronic devices; the support layer 50 can also effectively reduce energy loss during power transmission, reduce heat generation, and reduce electromagnetic interference to the environment surrounding the coil module 100. In other embodiments, the support layer 50 may also be made of other materials that have the above-mentioned effects, besides nanocrystalline materials.
[0072] As shown in Figures 4 and 11, the receiving groove 520 includes a first receiving section 522, a second receiving section 524 and a third receiving section 526 that are interconnected. The first receiving section 522 is located between the second receiving section 524 and the third receiving section 526. The third receiving section 526 is closer to the center of the first surface 52 than the second receiving section 524. One end of the second receiving section 524 away from the third receiving section 526 passes through the outer side of the support layer 50. The first receiving segment 522 is directly opposite the first strip 422, and the width of the first receiving segment 522 is greater than or equal to the width of the first strip 422; the second receiving segment 524 is directly opposite the second strip 424, and the width of the second receiving segment 524 is greater than or equal to the width of the second strip 424; the third receiving segment 526 is directly opposite the first solder joint 442, and the width of the third receiving segment 526 is greater than or equal to the width of the first solder joint 442; that is, when the second flexible circuit board 42 is received in the receiving groove 520, the first strip 422 can be received in the first receiving segment 522, the second strip 424 can be received in the second receiving segment 524, and the first solder joint 442 can be received in the third receiving segment 526.
[0073] In this embodiment, the receiving groove 520 penetrates the second surface 54, and both the isolation film 41 and the second flexible circuit board 42 are received in the receiving groove 520. It can be understood that when the depth of the receiving groove 520 is greater than or equal to the sum of the thicknesses of the second flexible circuit board 42 and the isolation film 41, both the isolation film 41 and the second flexible circuit board 42 are received in the receiving groove 520; when the depth of the receiving groove 520 is less than the sum of the thicknesses of the second flexible circuit board 42 and the isolation film 41, only the second flexible circuit board 42 is received in the receiving groove 520.
[0074] In some embodiments, the receiving groove 520 is located on the first surface 52 of the support layer 50, and the receiving groove 520 does not penetrate the second surface 54 of the support layer 50.
[0075] As shown in Figure 4, a first insulating layer 60 is disposed between the first flexible circuit board 32 and the first surface 52. The first insulating layer 60 has a first clearance groove 62 corresponding to the second flexible circuit board 42. An isolation film 41 is accommodated in the first clearance groove 62. The isolation film 41 can not only effectively insulate and isolate the first flexible circuit board 32 and the second flexible circuit board 42, but also reduce the thickness of the coil module 100. The shape of the first insulating layer 60 is consistent with the shape of the first flexible circuit board 32. In this embodiment, the shape of the first insulating layer 60 is consistent with the shape of the coil part 352, that is, the first insulating layer 60 is an annular sheet. One end of the first clearance groove 62 passes through the inner cavity of the first insulating layer 60, and the other end of the first clearance groove 62 passes through the outer peripheral surface of the first insulating layer 60. The shape of the first clearance groove 62 is consistent with the shape of the isolation film 41. When the coil assembly 30 is placed on the first surface 52 of the support layer 50, the first insulating layer 60 is connected between the first flexible circuit board 32 and the first surface 52. Compared to the existing technology where an insulating film is provided between the coil and the support layer, requiring insulating adhesive to be provided on both opposite sides of the insulating film, this application only uses a first insulating adhesive layer 60 to replace the insulating film and the insulating adhesive on both opposite sides of the insulating film, thereby reducing the thickness of the coil module 100; and the isolation film 41 can be accommodated in the first clearance groove 62, and the second flexible circuit board 42 can be accommodated in the accommodating groove 520, thereby further reducing the thickness of the coil module 100.
[0076] Optionally, the coil module 100 further includes a first protective film 70, which covers the surface of the coil portion 352 facing away from the second flexible circuit board 42. The thickness of the isolation film 41 is less than the thickness of the first protective film 70. Understandably, in related technologies, protective films are respectively attached to opposite sides of the coil to protect it. However, the coil module 100 of this application only provides the first protective film 70 on the surface of the coil portion 352 facing away from the second flexible circuit board 42, thereby reducing the overall thickness of the coil assembly 30; and the thickness of the isolation film 41 is less than the thickness of the first protective film 70, thus reducing the thickness of the coil module 100. In this embodiment, the shape of the first protective film 70 is consistent with the shape of the coil portion 352, that is, the first protective film 70 is an annular film, and a clearance hole 72 is provided in the center of the first protective film 70. In this embodiment, the first protective film 70 is a polyimide film. In other embodiments, the first protective film 70 may also be, but is not limited to, a polycarbonate film, a polyethylene terephthalate film, or a polymethyl methacrylate film.
[0077] Optionally, the coil module 100 further includes a cover film 80, which covers the surface of the support layer 50 facing away from the second flexible circuit board 42. The cover film 80 has a second clearance groove 82 facing the coil portion 352, and the first protective film 70 is accommodated in the second clearance groove 82. The cover film 80 is used to protect the surface of the support layer 50 from corrosion by external substances, increase the wear resistance and dirt resistance of the coil module 100, and improve the reliability and service life of the coil module 100. The shape of the cover film 80 is consistent with the shape of the first surface 52 of the support layer 50. In this embodiment, the cover film 80 is a rectangular film. In other embodiments, the cover film 80 may be, but is not limited to, a circular film, a polygonal film, an elliptical film, or an irregularly shaped film. The shape of the second clearance groove 82 is consistent with the shape of the first protective film 70, so that the first protective film 70 can be completely accommodated in the second clearance groove 82. When the second clearance groove 82 is formed on the cover film 80, a circular cover 84 is formed around the inner periphery of the cover film 80 in the second clearance groove 82. When the first protective film 70 is accommodated in the second clearance groove 82, the outer peripheral surface of the first protective film 70 is sealed and fitted with the outer peripheral surface of the second clearance groove 82, and the outer peripheral surface of the circular cover 84 is sealed and fitted with the inner peripheral surface of the clearance hole 72, so that the first protective film 70 and the cover film 80 can completely cover the first flexible circuit board 32 and the support layer 50. Since the first protective film 70 is directly accommodated in the second clearance groove 82 of the cover film 80, that is, the first protective film 70 replaces the cover film 80 and the polyester film on the coil part 352, the first protective film 70 is avoided from occupying the overall thickness of the coil module 100, thereby further reducing the overall thickness of the coil module 100. The cover film 80 can be, but is not limited to, an ultra-thin black cover film, a polyimide film or an FPC cover film, etc. In this embodiment, the cover film 80 is a polyester film. The first protective film 70 and the covering film 80 can protect the surface of the first flexible circuit board 32 from corrosion by external substances, increase the wear resistance and stain resistance of the coil part 352 and the first flexible circuit board 32, and improve the reliability and service life of the coil part 352 and the first flexible circuit board 32.
[0078] As shown in Figures 3-4 and 11, the second insulating adhesive 91 is adhered to the second surface 54 of the support layer 50. The second insulating adhesive 91 has a third clearance groove 910 facing the second flexible circuit board 42. The second protective film 43 is accommodated in the third clearance groove 910 to reduce the overall thickness of the coil module 100. The third clearance groove 910 includes a first clearance section 912, a second clearance section 914, and a third clearance section 916 that are interconnected. The second clearance section 914 is located between the first clearance section 912 and the third clearance section 916. The third clearance section 916 is closer to the center of the second insulating adhesive 91 than the second clearance section 914. One end of the second clearance section 914 away from the third clearance section 916 passes through the outer surface of the second insulating adhesive 91. When the second insulating adhesive 91 is attached to the second surface 54, the first clearance section 912 is directly opposite the first receiving section 522, the second clearance section 914 is directly opposite the second receiving section 524, and the third clearance section 916 is directly opposite the third receiving section 526. The width of the first clearance section 912 is greater than or equal to the width of the first protective sheet 432, the width of the second clearance section 914 is greater than or equal to the width of the second protective sheet 434, and the width of the third clearance section 916 is greater than or equal to the width of the third protective sheet 436; that is, when the second insulating adhesive 91 is attached to the second surface 54, the first protective sheet 432 can be accommodated in the first clearance section 912, the second protective sheet 434 can be accommodated in the second clearance section 914, and the third protective sheet 436 can be accommodated in the third clearance section 916.
[0079] The third clearance groove 910 may penetrate the surface of the second insulating adhesive 91 away from the support layer 50, or it may not penetrate the surface of the second insulating adhesive 91 away from the support layer 50. In this embodiment, the third clearance groove 910 penetrates the surface of the second insulating adhesive 91 away from the support layer 50.
[0080] As shown in Figure 4, the heat dissipation film 95 is disposed on the surface of the second insulating adhesive 91 facing away from the support layer 50, that is, the heat dissipation film 95 is attached to the surface of the second insulating adhesive 91 facing away from the support layer 50, and the heat dissipation film 95 is attached to the surface of the second protective film 43 facing away from the second flexible circuit board 42. The heat dissipation film 95 is used to dissipate heat from the coil assembly 30 during operation, preventing the coil assembly 30 from overheating, thereby protecting the normal operation of the coil assembly 30 and extending its service life. The shape of the heat dissipation film 95 is consistent with the shape of the support layer 50 so that the heat dissipation film 95 can completely adhere to the second surface 54 of the support layer 50. In this embodiment, the heat dissipation film 95 is a rectangular heat sink, specifically, the heat dissipation film 95 is made of heat-dissipating graphite, thereby improving the heat dissipation efficiency of the coil module 100. In other embodiments, the heat dissipation film 95 may also be, but is not limited to, thermally conductive silicone pads, thermally conductive grease, etc.
[0081] As shown in Figures 1-4 and 15-16, when assembling the coil module 100, the heat dissipation film 95 is attached to the second surface 54 of the support layer 50 using the second insulating adhesive 91, so that the third clearance groove 910 faces the receiving groove 520. Specifically, the first clearance section 912 faces and connects to the first receiving section 522, the second clearance section 914 faces and connects to the second receiving section 524, and the third clearance section 916 faces and connects to the third receiving section 526. The coil assembly 30 and the jumper assembly 40 are installed onto the support layer 50 using the first insulating adhesive layer 60, so that the first flexible electrical... The circuit board 32 is positioned on the first surface 52 by the first insulating adhesive layer 60. The first clearance groove 62 is directly opposite to and connected to the receiving groove 520. The isolation film 41 is received in the first clearance groove 62, the jumper assembly 40 is received in the receiving groove 520, and the second protective film 43 is received in the third clearance groove 910. This allows the first flexible circuit board 32 to be supported on the first surface 52, thereby ensuring the flatness of the entire coil assembly 30, improving the wireless power transmission efficiency, reducing the power transmission temperature rise of the coil module 100, thereby improving the user experience, and further reducing the thickness of the coil module 100. The end of the second flexible circuit board 42 away from the coil assembly 30 extends out of the outer side of the support layer 50, so that the first electrical contact point 445 and the second electrical contact point 465 are exposed; the first protective film 70 is covered on the surface of the first flexible circuit board 32 away from the support layer 50, and the cover film 80 is covered on the first surface 52 of the support layer 50 and the first flexible circuit board 32, so that the first protective film 70 is accommodated in the second relief groove 82, and the circular cover 84 is accommodated in the relief hole 72 of the first protective film 70. The first protective film 70 and the cover film 80 together protect the coil assembly 30 and the support layer 50.
[0082] In this application, the second protective film 43 is housed in the third clearance groove 910, the second flexible circuit board 42 is housed in the receiving groove 520, the isolation film 41 is housed in the first clearance groove 62, and the first protective film 70 is housed in the second clearance groove 82 of the covering film 80, so that the overall thickness of the coil module 100 is relatively thin.
[0083] As shown in Figures 17 and 18, the structure of the coil module in the second embodiment of the present invention is similar to that of the coil module 100 in the first embodiment, except that the structure of the first flexible circuit board 32a in the second embodiment is slightly different from that in the first embodiment. Specifically, the first flexible circuit board 32a in the second embodiment is rectangular, and the coil portion 352a is rectangular. A metal trace is formed by winding multiple turns of spaced metal trace from the outside to the inside on one side of the first flexible circuit board 32a. The multiple turns of metal trace form a spiral coil, and each turn of metal trace is rectangular. The multiple turns of metal trace can be wound clockwise or counterclockwise. In this embodiment, the multiple turns of metal trace are wound clockwise.
[0084] In other embodiments, on one side of the first flexible circuit board 32a, a metal trace is formed by wrapping around in a counterclockwise direction from the outside to the inside to form a multi-turn spaced metal trace, the multi-turn metal trace forming a spiral coil, and each turn of the metal trace being rectangular.
[0085] The function and beneficial effects of the coil module in the second embodiment are the same as those of the coil assembly in the first embodiment, and will not be repeated here.
[0086] As shown in Figures 19 and 20, the structure of the coil module in the third embodiment of the present invention is similar to that of the coil module 100 in the first embodiment, except that the winding direction of the metal trace of the coil portion 352b in the third embodiment is opposite to that of the metal trace of the coil portion 352 in the first embodiment. In the third embodiment, the coil portion 352b is formed by a metal trace winding around one side of the first flexible circuit board 32 from the outside to the inside to form a spiral coil, with multiple turns of the metal trace winding counterclockwise. The multiple turns of the metal trace are spaced apart from each other, each turn of the metal trace is circular, and the multiple turns of the metal trace are coaxial.
[0087] The function and beneficial effects of the coil module in the third embodiment are the same as those of the coil assembly in the first embodiment, and will not be repeated here.
[0088] In other embodiments, the first flexible circuit board 32 may also be, but is not limited to, elliptical, polygonal, etc.; the shape formed by the metal traces of each coil portion may also be, but is not limited to, elliptical, polygonal, etc.
[0089] As shown in Figure 21, the structure of the coil module in the fourth embodiment of this application is similar to that of the coil module in the first embodiment. The difference is that: the first surface 52 of the support layer 50 in the fourth embodiment is provided with a relief groove 523, and the receiving groove 520 is connected to the relief groove 523; the depth of the relief groove 523 is greater than or equal to the thickness of the first insulating adhesive layer 60. When the coil assembly 30 is installed on the first surface 52 of the support layer 50, the first insulating adhesive layer 60 is received in the relief groove 523, and the surface of the first flexible circuit board 32 facing the second flexible circuit board 42 is coplanar with the first surface 52, thereby further reducing the overall thickness of the coil module.
[0090] In other embodiments, the depth of the recess 523 is equal to the sum of the thickness of the first insulating layer 60 and the thickness of the first flexible circuit board 32. When the coil assembly 30 is mounted on the first surface 52 of the support layer 50, both the first insulating layer 60 and the first flexible circuit board 32 are accommodated in the recess 523. The surface of the first flexible circuit board 32 facing away from the second flexible circuit board 42 is coplanar with the first surface 52, thereby further reducing the overall thickness of the coil module, improving wireless power transmission efficiency, further improving charging temperature rise, and enhancing user experience.
[0091] As shown in Figure 22, one embodiment of this application also provides a wireless charging device 200. The wireless charging device 200 includes a coil module 100, a housing 202, and a circuit board 204 as described in any of the above embodiments. The coil module 100 and the circuit board 204 are disposed within the housing 202. The coil module 100 is electrically connected to the circuit board 204 and is used for contactless power transmission. A charging platform is provided on the housing 202, and the coil module 100 is located near the inner surface of the charging platform or disposed on the charging platform. When the wireless charging device 200 charges a device placed on the charging platform, the coil module 100 generates a magnetic field. The coil in the device being charged undergoes electromagnetic induction with this magnetic field, thereby generating a current and converting electromagnetic energy into electrical energy to charge the battery in the device being charged.
[0092] Because the coil module 100 is thinner, the overall thickness of the wireless charging device 200 can be reduced to meet the requirements of lightweight design of the wireless charging device 200.
[0093] As shown in Figure 23, another embodiment of this application provides an electronic device 400. The electronic device 400 includes a coil module 100, a housing 402, a motherboard 404, and a battery 406 as described in any of the above embodiments. The coil module 100, motherboard 404, and battery 406 are all disposed within the housing 402. The coil module 100 and battery 406 are electrically connected to the motherboard 404. The battery 406 provides power to the motherboard 404 and other electronic components. The coil module 100 is used for contactless power reception to provide power to the battery 406. When the battery 406 of the electronic device 400 needs charging, the electronic device 400 is placed on the charging platform of a wireless charging device, so that the coil module 100 on the electronic device 400 is directly opposite the coil module 100 of the wireless charging device. After the wireless charging device is powered on, the coil module 100 of the wireless charging device generates a changing magnetic field. The coil module 100 on the electronic device 400 senses this magnetic field and generates current to charge the battery 406.
[0094] Optionally, the coil module 100 is located near or disposed on the inner surface of the housing 402.
[0095] In this embodiment, the electronic device 400 is a mobile phone. The electronic device 400 also includes a display screen 405, and a battery 406 provides power to the display screen 405. The display screen 405 is electrically connected to the motherboard. In other embodiments, the electronic device 400 may also be, but is not limited to, electronic products that require charging, such as tablet computers, smartwatches, or smart wearable devices. Various electronic products are equipped with coil modules 100.
[0096] The coil module 100 in the electronic device 400 of this application is thinner, thereby reducing the overall thickness of the electronic device 400 to meet the requirements of lightweight design of the electronic device 400 and facilitating the layout of other electronic components within the electronic device 400.
[0097] As shown in Figure 24, when the wireless charging device 200 is used to charge the electronic device 400, the electronic device 400 is placed on the charging platform of the wireless charging device 200. The wireless charging device 200 is connected to an external power source. The coil module 100 of the wireless charging device 200 generates a magnetic field. The coil module 100 in the electronic device 400 senses the magnetic field and generates a current to charge the battery 406 of the electronic device 400.
[0098] The above are the implementation methods of the embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the embodiments of this application, and these improvements and modifications are also considered to be within the protection scope of this application.
Claims
1. A coil module, characterized in that, The coil module includes: A coil assembly includes a first flexible circuit board and a coil bundle disposed on the first flexible circuit board. The coil bundle includes a coil portion, a first connecting end connected to one end of the coil portion, and a second connecting end connected to the other end of the coil portion. The first connecting end is located on the first flexible circuit board, and the second connecting end extends out of the edge of the first flexible circuit board. A jumper assembly, the jumper assembly including a second flexible circuit board, a first wire harness and a second wire harness, the first wire harness and the second wire harness being disposed at intervals on the second flexible circuit board, one end of the first wire harness being connected to a first connection terminal, one end of the second wire harness being connected to a second connection terminal, and; An isolation membrane is located between the first flexible circuit board and the second flexible circuit board.
2. The coil module according to claim 1, characterized in that, One end of the first wire harness is welded to the first connecting end, and one end of the second wire harness is welded to the second connecting end.
3. The coil module according to claim 1, characterized in that, One end of the first wire harness is provided with a first solder point, and the first connecting end is exposed on both sides of the first flexible circuit board. The first solder point is soldered to the first connecting end through a first solder part. One end of the second wire harness is provided with a second solder point, and the second connecting end extends out of the edge of the first flexible circuit board. The second solder point is soldered to the second connecting end through a second solder part.
4. The coil module according to claim 3, characterized in that, The first wire harness is parallel to the first flexible circuit board. One end of the first wire harness with the first solder point is parallel to and spaced apart from the surface of the first flexible circuit board. The other end of the first wire harness away from the first solder point extends out of the edge of the first flexible circuit board.
5. The coil module according to claim 3, characterized in that, The first wire harness has a first electrical contact point at the end opposite to the first welding point, and the second wire harness has a second electrical contact point at the end opposite to the second welding point.
6. The coil module according to claim 2, characterized in that, The first connection end of the coil bundle is closer to the center line of the first flexible circuit board than the second connection end. The first coil bundle is parallel to the second coil bundle, and the length of the first coil bundle is greater than the length of the second coil bundle.
7. The coil module according to claim 2, characterized in that, The second flexible circuit board includes a first strip and a second strip located at opposite ends thereon. The length of the first strip is greater than the length of the second strip, and the width of the second strip is greater than the width of the first strip. The first wire harness is located on the first strip and the second strip, and the second wire harness is located on the second strip. The first strip is attached to the surface of the isolation film away from the surface of the first flexible circuit board.
8. The coil module according to claim 2, characterized in that, The coil module further includes a support layer, which includes a first surface and a second surface disposed opposite to each other. The first flexible circuit board is stacked on the first surface, and a receiving groove is provided on the first surface. The second flexible circuit board is received in the receiving groove.
9. The coil module according to claim 8, characterized in that, The receiving groove extends through the second surface, and the isolation membrane is housed in the receiving groove.
10. The coil module according to claim 8, characterized in that, A first insulating adhesive layer is provided between the first flexible circuit board and the first surface. The first insulating adhesive layer has a first clearance groove corresponding to the second flexible circuit board, and the isolation film is accommodated in the first clearance groove.
11. The coil module according to claim 8, characterized in that, The coil module further includes a first protective film, which covers the surface of the coil portion away from the second flexible circuit board, and the thickness of the isolation film is less than the thickness of the first protective film.
12. The coil module according to claim 11, characterized in that, The coil module further includes a cover film, which covers the surface of the first flexible circuit board away from the second flexible circuit board. The cover film has a second clearance groove facing the coil portion, and the first protective film is accommodated in the second clearance groove.
13. The coil module according to claim 8, characterized in that, The coil module also includes a second protective film, which covers the surface of the second flexible circuit board away from the first flexible circuit board, and the thickness of the isolation film is less than the thickness of the second protective film.
14. The coil module according to claim 13, characterized in that, The two protective films include a strip-shaped first protective sheet, a strip-shaped second protective sheet, and a third protective sheet. The first protective sheet is connected between the second protective sheet and the third protective sheet. The shape of the first protective sheet is the same as the shape of the first strip-shaped sheet, the shape of the second protective sheet is the same as the shape of the second strip-shaped sheet, and the shape of the third protective sheet is the same as the shape of the first welding point.
15. The coil module according to claim 13, characterized in that, The coil module also includes a second insulating adhesive, which is attached to the second surface of the support layer. The second insulating adhesive has a third clearance groove facing the second flexible circuit board, and the second protective film is accommodated in the third clearance groove.
16. The coil module according to claim 15, characterized in that, The coil module also includes a heat dissipation film, which is attached to the surface of the second insulating adhesive away from the support layer.
17. The coil module according to claim 8, characterized in that, The support layer is made of nanocrystals.
18. The coil module according to claim 1, characterized in that, The coil section includes multiple turns of metal traces, which are formed by a single metal trace wrapping around one side of the first flexible circuit board from the outside to the inside to form a spiral coil. The multiple turns of metal traces can be wound clockwise or counterclockwise.
19. A wireless charging device, characterized in that, The wireless charging device includes a coil module, a housing, and a circuit board as described in any one of claims 1-18. The coil module and the circuit board are disposed within the housing. The coil module is electrically connected to the circuit board. The coil module is used for contactless power transmission.
20. An electronic device, characterized in that, The electronic device includes a coil module, a housing, a battery, and a motherboard as described in any one of claims 1-19. The coil module, the motherboard, and the battery are all disposed within the housing. The coil module is electrically connected to the motherboard. The coil module is used for contactless power reception. The battery stores the power supplied by the coil module.