Magnetic shielding structure and method of manufacturing the same, wireless charging system

Abstract

The application discloses a magnetic shielding structure and a manufacturing method thereof and a wireless charging system, and belongs to the technical field of wireless charging, wherein the magnetic shielding structure comprises a magnetic isolation plate, a ferrite layer and a nanocrystalline layer; the ferrite layer comprises a plurality of ferrite sheets which are laid on the magnetic isolation plate; the nanocrystalline layer is laid on the ferrite layer and comprises a plurality of layers of nanocrystalline strip materials which are arranged in a stack and insulating adhesive tapes which are arranged between two adjacent layers of the nanocrystalline strip materials; the insulating adhesive tapes are used for bonding the adjacent nanocrystalline strip materials; the nanocrystalline layer has a plurality of through holes which penetrate through the nanocrystalline layer along the stacking direction, and the plurality of through holes are uniformly and spacedly distributed. The magnetic shielding structure, the manufacturing method thereof and the wireless charging system provided by the application can relieve the heating condition in the charging process and have a relatively high electric energy transmission efficiency.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and in particular to a magnetic shielding structure and its manufacturing method, as well as a wireless charging system. Background Technology

[0002] Wireless charging technology enables electrical isolation between the power source and the load, and is characterized by its convenience, flexibility, safety, and reliability. It has been applied to consumer electronics products and is gradually being expanded to electric vehicles, smart homes, robots, and other fields.

[0003] In existing technologies, the magnetic conductive structure of wireless charging systems is mainly composed of square soft magnetic ferrite materials. Soft magnetic ferrite materials have high resistivity, which can suppress eddy currents, allowing the magnetic conductive structure to be applied in high-frequency fields. They also possess chemical stability and customizable shape and size. However, a drawback of soft magnetic ferrite magnetic conductive structures is their low saturation magnetic flux density, directly resulting in a large volume and weight of the power coupling mechanism in high-power wireless charging systems, leading to a very bulky overall device. Existing technologies include using nanocrystals to replace soft magnetic ferrites. However, while nanocrystals perform well in low-power applications such as mobile phones, in high-power applications, such as electric vehicles, the magnetic field strength within the wireless charging system is much greater. This leads to severe losses and heat generation in the nanocrystal tape, affecting the energy transfer efficiency of the wireless charging system.

[0004] Therefore, there is an urgent need for a magnetic shielding structure and its manufacturing method, as well as a wireless charging system, to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a magnetic shielding structure and its manufacturing method, as well as a wireless charging system, which can alleviate the heat generation during charging and has high power transmission efficiency.

[0006] Based on the above concept, the technical solution adopted by this invention is as follows:

[0007] The magnetic shielding structure includes:

[0008] Magnetic shielding plate;

[0009] The ferrite layer includes multiple ferrite sheets, which are laid flat on the magnetic shielding plate.

[0010] A nanocrystalline layer is laid flat on the ferrite layer and includes multiple layers of nanocrystalline ribbons stacked together and an insulating tape located between two adjacent nanocrystalline ribbons. The insulating tape is used to bond adjacent nanocrystalline ribbons. The nanocrystalline layer has multiple through holes penetrating it along the stacking direction, and the multiple through holes are evenly spaced.

[0011] Optionally, the through hole is a round hole, a polygonal hole, or a fan-shaped hole.

[0012] Optionally, the through hole is a circular hole, and the diameter of the through hole is 3 to 6 mm.

[0013] Optionally, the nanocrystalline ribbon has 12 to 90 layers and a thickness of 0.28 to 3 mm.

[0014] Optionally, the ferrite sheet is square, with a side length of 50-100 mm and a thickness of 1-3 mm.

[0015] Optionally, the magnetic permeability of the nanocrystalline ribbon is 200 to 2000, and the magnetic permeability of the ferrite sheet is 2000 to 4000.

[0016] Optionally, the top surface of the magnetic shielding plate has multiple spacers, which are connected longitudinally and transversely to form multiple mounting grooves, and the multiple ferrite sheets are respectively installed in the mounting grooves.

[0017] Optionally, the plurality of through-hole arrays are arranged in a specific pattern.

[0018] A method for manufacturing a magnetic shielding structure, used to manufacture the aforementioned magnetic shielding structure, includes the following steps:

[0019] Multilayer nanocrystalline ribbons are sequentially bonded together with insulating tape to form a multilayer nanocrystalline structure.

[0020] The nanocrystalline structure is punched.

[0021] The nanocrystalline structure after punching is trimmed to obtain a nanocrystalline layer;

[0022] Cut the whole sheet of ferrite into multiple ferrite sheets;

[0023] Multiple ferrite sheets are laid flat on a magnetic shielding plate to form a ferrite layer;

[0024] The nanocrystalline layer is laid flat on the surface of the ferrite layer away from the magnetic shielding plate to obtain a magnetic shielding structure.

[0025] The wireless charging system includes the aforementioned magnetic shielding structure.

[0026] The beneficial effects of this invention are:

[0027] The magnetic shielding structure, its manufacturing method, and wireless charging system provided by this invention include a nanocrystalline layer comprising multiple nanocrystalline ribbons, each with multiple through-holes. These through-holes divide each nanocrystalline ribbon into different regions, disrupting the integrity of the multi-layer nanocrystalline ribbon and reducing surface eddy current losses. Consequently, when the magnetic shielding structure is applied to high-power devices, it can alleviate heat generation during charging. Furthermore, the composite of a high-permeability ferrite sheet and a low-permeability nanocrystalline layer allows magnetic lines of force to pass more effectively from bottom to top through the magnetic shielding plate and concentrates them better, reducing magnetic leakage. This results in a magnetic shielding structure with high power transmission efficiency, which in turn leads to better charging efficiency. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the stacked magnetic shielding structure provided in Embodiment 1 of the present invention;

[0029] Figure 2 This is a schematic diagram of the stacking of nanocrystalline layers provided in Embodiment 1 of the present invention;

[0030] Figure 3 This is a top view of the nanocrystalline layer provided in Embodiment 1 of the present invention;

[0031] Figure 4 This is a flowchart of the manufacturing method of the magnetic shielding structure provided in Embodiment 2 of the present invention.

[0032] In the picture:

[0033] 1. Magnetic shielding plate; 2. Ferrite layer; 21. Ferrite sheet; 3. Nanocrystalline layer; 31. Nanocrystalline tape; 32. Insulating tape; 33. Through hole. Detailed Implementation

[0034] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0035] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0038] Example 1

[0039] This embodiment provides a magnetic shielding structure that can alleviate heat generation during charging and has high power transmission efficiency.

[0040] like Figure 1 As shown, the magnetic shielding structure includes a magnetic shielding plate 1, a ferrite layer 2, and a nanocrystalline layer 3 stacked together.

[0041] The magnetic shielding plate 1 can be a plate-like structure disposed on one side of the coil in the wireless charging system, used to support the ferrite layer 2 and the nanocrystalline layer 3. The magnetic shielding plate 1 is an insulating plate, and the specific material can be found in the prior art.

[0042] The aforementioned ferrite layer 2 includes a plurality of ferrite sheets 21, which are either in contact with each other or spaced apart. Furthermore, the plurality of ferrite sheets 21 are laid flat on the magnetic shielding plate 1; in some embodiments, the plurality of ferrite sheets 21 are arranged in an array on the top surface of the magnetic shielding plate 1. To improve the integrity of the plurality of ferrite sheets 21, they can be bonded together, such as by using a film.

[0043] The nanocrystalline layer 3 is laid flat on the ferrite layer 2, that is, the nanocrystalline layer 3 is located on the surface of the ferrite layer 2 away from the magnetic shielding plate 1. Furthermore, the nanocrystalline layer 3 includes multiple layers of nanocrystalline ribbons 31 stacked together and insulating tape 32 located between adjacent nanocrystalline ribbons 31. Adjacent nanocrystalline ribbons 31 are bonded together by the insulating tape 32. The nanocrystalline layer 3 has multiple through-holes 33 penetrating along the stacking direction of the multiple nanocrystalline ribbons 31, and the multiple through-holes 33 are evenly spaced. In some embodiments, the through-holes 33 are formed by stamping. In this embodiment, the nanocrystalline layer 3 can be bonded to the ferrite layer 2 with an adhesive layer, making the magnetic shielding structure a single unit, facilitating subsequent assembly.

[0044] The magnetic shielding structure provided in this embodiment includes a nanocrystalline layer 3 comprising multiple nanocrystalline ribbons 31, and the nanocrystalline layer 3 having multiple through holes 33. The through holes 33 split each nanocrystalline ribbon 31 into different regions, disrupting the integrity of the multiple nanocrystalline ribbons 31, thereby reducing the surface eddy current loss of the multiple nanocrystalline ribbons 31. As a result, when the magnetic shielding structure is applied to high-power devices, it can alleviate the heat generation during charging. Furthermore, the combination of a high-permeability ferrite sheet 21 and a low-permeability nanocrystalline layer 3 allows magnetic lines of force to pass better from bottom to top through the magnetic shielding plate 1 and can better concentrate magnetic lines of force, reducing magnetic leakage. This enables the magnetic shielding structure to have high power transmission efficiency, which is also a good charging efficiency.

[0045] Optionally, the through hole 33 can be a round hole, a polygonal hole, a fan-shaped hole, etc., and this embodiment is not limited thereto. Preferably, the through hole 33 is a round hole, and the diameter of the through hole 33 is 3-6 mm. More preferably, the diameter of the through hole 33 is 4 mm. In some embodiments, such as Figure 3 As shown, the through holes 33 are arranged in an array along the length and width directions of the nanocrystalline layer 3.

[0046] In this embodiment, the number of layers of the nanocrystalline ribbon 31 is 12 to 90, and the specific number of layers can be set as needed. The thickness of each layer of the nanocrystalline ribbon 31 is 0.28 to 3 mm. The magnetic permeability of the nanocrystalline ribbon 31 is 200 to 2000, and the preferred magnetic permeability is 700.

[0047] Optionally, the ferrite sheet 21 in this embodiment is square to have better magnetic permeability. Furthermore, the side length of the ferrite sheet 21 is 50–100 mm, preferably 100 mm, and the thickness is 1–3 mm, preferably 2 mm. The magnetic permeability of the ferrite sheet 21 is 2000–4000, preferably 3300.

[0048] Optionally, the top surface of the magnetic shielding plate 1 has multiple spacers, which are connected longitudinally and transversely to form multiple mounting grooves. Multiple ferrite sheets 21 are installed in the mounting grooves respectively to prevent collisions between adjacent ferrite sheets 21 and improve the reliability of the magnetic shielding structure.

[0049] The magnetic shielding structure provided in this embodiment solves the problem of severe power loss and heat generation under high power, and improves the charging efficiency of wireless charging.

[0050] The embodiments provide the following three examples to illustrate the performance of the magnetic shielding structure provided in this embodiment with the magnetic permeable structure formed by a single ferrite and the magnetic permeable structure formed by a single nanocrystal.

[0051] Table 1

[0052] High-power wireless charging magnetic shielding material Thickness (mm) PC95 ferrite (flat) 5 3 layers of MS700 nanocrystals (laid out) 2.4 Ferrite layer + nanocrystalline layer 4.4

[0053] Table 2

[0054]

[0055] Example 1: After bonding the nanocrystalline ribbon 31 with insulating tape 32, a 72-layer composite bonding is formed to obtain a 72-layer nanocrystalline layer 3 of the nanocrystalline ribbon 31. The sample is cut to a size of 400 mm × 60 mm × 2.4 mm. Then, the nanocrystalline layer 3 is punched, with through holes 33 having a diameter of 4 mm. There are 14 holes in the horizontal row and 95 holes in the vertical row of the nanocrystalline layer 3, evenly distributed on the surface of the nanocrystalline layer 3. The magnetic permeability of the nanocrystalline layer 3 after processing is 700. The ferrite sheet is cut to a size of 100 mm × 100 mm × 2 mm, and the magnetic permeability of the ferrite sheet 21 is selected to be 3300. The charging efficiency and heat generation of the magnetic shielding structure with the above dimensions are tested, and the charging efficiency and heat generation of PC95 ferrite and 3 layers of MS700 nanocrystalline are also tested, as shown in Table 2. As can be seen from Table 2, the initial system efficiency of the magnetic shielding result provided in this embodiment is the highest among the three. The initial magnetic sheet surface temperature is the same as that of the 3-layer MS700 nanocrystal. The system efficiency at the end of operation is also the highest. The magnetic sheet surface temperature at the end of operation is slightly higher than that of PC95 ferrite, but much lower than that of the 3-layer MS700 nanocrystal.

[0056] Example 2: After bonding the nanocrystalline ribbon 31 with insulating tape 32, a 72-layer composite bonding is formed to obtain a 72-layer nanocrystalline layer 3 of the nanocrystalline ribbon 31. The sample is cut to a size of 400 mm × 60 mm × 2.4 mm. Then, the nanocrystalline layer 3 is punched with holes of 6 mm in diameter. There are 11 holes in the horizontal row and 75 holes in the vertical row of the nanocrystalline layer 3, evenly distributed on the surface of the nanocrystalline layer 3. The permeability of the nanocrystalline layer 3 after processing is 200. The ferrite sheet is cut to a size of 50 mm × 50 mm × 1 mm. The ferrite sheet 21 has a permeability of 2000. The charging efficiency and heat generation of the magnetic shielding structure with the above dimensions are tested. The charging efficiency and heat generation of PC95 ferrite and 3 layers of MS700 nanocrystalline are also tested, and the results are shown in Table 4. As can be seen from Table 4, the initial system efficiency of the magnetic shielding results provided in this embodiment is the highest among the three. The initial magnetic sheet surface temperature is the same as that of the 3-layer MS700 nanocrystal. The system efficiency at the end of operation is slightly lower than that of PC95 ferrite, but much higher than that of the 3-layer MS700 nanocrystal. The magnetic sheet surface temperature at the end of operation is slightly higher than that of PC95 ferrite, but much lower than that of the 3-layer MS700 nanocrystal.

[0057] Table 3

[0058]

[0059] Table 4

[0060]

[0061] Example 3: After bonding the nanocrystalline ribbon 31 with insulating tape 32, a 72-layer composite bonding is formed to obtain a 72-layer nanocrystalline layer 3 of the nanocrystalline ribbon 31. The sample is cut to a size of 400 mm × 60 mm × 2.4 mm. Then, the nanocrystalline layer 3 is punched with holes of 3 mm in diameter. There are 16 holes in the horizontal row and 110 holes in the vertical row of the nanocrystalline layer 3, evenly distributed on the surface of the nanocrystalline layer 3. The permeability of the nanocrystalline layer 3 after processing is 700. The ferrite sheet is cut to a size of 100 mm × 100 mm × 3 mm. The permeability of the ferrite sheet 21 is 4000. The charging efficiency and heat generation of the magnetic shielding structure with the above dimensions are tested. The charging efficiency and heat generation of PC95 ferrite and 3 layers of MS700 nanocrystalline are also tested, and the results are shown in Table 6. As can be seen from Table 6, the initial system efficiency of the magnetic shielding results provided in this embodiment is the highest among the three. The initial magnetic sheet surface temperature is the same as that of the 3-layer MS700 nanocrystal. The system efficiency at the end of operation is the highest among the three. The magnetic sheet surface temperature at the end of operation is slightly higher than that of PC95 ferrite, but much lower than that of the 3-layer MS700 nanocrystal.

[0062] Table 5

[0063]

[0064] Table 6

[0065]

[0066] Example 2

[0067] This embodiment provides a method for manufacturing a magnetic shielding structure, used to manufacture the magnetic shielding structure in Embodiment 1, such as... Figure 4 As shown, the manufacturing method of the magnetic shielding structure includes the following steps:

[0068] S1. Multilayer nanocrystalline ribbon 31 is sequentially bonded together with insulating tape 32 to form a multilayer nanocrystalline structure.

[0069] In step S1, insulating tape 32 is applied to both sides of a single nanocrystalline ribbon 31, and then the single-layer nanocrystalline ribbon is laminated in multiple layers.

[0070] S2. Punching treatment of nanocrystalline structures.

[0071] In step S2, the nanocrystalline structure obtained in step S1 is punched to create through holes 33 that are evenly distributed on the surface of the nanocrystalline structure.

[0072] S3. After punching, the nanocrystalline structure is trimmed to obtain nanocrystalline layer 3.

[0073] The nanocrystalline structure with through-hole 33 was cut to obtain the desired size.

[0074] S4. Cut the whole ferrite sheet into multiple ferrite sheets 21.

[0075] In step S4, the entire ferrite sheet is cut into squares of appropriate size.

[0076] S5. Lay multiple ferrite sheets 21 flat on the magnetic shielding plate 1 to form a ferrite layer 2.

[0077] S6. Spread the nanocrystalline layer 3 on the surface of the ferrite layer 2 away from the magnetic shielding plate 1 to obtain a magnetic shielding structure.

[0078] The manufacturing method of the magnetic shielding structure provided in this embodiment first prepares a nanocrystalline layer 3 and a ferrite layer 2, and then lays them flat on a magnetic shielding plate 1. The nanocrystalline layer 3 includes multiple nanocrystalline ribbons 31 and has multiple through holes 33, which split each nanocrystalline ribbon 31 into different regions, destroying the integrity of the multiple nanocrystalline ribbons 31. This reduces the surface eddy current loss of the multiple nanocrystalline ribbons 31. As a result, when the magnetic shielding structure is applied to high-power equipment, it can alleviate the heat generation during charging. Furthermore, by using a composite of a high-permeability ferrite sheet 21 and a low-permeability nanocrystalline layer 3, the magnetic lines of force can pass through the magnetic shielding plate 1 better from bottom to top and can better concentrate the magnetic lines of force, reducing magnetic leakage. This allows the magnetic shielding structure to have high power transmission efficiency, that is, good charging efficiency.

[0079] Example 3

[0080] This embodiment provides a wireless charging system, including the magnetic shielding structure described in Embodiment 1. The wireless charging system provided in this embodiment has good charging performance and, when applied to high-power devices, can also alleviate heat generation during charging.

[0081] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A magnetic shielding structure, characterized in that, include: Magnetic shielding plate (1); Ferrite layer (2) includes a plurality of ferrite sheets (21), which are laid flat on the magnetic shielding plate (1); The nanocrystalline layer (3) is laid flat on the ferrite layer (2) and includes multiple layers of nanocrystalline ribbons (31) stacked together and an insulating tape (32) located between two adjacent nanocrystalline ribbons (31). The insulating tape (32) is used to bond adjacent nanocrystalline ribbons (31). The nanocrystalline layer (3) has a plurality of through holes (33) penetrating it along the stacking direction. The plurality of through holes (33) are evenly spaced. The top surface of the magnetic shielding plate (1) has multiple spacers, which are connected longitudinally and transversely to form multiple mounting grooves. Each of the multiple ferrite sheets (21) is installed in a corresponding mounting groove.

2. The magnetic shielding structure according to claim 1, characterized in that, The through hole (33) can be a round hole, a polygonal hole, or a fan-shaped hole.

3. The magnetic shielding structure according to claim 2, characterized in that, The through hole (33) is a round hole, and the diameter of the through hole (33) is 3 to 6 mm.

4. The magnetic shielding structure according to claim 1, characterized in that, The nanocrystalline ribbon (31) has 12 to 90 layers and a thickness of 0.28 to 3 mm.

5. The magnetic shielding structure according to claim 1, characterized in that, The ferrite sheet (21) is square, and the side length of the ferrite sheet (21) is 50-100 mm and the thickness is 1-3 mm.

6. The magnetic shielding structure according to claim 1, characterized in that, The permeability of the nanocrystalline ribbon (31) is 200 to 2000, and the permeability of the ferrite sheet (21) is 2000 to 4000.

7. The magnetic shielding structure according to claim 1, characterized in that, The plurality of through holes (33) are arranged in an array.

8. A method for manufacturing a magnetic shielding structure, used to manufacture the magnetic shielding structure according to any one of claims 1-7, characterized in that, Includes the following steps: Multilayer nanocrystalline ribbons (31) are sequentially bonded together with insulating tape (32) to form a multilayer nanocrystalline structure; The nanocrystalline structure is punched. The nanocrystalline structure after punching is trimmed to obtain a nanocrystalline layer (3); The whole ferrite sheet is cut into multiple ferrite sheets (21); Multiple ferrite sheets (21) are laid flat on the magnetic shielding plate (1) to form a ferrite layer (2); The nanocrystalline layer (3) is laid flat on the surface of the ferrite layer (2) away from the magnetic shielding plate (1) to obtain a magnetic shielding structure.

9. A wireless charging system, characterized in that, Includes the magnetic shielding structure as described in any one of claims 1-7.

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