Soft magnet and hard magnet combined wireless charging assembly and production process thereof

Abstract

The invention relates to a soft magnet and hard magnet combined wireless charging assembly and a production process thereof, the soft magnet and hard magnet combined wireless charging assembly comprises an inner ring magnet and an outer ring magnet, one of the inner ring magnet and the outer ring magnet is made of a soft magnetic material, the other is made of a hard magnetic material, and at least one of the soft magnet and the hard magnet is provided with a concave-convex structure or a through hole. Enabling the soft magnet and the hard magnet to form an integrated composite structure through an injection molding coating process; the distribution states of the concave-convex structures or the through holes on the magnet comprise one or more of annular distribution, circumferential uniform distribution, fan-shaped distribution, radial distribution and spiral distribution. The wireless charging assembly is of an integral structure, direct positioning is achieved through injection molding, installation is convenient, the structural strength is high, and the structure is flexible.

Description

Technical Field

[0001] This application relates to the field of wireless charging technology, and more specifically, to a wireless charging component combining soft and hard magnetic properties and its manufacturing process. Background Technology

[0002] Currently, wireless charging components are widely used in the charging of smart devices, especially mobile smart devices such as mobile phones, watches, and tablets. Structurally, these wireless charging components mostly employ a two-layer structure: an inner layer using a coil assembly, a wireless charging magnetic shielding material combined with the coil, and an outer layer using a ring of hard magnets. In practical applications, the outer hard magnets ensure the device is positioned and aligned during wireless charging, while the inner coil assembly completes the wireless charging process.

[0003] However, this setup has several problems: 1. The stacked components make the gluing and assembly process time-consuming and labor-intensive; 2. Since the overall wireless charging assembly consists of multiple components, its structural stability needs to be improved, and components are prone to detachment and damage due to collisions; 3. The structure is relatively fixed, making it difficult to achieve further improvements.

[0004] Therefore, in order to better meet the requirements of miniaturization, integration, and personalization of advanced electromagnetic components, it is of great research and development value to provide an integrated wireless charging component that combines soft and hard magnetic materials while possessing high performance and mechanical stability. Summary of the Invention

[0005] In order to provide an integrated, high-performance, and high-strength wireless charging component, this application provides a wireless charging component combining soft and hard magnets and its manufacturing process.

[0006] In a first aspect, this application provides a wireless charging component combining soft and hard magnets, including an inner magnet and an outer magnet, wherein one of the inner magnet and the outer magnet is a soft magnetic material and the other is a hard magnetic material, and at least one of the soft magnet and the hard magnet has a concave-convex structure or a through hole, and the soft magnet and the hard magnet are integrated into a composite structure by an injection molding process. The concave-convex structure or through hole is configured to mechanically interlock the soft magnet and the hard magnet after injection molding. The distribution of the concave-convex structure or through hole on the magnet includes one or more of the following: annular distribution, circumferentially uniform distribution, fan-shaped distribution, radial distribution, and spiral distribution.

[0007] This application significantly improves the integrated bonding strength of soft and hard magnets through injection molding and encapsulation, completely solving the delamination and peeling problems that are prone to occur in traditional injection molding encapsulation. Compared with the traditional inner ring magnets that directly resist shear and peeling forces through adhesive bonding, it reduces the assembly process and is more robust and reliable under vibration during wireless charging and external forces during assembly. It can also adapt to the structural design requirements of different products, avoiding the traditional upper and lower molding that can only be done on flat plates or magnetic cans. Injection molding can design more flexible structures and ensure that the magnet is subjected to uniform force, avoiding structural failure caused by local stress concentration.

[0008] Preferably, the remanence decay rate of the injection-molded magnet after heat aging at 150℃ for 2 hours is ≤10%, and the difference in the coefficient of thermal expansion between the injection-molded magnet and the magnet used for coating does not exceed 8×10. -6 / ℃, and the coefficient of thermal expansion of the magnet being injection molded is not less than the coefficient of thermal expansion of the magnet used for the coating.

[0009] By limiting the above scheme, the wireless charging component can maintain stable magnetic properties and no obvious demagnetization when it is heated during long-term operation in high-temperature injection molding and use. It also avoids excessive differences in expansion and contraction between the two when the temperature changes, such as when the injection molding is cooled or when it is heated during use, which would generate internal stress. The coefficient of thermal expansion of the coated magnet is greater than or equal to that of the coated magnet. When the coated magnet is cooled, the contraction of the coated magnet is slightly greater than that of the coating layer, forming a state of "the coating layer is slightly compressed", which further improves the tightness of the bond and makes the product performance more stable.

[0010] Preferably, the outer magnet is made of hard magnetic material, and the inner magnet is made of soft magnetic material.

[0011] The core of wireless charging is the coupling of alternating magnetic fields generated by the coil. The outer hard magnet can form a ring-shaped "magnetic field barrier" to limit the diffusion of magnetic field lines to the outside. The inner soft magnet has high permeability and low coercivity, which guides the magnetic field lines and concentrates the magnetic field lines generated by the coil inside the component, thereby improving the magnetic coupling efficiency between the coil and the receiver.

[0012] Preferably, the hard magnetic material comprises the following raw materials in parts by weight: 50-70 parts of samarium cobalt magnetic powder, 30-40 parts of PA66, 3-7 parts of glass fiber, and 2-4 parts of dysprosium powder; the soft magnetic material comprises the following raw materials in parts by weight: 60-70 parts of pre-calcined Mn-Zn ferrite powder, 25-35 parts of PA6, 3-7 parts of glass fiber, 0.5-1.5 parts of calcium stearate, and 1-3 parts of DOP plasticizer.

[0013] Samarium cobalt magnetic powder is the core magnetic performance carrier with good thermal stability. PA66 is used as a binder with good mechanical strength and heat resistance, which is suitable for the structural load-bearing requirements of hard magnets. The addition of a certain amount of glass fiber enhances rigidity and prevents the hard magnetic preform from deforming during secondary injection molding. Dysprosium powder, as a rare earth dopant, improves coercivity through magnetocrystalline anisotropy control, preventing demagnetization caused by high temperature or external magnetic field interference, and better adapts to the secondary injection molding process, resulting in more stable product charging efficiency.

[0014] Pre-calcined Mn-Zn ferrite powder has high magnetic permeability and low iron loss, making it suitable for wireless charging magnetization. PA6 has good fluidity and can fill the tiny gaps in uneven structures. Calcium stearate lubricant reduces the melt viscosity during injection molding, reduces mold wear, and forms a tighter coating on the inner magnet. DOP plasticizer improves the flexibility of soft magnetic materials and avoids cracking due to brittleness during filling.

[0015] Preferably, in the hard magnetic material, the samarium cobalt magnetic powder has a particle size of 1-10 μm, the dysprosium powder has a particle size of 5-50 μm, and the glass fiber has a length of 50-100 μm; in the soft magnetic material, the pre-calcined Mn-Zn ferrite powder has a particle size of 2-5 μm, and the glass fiber has a length of 50-100 μm.

[0016] Samarium cobalt magnetic powder is neither too fine, which would cause agglomeration due to van der Waals forces, nor too coarse, which would result in uneven dispersion and affect melt flowability. It can better balance magnetic property density and molding flowability. Dysprosium powder is slightly finer than SmCo5, which can better fill the gaps between SmCo5 particles and uniformly exert its coercive force, avoiding local dysprosium powder enrichment that would lead to a decrease in magnetic energy product. Glass fibers are not too long, which would cause entanglement and agglomeration, thus hindering melt flow; nor are they too short, which would cause the reinforcement effect to fail. They can better form a three-dimensional network reinforcement structure within the system, improve the tensile strength of the material, and do not affect the filling of fine structures, avoiding uneven magnetic permeability caused by magnetic powder agglomeration, resulting in higher magnetic field distribution uniformity. Mn-Zn ferrite powder in soft magnetic materials has good compatibility with PA6, and its fine particle size can increase the specific surface area of ​​the magnetic powder, improve magnetic permeability, and at the same time ensure melt flowability. The magnetic particles are uniformly dispersed without agglomeration, ensuring consistent magnetic properties. The material is relatively dense with few internal voids, resulting in high mechanical strength and magnetic conductivity. At the same time, the injection molding process is smooth, without missing material or inclusions, making it suitable for fine molding requirements such as uneven structures and through holes. Preferably, the dysprosium powder is a high-temperature resistant protective dysprosium powder, including one or more of Mn-Zn ferrite deposited dysprosium powder or alumina coated dysprosium powder.

[0017] Preferably, the dysprosium powder electrophoretic deposition of Mn-Zn ferrite-coated dysprosium powder includes the following preparation steps: dispersing Mn-Zn ferrite powder in an ethanol aqueous solution, adding polyvinylpyrrolidone, ultrasonically dispersing, using dysprosium powder as the cathode and Pt sheet as the anode, electrodepositing, calcining, and obtaining Mn-Zn ferrite-deposited dysprosium powder.

[0018] The preparation method is simple, and the surface of the obtained dysprosium powder is uniformly coated with a uniform and dense Mn-Zn film. The product has better performance stability under high temperature and long-term use. After the dysprosium powder is uniformly dispersed, the magnetic domain pinning effect covers the entire hard magnetic region, while reducing the eddy current loss inside the hard magnetic field. The product has better performance, and a continuous low magnetic resistance interface is formed between the interfaces, which facilitates smooth magnetic field line conduction and higher charging efficiency.

[0019] The Mn-Zn ferrite coating layer has high permeability and is in phase with the soft magnetic matrix, eliminating abrupt changes in permeability. After calcination, the Mn-Zn ferrite coating layer forms a spinel structure, which is combined with the Si-O bond on the surface of the hard magnetic SmCo5 through the "Si-O-Fe" bridge bond. The interface gap is small, the interface magnetic resistance and coupling coefficient are reduced, the dispersion loss of magnetic field lines inside the hard magnetic matrix is ​​reduced, and the hysteresis loss is low. It forms a better Mn-Zn ferrite to Mn-Zn ferrite continuous magnetic circuit with the soft magnetic Si-O layer.

[0020] Preferably, the mass ratio of samarium cobalt magnetic powder to high-temperature resistant dysprosium powder is (19-21):1.

[0021] The role of dysprosium powder is to enhance the magnetocrystalline anisotropy field of SmCo5 through spin and orbital coupling, thereby improving coercivity. At this mass ratio, a balance between "high magnetic energy product" and "high coercivity" can be achieved, avoiding the overall performance degradation caused by optimizing a single performance.

[0022] Preferably, the deposition voltage is 40-60V and the deposition time is 15-25min.

[0023] The deposition effect is suitable, and the interfacial magnetic resistance is reduced while achieving a good pinning effect.

[0024] Preferably, the hard magnetic material includes the following preparation steps: modifying samarium cobalt magnetic powder to obtain aminated samarium cobalt magnetic powder, weighing the hard magnetic material raw materials according to the weight parts, mixing them evenly, and extruding and granulating to obtain the hard magnetic material; the soft magnetic material includes the following preparation steps: mixing MnO, ZnO, and Fe2O3 in a mass ratio of (1-2):(1-2):(5-8), pre-calcining, cooling and crushing to obtain pre-calcined Mn-Zn ferrite powder, weighing the soft magnetic material raw materials according to the weight parts, mixing them evenly, and extruding and granulating to obtain the soft magnetic material.

[0025] Introducing -NH2 onto the surface of the magnetic powder allows it to form hydrogen bonds with -CONH- of PA66, further enhancing interfacial bonding. The magnetic powder is uniformly dispersed in the PA66 matrix, reducing internal voids. Pre-firing promotes the reaction of the three components to form a stable spinel-type Mn-Zn ferrite, eliminating amorphous phases, increasing magnetic permeability, and reducing hysteresis loss. At the same time, the powder morphology is regular after pre-firing, resulting in more uniform dispersion during subsequent mixing and molding.

[0026] The amino group of aminated SmCo5 forms a hydrogen bond with the amide bond of PA66. The Al2O3 layer of alumina-coated dysprosium powder and the Si-O bond of SmCo5 may also form a Si-O-Al-O-bridge bond. By constructing a magnetic powder-matrix-additive chemical network, the product has good high-temperature stability and mechanical strength after the above modified components are used together.

[0027] Secondly, this application provides a manufacturing process for a wireless charging component combining soft and hard magnetic materials, comprising the following preparation steps: a hard magnetic material is injection molded in one step to form a hard magnetic blank; a soft magnetic material is then injection molded to fill the blank, with the cavity matching the hard magnetic blank, and the material is fed from a position away from the coil. The feed port is located in the cavity at a position corresponding to the outer edge of the wireless charging component or the non-magnetic core conduction area, so that the soft magnetic material only fills one side of the concave-convex structure or through hole of the hard magnetic material, without covering the opposite side surface of the filled side, thereby obtaining a wireless charging component combining soft and hard magnetic materials.

[0028] Preferably, the injection temperature for one-time injection molding and two-time injection molding is 180-350℃, and the injection pressure is 12-20Mpa.

[0029] Preferably, the primary injection molding barrel temperature is 230-250℃, the mold temperature is 75-85℃, the injection pressure is 15-20MPa, and the holding time is 12-18s; the secondary injection molding barrel temperature is 210-230℃, the mold temperature is 55-65℃, the injection pressure is 12-15MPa, and the holding time is 10-12s.

[0030] Through the above preparation steps, the hard magnet is first formed by injection molding to ensure the dimensional accuracy of the concave-convex structure / through hole, avoiding structural misalignment caused by simultaneous injection molding of soft and hard magnets. The soft magnet is filled on one side without covering the opposite side surface, avoiding the core area coupled with the coil from being covered and increasing magnetic resistance. The one-sided filling ensures structural strength without affecting magnetic circuit conduction. The material is fed away from the coil position to avoid the impact force during molten material injection causing displacement of the hard magnet blank. At the same time, it allows the soft magnetic molten material to fill smoothly, reducing air bubbles and shear stress, resulting in better product performance. The first injection molding fully melts and the high pressure ensures dense filling. The holding pressure compensates for the cooling shrinkage of PA66 and magnetic powder, avoiding shrinkage. The second injection molding rapidly cools and solidifies, preventing the soft magnetic molten material from excessively penetrating the gaps of the hard magnet. The good fluidity of PA6 prevents the hard magnet from shifting. The holding pressure of 10-12s is more suitable for the shrinkage rate of the material, ensuring full filling.

[0031] In summary, this application has the following beneficial effects: This solution achieves stable connection through a nested structure design and direct injection molding. The nested structure, matching of material thermal expansion coefficients, chemical bonding, and synergistic processes ensure a tight connection between the inner and outer magnets. The hard magnets provide high negative energy product and high temperature resistance, while the soft magnets contribute high permeability and low loss. Through magnetic powder modification, particle size matching, and precise parameter control, an optimal balance between mechanical strength, magnetic properties, and process compatibility is achieved. This solves core problems such as magnetic powder agglomeration, interface debonding, and magnetic performance decay at high temperatures. The magnet material can withstand the high temperatures of secondary injection molding with no significant permanent magnetic performance degradation. The matching thermal expansion coefficients prevent interface loosening after thermal cycling, extending service life and performance. Simultaneously, the integrated injection molding process addresses the pain points of complex assembly and low reliability found in conventional solutions, making it suitable for various applications including automotive, wearable, and high-end consumer electronics. Attached Figure Description

[0032] Figure 1 A schematic diagram of a traditional wireless charging component; Figure 2 This is a schematic diagram of the injection-molded wireless charging component combining soft and hard magnets obtained in this application. Detailed Implementation

[0033] To further aid in understanding the technical solution of this invention, several specific implementation examples are provided below to describe the technical solution of this invention in more detail. All of these described embodiments are only some embodiments of this invention, and not all of them. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments; and the reaction devices, monomer compounds, etc. involved in the following embodiments are all commercially available.

[0034] The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0035] The following examples are further illustrations of the present invention, but the present invention is not limited thereto.

[0036] Samarium cobalt magnetic powder was purchased from Zhongkuang Yaoxie ZKYX-CoSm-2541; PA66 was purchased from Suzhou Hegengli A101; glass fiber was purchased from Yataida ECS-11-200; dysprosium powder was purchased from Shanghai Yanbei RDB-FM-Dy; MnO was purchased from Dongjun Metal Materials DJ-3847; ZnO was purchased from Zhuyan Alloy Materials ZY15; Fe2O3 was purchased from Jiupeng New Materials CY-E01; PA6 was purchased from Lanxess B30S in Germany.

[0037] Preparation Example Preparation Example 1: Hard magnetic materials 100g of samarium cobalt magnetic powder and 3g of silane coupling agent KH550 were added to 1500ml of 50vt% ethanol aqueous solution and heated to react at 60℃. After filtration, washing and drying, ammoniated samarium cobalt magnetic powder was obtained. 70g of PA66, 10g of glass fiber and 7.0g of dysprosium powder were added and mixed evenly. The mixture was extruded and granulated at 240℃ with a screw speed of 300rpm to obtain a hard magnetic material.

[0038] soft magnetic materials 10g MnO, 10g ZnO, and 50g Fe2O3 were mixed and pre-calcined at 1000℃ for 2 hours. After cooling and crushing to 2-5μm, pre-calcined Mn-Zn ferrite powder was obtained. 30g PA6, 5g glass fiber, 1g calcium stearate, and 2g DOP plasticizer were added and mixed evenly. The mixture was then extruded and granulated at 280rpm and 210℃ to obtain a soft magnetic material.

[0039] Preparation Example 2: Mn-Zn ferrite deposition of dysprosium powder 10g of Mn-Zn ferrite powder was dispersed in 450ml of 70wt% ethanol aqueous solution, 0.5wt% polyvinylpyrrolidone was added, and the mixture was ultrasonically dispersed. Dysprosium powder was used as the cathode and Pt sheet was used as the anode. The mixture was deposited at 50V for 20min and calcined at 600℃ for 1.5h to obtain Mn-Zn ferrite deposited dysprosium powder.

[0040] Preparation Example 3: Hard Magnetic Materials 100g of samarium cobalt magnetic powder and 3g of silane coupling agent KH550 were added to 1500ml of 50vt% ethanol aqueous solution and heated to react at 60℃. After filtration, washing and drying, samarium cobalt magnetic powder with amino groups was obtained. 70g of PA66, 10g of glass fiber and 7.0g of Mn-Zn ferrite deposition dysprosium powder prepared in Preparation Example 2 were added and mixed evenly. The mixture was extruded and granulated at 240℃ with a screw speed of 300rpm to obtain a hard magnetic material.

[0041] Preparation Example 4: Hard Magnetic Materials 100g of samarium cobalt magnetic powder and 3g of silane coupling agent KH550 were added to 1500ml of 50vt% ethanol aqueous solution and heated to react at 60℃. After filtration, washing and drying, ammoniated samarium cobalt magnetic powder was obtained. 70g of PA66, 10g of glass fiber and 5g of Mn-Zn ferrite deposition dysprosium powder prepared in Preparation Example 2 were added and mixed evenly. The mixture was extruded and granulated at 240℃ with a screw speed of 300rpm to obtain a hard magnetic material.

[0042] Preparation Example 5: Hard Magnetic Materials 100g of samarium cobalt magnetic powder and 3g of silane coupling agent KH550 were added to 1500ml of 50vt% ethanol aqueous solution and heated to react at 60℃. After filtration, washing and drying, samarium cobalt magnetic powder with amino groups was obtained. 70g of PA66, 10g of glass fiber and 3g of Mn-Zn ferrite deposition dysprosium powder prepared in Preparation Example 2 were added and mixed evenly. The mixture was extruded and granulated at 240℃ with a screw speed of 300rpm to obtain a hard magnetic material.

[0043] Preparation Example 6: Soft Magnetic Materials 11g MnO, 11g ZnO, and 53g Fe2O3 were mixed and pre-calcined at 1000℃ for 2 hours. After cooling and crushing to 2-5μm, pre-calcined Mn-Zn ferrite powder was obtained. 60g of pre-calcined Mn-Zn ferrite powder was weighed, and 30g PA6, 5g glass fiber, 1g calcium stearate, and 2g DOP plasticizer were added. The mixture was mixed evenly and extruded at 280rpm and 210℃ to obtain soft magnetic material.

[0044] Preparation Example 7: Soft Magnetic Materials 11g MnO, 11g ZnO, and 53g Fe2O3 were mixed and pre-calcined at 1000℃ for 2 hours. After cooling and crushing to 2-5μm, pre-calcined Mn-Zn ferrite powder was obtained. 80g of pre-calcined Mn-Zn ferrite powder was weighed, and 30g PA6, 5g glass fiber, 1g calcium stearate, and 2g DOP plasticizer were added. The mixture was mixed evenly and extruded at 280rpm and 210℃ to obtain soft magnetic material. Example

[0045] Example 1 The hard magnetic material prepared in Preparation Example 1 was injection molded in one step to form a hard magnetic preform. The protrusions on the magnet were distributed in a ring shape. The barrel temperature was 240°C, the mold temperature was 80°C, the injection pressure was 18 MPa, and the holding time was 15 s. The soft magnetic material prepared in Preparation Example 1 was then filled by a second injection molding process. The barrel temperature was 220°C, the mold temperature was 60°C, the injection pressure was 12 MPa, and the holding time was 10 s. The cavity matched the hard magnetic preform, and the material was fed into the cavity corresponding to the outer edge of the wireless charging component. This ensured that the soft magnetic material only filled one side of the concave and convex structure of the hard magnetic material and did not cover the opposite side of the filled side, thus obtaining a wireless charging component that combines soft and hard magnetic materials.

[0046] Example 2 The only difference between this embodiment and Example 1 is that the hard magnetic material was prepared in Example 3.

[0047] Example 3 The only difference between this embodiment and Example 1 is that the hard magnetic material was prepared in Example 4.

[0048] Example 4 The only difference between this embodiment and Example 1 is that the hard magnetic material was prepared by Example 5.

[0049] Example 5 The only difference between this embodiment and Example 1 is that the soft magnetic material was prepared by Example 6.

[0050] Example 6 The only difference between this embodiment and Example 1 is that the soft magnetic material was prepared in Example 7.

[0051] Example 7 The hard magnetic material prepared in Preparation Example 1 was injection molded in one step to form a hard magnetic preform. The protrusions on the magnet were distributed in a ring shape. The barrel temperature was 240°C, the mold temperature was 80°C, the injection pressure was 18MPa, and the holding time was 15s. The soft magnetic material prepared in Preparation Example 1 was filled by a second injection molding process. The barrel temperature was 220°C, the mold temperature was 60°C, the injection pressure was 8MPa, and the holding time was 10s. The cavity matched the hard magnetic preform, and the material was fed away from the coil position so that the soft magnetic material only filled one side of the concave and convex structure of the hard magnetic material and did not cover the opposite side of the filled side, thus obtaining a wireless charging component that combines soft and hard magnetic materials.

[0052] Comparative Example Comparative Example 1 The hard magnetic material prepared in Example 1 was injection molded in one step to form a hard magnetic preform. The distribution of the protrusions on the magnet was random and discrete. The number of protrusions was the same as in Example 1. The barrel temperature was 240°C, the mold temperature was 80°C, the injection pressure was 18MPa, and the holding time was 15s. The soft magnetic material prepared in Example 1 was then filled by a second injection molding process. The barrel temperature was 220°C, the mold temperature was 60°C, the injection pressure was 12MPa, and the holding time was 10s. The cavity matched the hard magnetic preform, and the material was fed into the cavity corresponding to the outer edge of the wireless charging component. This ensured that the soft magnetic material only filled one side of the concave and convex structure of the hard magnetic material and did not cover the opposite side of the filled side, thus obtaining a wireless charging component that combines soft and hard magnetic materials.

[0053] Comparative Example 2 Commercially available wireless charging components.

[0054] Performance testing test 1: Residual magnetism attenuation rate of the wireless charging component after thermal aging at 150℃ / 2h.

[0055] Test 2: Measure the thermal expansion coefficient of the injection-molded magnet and the thermal expansion coefficient of the magnet used for coating, respectively. The difference in thermal expansion coefficient = thermal expansion coefficient of the injection-molded magnet - thermal expansion coefficient of the magnet used for coating. Test 3: Coupling coefficient k of the wireless charging component in the product; Test 4: Interface connection strength: Test the maximum force when soft magnets and hard magnets are separated, and calculate the strength based on the shear area.

[0056] The test results are summarized in Table 1.

[0057] Table 1 As can be seen from Examples 1 and 7 and Comparative Example 1 and Table 1, the product of this application has sufficient soft magnetic filling, tight connection between soft and hard magnetic interfaces, and small magnetic property decay after thermal aging, exhibiting high performance.

[0058] As can be seen from Examples 1-4 and Table 1, this application, by adding a certain mass of dysprosium powder and depositing it with Mn-Zn ferrite at a limited mass ratio, forms an antioxidant barrier by coating the dysprosium powder with Mn-Zn ferrite deposition. It exhibits no oxidation loss during 50°C thermal aging, and its magnetic performance stability is superior to that of the uncoated type. The deposited dysprosium powder and samarium cobalt magnetic powder are more evenly dispersed, resulting in high magnetic moment coupling efficiency, smaller remanence attenuation, and superior performance of the product.

[0059] Combining Examples 1 and 5-6 with Table 1, it can be seen that, by limiting the interface gap, the heat conduction to the hard magnet is more uniform during thermal aging, reducing local magnetic domain disorder in the hard magnet, lowering the interface magnetic resistance and coupling coefficient, reducing the dispersion loss of magnetic lines of force inside the hard magnet, and reducing hysteresis loss, resulting in better performance.

[0060] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A wireless charging component combining soft and hard magnetic properties, characterized in that: It includes an inner magnet and an outer magnet, one of which is a soft magnetic material and the other is a hard magnetic material. At least one of the soft magnet and the hard magnet has a concave-convex structure or a through hole. The soft magnet and the hard magnet are integrated into a composite structure by injection molding. The concave-convex structure or through hole is configured to mechanically interlock the soft magnet and the hard magnet after injection molding. The distribution of the concave-convex structure or through hole on the magnet includes one or more of the following: annular distribution, circumferentially uniform distribution, fan-shaped distribution, radial distribution, and spiral distribution.

2. The wireless charging component combining soft and hard magnets according to claim 1, characterized in that: The residual magnetism attenuation rate after heat aging at 150℃ for 2 hours is ≤10%, and the difference in the coefficient of thermal expansion between the injection-molded magnet and the magnet used for coating does not exceed 8×10⁻⁻⁻⁶. 6 / ℃, and the coefficient of thermal expansion of the magnet being injection molded is not less than the coefficient of thermal expansion of the magnet used for the coating.

3. The wireless charging component combining soft and hard magnets according to claim 1, characterized in that: The hard magnetic material comprises the following raw materials in parts by weight: 50-70 parts of samarium cobalt magnetic powder, 30-40 parts of PA66, 3-7 parts of glass fiber, and 2-4 parts of dysprosium powder; the soft magnetic material comprises the following raw materials in parts by weight: 60-70 parts of pre-calcined Mn-Zn ferrite powder, 25-35 parts of PA6, 3-7 parts of glass fiber, 0.5-1.5 parts of calcium stearate, and 1-3 parts of DOP plasticizer.

4. The wireless charging component combining soft and hard magnets according to claim 3, characterized in that: The hard magnetic material contains samarium cobalt magnetic powder with a particle size of 1-10 μm, dysprosium powder with a particle size of 5-50 μm, and glass fiber with a length of 50-100 μm. The soft magnetic material contains pre-calcined Mn-Zn ferrite powder with a particle size of 2-5 μm and glass fiber with a length of 50-100 μm.

5. A wireless charging component combining soft and hard magnets according to claim 3, characterized in that: The dysprosium powder is a high-temperature resistant protective dysprosium powder, including one or more of Mn-Zn ferrite deposited dysprosium powder or alumina coated dysprosium powder.

6. A wireless charging component combining soft and hard magnets according to claim 5, characterized in that: The preparation steps of the Mn-Zn ferrite-deposited dysprosium powder include: dispersing Mn-Zn ferrite powder in an ethanol aqueous solution, adding polyvinylpyrrolidone, ultrasonically dispersing, using dysprosium powder as the cathode and Pt sheet as the anode, electrodepositing, and calcining to obtain Mn-Zn ferrite-deposited dysprosium powder.

7. A wireless charging component combining soft and hard magnets according to claim 6, characterized in that: The deposition voltage is 40-60V, and the deposition time is 15-25min.

8. A wireless charging component combining soft and hard magnets according to claim 5, characterized in that: The mass ratio of the samarium cobalt magnetic powder to the high-temperature resistant protective dysprosium powder is (19-21):

1.

9. A wireless charging component combining soft and hard magnets according to claim 3, characterized in that: The hard magnetic material includes the following preparation steps: modifying samarium cobalt magnetic powder to obtain aminated samarium cobalt magnetic powder, weighing the hard magnetic material raw materials according to the weight parts, mixing them evenly, and extruding and granulating to obtain the hard magnetic material; the soft magnetic material includes the following preparation steps: mixing MnO, ZnO, and Fe2O3 according to the mass ratio (1-2):(1-2):(5-8), pre-calcining, cooling and crushing to obtain pre-calcined Mn-Zn ferrite powder, weighing the soft magnetic material raw materials according to the weight parts, mixing them evenly, and extruding and granulating to obtain the soft magnetic material.

10. A manufacturing process for a wireless charging component combining soft and hard magnetic properties according to any one of claims 1-9, characterized in that: The preparation process includes the following steps: a hard magnetic material is injection molded in one step to form a hard magnetic blank; a soft magnetic material is then injection molded to fill the blank, with the cavity matching the hard magnetic blank and the material being fed away from the coil position, so that the soft magnetic material only fills one side of the concave-convex structure or through hole of the hard magnetic material, without covering the opposite side surface, thus obtaining a wireless charging component combining soft and hard magnetic materials; the injection temperature for the first and second injection molding is 180-350℃, and the injection pressure is 12-20Mpa.

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