阅读说明：本技术 一种磁性复合材料三维结构、其加工方法和用途 (Magnetic composite material three-dimensional structure, processing method and application thereof ) 是由 肖强 郭雄志 张云帆 何恺 曹允开 常良 段亚承 沈可 刘良 王国华 于 2021-06-25 设计创作，主要内容包括：本发明提供了一种磁性复合材料三维结构、其加工方法和用途,所述的磁性复合材料三维结构包括底盘,以及设置于底盘表面上的凸起结构,所述底盘和凸起结构均包括热压树脂和片状磁性粉末,所述片状磁性粉末堆叠设置于所述热压树脂内；所述底盘内片状磁性粉末所在平面与底盘所在平面平行,所述凸起结构内片状磁性粉末所在平面与凸起结构的侧面平行。利用热压树脂,并通过采用热压成型、加载外磁场和分步成型的方法,将片状磁性粉末堆叠设置于所述热压树脂内,并且片状磁性粉末长度方向沿三维结构设计方向排列,最大程度利用片状磁性粉末的高磁导率特性,高磁导率材料结合三维结构设计,可以有效聚集线圈磁力线,减少漏磁,增加无线充电的效率。(The invention provides a magnetic composite material three-dimensional structure, a processing method and application thereof, wherein the magnetic composite material three-dimensional structure comprises a chassis and a raised structure arranged on the surface of the chassis, the chassis and the raised structure both comprise hot-pressing resin and flaky magnetic powder, and the flaky magnetic powder is stacked in the hot-pressing resin; the plane of the flaky magnetic powder in the base plate is parallel to the plane of the base plate, and the plane of the flaky magnetic powder in the protruding structure is parallel to the side face of the protruding structure. By utilizing hot-pressing resin and adopting the methods of hot-pressing molding, external magnetic field loading and step-by-step molding, the flaky magnetic powder is stacked and arranged in the hot-pressing resin, the length direction of the flaky magnetic powder is arranged along the design direction of the three-dimensional structure, the high magnetic conductivity characteristic of the flaky magnetic powder is utilized to the greatest extent, and the high magnetic conductivity material is combined with the design of the three-dimensional structure, so that the magnetic force lines of the coil can be effectively gathered, the magnetic leakage is reduced, and the wireless charging efficiency is increased.)

1. The magnetic composite material three-dimensional structure is characterized by comprising a chassis and a raised structure arranged on the surface of the chassis, wherein the chassis and the raised structure respectively comprise hot-pressing resin and flaky magnetic powder, and the flaky magnetic powder is stacked in the hot-pressing resin;

the plane of the flaky magnetic powder in the base plate is parallel to the plane of the base plate, and the plane of the flaky magnetic powder in the protruding structure is parallel to the side face of the protruding structure.

2. The three-dimensional structure of a magnetic composite material according to claim 1, wherein the thermo-compression resin comprises an epoxy resin, preferably a polyimide and/or polyphenylene ether resin.

3. The three-dimensional structure of the magnetic composite material according to claim 1 or 2, wherein the D50 of the flaky magnetic powder is 50-70 μm;

preferably, the thickness of the flaky magnetic powder is less than or equal to 1 mu m;

preferably, the oxygen mass content of the flaky magnetic powder is less than or equal to 2500 ppm;

preferably, the sheet-shaped magnetic powder has a coercive force of 70A/m or less, but 0 is excluded;

preferably, the material of the sheet-shaped magnetic powder comprises one or a combination of at least two of sendust, ferrosilicon chromium, iron nickel or iron nickel molybdenum.

4. The magnetic composite three-dimensional structure according to any one of claims 1 to 3, wherein the raised structures are vertically disposed on the base plate;

preferably, the raised structure is disposed along an edge of the chassis;

preferably, the convex structure is arranged at the center of the chassis surface;

preferably, the density of the three-dimensional structure of the magnetic composite material is 4.5-5.5 g/cm³。

5. A method of fabricating a three-dimensional structure of a magnetic composite material according to any of claims 1 to 4, wherein the method comprises:

preparing magnetic powder into flaky magnetic powder, mixing hot-pressing resin with the flaky magnetic powder under the action of a magnetic field to prepare magnetic particles with a flaky magnetic powder stacking structure, performing pre-pressing on a base plate and a protrusion structure by utilizing the magnetic particles, and performing hot-pressing on the base plate and the protrusion structure again to prepare the magnetic composite material three-dimensional structure.

6. The process according to claim 5, wherein the preparation of the magnetic powder in the form of flakes comprises: spherical magnetic powder is prepared by vacuum gas atomization, and a flaky structure is formed by flattening treatment to prepare the flaky magnetic powder;

preferably, the magnetic material powder in sheet form is subjected to a vacuum annealing treatment.

7. The process according to claim 5 or 6, characterized in that the step of preparing the magnetic particles comprises: under the action of a magnetic field, mixing hot-pressing resin with a solvent, adding flaky magnetic powder, stirring, volatilizing the solvent to obtain particles, and drying to obtain the magnetic particles;

preferably, the mass of the hot-pressing resin is 3-15% of that of the flaky magnetic powder;

preferably, the solvent comprises acetone and/or ethanol;

preferably, the strength of the magnetic field is 0.05-0.3T;

preferably, the drying mode is baking;

preferably, the baking temperature is 40-70 ℃;

preferably, the baking time is 0.5-2 h.

8. The process of any one of claims 5 to 7, wherein the method of pre-press forming the base plate comprises: putting the magnetic particles into a die for prepressing and forming, and under the action of die pressure, deforming the flaky magnetic powder along the width direction to enable the plane of the flaky magnetic powder to be parallel to the plane of the chassis, so as to prepare the chassis;

preferably, the method for pre-press forming the convex structure comprises the following steps: applying a magnetic field in the vertical direction to the die, putting the magnetic particles into the die for prepressing and forming, wherein the length direction of the flaky magnetic powder is the same as the vertical magnetic field direction, and the plane of the flaky magnetic powder is parallel to the side surface of the convex structure, so as to prepare the convex structure;

preferably, the pressure of the pre-pressing forming is 1 to 3 tons/cm²；

Preferably, the method of hot press forming includes: placing the convex structure and the chassis in a mold, placing the convex structure on the upper part of the chassis according to the mold structure, heating the mold, loading pressure after the heating temperature is reached, connecting the convex structure and the chassis, and finally performing compression molding to obtain the magnetic composite material three-dimensional structure;

preferably, the heating position comprises a connection part of the protruding structure and the chassis;

preferably, the heating temperature is 130-180 ℃;

preferably, the pressure of the compression molding is 6-12 tons/cm²。

9. The machining method according to claim 8, characterized in that it comprises in particular the steps of:

preparing spherical magnetic powder by vacuum gas atomization, forming a sheet structure by flattening treatment, and preparing the sheet magnetic powder by vacuum annealing treatment;

(II) under the action of a magnetic field of 0.05-0.3T, mixing hot-pressing resin with a solvent, adding flaky magnetic powder, stirring, wherein the mass of the hot-pressing resin is 3-15% of that of the flaky magnetic powder, volatilizing the solvent to obtain particles, and baking at 40-70 ℃ for 0.5-2 h to obtain the magnetic particles;

(III) putting the magnetic particles into a mould for prepressing and forming at 1-3 tons/cm²Under the action of the pressure, the flaky magnetic powder deforms and rotates along the width direction, so that the plane where the flaky magnetic powder is located is parallel to the plane where the point is located, the chassis is prepared, a magnetic field in the vertical direction is applied to the mold, and the magnetic particles are placed in the mold at the speed of 1-3 tons/cm²Carrying out pre-pressing molding, wherein the length direction of the flaky magnetic powder is the same as the vertical magnetic field direction, and the plane of the flaky magnetic powder is parallel to the side surface of the convex structure, so as to prepare the convex structure;

(IV) placing the protruding structure and the chassis in a mould, heating the mould where the connecting position of the protruding structure and the chassis is located to 130-180 ℃, pressurizing to connect the protruding structure and the chassis, and finally, when the pressure reaches 6-12 tons/cm²And carrying out lower compression molding to obtain the three-dimensional structure of the magnetic composite material.

10. Use of the magnetic composite three-dimensional structure according to any one of claims 1 to 4 for wireless charging.

Technical Field

The invention belongs to the technical field of magnetic materials, and particularly relates to a magnetic composite material three-dimensional structure, a processing method and application thereof.

Background

The wireless power transmission technology refers to a technology that transmits in the form of a magnetic field or an electromagnetic wave without depending on a medium such as a wire. The electromagnetic induction basic principle is that a coil is arranged at both a transmitting end and a receiving end, the coil at the transmitting end is connected with a wired power supply and generates an electromagnetic signal, and the coil at the receiving end induces the electromagnetic signal, so that power transmission is achieved.

Wireless charging of magnetic induction mode wants to improve charge efficiency, must promote the inductance value of coil with the magnetic field of receiving end coil induction harmless bundling, has metallic substance near receiving end coil in addition, and the induction field can produce the vortex in can the metallic substance, and the vortex can cause magnetic material or coil to generate heat, can reduce wireless charge efficiency or can appear the abnormal phenomenon of operation. In order to improve the wireless charging efficiency, materials with the characteristics of high magnetic permeability, high loss factor and low loss factor are generally adopted in the frequency range of 100-200 kHz.

The magnetic materials mainly used for wireless charging comprise neodymium iron boron permanent magnets, nickel zinc ferrite thin magnetic sheets, manganese zinc ferrite thin magnetic sheets, flexible ferrite magnetic sheets, amorphous nanocrystalline strips and composite materials formed by mixing metal and resin, various magnetic separation sheets made of soft magnetic materials are used as main components of a wireless charging technology, and the magnetic separation sheets play roles in increasing an induction field and shielding coil interference in wireless charging equipment.

Manganese zinc ferrite, as well as iron-based amorphous and nanocrystalline can be used for the transmitting/receiving end, while nickel zinc ferrite is only suitable for the receiving end. The magnetic conductivity and the charging efficiency of the iron-based amorphous and nanocrystalline are higher than those of ferrite, and the iron-based amorphous and nanocrystalline are soft and ultrathin, but the amorphous and nanocrystalline can only be made into strips at present and cannot be made into three-dimensional structural materials. The sintered manganese-zinc ferrite material can be prepared in a three-dimensional structure, but is highly brittle and easily broken, and must be designed with consideration for ensuring impact resistance.

In order to improve the wireless charging efficiency, it is very necessary to prepare the magnetic material into a three-dimensional structure, and the magnetic material with the three-dimensional structure is embedded in the coil, so that the magnetic leakage can be effectively reduced, and the electromagnetic induction efficiency is enhanced. Therefore, the key problem faced at present is to develop a three-dimensional structure magnetic composite material for use in the 150kHZ frequency band. The relative permeability of the existing magnetic composite material can reach more than 200, and although the magnetic composite material has a remarkable effect on the aspect of electromagnetic wave shielding, the magnetic composite material cannot be made into a three-dimensional structure with a high U value. Aiming at the magnetic composite material with a three-dimensional structure, the highest relative magnetic permeability currently reaches only about 40.

CN110060832A discloses a wireless charging module and a method for manufacturing a magnetic material thereof, where the wireless charging module includes a magnetic material and a coil winding disposed on the magnetic material, the magnetic material is a manganese-zinc ferrite magnetic material, the initial permeability of the manganese-zinc ferrite magnetic material is not less than 500, the magnetic loss is not more than 20, and the saturation magnetic field strength is not less than 0.45T. The wireless charging module has the advantages of high charging efficiency, large saturation current, and high center efficiency and center offset efficiency. And synchronously discloses a preparation method of a novel manganese-zinc ferrite magnetic material with three high and one low (high initial permeability, high frequency characteristic, high saturation magnetic field intensity and low magnetic loss) suitable for being used by a wireless charging module.

CN108231381A discloses a magnetic conductive sheet structure for wireless charging, which includes a first magnetic layer and a second magnetic layer stacked in sequence, wherein the magnetic conductivity and the thermal conductivity of the first magnetic layer are respectively smaller than those of the second magnetic layer. The magnetic permeability of the first magnetic layer and the second magnetic layer is designed in a gradient manner, the magnetic permeability of the second magnetic layer can be designed to be high so as to improve the shielding performance of the magnetic conducting sheet structure, and the magnetic permeability of the first magnetic layer can be designed to be low so as to reduce the generation of eddy current; the heat conductivity of the first magnetic layer and the second magnetic layer is gradually increased, and the temperature uniformity and the heat dissipation performance of the magnetic conductive sheet structure can be improved.

At present, wireless charging materials all have the problems of low magnetic permeability, poor toughness, low saturation magnetic flux density and the like, and cannot be made into a stable three-dimensional structure, so that the problem of wireless charging efficiency is urgently needed to be solved by developing a magnetic composite material with a high magnetic permeability and a three-dimensional structure.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a magnetic composite material three-dimensional structure, a processing method and application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a magnetic composite three-dimensional structure, the magnetic composite three-dimensional structure includes a bottom plate and a protrusion structure disposed on a surface of the bottom plate, the bottom plate and the protrusion structure both include a hot-pressing resin and a magnetic flake powder, and the magnetic flake powder is stacked and disposed in the hot-pressing resin; the plane of the flaky magnetic powder in the base plate is parallel to the plane of the base plate, and the plane of the flaky magnetic powder in the protruding structure is parallel to the side face of the protruding structure.

According to the invention, the hot-pressing resin is used as a matrix, the length direction of the flaky magnetic powder can be consistent with the three-dimensional structure of the magnetic composite material, so that a magnetic line loop is effectively formed in the three-dimensional structure direction, especially the middle part and the edge part can effectively form the bundling of magnetic lines, the magnetic leakage is reduced, and the wireless charging efficiency is improved; in addition, the hot-pressing resin can form a flowing molten state at high temperature and can be rapidly solidified after being cooled, so that the hot-pressing resin has strength and toughness, the problem that magnetic materials such as ferrite are brittle is avoided, and the use environment of wireless charging of intelligent wearable equipment is effectively improved.

As a preferred embodiment of the present invention, the thermocompression bonding resin includes an epoxy resin, preferably a polyimide and/or polyphenylene ether resin.

According to the invention, polyimide and/or polyphenylene ether resin is selected, a flowing melting state can be formed at a certain temperature, and the flowing melting state can ensure that the flaky magnetic powder is rearranged in the forming process, so that the arrangement of a micro three-dimensional structure is formed.

In a preferred embodiment of the present invention, the D50 of the magnetic powder in the form of flakes is 50 to 70 μm, for example, 50 μm, 52 μm, 54 μm, 56 μm, 58 μm, 60 μm, 62 μm, 64 μm, 66 μm, 68 μm or 70 μm.

Preferably, the thickness of the flaky magnetic powder is 1 μm or less, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1.0 μm.

Preferably, the oxygen content of the flaky magnetic powder is 2500ppm or less by mass, for example, 1000ppm, 1200ppm, 1400ppm, 1600ppm, 1800ppm, 2000ppm, 2200ppm, 2400ppm or 2500 ppm.

Preferably, the coercivity of the magnetic flake powder is 70A/m or less, but not 0, such as 10A/m, 20A/m, 30A/m, 40A/m, 50A/m, 60A/m or 70A/m.

Preferably, the material of the sheet-shaped magnetic powder comprises one or a combination of at least two of sendust, ferrosilicon chromium, iron nickel or iron nickel molybdenum.

As a preferred technical solution of the present invention, the protrusion structure is vertically disposed on the chassis.

Preferably, the raised structure is disposed along an edge of the chassis.

Preferably, the raised structure is disposed in the center of the chassis surface.

Preferably, the density of the three-dimensional structure of the magnetic composite material is 4.5-5.5 g/cm³For example, 4.5g/cm³、4.6g/cm³、4.7g/cm³、4.8g/cm³、4.9g/cm³、5.0g/cm³、5.1g/cm³、5.2g/cm³、5.3g/cm³、5.4g/cm³Or 5.5g/cm³。

In a second aspect, the present invention provides a method of processing a three-dimensional structure of a magnetic composite material as described in the first aspect, the method comprising:

preparing magnetic powder into flaky magnetic powder, mixing hot-pressing resin with the flaky magnetic powder under the action of a magnetic field to prepare magnetic particles with a flaky magnetic powder stacking structure, performing pre-pressing on a base plate and a protrusion structure by utilizing the magnetic particles, and performing hot-pressing on the base plate and the protrusion structure again to prepare the magnetic composite material three-dimensional structure.

According to the invention, the flaky magnetic powder and the hot-pressing resin are mixed and granulated, and the flaky magnetic powder can form an arrangement mode with a specific orientation under the action of a magnetic field, so that the flaky magnetic powder in the three-dimensional structure of the magnetic composite material can have the arrangement mode with the same orientation as the three-dimensional structure of the magnetic composite material during compression molding, and regular layered arrangement is formed; in addition, the chassis and the protrusion structure are prepared by step-by-step molding, namely respectively performing pre-pressing molding, and then the chassis and the protrusion structure are assembled into an integrated magnetic composite material three-dimensional structure by utilizing the high-temperature melting property of the hot-pressing resin, so that the length orientation direction of the flaky magnetic powder can be consistent with the magnetic composite material three-dimensional structure, a magnetic line loop is formed in the magnetic composite material three-dimensional structure direction, especially the middle part and the edge part can form a magnetic line cluster, the magnetic flux leakage is reduced, and the wireless charging efficiency is improved.

As a preferred embodiment of the present invention, the method for preparing the magnetic powder in a flake form comprises: spherical magnetic powder is prepared by vacuum gas atomization, and a flaky structure is formed by flattening treatment to prepare the flaky magnetic powder.

Preferably, the magnetic material powder in sheet form is subjected to a vacuum annealing treatment.

As a preferred embodiment of the present invention, the preparation of the magnetic particles comprises: under the action of a magnetic field, mixing the hot-pressing resin with a solvent, adding the flaky magnetic powder, stirring, volatilizing the solvent to obtain particles, and drying to obtain the magnetic particles.

Preferably, the mass of the hot-pressing resin is 3 to 15% of the mass of the sheet-like magnetic powder, for example, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%.

According to the invention, the mass of the hot-pressing resin is controlled to be 3-15% of that of the flaky magnetic powder, so that the magnetic powder can be bonded to form magnetic particles, the flaky magnetic powder has good arrangement orientation, and the requirement that the three-dimensional structure of the magnetic composite material has high density can be met in the forming process.

Preferably, the solvent comprises acetone and/or ethanol.

Preferably, the magnetic field has a strength of 0.05 to 0.3T, such as 0.05T, 0.07T, 0.09T, 0.11T, 0.13T, 0.15T, 0.17T, 0.19T, 0.21T, 0.23T, 0.25T, 0.27T, 0.29T, or 0.30T.

According to the invention, a magnetic field of 0.05-0.3T is added in the process of preparing the magnetic particles, so that the flaky magnetic powder has consistent alignment orientation, and if the magnetic field strength is lower than 0.05T, the alignment orientation of the flaky magnetic powder is inconsistent.

Preferably, the drying means is baking.

Preferably, the baking temperature is 40-70 ℃, for example 40 ℃, 42 ℃, 44 ℃, 46 ℃, 48 ℃, 50 ℃, 52 ℃, 54 ℃, 56 ℃, 58 ℃, 60 ℃, 62 ℃, 64 ℃, 66 ℃, 68 ℃ or 70 ℃.

Preferably, the baking time is 0.5-2 h, such as 0.5h, 0.7h, 0.9h, 1.1h, 1.3h, 1.5h, 1.7h, 1.9h or 2.0 h.

According to the invention, the magnetic particles are further baked at low temperature, so that the complete volatilization of the solvent is ensured, and the problems of cracking of the three-dimensional structure or poor appearance and the like of the magnetic composite material caused by the volatilization of the solvent in the pressing process are effectively avoided.

As a preferred technical solution of the present invention, the method for prepressing and forming the chassis includes: the prepressing forming method of the chassis comprises the following steps: and putting the magnetic particles into a die for prepressing and forming, and deforming the flaky magnetic powder along the width direction under the action of die pressure to enable the plane of the flaky magnetic powder to be parallel to the plane of the chassis, thus preparing the chassis.

Preferably, the method for pre-press forming the convex structure comprises the following steps: and applying a magnetic field in the vertical direction to the die, putting the magnetic particles into the die for pre-pressing and forming, wherein the length direction of the flaky magnetic powder is the same as the vertical magnetic field direction, and the plane of the flaky magnetic powder is parallel to the side surface of the convex structure, so that the convex structure is prepared.

Preferably, the pressure of the pre-pressing forming is 1 to 3 tons/cm²For example, 1.0 ton/cm²1.2 ton/cm²1.4 ton/cm²1.6 ton/cm²1.8 ton/cm²2.0 ton/cm²2.2 ton/cm²2.4 ton/cm²2.6 ton/cm²2.8 ton/cm²Or 3.0 tons/cm²。

It should be noted that, in the present invention, the pre-pressing molding is performed slowly, the molding pressure is controlled, and a gradual pressurization manner is adopted, so as to avoid the damage to the flaky magnetic powder formed with a stacked structure with a specific order in the magnetic particles due to an excessive sudden change of pressure.

Preferably, the method of hot press forming includes: and placing the convex structure and the chassis in a mold, placing the convex structure on the upper part of the chassis according to the mold structure, heating the mold, loading pressure after the heating temperature is reached, connecting the convex structure and the chassis, and finally performing compression molding to obtain the magnetic composite material three-dimensional structure.

According to the invention, the connection part of the convex structure and the chassis is heated and pressurized, the high-temperature melting property of the hot-pressing resin is utilized, so that the convex structure and the chassis are connected into a whole, and in addition, the flaky magnetic powder at the connection part is further arranged under the action of the magnetic field of the three-dimensional structure of the magnetic composite material to form a good magnetic line of force passage, thus the magnetic conductivity of the product is improved, the aggregation of the wirelessly charged magnetic lines of force is improved, and the wireless charging efficiency is effectively improved.

Preferably, the heating location comprises a junction of the raised structure and the chassis.

Preferably, the heating temperature is 130 to 180 ℃, such as 130 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃, 155 ℃, 160 ℃, 165 ℃, 170 ℃, 175 ℃ or 180 ℃.

Preferably, the pressure of the compression molding is 6-12 tons/cm²For example, 6.0 ton/cm²6.5 ton/cm²7.0 ton/cm²7.5 ton/cm²8.0 ton/cm²8.5 ton/cm²9.0 ton/cm²9.5 ton/cm²10.0 ton/cm²10.5 ton/cm²11.0 ton/cm²11.5 ton/cm²Or 12.0 tons/cm²。

As a preferred technical solution of the present invention, the processing method specifically includes the steps of:

preparing spherical magnetic powder by vacuum gas atomization, forming a sheet structure by flattening treatment, and preparing the sheet magnetic powder by vacuum annealing treatment;

(II) under the action of a magnetic field of 0.05-0.3T, mixing hot-pressing resin with a solvent, adding flaky magnetic powder, stirring, wherein the mass of the hot-pressing resin is 3-15% of that of the flaky magnetic powder, volatilizing the solvent to obtain particles, and baking at 40-70 ℃ for 0.5-2 h to obtain the magnetic particles;

(III) putting the magnetic particles into a mould for prepressing and forming at 1-3 tons/cm²Under the action of the pressure, the flaky magnetic powder deforms and rotates along the width direction, so that the plane where the flaky magnetic powder is located is parallel to the plane where the chassis is located, the chassis is prepared, a magnetic field in the vertical direction is applied to the mold, and the magnetic particles are placed in the mold at the speed of 1-3 tons/cm²Carrying out pre-pressing molding, wherein the length direction of the flaky magnetic powder is the same as the vertical magnetic field direction, and the plane of the flaky magnetic powder is parallel to the side surface of the convex structure, so as to prepare the convex structure;

(IV) placing the protruding structure and the chassis in a mould, heating the mould where the connecting position of the protruding structure and the chassis is located to 130-180 ℃, pressurizing to connect the protruding structure and the chassis, and finally, when the pressure reaches 6-12 tons/cm²And carrying out lower compression molding to obtain the three-dimensional structure of the magnetic composite material.

In a third aspect, the present invention provides a use of the magnetic composite three-dimensional structure according to the first aspect for wireless charging.

The recitation of numerical ranges herein includes not only the above-recited numerical values, but also any numerical values between non-recited numerical ranges, and is not intended to be exhaustive or to limit the invention to the precise numerical values encompassed within the range for brevity and clarity.

Compared with the prior art, the invention has the beneficial effects that:

(1) according to the invention, the hot-pressing resin is used as a matrix, the length direction of the flaky magnetic powder can be consistent with the three-dimensional structure of the magnetic composite material, so that a magnetic line loop is effectively formed in the three-dimensional structure direction, especially the middle part and the edge part can effectively form the bundling of magnetic lines, the magnetic leakage is reduced, and the wireless charging efficiency is improved; in addition, the hot-pressing resin can form a flowing molten state at high temperature and can be rapidly solidified after being cooled, so that the hot-pressing resin has strength and toughness, the problem that magnetic materials such as ferrite are brittle is avoided, and the use environment of wireless charging of intelligent wearable equipment is effectively improved.

(2) According to the invention, the flaky magnetic powder and the hot-pressing resin are mixed and granulated, and the flaky magnetic powder can form an arrangement mode with a specific orientation under the action of a magnetic field, so that the flaky magnetic powder in the three-dimensional structure of the magnetic composite material can have the arrangement mode with the same orientation as the three-dimensional structure of the magnetic composite material during compression molding, and regular layered arrangement is formed; in addition, the chassis and the protrusion structure are prepared by step-by-step molding, namely respectively performing pre-pressing molding, and then the chassis and the protrusion structure are assembled into an integrated magnetic composite material three-dimensional structure by utilizing the high-temperature melting property of the hot-pressing resin, so that the length orientation direction of the flaky magnetic powder can be consistent with the magnetic composite material three-dimensional structure, a magnetic line loop is formed in the magnetic composite material three-dimensional structure direction, especially the middle part and the edge part can form a magnetic line cluster, the magnetic flux leakage is reduced, and the wireless charging efficiency is improved.

Drawings

FIG. 1 is a schematic cross-sectional view of a three-dimensional structure of a magnetic composite material provided in an embodiment of the present invention;

fig. 2 is a schematic diagram of a three-dimensional structure of a magnetic composite material according to an embodiment of the present invention.

Wherein, 1-chassis; 2-a raised structure; 3-magnetic powder in flake form.

Detailed Description

It is to be understood that in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be taken as limiting the present invention.

It should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "disposed," "connected" and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The technical solution of the present invention is further explained by the following embodiments.

In one embodiment, the present invention provides a magnetic composite three-dimensional structure, as shown in fig. 1, the magnetic composite three-dimensional structure includes a bottom plate 1 and a protrusion structure 2 disposed on a surface of the bottom plate 1, the bottom plate 1 and the protrusion structure 2 each include a hot-pressing resin and a flake magnetic powder 3, and the flake magnetic powder 3 is stacked and disposed in the hot-pressing resin; the plane of the flaky magnetic powder 3 in the base plate 1 is parallel to the plane of the base plate 1, and the plane of the flaky magnetic powder 3 in the convex structure 2 is parallel to the side surface of the convex structure 2.

According to the invention, the hot-pressing resin is used as a matrix, the length direction of the flaky magnetic powder 3 can be consistent with the three-dimensional structure of the magnetic composite material, so that a magnetic line loop is effectively formed in the three-dimensional structure direction, especially the middle part and the edge part can effectively form the bundling of magnetic lines, the magnetic leakage is reduced, and the wireless charging efficiency is improved; in addition, the hot-pressing resin can form a flowing molten state at high temperature and can be rapidly solidified after being cooled, so that the hot-pressing resin has strength and toughness, the problem that magnetic materials such as ferrite are brittle is avoided, and the use environment of wireless charging of intelligent wearable equipment is effectively improved.

Further, the thermocompression resin includes an epoxy resin, preferably a polyimide and/or polyphenylene ether resin. According to the invention, polyimide and/or polyphenylene ether resin is selected, a flowing melting state can be formed at a certain temperature, and the flowing melting state can ensure that the flaky magnetic powder 3 is rearranged in the forming process, so that the arrangement of a micro three-dimensional structure is formed.

Furthermore, the D50 of the flaky magnetic powder 3 is 50-70 μm, the thickness of the flaky magnetic powder 3 is less than or equal to 1 μm, the oxygen mass content of the flaky magnetic powder 3 is less than or equal to 2500ppm, and the coercive force of the flaky magnetic powder 3 is less than or equal to 70A/m. The sheet-shaped magnetic powder 3 is made of one or a combination of at least two of iron-silicon-aluminum, iron-silicon-chromium, iron-nickel or iron-nickel-molybdenum.

Further, as shown in fig. 2, the protruding structure 2 is vertically disposed on the chassis 1; the raised structure 2 is disposed along an edge of the chassis 1. The convex structure 2 is arranged in the center of the surface of the chassis 1.

Further, the density of the three-dimensional structure of the magnetic composite material is 4.5-5.5 g/cm³。

In another embodiment, the present invention provides a method for processing a three-dimensional structure of a magnetic composite material, wherein the method specifically comprises the following steps:

preparing spherical magnetic powder by vacuum gas atomization, forming a sheet structure by flattening treatment, and preparing the sheet magnetic powder 3 by vacuum annealing heat treatment;

(II) under the action of a magnetic field of 0.05-0.3T, mixing hot-pressing resin and a solvent, adding flaky magnetic powder 3, stirring, wherein the mass of the hot-pressing resin is 3-15% of that of the flaky magnetic powder 3, volatilizing the solvent to obtain particles, and baking at 40-70 ℃ for 0.5-2 hours to obtain the magnetic particles;

(III) putting the magnetic particles into a mould for prepressing and forming at 1-3 tons/cm²Under the action of the pressure, the flaky magnetic powder 3 deforms and rotates along the width direction, so that the plane of the flaky magnetic powder 3 is parallel to the plane of the chassis 1 to prepare the chassis 1, a magnetic field in the vertical direction is applied to the mold, and the magnetic particles are placed in the mold at the speed of 1-3 tons/cm²Performing pre-pressing molding, wherein the length direction of the flaky magnetic powder 3 is the same as the vertical magnetic field direction, and the plane of the flaky magnetic powder 3 is parallel to the side surface of the convex structure 2, so as to prepare the convex structure 2;

(IV) placing the convex structure 2 and the chassis 1 in a mould, heating the mould where the connecting position of the convex structure 2 and the chassis 1 is located to 130-180 ℃, then pressurizing to connect the convex structure and the chassis, and finally, when the pressure reaches 6-12 tons/cm²And carrying out lower compression molding to obtain the three-dimensional structure of the magnetic composite material.

The invention also provides application of the magnetic composite material three-dimensional structure, and the magnetic composite material three-dimensional structure is used for wireless charging.

Example 1

The embodiment provides a three-dimensional structure of a magnetic composite material, which is based on a specific embodiment, wherein the hot-pressing resin is polyimide; d50 of the magnetic flake powder 3 was 70 μm, the thickness of the magnetic flake powder 3 was 0.5. mu.m, the oxygen content of the magnetic flake powder 3 was 1250ppm by mass, and the coercive force of the magnetic flake powder 3 was 35A/m. The sheet-shaped magnetic powder 3 is made of sendust.

Four convex structures 2 are uniformly arranged along the edge of the chassis 1, the center of the surface of the chassis 1 is provided with one convex structure 2, and the density of the three-dimensional structure of the magnetic composite material is 5.0g/cm³。

The embodiment also provides a processing method of the three-dimensional structure of the magnetic composite material, which specifically comprises the following steps:

preparing spherical magnetic powder by vacuum gas atomization, forming a sheet structure by flattening treatment, and preparing the sheet magnetic powder 3 by vacuum annealing heat treatment;

(II) under the action of a 0.15T magnetic field, mixing hot-pressing resin with ethanol, adding the flaky magnetic powder 3, stirring, volatilizing a solvent to obtain particles, and baking at 55 ℃ for 1.2h to obtain the magnetic particles;

(III) putting the magnetic particles into a mould for prepressing and forming at 2 tons/cm²Under the action of the pressure, the flaky magnetic powder 3 deforms and rotates along the width direction, so that the plane of the flaky magnetic powder 3 is parallel to the plane of the base plate 1 to prepare the base plate 1, a magnetic field in the vertical direction is applied to the die, and the magnetic particles are placed in the die at 2 tons/cm²Performing pre-pressing molding, wherein the length direction of the flaky magnetic powder 3 is the same as the vertical magnetic field direction, and the plane of the flaky magnetic powder 3 is parallel to the side surface of the convex structure 2, so as to prepare the convex structure 2;

(IV) placing the convex structure 2 and the chassis 1 in a mould, heating the mould where the connecting position of the convex structure 2 and the chassis 1 is positioned to 155 ℃, then pressurizing to connect the convex structure and the chassis, and finally, when the pressure reaches 9 tons/cm²And carrying out lower compression molding to obtain the three-dimensional structure of the magnetic composite material.

Example 2

This example provides a three-dimensional structure of a magnetic composite material, according to one embodiment, wherein the thermal compression resin is polyphenylene oxide; d50 of the magnetic flake powder 3 was 50 μm, the thickness of the magnetic flake powder 3 was 1 μm, the oxygen content of the magnetic flake powder 3 was 1000ppm by mass, and the coercive force of the magnetic flake powder 3 was 10A/m. The sheet-shaped magnetic powder 3 is made of sendust.

Four convex structures 2 are uniformly arranged along the edge of the chassis 1, the center of the surface of the chassis 1 is provided with one convex structure 2, and the density of the three-dimensional structure of the magnetic composite material is 5.4g/cm³。

The embodiment also provides a processing method of the three-dimensional structure of the magnetic composite material, which specifically comprises the following steps:

preparing spherical magnetic powder by vacuum gas atomization, forming a sheet structure by flattening treatment, and preparing the sheet magnetic powder 3 by vacuum annealing heat treatment;

(II) under the action of a 0.05T magnetic field, mixing hot-pressing resin with ethanol, adding the flaky magnetic powder 3, stirring, volatilizing a solvent to obtain particles, and baking at 40 ℃ for 2 hours to obtain the magnetic particles;

(III) putting the magnetic particles into a mould for prepressing and forming at 1 ton/cm²Under the action of the pressure, the flaky magnetic powder 3 deforms and rotates along the width direction, so that the plane of the flaky magnetic powder 3 is parallel to the plane of the base plate 1 to prepare the base plate 1, a magnetic field in the vertical direction is applied to the die, and the magnetic particles are placed in the die at 1 ton/cm²Performing pre-pressing molding, wherein the length direction of the flaky magnetic powder 3 is the same as the vertical magnetic field direction, and the plane of the flaky magnetic powder 3 is parallel to the side surface of the convex structure 2, so as to prepare the convex structure 2;

(IV) placing the convex structure 2 and the chassis 1 in a mould, heating the mould where the connecting position of the convex structure 2 and the chassis 1 is positioned to 130 ℃, then pressurizing to connect the convex structure and the chassis, and finally, when the pressure reaches 6 tons/cm²And carrying out lower compression molding to obtain the three-dimensional structure of the magnetic composite material.

Example 3

This example provides a three-dimensional structure of a magnetic composite material, according to a specific embodiment, wherein the hot-pressing resin is polyimide and polyphenylene oxide at a mass ratio of 1: 1; d50 of the magnetic flake powder 3 was 100. mu.m, the thickness of the magnetic flake powder 3 was 0.1. mu.m, the oxygen content of the magnetic flake powder 3 was 2500ppm by mass, and the coercive force of the magnetic flake powder 3 was 70A/m. The sheet-shaped magnetic powder 3 is made of sendust.

Four convex structures 2 are uniformly arranged along the edge of the chassis 1, the center of the surface of the chassis 1 is provided with one convex structure 2, and the density of the three-dimensional structure of the magnetic composite material is 4.5g/cm³。

The embodiment also provides a processing method of the three-dimensional structure of the magnetic composite material, which specifically comprises the following steps:

preparing spherical magnetic powder by vacuum gas atomization, forming a sheet structure by flattening treatment, and preparing the sheet magnetic powder 3 by vacuum annealing heat treatment;

(II) under the action of a 0.3T magnetic field, mixing hot-pressing resin with acetone, adding the flaky magnetic powder 3, stirring, volatilizing a solvent to obtain particles, and baking at 70 ℃ for 0.5h to obtain the magnetic particles;

(III) putting the magnetic particles into a mould for prepressing and forming at 3 tons/cm²Under the action of the pressure, the flaky magnetic powder 3 deforms and rotates along the width direction, so that the plane of the flaky magnetic powder 3 is parallel to the plane of the base plate 1 to prepare the base plate 1, a magnetic field in the vertical direction is applied to the mold, and the magnetic particles are placed in the mold at 3 tons/cm²Performing pre-pressing molding, wherein the length direction of the flaky magnetic powder 3 is the same as the vertical magnetic field direction, and the plane of the flaky magnetic powder 3 is parallel to the side surface of the convex structure 2, so as to prepare the convex structure 2;

(IV) placing the convex structure 2 and the chassis 1 in a mould, heating the mould where the connecting position of the convex structure 2 and the chassis 1 is to 180 ℃, pressurizing to connect the convex structure and the chassis, and finally, when the pressure reaches 12 tons/cm²And carrying out lower compression molding to obtain the three-dimensional structure of the magnetic composite material.

Example 4

This example provides a three-dimensional structure of a magnetic composite material, which is different from example 1 in that the mass of the hot-press resin in the processing method is 2% of the mass of the flaky magnetic powder 3, and the rest of the structure and parameters are identical to those of example 1.

Example 5

This example provides a three-dimensional structure of a magnetic composite material, which is different from example 1 in that the mass of the hot-press resin in the processing method is 20% of the mass of the magnetic powder in the form of a sheet 3, and the rest of the structure and parameters are identical to those of example 1.

Comparative example 1

This comparative example provides a three-dimensional structure of a magnetic composite material, which is different from example 1 in that the preparation of magnetic particles in the processing method is not performed under the action of a magnetic field.

The performance detection method of the magnetic composite material three-dimensional structure prepared in the above examples and comparative examples includes: testing the density of the composite material, namely performing density analysis on the three-dimensional structure material by adopting a densimeter through a drainage method; the magnetic conductivity adopts a fixed coil to be sleeved in a three-dimensional structure of the magnetic composite material for inductance test (test equipment is HIOKI IM7581), the contrast inductance is high and low to represent the height of the magnetic conductivity, wherein the coil adopts a wire diameter of 0.5mm, and the number of winding turns is 10.

The test results are shown in table 1.

TABLE 1

From the above table, it can be seen that:

(1) compared with the examples 4 and 5, the example 1 has obviously better inductance than the examples 4 and 5, although the example 4 has equivalent inductance to the example 1, the toughness is low, and the problem of easy crushing exists, so the invention can ensure that the magnetic powder is bonded to form the magnetic particles by controlling the mass of the hot-pressing resin to be 3-15% of the mass of the flaky magnetic powder 3, and the flaky magnetic powder 3 has good arrangement orientation, and can meet the requirement that the three-dimensional structure of the magnetic composite material has high density in the molding process. If the mass of the hot-pressing resin is less than 3% of the mass of the flaky magnetic powder 3, the magnetic particles formed by bonding are unstable, and the molding effect is poor; if the mass of the hot-pressing resin is higher than 15% of the mass of the flaky magnetic powder 3, the amount of the hot-pressing resin is large, resulting in low density of the three-dimensional structure of the magnetic composite material and affecting the magnetic effect.

(2) Compared with the comparative example 1, the sensing amount of the example 1 is obviously better than that of the comparative example 1, so that the flaky magnetic powder 3 is mixed and granulated with the hot-pressing resin, the flaky magnetic powder 3 can form a specific orientation arrangement mode under the action of a magnetic field, and the flaky magnetic powder 3 in the three-dimensional structure of the magnetic composite material can have the same orientation arrangement mode as the three-dimensional structure of the magnetic composite material during compression molding to form regular layered arrangement.

Through the embodiment and the comparative example, the length direction of the flaky magnetic powder 3 can be consistent with the three-dimensional structure of the magnetic composite material by using the hot-pressing resin as the matrix, so that a magnetic line loop is effectively formed in the three-dimensional structure direction, and especially the middle part and the edge part can effectively form the clustering of magnetic lines, thereby reducing the magnetic leakage and improving the wireless charging efficiency; in addition, the hot-pressing resin can form a flowing molten state at high temperature and can be rapidly solidified after being cooled, so that the hot-pressing resin has strength and toughness, the problem that magnetic materials such as ferrite are brittle is avoided, and the use environment of wireless charging of intelligent wearable equipment is effectively improved.

In addition, the chassis 1 and the protrusion structure 2 are prepared by step-by-step molding, namely respectively performing pre-pressing molding, and then the chassis 1 and the protrusion structure 2 are assembled into an integrated magnetic composite three-dimensional structure by utilizing the high-temperature melting property of the hot-pressing resin, so that the length orientation direction of the sheet-shaped magnetic powder 3 can be ensured to be consistent with the magnetic composite three-dimensional structure, a magnetic line loop is formed in the magnetic composite three-dimensional structure, especially the middle part and the edge part can form a cluster of magnetic lines, the magnetic flux leakage is reduced, and the wireless charging efficiency is improved.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.