WO2022241736A1

WO2022241736A1 - Magnetic powder for manufacturing magnet, and magnet and magnetic element

Info

Publication number: WO2022241736A1
Application number: PCT/CN2021/094984
Authority: WO
Inventors: 姚骋; 刘宁; 蒋帆; 胡章荣; 吴琨
Original assignee: 华为技术有限公司
Priority date: 2021-05-20
Filing date: 2021-05-20
Publication date: 2022-11-24
Also published as: CN116670314A

Abstract

The embodiments of the present application provide a magnetic powder for manufacturing a magnet, the magnetic powder comprising a first soft magnetic powder and a second soft magnetic powder, wherein the first soft magnetic powder is a metal crystal soft magnetic material, the second soft magnetic powder comprises at least one of an amorphous soft magnetic material and a nanocrystalline soft magnetic material, and the mass of the first soft magnetic powder accounts for 5%-45% of the sum of the mass of the first soft magnetic powder and the second soft magnetic powder. The magnetic powder can achieve a better molding effect and takes into consideration a higher saturation magnetic flux density and a lower high-frequency loss, etc. The present application further provides a magnet, a magnetic element, and an electronic device.

Description

Magnetic powders, magnets and magnetic components for the manufacture of magnets

technical field

The present application relates to the technical field of semiconductors, in particular to a magnetic powder for manufacturing a magnet, a magnet and a magnetic element.

Background technique

Electronic devices such as mobile phones, tablet computers, and notebook computers are developing in the direction of thinner and lighter, and correspondingly, magnetic components such as inductors used in their internal power circuits should also meet the requirements of miniaturization, thinning, and high functionality. However, when the inductors made of magnetic materials meet the requirements of miniaturization and thinning, the inductance performance will usually deteriorate due to the reduction of magnetic materials used in the inductor, such as the decrease of saturation current, the increase of DC resistance, and the high loss. .

Contents of the invention

In view of this, the embodiment of the present application provides a magnetic powder for manufacturing magnets, which has high saturation magnetic flux density, low magnetic loss factor, high resistivity, and good processability, and can be used to manufacture magnets with high packing density, and then make The inductance of magnetic components such as inductors is improved, the DC resistance is reduced, the loss is reduced, and the efficiency is improved.

The first aspect of the embodiment of the present application provides a magnetic powder for manufacturing a magnet, the magnetic powder includes a first soft magnetic powder and a second soft magnetic powder, the first soft magnetic powder is a metal crystal soft magnetic material, The second soft magnetic powder includes at least one of an amorphous soft magnetic material and a nanocrystalline soft magnetic material, and the mass of the first soft magnetic powder accounts for 1% of the mass of the first soft magnetic powder and the second soft magnetic powder 5%-45% of the sum of the masses.

Metal crystal soft magnetic materials have good flexibility, strong deformation ability, high saturation magnetic flux density (Bs), low frequency loss of amorphous soft magnetic materials and nanocrystalline soft magnetic materials, through the suitable compounding of the above two types of soft magnetic powders , can combine the advantages of various materials, can ensure that the obtained magnetic powder can achieve better molding effect, and take into account the higher Bs and lower high-frequency loss.

In some embodiments of the present application, the mass of the first soft magnetic powder accounts for 10%-40% of the sum of the mass of the first soft magnetic powder and the second soft magnetic powder. At this time, the magnetic powder can better balance good molding effect, higher Bs and lower high-frequency loss.

In an embodiment of the present application, the D50 particle size of the second soft magnetic powder is larger than the D50 particle size of the first soft magnetic powder. D50 The first soft magnetic powder with small particle size and good flexibility is easy to fill in the interparticle spaces of the second soft magnetic powder, which is beneficial to increase the compaction density of the magnetic powder.

In an embodiment of the present application, the D50 particle size of the second soft magnetic powder is 2-5 times the D50 particle size of the first soft magnetic powder. At this time, the above-mentioned magnetic powder can be compacted to form a relatively dense packing, thereby increasing the density and magnetic permeability of the obtained magnet.

In the embodiment of the present application, the D50 particle size of the first soft magnetic powder is in the range of 1 μm-10 μm; the D50 particle size of the second soft magnetic powder is in the range of 5 μm-20 μm. With the help of the special D50 particle size range of these two soft magnetic powders, the above-mentioned magnetic powders can be compacted to form relatively dense packing, which can increase the density and magnetic permeability of the obtained magnets, reduce losses, etc.

In some embodiments of the present application, in the second soft magnetic powder, the mass of the amorphous soft magnetic material is 0.5-1.5 times that of the nanocrystalline soft magnetic material. At this time, the magnetic powder composed of the second soft magnetic powder and the first soft magnetic powder can have higher resistivity and lower coercive force, and better high-frequency loss performance.

In the implementation manner of the present application, the saturation magnetic flux density of the metal crystal soft magnetic material is greater than or equal to 1.35T. Combining the first soft magnetic powder with high Bs with the second soft magnetic powder is beneficial to increase the Bs of the obtained magnetic powder, which in turn is beneficial to improve the saturation characteristics and inductance of the inductor made from the magnetic powder.

In the embodiment of the present application, the saturation magnetic flux density of the amorphous soft magnetic material and the nanocrystalline soft magnetic material is greater than or equal to 1.2T, and the unit power loss of the amorphous soft magnetic material and the nanocrystalline soft magnetic material is equal to The unit power loss ratio of Fe _95.5 Si _4.5 is less than or equal to 0.5. At this time, the second soft magnetic powder cooperates with the above-mentioned first soft magnetic powder to ensure that the magnetic powder has relatively low magnetic loss performance while having a large Bs.

In the implementation manner of the present application, the metal crystal soft magnetic material includes at least one of carbonyl iron, iron-silicon alloy, iron-nickel alloy and iron-silicon-chromium alloy.

In some embodiments of the present application, the amorphous soft magnetic material includes at least one of Fe-Ni-B system, Fe-Ni-Si-B-P-C system, and Fe-Si-B-Cr-C system.

In the embodiment of the present application, the constituent elements of the nanocrystalline soft magnetic material include a first element, a second element, and a third element, wherein the first element includes at least one of Fe, Co, and Ni, and Fe must be contained, the second element includes at least one of Si, B, C, and P, and the third element includes at least one of Cr, Cu, Nb, V, and Zr.

In some embodiments of the present application, the nanocrystalline soft magnetic material includes Fe-B-Cu-C system, Fe-Zr-B-Cu system, Fe-Si-B-Cu-P system and Fe-Si-B- At least one of the Cu-Nb system.

In the implementation manner of the present application, the surfaces of the first soft magnetic powder and the second soft magnetic powder both have an insulating coating layer. The insulating coating layer can endow each soft magnetic material with good insulation. When the subsequent magnetic components such as inductors made of the magnetic powder are applied with voltage, the eddy current between the contact particles is small, and the inductance loss caused by it is small. And the inductance has a strong ability to withstand voltage breakdown.

In the embodiment of the present application, the material of the insulating coating layer includes one or more of phosphoric acid, sulfuric acid, nitric acid, chromic acid, phosphate, silicate, nitrate, chromate, and inorganic oxides.

The second aspect of the embodiment of the present application provides a magnet, which is obtained by molding a magnetic composite material, wherein the magnetic composite material includes the magnetic powder and the binder described in the first aspect of the present application.

In the embodiment of the present application, the binder is selected from at least one of epoxy resin, phenolic resin, silicone resin, acrylic resin, cyanate resin, polyimide, polyphenylene sulfide and their modified products. kind. The existence of the binder can improve the forming effect of the magnetic composite material.

The magnet provided in the second aspect of the embodiment of the present application has a high density, and the magnet can be used to realize the preparation of a magnetic element with excellent performance, for example, an inductor with excellent magnetic properties such as high inductance and low high-frequency loss can be produced.

The third aspect of the embodiment of the present application provides a magnetic element, the magnetic element includes the magnet as described in the second aspect of the application and a coil arranged in the magnet.

In the implementation manner of the present application, the magnetic element includes an inductor.

The fourth aspect of the embodiment of the present application provides an electronic device, the electronic device includes the magnetic element and the circuit board according to the third aspect of the application, and the magnetic element is arranged on the circuit board.

Since the above-mentioned magnetic components such as inductors with excellent performance are used in the electronic equipment, the electronic equipment can realize high-speed and large-capacity operation and ensure quality and reliability.

Description of drawings

FIG. 1 is a schematic structural diagram of an electronic device provided in an embodiment of the present application;

Figure 2a is a schematic structural view of an inductor used in an electronic device;

Fig. 2b is another schematic structural diagram of the inductor in Fig. 2a;

FIG. 3 is a schematic diagram of another structure of an inductor used in an electronic device.

Detailed ways

Please refer to FIG. 1 . FIG. 1 is a schematic structural diagram of an electronic device 100 provided in an embodiment of the present application. The electronic device 100 may be a mobile phone, a tablet computer, a notebook computer, a wearable device (such as a smart watch), a smart TV, a vehicle device (such as a driving recorder), a server and other electronic products. In the embodiment of the present application, description is made by taking the electronic device 100 as a mobile phone as an example.

As shown in FIG. 1 , in some embodiments, an electronic device 100 includes a housing 11 assembled outside the electronic device, and components such as circuit boards and batteries inside the housing 11 (not shown in FIG. 1 ). The battery is electrically connected to the circuit board for powering the electronic device 100 . Wherein, the circuit board of the electronic device 100 may be provided with a magnetic element, and the magnetic element may be an inductor, a wave absorbing sheet, a wireless charging magnetic sheet, an antenna magnetic core, and the like. In the embodiment of the present application, description is made by taking the magnetic element as an inductor as an example.

For example, the electronic device 100 generally requires a power supply circuit using a DC (direct current)/DC converter to obtain operating power with various voltage levels required in internal circuits. Wherein, the DC/DC converter can convert the high-voltage DC voltage into a low-voltage DC voltage for use by the chip. In such a power supply circuit, magnetic components such as inductors that can withstand high frequency and high current are required to realize electromagnetic signal and voltage conversion.

FIG. 2a, FIG. 2b, and FIG. 3 show several structural schematic diagrams of power inductors (ie, chip inductors). Among them, Fig. 2a and Fig. 2b are specifically molded inductors made by compression molding, and Fig. 3 is a thin film inductor made by tape casting. In general, the power inductor 200 includes a magnet 20 and a coil (or winding) 30 as an electrical conductor. In FIG. 2 a , the coil 30 is embedded in the magnet 20 , and the coil 30 may have a pair of lead-out

terminals

31 and 32 protruding from the magnet 20 . The inductor 200 may also include an external electrode 240 (see FIG. 2 b ), which may be connected to the externally exposed

lead terminals

31 and 32 of the coil 30. The external electrode 240 is provided with a coating for connecting with other devices, and the coating may specifically be It is nickel plating and tin plating. In FIG. 3 , the magnets 20 are in sheet shape, and the coil 30 disposed on the base 40 is sandwiched between the two magnets 20 to form a sandwich structure.

The magnet 20 is generally made of a magnetic composite material including magnetic material powder and a binder such as resin. At present, some magnetic materials that form magnets cannot take into account high saturation magnetic flux density (Bs) and low high-frequency loss. Therefore, the inductance formed by the magnet has low DC resistance, low inductance, and high loss, thereby reducing the electron density. The conversion efficiency of the power supply system of the equipment affects the high-speed and large-capacity operation of its CPU. Based on this, the embodiment of the present application provides a magnetic powder that is more suitable for manufacturing an induction magnet.

Specifically, the magnetic powder provided by this application includes a first soft magnetic powder and a second soft magnetic powder, the first soft magnetic powder is a metal crystal soft magnetic material, and the second soft magnetic powder includes an amorphous soft magnetic material and at least one of the nanocrystalline soft magnetic materials, the mass of the first soft magnetic powder accounts for 5%-45% of the sum of the mass of the first soft magnetic powder and the second soft magnetic powder.

In this application, nanocrystalline soft magnetic material refers to a soft magnetic material with a grain size of nanoscale (1nm-100nm), and an amorphous structure at the grain boundary; atoms in the amorphous soft magnetic material are long-range disordered and short-range ordered Therefore, the resistivity of amorphous soft magnetic materials and nanocrystalline soft magnetic materials is higher, and the high-frequency loss performance is better than that of metal crystal soft magnetic materials. The metal crystal soft magnetic material has a larger grain size and a crystal structure arranged in a certain period, so the resistivity is lower and the high frequency loss is high; but due to the high content of Fe in the metal crystal soft magnetic material, compared with the amorphous /Nanocrystalline soft magnetic materials are easier to process and shape, while amorphous/nanocrystalline soft magnetic materials have high hardness and low deformation under pressure.

In this application, the second soft magnetic powder composed of at least one of amorphous soft magnetic material and nanocrystalline soft magnetic material is mixed with the first soft magnetic powder composed of metal crystal soft magnetic material, which can combine the advantages of various materials, Complementing the deficiency when there is a single material powder, wherein, the existence of the first soft magnetic powder can facilitate the molding of the magnetic powder during the compaction process, so that the compaction density of the magnetic powder can be effectively improved, and it is beneficial to improve the sensitivity of the formed magnet. Quantity, improve the mechanical strength, and also help to reduce the gap of the magnetic powder after pressing, and help to reduce the magnetic loss performance. And the mass ratio of the first soft magnetic powder is controlled in the range of 5%-45%, which can avoid that the molding effect of the magnetic powder cannot be effectively improved when the content is too low, and the compression molding pressure of the magnetic powder will not be too high , and can avoid that when its content is too high, it is not conducive to reducing the magnetic loss performance of the magnetic powder because of its large loss, and avoiding that its magnetic performance may not be as good as that of a single second soft magnetic powder.

In the present application, the mass of the above-mentioned first soft magnetic powder may account for 6%, 8%, 10%, 12%, 15%, 20% of the sum of the mass of the above-mentioned first soft magnetic powder and the above-mentioned second soft magnetic powder , 25%, 30%, 35%, 40% or 45%, etc. In some embodiments, the mass of the first soft magnetic powder may account for 10%-40% of the sum of the mass of the first soft magnetic powder and the second soft magnetic powder. At this time, the magnetic powder composed of the first soft magnetic powder and the second soft magnetic powder can better integrate the advantages of various materials, better take into account the good molding effect, higher Bs and lower high-frequency loss .

Among them, the meaning of "the second soft magnetic powder includes at least one of amorphous soft magnetic material and nanocrystalline soft magnetic material" in this application is explained as follows: the second soft magnetic powder can be made from amorphous soft magnetic material and At least one selected from the group consisting of nanocrystalline soft magnetic materials may specifically include the following three situations: a) the second soft magnetic powder only includes amorphous soft magnetic materials; or b) the second soft magnetic powder only includes It includes nanocrystalline soft magnetic material; or c) the second soft magnetic powder includes both amorphous soft magnetic material and nanocrystalline soft magnetic material. Similarly, when the similar expression "comprising at least one of A, B and C" appears in this application, it means that at least one can be selected from the group consisting of A, B and C, specifically it can be optional One, or choose two, ..., or choose all.

In some embodiments of the present application, in the second soft magnetic powder, the mass of the amorphous soft magnetic material is 0.5-1.5 times that of the nanocrystalline soft magnetic material. At this time, the magnetic powder composed of the second soft magnetic powder and the first soft magnetic powder can have higher resistivity and lower coercive force, and better high-frequency loss performance. In some embodiments, the mass of the amorphous soft magnetic material is 0.5-1 times that of the nanocrystalline soft magnetic material. In the presence of a certain amount of the first soft magnetic powder, the nanocrystalline soft magnetic material with a larger mass proportion in the second soft magnetic powder is more conducive to the improvement of the magnetic properties of the magnetic powder.

In an embodiment of the present application, the D50 particle size of the second soft magnetic powder is larger than the D50 particle size of the first soft magnetic powder. In this way, the first soft magnetic powder with small D50 particle size and good flexibility can be more easily filled into the interparticle spaces of the second soft magnetic powder, which is beneficial to increase the compaction density of the magnetic powder. The term "D50 particle size" is a typical value representing the size of the particle size, which can also be called the median particle size, which specifically refers to the particle size corresponding to when the cumulative particle size distribution percentage of a sample reaches 50%.

In some embodiments of the present application, the D50 particle size of the second soft magnetic powder is 2-5 times the D50 particle size of the first soft magnetic powder. At this time, the magnetic powder composed of the first soft magnetic powder and the second soft magnetic powder can be compacted to form a denser packing, with fewer gaps between the magnetic powders, thereby increasing the density and magnetic permeability of the obtained magnet. In some embodiments, the D50 particle size of the second soft magnetic powder is 2-4.5 times the D50 particle size of the first soft magnetic powder.

In some embodiments of the present application, the D50 particle size of the first soft magnetic powder is in the range of 1 μm-10 μm. The D50 particle size of the second soft magnetic powder is in the range of 5 μm-20 μm. With the help of the special D50 particle size range of these two soft magnetic powders, during the pressing process of the magnetic powders, these two soft magnetic powders can form relatively dense packing, which can greatly increase the pressing density of the magnetic powders and increase the density of the obtained magnets And magnetic permeability, reduce loss.

In the embodiment of the present application, the Bs of the metal crystal soft magnetic material is greater than or equal to 1.35T. In some embodiments, the Bs of the metal crystal soft magnetic material is greater than or equal to 1.5T, for example, 1.6-2T. Combining the first soft magnetic powder with high Bs and the second soft magnetic powder is beneficial to increase the Bs of the obtained magnetic powder, which in turn is beneficial to improve the saturation induction characteristics of the inductor made from the magnetic powder.

In the embodiment of the present application, the Bs of the amorphous soft magnetic material and the nanocrystalline soft magnetic material is greater than or equal to 1.2T, and the ratio between the unit power loss of the amorphous soft magnetic material and the nanocrystalline soft magnetic material and the unit power loss of Fe _95.5 Si _4.5 The ratios (which may be referred to as loss relative values in this application) are all less than or equal to 0.5. Wherein, the aforementioned "unit power loss" can be represented by the symbol P _cv , and its unit can be kW/m ³ , which is measured at a frequency of 1 MHz and a magnetic flux density of 30 mT. In some embodiments, the Bs of the amorphous soft magnetic material and the nanocrystalline soft magnetic material is greater than or equal to 1.4T (such as 1.4T-2T, 1.4T-1.9T, or 1.5T-1.8T), and the relative loss is less than or equal to Equal to 0.35. Amorphous/nanocrystalline soft magnetic materials with large Bs and small relative loss value are combined with the above-mentioned first soft magnetic powder to ensure that the magnetic element made of the above-mentioned magnetic powder will not cause inductance saturation while working under high current. , also has low magnetic loss performance. Due to the existence of nanoscale grains, nanocrystalline soft magnetic materials have a magnetostriction coefficient close to 0, ultra-low coercive force and high resistivity, and their loss characteristics are generally better than those of traditional metal crystal materials and common amorphous soft magnetic materials such as FeSiB. magnetic material. In some embodiments, the relative loss of the nanocrystalline soft magnetic material may be less than or equal to 0.2.

In the embodiment of the present application, the above-mentioned metal crystal soft magnetic material may include at least A sort of. In other words, the above-mentioned metal crystal soft magnetic material can be at least one selected from the group consisting of carbonyl iron, iron-silicon alloy, iron-nickel alloy, iron-silicon-chromium alloy, etc., specifically, it can be selected from this group, or Choose two, or three, or all.

In the embodiment of the present application, the constituent elements of the above-mentioned amorphous soft magnetic material include a first element and a second element, wherein the first element includes at least one of Fe, Co and Ni, and must contain Fe, and the The second element includes at least one of Si, B, C, and P. Further, the constituent elements of the amorphous soft magnetic material may further include a third element, wherein the third element may include at least one of Cr, Cu, Nb, V, and Zr. Generally, the amorphous soft magnetic material is not Fe-Si or Fe-Si-Cr system. Exemplarily, the amorphous soft magnetic material may be at least one of Fe-Ni-B system, Fe-Ni-Si-B-P-C system, Fe-Si-B-Cr-C system and the like.

In the embodiment of the present application, the constituent elements of the nanocrystalline soft magnetic material include the first element, the second element and the third element at the same time, wherein the first element includes at least one of Fe, Co and Ni, and must Containing Fe, the second element includes at least one of Si, B, C, and P, and the third element may include at least one of Cr, Cu, Nb, V, and Zr. In some embodiments, the first element is Fe, and the nanocrystalline soft magnetic material at this time may be called "iron-based nanocrystalline alloy". Exemplarily, the nanocrystalline soft magnetic material can be Fe-B-Cu-C system, Fe-Zr-B-Cu system, Fe-Si-B-Cu-P system, Fe-Si-B-Cu-Nb system , Fe-Nb-B-P-Cu system, Fe-Nb-B-P-Si-Cu system, Fe-Nb-B-P-Cu-C system, FeBNbCu system, and the like.

Table 1 below shows the relative values of Bs and loss _Pcv , coercive force (symbol Hc) of some soft magnetic materials.

It should be noted that, in the structural formulas of the soft magnetic materials listed herein, the subscripts of the alloying elements all represent their mass fraction percentages.

Except for carbonyl iron powder, the powders of the above-mentioned various soft magnetic materials can be particles prepared by water atomization or gas atomization. Specifically, high-pressure water or high-pressure gas with a certain speed is used to crush the molten metal liquid column into fine droplets and then rapidly cooled to obtain powder, which is basically composed of approximately spherical particles. Nearly spherical particles have better magnetic properties than other irregularly shaped particles.

In some embodiments of the present application, the surfaces of the first soft magnetic powder and the second soft magnetic powder also have insulating coating layers. At this time, each metal crystal soft magnetic material powder, each amorphous soft magnetic material powder and each nanocrystalline soft magnetic material powder can be insulated and coated after being completely or partially mixed, and each soft magnetic material powder can be insulated and coated. Mix again. The insulating coating layer can improve the insulation and heat resistance of each soft magnetic material. When the magnetic powder with the insulating coating layer is used in the inductor, it can meet the requirements of voltage breakdown and heat aging resistance during the use of the inductor. demand. Wherein, the insulating coating layer may cover at least a part of the surface of the soft magnetic material particle, but preferably covers the entire surface. In addition, the insulating coating layer may cover the surface of the particles continuously or intermittently.

The embodiment of the present application also provides a magnet, which is obtained by molding a magnetic composite material, wherein the magnetic composite material includes the aforementioned magnetic powder and a binder.

In the embodiment of the present application, the magnet can be made from the above-mentioned magnetic composite material through a compression molding method, or through a tape casting method, but is not limited thereto. In particular, magnets produced by compression molding have higher densities. Wherein, when the magnet is prepared by compression molding, the magnetic composite material may be granulated powder (or called "feeding particles") formed by granulating the aforementioned magnetic powder and binder. The granulated powder can be filled in a mold, pressed into shape, and then baked and solidified to obtain a finished product. When the coil is placed in the mold to be filled with granulated powder in advance, an integrally formed inductor can be obtained by compression molding at this time, and the inductor can also be called a "molded inductor". When the tape casting method is used to prepare the magnet, the magnetic composite material used can be a viscous fluid, which can be made into a green film (also called a prepreg) with a certain thickness on the tape casting machine, and then baked Bake and solidify to obtain a finished product. Subsequently, the semi-cured magnetic sheet obtained by the casting method and the coil produced by the photolithography process can be hot-pressed, cut, and then baked and solidified to obtain an inductor product. The inductor produced by this process can also be called For "thin film inductor".

In the embodiment of the present application, the adhesive can be a resin, specifically including epoxy resin, phenolic resin, silicone resin, acrylic resin, cyanate resin, polyimide, polyphenylene sulfide and its modified products, etc. at least one of . The presence of binder can improve the forming effect of magnetic composite materials. In particular, it can make the granulated powdery magnetic composite material have a certain fluidity, and improve the molding effect and the uniformity of cavity filling during compression molding.

In the embodiment of the present application, the mass of the binder may be 2%-6% of the mass of the aforementioned magnetic powder. In this way, the presence of more binders can avoid reducing the molding density of the obtained magnet and reducing its magnetic loss performance. In some embodiments, the mass of the binder may be 2%-5% of the aforementioned magnetic powder. Due to containing the aforementioned magnetic powder, the compression molding pressure of the granulated powdery magnetic composite material will not be too high, which can avoid the excessive pressure and cause the granulated powder to be damaged (such as the insulating coating layer is destroyed) and placed in the granulated powder The deformation or damage of the coil structure in the coil (such as the damage of the insulating layer) prevents the short circuit of the manufactured inductor and the attenuation of the initial withstand voltage capacity of the coil, and improves the reliability of the manufactured inductor. In other embodiments of the present application, when the tape casting method is used to prepare the magnet, the mass of the binder may be 3%-6% of the aforementioned magnetic powder. This ensures proper flow of magnetic composites for viscous fluids.

Wherein, the preparation method of the above-mentioned magnetic composite material includes:

mixing the first soft magnetic powder and the second soft magnetic powder to obtain magnetic powder;

After mixing the magnetic powder and binder, a magnetic composite material is made.

In the embodiment of the present application, the above-mentioned preparation method of the magnetic composite material further includes: before mixing the first soft magnetic powder and the second soft magnetic powder, separately performing the first soft magnetic powder and the second soft magnetic powder annealing treatment; or annealing the magnetic powder mixed with the first soft magnetic powder and the second soft magnetic powder.

Among them, the annealing treatment can eliminate the internal stress and some impurities (such as carbon, oxygen, etc.) of the soft magnetic material, and improve the magnetic properties of the soft magnetic material to meet the requirements of the inductor working at high frequency and high current. Wherein, the temperature of the annealing treatment may be 300° C.-900° C., and the annealing treatment may be performed in an atmosphere containing at least one of nitrogen, hydrogen, argon, air and the like. Among them, the annealing temperature should be above 300°C, which can ensure that the internal stress of each material can be fully removed and improve the magnetic properties. At the same time, it should be noted that the annealing temperature should not exceed the crystallization temperature of the soft magnetic material to avoid deterioration of loss characteristics. In particular, the annealing temperature for the second soft magnetic powder generally does not exceed 550° C., so as not to exceed the crystallization temperature of the second soft magnetic powder.

In the embodiment of the present application, before mixing the magnetic powder and the binder, it also includes: before or after the mixing of the first soft magnetic powder and the second soft magnetic powder, mixing the first soft magnetic powder and the second soft magnetic powder The surfaces of the second soft magnetic powder form insulating coating layers respectively.

In some embodiments of the present application, the preparation method of the magnetic composite material includes:

After annealing the first soft magnetic powder, a first insulating coating layer wrapping the surface of the first soft magnetic powder is formed; after annealing the second soft magnetic powder, forming a coating layer wrapping the A second insulating coating layer on the surface of the second soft magnetic powder;

mixing the first soft magnetic powder with the first insulating coating layer and the second soft magnetic powder with the second insulating coating layer to obtain magnetic powder;

The magnetic powder and the binder are mixed to prepare a magnetic composite material.

At this time, the surface of each soft magnetic material is well wrapped by the insulating coating layer, and the insulation is better. When the subsequent magnetic components such as inductors made of the magnetic powder are applied with voltage, the eddy current between the contact particles is small. The inductance loss caused by it is small, and the inductance has a strong ability to withstand voltage breakdown.

In some other embodiments of the present application, the preparation method of the above-mentioned magnetic composite material includes:

Mixing the first soft magnetic powder and the second soft magnetic powder and then performing annealing treatment, or separately performing annealing treatment and then mixing to obtain a mixed powder;

Carrying out insulating coating on the mixed powder, so that the surfaces of the first soft magnetic powder and the second soft magnetic powder both form an insulating coating layer to obtain a magnetic powder;

The magnetic powder is mixed with a binder to obtain a magnetic composite material. At this time, the operation of the preparation method of the magnetic composite material is simpler.

Wherein, the material of the insulating coating layer includes one or more of phosphoric acid, sulfuric acid, nitric acid, chromic acid, phosphate, silicate, nitrate, chromate, inorganic oxide, and the like. Exemplarily, the phosphate may be at least one selected from the group consisting of sodium hydrogen phosphate, aluminum dihydrogen phosphate and aluminum phosphate. The silicate may be at least one selected from the group consisting of sodium silicate, magnesium silicate, magnesium aluminum silicate and the like. The inorganic oxide may be at least one selected from the group consisting of silica, iron oxide, titania, alumina, calcium oxide, zinc oxide, zirconia and the like.

Specifically, the method for forming the insulating coating layer may include at least one of physical fusion, coating, physical vapor deposition, chemical vapor deposition, and in-situ heat treatment. Wherein, physical fusion may include ball milling, sand milling, etc., and the coating method may specifically include one or a combination of dripping, brushing, spraying, dipping, etc. methods. The physical vapor deposition may include vapor deposition, sputtering, and the like. The in-situ heat treatment method is to chemically react with the surface of the soft magnetic material to be coated to form an insulating coating layer. Exemplarily, the in-situ heat treatment method can be performed by placing the soft magnetic material to be coated in a dry air or oxygen atmosphere In situ oxidation is carried out. In this process, specifically, elements such as iron and silicon in the soft magnetic material undergo oxidation reactions, and the insulating coating layer formed at this time may include at least one of silicon dioxide, iron oxide, and the like.

The method for forming the insulating coating layer can be selected according to its specific material. Among them, silicon dioxide, iron oxide, etc. are particularly suitable for in-situ oxidation. The method of physical fusion and coating is suitable for the construction of insulating coatings of various materials. Exemplarily, the material includes phosphoric acid, sulfuric acid, nitric acid, chromic acid, phosphate, silicate, nitrate, chromate, etc. The insulating coating layer is more suitable for soaking the soft magnetic material in the insulating coating layer material and water. , alcohol, acetone, etc., and then dried to form. The insulating coating layer made of inorganic oxide is more suitable to be formed by performing dry or wet ball milling with the soft magnetic material.

In some embodiments of the present application, the aforementioned magnetic composite material may further include at least one of a lubricant, a silane coupling agent, a curing agent, a dispersant, a plasticizer, and the like. Among them, the lubricant is generally used in the magnetic composite material in the form of granulated powder to improve its compression molding effect. The lubricant can be selected from zinc stearate, magnesium stearate, calcium stearate, amide wax micropowder, etc. at least one. The curing agent is generally used when the adhesive includes epoxy resin, and generally includes one or more of imidazole curing agents, dicyandiamide curing agents, organic amine curing agents, polyisocyanates and the like. Exemplarily, the imidazole curing agent may include one or more of imidazole, 2-methylimidazole, 2-ethylimidazole, 2,4-dimethylimidazole and 2-ethyl 4-methylimidazole. The dicyandiamide curing agent may include one or more of dicyandiamide and aniline-modified dicyandiamide. Examples of organic amine curing agents include aliphatic amines, alicyclic amines, aromatic amines, polyamides, and the like. Dispersants, silane coupling agents, and plasticizers are generally used in magnetic composite materials in the form of viscous fluids. Of course, the magnetic composite materials also contain solvents at this time, acting as diluents. Exemplarily, the dispersant may be at least one of phosphoric acid ester, triolein, triethanolamine and the like. The plasticizer can be at least one of glycerin, dioctyl phthalate, polyethylene glycol, phthalic acid and the like.

Among them, when the magnet is prepared by the die calendering method, the magnetic composite material in the form of granulated powder can be molded into a magnet first, and then assembled with a coil to form an inductor, or the granulated powder can also be molded together with the coil to form an integrated body. The molded inductor body is then baked and solidified to produce an inductor (the inductor made by this method can be called a "molded inductor"). Specifically, the granulated powder can be filled into a mold in which coils have been placed in advance, and shaped under pressure. Exemplarily, the molding pressure of compression molding is 3-10 ton/cm ² ; the baking temperature is 160°C-220°C, and the holding time is 0.1h-3h.

When tape-casting method is used to prepare magnets, the above-mentioned viscous fluid-like magnetic composite material can be formed into a semi-cured magnetic sheet after tape-casting. Exemplarily, the casting speed may be 0.1-2 m/min, and the casting temperature may be 50-90°C. When the semi-cured magnetic sheet needs to be made into an inductor later, it can be hot-pressed and pressed with the coil made by the photolithography process. After cutting, the inductor body of the required size is obtained, and then baked and solidified to obtain inductance. At this time, the inductor manufactured by this method can be called "thin film inductor". Exemplarily, the baking temperature is 160-220°C, and the holding time is 0.1h-3h.

The magnet provided in the embodiment of the present application uses the above-mentioned magnetic powder with good molding effect, high saturation magnetic flux density and low relative magnetic loss value, so that the magnet has a high packing density, a large saturation magnetic flux under high current, and low eddy current loss. . When the magnet is used to prepare the inductance, the inductance has large inductance, low DC resistance, low loss and high efficiency. In addition, the preparation method of the above-mentioned magnetic composite material has a simple process, high efficiency and environmental protection, and can be produced on a large scale. The method of molding the magnetic composite material into a magnet is also relatively convenient.

The embodiments of the present application will be further described below in terms of multiple specific embodiments. Wherein, the embodiments of the present application are not limited to the following specific embodiments.

Example 1

A method for preparing magnetic powder for manufacturing magnets, comprising:

45wt.% metal crystal powder (specifically carbonyl iron powder, D50 particle size is 3 μm) and 55wt.% amorphous soft magnetic material powder (specifically Fe _87.8 Si _6.6 B _2.5 Cr _2.5 C _0.6 , D50 particle size is 10 μm) were mixed, and then the resulting mixed powder was annealed at 430° C. for 3 hours under a nitrogen atmosphere, and cooled naturally;

Add phosphoric acid aqueous solution to the annealed mixed powder for insulation coating, wherein the mass of phosphoric acid accounts for 0.5% of the mass of the annealed mixed powder; stir at 150°C for 1 hour to mix the mixed powder and phosphoric acid aqueous solution evenly, and make the moisture Dry to obtain magnetic powder.

A method for preparing an inductor, comprising:

The above-mentioned magnetic powder is mixed with a thermosetting epoxy resin and a curing agent (specifically dicyandiamide) and diluent acetone with a mass of 4wt.% of the above-mentioned magnetic powder, and the obtained mixed slurry is sent into a granulator for granulation, After drying, a granulated powder with a particle size of 100-300 μm is obtained, and the granulated powder is used to manufacture an inductor magnet;

Fill the above-mentioned granulated powder into the mold where the coil is placed in advance, and perform compression molding at a molding pressure of 6.6ton/ ^cm2 to obtain an inductor body; then heat-preserve and bake the inductor body at a temperature of 180°C for 1 hour, A coil-embedded integrated molded inductor is obtained.

Example 2

A method for preparing magnetic powder for manufacturing magnets, comprising:

Get 20wt.% metal crystal soft magnetic material powder (specifically Fe ₉₂ Si _3.5 Cr _4.5 alloy powder, D50 particle size is 5 μm) and 40wt.% amorphous soft magnetic material powder (specifically Fe _87.5 Si _6.6 B _2.7 Cr _2.7 C _0.5 , D50 particle size is 14 μm), 40wt.% nanocrystalline soft magnetic material powder (specifically Fe _83.4 Si _7.7 B ₂ Cu _1.3 Nb _5.6 , D50 particle size is 16 μm), the above-mentioned various soft magnetic materials The annealing procedure of Fe ₉₂ Si _3.5 Cr _4.5 alloy powder is annealing at 700°C for 3 hours under nitrogen atmosphere, and the annealing procedure of Fe _87.5 Si _6.6 B _2.7 Cr _2.7 C _0.5 amorphous powder is annealing at 450°C under nitrogen atmosphere 1h, the annealing procedure of Fe _83.4 Si _7.7 B ₂ Cu _1.3 Nb _5.6 nanocrystalline powder is annealing at 550°C for 0.5h under argon atmosphere;

Mix the above-mentioned various soft magnetic material powders after annealing treatment to obtain a mixed powder, add an aqueous solution of aluminum dihydrogen phosphate to it for insulation coating, wherein the mass of aluminum dihydrogen phosphate is 0.8% of the mass of the mixed powder; at 150 Stir at ℃ for 1 h to mix the materials evenly and dry the water to obtain magnetic powder.

A method for preparing an inductor, comprising:

The above-mentioned magnetic powder is mixed with a binder (specifically epoxy resin and silicone resin with a mass ratio of 1:1) and a curing agent (specifically imidazole) and a diluent acetone whose mass is 3.5wt.% of the above-mentioned magnetic powder, Send the obtained mixed slurry into a granulator for granulation, and after drying, obtain a granulated powder with a particle size of 100-300 μm, which is used to manufacture an inductor magnet;

Fill the above-mentioned granulated powder into the mold with the coil placed in advance, and carry out compression molding at a molding pressure of 8 ton/cm ² to obtain an inductor green body; then heat-preserve and bake the inductor green body at a temperature of 220°C for 3 hours to obtain Coil built-in one-piece inductor.

Example 3

A method for preparing magnetic powder for manufacturing magnets, comprising:

Get 10wt.% metal crystal soft magnetic material powder (specifically Fe _95.5 Si _4.5 alloy powder, D50 particle size is 1 μm) and 50wt.% amorphous soft magnetic material powder (specifically Fe ₈₀ Ni ₁₁ Si _4.5 B _2.6 P _1.4 C _0.5 , D50 particle size is 20 μm), 40wt.% nanocrystalline soft magnetic material powder (specifically Fe ₉₂ Si _2.2 B _1.7 Cu _1.6 P _2.5 , D50 particle size is 5 μm), first the above-mentioned various soft magnetic materials The powders were annealed. The annealing procedure for Fe _95.5 Si _4.5 alloy powder was annealing at 700°C for 0.5h in nitrogen atmosphere, and the annealing procedure for Fe ₈₀ Ni ₁₁ Si _4.5 B _2.6 P _1.4 C _0.5 amorphous powder was at 550°C in hydrogen atmosphere. Annealing for 0.5h, the annealing procedure for Fe ₉₂ Si _2.2 B _1.7 Cu _1.6 P _2.5 nanocrystalline powder is annealing at 530°C for 1h under argon atmosphere;

Insulate and coat the annealed Fe _95.5 Si _4.5 alloy powder: add phosphoric acid in acetone solution, wherein the mass of phosphoric acid accounts for 0.1% of the mass of Fe _95.5 Si _4.5 powder after annealing, stir at 150°C for 1 hour, mix the materials evenly and Completely volatilize propanol; Fe ₈₀ Ni ₁₁ Si _4.5 B _2.6 P _1.4 C _0.5 amorphous powder and Fe ₉₂ Si _2.2 B _1.7 Cu _1.6 P _2.5 nanocrystalline powder are simultaneously insulated and coated: air is introduced, and thermal oxidation is carried out at 300°C 1h: Mix various soft magnetic material powders coated with insulation according to the above ratio to obtain magnetic powder.

A method for preparing an inductor, comprising:

The above-mentioned magnetic powder is mixed with a binder (specifically, a silicone resin) and a diluent acetone whose mass is 3wt.% of the above-mentioned magnetic powder, and the obtained mixed slurry is sent into a granulator for granulation, and after drying, the obtained Granulated powder with a particle size of 100-300 μm, which is used to manufacture inductor magnets;

The above-mentioned granulated powder and coil were molded under a molding pressure of 10 ton/cm ² to obtain an inductor green body, and then the inductor green body was baked at a temperature of 160°C for 1 hour to obtain an inductor.

Example 4

A method for preparing magnetic powder for manufacturing magnets, comprising:

Get 40wt.% metal crystal soft magnetic material powder (specifically Fe ₅₀ Ni ₅₀ powder and Fe ₉₁ Si _3.5 Cr _5.5 powder with a mass ratio of 1:1, the D50 particle size of FeNi powder is 5 μm, Fe ₉₁ Si _3.5 Cr _5.5 The D50 particle size of the powder is 2 μm), and 20wt.% of the amorphous soft magnetic material powder (specifically Fe ₇₈ Ni ₁₅ B ₇ , the D50 particle size is 17 μm), 40wt.% of the nanocrystalline soft magnetic material powder (specifically 10wt .% Fe _87.5 Zr ₆ B _5.5 Cu and 30wt.% Fe _94.2 Si _0.3 B ₂ CuP _2.5 , the D50 particle size of Fe _87.5 Zr ₆ B _5.5 Cu nanocrystalline powder is 8 μm, Fe _94.2 Si _0.3 B ₂ CuP _2.5 nm The D50 particle size of the crystal powder is 10μm), and the above-mentioned various soft magnetic material powders are first annealed. Among them, the annealing procedure of Fe ₅₀ Ni ₅₀ powder is annealing at 800°C for 3 hours in a hydrogen atmosphere, and Fe ₉₁ Si _3.5 Cr _5.5 powder The annealing procedure for Fe ₇₈ Ni ₁₅ B ₇ amorphous powder is annealing at 400°C for 0.5 hours in a mixed atmosphere of hydrogen and nitrogen. Fe _87.5 Zr ₆ B _5.5 Cu nanocrystalline powder The annealing procedure for the annealing procedure is 500°C for 1 hour under a nitrogen atmosphere, and the annealing procedure for Fe _94.2 Si _0.3 B ₂ CuP _2.5 nanocrystalline powder is annealing at 530°C for 1 hour under an argon atmosphere;

Insulate and coat the annealed Fe ₅₀ Ni ₅₀ powder and Fe ₉₁ Si _3.5 Cr _5.5 powder: first add sulfuric acid in acetone solution, where the mass of sulfuric acid accounts for 0.2% of the powder mass, stir at 150°C for 1 hour, and mix the materials Homogenize and completely volatilize the propanol, then add 0.3% of the powder mass to the silica sol of nano-SiO ₂ to stir and mix, and dry; Fe _87.5 Zr ₆ B _5.5 Cu nanocrystalline powder and Fe ₇₈ Ni ₁₅ B ₇ amorphous powder Simultaneous insulation coating: use phosphoric acid in acetone solution for insulation coating, the mass of phosphoric acid accounts for 0.5% of the powder weight, stir at 120°C for 1 hour to mix the materials evenly and completely volatilize the propanol; Fe _94.2 Si _0.3 B ₂ CuP _2.5 The nanocrystalline powder is insulated and coated by air thermal oxidation: air is introduced, and thermal oxidation is performed at 400°C for 0.5h; the above-mentioned five kinds of soft magnetic material powders that have been insulated and coated are mixed according to the above ratio to obtain magnetic powder.

A method for preparing an inductor, comprising:

The above-mentioned magnetic powder is mixed with a binder (specifically, a phenolic resin and a silicone resin with a mass ratio of 1:2) and a diluent (specifically, acetone) that is 3.5wt.% of the above-mentioned magnetic powder, and the resulting mixed slurry The raw material is sent to the granulator for granulation, and after drying, the granulated powder with a particle size of 100-300 μm is obtained, and the granulated powder is used to manufacture inductor magnets;

The above-mentioned granulated powder and coil were molded at a molding pressure of 5 ton/cm ² to obtain an inductor green body, and then the inductor green body was baked at a temperature of 190°C for 1.5 hours to obtain an inductor.

Example 5

A method for preparing magnetic powder for manufacturing magnets, comprising:

Get 50wt.% metal crystal soft magnetic material powder (specifically 30wt.% carbonyl iron powder and _5wt .% Fe 5 5 Ni ₄₅ powder, the D50 particle diameter of carbonyl iron powder is 2 μ m, the D50 grain of Fe _{5 5} Ni ₄₅ powder diameter is 4μm) and 50wt.% nanocrystalline soft magnetic material powder (specifically 30wt.% Fe _89.3 Si _1.1 B _2.8 Cu _1.3 Nb _5.5 and 35wt.% Fe _93.5 Si _1.1 B _1.7 Cu _1.3 P _2.4 , both The D50 particle size is 12μm and 15um respectively). Firstly, the above-mentioned soft magnetic material powders are annealed. Among them, the annealing procedure of the carbonyl iron powder is annealing at 450°C for 3 hours in a nitrogen atmosphere, and the annealing procedure of the Fe ₅₅ Ni ₄₅ powder is in Annealing at 800°C for 3h in hydrogen atmosphere, the annealing procedure for Fe _89.3 Si _1.1 B _2.8 Cu _1.3 Nb _5.5 nanocrystalline powder and Fe _93.5 Si _1.1 B _1.7 Cu _1.3 P _2.4 nanocrystalline powder is annealing at 530°C for 1h in argon atmosphere;

The annealed carbonyl iron powder, Fe ₅₅ Ni ₄₅ powder, Fe _89.3 Si _1.1 B _2.8 Cu _1.3 Nb _5.5 powder were respectively insulated and coated: adding phosphoric acid in acetone solution, wherein the mass of phosphoric acid accounted for 0.15% of the mass of each powder. Stir at 150°C for 1 hour to mix the materials evenly and completely volatilize the propanol; conduct insulating coating on Fe _93.5 Si _1.1 B _1.7 Cu _1.3 P _2.4 nanocrystalline powder: air is introduced, and thermal oxidation is carried out at 300°C for 1 hour; Various soft magnetic material powders coated with insulation are mixed according to the above ratio to obtain the desired magnetic powder.

A method for preparing an inductor, comprising:

The above-mentioned magnetic powder is mixed with a binder (specifically, acrylic resin and silicone resin with a mass ratio of 1:2.5) and a diluent (specifically, acetone) that is 4wt.% of the above-mentioned magnetic powder, and the resulting mixed slurry Send it into a granulator for granulation, and after drying, a granulated powder with a particle size of 100-300 μm is obtained, and the granulated powder is used to manufacture an inductor magnet;

The above-mentioned granulated powder and coil were molded at a molding pressure of 7 ton/cm ² to obtain an inductor green body, and then the inductor green body was baked at a temperature of 200°C for 1 hour to obtain an inductor.

Example 6

A method for preparing magnetic powder for manufacturing magnets, comprising:

Take 40wt.% metal crystal soft magnetic material powder (specifically Fe ₅₃ Ni ₄₇ powder, its D50 particle size is 3.6 μm), 30wt.% amorphous soft magnetic material powder (specifically Fe _82.5 Ni _10.5 Si _3.5 B _1.5 P _1.5 C _0.5 , D50 particle size is 11.3 μm) and 30wt.% nanocrystalline soft magnetic material powder (specifically Fe _92.5 Si _1.6 B ₂ Cu _1.4 P _2.5 , and its D50 particle size is 18.2 μm), the above-mentioned All kinds of soft magnetic material powders are annealed. Among them, the annealing procedure of FeNi powder is annealing at 800 ° C for 3 hours under hydrogen atmosphere, and the annealing procedure of Fe _82.5 Ni _10.5 Si _3.5 B _1.5 P _1.5 C _0.5 amorphous powder is 550 ° C under hydrogen atmosphere. ℃ annealing for 0.5h, the annealing procedure for Fe _92.5 Si _1.6 B ₂ Cu _1.4 P _2.5 nanocrystalline powder is annealing at 530℃ for 1h under argon atmosphere;

Insulate and coat the annealed Fe ₅₃ Ni ₄₇ powder: add phosphoric acid in acetone solution, wherein the mass of phosphoric acid accounts for 0.15% of the mass of Fe ₅₃ Ni ₄₇ powder, stir at 150°C for 1 hour, mix the materials evenly and make the propanol Completely volatilize; Insulate Fe _82.5 Ni _10.5 Si _3.5 B _1.5 P _1.5 C _0.5 amorphous powder and Fe _92.5 Si _1.6 B ₂ Cu _1.4 P _2.5 nanocrystalline powder at the same time for insulation coating: first pass air, thermal oxidation at 300°C 1h, then add 0.2% of the powder mass nano-alumina sol for stirring and mixing, and dry; mix various soft magnetic material powders coated with insulation according to the above ratio to obtain magnetic powder.

A method for preparing an inductor, comprising:

The above-mentioned magnetic powder is mixed with a binder (specifically phenolic resin and epoxy resin with a mass ratio of 1:1) and a curing agent (specifically polyamide) and diluent butanone that are 5wt.% of the above-mentioned magnetic powder, And the obtained mixed slurry is defoamed;

Cast the above mixed slurry on a tape casting machine to form a prepreg with a certain thickness, wherein the casting speed is 1m/min, and the temperature is 65°C; hot press the prepreg and the coil made by photolithography Pressing and then cutting to obtain an inductor green body of the required size, and then baking the inductor green body at 200°C for 0.2h to obtain an inductor.

Example 7

A method for preparing magnetic powder for manufacturing magnets, comprising:

Get 20wt.% metal crystal soft magnetic material powder (specifically Fe _96.5 Si _3.5 powder, its D50 particle size is 1.5 μm), 30wt.% amorphous soft magnetic material powder (specifically Fe _86.5 Si _6.6 B _3.2 Cr ₃ C _0.7 , D50 particle size is 8.4 μm) and 50wt.% nanocrystalline soft magnetic material powder (specifically Fe ₉₄ Si _0.3 B ₂ CuP _2.4 C _0.3 , whose D50 particle size is 14.8 μm), the above-mentioned various The soft magnetic material powder is annealed. The annealing procedure for FeSi alloy powder is annealing at 700°C for 0.5h in a nitrogen atmosphere, and the annealing procedure for Fe _86.5 Si _6.6 B _3.2 Cr ₃ C _0.7 amorphous powder is annealing at 450°C for 1h in a nitrogen atmosphere. , the annealing procedure of Fe ₉₄ Si _0.3 B ₂ CuP _2.4 C _0.3 nanocrystalline powder is annealing at 550°C for 0.5h under argon atmosphere;

The above-mentioned various soft magnetic material powders after annealing treatment are mixed to obtain mixed powder, and an aqueous solution of sodium hydrogen phosphate is added to it for insulation coating, wherein the mass of sodium hydrogen phosphate is 0.6% of the mass of the mixed powder; Stir at 150 ° C 1h, mix the materials evenly and dry the water to obtain magnetic powder.

According to the inductor preparation method described in Example 6, the magnetic powder in Example 7 was prepared into an inductor.

In order to strongly support the beneficial effects brought by the technical solutions of the embodiments of the present application, the saturation magnetic flux density (Bs) of the magnetic powder in each embodiment is tested and its relative value with the loss of Fe _95.5 Si _4.5 , and the specifications obtained by the test are The saturation current (Isat) and DC resistance (Rdc) of the inductor of 201208-240nH, and the test specifications of each inductor of 201208-240nH are used for step-down DC/DC converters with 5V-1V (switching frequency is 3MHz) Efficiency (η) measured on the circuit test board, the results are summarized in Table 2 below. Among them, the parameter Rdc refers to the resistance value of the inductor under direct current. The above parameter η refers to the ratio of the output power of the inductor to the power input to the inductor.

Table 2

It can be known from the above Table 1 and Table 2 that the magnetic powder provided by the embodiment of the present application can have a higher Bs, compared with the relative loss of Fe _95.5 Si _4.5 , the saturation current of the inductor made by using this magnetic powder Large, small DC resistance, large inductance, low loss, high inductance conversion efficiency, can improve the quality and reliability of electronic equipment using this inductance.

Claims

A magnetic powder for manufacturing a magnet, characterized in that the magnetic powder includes a first soft magnetic powder and a second soft magnetic powder, the first soft magnetic powder is a metal crystal soft magnetic material, and the second soft magnetic powder The magnetic powder includes at least one of an amorphous soft magnetic material and a nanocrystalline soft magnetic material, and the mass of the first soft magnetic powder accounts for 5% of the sum of the mass of the first soft magnetic powder and the second soft magnetic powder. %-45%.
The magnetic powder according to claim 1, wherein the mass of the first soft magnetic powder accounts for 10%-40% of the sum of the mass of the first soft magnetic powder and the second soft magnetic powder.
The magnetic powder according to claim 1 or 2, characterized in that, in the second soft magnetic powder, the mass of the amorphous soft magnetic material is 0.5-1.5 times the mass of the nanocrystalline soft magnetic material.
The magnetic powder according to claim 1, wherein the saturation magnetic flux density of the amorphous soft magnetic material and the nanocrystalline soft magnetic material is greater than or equal to 1.2T, and the amorphous soft magnetic material and the nanocrystalline soft magnetic material The ratio of the unit power loss of the soft magnetic material to the unit power loss of Fe 95.5 Si 4.5 is less than or equal to 0.5.
The magnetic powder according to claim 1, characterized in that the saturation magnetic flux density of the metal crystal soft magnetic material is greater than or equal to 1.35T.
The magnetic powder according to any one of claims 1-5, characterized in that the D50 particle size of the second soft magnetic powder is larger than the D50 particle size of the first soft magnetic powder.
The magnetic powder according to claim 6, wherein the D50 particle size of the second soft magnetic powder is 2-5 times of the D50 particle size of the first soft magnetic powder.
The magnetic powder according to claim 6, wherein the D50 particle size of the first soft magnetic powder is in the range of 1 μm-10 μm; the D50 particle size of the second soft magnetic powder is in the range of 5 μm-20 μm Inside.
The magnetic powder according to any one of claims 1-8, wherein the metal crystal soft magnetic material comprises at least one of carbonyl iron, iron-silicon alloy, iron-nickel alloy and iron-silicon-chromium alloy.
The magnetic powder according to any one of claims 1-8, wherein the amorphous soft magnetic material comprises Fe-Ni-B series, Fe-Ni-Si-B-P-C series, Fe-Si-B-Cr series - At least one of the C series.
The magnetic powder according to any one of claims 1-8, characterized in that, the constituent elements of the nanocrystalline soft magnetic material simultaneously include a first element, a second element and a third element, wherein the first element Including at least one of Fe, Co and Ni, and must contain Fe, the second element includes at least one of Si, B, C, P, and the third element includes Cr, Cu, Nb, V, Zr at least one of .
The magnetic powder according to claim 11, wherein said nanocrystalline soft magnetic material comprises Fe-B-Cu-C system, Fe-Zr-B-Cu system, Fe-Si-B-Cu-P system and at least one of the Fe-Si-B-Cu-Nb system.
The magnetic powder according to any one of claims 1-12, characterized in that the surfaces of the first soft magnetic powder and the second soft magnetic powder both have insulating coating layers.
The magnetic powder according to claim 13, wherein the material of the insulating coating layer is independently selected from phosphoric acid, sulfuric acid, nitric acid, chromic acid, phosphate, silicate, nitrate, chromate, inorganic One or more of oxides.
A magnet, characterized in that the magnet is formed by forming a magnetic composite material, wherein the magnetic composite material includes the magnetic powder and the binder according to any one of claims 1-14.
A magnetic element, characterized in that it comprises the magnet as claimed in claim 15 and a coil arranged in the magnet.
The magnetic element of claim 16, wherein said magnetic element comprises an inductor.
An electronic device, characterized by comprising the magnetic element according to any one of claims 16-17 and a circuit board, the magnetic element being arranged on the circuit board.