Soft magnetic composite material and method for manufacturing the same, metal powder core and method for manufacturing the same, and molded inductor and method for manufacturing the same

Abstract

The application discloses a soft magnetic composite material, which comprises a first soft magnetic metal powder, a first insulating coating material and airflow broken granulation powder. The airflow broken granulation powder comprises a second soft magnetic metal powder and a second insulating coating material, and the second insulating coating material is completely solidified. The first insulating coating material and / or the second insulating coating material in the soft magnetic composite material is uniformly dispersed, the soft magnetic composite material is used for preparing a metal powder core and a molded inductor, and the prepared molded inductor has higher insulation resistance and initial magnetic permeability. Accordingly, the application further discloses a preparation method of the soft magnetic composite material, the first insulating coating material and / or the second insulating coating material in the prepared soft magnetic composite material is uniformly dispersed, and the operation is simple and the cost is low. Accordingly, the application further discloses a metal powder core and a preparation method thereof, and a molded inductor and a preparation method thereof.

Description

Technical Field

[0001] This invention relates to the field of electrical component technology, and in particular to a soft magnetic composite material and its preparation method, a metal powder core and its preparation method, and a molded inductor and its preparation method. Background Technology

[0002] Molded inductors are widely used in various power electronic devices as one of the key components in the modern power electronics field. With the popularization of electric vehicles, the Internet of Things, cloud servers, intelligent technologies and new generation semiconductor materials, the stability requirements of molded inductors are getting higher and higher, and the operating conditions of molded inductors are becoming more and more demanding, requiring higher thermal stability of related molded inductors. Therefore, improving the insulation resistance of molded inductors is the core issue in the technical development of this type of product.

[0003] Molded inductors can be directly fabricated from soft magnetic composite materials and windings, or obtained by pressing a metal powder core made from soft magnetic composite materials with windings. Soft magnetic composite materials are composite materials with soft magnetic metal powder as the matrix and coated with at least one insulating coating material. Soft magnetic composite materials have lower eddy current losses, higher permeability, lower coercivity, and higher insulation resistance. Furthermore, they possess the advantages of three-dimensional anisotropy and ease of machining, and are widely used in the fabrication of metal powder core and / or molded inductors.

[0004] However, in actual production, the insulation resistance of the metal powder core and / or molded inductor may decrease due to uneven dispersion of the insulating coating material in the soft magnetic material or poor coating of the soft magnetic metal powder. To solve this problem, the traditional method is to increase the amount of insulating coating material added to improve the insulation resistance of the soft magnetic composite material; however, this method will reduce the initial permeability of the soft magnetic composite material to some extent. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is how to make soft magnetic composite materials have high insulation resistance and initial magnetic permeability.

[0006] To address the aforementioned technical problems, the present invention provides a soft magnetic composite material comprising a first soft magnetic metal powder, a first insulating coating material, and airflow-crushed granulated powder.

[0007] The airflow crushing granulation powder includes a second soft magnetic metal powder and a second insulating coating material, and the second insulating coating material is completely cured.

[0008] In one feasible implementation, the average particle size of the air-jet crushed granulated powder is 1.1 to 3.0 times the average particle size of the first soft magnetic metal powder.

[0009] In one feasible implementation, the mass ratio of airflow-crushed granulated powder to the first soft magnetic metal powder is 0.05-0.2.

[0010] In one feasible implementation, the first soft magnetic metal powder and the second soft magnetic metal powder are independently selected from carbonyl iron powder, reduced iron powder, atomized iron powder, and atomized Fe. (100-x-y) Si x Cr y At least one of the following: powder (x = 3.5-6.5, y = 0.0-6.5), iron-based amorphous soft magnetic powder, iron-based amorphous nanocrystalline powder, Sandust powder, and HighFlux powder.

[0011] In one feasible implementation, the first soft magnetic metal powder and the second soft magnetic metal powder have the same composition.

[0012] In one feasible implementation, the first insulating coating material comprises at least a first thermosetting resin, and the second insulating coating material comprises at least a second thermosetting resin, wherein the first thermosetting resin and the second thermosetting resin are independently selected from at least one of epoxy resin, cyanate ester resin and linear phenolic resin.

[0013] The soft magnetic composite material provided by this invention includes air-jet granulated powder. This powder has a small particle size, a normally distributed particle size distribution, and good sphericity. During subsequent preparation of the metal core and molded inductor, the air-jet granulated powder can displace under pressure, thereby reducing the inter-powder voids between the first and / or second soft magnetic metal powders. This reduces the problem of uneven dispersion of the first and / or second insulating coating materials, resulting in metal cores and molded inductors with higher insulation resistance and initial permeability. Furthermore, because the second insulating coating material in the air-jet granulated powder used in this invention is completely solidified, it improves the crushing strength of the air-jet granulated powder, enabling it to uniformly withstand temperature and pressure, further promoting uniform dispersion of the first and / or second insulating coating materials.

[0014] Accordingly, the present invention also provides a method for preparing the above-mentioned soft magnetic composite material, comprising the following steps:

[0015] The airflow crushing granulation powder is provided, which includes a second soft magnetic metal powder and a second insulating coating material, wherein the second insulating coating material is completely cured.

[0016] The air-jet crushed granulated powder, the first soft magnetic metal powder, and the first insulating coating material are mixed to obtain a soft magnetic composite material.

[0017] In one feasible implementation, the method for preparing airflow-driven granulated powder includes the following steps:

[0018] The second insulating coating material and the second soft magnetic metal powder are mixed and then subjected to granulation, complete curing and airflow crushing processes to obtain airflow crushed granulated powder.

[0019] The soft magnetic composite material prepared by the method provided by this invention produces a soft magnetic composite material in which the first insulating coating material and / or the second insulating coating material are uniformly dispersed. The soft magnetic composite material prepared by this method is used to prepare metal powder cores and molded inductors, resulting in metal powder cores and molded inductors with high insulation resistance and initial permeability.

[0020] In actual production, the preparation of soft magnetic composite materials generates waste material, which is equivalent to the intermediate product of the second insulating coating material and the second soft magnetic metal powder mixed and granulated in this invention. Therefore, this invention recycles the waste material, resulting in lower costs.

[0021] Accordingly, the present invention also provides a metal powder core made of the above-mentioned soft magnetic composite material, which has high insulation resistance and initial magnetic permeability.

[0022] Accordingly, the present invention also provides a method for preparing a metal powder core, comprising the following steps:

[0023] The above soft magnetic composite material was subjected to granulation and thermo-pressing treatment in sequence to obtain a metal powder core soft magnetic composite material.

[0024] The metal powder core prepared by this method has high insulation resistance and initial magnetic permeability.

[0025] Accordingly, the present invention also provides a molded inductor made from the above-mentioned soft magnetic composite material, which has high insulation resistance and initial permeability.

[0026] Accordingly, the present invention also provides a method for preparing a molded inductor, comprising the following steps:

[0027] The above-mentioned soft magnetic composite material is granulated to obtain soft magnetic composite material granulated powder.

[0028] The soft magnetic composite material granules and windings are placed in a mold, and then subjected to temperature and pressing treatment to obtain a metal powder core.

[0029] The molded inductors prepared by this method have high insulation resistance and initial permeability. Detailed Implementation

[0030] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, a detailed description is provided below in conjunction with specific embodiments of the present invention. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] It should be noted that the term "complete curing" as used in this invention is a common term in the field. Complete curing refers to a certain degree of cross-linking reaction between polymer resins, rather than the reaction of all active groups of the polymer resin.

[0033] A soft magnetic composite material includes a first soft magnetic metal powder, a first insulating coating material, and air-jet granulated powder. The air-jet granulated powder includes a second soft magnetic metal powder and a second insulating coating material, wherein the second insulating coating material is completely cured.

[0034] The soft magnetic composite material provided by this invention includes air-jet granulated powder. This powder has a small particle size, a normally distributed particle size distribution, and good sphericity. During subsequent preparation of the metal core and molded inductor, the air-jet granulated powder can displace under pressure, thereby reducing the voids between the first and / or second soft magnetic metal powders. This reduces the uneven dispersion of the first and / or second insulating coating materials, resulting in metal cores and molded inductors with higher insulation resistance and initial permeability. Furthermore, because the second insulating coating material in the air-jet granulated powder used in this invention is completely solidified, the air-jet granulated powder has high compressive strength, enabling it to uniformly withstand temperature and pressure, further promoting uniform dispersion of the first and / or second insulating coating materials.

[0035] In one feasible implementation, the average particle size of the air-jet crushed granulated powder is 1.1 to 3.0 times the average particle size of the first soft magnetic metal powder.

[0036] At this ratio, air-jet crushing and granulation can slow down the flow of the first insulating coating material and / or the second insulating coating material and uniformly bear the pressing force. This avoids the problem in traditional soft magnetic composite materials where, during thermo-pressing, the thickness of the first insulating coating material and / or the second insulating coating material at the powder contact interface between the first soft magnetic metal powder and / or the second soft magnetic metal powder is thin, and the gap between the first soft magnetic metal powder and / or the second soft magnetic metal powder is filled with insulating coating material. This ensures that the insulating coating material is uniformly dispersed in the soft magnetic composite material.

[0037] In one feasible implementation, the mass ratio of air-jet granulated powder to the first soft magnetic metal powder is 0.05-0.2. With increasing amounts of air-jet granulated powder, the insulation resistance of the metal powder core and / or molded inductor made from the soft magnetic composite material increases, while the initial permeability decreases. When the mass ratio of air-jet granulated powder to the first soft magnetic metal powder is 0.05-0.2, the overall performance of the metal powder core and / or molded inductor made from the soft magnetic composite material is superior.

[0038] In one feasible implementation, the first soft magnetic metal powder and the second soft magnetic metal powder are independently selected from carbonyl iron powder, reduced iron powder, atomized iron powder, and atomized Fe, respectively. (100-x-y) Si x Cr y At least one of the following: powder (x = 3.5-6.5, y = 0.0-6.5), iron-based amorphous soft magnetic powder, iron-based amorphous nanocrystalline powder, Sandust powder, and HighFlux powder.

[0039] In one feasible implementation, the first soft magnetic metal powder and the second soft magnetic metal powder have the same composition. Having the same composition for both can reduce other performance changes in the metal powder cores and / or molded inductors made from soft magnetic composite materials due to the addition of air-jet granulated powder.

[0040] In one feasible implementation, the first insulating coating material includes at least a first thermosetting resin. Furthermore, the first insulating coating material also includes a curing agent compatible with the first thermosetting resin, the first thermosetting resin and the curing agent together constituting a first thermosetting resin system.

[0041] In one feasible implementation, the second insulating coating material includes at least a second thermosetting resin. Furthermore, the second insulating coating material also includes a curing agent compatible with the second thermosetting resin, and the second thermosetting resin and the curing agent together constitute a second thermosetting resin system.

[0042] In one feasible implementation, the first thermosetting resin and the second thermosetting resin are each independently selected from at least one of epoxy resin, cyanate ester resin and linear phenolic resin.

[0043] In one feasible implementation, the first thermosetting resin and the second thermosetting resin have the same composition.

[0044] In one feasible implementation, the first insulating coating material is a first thermosetting resin system, and the second insulating coating material is a second thermosetting resin system. The first and / or second insulating coating materials may also include inorganic coating materials such as mineral powder, silicates, and phosphates. However, compared to organic / inorganic coatings, when the insulating coating method in the soft magnetic composite material is only organic coating, the metal powder core and / or molded inductor made from the soft magnetic composite material exhibits superior magnetic properties.

[0045] The first insulating coating material and / or the second insulating coating material in the soft magnetic composite material provided by the present invention are uniformly dispersed, and the metal powder core and / or molded inductor made from the soft magnetic composite material have high insulation resistance and initial permeability.

[0046] Accordingly, the present invention also provides a method for preparing a soft magnetic composite material, comprising the following steps:

[0047] The airflow crushing granulation powder is provided, which includes a second soft magnetic metal powder and a second insulating coating material, wherein the second insulating coating material is completely cured.

[0048] The air-jet crushed granulated powder, the first soft magnetic metal powder, and the first insulating coating material are mixed to obtain a soft magnetic composite material.

[0049] The first insulating coating material and / or the second insulating coating material in the soft magnetic composite material prepared by this method are uniformly dispersed. The soft magnetic composite material prepared by this method is used to prepare metal powder cores and molded inductors, and the prepared metal powder cores and molded inductors have high insulation resistance and initial permeability. In one feasible implementation, the method for preparing air-jet crushed granulated powder includes the following steps: mixing the second insulating coating material and the second soft magnetic metal powder, and sequentially performing granulation treatment, complete curing treatment, and air-jet crushing treatment to obtain air-jet crushed granulated powder.

[0050] The airflow abrasion treatment and complete curing treatment enable the airflow abrasion granulation powder to produce soft magnetic composite materials, metal powder cores made from soft magnetic composite materials, and molded inductors with advantages such as good mechanical properties, high density, and surface gloss.

[0051] In one feasible implementation, the second soft magnetic metal powder is subjected to surface insulation treatment before the step of mixing the second insulating coating material and the second soft magnetic metal powder.

[0052] In one feasible implementation, the first soft magnetic metal powder is subjected to surface insulation treatment before the step of mixing the air-jet crushed granulated powder, the first soft magnetic metal powder, and the first insulating coating material.

[0053] By insulating the surfaces of the first and / or second soft magnetic metal powders, the current path can be further blocked, effectively reducing the eddy current loss of the soft magnetic composite material and improving the initial permeability of the soft magnetic composite material.

[0054] The soft magnetic composite material prepared by this method is used to fabricate metal powder cores and molded inductors. The prepared metal powder cores and molded inductors have high insulation resistance and initial permeability. Specifically, according to the test data, the insulation resistance of the prepared metal powder core is ≥10 (MΩ@100V, 3s), and the initial permeability of the metal powder core is ≥33.0 (H / m).

[0055] Accordingly, the present invention also provides a metal powder core made of the above-mentioned soft magnetic composite material, which has high insulation resistance and initial magnetic permeability.

[0056] Accordingly, the present invention also provides a method for preparing a metal powder core, comprising the following steps:

[0057] The soft magnetic composite material is subjected to granulation and thermo-pressing processes in sequence to obtain a metal powder core soft magnetic composite material. The thermo-pressing temperature is at least the temperature at which the first and second insulating coating materials can initially solidify.

[0058] The metal powder core prepared by this method has high insulation resistance and initial magnetic permeability.

[0059] Accordingly, the present invention also provides a molded inductor made from the above-mentioned soft magnetic composite material, which has high insulation resistance and initial permeability.

[0060] Accordingly, the present invention also provides a method for preparing a molded inductor, comprising the following steps:

[0061] The soft magnetic composite material is granulated to obtain soft magnetic composite material granulated powder.

[0062] The soft magnetic composite material granules and windings are placed in a mold, and then subjected to temperature and pressing treatment to obtain a metal powder core.

[0063] The molded inductors prepared by this method have high insulation resistance and initial permeability.

[0064] Referring to the above embodiments, in order to make the technical solution of the present invention more specific, clear and easy to understand, examples of the technical solution of the present invention are given below. However, it should be noted that the content to be protected by the present invention is not limited to the following embodiments 1 to 8.

[0065] Example 1

[0066] The first soft magnetic metal powder was obtained by surface insulating 150g of carbonyl iron powder with an average particle size of 6.2μm using 0.45g of phosphoric acid and 7.5g of acetone.

[0067] Surface insulation treatment was performed on 150g of carbonyl iron powder with an average particle size of 6.2μm using 0.45g of phosphoric acid and 7.5g of acetone to obtain a second soft magnetic metal powder. 3g of bisphenol A cyanate and 0.75g of bisphenol A epoxy resin were mixed to obtain a first insulating coating material. 3g of bisphenol A cyanate and 0.75g of bisphenol A epoxy resin were then mixed to obtain a second insulating coating material.

[0068] 30g of phosphated carbonyl iron powder, 0.75g of second insulating coating material and 3g of acetone were mixed and then granulated to obtain granulated powder with a particle size of -60 mesh to +300 mesh.

[0069] The granulated powder was dried and then completely cured at 180°C for 60 minutes to obtain dried granulated powder.

[0070] The dried granulated powder was subjected to air jet milling to obtain air jet milled granulated powder with an average particle size of 8 μm.

[0071] 100g of first soft magnetic metal powder, 2.5g of first insulating coating material, 5g of airflow crushing granulation powder and 10g of acetone were mixed to obtain a soft magnetic composite material.

[0072] The soft magnetic composite material is granulated to obtain soft magnetic composite material granulated powder.

[0073] The soft magnetic composite granulated powder was dried and then subjected to a temperature and pressure treatment (180℃, 150s, temperature and pressure of 2T) to obtain a ring-shaped metal powder core sample with an outer diameter of 14mm, an inner diameter of 8mm, and a height of 3mm.

[0074] Example 2

[0075] The difference between Example 2 and Example 1 is that 10g of airflow crushing granulation powder was added.

[0076] Example 3

[0077] The difference between Example 3 and Example 1 is that 15g of airflow crushing granulation powder was added.

[0078] Example 4

[0079] The difference between Example 4 and Example 1 is that 20g of airflow crushing granulation powder was added.

[0080] Example 5

[0081] The difference between Example 5 and Example 3 is that the average particle size of the airflow crushed granulated powder is 7 μm.

[0082] Example 6

[0083] The difference between Example 6 and Example 3 is that the average particle size of the airflow crushed granulated powder is 10.4 μm.

[0084] Example 7

[0085] The difference between Example 7 and Example 3 is that the average particle size of the airflow crushed granulated powder is 12.2 μm.

[0086] Example 8

[0087] The difference between Example 8 and Example 3 is that the average particle size of the airflow crushed granulated powder is 15 μm.

[0088] Comparative Example 1

[0089] The difference between Comparative Example 1 and Example 1 is that 0g of airflow crushing granulation powder was added.

[0090] Comparative Example 2

[0091] The difference between Comparative Example 2 and Example 1 is that 2g of airflow crushing granulation powder was added.

[0092] Comparative Example 3

[0093] The difference between Comparative Example 3 and Example 1 is that 30g of airflow crushing granulation powder was added.

[0094] Comparative Example 4

[0095] The difference between Comparative Example 4 and Example 3 is that the average particle size of the airflow crushed granulated powder is 20.2 μm.

[0096] Performance testing:

[0097] The annular metal powder core samples from Comparative Examples 1-4 and Examples 1-8 were subjected to complete curing treatment (180°C, 60 min), followed by insulation resistance and initial permeability tests:

[0098] The insulation resistance test in this invention is performed using a Chroma19053 withstand voltage tester, with the voltage set to 100V and the test time to be 3s.

[0099] The initial permeability in this invention was measured using a soft magnetic DC tester, MATS-2010SD.

[0100] The test results are shown in Tables 1 and 2.

[0101] Table 1 Performance tests of Comparative Examples 1-3 and Examples 1-4

[0102]

[0103] Table 2 shows the performance tests of Comparative Example 4 and Examples 3, 5-8.

[0104]

[0105]

[0106] As shown in Table 1, Examples 1-4 exhibit superior insulation resistance and initial permeability; while Comparative Examples 1-2 show lower insulation resistance due to the smaller amount of air-jet granulation powder added; and Comparative Example 3 shows a significant decrease in initial permeability due to the larger amount of air-jet granulation powder added. In summary, the optimal mass ratio of air-jet granulation powder to the first soft magnetic metal powder is 0.05-0.2.

[0107] As can be seen from Table 2, Examples 3 and Examples 5-8 have better insulation resistance and initial permeability; when the ratio of the average particle size of the airflow crushed granulated powder to the average particle size of the first soft magnetic metal powder is 3.2, the insulation resistance is significantly reduced and the initial permeability also decreases significantly.

[0108] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0109] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A soft magnetic composite material, characterized in that, It includes a first soft magnetic metal powder, a first insulating coating material, and airflow crushed granulated powder; The airflow crushing granulation powder includes a second soft magnetic metal powder and a second insulating coating material, and the second insulating coating material is completely cured; The airflow crushing granulation powder is obtained by mixing a second insulating coating material and a second soft magnetic metal powder, and then sequentially performing granulation, complete curing, and airflow crushing processes.

2. The soft magnetic composite material according to claim 1, characterized in that, The average particle size of the airflow crushed granulated powder is 1.1 to 3.0 times the average particle size of the first soft magnetic metal powder.

3. The soft magnetic composite material according to claim 1, characterized in that, The mass ratio of the airflow crushed granulated powder to the first soft magnetic metal powder is 0.05-0.

2.

4. The soft magnetic composite material according to claim 1, characterized in that, The first soft magnetic metal powder and the second soft magnetic metal powder are independently selected from carbonyl iron powder, reduced iron powder, atomized iron powder, and atomized Fe. (100-x-y) Si x Cr y At least one of the following: iron-based amorphous soft magnetic powder, iron-based amorphous nanocrystalline powder, Sandust powder, and HighFlux powder; wherein the atomized Fe... (100-x-y) Si x Cr y In the powder, x = 3.5-6.5, y = 0.0-6.

5.

5. The soft magnetic composite material according to claim 1 or 4, characterized in that, The first soft magnetic metal powder and the second soft magnetic metal powder have the same composition.

6. The soft magnetic composite material according to claim 1, characterized in that, The first insulating coating material includes at least a first thermosetting resin; The second insulating coating material includes at least a second thermosetting resin; The first thermosetting resin and the second thermosetting resin are each selected from at least one of epoxy resin, cyanate ester resin and linear phenolic resin.

7. A method for preparing a soft magnetic composite material according to any one of claims 1-6, characterized in that, Includes the following steps: A pneumatic air-jet granulation powder is provided, the pneumatic air-jet granulation powder comprising a second soft magnetic metal powder and a second insulating coating material, wherein the second insulating coating material is completely cured; and The airflow crushed granulated powder, the first soft magnetic metal powder, and the first insulating coating material are mixed to obtain a soft magnetic composite material; The airflow crushing granulation powder is obtained by mixing a second insulating coating material and a second soft magnetic metal powder, and then sequentially performing granulation, complete curing, and airflow crushing processes.

8. A metal powder core, characterized in that, It is made from the soft magnetic composite material described in any one of claims 1-6.

9. A method for preparing a metal powder core, characterized in that, Includes the following steps: The soft magnetic composite material described in any one of claims 1-6 is subjected to granulation and thermo-pressing treatment in sequence to obtain a metal powder core.

10. A molded inductor, characterized in that, It is made from the soft magnetic composite material described in any one of claims 1-6.

11. A method for preparing a molded inductor, characterized in that, Includes the following steps: The soft magnetic composite material according to any one of claims 1-6 is subjected to granulation treatment to obtain soft magnetic composite material granulated powder; and The soft magnetic composite material granules and windings are placed in a mold, and then subjected to temperature and pressure treatment to obtain a metal powder core.

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