High-voltage-resistant metal frame structure in-situ coated amorphous powder material for inductor and preparation method of high-voltage-resistant metal frame structure in-situ coated amorphous powder material

Abstract

The invention discloses a high-voltage-resistant metal frame structure in-situ coated amorphous powder material for an inductor and a preparation method of the high-voltage-resistant metal frame structure in-situ coated amorphous powder material. The surface of the amorphous powder material is coated with an inorganic metal frame structure serving as an insulating layer in situ. According to the invention, the amorphous powder material is coated in situ through the metal frame structure with the pore structure, so that the pressure resistance and chemical stability of an inductor product can be greatly improved, and the light weight of the inductor can be effectively realized; the method disclosed by the invention is simple, convenient to operate and good in coating effect, can realize industrialization, and has a great application prospect in the field of high-frequency inductors.

Description

[0001] Technology Neighborhood

[0002] The invention relates to the technical field of soft magnetic materials for inductors, in particular to soft magnetic powder capable of improving the withstand voltage performance of inductors and a preparation method thereof. Background Art

[0003] An excellent inductor product needs to ensure the normal operation of the circuit under extreme conditions. The winding and insulation parts of the inductor need to be able to withstand an electric field strength above the rated voltage, so as to prevent breakdown during use and cause safety hazards. Soft magnetic powders, including amorphous powders, are the basic raw materials for preparing inductors. However, due to differences in their chemical composition and microstructure, inductors generally have the problem of low breakdown voltage, resulting in short product life, poor reliability and stability. The withstand voltage of soft magnetic materials can be effectively improved by surface treatment or coating with an insulating layer. Depending on the insulating material, the insulation coating method can be divided into organic coating and inorganic coating. Inorganic coating materials are mainly non-magnetic oxides and phosphates, which require complex high-temperature treatment during preparation, and the coating layer formed has low strength and heavy weight, which cannot achieve lightweight inductors; organic coating materials are mainly phenolic resins and epoxy resins, and the coating layer formed has poor heat resistance and poor chemical stability. Summary of the invention

[0004] Based on the problems existing in the above-mentioned prior art, the present invention provides a high-voltage-resistant metal frame structure for in-situ coating of amorphous powder materials for inductance, aiming to improve the electromagnetic properties of the material through coating treatment without changing the crushing strength, so that the inductor made from it has a high breakdown voltage.

[0005] In order to achieve the purpose, the present invention adopts the following technical scheme:

[0006] A high-voltage metal frame structure for inductance in-situ coated amorphous powder material, the characteristic of which is that an inorganic metal frame structure as an insulating layer is in-situ coated on the surface of the amorphous powder material.

[0007] Furthermore, the inorganic metal framework structure is at least one of MOFs materials having a porous structure such as ZIF-8, MOF-74 and UIO-66.

[0008] Furthermore, the selected amorphous powder material has a micron-spherical morphology.

[0009] The preparation method of the in-situ coated amorphous powder material with a high withstand voltage metal frame structure for inductor of the present invention comprises the following steps: adding amorphous powder material and 2-methylimidazole accounting for 2-5% of the mass of the amorphous powder material into a solvent, stirring at a speed of 200-300r / min for 24h-36h in a nitrogen atmosphere, then adding zinc nitrate, the mass ratio of zinc nitrate to 2-methylimidazole is 1.2-1.4:1, and continuing stirring for 8h-10h; washing the obtained product with a solvent to remove unreacted 2-methylimidazole and zinc nitrate, and then drying at 40-60°C for 3-5h to obtain the in-situ coated amorphous powder material with a metal frame structure.

[0010] Furthermore, the stirring temperature is room temperature.

[0011] Furthermore, the solvent is at least one of methanol and ethanol.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] The present invention in-situ coats amorphous powder material through a metal frame structure with a porous structure. The porous structure has a certain strength and high resistivity, and can improve the electromagnetic properties of amorphous powder material without changing the crushing strength, thereby greatly improving the withstand voltage performance of inductor products, and making the inductor made of it as a raw material have a high breakdown voltage. At the same time, the in-situ coating of the metal frame has high chemical stability compared with organic and inorganic coatings, and the metal frame structure is usually relatively lightweight, which can effectively achieve lightweight inductance. The method of the present invention is simple, easy to operate, and has a good coating effect. It can be industrialized and has great application prospects in the high-frequency field of inductors. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a SEM image of the metal frame structure obtained in Example 2 in-situ coated with amorphous powder.

[0015] Figure 2 This is a BET test diagram of the metal frame structure obtained in Example 2 in-situ coated with amorphous powder.

[0016] Figure 3 The electromagnetic performance change curves (DC bias strength and breakdown voltage) of the toroidal inductors for testing obtained in various embodiments and comparative examples are shown.

[0017] Figure 4 The graphs are the changing curves of the widescreen dielectric constants of the toroidal inductors for testing obtained in the embodiments and comparative examples. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is described in detail below through specific embodiments. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0019] Example 1

[0020] In this embodiment, the metal frame structure is prepared by in-situ coating of amorphous powder material according to the following steps:

[0021] 200 g of amorphous powder (Fe-Si-BC amorphous powder, micron-spherical morphology, average particle size of 10 μm) and 6 g of 2-methylimidazole were added to 200 mL of methanol. Under a nitrogen atmosphere, the mixture was stirred at 300 r / min for 26 h. Then, 7.2 g of zinc nitrate was added and stirring was continued for 10 h. The obtained product was rinsed with methanol to remove unreacted 2-methylimidazole and zinc nitrate, and then dried at 60°C for 5 h to obtain a metal frame structure in-situ coated amorphous powder (the mass of 2-methylimidazole accounted for 3% of the mass of the amorphous powder).

[0022] The metal frame structure is in-situ coated with amorphous powder and epoxy resin accounting for 2% of the powder mass, and then added to acetone and stirred thoroughly to volatilize the acetone, and then passed through an 80-mesh stainless steel screen and left for 8 hours to remove the remaining solvent. The material is pressed into a magnetic ring at a pressure of 500MPa, and then the magnetic ring is cured at 180°C for 3 hours to obtain a toroidal inductor for testing.

[0023] Example 2

[0024] In this embodiment, the metal frame structure is prepared by in-situ coating of amorphous powder material according to the following steps:

[0025] 200 g of amorphous powder (Fe-Si-BC amorphous powder, micron-spherical morphology, average particle size of 10 μm) and 10 g of 2-methylimidazole were added to 200 mL of methanol. Under a nitrogen atmosphere, the mixture was stirred at 300 r / min for 26 h. Then 12 g of zinc nitrate was added and stirring was continued for 10 h. The resulting product was rinsed with methanol to remove unreacted 2-methylimidazole and zinc nitrate, and then dried at 60°C for 5 h to obtain a metal frame structure in-situ coated amorphous powder (the mass of 2-methylimidazole accounted for 5% of the mass of the amorphous powder).

[0026] The metal frame structure is in-situ coated with amorphous powder and epoxy resin accounting for 2% of the powder mass, and then added to acetone and stirred thoroughly to volatilize the acetone, and then passed through an 80-mesh stainless steel screen and left for 8 hours to remove the remaining solvent. The material is pressed into a magnetic ring at a pressure of 500MPa, and then the magnetic ring is cured at 180°C for 3 hours to obtain a toroidal inductor for testing.

[0027] Comparative Example 1

[0028] Amorphous powder (Fe-Si-BC amorphous powder, micron spherical morphology, average particle size of 10μm) and epoxy resin accounting for 2% of the powder mass were added to acetone and stirred thoroughly to volatilize the acetone, then passed through an 80-mesh stainless steel sieve and left for 8 hours to remove the remaining solvent. The material was pressed into a magnetic ring at a pressure of 500MPa, and then the magnetic ring was cured at 180℃ for 3 hours to obtain a toroidal inductor for comparison.

[0029] Figure 1 This is a SEM image of the metal frame structure obtained in Example 2 in-situ coated with amorphous powder. It can be seen that the surface of the amorphous powder is evenly coated and the product particle size is about 12 μm.

[0030] Figure 2 This is the BET test diagram of the metal framework structure obtained in situ coated with amorphous powder in Example 2. It can be seen that the metal framework with a porous structure is successfully coated on the magnetic powder, and the pore size is mesoporous and the specific surface area is 24.55m2 / g.

[0031] Figure 3 The electromagnetic performance change curves of the toroidal inductors obtained in the examples and the comparative examples are shown. Under the condition of fixed frequency of 100KHz and voltage of 1V, the DC bias strength (H) of the sample obtained in Example 2 is increased by 13.3% compared with the sample in Comparative Example 1. And with the increase of the coating amount of the metal frame structure (the coating amount is measured by the percentage of the mass of 2-methylimidazole to the mass of the amorphous powder material), the withstand voltage performance of the toroidal inductor is significantly improved, and the breakdown strength is increased from 899V in Comparative Example 1 to 1900V in Example 2, and the withstand voltage is increased by 111%.

[0032] Figure 4 The widescreen dielectric constant curves of the toroidal inductors obtained in the examples and the comparative examples show that as the coating amount increases, the dielectric constant of the samples decreases, and there is a dispersion phenomenon between the dielectric constant and the frequency. 7 Hz) The dielectric constants of the samples obtained in Example 1 and Example 2 are reduced by 4.9% and 19.2% respectively compared with the sample in Comparative Example 1. By reducing the dielectric constant of the material, the leakage current of the inductor can be effectively reduced, the capacitance effect between the wires can be reduced, and the heating phenomenon of the inductor can be reduced.

[0033] The above description is only an exemplary embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-voltage metal frame structure for inductors in-situ coated with amorphous powder, characterized in that: The surface of the amorphous powder material is in-situ coated with an inorganic metal framework structure as an insulating layer.

2. The high-voltage metal frame structure for inductance according to claim 1 is in-situ coated with amorphous powder material, characterized in that: The inorganic metal framework structure is at least one MOFs material selected from ZIF-8, MOF-74 and UIO-66.

3. The high-voltage metal frame structure for inductance in-situ coated with amorphous powder according to claim 1, characterized in that: The selected amorphous powder material has a micron-spherical morphology.

4. A method for preparing a high-voltage metal frame structure for inductance in-situ coated with amorphous powder material as claimed in any one of claims 1 to 3, characterized in that: Amorphous powder and 2-methylimidazole accounting for 2-5% of the mass of the amorphous powder are added to a solvent, and stirred at a speed of 200-300 r / min for 24h-36h under a nitrogen atmosphere, and then zinc nitrate is added, and the mass ratio of zinc nitrate to 2-methylimidazole is 1.2-1.4:1, and stirring is continued for 8h-10h; the obtained product is rinsed with a solvent to remove unreacted 2-methylimidazole and zinc nitrate, and then dried at 40-60°C for 3-5h to obtain a metal frame structure in-situ coated amorphous powder.

5. The preparation method according to claim 4, characterized in that: The stirring temperature is room temperature.

6. The preparation method according to claim 4, characterized in that: The solvent is at least one of methanol and ethanol.

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