Insulated coated soft magnetic powder as well as preparation method and application thereof

Abstract

The invention relates to insulation coated soft magnetic powder and a preparation method and application thereof, and the preparation method of the insulation coated soft magnetic powder comprises the following steps: (1) ball-milling and mixing FeSiCr soft magnetic powder and insulation powder to obtain ball-milled powder; and (2) heating and mixing an insulating agent solution and the ball-milled powder obtained in the step (1) until the solvent is volatilized, and drying the obtained powder to obtain the insulating coated soft magnetic powder, the insulating agent solution in the step (2) is obtained by mechanically mixing an insulating agent and a solvent. The insulating powder and the insulating agent are adopted to perform composite insulating coating on the soft magnetic powder, and the prepared insulating coated soft magnetic powder is good in antirust effect, excellent in magnetic performance and pressure resistance and capable of meeting the high-performance requirement of serving as an integrally-formed inductor raw material.

Description

Technical Field

[0001] The invention relates to the technical field of metal rust prevention, and in particular to an insulating coated soft magnetic powder and a preparation method and application thereof. Background Art

[0002] One-piece molded inductors have excellent properties such as small size, good frequency characteristics, and low loss, and are widely used in power modules, portable electronic devices, PC graphics cards, etc. With the advancement of electronic manufacturing fields such as automation control technology and smart terminals, the application environment of one-piece molded inductors has become increasingly harsh and diverse, especially in certain application environments with high temperature, high humidity, and high pH. Therefore, it is necessary to insulate the raw metal soft magnetic powder of the molded inductor to ensure the magnetic properties while improving its reliability.

[0003] At present, the mainstream insulation coating processes include organic coating, phosphating and inorganic coating. Among them, organic coating and phosphating require the use of a large amount of chemical reagents as solvents, which will cause pollution to the environment; in addition, organic coating generally uses epoxy resin and silicone resin. For example, CN 117711787A discloses a high magnetic permeability production process for metal magnetic powder cores, which uses FeSiCr magnetic powder as the main material, and MgO is coated on the surface of FeSiCr magnetic powder by sol-gel method, and then a certain proportion of CIP magnetic powder is compounded; then, epoxy resin is used for insulation coating, and then pressed and heat treated. The insulation layer formed by this method is generally thicker, and will cause metal powder agglomeration, affecting the subsequent molding process. The inductor pressed by it usually has the problem of greatly reduced insulation resistance after baking. The insulation layer prepared by traditional phosphating is easy to crack and peel off.

[0004] Inorganic coating, such as physical or chemical coating of nano oxides, phosphates, etc. The physical coating process is relatively simple, but the insulating auxiliary materials are easy to agglomerate and have poor dispersion, which will cause the overall powder coating to be uneven and easy to fall off; the chemical coating method can obtain a more uniform insulation layer, but the structure of the insulation layer will be affected by the concentration of the reactants and time, the density and strength of the insulation layer are difficult to control, and it will react with the metal elements in the powder, which will affect the electrical insulation performance and soft magnetic properties of the one-piece molded inductor.

[0005] CN 117095893A discloses a double-layer insulation coated soft magnetic powder and its preparation method and application. The double-layer insulation coated soft magnetic powder comprises soft magnetic powder, and the surface of the soft magnetic powder is coated with an inorganic insulation layer and an organic insulation layer in sequence. The raw materials for preparing the inorganic insulation layer include inorganic powder, silane coupling agent and dispersant, and the raw materials for preparing the organic insulation layer include thermosetting resin. The invention improves the comprehensive performance of the double-layer insulation coated soft magnetic powder by performing inorganic and organic insulation coating on the soft magnetic powder, but there are problems such as the process is relatively complicated and it is difficult to grasp the balance and achieve precise control of the double coating process.

[0006] Therefore, in view of the shortcomings of the prior art, it is necessary to provide an insulating coated soft magnetic powder with good rust prevention effect, simple process, excellent magnetic properties and good pressure resistance. Summary of the invention

[0007] The purpose of the present invention is to provide an insulating coated soft magnetic powder and a preparation method and application thereof. The obtained insulating coated soft magnetic powder has the characteristics of good rust prevention effect, excellent magnetic properties and good voltage resistance, and can be used to prepare high-performance one-piece molded inductors.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing an insulating coated soft magnetic powder, the preparation method comprising the following steps:

[0010] (1) ball milling and mixing FeSiCr soft magnetic powder and insulating powder to obtain ball milled powder;

[0011] (2) heating and mixing the insulating agent solution and the ball-milled powder obtained in step (1) until the solvent evaporates, and drying the obtained powder to obtain the insulating coated soft magnetic powder;

[0012] The insulating agent solution in step (2) is obtained by mechanically mixing the insulating agent and the solvent.

[0013] The preparation method of the insulating coated soft magnetic powder provided by the present invention adopts an insulating powder material and an insulating agent to perform composite insulating coating on the soft magnetic powder, and at the same time controls appropriate insulating coating process parameters, so that the prepared insulating coated soft magnetic powder has the characteristics of good rust prevention effect, excellent magnetic properties, and good pressure resistance, and can meet the high performance requirements as a raw material for an integrally formed inductor.

[0014] Preferably, the insulating powder in step (1) comprises any one of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, zirconium oxide, copper oxide, titanium dioxide, calcium oxide, antimony oxide, iron oxide, tin oxide, boron oxide, mica powder, kaolin or bentonite, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of silicon dioxide, aluminum oxide and titanium dioxide, a combination of zinc oxide, zirconium oxide and aluminum oxide, a combination of titanium dioxide, calcium oxide, antimony oxide, iron oxide, tin oxide and boron oxide, or a combination of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, zirconium oxide, copper oxide, titanium dioxide, calcium oxide, antimony oxide, iron oxide, tin oxide, boron oxide, mica powder, kaolin and bentonite.

[0015] Preferably, when the insulating powder is a combination of silicon dioxide, aluminum oxide and titanium dioxide, the mass ratio of silicon dioxide, aluminum oxide and titanium dioxide is 2:1:1.

[0016] Preferably, when the insulating powder is a combination of zirconium oxide, aluminum oxide and zinc oxide, the mass ratio of zirconium oxide, aluminum oxide and zinc oxide is 2:2:1.

[0017] Preferably, the amount of the insulating powder in step (1) is 0.1-2wt% of the mass of the FeSiCr soft magnetic powder, for example, it can be 0.1wt%, 0.5wt%, 0.75wt%, 1.8wt% or 2wt%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, preferably 0.5-1.8wt%.

[0018] Preferably, the rotation speed of the ball milling mixing in step (1) is 100-500 r / min, for example, it can be 100 r / min, 200 r / min, 300 r / min, 400 r / min or 500 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] Preferably, the ball milling mixing time in step (1) is 1-30 min, for example, 1 min, 5 min, 10 min, 20 min or 30 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] Preferably, the insulating agent includes any one of phosphoric acid, nitric acid, acetic acid, diammonium hydrogen phosphate, potassium dihydrogen phosphate, aluminum dihydrogen phosphate, amino trimethylene phosphonic acid, hydroxy ethylidene diphosphonic acid, ethylenediamine tetramethylene phosphonic acid, diethylene triamine penta methylene phosphonic acid, polyaspartic acid or polyepoxysuccinic acid, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of phosphoric acid, nitric acid and aluminum dihydrogen phosphate, a combination of nitric acid, aluminum dihydrogen phosphate and polyaspartic acid, or a combination of phosphoric acid, nitric acid, acetic acid, diammonium hydrogen phosphate, potassium dihydrogen phosphate, aluminum dihydrogen phosphate, amino trimethylene phosphonic acid, hydroxy ethylidene diphosphonic acid, ethylenediamine tetramethylene phosphonic acid, diethylene triamine penta methylene phosphonic acid, polyaspartic acid and polyepoxysuccinic acid.

[0021] Preferably, when the insulating agent is a combination of phosphoric acid, nitric acid and aluminum dihydrogen phosphate, the mass ratio of phosphoric acid, nitric acid and aluminum dihydrogen phosphate is 1:0.1:1.

[0022] Preferably, when the insulating agent is a combination of nitric acid, aluminum dihydrogen phosphate and polyaspartic acid, the mass ratio of nitric acid, aluminum dihydrogen phosphate and polyaspartic acid is 1:5:10.

[0023] Preferably, the amount of the insulating agent is 0.01-1wt% of the mass of the FeSiCr soft magnetic powder, for example, it can be 0.01wt%, 0.05wt%, 0.16wt%, 0.8wt% or 1wt%, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 0.05-0.8wt%.

[0024] Preferably, the amount of the solvent is 1-15wt% of the mass of the FeSiCr soft magnetic powder, for example, it can be 1wt%, 5wt%, 8wt%, 10wt% or 15wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the solvent comprises water.

[0026] Preferably, the mechanical mixing time is 5-10 min, for example, 5 min, 6 min, 8 min, 9 min or 10 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0027] Preferably, the mixing in step (2) is carried out in an inclined heatable drum.

[0028] Preferably, the mixing in step (2) is performed by adding an insulating agent solution to the ball-milled powder, followed by rolling stirring.

[0029] Preferably, the mixing speed in step (2) is 15-30 r / min, for example, it can be 15 r / min, 18 r / min, 20 r / min, 25 r / min or 30 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] Preferably, the heating temperature in step (2) is 40-80°C, for example, 40°C, 50°C, 60°C, 70°C or 80°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] Preferably, the drying temperature in step (2) is 155-165°C, for example, 155°C, 158°C, 160°C, 162°C or 165°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0032] Preferably, the drying time in step (2) is 1-2 h, for example, 1 h, 1.2 h, 1.5 h, 1.8 h or 2 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, step (2) further includes a screening step after the drying.

[0034] Preferably, the mesh size of the sieve is 120-200 mesh, for example, 120 mesh, 140 mesh, 160 mesh, 180 mesh or 200 mesh, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] As a preferred technical solution of the preparation method of the present invention, the preparation method comprises the following steps:

[0036] (1) ball-milling and mixing FeSiCr soft magnetic powder and insulating powder at a rotation speed of 100-500 r / min for 1-30 min to obtain ball-milled powder; the amount of the insulating powder is 0.1-2wt% of the mass of the FeSiCr soft magnetic powder;

[0037] (2) adding an insulating agent solution to the ball-milled powder obtained in step (1), heating the powder to 40-80° C. in an inclined heating drum, and rolling and stirring the powder at 15-30 r / min until the solvent evaporates, drying the powder at 155-165° C. and passing the powder through a 120-200 mesh sieve to obtain the insulating coated soft magnetic powder;

[0038] The insulating agent solution is obtained by mechanically mixing the insulating agent and the solvent for 5-10 minutes; the amount of the insulating agent is 0.01-1wt% of the mass of the FeSiCr soft magnetic powder; the amount of the solvent is 1-15wt% of the mass of the FeSiCr soft magnetic powder.

[0039] In a second aspect, the present invention provides an insulating coated soft magnetic powder, which is prepared by the method for preparing the insulating coated soft magnetic powder according to the first aspect.

[0040] The insulating coated soft magnetic powder provided by the present invention has good anti-rust effect, a magnetic permeability between 26-28.5, an initial withstand voltage of more than 600GΩ, and a withstand voltage test result after reflow soldering shows excellent withstand voltage performance.

[0041] In a third aspect, the present invention provides an application of the insulating coated soft magnetic powder as described in the second aspect, wherein the insulating coated soft magnetic powder is used to prepare an integrally formed inductor.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The preparation method of the insulating coated soft magnetic powder provided by the present invention adopts an insulating powder and an insulating agent to perform composite insulating coating on the soft magnetic powder, and at the same time controls appropriate insulating coating process parameters. The prepared insulating coated soft magnetic powder has good anti-rust effect, a magnetic permeability between 26 and 28.5, an initial withstand voltage of more than 600 GΩ, and a withstand voltage test result after reflow soldering shows that the withstand voltage performance is excellent, which can meet the high performance requirements as an integrally formed inductor raw material. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0045] Example 1

[0046] This embodiment provides an insulating coated soft magnetic powder, and the preparation method of the insulating coated soft magnetic powder comprises the following steps:

[0047] (1) ball-milling and mixing FeSiCr soft magnetic powder and insulating powder at a rotation speed of 300 r / min for 10 minutes to obtain ball-milled powder; the amount of the insulating powder is 0.75wt% of the mass of the FeSiCr soft magnetic powder; the insulating powder includes silicon dioxide, aluminum oxide and titanium dioxide in a mass ratio of 2:1:1;

[0048] (2) adding an insulating agent solution to the ball-milled powder obtained in step (1), then heating to 60° C. in an inclined heating drum, and rolling stirring at 20 r / min until water evaporates, drying the obtained powder at 160° C. and passing through a 160-mesh sieve to obtain the insulating coated soft magnetic powder;

[0049] The insulating agent solution is obtained by mechanically mixing the insulating agent and water for 8 minutes; the amount of the insulating agent is 0.16wt% of the mass of the FeSiCr soft magnetic powder; the insulating agent includes aluminum dihydrogen phosphate, nitric acid and polyaspartic acid in a mass ratio of 5:1:10; the amount of water is 10wt% of the mass of the FeSiCr soft magnetic powder.

[0050] Example 2

[0051] This embodiment provides an insulating coated soft magnetic powder, and the preparation method of the insulating coated soft magnetic powder comprises the following steps:

[0052] (1) ball-milling and mixing FeSiCr soft magnetic powder and insulating powder at a rotation speed of 100 r / min for 30 minutes to obtain ball-milled powder; the amount of the insulating powder is 1.8wt% of the mass of the FeSiCr soft magnetic powder; the insulating powder includes silicon dioxide, aluminum oxide and titanium dioxide in a mass ratio of 2:1:1;

[0053] (2) adding an insulating agent solution to the ball-milled powder obtained in step (1), then heating to 40° C. in an inclined heating drum, and rolling stirring at 30 r / min until water evaporates, drying the obtained powder at 155° C. and passing through a 120-mesh sieve to obtain the insulating coated soft magnetic powder;

[0054] The insulating agent solution is obtained by mechanically mixing the insulating agent and water for 5 minutes; the amount of the insulating agent is 0.05wt% of the mass of the FeSiCr soft magnetic powder; the insulating agent includes aluminum dihydrogen phosphate, nitric acid and polyaspartic acid in a mass ratio of 5:1:10; the amount of water is 10wt% of the mass of the FeSiCr soft magnetic powder.

[0055] Example 3

[0056] This embodiment provides an insulating coated soft magnetic powder, and the preparation method of the insulating coated soft magnetic powder comprises the following steps:

[0057] (1) ball-milling FeSiCr soft magnetic powder and insulating powder at a rotation speed of 500 r / min for 1 min to obtain ball-milled powder; the amount of the insulating powder is 0.5wt% of the mass of the FeSiCr soft magnetic powder; the insulating powder includes silicon dioxide, aluminum oxide and titanium dioxide in a mass ratio of 2:1:1;

[0058] (2) adding an insulating agent solution to the ball-milled powder obtained in step (1), and then heating to 80° C. in an inclined heating drum, and rolling stirring at 15 r / min until water evaporates, and drying the obtained powder at 165° C. and passing through a 200-mesh sieve to obtain the insulating coated soft magnetic powder;

[0059] The insulating agent solution is obtained by mechanically mixing the insulating agent and water for 10 minutes; the amount of the insulating agent is 0.8wt% of the mass of the FeSiCr soft magnetic powder; the insulating agent includes aluminum dihydrogen phosphate, nitric acid and polyaspartic acid in a mass ratio of 5:1:10; the amount of water is 15wt% of the mass of the FeSiCr soft magnetic powder.

[0060] Example 4

[0061] The present embodiment provides an insulating coated soft magnetic powder. The difference between the preparation method of the insulating coated soft magnetic powder and that of Example 1 is that, except for adjusting the amount of the insulating powder in step (1) to 0.1wt% of the mass of the FeSiCr soft magnetic powder and adjusting the amount of the insulating agent in step (2) to 1wt% of the mass of the FeSiCr soft magnetic powder, the rest is the same as that of Example 1.

[0062] Example 5

[0063] The present embodiment provides an insulating coated soft magnetic powder. The difference between the preparation method of the insulating coated soft magnetic powder and that of Example 1 is that, except for adjusting the amount of the insulating powder in step (1) to 2wt% of the mass of the FeSiCr soft magnetic powder and adjusting the amount of the insulating agent in step (2) to 0.01wt% of the mass of the FeSiCr soft magnetic powder, the rest is the same as that of Example 1.

[0064] Example 6

[0065] This embodiment provides an insulating coated soft magnetic powder. The difference between the preparation method of the insulating coated soft magnetic powder and that of Embodiment 1 is that, except for adjusting the mixing rotation speed in step (2) to 10 r / min, the rest is the same as that of Embodiment 1.

[0066] Example 7

[0067] This embodiment provides an insulating coated soft magnetic powder. The difference between the preparation method of the insulating coated soft magnetic powder and that of Embodiment 1 is that, except for adjusting the mixing rotation speed in step (2) to 40 r / min, the rest is the same as that of Embodiment 1.

[0068] Example 8

[0069] The present embodiment provides an insulating coated soft magnetic powder. The preparation method of the insulating coated soft magnetic powder is different from that of Example 1 in that the insulating powder in step (1) is adjusted to zirconium oxide, aluminum oxide and zinc oxide in a mass ratio of 2:2:1, and the insulating agent in step (2) is adjusted to phosphoric acid, nitric acid and aluminum dihydrogen phosphate in a mass ratio of 1:0.1:1. The rest is the same as in Example 1.

[0070] Comparative Example 1

[0071] This comparative example provides a FeSiCr soft magnetic powder, and the FeSiCr soft magnetic powder is not subjected to insulation coating treatment.

[0072] Comparative Example 2

[0073] The present comparative example provides an insulating coated soft magnetic powder, and the preparation method of the insulating coated soft magnetic powder comprises: mixing phosphoric acid and acetone solution, then adding FeSiCr soft magnetic powder into the acetone solution containing phosphoric acid, ultrasonically stirring until the solvent evaporates, and drying at 160°C; the amount of the phosphoric acid used is 0.2wt% of the mass of the FeSiCr soft magnetic powder, and the amount of the acetone solution used is 20wt% of the mass of the FeSiCr soft magnetic powder.

[0074] The insulating coated soft magnetic powders provided in Examples 1-8 and Comparative Examples 1 and 2 were made into ring-shaped samples according to the preparation parameters of the integrally formed inductor, and then the magnetic properties were tested using a DC bias tester, and the withstand voltage performance was tested using an insulation resistance tester. The results are shown in Table 1.

[0075] Table 1

[0076]

[0077]

[0078] It can be seen from Table 1 that the insulating coated soft magnetic powder provided by the present invention has good magnetic properties and excellent pressure resistance, and can meet the high performance requirements as a raw material for an integrated molded inductor;

[0079] By comparing Example 1 with Examples 6 and 7, it can be seen that too low or too high mixing speed will have an adverse effect on the insulation coating effect of the powder; by comparing Example 1 with Example 8, it can be seen that the insulating agent and insulating powder type provided by the present invention can be used to obtain an insulating coated soft magnetic powder with better comprehensive performance;

[0080] By comparing Example 1 with Comparative Example 1, it can be seen that the withstand voltage performance is significantly reduced when soft magnetic powder is used without insulation coating; by comparing Example 1 with Comparative Example 2, it can be seen that the use of a single phosphoric acid as the insulating raw material will reduce the withstand voltage performance after reflow soldering.

[0081] In summary, the preparation method of the insulating coated soft magnetic powder provided by the present invention adopts an insulating powder and an insulating agent to perform composite insulating coating on the soft magnetic powder, and at the same time controls appropriate insulating coating process parameters. The prepared insulating coated soft magnetic powder has good anti-rust effect, a magnetic permeability between 26-28.5, an initial withstand voltage of more than 600GΩ, and the withstand voltage test results after reflow soldering show excellent withstand voltage performance, which can meet the high performance requirements as an integrated molded inductor raw material.

[0082] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing an insulating coated soft magnetic powder, characterized in that: The preparation method comprises the following steps: (1) ball milling and mixing FeSiCr soft magnetic powder and insulating powder to obtain ball milled powder; (2) heating and mixing the insulating agent solution and the ball-milled powder obtained in step (1) until the solvent evaporates, and drying the obtained powder to obtain the insulating coated soft magnetic powder; The insulating agent solution in step (2) is obtained by mechanically mixing the insulating agent and the solvent.

2. The preparation method according to claim 1, characterized in that: The insulating powder in step (1) comprises any one of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, zirconium oxide, copper oxide, titanium dioxide, calcium oxide, antimony oxide, iron oxide, tin oxide, boron oxide, mica powder, kaolin or bentonite, or a combination of at least two thereof; Preferably, the amount of the insulating powder in step (1) is 0.1-2wt% of the mass of the FeSiCr soft magnetic powder, preferably 0.5-1.8wt%.

3. The preparation method according to claim 1 or 2, characterized in that: The rotation speed of the ball milling mixing in step (1) is 100-500 r / min; Preferably, the ball milling mixing time in step (1) is 1-30 min.

4. The preparation method according to any one of claims 1 to 3, characterized in that The insulating agent includes any one of phosphoric acid, nitric acid, acetic acid, diammonium hydrogen phosphate, potassium dihydrogen phosphate, aluminum dihydrogen phosphate, amino trimethylene phosphonic acid, hydroxy ethylidene diphosphonic acid, ethylenediamine tetramethylene phosphonic acid, diethylenetriamine penta methylene phosphonic acid, polyaspartic acid or polyepoxysuccinic acid, or a combination of at least two thereof; Preferably, the amount of the insulating agent is 0.01-1wt% of the mass of the FeSiCr soft magnetic powder, preferably 0.05-0.8wt%.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The amount of the solvent is 1-15wt% of the mass of the FeSiCr soft magnetic powder; Preferably, the solvent comprises water; Preferably, the mechanical mixing time is 5-10 min.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The mixing in step (2) is carried out in an inclined heatable drum; Preferably, the mixing in step (2) is to add an insulating agent solution to the ball-milled powder, followed by rolling stirring; Preferably, the mixing speed in step (2) is 15-30 r / min; Preferably, the heating temperature in step (2) is 40-80°C.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The drying temperature in step (2) is 155-165° C. Preferably, the drying time in step (2) is 1-2 hours; Preferably, step (2) further comprises a screening step after the drying; Preferably, the mesh size of the sieve is 120-200 meshes.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: (1) ball-milling and mixing FeSiCr soft magnetic powder and insulating powder at a rotation speed of 100-500 r / min for 1-30 min to obtain ball-milled powder; the amount of the insulating powder is 0.1-2wt% of the mass of the FeSiCr soft magnetic powder; (2) adding an insulating agent solution to the ball-milled powder obtained in step (1), heating the powder to 40-80° C. in an inclined heating drum, and rolling and stirring the powder at 15-30 r / min until the solvent evaporates, drying the powder at 155-165° C. and passing the powder through a 120-200 mesh sieve to obtain the insulating coated soft magnetic powder; The insulating agent solution is obtained by mechanically mixing the insulating agent and the solvent for 5-10 minutes; the amount of the insulating agent is 0.01-1wt% of the mass of the FeSiCr soft magnetic powder; the amount of the solvent is 1-15wt% of the mass of the FeSiCr soft magnetic powder.

9. An insulating coated soft magnetic powder, characterized in that: The insulating coated soft magnetic powder is prepared by the method for preparing the insulating coated soft magnetic powder according to any one of claims 1 to 8.

10. An application of the insulating coated soft magnetic powder as claimed in claim 9, characterized in that: The insulating coated soft magnetic powder is used to prepare an integrally formed inductor.

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