High-insulation coated powder for inductor and preparation method of high-insulation coated powder

Abstract

The invention relates to the technical field of powder metallurgy and magnetic materials, in particular to a preparation method of high-insulation coated powder for an inductor, which comprises the following steps of: 1, uniformly mixing raw powder, and adding a surfactant and a dispersing agent in the mixing process to obtain soft magnetic powder particle cores, 2, mixing a first solution with the sieved soft magnetic powder particle cores to form a first mixture, and enabling the first solution to form a first coating layer; 3, a second solution and the soft magnetic powder particle cores in the step 2 are mixed to form a second mixture, and a second coating layer is formed; 4, a third solution and the soft magnetic powder particle cores in the step 3 are mixed to form a third mixture, and a third coating layer is formed to coat the outer surface of the second coating layer; and 5, forming a bonding layer by using the fourth solution, and coating the outer surface of the coating layer III with the bonding layer. Through a three-layer insulation and bonding layer resin coating process, the structural stability is improved, the toughness of the insulation layer is increased, and the insulation of the powder is still maintained in the pressing process.

Description

Technical Field

[0001] The invention belongs to the technical field of powder metallurgy and magnetic materials, and in particular relates to a high-insulation coated powder for inductance and a preparation method thereof. Background Art

[0002] Metal soft magnetic powder cores can be divided into categories: alloy powder, amorphous powder, carbonyl iron powder, etc. When used in electronic components, the powder surface needs to be coated with an insulating layer to improve the powder's voltage resistance. At the same time, because the powder packing density needs to be increased, high temperature and high pressure pressing is often required during the production process, resulting in the breaking of the coated insulating layer, a sharp drop in the powder's voltage resistance, and major defects such as component short circuits, board burns, and increased device losses.

[0003] It is very important to improve the ability of the insulation layer of the powder to resist breakage during the pressing process. Therefore, a high-insulation coated powder for inductors and a preparation method thereof are needed to solve the above problems. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high-insulation coated powder for inductor and a preparation method thereof, so as to solve the problems in the existing market raised in the above background technology.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A method for preparing high-insulation coated powder for inductance comprises the following steps:

[0007] Step 1: Mix the raw powders evenly, and add surfactants and dispersants during the mixing process to obtain soft magnetic powder particle cores, and sieve the soft magnetic powder particle cores to obtain sieved soft magnetic powder particle cores. The addition of surfactants can effectively reduce the interaction force between metal powder particles and reduce the adsorption and aggregation phenomenon between metal particles; dispersants can improve the popularity and stability of metal powders;

[0008] Step 2: Mixing the first solution with the sieved soft magnetic powder particle core to form a first mixture, removing the solvent in the first mixture by evaporation, and then heating and drying, so that the first solution forms a coating layer that coats the outer surface of the soft magnetic powder particle core;

[0009] Step 3: mixing the second solution with the soft magnetic powder particle cores in step 2 to form a second mixture, volatilizing and removing the solvent in the second mixture, and then heating and drying, so that the second solution forms a coating layer 2 that coats the outer surface of the coating layer 1;

[0010] Step 4: mixing the third solution with the soft magnetic powder particle cores in step 3 to form a third mixture, removing the solvent in the third mixture by evaporation, and then heating and drying, so that the third solution forms a coating layer 3 that coats the outer surface of the coating layer 2;

[0011] Step five: Mix the fourth solution with the soft magnetic powder particle cores in step four to form a fourth mixture, evaporate and remove the solvent in the fourth mixture, and then heat and dry it, so that the fourth solution forms an adhesive layer coating the outer surface of the coating layer three.

[0012] As a preferred embodiment of the present invention, the first solution includes: a solution of phosphate and nitrate dissolved in a ketone solvent; the second solution includes a solution of thermoplastic resin dissolved in a ketone solvent; the third solution includes a solution of silicone resin dissolved in a ketone solvent; and the fourth solution includes a solution of a two-component thermosetting resin dissolved in a ketone solvent.

[0013] As a preferred embodiment of the present invention, the surfactant is any one of sodium dodecylbenzene sulfonate and polyethylene glycol octanoate; the dispersant is any one of ethylene acrylic acid, maleic acid, and tetraethylethylenediamine; the ketone solvent is any one of acetone and butanone; the thermoplastic resin is any one of polyvinyl alcohol butyral resin, polyamide, and polyester; the silicone resin is any one of epoxy-modified silicone resin, methyltrichlorosilane, and dimethyldichlorosilane; the thermosetting resin is an epoxy-modified resin and a curing agent, and the curing agent includes any one of amines and acid anhydrides.

[0014] As a preferred embodiment of the present invention, the raw powder preparation in step 1 further comprises the following steps:

[0015] S11, weigh FeS i Cr5.5 alloy powder according to proportion and mix them evenly at 80-100° C.;

[0016] S12, adding 0.3% sodium dodecylbenzene sulfonate and 0.1% ethylene acrylate by mass percentage of the alloy powder during the mixing process of step S11, heating to 80-100° C. and stirring for 0.5-2 hours to obtain soft magnetic powder particle cores;

[0017] S13, passing the soft magnetic powder particle cores in S12 through a 50-mesh sieve to obtain soft magnetic powder particle cores with a sieved diameter of 10-25 μm.

[0018] As a preferred embodiment of the present invention, the coating layer 1 in step 2 further comprises the following preparation steps:

[0019] S21, dissolving 0.1% to 1% analytically pure phosphoric acid and 0.1% to 1% analytically pure nitric acid in a mass ratio of 1% to the alloy powder in a 10% acetone solvent to form a first solution, and stirring the first solution and the soft magnetic powder particle core at 80-100° C. for 1-2 hours to obtain a first mixture;

[0020] S22, removing volatile acetone in the first mixture of S21 by a vacuum pump;

[0021] S23. Bake the volatilized first mixture at 120-150°C for 1-5 hours, so that the phosphate and nitrate react with the metal powder surface under high temperature to generate an oxidation reaction, passivate the abnormally sharp parts on the powder surface, and solidify the first solution to generate an oxide layer, which is coated on the outer surface of the soft magnetic powder particle core to form a coating layer 1, passivate the abnormally sharp parts on the original powder surface, and the generated oxide layer plays a role of insulating protection.

[0022] As a preferred embodiment of the present invention, the coating layer 2 in step 3 further comprises the following preparation steps:

[0023] S31, dissolving 0.1% to 0.5% polyvinyl butyral resin in a mass ratio to the alloy powder in 10% acetone solvent to form a second solution, and stirring the second solution and the soft magnetic powder particle core at 25° C. for 1 hour to form a second mixture;

[0024] S32, removing volatile acetone from the second mixture by means of a vacuum pump S31;

[0025] S33. Bake the volatilized second mixture at 55°C for 1 to 2 hours to solidify the second solution and coat the outer surface of coating layer 1 to form coating layer 2. This layer of coated thermoplastic resin provides fluidity during high-temperature pressing, allowing the powder to move smoothly during offset extrusion, so that the insulating layer will not break.

[0026] As a preferred embodiment of the present invention, the coating layer 3 in step 4 further comprises the following preparation steps:

[0027] S41, dissolving 0.3% polyvinyl butyral resin by mass ratio to alloy powder in 10% acetone solution to form a third solution, stirring the third solution and magnetic powder particle cores at 80° C. for 1 hour to form a third mixture;

[0028] S42, removing volatile acetone in the third mixture in S41 by a vacuum pump;

[0029] S43, baking the volatilized third mixture at 120°C for 1-2 hours, so that the third solution solidifies and is coated on the outer surface of the coating layer 2 to form a coating layer 3. The purpose of the coating layer 3 is to increase the hardness during the pressing process. Silicones can effectively control deformation under high pressure.

[0030] As a preferred embodiment of the present invention, the adhesive layer in step 5 further comprises the following preparation steps:

[0031] S51, dissolving a two-component thermosetting resin having a mass ratio of 2% to 5% to the alloy powder in a 10% acetone solution to form a fourth solution, and stirring the fourth solution and the magnetic powder particle core at 25±5° C. for 0.5 to 2 hours to form a fourth mixture;

[0032] S52, removing volatile acetone in the fourth mixture in S51 by a vacuum pump;

[0033] S53, baking the volatilized fourth mixture at 55°C for 1-2 hours to completely volatilize the acetone solvent, and solidifying the fourth solution and coating the outer surface of the third coating layer to form an adhesive layer, the purpose of the adhesive layer is mainly to provide bonding ability after the device is pressed and formed.

[0034] A high-insulation coated powder for inductance, the inductance powder comprising:

[0035] Inductor powder, including soft magnetic powder particle core with magnetic properties, surfactant, and dispersant;

[0036] An insulating layer, coated on the outer surface of the soft magnetic powder particle core, the insulating layer comprising an insulating coating layer 1, an insulating coating layer 2, and an insulating coating layer 3;

[0037] The adhesive layer is coated on the outer surface of the insulating layer three.

[0038] An integrally formed inductor is obtained by molding the inductor powder.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The addition of surfactants can effectively reduce the interaction between metal powder particles, reduce the adsorption and aggregation between metal particles; dispersants can improve the circulation and stability of metal powders;

[0041] Phosphates and nitrates react with the surface of metal powders under high temperature to passivate the abnormally sharp parts on the surface of the powders. The first solution solidifies to form an oxide layer, which is coated on the outer surface of the soft magnetic powder particle core to form a coating layer 1, passivating the abnormally sharp parts on the surface of the original powders. The generated oxide layer plays a role of insulation protection.

[0042] The thermoplastic resin of the second coating layer provides fluidity during high-temperature pressing, allowing the powder to move smoothly during dislocation extrusion, so that the insulation layer will not break;

[0043] The purpose of coating layer 3 is to increase the hardness during the pressing process. Silicone can effectively control deformation under high pressure;

[0044] The purpose of the adhesive layer is mainly to provide bonding ability after the device is pressed and formed;

[0045] The original powder is 6T / cm under unit pressure. 2 It can still maintain high insulation performance, DC resistance>2KV.

[0046] Through the three-layer insulation and adhesive layer resin coating process, the structural stability is improved and the toughness of the insulation layer is increased, so that the insulation of the powder is still maintained during the pressing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 It is a schematic diagram of the process of the present invention;

[0049] Figure 2 This is a schematic diagram of the process of step 2 of the present invention;

[0050] Figure 3 It is a schematic diagram of the coated powder structure of the present invention. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] The present invention provides the following embodiments:

[0053] Embodiment 1:

[0054] A method for preparing high-insulation coated powder for inductance comprises the following steps:

[0055] Step 1: Mix the raw powders evenly, and add a surfactant and a dispersant during the mixing process to obtain a soft magnetic powder particle core 001, and sieve the soft magnetic powder particle core 001 to obtain the sieved soft magnetic powder particle core 001. The addition of a surfactant can effectively reduce the interaction force between metal powder particles and reduce the adsorption and aggregation between metal particles; the dispersant can improve the popularity and stability of the metal powder, and the surfactant is any one of sodium dodecylbenzene sulfonate and polyethylene glycol octanoate; the dispersant is any one of ethylene acrylic acid, maleic acid, and tetraethylethylenediamine; the ketone solvent is any one of acetone and butanone;

[0056] The preferred surfactant is sodium dodecylbenzene sulfonate and the dispersant is ethylene acrylate.

[0057] The raw powder preparation in step 1 also includes the following steps:

[0058] S11, weigh 50 kg of FeSiCr5.5 alloy powder according to proportion and mix them evenly at 80-100°C;

[0059] S12, adding 0.3% sodium dodecylbenzene sulfonate and 0.1% ethylene acrylate by mass percentage of the alloy powder during the mixing process of step S11, heating to 80-100° C. and stirring for 0.5-2 hours to obtain soft magnetic powder particle core 001;

[0060] Preferably: during the mixing process of step S11, 0.3% sodium dodecylbenzene sulfonate and 0.1% ethylene acrylate are added in percentage by mass of the alloy powder, and the mixture is heated to 80° C. and stirred for 0.5 h to obtain soft magnetic powder particle core 001;

[0061] S13, passing the soft magnetic powder particle core 001 in S12 through a 50-mesh sieve to obtain a soft magnetic powder particle core 001 with a sieved diameter of 10-25 μm.

[0062] Step 2: Mix the first solution with the sieved soft magnetic powder particle core 001 to form a first mixture, evaporate the solvent in the first mixture and then heat and dry it, so that the first solution forms a coating layer 002 that coats the outer surface of the soft magnetic powder particle core 001, and the first solution includes: a solution in which phosphates and nitrates are dissolved in a ketone solvent, and the ketone solvent is any one of acetone and butanone;

[0063] The preferred ketone solvent is acetone;

[0064] The coating layer 1 002 in step 2 also includes the following preparation steps:

[0065] S21, dissolving 0.1% to 1% analytically pure phosphoric acid and 0.1% to 1% analytically pure nitric acid in a mass ratio of 0.1% to 1% to the alloy powder in a 10% acetone solvent to form a first solution, and stirring the first solution and the soft magnetic powder particle core 001 at 80-100° C. for 1-2 hours to obtain a first mixture;

[0066] Preferably: 0.3% analytically pure phosphoric acid and 0.1% analytically pure nitric acid in a mass ratio to the alloy powder are dissolved in 10% acetone solvent to form a first solution, and the first solution and the soft magnetic powder particle core 001 are stirred at 80° C. for 2 hours to obtain a first mixture;

[0067] S22, removing volatile acetone in the first mixture of S21 by a vacuum pump;

[0068] S23, baking the volatilized first mixture at 120-150° C. for 1-5 hours, so that the phosphate and nitrate react with the surface of the metal powder under high temperature to passivate the abnormally sharp parts of the powder surface, and the first solution solidifies to form an oxide layer;

[0069] Preferably, the volatilized first mixture is baked at 150° C. for 3 hours, so that the phosphate and nitrate react with the surface of the metal powder under high temperature to passivate the abnormally sharp parts of the powder surface, and the first solution is solidified to form an oxide layer;

[0070] The outer surface of the soft magnetic powder particle core 001 is coated to form a coating layer 002, which passivates the abnormally sharp parts of the original powder surface, and the generated oxide layer plays a role of insulation protection.

[0071] Step 3: Mix the second solution with the soft magnetic powder particle core 001 in step 2 to form a second mixture, evaporate the solvent in the second mixture and then heat and dry it, so that the second solution forms a coating layer 2 003 that is coated on the outer surface of the coating layer 1 002;

[0072] The second solution includes a solution of a thermoplastic resin dissolved in a ketone solvent;

[0073] The thermoplastic resin is any one of polyvinyl alcohol butyral resin, polyamide and polyester;

[0074] Preferred thermoplastic resins are: polyvinyl alcohol butyral resin;

[0075] The coating layer 2 003 in step 3 also includes the following preparation steps:

[0076] S31, dissolving 0.1% to 0.5% polyvinyl alcohol butyral resin in a mass ratio to the alloy powder in 10% acetone solvent to form a second solution, and stirring the second solution and the soft magnetic powder particle core 001 at 25° C. for 1 hour to form a second mixture;

[0077] Preferably, 0.3% polyvinyl alcohol butyral resin by mass ratio to alloy powder is dissolved in 10% acetone solvent to form a second solution, and the second solution and soft magnetic powder particle core 001 are stirred at 25° C. for 1 hour to form a second mixture;

[0078] S32, removing volatile acetone from the second mixture by means of a vacuum pump S31;

[0079] S33. Bake the volatilized second mixture at 55°C for 1 to 2 hours to solidify the second solution and coat the outer surface of coating layer 1 002 to form coating layer 2 003. This layer of coated thermoplastic resin provides fluidity during high-temperature pressing, allowing the powder to move smoothly during offset extrusion, so that the insulating layer will not break.

[0080] Preferably, the volatilized second mixture is baked at 55° C. for 1 hour;

[0081] Step 4: Mix the third solution with the soft magnetic powder particle core 001 in step 3 to form a third mixture, evaporate the solvent in the third mixture and then heat and dry it, so that the third solution forms a coating layer 3 004 coating the outer surface of the coating layer 2 003;

[0082] The third solution includes a solution of silicone resin dissolved in a ketone solvent;

[0083] The silicone resin is any one of epoxy-modified silicone resin, methyltrichlorosilane and dimethyldichlorosilane;

[0084] The preferred silicone resin is polyvinyl alcohol butyral resin;

[0085] The coating layer 3 004 in step 4 also includes the following preparation steps:

[0086] S41, dissolving 0.3% polyvinyl butyral resin by mass ratio to alloy powder in 10% acetone solution to form a third solution, stirring the third solution and magnetic powder particle cores at 80° C. for 1 hour to form a third mixture;

[0087] S42, removing volatile acetone in the third mixture in S41 by a vacuum pump;

[0088] S43, baking the volatilized third mixture at 120°C for 1-2 hours, so that the third solution solidifies and is coated on the outer surface of the coating layer 2 003 to form the coating layer 3 004. The purpose of the coating layer 3 004 is to increase the hardness during the pressing process. Silicone can effectively control deformation under high pressure.

[0089] Preferably, the volatilized third mixture is baked at 120° C. for 1 hour.

[0090] Step 5: Mix the fourth solution with the soft magnetic powder particle core 001 in step 4 to form a fourth mixture, evaporate the solvent in the fourth mixture and then heat and dry it, so that the fourth solution forms an adhesive layer 005 that covers the outer surface of the coating layer 3 004;

[0091] The fourth solution includes a two-component thermosetting resin dissolved in a ketone solvent;

[0092] The thermosetting resin is a two-component thermosetting resin including an epoxy modified resin and a curing agent, wherein the curing agent includes any one of amines and acid anhydrides;

[0093] The preferred curing agent is: amine polyurethane curing agent;

[0094] The adhesive layer 005 of step five also includes the following preparation steps:

[0095] S51, dissolving 4% of modified epoxy resin and 0.8% of amine polyurethane curing agent in a mass ratio of the alloy powder in a 10% acetone solution to form a fourth solution, and stirring the fourth solution and the magnetic powder particle core at 25±5° C. for 0.5 to 2 hours to form a fourth mixture;

[0096] Preferably, the fourth solution and the magnetic powder particle core are stirred at 25° C. for 1.5 hours;

[0097] S52, removing volatile acetone in the fourth mixture in S51 by a vacuum pump;

[0098] S53, baking the volatilized fourth mixture at 55°C for 2 hours to completely volatilize the acetone solvent, and solidifying the fourth solution and coating the outer surface of the coating layer 004 to form an adhesive layer 005. The purpose of the adhesive layer 005 is mainly to provide bonding ability after the device is pressed and formed.

[0099] Embodiment 2:

[0100] 50 kg of FeSiCr5.5 alloy powder was heated to 80°C, 0.3% by mass of sodium dodecylbenzenesulfonate and 0.1% by mass of ethylene acrylate were added, and the mixture was heated and stirred for 0.5 h to obtain soft magnetic powder particle cores.

[0101] In an acetone solution containing 10% by mass of the alloy powder, add 0.3% by mass of analytical grade phosphoric acid and 0.1% by mass of analytical grade nitric acid, stir evenly and pour into the alloy powder, stir at 80°C for 2 hours, remove the volatile acetone by vacuum, and bake the powder in an oven at 150°C for 3 hours to obtain a coating layer 1 coated on the outer surface of the soft magnetic powder particle core.

[0102] In an acetone solution containing 10% by mass of the alloy powder, 0.3% by mass of polyvinyl alcohol butyral resin was added, stirred evenly and poured into the alloy powder, stirred at 25°C for 1 hour, and the volatile acetone was removed by vacuum, and the powder was baked in an oven at 55°C for 1 hour to obtain a coating layer 2 coated on the outer surface of the coating layer 1.

[0103] In an acetone solution containing 10% by mass of the alloy powder, 0.5% by mass of sodium silicate was added, stirred evenly and poured into the alloy powder, stirred at 80°C for 1 hour, and the volatile acetone was removed by vacuum, and the powder was baked in an oven at 120°C for 1 hour to obtain a coating layer three coated on the surface of the coating layer two.

[0104] In an acetone solution containing 10% by mass of the alloy powder, add 4% by mass of the alloy powder modified epoxy resin and 0.8% by mass of the amine polyurethane curing agent, stir evenly and pour into the alloy powder, stir at 25°C for 1.5 hours, remove the volatile acetone by vacuum, bake the powder in an oven at 55°C for 2 hours to obtain an adhesive layer coated on the three surfaces of the coating layer, and the above steps obtain the inductor powder.

[0105] Embodiment 3: A high-insulation coated powder for inductance, the inductance powder comprising:

[0106] Alloy powder, including soft magnetic powder particle core 001 with magnetic properties, surfactant, and dispersant;

[0107] An insulating layer, coated on the outer surface of the soft magnetic powder particle core 001, the insulating layer comprises an insulating coating layer 1 002, an insulating coating layer 2 003, and an insulating coating layer 3 004;

[0108] The adhesive layer 005 is coated on the outer surface of the insulating layer three.

[0109] Embodiment 4: An integrally formed inductor is obtained by molding the inductor powder in Embodiment 1.

[0110] The addition of surfactants in the present application can effectively reduce the interaction between metal powder particles and reduce the adsorption and aggregation between metal particles; dispersants can improve the popularity and stability of metal powders;

[0111] Phosphates and nitrates react with the surface of metal powders to produce an oxidation reaction at high temperature, passivating the abnormally sharp parts of the powder surface. The first solution solidifies to form an oxide layer, which is coated on the outer surface of the soft magnetic powder particle core 001 to form a coating layer 002, passivating the abnormally sharp parts of the original powder surface. The generated oxide layer plays a role in insulation protection; the thermoplastic resin of the coating layer 003 provides fluidity during high-temperature pressing, allowing the powder to move smoothly during dislocation extrusion, so that the insulating layer will not break; the purpose of the coating layer 004 is to increase the hardness during the pressing process, and silicone can effectively control deformation under high pressure; the purpose of the bonding layer 005 is mainly to provide bonding ability after the device is pressed and formed; the original powder is obtained at a unit pressure of 6T / cm 2 It can still maintain high insulation performance, with DC impedance > 2KV. Through the three-layer insulation and adhesive layer 005 resin coating process, the structural stability is improved and the toughness of the insulation layer is increased, so that the insulation of the powder is still maintained during the pressing process, reducing the complexity of the production process and technology, and being able to better serve and develop the market.

[0112] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing high insulation coated powder for inductor, characterized in that: The steps include: Step 1: Mix the raw powders evenly, and add a surfactant and a dispersant during the mixing process to obtain soft magnetic powder particle cores, and sieve the soft magnetic powder particle cores to obtain sieved soft magnetic powder particle cores; Step 2: Mixing the first solution with the sieved soft magnetic powder particle core to form a first mixture, removing the solvent in the first mixture by evaporation, and then heating and drying to form a coating layer that coats the outer surface of the soft magnetic powder particle core; Step 3: mixing the second solution with the soft magnetic powder particle cores in step 2 to form a second mixture, removing the solvent in the second mixture by evaporation, and then heating and drying to form a second coating layer covering the outer surface of the first coating layer; Step 4: mixing the third solution with the soft magnetic powder particle cores in step 3 to form a third mixture, removing the solvent in the third mixture by evaporation, and then heating and drying to form a coating layer 3 covering the outer surface of the coating layer 2; Step five: Mix the fourth solution with the soft magnetic powder particle cores in step four to form a fourth mixture, evaporate and remove the solvent in the fourth mixture, and then heat and dry to form an adhesive layer that is coated on the outer surface of the coating layer three.

2. The method for preparing high-insulation coated powder for inductance according to claim 1, characterized in that: The first solution includes: a solution in which phosphate and nitrate are dissolved in a ketone solvent; The second solution includes a solution of a thermoplastic resin dissolved in a ketone solvent; The third solution includes a solution of silicone resin dissolved in a ketone solvent; The fourth solution includes a two-component thermosetting resin dissolved in a ketone solvent.

3. The method for preparing high insulation coated powder for inductor according to claim 2, characterized in that: The surfactant is any one of sodium dodecylbenzene sulfonate and polyethylene glycol octanoate; The dispersant is any one of ethylene acrylic acid, maleic acid and tetraethylethylenediamine; The ketone solvent is any one of acetone and butanone; The thermoplastic resin is any one of polyvinyl alcohol butyral resin, polyamide and polyester; The silicone resin is any one of epoxy-modified silicone resin, methyltrichlorosilane and dimethyldichlorosilane; The thermosetting resin is an epoxy modified resin and a curing agent, and the curing agent includes any one of amines and acid anhydrides.

4. The method for preparing high-insulation coated powder for inductance according to claim 3, characterized in that: The raw powder in step 1 also includes the following steps: S11, weigh FeSiCr5.5 alloy powder according to proportion and mix them evenly at 80-100°C; S12, adding 0.3% sodium dodecylbenzene sulfonate and 0.1% ethylene acrylate by mass percentage of the alloy powder during the mixing process of step S11, heating to 80-100° C. and stirring for 0.5-2 hours to obtain soft magnetic powder particle cores; S13, passing the soft magnetic powder particle cores in S12 through a 50-mesh sieve to obtain soft magnetic powder particle cores with a sieved diameter of 10-25 μm.

5. The method for preparing high-insulation coated powder for inductance according to claim 4, characterized in that: The step 2 also includes the following steps: S21, dissolving 0.1% to 1% analytically pure phosphoric acid and 0.1% to 1% analytically pure nitric acid in a mass ratio of 1% to the alloy powder in a 10% acetone solvent to form a first solution, and stirring the first solution and the soft magnetic powder particle core at 80-100° C. for 1-2 hours to obtain a first mixture; S22, removing volatile acetone in the first mixture of S21 by a vacuum pump; S23. Bake the volatilized first mixture at 120-150° C. for 1-5 hours, so that the phosphate and nitrate react with the surface of the metal powder under high temperature to passivate the abnormally sharp parts of the powder surface, and the first solution solidifies to form an oxide layer, which is coated on the outer surface of the soft magnetic powder particle core to form a coating layer 1.

6. The method for preparing high-insulation coated powder for inductance according to claim 5, characterized in that: Step three also includes the following steps: S31, dissolving 0.1% to 0.5% polyvinyl butyral resin in a mass ratio to the alloy powder in 10% acetone solvent to form a second solution, and stirring the second solution and the soft magnetic powder particle core at 25° C. for 1 hour to form a second mixture; S32, removing volatile acetone from the second mixture by means of a vacuum pump S31; S33, baking the volatilized second mixture at 55°C for 1-2 hours, so that the second solution solidifies and is coated on the outer surface of the coating layer 1 to form the coating layer 2.

7. The method for preparing high-insulation coated powder for inductance according to claim 6, characterized in that: The coating layer 3 of step 4 also includes the following preparation steps: S41, dissolving 0.3% polyvinyl butyral resin by mass ratio to alloy powder in 10% acetone solution to form a third solution, stirring the third solution and magnetic powder particle cores at 80° C. for 1 hour to form a third mixture; S42, removing volatile acetone in the third mixture in S41 by a vacuum pump; S43, baking the volatilized third mixture at 120° C. for 1 to 2 hours, so that the third solution is solidified and coated on the outer surface of the coating layer 2 to form the coating layer 3.

8. The method for preparing high-insulation coated powder for inductance according to claim 7, characterized in that: The adhesive layer of step five also includes the following preparation steps: S51, dissolving a two-component thermosetting resin having a mass ratio of 2% to 5% to the alloy powder in a 10% acetone solution to form a fourth solution, and stirring the fourth solution and the magnetic powder particle core at 25±5° C. for 0.5 to 2 hours to form a fourth mixture; S52, removing volatile acetone in the fourth mixture in S51 by a vacuum pump; S53, baking the volatilized fourth mixture at 55°C for 1-2 hours to completely volatilize the acetone solvent, and solidifying the fourth solution and coating the outer surface of the third coating layer to form an adhesive layer.

9. A high-insulation coated powder for inductance, prepared by the method for preparing a high-insulation coated powder for inductance according to any one of claims 1 to 8, characterized in that ,Inductor powder includes: Granulated powder, including soft magnetic powder particle core with magnetic properties, surfactant, and dispersant; An insulating layer, coated on the outer surface of the soft magnetic powder particle core, the insulating layer comprising an insulating coating layer 1, an insulating coating layer 2, and an insulating coating layer 3; The adhesive layer is coated on the outer surface of the insulating layer three.

10. An integrally formed inductor, characterized in that: The inductor powder is obtained by molding.

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