Inductor and preparation method thereof, and preparation method of low-voltage integrally formed inductor material

Abstract

The invention discloses an inductor and a preparation method thereof, and a preparation method of a low-voltage integrally formed inductor material. The preparation method of the low-voltage integrally formed inductor material comprises a first particle powder processing step: mixing a first particle powder containing 90-94wt% Fe, 2.9-4.5wt% Si, 0.5-3.0wt% P, 0.5-3.0wt% B, 0.05-0.75wt% C and 0.05-0.75wt% Mn with ammonia water, drying to a moisture content of 1wt%-10wt%, and then heat treating; a resin suspension preparation step: mixing a second particle powder with at least one of a liquid epoxy resin, a liquid phenolic resin or a liquid polyester resin, and adding ester and ketone solvents for dispersion to form a resin suspension; and a mixing treatment step: mixing the resin suspension with the first particle powder after the heat treatment, and drying to obtain the low-voltage integrally formed material. The solution of the present application can reduce the pressure required for molding and improve the magnetic permeability by coordinating the selection of material components, the design of processing technology, and the design of resin formula, thereby solving the technical problems existing in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of soft magnetic alloy material preparation, and in particular to an inductor and a preparation method thereof, and a preparation method of a low-voltage integrally formed inductor material. Background Art

[0002] With the development of electronic products, their functions are increasing and their sizes are getting smaller. The size of inductor components is also decreasing rapidly. Among them, integrated inductors are increasingly used due to their superior performance. However, as the size is miniaturized, the difficulty of processing is also increasing. This is mainly manifested in that after integrated pressing and molding, either the product has a serious open circuit problem or the performance cannot meet the requirements, such as too low magnetic permeability, poor insulation, etc. Therefore, it is urgent to solve this dilemma caused by the miniaturization of inductors.

[0003] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0004] In order to overcome the defects of the above-mentioned prior art, the present application provides a method for preparing a low-pressure one-piece molded inductor material with high magnetic permeability and low molding pressure, comprising the following steps:

[0005] The first particle powder treatment step comprises: mixing the first particle powder containing 90-94wt% Fe, 2.9-4.5wt% Si, 0.5-3.0wt% P, 0.5-3.0wt% B, 0.05-0.75wt% C and 0.05-0.75wt% Mn with aqueous ammonia, drying the mixture to a moisture content of 1wt% to 10wt%, and then heat treating the mixture in a nitrogen furnace;

[0006] The resin suspension preparation step comprises: selecting a second particle powder composed of at least one of carbonyl iron, FeNi and FeSi with a particle size of 1-3 μm, mixing it with at least one of liquid epoxy resin, liquid phenolic resin or liquid polyester resin, and adding ester and ketone solvents for dispersion to form a resin suspension;

[0007] Mixing treatment step: mixing the resin suspension and the first particle powder after heat treatment, and drying to obtain a mixed powder, which is the low-pressure one-piece molding material;

[0008] The resin suspension accounts for 30-50 wt % of the mass of the first particle powder.

[0009] The present invention can also adopt the following optional / preferred solutions:

[0010] The mass ratio of the ester solvent to the ketone solvent is 1:10 to 1:12, and the mass ratio of the resin suspension to the first particle powder after heat treatment is 1:1 to 1:3.

[0011] The heat treatment temperature is 250°C to 350°C, the time is 2 to 6 hours, and the drying temperature is 60°C to 120°C.

[0012] The first particle powder includes coarse particles and fine particles, the mass ratio of the coarse particles to the fine particles is 7:3-9:1, the ratio of the particle size of the coarse particles to the particle size of the fine particles is 5:1-7:1, and the particle size of the coarse particles is 20-35 um.

[0013] The concentration of the ammonia water is 3wt% to 10wt%, the amount of the ammonia water added is 20wt% to 50wt% of the mass of the first particle powder, and the temperature of the drying place is 90 to 110°C.

[0014] The preparation method of the resin suspension is as follows: the second particle powder is mixed with liquid epoxy resin and liquid phenolic formaldehyde, and an ester solvent and a ketone solvent are added for dispersion to form a mixed resin suspension; the mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic formaldehyde is 8:1 to 10:1; the mass ratio of the liquid epoxy resin to the liquid phenolic formaldehyde is 45:55 to 35:75; the mass ratio of the ester solvent to the ketone solvent is 1:10 to 1:12; the mass ratio of the ester solvent to the ketone solvent to the resin suspension is 1:1 to 1:3.

[0015] The preparation method of the resin suspension is as follows:

[0016] The second particle powder is mixed with liquid epoxy resin and liquid phenolic resin, and an ester solvent and a ketone solvent are added for dispersion to form a mixed resin suspension;

[0017] The mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic formaldehyde is 8:1, the mass ratio of the liquid epoxy resin to the liquid phenolic formaldehyde is 45:55, the mass ratio of the ester solvent to the ketone solvent is 1:10, and the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:1, or the mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic formaldehyde is 9:1, the mass ratio of the liquid epoxy resin to the liquid phenolic formaldehyde is 50:50, the mass ratio of the ester solvent to the ketone solvent is 1:11, and the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:2.

[0018] The preparation method of the resin suspension is as follows:

[0019] The second particle powder is mixed with a liquid epoxy resin and a liquid polyester resin, and an ester solvent and a ketone solvent are added for dispersion to form a mixed resin suspension;

[0020] The mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenol formaldehyde is 10:1, the mass ratio of the liquid epoxy resin to the liquid phenol formaldehyde is 35:75, the mass ratio of the ester solvent to the ketone solvent is 1:12, and the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:3.

[0021] The present invention further provides an inductor, which is made of the low-voltage one-piece molded inductor material obtained by any of the preparation methods described in the foregoing.

[0022] The present invention further provides a method for producing an inductor, firstly adopting any of the preparation methods described above to prepare a low-voltage one-piece molded inductor material, and then producing the inductor through an one-piece molding method.

[0023] One or more technical solutions provided in the embodiments of the present application have at least the following beneficial effects compared with the prior art:

[0024] The scheme of the present application can reduce the pressure required for molding and improve the magnetic permeability by cooperating with the selection of material components and the design of processing technology, as well as the design of resin formula. The molding material obtained by the preparation method can avoid the problem of copper wire film damage during the integrated pressing process because the pressure required for pressing is reduced, thereby solving the open circuit problem of the product existing in the processing of the miniaturized integrated inductor. At the same time, the molding density of the product can be improved, so the magnetic permeability is high. Therefore, in general, it can not only solve the open circuit problem of the miniaturized integrated inductor product, but also meet the performance requirements of the magnetic permeability and the like required by the product, providing a key support for the miniaturization and good performance of the integrated inductor. The first particle powder is mixed with ammonia water and dried to a moisture content of 1wt% to 10wt%, which can ensure that the concentration of ammonia water on the surface of the powder is within a certain range. Otherwise, if the concentration is too low, the hydrogen generated by the decomposition of ammonia is insufficient, and the reduction effect cannot be achieved. If the concentration is too high, the excessive generation of hydrogen will lead to excessive reduction of the oxide film, and then lead to a decrease in insulation, which will cause the product to fail to meet the performance requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of a preparation method of an embodiment of the present application. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1The present invention is further described in the following specific embodiments, wherein the same reference numerals represent the same components unless otherwise specifically stated. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope of the present invention and its application.

[0027] A method for preparing a low-voltage integrally formed inductor material comprises the following steps:

[0028] First particle powder processing step S100: Mix the first particle powder containing 90-94wt% Fe, 2.9-4.5wt% Si, 0.5-3.0wt% P, 0.5-3.0wt% B, 0.05-0.75wt% C and 0.05-0.75wt% Mn with ammonia water and dry it to a moisture content of 1wt% to 10wt%, and then heat treat it in a nitrogen furnace; the temperature of the heat treatment is between 250°C and 350°C, and the time is 2 to 6 hours.

[0029] Resin suspension preparation step S200: select a second particle powder composed of at least one of carbonyl iron, FeNi, and FeSi with a particle size of 1-3um, mix it with at least one of liquid epoxy resin, liquid phenolic resin or liquid polyester resin, and add ester and ketone solvents to disperse to form a resin suspension; the mass ratio of the ester solvent to the ketone solvent is 1:10 to 1:12, and the mass ratio of the resin suspension to the first particle powder after heat treatment is 1:1 to 1:3.

[0030] Mixing step S300: Mix the resin suspension and the first particle powder after heat treatment, and dry to obtain a mixed powder, which is the low-pressure integral molding material. The drying temperature is preferably between 60°C and 120°C.

[0031] Preferably, the first particle powder includes coarse particles and fine particles, the mass ratio of the coarse particles to the fine particles is 7:3-9:1, the particle size ratio of the coarse particles to the fine particles is 5:1-7:1, and the particle size of the coarse particles is 20-35um. The concentration of the ammonia water is between 3wt% and 10wt%, the amount of the ammonia water added is 20wt%-50wt% of the mass of the first particle powder, and the temperature of the drying place is between 90 and 110°C. The resin suspension accounts for 30-50wt% of the mass of the first particle powder.

[0032] The preparation method of the resin suspension is preferably as follows: the second particle powder is mixed with liquid epoxy resin and liquid phenolic formaldehyde, and an ester solvent and a ketone solvent are added for dispersion to form a mixed resin suspension; the mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic formaldehyde is 8:1 to 10:1; the mass ratio of the liquid epoxy resin to the liquid phenolic formaldehyde is 45:55 to 35:75; the mass ratio of the ester solvent to the ketone solvent is 1:10 to 1:12; the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:1 to 1:3.

[0033] An inductor is made of a low-voltage one-piece molded inductor material obtained by any of the preparation methods described above.

[0034] A method for producing an inductor comprises firstly adopting any of the preparation methods described above to prepare a low-voltage one-piece molded inductor material, and then producing the inductor through an one-piece molding method.

[0035] The present invention controls the material composition and process, and reduces the influence of the insulation treatment on the magnetic permeability while ensuring insulation by grading the amorphous material and treating the composite structure of the oxide layer and the reduction phase. In general, this effect is achieved by partial reduction after oxidation under specific conditions. If the particles are completely coated by oxidation, if the coating is too thin, it is easy for the particles to be incompletely coated, resulting in deterioration of the insulation performance. If it is too thick, the influence on the magnetic permeability performance is large, which will cause the magnetic properties to decrease, and the difficulty of process control is relatively large. The present invention can achieve both complete coating and thinner coating state by first oxidizing to a thicker oxide layer and then performing reduction treatment, so that the magnetic permeability is maintained at a better level. In addition, the pressing pressure is reduced by preparing a liquid resin system, the molding density is increased (the reason is that the liquid resin can drive the powder filling and has better lubricity during the pressing stage, which can effectively reduce the friction resistance between the powders), reduce the influence of pressure on the copper wire film during the pressing process, and prevent the short circuit problem after pressing. In summary, the preparation method of the present invention can prepare an integrally formed inductor material with low molding pressure, high magnetic permeability and good insulation effect.

[0036] Embodiment 1

[0037] A method for preparing a low-voltage integrally formed inductor material comprises the following steps:

[0038] The first granular powder is preferably a metal spherical granular powder, the material composition of which is: 90wt% Fe, 4.5wt% Si, 3.0wt% P, 3.0wt% B, 0.75wt% C and 0.75wt% Mn. The granular powder is composed of coarse particles and fine particles, the mass ratio of the coarse particles to the fine particles is 7:3, the particle size ratio of the coarse particles to the fine particles is 7:1, and the particle size of the coarse particle powder is 35um.

[0039] The first particle powder is mixed with ammonia water and dried to a moisture content of 1wt%, and then heat-treated in a nitrogen furnace at 250°C for 6 hours. The concentration of the ammonia water is 10wt%, and the amount of the ammonia water added is 50wt% of the mass of the powder. The drying temperature during the heat treatment is 110°C.

[0040] 1-3um carbonyl iron is selected as the second particle powder, mixed with liquid epoxy resin and liquid phenolic resin, and ester and ketone solvents are added for dispersion to form a mixed resin suspension, the mass ratio of the liquid epoxy resin to the liquid phenolic resin is 45:55, the ratio of the ester solvent to the ketone solvent is 1:10, the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:1, and the mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic resin is 8:1.

[0041] The resin suspension and the treated first particle powder are mixed, wherein the resin suspension accounts for 30wt% of the mass of the first particle powder, and then dried at 60° C. to obtain a mixed powder, which is the low-pressure one-piece molding material.

[0042] The obtained mixed powder (ie, the low-pressure integral molding material) was pressed in a mold at a temperature of 120° C. and a pressure of 5 MPa to obtain a magnetic ring, which was used as a test sample 1 after solidification.

[0043] Embodiment 2

[0044] A method for preparing a low-voltage integrally formed inductor material comprises the following steps:

[0045] The first particle powder is preferably a metal spherical particle powder, the material composition of which is: 94wt% Fe, 2.9wt% Si, 0.5wt% P, 0.5wt% B, 0.05wt% C and 0.05wt% Mn. The particle powder is composed of coarse particles and fine particles, the mass ratio of the coarse particles to the fine particles is 9:1, the particle size ratio of the coarse particles to the fine particles is 5:1, and the particle size of the coarse particle powder is 20um.

[0046] The first particle powder is mixed with ammonia water and dried to a moisture content of 10wt%, and then heat-treated in a nitrogen furnace at 350°C for 2 hours. The concentration of the ammonia water is 3wt%, the amount of the ammonia water added is 20wt% of the mass of the first particle powder, and the drying temperature of the heat treatment is 90°C.

[0047] 1-3um FeNi is selected as the second particle powder, mixed with liquid epoxy resin and liquid polyester resin, and ester and ketone solvents are added for dispersion to form a mixed resin suspension. The mass ratio of the liquid epoxy resin to the liquid polyester resin is 35:75, the ratio of the ester solvent to the ketone solvent is 1:12, the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:3, and the mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic resin is 10:1.

[0048] The resin suspension and the treated first particle powder are mixed, wherein the resin suspension accounts for 50wt% of the mass of the first particle powder, and then dried at 60° C. to obtain a mixed powder, which is the low-pressure one-piece molding material.

[0049] The obtained mixed powder (ie, the low-pressure integral molding material) was pressed in a mold at a temperature of 60° C. and a pressure of 30 MPa to obtain a magnetic ring, which was used as the second test sample after solidification.

[0050] Embodiment 3

[0051] A method for preparing a low-voltage integrally formed inductor material comprises the following steps:

[0052] The first granular powder is preferably a metal spherical granular powder, the material composition of which is: 92.2wt% Fe, 3.5wt% Si, 2.0wt% P, 1.5wt% B, 0.45wt% C and 0.35wt% Mn. The granular powder is composed of coarse particles and fine particles, the mass ratio of the coarse particles to the fine particles is 8:2, the particle size ratio of the coarse particles to the fine particles is 6:1, and the particle size of the coarse particle powder is 25um.

[0053] The first particle powder is mixed with ammonia water and dried to a moisture content of 5wt%, and then heat-treated in a nitrogen furnace at 300°C for 4 hours. The concentration of the ammonia water is 6wt%, the amount of the ammonia water added is 35wt% of the mass of the first particle powder, and the drying temperature of the heat treatment is 100°C.

[0054] 1-3um FeSi is selected as the second particle powder, mixed with liquid epoxy resin and liquid phenolic resin, and ester and ketone solvents are added for dispersion to form a mixed resin suspension. The mass ratio of the liquid epoxy resin to the liquid phenolic resin is 50:50, the ratio of the ester solvent to the ketone solvent is 1:11, the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:2, and the mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic resin is 9:1.

[0055] The resin suspension and the treated first particle powder are mixed, wherein the resin suspension accounts for 40wt% of the mass of the first particle powder, and then dried at 60° C. to obtain a mixed powder, which is the low-pressure one-piece molding material.

[0056] The obtained mixed powder (ie, the low-pressure one-piece molding material) was pressed in a mold at a temperature of 100° C. and a pressure of 10 MPa to obtain a magnetic ring, which was solidified to form the test sample three.

[0057] Comparative Example 1:

[0058] The surface of a metal spherical particle powder with a particle size of 7um to 50um and a composition of 92.75wt% Fe, 3.5wt% Si, 3.0wt% B and 0.75wt% C is phosphated, wherein the amount of phosphoric acid added is 0.3wt% of the mass of the particle powder, and the drying temperature after phosphating is set to 110°C.

[0059] The phosphated particle powder is mixed with a mixed resin accounting for 3 wt % of the mass of the particle powder, wherein the mixed resin is an epoxy resin and a polyester resin in a mass ratio of 1:1.

[0060] Then, the obtained mixed powder was pressed into a mold at a temperature of 120° C. and a pressure of 30 MPa to obtain a magnetic ring, which was used as test sample 4 after solidification.

[0061] Comparative Example 2:

[0062] The surface of a metal spherical particle powder with a particle size of 7um to 50um and a composition of 92.75wt% Fe, 3.5wt% Si, 3.0wt% B and 0.75wt% C is phosphated, wherein the amount of phosphoric acid added is 0.3wt% of the mass of the particle powder, and the drying temperature after phosphating is set to 110°C.

[0063] Carbonyl iron powder of 4-6 um is selected, and the powder is graded according to a FeSiBC:carbonyl iron powder mass ratio of 3:7. The graded material is mixed with a mixed resin of 3 wt% of the powder mass, wherein the mixed resin is an epoxy resin and a polyester resin in a mass ratio of 1:1.

[0064] Then, the obtained mixed powder was pressed into a mold at a temperature of 120° C. and a pressure of 10 MPa to obtain a magnetic ring, which was used as test sample five after solidification.

[0065] The performance of the above-mentioned magnetic rings was evaluated. The number of winding turns N = 26Ts turns. The 3260B LCR tester was used to test the initial magnetic permeability μi (1V / 1MHz) and the inductance value under superimposed current of the magnetic ring samples, as shown in Table 1 below:

[0066] Table 1

[0067]

[0068]

[0069] By comparing the samples obtained from the embodiments and the comparative examples, it can be found that the magnetic permeability of the samples from the embodiments is significantly higher than that of the samples from the comparative examples. At the same time, the breaking strength of the magnetic ring is also improved to a certain extent, which indicates that the low-pressure molded integrated inductor material obtained by the preparation method of the present invention has better solved the problems existing in the prior art.

[0070] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A method for preparing a low-voltage integrally formed inductor material, characterized in that include: The first particle powder treatment step: mixing the first particle powder containing 90-94wt% Fe, 2.9-4.5wt% Si, 0.5-3.0wt% P, 0.5-3.0wt% B, 0.05-0.75wt% C and 0.05-0.75wt% Mn with ammonia water, drying to a moisture content of 1wt%-10wt%, and then heat treating in a nitrogen furnace, wherein the moisture content of 1wt%-10wt% can ensure that the concentration of ammonia water on the surface of the first particle powder is within a certain range so that the surface of the first particle powder is coated with a composite structure of an oxide layer and a reduction phase; The resin suspension preparation step comprises: selecting a second particle powder composed of at least one of carbonyl iron, FeNi and FeSi with a particle size of 1-3 μm, mixing it with at least one of liquid epoxy resin, liquid phenolic resin or liquid polyester resin, and adding ester and ketone solvents for dispersion to form a resin suspension; Mixing treatment step: mixing the resin suspension and the first particle powder after heat treatment, and drying to obtain a mixed powder, which is the low-voltage one-piece molded inductor material; The resin suspension accounts for 30-50 wt % of the mass of the first particle powder.

2. The preparation method according to claim 1, characterized in that The mass ratio of the ester solvent to the ketone solvent is 1:10 to 1:12, and the mass ratio of the resin suspension to the first particle powder after heat treatment is 1:1 to 1:

3.

3. The preparation method according to claim 1, characterized in that: The heat treatment temperature is 250°C to 350°C, the time is 2 to 6 hours, and the drying temperature is 60°C to 120°C.

4. The preparation method according to claim 1, characterized in that: The first particle powder includes coarse particles and fine particles, the mass ratio of the coarse particles to the fine particles is 7:3-9:1, the ratio of the particle size of the coarse particles to the particle size of the fine particles is 5:1-7:1, and the particle size of the coarse particles is 20-35 um.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The concentration of the ammonia water is 3wt% to 10wt%, the amount of the ammonia water added is 20wt% to 50wt% of the mass of the first particle powder, and the temperature of the drying place is 90 to 110°C.

6. The preparation method according to claim 1, characterized in that: The preparation method of the resin suspension is as follows: The second particle powder is mixed with liquid epoxy resin and liquid phenolic resin, and an ester solvent and a ketone solvent are added for dispersion to form a mixed resin suspension; The mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic formaldehyde is 8:1 to 10:1; The mass ratio of the liquid epoxy resin to the liquid phenolic resin is 45:55 to 35:75; The mass ratio of the ester solvent to the ketone solvent is 1:10 to 1:12; The mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:1 to 1:

3.

7. The preparation method according to claim 1, characterized in that: The preparation method of the resin suspension is as follows: The second particle powder is mixed with liquid epoxy resin and liquid phenolic resin, and an ester solvent and a ketone solvent are added for dispersion to form a mixed resin suspension; The mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic formaldehyde is 8:1, the mass ratio of the liquid epoxy resin to the liquid phenolic formaldehyde is 45:55, the mass ratio of the ester solvent to the ketone solvent is 1:10, and the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:1, or the mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenolic formaldehyde is 9:1, the mass ratio of the liquid epoxy resin to the liquid phenolic formaldehyde is 50:50, the mass ratio of the ester solvent to the ketone solvent is 1:11, and the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:

2.

8. The preparation method according to claim 1, characterized in that: The preparation method of the resin suspension is as follows: The second particle powder is mixed with a liquid epoxy resin and a liquid polyester resin, and an ester solvent and a ketone solvent are added for dispersion to form a mixed resin suspension; The mass ratio of the second particle powder to the mixed solution of the liquid epoxy resin and the liquid phenol formaldehyde is 10:1, the mass ratio of the liquid epoxy resin to the liquid phenol formaldehyde is 35:75, the mass ratio of the ester solvent to the ketone solvent is 1:12, and the mass ratio of the ester solvent and the ketone solvent to the resin suspension is 1:

3.

9. An inductor, characterized in that: The low-voltage one-piece molded inductor material is obtained by the preparation method according to any one of claims 1 to 8.

10. A method for producing an inductor, characterized in that: Firstly, a low-voltage one-piece molded inductor material is prepared by the preparation method as described in any one of claims 1 to 8, and then an inductor is produced by an one-piece molding method.

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