JP7157946B2 - Method for manufacturing magnetic material, method for manufacturing powder magnetic core, and method for manufacturing coil component - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to methods of manufacturing magnetic materials, dust cores and coil components, and methods of manufacturing these.

Conventionally, oxide magnetic materials such as ferrite and metal magnetic materials have been used as magnetic materials for magnetic cores of inductors and transformers. As a magnetic core using these magnetic materials, there is, for example, a powder magnetic core obtained by compression-molding metal powder. A powder magnetic core has a high saturation magnetic flux density and is a magnetic core that is advantageous for miniaturizing parts such as inductors and transformers. In addition, since powder magnetic cores can be molded with a mold, there is a high degree of freedom in the shape of the magnetic core, and even complex shapes can be manufactured with high precision in a simple process. (See Patent Document 1, for example).

Patent Literature 1 discloses a magnetic material mainly composed of iron (Fe) and silicon (Si) as a magnetic material constituting a dust core, and a dust core using the magnetic material. In Patent Document 1, an insulating coating is formed on the surface of magnetic powder containing Fe and Si as main components.

JP 2005-146315 A

Dust cores using magnetic materials with insulating coatings are added with silicone resins and silane coupling agents as binders and heat-dried to ensure insulation and adhesion between metal magnetic particles. It is made by high pressure molding after application. However, since the silane coupling agent begins to react and the binder begins to harden in the heat drying treatment, the magnetic material cannot be highly filled during molding of the powder magnetic core. As a result, there is a problem that a dust core with high magnetic properties cannot be obtained.

SUMMARY OF THE INVENTION In view of the problems described above, an object of the present invention is to provide a method for producing a magnetic material having high magnetic properties, a dust core, and a coil component.

A method for producing a magnetic material according to an aspect of the present disclosure includes an organic solvent, a magnetic powder containing iron as a main component, a resin material, and an additive whose main component is a metal chelate complex or a cyclic aluminum oligomer. By removing the organic solvent by heating the mixture containing A first heat treatment step of obtaining an intermediate material formed as a film, and a powdering step of powdering the intermediate material obtained by the first heat treatment step, wherein the molecular weight of the resin material is the same as that of the additive The molecular weight of the additive is 300 or more and 1000 or less, and the resin material is a thermoplastic material .

Further, a method for manufacturing a dust core according to an aspect of the present disclosure includes a first molding step of powder-molding the magnetic material obtained by the manufacturing method having the characteristics described above, and the first molding step. and a second heat treatment step of heating the formed body.

Further, a method for manufacturing a coil component according to an aspect of the present disclosure includes a second molding step of integrating the magnetic material and the coil obtained by the manufacturing method having the characteristics described above by powder molding; and a third heat treatment step of heating the compact obtained in the molding step of (1).

ADVANTAGE OF THE INVENTION According to this indication, the manufacturing method of the magnetic material which has a high magnetic property, a dust core, and coil components can be provided.

1 is a schematic perspective view showing the configuration of a coil component according to Embodiment 1; FIG. 1 is an exploded perspective view showing the configuration of a coil component according to Embodiment 1. FIG. Sectional view showing the configuration of the magnetic material according to the first embodiment 4 is a flow chart showing the manufacturing process of the magnetic material and the coil component according to the first embodiment; Flowchart showing granulated powder manufacturing process according to Embodiment 1 Flowchart showing a core manufacturing process according to Embodiment 1 Flowchart showing a coil assembly process according to the first embodiment FIG. 4 is a diagram showing types of additives in magnetic cores and initial magnetic permeability and magnetic loss of the magnetic cores according to examples and comparative examples of the first embodiment; 4 is a diagram showing the types of additives in the magnetic core and the density of the magnetic core according to Embodiment 1. FIG. Graph showing the type of additive in the magnetic core and the density of the magnetic core according to Embodiment 1 4 is a diagram showing the types of additives in the magnetic core and the initial magnetic permeability of the magnetic core according to Embodiment 1. FIG. Graph showing the type of additive in the magnetic core and the initial magnetic permeability of the magnetic core according to Embodiment 1 4 is a diagram showing the molecular weight and initial permeability of the magnetic material in the magnetic core according to Embodiment 1. FIG. 4 is a diagram showing the molecular weight and initial permeability of the magnetic material in the magnetic core according to Embodiment 1. FIG. 4 is a diagram showing the molecular weight and initial permeability of the magnetic material in the magnetic core according to Embodiment 1. FIG. 4 is a diagram showing the molecular weight, initial permeability, and filling rate of the magnetic material in the magnetic core according to Embodiment 1. FIG. 4 is a diagram showing the molecular weight, initial permeability, and filling rate of the magnetic material in the magnetic core according to Embodiment 1. FIG. Diagram for explaining the reaction mechanism between the inorganic powder and the chelate complex Schematic perspective view showing a configuration of a coil component according to Embodiment 2 Sectional view showing the configuration of the coil component according to the second embodiment Flowchart showing the manufacturing process of the coil component according to the second embodiment Flowchart showing core manufacturing and coil assembling processes according to Embodiment 2

Hereinafter, embodiments will be specifically described with reference to the drawings.

It should be noted that each of the embodiments described below is a specific example of the present disclosure. Numerical values, shapes, materials, components, arrangement positions of components, connection forms, steps, order of steps, and the like shown in the following embodiments are examples, and are not intended to limit the present disclosure. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept will be described as arbitrary constituent elements.

(Embodiment 1)
[1-1. Configuration of coil parts and magnetic core]
A coil component 1 according to the present embodiment includes a magnetic core (dust core) made of a magnetic material and a coil portion arranged inside the magnetic core.

FIG. 1A is a schematic perspective view showing the configuration of coil component 1 according to the present embodiment. FIG. 1B is an exploded perspective view showing the configuration of coil component 1 according to the present embodiment. FIG. 2 is a cross-sectional view showing the structure of the magnetic material according to this embodiment.

As shown in FIGS. 1A and 1B, the coil component 1 includes two split magnetic cores 12, conductors 13, and two coil supports 14. As shown in FIGS. Two split magnetic cores 12 form a magnetic core, and a conductor 13 and two coil supports 14 form a coil portion.

The split magnetic core 12 includes a base 12a and a cylindrical core portion 12b formed on one surface of the base 12a. Further, wall portions 12c are formed upright from edges of the base 12a on two opposite sides of the four sides constituting the base 12a. The core portion 12b and the wall portion 12c have the same height from one surface of the base 12a. Each of the two split magnetic cores 12 is a dust core formed by pressing a magnetic material into a predetermined shape.

The two split magnetic cores 12 are arranged such that their respective core portions 12b and wall portions 12c are in contact with each other. At this time, the conductor 13 is arranged so as to surround the periphery of the core portion 12b. Conductor 13 is incorporated into split core 12 via coil support 14 .

The two coil supports 14, as shown in FIG. 1B, have an annular base portion 14a and a cylindrical portion 14b. The core portion 12b of the split magnetic core 12 is arranged inside the cylindrical portion 14b, and the conductor 13 is arranged around the outer periphery of the cylindrical portion 14b.

The magnetic material forming the split magnetic core 12 is, for example, an Fe—Si based metallic magnetic material, which is an alloy containing Fe and Si as main components.

Specifically, as shown in FIG. 2 , in the split magnetic core 12 , a plurality of metal magnetic powders 17 are pressure-molded, and an insulating material 18 is formed on the surface of each metal magnetic powder 17 . The insulating material 18 covering the surface of each adjacent metal magnetic powder 17 is bound to each other. In other words, the insulating material 18 is arranged between each metal magnetic powder 17, and each metal magnetic powder 17 is insulated from each other.

The Fe—Si based metal magnetic powder 17 is a metal soft magnetic powder containing Fe and Si as main components, or a metal soft magnetic powder containing Fe, Si and Al as main components. The metal magnetic powder 17 may contain inevitable impurities other than Fe, Si, and Al. In metal magnetic powder 17 in the present embodiment, Si is used to improve soft magnetic properties. By adding Si, the magnetic anisotropy and magnetostriction constant of the metal magnetic powder 17 can be reduced, the electrical resistance can be increased, and the eddy current loss can be reduced. The amount of Si added is, for example, 1 wt % or more and 8 wt % or less. If the amount of Si added is less than 1 wt %, the effect of improving the soft magnetic properties is poor, and if it exceeds 8 wt %, the saturation magnetization is significantly reduced and the direct current superimposition characteristic is deteriorated. In this case, the composition of the metal magnetic powder 17 other than Si is Fe.

A method for producing the metal magnetic powder 17 according to the present embodiment is not particularly limited, and various atomization methods and various pulverization methods can be used.

The average particle diameter of metal magnetic powder 17 according to the present embodiment is preferably 1 μm or more and 100 μm or less. If the average particle size is less than 1 μm, the compacting density will be low and the magnetic permeability will be low. If the average grain size is larger than 100 μm, the eddy current loss at high frequencies increases. More preferably, the average particle size of the metal magnetic powder 17 is 50 μm or less. The average particle size of the metal magnetic powder is determined by laser diffraction particle size distribution measurement. For example, a particle to be measured that exhibits the same diffracted and scattered light pattern as a sphere with a diameter of 10 μm is assumed to have a diameter of 10 μm regardless of its shape. Then, the particle diameters are counted from the smallest one, and the particle diameter when the total is 50% of the total is taken as the average particle diameter.

The insulating material 18 contains at least one of Ti, Zr, and Al, for example. As will be described later, the insulating material 18 is a film formed in a manufacturing process so that an additive added to form the insulating material 18 covers the surface of the metal magnetic powder 17 . The metal magnetic powder 17 is insulated by the insulating material 18 . The additive contains, for example, a chelate containing Al, Ti, Zr, etc., an oligomer, an acylate as a coupling agent, a polymer (resin), etc. as main components.

By using these additives, an insulating film can be formed on the surface of the metal magnetic powder 17 as the insulating material 18 . When a material containing Ti as the main component of the additive is used, an insulating coating containing Ti is arranged as the insulating material 18 around the metal magnetic powder 17 . When a material containing Zr as the main component of the additive is used, an insulating film containing Zr is arranged as the insulating material 18 around the metal magnetic powder 17 . When a material containing Al as the main component of the additive is used, an insulating film containing Al is arranged as the insulating material 18 around the metal magnetic powder 17 .

In addition, by using these additives, the insulating material 18 can be configured to be easily plastically deformed. The distance between the magnetic powders 17 can be made close. Thereby, the density of the metal magnetic powder 17 in the magnetic core can be increased. That is, the filling rate of the metal magnetic powder 17 in the magnetic core can be increased. Thereby, the magnetic characteristics can be improved in the coil component 1 using the magnetic core.

[1-2. Coil component manufacturing method]
A method of manufacturing a magnetic material and a coil component according to the present embodiment will be described below. FIG. 3 is a flow chart showing the manufacturing process of the magnetic material and the coil component 1 according to this embodiment.

As shown in FIG. 3, the manufacturing process of coil component 1 according to the present embodiment includes a granulated powder manufacturing process S (step S10), a core manufacturing process (step S20), and a coil assembling process (step S30). contains. In the granulated powder manufacturing process, the magnetic material that constitutes the magnetic core described above is produced. In the core manufacturing process, the split magnetic cores 12 are formed by molding a magnetic material. In the coil assembly process, the above-described split magnetic cores 12, 13 and 14 are assembled to complete the coil component 1. As shown in FIG. Each step will be described in detail below.

FIG. 4 is a flow chart showing the granulated powder manufacturing process according to the present embodiment. As shown in FIG. 4, in the granulated powder production process, first, raw materials for producing a magnetic material are prepared (step S11). As raw materials for the magnetic material, metal magnetic powder 17, an additive for forming insulating material 18, a resin material as a binder, and an organic solvent are prepared.

As the metal magnetic powder 17, magnetic powder containing Fe as a main component is used. For example, the metal magnetic powder 17 is made of an alloy of Fe and Si, sendust, permalloy, or the like. When using an alloy of Fe and Si, the content of Fe and Si may be adjusted. The particle size of the metal magnetic powder 17 is, for example, 20 μm.

As an additive for forming the insulating material 18, metal chelate complexes containing metals such as Al, Ti and Zr, oligomers, acylates as coupling agents, polymers (resins) and the like are used as main components. Oligomers may be used, for example, cyclic aluminum oligomers. The main component of the additive may be an aluminum organic compound. The molecular weight of the additive is, for example, 300 or more and 1000 or less. In addition, the molecular weight of the additive is not limited to this, and may be smaller than 300 or larger than 1,000. Moreover, the amount of the additive added to the resin material described later is preferably 5% or more and 40% or less by weight with respect to the resin material described later. Further, an additive having a molecular weight of less than 300 and exhibiting other effects may be further added.

Resin materials such as acrylic resins, silicone resins, butyral resins, etc., are used as binders when the split magnetic cores 12 are pressure-molded. The molecular weight of the resin material is greater than that of the additive. The resin material is a thermosetting material that is liquid at room temperature, or a thermoplastic material.

Furthermore, for example, toluene, xylene, ethanol, or the like is used as an organic solvent for facilitating kneading and dispersing the metal magnetic powder 17, additive, and binder.

Next, the metal magnetic powder 17, the additive for forming the insulating material 18, the resin material as the binder, and the organic solvent are weighed. Then, the metal magnetic powder 17, additive, resin material and organic solvent are kneaded and dispersed (step S12). The kneading and dispersion are carried out by placing the weighed metal magnetic powder 17, additives, resin material and organic solvent in a container and mixing and dispersing them in a rotating ball mill. The kneading and dispersion are not limited to kneading and dispersion using a rotary ball mill, and other kneading and dispersion methods may be used.

Next, after kneading and dispersing the metal magnetic powder 17, additive, resin material and organic solvent, the magnetic material is granulated (step S13). At this time, the kneaded and dispersed metal magnetic powder 17, additive, resin material and organic solvent are dried by heat treatment at a temperature of around 100° C., for example. The heat treatment step at this time is the first heat treatment step.

By heat treatment, the organic solvent is removed from the kneaded and dispersed metal magnetic powder 17, the additive, the resin material, and the organic solvent, and the magnetic material is an intermediate material in which the metal magnetic powder 17, the additive, and the resin material are integrated. is obtained. In this magnetic material, an insulating material 18 is formed on the surface of the metal magnetic powder 17 . The thickness of the insulating material 18 is, for example, about 10 [nm]. Note that the thickness of the insulating material 18 is not limited to this, and may be 1 to 200 nm. Also, the insulating material 18 is formed to have a hardness that is plastically deformed during pressure molding in the core manufacturing process. Therefore, when the magnetic material is pressure-molded in the core manufacturing process, the density (filling rate) of the metal magnetic powder 17 contained in the magnetic material per unit volume can be increased.

Further, the granulated magnetic material is pulverized (step S14) to reduce the particle size. This step is a pulverization step. After that, the magnetic material is classified by predetermined particle size (step S15). As described above, a magnetic material having a powder diameter of 100 μm to 500 μm is obtained.

The method of forming the insulating material 18 around the metal magnetic powder 17 is not limited to the method described above, and a liquid material obtained by kneading and dispersing the metal magnetic powder 17, additives and resin material in an organic solvent is sprayed. It may be carried out by a spray-drying method of drying.

FIG. 5 is a flow chart showing the core manufacturing process according to this embodiment. In the core manufacturing process, a magnetic material is molded to produce a magnetic core.

First, a magnetic material is pressure-molded into a predetermined shape (step S21). This step is the first molding step. Specifically, the classified magnetic material is placed in a molding die and compressed to produce a compact. At this time, uniaxial molding is performed at a constant pressure of 10 [ton/cm ² ], for example. The shape of the compact is, for example, the shape of the split magnetic core 12 shown in FIG. 1B. The shape of the molded body is not limited to this, and may be, for example, a shape in which the core portion 12b of the split magnetic core 12 is configured separately.

After that, the compact is heated at a temperature of 200 to 450[° C.] in an atmosphere of an inert gas such as N ₂ gas or in the air for degreasing (step S22). As a result, the resin material as the binder contained in the molded body is removed. The degreasing step may be omitted depending on the type and characteristics of the binder used.

Further, the compact after degreasing is annealed (heat treated) (step S23). The annealing step at this time is the second heat treatment step. An atmosphere-controlled electric furnace, for example, is used for annealing the compact. Atmosphere-controlled electric furnaces include, for example, box furnaces, tubular furnaces, and belt furnaces. In addition, you may use not only these methods but another method. Annealing of the compact is carried out, for example, at a predetermined oxygen partial pressure at an annealing temperature of 800[° C.] for one hour.

The annealing temperature and annealing time are not limited to those described above. For example, the annealing temperature may be 600 to 1000 [° C.] and the annealing time may be several tens of minutes to several hours. Annealing relaxes the distortion caused by the pressure during uniaxial molding. At least part of the insulating material 18 may be decomposed in the compact by annealing.

Next, the annealed compact is impregnated with a resin material (step S24). For example, an epoxy resin may be used as the resin material. By impregnating the resin material, the strength of the molded body can be improved.

Through the above steps, the surface of the metal magnetic powder 17 is covered with the insulating material 18, and a magnetic core with a high filling rate of the metal magnetic powder 17 is completed. Here, two split magnetic cores 12 are formed as magnetic cores. The coil component 1 can be obtained by assembling the two split magnetic cores 12 and the coil portion in the following manner.

FIG. 6 is a flow chart showing a coil assembly process according to this embodiment.

First, a coil is formed by winding the conductor 13 a predetermined number of times (step S31).

Next, the split magnetic core 12, the conductor 13 and the coil support 14 are assembled (step S32). As shown in FIG. 1B, the conductor 13 is arranged so as to surround the core portions 12b of the two split magnetic cores 12. As shown in FIG. At this time, the cylindrical portions 14b of the two coil supports 14 are arranged between the conductor 13 and the core portions 12b of the two split magnetic cores 12, respectively. Also, between the conductor 13 and the bases 12a of the two split magnetic cores 12, the annular bases 14a of the two coil supports 14 are arranged. At this time, the ends of the cylindrical portions 14b of the two coil supports 14 opposite to the side on which the annular base portion 14a is formed are arranged so as to contact each other.

Also, the two split magnetic cores 12 are arranged so that their respective core portions 12b and wall portions 12c are in contact with each other. In this manner, the coil component 1 is assembled by incorporating the conductor 13 into the split magnetic core 12 via the coil support 14 . As a result, the structure in which the conductor 13 is wound around the core portion 12b of the split magnetic core 12 is completed. In other words, the split magnetic core 12 becomes a magnetic core in which the core portion 12b penetrates the conductor 13 in the winding axial direction of the conductor 13 .

Furthermore, the assembled coil component 1 is molded with a resin material (step S33). Thereby, the coil component 1 is completed.

[1-3. Filling rate and magnetic properties of magnetic material in coil parts]
The filling rate and magnetic properties of the magnetic material in the magnetic core of the coil component 1 will be described below.

[1-3-1. Type of insulating material and initial permeability and magnetic loss of compact]
FIG. 7 is a diagram showing the types of additives in magnetic cores and the initial magnetic permeability and magnetic loss of magnetic cores according to examples and comparative examples of the present embodiment.

In FIG. 7, the magnetic core shown in Example 1 is a magnetic core molded from a magnetic material formed using an Al chelate complex as an additive and an acrylic resin as a binder. The magnetic core shown in Example 2 is a magnetic core molded from a magnetic material formed using an Al chelate complex as an additive and a silicone resin as a binder.

The magnetic core shown in Comparative Example 1 is a magnetic core formed by molding a magnetic material using a silicone resin as an additive and an acrylic resin as a binder. The magnetic core shown in Comparative Example 2 is a magnetic core formed by molding a magnetic material using a silane coupling agent as an additive and an acrylic resin as a binder.

That is, the magnetic cores of Examples 1 and 2 according to the present embodiment use an Al chelate complex as an additive. In contrast, the magnetic cores according to Comparative Examples 1 and 2 do not use the Al chelate complex as an additive.

In Examples 1 and 2 and Comparative Examples 1 and 2, 0.2 parts by weight of the additive and 1 part by weight of the binder were mixed.

Further, when the initial magnetic permeability of each magnetic core was measured, as shown in FIG. Therefore, the magnetic cores according to Examples 1 and 2, in which the Al chelate complex was used as an additive, were superior to the magnetic cores according to Comparative Examples 1 and 2, in which the Al chelate complex was not used as an additive. It was found that the magnetic permeability was improved.

Further, when the magnetic core according to Example 1 and the magnetic core according to Example 2 are compared, the magnetic core according to Example 1 using an acrylic resin as a binder is higher than the magnetic core according to Example 2. It was found that the initial permeability was improved.

Further ^, when measuring the magnetic loss of ^each magnetic core, as shown in FIG. /m ³ ], and in Comparative Example 2, 1420 [kW/m ³ ] was obtained. Therefore, the magnetic cores according to Examples 1 and 2 using the Al chelate as an additive have a higher magnetic loss than the magnetic cores according to Comparative Examples 1 and 2 not using the Al chelate as an additive. was found to be reduced.

Further, when the magnetic core according to Example 1 and the magnetic core according to Example 2 are compared, the magnetic core according to Example 2 using an acrylic resin as a binder is higher than the magnetic core according to Example 1. It was found that the magnetic loss was slightly reduced.

[1-3-2. Molecular Weight of Additive and Filling Rate and Initial Permeability of Magnetic Material in Molded Body]
Next, the relationship between the molecular weight of the additive and the filling rate of the magnetic material in the compact will be described.

FIG. 8A is a diagram showing the types of additives in the magnetic core and the density of the magnetic core according to the present embodiment. FIG. 8B is a graph showing the types of additives in the magnetic core and the density of the magnetic core according to the present embodiment.

Here, samples 1, 2 and 3 were prepared as magnetic core samples. The metal magnetic powder 17 used in each sample is Fe—Si based magnetic powder. Sample 1 is a magnetic core using Al chelate as an additive and an acrylic resin as a binder. The molecular weight of Al chelate is 491. Sample 2 is a magnetic core using Si acylate as an additive and acrylic resin as a binder. The molecular weight of Si acylate is 179. Sample 3 is a magnetic core using only an acrylic resin as a binder without adding any additives. After kneading, samples 1, 2 and 3 were heat-dried at heat treatment temperatures of 80° C., 100° C. and 120° C., respectively. For each of Sample 1, Sample 2 and Sample 3, the density of each sample at the above heat treatment temperature was measured.

As shown in FIGS. 8A and 8B, in sample 1, as the heat treatment temperature increased to 80° C., 100° C., and 120° C., the density of the magnetic material in the magnetic core increased to 6.789 [g/cm ³ ], 6.789 [g/cm 3 ]. It is as high as 794 [g/cm ³ ] and 6.809 [g/cm ³ ]. On the other hand, in sample 2, as the heat treatment temperature increased to 80° C., 100° C., and 120° C., the density of the magnetic material in the magnetic core increased to 6.706 [g/cm ³ ] and 6.716 [g/cm ³ ]. ], 6.673 [g/cm ³ ], and the density of the magnetic material is highest when the heat treatment temperature is 100°C. Similarly, for sample 3, as the heat treatment temperature increased to 80° C., 100° C., and 120° C., the density of the magnetic material in the magnetic core increased to 6.748 [g/cm ³ ] and 6.775 [g/cm ³ ]. ], 6.740 [g/cm ³ ], and the density of the magnetic material is highest when the heat treatment temperature is 100°C.

Therefore, it can be seen that the density of the magnetic material in the magnetic core increases depending on the heat treatment temperature when the Al chelate having a molecular weight of 491 is used as the binder.

Also, the relationship between the molecular weight of the additive and the initial magnetic permeability of the magnetic material in the compact will be described.

FIG. 9A is a diagram showing the types of additives in the magnetic core and the initial magnetic permeability of the magnetic core according to the present embodiment. FIG. 9B is a graph showing the types of additives in the magnetic core and the initial magnetic permeability of the magnetic core according to the present embodiment.

The magnetic core samples are Sample 1, Sample 2, and Sample 3 described above, and the initial magnetic permeability was measured after heat treatment at 80° C., 100° C., and 120° C., respectively.

As shown in FIGS. 9A and 9B, in sample 1, as the heat treatment temperature increases to 80° C., 100° C., and 120° C., the initial magnetic permeability of the magnetic material in the magnetic core increases to 156, 161, and 168. . On the other hand, in sample 2, the initial magnetic permeability of the magnetic material in the magnetic core decreased to 136, 134, and 133 as the heat treatment temperature increased to 80°C, 100°C, and 120°C. Similarly, for sample 3, the initial magnetic permeability of the magnetic material in the magnetic core decreased to 149, 149, and 146 as the heat treatment temperature increased to 80°C, 100°C, and 120°C.

Therefore, it can be seen that the initial magnetic permeability of the magnetic material in the magnetic core increases depending on the heat treatment temperature only when the Al chelate having a molecular weight of 491 is used as the binder.

Here, the relationship between the molecular weight of the additive and the initial magnetic permeability of the magnetic core when the types of the metal magnetic powder 17 and the additive are changed will be described.

10A to 10C are diagrams showing the molecular weight and initial permeability of the magnetic material in the magnetic core according to this embodiment.

FIG. 10A shows the initial magnetic permeability of a magnetic core using Fe—Si magnetic powder as the metal magnetic powder 17 and a material mainly composed of different types of Al chelate complexes as additives. In FIG. 10A, sample names of magnetic cores using an additive containing an Al chelate complex as a main component are "Al chelate 1", "Al chelate 2", "Al chelate 3", "Al chelate 4", and "Al chelate 4". Five types of magnetic cores of "Chelate 5" were prepared. The chelate complexes used in "Al chelate 1", "Al chelate 2", "Al chelate 3", "Al chelate 4", and "Al chelate 5" are (iC ₃ H ₇ O) ₂ Al ( _C6H9O3 ), _{Al ( C6H9O3} ) _{2 ( C5H7O2} ) _{, Al ( C6H9O3 ) 3 , ( iC3H7O} ) _2Al ( _C22H39O3 ) _{, Al ( C22H39O3 ) 2 ( C5H7O2 )} . The molecular weights of the additives used in the magnetic cores of "Al chelate 1", "Al chelate 2", "Al chelate 3", "Al chelate 4", and "Al chelate 5" are 274, 384, 414, 491, 829.

In addition, for comparison with magnetic cores using an additive containing an Al chelate complex as a main component, magnetic permeability is also shown for magnetic cores with sample names of "Si acylate" and "acrylic resin only". A magnetic core with a sample name of "Si acylate" is a magnetic core using an additive containing Si acylate as a main component. The molecular weight of Si acylate is 179. A magnetic core with a sample name of "acrylic resin only" _{is a magnetic core formed only of acrylic resin (C5O2H8)n without using any} additive. The molecular weight of the acrylic resin is higher than that of the additive, for example 440,000. Each magnetic core was heat-dried at heat treatment temperatures of 90° C. and 120° C. after kneading. The initial magnetic permeability was measured for each magnetic core.

When the heat treatment temperature was 90° C., as shown in FIG. 10A , the initial magnetic permeability was 149 for the magnetic core of “acrylic resin only”. On the other hand, in the magnetic cores of "Al chelate 1", "Al chelate 2", "Al chelate 3", "Al chelate 4", and "Al chelate 5" using an additive containing an Al chelate complex as a main component, , the initial permeability was 156, 154, 152, 178 and 166, respectively. On the other hand, the magnetic core of "Si acylate" using an additive containing Si acylate as a main component had an initial magnetic permeability of 136.

Therefore, when the heat treatment temperature is 90° C., the initial magnetic permeability when using the additive containing Al chelate as the main component is higher than when the additive is not used, but the Si acylate is used as the main component. It was found that the initial magnetic permeability when the additive was used was lower than when the additive was not used.

Similarly, when the heat treatment temperature was 120° C., the initial magnetic permeability was 146 for the magnetic core of “acrylic resin only”, as shown in FIG. 10A. On the other hand, in the magnetic cores of "Al chelate 1", "Al chelate 2", "Al chelate 3", "Al chelate 4", and "Al chelate 5" using an additive containing an Al chelate complex as a main component, , the initial permeability was 149, 160, 162, 181 and 172, respectively. On the other hand, the magnetic core of "Si acylate" using an additive containing Si acylate as a main component had an initial magnetic permeability of 133.

Therefore, even when the heat treatment temperature is 120° C., the initial magnetic permeability when using the additive containing the Al chelate complex as the main component is improved compared to when the additive is not used, and the Si acylate is used as the main component. It was found that the initial magnetic permeability when the additive was used did not improve compared to when the additive was not used.

In addition, in FIG. 10A, as the determination result, ◯ indicates that the initial magnetic permeability is higher than in the case of "acrylic resin only", and x indicates that it is lower. From FIG. 10A, when an additive containing Si acylate with a low molecular weight of 179 as a main component is used, the initial magnetic permeability is not improved, but an additive containing an Al chelate complex with a molecular weight of 274 or more as a main component is used. It was found that the initial permeability was improved when the

FIG. 10B shows the initial magnetic permeability of a magnetic core using Fe—Si magnetic powder as the metal magnetic powder 17 and a material mainly composed of Al chelate, Ti chelate, Zr chelate, Ti acylate, and Ti oligomer as additives. showing.

In FIG. 10B, a magnetic core with a sample name of "Al chelate 6" was prepared as a magnetic core using an additive containing an Al chelate complex as a main component. The Al chelate complex used for "Al Chelate ₆ " is Al _{( C5H7O2} ) ₃ .

Magnetic cores with sample names of "Ti chelate 1", "Ti chelate 2", and "Ti chelate 3" were prepared as magnetic cores using an additive containing a Ti chelate complex as a main component. The Ti chelate complexes used in "Ti Chelate 1", "Ti Chelate 2", and "Ti Chelate 3" are (iC ₃ H ₇ O) ₂ Ti(C ₅ H ₇ O ₂ ) ₂ , Ti(C _{5 H7O2} ) ₄ , _{( C8H17O} ) _{2Ti ( O2C8H17 ) 2 .}

Magnetic cores with sample names of "Zr chelate 1", "Zr chelate 2", and "Zr chelate 3" were prepared as magnetic cores using an additive containing a Zr chelate complex as a main component. The Zr chelate complexes used in "Zr Chelate 1", "Zr Chelate ₂ ", and "Zr Chelate ₃ " are ( _nC4H9O ) _3Zr ( _C5H7O2 ), _{( nC4 H9O} ) _{2Zr ( C6H9O3} ) ₂ , _{Zr ( C5H7O2 )4 .}

Further, a magnetic core with a sample name of "Ti acylate" was prepared as a magnetic core using an additive containing Ti acylate as a main component. A magnetic core with a sample name of "Ti oligomer" was prepared as a magnetic core using an additive containing Ti oligomer as a main component.

"Al chelate 6", "Ti chelate 1", "Ti chelate 2", "Ti chelate 3", "Zr chelate 1", "Zr chelate 2", "Zr chelate 3", "Ti acylate", "Ti oligomer The molecular weights of the additives used in each magnetic core of '' are 324, 364, 444, 596, 409, 452, 487, 957, and thousands. Also, for comparison, a magnetic core with a sample name of "acrylic resin only" was prepared, which was formed only from acrylic resin without using any additive. The heat treatment temperature of each magnetic core is 90°C.

As shown in FIG. 10B, "Al chelate 6", "Ti chelate 1", "Ti chelate 2", "Ti chelate 3", "Zr chelate 1", "Zr chelate 2", "Zr chelate 3", " The initial magnetic permeability of "Ti acylate" and "Ti oligomer" was 135, 142, 148, 129, 147, 139, 144, 152 and 131, respectively. On the other hand, the initial magnetic permeability of the "acrylic resin only" magnetic core was 128.

Therefore, the initial magnetic permeability of the magnetic core using an additive containing an Al chelate complex, a Ti chelate complex, a Zr chelate complex, a Ti acylate, or a Ti oligomer as a main component is You can see that it is getting higher.

In addition, in FIG. 10B, as the determination result, ◯ indicates that the initial magnetic permeability is higher than in the case of "acrylic resin only", and x indicates that it is lower. From FIG. 10B, it was found that the initial permeability was improved when an additive with a molecular weight of 324 or more was used.

FIG. 10C shows the initial magnetic permeability of a magnetic core using Fe—Si—Al based magnetic powder as the metal magnetic powder 17 and a material containing oligomers and polymers as additives.

In FIG. 10C, magnetic cores with sample names "Algomer 1", "Algomer 2", and "Algomer 3" were prepared as magnetic cores using an additive containing a cyclic aluminum oligomer (algomer) as a main component. A magnetic core with a sample name of "Polymer" was prepared as a magnetic core using an additive containing Si-based polymer (resin) as a main component. The molecular weights of the additives used in the magnetic cores of "Algomer 1", "Algomer 2", "Algomer 3" and "Polymer" are 306, 559, 979 and tens of thousands. Also, for comparison, a magnetic core with a sample name of "acrylic resin only" was prepared, which was formed only from acrylic resin without using any additive. The heat treatment temperature of each magnetic core is 90°C.

As shown in FIG. 10C, the initial magnetic permeability of "Algomer 1", "Algomer 2", "Algomer 3" and "Polymer" was 83, 116, 111 and 79, respectively. On the other hand, the initial magnetic permeability of the "acrylic resin only" magnetic core was 82.

Therefore, it can be seen that the initial magnetic permeability of the magnetic core using the additive containing algomer as a main component is higher than the case where the additive is not used in any case.

In addition, in FIG. 10C, as the determination result, ◯ indicates that the initial magnetic permeability is higher than in the case of "acrylic resin only", and x indicates that it is lower. From FIG. 10C, it was found that the initial magnetic permeability was improved when an additive with a molecular weight of 306 or more and 979 or less was used.

11A and 11B are diagrams showing the molecular weight, initial permeability, and filling rate of the magnetic material in the magnetic core according to this embodiment.

FIG. 11A shows the filling rate of a magnetic core using Fe—Si magnetic powder as the metal magnetic powder 17 and additives containing different kinds of Al chelate complexes as main components. The filling rate refers to the ratio of the metal magnetic powder 17 contained in the magnetic core per unit volume.

The magnetic core shown in FIG. 11A has five types of magnetic properties with the sample names "Al chelate 1", "Al chelate 2", "Al chelate 3", "Al chelate 4", and "Al chelate 5" shown in FIG. 10A. is the core. In addition, for comparison, the filling rate is also shown for the magnetic cores with the sample names "Si acylate" and "acrylic resin only". The heat treatment temperatures for each magnetic core are 90°C and 120°C. The initial magnetic permeability of each magnetic core is also shown to show the relationship between the filling rate and the initial magnetic permeability.

When the heat treatment temperature was 90° C., as shown in FIG. 11A, the filling rate was 89.9% for the magnetic core of “acrylic resin only”. On the other hand, in the magnetic cores of "Al chelate 1", "Al chelate 2", "Al chelate 3", "Al chelate 4", and "Al chelate 5" using an additive containing an Al chelate complex as a main component, , the filling rates were 90.7%, 90.3%, 90.4%, 90.8% and 90.7%, respectively. On the other hand, in the magnetic core of "Si acylate" using an additive containing Si acylate as a main component, the filling rate was 89.2%.

Therefore, when the heat treatment temperature is 90 ° C., the filling rate when using the additive containing the Al chelate complex as the main component is higher than when the additive is not used, but the Si acylate is used as the main component. It was found that the fill factor with the additive was lower than without the additive.

Similarly, when the heat treatment temperature was 120° C., as shown in FIG. 11A, the filling rate was 89.6% for the magnetic core of “acrylic resin only”. On the other hand, in the magnetic cores of "Al chelate 1", "Al chelate 2", "Al chelate 3", "Al chelate 4", and "Al chelate 5" using an additive containing an Al chelate complex as a main component, , the filling rates were 90.6%, 90.3%, 90.7%, 91.1% and 90.8%, respectively. On the other hand, in the magnetic core of "Si acylate" using an additive containing Si acylate as a main component, the filling rate was 88.7%.

Therefore, even when the heat treatment temperature is 120 ° C., the filling rate when using the additive containing the Al chelate complex as the main component is improved compared to the case where the additive is not used, and the Si acylate is used as the main component. It was found that the fill factor with the additive did not improve as compared to the case without the additive. Therefore, when the magnetic core is formed by using the Fe—Si magnetic powder as the metal magnetic powder 17, if the Si acylate with a low molecular weight of 179 is used as an additive, the packing rate is not improved, but the molecular weight is 274 or more. It was found that the packing rate was improved when the Al chelate complex of was used as an additive. In this case, the filling factor is, for example, 90% or more, and the initial magnetic permeability is, for example, 149 or more.

FIG. 11B shows the filling rate of a magnetic core using Fe—Si—Al based magnetic powder as the metal magnetic powder 17 and a material containing oligomers and polymers as main components as additives.

The magnetic cores shown in FIG. 11B are the magnetic cores with the sample names "Algomer 1", "Algomer 2", and "Algomer 3" shown in FIG. 10C. For comparison, the filling rate is also shown for the magnetic core with the sample name "Polymer". The heat treatment temperature of each magnetic core is 90°C.

As shown in FIG. 11B, the respective filling rates of “Algomer 1”, “Algomer 2”, “Algomer 3” and “Polymer” are 81.3%, 82.3%, 83.0% and 81.0%. %Met. On the other hand, the filling rate of the magnetic core of "acrylic resin only" was 81.0%.

Therefore, it was found that the filling rate of the magnetic core using the additive containing algomer as a main component was higher than that in the case where the additive was not used in any case. In addition, the filling rate of the magnetic core using the polymer-based additive as the additive is equivalent to the filling rate of the magnetic core "acrylic resin only", and the filling rate of the magnetic core using the algomer-based additive is It was found that the filling factor was lower than that of the magnetic core. From the above, it was found that when an additive having a molecular weight of 306 or more and 979 or less was used, the filling rate was improved. In this case, the filling rate is, for example, 81% or more, and the initial magnetic permeability is, for example, 83 or more.

Here, the molecular weight, filling rate and initial permeability of the additive will be explained. As described above, when an additive containing Si acylate having a molecular weight of 179 as a main component is used, the filling factor and the initial magnetic permeability are not improved as compared with the case where the additive is not used, but the molecular weight is 274 or more. When the additive containing the Al chelate complex as the main component is used, the filling rate and the initial magnetic permeability are improved as compared with the case where the additive is not used. Therefore, it can be said that by using an additive having a molecular weight of 274 or more, the filling rate and the initial magnetic permeability of the magnetic core can be improved. More reliably, it can be said that by using an additive having a molecular weight of 300 or more, the filling rate and initial permeability of the magnetic core can be improved.

In addition, when an additive containing a polymer having a molecular weight of several tens of thousands as a main component is used, the filling rate and the initial magnetic permeability are not improved as compared with the case where no additive is used, but a Ti oligomer having a molecular weight of several thousand is used as the main component, the filling rate and the initial magnetic permeability are improved as compared with the case where the additive is not used. Therefore, it can be said that the filling rate and the initial magnetic permeability of the magnetic core can be improved by using an additive with a molecular weight of several thousand or less. More reliably, it can be said that by using an additive having a molecular weight of 1000 or less, the filling rate and initial permeability of the magnetic core can be improved.

The above-mentioned material having a molecular weight of 300 or more and 1000 or less has high heat resistance and has a property that the plasticizing effect is maintained even after heat treatment. Therefore, by adding these materials as additives to Fe-based metal magnetic powder to produce a magnetic core, the binder (resin material) having a higher molecular weight than the additive is softened, and The metal magnetic powder 17 can be held in closer proximity. Thereby, the filling rate of the metal magnetic powder 17 in the magnetic core can be improved. Thus, by using an additive having a molecular weight of 300 or more and 1000 or less, it is possible to improve the filling rate of the metal magnetic powder 17 and improve the magnetic permeability.

Further, when comparing "Al chelate 1" and "Al chelate 4" with respect to the magnetic core using an additive containing an Al chelate complex as a main component, as shown in FIG. 11A, "Al chelate 4" It has a higher initial permeability and a higher filling rate than "Al chelate 1".

The reason for this is as follows. FIG. 12 is a diagram for explaining the reaction mechanism between the inorganic powder and the chelate complex.

“Al chelate 1” has an ethyl group (C ₂ H ₅ ) in the alkyl moiety of the alkylacetoacetate group (chelating agent) in the chelate complex. In contrast, “Al Chelate 4” has an oleyl group (C ₁₈ H ₃₅ ) in the alkyl portion of the chelating agent. An oleyl group is a hydrocarbon with a longer carbon chain length than an ethyl group.

In general, a chelate complex has an alkoxyl group (RO) as a hydrophilic group and an alkylacetoacetate group as a hydrophobic group. , carboxyl groups, and adsorbed water. Therefore, the inorganic powder has a structure in which the alkyl portion of the alkylacetoacetate group of the chelate complex is covered with hydrocarbons. As a result, the inorganic powder coated with hydrocarbons in the alkyl moiety has an affinity for organic substances.

In addition, the chelate complex lowers the surface energy of the inorganic powder by coating the inorganic powder with the hydrocarbon in the alkyl moiety, and significantly improves the wettability and dispersibility of the inorganic powder with respect to organic resins such as acrylic resins. can be improved. In addition, the chelate complex relieves the stress and strain applied to the interface and plasticizes the organic resin by causing the hydrocarbon in the alkyl portion to dissolve and intertwine with the organic resin. At this time, the longer the carbon chain length of the hydrocarbon in the alkyl portion, the more the chelate complex lowers the surface energy of the inorganic powder and relaxes the stress and strain applied to the interface. Also, the longer the carbon chain length of the hydrocarbon in the alkyl moiety, the more the chelate complex plasticizes the organic resin.

Therefore, when using "Al chelate 4" having a long-chain oleyl group in the alkyl moiety, the surface energy of the inorganic powder is higher than when using "Al chelate 1" having a short-chain ethyl group in the alkyl moiety. can be significantly reduced, the stress and strain applied to the interface can be more relaxed, and the organic resin can be more plasticized. As a result, the viscosity of the granulated powder can be lowered and the moldability can be improved, so that a high filling of the magnetic material can be realized.

In addition, when comparing the initial magnetic permeability at a heat treatment temperature of 90° C. for the magnetic core using an additive containing an Al chelate complex, a Ti chelate complex, and a Zr chelate complex as main components, the magnetic core shown in FIG. Among them, "Ti chelate 2" using an additive containing acetylacetone chelate as a main component has the highest initial permeability, and "Ti chelate 3" using an additive containing glycol chelate as a main component has the highest initial permeability. You can see that it is getting lower.

As for other magnetic cores, magnetic cores using an additive having acetylacetone chelate as a ligand tend to have high initial magnetic permeability. In addition, the initial magnetic permeability of the magnetic core using the additive having ethyl acetoacetate chelate as a ligand is higher than that of the magnetic core using the additive having glycol chelate as the ligand. .

In general, the reaction rate of chelates is slower than that of alkoxides. Comparing the reaction rates according to the type of ligand, acetylacetone chelate has the highest reaction rate among acetylacetone chelate, ethyl acetoacetate chelate, and glycol chelate. slow, with the fastest reaction rate for glycol chelates. For this reason, by using an additive whose main component is a metal chelate complex having a ligand with a slow reaction rate, the resin material that is a binder is softened and the metal magnetic powder 17 in the magnetic core is softened. It can be said that the filling rate of can be increased. Therefore, the initial magnetic permeability of the magnetic core can be improved by using an additive containing a metal chelate complex having a slow reaction rate as a main component.

The main component of the additive is not limited to the metal chelate complex, and may be a cyclic aluminum oligomer or other material as long as the material has a molecular weight of 300 or more and 1000 or less.

[1-4. effects, etc.]
As described above, in the method for manufacturing a magnetic material according to the present embodiment, a mixture containing an organic solvent, a magnetic powder containing iron as a main component, a resin material, and an additive is heated to remove the organic solvent. a first heat treatment step for obtaining an intermediate material in which the magnetic powder, the resin material, and the additive are integrated; and a powder for pulverizing the intermediate material obtained by the first heat treatment step. The molecular weight of the resin material is greater than the molecular weight of the additive, and the molecular weight of the additive is 300 or more and 1000 or less.

According to this configuration, a magnetic material is produced by adding a material having a molecular weight of 300 to 1000 as an additive to the Fe-based metal magnetic powder, thereby softening the resin material having a molecular weight higher than that of the additive. It is possible to hold the metal magnetic powder in close proximity within the magnetic material. Thereby, the filling rate of the metal magnetic powder in the magnetic material can be improved. Therefore, the magnetic permeability of the magnetic material can be improved.

Also, the main component of the additive may be a metal chelate complex or a cyclic aluminum oligomer.

According to this configuration, the filling rate of the metal magnetic powder in the magnetic material can be further improved, and the magnetic permeability of the magnetic material can be further improved.

Further, the main component of the additive may be an aluminum organic compound.

According to this configuration, the filling rate of the metal magnetic powder in the magnetic material can be further improved, and the magnetic permeability of the magnetic material can be further improved.

Further, the weight ratio of the additive to the resin material may be 5% or more and 40% or less.

According to this configuration, the softness of the resin material can be changed by changing the weight ratio of the additive according to the types of the metal magnetic powder, the magnetic material, and the additive. Therefore, the filling rate of the metal magnetic powder in the magnetic material can be improved, and the magnetic permeability of the magnetic material can be improved.

Further, the resin material may be a thermosetting material that is liquid at room temperature.

According to this configuration, the metal magnetic powder, the resin material, and the additive can be easily kneaded and dispersed at room temperature, and the molded body can be easily formed by heat treatment, thereby facilitating the manufacturing process.

Further, the resin material may be a thermoplastic material.

According to this configuration, when forming the magnetic core by compressing the powder of the magnetic material, the filling rate of the metal magnetic powder can be further improved, and the magnetic permeability of the magnetic material can be improved.

Further, the method for manufacturing a powder magnetic core (magnetic core) according to the present embodiment includes a first molding step of powder molding the magnetic material obtained by the manufacturing method having the characteristics described above, and the first molding step. and a second heat treatment step of heating the compact obtained in the step.

According to this configuration, the magnetic core can be easily formed by compacting the powder of the magnetic material.

Further, the powder magnetic core according to the present embodiment contains a magnetic material made of Fe—Si, the filling rate of the magnetic material is 90% or more, and the initial magnetic permeability is 149 or more.

According to this configuration, in the magnetic core using the magnetic material made of Fe—Si, the filling rate of the metal magnetic powder can be improved, and the magnetic permeability of the magnetic material can be improved.

Further, a magnetic material made of Fe--Si--Al may be included, and the magnetic material may have a filling rate of 81% or more and an initial magnetic permeability of 83 or more.

According to this configuration, in the magnetic core using the magnetic material made of Fe--Si--Al, it is possible to improve the filling rate of the metal magnetic powder and improve the magnetic permeability of the magnetic material.

Also, an insulating coating containing Ti may be arranged around the magnetic material.

According to this configuration, in the magnetic core in which the insulating film containing Ti is formed around the metal magnetic powder, the filling rate of the metal magnetic powder can be improved, and the magnetic permeability of the magnetic material can be improved.

Also, an insulating coating containing Zr may be arranged around the magnetic material.

According to this configuration, in the magnetic core in which the insulating film containing Zr is formed around the metal magnetic powder, the filling rate of the metal magnetic powder can be improved, and the magnetic permeability of the magnetic material can be improved.

Further, an insulating coating containing Al may be arranged around the magnetic material.

According to this configuration, in the magnetic core in which the insulating film containing Al is formed around the metal magnetic powder, the filling rate of the metal magnetic powder can be improved, and the magnetic permeability of the magnetic material can be improved.

Moreover, the coil component according to the present embodiment includes the dust core having the characteristics described above.

According to this configuration, it is possible to provide a coil component including a magnetic core having the characteristics described above.

(Embodiment 2)
Next, Embodiment 2 will be described. The coil component 1 according to the first embodiment is a coil component using a so-called dust core as a magnetic core, but the coil component 2 according to the present embodiment is a metal composite in which a coil is incorporated in the magnetic core in the manufacturing process. It is a coil component of the type.

[2-1. Structure of Magnetic Powder]
FIG. 13A is a schematic perspective view showing the configuration of coil component 2 according to the present embodiment. FIG. 13B is a cross-sectional view showing the configuration of coil component 2 according to the present embodiment. FIG. 13B shows a cross section along line XIIB-XIIB in FIG. 13A.

As shown in FIGS. 13A and 13B, the coil component 2 includes a magnetic core portion 22 made of metal composite material and a coil portion 23 .

The magnetic core portion 22 has a cylindrical core portion 22a in the vicinity of the center in plan view. The magnetic material forming the magnetic core portion 22 is, like the split magnetic core 12 of the coil component 1 according to the first embodiment, an Fe—Si based metallic magnetic material, which is an alloy containing Fe and Si as main components, for example. Note that the magnetic material is the same as the magnetic material described in Embodiment 1, so detailed description is omitted. A coil portion 23 is arranged around the cylindrical core portion 22 a of the magnetic core portion 22 .

The coil portion 23 has a winding portion 23 a in which a conductor is wound multiple times, and a wiring portion 23 b formed outside the magnetic core portion 22 . The core portion 22a of the magnetic core portion 22 is arranged as a winding axis of the conductor around which the winding portion 23a is wound. The conductor is made of copper, for example. The conductor is made of a material that is not destroyed by the heat applied when forming the coil component 2 .

The coil portion 23 is formed integrally with the magnetic core portion 22 . The winding portion 23 a of the coil portion 23 is embedded in the magnetic core, and the wiring portion 23 b is arranged outside the magnetic core portion 22 .

[2-2. Coil component manufacturing method]
A method for manufacturing the coil component 2 according to this embodiment will be described below. FIG. 14 is a flow chart showing the manufacturing process of the coil component 2 according to this embodiment.

As shown in FIG. 14, the manufacturing process of the coil component 2 includes a granulated powder manufacturing process S (step S10) and a core manufacturing and coil assembling process (step S40). In the granulated powder manufacturing process, the magnetic material that constitutes the magnetic core described above is produced. In the core manufacturing process, the magnetic core portion 22 and the coil portion 23 are formed by molding a magnetic material, and the magnetic core portion 22 and the coil portion 23 are assembled to complete the coil component 2 .

Note that the granulated powder manufacturing process in the manufacturing process of the coil component 2 is the same as the granulated powder manufacturing process shown in the first embodiment, so the description is omitted.

The core manufacturing and coil assembly processes are described in detail below. FIG. 15 is a flow chart showing core manufacturing and coil assembling processes according to the present embodiment.

As shown in FIG. 15, first, the coil portion 23 is formed (step S41). As with the conductor 13 shown in the first embodiment, the coil portion 23 is formed by winding a conductor made of metal such as copper a predetermined number of times to form a wound portion 23a.

Next, the magnetic core portion 22 and the coil portion 23 are integrally molded (step S42). Step S42 is the second molding step. As the material of the magnetic core portion 22, a magnetic material manufactured in the granulated powder manufacturing process is used. First, the magnetic material classified in the granulated powder manufacturing process is put into a molding die. At this time, the coil portion 23 and the magnetic material are put into a molding die so that the magnetic material covers the coil portion 23 except for the end portion of the wound portion 23a of the conductor.

Subsequently, uniaxial molding is performed at a constant pressure of 4 to 5 [ton/cm ² ], for example, to produce a compact. The pressure at this time is lower than the uniaxial molding pressure in the core manufacturing process of the coil component 1 shown in the first embodiment. As a result, it is possible to prevent the coil portion 23, which is molded together with the magnetic material, from being destroyed during molding.

The shape of the compact is, for example, the shape of the magnetic core portion 22 shown in FIGS. 13A and 13B. The shape of the molded body is not limited to this, and may be other shapes.

Further, the compact after degreasing is thermally cured (step S43). This step is the third heat treatment step. An atmosphere-controlled electric furnace, for example, is used for thermosetting the compact. It should be noted that other methods may be used for thermosetting the molded body.

The thermosetting of the molded product is performed, for example, at a predetermined oxygen partial pressure at a temperature of 200[° C.] for 1 hour. The temperature at this time is lower than the annealing temperature of the compact of coil component 1 shown in the first embodiment. Thereby, it is possible to prevent the coil portion 23 from being broken during the thermosetting of the molded body.

Further, after the molded body is thermally cured, the wiring portion 23b arranged outside the magnetic core portion 22 may be connected to the end portion of the wound portion 23a of the coil portion 23 .

Through the above steps, the coil component 2 in which the magnetic core portion 22 and the coil portion 23 are integrated is completed.

[2-3. effects, etc.]
As described above, the method of manufacturing a coil component according to the present embodiment includes a second molding step of integrating the magnetic material obtained by the manufacturing method having the above-described features and the coil by powder molding, and the molding step. and a third heat treatment step of heating the obtained compact.

According to this configuration, it is possible to easily form a coil component in which the dust core and the coil are integrated.

Further, by adding a material having a molecular weight of 300 or more and 1000 or less as an additive to Fe-based metal magnetic powder to produce a magnetic material, the resin material having a molecular weight higher than that of the additive is softened and incorporated into the magnetic material. It is possible to hold the metal magnetic powder in close proximity. Thereby, the filling rate of the metal magnetic powder in the magnetic material can be improved. Therefore, the magnetic permeability of the magnetic material can be improved.

(Other embodiments, etc.)
Although the magnetic material and the magnetic powder according to the embodiments and modifications of the present disclosure have been described above, the present disclosure is not limited to these embodiments.

For example, the present invention also includes a coil component using the magnetic material described above. Examples of coil components include high-frequency reactors, inductors, and inductance components such as transformers. The present invention also includes a power supply device including the coil component described above.

Further, the metal magnetic powder is not limited to Fe--Si and Fe--Si--Al magnetic materials, and may be other magnetic materials containing Fe as a main component.

Moreover, the main component of the additive may be a chelate complex other than the Al chelate complex, or may be a chelate complex containing other metals. In addition to the chelate complex, it may contain an oligomer, an acylate, a polymer, or the like as a main component.

Moreover, the resin material may be the acrylic resin described above, or may be a silicone resin, a butyral resin, or another resin material. Also, the organic solvent is not limited to toluene, xylene, ethanol, etc., and other organic solvents may be used.

In addition, the method of kneading and dispersing the Fe—Si based metallic magnetic material and the method of mixing the metallic magnetic powder, additive, resin material, organic solvent, etc. are limited to kneading and dispersing by the rotary ball mill described above. However, other mixing methods may be used.

Moreover, the heat treatment methods in the first heat treatment step, the second heat treatment step, and the third heat treatment step are not limited to the methods described above, and other methods may be used. Also, the pressure, temperature and time in each step described above are examples, and other pressures, temperatures and times may be adopted.

Also, the present disclosure is not limited to this embodiment. As long as it does not deviate from the spirit of the present disclosure, various modifications that a person skilled in the art can think of are applied to this embodiment, and a form constructed by combining the components of different embodiments is also within the scope of one or more aspects may be included within

The magnetic material according to the present disclosure can be applied to high-frequency inductors, transformer magnetic core materials, and the like.

1, 2 coil parts 12 split magnetic core (magnetic material)
12a base 12b core 12c wall 13 conductor (coil)
REFERENCE SIGNS LIST 14 coil support 14a base 14b cylindrical portion 17 metal magnetic powder (magnetic powder)
18 insulating material 22 magnetic core portion (magnetic material)
22a core portion 23 coil portion (coil)
23a Winding portion 23b Wiring portion

Claims (5)

By heating a mixture containing an organic solvent, a magnetic powder containing iron as a main component, a resin material, and an additive whose main component is a metal chelate complex or a cyclic aluminum oligomer to remove the organic solvent. a first heat treatment step of obtaining an intermediate material in which the magnetic powder, the resin material, and the additive are integrated, and an insulating material formed from the additive is formed as an insulating coating on the surface of the magnetic powder; When,
a powdering step of powdering the intermediate material obtained by the first heat treatment step;
The molecular weight of the resin material is greater than the molecular weight of the additive,
The additive has a molecular weight of 300 or more and 1000 or less ,
The resin material is a thermoplastic material,
A method for manufacturing a magnetic material. The main component of the additive is an aluminum organic compound,
A method for manufacturing the magnetic material according to claim 1 . The weight ratio of the additive to the resin material is 5% or more and 40% or less.
3. A method for manufacturing the magnetic material according to claim 1 or 2 . A first molding step of powder molding the magnetic material obtained by the manufacturing method according to any one of claims 1 to 3 ;
and a second heat treatment step of heating the molded body obtained in the first molding step,
A method for manufacturing a powder magnetic core. A second molding step of integrating the magnetic material and the coil obtained by the manufacturing method according to any one of claims 1 to 3 by powder molding;
and a third heat treatment step of heating the molded body obtained in the second molding step,
A method of manufacturing a coil component.

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