JP2022085471A - Composite magnetic thermosetting molded body, coil component obtained by using the same, and manufacturing method thereof - Google Patents

Abstract

To provide a composite magnetic thermosetting molded body with high density and high dielectric breakdown voltage when a DC voltage is applied, a coil component obtained by using the same, and a manufacturing method thereof.SOLUTION: A composite magnetic thermosetting molded body includes metallic magnetic powder and thermosetting resin. The mass ratio of the thermosetting resin to the total mass of the metallic magnetic powder and the thermosetting resin is 2.0 wt% or more and 4.5 wt% or less, the density is 5.2 g/cm3 or more, and the dielectric breakdown voltage is 300 V/mm or more when a direct current voltage is applied further.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composite magnetic thermosetting molded body, coil parts obtained by using the composite magnetic thermosetting molded body, and a method for manufacturing them.

Various forms of coil parts used in electronic devices and the like are known, but a magnetic core material composed of a composite magnetic material in which a metallic magnetic powder is dispersed in a binder resin and a coil or a coil assembly are integrally molded. Many coil parts are used. For example, in Patent Document 1, a winding coil is enclosed in a powder magnetic body composed of an admixture containing a soft magnetic powder and a binder, and is pressurized at a molding pressure of 4.5 to 10.0 ton / cm ² . Inductance parts (coil parts) that have been molded and integrated are described.

Japanese Unexamined Patent Publication No. 2006-31920

By the way, conventionally, in an inductance component, a high dielectric breakdown voltage between terminals has not been required because it is conducted by a coil. In particular, in in-vehicle products, since the power supply of the in-vehicle battery is about 12 V, even the inductance component used for the DC / DC converter (DC voltage converter) can sufficiently cope with the insulation breakdown voltage of about several tens of V. rice field.

However, in recent years, commercial AC100V is directly rectified and controlled to 5V of a portable device by a DC / DC converter, and a system using a high voltage power supply is used in a hybrid vehicle or an electric vehicle. I came. Further, in a step-up converter or the like for LED control, a high voltage is instantaneously applied to an inductance component used in a circuit in order to switch a direct current of about 100V to 300V. Therefore, a high dielectric breakdown voltage is required for inductance components as well.

On the other hand, since the above power supply circuit is increasing in current, in order to cope with a large current in a small size, the material constituting the inductance component is not a ferrite material which is an oxide and an insulator, but has excellent superimposition characteristics. Metallic magnetic powder is often used. Since this metallic magnetic powder is an electric conductor, insulation cannot be obtained even if it is compression-molded as it is with a resin as a molded body. Therefore, as in Patent Document 1 described above, by mixing in advance with an insulating binder resin and forming an insulating layer of the binder resin on the particle surface of the metal magnetic powder, the insulating property when formed into a molded body is ensured. ing.

Conventionally, a composite magnetic material in which such a metallic magnetic powder and an insulating thermosetting resin are mixed is placed in a mold at room temperature at about 1 to 10 ton / cm ² as in Patent Document 1 described above. The molded product is manufactured by compression molding at the pressure of the above, taking it out of the mold, and then performing a thermosetting treatment at the required temperature. However, in this manufacturing method, compression molding is performed with an extremely high pressure in order to obtain the desired density, so that the resin component between the metallic magnetic powders that insulate the metallic magnetic powders that are electrical conductors is easily eliminated. There is a problem that the insulating breakdown voltage of the molded body is lowered due to the extremely thin insulating layer of the resin component between the metal magnetic powders and the electrical contact between the metal magnetic powders.

The present invention has been made in view of the above problems, and uses a composite magnetic thermocurable molded body having a high density and a high dielectric breakdown voltage when a DC voltage is applied, and a composite magnetic thermocured molded body thereof. It is an object of the present invention to provide the coil parts obtained by the above-mentioned materials and a method for manufacturing them.

In order to solve the above problems, the present inventor has diligently studied and adjusted the composite magnetic material containing a predetermined amount of the metallic magnetic powder and the thermosetting resin to a temperature equal to or higher than the softening temperature of the thermosetting resin. A DC voltage was applied while maintaining a high density by compression molding using a mold so that the composite magnetic material had a predetermined density or higher while the composite magnetic material had fluidity under a predetermined low molding pressure. The present invention has been completed by finding that it is possible to obtain a composite magnetic thermocurable molded body having a high insulation breakdown voltage.

That is, the present invention includes the metal magnetic powder and the thermosetting resin, and the mass ratio of the thermosetting resin to the total mass of the metal magnetic powder and the thermosetting resin is 2.0 wt% or more and 4.5 wt% or less. It is a composite magnetic thermosetting molded body having a density of 5.2 g / cm ³ or more and an insulation breakdown voltage of 300 V / mm or more when a DC voltage is applied.

Further, one aspect of the present invention is a coil component in which a coil is contained in the above-mentioned composite magnetic thermosetting molded body.

Further, in the present invention, the mass ratio of the heat-curable resin to the total mass of the metal magnetic powder and the heat-curable resin of the material containing the metal magnetic powder and the heat-curable resin is 2.0 wt% or more. Using a material preparation step of mixing so as to be 5 wt% or less to obtain a composite magnetic material and a mold in which the composite magnetic material is adjusted to a temperature equal to or higher than the softening temperature of the heat-curable resin, 1 kg / cm. A compression molding step of obtaining a composite magnetic molded body by compression molding so that the density becomes 5.2 g / cm ³ or more while the composite magnetic material has fluidity with a molding pressure of ² or more and 30 kg / cm ² or less. Also included is a method for producing a thermosetting molded body of a metal magnetic composite material, which comprises a heat curing step of heat-treating the composite magnetic molded body to obtain a composite magnetic thermocuring molded body.

According to the present invention, a composite magnetic heat-curable molded body having a high density and a high dielectric breakdown voltage when a DC voltage is applied, and a coil component in which a coil is contained in the composite magnetic heat-cured molded body are obtained. be able to.

It is a process diagram (process sectional view) which shows an example of the manufacturing process of the coil component which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described.
First, an embodiment of the composite magnetic thermosetting molded body according to the present invention will be described in detail.

The composite magnetic thermosetting molded product according to the present embodiment contains at least a metal magnetic powder and a thermosetting resin. In addition, an embodiment containing a material other than the above (for example, a dispersant, a plasticizer, etc.) is not excluded as long as the effect of the present invention is not affected.
Hereinafter, each material and the like will be described in detail.

<Metallic magnetic powder>
First, the metallic magnetic powder will be described.
The metallic magnetic powder is a magnetic powder that can be obtained by a method of pulverizing a metallic magnetic material or the like, and contains iron as a main component. As the metal magnetic material, for example, iron, an alloy containing iron (iron-silicon, iron-aluminum-silicon alloy, iron-nickel alloy, etc.) can be used. However, these are only examples, and other metallic magnetic materials may be adopted. Further, the metal magnetic powder may be a powder of one kind of metal magnetic material or a powder in which two or more kinds of metal magnetic materials are mixed.

In particular, from the viewpoint of magnetic properties and availability, iron is contained as a main component, and as sub-components, chromium (Cr), silicon (Si), nickel (Ni), aluminum (Al), cobalt (Co), etc. It is more preferable to use a metallic magnetic powder containing carbon (C), boron (B) and the like. Further, amorphous metal powder or pure iron powder may be used. Specifically, Fe-Ni-based (permalloy), Fe-Si-based (silicon steel), Fe-Al-based, Fe-Co-based (permenzur), Fe-Si-Cr-based, Fe-Al-Cr-based. , Fe—Si—Al based alloy powder, non-crystalline metal powder such as Fe—Si—B—Cr based amorphous powder, crystalline iron powder such as carbonyl iron powder and the like. Then, it is more preferable to use a material that can be a substantially spherical metal magnetic powder (for example, Fe—Si—B—Cr-based amorphous powder, Fe—Si—Cr-based alloy powder, or the like) among the above materials. This is because the compression molding of the composite magnetic material containing the metallic magnetic powder becomes easier.

The content of iron, which is the main component of the metallic magnetic powder, is preferably 85 wt% or more, more preferably 87 wt% or more. Further, it is preferably 98 wt% or less, and more preferably 97 wt% or less. It is preferable that the mixture contains one or more selected from the above-mentioned subcomponents, and the balance is iron and unavoidable impurities.

Further, the metal magnetic powder preferably has a chromium content of 2 wt% or more and 10 wt% or less, and more preferably 3 wt% or more and 8 wt% or less.
Chromium combines with oxygen in the atmosphere to easily form chemically stable oxides (eg, Cr ₂ O ₃ ). Therefore, the composite magnetic thermosetting molded body containing chromium is particularly excellent in corrosion resistance. Further, since the chromium oxide has a large specific resistance, the chromium oxide layer is formed near the surface of the particles constituting the composite magnetic thermosetting molded product, so that the particles can be more easily insulated from each other.
Therefore, by setting the chromium content within the above range, a metallic magnetic powder having excellent corrosion resistance and capable of manufacturing a coil component or the like having a small eddy current loss can be obtained.

For the same reason, the nickel content of this metallic magnetic powder is preferably 2 wt% or more and 10 wt% or less, and more preferably 3 wt% or more and 8 wt% or less. Similarly, the content of aluminum in this metallic magnetic powder is preferably 2 wt% or more and 10 wt% or less, and more preferably 3 wt% or more and 8 wt% or less.

Further, the metal magnetic powder preferably has a silicon content of 2 wt% or more and 10 wt% or less, and more preferably 3 wt% or more and 8 wt% or less.
Silicon is a component that can increase the relative magnetic permeability of coil parts and the like obtained by using a composite magnetic thermosetting molded body containing a metallic magnetic powder. Further, since the specific resistance becomes high when the metallic magnetic powder contains silicon, it is also a component that can suppress the eddy current loss between particles. Therefore, by setting the silicon content within the above range, a metallic magnetic powder capable of producing a coil component or the like having a smaller eddy current loss while increasing the relative permeability can be obtained.

The metallic magnetic powder contains boron (B), titanium (Ti), V (vanadium), manganese (Mn), copper (Cu), Ga (gallium), and germanium (Gallium) as components having a smaller content than the above components. It may contain at least one selected from the group consisting of Ge), zirconium (Zr), Nb (niobium), Mo (molybdenum), Ru (ruthenium), Rh (boronium), and tantalum (Ta). In that case, the total content of these components is preferably 1 wt% or less.
Further, it may contain components such as phosphorus (P) and sulfur (S) that are inevitably mixed in the manufacturing process, but in that case, the total content of these components is 1 wt% or less. preferable.

The average particle size (D ₅₀ ) of the metallic magnetic powder is preferably 8 μm or more and 25 μm or less, and more preferably 10 μm or more and 20 μm or less. Further, as described above, the particle shape of the metallic magnetic powder is substantially spherical (for example, the value obtained by dividing the major axis by the minor axis is 2) because the composite magnetic material containing the metallic magnetic powder can be easily compression-molded. Hereinafter, it is preferable that the shape is a substantially spherical shape of 1.5 or less).

Here, this "average particle size (D ₅₀ )" is a powder at an integrated value of 50% in a volume-based particle size distribution obtained by using a particle size distribution measuring device by a laser diffraction / scattering method (microtrack method). It means the diameter (median diameter). When the particles are agglomerated, it means the particle size of the agglomerates. As a specific measuring device for the average particle size (D ₅₀ ), a laser diffraction / scattering type particle size distribution measuring device (particle size distribution) LA-960 (manufactured by HORIBA, Ltd.) can be mentioned.

Further, as the metal magnetic powder, it is preferable to use a metal magnetic material powdered by a water atomization method or a gas atomization method.
Here, the "water atomizing method" is a method of producing a metal powder by colliding the molten metal (molten metal) with water jetted at high speed (atomized water) to atomize and cool the molten metal. be.
The "gas atomizing method" is a method in which a jet stream such as an inert gas or air is blown from the surroundings onto the flow of the molten metal to pulverize the flow of the molten metal and quasi-solidify it into a metal powder.

Since the metal magnetic powder produced by the water atomization method or the gas atomization method has a substantially spherical shape (close to a spherical shape), a composite magnetic thermocured molded product containing the metal magnetic powder is used to form a composite magnetic thermocurable molded product. The filling rate can be easily increased during production. Further, as described above, compression molding of the composite magnetic material containing the metallic magnetic powder becomes easier. As a result, it is easy to obtain a composite magnetic thermosetting molded product having higher density and higher relative permeability.

As the metallic magnetic powder, a powder that has been dried to remove adsorbed water on the surface of the powder, that is, a metallic magnetic dry powder obtained by drying the powder may be used. Examples of the powder drying treatment method include hot air treatment and dry heat treatment, and examples of the drying treatment condition include conditions for treatment at a temperature of 100 to 150 ° C. for 30 to 120 minutes.

Further, this metallic magnetic powder is surface-treated with a silane-based or titanium-based coupling agent in order to improve wettability with a thermosetting resin, that is, the powder is silane-based or titanium-based coupling. A surface-treated metal magnetic powder obtained by surface-treating with an agent may be used. The silane-based or titanium-based coupling agent is a silane-based or titanium-based coupling agent having an epoxy group, an amino group, or an isocyanate group as a functional group from the viewpoint of compatibility with a thermosetting resin described later. Is more preferable to use. As a surface treatment method for the powder, a dry treatment method in which a solution containing a coupling agent is dropped or sprayed while stirring the powder with a mixer or the like, or a solvent is added to the powder to form a slurry, and the coupling agent is added to the slurry. Examples thereof include a wet treatment method in which a solution containing the above-mentioned powder is added, stirred, and then filtered and dried. In addition, this surface treatment may be performed in combination with the above-mentioned drying treatment.

Further, as this metallic magnetic powder, a phosphate-treated metal magnetic powder obtained by subjecting the surface to a phosphate treatment for coating the surface with an insulating film, that is, a phosphate-treated powder. May be used. Examples of the phosphate include zinc phosphate, zinc phosphate-calcium, manganese phosphate, iron phosphate and the like, and in particular, from the viewpoint of ease of forming an insulating film with a magnetic powder containing iron as a main component. , Zinc phosphate is more preferred. Examples of the method for treating the powder with phosphate include a method in which the powder is washed with acid or water as necessary, then treated with phosphate, and then washed with water and dried. In addition, this phosphate treatment may also be performed in combination with the above-mentioned drying treatment.

In the composite magnetic thermosetting molded body according to the present embodiment, the content of the metallic magnetic powder is preferably 90 to 98 wt%, more preferably 92 to 97.5 wt%.

In the semiconductor encapsulation material, non-conductive, that is, insulating metal oxide powder (ferrite powder), glass beads, etc. are used as the filler, but the metal magnetic powder of the present invention is used. Does not include powders of such insulating materials. That is, the metallic magnetic powder of the present invention is made of a conductive material.

<Thermosetting resin>
Next, the thermosetting resin will be described.
The thermosetting resin is a reactive resin composition containing a prepolymer having a functional group as a main component (content rate of 90 wt% or more), and is a cross-linking reaction that softens and flows by heating to gradually form a three-dimensional network structure. It is a resin composition that causes and cures. Although the composite magnetic thermosetting molded body according to the present embodiment contains a thermosetting resin composition, in the present invention, this thermosetting resin composition is also referred to as "thermosetting resin". It is called. The thermosetting resin is not particularly limited as long as it serves as a binder resin and can be cured by heating (for example, a resin used as a sealing material for semiconductors), and is a thermosetting type. , Epoxy resin (bisphenol type, naphthalene type, novolak type, aliphatic type, glycidylamine type, etc.), silicon resin (methylphenylsilicon resin, etc.), phenol resin (novolak type, resol type, etc.), polyamide type A resin, a polyimide resin, a melamine resin, a polyphenylene sulfide resin, or the like can be used. Then, a mixture of two or more types of thermosetting resins may be used. In particular, from the viewpoint of heat resistance and the like, it is more preferable to use an epoxy resin, and it is further preferable to use a novolak type epoxy resin.

The softening temperature of this thermosetting resin before the thermosetting reaction is not limited, but is more preferably 0 ° C. or higher, and even more preferably 40 ° C. or higher. And, although this is also not limited, the softening temperature of this thermosetting resin before the thermosetting reaction is preferably 100 ° C. or lower.

Further, the thermosetting resin is preferably a mixture of a curing agent from the viewpoint of ease of thermosetting. Examples of the curing agent include phenol novolac type curing agents (phenol novolak resin, bisphenol A type novolak resin, etc.), polyamide-based curing agents (polyamide resin, etc.), acid anhydride-based curing agents such as maleic anhydride and phthalic anhydride. Latent amine-based curing agents such as dicyandiamide and imidazole, aromatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone can be used. These curing agents may be used alone or in combination of two or more.
Further, other additives such as a diluent, a filler, and a mold release agent may be further mixed within a range that does not affect the effect of the present invention.

In preparing the composite magnetic material, a solvent may be mixed with the thermosetting resin in order to prepare the thermosetting resin as a resin solution. This solvent is removed by drying or the like in the manufacturing process, but from the viewpoint of ease of removal, it is preferable that the amount of the solvent used is small (for example, the material used for the composite magnetic material excluding the solvent). The ratio of the volume of the solvent to the total volume is less than 5.0 vol%, further 0.5 vol% or more and 2.0 vol% or less, etc.). The solvent is preferably one that can be removed by drying or the like in the material preparation step in the method for producing a composite magnetic thermocuring molded product described later, the subsequent compression molding step, the thermocuring step, and the like, and alcohol, toluene, and chloroform. , Methyl ethyl ketone, acetone, ethyl acetate and the like are shown as preferred examples.

Then, in order to enable the composite magnetic thermosetting molded body manufactured using this thermosetting resin to obtain a predetermined density and insulation breakdown voltage, the thermosetting property in the composite magnetic thermosetting molded body according to the present embodiment is heat-curable. The content of the resin is the mass ratio of the thermosetting resin to the total mass of the metal magnetic powder and the thermosetting resin, that is, [the content (mass) of the thermosetting resin / the content (mass) of the metal magnetic powder + The content (mass) of the thermosetting resin] × 100 is calculated to be 2.0 wt% or more and 4.5 wt% or less. The lower limit of this mass ratio is more preferably 2.5 wt% or more. Further, the upper limit is more preferably 4.0 wt% or less, and further preferably 3.5 wt% or less.

<Composite magnetic thermosetting molded body>
Next, the composite magnetic thermosetting molded body according to the present embodiment, in which the composite magnetic material containing the above-mentioned metal magnetic powder and the thermosetting resin is compression-molded and thermosetting under predetermined conditions, will be described.

In the composite magnetic thermosetting molded body according to the present embodiment, the composite magnetic material containing the above-mentioned metal magnetic powder and the thermosetting resin in a predetermined amount is compression-molded at a predetermined temperature and molding pressure described later, and further at a predetermined temperature. It is heat-cured by heat treatment. The density of the composite magnetic thermocurable molded body according to the present embodiment is 5.2 g / cm ³ or more, and the dielectric breakdown voltage when a direct current voltage is applied (electrical resistance suddenly increases between specific distances in the molded body). The voltage at which a large current flows after a decrease) is 300 V / mm or more, and the specific magnetic permeability is also high.

The density of the composite magnetic heat-curable molded product according to the present embodiment is more preferably 5.4 g / cm ³ or more, and further preferably 5.5 g / cm ³ or more. The upper limit of this density is not limited, but may be 7.0 g / cm ³ or less, 6.5 g / cm ³ or less, and 6.2 g / cm ³ or less. It may be 6.0 g / cm ³ or less, or 5.8 g / cm ³ or less. Further, the dielectric breakdown voltage when a DC voltage is applied to the composite magnetic thermocurable molded body according to the present embodiment is more preferably 400 V / mm or more, further preferably 500 V / mm or more, and further preferably 550 V. It is more preferably / mm or more, and even more preferably 600 V / mm or more. Further, the specific magnetic permeability of the composite magnetic thermosetting molded body according to the present embodiment is more preferably 20 or more, and further preferably 22 or more.

<Coil parts>
Next, an embodiment of a coil component in which a coil is contained in a composite magnetic thermosetting molded body according to the present embodiment will be described in detail.
That is, the coil component according to the present embodiment includes a magnetic core material made of the above-mentioned composite magnetic heat-curable molded body and a coil contained in the composite magnetic heat-cured molded body. A plurality (for example, two) ends of the coil serving as the terminal are exposed from the composite magnetic thermosetting molded body.

Here, the coil is formed by winding a wire such as a round wire or a flat wire, and the shape, number of wires, number of turns (number of turns), and the like of the wire are not particularly limited. Further, the surface of this wire may be insulated and coated.
Further, the magnetic core material is a magnetic core of the coil (inner core material provided in the core portion of the coil) and a magnetic outer body (outer core material in which the coil is embedded) that embeds the coil. In the coil component according to the present embodiment, both the magnetic outer body or the magnetic core and the magnetic outer body are made of the above-mentioned composite magnetic thermocurable molded body.

In the coil component according to the present embodiment, the "magnetic core material composed of the composite magnetic heat-curable molded body" is mainly composed of the composite magnetic heat-cured molded body (90% by mass or more of the magnetic core material, more preferably. Is 95% by mass or more).

Such a coil component according to the present embodiment has a high dielectric breakdown voltage between terminals, and is suitably used as a coil (including a choke coil), a metal inductor, or the like.
For example, in the coil component according to the present embodiment, the dielectric breakdown voltage (voltage at which the inductance value is −20% from the initial value) when an impulse voltage is applied between the terminals is 300 V or more, and further 350 V or more.

<Manufacturing method of composite magnetic thermosetting molded body>
Next, a method for manufacturing the composite magnetic thermosetting molded body according to the present embodiment will be described.

The method for producing a composite magnetic thermosetting molded product according to the present embodiment includes at least the following material preparation steps, compression molding steps, and thermosetting steps. The composite magnetic thermocurable molded body manufactured by this manufacturing method includes not only a non-embedded type magnetic core material in which a coil or the like is not embedded inside, but also a coil component in which a coil is embedded inside. ..
Hereinafter, each of the above steps will be described in detail.

[Material preparation process]
The material preparation step is a step of preparing a composite magnetic material containing a metallic magnetic powder and a thermosetting resin. Specifically, the metal magnetic powder and the thermosetting resin as described above are prepared, and the metal magnetic powder is mixed and dispersed in the thermocurable resin (resin solution to which a solvent is added if necessary) using a mixer or the like. Then, if necessary, dry to prepare a granular (granulated powder) or paste-like composite magnetic material. Here, if necessary, a dispersant, a plasticizer, or the like may be further added and then mixed and dispersed. Further, for the above-mentioned reason, the mass ratio of the thermosetting resin to the total mass of the metal magnetic powder and the thermosetting resin is set to 2.0 wt% or more and 4.5 wt% or less. The lower limit of the mass ratio is more preferably 2.5 wt% or more, the upper limit is more preferably 4.0 wt% or less, and further preferably 3.5 wt% or less.

The order of mixing the metal magnetic powder, the thermosetting resin and the solvent is not limited, but the thermosetting resin and the solvent were mixed and obtained from the viewpoint of ease of mixing and dispersion. It is more preferable to mix the metallic magnetic powder (and other materials) with the resin solution. The above mixing may be kneaded granulation. Further, when a granular (granulated powder) metallic magnetic powder is obtained by granulation, it may be mixed and then classified. Examples of the classification method include sieving classification, inertial classification, dry classification such as centrifugal classification, and wet classification such as sedimentation classification. When a solvent is used, it is preferable to dry the mixture after mixing to set the solvent content to about 0 vol%.

[Compression molding process]
The compression molding step is a step of compression molding the composite magnetic material obtained in the material preparation step under predetermined conditions to obtain a molded body. Specifically, first, the die of the press machine is adjusted to a temperature equal to or higher than the softening temperature of the thermosetting resin contained in the composite magnetic material, and then the composite magnetic material is injected into the die from the die opening by an injector or the like. Fill in. The shape and size of the mold are not particularly limited. Further, when the composite magnetic material is charged into the mold, it may be charged while applying vibration in order to prevent the occurrence of a portion where the composite magnetic material is not sufficiently filled inside the mold.

Here, since the composite magnetic material before compression molding can be compression-molded to a predetermined density in a shorter time, it is preferable to adjust the temperature of the composite magnetic material before compression molding to a temperature equal to or higher than the softening temperature of the thermosetting resin. For example, by putting the composite magnetic material into a mold adjusted to a temperature equal to or higher than the softening temperature of the thermosetting resin and holding it for about 10 to 120 seconds, not only the mold but also the composite magnetic material before compression molding is performed. The temperature of the above can also be adjusted to a temperature higher than the softening temperature of the thermosetting resin. Further, the composite magnetic material may be heated by another method before being charged into the mold to adjust the temperature to a temperature equal to or higher than the softening temperature of the thermosetting resin.

Further, since this mold can make it difficult for the thermosetting resin contained in the composite magnetic material to proceed with the thermosetting reaction before and during compression molding, the temperature is lower than the heat treatment temperature in the thermosetting step described later. It is more preferable that it is adjusted to. Further, it is more preferable that the temperature of the composite magnetic material is similarly adjusted to a temperature lower than the heat treatment temperature in the thermosetting step described later. The specific temperature may be appropriately set depending on the type of the thermosetting resin contained in the composite magnetic material, and examples thereof include temperatures below 160 ° C. and further below 150 ° C.

Further, the temperature of the mold and the composite magnetic material in the compression molding step is the temperature obtained by adding 55 ° C. to the softening temperature of the thermosetting resin contained in the composite magnetic material (softening temperature + 55 ° C.), more preferably the softening temperature. It is preferable to adjust the temperature to + 50 ° C. or lower. In this case, in the thermosetting step described later, it is preferable to perform the heat treatment at the softening temperature of more than + 55 ° C. and further, the heat treatment at the softening temperature of more than + 50 ° C.

After this temperature adjustment, the composite magnetic material has fluidity due to a low molding pressure of 1 kg / cm ^{2 or more and 30 kg / cm 2 or} less from either the upper or lower side of the movable punch (press head) of the mold. The composite magnetic molded body is obtained by compression molding so that the density is 5.2 g / cm ³ or more, more preferably 5.4 g / cm ³ or more, and further preferably 5.5 g / cm ³ or more. Since it is easier to improve the dielectric breakdown voltage of the composite magnetic thermosetting molded body after thermosetting, the molding pressure is more preferably 15 kg / cm ² or less, and more preferably 12 kg / cm ² or less. It is more preferably 10 kg / cm ² or less, and even more preferably 10 kg / cm 2.

Here, "compressed molding so that the density of the composite magnetic material is 5.2 g / cm ³ or more while the composite magnetic material has fluidity" means that the density of the composite magnetic material is 5.2 g / cm ³ or more. By the time the composite magnetic material is maintained in a state of having fluidity (for example, the melt viscosity of the composite magnetic material is 1300 Ps · s or less, further 1100 Ps · s or less), that is, it is included in the composite magnetic material. The thermosetting resin is compression-molded so that the density becomes 5.2 g / cm ³ or more before the thermosetting reaction substantially proceeds. It depends on the type of thermosetting resin contained in the composite magnetic material, but as a guide, for example, when an epoxy resin is contained, the density is 5. in 5 to 120 seconds from the start of compression molding, and further in 5 to 90 seconds. It is preferable to perform compression molding so that the content is 2 g / cm ³ or more.
After the density becomes 5.2 g / cm ³ or more, the composite magnetic material has no fluidity (a state in which the thermosetting reaction of the contained thermosetting resin has substantially proceeded). You may have.

The composite magnetic molded body obtained by compression molding the composite magnetic material under such conditions is compression-molded to a predetermined density with a molding pressure significantly lower than that of the conventional one, so that the composite magnetic molded body is electrically operated while having a high density. The thermosetting resin existing between the metal magnetic powders, which are the target conductors, is not excluded, and an insulating layer having a sufficient thickness is formed between the metal magnetic powders. By thermally curing this, a high density is obtained. Moreover, it is possible to obtain a composite magnetic heat-curable molded body that exhibits a high insulation breakdown voltage.

[Thermosetting process]
The heat-curing step is a step of heat-treating the composite magnetic molded body obtained in the compression molding step to heat-cure the composite magnetic molded body to obtain a composite magnetic thermo-cured molded body. Specifically, the composite magnetic molded body taken out from the mold after the compression molding step is heat-treated at a temperature equal to or higher than the recommended thermosetting temperature of the contained thermosetting resin to be thermosetting. The temperature of this heat treatment may be appropriately set according to the type of the thermosetting resin contained in the composite magnetic material, and examples thereof include temperatures of 150 ° C. or higher and 230 ° C. or lower, and further 160 ° C. or higher and 200 ° C. or lower. Will be done. The heat treatment time may be, for example, 0.1 hour or more and 5 hours or less, and further may be 0.2 hours or more and 3 hours or less. It should be noted that this heat treatment may be performed in the mold or both in the mold and after being taken out from the mold. After that, the obtained composite magnetic thermosetting molded body can be further selectively subjected to steps such as surface polishing and coating, if necessary.

In this way, the mass ratio of the thermosetting resin to the total mass of the metal magnetic powder and the thermosetting resin is 2.0 wt% or more and 4.5 wt% or less, and the density is 5.2 g / cm ³ or more. Further, it is possible to manufacture a composite magnetic thermosetting molded body according to the present embodiment, in which the insulation breakdown voltage when a direct current voltage is applied is 300 V / mm or more.

Further, in the case of manufacturing a coil component in which a coil is included in the composite magnetic thermocuring molded body according to the present embodiment, this is also not limited, but the composite magnetic thermocuring molding according to the present embodiment described above. As a modification of the method for manufacturing the body, it can be manufactured by, for example, the method shown in FIG.

Specifically, first, an air-core coil 11 of a winding made of a wire such as a round wire is prepared. The air-core coil 11 is composed of a winding portion 11b around which an insulatingly coated wire is wound and an end portion 11a of a winding drawn from the winding portion 11b. Next, the die 21 including the lower punch 21a of the press machine is adjusted to have a temperature equal to or higher than the softening temperature of the heat-curable resin contained in the composite magnetic material 31 and lower than the heat treatment temperature in the heat-curing step (FIG. 1). (A)), The air core coil 11 is placed in the mold 21, and the winding portion 11 of the coil (including the inside of the loop of the wound wire and the gap between the loops) and the winding portion 11 thereof are placed through the opening of the mold 21. The composite magnetic material 31 prepared by the material preparation step described above is filled so as to bury the upper and lower spaces. However, the two ends 11a of the winding are exposed from the composite magnetic material 31 ((b) in FIG. 1). Then, the temperature is held for several tens of seconds to several minutes until the temperature becomes equal to or higher than the softening temperature of the thermosetting resin containing the temperature of the composite magnetic material 31. After that, the composite magnetic material is compression-molded so that the density becomes 5.2 g / cm ³ or more while the composite magnetic material has fluidity under the above-mentioned molding pressure by the upper punch 21b whose temperature is adjusted in the same manner. The 31 and the air-core coil 11 are integrally molded by compression to obtain a coil-encapsulating composite magnetic molded body ((c) in FIG. 1). After that, the coil-encapsulated composite magnetic molded body is taken out from the mold and heat-cured by heat treatment at a predetermined temperature to mold the composite magnetic material 31 into a substantially rectangular shape and heat-cured the composite magnetic heat according to the present embodiment. An air-core coil 11 is embedded in a hardened molded body 32 (a magnetic exterior body and a magnetic core material that serves as a magnetic core), and the end portions 11a of the two windings are exposed to the outside to obtain a coil component that is a terminal. ((D) in FIG. 1).

Instead of the air-core coil, a coil assembly made of a coil and another magnetic core material serving as a magnetic core may be prepared, and coil parts may be manufactured by the same method as described above using the coil assembly. In this case, the magnetic exterior body (outer core material) is composed of the composite magnetic thermocuring molded body according to the present embodiment, but the magnetic core (inner core material) is different from the composite magnetic thermocuring molded body according to the present embodiment. It is a coil component composed of a material (for example, a ferrite core). However, it is more preferable that both the outer core material and the inner core material are coil parts made of the composite magnetic thermosetting molded body according to the present embodiment.

When manufacturing a coil component containing a coil, the conventional method is compression molding with a very high molding pressure (at least 100 kg / cm ² or more) in order to obtain a predetermined density of the obtained molded body. There is also a problem that the cross-sectional shape of the coil wire (particularly the round wire) contained therein is crushed, and the insulation coating of the wire is easily damaged. However, according to the method for manufacturing a composite magnetic heat-curable molded body according to the present embodiment, a molded body having a high density can be obtained, there is no concern that the cross-sectional shape of the wire of the coil contained therein is crushed, and the metal magnetism is formed. It is possible to manufacture a suitable coil component in which the insulating layer between powder particles and between wires is sufficiently maintained.

Although the composite magnetic thermocurable molded body according to the present embodiment, the coil parts in which the coil is contained in the composite magnetic thermocurable molded body, and the manufacturing method thereof have been described above, the present invention is limited to the above-described embodiment. However, it also includes various modifications, improvements, and the like as long as the object of the present invention is achieved.
In addition, each of the above embodiments can be appropriately combined as long as the gist of the present invention is not deviated.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples, and as described above, various modifications and the like are possible within the technical idea of the present invention.

(Example 1)
As a metallic magnetic powder used for a composite magnetic material, an amorphous Fe—Si—B—Cr-based amorphous powder having an average particle diameter (D ₅₀ ) of 11 μm and a substantially spherical shape (Fe content is 85 wt% or more, Si and Cr content is contained). The rates were 3 wt% or more and 8 wt% or less, and the B content was 1 wt% or less). The amorphous powder was dried at 120 ° C. for 1 hour in order to remove the adsorbed water on the surface of the powder. The average particle size (D ₅₀ ) is a value measured using a laser diffraction / scattering type particle size distribution measuring device (particle size distribution) LA-960 (manufactured by HORIBA, Ltd.) (the same applies hereinafter). ..

Further, as a thermosetting resin used for the composite magnetic material, a novolac type epoxy resin to which a required amount of a phenol novolac type curing agent was added as a curing agent was prepared. Three types of thermosetting resins having different softening temperatures (softening temperatures of 100 ° C., 60 ° C., and 0 ° C.) were prepared.

Then, first, the thermosetting resin weighed in a predetermined amount was diluted with methyl ethyl ketone (MEK) as a solvent. It was sufficiently dissolved to form a resin solution, and the above-mentioned metallic magnetic powder weighed in a predetermined amount was mixed with this resin solution, and sufficiently stirred and mixed with a planetary mixer (total mass of the metallic magnetic powder and the thermosetting resin in each sample). The amount (mass ratio) of the heat-curable resin with respect to the amount is shown in Table 1 below). Further, the methyl ethyl ketone (MEK), which is a diluting solvent, was dried while stirring with a planetary mixer to obtain a mixture of the metallic magnetic powder and the thermosetting resin. Further, this mixture was crushed by a high-speed crusher to prepare a composite magnetic material which is a granulated powder having an average particle size (D ₅₀ ) of less than 500 μm. For each of the produced composite magnetic materials, the melt viscosity of the contained thermosetting resin before curing at a softening temperature of + 40 ° C. was measured by Capillograph F-1 manufactured by Toyo Seiki Seisakusho Co., Ltd. and found to be approximately 1000 Ps · s. Met.

Next, the mold including the lower punch of the press machine with a built-in air cylinder and capable of temperature control control was adjusted to a predetermined temperature (the temperature of the mold used for compression molding of each sample (molding temperature)). Is shown in Table 1 below). When the mold temperature became stable, the above-mentioned composite magnetic material was put into the mold and held as it was for 30 seconds to make the temperature of the composite magnetic material substantially the same as the mold temperature. After 30 seconds had elapsed, an upper punch adjusted to the same temperature was inserted, and a predetermined molding pressure was applied to the upper punch to perform compression molding (the molding pressure of each sample is shown in Table 1 below). As a reference, one of the samples was used at room temperature without adjusting the temperature of the mold and the composite magnetic material, and was compression-molded at a high pressure (3000 kg / cm ² ). Then, after holding each in a compressed state for 5 minutes, the obtained composite magnetic molded body was taken out from the mold. Further, the composite magnetic molded product taken out from the mold was heat-treated at 160 ° C. for 2 hours, and the thermosetting resin was thermally cured (aftercure) to obtain a composite magnetic thermosetting molded product of Samples 1 to 55. .. The molding shape was a disk shape having a diameter of 15 mm and a thickness of 3 mm.

This disk-shaped composite magnetic thermosetting molded body was used for the evaluation of the density and the dielectric breakdown voltage. In addition, a toroidal-shaped composite magnetic thermo-cured molded body with a hole having a diameter of 8 mm is formed in the center of this disk-shaped composite magnetic thermo-cured molded body, and this toroidal-shaped composite magnetic heat is used for evaluation of relative permeability. A cured molded body was used.

The sample evaluation method is to evaluate the density of the molded body by calculating it from the measured values of the outer diameter, height, and mass of the disk-shaped composite magnetic heat-cured molded body, and evaluate it if it is less than 5.20 g / cm ³ . 5.20 g / cm ³ or more and less than 5.50 g / cm ³ was judged as 〇, and 5.50 g / cm ³ or more was judged as ⊚. Regarding the dielectric breakdown voltage of the molded body, the DC voltage is obtained by sandwiching both sides of the main surface of the disk-shaped composite magnetic heat-cured molded body with a bipolar copper plate electrode via a conductive rubber sheet (thickness 0.3 mm). Was applied and measured. The insulation breakdown voltage is evaluated by a voltage sweep using an insulation resistance tester SM7110 manufactured by Hioki Electric Co., Ltd., and a voltage of less than 300 V / mm is x, and a voltage of 300 V / mm or more and less than 600 V / mm is 〇, 600 V / mm or more. It was judged as ◎. Regarding the relative magnetic permeability of the molded body, an insulating coated copper wire (enamel wire) is wound around a toroidal-shaped composite magnetic thermocurable molded body for 20 turns, and the inductance value is measured with an LCR meter (E4980A LCR Meter manufactured by Agent). Then, the core multiplier is calculated from the outer diameter, inner diameter, and thickness of the toroidal-shaped composite magnetic thermocurable molded body, and the relative permeability is calculated from the inductance value. 22 or more was judged as ⊚. These results are shown in Table 1 below.

From this result, the insulation of the composite magnetic heat-curable molded body obtained when compression molding is performed at room temperature (a temperature lower than the softening temperature of the thermosetting resin) under the condition of 3000 kg / cm ² as the molding pressure, which is a conventional manufacturing method. Although the breakdown voltage is considerably low at less than 150 V / mm (Sample 55 in Table 1), the temperature of the mold and composite magnetic material used is adjusted to be higher than the softening temperature of the thermosetting resin before compression molding. Then, by performing compression molding so that the density becomes 5.2 g / cm ³ or more while the composite magnetic material has fluidity under the condition that the molding pressure is 1 kg / cm ² or more and 30 kg / cm ² or less. It was clarified that the obtained composite magnetic heat-curable molded product had a density of 5.2 g / cm ³ or more and a high insulation breakdown voltage of 500 V / mm or more (Sample 2- in Table 1). 4, 7-12, 17-21, 23-28, 32-37, 39-44, 49-53).

Further, in particular, when the molding pressure is 1 kg / cm ² or more and 10 kg / cm ² or less, the insulation breakdown voltage of the obtained composite magnetic thermosetting molded product is further increased, and the contained metal magnetic powder and thermosetting resin are further increased. It was also clarified that the specific magnetic permeability of the obtained composite magnetic thermosetting molded product is further increased when the mass ratio of the thermosetting resin to the total mass is 2.0 wt% or more and 4.0 wt% or less (Table 1). ..

On the other hand, if the molding pressure is less than 1 kg / cm ² , the density cannot be 5.2 g / cm ³ or more, and the specific magnetic permeability of the obtained composite magnetic heat-cured molded product is also less than 19 (Table 1). Samples 6, 22, 38), and the insulation breakdown voltage of the composite magnetic thermocurable molded product obtained when the molding pressure is more than 30 kg / cm ² becomes less than 300 V / mm (Sample 13- in Table 1). 15, 29-31, 45-47) were also shown.

Further, if the temperature of the mold used and the composite magnetic material before compression molding is lower than the softening temperature of the thermosetting resin, or the composite magnetic material loses fluidity during compression molding, compression molding is performed at a high temperature. Then, it was also shown that the density could not be 5.2 g / cm ³ or more, and the specific magnetic permeability of the obtained composite magnetic thermosetting molded product was less than 19 (Samples 1, 5, and 16 in Table 1). ..

Furthermore, if the mass ratio of the thermosetting resin to the total mass of the contained metallic magnetic powder and the thermosetting resin is less than 2.0 wt%, the density cannot be 5.2 g / cm ³ or more (sample in Table 1). 48), and if the mass ratio of the thermosetting resin to the total mass of the contained metal magnetic powder and the thermosetting resin is more than 4.5 wt%, the density cannot be 5.2 g / cm ³ or more. It was also shown that the specific magnetic permeability of the composite magnetic heat-cured molded product is less than 18 (Sample 54 in Table 1).

(Example 2)
The same metal magnetic powder as in Example 1 was prepared as the metal magnetic powder used for the composite magnetic material. Further, as the thermosetting resin used for the composite magnetic material, the thermosetting resin having a softening temperature of 60 ° C. of Example 1 was prepared. Then, a composite magnetic material which is a granulated powder was produced by the same method as in Example 1. Further, an air-core coil having an inner diameter of 4 mm, an outer diameter of 6 mm, and a number of turns of 23 turns was prepared using an insulated coated copper wire having a wire diameter of 0.3 mm. Then, the two ends of the air-core coil were welded to a tin-plated copper plate to be an external electrode to form a coil assembly.

Next, the mold including the lower punch of the same press machine as in Example 1 was adjusted to a predetermined temperature (the temperature (molding temperature) of the mold used for compression molding of each sample is shown in Table 2 below). .. When the mold temperature is stable, the composite magnetic material is arranged in the lower part and the upper part of the winding portion of the air core coil in the mold, and the coil assembly and the composite are exposed so that the end portion of the air core coil is exposed. The magnetic material was charged and held as it was for 30 seconds to make the temperature of the composite magnetic material almost the same as the mold temperature. After 30 seconds had elapsed, an upper punch adjusted to the same temperature was inserted and compression molding was performed at a predetermined pressure (the molding pressure in each sample is shown in Table 2 below). Again, as a reference, one of the samples was used at room temperature without adjusting the temperature of the mold and the composite magnetic material, and compression molding was performed at high pressure. Then, after holding each in a compressed state for 5 minutes, the obtained composite magnetic molded body was taken out from the mold. Further, the composite magnetic molded body taken out from the mold was heat-treated at 160 ° C. for 2 hours, and the thermosetting resin was heat-cured (aftercure) to obtain coil parts of samples 101 to 104. The molding shape was a disk shape having a diameter of 8 mm and a thickness of 5 mm, and the inductance value was about L = 22 μH.

The sample evaluation method was performed using an impulse tester (DWX-01A, manufactured by Electronic Control International Co., Ltd.) for the dielectric breakdown voltage between the terminals of the coil components. Specifically, the impulse voltage applied to the external electrode was increased, and the voltage at which the inductance value became −20% from the initial value was defined as the dielectric breakdown voltage. Then, less than 300V was determined as x, and 300V or more was determined as ⊚. The results are shown in Table 2 below.

The dielectric breakdown test of the composite magnetic thermocurable molded body of Example 1 is the dielectric breakdown test of the molded body at a DC voltage, whereas the dielectric breakdown test of the coil component of Example 2 is a terminal at an impulse voltage. Due to the dielectric breakdown test between them, these have different units and different numerical values.

From this result, when compression molding is performed at room temperature under the condition that the molding pressure is 3000 kg / cm ² , which is the conventional manufacturing method, the insulation breakdown voltage between the terminals of the obtained coil parts is considerably low at 95 V (Table 2). Sample 104), the temperature of the mold and composite magnetic material used was adjusted to be higher than the softening temperature of the thermosetting resin contained before compression molding, and the molding pressure was 10 kg / cm ² or more and 30 kg / cm ² By performing compression molding so that the density is 5.2 g / cm ³ or more while the composite magnetic material has fluidity under the following conditions, the insulation breakdown voltage between the terminals of the obtained coil parts is 300 V or more. (Samples 101 and 102 in Table 2).
On the other hand, even if a temperature-adjusted mold is used, if the molding pressure is more than 30 kg / cm ² , the dielectric breakdown voltage between the terminals of the obtained coil parts will be as low as 130 V (Sample 103 in Table 2). Shown.

This embodiment includes the following technical ideas.
(1) A composite magnetic thermosetting molded body containing a metal magnetic powder and a thermosetting resin, wherein the mass ratio of the thermosetting resin to the total mass of the metal magnetic powder and the thermosetting resin is When 2.0 wt% or more and 4.5 wt% or less, the density of the composite magnetic thermosetting molded body is 5.2 g / cm ³ or more, and a DC voltage is applied to the composite magnetic thermosetting molded body. A composite magnetic thermosetting molded body having an insulation breakdown voltage of 300 V / mm or more.
(2) The composite magnetic thermosetting molding according to (1), wherein the mass ratio of the thermosetting resin is 4.0 wt% or less, and the specific magnetic permeability of the composite magnetic thermosetting molded body is 20 or more. body.
(3) A coil component in which a coil is contained in the composite magnetic thermosetting molded body according to (1) or (2).
(4) A method for manufacturing a composite magnetic heat-curable molded product including a material preparation step, a compression molding step, and a heat-curing step, wherein the material preparation step includes a metal magnetic powder, a heat-curable resin, and the like. The material containing the above is mixed so that the mass ratio of the thermosetting resin to the total mass of the metal magnetic powder and the thermosetting resin is 2.0 wt% or more and 4.5 wt% or less to obtain a composite magnetic material. In the compression molding step, the composite magnetic material is molded into 1 kg / cm ² or more and 30 kg / cm ² or less using a mold adjusted to a temperature equal to or higher than the softening temperature of the thermosetting resin. It is a step of compression-molding the composite magnetic material so that the density becomes 5.2 g / cm ³ or more while the composite magnetic material has fluidity by pressure to obtain a composite magnetic molded body, and the heat curing step is the step of obtaining the composite. A method for producing a composite magnetic heat-curable molded body, which is a step of heat-treating the magnetic molded body to obtain the composite magnetic heat-curable molded body.
(5) The compression molding step adjusts the composite magnetic material before compression molding to a temperature equal to or higher than the softening temperature of the thermosetting resin, and the temperature is adjusted to the composite magnetic material using the mold. The method for manufacturing a composite magnetic thermocurable molded body according to (4), which is a step of compression molding with the molding pressure to obtain the composite magnetic molded body.
(6) The composite magnetic thermocurable molded product according to (4) or (5), wherein the mold or the composite magnetic material in the compression molding step is adjusted to a temperature lower than the heat treatment temperature in the thermosetting step. Manufacturing method.
(7) The method for producing a composite magnetic thermosetting molded product according to any one of (4) to (6), wherein the metal magnetic powder in the material preparation step is substantially spherical.
(8) Production of the composite magnetic thermocurable molded product according to any one of (4) to (7), wherein the metal magnetic powder in the material preparation step is a metal magnetic dry powder that has been subjected to a drying treatment. Method.
(9) Any one of (4) to (8), wherein the metal magnetic powder in the material preparation step is a surface-treated metal magnetic powder surface-treated with a silane-based or titanium-based coupling agent. A method for manufacturing a composite magnetic thermocurable molded body according to the above.
(10) Described in any one of (4) to (8), wherein the metal magnetic powder in the material preparation step is a phosphate-treated metal magnetic powder that has been phosphate-treated with a phosphate. Method for manufacturing a composite magnetic thermosetting molded product.
(11) The step according to any one of (4) to (10), wherein the compression molding step is a step of encapsulating a coil in the composite magnetic material and performing compression integral molding to obtain a coil-encapsulating composite magnetic molded body. Method for manufacturing a composite magnetic thermocurable molded product.

11 Air-core coil 11a End of air-core coil 11b Winding part of air-core coil 21 Mold 21a Lower punch of mold 21b Upper punch of mold 31 Composite magnetic material 32 Composite magnetic thermocurable molded body

Claims (11)

A composite magnetic thermosetting molded body containing a metallic magnetic powder and a thermosetting resin.
The mass ratio of the thermosetting resin to the total mass of the metal magnetic powder and the thermosetting resin is 2.0 wt% or more and 4.5 wt% or less.
The density of the composite magnetic thermosetting molded body is 5.2 g / cm ³ or more, and the composite magnetic thermosetting molded body has a density of 5.2 g / cm 3 or more.
Further, the dielectric breakdown voltage when a DC voltage is applied to the composite magnetic thermosetting molded body is 300 V / mm or more.
Composite magnetic thermosetting molded body. The composite magnetic thermosetting molded product according to claim 1, wherein the mass ratio of the thermosetting resin is 4.0 wt% or less, and the specific magnetic permeability of the composite magnetic thermosetting molded product is 20 or more. A coil component in which a coil is contained in the composite magnetic thermosetting molded body according to claim 1 or 2. A method for manufacturing a composite magnetic thermosetting molded product, which includes a material preparation step, a compression molding step, and a thermosetting step.
In the material preparation step, the mass ratio of the thermosetting resin to the total mass of the metal magnetic powder and the thermosetting resin is 2.0 wt% of the material containing the metal magnetic powder and the thermosetting resin. It is a step of obtaining a composite magnetic material by mixing so as to be 4.5 wt% or less.
In the compression molding step, the composite magnetic material is subjected to a molding pressure of 1 kg / cm ² or more and 30 kg / cm ² or less using a mold adjusted to a temperature equal to or higher than the softening temperature of the thermosetting resin. This is a step of obtaining a composite magnetic molded body by compression molding so that the density becomes 5.2 g / cm ³ or more while the material has fluidity.
The thermosetting step is a step of heat-treating the composite magnetic molded body to obtain the composite magnetic thermosetting molded body.
A method for manufacturing a composite magnetic thermosetting molded body. The compression molding step adjusts the composite magnetic material before compression molding to a temperature equal to or higher than the softening temperature of the thermosetting resin, and the temperature-adjusted composite magnetic material is subjected to the molding pressure using the mold. The method for producing a composite magnetic thermocurable molded body according to claim 4, which is a step of obtaining the composite magnetic molded body by compression molding. The method for producing a composite magnetic thermocurable molded product according to claim 4 or 5, wherein the mold or the composite magnetic material in the compression molding step is adjusted to a temperature lower than the heat treatment temperature in the thermocuring step. The method for producing a composite magnetic thermosetting molded product according to any one of claims 4 to 6, wherein the metal magnetic powder in the material preparation step is substantially spherical. The method for producing a composite magnetic thermocurable molded product according to any one of claims 4 to 7, wherein the metal magnetic powder in the material preparation step is a metal magnetic dry powder that has been subjected to a drying treatment. The composite magnetism according to any one of claims 4 to 8, wherein the metal magnetic powder in the material preparation step is a surface-treated metal magnetic powder surface-treated with a silane-based or titanium-based coupling agent. A method for manufacturing a thermosetting molded product. The composite magnetic thermal curing according to any one of claims 4 to 8, wherein the metal magnetic powder in the material preparation step is a phosphate-treated metal magnetic powder that has been phosphate-treated with a phosphate. Manufacturing method of molded body. The composite magnetic thermal curing according to any one of claims 4 to 10, wherein the compression molding step is a step of encapsulating a coil in the composite magnetic material and performing compression integral molding to obtain a coil-encapsulated composite magnetic molded body. Manufacturing method of molded body.

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