JPWO2019112002A1 - Composite magnetic powder, magnetic resin composition, magnetic resin paste, magnetic resin powder, magnetic resin slurry, magnetic resin sheet, magnetic resin sheet with metal foil, magnetic prepreg and inductor parts - Google Patents

Abstract

An object of the present invention is to provide a composite magnetic powder capable of increasing the Q value of a magnetic material at a high frequency. The composite magnetic powder according to the present invention contains a magnetic powder containing the first powder and a non-magnetic powder containing the second powder. The first powder consists of ferroalloy powder. The second powder comprises at least one of alumina powder and silica powder. The average particle size of the first powder is less than 5 μm, and is 3 times or more and 30 times or less the average particle size of the second powder.

Description

The present invention relates to a composite magnetic powder, a magnetic resin composition, a magnetic resin paste, a magnetic resin powder, a magnetic resin slurry, a magnetic resin sheet, a magnetic resin sheet with a metal leaf, a magnetic prepreg, and an inductor component.

In recent years, the drive frequency has become higher due to the miniaturization and multifunctionality of various information and communication devices such as smartphones and the increase in arithmetic processing speed. Inductor components are used in high-frequency circuits used in such information and communication equipment.

As an inductor component, Patent Document 1 discloses an inductor component including a coiled wiring and a cured product (hereinafter, magnetic material) of a resin sheet that covers the coiled wiring. This resin sheet contains an epoxy resin, a phenoxy resin, a linear elastomer, a curing agent, and an inorganic filler. The content of the inorganic filler is 80 to 98% by mass with respect to the total amount of the resin sheet. The content of the linear elastomer is 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the total components of the resin sheet excluding the linear elastomer.

However, in the conventional magnetic material as described in Patent Document 1, the Q value (quality factor, hereinafter referred to as the Q value of the magnetic material) indicating the small loss of the magnetic material is in the high frequency band (for example, 100 MHz). It is low and has high loss in the high frequency band. Inductor components using such conventional magnetic materials have a large resistance component of the inductor in the high frequency band, and the Q value (quality factor, Q = 2πfL / R, L is inductance, R is the inductor) of the inductor in the high frequency band. Resistance component, f is frequency) is low. Therefore, for example, there is a possibility that a conventional magnetic material cannot be used as a material for an inductor component that controls noise in a high frequency band.

Japanese Patent No. 5881027

An object of the present invention is a composite magnetic powder, a magnetic resin composition, a magnetic resin paste, a magnetic resin powder, a magnetic resin slurry, a magnetic resin sheet, and magnetism with a metal foil, which can increase the Q value of a magnetic material in a high frequency band. To provide resin sheets, magnetic prepregs and inductor components.

The composite magnetic powder of one aspect according to the present invention contains a magnetic powder containing a first powder and a non-magnetic powder containing a second powder, wherein the first powder is made of an alloy iron powder. The second powder is composed of at least one of alumina powder and silica powder, and the average particle size of the first powder is less than 5 μm, and is 3 times or more and 30 times the average particle size of the second powder. It is as follows.

The magnetic resin composition of one aspect according to the present invention contains the composite magnetic powder and at least one resin selected from the group consisting of curable resins and thermoplastic resins.

In the magnetic resin paste of one aspect according to the present invention, the magnetic resin composition is in the form of a paste.

In the magnetic resin powder of one aspect according to the present invention, the magnetic resin composition is in the form of powder.

In the magnetic resin slurry of one aspect according to the present invention, the magnetic resin composition further contains a solvent and is in the form of a slurry.

In the magnetic resin sheet of one aspect according to the present invention, the magnetic resin composition is in the form of a sheet.

The magnetic resin sheet with a metal foil according to the present invention includes the magnetic resin sheet and a metal foil having a thickness of 5 μm or less laminated on at least one surface of the magnetic resin sheet.

One aspect of the magnetic prepreg according to the present invention includes a fibrous base material and the magnetic resin composition or a semi-cured product of the magnetic resin composition.

The inductor component of one aspect according to the present invention includes a coiled wiring and an insulating layer that covers the coiled wiring, and the insulating layer is formed of a cured product or a solidified product of the magnetic resin composition.

FIG. 1A is a schematic cross-sectional view for explaining the arrangement relationship between the magnetic particles constituting the first powder and the non-magnetic particles constituting the second powder in the composite magnetic powder of the present invention. FIG. 1B is a schematic cross-sectional view showing an apparently large mass of large particles formed by a plurality of large-diameter magnetic particles in close proximity to each other. FIG. 1C is a schematic cross-sectional view for explaining the arrangement relationship between magnetic particles and non-magnetic particles when the average particle size of the first powder is less than three times the average particle size of the second powder. .. FIG. 1D is a schematic cross-sectional view for explaining the arrangement relationship between magnetic particles and non-magnetic particles when the average particle size of the first powder is more than 30 times the average particle size of the second powder. .. FIG. 2A is a schematic cross-sectional view for explaining a part of the method for manufacturing a magnetic resin sheet according to an embodiment of the present invention. FIG. 2B is a schematic cross-sectional view for explaining a part of the method for manufacturing a magnetic resin sheet according to an embodiment of the present invention. FIG. 2C is a schematic cross-sectional view for explaining a part of the method for manufacturing a magnetic resin sheet according to an embodiment of the present invention. FIG. 3 is a schematic view for explaining a method of measuring the greenis value. FIG. 4 is a schematic cross-sectional view of a magnetic resin sheet with a metal foil according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of a magnetic prepreg according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described.

The present embodiment relates to a composite magnetic powder, particularly to a composite magnetic powder preferably used as a magnetic material.

[Composite magnetic powder]
The composite magnetic powder according to the present embodiment (hereinafter, composite magnetic powder) contains a magnetic powder and a non-magnetic powder. The magnetic powder includes the first powder. The first powder consists of ferroalloy powder. The non-magnetic powder includes a second powder. The second powder comprises at least one of alumina powder and silica powder. The average particle size of the first powder is less than 5 μm, and is 3 times or more and 30 times or less the average particle size of the second powder.

A magnetic powder is an aggregate of magnetic particles. The non-magnetic powder is an aggregate of non-magnetic particles. Hereinafter, among the magnetic particles, the magnetic particles constituting the first powder are referred to as large-diameter magnetic particles 10, and among the non-magnetic particles, the non-magnetic particles constituting the second powder are referred to as small-diameter non-magnetic particles 20. Magnetic particles are particles composed of a substance (magnetic substance) that can be magnetized by an external magnetic field, and typical substances include iron oxide, chromium oxide, cobalt, and ferrite. Non-magnetic particles are particles of a substance that is not contained in the magnetic material (it does not become magnetic even when an external magnetic field is applied). In the present specification, the "average particle size" is, in principle, the particle size at an integrated value of 50% in the particle size distribution measured based on the particle size distribution measuring device based on the laser scattering / diffraction method, that is, the 50% volume average particle size ( It means D ₅₀ ). When the average particle size is fine particles such as 50 nm, the “average particle size” in the present specification means the average value of the particle size measured by scanning electron microscope (SEM) observation.

The composite magnetic powder is suitably used as a raw material for a magnetic material of an inductor component (hereinafter, high frequency inductor component) that controls noise in the high frequency band. The performance of high-frequency inductor components can be evaluated by the Q value of the magnetic material. The higher the Q value of the magnetic material, the smaller the loss of the magnetic material and the smaller the resistance component R of the inductor. Therefore, the Q value of the inductor is high and the performance of the high frequency inductor component is high. In order to function as a high frequency inductor component, the Q value of the magnetic material at 100 MHz needs to be 20 or more, and is preferably 33 or more in terms of improving the performance of the high frequency inductor component. The high frequency band means several tens of MHz or more and several GHz or less. The magnetic material refers to a cured product of the first magnetic resin composition described later or a solidified product of the second magnetic resin composition described later. The Q value of the magnetic material can be obtained in the same manner as the method described in the examples (RF impedance analyzer).

The Q value of a magnetic material is the loss coefficient (tan δ = μ) represented by the real part (μ') and the imaginary part (μ ”) of the complex magnetic permeability (μ = μ'−i × μ”, i is an imaginary unit). It is the reciprocal of "/ μ') (1 / tan δ = μ'/ μ"). Since the real part (μ') and the imaginary part (μ ″) depend on the frequency, the Q value of the magnetic material also depends on the frequency. Specifically, when the frequency exceeds a certain level, the imaginary part (μ ”) suddenly increases. On the other hand, the real part (μ') tends to decrease. In order to increase the Q value of the magnetic material at 100 MHz, the real part (μ') is high and the imaginary part (μ” at 100 MHz, as is clear from the equation of Q value of the magnetic material = μ'/ μ ". ) Is preferably low. The real part (μ') at 100 MHz is preferably 6.0 or more in designing a high frequency inductor component.

In the present embodiment, the average particle size of the first powder is 3 times or more and 30 times or less the average particle size of the second powder. As a result, at 100 MHz, the imaginary part (μ ") is low, and the Q value of the magnetic material can be set to 20 or more. This is because the adjacent large-diameter magnetic particles 10 and 10 are less likely to aggregate and are adjacent to each other. It is presumed that the main factor is that the electrical insulation between the large-diameter magnetic particles 10 and 10 is ensured. Specifically, in the magnetic material before treatment, as shown in FIG. 1A, the large diameter A plurality of small-diameter non-magnetic particles 20 are uniformly arranged around one particle of the magnetic particles 10, and a layer 21 composed of the small-diameter non-magnetic particles 20 is likely to be formed on the surface of the large-diameter magnetic particles 10. Each of the large-diameter magnetic particles 10 tends to behave as an independent particle, and the distance I between adjacent large-diameter magnetic particles 10 and 10 can be optimized. In other words, as shown in FIG. The large-diameter magnetic particles 10 and 10 of the above are apparently difficult to behave as a large particle 11 in a mass. Further, since the second powder is composed of at least one of alumina powder and silica powder, the layer 21 has an insulating property. Therefore, the interparticle vortex current that flows across the adjacent large-diameter magnetic particles 10 is less likely to be generated, and the vortex current loss can be further reduced. As a result, the imaginary part (μ ”) at 100 MHz becomes low. Guess. The magnetic material before treatment is a state before the magnetic material is cured or solidified, and is a first magnetic resin composition before curing, a magnetic resin paste described later, a magnetic resin powder described later, and a resin magnetic slurry described later. , A magnetic resin sheet described later, a second magnetic resin composition before solidification, and the like.

The composite magnetic powder may further contain a powder different from the first powder and the second powder as long as it is a mixed powder containing the first powder and the second powder. That is, in the particle size distribution measured in terms of volume of the composite magnetic powder, it is sufficient that there are at least two peaks representing the frequency of existence thereof, and there may be three or more peaks.

The shapes of the magnetic particles and the non-magnetic particles constituting the composite magnetic powder are not particularly limited, and examples thereof include a spherical shape, an ellipsoidal shape, a flat shape, and a crushed shape. The shapes of the magnetic particles and the non-magnetic particles may all be the same or different. Above all, it is preferable that the shapes of the magnetic particles and the non-magnetic particles are all spherical. When the shapes of the magnetic particles and the non-magnetic particles are all spherical, the filling amount of the composite magnetic powder with respect to the magnetic material can be increased. Further, the magnetic material before the treatment in which the shapes of the magnetic particles and the non-magnetic particles are all spherical and the magnetic material before the treatment in which the shapes of the magnetic particles and the non-magnetic particles are not all spherical are used with respect to the magnetic material before the treatment. When the filling amount of the composite magnetic powder is the same, the former is superior in the fluidity of the magnetic material before the treatment. Further, the Q value of the magnetic material at 100 MHz can be further increased.

The spheres include those having an average sphericity of 0.7 or more. The average sphericity can be obtained as follows. Each particle image of each magnetic particle is photographed with a scanning electron microscope or the like, each particle image is taken into an image analyzer or the like, and the projected area (S) and the peripheral length (L) of each magnetic particle are measured from the photograph. .. Then, the measurement result is substituted into the following formula to calculate the sphericity.
Sphericity = 4πS / L ²

In this way, for each of the magnetic particles, the sphericity of a certain number (preferably 200 or more) of particles is obtained, and this average value is taken as the average sphericity.

{Magnetic powder}
The composite magnetic powder contains a magnetic powder. The magnetic powder contains the first powder and may further contain other magnetic powders.

The magnetic powder is preferably insulated. That is, it is preferable that the surface of each magnetic particle is covered with an electrically insulating film. As a result, the imaginary part (μ ") can be made lower and the Q value of the magnetic material can be made higher at 100 MHz. Further, the electrical insulation reliability of the magnetic material itself can be improved. The imaginary number at 100 MHz. It is presumed that the reason why the part (μ ”) can be made lower is that the insulating film makes it difficult for interparticle vortex currents that flow across adjacent magnetic particles to be generated, and the vortex current loss can be further reduced. Will be done.

Examples of the method of insulation treatment include a method of mixing a magnetic powder and an aqueous solution containing an electrically insulating filler and drying them. As the material of the electrically insulating filler, for example, phosphoric acid, boric acid, magnesium oxide and the like can be used. This electrically insulating film is different from the layer 21 made of the small-diameter non-magnetic particles 20. When the magnetic particles themselves have electrical insulating properties, they do not have to be covered with the electrical insulating film.

The mixing ratio of the magnetic powder is preferably 4.0 parts by mass or more and 19.0 parts by mass or less, and more preferably 4.0 parts by mass or more and 5.7 parts by mass or less with respect to 1 part by mass of the non-magnetic powder. More preferably, it is 4.3 parts by mass or more and 5.2 parts by mass or less. When the mixing ratio of the magnetic powder is within the above range, the Q value of the magnetic material at 100 MHz and the fluidity of the magnetic material before the treatment can be balanced. It is presumed that this is because, as shown in FIG. 1A, the thickness of the layer 21 composed of the non-magnetic particles 20 arranged around the large-diameter magnetic particles 10 can be made thinner, and the interval I can be more optimized.

(First powder)
The first powder consists of ferroalloy powder. Ferroalloy powder is an aggregate of ferroalloy particles. The material of the ferroalloy particles is an alloy mainly composed of iron. Examples of the material of the alloy iron particles include Sendust, permendur, silicon steel, permalloy, Fe-Si—Cr alloy and the like. These are ferroalloys with high magnetic permeability.

Sendust is an alloy (Fe-Si-Al alloy) composed of iron, silicon, and aluminum. Sendust has high saturation magnetic flux density and magnetic permeability, small iron loss, and excellent wear resistance. An example of the composition of sendust is Fe-9.5Si-5.5Al (numerical value is mass%, remaining Fe). In the vicinity of this composition region, both the magnetostriction constant and the magnetic anisotropy constant are almost zero. Therefore, high magnetic permeability and low coercive force can be obtained. Permendur is an alloy containing iron and cobalt as main components. Permendur has the highest saturation magnetic flux density among the soft magnetic materials that have been put into practical use. An example of the composition of permendur is Fe-49Co-2V (numerical value is mass%, remaining Fe). Silicon steel is an alloy of iron with a small amount of silicon added. Silicon steel is also called silicon iron because it does not contain carbon. Permalloy is an alloy of Ni—Fe. Permalloy includes those called Permalloy A, Permalloy B, Permalloy C, Permalloy D and JIS standards.

The average particle size of the first powder is 3 times or more and 30 times or less, preferably 3.5 times or more and 20 times or less, and more preferably 4 times or more and 15 times or less of the average particle size of the second powder. .. If the average particle size of the first powder is less than three times the average particle size of the second powder, the imaginary part (μ'') is high at 100 MHz, and the Q value of the magnetic material may be less than 20. There is. It is presumed that the imaginary part (μ'') at 100 MHz becomes high because, as shown in FIG. 1C, it becomes difficult for the layer 21 made of the small diameter non-magnetic particles 20 to be formed on the surface of the large diameter magnetic particles 10. .. If the average particle size of the first powder is more than 30 times the average particle size of the second powder, the real part (μ') is low at 100 MHz, and the Q value of the magnetic material may be less than 20. is there. The reason why the real part (μ') at 100 MHz is low is that, as shown in FIG. 1D, the layer 21 composed of the small diameter non-magnetic particles 20 is easily formed on the surface of the large diameter magnetic particles 10, and the adjacent large diameter magnetic particles 20 are easily formed. It is presumed that the distance I between the particles 10 and 10 becomes too wide. When the first powder is a mixed powder obtained by mixing two or more powders having different average particle sizes, the average particle size of the first powder refers to the average particle size of the mixed powder. Similarly, when the second powder is a mixed powder in which two or more powders having different average particle sizes are mixed, the average particle size of the second powder refers to the average particle size of the mixed powder.

The average particle size of the first powder is less than 5 μm, preferably 0.05 μm or more and less than 5 μm, and more preferably 0.5 μm or more and less than 5 μm. When the average particle size of the first powder is 5 μm or more, the imaginary part (μ ”) at 100 MHz is high, and the Q value of the magnetic material may be less than 20.

The content of the first powder may be appropriately adjusted according to the material of the other magnetic powder, the average particle size, etc., and is preferably 20% by mass or more and 100% by mass or less, based on the total mass of the magnetic powder. It is preferably 40% by mass or more and 100% by mass or less. When the content of the first powder is within the above range, the real number part (μ') can be further improved while maintaining the high Q value of the magnetic material at 100 MHz.

(Other magnetic powder)
The magnetic powder may contain other magnetic powder different from the first powder. The other magnetic powder is an aggregate of other magnetic particles different from the large-diameter magnetic particles 10.

As the material of the other magnetic particles, for example, pure iron, metal oxide, alloy, resin and the like can be used. Pure iron is high-purity iron of 99.90% by mass or more and 99.95% by mass or less. Specific examples of pure iron include carbonyl iron, armco iron, sponge iron, and electrolytic iron. Carbonyl iron is obtained by thermally decomposing iron carbonyl Fe (CO) ₅ . As the metal oxide, for example, ferrite, magnetite and the like can be used. Ferrite is a general term for ceramics containing iron oxide as a main component, and has insulating properties. As the alloy, for example, nickel, cobalt-based alloy and the like can be used. Among them, it is preferable to use ferrite as a material for other magnetic particles. Since the magnetic material contains ferrite, the real part (μ') at 100 MHz can be further improved.

The ferrite may be a soft ferrite exhibiting soft magnetism or a hard ferrite exhibiting ferromagnetism. Examples of the crystal structure of ferrite include spinel ferrite, hexagonal ferrite, and garnet ferrite.

Spinel ferrite has a spinel-type crystal structure, and its composition formula is represented by MeO · Fe ₂ O ₃ or Me Fe ₂ O ₄ (transition metal such as Me: Zn, Ni, Cu, Mn, Mg, Co). Most of the spinel ferrites are soft ferrites. Specific examples include manganese magnesium ferrite, manganese zinc ferrite, nickel zinc ferrite, and copper zinc ferrite. Spinel ferrite has high magnetic permeability and high electrical resistance, so that eddy current loss in the high frequency region is small, so it is effective as an inductor component for high frequency circuits.

Hexagonal ferrite has a magnetoplumbite-type hexagonal crystal structure, and its composition formula is represented by MO · 6Fe ₂ O ₃ or MFe ₁₂ O ₁₉ (alkaline earth metals such as M: Ba, Sr, Pb). .. Hexagonal ferrite is also called magnetoplumbite-type ferrite or M-type ferrite. Hexagonal ferrite is a typical hard ferrite that exhibits a large coercive force because it has a larger magnetic anisotropy than spinel ferrite. Specific examples include barium ferrite and strontium ferrite.

Garnet ferrite has a garnet-type crystal structure, composition formula _{3R 2 O 3 · 5Fe 2 O} 3 or _R 3 _Fe 5 _O 12: represented by (R Y, Sm, rare earth elements such as Gd). Garnet ferrite is also called RIG (Rare-earth Iron Garnet). A typical example is YIG (Yttrium Iron Garnet). Garnet ferrite has a small magnetic loss in the high frequency region, and is therefore effective as an inductor component for microwaves.

The average particle size of the other magnetic powder is not particularly limited, and is preferably 0.05 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 5 μm or less. When the average particle size of the other magnetic particle size is within the above range, the imaginary part (μ ") at 100 MHz can be made lower.

The mixing ratio of the other magnetic powder may be appropriately adjusted according to the average particle size of the other magnetic powder and the like. When the average particle size of the other magnetic powder is 0.02 μm or more and 0.1 μm or less, the mixing ratio of the other magnetic powder is preferably less than 12% by mass, more preferably 0.5, based on the first powder. It is mass% or more and 10 mass% or less. If the average particle size of the other magnetic powder is within the above range and the mixing ratio thereof is within the above range, the Q value of the magnetic material at 100 MHz can be 20 or more, and the obtained magnetic resin sheet can be obtained. Has excellent fluidity.

{Non-magnetic powder}
The composite magnetic powder contains a non-magnetic powder. The non-magnetic powder contains a second powder and may further contain other non-magnetic powder.

(Second powder)
The second powder is at least one of silica powder and alumina powder. That is, the composition of the second powder is a composition composed of only silica powder, a composition composed of only alumina powder, or a composition composed of silica powder and alumina powder. Since both the silica powder and the alumina powder have high electrical insulation properties, the second powder can suppress the flow of eddy currents.

Silica powder is an aggregate of silica particles. As the silica particles, for example, crystalline silica particles, non-crystalline silica particles and the like can be used. The silica particles may be porous.

Alumina powder is an aggregate of alumina particles. As the material of the alumina particles, for example, α-alumina, γ-alumina, δ-alumina, θ-alumina, η-alumina, κ-alumina and the like can be used.

The average particle size of the second powder depends on the average particle size of the first powder so that the average particle size of the first powder is 3 times or more and 30 times or less the average particle size of the second powder. It is adjusted, preferably 0.05 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 2 μm or less. When the average particle size of the second powder is within the above range, it becomes easy to secure the fluidity of the magnetic material before the treatment.

The content of the second powder may be appropriately adjusted according to the material, average particle size, etc. of the other non-magnetic powder, and is preferably 50% by mass or more and 100% by mass or less with respect to the total mass of the non-magnetic powder. , More preferably 70% by mass or more and 100% by mass or less.

(Other non-magnetic powder)
The non-magnetic powder may further contain other non-magnetic powder. The other non-magnetic powder is an aggregate of other non-magnetic particles different from the small-diameter non-magnetic particles 20.

As the material of the other non-magnetic particles, for example, carbon black, titanium oxide, cerium oxide, tin oxide, tungsten oxide, ZnO, ZrO ₂ , SiO ₂ , Cr ₂ O _{3 and the} like can be used.

Other non-magnetic powders preferably have electrical insulation. That is, it is preferable that the surface of the other non-magnetic particles is covered with an electrically insulating film. Examples of the method of insulation treatment include a method of mixing a non-magnetic powder and an aqueous solution containing an electrically insulating filler and drying them. As the material of the electrically insulating filler, for example, phosphoric acid, boric acid, magnesium oxide and the like can be used. When the other non-magnetic particles themselves have electrical insulating properties, they do not have to be covered with the electrical insulating film. The average particle size of the other non-magnetic powder is not particularly limited, and may be about the same as the average particle size of the second powder.

[Magnetic resin composition]
The magnetic resin composition according to the present embodiment contains a composite magnetic powder and at least one resin selected from the group consisting of a curable resin and a thermoplastic resin. The magnetic resin composition may be a resin composition containing a curable resin (hereinafter, referred to as a first magnetic resin composition), or a resin composition containing a thermoplastic resin (hereinafter, a second magnetic resin). It may be (referred to as a composition).

The cured product or solidified product of the magnetic resin composition preferably has a Q value of 20 or more at a frequency of 100 MHz. That is, the cured product of the first magnetic resin composition preferably has a Q value of 20 or more at a frequency of 100 MHz, and the solidified product of the second magnetic resin composition has a Q value of 20 or more at a frequency of 100 MHz. Is preferable. In this case, the magnetic resin composition can be suitably used as a magnetic material for high-frequency inductor components. The cured product or solidified product of the magnetic resin composition more preferably has a Q value of 33 or more at a frequency of 100 MHz.

{First magnetic resin composition}
The first magnetic resin composition contains a composite magnetic powder and a curable resin.

The first magnetic resin composition contains a curable resin. Examples of curable resins include thermosetting resins and photocurable resins. The first magnetic resin composition may contain only a thermosetting resin, may contain only a photocurable resin, or may contain both a thermosetting resin and a photocurable resin. Good.

A photocurable resin is a reactive compound that can absorb light and cause a cross-linking reaction. The photocurable resin is not particularly limited as long as it is a photocurable resin. As the photocurable resin, for example, a resin having a polymerizable unsaturated group may be used. Examples of photocurable resins include methacrylic resins, acrylic resins, epoxy resins, and oxetane resins. The photocurable resin contained in the first magnetic resin composition may be only one type or two or more types. The photocurable resin may be liquid at room temperature or solid such as powder.

Examples of methacrylic acids include methacrylic acid esters, polymethacrylic acid esters, and ethylene-methacrylic acid copolymers.

Examples of acrylic resins include ethylene-acrylic acid copolymers, ethylene-methyl acrylate copolymers, acrylic acid esters, and polyacrylic acid esters.

The epoxy resin may be a monofunctional epoxy resin having one epoxy group in one molecule, or a polyfunctional epoxy resin having two or more epoxy groups in one molecule. Examples of polyfunctional epoxy resins include polybutadiene epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins and other bisphenol type epoxy compounds, naphthalene type epoxy compounds, aliphatic epoxy compounds, biphenyl type epoxies, and glycidylamine type epoxy compounds. Alcohol type epoxy compounds such as hydrogenated bisphenol A type epoxy compounds, epoxy-modified silicones, phenol novolac type epoxy compounds, novolak type epoxy compounds such as cresol novolac type epoxy compounds, alicyclic epoxy compounds, anobolite cyclic epoxy compounds, many Halogenized epoxy compounds such as functional epoxy compounds, glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, brominated epoxy compounds, rubber modified epoxy compounds, urethane modified epoxy compounds, epoxidized polybutadiene, epoxidized styrene-butadiene-styrene block Includes copolymers, epoxy group-containing polyester compounds, epoxy group-containing polyurethane compounds, and epoxy group-containing acrylic compounds. These epoxy resins may be used alone or in combination of two or more.

The oxetane resin may be used alone or in combination of two or more.

When the first magnetic resin composition contains a photocurable resin, the first magnetic resin composition may contain a photopolymerization initiator, if necessary. Examples of photopolymerization initiators include photoradical generation initiators and photoacid generation initiators. When the first magnetic resin composition contains at least one of a methacrylic resin and an acrylic resin, the first magnetic resin composition preferably contains a photoradical generation initiator. The photo-radical generation initiator is not particularly limited as long as it generates radicals to initiate the photopolymerization reaction. When the first magnetic resin composition contains at least one of an epoxy resin and an oxetane resin, the first magnetic resin composition preferably contains a photoacid generation initiator. The photoacid generation initiator is not particularly limited, and may be an ionic photoacid generation initiator or a nonionic photoacid generation initiator.

The first magnetic resin composition preferably contains a thermosetting resin. Thermosetting resin is a reactive compound that can cause a cross-linking reaction by heat. As the thermosetting resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyfunctional epoxy resin, biphenyl type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, imide resin and the like can be used. .. The polyfunctional epoxy resin is a resin having three or more epoxy groups in one molecule. The thermosetting resin contained in the first magnetic resin composition may be only one type or two or more types. The thermosetting resin may be liquid at room temperature or solid such as powder. The content of the thermosetting resin is preferably 75% by mass or more and 100% by mass or less with respect to the total mass of the resin components in the first magnetic resin composition.

When the first magnetic resin composition contains a thermosetting resin, the first magnetic resin composition may further contain a curing agent. The curing agent is an additive that cures a thermosetting resin. As the curing agent, dicyandiamide, phenol-based curing agent, cyclopentadiene, amine-based curing agent, acid anhydride and the like can be used. The phenolic curing agent has two or more phenolic hydroxyl groups in one molecule. As the phenolic curing agent, for example, phenol novolac resin, phenol aralkyl resin, naphthalene type phenol resin, bisphenol resin and the like can be used. As the bisphenol resin, for example, a bisphenol A resin, a bisphenol F resin, or the like can be used. The curing agent may be liquid or solid at room temperature. The content of the curing agent is preferably 20% by mass or less with respect to the total mass of the resin components of the first magnetic resin composition.

When the first magnetic resin composition contains a thermosetting resin, the first magnetic resin composition may further contain a curing accelerator. As the curing accelerator, for example, a tertiary amine, a tertiary amine salt, an imidazole, a phosphine, a phosphonium salt and the like can be used. As the imidazole, 2-ethyl-4-methylimidazole or the like can be used. The content of the curing accelerator may be appropriately adjusted according to the material of the thermosetting resin and the curing agent.

The first magnetic resin composition may further contain a thermoplastic resin. As a result, it is possible to impart bending followability, elasticity, and the like to the magnetic resin sheet 1 described later. As the thermoplastic resin, a phenoxy resin or the like can be used. The content of the thermoplastic resin is preferably 2% by mass or more and 50% by mass or less with respect to the total mass of the resin components of the first magnetic resin composition.

The first magnetic resin composition may further contain a surface treatment agent. As the surface treatment agent, for example, a silane coupling agent, a dispersant, or the like can be used. As the silane coupling agent, for example, 3-glycidyloxypropyltriethoxysilane or the like can be used. As the dispersant, for example, a higher fatty acid phosphoric acid ester, an amine salt of a higher fatty acid phosphoric acid ester, an alkylene oxide of a higher fatty acid phosphoric acid ester, or the like can be used. As the higher fatty acid phosphate ester, octyl phosphate ester, decyl phosphate ester, lauryl phosphate ester and the like can be used. The content of the surface treatment agent is preferably 0% by mass or more and 30% by mass or less with respect to the total mass of the resin components of the first magnetic resin composition.

The first magnetic resin composition may further contain an elastomer. As a result, when the first magnetic resin composition contains an elastomer, rubber elasticity can be imparted to the cured product of the first magnetic resin composition. As the elastomer, for example, a thermosetting elastomer or a thermoplastic elastomer can be used.

The first magnetic resin composition may further contain a solvent. Methyl ethyl ketone (MEK), N, N-dimethylformamide (DMF), acetone, methyl isobutyl ketone (MIBK) and the like can be used. Only one type of solvent may be used, or two or more types may be mixed and used. When two or more kinds of solvents are mixed, the mixing ratio (mass ratio and volume ratio) is not particularly limited.

The content of the composite magnetic powder is preferably 70% by mass or more, more preferably 75% by mass or more, and particularly preferably 80% by mass or more of the total solid content of the first magnetic resin composition. preferable. When the content of the composite magnetic powder is 70% by mass or more of the total solid content of the magnetic resin composition, the real part (μ') at 100 MHz tends to be 6.0 or more, and a high-frequency inductor should be satisfactorily designed. Can be done. The content of the composite magnetic powder is preferably 99.5% by mass or less, more preferably 99% by mass or less, and 98.5% by mass, based on the total solid content of the first magnetic resin composition. The following is particularly preferable. When the content of the composite magnetic powder is 99.5% by mass or less of the total solid content of the magnetic resin composition, the Q value of the magnetic material tends to be high. Here, the solid content of the magnetic resin composition is the content obtained by removing the solvent from the magnetic resin composition.

As a method for preparing the first magnetic resin composition, for example, a method of mixing a composite magnetic powder, a curable resin, a curing agent, a curing accelerator, a thermoplastic resin, a surface treatment agent, an elastomer, etc., if necessary. And so on.

As will be described later, since the first magnetic resin composition can take any form of paste, slurry, powder, or sheet, the first magnetic resin composition having an appropriate form depending on the subsequent steps. You can use things. Examples of the subsequent steps include a transfer molding step using a mold and a step of embedding molding by heating and pressurizing.

{Second magnetic resin composition}
The second magnetic resin composition (hereinafter, the second magnetic resin composition) contains a composite magnetic powder and a thermoplastic resin.

A thermoplastic resin is a compound that softens by heating to a glass transition temperature or melting point and solidifies by cooling to a temperature lower than the glass transition temperature or melting point. As the thermoplastic resin, for example, nylon or the like can be used. As the nylon, for example, nylon 6 or the like can be used.

The second magnetic resin composition may further contain a curable resin. As a result, good strength can be imparted to the magnetic resin sheet 1 described later. As the curable resin, a curable resin that can be contained in the above-mentioned first magnetic resin composition can be used. The content of the curable resin is preferably 2% by mass or more and 50% by mass or less with respect to the total mass of the resin components of the second magnetic resin composition.

The second magnetic resin composition may further contain a surface treatment agent. As the surface treatment agent, for example, a silane coupling agent, a dispersant, or the like can be used. As the silane coupling agent, for example, 3-glycidyloxypropyltriethoxysilane or the like can be used. As the dispersant, for example, a higher fatty acid phosphoric acid ester, an amine salt of a higher fatty acid phosphoric acid ester, an alkylene oxide of a higher fatty acid phosphoric acid ester, or the like can be used. As the higher fatty acid phosphate ester, octyl phosphate ester, decyl phosphate ester, lauryl phosphate ester and the like can be used. The content of the surface treatment agent is preferably 0% by mass or more and 30% by mass or less with respect to the total mass of the resin components of the second magnetic resin composition.

The second magnetic resin composition may further contain an elastomer. As a result, rubber elasticity can be imparted to the solidified product of the second magnetic resin composition. As the elastomer, for example, a thermosetting elastomer, a thermoplastic elastomer, or the like can be used. The content of the elastomer may be appropriately adjusted depending on the intended use of the second magnetic resin composition and the like.

The second magnetic resin composition may further contain a solvent. As the solvent, methyl ethyl ketone (MEK), N, N-dimethylformamide (DMF), acetone, methyl isobutyl ketone (MIBK) and the like can be used. Only one type of solvent may be used, or two or more types may be mixed and used. When two or more kinds of solvents are mixed, the mixing ratio (mass ratio and volume ratio) is not particularly limited.

The content of the composite magnetic powder is preferably 70% by mass or more, more preferably 75% by mass or more, and particularly preferably 80% by mass or more of the total solid content of the second magnetic resin composition. preferable. When the content of the composite magnetic powder is 70% by mass or more of the total solid content of the magnetic resin composition, the proportion of the composite magnetic powder in the second magnetic resin composition becomes high, and the solidified product having a high complex magnetic permeability Can be obtained. The content of the composite magnetic powder is preferably 99.5% by mass or less, more preferably 99% by mass or less, and 98.5% by mass, based on the total solid content of the second magnetic resin composition. The following is particularly preferable. When the content of the composite magnetic powder is 99.5% by mass or less of the total solid content of the magnetic resin composition, the fluidity of the second magnetic resin composition at the time of molding can be ensured, and moreover, the complex permeability can be ensured. A solidified product having a high magnetic coefficient can be obtained. Here, the solid content of the magnetic resin composition is the content obtained by removing the solvent from the magnetic resin composition.

Examples of the method for adjusting the second magnetic resin composition include a method in which a composite magnetic powder, a thermoplastic resin, and an elastomer, if necessary, are put into a kneader and melt-kneaded. As the kneader, for example, a screw extruder, a kneader, a Banbury mixer, a twin-screw kneading extruder and the like can be used. Further, the obtained second magnetic resin composition may be molded into a desired shape. Examples of the molding method of the second magnetic resin composition include extrusion molding and injection molding.

As will be described later, since the second magnetic resin composition can take any form of paste, slurry, powder, or sheet, the second magnetic resin composition having an appropriate form depending on the subsequent steps. You can use things. Examples of the subsequent steps include a transfer molding step using a mold and a step of embedding molding by heating and pressurizing.

[Magnetic resin paste]
In the magnetic resin paste according to the present embodiment (hereinafter, magnetic resin paste), the magnetic resin composition is in the form of a paste. The pasty state means that the magnetic resin composition has fluidity at room temperature. The magnetic resin composition may be the first magnetic resin composition or the second magnetic resin composition. That is, in the magnetic resin paste, the first magnetic resin composition may be in the form of a paste, or the second magnetic resin composition may be in the form of a paste.

The filling ratio of the magnetic powder in the magnetic resin paste (hereinafter, the content of the magnetic powder) is preferably 20% by volume or more and 99% by volume or less, more preferably 53% by volume or more and 95% by volume, based on the total solid content of the magnetic resin paste. % Or less. When the content of the magnetic powder is within the above range, the real part (μ') at 100 MHz can be increased, and the fluidity of the magnetic resin paste can be easily controlled. The method for calculating the content of the magnetic powder was calculated from the blending amount of each material constituting the solid content of the magnetic resin paste and the specific gravity of each material. In the magnetic resin paste, when the magnetic resin composition contains a solvent, the solid content of the magnetic resin paste is the amount obtained by removing the solvent from the magnetic resin composition.

As a method for preparing the magnetic resin paste, for example, at least one liquid type resin selected from the group consisting of a curable resin and a thermoplastic resin is used, and a composite magnetic powder, a liquid type resin, and if necessary Examples thereof include a method of mixing a curing agent, a curing accelerator, a surface treatment agent, an elastomer and the like. When the magnetic resin composition contains a solvent in the magnetic resin paste, for example, at least one resin selected from the group consisting of curable resin and thermoplastic resin is dissolved in the solvent to obtain a resin solution. A magnetic resin paste can be obtained by mixing a composite magnetic powder with a curing agent, a curing accelerator, a surface treatment agent, an elastomer, or the like, if necessary, in the obtained resin solution.

The magnetic resin paste may be in the form of a paste in which the magnetic resin composition contains a solvent, or may be in the form of a paste containing no solvent. That is, the first magnetic resin composition may be in the form of a solvent-containing paste, or may be in the form of a solvent-free paste. Further, the second magnetic resin composition may be in the form of a paste containing a solvent, or may be in the form of a paste containing no solvent.

The magnetic resin paste is preferably in the form of a solvent-free magnetic resin composition. In this case, an environment-friendly magnetic resin paste can be obtained by not using a solvent. Further, since the magnetic resin paste does not contain a solvent, it is possible to prevent the generation of voids when the magnetic resin paste is stored or heated. Further, when the magnetic resin paste is used, it is possible to reduce the risk that the members and equipment used together with the magnetic resin paste are contaminated by the solvent contained in the magnetic resin paste. Further, when the magnetic resin paste contains a solvent, it may be necessary to make a dedicated process or equipment used explosion-proof in the manufacturing process. However, since the magnetic resin paste does not contain a solvent, the manufacturing process can be simplified.

In the magnetic resin paste, when the magnetic resin composition is in the form of a paste containing a solvent, the content of the solvent contained in the magnetic resin composition shall be 5% by mass or less of the total solid content of the magnetic resin composition. Is preferable, and it is more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

As the solvent, methyl ethyl ketone (MEK), N, N-dimethylformamide (DMF), acetone, methyl isobutyl ketone (MIBK) and the like can be used. Only one type of solvent may be used, or two or more types may be mixed and used. When two or more kinds of solvents are mixed, the mixing ratio (mass ratio and volume ratio) is not particularly limited.

[Magnetic resin powder]
The magnetic resin powder according to the present embodiment (hereinafter referred to as magnetic resin powder) has a magnetic resin composition in the form of powder. The magnetic resin composition may be the first magnetic resin composition or the second magnetic resin composition. When the magnetic resin composition is the first magnetic resin composition, the magnetic resin powder may be a powder of the semi-cured product of the first magnetic resin composition, and the first magnetic resin composition may be in the form of powder. It may be in the form. The semi-cured product is a state in which the resin composition is partially cured to the extent that it can be further cured. That is, the semi-cured product refers to a B-stage state, which is an intermediate stage state of the curing reaction. The intermediate stage refers to a stage between a varnish state (A stage state) and a completely cured state (C stage state). For example, when the thermosetting resin composition is heated, the viscosity gradually decreases, then curing starts, and the viscosity gradually increases. In this case, the semi-cured state is a state between the time when the viscosity starts to increase and the time before it is completely cured. The average particle size of the particles constituting the magnetic resin powder is not particularly limited.

As a method for preparing the magnetic resin powder, for example, a method using an atomizing method using a magnetic resin slurry described later, or at least one resin selected from the group consisting of a composite magnetic powder and a curable resin and a thermoplastic resin. Examples thereof include a method of mixing the powder with a three-roll mill or the like, and a method of crushing a magnetic resin sheet described later. The atomizing method is particularly preferable in that the individual particles constituting the magnetic resin powder can be made substantially spherical. When the individual particles constituting the magnetic resin powder are substantially spherical, the fluidity during the subsequent molding process becomes good. In the atomizing method, the magnetic resin slurry is sprayed in an environment of a high temperature (for example, 140 ° C.) to form mist-like particles, and the magnetic resin powder is rapidly dried to volatilize the solvent to prepare a magnetic resin powder. Since the first magnetic resin composition contains a large amount of the composite magnetic powder, the viscosity may increase. However, once the magnetic resin slurry is prepared by using the solvent as described above, when the slurry is exposed to a high temperature environment while being sprayed, the solvent, which is a volatile component, is rapidly released and becomes powdery. Will be handled well.

[Magnetic resin slurry]
The magnetic resin slurry (hereinafter referred to as magnetic resin slurry) according to the present embodiment is in the form of a slurry in which the magnetic resin composition further contains a solvent. “Slurry” means that the magnetic resin composition contains a solvent and has fluidity at room temperature. The magnetic resin composition may be the first magnetic resin composition or the second magnetic resin composition. That is, the magnetic resin slurry may be in the form of a slurry in which the first magnetic resin composition contains a solvent, or may be in the form of a slurry in which the second magnetic resin composition contains a solvent.

As the solvent, methyl ethyl ketone (MEK), N, N-dimethylformamide (DMF), acetone, methyl isobutyl ketone (MIBK) and the like can be used. Only one type of solvent may be used, or two or more types may be mixed and used. When two or more kinds of solvents are mixed, the mixing ratio (mass ratio and volume ratio) is not particularly limited. The content of the solvent in the magnetic resin slurry is not particularly limited.

The filling ratio of the magnetic powder in the magnetic resin slurry (hereinafter, the content of the magnetic powder) is preferably 20% by volume or more and 99% by volume or less, and more preferably 53% by volume or more and 95% by volume with respect to the total solid content of the magnetic resin slurry. % Or less. When the content of the magnetic powder is within the above range, the real number part (μ') at 100 MHz can be increased, and the fluidity of the magnetic resin sheet can be easily controlled. The method for calculating the content of the magnetic powder was calculated from the blending amount of each material constituting the solid content of the magnetic resin slurry and the specific gravity of each material. Here, the solid content of the magnetic resin slurry is the amount obtained by removing the solvent from the magnetic resin slurry.

As a method for preparing the magnetic resin slurry, for example, at least one resin selected from the group consisting of a curable resin and a thermoplastic resin is dissolved in a solvent to obtain a resin solution, and a composite magnetic powder is added to the obtained resin solution. Then, kneading is carried out, and if necessary, a curing agent, a curing accelerator, a surface treatment agent, an elastomer and the like are finally added and stirred so as to be uniform.

[Magnetic resin sheet]
The magnetic resin sheet 1 (hereinafter referred to as the magnetic resin sheet 1) according to the present embodiment has a magnetic resin composition in the form of a sheet. The magnetic resin composition may be the first magnetic resin composition or the second magnetic resin composition. When the magnetic resin composition is the first magnetic resin composition, the magnetic resin sheet 1 may have the first magnetic resin composition in the form of a sheet, and the semi-cured product of the first magnetic resin composition. It may be in the form of a sheet.

The size of the magnetic resin sheet 1 may be appropriately adjusted according to the intended use of the magnetic resin sheet 1. The thickness of the magnetic resin sheet 1 is preferably 10 μm or more and 500 μm or less, and more preferably 50 μm or more and 300 μm or less. The greenis value indicating the fluidity of the magnetic resin sheet 1 is preferably 60% or more and 95% or less, and more preferably 70% or more and less than 90%. When the greenis value of the magnetic resin sheet 1 is within the above range, for example, when molding a laminated plate in which the magnetic resin sheet 1 is laminated on the main surface of a wiring substrate in which wiring is formed on the main surface by laminating or pressing. The magnetic resin sheet 1 having an appropriate fluidity can sufficiently embed wiring, and the magnetic resin sheet 1 flows too much, causing problems such as the laminator or the press machine being contaminated by the protrusion of the magnetic resin sheet 1. Can be avoided. The greenis value can be measured in the same manner as described in the examples.

The amount of volatile of the magnetic resin sheet 1 is preferably 1% by mass or less, more preferably 0.2% by mass or less. When the amount of volatile of the magnetic resin sheet 1 is within the above range, the magnetic resin sheet 1 and the cover film are stored when the magnetic resin sheet 1 whose surface is covered with a cover film is repeatedly frozen or refrigerated and returned to room temperature. It is possible to prevent the occurrence of a speckled pattern due to the volatilization of the solvent in the magnetic resin sheet 1 and prevent the magnetic resin sheet 1 from becoming too fluid. The amount of volatility can be measured in the same manner as described in the examples.

Since the magnetic resin sheet 1 is in the form of a sheet, it is easy to form a large area with a magnetic material having a uniform thickness, and it is useful as a material for a printed wiring board, which is difficult in the form of powder or paste. Since the magnetic resin sheet 1 is a semi-cured product, it can be used, for example, when heating and pressurizing while evacuating to embed and mold a circuit of a printed wiring board or the like.

Examples of the method for producing the magnetic resin sheet 1 include a method in which a magnetic resin slurry is applied onto a film 2 to form a magnetic resin slurry layer 3 and dried or heated, as shown in FIGS. 2A to 2C. .. As the film 2, for example, a polyethylene terephthalate (PET) film, a metal foil, or the like can be used. The thickness of the film 2 is not particularly limited. It is preferable that the surface of the film 2 to which the magnetic resin slurry layer 3 is applied is previously subjected to a mold release treatment. Further, the magnetic resin sheet 1 may be produced by applying the magnetic resin paste on the film 2 and drying or heating the film 2.

[Magnetic resin sheet with metal foil]
As shown in FIG. 4, the magnetic resin sheet 30 with a metal foil (hereinafter, the magnetic resin sheet 30 with a metal foil) according to the present embodiment is laminated on the magnetic resin sheet 1 and at least one surface of the magnetic resin sheet 1. The metal foil 8 having a thickness of 5 μm or less is provided. In FIG. 4, the magnetic resin sheet 30 with a metal foil has a two-layer structure composed of a magnetic resin sheet 1 and a metal foil 8 laminated on one side of the magnetic resin sheet 1. The magnetic resin sheet 30 with a metal foil may have a three-layer structure including the magnetic resin sheet 1 and two metal foils 8 laminated on both sides of the magnetic resin sheet 1. The magnetic resin sheet 30 with a metal foil may be provided with another layer between the magnetic resin sheet 1 and the metal foil 8.

As described above, in the magnetic resin sheet 1, the first magnetic resin composition may be in the form of a sheet, the first magnetic resin composition may be in the form of a sheet of a semi-cured product, and the second magnetism. The resin composition may be in the form of a sheet.

The thickness of the magnetic resin sheet 30 with metal foil is preferably 10 μm or more and 800 μm or less. As the material of the metal foil, for example, copper, silver, aluminum, nickel, stainless steel and the like can be used. The thickness of the metal foil is preferably 0.5 μm or more and 300 μm or less.

Examples of the method for adjusting the magnetic resin sheet 30 with a metal foil include a method of forming the metal foil 8 on one side or both sides of the magnetic resin sheet 1 by a physical vapor deposition method. Examples of the physical vapor deposition method include a vacuum vapor deposition method, an ion plating method, and a sputtering method. Further, the magnetic resin sheet 30 with a metal foil may be produced by applying a magnetic resin slurry or a magnetic resin paste on the metal foil 8 using a bar coater or the like and drying or heating the metal foil 8.

[Magnetic prepreg]
As shown in FIG. 5, the magnetic prepreg 40 (hereinafter referred to as magnetic prepreg 40) according to the present embodiment includes a fibrous base material 42 and a semi-cured product of the magnetic resin composition 41 or the magnetic resin composition 41. Examples of the magnetic prepreg 40 include those in which the fibrous base material 42 is present in the magnetic resin composition 41 or the semi-cured product of the magnetic resin composition 41. That is, the magnetic prepreg 40 includes a semi-cured product of the magnetic resin composition 41 or the magnetic resin composition 41, and a fibrous base material 42 existing in the semi-cured product of the magnetic resin composition 41 or the magnetic resin composition 41. To be equipped. Since the magnetic prepreg 40 includes the fibrous base material 42, it is superior in bending strength and the like to the magnetic resin sheet 1.

The magnetic resin composition may be the first magnetic resin composition or the second magnetic resin composition. That is, the magnetic prepreg 40 may include the one before curing the first resin composition and the fibrous base material 42, and the semi-cured product of the first resin composition and the fibrous base material. 42 may be provided. Further, the magnetic prepreg 40 may include a second resin composition and a fibrous base material 42.

The thickness of the magnetic prepreg is preferably 10 μm or more and 500 μm or less. As the fibrous base material 42, for example, woven cloth (cloth), non-woven fabric, pulp paper, linter paper and the like can be used. As the woven fabric, for example, organic fiber cloth such as glass cloth, aramid cloth and polyester cloth, graphite cloth and the like can be used. As the non-woven fabric, for example, organic fiber non-woven fabrics such as glass non-woven fabrics, aramid non-woven fabrics and polyester non-woven fabrics, graphite non-woven fabrics, and inorganic (for example, magnesium oxide) non-woven fabrics can be used. When a glass cloth is used, a magnetic prepreg 40 having excellent mechanical strength can be obtained. In particular, it is preferable to use the flattened glass cloth as the fibrous base material 42. Specific examples of the flattening process include a method in which a glass cloth is continuously pressed with a press roll at an appropriate pressure to flatten the yarn. The thickness of the fibrous base material 42 is not particularly limited, and for example, one having a thickness of 0.02 mm or more and 0.3 mm or less can be used.

When producing the magnetic prepreg 40, the magnetic resin composition 41 may be prepared in the form of a varnish and used in order to impregnate the fibrous base material 42, which is a base material for forming the magnetic prepreg 40. .. That is, a resin varnish in which the magnetic resin composition 41 is prepared in the form of a varnish may be used. Such a resin varnish can be prepared, for example, as follows.

First, each component of the magnetic resin composition 41 that is soluble in a solvent, including at least one resin selected from the group consisting of a curable resin and a thermoplastic resin, is put into a solvent and dissolved. At this time, heating may be performed if necessary. Then, a component that is insoluble in a solvent, including a composite magnetic powder, is added and dispersed using a ball mill, a bead mill, a planetary mixer, a roll mill, or the like until a predetermined dispersion state is obtained, thereby forming a varnish-like composition. Prepared. As the solvent used here, the same solvent as described above can be used as the solvent that can be contained in the magnetic resin composition.

When producing the magnetic prepreg 40, a resin varnish in which the magnetic resin composition 41 is prepared in the form of a varnish may be used, and the magnetic resin paste which is the paste-like magnetic resin composition 41 described above may be used. A magnetic resin slurry which is a slurry-like magnetic resin composition 41 may be used.

As a method for producing the magnetic prepreg 40, for example, the fibrous base material 42 contains a magnetic resin composition 41 prepared in a varnish shape, a magnetic resin paste containing the magnetic resin composition 41, or a magnetic resin composition 41. Examples thereof include a method of impregnating the magnetic resin slurry to be dried and drying the mixture.

The magnetic resin composition 41 can be impregnated into the fibrous base material 42 by dipping, coating or the like. If necessary, dipping and coating may be repeated a plurality of times for impregnation. Further, by repeating impregnation using a plurality of magnetic resin compositions 41 having different compositions and concentrations, or a magnetic resin paste or magnetic resin slurry containing the magnetic resin composition 41, the final desired composition and impregnation amount can be obtained. It is also possible to adjust.

When the first magnetic resin composition containing a thermosetting resin is used as the magnetic resin composition 41, after impregnating the fibrous base material 42 with the first magnetic resin composition, desired heating conditions, for example, You may heat at 80 degreeC or more and 180 degreeC or less for 1 minute or more and 10 minutes or less. By heating, a magnetic prepreg 40 comprising a semi-cured product of the first magnetic resin composition can be obtained.

[Inductor parts]
The inductor component according to the present embodiment (hereinafter, inductor component) includes a coil-shaped wiring and an insulating layer that covers the coil-shaped wiring, and the insulating layer is a cured product of the first magnetic resin composition or a second. It is molded from a solidified product of the magnetic resin composition (hereinafter, may be referred to as a magnetic material). In the present embodiment, since it is molded from the cured product of the first magnetic resin composition or the solidified product of the second magnetic resin composition, the Q value of the magnetic material of the insulating layer at 100 MHz tends to be high. It can be suitably used as a high-frequency inductor component. In particular, when the cured product of the first magnetic resin composition and the solidified product of the second magnetic resin composition have a Q value of 20 or more at 100 MHz, the Q value of the magnetic material of the insulating layer at 100 MHz is 20 or more. Therefore, the inductor component of the present embodiment can be particularly preferably used as a high-frequency inductor component. Examples of high frequency inductor components include coils, inductors, filters, reactors, and transformers. Applications of such inductor components include, for example, noise filter components, impedance matching circuit components, and the like. Examples of the noise filter include a low-pass filter and a common choke coil.

The structure of the inductor component may be appropriately adjusted according to the application of the inductor component, and examples thereof include a winding type, a laminated type, and a film type.

The size of the inductor component may be appropriately adjusted according to the intended use of the inductor component, and when used as a substantially cubic high-frequency inductor component, it is preferably 15 mm or less in length × 15 mm or less in width × 10 mm or less in height. is there.

The shape of the coiled wiring may be appropriately selected according to the intended use of the inductor component. For example, the spiral shape may be formed in a plane, or the spiral shape may be formed three-dimensionally. When the spiral shape is formed three-dimensionally, the winding structure may be a horizontal winding structure or a vertical winding structure. The start and end of the coiled wiring are electrically connected to different external electrode terminals for use. As the material of the coiled wiring, for example, Ag, Au, Cu, Ag-Pd, Ni and the like can be used.

The insulating layer covers the coiled wiring except for the beginning and the end of the coiled wiring. The raw material of the insulating layer is a first magnetic resin composition or a second magnetic resin composition.

The method for manufacturing the inductor component may be appropriately selected according to the configuration of the inductor component according to the intended use of the inductor component. For example, coiled wiring is continuously formed three-dimensionally by a printing method, a sheet method, or the like. There is a way to do it. The printing method is as follows: a magnetic resin sheet or a sheet of a second magnetic resin composition (hereinafter collectively referred to as a green sheet) and a conductor paste constituting the coiled wiring are alternately printed and laminated to form the inside of the inductor component. It is a method of forming a three-dimensional winding. The sheet construction method is a method of forming through holes in a green sheet, printing and filling conductor paste, and laminating.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the Examples.

The raw materials for the magnetic resin slurry are shown below.
[Magnetic powder]
(First powder)
-Alloy iron powder 1 ("AW2-08 / PF5KG" manufactured by Epson Atmix Co., Ltd., representative composition: Fe-Si-Cr, average particle size: 4 μm, particle shape: all spherical, insulation treatment: yes)
-Alloy iron powder 2 ("AW2-08 / PF3KG" manufactured by Epson Atmix Co., Ltd., representative composition: Fe-Si-Cr, average particle size: 3 μm, particle shape: all spherical, insulation treatment: yes)
(Other magnetic powder)
-Alloy powder ("AW2-08 / PF8KG" manufactured by Epson Atmix Co., Ltd., representative composition: Fe-Si-Cr, average particle size: 5 μm, particle shape: all spherical, insulation treatment: yes)
-Pure iron powder ("CIP FM" manufactured by BASF Japan Ltd., representative composition: Fe, average particle size: 2 μm, particle shape: all spherical, insulation treatment: none)
Ferrite powder 1 ("E001" manufactured by Powdertech Co., Ltd., composition: Mn-Mg-Sr-based ferrite, average particle size: 50 nm, particle shape: all spherical, insulation treatment: none)
Ferrite powder 2 ("M001" manufactured by Powdertech Co., Ltd., composition: Mn-based ferrite, average particle size: 50 nm, particle shape: all spherical, insulation treatment: none)
[Non-magnetic powder]
(Second powder)
-Silica powder 1 ("SSP-10M" manufactured by Tokuyama Corporation, average particle size: 1 μm, particle shape: all spherical)
-Alumina powder ("AO502" manufactured by Admatex Co., Ltd., average particle size: 0.7 μm, particle shape: all spherical)
-Silica powder 2 ("SSP-01M" manufactured by Tokuyama Corporation, average particle size: 0.1 μm, particle shape: all spherical)
[Thermosetting resin]
-Bisphenol A type epoxy resin ("850S" manufactured by DIC Corporation)
-Bisphenol F type epoxy resin ("YDF8170" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
・ Trifunctional epoxy resin (“VG3101” manufactured by Printec Co., Ltd.)
-Multifunctional epoxy resin ("NC3000" manufactured by Nippon Kayaku Co., Ltd.)
[Thermoplastic resin]
・ Phenoxy resin (“YP50EK35” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
[Additive]
(Hardener)
・ Dicyandiamide (“Dicyandiamide” manufactured by Nippon Carbide Industry Co., Ltd.)
(Curing accelerator)
・ Imidazole 1 (“2E4MZ” manufactured by Shikoku Chemicals Corporation)
・ Imidazole 2 (“2MAOK-PW” manufactured by Shikoku Chemicals Corporation)
(Surface treatment agent)
・ Silane Coupling Agent 1 (“A1871” manufactured by Momentive Performance Materials Japan LLC)
・ Silane Coupling Agent 2 (“A186” manufactured by Momentive Performance Materials Japan LLC)
・ Dispersant (“BYK-W903” manufactured by BYK Japan KK, Big Chemie Japan Co., Ltd.)
(solvent)
・ MEK (Methyl Ethyl Ketone)
-DMF (N, N-dimethylformamide)

The methods for measuring the greenis value, the amount of volatile, the viscosity at 2.0 rpm, the Chixo index, the DMA-Tg, the surface resistance value, and the magnetic properties are shown below.

[Measurement of Greenis value]
The Greenis value was calculated as follows.
1) A magnetic sheet having a thickness of 200 μm was punched out with a die having a thickness of 60 mmφ, and a state in which the polyethylene terephthalate film was peeled off was prepared as a test plate 4.
2) As shown in FIG. 3, a release PET film 5 having a thickness of 75 μm and a SUS plate 6 having a thickness of 1.8 mm were laminated in this order on both sides of the test plate 4 to obtain a sample set.
3) The sample set was molded by pressing the sample set from above and below for 10 minutes at an actual pressure of 2.0 Mpa under atmospheric pressure with a heat plate 7 in which the press heat plate temperature was set to 135 ° C.
4) The area of the test plate after molding was calculated by image processing.
5) The measured values were calculated twice by the following formula, and the average value was taken as the Greenis value. The area of the 6 cmφ test piece before molding was 28.26 cm ² (30 m × 30 mm × 3.14).
Greenis value (%) = {1-28.26 / area of test piece after molding} x 100
Greenis value of 60 or more: essential for molding Greenis value of 70 or more and less than 90: preferable for wiring embedding
Greenis value of 90 or more: It is not preferable because the amount of protrusion is large during molding.

[Measurement of volatile amount]
A magnetic sheet having a thickness of 200 μm was punched out with a die having a diameter of 80 mm, and after standing in a desiccator for 30 minutes, the initial weight was measured. Then, it was put into an oven at 163 ° C. for 15 minutes, and immediately after being taken out, it was allowed to stand and cooled in a desiccator for 30 minutes or more. The weight was measured immediately after being taken out from the desiccator, and the amount of volatility was calculated by the following formula.
Volatile (%) = {Reduced weight of sheet / Initial weight of sheet} x 100

[2.0 rpm viscosity]
The viscosity of the magnetic resin paste was measured using a rheometer "AR2000ex" manufactured by TA Instruments. Specifically, the gap between the upper and lower parallel plates having a diameter of 25 mm is set to 300 μm, and after filling the gap with the magnetic resin paste, a temperature equilibrium time of 2 minutes is allowed at room temperature, and the rotation speed is 0.2 rpm. Viscosity measurement was performed. Further, the viscosity was measured at a rotation speed of 2.0 rpm in the same manner.

[Chixo Index]
The chixo index of the magnetic resin paste was calculated by the following formula using the values of 0.2 rpm viscosity and 2.0 rpm viscosity measured in the above measurement of [2.0 rpm viscosity].
Chixo index = 0.2 rpm viscosity / 2.0 rpm viscosity

[Measurement of DMA-Tg]
The DMA-Tg of the magnetic resin sheet was measured using a viscoelastic spectrometer "DMS100" manufactured by Seiko Instruments Co., Ltd. Specifically, dynamic viscoelasticity measurement (DMA) is performed with a tensile module at a frequency of 10 Hz, and the temperature at which tan δ reaches the maximum when the temperature is raised from room temperature to 320 ° C. It was set to −Tg.

[Measurement of surface resistance value]
The surface resistance value was measured using "R8340A" manufactured by ADVANTEST in accordance with the standard ASTM D257. Specifically, a test piece (50 mm × 50 mm × 1 mmt) is placed between the front electrode (25 mmφ) and the front electrode composed of the main electrode (inner diameter 38 mmφ, outer diameter 50 mmφ) and the back electrode (50 mmφ). It was arranged and measured under the following setting conditions.
Setting conditions: applied voltage 100V, charge time 60 seconds, discharge time 0.1 seconds

[Measurement of complex magnetic permeability]
Ten magnetic resin sheets are stacked, heated and pressed to cure, and cut out into a ring shape for evaluation ring core (thickness: 1.0 mmt, outer diameter: 7.0 mm, inner diameter: 3.2 mm) (hereinafter, magnetic material ) Was obtained. The heating and pressurizing conditions were 180 ° C., 4.5 MPa (50 kgf / cm ² ), and 1 hour. The complex magnetic permeability of the obtained magnetic material at 100 MHz was measured using a "4291A RF Impedance / Material Analyzer" manufactured by Hewlett-Packard Company. The measurement conditions were that the frequency of the current was in the range of 1 MHz or more and 1.8 GHz or less, and was at room temperature. The real part (μ') and the imaginary part (μ ″) are obtained from the measured initial magnetization curve, and the loss coefficient (Tanδ) and the Q value of the magnetic material are obtained from the obtained real part (μ ′) and imaginary part (μ ”). Was calculated. In designing the high frequency inductor component, the real part (μ') is preferably 6.0 or more. In order to function as a high-frequency inductor component, it is essential that the Q value of the magnetic material is 20 or more. Further, in order to exhibit good performance as a high frequency inductor component, it is preferable that the Q value of the magnetic material is 33 or more.

[Examples 1 to 6]
In Examples 1 to 6, the content of the magnetic powder is changed to show the real part (μ') appropriate for functioning as a high-frequency inductor component, that is, the real part (μ') at 100 MHz is obtained. The content of the magnetic powder showing 6.0 or more was examined.

Bisphenol A type epoxy resin, trifunctional epoxy resin, polyfunctional epoxy resin, phenoxy resin, MEK and DMF were mixed at the blending ratios shown in Table 1 to obtain a resin solution. Ferroalloy 2 (average particle size: 3 μm) and alumina (average particle size: 0.7 μm) are added to the obtained resin solution at the blending ratios shown in Table 1 and kneaded, and dicyandiamide, imidazole 1, and silane cup are added. A magnetic resin slurry was obtained by adding a ring agent 1 and a dispersant and stirring the mixture so as to be uniform.

The obtained magnetic resin slurry was applied to the surface of the polyethylene terephthalate film subjected to the mold release treatment and dried to obtain a magnetic resin sheet in a B stage state having a thickness of 200 μm. Using the obtained magnetic resin sheet, the greenis value, the amount of volatile, DMA-Tg, the surface resistance value and the magnetic characteristics were measured. The results are shown in Table 1.

As is clear from Table 1, as the content of the magnetic powder increases, the real part (μ') and the imaginary part (μ ”) tend to increase, while the Q value and the greenis value of the magnetic material tend to decrease. It was found that among Examples 1 to 6, the one with the best balance between the real part (μ') and the greenis value was Example 4 in which the content of the magnetic powder was 53.0% by volume. ..

[Examples 7 and 8, Comparative Examples 1 to 4]
In Examples 7 and 8 and Comparative Examples 1 and 2, the particle size ratio of the first powder to the second powder (hereinafter, simply referred to as simply) is maintained while maintaining the content (53.0% by volume) of the magnetic powder of Example 4. By changing the particle size ratio), a particle size ratio that satisfies the Q value of the magnetic material, which is essential for functioning as a high-frequency inductor component, that is, a particle size ratio in which the Q value of the magnetic material at 100 MHz is 20 or more is examined. It was. Comparative Example 3 and Comparative Example 4 do not contain the first powder. Specifically, a magnetic resin slurry was obtained in the same manner as in [Examples 1 to 6] except that the raw materials were blended in the blending ratios shown in Table 2. Using the obtained magnetic resin sheet, the greenis value, the amount of volatile, DMA-Tg, the surface resistance value and the magnetic characteristics were measured. The results are shown in Table 2.

As is clear from Table 2, the real part (μ') and the greenis value tended to decrease as the particle size ratio increased. The imaginary part (μ ”) tended to decrease as the particle size ratio increased, and became almost constant when the particle size ratio exceeded 4.3 (Example 4). The Q value of the magnetic material tended to be substantially constant. As the ratio increased, it tended to increase, and when the particle size ratio exceeded 4.3 (Example 4), it tended to decrease. Further, in Comparative Example 3, since the alloy iron powder was not contained, the Q value of the magnetic material was Was less than 20. In Comparative Example 4, the Q value of the magnetic material was less than 20 because the average particle size of the alloy iron powder was not less than 5 μm. Examples 4, 7, 8 and Comparative Example 1. In Example 4 having a particle size ratio of 4.3, the magnetic material having the highest Q value and the best Grinis value among the materials to 4).

[Examples 9 to 13, Comparative Example 5]
In Examples 9 to 13, the mass ratio (hereinafter, mass ratio) of the magnetic powder to the non-magnetic powder is maintained while maintaining the content (53.0% by volume) and the particle size ratio (4.3) of the magnetic powder of Example 4. ) Was changed, and the first mass ratio satisfying the Q value of the magnetic material exhibiting good performance as a high-frequency inductor component, that is, the mass ratio in which the Q value of the magnetic material at 100 MHz was 33 or more was examined. Comparative Example 5 does not contain non-magnetic powder. Specifically, a magnetic resin slurry was obtained in the same manner as in [Examples 1 to 6] except that the raw materials were blended in the blending ratios shown in Table 3. Using the obtained magnetic resin sheet, the greenis value, the amount of volatile, DMA-Tg, the surface resistance value and the magnetic characteristics were measured. The results are shown in Table 3.

As is clear from Table 3, as the mass ratio decreased, the greenis value tended to decrease and the Q value of the magnetic material tended to increase. On the other hand, in Comparative Example 5, since the non-magnetic powder was not contained, the Q value of the magnetic material was less than 20. Among Examples 4, 9 to 13 and Comparative Example 5, the Q value of the magnetic material is 33 or more in Examples 11 to 13 having a mass ratio in the range of 4.0 to 5.7. It was. In Examples 11 to 13, the best balance between the Q value and the Grinnis value of the magnetic material was found in Example 12 having a mass ratio of 4.7.

[Examples 14 and 15]
In Examples 14 and 15, while maintaining the particle size ratio at 4.3 and the mass ratio at 6.0, ferrite powder was added as another magnetic powder, and the change in the Q value of the magnetic material due to the addition of the ferrite powder was changed. Examined. Specifically, a magnetic resin slurry was obtained in the same manner as in [Examples 1 to 6] except that the raw materials were blended in the blending ratios shown in Table 4. Using the obtained magnetic resin sheet, the greenis value, the amount of volatile, DMA-Tg, the surface resistance value and the magnetic characteristics were measured. The results are shown in Table 4.

As is clear from Table 4, in Examples 14 and 15 in which the mixing ratio of the ferrite powder to the entire first powder was about 6% by mass, the Q value of the magnetic material was lower than that in Example 11, but it was 20 or more. there were. From these results, it was found that the Q value of the magnetic material containing ferrite powder was lower than that of the magnetic material not containing ferrite powder. Furthermore, it was found that the magnetic resin slurry satisfies the Q value of the magnetic material, which is indispensable for functioning as a high-frequency inductor component, even if it contains a small amount of fine ferrite powder mixed.

[Example 16]
In Example 16, a magnetic resin paste was obtained without containing a solvent. Specifically, the raw materials shown in Table 5 were mixed at the blending ratios shown in Table 5 and kneaded so as to be uniform to obtain a magnetic resin paste. A known mixer and kneader were used for mixing and kneading the raw materials.

As is clear from Table 5, the Chixo index of Example 16 prepared without containing a solvent was 3.8, and the Q value was 20 or more. From this result, even if the magnetic resin composition is a paste-like magnetic resin paste containing no solvent, it is possible to satisfy the Q value of the magnetic material which is excellent in fluidity and is essential for functioning as a high frequency inductor component. all right.

As is clear from the above-described embodiment, the composite magnetic powder of the first aspect according to the present invention contains a magnetic powder containing the first powder and a non-magnetic powder containing the second powder. The first powder is made of ferroalloy powder and the second powder is made of at least one of alumina powder and silica powder. The average particle size of the first powder is less than 5 μm, and is 3 times or more and 30 times or less the average particle size of the second powder.

According to the first aspect, the Q value of the magnetic material in the high frequency band can be increased.

In the composite magnetic powder of the second aspect according to the present invention, in the first aspect, the mixing ratio of the magnetic powder is 4 parts by mass or more and 19 parts by mass or less with respect to 1 part by mass of the non-magnetic powder.

According to the second aspect, the Q value of the magnetic material at 100 MHz and the fluidity of the magnetic material before the treatment can be balanced.

In the composite magnetic powder of the third aspect according to the present invention, the magnetic powder is insulated in the first or second aspect.

According to the third aspect, the Q value of the magnetic material can be made higher.

The magnetic resin composition of the fourth aspect according to the present invention is at least one resin selected from the group consisting of the composite magnetic powder of any one of the first to third aspects, a curable resin and a thermoplastic resin. And contains.

According to the fourth aspect, a magnetic material having a high Q value in the high frequency band can be obtained.

In the magnetic resin composition of the fifth aspect according to the present invention, in the fourth aspect, the content of the composite magnetic powder is 70% by mass or more and 99.5% by mass or less of the total solid content of the magnetic resin composition. ..

According to the fifth aspect, a magnetic material that can be suitably used for high frequency inductor applications can be obtained.

In the magnetic resin composition of the sixth aspect according to the present invention, in the fourth or fifth aspect, the cured product or solidified product of the magnetic resin composition has a Q value of 20 or more at a frequency of 100 MHz.

According to the sixth aspect, it is possible to obtain a magnetic material that can be suitably used for high frequency inductor applications.

In the magnetic resin paste of the seventh aspect according to the present invention, the magnetic resin composition of any one of the fourth to sixth aspects is in the form of a paste.

According to the seventh aspect, a magnetic material having good fluidity can be obtained.

In the magnetic resin powder of the eighth aspect according to the present invention, the magnetic resin composition of any one of the fourth to sixth aspects is in the form of powder.

According to the eighth aspect, a powdery magnetic material can be obtained.

In the magnetic resin slurry of the ninth aspect according to the present invention, the magnetic resin composition of any one of the fourth to sixth aspects further contains a solvent and is in the form of a slurry.

According to the ninth aspect, a magnetic material having good fluidity can be obtained.

In the magnetic resin sheet of the tenth aspect according to the present invention, the magnetic resin composition of any one of the fourth to sixth aspects is in the form of a sheet.

According to the tenth aspect, a magnetic material having a uniform thickness can be obtained.

The magnetic resin sheet of the eleventh aspect according to the present invention has a thickness of 10 μm or more and 500 μm or less in the tenth aspect.

According to the eleventh aspect, a magnetic material having a certain thickness can be obtained.

The magnetic resin sheet with a metal foil according to the twelfth aspect of the present invention is a metal foil having a thickness of 5 μm or less, which is laminated on at least one surface of the magnetic resin sheet of the tenth or eleventh aspect and the magnetic resin sheet. And.

According to the twelfth aspect, a magnetic material with a metal foil can be obtained.

The magnetic prepreg according to the thirteenth aspect according to the present invention includes a fibrous base material and a magnetic resin composition or a semi-cured product of the magnetic resin composition according to any one of the fourth to sixth aspects.

According to the thirteenth aspect, a magnetic material having excellent bending strength can be obtained.

The inductor component of the fourteenth aspect according to the present invention includes a coiled wiring and an insulating layer covering the coiled wiring, and the insulating layer is a magnetic resin composition of any one of the fourth to sixth aspects. It is molded from the cured product or solidified product of.

According to the fourteenth aspect, an inductor component that can be suitably used as a high frequency inductor component can be obtained.

1 Magnetic resin sheet 2 Film 3 Magnetic resin slurry layer 8 Metal foil 10 Large-diameter magnetic particles 11 Large particles that are apparently a mass formed by a plurality of large-diameter magnetic particles in close proximity 20 Small-diameter non-magnetic particles 21 Small-diameter non-magnetic particles Layer composed of particles 30 Magnetic resin sheet with metal foil 40 Magnetic prepreg 41 Magnetic resin composition 42 Fibrous base material

Claims (14)

Magnetic powder containing the first powder and
Containing with non-magnetic powder, including a second powder,
The first powder is composed of ferroalloy powder.
The second powder comprises at least one of alumina powder and silica powder.
A composite magnetic powder in which the average particle size of the first powder is less than 5 μm and is 3 times or more and 30 times or less the average particle size of the second powder. The composite magnetic powder according to claim 1, wherein the mixing ratio of the magnetic powder is 4 parts by mass or more and 19 parts by mass or less with respect to 1 part by mass of the non-magnetic powder. The composite magnetic powder according to claim 1 or 2, wherein the magnetic powder is insulated. The composite magnetic powder according to any one of claims 1 to 3 and
A magnetic resin composition containing at least one resin selected from the group consisting of a curable resin and a thermoplastic resin. The magnetic resin composition according to claim 4, wherein the content of the composite magnetic powder is 70% by mass or more and 99.5% by mass or less of the total solid content of the magnetic resin composition. The magnetic resin composition according to claim 4 or 5, wherein the cured product or solidified product of the magnetic resin composition has a Q value of 20 or more at a frequency of 100 MHz. A magnetic resin paste in which the magnetic resin composition according to any one of claims 4 to 6 is in the form of a paste. The magnetic resin composition according to any one of claims 4 to 6 is a powdery magnetic resin powder. A magnetic resin slurry in which the magnetic resin composition according to any one of claims 4 to 6 further contains a solvent and is in the form of a slurry. A magnetic resin sheet in which the magnetic resin composition according to any one of claims 4 to 6 is in the form of a sheet. The magnetic resin sheet according to claim 10, wherein the thickness is 10 μm or more and 500 μm or less. The magnetic resin sheet according to claim 10 or 11.
A magnetic resin sheet with a metal foil, comprising a metal foil having a thickness of 5 μm or less laminated on at least one surface of the magnetic resin sheet. With a fibrous base material
A magnetic prepreg comprising the magnetic resin composition according to any one of claims 4 to 6 or a semi-cured product of the magnetic resin composition. With coiled wiring
With an insulating layer that covers the coiled wiring,
An inductor component in which the insulating layer is formed of a cured product or solidified product of the magnetic resin composition according to any one of claims 4 to 6.

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