Magnetic composition, magnetic film, laminate, and circuit member

Abstract

A magnetic composition containing a magnetic powder and a thermosetting component, the 10% cumulative particle size of the magnetic powder on a volume basis being 0.01-0.50 μm, the 50% cumulative particle size of the magnetic powder on a volume basis being 0.10-2.00 μm, and the 90% cumulative particle size of the magnetic powder on a volume basis being 0.70-4.00 μm.

Description

Technical Field

[0001] This invention relates to a magnetic composition, a magnetic film, a laminate, and a circuit component. Background Technology

[0002] Depending on the characteristics required for the industrial product, materials containing metal powders with various physical properties are used. For example, magnetic materials containing magnetic powders are used in fields such as inductors, electromagnetic wave shielding, and bond magnets (see, for example, Patent Document 1).

[0003] Previous technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2014-127624 Summary of the Invention

[0004] The technical problem to be solved by the invention There is a growing demand for magnetic materials with improved magnetic properties, specifically permeability. Furthermore, in recent years, with the miniaturization of circuit components such as inductors, the gaps between wirings in circuit components that utilize magnetic materials have become increasingly narrow, making it difficult to fully embed the magnetic material within these wirings.

[0005] Therefore, some aspects of the present invention aim to provide a magnetic composition capable of forming a magnetic film with sufficiently high permeability and excellent embeddability to the gaps between wirings, and a magnetic film composed of the magnetic composition. Furthermore, some aspects of the present invention aim to provide a laminate comprising the aforementioned magnetic film, and a circuit component comprising a layer composed of a cured product of the aforementioned magnetic composition.

[0006] means for solving technical problems The present invention provides the following [1] to [9] in some aspects. [1] A magnetic composition comprising: magnetic powder and thermosetting components. The magnetic powder has a volume-based cumulative particle size of 0.01–0.50 μm at 10% of its volume. The magnetic powder has a volumetric cumulative particle size of 0.10–2.00 μm, which is 50% of the total particle size. The magnetic powder has a 90% cumulative particle size of 0.70–4.00 μm based on volume. [2] According to the magnetic composition described in [1], wherein, Based on the total mass of the non-volatile components in the magnetic composition, the content of the magnetic powder is 60% by mass or more. [3] The magnetic composition according to [1] or [2] also contains a rubber component. [4] According to the magnetic composition described in [3], wherein, Based on the total mass of the non-volatile components in the magnetic composition, the content of the rubber component is 0.05 to 10.0% by mass. [5] The magnetic composition according to any one of [1] to [4], wherein, The thermosetting component includes epoxy-containing compounds and phenolic curing agents. [6] A magnetic film comprising any one of the magnetic compositions described in [1] to [5]. [7] A layered body having: The support body; and the magnetic film described in [6] disposed on the support body. [8] A circuit component comprising: A substrate having wiring on its surface; and a magnetic layer disposed to fill the gaps between the wiring in the substrate. The magnetic layer comprises a cured form of the magnetic composition described in any one of [1] to [5]. [9] According to the circuit component described in [8], wherein, The wiring is the coil wiring of the inductor.

[0016] Invention Effects According to some aspects of the present invention, it is possible to provide a magnetic composition capable of forming a magnetic film with sufficiently high permeability and excellent embeddability to the gaps between wirings, and a magnetic film composed of the magnetic composition. Furthermore, according to some aspects of the present invention, it is possible to provide a laminate comprising the aforementioned magnetic film, and a circuit component comprising a layer composed of a cured product of the aforementioned magnetic composition. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view illustrating an example of a method for manufacturing a circuit component according to one embodiment of the present invention. Detailed Implementation

[0018] In this specification, the numerical range indicated by "~" represents the range encompassed by the values ​​before and after "~" as the minimum and maximum values, respectively. Furthermore, unless specifically stated otherwise, the units of the values ​​before and after "~" are the same. In the numerical ranges described progressively in this specification, the upper or lower limit of any stage of the numerical range can be replaced by the upper or lower limit of other stages. Furthermore, within the numerical range described in this specification, the upper or lower limit of that range can be replaced by the values ​​shown in the examples. Furthermore, the individually described upper and lower limits can be arbitrarily combined. Furthermore, "A or B" can include either A or B, or both. Furthermore, unless otherwise specified, the materials exemplified below can be used individually or in combination of two or more. When multiple substances corresponding to each component are present in the composition, unless otherwise specified, the content of each component in the composition refers to the total amount of the multiple substances present in the composition.

[0019] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the embodiments described below.

[0020] <Magnetic Composition> One embodiment of the magnetic composition comprises magnetic powder and a thermosetting component. In one embodiment, the magnetic powder has a cumulative particle size of 10% of its volume (hereinafter referred to as "D"). 10 The cumulative particle size (D) of the magnetic powder is 0.01–0.50 μm, which is the 50% cumulative particle size based on volume (hereinafter referred to as "D"). 50 The particle size distribution (D) is 0.10–2.00 μm, and the 90% cumulative particle size based on volume of the magnetic powder (hereinafter referred to as "D") is... 90 The micrometer diameter (μm) ranges from 0.70 to 4.00 μm.

[0021] Here, D 10 This refers to the particle size at which the cumulative volume of the smaller particle size reaches 10% of the total volume of the magnetic powder in the volumetric particle size distribution. (D) 50 This refers to the particle size at which the cumulative volume of the smaller particle size reaches 50% of the total volume of the magnetic powder in the volumetric particle size distribution. (D) 90 This refers to the particle size at which the cumulative volume of the smallest particle size reaches 90% of the total volume of the magnetic powder in a volumetric particle size distribution. It is used to calculate the D of magnetic powder. 10 D 50 and D 90 The particle size distribution can be obtained by using a laser diffraction scattering particle size distribution measuring device and by measuring the particle size distribution under the conditions described in the embodiments.

[0022] The magnetic composition of the above-described embodiment, containing magnetic powder with the aforementioned particle size distribution, can produce a magnetic film with excellent embeddability in narrow gaps (e.g., gaps with a depth of 20 μm or more and a width of 25 μm or less) between wirings. This is presumably due to the effect of the particle size of the magnetic powder (especially D). 90 The particle size of the magnetic powder is small enough to fit into the gaps between the aforementioned wirings; and the particle size of the magnetic powder (especially D) 10 The viscosity is sufficiently high so that the viscosity (melt viscosity) when heated to the point of melting is not excessively high. Furthermore, the magnetic composition of the above embodiment has sufficiently high magnetic permeability because it contains magnetic powder with the above-mentioned particle size distribution.

[0023] (Magnetic powder) Magnetic powder is an aggregate of magnetic particles. Magnetic particles contain at least one magnetic component. Magnetic particles may contain only one magnetic component or multiple magnetic components. Magnetic particles may consist solely of magnetic components or contain components other than magnetic components. The content of magnetic components, based on the total mass of the magnetic particles, can be 20% by mass or more, 50% by mass or more, or 80% by mass or more.

[0024] The magnetic component may contain, for example, a metallic element. The metallic element contained in the magnetic component may be at least one element selected from the group consisting of base metals, noble metals, transition metals, and rare earth elements. The metallic element may be at least one element selected from the group consisting of iron (Fe), copper (Cu), titanium (Ti), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), niobium (Nb), aluminum (Al), tin (Sn), chromium (Cr), barium (Ba), strontium (Sr), lead (Pb), silver (Ag), praseodymium (Pr), neodymium (Nd), samarium (Sm), and dysprosium (Dy).

[0025] The magnetic composition can be a metallic monomer composed of only one metallic element, or an alloy composed of two or more metallic elements. The alloy can include at least one element selected from the group consisting of solid solutions, eutectics, and intermetallic compounds. Examples of alloys include stainless steels such as Fe-Cr alloys and Fe-Ni-Cr alloys. Furthermore, it can be copper alloys such as Cu-Sn alloys, Cu-Sn-P alloys, Cu-Ni alloys, and Cu-Be alloys.

[0026] The magnetic component can be a powder containing the aforementioned metallic elements and elements other than the aforementioned metallic elements. The elements other than the aforementioned metallic elements can be, for example, at least one element selected from the group consisting of carbon (C), oxygen (O), beryllium (Be), phosphorus (P), boron (B), and silicon (Si). The metallic compound can be, for example, a metal oxide such as iron oxide. The metallic compound can be a sintered body with metal oxide as the main component (e.g., a sintered body formed by mixing and sintering metal oxides with metallic elements such as cobalt, nickel, and manganese).

[0027] The magnetic composition can be either a soft magnetic alloy or a strong magnetic alloy. For example, the magnetic composition can be at least one element selected from the group consisting of Fe-Si alloys, Fe-Si-Al alloys (Sendust), Fe-Ni alloys (Permalloy), Fe-Cu-Ni alloys (Permalloy), Fe-Co alloys (Permendur), Fe-Cr-Si alloys (electromagnetic stainless steel), Nd-Fe-B alloys (rare earth magnets), Sm-Fe-N alloys (rare earth magnets), Al-Ni-Co alloys (AlNiCo magnets), and ferrite. The ferrite can be, for example, spinel ferrite, hexagonal ferrite, or garnet ferrite.

[0028] From the viewpoint of achieving higher magnetic permeability, the magnetic powder may contain at least one powder selected from the group consisting of Fe monomers and Fe-based alloys. Fe-based alloys may, for example, be at least one selected from the group consisting of Fe-Si alloys, Fe-Si-Al alloys, Fe-Ni alloys, Fe-Cu-Ni alloys, Fe-Co alloys, Fe-Cr-Si alloys, Fe-Si-B alloys, and Fe-Si-BP-Nb-Cr alloys. From the viewpoint of achieving even higher magnetic permeability, the magnetic powder may contain Fe amorphous alloy powder.

[0029] Fe amorphous alloy is an amorphous powder obtained by rapidly cooling an alloy in which Fe, the main component, is melted at high temperature with other elements such as Si. It is also known as a metallic glass. Fe amorphous alloy powder can be manufactured according to methods known in the art. Fe amorphous alloy powder is also available as a commercially available product. Examples include products manufactured by EPSON ATMIX CORPORATION (AW2-08 and KUAMET-6B2), Daido Steel Co., Ltd. (DAPMS3, DAPMS7, DAPMSA10, DAPPB, DAPPC, DAPMKV49, DAP410L, DAP430L, and the DAPHYB series), and products manufactured by KOBE STEEL, LTD. (MH45D, MH28D, MH25D, and MH20D). One or more of these Fe amorphous alloy powders can be used, or they can be combined.

[0030] The entire surface or a portion thereof of the magnetic powder can be coated with a surface treatment agent. Surface treatment agents can be, for example, inorganic oxides, phosphoric acid compounds and phosphate compounds, inorganic surface treatment agents such as silane coupling agents, organic surface treatment agents such as lignite wax, and cured resins. Coupling agents, described later, can also be used as surface treatment agents.

[0031] The entire surface or a portion thereof of magnetic powder (e.g., magnetic powder containing Fe-based alloys) may be coated with an insulating material. That is, the magnetic powder may contain magnetic particles whose surfaces are coated with an insulating material (hereinafter referred to as "insulating coated magnetic particles"). Examples of insulating materials include, for example, silica, titanium dioxide, calcium phosphate, lignite wax, and epoxy resin cured products. The insulating coated magnetic particles may be Fe amorphous alloy powder with an insulating coating. The thickness of the inorganic oxide coating constituting the insulating coating may, for example, be 1–100 nm.

[0032] As an insulating coated magnetic particle, for example, it is possible to use "KUAMET9A4" (Fe-Si-B alloy, D) manufactured by EPSON ATMIX CORPORATION. 50 : 20μm, with insulating coating), manufactured by SINTOKOGIO, LTD. "SAP-2DC" (Fe-Si-BP-Nb-Cr alloy, D 50 (2.2μm, with insulating coating). These insulatingly coated magnetic particles can be used in conjunction with magnetic particles without insulating coating, for example, with soft ferrite powder "BSN-125" (Ni-Zn ferrite, D240 ... 50 (10μm, without insulating coating) and other materials are used together.

[0033] The shape of the magnetic particles is not particularly limited. Magnetic particles can be, for example, spherical, ellipsoidal, flat, plate-like, rod-like, and needle-like. From the viewpoint of further improving the embedding of gaps between wirings, the magnetic particles can be spherical. Here, "spherical" means that the average ratio of the major axis to the minor axis (major axis / minor axis), i.e., the aspect ratio, measured by the following method, is 1.0 to 4.0. In this specification, the average aspect ratio is the value obtained by averaging the ratios of the major axis to the minor axis (major axis / minor axis) of 100 randomly selected magnetic particles. The major axis of a magnetic particle is the distance between the two planes that are circumscribed by the magnetic particle and are selected to be parallel to each other, with the largest distance between them. The minor axis of a magnetic particle is the distance between the two planes that are circumscribed by the magnetic particle and are selected to be parallel to each other, with the smallest distance between them. From the viewpoints of the fluidity and embeddability of the magnetic composition and the dense filling of magnetic particles, the aspect ratio can be 1.0–3.0, 1.0–2.0, or 1.0–1.5.

[0034] D of magnetic powder 10 The micrometer size is 0.01 μm or larger; from the viewpoint of the flowability of the magnetic composition, it can be 0.02 μm or larger, 0.05 μm or larger, or 0.08 μm or larger. The D0.01 of the magnetic powder... 10 From the viewpoint of dense filling of magnetic particles in the magnetic composition, the particle size can be 0.40 μm or less, 0.30 μm or less, 0.20 μm or less, or 0.15 μm or less. From these viewpoints, the D of the magnetic powder... 10 The micrometers can be 0.01–0.40 μm, 0.02–0.40 μm, 0.02–0.50 μm, 0.05–0.30 μm, 0.08–0.20 μm, or 0.08–0.15 μm.

[0035] D of magnetic powder 50 The thickness is 0.10 μm or more; from the viewpoint of the flowability and permeability of the magnetic composition, it can be 0.20 μm or more, 0.30 μm or more, or 0.40 μm or more. The D of the magnetic powder... 50 From the viewpoint of dense filling of magnetic particles in the magnetic composition, the particle size can be 1.90 μm or less, 1.50 μm or less, 1.00 μm or less, or 0.70 μm or less, and is 2.00 μm or less. From these viewpoints, the D0 of the magnetic powder... 50 The micrometers can be 0.10–1.90 μm, 0.20–2.00 μm, 0.20–1.90 μm, 0.30–1.50 μm, 0.40–1.00 μm, or 0.40–0.70 μm.

[0036] D of magnetic powder90 The diameter (D) of the magnetic powder is 0.70 μm or larger. From the viewpoint of the fluidity and permeability of the magnetic composition, it can be 0.80 μm or larger, 1.00 μm or larger, 1.40 μm or larger, or 2.00 μm or larger. 90 From the viewpoint of the embedding properties of the magnetic composition into the gaps, the micrometer size can be 3.90 μm or less, 3.30 μm or less, 2.80 μm or less, or 2.00 μm or less. From these perspectives, the D0 of the magnetic powder... 90 The micrometers can be 0.70–3.90 μm, 0.80–4.00 μm, 0.80–3.90 μm, 1.00–3.30 μm, 1.40–2.80 μm, 2.00–4.00 μm, or 0.70–2.00 μm.

[0037] Magnetic powders with the particle size distribution described above can be obtained, for example, by atomization, chemical vapor deposition (CVD), or liquid-phase synthesis. The particle size distribution of magnetic powders produced by the above methods can be adjusted using pulverizers, ball mills, bead mills, air classifiers, wet sieves, sieves, etc. Compared to methods that adjust particle size distribution by applying force to the particles using pulverizers, ball mills, etc., the method of adjusting the particle size distribution to the target particle size distribution using classifiers, sieves, etc., allows for the easier acquisition of magnetic powders with excellent flowability because the particle shape can be maintained spherical. Furthermore, because structural defects and crystal distortion at the interface caused by pulverization are less likely to occur, magnetic powders with excellent magnetic permeability are more easily obtained.

[0038] From the viewpoint of achieving higher magnetic permeability, the content of magnetic powder can be 60% by mass or more, or 65% by mass or more, or 70% by mass or more, based on the total mass of non-volatile components in the magnetic composition. From the viewpoint of further improving the embedding of gaps between wirings, the content of magnetic powder can be 97% by mass or less, or 95% by mass or less, or 93% by mass or less, based on the total mass of non-volatile components in the magnetic composition. From these viewpoints, the content of magnetic powder can be 60–97% by mass, 65–95% by mass, or 70–93% by mass, based on the total mass of non-volatile components in the magnetic composition. Here, non-volatile components in the magnetic composition refer to components other than volatile components contained in the magnetic composition. Volatile components refer to components that show a mass reduction of 10% by mass or more when heated at 180°C for 60 minutes and components with a boiling point of 300°C or less.

[0039] (Thermosetting components) Thermosetting components may include, for example, thermosetting compounds. Thermosetting components may also include curing agents for the thermosetting compounds, and may also include curing accelerators.

[0040] [Thermosetting compounds] Thermosetting compounds are, for example, compounds that are cured individually by heat treatment or by reaction with a curing agent. Thermosetting compounds can be monomers or compounds (oligomers or polymers) that are commonly referred to as thermosetting resins and have structural units formed by the polymerization of monomers. From the viewpoint of improving the shape retention of magnetic films as molded bodies of magnetic compositions, thermosetting compounds may contain thermosetting resins.

[0041] Thermosetting resins can function as adhesive resins for bonding magnetic powders. Examples of thermosetting resins include epoxy resins, phenolic resins, acrylic resins, polyimide resins, and polyamide-imide resins.

[0042] The weight-average molecular weight of thermosetting resins is, for example, 150 or more, and can range from 400 to 1,000,000. Furthermore, the weight-average molecular weight in this specification is a converted value of standard polystyrene obtained by gel permeation chromatography (GPC).

[0043] For example, based on the total mass of the thermosetting compound, the content of the thermosetting resin can be 100% by mass, or it can be 0-99% by mass, 10-98% by mass, or 20-97% by mass.

[0044] From the perspective of improving curability, thermosetting compounds can include compounds having one or more epoxy groups in their molecules (hereinafter referred to as "epoxy-containing compounds"). For example, based on the total mass of the thermosetting compound, the content of epoxy-containing compounds can be 100% by mass, or 0–99% by mass, 20–95% by mass, or 30–90% by mass.

[0045] As epoxy-containing compounds, compounds known as epoxy resins (e.g., oligomers and polymers having two or more epoxy groups in the molecule) can generally be used. Examples of such compounds include, for instance, biphenyl-type epoxy resins, arsenic-type epoxy resins, diphenylmethane-type epoxy resins, sulfur-containing epoxy resins, phenolic varnish-type epoxy resins, biphenyl-phenolic varnish-type epoxy resins, dicyclopentadiene-type epoxy resins, salicylaldehyde-type epoxy resins, copolymers of naphthols and phenols, epoxides of aralkyl-type phenolic resins, bisphenol-type epoxy resins, glycidyl ether-type epoxy resins of alcohols, and glycidyl ether-type phenolic resins modified with paraxylylene and / or metaxylylene. The epoxy resin comprises at least one of the following groups: oil-ether type epoxy resin, glycidyl ether type epoxy resin of terpene-modified phenolic resin, cyclopentadiene type epoxy resin, glycidyl ether type epoxy resin of polycyclic aromatic ring modified phenolic resin, glycidyl ether type epoxy resin of naphthalene-containing phenolic resin, glycidyl ester type epoxy resin, glycidyl-based or methylglycidyl-based epoxy resin, alicyclic type epoxy resin, halogenated phenolic varnish type epoxy resin, hydroquinone type epoxy resin, trimethylolpropane type epoxy resin, and linear aliphatic epoxy resin obtained by oxidizing olefin bonds with peracids such as peracetic acid. Among these, from the viewpoint of further improving curability, biphenyl phenolic varnish type epoxy resin can be used. For example, based on the total mass of the epoxy-containing compound, the epoxy resin content can be 10–100% by mass, 20–100% by mass, or 30–100% by mass.

[0046] As the epoxy-containing compound, compounds known as reactive diluents (e.g., epoxy-containing compounds with a molecular weight of 100 to 700) can generally be used. For example, at least one compound selected from the group consisting of n-butyl glycidyl ether, versatic acid glycidyl ether, styrene oxide, ethylhexyl glycidyl ether, phenyl glycidyl ether, butylphenyl glycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, diethylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether can be used. For example, based on the total mass of the epoxy-containing compound, the content of the epoxy-containing compound with a molecular weight of 100 to 700 can be 0 to 95% by mass, 0 to 80% by mass, or 0 to 60% by mass.

[0047] Epoxy-containing compounds can include those that are liquid at 25°C. "Liquid at 25°C" means that the viscosity of the epoxy-containing compound at 25°C is less than 200 Pa·s. The viscosity values ​​mentioned above are measured using an E-type viscometer at a temperature of 25°C, a rotor of SPP, and a rotation speed of 2.5 rpm. Examples of epoxy-containing compounds that are liquid at 25°C include, for example, bisphenol-type liquid epoxy resins such as bisphenol A type liquid epoxy resin, bisphenol F type liquid epoxy resin, bisphenol AD ​​type liquid epoxy resin, bisphenol S type liquid epoxy resin, and hydrogenated bisphenol A type liquid epoxy resin; naphthalene glycol type liquid epoxy resin; aminoglycidyl ether type liquid epoxy resin; and phenolic varnish type liquid epoxy resin. Epoxy-containing compounds that are liquid at 25°C can be compounds formulated as dispersion media for the rubber particles described later. From the viewpoint of improving the flexibility and embeddability of the magnetic film, at least one epoxy-containing compound that is liquid at 25°C can be used as the epoxy-containing compound that is liquid at 25°C. For example, based on the total mass of the epoxy-containing compound, the content of the epoxy-containing compound that is liquid at 25°C can be 0–100% by mass, 10–90% by mass, or 20–80% by mass.

[0048] Epoxy-containing compounds can be used in combination with those that are liquid at 25°C and those that are non-liquid (solid) at 25°C. In this case, from the viewpoint of further improving curability, a biphenyl phenolic varnish-type epoxy resin can be used as the non-liquid (solid) epoxy-containing compound at 25°C. Furthermore, "non-liquid (solid) at 25°C" means that the viscosity of the epoxy-containing compound at 25°C exceeds 200 Pa·s.

[0049] The epoxy equivalent of epoxy-containing compounds can be 80–500 g / eq, 100–400 g / eq, or 150–350 g / eq. The epoxy equivalent of epoxy-containing compounds can be determined according to JIS K 7236. Furthermore, when a thermosetting compound contains multiple epoxy-containing compounds, the epoxy equivalent of a mixture of all epoxy-containing compounds can be measured within the above ranges.

[0050] [Curing agent] The curing agent can be a known curing agent corresponding to the thermosetting compound. For example, when the thermosetting compound is an epoxy-containing compound, a compound that reacts with the epoxy groups of the epoxy-containing compound to form a cured product can be used. Specific examples of epoxy-containing compound curing agents include phenolic curing agents, acid anhydride curing agents, amine curing agents, imidazole curing agents, and imidazoline curing agents. Among these, phenolic curing agents can be used from the viewpoint of improving curing properties. In addition, amine curing agents (more specifically, tertiary amines), imidazole curing agents, and imidazoline curing agents can also be used as curing accelerators in combination with other curing agents (e.g., phenolic curing agents).

[0051] Phenolic curing agents are compounds having at least two phenolic groups within their molecules. Examples of phenolic curing agents include: phenolic varnish-type phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and / or naphthols such as α-naphthol, β-naphthol, and dihydroxynaphthol with aldehydes such as formaldehyde, benzaldehyde, and salicylaldehyde, under an acidic catalyst; and phenolic varnish-type phenolic resins obtained by reacting phenols and / or naphthols with dimethoxy-p-xylene or bis(methoxymethyl)biphenyl. Synthetic phenol-aralkyl resins; aralkyl-type phenol resins such as biphenyl-type phenol-aralkyl resins and naphthol-aralkyl resins; dicyclopentadiene-type phenolic resins synthesized by copolymerization of phenols and / or naphthols with dicyclopentadiene; triphenylmethane-type phenolic resins; terpene-modified phenolic resins; p-xylene and / or m-xylene-modified phenolic resins; melamine-modified phenolic resins; and phenolic resins obtained by copolymerizing two or more of these. Among these, phenolic varnish-type phenolic resins can be used from the viewpoint of further improving curability.

[0052] The content of the curing agent can be set by considering the ratio of the equivalent number of reactive groups in the thermosetting compound to the equivalent number of active groups in the curing agent that react with the reactive groups. The equivalent number of active groups in the curing agent relative to one equivalent of reactive groups in the thermosetting compound can be 0.5 to 1.5 equivalents, 0.9 to 1.4 equivalents, or 1.0 to 1.2 equivalents. For example, when using an epoxy-containing compound as the thermosetting compound and a phenolic curing agent as its curing agent, the above ratio can be expressed as the ratio of the equivalent number of phenolic hydroxyl groups in the phenolic curing agent to one equivalent of epoxy groups in the epoxy-containing compound. When the above ratio is 0.5 equivalents or more, the following effects can be expected: suppression of the decrease in curing speed; suppression of the decrease in the glass transition temperature and elastic modulus of the obtained cured product; and suppression of the decrease in the insulation reliability of the cured product caused by unreacted components. When the above ratio is 1.5 equivalents or less, the following effects can be expected: suppression of the decrease in the mechanical strength of the obtained cured product; and suppression of the decrease in the insulation reliability of the cured product caused by unreacted components. However, in the above embodiments, the ratio of active groups in the curing agent (the equivalent number of active groups in the curing agent relative to 1 equivalent of reactive groups in the thermosetting compound) is not limited, and the effects of the present invention can be obtained even if the ratio exceeds the above range.

[0053] [Curing Accelerator] Curing accelerators are not limited to any compound capable of promoting the curing reaction between a thermosetting compound and a curing agent (e.g., the curing reaction between an epoxy-containing compound and a phenolic curing agent). Examples of curing accelerators include tertiary amines, imidazole-based curing accelerators, imidazole-linen-based curing accelerators, and phosphorus compounds. Among these, imidazole-based curing accelerators can be used from the viewpoint of improving the curing promotion effect.

[0054] Imidazole-based curing accelerators are compounds with an imidazole skeleton, or they can be imidazole compounds obtained by substituting hydrogen atoms in the molecule with substituents. Imidazole-based curing accelerators can be compounds with an imidazole skeleton, such as alkyl-substituted imidazoles. Examples of imidazole-based curing accelerators include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole propionitrile, 1-cyanoethyl-2-phenylimidazole, and 2-isopropylimidazole. From the viewpoint of further improving the curing accelerator effect, 2-ethyl-4-methylimidazole (e.g., "Curesol 2E4MZ" manufactured by SHIKOKU CHEMICALSCORPORATION) can be used as an imidazole-based curing accelerator.

[0055] The content of the curing accelerator is not particularly limited as long as it is sufficient to achieve the curing-promoting effect. For example, relative to 100 parts by mass of the thermosetting compound and the curing agent, the content of the curing accelerator can be 0.001 parts by mass or more, 0.01 parts by mass or more, or 0.1 parts by mass or more, or it can be 5 parts by mass or less, 4 parts by mass or less, or 3 parts by mass or less. When the content of the curing accelerator is 0.001 parts by mass or more, a sufficient curing-promoting effect can be easily obtained. When the content of the curing accelerator is 5 parts by mass or less, excellent storage stability can be easily obtained as a magnetic composition. However, even when the content of the curing accelerator exceeds the above range, the effects of the present invention can still be obtained. In addition, the curing accelerator can sometimes be included as a curing agent, in which case the component in a smaller amount is considered as the curing accelerator.

[0056] From the viewpoint of obtaining cured products with higher heat resistance, the content of thermosetting components can be 3% by mass or more, or 4% by mass or more, or 5% by mass or more, based on the total mass of non-volatile components in the magnetic composition. From the viewpoint of obtaining higher magnetic permeability, the content of thermosetting components can be 30% by mass or less, or 25% by mass or less, or 20% by mass or less, based on the total mass of non-volatile components in the magnetic composition. From these viewpoints, the content of thermosetting components can be 3 to 30% by mass, 4 to 25% by mass, or 5 to 20% by mass, based on the total mass of non-volatile components in the magnetic composition.

[0057] (Other ingredients) The magnetic composition may also contain components other than magnetic powder and thermosetting components (other components). Examples of other components include, for example, rubber components, thermoplastic resins, coupling agents, flame retardants, etc.

[0058] [Rubber Composition] The rubber component is a compound with rubber-like elasticity, referred to as a thermosetting elastomer or thermoplastic elastomer. Specifically, it is a compound with a Young's modulus of 0.01 to 100, as measured by a dynamic viscoelasticity measuring device (Dynamic Mechanical Analysis). This rubber component helps to improve the flexibility of magnetic films and their cured forms as molded bodies of magnetic compositions.

[0059] Examples of rubber components include, for example, acrylic rubber, isoprene rubber, butyl rubber, styrene-butadiene rubber, butadiene rubber, acrylonitrile-butadiene rubber, silicone rubber, urethane rubber, chloroprene rubber, ethylene-propylene rubber, fluororubber, vulcanized rubber, epichlorohydrin rubber, and chlorinated butyl rubber. Acrylic block copolymers (e.g., block copolymers having a block structure of polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate) and styrene block copolymers (e.g., block copolymers having a block structure of polystyrene-polybutene-polyethylene-polystyrene) can also be used. Among these, from the viewpoint of further improving the flexibility of the magnetic film and its cured product, as well as the embedding properties of the gaps between wirings, at least one type selected from the group consisting of butadiene rubber, silicone rubber, styrene-butadiene rubber, and acrylic rubber can be used.

[0060] The magnetic composition may contain particles (rubber particles) comprising the aforementioned rubber component. When the rubber component in the magnetic composition is insoluble in the thermosetting component and exists in particle form, the magnetic composition tends to have a lower melt viscosity and better embedding properties into the gaps between wirings compared to when the rubber component exists dissolved in the thermosetting component. Furthermore, for the same reason, the amount of magnetic powder can be increased, thus easily obtaining a higher magnetization. The rubber particles may consist solely of the rubber component, but may also contain components other than the rubber component. Based on the total mass of the rubber particles, the content of the rubber component in the rubber particles may be 40% by mass or more, or 60% by mass or more, or 80% by mass or more.

[0061] Rubber particles can have a core-shell structure. For example, a core-shell rubber particle can have a core layer composed of rubber components and a shell layer composed of resin. Examples of resins include epoxy resins (e.g., resins composed of homopolymers of epoxy-containing monomers, resins composed of copolymers of epoxy-containing monomers with alkyl (meth)acrylate monomers or other copolymerizable monomers) and acrylic resins (e.g., resins composed of homopolymers of (meth)acrylate monomers, resins composed of copolymers of (meth)acrylate monomers with alkyl (meth)acrylate monomers or other copolymerizable monomers) that have polymers containing alkyl (meth)acrylate monomers as monomer units. By forming a shell layer around the core layer, the dispersibility and flowability of the rubber particles can be improved.

[0062] Examples of epoxy-containing monomers include allyl glycidyl ether and glycidyl methacrylate. Examples of alkyl acrylate monomers include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and ethylhexyl methacrylate. Examples of other copolymerizable monomers include styrene, α-methylstyrene, 1,4-divinylbenzene, 1- or 2-vinylnaphthalene, methacrylonitrile, 2-methoxyethyl (meth)acrylate, and 2-ethoxyethyl (meth)acrylate. From the viewpoints of storage stability, viscosity, toughness, and adhesion, the resin constituting the shell can be a copolymer containing glycidyl methacrylate, methyl methacrylate, and styrene as monomer units.

[0063] The core and shell can be a multi-layered structure. In this case, the composition of each layer can be different. Furthermore, there can be an adhesive layer between the core and shell.

[0064] From the viewpoint of flexibility and flowability, the average particle size of rubber particles can be 10 nm or more, or 30 nm or more, 40 nm or more, or 50 nm or more. From the viewpoint of heat resistance, strength, flexibility, uniformity of magnetic properties, and embeddability of the magnetic composition, the average particle size of rubber particles can be less than 2000 nm, or less than 1000 nm or less, or less than 500 nm. From these viewpoints, the average particle size of rubber particles can be 10–2000 nm, 30–2000 nm, 40–1000 nm, or 50–500 nm. Furthermore, the above-mentioned average particle size is determined by the D-axis of the magnetic powder. 50 The 50% cumulative particle size of the volume reference was measured using the same method.

[0065] From the viewpoint of further improving the flexibility and magnetic permeability of the magnetic film and its cured product, based on the total mass of the non-volatile components in the magnetic composition, the content of the rubber component in the magnetic composition can be 0.05% by mass or more, or 0.1% by mass or more, 0.3% by mass or more, or 0.5% by mass or more. From the viewpoint of further improving the adhesion, magnetic properties, low thermal expansion, chemical resistance, and embedding properties between wiring gaps of the magnetic composition, based on the total mass of the non-volatile components in the magnetic composition, the content of the rubber component can be 10.0% by mass or less, or 5.0% by mass or less, or 3.0% by mass or less. From these viewpoints, based on the total mass of the non-volatile components in the magnetic composition, the content of the rubber component can be 0.05 to 10.0% by mass, 0.1 to 10.0% by mass, 0.3 to 5.0% by mass, or 0.5 to 3.0% by mass. In this embodiment, the content of rubber particles can be within the above ranges.

[0066] [Thermoplastic resin] The thermoplastic resin may be, for example, at least one selected from the group consisting of acrylic resin, polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate. For example, the content of the thermoplastic resin may be 0.01 to 1.0% by mass, based on the total mass of the non-volatile components in the magnetic composition.

[0067] [Coupled agent] Coupling agents help improve the dispersibility of magnetic powder, the adhesion between thermosetting components and magnetic powder, and the adhesion, flexibility, and mechanical strength of the cured product obtained from the magnetic composition to the substrate. Coupling agents can be, for example, at least one selected from the group consisting of silane compounds (silane coupling agents), titanium compounds, aluminum compounds (aluminum chelates), and aluminum / zirconium compounds. From the viewpoint of improving the effects of the above-mentioned coupling agents, the coupling agent can be a silane coupling agent, or at least one selected from the group consisting of epoxy silanes, mercaptosilanes, aminosilanes, alkylsilanes, ureosilanes, anhydride silanes, and vinylsilanes. Among these, the use of aminosilanes can further enhance the above-mentioned effects. Examples of aminosilanes include 3-aminopropyltrimethoxysilane (such as KBM-903 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-aminopropyltriethoxysilane (such as KBE-903 manufactured by Shin-Etsu Chemical Co., Ltd.), N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (such as KBM-603 manufactured by Shin-Etsu Chemical Co., Ltd.), N-2-(aminoethyl)-8-aminooctyltrimethoxysilane (such as KBM-6803 manufactured by Shin-Etsu Chemical Co., Ltd.), N-2-(aminoethyl)-3-aminopropyltriethoxysilane (such as KBE-603 manufactured by Shin-Etsu Chemical Co., Ltd.), and N-phenyl-3-aminopropyltrimethoxysilane (such as KBE-603 manufactured by Shin-Etsu Chemical Co., Ltd.). Products manufactured by Shin-Etsu Chemical Co., Ltd. include KBM-573, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (KBM-602, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane (KBE-602, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane (KBE-602, N-2-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane (KBM-575, N-2-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane (KBE-9103P, N-2-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane (KBE-9103P, N-2-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane (KBE-9103P, N-2-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane (KBE-9103P, N-2-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane (KBE-9103P, N-2-(vinylbenzyl)-2-(vin ... For example, the content of the coupling agent can be 0.01 to 1.0 by mass, based on the total mass of the non-volatile components in the magnetic composition.

[0068] [Flame retardant] Flame retardants help improve the environmental safety, recyclability, processability, and cost reduction of magnetic compositions. For example, the flame retardant can be at least one selected from the group consisting of brominated flame retardants, phosphorus-based flame retardants, hydrated metal compound flame retardants, silicone-based flame retardants, nitrogen-containing compounds, hindered amine compounds, organometallic compounds, and aromatic engineering plastics. For example, the content of the flame retardant can be 0.01 to 0.5% by mass, based on the total mass of the non-volatile components in the magnetic composition.

[0069] In this embodiment, because magnetic powder with the aforementioned particle size distribution is used, the magnetic composition tends to exhibit a sufficiently low minimum melt viscosity. The minimum melt viscosity of the magnetic composition is, for example, 10000 Pa·s or less (e.g., 50–10000 Pa·s) at 120°C. The minimum melt viscosity of the magnetic composition can also be appropriately adjusted according to the type and amount of thermosetting components, rubber components, etc. The minimum melt viscosity of the magnetic composition can be 50–5000 Pa·s or 50–3000 Pa·s. Furthermore, the minimum melt viscosity of the magnetic composition refers to the minimum value of the shear viscosity measured by dynamic viscoelasticity determination of the magnetic composition.

[0070] The magnetic composition of this embodiment, for example, has insulating properties. The resistivity of the magnetic composition, measured by a resistivity meter, can be 10. 7 Ω·cm or more, 10 8 Ω·cm or above or 10 9 Ω·cm or higher. Magnetic compositions with this resistivity can be readily obtained by using insulating thermosetting components.

[0071] <Magnetic Film> One embodiment of the magnetic film is composed of the magnetic composition described in the above embodiment. That is, one embodiment of the magnetic film contains D 10 The micrometer diameter is 0.01–0.50 μm, and the density is D. 50 The range is 0.10–2.00 μm, D 90 The magnetic powder has a particle size of 0.70–4.00 μm and contains thermosetting components. Therefore, the magnetic film of one embodiment exhibits excellent embedding properties into the gaps between wirings.

[0072] The magnetic film can be in the form of a film or a sheet. The thickness of the magnetic film is, for example, 5 to 200 μm. The thickness of the magnetic film can be more than 0.2 times, 0.4 times, or 0.6 times the depth of the gap between the wires embedded in the magnetic composition.

[0073] Magnetic films can be formed, for example, by mixing and stirring a liquid composition (e.g., a slurry) for forming a magnetic film with magnetic powder (magnetic powder having the above-mentioned particle size distribution), thermosetting components and other components (such as rubber components) as appropriate, together with an organic solvent, and then coating the liquid composition onto a support and drying it.

[0074] As an organic solvent, for example, an organic solvent capable of dissolving thermosetting components can be used. When using rubber components, an organic solvent that dissolves thermosetting components but not rubber components can be used. The organic solvent can be, for example, at least one selected from the group consisting of acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, carbitol acetate, butyl carbitol acetate, cyclohexanone, and xylene. From an operational point of view, the organic solvent can be liquid at room temperature (25°C). From an operational point of view, the boiling point of the organic solvent can be above 50°C and below 160°C.

[0075] As the support, polymer films (support films) with heat resistance and solvent resistance, such as polyethylene terephthalate (PET) and other polyesters, polypropylene, polyethylene and other polyolefins, can be used. Metal foils such as copper foil can also be used as the support. From the viewpoint of easy availability and excellent operability in the manufacturing process (especially heat resistance, heat shrinkage rate, and tensile strength), PET film is preferred. The thickness of the support is, for example, 1 to 150 μm. The surface of the support can be molded.

[0076] As needed, a cover film can be attached to the magnetic film. That is, as another embodiment, the present invention provides a laminate comprising a magnetic film and a cover film disposed on the magnetic film. As the cover film, a polymer film (support film) with heat resistance and solvent resistance, such as polyethylene terephthalate (PET) or other polyesters, polypropylene, polyethylene, or other polyolefins, can be used. From the viewpoint of easy availability and excellent operability in manufacturing processes and product use (especially heat resistance, heat shrinkage rate, tensile strength, and mold release properties), PET or polyethylene films can be used. The thickness of the cover film is, for example, 20–100 μm. The surface of the cover film can be subjected to a mold release treatment.

[0077] There are no particular limitations on the mixing method; for example, stirring blades, self-rotating and revolution-rotating agitators, roller mills, disc mills, and ball mills can be used.

[0078] Drying can be carried out under conditions that allow the organic solvent to evaporate without curing the thermosetting components. The drying temperature can be, for example, 60–180°C. The drying time can be, for example, 2–45 minutes.

[0079] The magnetic film obtained after drying may contain organic solvents, but the content of organic solvents may be less than 5% by mass, less than 3% by mass, or less than 1% by mass, based on the total mass of the magnetic film (i.e., the total mass of the magnetic composition). The magnetic film may be substantially free of organic solvents. That is, based on the total mass of the magnetic film, it may be less than 0.5% by mass.

[0080] The magnetic film described above can be used, for example, in circuit components (such as circuit components with inductors) where it is desired to improve characteristics through magnetic materials. The magnetic film exhibits excellent embedding properties in gaps between wirings, and therefore can be used to embed in gaps in circuit components with narrow gaps between wirings (e.g., gaps with a depth of 20 μm or more and a width of 20 μm or less). However, the magnetic film can be used not only for gaps between wirings (e.g., gaps between wirings in circuit components with inductors), but also for covering the periphery of circuit components, as a core material, etc. The magnetic film can also be used for crosstalk suppression, antenna-in-package, electromagnetic wave shielding, and other applications.

[0081] <Layered Body> One embodiment of the laminate includes a support and a magnetic film disposed on the support. The laminate is, for example, sheet-like or film-like. Details of the support and magnetic film are described above. The laminate can be used to manufacture circuit components described later. The laminate may also include layers other than the support and the magnetic film. For example, to prevent the magnetic film from being scratched, contaminated, deteriorated, or stuck, a cover film can be disposed on the magnetic film. Details of the cover film are described above.

[0082] <Circuit Components> One embodiment of the circuit component includes: a substrate on which wiring is provided on its surface; and a magnetic layer provided in such a way as to fill the gaps between the wirings in the substrate.

[0083] The substrate is, for example, a wiring substrate (circuit board) having a substrate and wiring (circuit) disposed on the surface of the substrate. Examples of substrates include inorganic materials such as semiconductors, glass, ceramics, and magnetic materials; organic materials such as polyimide and polycarbonate; and substrates containing both inorganic and organic materials (glass / epoxy resin). The wiring is formed, for example, of gold, silver, or copper. The minimum distance between wirings (the width of the gap between adjacent wirings) can be 5 μm or less (e.g., 1 to 400 μm). The height of the wiring (the depth of the gap of the aforementioned width) can be 5 μm or more (e.g., 1 to 200 μm), or 20 μm or more, or 90 μm or more.

[0084] The magnetic layer comprises a cured product of the magnetic composition of the above embodiments. The magnetic layer is, for example, a cured product of the magnetic film of the above embodiments. The thickness of the magnetic layer is, for example, 5 to 200 μm.

[0085] The circuit components in the implementation can be, for example, inductors or intermediate components used to manufacture inductors. In either case, the magnetic layer is provided in a manner that fills the gaps between the coil wirings of the inductor.

[0086] Figure 1 This is a schematic cross-sectional view illustrating an example of a method for manufacturing a circuit component according to the above embodiment. One embodiment of the method for manufacturing a circuit component includes: a step of preparing a laminate 3 and a wiring substrate 10, wherein the laminate 3 includes a support 1 and a magnetic film 2 disposed on the support 1, and the wiring substrate 10 includes a substrate 11 and wirings 12 disposed on a surface 11a of the substrate 11; a step of pressing the magnetic film 2 onto the wiring substrate 10 to cover the wirings 12 (pressing step); and a step of heating and curing a layer composed of the magnetic film 2 (heat curing step). According to this method, the gaps 12a between the wirings 12 of the wiring substrate 10 are filled by a layer composed of the magnetic film 2, thereby obtaining a circuit component 100, which includes a wiring substrate 10 and a magnetic layer 5 formed by curing a layer composed of the magnetic film 2. Alternatively, the support 1 can be removed during the lamination of the magnetic film 2, or after the magnetic film 2 has been laminated but before the layer composed of the magnetic film 2 has been heated and cured, or after the magnetic layer 5 has been obtained.

[0087] The method for depositing the magnetic film 2 on the wiring substrate 10 is not particularly limited, for example, Figure 1 As shown, a laminating apparatus equipped with an upper heater 21 and a lower heater 22 can be used. Figure 1 In the method shown, firstly, a wiring board 10 is arranged on the lower heater 22 side between the upper heater 21 and the lower heater 22, with the wiring 12 side facing the upper heater 21 side. Then, on the upper heater 21 side between the upper heater 21 and the lower heater 22, a laminate 3 is arranged with the magnetic film 2 facing the lower heater 22 side (see reference). Figure 1 (a). Next, the lamination apparatus is started, and while heating the laminate 3 and the wiring board 10, the laminate 3 is moved from the upper heater 21 side to the direction opposite to the wiring board 10. Figure 1 Press the magnetic film 2 against the wiring substrate 10 by pressing in the direction of the arrow in (a).

[0088] As the aforementioned lamination apparatus, a vacuum lamination apparatus, such as a vacuum roller lamination apparatus, can be used. Lamination can be performed, for example, under conditions of heating and pressurizing at 40–150°C and 0.1–1.0 MPa for 0.5–10 minutes. Alternatively, a pressurizing device (such as a vacuum pressurizing device) can be used instead of the lamination apparatus.

[0089] The heating in the heat curing process can be carried out, for example, in an inert gas atmosphere such as nitrogen, at 80–250°C for 10–150 minutes. Heating can be performed in a vacuum atmosphere or an atmospheric atmosphere.

[0090] In the above method, a portion of the magnetic film 2 is sometimes cured by heating during the pressing process; however, in this case, the pressing process is also included in the heating and curing process. However, in addition to the heating during the pressing process, the heating and curing process may also include a second heating process that heats a portion of the cured magnetic film 2. The second heating process can be carried out under an inert gas atmosphere such as nitrogen and at 80–250°C for 10–150 minutes. Heating can be performed under a vacuum atmosphere or an atmospheric atmosphere.

[0091] The circuit component 100 obtained by the above method is, for example, an intermediate component for manufacturing an inductor. The manufacturing method of the circuit component may also include steps such as forming through-holes in the circuit component 100, performing a cleaning process, performing electroless plating, and forming wiring. These steps can be repeated multiple times to obtain the circuit component, such as an inductor. When forming wiring, for example, it can be performed by: after performing electroless plating, forming a resist corresponding to the wiring pattern, performing electrolytic copper plating, and then performing resist stripping and flash etching.

[0092] Example The present invention will now be described in more detail using examples and comparative examples, but the present invention is not limited to the following examples.

[0093] <Preparation of Magnetic Powder> Magnetic powders A to E with particle size distributions shown in Table 1 were prepared. The particle size distribution of the magnetic powders, D, was obtained by measuring the particle size distribution using a laser diffraction scattering particle size distribution measuring device under the following conditions. 10 D 50 and D 90 .

[0094] [condition] Magnetic powder and cyclohexanone were weighed to prepare a magnetic powder dispersion of approximately 50% by mass. The prepared dispersion was dispersed using an ultrasonic dispersion device for 90 seconds, and then placed in a particle size distribution measuring device (Beckman Coulter LS 13 320, laser diffraction method) to determine the particle size distribution of the magnetic powder.

[0095] As magnetic powder A, magnetic powder "MO3S" (Mn ferrite, without insulating coating) manufactured by POWDERTECH CO., LTD. was used.

[0096] Magnetic powder B is prepared by classifying and removing large-diameter magnetic powder from the metallic glass magnetic powder "SAP-2DC" (Fe-Si-BP-Nb-Cr alloy with insulating coating) manufactured by SINTOKOGIO, LTD. using a nylon mesh with a mesh size of 2μm.

[0097] Magnetic powder C is prepared by dispersing magnetic powder B in cyclohexanone, allowing it to stand, removing the upper suspension, and removing small-diameter magnetic powder.

[0098] Magnetic powder D is prepared by mixing magnetic powder B into "SAP-2DC", a metallic glass magnetic powder manufactured by SINTOKOGIO, LTD.

[0099] Magnetic powder E is prepared by dispersing magnetic powder B in cyclohexanone, allowing it to stand, and then collecting the upper suspension.

[0100] [Table 1]

[0101] <Example 1> 10.0g of solid epoxy resin "NC-3000-H" (biphenyl phenolic varnish type epoxy resin) manufactured by Nippon Kayaku Co., Ltd., 4.0g of curing agent "HP-850N" (phenolic varnish type phenolic resin) manufactured by Resonac Corporation, and 6.0g of "cyclohexanone" manufactured by FUJIFILM Wako Pure Chemical Corporation were weighed out. These raw materials were placed in a 250ml ointment container, and all the raw materials in the ointment container were mixed using a rotary mixer. A "ARE-500" manufactured by THINKY CORPORATION was used as the rotary mixer. Mixing was performed twice by setting the rotary mixer's rotation speed to 2000 rpm for 20 minutes each time. Next, 0.090 g of curing accelerator "2E4MZ" (2-ethyl-4-methylimidazolium) manufactured by SHIKOKU CHEMICALS CORPORATION was added to the mixture obtained by stirring and kneading, and the rotation speed of the rotary mixer was set to 2000 rpm for 1 minute. This yielded varnish X. The NV (non-volatile matter content) of the obtained varnish X was 58.5% by mass.

[0102] 11.9 g of varnish, 40.0 g of magnetic powder A, and 0.12 g of silane coupling agent (KBM-573, N-phenyl-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Silicone Co., Ltd.) were weighed. These were placed into a 50 ml ointment container. All ingredients in the ointment container were stirred and mixed at 2000 rpm for 45 seconds using a rotary mixer. Then, the ingredients in the ointment container were stirred with a spatula. Furthermore, the mixture was stirred twice more at 2000 rpm for 45 seconds, thereby preparing a liquid composition (slurry) for magnetic film formation. The content of magnetic powder A, based on the total mass of the non-volatile components of the obtained slurry, was 79.8% by mass.

[0103] The slurry obtained above is applied onto a PET film serving as a support using a doctor blade and dried at 120°C for 20 minutes, thereby forming a magnetic film. Thus, a laminate comprising a support and a magnetic film disposed on the support is obtained.

[0104] <Example 2, Comparative Examples 1-3> Magnetic powders B to E were used instead of magnetic powder A. Otherwise, the liquid compositions (slurries) and laminates of Examples 2 and Comparative Examples 1 to 3 were obtained in the same manner as in Example 1.

[0105] <Example 3> As raw materials, KANEKA CORPORATION's "MX-136" (a mixture of bisphenol-type liquid epoxy resin and core-shell structured rubber particles dispersed in the resin (core: butadiene rubber, shell: acrylic resin), with a rubber particle content of 25% by mass) was further used. The amount of raw materials was adjusted to obtain a magnetic film composed of a magnetic composition having the composition shown in Table 2. Otherwise, the liquid composition (slurry) and laminate of Example 3 were obtained in the same manner as in Example 2.

[0106] <Evaluation 1> (Evaluation of flexibility) The magnetic films of Examples 1-3 and Comparative Examples 1-3 were wound onto a rod with a diameter of 6 mm, and the presence of cracks and peeling from the support was visually confirmed. If neither cracking nor peeling was observed, the film was rated as having good flexibility (A); if either cracking or peeling was observed, the film was rated as having poor flexibility (B). The evaluation results are shown in Table 2.

[0107] <Rating 2> The magnetic permeability and embedding properties of the magnetic layers fabricated using the magnetic films of Examples 1-3 and Comparative Examples 1-3 were evaluated. The order of evaluation for magnetic permeability and embedding properties is shown below, and the evaluation results are presented in Table 2.

[0108] (Evaluation of magnetic permeability) A 1.1 mm thick magnetic film was prepared by laminating magnetic films together under vacuum. A 1 mm thick stainless steel plate was then placed around the magnetic film to surround it. Using a vacuum press (manufactured by Imoto Machinery Co.,LTD, manual hydraulic vacuum hot press, 1A31), the magnetic film was shaped and cured into a 1 mm thick plate under vacuum conditions and pressure at 180°C and 2 MPa for 60 minutes, thus obtaining the magnetic layer. This magnetic layer was then shaped into a ring-shaped sample with an outer diameter of 7 mm, an inner diameter of 3 mm, and a thickness of 1 mm by drilling. The relative permeability μ' of the magnetic layer at 1 GHz was determined using this ring sample and a network analyzer.

[0109] (Embedded evaluation) A dicer was used to dice grooves 25 μm wide and 90 μm deep on a silicon wafer. A magnetic film (laminated structure) was then deposited on the wafer, and the wafer was heated under vacuum at 120°C and 0.5 MPa for 5 minutes. A PET film serving as a support was peeled off from the wafer containing the magnetic film, and the magnetic film was cured by heating at 180°C for 60 minutes under a nitrogen atmosphere. The cured material was placed in an aluminum cup, secured with a sample clip (Buehler, Samplklip), and epoxy resin (Refine Tec Ltd., Epomount) was poured into it. The cup was then left to cure at room temperature for 12 hours. A fine saw (Refine Tec Ltd., RCA-005) with a diamond cutting wheel (Refine Tec Ltd., 11-304) was used to cut near the observation surface of the cast sample. The cut surface was polished with abrasive paper to expose the observation surface, and then smoothed with alumina powder to obtain the observation surface. The cross-section of the specimen was observed using a scanning electron microscope (SEM) (manufactured by Hitachi High-Tech Corporation, SU5000). If the magnetic composition filled to the bottom of the groove, the embedment performance was rated as good (A); if the magnetic composition did not fill to the bottom of the groove and voids existed, the embedment performance was rated as poor (B).

[0110] [Table 2]

[0111] The numerical values ​​in the table above represent the amount of non-volatile components in each material.

[0112] Symbol Explanation 1-Support body, 2-Magnetic film, 3-Laminated body, 5-Magnetic layer, 10-Wiring substrate, 11-Substrate, 12-Wiring, 100-Circuit component.

Claims

1. A magnetic composition comprising: magnetic powder and a thermosetting component, The magnetic powder has a volume-based cumulative particle size of 0.01–0.50 μm at 10% of its volume. The magnetic powder has a volumetric cumulative particle size of 0.10–2.00 μm, which is 50% of the total particle size. The magnetic powder has a 90% cumulative particle size of 0.70–4.00 μm based on volume.

2. The magnetic composition according to claim 1, wherein, Based on the total mass of the non-volatile components in the magnetic composition, the content of the magnetic powder is 60% by mass or more.

3. The magnetic composition according to claim 1, further comprising a rubber component.

4. The magnetic composition according to claim 3, wherein, Based on the total mass of the non-volatile components in the magnetic composition, the content of the rubber component is 0.05 to 10.0% by mass.

5. The magnetic composition according to claim 1, wherein, The thermosetting component includes epoxy-containing compounds and phenolic curing agents.

6. A magnetic film comprising the magnetic composition according to any one of claims 1 to 5.

7. A laminated body, comprising: A support body; and the magnetic film of claim 6 disposed on the support body.

8. A circuit component comprising: A substrate having wiring on its surface; and a magnetic layer disposed such that it fills the gaps between the wiring in the substrate. The magnetic layer comprises a cured product of the magnetic composition according to any one of claims 1 to 5.

9. The circuit component according to claim 8, wherein, The wiring is the coil wiring of the inductor.

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