Magnetic paste, circuit component, and method for manufacturing circuit component

Abstract

A magnetic slurry containing (A) a magnetic powder, (B) a radical polymerizable compound, and (C) a thermal radical polymerization initiator.

Description

Technical Field

[0001] This invention relates to a magnetic paste, a circuit component, and a method for manufacturing the circuit component. Background Technology

[0002] Materials containing metal powders with various physical properties are used depending on the characteristics required for industrial products. For example, magnetic materials containing magnetic powders are used in fields such as inductors, electromagnetic wave shielding, and bond magnets. In recent years, the requirements for materials containing magnetic powders and resins have been continuously increasing (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 As a method for manufacturing circuit components, a method is being investigated to fill the fine gaps (e.g., gaps between wirings, vias, non-through holes, cavities, trenches) formed in a substrate with a paste-like magnetic material (magnetic paste). However, as circuit components become increasingly miniaturized, the size of the gaps in which the magnetic paste is applied also decreases, requiring the magnetic paste to have higher fluidity in order to adequately fill these gaps.

[0005] Therefore, one aspect of the present invention aims to provide a magnetic paste with improved fluidity. Furthermore, other aspects of the present invention aim to provide a circuit component obtained using the aforementioned magnetic paste and a method for manufacturing the same.

[0006] means for solving technical problems The present invention provides the following [1] to

[10] in some aspects. [1] A magnetic paste comprising: (A) Magnetic powder; (B) Free radical polymerizable compounds; and (C) Thermal free radical polymerization initiator. [2] According to the magnetic paste described in [1], wherein, Component (B) comprises a compound having a (meth)acryloyl group. [3] According to the magnetic paste described in [1], wherein, The (B) component comprises compounds having one (meth)acryloyl group and compounds having two or more (meth)acryloyl groups. [4] According to the magnetic paste described in [3], wherein, The compound having two or more (meth)acryloyl groups includes a compound represented by the following formula (1).

[0011] In equation (1), R 11 and R 12 Each can be used independently to represent a hydrogen atom or a methyl group, R 13 This indicates a divalent group having a poly(meth)acrylate chain. [5] The magnetic paste according to any one of [1] to [4], wherein, Component (B) is liquid at 25°C. [6] The magnetic paste according to any one of [1] to [5], wherein, Based on the total volume of the magnetic slurry, the content of component (A) is 40-90% by volume. [7] The magnetic slurry according to any one of [1] to [6] has a viscosity of 1 to 600 Pa·s at 25°C. [8] The magnetic paste according to any one of [1] to [7] is used to fill gaps, through holes, non-through holes, cavities or trenches between wirings disposed in a substrate for circuit components. [9] A circuit component comprising: Substrate; and magnetic material, filling gaps, through holes, non-through holes, cavities, or trenches between wirings disposed in the substrate. The magnetic body comprises a cured form of the magnetic slurry as described in any one of [1] to [8].

[10] A method for manufacturing a circuit component, comprising: The process of filling the gaps, through holes, non-through holes, cavities or trenches between wirings disposed on a substrate with the magnetic paste described in any one of [1] to [8]; and The process of heating the magnetic slurry to solidify it.

[0017] Invention Effects According to one aspect of the present invention, a magnetic paste with improved fluidity can be provided. Furthermore, according to other aspects of the present invention, a circuit component obtained using the aforementioned magnetic paste and a method for manufacturing the same can be provided. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional view illustrating an example of a method for manufacturing a circuit component according to an embodiment of the present invention. Detailed Implementation

[0019] In this specification, the numerical range represented by "~" indicates the range encompassing 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. Within the numerical range described in stages in this specification, the upper or lower limit of the numerical range for a certain stage can be replaced by the upper or lower limit of the numerical range for other stages. Furthermore, within the numerical range described in this specification, the upper or lower limit of the numerical range can also be replaced by the values ​​shown in the embodiments. 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 equivalent to each component are present in the slurry, unless otherwise specified, the content of each component in the slurry represents the total amount of the multiple substances present in the slurry. Furthermore, in this specification, "(meth)acryloyl" refers to at least one of an acryloyl group and its corresponding methacryloyl group. The same applies to other similar expressions such as "(meth)acrylate".

[0020] Hereinafter, exemplary embodiments of the present invention will be described. However, the present invention is not limited to the embodiments described below.

[0021] <Magnetic Paste> One embodiment of the magnetic slurry contains (A) magnetic powder (hereinafter also referred to as "(A) component"), (B) a free radical polymerizable compound (hereinafter also referred to as "(B) component"), and (C) a thermal free radical polymerization initiator (hereinafter also referred to as "(C) component").

[0022] The aforementioned magnetic paste contains a free radical polymerizable compound and a thermal free radical polymerization initiator as thermosetting components, thus exhibiting superior flowability compared to conventional magnetic pastes (e.g., magnetic pastes containing epoxy resin). Therefore, the aforementioned magnetic paste can be used to fill fine gaps (e.g., gaps between wirings, through-holes, non-through-holes, cavities, trenches) in substrates for circuit components, and can be used to fill through-holes, non-through-holes, cavities, or trenches where the use of organic solvents is strictly limited.

[0023] Furthermore, the fluidity of magnetic paste tends to decrease as the amount of magnetic powder increases. Therefore, in conventional magnetic pastes, it was necessary to reduce the amount of magnetic powder to ensure sufficient fluidity. However, the magnetic paste described above maintains sufficient fluidity while allowing for a greater amount of magnetic powder to be added. Thus, the magnetic paste described above achieves a balance between sufficient fluidity and higher magnetic permeability.

[0024] [(A) Ingredient] (A) Component (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 may further contain components other than magnetic components. The content of magnetic components, based on the total mass of the magnetic particles, may be 20% by mass or more, and the content of magnetic components, based on the total mass of component (A), may be 50% by mass or more.

[0025] 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).

[0026] 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 ferrous alloys such as Fe-Cr and Fe-Ni-Cr alloys. Furthermore, it can be copper alloys such as Cu-Sn, Cu-Sn-P, Cu-Ni, and Cu-Be alloys.

[0027] The magnetic component can be a metal compound containing the aforementioned metallic elements and elements other than the aforementioned metallic elements. Examples of elements other than the aforementioned metallic elements include at least one selected from the group consisting of carbon (C), oxygen (O), beryllium (Be), phosphorus (P), boron (B), and silicon (Si). The metal compound can be, for example, a metal oxide such as iron oxide. The metal compound can be a sintered body primarily composed of a metal oxide (e.g., a sintered body formed by mixing and sintering a metal oxide with metallic elements such as cobalt, nickel, and manganese).

[0028] The magnetic component can be either soft or strong magnetic. For example, the magnetic component can be at least one 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.

[0029] From the viewpoint of obtaining higher permeability, composition (A) may include at least one alloy selected from the group consisting of Fe monomers and Fe alloys. Fe alloys may be, for example, at least one alloy 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 obtaining even higher permeability, composition (A) may include Fe amorphous alloy powder.

[0030] 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 under the names AW2-08 and KUAMET-6B2; products manufactured by Daido Steel Co., Ltd. under the names DAPMS3, DAPMS7, DAPMSA10, DAPPB, DAPPC, DAPMKV49, DAP410L, DAP430L, and the DAPHYB series; and products manufactured by KOBE STEEL, LTD. under the names MH45D, MH28D, MH25D, and MH20D. One or more of these Fe amorphous alloy powders can be used, or they can be combined.

[0031] (A) The entire surface or a portion thereof of the component may be coated with a surface treatment agent. Surface treatment agents may be 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 may also be used as surface treatment agents.

[0032] (A) The entire surface or a portion thereof (e.g., magnetic powder containing Fe-based alloys) may be coated with an insulating material. That is, (A) may contain magnetic particles (hereinafter referred to as "insulating-coated magnetic particles") whose surfaces are coated with an insulating material. 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.

[0033] As insulating coated magnetic particles, for example, "KUAMET9A4" (Fe-Si-B alloy, D50: 20μm, with insulating coating) manufactured by EPSON ATMIX CORPORATION and "SAP-2C" (Fe-Si-BP-Nb-Cr alloy, D50: 2.2μm, with insulating coating) manufactured by SINTOKOGIO, LTD. can be used. These insulating coated magnetic particles can be used in combination with magnetic particles without insulating coating, for example, with soft ferrite powder "BSN-125" (Ni-Zn alloy, D50: 10μm, without insulating coating) manufactured by TODA KOGYO CORP.

[0034] 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 landfill performance, the shape of 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 two planes circumscribed by the magnetic particle that are parallel to each other, in a manner that maximizes the distance between them. The minor axis of a magnetic particle is the distance between two planes circumscribed by the magnetic particle that are parallel to each other, in a manner that minimizes the distance between them. From the perspective of the fluidity and landfill properties of magnetic slurry and the dense filling of magnetic particles, the aspect ratio of magnetic particles can be 1.0 to 3.0, or 1.0 to 2.0 or 1.0 to 1.5.

[0035] From the viewpoint of the fluidity and permeability of the magnetic slurry, the D50 of component (A) can be 1.1 μm or more, or 1.2 μm or more, or 1.3 μm or more. From the viewpoint of the dense filling of magnetic particles, the D50 of component (A) can be 3.6 μm or less, or 3.5 μm or less, or 3.4 μm or less. From these viewpoints, the D50 of component (A) can be 1.1–3.6 μm, 1.2–3.6 μm, 1.3–3.6 μm, 1.1–3.5 μm, 1.2–3.5 μm, 1.3–3.5 μm, 1.1–3.4 μm, 1.2–3.4 μm, or 1.3–3.4 μm. In addition, D50 refers to the particle size at which the accumulated volume from the smaller particle size side in the volumetric particle size distribution of component (A) reaches 50% of the total volume of component (A). The particle size distribution used to calculate the D50 of component (A) 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 examples.

[0036] (A) The composition can be a mixed powder obtained by combining multiple magnetic powders. The mixed powder may, for example, contain a first magnetic powder with a D50 (50% cumulative particle size in the volumetric particle size distribution) of 0.5–8.0 μm and a second magnetic powder with a D50 (50% cumulative particle size in the volumetric particle size distribution) of 8.0–50.0 μm. The D50 of the first magnetic powder can be 1.0–5.0 μm or 1.5–4.5 μm. The D50 of the second magnetic powder can be 10.0–40.0 μm or 12.0–30.0 μm.

[0037] From the perspective of particle density and magnetic loss suppression, based on the total mass of magnetic powder in the magnetic slurry, the amount of the first magnetic powder can be 5.0% by mass or more, or 8.0% by mass or more, or 10.0% by mass or more. From the perspective of particle density, slurry viscosity, magnetic permeability of the cured product, and coefficient of thermal expansion, based on the total mass of magnetic powder in the magnetic slurry, the amount of the first magnetic powder can be 95.0% by mass or less, or 92.0% by mass or less, 90.0% by mass or less, 30.0% by mass or less, 28.0% by mass or less, or 25.0% by mass or less. Based on these considerations, taking the total mass of magnetic powder in the magnetic slurry as a benchmark, the amount of the first magnetic powder can be 5.0–95.0% by mass, 5.0–92.0% by mass, 5.0–90.0% by mass, 8.0–95.0% by mass, 8.0–92.0% by mass, 8.0–90.0% by mass, 10.0–95.0% by mass, 10.0–92.0% by mass, or 10.0–90.0% by mass. Alternatively, it can be 5.0–30.0% by mass, 5.0–28.0% by mass, 5.0–25.0% by mass, 8.0–30.0% by mass, 8.0–28.0% by mass, 8.0–25.0% by mass, 10.0–30.0% by mass, 10.0–28.0% by mass, or 10.0–25.0% by mass.

[0038] Considering the particle density, slurry viscosity, magnetic permeability of the cured product, and coefficient of thermal expansion, based on the total mass of magnetic powder in the magnetic slurry, the amount of the second magnetic powder can be 5.0% by mass or more, or 10.0% by mass or more, 15.0% by mass or more, 70.0% by mass or more, 72.0% by mass or more, or 75.0% by mass or more. Considering the particle density and magnetic loss, based on the total mass of magnetic powder in the magnetic slurry, the amount of the second magnetic powder can be 95.0% by mass or less, or 92.0% by mass or less, or 90.0% by mass or less. Based on these considerations, taking the total mass of magnetic powder in the magnetic slurry as a benchmark, the amount of the second magnetic powder can be 5.0–95.0% by mass, 5.0–92.0% by mass, 5.0–90.0% by mass, 10.0–95.0% by mass, 10.0–92.0% by mass, 10.0–90.0% by mass, 15.0–95.0% by mass, 15.0–92.0% by mass, 15.0–90.0% by mass, 70.0–95.0% by mass, 70.0–92.0% by mass, 70.0–90.0% by mass, 72.0–95.0% by mass, 72.0–92.0% by mass, 72.0–90.0% by mass, 75.0–95.0% by mass, 75.0–92.0% by mass, or 75.0–90.0% by mass.

[0039] Considering the particle density, slurry viscosity, magnetic permeability of the cured product, coefficient of thermal expansion, and magnetic loss, the ratio of the volume of the first magnetic powder to the total volume of the first and second magnetic powders ("volume of the first magnetic powder" / "total volume of the first and second magnetic powders") can be 0.05 or more, or 0.08 or more, or 0.10 or more. Considering the particle density, slurry viscosity, magnetic permeability of the cured product, and coefficient of thermal expansion, the ratio of the volume of the first magnetic powder to the total volume of the first and second magnetic powders can be 0.95 or less, 0.92 or less, 0.90 or less, 0.30 or less, 0.28 or less, or 0.25 or less. From these perspectives, the ratio of the volume of the first magnetic powder to the total volume of the first and second magnetic powders can be 0.05–0.95, 0.05–0.92, 0.05–0.90, 0.08–0.95, 0.08–0.92, 0.08–0.90, 0.10–0.95, 0.10–0.92, or 0.10–0.90, or it can be 0.05–0.30, 0.05–0.28, 0.05–0.25, 0.08–0.30, 0.08–0.28, 0.08–0.25, 0.10–0.30, 0.10–0.28, or 0.10–0.25.

[0040] From the viewpoint of achieving high magnetic permeability, the content of component (A) can be 40% or more, 50% or more, or 60% or more, based on the total volume of the magnetic paste. From the viewpoint of achieving higher fluidity, the content of component (A) can be 90% or less, 85% or less, or 80% or less, based on the total volume of the magnetic paste. From the above viewpoints, the content of component (A) can be 40–90% by volume, 40–85% by volume, 40–80% by volume, 50–90% by volume, 50–85% by volume, 50–80% by volume, 60–90% by volume, 60–85% by volume, or 60–80% by volume.

[0041] [(B) Component] (B) Component (free radical polymerizable compound) is a compound polymerized by free radicals generated from (C) Component (thermal free radical polymerization initiator) due to heat. (B) Component can be any of a monomer or a polymer (or oligomer) formed by the polymerization of one or more monomers. (B) Component can be a single compound or a combination of multiple compounds.

[0042] (B) The component is a compound having a functional group (radical polymerizable group) that reacts via a free radical. Examples of free radical polymerizable groups include (meth)acryloyl, vinyl, allyl, styryl, alkenyl, alkenyl, maleimide, etc. The number of free radical polymerizable groups (number of functional groups) can be 1 to 10, 1 to 6, or 1 to 4.

[0043] As component (B), from the viewpoint of achieving a better balance between the flowability of the magnetic slurry and the properties of the cured product (e.g., adhesion, thermal properties, and mechanical properties), a compound having a (meth)acryloyl group (hereinafter also referred to as "component (B1)") can be used. Component (B1) can be a compound having one (meth)acryloyl group (hereinafter also referred to as "component (B1-1)") or a compound having two or more (meth)acryloyl groups (hereinafter also referred to as "component (B1-2)"). From the viewpoint of achieving a better balance between the flowability of the magnetic slurry and the properties of the cured product, components (B1-1) and (B1-2) can be used in combination.

[0044] As component (B1-1), from the viewpoint of achieving a better balance between the flowability of the magnetic slurry and the properties of the cured product, alkyl (meth)acrylate can be used. The alkyl group (the portion other than the (meth)acryloyl group) can be linear, branched, or cyclic. The number of carbon atoms in the alkyl group can be 1 or more, 3 or more, 5 or more, or 6 or more, and can be 30 or less, 24 or less, 20 or less, 18 or less, 14 or less, or 12 or less. For example, the number of carbon atoms in the alkyl group can be 1–30, 1–24, 3–18, 5–14, or 6–12, or 1–11, 1–8, 1–6, or 1–4, or 12–30, 12–28, 12–24, 12–22, 12–18, or 12–14.

[0045] From the viewpoint of achieving a better balance between the flowability of the magnetic slurry and the properties of the cured product, alkyl (meth)acrylates can have cyclic alkyl groups (cycloalkyl groups). Examples of alkyl (meth)acrylates having cyclic alkyl groups include cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, terpene (meth)acrylates, and dicyclopentyl (meth)acrylate.

[0046] Based on the total mass of component (B), the content of alkyl methacrylate can be 0 to 80% by mass, and from the viewpoint of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, it can be 5 to 80% by mass, 5 to 70% by mass, or 10 to 60% by mass.

[0047] As component (B1-1), from the viewpoint of achieving a better balance between the flowability of the magnetic slurry and the properties of the cured product, a compound represented by the following formula (I) (hereinafter also referred to as "acrylamide compounds") can be used.

[0048] In equation (I), R 1 and R 2 Each of the following groups can independently represent a hydrogen atom or a monovalent organic group, and can bond together to form a ring. 3 It represents a hydrogen atom or a methyl group.

[0049] By R 1 and R 2 The monovalent organic group can be a group containing carbon, hydrogen, oxygen, sulfur, etc., a group containing only carbon and hydrogen atoms, or a group containing only carbon, hydrogen, and oxygen atoms. For example, a monovalent organic group can be a monovalent hydrocarbon group such as an alkyl group. Examples of alkyl groups include methyl, ethyl, n-propyl, and isopropyl.

[0050] By R 1 and R 2 The resulting ring can be a 5-membered, 6-membered, or 7-membered ring. This ring consists of a nitrogen atom and R... 1 and R 2 The group formation can include carbon, hydrogen, oxygen, sulfur, etc., in addition to nitrogen atoms, or it can include only nitrogen, carbon, hydrogen and oxygen atoms.

[0051] Specific examples of acrylamide compounds include dimethylacrylamide, diethylacrylamide, diisopropylacrylamide, N-(meth)acryloylmorpholine, N-acryloylthiomorpholine, N-acryloyloxazoline, N-acryloylthiazoline, N-acryloylimidazoline, N-(meth)acryloylpiperazine, N-vinylpyrrolidone, and N-vinylcaprolactam.

[0052] Based on the total mass of component (B), the content of acrylamide compounds can be 0 to 80% by mass. From the viewpoint of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, it can be 5 to 80% by mass, 5 to 70% by mass, or 10 to 60% by mass.

[0053] As component (B1-1), from the viewpoint of achieving a better balance between the flowability of the magnetic paste and the properties of the cured product, hydroxyalkyl (meth)acrylates can be used. Hydroxyalkyl (meth)acrylates are compounds formed by replacing one or more hydrogen atoms of the aforementioned alkyl (meth)acrylates with hydroxyl groups. Examples of hydroxyalkyl (meth)acrylates include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methacrylate (methyl)acrylate.

[0054] Based on the total mass of component (B), the content of hydroxyalkyl methacrylate can be 0 to 80% by mass, and from the viewpoint of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, it can be 5 to 80% by mass, 5 to 70% by mass, or 10 to 60% by mass.

[0055] As component (B1-1), a single compound may be used alone, or multiple compounds may be used in combination. From the viewpoint of achieving a better balance between the flowability of the magnetic slurry and the properties of the cured product, at least one compound selected from the group consisting of alkyl (meth)acrylates and hydroxyalkyl (meth)acrylates may be used in combination. Based on the total mass of component (B1-1), the total mass percentage of these compounds may be 90–100% by mass, 95–100% by mass, or 99–100% by mass.

[0056] As a component (B1-1), compounds other than those mentioned above may be used. Based on the total mass of the component (B1-1), the content of the compound may be less than 40% by mass, less than 30% by mass, or less than 20% by mass.

[0057] From the perspective of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, the content of component (B1-1) can be 20-99% by mass, 30-95% by mass, or 40-90% by mass, based on the total mass of component (B).

[0058] From the viewpoint of improving the thermal and mechanical properties of the cured material, a compound represented by the following formula (1) can be used as component (B1-2).

[0059] In equation (1), R 11 and R 12 Each can be used independently to represent a hydrogen atom or a methyl group, R 13It indicates a divalent group having a poly(meth)acrylate chain.

[0060] The poly(meth)acrylate chain contains structural units represented by the following formula (1a).

[0061] In equation (1a), R 14 R represents a hydrogen atom or a monovalent organic group. 15 It represents a hydrogen atom or a methyl group.

[0062] By R 14 The monovalent organic group can be, for example, a hydrocarbon group, an organic group with an oxygen atom, or an organic group with a nitrogen atom.

[0063] The hydrocarbon group can be chain-like or cyclic (e.g., aromatic ring). The number of carbon atoms in the hydrocarbon group can be, for example, 1 or more, or 18 or less. Examples of hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, 2-propylheptyl, nonyl, decyl, isodecyl, dodecyl, octadecyl, phenyl, tolyl, and benzyl.

[0064] Examples of organic groups containing oxygen atoms include groups containing alkoxy groups, groups containing hydroxyl groups, groups containing carboxyl groups, and groups containing epoxypropyl groups. Examples of alkoxy groups include 2-methoxyethyl and 3-methoxybutyl. Examples of hydroxyl groups include 2-hydroxyethyl, 2-hydroxypropyl, and 4-hydroxybutyl. Examples of carboxyl groups include the carboxyl group. Examples of epoxypropyl groups include the epoxypropyl group.

[0065] Examples of organic groups having a nitrogen atom include groups having an amino or nitrile group. For example, 2-aminoethyl is an example of a group having an amino group. For example, a nitrile group is an example of a group having a nitrile group.

[0066] From the perspective of achieving a better balance between the flowability of magnetic slurry and the properties of the cured product, R 14 The monovalent organic group can be a group with a polar group, or a group with a hydroxyl or carboxyl group.

[0067] The compound represented by formula (1) can be a compound represented by the following formula (1-1).

[0068] In equation (1-1), R 11 and R 12 respectively with R in equation (1) 11and R 12 The meanings are the same, R 14 and R 15 respectively with R in equation (1a) 14 and R 15 The meaning is the same, where n is an integer greater than 2 (e.g., 2 to 1000).

[0069] The viscosity of the compound represented by formula (1) at 23°C is, for example, 5 to 1000 Pa·s, and can be 10 Pa·s or more, 15 Pa·s or more, 20 Pa·s or more, 25 Pa·s or more, 30 Pa·s or more, or 35 Pa·s or more, or it can be 800 Pa·s or less, 700 Pa·s or less, 600 Pa·s or less, or 550 Pa·s or less.

[0070] The viscosity referred to in this manual refers to the value measured according to JIS Z8803, specifically, the value measured using a type E viscometer (e.g., TOKI SANGYO CO., LTD., PE-80L). Furthermore, the viscometer can be calibrated according to JIS Z8809-JS14000.

[0071] The glass transition temperature (Tg) of the compound represented by formula (1) is, for example, -60 to 0 °C, but can be above -50 °C or above -40 °C, or below -10 °C or below -30 °C. The glass transition temperature (Tg) of the compound represented by formula (1) can be -60 to -10 °C, -60 to -30 °C, -50 to 0 °C, -50 to -10 °C, -50 to -30 °C, -40 to 0 °C, -40 to -10 °C, or -40 to -30 °C. The glass transition temperature refers to the value determined by differential scanning calorimetry.

[0072] From the viewpoint of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, based on the total mass of component (B), the content of the compound represented by formula (1) can be 0–70% by mass, 5–60% by mass, or 10–50% by mass. The content of the compound represented by formula (1-1) can be within the above range.

[0073] As a component (B1-2), one compound may be used alone or in combination with multiple compounds. As a component (B1-2), compounds other than those mentioned above may be used, but the content of the compound may be less than 10% by mass, less than 5% by mass, or less than 1% by mass, based on the total mass of the components (B1-2).

[0074] From the perspective of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, the content of component (B1-2) can be 0-70% by mass, 5-60% by mass, or 10-50% by mass, based on the total mass of component (B).

[0075] From the perspective of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, the mass ratio of component (B1-2) to component (B1-1) (content of component (B1-2) / content of component (B1-1)) can be 0.02 to 4.0, 0.1 to 1.5, or 0.2 to 0.7.

[0076] From the perspective of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, based on the total mass of component (B), the content of component (B1) (the sum of the contents of component (B1-1) and component (B1-2)) can be 60-100% by mass, 70-100% by mass, or 80-100% by mass.

[0077] From the viewpoint of improving the properties of the cured product, component (B) may contain a compound with a weight-average molecular weight of 3000 or more (hereinafter also referred to as "polymer compound"). From the viewpoint of suppressing warping of the cured product and improving the strength of the cured product, the weight-average molecular weight of the polymer compound may be 4000 or more, 5000 or more, 6000 or more, 7000 or more, 8000 or more, 9000 or more, 10000 or more, 11000 or more, 12000 or more, or 13000 or more. From the viewpoint of improving the flowability of the magnetic slurry, the weight-average molecular weight of the polymer compound may be less than 100000, less than 80000, less than 60000, less than 34000, less than 31000, or less than 28000. From the above viewpoints, the weight-average molecular weight of the polymer compound may, for example, be 3000 to 100000.

[0078] The polymer compound can be component (B1) as described above. The polymer compound can be either component (B1-1) or component (B1-2), but from the viewpoint of achieving a better balance between the flowability of the magnetic slurry and the properties of the cured product, it can be the compound represented by formula (1). That is, the weight-average molecular weight of the compound represented by formula (1) can be within the range described above. n in formula (1-1) can be an integer that makes the weight-average molecular weight of the compound represented by formula (1) within the range described above.

[0079] The weight-average molecular weight in this specification refers to the value determined using gel permeation chromatography (GPC) under the following conditions, with polystyrene identified as a standard substance.

[0080] • Measuring equipment: HLC-8320GPC (product name, manufactured by TOSOH CORPORATION) • Analytical column: TSKgel SuperMultipore HZ-H (connects 3 columns) (Product name, manufactured by TOSOHCORPORATION) • Guard column: TSKguardcolumn SuperMP (HZ)-H (Product name, manufactured by TOSOH CORPORATION) • Elution buffer: THF • Measurement temperature: 25℃ From the perspective of achieving a better balance between the fluidity of the magnetic slurry and the properties of the cured product, the content of polymer compounds can be 0–70% by mass, 5–60% by mass, or 10–50% by mass, based on the total mass of component (B).

[0081] (B) Component can be liquid at 25°C. Here, "liquid at 25°C" means that the viscosity at 25°C measured by an E-type viscometer is less than 600 Pa·s. In the case where component (B) contains multiple compounds, it means that the mixture composed of all compounds equivalent to component (B) is liquid at 25°C.

[0082] From the viewpoint of achieving higher fluidity, based on the total mass of non-volatile components in the magnetic paste, the content of component (B) can be 1.0% by mass or more, 1.5% by mass or more, or 2.0% by mass or more. From the viewpoint of achieving high magnetic permeability, based on the total mass of non-volatile components in the magnetic paste, the content of component (B) can be 20% by mass or less, 15% by mass or less, or 10% by mass or less. From the above viewpoints, based on the total mass of non-volatile components in the magnetic paste, the content of component (B) can be 1.0–20% by mass, 1.0–15% by mass, 1.0–10% by mass, 1.5–20% by mass, 1.5–15% by mass, 1.5–10% by mass, 2.0–20% by mass, 2.0–15% by mass, or 2.0–10% by mass. Furthermore, non-volatile components in the magnetic paste refer to components other than volatile components contained in the magnetic paste. Volatile components refer to those components that show a mass reduction of more than 20% by mass and have a boiling point below 300°C when heated at 180°C for 60 minutes in the presence of a thermal free radical polymerization initiator.

[0083] [(C) Component] As component (C) (thermal free radical polymerization initiator), examples include azo compounds and organic peroxides. Examples of azo compounds include azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylpentanonitrile, azobiscyclohexane-1-carboxynitrile, and azobisbenzoyl. Examples of organic peroxides include benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, di-tert-butyl hexahydroterephthalate, tert-butyl peroxide-2-ethylhexanoate, 1,1-tert-butylperoxide-3,3,5-trimethylcyclohexane, and tert-butylperoxyisopropyl carbonate. As component (C), one of these may be used alone or in combination of two or more.

[0084] From the viewpoint of ensuring proper polymerization of component (B), the content of component (C) relative to 100 parts by mass of component (B) can be 0.01 parts by mass or more, 0.05 parts by mass or more, 0.1 parts by mass or more, or 0.5 parts by mass or more. From the viewpoint of ensuring proper polymerization, the content of component (C) relative to 100 parts by mass of component (B) can be 10 parts by mass or less, 5 parts by mass or less, or 3 parts by mass or less. From the above viewpoints, the content of component (C) relative to 100 parts by mass of component (B) can be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, 0.1 to 3 parts by mass, or 0.5 to 3 parts by mass.

[0085] [(D) component] The magnetic paste may further contain antioxidants (hereinafter also referred to as "(D) components"). Examples of antioxidants include, for example, phenolic antioxidants, benzophenone antioxidants, benzoic acid ester antioxidants, hindered amine antioxidants, and benzotriazole antioxidants.

[0086] From the viewpoint of heat resistance and low volatility, phenolic antioxidants can be used as antioxidants. Phenolic antioxidants, for example, have a hindered phenolic structure (hindered phenolic ring). The hindered phenolic structure (hindered phenolic ring) can, for example, be a structure in which tert-butyl groups are bonded to one or two adjacent positions relative to the hydroxyl group in the phenolic ring. Phenolic antioxidants may have one or more such hindered phenolic rings, or they may have two or more, three or more, or four or more such hindered phenolic rings.

[0087] Examples of phenolic antioxidants include, for example, 2-tert-butyl-4-methoxyphenol, 3-tert-butyl-4-methoxyphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and tetra[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane.

[0088] The content of antioxidant can be 0.01 to 10 parts by mass, 0.05 to 8 parts by mass, or 0.1 to 5 parts by mass relative to 100 parts by mass of component (B) in the magnetic slurry.

[0089] [Other ingredients] Magnetic pastes may further contain components other than those mentioned above (other components). Examples of other components include, for instance, thermoplastic resins, coupling agents, flame retardants, dispersants, viscosity modifiers, lubricants, etc.

[0090] 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. 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 slurry.

[0091] 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 slurry to the substrate. Therefore, by using coupling agents, it is easier to further improve the filling properties and obtain magnetic materials that are less prone to cracking. 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 easily obtaining the above-mentioned effects, silane coupling agents are preferred.

[0092] Silane coupling agents are those with the formula: -SiR 1 n (OR) 2 ) 3-n This indicates a hydrolyzable silyl organic compound. Here, R in the formula... 1 and R 2 Each group represents a hydrocarbon group independently, and n represents an integer from 0 to 2. When R 1 and R 2 When multiple R exist, multiple R 1 and R2 They can be the same or different. The hydrocarbon group can be, for example, an alkyl group with 1 to 20 carbon atoms.

[0093] In addition to the aforementioned hydrolyzable silane groups, silane coupling agents may also possess reactive functional groups such as epoxy, mercapto, (meth)acryloyl, styryl, vinyl, anhydride, and urea groups, and / or organic functional groups such as alkyl and aryl groups. Furthermore, silane coupling agents possessing free radical polymerizable groups are equivalent to component (B).

[0094] The silane coupling agent may be, for example, at least one selected from the group consisting of epoxy silane, mercaptosilane, aminosilane, alkylsilane, ureosilane, acid anhydride silane, methacrylate silane, styryl silane and vinyl silane.

[0095] Specific examples of silane coupling agents include N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, octyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 8-methacryloyloxyoctyltrimethoxysilane, p-styryltrimethoxysilane, vinyltrimethoxysilane, 7-octenyltrimethoxysilane, etc.

[0096] From the perspective of adhesion and dispersibility, based on the total mass of non-volatile components in the magnetic slurry, the content of the coupling agent can be 0.01% by mass or more, or 0.05% by mass or more, or 0.1% by mass or more. From the perspective of magnetic permeability, based on the total mass of non-volatile components in the magnetic slurry, the content of the coupling agent can be less than 1.0% by mass, or less than 0.9% by mass, or less than 0.8% by mass. From these perspectives, based on the total mass of non-volatile components in the magnetic slurry, the content of the coupling agent can be 0.01–1.0% by mass, 0.05–0.9% by mass, or 0.1–0.8% by mass.

[0097] Flame retardants contribute to the environmental safety, recyclability, and cost reduction of magnetic slurries. Flame retardants can be, for example, at least one selected from the group consisting of brominated flame retardants, phosphorus flame retardants, hydrated metal compound flame retardants, silicone flame retardants, nitrogen-containing compounds, hindered amine compounds, organometallic compounds, and aromatic engineering plastics. For example, based on the total mass of non-volatile components in the magnetic slurry, the content of the flame retardant can be 0.01 to 0.5% by mass.

[0098] Dispersants contribute to higher filling rates, lower viscosity, and improved printability of magnetic powders. Dispersants can be, for example, at least one selected from the group consisting of polyesters, polyethers, polyoxyalkylene compounds, phosphoric acid, phosphate esters, alkylammonium salts, polyacrylic acid, and sulfonic acids. Based on the total mass of non-volatile components in the magnetic paste, the content of the dispersant can be 0.01–1.0% by mass, 0.02–0.9% by mass, or 0.03–0.8% by mass.

[0099] The magnetic paste may contain compounds having one or more epoxy groups in the molecule (hereinafter referred to as "epoxy-containing compounds") to a extent that does not impair the effects of the present invention, but for example, the content of epoxy-containing compounds is less than 1% by mass based on the total mass of the non-volatile components in the magnetic paste.

[0100] Magnetic pastes may contain organic solvents as needed. There are no particular limitations on the organic solvents. For example, organic solvents capable of dissolving thermosetting components can be used. Examples of organic solvents include at least one selected from the group consisting of acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, carbitol acetate, butyl carbitol acetate, cyclohexanone, ethyl acetate, butyl acetate, toluene, 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 250°C.

[0101] On the other hand, when the magnetic slurry contains organic solvents, a drying process is required after filling the magnetic slurry into fine gaps such as through holes, generating an environmental burden due to volatile components. Furthermore, especially when the boiling point of the organic solvent is lower than the curing temperature, it sometimes evaporates rapidly during heating, creating voids in the cured magnetic slurry. Conversely, when the boiling point of the organic solvent is higher than the curing temperature, it sometimes does not readily evaporate during heating, remaining directly in the slurry and reducing the properties of the cured product. For example, if voids exist in the cured product, properties such as mechanical strength and magnetic properties are easily reduced. Moreover, especially if organic solvents remain in the cured product, ionic components in the cured product are easily mobile, easily reducing insulation properties such as insulation resistance and insulation reliability. These phenomena occur significantly, particularly in the filling of through holes, non-through holes, cavities, and trenches.

[0102] From these perspectives, especially when using magnetic pastes for filling through holes, non-through holes, cavities, or trenches, the organic solvent content can be 5% by mass or less, 3% by mass or less, or 1% by mass or less, based on the total mass of the magnetic paste. Magnetic pastes used for the above applications can be so-called "solvent-free magnetic pastes" that are substantially free of organic solvents. In this specification, "substantially free of organic solvents" means that no organic solvents have been intentionally added to the magnetic paste. Magnetic pastes that are substantially free of organic solvents, for example, used in the manufacture of resins, may contain residual organic solvents in the resin.

[0103] From the same perspective as above, the thermal weight reduction rate of magnetic paste used to fill fine gaps (especially through holes, non-through holes, cavities, and trenches) after heat treatment and curing at 180°C can be 5% or less. This thermal weight reduction rate can be 3% or less, 2% or less, or 0%. The thermal weight reduction rate can be calculated from measurements obtained using a thermogravimetric differential thermal analyzer (TG-DTA). When the thermal weight reduction rate of the magnetic paste is 5% or less, the aforementioned gaps can be easily filled with a cured product possessing desirable properties such as excellent insulation.

[0104] When magnetic paste is used for filling between wirings, the content of organic solvent can be 0.01 to 10% by mass, 0.1 to 8% by mass, or 0.5 to 5% by mass, based on the total mass of the magnetic paste.

[0105] The viscosity of the magnetic slurry can be 1 Pa·s or higher, or 10 Pa·s or higher, or 100 Pa·s or higher. By adjusting the viscosity to 1 Pa·s or higher, the sedimentation of magnetic powder in the magnetic slurry can be suppressed, and the decrease in filling properties caused by the passage of time after stirring can be easily mitigated. On the other hand, the viscosity of the magnetic slurry can be 600 Pa·s or lower, or 400 Pa·s or lower, or 200 Pa·s or lower. By adjusting the viscosity to 600 Pa·s or lower, it is easier to generate fluidity in the magnetic slurry, and better filling properties can be easily obtained. From these perspectives, the viscosity of the magnetic slurry can be 1–600 Pa·s, 1–400 Pa·s, 1–200 Pa·s, 10–600 Pa·s, 10–400 Pa·s, 10–200 Pa·s, 100–600 Pa·s, 100–400 Pa·s, or 100–200 Pa·s. The viscosity mentioned above is the viscosity at 25°C, determined by the method described in the examples.

[0106] The viscosity of magnetic slurry can be adjusted according to the type and ratio of the ingredients.

[0107] The magnetic slurry described above can be produced, for example, by uniformly mixing and kneading components (A), (B), (C), and other components as appropriate. The mixing and kneading method is not particularly limited; for example, stirring blades, rotary mixers, planetary mixers, roller mills, disc mills, and ball mills can be used.

[0108] <Circuit Components> Another embodiment of the present invention is a circuit component comprising: a substrate; and a magnetic body that fills the gaps, through holes, non-through holes, cavities or trenches between wirings disposed on the substrate, wherein the magnetic body comprises a cured product of the magnetic paste of the above embodiment.

[0109] The circuit components in the implementation can be, for example, inductors or intermediate components used to manufacture inductors.

[0110] <Manufacturing Methods of Circuit Components> Another embodiment of the present invention is a method for manufacturing a circuit component, comprising: a step of filling the gaps, through holes, non-through holes, cavities or trenches between wirings disposed on a substrate with the magnetic paste of the above embodiment; and a step of heating the magnetic paste to cure it.

[0111] According to the above method, the circuit component of the above embodiment can be obtained. Furthermore, in the above method, the magnetic paste of the above embodiment is used; therefore, according to the above method, a circuit component in which the gaps between wirings, through holes, non-through holes, cavities, or trenches are well filled with a magnetic material can be obtained.

[0112] The following is for reference. Figure 1 Furthermore, taking the method of filling through holes as an example, the circuit components and their manufacturing methods of the above embodiments will be described in more detail.

[0113] Figure 1 This is a schematic cross-sectional view illustrating a method for manufacturing a circuit component 10 according to one embodiment. The method for manufacturing a circuit component 10 according to one embodiment includes at least the step of filling a magnetic paste 2 into the through hole 1a of a substrate 1 having a through hole 1a (hereinafter referred to as "step (1)") and the step of heating the magnetic paste 2 to cure it (hereinafter referred to as "step (2)").

[0114] [Process (1)] In process (1), magnetic paste 2 is filled into the through hole 1a of the substrate 1 having the through hole 1a (see reference). Figure 1(a). The substrate 1 can be a substrate having a metal layer (e.g., a copper layer) on the surface of an insulating substrate such as a glass epoxy resin substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, or a thermosetting polyphenylene ether substrate. Although not shown, the metal layer can be a single layer or multiple layers. The metal layer can be formed on the inner wall of the through hole constituting the via 1a. The substrate 1 typically has multiple through holes 1a, but the number of through holes 1a is not particularly limited.

[0115] The filling of magnetic paste 2 can be achieved, for example, by printing the magnetic paste using a doctor blade, a vacuum printer, or other known printing methods (such as screen printing), or by methods such as roller coating, inkjet printing, or dispensing. Alternatively, a film obtained by coating a substrate with through holes with magnetic paste can be filled by pressing it together using a vacuum press or vacuum laminator.

[0116] In process (1), a pre-made substrate 1 can be used, or a substrate without through holes 1a can be prepared. Through holes are formed on the substrate by drilling, laser irradiation, plasma irradiation, etc., to prepare a substrate 1 with through holes 1a. After the through holes are formed, a metal layer can be formed on the inner wall of the through holes by roughening treatment (plasma treatment, wet treatment using swelling liquid, oxidant, etc.) and plating treatment.

[0117] [Process (2)] In step (2), the magnetic paste 2 is heated to solidify it. This forms a magnetic body 3 containing the solidified magnetic paste, thereby obtaining the circuit component 10 (see reference). Figure 1 (b). The heating temperature is, for example, 80°C or higher, and can be 90–240°C, 100–220°C, or 110–200°C. The heating time is, for example, 1–180 minutes, 5–120 minutes, or 10–60 minutes. Heating can be performed in multiple stages, including preheating. For example, it can be preheated at 80°C for 60 minutes, and then heated at 150°C for 30 minutes. Heating can be performed to achieve a curing degree of 80% or higher for the magnetic slurry. The curing degree after heating can be 85% or higher or 90% or higher. In addition, the curing degree can be measured, for example, using a differential scanning calorimeter.

[0118] The above describes one embodiment of the method for manufacturing circuit components, but the method for manufacturing circuit components of the present invention is not limited to the above method.

[0119] For example, in step (1), when a portion of the magnetic paste protrudes from the surface of the substrate 1, a step to remove the remaining magnetic paste can be performed. This step can be performed after step (2). There are no particular limitations on the removal method, but for example, the magnetic body 3 can be polished by buff polishing, belt polishing, etc., to remove the remaining magnetic body.

[0120] Furthermore, for example, it may include: a process of cleaning the chips adhering to the through holes formed in the magnetic body with water or air; a process of roughening the magnetic body 3 (desmear process); and a process of forming a conductor layer on the magnetic body 3. The conductor layer can be formed, for example, by performing an electroless plating process, forming a resist corresponding to the wiring pattern, performing an electrolytic copper plating process, and then performing resist stripping and flash etching.

[0121] 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.

[0122] The following components were used in the examples and comparative examples.

[0123] (A) Magnetic powder • A1: "KUAMET 9A4-II" (trade name, iron amorphous alloy powder, D50=25.0μm) manufactured by EPSON ATMIX CORPORATION • A2: "AW2-08" manufactured by EPSON ATMIX CORPORATION (trade name, powder of Fe-Si-BC-Cr alloy, D50=3.3μm) • A3: “M001” (trade name, manganese ferrite powder, D50=0.1μm) manufactured by Powdertech Co., Ltd. (B) Free radical polymerizable compounds •B1: "IBXA" (trade name, isobornyl acrylate, liquid at 25°C) manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD. •B2: “4HBA” (trade name, 4-hydroxybutyl acrylate, liquid at 25°C) manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD. •B3: “ACMO” (trade name, N-acryloylmorpholine, liquid at 25°C) manufactured by KJ Chemicals Co., Ltd. • B4: “RC200C” (trade name) manufactured by Kaneka Corporation, which is a compound represented by the above formula (1-1) (R in formula (1-1)). 11 and R 12 R is a hydrogen atom or a methyl group. 14 R is a group with a polar group. 15 (Contains hydrogen atoms), weight-average molecular weight: 18000, viscosity at 23℃: 530 Pa·s, Tg: -39℃, liquid at 25℃. (C) Thermal free radical polymerization initiator • C1: NOF CORPORATION's "PERBUTYL O" (trade name: tert-butyl peroxide-2-ethylhexanoate) (D) Antioxidants • D1: "Irganox1010" (trade name, tetra-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane) manufactured by BASF Japan Ltd. dispersant • BYK Corporation's "DISPERBYK-111" (product name) • BYK Corporation's "DISPERBYK-2152" (product name) Coupling agent • KBM-5803 (trade name: 8-methacryloyloxyoctyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. • KBM-573 (trade name: N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. <Preparation Examples 1-2> Weigh out components (B) (free radical polymerizable compound), (C) (thermal free radical polymerizable compound), and (D) (antioxidant) according to the mixing ratios shown in Table 1 (unit: parts by mass) and place them into an ointment container. The ingredients in the ointment container were mixed using a rotary mixer (THINKY CORPORATION's "ARE-500") at a rotation speed of 2000 rpm for 1 minute. Then, the ingredients in the ointment container were further stirred using a spatula, and then mixed again using the rotary mixer at a rotation speed of 2000 rpm for 1 minute to prepare compositions A and B, respectively.

[0124] [Table 1]

[0125] <Preparation Example 3> 70 parts by weight of Nippon Steel Chemicals' liquid epoxy resin "YDF-8170C", 30 parts by weight of ADEKA CORPORATION's liquid epoxy resin "ADEKA glycyrol ED-503G", and 30 parts by weight of Mitsubishi Chemical Corporation's curing agent "jER cure WA" (liquid aromatic amine) were weighed and placed into an ointment container. All the ingredients in the ointment container were mixed using a rotary mixer (THINKY CORPORATION's "ARE-500") at a rotation speed of 2000 rpm for 1 minute. Next, the ingredients in the ointment container were further stirred with a spatula, and then mixed again using the rotary mixer at a rotation speed of 2000 rpm for 1 minute to prepare composition C.

[0126] <Example 1> (Preparation of magnetic paste) Weigh out component (A), the prepared composition A, the dispersant, and the coupling agent according to the mixing ratio (parts by mass) shown in Table 2, and place them in an ointment container. The volume ratio of magnetic powder A1 to magnetic powder A2 is 79% by volume of magnetic powder A1 and 21% by volume of magnetic powder A2. After stirring the raw materials in the ointment container with a spatula, the mixture was stirred and mixed using a rotary mixer (THINKYCORPORATION's "ARE-500") at a rotation speed of 2000 rpm for 45 seconds. Then, after further stirring the raw materials in the ointment container with a spatula, the process of stirring and mixing using a rotary mixer at a rotation speed of 2000 rpm for 45 seconds was repeated twice to obtain the magnetic slurry of Example 1.

[0127] <Example 2> The magnetic paste of Example 2 was obtained in the same manner as in Example 1, except that composition B was used instead of composition A.

[0128] <Examples 3-7> Except for changes to component (A), the type of dispersant, and / or the formulation of each component as shown in Table 2, the magnetic slurries of Examples 3 to 7 were obtained in the same manner as in Example 2. In Example 6, the volume ratio of magnetic powder A2 to magnetic powder A3 was 83% by volume of magnetic powder A2 and 17% by volume of magnetic powder A3.

[0129] <Comparative Example 1> Except for using composition C instead of composition A in the mixing ratio shown in Table 2 and changing the type of coupling agent as shown in Table 2, the magnetic paste of Comparative Example 1 was obtained in the same manner as in Example 1.

[0130] <Evaluation> (Evaluation of magnetic permeability) Magnetic paste was applied to a PET film serving as a support using a doctor blade and dried at 120°C for 20 minutes to form a magnetic film. Two magnetic films were then overlapped by vacuum lamination to prepare a 1.1 mm thick magnetic film. A 1 mm thick stainless steel plate was placed around the perimeter of the magnetic film. Using a vacuum press (manufactured by Imoto Machinery Co., Ltd., manual hydraulic vacuum heating press, 1A31), the magnetic film was cured into a 1 mm thick plate under vacuum conditions at 180°C, 2 MPa, and 60 minutes. This plate was then drilled to form a ring-shaped sample with an outer diameter of 7 mm, an inner diameter of 3 mm, and a thickness of 1 mm. The relative permeability μ' at 20 MHz was measured using a network analyzer.

[0131] (Liquidity assessment) The flowability of the magnetic slurry was evaluated based on its viscosity. Viscosity was measured using a TV-33 viscometer manufactured by Toki Sangyo Co., Ltd., at a temperature of 25°C, a rotor of SPP, and a rotation speed of 2.5 rpm. The results are shown in Table 2. The magnetic slurry with a viscosity below 600 Pa·s was evaluated as having good flowability. Furthermore, the improvement in flowability was evaluated using Comparative Example 1 as a baseline.

[0132] Symbol Explanation 1-Substrate, 1a-Through hole, 2-Magnetic paste, 3-Magnetic body, 10-Circuit component.

Claims

1. A magnetic paste, comprising: (A) Magnetic powder; (B) Free radical polymerizable compounds; and (C) Thermal free radical polymerization initiator.

2. The magnetic paste according to claim 1, wherein, Component (B) comprises a compound having a (meth)acryloyl group.

3. The magnetic paste according to claim 1, wherein, The (B) component comprises compounds having one (meth)acryloyl group and compounds having two or more (meth)acryloyl groups.

4. The magnetic paste according to claim 3, wherein, The compounds having two or more (meth)acryloyl groups include compounds represented by the following formula (1), In equation (1), R 11 and R 12 Each can be used independently to represent a hydrogen atom or a methyl group, R 13 It indicates a divalent group having a poly(meth)acrylate chain.

5. The magnetic paste according to claim 1, wherein, Component (B) is liquid at 25°C.

6. The magnetic paste according to claim 1, wherein, Based on the total volume of the magnetic slurry, the content of component (A) is 40-90% by volume.

7. The magnetic slurry according to claim 1 has a viscosity of 1 to 600 Pa·s at 25°C.

8. The magnetic paste according to claim 1, used to fill gaps, through holes, non-through holes, cavities or trenches between wirings disposed in a substrate for circuit components.

9. A circuit component comprising: Substrate; and magnetic material, filling gaps, through holes, non-through holes, cavities, or trenches between wirings disposed in the substrate. The magnetic material comprises a cured product of the magnetic slurry according to any one of claims 1 to 8.

10. A method for manufacturing a circuit component, comprising: The process of filling the gaps, through holes, non-through holes, cavities, or trenches between wirings disposed on a substrate with the magnetic paste as described in any one of claims 1 to 8; and The process of heating the magnetic slurry to solidify it.

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