WO2020021968A1 - Magnetic paste - Google Patents

Abstract

A magnetic paste that includes (A) a magnetic powder, (B) an organified layered silicate mineral, and (C) a binder resin.

Description

Magnetic paste

The present invention relates to a magnetic paste, an inductor element obtained by using the magnetic paste, and a circuit board.

Numerous inductor elements are mounted on information terminals such as mobile phones and smartphones. Conventionally, an independent inductor component has been mounted on a substrate, but in recent years, a method of forming a coil using a conductor pattern of the substrate and providing an inductor element inside the substrate has been used.

As a method of providing an inductor element inside a substrate, for example, a method of screen-printing a paste material containing a magnetic material on a substrate including wiring to form a magnetic layer is known (Patent Document 1, Patent Document 1). Reference 2).

JP-A-6-69058 JP-A-2017-63100

Conventional paste material has high resin seeping property. Therefore, when screen printing is performed using the paste material and the magnetic layer is formed by curing, a part of the resin component and the magnetic powder constituting the paste material exude from the edge of the magnetic layer. Since it is difficult to form a conductor layer and install components on the portion of the substrate where the exuded components are present, the degree of freedom in circuit design is reduced, and miniaturization of the circuit is hindered. Patent Literature 1 and Patent Literature 2 describe a method of suppressing resin exudation by improving a screen printing method or improving a structure of an inductor element. The method described in No. 2 was not always satisfactory.

The present invention has been made in view of the above circumstances, and provides a magnetic paste capable of obtaining a cured product in which resin exudation is suppressed, and an inductor element and a circuit board using the magnetic paste. With the goal.

The present inventors have made intensive studies to achieve the above object, and as a result, have found that the use of a magnetic paste containing an organically modified layered silicate mineral suppresses resin exudation. Was completed.

That is, the present invention includes the following contents.
[1] (A) magnetic powder,
A magnetic paste comprising (B) an organically modified layered silicate mineral, and (C) a binder resin.
[2] The magnetic paste according to [1], wherein the component (B) contains organic smectite.
[3] The magnetic paste according to [2], wherein the component (B) includes smectite ion-exchanged with a quaternary ammonium ion.
[4] The magnetic paste according to any one of [1] to [3], wherein the component (B) is at least one selected from organized hectorite and organized montmorillonite.
[5] The magnetism according to [4], wherein the component (B) is at least one selected from hectorite ion-exchanged with quaternary ammonium ions and montmorillonite ion-exchanged with quaternary ammonium ions. paste.
[6] The magnetic paste according to any one of [1] to [5], wherein the component (C) contains a thermosetting resin.
[7] The magnetic paste according to any one of [1] to [6], wherein the component (C) contains an epoxy resin.
[8] The magnetic paste according to any one of [1] to [7], wherein the component (A) is at least one selected from iron oxide powder and iron alloy-based metal powder.
[9] The content of the component (B) when the non-volatile component in the magnetic paste is 100% by mass is B1, and the content of the component (C) when the non-volatile component in the magnetic paste is 100% by mass is The magnetic paste according to any one of [1] to [8], wherein C1 / B1 is 1 or more and 30 or less when C1.
[10] The magnetic paste according to any one of [1] to [9], which is for forming an inductor element.
[11] An inductor element including a magnetic layer which is a cured product of the magnetic paste according to any one of [1] to [10].
[12] A circuit board including the inductor element according to [11].

According to the present invention, it is possible to provide a magnetic paste capable of obtaining a cured product in which resin exudation is suppressed, and an inductor element and a circuit board using the magnetic paste.

FIG. 1 is a schematic plan view of an inductor element according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically illustrating an example of a cross section of a magnetic layer formed on a substrate.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, the shape, size, and arrangement of the components are only schematically shown so that the invention can be understood. The present invention is not limited by the following embodiments, and each component can be appropriately changed. Further, the configuration according to the embodiment of the present invention is not necessarily manufactured or used according to the arrangement of the illustrated example.

[Magnetic paste]
The magnetic paste of the present invention contains (A) a magnetic powder, (B) an organically modified layered silicate mineral, and (C) a binder resin.

で は In the present invention, by containing (B) an organically modified layered silicate mineral, it is possible to obtain a cured product in which resin exudation is suppressed. Further, the obtained cured product can improve the relative magnetic permeability and reduce the magnetic loss when the frequency is usually in the range of 10 to 200 MHz.

The magnetic paste may further contain (D) a curing accelerator, (E) a dispersant, and (F) other additives as necessary. Hereinafter, each component contained in the magnetic paste of the present invention will be described in detail.

<(A) Magnetic powder>
The magnetic paste contains (A) a magnetic powder. (A) As the magnetic powder, for example, pure iron powder; Mg—Zn ferrite, Fe—Mn ferrite, Mn—Zn ferrite, Mn—Mg ferrite, Cu—Zn ferrite, Mg—Mn—Sr Ferrite, Ni-Zn ferrite, Ba-Zn ferrite, Ba-Mg ferrite, Ba-Ni ferrite, Ba-Co ferrite, Ba-Ni-Co ferrite, Y ferrite, iron oxide powder (III ), Iron oxide powder such as triiron tetroxide; Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Cr alloy powder, Fe-Cr-Si alloy powder, Fe-Ni-Cr alloy powder Alloy powder, Fe-Cr-Al alloy powder, Fe-Ni alloy powder, Fe-Ni-Mo alloy powder, Fe-Ni-Mo-Cu alloy powder, Fe-Co alloy powder, Rui iron alloy-based metal powders such as Fe-Ni-Co alloy powders; amorphous alloy such as Co-based amorphous, and the like.

Above all, the magnetic powder (A) is preferably at least one selected from iron oxide powder and iron alloy-based metal powder. The iron oxide powder is preferably a ferrite containing at least one selected from Ni, Cu, Mn, and Zn. The iron alloy-based metal powder is preferably an iron alloy-based metal powder containing at least one selected from Si, Cr, Al, Ni, and Co.

市 販 A commercially available magnetic powder can be used as the (A) magnetic powder. Specific examples of commercially available magnetic powders that can be used include "M05S" manufactured by Powdertech; "PST-S" manufactured by Sanyo Special Steel Co., Ltd .; "AW2-08" and "AW2-08PF20F" manufactured by Epson Atmix. “AW2-08PF10F”, “AW2-08PF3F”, “Fe-3.5Si-4.5CrPF20F”, “Fe-50NiPF20F”, “Fe-80Ni-4MoPF20F”; “LD-M”, “LD” manufactured by JFE Chemical Corporation -MH "," KNI-106 "," KNI-106GSM "," KNI-106GS "," KNI-109 "," KNI-109GSM "," KNI-109GS ";" KNS-415 "manufactured by Toda Kogyo, “BSF-547”, “BSF-029”, “BSN-125”, “BSN-125”, “BSN-714”, “ SN-828 "," S1281 "," S-1641 "," S-1651 "," S-1470 "," S-1511 "," S-2430 ";" JR09P2 "manufactured by Nippon Heavy Chemical Industry; "Nanotek" manufactured by CIK Nanotech; "JEMK-S" manufactured by Kinsei Matech, "JEMK-H": "Yttrium \ iron \ oxide" manufactured by ALDRICH. One type of magnetic powder may be used alone, or two or more types may be used in combination.

(A) The magnetic powder is preferably spherical. The value obtained by dividing the length of the major axis of the magnetic powder by the length of the minor axis (aspect ratio) is preferably 2 or less, more preferably 1.5 or less, and even more preferably 1.2 or less. Generally, when the magnetic powder has a flat shape that is not spherical, the relative magnetic permeability is easily improved. However, the use of a spherical magnetic powder is particularly preferable from the viewpoints of reducing the magnetic loss and obtaining a paste having a preferable viscosity.

(A) The average particle diameter of the magnetic powder is preferably 0.01 μm or more, more preferably 0.5 μm or more, and still more preferably 1 μm or more, from the viewpoint of improving the relative magnetic permeability. Further, it is preferably 10 μm or less, more preferably 9 μm or less, and still more preferably 8 μm or less.

(A) The average particle size of the magnetic powder can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, it can be measured by preparing a particle size distribution of a magnetic powder on a volume basis by using a laser diffraction scattering type particle size distribution measuring device, and setting a median diameter to an average particle size. As the measurement sample, a sample in which magnetic powder is dispersed in water by ultrasonic waves can be preferably used. As the laser diffraction / scattering type particle size distribution measuring device, “LA-500” manufactured by Horiba, Ltd., “SALD-2200” manufactured by Shimadzu, etc. can be used.

(A) a specific surface area of the magnetic powder, from the viewpoint of improving the relative permeability, preferably 0.05 m ² / g or more, more preferably 0.1 m ² / g or more, more preferably 0.3 m ² / g That is all. Further, it is preferably 10 m ² / g or less, more preferably 8 m ² / g or less, and still more preferably 5 m ² / g or less. (A) The specific surface area of the magnetic powder can be measured by the BET method.

(A) The content (volume%) of the magnetic powder is preferably 10 vol% or more when the non-volatile component in the magnetic paste is 100 vol% from the viewpoint of improving the relative magnetic permeability and reducing the magnetic loss. , More preferably at least 20% by volume, still more preferably at least 30% by volume. Further, it is preferably at most 85% by volume, more preferably at most 80% by volume, further preferably at most 75% by volume.

(A) The content (% by mass) of the magnetic powder is preferably 60% by mass or more when the nonvolatile component in the magnetic paste is 100% by mass from the viewpoint of improving the relative magnetic permeability and reducing the magnetic loss. , More preferably 65% by mass or more, even more preferably 70% by mass or more. Further, it is preferably at most 98% by mass, more preferably at most 96% by mass, further preferably at most 94% by mass.
In the present invention, the content of each component in the magnetic paste is a value when the nonvolatile component in the magnetic paste is 100% by mass, unless otherwise specified.

<(B) Organized layered silicate mineral>
The magnetic paste contains (B) an organized layered silicate mineral. (B) By incorporating the organic layered silicate mineral into the magnetic paste, it becomes possible to obtain a cured product with reduced resin exudation. Here, “organized (performed)” means “ion-exchanged with an organic onium ion”.

Layered silicate minerals are also commonly referred to as phyllosilicate minerals. Layered silicate minerals can be used alone or in combination of two or more. As the layered silicate mineral, a natural product or a synthetic product may be used. As the crystal structure of the layered silicate mineral, it is preferable to use one having a high degree of purity, which is regularly stacked in the c-axis direction, but a so-called mixed layered mineral in which the crystal cycle is disordered and a plurality of types of crystal structures are mixed. May be used.

Examples of the layered silicate mineral include smectite, kaolinite, halloysite, talc, and mica. Among these, smectite is preferable from the viewpoint of obtaining a cured product that can effectively suppress resin exudation.

Smectite has a general formula: X _{0.2 to 0.6} Y _{2 to 3} Z ₄ O ₁₀ (OH) ₂ .nH ₂ O (where X is a group consisting of K, Na, 1 / 2Ca, and 1 / 2Mg) Y is one or more selected from the group consisting of Mg, Fe, Mn, Ni, Zn, Li, Al, and Cr; and Z is selected from the group consisting of Si and Al. Wherein H ₂ O represents a water molecule bonded to an interlayer ion, n represents an integer, and may fluctuate significantly depending on the interlayer ion and relative humidity.) Or they are synthesized. Examples of the smectite include hectorite, montmorillonite, beidellite, nontronite, saponite, iron saponite, sauconite, stevensite, bentonite, a substituted product thereof, a derivative thereof, and a mixture thereof. Among these, hectorite and montmorillonite are preferred from the viewpoint of obtaining a cured product that can effectively suppress resin exudation.

The organic onium ion represents an ion having an onium ion structure containing an organic group. This organic onium ion is usually contained in the interlayer portion of the silicate layer of the layered silicate mineral in the component (B).

Examples of the organic onium ion include an organic ammonium ion, an organic phosphonium ion, an organic sulfonium ion, and an organic imidazolium ion. Among them, from the viewpoint of obtaining a cured product in which resin exudation is effectively suppressed, an organic ammonium ion and an organic phosphonium ion are preferable, and an organic ammonium ion is particularly preferable.

Examples of the organic group contained in the organic onium ion include a monovalent hydrocarbon group such as an alkyl group, an alkenyl group, an aryl group, and an aralkyl group; a hydroxyalkyl group; a carboxyalkyl group; a polyalkylene ether group; . One of these organic groups may be used, or two or more thereof may be used in combination. Among them, a monovalent hydrocarbon group and a polyalkylene ether group are preferable from the viewpoint of obtaining a cured product in which the resin exudation property is effectively suppressed.

As the monovalent hydrocarbon group, a monovalent aliphatic hydrocarbon group is preferable, a monovalent saturated aliphatic hydrocarbon group is more preferable, and an alkyl group is particularly preferable. The alkyl group may be linear or branched. The number of carbon atoms of the monovalent hydrocarbon group is usually 1 to 40, preferably 1 to 25, and more preferably 1 to 20. When the monovalent hydrocarbon group satisfies the above preferable requirements, a cured product having particularly low resin exudation properties can be obtained.

Preferred examples of the monovalent hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, isobutyl, n-pentyl, isopentyl Group, neopentyl group, t-pentyl group, n-hexyl group, isohexyl group, 1-methylpentyl group, 2-methylpentyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-icosyl group, etc. Is mentioned.

The polyalkylene ether group refers to a group represented by the following formula (I).
-(RO) _m -H (I)

In the formula (I), R independently represents an alkylene group. The alkylene group preferably has 2 to 20 carbon atoms. Examples of the alkylene group include an ethylene group and a propylene group.
In the formula (I), m represents an integer of 1 to 20.

Particularly preferred organic onium ions include organic onium ions represented by the following formula (II).

In the formula (II), X ¹ represents a non-metallic atom belonging to Group 15 of the long-period periodic table. Therefore, X ¹ represents a nitrogen atom or a phosphorus atom. Among them, X ¹ is preferably a nitrogen atom from the viewpoint of obtaining a cured product in which resin exudation is effectively suppressed.

In the formula (II), R ¹ represents the aforementioned organic group. Among the organic groups, those selected from the group consisting of monovalent hydrocarbon groups and polyalkylene ether groups are preferable from the viewpoint of obtaining a cured product in which resin exudation is effectively suppressed, and an alkyl group or polyalkylene ether is preferred. Groups are more preferred, and alkyl groups are particularly preferred.

In the formula (II), R ² , R ³ and R ⁴ each independently represent a group selected from the group consisting of a hydrogen atom and the organic group. Among the organic groups, those selected from the group consisting of monovalent hydrocarbon groups and polyalkylene ether groups are preferable from the viewpoint of obtaining a cured product in which resin exudation is effectively suppressed, and an alkyl group or polyalkylene ether is preferred. Groups are more preferred, and alkyl groups are particularly preferred.

From the viewpoint of obtaining a cured product in which resin exudation is effectively suppressed, among the organic onium ions, organic ammonium ions are preferable, secondary to quaternary organic ammonium ions are more preferable, and tertiary to quaternary organic ammonium ions are preferable. Ammonium ions are more preferred, and quaternary organic ammonium ions are particularly preferred. Therefore, in the organic onium ion represented by the formula (II), one or more of R ² , R ³ and R ⁴ are preferably an organic group, and more preferably two or more are an organic group. Preferably, all three are organic groups.

Among the quaternary ammonium ions represented by the formula (II), at least a part of R ¹ , R ² , R ³ and R ⁴ is preferably a long-chain organic group. Further, it is more preferable that a part of R ¹ , R ² , R ³ and R ⁴ is a long-chain organic group, and the rest is a short-chain organic group. Among them, it is particularly preferable that 2 to 3 of R ¹ , R ² , R ³ and R ⁴ are long-chain organic groups, and the remaining 1 to 2 are short-chain organic groups. The long-chain organic group means an organic group having usually 8 or more, preferably 12 or more carbon atoms. The short-chain organic group refers to an organic group having 1 to 7 carbon atoms. By using a quaternary ammonium ion that satisfies such requirements, a cured product having particularly low resin exudation properties can be obtained, and the effect is particularly remarkable when the organic group is an alkyl group.

Preferred specific examples of the organic onium ion include trimethyloctylammonium ion, trimethyldecylammonium ion, trimethyldodecylammonium ion, trimethyltetradecylammonium ion, trimethylhexadecylammonium ion, trimethyloctadecylammonium ion, and trimethyleicosylammonium ion. Trimethylalkylammonium ion; triethylalkylammonium ion such as triethyldodecylammonium ion, triethyltetradecylammonium ion, triethylhexadecylammonium ion, and triethyloctadecylammonium ion; tributyldodecylammonium ion, tributyltetradecylammonium ion, tributylhexa Tributyl alkyl ammonium ions such as silammonium ion and tributyl octadecyl ammonium ion; dimethyl dioctyl ammonium ion, dimethyl didecyl ammonium ion, dimethyl ditetradecyl ammonium ion, dimethyl dihexadecyl ammonium ion, dimethyl dioctadecyl ammonium ion (dimethyl distearyl) Dimethyldialkylammonium ion such as ammonium ion) and dimethyldidodecylammonium ion; diethyldialkylammonium ion such as diethyldidodecylammonium ion, diethylditetradecylammonium ion, diethyldihexadecylammonium ion and diethyldioctadecylammonium ion; Dibutyl dioctyl ammonium Ion, dibutyldidecylammonium ion, dibutyldidodecylammonium ion, dibutylditetradecylammonium ion, dibutyldihexadecylammonium ion, dibutyldioctadecylammonium ion, etc., dibutyldialkylammonium ion; trioctylmethylammonium ion, tridodecylmethyl Trialkylmethylammonium ion such as ammonium ion and tritetradecylmethylammonium ion; trialkylethylammonium ion such as trioctylethylammonium ion and tridodecylethylammonium ion; trioctylbutylammonium ion and tridecylbutylammonium ion Organic ammonium such as trialkylbutylammonium ion; Ions.

The component (B) can be produced by ion-exchanging a layered silicate mineral with an organic onium ion. At the time of ion exchange, the organic onium ion may be a salt (organic onium salt) between the organic onium ion and an anion. Examples of the anion include Cl ⁻ , Br ⁻ , NO ₃ ⁻ , OH ⁻ , CH ₃ COO ⁻ , CH ₃ SO ₃ ^{− and the} like. In addition, these anions may be used alone or in any combination of two or more.

As a specific example of the method for producing the component (B), a method in which an aqueous dispersion of the layered silicate mineral and an aqueous solution of an organic onium salt are mixed at an appropriate temperature (for example, 60 ° C. to 70 ° C.). . Another specific example is a method of appropriately kneading a layered silicate mineral and an organic onium salt.

市 販 A commercially available product can be used as the component (B). Commercially available products include, for example, "Smecton STN" and "Smecton SAN" (organized hectorite) manufactured by Kunimine Industries, "Orben M" (organized montmorillonite) manufactured by Shiroishi Kogyo, and "Esven" manufactured by Hojun. NX "(organized montmorillonite)," Shinton Kasei's "Benton series" (organized montmorillonite), and the like.

(B) The organized layered silicate mineral may be used alone or in combination of two or more.

(B) The average particle size of the organized layered silicate mineral is preferably 1 nm to 100 μm, more preferably 5 nm to 50 μm, and further preferably 10 nm to 10 μm. This average particle size can be measured in the same manner as for the component (A).

(B) The content of the organically modified layered silicate mineral is preferably 0.1% when the nonvolatile component in the magnetic paste is set to 100% by mass from the viewpoint of obtaining a cured product in which resin exudation is suppressed. It is at least 1% by mass, more preferably at least 0.3% by mass, further preferably at least 0.5% by mass. The upper limit is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 2% by mass, from the viewpoint of maintaining good magnetic properties and improving the printability by lowering the paste viscosity. It is as follows.

<(C) Binder resin>
The magnetic paste contains (C) a binder resin. (C) As the binder resin, for example, epoxy resin, phenol resin, naphthol resin, benzoxazine resin, active ester resin, cyanate ester resin, carbodiimide resin, amine resin, acid anhydride resin, etc. And a thermoplastic resin such as a phenoxy resin, an acrylic resin, a polyvinyl acetal resin, a butyral resin, a polyimide resin, a polyamideimide resin, a polyethersulfone resin, and a polysulfone resin. As the binder resin (C), it is preferable to use a thermosetting resin used when forming an insulating layer of a wiring board, and an epoxy resin is particularly preferable. (C) The binder resin may be used alone or in combination of two or more. Hereinafter, each resin will be described. Here, it reacts with an epoxy resin, such as a phenolic resin, a naphthol resin, a benzoxazine resin, an active ester resin, a cyanate ester resin, a carbodiimide resin, an amine resin, and an acid anhydride resin. The components that can cure the magnetic paste are sometimes collectively referred to as “curing agents”.

-Thermosetting resin-
Epoxy resins as thermosetting resins include, for example, glycylol type epoxy resin; bisphenol A type epoxy resin; bisphenol F type epoxy resin; bisphenol S type epoxy resin; bisphenol AF type epoxy resin; dicyclopentadiene type epoxy resin; Epoxy resin having a condensed ring structure such as phenol novolak type epoxy resin; tert-butyl-catechol type epoxy resin; naphthol novolak type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin; Amine type epoxy resin; Glycidyl ester type epoxy resin; Cresol novolak type epoxy resin; Biphenyl type epoxy resin; Linear aliphatic epoxy resin; Butadiene structure Alicyclic epoxy resins; heterocyclic epoxy resin; spiro ring-containing epoxy resin; cyclohexanedimethanol type epoxy resins; trimethylol type epoxy resin; tetraphenyl ethane epoxy resins Epoxy resins having. One epoxy resin may be used alone, or two or more epoxy resins may be used in combination. The epoxy resin is preferably at least one selected from a bisphenol A epoxy resin and a bisphenol F epoxy resin.

The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. The epoxy resin preferably has an aromatic structure, and when two or more epoxy resins are used, it is more preferable that at least one of the epoxy resins has an aromatic structure. The aromatic structure is a chemical structure generally defined as aromatic, and includes polycyclic aromatic and aromatic heterocyclic rings. The proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass with respect to 100% by mass of the nonvolatile component of the epoxy resin. % Or more.

The epoxy resin may be a liquid epoxy resin at a temperature of 25 ° C. (hereinafter, sometimes referred to as “liquid epoxy resin”) or a solid epoxy resin at a temperature of 25 ° C. (hereinafter, “solid epoxy resin”). ). When the epoxy resin is contained as the component (C), the epoxy resin may include only a liquid epoxy resin, or may include only a solid epoxy resin, or may be a combination of a liquid epoxy resin and a solid epoxy resin. Although it may be included, it is preferable to include only the liquid epoxy resin from the viewpoint of reducing the viscosity of the magnetic paste.

As the liquid epoxy resin, glycylol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolak type epoxy resin A resin, an alicyclic epoxy resin having an ester skeleton, a cyclohexane dimethanol type epoxy resin, and an epoxy resin having a butadiene structure are preferable, and a glycylol type epoxy resin, a bisphenol A type epoxy resin, and a bisphenol F type epoxy resin are more preferable. Specific examples of the liquid epoxy resin include “HP4032”, “HP4032D”, and “HP4032SS” (naphthalene type epoxy resin) manufactured by DIC; “828US” and “jER828EL” (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation. "JER807" (bisphenol F type epoxy resin), "jER152" (phenol novolak type epoxy resin); "630" and "630LSD" manufactured by Mitsubishi Chemical Corporation, "ED-523T" (glycylol type epoxy resin manufactured by ADEKA Corporation) (Adecaglycylol)), "EP-3980S" (glycidylamine type epoxy resin), "EP-4088S" (dicyclopentadiene type epoxy resin); "ZX1059" (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) Bisphenol "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation; "Celoxide 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel, "PB" -3600 "(epoxy resin having a butadiene structure);" ZX1658 "and" ZX1658GS "(liquid 1,4-glycidylcyclohexane) manufactured by Nippon Steel Chemical Co., Ltd., and the like. These may be used alone or in combination of two or more.

Examples of the solid epoxy resin include a naphthalene type tetrafunctional epoxy resin, a cresol novolak type epoxy resin, a dicyclopentadiene type epoxy resin, a trisphenol type epoxy resin, a naphthol type epoxy resin, a biphenyl type epoxy resin, a naphthylene ether type epoxy resin, Anthracene type epoxy resin, bisphenol A type epoxy resin, and tetraphenylethane type epoxy resin are preferred, and naphthalene type tetrafunctional epoxy resin, naphthol type epoxy resin, and biphenyl type epoxy resin are more preferred. Specific examples of the solid epoxy resin include “HP4032H” (naphthalene type epoxy resin), “HP-4700”, “HP-4710” (naphthalene type tetrafunctional epoxy resin), and “N-690” (DIC) manufactured by DIC. Cresol novolak type epoxy resin), "N-695" (cresol novolak type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (dicyclopentadiene type epoxy resin), "EXA-7311" "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin); "EPPN-502H" (Nippon Kayaku) Trisphenol type epoxy resin), "NC7000L" (naphthol novolak type epoxy) Fat), "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthalene type epoxy resin), "ESN485" (naphthol novolak type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. ); "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixylenol type epoxy resin), "YX8800" (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG manufactured by Osaka Gas Chemical Company" "-100", "CG-500", "YL7760" (bisphenol AF type epoxy resin), "YL7800" (fluorene type epoxy resin), "jER1010" (solid bisphenol A type epoxy resin) and "YLER6010" manufactured by Mitsubishi Chemical Corporation. jER 031S "(tetraphenyl ethane epoxy resin) and the like. These may be used alone or in combination of two or more.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the component (C), their quantitative ratio (liquid epoxy resin: solid epoxy resin) is preferably from 1: 0.1 to 1: 4, more preferably 1: 0.3 to 1: 3.5, even more preferably 1: 0.6 to 1: 3. When the ratio between the liquid epoxy resin and the solid epoxy resin is within the above range, the desired effects of the present invention can be remarkably obtained.

エ ポ キ シ The epoxy equivalent of the epoxy resin as the component (C) is preferably from 50 to 5,000, more preferably from 50 to 3,000, further preferably from 80 to 2,000, and still more preferably from 110 to 1,000. Within this range, the crosslinked density of the cured product becomes sufficient and a magnetic layer having a small surface roughness can be obtained. The epoxy equivalent can be measured according to JIS K7236 and is the mass of a resin containing one equivalent of an epoxy group.

エ ポ キ シ The weight average molecular weight of the epoxy resin as the component (C) is preferably from 100 to 5000, more preferably from 250 to 3000, and still more preferably from 400 to 1500. Here, the weight average molecular weight of the epoxy resin is a weight average molecular weight in terms of polystyrene measured by a gel permeation chromatography (GPC) method.

樹脂 As the active ester resin, a resin having one or more active ester groups in one molecule can be used. Among them, active ester resins include two or more highly reactive ester groups in one molecule such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Resins are preferred. The active ester resin is preferably obtained by a condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferable.

Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

Examples of the phenol compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, Examples include benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolak, and the like. Here, the “dicyclopentadiene-type diphenol compound” refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

Preferred specific examples of the active ester resin include an active ester resin containing a dicyclopentadiene-type diphenol structure, an active ester resin containing a naphthalene structure, an active ester resin containing an acetylated phenol novolak, and benzoyl phenol novolak. And an active ester resin containing a compound. Among them, an active ester resin having a naphthalene structure and an active ester resin having a dicyclopentadiene-type diphenol structure are more preferable. The “dicyclopentadiene-type diphenol structure” represents a divalent structural unit composed of phenylene-dicyclopentylene-phenylene.

Commercially available active ester resins include “EXB9451”, “EXB9460”, “EXB9460S”, “HPC-8000-65T”, and “HPC-8000H-” as active ester resins having a dicyclopentadiene-type diphenol structure. 65TM "," EXB-8000L-65TM "(manufactured by DIC);" EXB9416-70BK "," EXB-8150-65T "(manufactured by DIC) as an active ester resin having a naphthalene structure; and acetylated phenol novolak. An active ester-based resin containing “DC808” (manufactured by Mitsubishi Chemical Corporation); an active ester-based resin containing benzoylated phenol novolak “YLH1026” (manufactured by Mitsubishi Chemical Corporation); an active ester-based resin that is an acetylated phenol novolak; "DC808" (manufactured by Mitsubishi Chemical Corporation); "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin which is a benzoylated phenol novolak. Manufactured).

As the phenol-based resin and the naphthol-based resin, those having a novolak structure are preferable from the viewpoint of heat resistance and water resistance. Further, from the viewpoint of adhesion to the conductor layer, a nitrogen-containing phenol-based curing agent is preferable, and a triazine skeleton-containing phenolic resin is more preferable.

Specific examples of the phenolic resin and the naphthol resin include, for example, “MEH-7700”, “MEH-7810”, “MEH-7851” manufactured by Meiwa Kasei Co., Ltd., “NHN”, “CBN” manufactured by Nippon Kayaku Co., Ltd. "," GPH "," SN170 "," SN180 "," SN190 "," SN475 "," SN485 "," SN495 "," SN-495V "," SN375 "," SN395 ", DIC manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. And “LA-2052”, “LA-7052”, “LA-7054”, “LA-1356”, “LA-3018-50P”, “EXB-9500”, and the like.

Specific examples of the benzoxazine resin include “JBZ-OD100” (benzoxazine ring equivalent 218), “JBZ-OP100D” (benzoxazine ring equivalent 218), and “ODA-BOZ” (benzoxazine ring) manufactured by JFE Chemical Company. Equivalent 218); "Pd" (benzoxazine ring equivalent 217), "Fa" (benzoxazine ring equivalent 217) manufactured by Shikoku Chemicals; "HFB2006M" (benzoxazine ring equivalent) manufactured by Showa Polymer Co., Ltd. 432) and the like.

Examples of the cyanate ester resin include bisphenol A dicyanate, polyphenol cyanate, oligo (3-methylene-1,5-phenylene cyanate), 4,4′-methylenebis (2,6-dimethylphenyl cyanate), and 4,4 ′. -Ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanatephenylmethane), bis (4-cyanate-3,5-dimethylphenyl) ) Bifunctional cyanate resins such as methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether; phenol Novolak and Polyfunctional cyanate resin derived from resol novolac; prepolymer these cyanate resin is partially triazine of; and the like. Specific examples of the cyanate ester-based resin include “PT30” and “PT60” (phenol novolak type polyfunctional cyanate ester resin), “ULL-950S” (polyfunctional cyanate ester resin), “BA230” manufactured by Lonza Japan. "BA230S75" (a prepolymer in which part or all of bisphenol A dicyanate is triazined to be a trimer) and the like.

Specific examples of the carbodiimide-based resin include Carbodilite (registered trademark) V-03 (carbodiimide group equivalent: 216, V-05 (carbodiimide group equivalent: 262), V-07 (carbodiimide group equivalent: 200) manufactured by Nisshinbo Chemical Inc. V-09 (carbodiimide group equivalent: 200); and Stavacol (registered trademark) P (carbodiimide group equivalent: 302) manufactured by Rhein Chemie.

Examples of the amine-based resin include resins having one or more amino groups in one molecule, such as aliphatic amines, polyetheramines, alicyclic amines, and aromatic amines. Among them, aromatic amines are preferred from the viewpoint of achieving the desired effects of the present invention. The amine resin is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of the amine-based curing agent include 4,4′-methylenebis (2,6-dimethylaniline), diphenyldiaminosulfone, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, and 3,3 ′. -Diaminodiphenyl sulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl- 4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis (3-amino-4-hydroxyphenyl) propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethane Diamine, 2,2-bis (4-aminophenyl) propane, 2,2-bis (4- (4 (Aminophenoxy) phenyl) propane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4 ′ -Bis (4-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, and the like. Commercially available amine resins may be used. For example, “KAYABOND @ C-200S”, “KAYABOND @ C-100”, “Kayahard AA”, “Kayahard AB”, “Kayahard AB” manufactured by Nippon Kayaku Co., Ltd. AS "and" Epicure W "manufactured by Mitsubishi Chemical Corporation.

Examples of the acid anhydride-based resin include resins having one or more acid anhydride groups in one molecule. Specific examples of the acid anhydride resin include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride. , Trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride Acid, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenyl Sulfonetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexa Dro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-C] furan-1,3-dione, ethylene glycol bis (anhydrotrimellitate), styrene and maleic acid And a polymer type acid anhydride such as styrene / maleic acid resin copolymerized with

When the epoxy resin and the curing agent are contained as the component (C), the quantitative ratio of the epoxy resin to all the curing agents is represented by [the total number of epoxy groups of the epoxy resin]: [the total number of reactive groups of the curing agent]. The ratio is preferably in the range of 1: 0.01 to 1: 5, more preferably 1: 0.5 to 1: 3, and still more preferably 1: 1 to 1: 2. Here, the “number of epoxy groups in the epoxy resin” is a value obtained by summing all values obtained by dividing the mass of the non-volatile component of the epoxy resin present in the first resin composition by the epoxy equivalent. Further, the “number of active groups of the curing agent” is a value obtained by summing all values obtained by dividing the mass of the non-volatile component of the curing agent present in the first resin composition by the equivalent of the active group.

-Thermoplastic resin-
The weight average molecular weight of the thermoplastic resin in terms of polystyrene is preferably 30,000 or more, more preferably 50,000 or more, and further preferably 100,000 or more. Further, it is preferably 1,000,000 or less, more preferably 750,000 or less, and further preferably 500,000 or less. The weight average molecular weight in terms of polystyrene of the thermoplastic resin is measured by a gel permeation chromatography (GPC) method. Specifically, the polystyrene-equivalent weight average molecular weight of the thermoplastic resin is determined by using “LC-9A / RID-6A” manufactured by Shimadzu Corporation as a measuring device and “Shodex K-800P / K-804L” manufactured by Showa Denko as a column. / K-804L "can be calculated using a calibration curve of standard polystyrene by measuring the column temperature at 40 ° C. using chloroform or the like as a mobile phase.

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, novolak skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene Phenoxy resins having a skeleton and at least one skeleton selected from the group consisting of a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group and an epoxy group. One phenoxy resin may be used alone, or two or more phenoxy resins may be used in combination. Specific examples of the phenoxy resin include “1256” and “4250” (both phenoloxy resins containing a bisphenol A skeleton), “YX8100” (a phenoxy resin containing a bisphenol S skeleton), and “YX6954” (bisphenol acetophenone) manufactured by Mitsubishi Chemical Corporation. Skeleton-containing phenoxy resin), and “FX280” and “FX293” manufactured by Nippon Steel & Sumitomo Metal Corporation, “YL7500BH30”, “YX6954BH30”, “YX7553”, “YX7553BH30”, “YL7769BH30” manufactured by Mitsubishi Chemical Corporation. , "YL6794", "YL7213", "YL7290", and "YL7482".

From the viewpoint of further reducing the coefficient of thermal expansion and the modulus of elasticity, the acrylic resin is preferably a functional group-containing acrylic resin, and more preferably an epoxy group-containing acrylic resin having a glass transition temperature of 25 ° C. or lower.

(4) The number average molecular weight (Mn) of the functional group-containing acrylic resin is preferably from 10,000 to 1,000,000, more preferably from 30,000 to 900,000.

官能 The functional group equivalent of the functional group-containing acrylic resin is preferably from 1,000 to 50,000, more preferably from 2,500 to 30,000.

As the epoxy group-containing acrylic resin having a glass transition temperature of 25 ° C. or lower, an epoxy group-containing acrylate copolymer resin having a glass transition temperature of 25 ° C. or lower is preferable, and specific examples thereof include “SG” manufactured by Nagase ChemteX Corporation. -80H "(epoxy group-containing acrylate copolymer resin (number average molecular weight Mn: 350,000 g / mol, epoxy value 0.07 eq / kg, glass transition temperature 11 ° C))," SG-P3 "manufactured by Nagase ChemteX Corporation (Epoxy group-containing acrylate copolymer resin (number average molecular weight Mn: 850000 g / mol, epoxy value 0.21 eq / kg, glass transition temperature 12 ° C.)).

Specific examples of the polyvinyl acetal resin and butyral resin include electrified butyral “4000-2”, “5000-A”, “6000-C”, “6000-EP” manufactured by Denki Kagaku Kogyo Co., Ltd., and Sekisui Chemical Co., Ltd. Examples include the LES series such as the ESREC BH series, the BX series and the “KS-1”, the BL series such as the “BL-1”, and the BM series.

具体 Specific examples of the polyimide resin include “Likacoat SN20” and “Likacoat PN20” manufactured by Shin Nippon Rika Co., Ltd. Specific examples of the polyimide resin include a linear polyimide (polyimide described in JP-A-2006-37083) obtained by reacting a bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound and a tetrabasic anhydride, and a polysiloxane skeleton. And modified polyimides such as polyimides contained therein (polyimides described in JP-A-2002-12667 and JP-A-2000-319386).

具体 Specific examples of the polyamideimide resin include “Viromax HR11NN” and “Viromax HR16NN” manufactured by Toyobo. Specific examples of the polyamideimide resin also include modified polyamideimides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamideimide) manufactured by Hitachi Chemical Co., Ltd.

具体 Specific examples of the polyether sulfone resin include “PES5003P” manufactured by Sumitomo Chemical Co., Ltd. Specific examples of the polyphenylene ether resin include an oligophenylene ether / styrene resin having a vinyl group “OPE-2St @ 1200” manufactured by Mitsubishi Gas Chemical Company.

具体 Specific examples of the polysulfone resin include polysulfone “P1700” and “P3500” manufactured by Solvay Advanced Polymers.

Among them, the thermoplastic resin is preferably one or more selected from phenoxy resin, polyvinyl acetal resin, butyral resin, and acrylic resin having a weight average molecular weight of 30,000 to 1,000,000.

(C) The content of the binder resin is preferably 1% by mass or more, more preferably 1% by mass or more, when the nonvolatile component in the magnetic paste is 100% by mass, from the viewpoint of obtaining a magnetic layer exhibiting good mechanical strength and insulation reliability. Is at least 3% by mass, more preferably at least 5% by mass. The upper limit is not particularly limited as long as the effects of the present invention are exerted, but is preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably 20% by mass or less.

磁性 The magnetic paste of the present invention contains (B) an organically modified layered silicate mineral, whereby the resin exuding property of (C) the binder resin is suppressed. The content of the component (B) when the nonvolatile component in the magnetic paste was 100% by mass was B1, and the content of the component (C) when the nonvolatile component in the magnetic paste was 100% by mass was C1. In this case, C1 / B1 is preferably 1 or more, more preferably 3 or more, and still more preferably 5 or more, from the viewpoints of shape maintenance and handling after printing. The upper limit is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less.

<(D) Curing accelerator>
The magnetic paste may further contain (D) a curing accelerator as an optional component.

Examples of the curing accelerator include an amine-based curing accelerator, an imidazole-based curing accelerator, a phosphorus-based curing accelerator, a guanidine-based curing accelerator, and a metal-based curing accelerator. As the curing accelerator, an amine-based curing accelerator and an imidazole-based curing accelerator are preferable from the viewpoint of reducing the viscosity of the magnetic paste. The curing accelerator may be used alone or in combination of two or more.

Examples of the amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, and 1,8-diazabicyclo. (5,4,0) -undecene and the like are preferable, and 4-dimethylaminopyridine and 1,8-diazabicyclo (5,4,0) -undecene are preferable.

As the amine-based curing accelerator, a commercially available product may be used, and examples thereof include "PN-50", "PN-23", and "MY-25" manufactured by Ajinomoto Fine-Techno.

Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- -Phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl -(1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino -6- [2'-Methylimidazolyl- (1 ')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl -4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, 1-dodecyl-2- Imidazole compounds such as tyl-3-benzylimidazolium chloride, 2-methylimidazoline and 2-phenylimidazoline, and adducts of imidazole compounds and epoxy resins; 2-ethyl-4-methylimidazole, 1-benzyl-2; -Phenylimidazole is preferred.

As the imidazole-based curing accelerator, commercially available products may be used, and examples thereof include “2PHZ-PW” manufactured by Shikoku Chemicals, and “P200-H50” manufactured by Mitsubishi Chemical Corporation.

Examples of the phosphorus-based curing accelerator include triphenylphosphine, a phosphonium borate compound, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, and (4-methylphenyl) triphenylphosphonium thiocyanate , Tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate and the like, and triphenylphosphine and tetrabutylphosphonium decanoate are preferred.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] dec-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0] Deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -Allyl biguanide, 1-phenyl biguanide, 1- o- tolyl) biguanide, and the like, dicyandiamide, 1,5,7-triazabicyclo [4.4.0] dec-5-ene are preferred.

Examples of the metal-based curing accelerator include an organic metal complex or an organic metal salt of a metal such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the organometallic complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. And the like, an organic iron complex such as iron (III) acetylacetonate, an organic nickel complex such as nickel (II) acetylacetonate, and an organic manganese complex such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, zinc stearate and the like.

(D) From the viewpoint of obtaining the desired effects of the present invention, the curing accelerator is at least one selected from acid anhydride epoxy resin curing agents, amine curing accelerators, and imidazole curing accelerators. Is preferred, and more preferably at least one selected from an amine-based curing accelerator and an imidazole-based curing accelerator.

(D) From the viewpoint of lowering the viscosity of the magnetic paste, the content of the curing accelerator is preferably 0.1% by mass or more, more preferably 0.3% by mass, when the nonvolatile component in the magnetic paste is 100% by mass. %, More preferably 0.5% by mass or more, and the upper limit is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less.

<(E) Dispersant>
The magnetic paste may further contain (E) a dispersant as an optional component.

(E) Examples of the dispersant include phosphate ester dispersants such as polyoxyethylene alkyl ether phosphoric acid; and anionic dispersants such as sodium dodecylbenzenesulfonate, sodium laurate, and ammonium salts of polyoxyethylene alkyl ether sulfate. Dispersant: organosiloxane dispersant, acetylene glycol, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, etc. And the like. Of these, anionic dispersants are preferred. One type of dispersant may be used alone, or two or more types may be used in combination.

市 販 A commercial product can be used as the phosphate ester-based dispersant. Examples of commercially available products include “RS-410”, “RS-610”, and “RS-710” of the “Phosphanol” series manufactured by Toho Chemical Industry Co., Ltd.

As the organosiloxane dispersant, commercially available products include "BYK347" and "BYK348" manufactured by BYK Chemie.

As polyoxyalkylene-based dispersants, as commercial products, "AKM-0531", "AFB-1521", "SC-0505K", "SC-1015F" and "SC-0708A" of the "Mariarim" series manufactured by NOF Corporation And "HKM-50A".

As acetylene glycol, as a commercial product, Air Products and Chemicals Inc. "82", "104", "440", "465" and "485" of "Surfinol" series, and "Olefin Y".

(E) The content of the dispersant is preferably 0.1% by mass or more, more preferably 0.1% by mass, when the nonvolatile component in the magnetic paste is 100% by mass, from the viewpoint of remarkably exhibiting the effects of the present invention. It is at least 3% by mass, more preferably at least 0.5% by mass, and the upper limit is preferably at most 5% by mass, more preferably at most 3% by mass, further preferably at most 1% by mass.

<(F) Other additives>
The magnetic paste may further contain (F) other additives as needed. Examples of such other additives include a curing retarder such as triethyl borate for improving pot life; Inorganic fillers (excluding those that correspond to magnetic powders or organically modified layered silicate minerals), flame retardants, organic fillers, organometallic compounds such as organocopper compounds, organozinc compounds and organocobalt compounds And a resin additive such as a thickener, an antifoaming agent, a leveling agent, an adhesion-imparting agent, and a coloring agent.

The content of the solvent contained in the magnetic paste described above is preferably less than 1.0% by mass, more preferably 0.8% by mass or less, and still more preferably 0.5% by mass, based on the total mass of the magnetic paste. Or less, particularly preferably 0.1% by mass or less. The lower limit is not particularly limited, but is 0.001% by mass or more, or is not contained. The viscosity of the magnetic paste can be reduced without containing a solvent. When the amount of the solvent in the magnetic paste is small, generation of voids due to volatilization of the solvent can be suppressed, and application to vacuum printing becomes possible.

<Production method of magnetic paste>
The magnetic paste can be produced, for example, by a method of stirring the compounding components using a stirring device such as a three-roll or rotary mixer.

<Physical properties of magnetic paste>
FIG. 2 is a cross-sectional view schematically illustrating an example of a cross section of the magnetic layer 120 formed on the substrate 110. As shown in FIG. 2, when a magnetic paste (not shown) is printed on the substrate 110 and cured to form the magnetic layer 120, a part of the resin exudes from the edge 120 </ b> E of the magnetic layer 120. The protrusion 130 may be formed. When the above-mentioned magnetic paste is used, the exudation of the resin can be suppressed. Therefore, the flow distance L of the exuded resin can be shortened. For example, a cured product obtained by thermally curing a magnetic paste (for example, a cured product obtained by thermally curing at 150 ° C. for 60 minutes) exhibits a property that the resin exudation after screen printing is suppressed. Specifically, the magnetic paste is screen-printed on a printed board, and after printing, thermally cured at 150 ° C. for 60 minutes to obtain an evaluation board. The maximum distance among the flow distances of the resin exuding from the printed pattern edge of the evaluation board is preferably 500 μm or less, more preferably 480 μm or less, and further preferably 450 μm or less. The lower limit may be 0.001 μm or more. Since a cured product having such a high relative magnetic permeability can be obtained, the above-mentioned magnetic paste can be used as a magnetic paste for forming an inductor element.

The magnetic paste may contain a solvent, but preferably contains no solvent and is a paste at an appropriate temperature. The viscosity of the magnetic paste is, specifically, from the viewpoint of printability, at 25 ° C., usually at least 20 Pa · s, preferably at least 30 Pa · s, more preferably at least 50 Pa · s, even more preferably at least 60 Pa · s, particularly It is preferably at least 70 Pa · s, and is usually at most 200 Pa · s, preferably at most 190 Pa · s, more preferably at most 180 Pa · s, from the viewpoint of printability and the ease with which bubbles can be removed during printing. The viscosity can be measured using an E-type viscometer while maintaining the temperature of the magnetic paste at 25 ± 2 ° C.

(4) A cured product obtained by thermally curing a magnetic paste (for example, a cured product obtained by thermally curing at 180 ° C. for 90 minutes) generally has a characteristic of high relative permeability at a frequency of 100 MHz. For example, a sheet-like magnetic paste is thermally cured at 180 ° C. for 90 minutes to obtain a sheet-like cured product. The relative permeability of the cured product at a frequency of 100 MHz is preferably 3 or more, more preferably 4 or more, and still more preferably 5 or more. In addition, the upper limit can be usually 20 or less.

(4) A cured product obtained by thermally curing a magnetic paste (for example, a cured product obtained by thermally curing at 180 ° C. for 90 minutes) generally has a characteristic of low magnetic loss at a frequency of 100 MHz. For example, a sheet-like magnetic paste is thermally cured at 180 ° C. for 90 minutes to obtain a sheet-like cured product. The magnetic loss of this cured product at a frequency of 100 MHz is preferably 0.5 or less, more preferably 0.4 or less, and even more preferably 0.3 or less. In addition, the lower limit can be usually 0.001 or more.

[Inductor element]
The inductor element of the present invention includes a magnetic layer that is a cured product of the magnetic paste of the present invention. Here, the inductor element includes not only an inductor element as an electronic component but also an inductor element included in a circuit board. FIG. 1 is a schematic plan view of an inductor element according to one embodiment of the present invention. The inductor element 1 includes a substrate 11, a magnetic layer 12, and a wiring 13 formed of a conductor. The wiring 13 is covered with the magnetic layer 12, and the wiring 13 is formed in a spiral shape around a core portion 14. Have been. Further, the magnetic layer 12 is embedded in the core portion 14.

The magnetic layer 12 is a cured product of the magnetic paste of the present invention. Since the magnetic layer 12 is a cured product of a magnetic paste, the magnetic layer 12 is suppressed from exuding resin. Thus, the distance between the wirings 13 can be reduced. Hereinafter, the inductor element and its manufacturing method will be described through the method for manufacturing the inductor element.

The manufacturing method of the inductor element
(1) printing a magnetic paste on a substrate, thermally curing the magnetic paste, and forming a first magnetic layer;
(2) forming a wiring on the first magnetic layer;
(3) printing a magnetic paste on the first magnetic layer, the core portion, and the wiring, thermally curing the magnetic paste, and forming a second magnetic layer;
including. Here, the magnetic layer 12 includes the first and second magnetic layers.

<Step (1)>
In the step (1), a magnetic paste is printed on a substrate, and the magnetic paste is thermally cured to form a first magnetic layer. In performing the step (1), a step of preparing a magnetic paste may be included. The magnetic paste is as described above.

The substrate is usually an insulating substrate. Examples of the material of the substrate include an insulating substrate such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate. The substrate may be an inner-layer circuit board in which wiring and the like are formed within its thickness.

As the substrate, for example, a wiring board which is a conductor layer formed by etching a copper layer using “R1515E” manufactured by Panasonic Corporation, which is a glass cloth base epoxy resin double-sided copper-clad laminate.

The magnetic paste is applied on the substrate by printing on the entire surface or by pattern printing. As a printing method, screen printing is usually performed, but other printing methods may be adopted. After application, the composition is thermally cured to obtain a first magnetic layer.

The thermosetting conditions of the magnetic paste vary depending on the composition and type of the magnetic paste, but the curing temperature is preferably 120 ° C or higher, more preferably 130 ° C or higher, even more preferably 150 ° C or higher, preferably 240 ° C or lower, The temperature is more preferably 220 ° C or lower, and further preferably 200 ° C or lower. The hardening time of the magnetic paste is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 15 minutes or more, preferably 120 minutes or less, more preferably 100 minutes or less, and even more preferably 90 minutes or less. .

前 Before heat-curing the magnetic paste, the magnetic paste may be subjected to a preliminary heat treatment of heating at a temperature lower than the curing temperature. The temperature of the preheating treatment is preferably 50 ° C. or higher, preferably 60 ° C., more preferably 70 ° C. or higher, preferably less than 120 ° C., preferably 110 ° C. or lower, more preferably 100 ° C. or lower. The time of the preheating treatment is usually preferably 5 minutes or more, more preferably 15 minutes or more, preferably 150 minutes or less, more preferably 120 minutes or less.

<Step (2)>
In step (2), a wiring is formed on the first magnetic layer formed in step (1). Examples of the method for forming the wiring include a plating method, a sputtering method, and a vapor deposition method. Among them, the plating method is preferable. In a preferred embodiment, the surface of the first magnetic layer is plated by a suitable method such as a semi-additive method or a full-additive method to form a wiring having a spiral wiring pattern.

Examples of the wiring material include single metals such as gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium; gold, platinum, palladium, silver, Examples include alloys of two or more metals selected from the group consisting of copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. Among them, from the viewpoints of versatility, cost, ease of patterning, and the like, chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy may be used. Preferably, chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy is more preferably used, and copper is more preferably used.

Here, an example of an embodiment in which a wiring is formed on the first magnetic layer will be described in detail. A plating seed layer is formed on the surface of the first magnetic layer by electroless plating. Next, an electrolytic plating layer is formed on the formed plating seed layer by electrolytic plating, and if necessary, unnecessary plating seed layers are removed by a process such as etching to form a wiring having a desired wiring pattern. it can. After forming the wiring, an annealing treatment may be performed as necessary for the purpose of improving the peel strength of the wiring. The annealing treatment can be performed, for example, by heating the substrate at 150 to 200 ° C. for 20 to 90 minutes.

After forming the wiring, a mask pattern for exposing a part of the plating seed layer is formed on the formed plating seed layer corresponding to the spiral pattern. In this case, after the electrolytic plating layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, the unnecessary plating seed layer is removed by a process such as etching to form a wiring having a desired pattern.

The thickness of the wiring is preferably 70 μm or less, more preferably 60 μm or less, further preferably 50 μm or less, still more preferably 40 μm or less, particularly preferably 30 μm or less, 20 μm or less, and 15 μm from the viewpoint of thinning. Or 10 μm or less. The lower limit is preferably at least 1 μm, more preferably at least 3 μm, even more preferably at least 5 μm.

<Step (3)>
In the step (3), a magnetic paste is printed on the first magnetic layer, the core, and the wiring, and the magnetic paste is cured by heat to form a second magnetic layer. The method for forming the second magnetic layer is the same as that for the first magnetic layer. The magnetic paste forming the first magnetic layer and the magnetic paste forming the second magnetic layer may be the same or different.

(4) After the step (1), a step of forming an insulating layer on the first magnetic layer may be provided. After the step (2), a step of forming an insulating layer on the wiring may be provided. The insulating layer may be formed in the same manner as the insulating layer of the printed wiring board, or may be made of the same material as the insulating layer of the printed wiring board.

[Circuit board]
The circuit board includes the inductor element of the present invention. The circuit board can be used as a wiring board on which electronic components such as semiconductor chips are mounted, and can also be used as a (multi-layer) printed wiring board using such a wiring board as an inner layer board. Further, such a wiring board can be used as a chip inductor component which is divided into individual pieces, and can also be used as a printed wiring board on which the chip inductor component is surface-mounted.

半導体 Further, various types of semiconductor devices can be manufactured using the wiring board. The semiconductor device including such a wiring board can be suitably used for electric products (for example, computers, mobile phones, digital cameras, televisions, and the like) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircrafts). .

Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. In the following description, “parts” and “%” representing amounts mean “parts by mass” and “% by mass”, respectively, unless otherwise specified.

<Example 1>
Epoxy resin (“ZX-1059”, mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) 10 parts by mass, epoxy resin (“ED-523T”, low viscosity epoxy resin, ADEKA Corporation) 5 parts, dispersant (“RS-710”, polymer anionic dispersant, manufactured by Toho Chemical Co., Ltd.) 1 part by mass, curing accelerator (“2P4MZ”, imidazole-based curing accelerator, manufactured by Shikoku Chemicals) 1 Parts by mass, 100 parts by mass of magnetic powder (“M05S”, Fe—Mn-based ferrite, average particle size 3 μm, manufactured by Powdertech), organized smectite (“Smecton STN”, trioctylmethylammonium-treated hectorite, Kunimine Industries) 2 parts by mass) and uniformly dispersed with a three-roll mill to prepare a magnetic paste.

<Example 2>
In Example 1, the amount of the organized smectite ("Smecton STN", hectorite treated with trioctylmethylammonium, manufactured by Kunimine Industries) was changed from 2 parts by mass to 1.5 parts by mass. A magnetic paste was prepared in the same manner as in Example 1 except for the above.

<Example 3>
In Example 1, the amount of the organized smectite ("Smecton STN", hectorite treated with trioctylmethylammonium, manufactured by Kunimine Industries) was changed from 2 parts by mass to 1 part by mass. A magnetic paste was prepared in the same manner as in Example 1 except for the above.

<Example 4>
In Example 1, 100 parts by mass of a magnetic powder (“M05S”, Fe—Mn-based ferrite, average particle diameter 3 μm, manufactured by Powder Tech) was mixed with a magnetic powder (“AW2-08PF3F”, Fe—Cr—Si-based). Alloy (amorphous), average particle size 3.0 μm, manufactured by Epson Atmix Co.) (100 parts by mass). A magnetic paste was prepared in the same manner as in Example 1 except for the above.

<Example 5>
In Example 1, 2 parts by mass of an organized smectite ("Smecton STN", a hectorite treated with trioctylmethylammonium, manufactured by Kunimine Industries Co., Ltd.) was added to 2 parts by mass of an organized smectite ("Smecton SAN", a hectorite treated with dimethyldistearylammonium, kunimine). (Manufactured by Kogyo Co., Ltd.). A magnetic paste was prepared in the same manner as in Example 1 except for the above.

<Example 6>
In Example 1, 2 parts by mass of organic smectite (“Smecton STN”, trioctylmethylammonium-treated hectorite, manufactured by Kunimine Industries Co., Ltd.) was treated with organically treated montmorillonite (“Orben M”, dimethyldioctadecyl ammonium-treated montmorillonite, Shiraishi Kogyo). 2 parts by mass. A magnetic paste was prepared in the same manner as in Example 1 except for the above.

<Comparative Example 1>
In Example 1, 2 parts by mass of organic smectite ("Smecton STN", a hectorite treated with trioctylmethylammonium, manufactured by Kunimine Industries) was not used. A magnetic paste was prepared in the same manner as in Example 1 except for the above.

<Comparative Example 2>
In Example 1, 2 parts by mass of organic smectite (“Smecton STN”, trioctylmethylammonium-treated hectorite, manufactured by Kunimine Industries Co., Ltd.) was mixed with unorganized smectite (“Smecton SWN”, hectorite, Kunimine Industries Co., Ltd.). 1 part by mass. A magnetic paste was prepared in the same manner as in Example 1 except for the above.

<Comparative Example 3>
In Example 1, 2 parts by mass of organized smectite ("Smecton STN", trioctylmethylammonium-treated hectorite, manufactured by Kunimine Industries) was added to 1 part by mass of hydrophobic fumed silica (AEROSIL RY200, manufactured by Nippon Aerosil Co., Ltd.). changed. A magnetic paste was prepared in the same manner as in Example 1 except for the above.

<Measurement of viscosity of magnetic paste>
The temperature of the magnetic paste of each Example and each Comparative Example was kept at 25 ± 2 ° C., and an E-type viscometer (“RE-80U” manufactured by Toki Sangyo Co., Ltd., 3 ° × R9.7 cone, rotation speed was 5 rpm) was used. And the viscosity was measured. The measured viscosity was evaluated based on the following criteria from the viewpoint of printability and ease of air bubble removal.
○: 20 Pa · s or more and less than 200 Pa · s ×: less than 20 Pa · s or 200 Pa · s or more

<Measurement of resin exudation after screen printing>
(1) Production of Print Evaluation Board As a print board, both sides of a glass cloth base epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, board thickness 0.8 mm, R5715E manufactured by Matsushita Electric Works, Ltd.) are micro-etched ( A copper surface roughened by etching at 1 μm using CZ8100 manufactured by Mec Corporation was prepared. As a printing member, a metal mask (plate material SUS304, opening method laser, no surface treatment, mask thickness 40 μm, opening pattern 1 mm × 3 mm rectangle, manufactured by Process Lab Micron) was prepared, and a metal squeegee (plate material SUS304, squeegee) was prepared. 0.25 mm in thickness, no surface treatment, manufactured by Taku Giken Co., Ltd.).

For printing, the printed substrate and the printing member are closely adhered and fixed, and a metal squeegee is swept at an angle of 45 deg, a speed of 10 mm / sec, and a linear pressure of 6.5 N / cm over the magnetic paste produced in each of the examples and comparative examples. I went in. After printing, the printing member was removed, and the magnetic paste was cured under the curing conditions of 150 ° C. for 60 minutes to produce a print evaluation substrate.

(2) Evaluation of resin exudation property (resin exudation amount) The edge of a 1 mm × 3 mm rectangular print pattern of the produced print evaluation board was photographed using a digital microscope (VHX-900, manufactured by KEYENCE CORPORATION). Then, the resin exuding from the printing evaluation substrate was observed. Among the flow distances of the resin exuded from the edge of the print pattern, the maximum distance was measured as the resin exudation property (resin exudation amount). The resin exudation was evaluated according to the following criteria.
：: Resin exudation amount is less than 500 μm ×: Resin exudation amount is 500 μm or more

<Measurement of relative permeability and magnetic loss>
As a support, a polyethylene terephthalate (PET) film ("PET501010" manufactured by Lintec Corporation, thickness: 50 µm) treated with a silicone-based release agent was prepared. The magnetic paste prepared in each example and each comparative example was uniformly applied on a release surface of the PET film by a doctor blade so that the thickness of the dried paste layer was 100 μm, to obtain a resin sheet. . The resulting resin sheet was heated at 180 ° C. for 90 minutes to thermally cure the magnetic paste layer, and the support was peeled off to obtain a sheet-like cured product. The obtained cured product was cut into a test piece having a width of 5 mm and a length of 18 mm to obtain an evaluation sample. Using a 3-turn coil method at a measurement frequency of 100 MHz, the relative permeability (μ ′) and the magnetic loss (μ) were measured at room temperature 23 ° C. using Agilent Technologies (“HP8362B” manufactured by Agilent Technologies). '') Was measured.

Table 1 shows the results of Examples 1 to 6 and Comparative Examples 1 to 3. From Examples 1 to 6, it was found that the magnetic paste containing the organic smectite of the present invention greatly improved the resin exudation property. On the other hand, Comparative Example 1 contained no organic smectite, and large resin seepage was observed. Moreover, as can be seen from Comparative Example 2, when smectite that was not organized was used, the resin exudation property was not improved. Further, in Comparative Example 3, although hydrophobic fumed silica, which is widely used as a thixotropic agent, was added, the resin exudation property was not improved, and the viscosity was increased, and from the viewpoint of printability and air bubble removal, It has fallen out of the preferred range.

DESCRIPTION OF SYMBOLS 1 Inductor element 11 Substrate 12 Magnetic layer 13 Wiring layer 14 Core part 110 Substrate 120 Magnetic layer 120E Edge of magnetic layer 130 Seepage part L Flow distance

Claims (12)

1. (A) magnetic powder,
   A magnetic paste comprising (B) an organically modified layered silicate mineral, and (C) a binder resin.
2. The magnetic paste according to claim 1, wherein the component (B) contains organic smectite.
3. The magnetic paste according to claim 2, wherein the component (B) includes smectite ion-exchanged with a quaternary ammonium ion.
4. 磁性 The magnetic paste according to any one of claims 1 to 3, wherein the component (B) is at least one selected from organized hectorite and organized montmorillonite.
5. The magnetic paste according to claim 4, wherein the component (B) is at least one selected from hectorite ion-exchanged with quaternary ammonium ions and montmorillonite ion-exchanged with quaternary ammonium ions.
6. 6. The magnetic paste according to claim 1, wherein the component (C) contains a thermosetting resin.
7. The magnetic paste according to any one of claims 1 to 6, wherein the component (C) contains an epoxy resin.
8. The magnetic paste according to any one of claims 1 to 7, wherein the component (A) is at least one selected from iron oxide powder and iron alloy-based metal powder.
9. The content of the component (B) when the nonvolatile component in the magnetic paste was 100% by mass was B1, and the content of the component (C) when the nonvolatile component in the magnetic paste was 100% by mass was C1. The magnetic paste according to any one of claims 1 to 8, wherein C1 / B1 is 1 or more and 30 or less.
10. 10. The magnetic paste according to claim 1, which is for forming an inductor element.
11. An inductor element comprising a magnetic layer which is a cured product of the magnetic paste according to any one of claims 1 to 10.
12. A circuit board comprising the inductor element according to claim 11.

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