JP2000100629A - Inductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an inductor with excellent high frequency characteristics, high Q, low dielectric characteristics, heat-resistance to a high temperature reflow furnace, high self-resonance frequencies, and low resistance. SOLUTION: This inductor is provided with a core 1, conductor wire materials 2 wound around this core 1, and case 5 in which the core 1 around which the conductor wire materials 2 are wound is arranged. The core 1 is formed of heat-resistant low dielectric high polymer materials being a resin composition made of one kind or two kinds or more of resin whose weight average absolute molecular weight is 1000 or more, and the sum of the number of carbon atoms and hydrogen atoms of the composition is 99% or more, and one part or whole part of the resin molecules are mutually provided with chemical connection. The case 5 is formed of an inductor whose relative permittivity is 3.0 or less and whose resolution temperature is 290 deg.C or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type chip inductor used for a mobile communication device such as a portable telephone, and more particularly, to a chip inductor using a novel low dielectric polymer material. .

[0002]

2. Description of the Related Art In recent years, with the rapid increase in the amount of communication information, there has been a strong demand for smaller, lighter, and faster communication devices, and electronic devices capable of responding to such demands. In particular, the frequency band of radio waves used for portable mobile communications such as automobile telephones and digital portable telephones, and satellite communications has a high frequency band of mega to giga band. With the rapid development of communication devices used as these communication means, small-sized, high-density mounting of housings, substrates, and electronic elements has been attempted. In order to reduce the size and weight of a communication device compatible with a high frequency range such as the megahertz to gigahertz band, it is necessary to develop an inductor having both high Q and low dielectric characteristics.

FIG. 9 shows a configuration example of a conventional chip inductor. The inductor 21 in the illustrated example has a conductor 23 formed in a coil shape in a dielectric ceramic 22, and has terminals 24 connected to the conductor 23 at both ends. This inductor can be obtained by alternately laminating and printing low-temperature sintered ceramic sheets and conductor paste. The relative dielectric constant of such a multilayer inductor is about 4 to 5. Multilayer inductors are very small,
It is widely used because it has a relatively large inductance value and is excellent in mass productivity.

However, since the Q value is low and the self-resonance frequency is low, it is not suitable as an inductor in a wireless device having a high operating frequency such as a portable telephone. This is because the conductor is formed by the sintering method, the conductivity is lower than that of bulk metal, and the dielectric constant of the dielectric supporting the conductor is large, so the stray capacitance between the windings is large. It is caused by that.

FIG. 10 shows another configuration example of a conventional chip inductor. In the illustrated example, the winding 2 is applied to a core 1 made of dielectric ceramics such as alumina or ferrite or the like, and molded with a resin 5 such as a liquid crystal polymer. It is difficult to make the winding 2 so-called space-wound, so that it is difficult to increase the self-resonant frequency (SRF). In FIG. 10, the core 1 has a contact open metal foil 6.
Thereby, it is supported in the case 5 and an external electric circuit can be connected.

The present inventors have disclosed in Japanese Patent Laid-Open No. 10-189344.
In Japanese Unexamined Patent Publication (Kokai) No. 8-345241, good characteristics could be obtained by forming a coil of an edgewise type metal conductor in a resin dielectric. However, 1
With small coils such as 608 type and 1005 type, it is difficult to secure the winding diameter of the coil. Further, it is difficult to change the shape of the die for forming the edgewise type coil by changing the setting, which is not suitable for multi-product production.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide high-frequency characteristics, high Q, low dielectric properties, heat resistance enough to withstand high-temperature reflow furnaces, and a high self-resonant frequency. And to realize a low-resistance inductor.

[0008]

Conventionally, many resins, including glass epoxy resins, have been developed as casting resins for high-frequency components. However, these resins have a dielectric loss tangent (tan δ) at a high frequency of 0.03 to 0.0
5, which was below 0.001 of ceramics.

However, in recent years, the present applicant has filed Japanese Patent Application No. 8-4.
No. 2073, and a heat-resistant low-dielectric polymer material disclosed in Japanese Patent Application No. 9-246052 are developed.
Attempts to use it as a core material have been made by the present inventors, and have reached the present invention.

That is, the fumarate resin has a relative dielectric constant (εr) of 1 to 3 and a dielectric loss tangent (tan δ) of 0.002 or less, and has excellent castability and can be cast at room temperature. It is most suitable as a case material (mold material) of a wire wound type inductor with a wire wound. Therefore, an inductor having a low conductor resistance and a high Q can be obtained as compared with the metal paste used for the ceramic sintered body inductor. Furthermore, since the fumarate resin that covers the core and the formed coil has a low dielectric constant, and has good workability of the core material, a groove necessary for performing so-called space winding can be easily formed. Spacing can be provided and the self-resonant frequency can be higher than conventional ones.

Further, since the fumarate resin and the low dielectric polymer material have good heat resistance, they can be used in a high temperature solder reflow furnace. In particular, since lead will be removed from the solder material in the future, there is a great merit that it can cope with lead-free solder reflow having a high melting temperature. Furthermore, since the temperature of the reflow furnace is equal to or higher than the annealing temperature of metallic copper, copper hardened by stress due to mechanical processing during forming becomes copper by heating in the reflow furnace (copperization temperature: 2).
10 ° C.), the effect of lowering the conductor resistance and further increasing the Q value can be expected. This is a characteristic when a bulk metal is used for the conductor, and such an effect cannot be expected in a chip inductor made of sintered copper.

In addition, according to the resin molding, almost no phenomena such as distortion or peeling of the element body, which are often observed in ceramic sintered elements or the like, occur.

That is, the above-mentioned object is achieved by the following constitutions. (1) A core, a conductor wire wound around the core, and a case having the core wound inside the conductor wire therein, wherein the core has a weight average absolute molecular weight of 100
A low-dielectric polymer material which is one or more resin compositions of 0 or more resins, wherein the sum of the number of carbon atoms and hydrogen atoms in the composition is 99% or more, and Part or all of the molecules have a chemical bond with each other, and the case is a dielectric polymer material having a relative dielectric constant of 3.0 or less and a decomposition temperature of 290 ° C. or more. (2) The inductor according to (1), wherein the low-dielectric polymer material has one or more chemical bonds selected from cross-linking, block polymerization, and graft polymerization. (3) In the composition resin of the low dielectric polymer material, a nonpolar α-olefin polymer segment and / or a nonpolar conjugated diene polymer segment and a vinyl aromatic polymer segment are chemically bonded. A copolymer,
The inductor according to the above (1) or (2), which is a thermoplastic resin having a multiphase structure in which a dispersed phase formed by one segment is finely dispersed in a continuous phase formed by the other segment. (4) The inductor according to (3), wherein the low dielectric polymer material is a copolymer in which a nonpolar α-olefin polymer segment and a vinyl aromatic polymer segment are chemically bonded. (5) The inductor according to the above (3) or (4), wherein in the low dielectric polymer material, the vinyl aromatic polymer segment is a vinyl aromatic copolymer segment containing a divinylbenzene monomer. (6) The inductor according to the above (4) or (5), wherein the low dielectric polymer material is a copolymer chemically bonded by graft polymerization. (7) The inductor according to any one of (1) to (6), wherein the low dielectric polymer material further comprises a non-polar α-olefin polymer containing a monomer of 4-methylpentene-1. (8) The inductor according to any one of (1) to (7), wherein the dielectric polymer material is obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer. (9) The inductor according to the above (8), wherein the fumaric diester is represented by the following formula (I).

[0014]

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[In the formula (I), R ¹ represents an alkyl group or a cycloalkyl group, R ² represents an alkyl group, a cycloalkyl group or an aryl group, and R ¹ and R ²
May be the same or different. (10) The above (8) or (9), wherein the monomer composition further contains a vinyl monomer represented by the following formula (II):
Inductor.

[0016]

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[In the formula (II), X represents a hydrogen atom or a methyl group, and Y represents a fluorine atom, a chlorine atom, an alkyl group, an alkenyl group, an aryl group, an ether group, an acyl group or an ester group. (11) The inductor according to any one of (1) to (10), wherein the core has a groove for space winding. (12) The inductor according to any one of (1) to (11), wherein the conductor wire is made of a metal conductive material having copper as a main component and a diameter of 0.03 to 0.2 mm.

[0018]

DETAILED DESCRIPTION OF THE INVENTION An inductor according to the present invention comprises a core,
A conductive wire wound around the core; and a case having a core wound with the conductive wire therein, wherein the core is made of a resin having a weight average absolute molecular weight of 1,000 or more.
A low-dielectric polymer material of one or more resin compositions, wherein the sum of the number of carbon atoms and hydrogen atoms in the composition is 99% or more, and a part or All have a chemical bond with each other, and the case is a dielectric polymer material having a relative dielectric constant of 3.0 or less and a decomposition temperature of 290 ° C. or more.

By arranging a coil formed by winding a conductor material around a core made of a low dielectric polymer material in a case of a dielectric polymer material, excellent high frequency characteristics, high Q, and low dielectric characteristics are obtained. It has a heat resistance enough to withstand a high-temperature reflow furnace, a high self-resonance frequency, and a low-resistance inductor. In addition, it can be manufactured by a conventional process, and does not require new capital investment. Furthermore, since the core has good workability and moldability, it is possible to extremely easily perform space winding by forming a groove or the like in the core, and to significantly improve the self-resonant frequency.

The low dielectric polymer material used in the inductor of the present invention is a resin composition comprising one or more resins having a weight average absolute molecular weight of 1,000 or more,
The sum of the number of carbon atoms and hydrogen atoms is 99% or more, and some or all of the resin molecules are chemically bonded to each other. By using a resin composition having such a weight average absolute molecular weight, the strength, adhesion to metal, and heat resistance when used as a low dielectric polymer material are sufficient. In contrast, the weight average absolute molecular weight is 100
If it is smaller than 0, the mechanical properties, heat resistance and the like become insufficient, which is not suitable. Particularly preferably, it is 3000 or more, most preferably 5000 or more. The upper limit of the weight average absolute molecular weight at this time is not particularly limited, but is usually about 10,000,000.

The reason why the sum of carbon, hydrogen and the number of atoms in the above resin composition is 99% or more is to make the existing chemical bond a non-polar bond, thereby making it possible to use a low dielectric polymer material. Electrical characteristics when used as On the other hand, when the sum of the number of atoms of carbon and hydrogen is less than 99%, particularly when the number of atoms forming a polar molecule such as an oxygen atom or a nitrogen atom is contained more than 1%, the electric characteristics, particularly It is not suitable because the dielectric loss tangent becomes high.

Specific examples of the resin constituting the polymer material include low-density polyethylene, ultra-low-density polyethylene,
Ultra low density polyethylene, high density polyethylene, low molecular weight polyethylene, ultra high molecular weight polyethylene, ethylene
Non-polar α-olefin homo- or copolymers (hereinafter also referred to as (co) polymers) such as propylene copolymer, polypropylene, polybutene, and poly-4-methylpentene, butadiene, isoprene, pentadiene, hexadiene, heptadiene, octadiene Phenylbutadiene, (co) polymers of each monomer of conjugated diene such as diphenylbutadiene, styrene, nucleus-substituted styrene, for example, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, chlorostyrene, α-substituted styrene, for example (co) polymers of each monomer of carbon ring-containing vinyl such as α-methylstyrene, α-ethylstyrene, divinylbenzene, vinylcyclohexane and the like.

In the above description, polymers of non-polar α-olefin monomers, conjugated diene monomers, and carbon ring-containing vinyl monomers are mainly exemplified.
Olefin monomer and conjugated diene monomer, non-polar α-
Copolymers obtained from monomers of different compound types, such as an olefin monomer and a carbon ring-containing vinyl monomer, may be used.

As described above, a resin composition is composed of one or more of these polymers, that is, resins, and some or all of these resin molecules are chemically bonded to each other. There must be. Therefore, some may be in a mixed state. By having a chemical bond at least in part as described above, the strength, adhesion to metal, and heat resistance when used as a low dielectric polymer material are sufficient. On the other hand, when it is a mere mixture and has no chemical bond, it is insufficient from the viewpoint of heat resistance and mechanical properties.

The form of the chemical bond in the present invention is not particularly limited, and examples thereof include a crosslinked structure, a block structure, and a graft structure. A known method may be used to generate such a chemical bond. Preferred embodiments of the graft structure and the block structure will be described later. As a specific method for generating a crosslinked structure, thermal crosslinking is preferable,
The temperature at this time is preferably about 50 to 300 ° C. Other examples include cross-linking by electron beam irradiation.

The presence or absence of a chemical bond according to the present invention depends on the degree of crosslinking,
In the case of the graft structure, it can be confirmed by obtaining the graft efficiency and the like. It can also be confirmed by a transmission electron microscope (TEM) photograph or a scanning electron microscope (SEM) photograph. Generally, one polymer segment has the other polymer segment dispersed as fine particles of about 10 μm or less, more specifically 0.01 to 10 μm. On the other hand, in a mere mixture (blend polymer), compatibility between both polymers such as a graft copolymer is not observed, and the particle size of the dispersed particles becomes large.

The resin composition according to the present invention is a copolymer in which a non-polar α-olefin polymer segment and a vinyl aromatic copolymer segment are chemically bonded. A preferred example is a thermoplastic resin having a multiphase structure in which the formed dispersed phase is finely dispersed in the continuous phase formed from the other segment.

The non-polar α-olefin polymer which is one of the segments in the thermoplastic resin having the specific multiphase structure as described above is a non-polar α-olefin polymer obtained by high-pressure radical polymerization, medium-low pressure ionic polymerization or the like. It must be a homopolymer of an α-olefin monomer or a copolymer of two or more non-polar α-olefin monomers. Copolymers with polar vinyl monomers are unsuitable because of their high dielectric loss tangent. As the non-polar α-olefin monomer of the polymer, ethylene, propylene, butene-1, hexene-1, octene-1, 4-
Methylpentene-1s, among which ethylene,
Propylene, butene-1, 4-methylpentene-1
It is preferable because the dielectric constant of the obtained non-polar α-olefin polymer is low.

Specific examples of the non-polar α-olefin (co) polymer include low-density polyethylene, ultra-low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, low-molecular-weight polyethylene, ultra-high-molecular-weight polyethylene,
Ethylene-propylene copolymer, polypropylene, polybutene, poly-4-methylpentene and the like can be mentioned. These non-polar α-olefin (co) polymers can be used alone or in combination of two or more.

The preferred molecular weight of such a nonpolar α-olefin (co) polymer is 1000 in terms of weight average absolute molecular weight.
That is all. There is no particular upper limit, but 1000
It is about ten thousand.

On the other hand, the vinyl aromatic polymer which is one of the segments in the thermoplastic resin exhibiting a specific multi-phase structure is a non-polar polymer.
Nuclear-substituted styrene such as methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, chlorostyrene, α-substituted styrene such as α-methylstyrene, α-ethylstyrene, o-, m-, p-divinylbenzene (preferably m-styrene) -, P-divinylbenzene, particularly preferably p-divinylbenzene). Such non-polarity is achieved by introducing a monomer having a polar functional group by copolymerization.
This is because the dielectric loss tangent becomes high and is not suitable. The vinyl aromatic polymers can be used alone or in combination of two or more.

Among the vinyl aromatic copolymers, a vinyl aromatic copolymer containing a divinylbenzene monomer is preferred from the viewpoint of improving heat resistance. The vinyl aromatic copolymer containing divinylbenzene is, specifically, styrene,
Copolymers of each monomer such as a nuclear-substituted styrene such as methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, chlorostyrene and α-substituted styrene such as α-methylstyrene and α-ethylstyrene, and a monomer of divinylbenzene It is a polymer.

The ratio between the divinylbenzene monomer and the other vinyl aromatic monomer as described above is not particularly limited. However, in order to satisfy the solder heat resistance, the divinylbenzene monomer is used. Is preferably 1% by weight or more. The divinylbenzene monomer may be 100% by weight, but the upper limit is preferably 90% by weight in view of synthesis.

The molecular weight of the vinyl aromatic polymer as one of the segments is 10% by weight average absolute molecular weight.
It is preferably at least 00. The upper limit is not particularly limited, but is about 10 million.

The thermoplastic resin having a specific multiphase structure of the present invention has an olefin polymer segment of 5 to 95% by weight, preferably 40 to 90% by weight, most preferably 50% by weight.
~ 80% by weight. Accordingly, the content of the vinyl polymer segment is 95 to 5% by weight, preferably 60 to 50% by weight.
10 to 10% by weight, most preferably 50 to 20% by weight.

When the number of the olefin-based polymer segments is reduced, the molded product becomes brittle, which is not preferable. Further, when the number of the olefin-based polymer segments increases, the adhesion to the metal is low, which is not preferable.

The thermoplastic resin has a weight average absolute molecular weight of 1,000 or more. The upper limit is not particularly limited, but is about 10,000,000 from the viewpoint of moldability.

Specific examples of the copolymer having a structure in which the olefin polymer segment and the vinyl polymer segment are chemically bonded include a block copolymer and a graft copolymer. Above all, a graft copolymer is particularly preferred because of ease of production. These copolymers may include an olefin-based polymer or a vinyl-based polymer without departing from the characteristics of the block copolymer, the graft copolymer, and the like.

The method for producing the thermoplastic resin having a specific multi-phase structure of the present invention may be any of the methods generally known as grafting methods, such as chain transfer method and ionizing radiation irradiation method. Most preferred is the method described below. This is because the grafting efficiency is high and secondary aggregation due to heat does not occur, so that the expression of performance is more effective and the production method is simple.

Hereinafter, the method for producing a graft copolymer which is a thermoplastic resin having a specific multiphase structure of the present invention will be specifically described in detail. That is, 100 parts by weight of an olefin-based polymer are suspended in water, and the vinyl aromatic-based monomer 5 to 40 is separately added.
One part or a mixture of two or more kinds of radically polymerizable organic peroxides represented by the following general formula (1) or (2) is added to 0.1 part by weight with respect to 100 parts by weight of the vinyl monomer. ~
10 parts by weight and a radical polymerization initiator having a decomposition temperature of 40 to 90 ° C. for obtaining a half-life of 10 hours are added in an amount of 0 to a total of 100 parts by weight of the vinyl monomer and the radically polymerizable organic peroxide. And a solution prepared by dissolving the vinyl monomer, the radically polymerizable organic peroxide and the radical polymerization initiator under conditions that do not substantially decompose the radical polymerization initiator. The olefin polymer is impregnated, the temperature of the aqueous suspension is increased, and the vinyl monomer and the radical polymerizable organic peroxide are copolymerized in the olefin copolymer to form the graft precursor. obtain.

Next, the grafting precursor was added in an amount of 100 to 300.
The graft copolymer of the present invention can be obtained by kneading while melting at a temperature of ° C. At this time, the graft copolymer can be obtained by separately mixing an olefin polymer or a vinyl polymer with the grafting precursor and kneading the mixture under melting. Most preferred is a graft copolymer obtained by kneading a grafting precursor.

[0042]

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In the general formula (1), R ₁ represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ₂ represents a hydrogen atom or a methyl group, and R ₃ and R ₄ each represent 1 to 4 carbon atoms.
R ₅ represents an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkyl-substituted phenyl group, or a cycloalkyl group having 3 to 12 carbon atoms. m ₁ is 1 or 2
It is.

[0044]

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In the general formula (2), R ₆ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₇ represents a hydrogen atom or a methyl group, and R ₈ and R ₉ each represent 1 to 4 carbon atoms.
R ₁₀ represents an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkyl-substituted phenyl group, or a cycloalkyl group having 3 to 12 carbon atoms. m ₂ is 0, 1 or 2.

Specific examples of the radical polymerizable organic peroxide represented by the general formula (1) include t-butylperoxyacryloyloxyethyl carbonate; t-amylperoxyacryloyloxyethyl carbonate. T-hexylperoxyacryloyloxyethyl carbonate;
1,1,3,3-tetramethylbutyl peroxyacryloyloxyethyl carbonate; cumyl peroxyacryloyloxyethyl carbonate; p-isopropylcumylperoxyacryloyloxyethyl carbonate ;
t-butylperoxymethacryloyloxyethyl carbonate; t-amylperoxymethacryloyloxyethyl carbonate; t-hexylperoxymethacryloyloxyethyl carbonate; 1,1,3,3-carbonate Tetramethylbutyl peroxymethacryloyloxyethyl carbonate; cumyl peroxymethacryloyloxyethyl carbonate; p-isopropylcumylperoxymethacryloyloxyethyl carbonate; t-butylperoxymethacryloyloxyethyl carbonate Ethyl carbonate-bonate; t-
Amyl peroxyacryloyloxyethoxyethyl car
Carbonate; t-hexylperoxyacryloyloxyethoxyethyl carbonate; 1,1,3,3-tetramethylbutylperoxyacryloyloxyethoxyethyl carbonate; cumylperoxyacryloyloxyethoxyethyl Carbonate; p-isopropylcumylperoxyacryloyloxyethoxyethyl carbonate;
t-butyl peroxymethacryloyloxyethoxyethyl carbonate; t-amylperoxymethacryloyloxyethoxyethyl carbonate; t-hexylperoxymethacryloyloxyethoxyethyl carbonate;
1,1,3,3-tetramethylbutyl peroxymethacryloyloxyethoxyethyl carbonate; cumyl peroxymethacryloyloxyethoxyethyl carbonate
P-isopropylcumylperoxymethacryloyloxyethoxyethyl carbonate; t-butylperoxyacryloyloxyisopropylcarbonate; t-amylperoxyacryloyloxyisopropylcarbonate; t-hexyl Peroxyacryloyloxyisopropyl carbonate; 1,1,3,3-tetramethylbutylperoxyacryloyloxyisopropyl carbonate; cumylperoxyacryloyloxyisopropyl carbonate; p-isopropyl alcohol Milperoxyacryloyloxyisopropyl carbonate; t-butylperoxymethacryloyloxyisopropyl carbonate
T; t-amyl peroxymethacryloyloxyisopropyl carbonate; t-hexylperoxymethacryloyloxyisopropyl carbonate; 1,1,3,3-
Examples thereof include tetramethylbutyl peroxymethacryloyloxyisopropyl carbonate; cumyl peroxymethacryloyloxyisopropyl carbonate; p-isopropylcumylperoxymethacryloyloxyisopropyl carbonate.

Further, the compound represented by the general formula (2) includes t-butylperoxyallylcarbonate;
Amyl peroxy allyl carbonate; t-hexyl peroxy allyl carbonate; 1,1,3,3-tetramethylbutyl peroxy allyl carbonate; p-menthane peroxy allyl carbonate Cumyl peroxy allyl carbonate; t-butyl peroxy methallyl carbonate; t-amyl peroxy methallyl carbonate; t-hexyl peroxy methallyl carbonate;
1,1,3,3-tetramethylbutyl peroxymethallyl carbonate; p-menthaneperoxymethallyl carbonate
Carbonate; cumyl peroxymethallyl carbonate; t
-Butyl peroxyallyloxyethyl carbonate; t
-Amyl peroxy allyloxyethyl carbonate; t
Hexyl peroxyallyloxyethyl carbonate;
t-butylperoxymetalaryloxyethylcarbonate
G; t-amyl peroxymetalaryloxyethyl carbonate
T-hexyl peroxymetalloxyethyl carbonate; t-butylperoxyallyloxyisopropyl carbonate; t-amylperoxyallyloxyisopropyl carbonate; t-hexylperoxyaryloxyisopropyl carbonate Bonnet; t-butyl peroxy metalaryloxy isopropyl carbonate; t-amyl peroxy metalaryloxy isopropyl carbonate; t-hexyl peroxy metalaryloxy isopropyl carbonate
And the like.

Among them, t-butylperoxyacryloyloxyethyl carbonate; t-butylperoxymethacryloyloxyethyl carbonate; t-butylperoxyallylcarbonate; t-butylperoxy Methallyl carbonate.

The graft efficiency of the thus obtained graft copolymer is 20 to 100% by weight. Grafting efficiency is performed by solvent extraction of ungrafted polymer,
It can be obtained from the ratio.

The thermoplastic resin having a specific multiphase structure of the present invention is preferably a graft copolymer of the above-mentioned non-polar α-olefin polymer segment and vinyl aromatic polymer segment. In such a graft copolymer, a non-polar conjugated diene-based polymer segment may be used instead of or in addition to the non-polar α-olefin-based polymer segment. As the nonpolar conjugated diene-based polymer, those described above can be used, and they may be used alone or in combination of two or more.

The non-polar α-olefin-based polymer in the above graft copolymer may contain a conjugated diene monomer, and the non-polar conjugated diene-based polymer may include α-olefin.
An olefin monomer may be contained.

In the present invention, the obtained graft copolymer can be further crosslinked using divinylbenzene or the like. Particularly, a graft copolymer containing no divinylbenzene monomer is preferable from the viewpoint of improving heat resistance.

On the other hand, the thermoplastic resin having a specific multiphase structure of the present invention may be a block copolymer,
Examples of the block copolymer include a block copolymer containing at least one polymer of a vinyl aromatic monomer and at least one polymer of a conjugated diene.
It may be a linear type or a radial type, that is, a type in which a hard segment and a soft segment are radially bonded. Further, the polymer containing a conjugated diene may be a random copolymer with a small amount of a vinyl aromatic monomer, and a so-called tapered block copolymer, that is, 1
The vinyl aromatic monomer may be gradually increased in one block.

The structure of the block copolymer is not particularly limited, and may be any of (AB) _n type, (AB) _n -A type or (A, B) _n -C type. . Where A
Represents a polymer of a vinyl aromatic monomer, B represents a polymer of a conjugated diene, C represents a residue of a coupling agent, and n represents an integer of 1 or more. In addition, in this block copolymer, it is also possible to use a block copolymer in which a conjugated diene portion is hydrogenated.

In such a block copolymer, the above-mentioned non-polar α-olefin-based polymer may be used instead of or in addition to the above-mentioned non-polar conjugated diene-based copolymer. The diene-based polymer may contain an α-olefin monomer, and may be a non-polar α-olefin monomer.
The olefin-based polymer may contain a conjugated diene monomer. The ratio of each segment in the block copolymer and the preferred embodiment are the same as those of the graft copolymer.

The resin composition of the present invention, preferably a thermoplastic resin having a specific multiphase structure (particularly preferably a graft copolymer), is added with 4-methylpentene-1 in order to improve heat resistance. It is preferable to add a nonpolar α-olefin-based polymer containing a monomer. In the present invention, 4-
The non-polar α-olefin-based polymer containing the monomer of methylpentene-1 may be contained in the resin composition without forming a chemical bond, but in such a case, the addition is not necessarily required. Not required. However, it may be further added to obtain predetermined characteristics.

In such a non-polar α-olefin-based copolymer containing a monomer of 4-methylpentene-1, 4-
The proportion of the monomer of methylpentene-1 is preferably at least 50% by weight. The non-polar α-olefin copolymer may include a conjugated diene monomer.

In particular, the non-polar α-olefin-based copolymer containing a 4-methylpentene-1 monomer includes poly (4-methylpentene-1) homopolymer,
Methylpentene-1 is preferred.

Poly 4-methyl pentene-1 is crystalline poly 4-methyl pentene-1, which is a 2-component of propylene.
Isotactic poly-4-methylpentene-1 obtained by polymerizing 4-methylpentene-1 as a monomer using a Ziegler-Natta catalyst or the like is preferred.

The proportion of poly-4-methylpentene-1 and a thermoplastic resin having a specific multiphase structure is not particularly limited,
In order to satisfy heat resistance and adhesion to metal, poly 4
The proportion of -methylpentene-1 is preferably from 10 to 90% by weight. When the proportion of poly-4-methylpentene-1 is small, the solder heat resistance tends to be insufficient. Also poly 4
When the ratio of -methylpentene-1 increases, the adhesion to metal tends to be insufficient. Poly 4-methylpentene-1
Instead, the amount of addition when the copolymer is used may be in accordance with this.

The softening point of the resin composition of the present invention (including those to which a non-polar α-olefin polymer containing a monomer of 4-methylpentene-1 is added) is 200 to 260 ° C.
Sufficient solder heat resistance can be obtained by appropriately selecting and using.

The low dielectric polymer material of the present invention can be obtained by a method of molding a resin material composed of the resin composition into a desired shape by hot pressing or the like.
A method of forming a desired shape by melt-mixing with another thermoplastic resin using a shear mixer, such as a roll mixer, a Banbury mixer, a kneader, or a single-screw or twin-screw extruder. Can also be obtained by

The low dielectric polymer material of the present invention is formed into a core material having a predetermined shape, and after a necessary winding is wound,
It is placed in a case (resin mold) and used as a fixed inductor, a chip inductor and the like in various electronic devices such as mobile communication such as a mobile phone and a car phone. Although the shape of the core is not particularly limited, for example, a drum type having an outer diameter of 0.3 to 5.0 mm and a length of 0.5 to 5.0 mm (for example, 1.4 × 0.5 mm) Cores and the like.

Next, the dielectric polymer material used for the case will be described.

The dielectric polymer material has a relative dielectric constant of 3.0 or less, preferably 1.0 to 3.0, and more preferably 2.4 to 2.8. As the relative permittivity increases, the loss of the inductor increases. Further, the decomposition temperature is preferably 280 ° C or higher, particularly 290 ° C or higher, and more preferably 300 ° C or higher. The upper limit is not particularly limited, but is usually 3
It is about 10 ° C.

The dielectric polymer material is preferably obtained by polymerizing a monomer composition containing a fumaric acid diester as a monomer, and comprises a fumarate-based material having a repeating unit derived from the fumaric acid diester. It is a polymer.

The polymer of the fumaric acid diester in the present invention is not particularly limited as long as it imparts low dielectric property and heat resistance to the polymer material. ) A compound represented by the above formula 3 is preferred.

As for the formula (I), in the formula (I), R
¹ represents an alkyl group or a cycloalkyl group, R ² represents an alkyl group, a cycloalkyl group or an aryl group, and R ¹ and R ² may be the same or different.

The alkyl group represented by R ¹ and R ² is preferably one having a total of 2 to 12 carbon atoms, which may be linear or branched, and further having a substituent. You may have. When the compound has a substituent, examples of the substituent include a halogen atom (F, Cl), an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group);
And an aryl group (eg, a phenyl group).

Specific examples of the alkyl group represented by R ¹ and R ² include an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group and an n-pentyl group. (N-amyl group), sec-amyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, 4-methyl-2-pentyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl Group, dodecyl group, trifluoroethyl group, hexafluoroisopropyl group, perfluoroisopropyl group, perfluorobutylethyl group, perfluorooctylethyl group, 2-chloroethyl group, 1-butoxy-2-
Examples include a propyl group, a methoxyethyl group, and a benzyl group.

The cycloalkyl group represented by R ¹ and R ² is preferably a group having 3 to 14 carbon atoms in total, and may be a single ring or a group having a bridged ring. It may have a group. In this case, the substituent may be the same as those exemplified above for the alkyl group, and examples thereof include an alkyl group (a linear or branched one having 1 to 14 carbon atoms such as a methyl group). be able to.

Specific examples of the cycloalkyl group represented by R ¹ and R ² include a cyclopentyl group, a cyclohexyl group, an adamantyl group and a dimethyladamantyl group.

The aryl group represented by R ² is preferably one having a total of 6 to 18 carbon atoms, and is preferably a single ring, but may be a polycyclic (condensed ring or ring assembly) and has a substituent. May be. In this case, the substituents are the same as those exemplified for the alkyl group and the cycloalkyl group.

Specific examples of the aryl group represented by R ² include a phenyl group.

As R ¹ and R ² , an alkyl group and a cycloalkyl group are preferable. As the alkyl group, an alkyl group having a branch is preferable, and an isopropyl group, sec-
A butyl group and a tert-butyl group are preferred. Also,
As the cycloalkyl group, a cyclohexyl group or the like is preferable.

Preferable examples of the fumaric acid diester monomer represented by the formula (I) include diethyl fumarate,
Di-n-propyl fumarate, di-n-hexyl fumarate, isopropyl-n-hexyl fumarate, diisopropyl fumarate, di-n-butyl fumarate, di-
sec-butyl fumarate, di-tert-butyl fumarate, di-sec-amyl fumarate, n-butyl-
Isopropyl fumarate, isopropyl-sec-butyl fumarate, tert-butyl-4-methyl-2-pentyl fumarate, isopropyl-tert-butyl fumarate, isopropyl-sec-amyl fumarate,
Dialkyl fumarate such as di-4-methyl-2-pentyl fumarate, di-isoamyl fumarate, di-4-methyl-2-hexyl fumarate, tert-butyl-isoamyl fumarate; dicyclopentyl fumarate;
Dicycloalkyl fumarate such as dicyclohexyl fumarate, dicycloheptyl fumarate, cyclopentyl-cyclohexyl fumarate, bis (dimethyladamantyl) fumarate, bis (adamantyl) fumarate; isopropyl-cyclohexyl fumarate, isopropyl-dimethyl adamantyl fumarate; Alkylcycloalkyl fumarate such as isopropyl-adamantyl fumarate and tert-butyl-cyclohexyl fumarate; alkylaryl fumarate such as isopropyl-phenyl fumarate; alkyl such as tert-butylbenzyl fumarate and isopropyl-benzyl fumarate Aralkyl fumarate; ditrifluoroethyl fumarate, dihexafluoroisopropyl fumarate, diperfluoroi Di-fluoroalkyl fumarate such as propyl fumarate and dibis (perfluorobutylethyl) fumarate; alkyl fluoroalkyl fumarate such as isopropyl-perfluorooctylethyl fumarate and isopropyl-hexafluoroisopropyl fumarate; 1-butoxy -2-propyl-
Other substituted alkylalkyl fumarate such as tert-butyl fumarate, methoxyethyl-isopropyl fumarate, 2-chloroethyl-isopropyl fumarate and the like can be mentioned.

Among them, diisopropyl fumarate, dicyclohexyl fumarate, di-sec-butyl fumarate, di-tert-butyl fumarate, isopropyl-tert-butyl fumarate, n-butyl-isopropyl fumarate, n-hexyl-fumarate Isopropyl fumarate and the like are particularly preferred.

These diesters can be synthesized by combining ordinary esterification techniques and isomerization techniques.

In obtaining a fumarate-based polymer which is a dielectric polymer material, the fumaric acid diester (fumarate-based compound) may be used alone or in combination of two or more. Therefore, the fumarate-based polymer of the present invention may be a homopolymer obtained by polymerizing only one type of the above fumaric acid diester, or a copolymer obtained by polymerizing two or more types. The copolymer may be any of a random copolymer, an alternating copolymer, a block copolymer and the like.

As described above, the fumarate-based polymer of the present invention may use only the fumaric acid diester as a monomer component. However, it is possible to use other monomers in addition to the fumaric acid diester. And a copolymer with another monomer component. As such another monomer component, a vinyl monomer (monomer) may be used, and the vinyl monomer which is a comonomer imparts moldability, film forming property, and mechanical strength. The compound is not particularly limited as long as it can be copolymerized with the fumarate-based compound, but preferably includes a compound represented by the formula (II) [Formula 4].

Referring to the formula (II), X represents a hydrogen atom or a methyl group, Y represents a fluorine atom, a chlorine atom,
Alkyl group, alkenyl group, aryl group, ether group,
Represents an acyl group or an ester group.

The alkyl group represented by Y is preferably one having a total carbon number of 1 to 14, and may be linear or branched.

The alkenyl group represented by Y is preferably one having a total of 2 to 14 carbon atoms, which may be linear or branched, and further having a substituent. Examples thereof include a vinyl group, an allyl group, a propenyl group, and a butenyl group.

The aryl group represented by Y is preferably one having a total of 6 to 18 carbon atoms, and may be a single ring or a polycyclic ring such as a condensed ring.
l) may have a substituent of an alkyl group (eg, a methyl group). Specifically, phenyl group, α-naphthyl group, β
-Naphthyl group, (o-, m-, p-) tolyl group, (o
-, M-, p-) chlorophenyl group and the like.

The ether group represented by Y is represented by —OR ³ , and R ³ in this case includes an alkyl group and an aryl group. The alkyl group represented by R ³ preferably has 1 to 8 carbon atoms in total, and may be linear or branched, and further has a substituent (eg, a halogen atom). You may have. The aryl group represented by R ³ preferably has 6 to 18 carbon atoms in total, and is preferably a single ring, but may be a polycyclic ring such as a condensed ring.

Examples of the ether group represented by Y include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an isobutoxy group and a phenoxy group.

The acyl group represented by Y is represented by —COR ⁴ , wherein R ⁴ includes an alkyl group, an aryl group and the like. The alkyl group represented by R ⁴ preferably has 1 to 8 carbon atoms in total, and may be linear or branched, and further has a substituent (eg, a halogen atom). It may be. The aryl group represented by R ⁴ preferably has 6 to 18 carbon atoms, and is preferably a single ring, but may be a polycyclic ring such as a condensed ring.

The acyl group represented by Y includes an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a benzoyl group and the like.

The ester group represented by Y is —OCOR ⁵
Or represented by -COOR ^5, the alkyl group as R ⁵ in this case, and an aryl group. The alkyl group represented by R ⁵ preferably has 1 to 20 carbon atoms in total, and may be linear or branched, and further has a substituent (eg, a halogen atom). You may have. The aryl group represented by R ⁵ preferably has 6 to 18 carbon atoms in total, and is preferably a single ring, but may be a polycyclic ring such as a condensed ring.

Examples of the ester group represented by Y include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a valeryloxy group, an isovaleryloxy group, —OCOC ₄ H ₉ (−sec), and —OCOC.
_{4 H 9 (-tert), -} OCOC (CH 3) 2 CH 2
CH ₃ , —OCOC (CH ₃ ) ₂ CH ₂ CH ₂ CH ₃ ,
Stearoyloxy group, benzoyloxy group, tert
-Butylbenzoyloxy group, methoxycarbonyl group,
Examples include an ethoxycarbonyl group, a butoxycarbonyl group, a 2-ethylhexyloxycarbonyl group, and a phenoxycarbonyl group.

The copolymer component used in the dielectric polymer material is a vinyl comonomer mainly composed of an olefinic hydrocarbon. Examples of the vinyl monomer represented by the formula (II) include vinyl acetate and vinyl pivalate. Carboxylic acids such as vinyl 2,2-dimethylbutanoate, vinyl 2,2-dimethylpentanoate, vinyl 2-methyl-2-butanoate, vinyl propionate, vinyl stearate, and vinyl 2-ethyl-2-methylbutanoate Vinyls; p-tert
Aromatic vinyl monomers such as -butyl vinyl benzoate, N, N-dimethylamino vinyl benzoate and vinyl benzoate; styrene, o-, m-, p-chloromethylstyrene, α-methylstyrene and the like. Α-
Substituted styrene derivatives; alkyl nucleus-substituted styrenes such as o-, m- and p-methylstyrene; α-olefins such as vinyl chloride and vinyl fluoride; o-, m- and p- such as p-chlorostyrene. Halogen nucleus substituted styrene such as halogenated styrene; vinyl ethers such as ethyl vinyl ether, vinyl butyl ether and isobutyl vinyl ether; naphthalene derivatives such as α- and β-vinyl naphthalene; alkyl vinyl ketones such as methyl vinyl ketone and isobutyl vinyl ketone; butadiene And diene such as isoprene; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-
Known radical polysynthetic monomers such as (meth) acrylates such as ethylhexyl (meth) acrylate and phenyl (meth) acrylate can be preferably exemplified.

In order to produce such a vinyl monomer, for example, a transesterification reaction between vinyl acetate and a corresponding organic acid is carried out in the presence of mercury acetate or sulfuric acid, or another catalyst such as platinum or rhodium. Can be easily synthesized by performing the reaction in the presence of a metal complex and a catalyst.

As such a vinyl monomer, only one kind may be used as a comonomer, or two or more kinds may be used in combination.

Further, the fumarate-based polymer of the present invention having a repeating unit derived from such a vinyl-based monomer is a copolymer, such as a random copolymer, an alternating copolymer, or a block copolymer. Any of them may be used.

The polymer material having a repeating unit derived from the above fumaric acid diester has a low dielectric property and is excellent in film formability, film adhesion, mechanical properties and the like. As described above, such a polymer material is, as described above, a homopolymer using only the same fumaric diester, a copolymer of fumaric diesters, and a fumaric diester and another vinyl monomer copolymerizable therewith. Any of a copolymer with a monomer may be used.

The molecular weight of the fumarate-based polymer is not particularly limited. For example, in order to form an electric insulating film and an electric insulating substrate obtained by laminating the same, a considerable stress generated during the production of electronic parts is required. Since mechanical strength enough to withstand the electrically insulating substrate is required, a high molecular weight material is desirable in view of its use and the like, and the number average molecular weight is preferably 10,000 to 1500,000. When the molecular weight is small, mechanical strength and chemical stability are likely to be inferior, and heat resistance is also poor. In particular, it is desirable that the molecular weight be as high as possible in order to eliminate film defects, film adhesion to a substrate, and film defects. However, if the molecular weight is too large, workability is poor, such as difficulty in forming a uniform and smooth film, and workability is also poor.

The dielectric polymer material is prepared by polymerizing a monomer composition substantially containing only the above-mentioned fumaric acid diester as a monomer component, or further as a monomer component as described above. It is obtained by polymerizing a monomer composition containing a vinyl monomer.

In this case, the content of the fumaric acid diester is preferably at least 50% by weight, more preferably at least 60% by weight, and particularly preferably at least 80% by weight, based on the total amount of the monomer as a raw material (raw material monomer). When the amount of fumaric acid diester is small, electric characteristics (dielectric constant and low dielectric loss tangent), heat resistance and the like become insufficient, which is not preferable.

On the other hand, the ratio of the above-mentioned vinyl monomer to the total amount of the raw material monomers may be low dielectric constant (low dielectric constant, low dielectric loss tangent), moldability, solution viscosity, film adhesion, mechanical properties, etc. In view of the above, it is preferably 0 to 50% by weight, more preferably 0 to 40% by weight, and particularly preferably 0 to 20% by weight.

The component derived from the fumaric acid diester in such a fumarate-based polymer is preferably at least 50% by weight, more preferably at least 60% by weight, particularly preferably at least 80% by weight.

The softening temperature of the fumarate-based polymer used in the present invention is 200 ° C. or higher, and is usually from 230 to 3
It is in the range of 50 ° C. Since the softening temperature is high as described above, the heat resistance in the soldering step essential for the device forming step is sufficient. The reason for having such a high softening temperature is that the main chain structure does not have a methylene group and the substituent is bonded on the carbon of the main chain, thereby suppressing the thermal kinetic of the main chain. Conceivable.

As described above, the fumarate-based polymer used in the present invention has a rod-like structure and is a rigid polymer. Therefore, they are not easily attacked by the side chain bond,
A polymer having excellent heat resistance, acid resistance and alkali resistance (etching resistance) can be obtained.

The fumarate-based polymers preferably used in the present invention are illustrated below. The polymer is represented by a raw material monomer.

I) Di-alkyl fumarate type I-1 di-isopropyl fumarate I-2 di-cyclohexyl fumarate I-3 di-sec-butyl fumarate I-4 di-tert-butyl fumarate I-5 tert-butyl-isopropyl fumarate I-6 di-isopropyl fumarate / di-sec-butyl fumarate I-7 tert-butyl-isopropyl fumarate /
Di-isopropyl fumarate I-8 Di-isopropyl fumarate / di-cyclohexyl fumarate I-9 Di-isopropyl fumarate / n-butyl-isopropyl fumarate I-10 Di-isopropyl fumarate / n-hexyl-
Isopropyl fumarate I-11 di-cyclohexyl fumarate / n-butyl-
Isopropyl fumarate I-12 di-cyclohexyl fumarate / di-sec-
Butyl fumarate

II) Di-alkyl fumarate / vinyl type II-1 di-isopropyl fumarate / styrene II-2 di-sec-butyl fumarate / vinyl tert-butyl benzoate II-3 di-cyclohexyl fumarate / 2 -Ethyl-
Vinyl 2-methylbutanoate II-4 Di-isopropyl fumarate / vinyl tert-butyl benzoate II-5 Di-isopropyl fumarate / vinyl p-N, N-dimethylaminobenzoate II-6 Di-cyclohexyl fumarate / tert -Butyl vinyl benzoate II-7 cyclohexyl-isopropyl fumarate / vinyl acetate II-8 di-tert-butyl fumarate / di-cyclohexyl fumarate-tert-vinyl vinyl benzoate II-9 di-isopropyl fumarate / di- Cyclohexyl fumarate / vinyl 2-ethyl-2-methylbutanoate II-10 di-isopropyl fumarate / di-sec-butyl fumarate / vinyl N, N-dimethylaminobenzoate II-11 di-sec-butyl fumarate / Di-cyclohexyl fumarate / tert-butyl Vinyl benzoate II-12 di - cyclohexyl fumarate / di - isopropyl fumarate / styrene

In the present invention, in order to produce the fumarate-based polymer, a usual radical polymerization method can be preferably used. The polymerization initiator used for the polymerization has a 10-hour half-life temperature of 80 to increase the molecular weight.
One or more of an organic peroxide and an azo compound having a temperature of not higher than
More than one species can be preferably used. Examples of such a polymerization initiator include benzoyl peroxide, diisopropyl peroxydicarbonate, tert-butyl peroxydi-2-ethylhexanoate, tert-butyl peroxydiisobutyrate, cumene peroxide,
Organic peroxides such as tert-butyl hydroperoxide, tert-butyl peroxypivalate, lauroyldiacyl peroxide, 2,2′-azobisbutyronitrile, 2,2′-azobis (2-methylbutyro Nitrile), azobis (2,4-dimethylvaleronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (isobutyric acid) dimethyl, 2,2′-azobis (2 Azo compounds such as 4-dimethylvaleronitrile) and tert-butylperoxyisopropyl carbonate. The amount of the polymerization initiator to be used is 10 to 100 parts by weight of the raw material monomer.
It is preferably at most 5 parts by weight, more preferably at most 5 parts by weight.

The conditions for polymerizing or copolymerizing each monomer in such a preparation method are as follows: a polymerization system is appropriately set with an inert gas such as nitrogen, carbon dioxide, helium,
It is preferable to carry out the polymerization under a substitution or atmosphere with argon or the like, or under degassing conditions. The temperature at the time of polymerization or copolymerization varies depending on the type of polymerization initiator used, but is preferably in the range of 30 ° C to 120 ° C. The total time required for the polymerization is desirably about 10 to 72 hours. It is also possible to polymerize the starting monomer by adding a coloring agent such as a dye or an additive such as an ultraviolet absorber.

The radical polymerization can be carried out by any of a number of polymerization methods used for radical polymerization of general-purpose vinyl monomers such as solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization and radiation polymerization. In the present invention, in the application for a high frequency band, it is important to make the low dielectric loss tangent extremely low as an electrical characteristic of the low dielectric electric insulating substrate. The presence of low-molecular-weight polymers in the polymer material causes external plasticization, which increases the dielectric loss tangent, and deteriorates the dielectric properties in the high-frequency band, so that the molecular weight of the fumarate-based polymer and copolymer becomes extremely high. It is important to take such a polymerization method, it is possible to increase the concentration of the charged monomer, for example, fumaric acid diester which is a charged monomer at the time of copolymerization,
A bulk polymerization method or a suspension polymerization method that can sufficiently increase the concentration of both monomers with a vinyl monomer is most desirable. Further, as the polymerization temperature becomes higher, the molecular weight of the polymer or copolymer becomes smaller.
It is preferable to carry out radical polymerization or copolymerization at a low temperature of ° C.

The fumarate polymer of the present invention has a nuclear magnetic resonance spectrum (NMR) and an infrared absorption spectrum (IR).
And the like.

Various terminal groups can be introduced according to the purpose.

The shape of the coil disposed in the above-mentioned dielectric resin case and having a core made of a low dielectric polymer material is not particularly limited, but depends on the required performance and the overall shape of the inductor. What is necessary is just to form into a required shape and size suitably.

The conductor wire as the coil winding is preferably a simple metal or an alloy thereof which is low in resistance and easy to form. As such a metal wire, for example, Cu, A
g, Au, Al, Cr, Co, Ni, Fe and the like can be used, and among them, Cu and its alloys are preferable. The wire diameter of the conductor wire is preferably 0.03 to 0.03.
The range is 0.2 mm.

The method for winding the conductor wire around the core is not particularly limited, and may be any of various known methods. Especially, what is called space winding which has a predetermined space | interval between windings is preferable. By using the space winding, the capacity between the windings is reduced, and the self-resonant frequency can be significantly improved.

As the electrodes (terminals) of the inductor of the present invention, various electrode materials (terminal plates and the like) conventionally used can be used. Specifically, C (terminal)
u, Ni, Cr, Co, etc., especially Cu and Ni plating may be applied. As plating, electroless plating or electrolytic plating may be performed after forming an underlayer, or electrodes may be formed using a vapor deposition method such as a vapor deposition method. The portions where the electrodes are formed are usually both ends of the core.

As the terminals of the inductor according to the present invention, it is possible to use various terminal materials (contact open metal foil and the like) conventionally used. This terminal functions as a terminal by being in contact with, welding, or soldering to the electrode portion of the core, and exposing a part of the terminal to the outside of the case (mold). The materials constituting the terminals are Ag, C
Examples thereof include simple metals such as u and Ni, or alloys thereof, and those obtained by plating the above metals on a metal support serving as a nucleus such as Fe.

Means for arranging (molding) the core around which the winding is wound in the case may be dip, coating, spraying, or the like, injection molding, casting, or the like.

Next, a typical configuration example of the inductor of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a configuration example of the inductor of the present invention. The chip inductor of the illustrated configuration example is formed of a low dielectric polymer material, and has a core 1 having jaws with large diameters at both ends, a conductor wire 2 wound around the body of the core 1, An electrode 3 to which an end of the body wire 2 is connected and fixed by soldering or the like; a contact open metal foil 6 connected to the electrode 3 for connecting an external electric circuit and fixing the core 1 in the case 5; And a case (also serving as a mold material) 5 provided so as to cover the outside.
The case 5 may be a so-called resin mold, a box shape formed in a predetermined shape, or a case in which the core 1 is inserted into a pair of hollow cases, or a combination thereof.

The configuration of the chip inductor is not limited to the illustrated example, but may take various forms. For example, the configuration may be such that the lead wire is connected in the axial direction from the center of the cylindrical shaft of the core. Alternatively, a configuration may be adopted in which a coil body having a core provided with windings, lead wires, and the like is inserted into a box-shaped resin case, and the opening is sealed with the same molding material as the case.

As shown in FIG. 2, a guide groove 11 for winding a conductor wire around the core 1 may be formed. By forming the groove 11 and winding the conductor wire around it, it is possible to easily and precisely wind the space winding at a constant interval. The groove 11 is usually formed in a screw-shaped spiral shape. Electrodes 12 are formed on the core 1 at the concave portions at both ends.

Further, as shown in FIG.
May be provided partially in a belt shape in the axial direction, and a flat portion 13 in which a groove (mountain) is not formed may be provided. By providing such a flat portion 13, one or two grooves 11 can be skipped, and the pitch and the space can be adjusted.

Further, as shown in FIG. 4, notches 14 for borrowing and fixing lead wires to the jaws at both ends of the core 1.
May be provided. Alternatively, the electrode 12 at both ends may be formed in a convex shape and pressed against a terminal (contact metal foil).

The inductor element of the present invention has a microwave,
It can be suitably used for high frequency circuits such as millimeter waves. In particular, it is preferably used as a surface mount type chip inductor used for mobile communication devices such as mobile phones.

[0124]

Next, the present invention will be described more specifically with reference to examples.

First, a low-dielectric polymer material obtained by grafting block polypropylene / styrene / divinylbenzene at a weight ratio of 70:20:10 as a grafted polymer was used. Mold core (size: maximum diameter 1.4mm, coil part (diameter)
1.0 mm, length 1.5 mm). A coil was formed by winding a wire (copper wire) having a wire diameter of 0.08 mm 5.5 times in a coil shape. At the end, Cu was formed to a thickness of 5 μm by electroless plating.

Next, the core in which the conductor wire is wound in a coil shape is mounted on a metal fitting to be formed and soldered.
The mixture was charged into a mold, cast with a liquid fumarate resin, and subjected to transformer molding. As the fumarate resin, dicyclohexyl fumarate resin was used, dissolved in a solvent (toluene), and then injected into the mold. The solvent was removed under conditions of 40 ° C. and 48 hours, dried and solidified to obtain an inductor element.

As a comparative sample, a core having the same shape was formed of alumina, and a molding resin was changed from a fumarate resin to a liquid crystal resin [diaryl fumarate resin: trade name DP-1150, Asahi Organic Material Co., Ltd.]. Except for the change, a sample prepared in the same manner as the above sample was prepared.

The self-resonant frequency characteristics of the inventive sample and the comparative sample manufactured in this manner are shown in FIGS. 5 and 6, respectively, and the impedance-frequency characteristics are shown in FIGS. 7 and 8, respectively. As is clear from FIGS. 5 to 8, the sample of the present invention has better self-resonance frequency and Q than the comparative sample.

[0129] Substantially the same results were obtained when the core material and the case material used in the above examples were replaced with the above-mentioned other exemplary resins. In this embodiment, the center axis of the coil is parallel to the mounting board. However, a structure in which the center axis of the coil passes through the mounting board is also possible.

[0130]

As described above, according to the present invention, the high-frequency characteristics are excellent, the Q is high, the dielectric characteristics are low, the heat resistance is high enough to withstand a high-temperature reflow furnace, and the self-resonant frequency is high. A high and low resistance inductor can be realized.

[Brief description of the drawings]

FIG. 1 is a partially transparent perspective view showing an example of the configuration of an inductor element according to the present invention.

FIG. 2 is an external perspective view showing a second configuration example of a core used in the inductor element of the present invention.

FIG. 3 is an external perspective view showing a third configuration example of a core used in the inductor element of the present invention.

FIG. 4 is an external perspective view showing a fourth configuration example of a core used in the inductor element of the present invention.

FIG. 5 is a graph showing a self-resonant frequency characteristic of an inventive sample.

FIG. 6 is a graph showing a self-resonant frequency characteristic of a comparative sample.

FIG. 7 is a graph showing impedance-frequency characteristics of an inventive sample.

FIG. 8 is a graph showing impedance-frequency characteristics of a comparative sample.

FIG. 9 is a partially cut external perspective view showing a configuration example of a conventional inductor element.

FIG. 10 is a partially cut external perspective view showing another configuration example of a conventional inductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core 2 Conductor wire 3 Electrode 5 Case (mold) 6 Terminal (contact open metal foil)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 37/00 H01F 37/00 EF term (Reference) 5E044 AA04 AB02 AC02 AD02 AD07 BA01 BB02 BB08 5E070 AA01 AB06 AB07 BA01 CA06 CA12 CA20 DA02 DA12 EA01 EA02 EB02

Claims (12)

[Claims] 1. A core comprising: a core; a conductor wire wound around the core; and a case having therein a core wound with the conductor wire, wherein the core has a weight average absolute molecular weight of 1000 A low-dielectric polymer material which is a resin composition of one or more of the above resins, wherein the sum of the number of carbon atoms and hydrogen atoms of the composition is 99% or more, and the resin molecules Some or all of them have a chemical bond with each other, and the case has a relative dielectric constant of 3.0 or less and a decomposition temperature of 290 ° C.
An inductor made of the above dielectric polymer material. 2. The inductor according to claim 1, wherein the low-dielectric polymer material has one or more chemical bonds selected from crosslinking, block polymerization, and graft polymerization. 3. The composition resin of a low dielectric polymer material, wherein a non-polar α-olefin polymer segment and / or a non-polar conjugated diene polymer segment and a vinyl aromatic polymer segment are chemically bonded. And a thermoplastic resin having a multiphase structure in which a dispersed phase formed by one segment is finely dispersed in a continuous phase formed by the other segment. 2 inductor. 4. The inductor according to claim 3, wherein the low dielectric polymer material is a copolymer in which a nonpolar α-olefin polymer segment and a vinyl aromatic polymer segment are chemically bonded. 5. The inductor according to claim 3, wherein in the low dielectric polymer material, the vinyl aromatic polymer segment is a vinyl aromatic copolymer segment containing a divinylbenzene monomer. 6. The inductor according to claim 4, wherein the low dielectric polymer material is a copolymer chemically bonded by graft polymerization. 7. The inductor according to claim 1, wherein said low dielectric polymer material further comprises a non-polar α-olefin polymer containing a monomer of 4-methylpentene-1. 8. The inductor according to claim 1, wherein said dielectric polymer material is obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer. 9. The inductor according to claim 8, wherein the fumaric acid diester is represented by the following formula (I). Embedded image [In the formula (I), R ¹ represents an alkyl group or a cycloalkyl group, R ² represents an alkyl group, a cycloalkyl group or an aryl group, and R ¹ and R ² may be the same or different. ] 10. The inductor according to claim 8, wherein the monomer composition further contains a vinyl monomer represented by the following formula (II). Embedded image [In the formula (II), X represents a hydrogen atom or a methyl group, and Y represents a fluorine atom, a chlorine atom, an alkyl group, an alkenyl group, an aryl group, an ether group, an acyl group, or an ester group. ] 11. The inductor according to claim 1, wherein the core is provided with a groove for space winding. 12. The conductor wire is mainly composed of copper,
12. The inductor according to claim 1, wherein said inductor is formed of a metal conductive material having a diameter of 0.03 to 0.2 mm.