JP2024021200A - Thermosetting resin composition for LDS and its uses - Google Patents

Abstract

An object of the present invention is to provide a thermosetting resin composition for LDS, which can yield a cured product that has excellent dielectric properties such as low dielectric constant and low dielectric loss tangent, and is also excellent in forming a plating layer. [Solution] The thermosetting resin composition for LDS of the present invention includes (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D) a LASER DIRECT STRUCTURING (LDS) additive. and the LDS additive (D) includes copper tungstate. [Selection diagram] None

Description

The present invention relates to a thermosetting resin composition for LDS and its uses.

LASER DIRECT STRUCTURING (LDS) is known as a technique for forming three-dimensional circuits. In this technique, a resin composition containing an LDS additive is used, and the surface of a molded article obtained from the composition is irradiated with a laser to activate the laser-irradiated part, and the activated part A three-dimensional circuit can be formed by forming a metal plating layer on the surface.

Patent Document 1 discloses a thermosetting maleimide resin composition containing a cyclic imide compound containing at least two cyclic imide groups and a predetermined LDS additive. This document states that the cured product of this composition has excellent dielectric properties, and that a metal layer (plated layer) can be selectively and easily formed on the surface or inside thereof by electroless plating.

JP 2021-20996 Publication

However, the cured product obtained from the maleimide resin composition described in Patent Document 1 has room for improvement in dielectric properties such as low dielectric constant and low dielectric loss tangent, and there is also room for improvement in the formation of a plating layer.

The present inventors have discovered that by using a specific LDS additive, the dielectric properties are improved by having an excellent low dielectric constant and low dielectric loss tangent, and the formation of a plating layer is also excellent, and the present invention has been completed. I let it happen.
That is, the present invention can be shown below.

（一般式（１）中、Ａは、脂肪族環状炭化水素基を介して連結された置換または非置換のアリーレン基であり、Ａｒ’は、置換または非置換のアリール基であり、
Ｂは、下記一般式（Ｂ）で表される構造であり、

（一般式（Ｂ）中、Ａｒは、置換または非置換のアリーレン基であり、Ｙは、単結合、置換または非置換の炭素原子数１～６の直鎖のアルキレン基、または置換または非置換の炭素原子数３～６の環式のアルキレン基、置換または非置換の２価の芳香族炭化水素基、エーテル結合、カルボニル基、カルボニルオキシ基、スルフィド基、あるいはスルホン基である。ｎは０または１である。）
ｋは、繰り返し単位の平均値であり、０．２５～３．５の範囲である。）
［５］ 無機充填材（Ｃ）の比誘電率は４．２以下である、［１］または［２］に記載のＬＤＳ用熱硬化性樹脂組成物。
［６］ 無機充填材（Ｃ）はシリカを含む、［１］～［５］のいずれかに記載のＬＤＳ用熱硬化性樹脂組成物。
［７］ エポキシ樹脂（Ａ）が、オルソクレゾールノボラック型エポキシ樹脂、ビフェニレン骨格を有するフェノールアラルキル型エポキシ樹脂、およびトリフェニルメタン型エポキシ樹脂から選択される少なくとも１種を含む、［６］に記載のＬＤＳ用熱硬化性樹脂組成物。
［８］ さらにカップリング剤（Ｅ）を含む、［１］～［７］のいずれかに記載のＬＤＳ用熱硬化性樹脂組成物。
［９］ ［１］～［８］のいずれかに記載のＬＤＳ用熱硬化性樹脂組成物の硬化物を備える成形品。
［１０］ ［１］～［８］のいずれかに記載のＬＤＳ用熱硬化性樹脂組成物の硬化物と、前記硬化物の表面に形成された回路と、を備える、回路部品。
［１１］ ［１０］に記載の回路部品を含む回路基板。
［１２］ ［１０］に記載の回路部品を含む高周波アンテナ。
［１３］ ［１］～［８］のいずれかに記載のＬＤＳ用熱硬化性樹脂組成物の硬化物からなる誘電体基板と、
前記誘電体基板の一方の面に設けられた放射導体板と、
前記誘電体基板の他方の面に設けられた地導体板と、
を備える、マイクロストリップアンテナ。
［１４］ 金属基板の表面に［１］～［８］のいずれかに記載のＬＤＳ用熱硬化性樹脂組成物の硬化物からなる誘電体基板を形成する工程と、
活性エネルギー線を前記誘電体基板表面の所定の範囲に照射し、金属が堆積可能な状態に活性化させる工程と、
めっき処理を行い、活性化された前記誘電体基板の表面に金属を堆積して金属層を形成する工程と、
を含む、回路基板の製造方法。
［１５］ 前記活性化工程の前に、前記誘電体基板に、底部に前記金属基板の表面が露出する貫通孔を形成する工程を備え、
前記活性化工程は、前記活性エネルギー線を前記貫通孔の側面および前記誘電体基板の表面の所定の範囲に照射し、金属が堆積可能な状態に活性化させる工程であり、
前記金属層形成工程は、めっき処理を行い、活性化された前記貫通孔の前記側面および活性化された前記誘電体基板の表面に金属を堆積し金属層を形成する工程である、［１４］に記載の回路基板の製造方法。 [1] (A) Epoxy resin;
(B) a curing agent;
(C) an inorganic filler;
(D) LASER DIRECT STRUCTURING (LDS) additive;
including;
The LDS additive (D) is a thermosetting resin composition for LDS containing copper tungstate.
[2] The thermosetting resin composition for LDS according to [1], wherein the curing agent (B) contains at least one selected from an active ester compound (B1) and a phenolic curing agent (B2).
[3] The active ester curing agent (B1) is an active ester curing agent containing a dicyclopentadiene diphenol structure, an active ester curing agent containing a naphthalene structure, or an active ester curing agent containing an acetylated product of phenol novolak. The thermosetting resin composition for LDS according to [2], which is at least one selected from active ester curing agents containing benzoylated products of phenol novolacs.
[4] The thermosetting resin composition for LDS according to [2] or [3], wherein the active ester curing agent (B1) has a structure represented by the following general formula (1).

(In general formula (1), A is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group, Ar' is a substituted or unsubstituted aryl group,
B is a structure represented by the following general formula (B),

(In the general formula (B), Ar is a substituted or unsubstituted arylene group, and Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted is a cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. n is 0 or 1)
k is the average value of repeating units and ranges from 0.25 to 3.5. )
[5] The thermosetting resin composition for LDS according to [1] or [2], wherein the inorganic filler (C) has a dielectric constant of 4.2 or less.
[6] The thermosetting resin composition for LDS according to any one of [1] to [5], wherein the inorganic filler (C) contains silica.
[7] The epoxy resin (A) according to [6], wherein the epoxy resin (A) contains at least one selected from an orthocresol novolak epoxy resin, a phenol aralkyl epoxy resin having a biphenylene skeleton, and a triphenylmethane epoxy resin. Thermosetting resin composition for LDS.
[8] The thermosetting resin composition for LDS according to any one of [1] to [7], further comprising a coupling agent (E).
[9] A molded article comprising a cured product of the thermosetting resin composition for LDS according to any one of [1] to [8].
[10] A circuit component comprising a cured product of the thermosetting resin composition for LDS according to any one of [1] to [8], and a circuit formed on the surface of the cured product.
[11] A circuit board including the circuit component according to [10].
[12] A high frequency antenna including the circuit component according to [10].
[13] A dielectric substrate made of a cured product of the thermosetting resin composition for LDS according to any one of [1] to [8];
a radiation conductor plate provided on one surface of the dielectric substrate;
a ground conductor plate provided on the other surface of the dielectric substrate;
Microstrip antenna.
[14] Forming a dielectric substrate made of a cured product of the thermosetting resin composition for LDS according to any one of [1] to [8] on the surface of the metal substrate;
irradiating active energy rays to a predetermined range of the dielectric substrate surface to activate it to a state where metal can be deposited;
performing plating treatment and depositing metal on the activated surface of the dielectric substrate to form a metal layer;
A method of manufacturing a circuit board, including:
[15] Before the activation step, a step of forming a through hole in the dielectric substrate from which the surface of the metal substrate is exposed at the bottom,
The activation step is a step of irradiating the active energy rays to a predetermined range of the side surface of the through hole and the surface of the dielectric substrate to activate the metal to a state where metal can be deposited,
The metal layer forming step is a step of performing plating and depositing metal on the side surface of the activated through hole and the activated surface of the dielectric substrate to form a metal layer, [14] A method for manufacturing a circuit board as described in .

The thermosetting resin composition for LDS of the present invention can provide a cured product that has excellent dielectric properties such as low dielectric constant and low dielectric loss tangent, and is also excellent in forming a plating layer. Antennas and the like that include molded products on which circuits are formed have excellent reception sensitivity, and can be made smaller and lighter.

FIG. 2 is a top perspective view showing the microstrip antenna of this embodiment. FIG. 2 is a cross-sectional view and a top perspective view showing a method for manufacturing a microstrip antenna according to the present embodiment. FIG. 3 is a cross-sectional view and a top perspective view showing a method of manufacturing a microstrip antenna according to the present embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that in all the drawings, similar components are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate. Further, for example, "1 to 10" represents "1 or more" to "10 or less" unless otherwise specified.

The thermosetting resin composition for LDS of this embodiment is a thermosetting resin composition used for LASER DIRECT STRUCTURING (Laser Direct Structuring (LDS)). LDS is one of the manufacturing methods for three-dimensional molded circuit components (MID), in which active energy rays are irradiated to generate metal nuclei on the surface of resin molded products containing LDS additives. Using as a seed, a plating pattern (wiring) can be formed in the energy beam irradiation region by, for example, electroless plating treatment or the like.

The thermosetting resin composition for LDS of this embodiment is
(A) an epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D) a LASER DIRECTED STRUCTURING (LDS) additive, where the LDS additive (D) includes copper tungstate. .
According to such a thermosetting resin composition for LDS, it is possible to provide a cured product etc. that is excellent in low dielectric constant and low dielectric loss tangent, has improved dielectric properties, and is also excellent in forming a plating layer. can.

[Epoxy resin (A)]
As the epoxy resin (A), monomers, oligomers, and polymers in general having two or more epoxy groups in one molecule can be used, and the molecular weight and molecular structure thereof are not limited.

Examples of the epoxy resin (A) include bisphenol A epoxy resin, bisphenol F epoxy resin, tetramethylbisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol E epoxy resin, bisphenol M epoxy resin, and bisphenol P epoxy resin. Epoxy resin, bisphenol type epoxy resin such as bisphenol Z type epoxy resin; novolac type epoxy resin such as phenol novolac type epoxy resin, orthocresol novolac type epoxy resin; biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, aryl alkylene type epoxy resin , naphthalene type epoxy resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin, fluorene type epoxy resin, trisphenylmethane type epoxy resin, Zylock type epoxy resin, etc. can be mentioned.

The resin molding material of this embodiment may contain only one type of epoxy resin, or may contain two or more types of epoxy resin. Furthermore, even if the epoxy resins are of the same type, those having different molecular weights may be used in combination.

From the viewpoint of the effects of the present invention, the epoxy resin (A) of the present embodiment is at least one selected from orthocresol novolac type epoxy resins, phenol aralkyl type epoxy resins having a biphenylene skeleton, and triphenylmethane type epoxy resins. is preferable, and a phenol aralkyl type epoxy resin having a biphenylene skeleton is more preferable.

Specifically, the triphenylmethane type epoxy resin is an epoxy resin containing a partial structure in which three of the four hydrogen atoms of methane (CH ₄ ) are substituted with benzene rings. The benzene ring may be unsubstituted or substituted with a substituent. Examples of the substituent include a hydroxy group and a glycidyloxy group.

Specifically, the triphenylmethane type epoxy resin includes a structural unit represented by the following general formula (a1). A triphenylmethane skeleton is composed of two or more of these structural units connected together.

In general formula (a1),
R ¹¹ is each independently a monovalent organic group, a halogen atom, a hydroxy group or a cyano group, if there are multiple R 11s;
R ¹² is each independently a monovalent organic group, a halogen atom, a hydroxy group or a cyano group, if there are multiple R 12s;
i is an integer from 0 to 3,
j is an integer from 0 to 4.

Examples of monovalent organic groups for R ¹¹ and R ¹² include those listed as monovalent organic groups for R ^a and R ^b in general formula (BP) described below.
i and j are each independently preferably 0-2, more preferably 0-1.

In one aspect, i and j are both 0. That is, as one embodiment, all of the benzene rings in general formula (a1) do not have substituents other than the specified glycidyloxy group as monovalent substituents.

Specifically, the epoxy resin containing a biphenyl structure is an epoxy resin containing a structure in which two benzene rings are connected by a single bond. The benzene ring here may or may not have a substituent.
Specifically, the epoxy resin containing a biphenyl structure has a partial structure represented by the following general formula (BP).

In the general formula (BP),
R ^a and R ^b are each independently a monovalent organic group, a hydroxyl group, or a halogen atom, if there are two or more,
r and s are each independently from 0 to 4;
* indicates that it is connected to another atomic group.

Specific examples of monovalent organic groups for R ^a and R ^b include alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkaryl groups, cycloalkyl groups, alkoxy groups, heterocyclic groups, and carboxyl groups. Examples include groups.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, Examples include octyl group, nonyl group, and decyl group.
Examples of the alkenyl group include an allyl group, a pentenyl group, and a vinyl group.
Examples of the alkynyl group include ethynyl group.
Examples of the alkylidene group include a methylidene group and an ethylidene group.
Examples of the aryl group include tolyl group, xylyl group, phenyl group, naphthyl group, and anthracenyl group.
Examples of the aralkyl group include benzyl group and phenethyl group.
Examples of the alkaryl group include tolyl group and xylyl group.
Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, s-butoxy group, isobutoxy group, t-butoxy group, n-pentyloxy group, and neopentyloxy group. , n-hexyloxy group, etc.
Examples of the heterocyclic group include an epoxy group and an oxetanyl group.

The total number of carbon atoms in the monovalent organic groups R ^a and R ^b is, for example, 1 to 30, preferably 1 to 20, more preferably 1 to 10, particularly preferably 1 to 6.
r and s are each independently preferably 0-2, more preferably 0-1. In one aspect, r and s are both 0.

More specifically, the epoxy resin containing a biphenyl structure is preferably a biphenylaralkyl-type epoxy resin having a structural unit represented by the following general formula (BP1).

In the general formula (BP1),
The definitions and specific aspects of R ^a and R ^b are the same as in general formula (BP),
The definitions and preferred ranges of r and s are the same as in general formula (BP),
R ^c is each independently a monovalent organic group, a hydroxyl group, or a halogen atom when there is a plurality of them;
t is an integer from 0 to 3.
Specific examples of the monovalent organic group for R ^c include those listed as specific examples for R ^a and R ^b .
t is preferably 0-2, more preferably 0-1.

The content of the epoxy resin (A) is 1% by mass or more and 30% by mass or less, preferably 3% by mass or more and 20% by mass or less, more preferably 5% by mass or more in 100% by mass of the thermosetting resin composition for LDS. It can be contained in an amount of 15% by mass or less.

[Curing agent (B)]
The curing agent (B) contains at least one selected from an active ester compound (B1) and a phenolic curing agent (B2).

(Active ester compound (B1))
The active ester compound (active ester curing agent) (B1) functions as a curing agent for thermosetting resins such as epoxy resins.
The active ester compound (B1) is an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of phenol novolac, and an active ester compound containing a benzoylated product of phenol novolak. One or more selected from the group consisting of:
Among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene type diphenol structure are more preferable. "Dicyclopentadiene type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

In this embodiment, the active ester compound (B1) can be, for example, a resin having a structure represented by the following general formula (1).

In the above general formula (1),
A is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group,
Ar' is a substituted or unsubstituted aryl group,
B is a structure represented by the following general formula (B),
k is the average value of repeating units and ranges from 0.25 to 3.5.

In the above general formula (B),
Ar is a substituted or unsubstituted arylene group. Examples of the substituents of the substituted arylene group include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, an aralkyl group, and the like.
Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, a substituted or unsubstituted cyclic alkylene group having 3 to 6 carbon atoms, or a substituted or unsubstituted divalent aromatic hydrocarbon group, ether bond, carbonyl group, carbonyloxy group, sulfide group, or sulfone group. Examples of the substituent of the above group include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, an aralkyl group, and the like.
Preferred examples of Y include a single bond, a methylene group, -CH(CH ₃ ) ₂ -, an ether bond, an optionally substituted cycloalkylene group, and an optionally substituted 9,9-fluorenylene group.
n is an integer from 0 to 4, preferably 0 or 1.
Specifically, B is a structure represented by the following general formula (B1) or the following general formula (B2).

In the general formula (B1) and the general formula (B2), Ar and Y have the same meanings as in the general formula (B).

Since the thermosetting resin composition of this embodiment contains a specific active ester compound, the obtained cured product can have excellent dielectric properties and is excellent in low dielectric loss tangent.

The active ester compound (B1) used in the thermosetting resin composition of this embodiment has an active ester group represented by formula (B). In the curing reaction between the epoxy resin (A) and the active ester compound (B1), the active ester group of the active ester compound (B1) reacts with the epoxy group of the epoxy resin (A) to generate a secondary hydroxyl group. This secondary hydroxyl group is blocked by the ester residue of the active ester compound (B1). Therefore, the dielectric loss tangent of the cured product is reduced.

In one embodiment, the structure represented by the above formula (B) is preferably at least one selected from the following formulas (B-1) to (B-6).

In formulas (B-1) to (B-6),
R ¹ is each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group,

R ² is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group, and X is a linear alkylene group having 2 to 6 carbon atoms, an ether a bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group,
n is an integer from 0 to 4, and p is an integer from 1 to 4.

The structures represented by the above formulas (B-1) to (B-6) are all highly oriented structures, so when an active ester compound (B1) containing them is used, the resulting thermosetting The cured product of the resin composition has a low dielectric loss tangent in a high frequency band.
Among these, from the viewpoint of low dielectric loss tangent, active ester compounds having a structure represented by formula (B-2), formula (B-3) or (B-5) are preferable, and furthermore, n of formula (B-2) is preferable. is 0, a structure in which X in formula (B-3) is an ether bond, or an active ester compound having a structure in which two carbonyloxy groups are at the 4,4'-position in formula (B-5). More preferred. Further, it is preferable that all R ¹ in each formula are hydrogen atoms.

"Ar'" in formula (1) is an aryl group, for example, phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 3,5-xylyl group, o-biphenyl group, m-biphenyl group. p-biphenyl group, 2-benzylphenyl group, 4-benzylphenyl group, 4-(α-cumyl)phenyl group, 1-naphthyl group, 2-naphthyl group, etc. Among these, 1-naphthyl group or 2-naphthyl group is preferable because a cured product with a particularly low dielectric loss tangent can be obtained.

In this embodiment, [A] in the active ester compound (B1) represented by formula (1) is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group, and such Examples of the arylene group include a structure obtained by polyaddition reaction of an unsaturated aliphatic cyclic hydrocarbon compound containing two double bonds in one molecule and a phenolic compound.

Examples of the unsaturated aliphatic cyclic hydrocarbon compound containing two double bonds in one molecule include dicyclopentadiene, cyclopentadiene polymer, tetrahydroindene, 4-vinylcyclohexene, and 5-vinyl-2-norbornene. , limonene, etc., and each of these may be used alone or two or more types may be used in combination. Among these, dicyclopentadiene is preferred because it provides a cured product with excellent heat resistance. Since dicyclopentadiene is contained in petroleum fractions, industrial dicyclopentadiene may contain cyclopentadiene polymers and other aliphatic or aromatic diene compounds as impurities. However, in consideration of performance such as heat resistance, curability, and moldability, it is desirable to use a product with dicyclopentadiene purity of 90% by mass or more.

On the other hand, the phenolic compounds include, for example, phenol, cresol, xylenol, ethylphenol, isopropylphenol, butylphenol, octylphenol, nonylphenol, vinylphenol, isopropenylphenol, allylphenol, phenylphenol, benzylphenol, chlorophenol, bromophenol, Examples include 1-naphthol, 2-naphthol, 1,4-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene, each of which can be used alone. It may be used or two or more types may be used together. Among these, phenol is preferred because it provides an active ester compound with high curability and excellent dielectric properties in a cured product.

In a preferred embodiment, [A] in the active ester compound represented by formula (1) has a structure represented by formula (A). A cured product of a thermosetting resin composition containing an active ester compound in which [A] in formula (1) has the following structure can realize a low dielectric loss tangent in a high frequency band.

In formula (A),
R ³ is each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group,
l is 0 or 1, and m is an integer of 1 or more.

Among the active ester curing agents represented by formula (1), more preferable ones include resins represented by the following formulas (1-1), (1-2), and (1-3), Particularly preferred are resins represented by the following formula (1-3).

In formula (1-1), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

In formula (1-2), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

In formula (1-3), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

The active ester compound (B1) represented by the above general formula (A) is a phenolic compound (a) having a structure in which a plurality of aryl groups having a phenolic hydroxyl group are linked via an aliphatic cyclic hydrocarbon group, It can be produced by a known method of reacting an aromatic nucleus-containing dicarboxylic acid or its halide (b) with an aromatic monohydroxy compound (c).

The reaction ratio of the phenolic compound (a), the aromatic nucleus-containing dicarboxylic acid or its halide (b), and the aromatic monohydroxy compound (c) can be adjusted as appropriate depending on the desired molecular design. Among them, since an active ester compound (B1) with higher curability is obtained, the phenolic compound is The ratio of the phenolic hydroxyl group possessed by (a) being in the range of 0.25 to 0.90 mol, and the hydroxyl group possessed by the aromatic monohydroxy compound (c) being in the range of 0.10 to 0.75 mol. It is preferable to use each raw material in such a manner that the phenolic hydroxyl group of the phenolic compound (a) is in the range of 0.50 to 0.75 mol, and the hydroxyl group of the aromatic monohydroxy compound (c) is in the range of 0.50 to 0.75 mol. It is more preferable to use each raw material in a proportion ranging from 0.25 to 0.50 mol.

In addition, the functional group equivalent of the active ester compound (B1) is a cured product with excellent curability and a low dielectric loss tangent, when the total number of aryl carbonyloxy groups and phenolic hydroxyl groups in the resin structure is taken as the number of functional groups in the resin. Therefore, it is preferably in the range of 200 g/eq or more and 230 g/eq or less, and more preferably in the range of 210 g/eq or more and 220 g/eq or less.

In the thermosetting resin composition of the present embodiment, the content of the active ester compound (B1) and the epoxy resin (A) is such that a cured product with excellent curability and a low dielectric loss tangent can be obtained. It is preferable that the epoxy group in the epoxy resin (A) be in a proportion of 0.8 to 1.2 equivalents per total equivalent of active groups in (B1). Here, the active group in the active ester compound (B1) refers to an arylcarbonyloxy group and a phenolic hydroxyl group contained in the resin structure.

The active ester compound (B1) is preferably 0.5% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 12% by mass or less, and even more preferably 2% by mass in 100% by mass of the thermosetting resin composition. It is used in an amount of 8% by mass or less.
By containing the specific active ester compound (B1) in the above range, the obtained cured product can have better dielectric properties and is further excellent in low dielectric loss tangent.

(Phenol curing agent (B2))
The phenolic curing agent (B2) functions as a curing agent for thermosetting resins such as epoxy resins (A).
The phenolic curing agent (B2) contains a biphenylaralkyl phenol resin and/or a phenol novolak resin.

The thermosetting resin composition may contain a curing agent other than the biphenylaralkyl phenolic resin and the phenol novolac resin.
Examples of the biphenylaralkyl phenol resin include phenol aralkyl resin containing a biphenylene skeleton, naphthol aralkyl resin containing a biphenylene skeleton, and the like.

The thermosetting resin composition of this embodiment can contain a curing agent other than the active ester compound (B1).
As other curing agents, phenolic resin curing agents other than biphenylaralkyl phenol resins and phenol novolac resins, amine compound curing agents, amide compound curing agents, acid anhydride curing agents, etc. are used. These may be used alone or in combination of two or more. Among these, a phenolic resin curing agent may be used.

Examples of the phenolic resin curing agent include cresol novolac resin, aromatic hydrocarbon formaldehyde resin-modified phenol resin, dicyclopentadiene phenol addition type resin, phenol resin containing a biphenylene skeleton, trimethylolmethane resin, tetraphenylolethane resin, and naphthol. Novolak resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin (a polyhydric phenol compound in which phenol nuclei are linked by bismethylene groups), biphenyl-modified naphthol resin (phenol nuclei are linked by bismethylene groups), Examples include polyhydric phenol compounds such as polyhydric naphthol compounds (linked polyhydric naphthol compounds) and aminotriazine-modified phenol resins (polyhydric phenol compounds whose phenol nuclei are linked with melamine, benzoguanamine, etc.).

Examples of the amine compound curing agent include amine compounds such as diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complex, and guanidine derivatives.
Examples of the amide compound curing agent include polyamide resins synthesized from dicyandiamide, a dimer of linolenic acid, and ethylenediamine.
Examples of acid anhydride curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methyl Hexahydrophthalic anhydride is mentioned.

When using the phenolic curing agent (B2), the blending amount of the phenolic curing agent (B2) is preferably 0.5% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more and 15% by mass or less, based on 100% by mass of the thermosetting resin. It is used in an amount of 1% by mass or more and 10% by mass or less, more preferably 2% by mass or more and 8% by mass or less. is the amount of By using the curing agent in an amount within the above range, a thermosetting resin composition having excellent curability can be obtained.

[Inorganic filler (C)]
Examples of the inorganic filler (C) include silica such as fused silica and crystalline silica, alumina, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, and fosterlite. Examples include powders such as steatite, spinel, mullite, and titania, beads made of these powders, and glass fibers. These inorganic fillers may be used alone or in combination of two or more. Among the above-mentioned inorganic fillers, silica is preferred from the viewpoint of reducing the coefficient of linear expansion, and the shape of the filler is preferably spherical from the viewpoint of fluidity during molding and mold abrasion resistance.

The dielectric constant of the inorganic filler is not particularly limited, but is preferably 4.2 or less. Thereby, when a cured product is obtained from the resin composition of the present invention, the strength can be improved without deteriorating the dielectric properties. Examples of the inorganic filler having a dielectric constant of 4.2 or less include alumina, silica, and the like.

The blending amount of the inorganic filler (C) is preferably 50% by mass or more and 95% by mass or less based on the entire thermosetting resin composition for LDS, from the viewpoint of moldability, reduction of thermal expansion, and improvement of strength. , more preferably in a range of 60% by mass or more and 90% by mass or less. Within the above range, thermal expansion property reduction and moldability are excellent.

[LDS additive (D)]
The LDS additive (D) is a non-conductive metal compound that forms a metal nucleus upon irradiation with active energy rays.

As the non-conductive metal compound, (i) a spinel-type metal oxide, (ii) two or more transition metal elements selected from Groups 3 to 12 of the periodic table and adjacent to each other. (iii) a tin-containing oxide, and the like.

A non-conductive metal compound is one that can form a metal nucleus by irradiation with active energy rays. Although the detailed mechanism is not clear, when such a non-conductive metal compound is irradiated with active energy rays such as a YAG laser that has an absorbable wavelength range, the metal nucleus becomes activated (for example, it is reduced). ), it is thought that metal nuclei capable of metal plating are generated. When the surface of the cured thermosetting resin composition in which the non-conductive metal compound is dispersed is irradiated with the active energy ray, a seed region having a metal core capable of metal plating is formed on the irradiated surface. It is formed. By using the obtained seed region, it becomes possible to form a plating pattern such as a circuit on the surface of the cured product of the thermosetting resin composition.

In this embodiment, copper tungstate (CuWO ₄ ), which is a non-conductive metal compound, is included as the LDS additive (D).
The thermosetting resin composition for LDS of the present embodiment contains copper tungstate as the LDS additive (D) to obtain a cured product that is excellent in low dielectric constant and low dielectric loss tangent, and particularly excellent in low dielectric loss tangent. It is possible to provide a cured product that is capable of forming a plating layer and is also excellent in forming a plating layer. Furthermore, an antenna or the like containing a molded product in which a three-dimensional circuit is formed in the cured product has excellent reception sensitivity, and the antenna or the like can be made smaller and lighter.

From the viewpoint of the effects of the present invention, copper tungstate is preferably 0.5% by mass or more and 30% by mass or less, more preferably 1% by mass or more and 20% by mass in 100% by mass of the thermosetting resin composition for LDS. Further, it can be contained in an amount of 2% by mass or more and 15% by mass or less.

The LDS additive (D) can contain other LDS additives together with copper tungstate within a range that achieves the effects of the present invention.
Other LDS additives include the non _- conductive metal compounds _{FeCr2O4 , CuCrO4} , _CuCr2O4 , _{NiCr2O4 , MnCr2O4 , MgCr2O4 , ZnCr2O4} , _{CoCr 2} O ₄ , CuFe ₂ O ₄ , NiFe ₂ O ₄ , MnFe ₂ O ₄ , MgFe ₂ O ₄ , ZnFe ₂ O ₄ , CoFe ₂ O ₄ and the like.

[Coupling agent (E)]
The thermosetting resin composition for LDS of this embodiment can further contain a coupling agent (E).
The coupling agent (E) may include one or more selected from the group consisting of mercaptosilane, aminosilane, and epoxysilane.

Examples of the epoxysilane include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane. Examples include methoxysilane.

In addition, examples of the aminosilane include phenylaminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β (aminoethyl)γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane , N-(6-aminohexyl)3-aminopropyltrimethoxysilane, N-(3-(trimethoxysilylpropyl)-1,3-benzenedimethanane, etc.). Alternatively, it may be used as a latent aminosilane coupling agent protected by reacting with an aldehyde.Also, the aminosilane may have a secondary amino group.

Examples of the mercaptosilane include γ-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, and bis(3-triethoxysilylpropyl)disulfide. Examples include silane coupling agents that exhibit the same functions as mercaptosilane coupling agents when thermally decomposed.

These silane coupling agents may be previously hydrolyzed and blended. These silane coupling agents may be used alone or in combination of two or more.

In this embodiment, by including one or more selected from the group consisting of mercaptosilane, aminosilane, and epoxysilane as a coupling agent, the viscosity of the thermosetting resin composition is optimized, and mold moldability is improved. can be improved.

From the viewpoint of continuous moldability, mercaptosilane is preferred, from the viewpoint of fluidity, secondary aminosilane is preferred, and from the viewpoint of adhesiveness, epoxysilane is preferred.

The lower limit of the content of the coupling agent is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, particularly preferably 0.1% by mass based on the entire thermosetting resin composition. % or more. This makes it possible to lengthen the flow length of the thermosetting resin composition, thereby improving injection moldability. On the other hand, the upper limit of the content of the coupling agent is preferably 1% by mass or less, more preferably 0.8% by mass or less, particularly preferably 0.6% by mass, based on the entire thermosetting resin composition. % or less.

[Curing catalyst]
The thermosetting resin composition of this embodiment can further contain a curing catalyst.
A curing catalyst is sometimes called a curing accelerator. The curing catalyst is not particularly limited as long as it accelerates the curing reaction of the thermosetting resin (A), and any known curing catalyst can be used.

Specifically, phosphorus atom-containing compounds such as organic phosphines, tetra-substituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, and adducts of phosphonium compounds and silane compounds; 2-methylimidazole, 2- Imidazole such as phenylimidazole (imidazole curing accelerator); 1,8-diazabicyclo[5.4.0]undecene-7, benzyldimethylamine, etc. are examples of amidine and tertiary amine; quaternary of amidine and amine; Nitrogen atom-containing compounds such as salts can be mentioned, and only one type may be used, or two or more types may be used.

Among these, from the viewpoint of improving curability and obtaining a cured product with excellent mechanical strength such as bending strength, it is preferable to include compounds containing phosphorus atoms, such as tetra-substituted phosphonium compounds, phosphobetaine compounds, phosphine compounds and quinone compounds. It is more preferable to include compounds with latent properties such as adducts between phosphonium compounds and silane compounds, tetra-substituted phosphonium compounds, adducts between phosphine compounds and quinone compounds, and adducts between phosphonium compounds and silane compounds. Adducts are particularly preferred.

By using the active ester curing agent (B1) represented by the general formula (1) in combination with a curing catalyst having latent properties, a cured product with excellent moldability and mechanical strength such as bending strength can be obtained. be able to.

Examples of the organic phosphine include primary phosphines such as ethylphosphine and phenylphosphine; secondary phosphines such as dimethylphosphine and diphenylphosphine; and tertiary phosphines such as trimethylphosphine, triethylphosphine, tributylphosphine and triphenylphosphine.
Examples of the tetra-substituted phosphonium compound include compounds represented by the following general formula (6).

In general formula (6),
P represents a phosphorus atom.
R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent an aromatic group or an alkyl group.
A represents an anion of an aromatic organic acid having at least one functional group selected from a hydroxyl group, a carboxyl group, and a thiol group in its aromatic ring.

AH represents an aromatic organic acid having at least one functional group selected from a hydroxyl group, a carboxyl group, and a thiol group in an aromatic ring.
x and y are 1 to 3, z is 0 to 3, and x=y.

The compound represented by general formula (6) can be obtained, for example, as follows.
First, a tetra-substituted phosphonium halide, an aromatic organic acid, and a base are mixed uniformly in an organic solvent, and an aromatic organic acid anion is generated in the solution system. Then, by adding water, the compound represented by general formula (6) can be precipitated. In the compound represented by general formula (6), R ⁴ , R ⁵ , R ⁶ and R ⁷ bonded to the phosphorus atom are phenyl groups, and AH is a compound having a hydroxyl group in the aromatic ring, that is, a phenol. , and A is preferably an anion of the phenol. The above-mentioned phenols include monocyclic phenols such as phenol, cresol, resorcinol, and catechol; condensed polycyclic phenols such as naphthol, dihydroxynaphthalene, and anthraquinol; and bisphenols such as bisphenol A, bisphenol F, and bisphenol S; Examples include polycyclic phenols such as phenylphenol and biphenol.

Examples of the phosphobetaine compound include a compound represented by the following general formula (7).

In general formula (7),
P represents a phosphorus atom.
R ⁸ represents an alkyl group having 1 to 3 carbon atoms, and R ⁹ represents a hydroxyl group.
f is 0-5 and g is 0-3.

The compound represented by general formula (7) can be obtained, for example, as follows.
First, a triaromatic substituted phosphine, which is a tertiary phosphine, is brought into contact with a diazonium salt, and the diazonium group of the triaromatic substituted phosphine and the diazonium salt is substituted.

Examples of the adduct of a phosphine compound and a quinone compound include a compound represented by the following general formula (8).

In general formula (8),
P represents a phosphorus atom.
R ¹⁰ , R ¹¹ and R ¹² represent an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be the same or different from each other.

R ¹³ , R ¹⁴ and R ¹⁵ represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and may be the same or different from each other, and R ¹⁴ and R ¹⁵ are bonded to form a cyclic structure. You can.

Examples of phosphine compounds used in the adduct of a phosphine compound and a quinone compound include triphenylphosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, trinaphthylphosphine, tris(benzyl)phosphine, etc. It is preferable that the substituent is substituted or has a substituent such as an alkyl group or an alkoxyl group, and examples of the substituent such as an alkyl group or an alkoxyl group include those having 1 to 6 carbon atoms. Triphenylphosphine is preferred from the viewpoint of availability.

Furthermore, examples of the quinone compound used in the adduct of a phosphine compound and a quinone compound include benzoquinone and anthraquinones, and among them, p-benzoquinone is preferred from the viewpoint of storage stability.

As a method for producing an adduct of a phosphine compound and a quinone compound, the adduct can be obtained by contacting and mixing both the organic tertiary phosphine and the benzoquinone in a solvent that can dissolve them. The solvent is preferably a ketone such as acetone or methyl ethyl ketone, which has low solubility in the adduct. However, it is not limited to this.

A compound represented by general formula (8) in which R10, R11 and R12 bonded to the phosphorus atom are phenyl groups, and R ¹³ , R ¹⁴ and R ¹⁵ are hydrogen atoms, that is, 1,4-benzoquinone A compound to which triphenylphosphine is added is preferable because it lowers the thermal modulus of the cured product of the sealing resin composition.

Examples of the adduct of a phosphonium compound and a silane compound include a compound represented by the following general formula (9).

In general formula (9),
P represents a phosphorus atom, and Si represents a silicon atom.

R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each represent an organic group having an aromatic ring or a heterocycle, or an aliphatic group, and may be the same or different from each other.
R ²⁰ is an organic group bonded to groups Y ² and Y ³ .
R ²¹ is an organic group bonded to groups Y ⁴ and Y ⁵ .

Y ² and Y ³ represent a group formed by a proton-donating group releasing a proton, and the groups Y ² and Y ³ in the same molecule bond to a silicon atom to form a chelate structure.

Y ⁴ and Y ⁵ represent a group formed by a proton-donating group releasing a proton, and the groups Y ⁴ and Y ⁵ in the same molecule bond to a silicon atom to form a chelate structure.
R ²⁰ and R ²¹ may be the same or different from each other, and Y ² , Y ³ , Y ⁴ and Y ⁵ may be the same or different from each other.
Z1 is an organic group having an aromatic ring or a heterocycle, or an aliphatic group.

In general formula (9), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ are, for example, phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, naphthyl group, hydroxynaphthyl group, benzyl group, methyl group. , ethyl group, n-butyl group, n-octyl group, cyclohexyl group, etc. Among these, alkyl groups such as phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, hydroxynaphthyl group, and alkoxy groups , an aromatic group having a substituent such as a hydroxyl group, or an unsubstituted aromatic group is more preferable.

In general formula (9), R ²⁰ is an organic group bonded to Y ² and Y ³ . Similarly, R ²¹ is an organic group that is bonded to groups Y ⁴ and Y ⁵ . Y ² and Y ³ are groups formed by a proton-donating group releasing protons, and the groups Y ² and Y ³ in the same molecule bond to a silicon atom to form a chelate structure. Similarly, Y ⁴ and Y ⁵ are groups formed by a proton-donating group releasing protons, and the groups Y ⁴ and Y ⁵ in the same molecule combine with a silicon atom to form a chelate structure. The groups R ²⁰ and R ²¹ may be the same or different from each other, and the groups Y ² , Y ³ , Y ⁴ and Y5 may be the same or different from each other. The groups represented by -Y ² -R ²⁰ -Y ³ - and Y ⁴ -R ²¹ -Y ⁵ - in general formula (9) are groups in which the proton donor releases two protons. As a proton donor, an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule is preferable, and furthermore, an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule constituting the aromatic ring is preferable. An aromatic compound having at least two hydroxyl groups is preferred, and an aromatic compound having at least two hydroxyl groups on adjacent carbons constituting an aromatic ring is more preferred, such as catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxy Naphthalene, 2,2'-biphenol, 1,1'-bi-2-naphthol, salicylic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chloranilic acid, tannic acid, 2-hydroxybenzyl Examples include alcohol, 1,2-cyclohexanediol, 1,2-propanediol, and glycerin, but among these, catechol, 1,2-dihydroxynaphthalene, and 2,3-dihydroxynaphthalene are more preferred.

^Z1 in the general formula (9) represents an organic group or aliphatic group having an aromatic ring or a heterocycle, and specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group. and aliphatic hydrocarbon groups such as octyl groups, aromatic hydrocarbon groups such as phenyl, benzyl, naphthyl, and biphenyl groups, glycidyloxy groups such as glycidyloxypropyl, mercaptopropyl, and aminopropyl groups, and mercapto Among these, methyl, ethyl, phenyl, naphthyl, and biphenyl groups are more preferable in terms of thermal stability. preferable.
A method for producing an adduct of a phosphonium compound and a silane compound is, for example, as follows.

A silane compound such as phenyltrimethoxysilane and a proton donor such as 2,3-dihydroxynaphthalene are added and dissolved in a flask containing methanol, and then a sodium methoxide-methanol solution is added dropwise while stirring at room temperature. Furthermore, when a solution prepared in advance in which a tetra-substituted phosphonium halide such as tetraphenylphosphonium bromide is dissolved in methanol is added dropwise thereto under stirring at room temperature, crystals are precipitated. When the precipitated crystals are filtered, washed with water, and dried under vacuum, an adduct of a phosphonium compound and a silane compound is obtained.

When a curing catalyst is used, its content is preferably 0.01 to 2% by mass, more preferably 0.02 to 1% by mass, based on the entire thermosetting resin composition. By setting the value within such a numerical range, a sufficient curing accelerating effect can be obtained without excessively deteriorating other properties.

(Other ingredients)
The thermosetting resin composition for LDS of this embodiment contains additives such as a mold release agent, a flame retardant, an ion scavenger, a coloring agent, a low stress agent, and an antioxidant, as necessary. be able to. These may be used alone or in combination of two or more.

The above mold release agent may be one or two types selected from natural waxes such as carnauba wax, synthetic waxes such as montanic acid ester wax and oxidized polyethylene wax, higher fatty acids and their metal salts such as zinc stearate, and paraffin. The above can be included.

The flame retardant may include one or more selected from, for example, aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and phosphazene.
The ion scavenger may include one or more selected from hydrotalcites or hydrous oxides of elements selected from magnesium, aluminum, bismuth, titanium, and zirconium.

The coloring agent may include one or more selected from carbon black, red iron oxide, and titanium oxide.
The low stress agent may include one or more silicone compounds selected from polybutadiene compounds, acrylonitrile butadiene copolymer compounds, silicone oils, silicone rubbers, and the like.

Moreover, the thermosetting resin composition for LDS of this embodiment can be configured not to contain carbon such as carbon black used as the colorant. Thereby, the plating characteristics can be improved.

[Method for producing thermosetting resin composition for LDS]
As a method for manufacturing the thermosetting resin composition for LDS according to the present embodiment, for example, a mixture is obtained by mixing the above-mentioned components by known means. Furthermore, a kneaded product is obtained by melt-kneading the mixture. As the kneading method, for example, an extrusion kneader such as a single-screw kneading extruder or a twin-screw kneading extruder, or a roll-type kneader such as a mixing roll can be used, but a twin-screw kneading extruder is used. It is preferable. After cooling, the kneaded material can be shaped into a predetermined shape.

The thermosetting resin composition for LDS of this embodiment may have a predetermined shape such as powder, granules, tablet, or sheet. Thereby, a thermosetting resin composition for LDS suitable for known molding methods such as transfer molding, injection molding, and compression molding can be obtained.

In this embodiment, the granular thermosetting resin composition for LDS is a pulverized product obtained by pulverizing the obtained kneaded product, and the granular thermosetting resin composition for LDS is a thermosetting resin composition for LDS. A tablet-shaped thermosetting resin composition for LDS is an aggregate obtained by solidifying composition powders (powder-like kneaded material) or granules obtained by a known granulation method. It is a shaped body shaped to have a predetermined shape by compressing a resin composition under high pressure, and a sheet-shaped thermosetting resin composition for LDS is, for example, a sheet shaped body or a roll that can be rolled up. It means a resin film made of a thermosetting resin composition having a shape.

In this embodiment, the powder, granule, tablet, or sheet-like thermosetting resin composition for LDS may be in a semi-cured state (B-stage state).

[Molding]
Examples of the method for molding the thermosetting resin composition in this embodiment include mold formation such as injection molding and transfer molding. By using such a molding method, a resin molded article including a cured product of the thermosetting resin composition can be manufactured.

[Circuit board]
The thermosetting resin composition of the present embodiment provides a cured product that has excellent dielectric properties such as low dielectric constant and low dielectric loss tangent, and is also excellent in forming a plating layer. It is possible to provide a circuit component including a circuit formed on the surface of the circuit, a circuit board or a high frequency antenna including the circuit component, and the like.
For example, a substrate obtained by curing the thermosetting resin composition can be used as a circuit board such as a dielectric substrate for a microstrip antenna.

Here, explanation will be given using a microstrip antenna as an example.
Specifically, as shown in FIG. 1, the microstrip antenna 10 includes a dielectric substrate 12 formed by curing the above-mentioned thermosetting resin composition, and a radiator provided on one surface of the dielectric substrate 12. It includes a conductor plate (radiating element) 14 and a ground conductor plate 16 provided on the other surface of the dielectric substrate 12. At least a portion of the radiation conductor plate 12 is embedded in the dielectric substrate 12.

The shape of the radiation conductor plate may be rectangular or circular. In this embodiment, an example using a rectangular radiation conductor plate 14 will be explained.

The radiation conductor plate 14 includes any one of a metal material, an alloy of metal materials, a cured product of metal paste, and a conductive polymer. Metal materials include copper, silver, palladium, gold, platinum, aluminum, chromium, nickel, cadmium lead, selenium, manganese, tin, vanadium, lithium, cobalt, titanium, and the like. Alloys include multiple metallic materials. The metal paste agent includes one obtained by kneading a powder of a metal material with an organic solvent and a binder. The binder includes epoxy resin, polyester resin, polyimide resin, polyamideimide resin, and polyetherimide resin. Conductive polymers include polythiophene polymers, polyacetylene polymers, polyaniline polymers, polypyrrole polymers, and the like.

As shown in FIG. 1, the microstrip antenna 10 of this embodiment has a radiation conductor plate 14 with a length L and a width W, and resonates at a frequency where L corresponds to an integral multiple of 1/2 wavelength. . When using the dielectric substrate 12 having a high dielectric constant as in this embodiment, the thickness h of the dielectric substrate 12 and the width W of the radiation conductor plate 14 are designed to be sufficiently small with respect to the wavelength.

The ground conductor plate 16 is a thin plate made of a highly conductive metal such as copper, silver, or gold. The thickness may be sufficiently thin relative to the center operating frequency of the antenna device, and may be about 1/50th to 1/1000th wavelength of the center operating frequency.

Power feeding methods for microstrip antennas include direct feeding methods such as back coaxial feeding and coplanar feeding, and electromagnetic coupling feeding methods such as slot coupled feeding and proximity coupled feeding.

In the rear coaxial power feeding, power can be fed from the back surface of the antenna to the radiation conductor plate 14 using a coaxial line or a connector that penetrates the ground conductor plate 16 and the dielectric substrate 12.
In coplanar power feeding, power can be fed to the radiation conductor plate 14 using a microstrip line (not shown) arranged on the same plane as the radiation conductor plate 14.

In the slot coupled power supply, another dielectric substrate (not shown) is provided to sandwich the ground conductor plate 16, and the radiation conductor plate 14 and the microstrip line are formed on separate dielectric substrates. The radiation conductor plate 14 is excited by electromagnetically coupling the radiation conductor plate 14 and the microstrip line through a slot formed in the ground conductor plate 16.

In the close-coupled power supply, the dielectric substrate 12 has a laminated structure, and includes a dielectric substrate on which the radiation conductor plate 14 is formed, and a dielectric substrate on which the strip conductor of the microstrip line and the ground conductor plate 16 are arranged. It is layered. The radiation conductor plate 14 is excited by extending the strip conductor of the microstrip line below the radiation conductor plate 14 and electromagnetically coupling the radiation conductor plate 14 and the microstrip line.
Note that a plurality of radiation conductor plates 14 may be provided on the dielectric substrate 12.

[Circuit board manufacturing method]
A circuit board can be manufactured using the thermosetting resin composition for LDS of this embodiment. The manufacturing method includes, for example, the following steps.
Step a: A dielectric substrate made of a cured product of the thermosetting resin composition for LDS of this embodiment is formed on the surface of a metal substrate.
Step b: irradiate active energy rays onto a predetermined range of the surface of the dielectric substrate to activate it to a state where metal can be deposited.
Step c: Perform plating to deposit metal on the activated surface of the dielectric substrate to form a metal layer.

In this embodiment, a method for manufacturing a microstrip antenna will be described as an example with reference to FIG.

In step a, a dielectric substrate 24 made of a cured product of the thermosetting resin composition for LDS of this embodiment is formed on the surface of the metal substrate 22 by transfer molding or compression molding (FIG. 2(a)). . The metal substrate 22 can have the same configuration as the ground conductor plate 16 described above.

In step b, a predetermined range 24a on the upper surface of the dielectric substrate 24, that is, a location where a radiation conductor plate is desired to be formed, is irradiated with active energy rays to activate the surface of the dielectric substrate 24 to a state where metal can be deposited. (Figure 2(b)).

In this embodiment, for example, a laser can be used as the active energy ray. The laser can be appropriately selected from known lasers such as a YAG laser, an excimer laser, and an electromagnetic beam, and a YGA laser is preferred. Further, the wavelength of the laser is not particularly limited, but is, for example, 200 nm to 12,000 nm. Among these, preferably 248 nm, 308 nm, 355 nm, 532 nm, 1064 nm or 10600 nm may be used.

Since the dielectric substrate 24 contains copper tungstate (CuWO ₄ ), which is a non-conductive metal compound, as the LDS additive (D), it cannot be irradiated with active energy rays such as a YAG laser having an absorbable wavelength range. It is thought that then, the metal nucleus is activated (for example, reduced) and a metal nucleus capable of metal plating is generated. When the surface of the cured thermosetting resin composition in which the non-conductive metal compound is dispersed is irradiated with the active energy ray, a seed region having a metal core capable of metal plating is formed on the irradiated surface. It is formed. By using the obtained seed region, it becomes possible to form a plating pattern such as a circuit on the surface of the cured product of the thermosetting resin composition.

Next, in step c, a plating process is performed to deposit metal in the activated predetermined area 24a to form a metal layer 28 (FIG. 2(c)). The metal layer 28 is a radiation conductor plate.

As the plating process, either electrolytic plating or electroless plating may be used. By performing plating treatment on the above-mentioned activated region, a metal layer 28 such as a circuit or a radiation conductor plate (plated layer) can be formed. The plating solution is not particularly limited, and a wide variety of known plating solutions can be used, and a plating solution containing copper, nickel, gold, silver, and palladium as metal components may also be used.
Through the above steps, a microstrip antenna can be obtained, and coplanar feeding can be adopted.

If the microstrip antenna uses a direct feeding method such as rear coaxial feeding, the following steps are included as shown in FIG.
Step 1: A dielectric substrate 24 made of a cured product of the thermosetting resin composition for LDS of this embodiment is formed on the surface of the metal substrate 22 (FIG. 3(a)).
Step 2: A through hole 25 is formed in the dielectric substrate 24 so that the surface of the metal substrate 22 is exposed at the bottom.
Step 3: Active energy rays are irradiated onto the side surface of the through hole 25 and a predetermined area 24a on the surface of the dielectric substrate 24 to activate the area to a state where metal can be deposited (FIG. 3(b)).
Step 4: Plating is performed to deposit metal on the side surface of the through hole 25 and a predetermined area 24a on the surface of the dielectric substrate 24 to form a metal layer 26 (FIG. 3(c)).

Since step 1 is the same as step a, the explanation will be omitted.
In step 2, for example, a photoresist layer is formed on the surface of the dielectric substrate 24, and then the portions where through holes are to be formed are selectively removed by exposure and development. Next, the dielectric substrate 24 is etched through the photoresist layer to form a through hole 25 at the bottom through which the surface of the metal substrate 22 is exposed.

Furthermore, in step 3, the photoresist layer is exposed and developed to expose a predetermined range 24a on the surface of the dielectric substrate 24, and active energy rays are applied to the side surface of the through hole 25 and the predetermined range 24a on the surface of the dielectric substrate 24. It is irradiated and activated to a state where metal can be deposited (FIG. 3(b)).

Next, in step 4, a plating process is performed to deposit metal on the side surfaces of the activated through holes 25 and a predetermined area 24a on the surface of the dielectric substrate 24 to form a metal layer 28 (FIG. 3(c)). ). The metal layer 28 constitutes a radiation conductor plate and a coaxial line.
Through the above steps, a microstrip antenna can be obtained, and rear coaxial power feeding can be adopted.

The resin molded product in this embodiment can also be used for three-dimensionally molded circuit components.
A three-dimensional molded circuit component (MOLDED INTERCONNECT DEVICE (hereinafter referred to as "MID")) has three elements: a three-dimensional shape, the above-mentioned resin molded product, and a three-dimensional circuit. This is a part with a circuit formed on the surface of the molded product using a metal film. Specifically, the three-dimensional molded circuit component can include, for example, a resin molded product having a three-dimensional structure and a three-dimensional circuit formed on the surface of this resin molded product. By using such a three-dimensional molded circuit component (MID), space can be used effectively, and the number of components can be reduced and the device can be made lighter, thinner, and smaller.

LDS in this embodiment is one of the manufacturing methods of MID, and active energy rays are used to coat the surface of a cured product (resin molded product with a three-dimensional structure) of a thermosetting resin composition containing an LDS additive. A metal nucleus is generated, and a plating pattern (wiring) can be formed in the energy beam irradiation region by, for example, electroless plating using the metal nucleus as a seed.

In the present embodiment, the manufacturing process of MID includes preparation of a thermosetting resin composition used for LDS, molding of this thermosetting resin composition, irradiation of the obtained resin molded product with active energy rays, and plating treatment. Can include circuit formation. Note that a surface cleaning step may be added before the plating treatment.

In this embodiment, the resin molded product (cured product of a thermosetting resin composition) is not limited to a final product, but can also include composite materials and various parts. The resin molded product can be used as parts for portable electronic devices, vehicles, and medical equipment, other electronic components including electric circuits, semiconductor encapsulants, and composite materials for forming these. Furthermore, the above-mentioned MID can also be applied to a built-in antenna of a mobile phone or a smartphone, an in-vehicle antenna, a sensor, or a semiconductor device. From the viewpoint of the effects of the present invention, the above MID can be suitably used for a built-in antenna of a mobile phone or a smartphone, an in-vehicle antenna, and the like.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above may also be adopted.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto.
The components used in Examples and Comparative Examples are shown below.
(Inorganic filler)
・Inorganic filler 1: Fine powder silica, SC-2500-SQ, manufactured by Admatex, average particle size 0.6 μm, specific surface area 6.4 m ² /g
・Inorganic filler 2: Fine powder silica, SC-5500-SQ, manufactured by Admatex, average particle diameter 1.6 μm, specific surface area 4.4 m ² /g
・Inorganic filler 3: Amorphous silica/crystalline silica, MUF-4V, manufactured by Ryumori Co., Ltd., average particle size 3.8 μm, specific surface area 4.0 m ² /g

(coupling agent)
・Coupling agent 1: N-phenylaminopropyltrimethoxysilane (manufactured by Dow Corning Toray, CF-4083)
・Coupling agent 2: 3-glycidoxypropyltrimethoxysilane (S510, manufactured by Chisso Corporation)

(Epoxy resin)
・Epoxy resin 1: Biphenylaralkyl epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000, containing a structural unit represented by the above general formula (BP1))

(hardening agent)
・Phenol resin: Biphenylene skeleton-containing phenol aralkyl resin (manufactured by Meiwa Kasei Co., Ltd., MEH-7851SS)
・Active ester resin: Active ester resin prepared by the following preparation method (Preparation method of active ester resin)
203.0 g of 1,3-benzenedicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene were placed in a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer. After charging, the system was replaced with nitrogen under reduced pressure to dissolve. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-3). The average value k of the repeating units of the active ester resin was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0. The obtained active ester resin specifically had a structure represented by the following chemical formula. In the following formula, the average value k of the repeating units was 0.5 to 1.0.

(Release agent)
・Release agent 1: Glycerin trimontanate ester (product name: Recolb WE-4, manufactured by Clariant Japan)

[Curing catalyst]
・Curing catalyst 1: Tetraphenylphosphonium-4,4'-sulfonyldiphenolate ・Curing catalyst 2: Tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenyl silicate

(Low stress agent)
・Low stress agent 1: Carboxyl group-terminated butadiene acrylic rubber (product name: CTBN1008SP, manufactured by Ube Industries, Ltd.)

(LDS additive)
・Copper tungstate (CuWO ₄ ): Manufactured by Kojundo Kagaku Kenkyusho Co., Ltd. ・Copper chromate (CuCrO ₄ ): Black3702, manufactured by Asahi Chemical Industries, Ltd.

[Examples 1 to 4, Comparative Examples 1 to 4]
The raw materials in the amounts shown in Table 1 below were mixed using a mixer at room temperature and then kneaded with rolls at 70 to 100°C. Next, the obtained kneaded material was cooled and then ground, to obtain a powdery thermosetting resin composition. Next, a tablet-shaped thermosetting resin composition was obtained by compression molding under high pressure.

(Permittivity (Dk)/Dielectric loss tangent (Df))
The thermosetting resin compositions of Examples 1 to 4 and Comparative Examples 1 to 4 were compressed into tablets, and then transfer molded using a carry-out mold to obtain cured products with a diameter of 50 mm.
Regarding the obtained cured product, the dielectric constant (Dk) and dielectric loss tangent (Df) at 10 GHz were measured using a Q meter according to JIS C2565.

(Plating property)
The resin compositions obtained in each example were molded and cured at 175°C to obtain cured products. The surface of the obtained cured product was irradiated with a YAG laser, and the plating properties in the laser irradiation area were evaluated using the following criteria.
○: No unevenness on the plating surface △: Unevenness is visible on the plating surface, but there are no unplated areas ×: Severe unevenness is visible on the plating surface, and there are unplated areas

As shown in Table 1, according to the thermosetting resin composition for LDS of the present invention, a cured product can be obtained that has excellent dielectric properties such as low dielectric constant and low dielectric loss tangent, and is also excellent in forming a plating layer. It became clear that it could be done.

10 Microstrip antenna 12 Dielectric substrate 14 Radiation conductor plate 16 Ground conductor plate 22 Metal substrate 24 Dielectric substrate 24a Predetermined range 25 Through hole 28 Metal layer

Claims (15)

(A) an epoxy resin;
(B) a curing agent;
(C) an inorganic filler;
(D) LASER DIRECT STRUCTURING (LDS) additive;
including;
LDS additive (D) is a thermosetting resin composition for LDS containing copper tungstate. The thermosetting resin composition for LDS according to claim 1, wherein the curing agent (B) contains at least one selected from an active ester compound (B1) and a phenolic curing agent (B2). The active ester curing agent (B1) includes an active ester curing agent containing a dicyclopentadiene type diphenol structure, an active ester curing agent containing a naphthalene structure, an active ester curing agent containing an acetylated product of phenol novolac, and a phenol curing agent. The thermosetting resin composition for LDS according to claim 2, wherein the thermosetting resin composition is at least one selected from active ester curing agents including benzoylated novolacs. The thermosetting resin composition for LDS according to claim 2 or 3, wherein the active ester curing agent (B1) has a structure represented by the following general formula (1).

(In general formula (1), A is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group, Ar' is a substituted or unsubstituted aryl group,
B is a structure represented by the following general formula (B),

(In the general formula (B), Ar is a substituted or unsubstituted arylene group, and Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted is a cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. n is 0 or 1)
k is the average value of repeating units and ranges from 0.25 to 3.5. ) The thermosetting resin composition for LDS according to claim 1 or 2, wherein the inorganic filler (C) has a dielectric constant of 4.2 or less. The thermosetting resin composition for LDS according to claim 1 or 2, wherein the inorganic filler (C) contains silica. The heat for LDS according to claim 6, wherein the epoxy resin (A) contains at least one selected from an orthocresol novolac type epoxy resin, a phenol aralkyl type epoxy resin having a biphenylene skeleton, and a triphenylmethane type epoxy resin. Curable resin composition. The thermosetting resin composition for LDS according to claim 1, further comprising a coupling agent (E). A molded article comprising a cured product of the thermosetting resin composition for LDS according to claim 1 or 2. A circuit component comprising a cured product of the thermosetting resin composition for LDS according to claim 1 or 2, and a circuit formed on the surface of the cured product. A circuit board comprising the circuit component according to claim 10. A high frequency antenna comprising the circuit component according to claim 10. A dielectric substrate made of a cured product of the thermosetting resin composition for LDS according to claim 1 or 2;
a radiation conductor plate provided on one surface of the dielectric substrate;
a ground conductor plate provided on the other surface of the dielectric substrate;
Microstrip antenna. forming a dielectric substrate made of a cured product of the thermosetting resin composition for LDS according to claim 1 or 2 on the surface of the metal substrate;
irradiating active energy rays to a predetermined range of the dielectric substrate surface to activate it to a state where metal can be deposited;
performing plating treatment and depositing metal on the activated surface of the dielectric substrate to form a metal layer;
A method of manufacturing a circuit board, including: Before the activation step, a step of forming a through hole in the dielectric substrate through which the surface of the metal substrate is exposed at the bottom,
The activation step is a step of irradiating the active energy rays to a predetermined range of the side surface of the through hole and the surface of the dielectric substrate to activate the metal to a state where metal can be deposited,
14. The metal layer forming step is a step of performing a plating process and depositing metal on the side surface of the activated through hole and the activated surface of the dielectric substrate to form a metal layer. A method for manufacturing a circuit board as described in .

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