JP7537146B2 - Resin composition - Google Patents

Description

The present invention relates to a resin composition. It also relates to a resin sheet, a printed wiring board, and a semiconductor device obtained using the resin composition.

A known manufacturing technique for printed wiring boards is a build-up method in which insulating layers and conductor layers are alternately stacked. For example, the resin composition disclosed in Patent Document 1 is known as an insulating material for printed wiring boards used in such insulating layers.

JP 2005-220270 A

With the recent trend towards higher transmission speeds, there is a demand for insulating materials with even lower dielectric tangents and dielectric constants. To improve such dielectric properties, a resin having a benzocyclobutene group, which is a reactive functional group with low polarity (hereinafter simply referred to as "benzocyclobutene resin") is expected to be used as a curable resin for insulating materials. However, the inventors have found that when such a benzocyclobutene resin is used to form a cured product (insulating layer), the adhesiveness to the conductor layer may be poor, and the obtained cured product may have poor mechanical strength.

The objective of the present invention is to provide a resin composition that exhibits excellent dielectric properties and produces a cured product that has good adhesion to a conductor layer and mechanical strength.

As a result of intensive research aimed at solving the above problems, the inventors discovered that by using a benzocyclobutene resin in combination with a maleimide compound having a specific structure and an inorganic filler, it is possible to obtain a cured product that has good adhesion to the conductor layer and good mechanical strength while maintaining low dielectric tangent and dielectric constant, and thus completed the present invention.

（式（Ｂ１－１）中、
Ａ^１は、置換基を有していてもよい炭素原子数５以上の脂肪族基を表し、
Ｌ^１は、単結合又は２価の連結基を表し、
ｎＢ１は０～２０の整数を表す。Ａ^１が複数ある場合、それらは同一でも相異なってもよく、Ｌ^１が複数ある場合、それらは同一でも相異なってもよい。）
［３］ （Ｂ２）成分が、下記式（Ｂ２－１）で表される化合物を含む、［１］又は［２］に記載の樹脂組成物。

（式（Ｂ２－１）中、
環Ａｒ^１は、置換基を有していてもよい芳香族環を表し、
Ｌ^２は、単結合又は２価の連結基を表し、
ｎＢ２は、１～１００の整数を表す。複数ある環Ａｒ^１は同一でも相異なってもよく、Ｌ^２が複数ある場合、それらは同一でも相異なってもよい。）
［４］ （Ｃ）成分の含有量が、樹脂組成物中の不揮発成分を１００質量％とした場合、３０質量％以上かつ８０質量％以下である、［１］～［３］の何れかに記載の樹脂組成物。
［５］ （Ａ）成分の含有量が、樹脂組成物中の不揮発成分を１００質量％とした場合、１質量％以上かつ５０質量％以下である、［１］～［４］の何れかに記載の樹脂組成物。
［６］ （Ａ）成分が２つ以上のベンゾシクロブテン基を有し、数平均分子量（Ｍｎ）が２０００以下である、［１］～［５］の何れかに記載の樹脂組成物。
［７］ （Ｄ）フェニレンエーテル骨格を含む硬化性樹脂をさらに含む、［１］～［６］の何れかに記載の樹脂組成物。
［８］ （Ｄ）成分が、下記式（Ｄ－１）で表される化合物を含む、［７］に記載の樹脂組成物。

（式（Ｄ－１）中、
Ｘは、ラジカル重合性不飽和基を有する１価の基を表し、
Ｌ^３は、２価の連結基を表し、
Ｒ^Ｄ１１及びＲ^Ｄ１２は、それぞれ独立に、置換基を表し、
ｎＤ１１及びｎＤ１２は、それぞれ独立に、０～４の整数を表し、
ｎＤ１及びｎＤ２は、少なくとも一方が１以上の整数であることを条件として、それぞれ独立に、０～３００の整数を表す。複数あるＸは同一でも相異なってもよく、Ｒ^Ｄ１１が複数ある場合、それらは同一でも相異なってもよく、Ｒ^Ｄ１２が複数ある場合、それらは同一でも相異なってもよい。）
［９］ （Ｄ）成分のＭｎが２５００以下である、［７］又は［８］に記載の樹脂組成物。
［１０］ （Ａ）成分がシロキサン骨格を有する、［１］～［９］の何れかに記載の樹脂組成物。
［１１］ （Ｂ）成分の含有量が、樹脂組成物中の不揮発成分を１００質量％とした場合、１質量％以上かつ３０質量％以下である、［１］～［１０］の何れかに記載の樹脂組成物。
［１２］ （Ｄ）成分の含有量が、樹脂組成物中の不揮発成分を１００質量％とした場合、１質量％以上かつ４０質量％以下である、［７］～［１１］の何れかに記載の樹脂組成物。
［１３］ （Ａ）成分が、下記式（Ａ－２）で表される化合物を含む、［１］～［１２］の何れかに記載の樹脂組成物。

（式（Ａ－２）中、
Ｒ^１は、不飽和結合を有する２価の脂肪族基を表し、
Ｒ^２は、水素原子、アルキル基、シクロアルキル基、アリールアルキル基、又はアリール基を表し、
Ｒ^Ａ１は、アルキル基、シアノ基又はハロゲン原子を表し、
Ｒ^Ａ２は、アルキル基、トリアルキルシリル基、アルコキシ基又はハロゲン原子を表し、
ｎＡ１は、０～２の整数を表し、
ｎＡ２は、０～３の整数を表し、
ｎＡ４は、１～１０の整数を表す。Ｒ^１、Ｒ^２、Ｒ^Ａ１及びＲ^Ａ２は、それぞれ独立に、置換基を有していてもよい。複数あるＲ^１は同一でも相異なってもよく、複数あるＲ^２は同一でも相異なってもよく、Ｒ^Ａ１が複数ある場合、それらは同一でも相異なってもよく、Ｒ^Ａ２が複数ある場合、それらは同一でも相異なってもよい。）
［１４］ （Ａ）成分が、下記式で表される化合物を含む、［１］～［１３］の何れかに記載の樹脂組成物。

［１５］ （Ｂ２）成分がビフェニル骨格を有する、［１］～［１４］の何れかに記載の樹脂組成物。
［１６］ 硬化物の誘電率の値が３．０以下である、［１］～［１５］の何れかに記載の樹脂組成物。
［１７］ 硬化物の誘電正接の値が０．００３０以下である、［１］～［１６］の何れかに記載の樹脂組成物。
［１８］ 硬化物の２５℃～８０℃の範囲における線熱膨張率が４０ｐｐｍ／℃以下である、［１］～［１７］の何れかに記載の樹脂組成物。
［１９］ プリント配線板の絶縁層用である、［１］～［１８］の何れかに記載の樹脂組成物。
［２０］ プリント配線板の層間絶縁層用である、［１］～［１９］の何れかに記載の樹脂組成物。
［２１］ 支持体と、該支持体上に設けられた［１］～［２０］の何れかに記載の樹脂組成物の層とを含む、樹脂シート。
［２２］ ［１］～［２０］の何れかに記載の樹脂組成物の硬化物からなる絶縁層を含む、プリント配線板。
［２３］ ［１］～［２０］の何れかに記載の樹脂組成物の硬化物からなる絶縁層を含む、半導体装置。 That is, the present invention includes the following.
[1] (A) benzocyclobutene resin,
(B) a maleimide compound,
(C) containing an inorganic filler,
The component (B) is
(B1) a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to a nitrogen atom of the maleimide, and (B2) a maleimide compound having an aromatic ring directly bonded to a nitrogen atom of the maleimide, the maleimide compound having a molecular weight of 500 or more;
The resin composition is one or more selected from the following.
[2] The resin composition according to [1], wherein the component (B1) contains a compound represented by the following formula (B1-1):

(In formula (B1-1),
A ¹ represents an aliphatic group having 5 or more carbon atoms which may have a substituent;
L ¹ represents a single bond or a divalent linking group;
nB1 represents an integer of 0 to 20. When there are a plurality of ^A1's , they may be the same or different, and when there are a plurality of ^L1's , they may be the same or different.
[3] The resin composition according to [1] or [2], wherein the component (B2) contains a compound represented by the following formula (B2-1):

(In formula (B2-1),
Ring Ar ¹ represents an aromatic ring which may have a substituent;
^L2 represents a single bond or a divalent linking group;
nB2 represents an integer of 1 to 100. A plurality of rings ^Ar1 may be the same or different, and when a plurality of ^L2s are present, they may be the same or different.
[4] The resin composition according to any one of [1] to [3], wherein the content of the component (C) is 30% by mass or more and 80% by mass or less, when the total amount of non-volatile components in the resin composition is 100% by mass.
[5] The resin composition according to any one of [1] to [4], wherein the content of the component (A) is 1 mass% or more and 50 mass% or less, when the total amount of non-volatile components in the resin composition is 100 mass%.
[6] The resin composition according to any one of [1] to [5], wherein the component (A) has two or more benzocyclobutene groups and has a number average molecular weight (Mn) of 2,000 or less.
[7] The resin composition according to any one of [1] to [6], further comprising (D) a curable resin having a phenylene ether skeleton.
[8] The resin composition according to [7], wherein the component (D) contains a compound represented by the following formula (D-1):

(In formula (D-1),
X represents a monovalent group having a radically polymerizable unsaturated group,
^L3 represents a divalent linking group;
^R and ^R each independently represent a substituent.
nD11 and nD12 each independently represent an integer of 0 to 4;
nD1 and nD2 each independently represent an integer from 0 to 300, provided that at least one of them is an integer of 1 or more. Multiple Xs may be the same or different, when there are multiple R ^D11s , they may be the same or different, and when there are multiple R ^D12s , they may be the same or different.
[9] The resin composition according to [7] or [8], wherein the Mn of the (D) component is 2,500 or less.
[10] The resin composition according to any one of [1] to [9], wherein the component (A) has a siloxane skeleton.
[11] The resin composition according to any one of [1] to [10], wherein the content of the component (B) is 1 mass% or more and 30 mass% or less, when the total amount of non-volatile components in the resin composition is 100 mass%.
[12] The resin composition according to any one of [7] to [11], wherein the content of the (D) component is 1 mass% or more and 40 mass% or less, when the total amount of non-volatile components in the resin composition is 100 mass%.
[13] The resin composition according to any one of [1] to [12], wherein the component (A) contains a compound represented by the following formula (A-2):

(In formula (A-2),
R ¹ represents a divalent aliphatic group having an unsaturated bond;
^R2 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an arylalkyl group, or an aryl group;
R ^A1 represents an alkyl group, a cyano group or a halogen atom;
R ^A2 represents an alkyl group, a trialkylsilyl group, an alkoxy group or a halogen atom;
nA1 represents an integer of 0 to 2;
nA2 represents an integer of 0 to 3;
nA4 represents an integer of 1 to 10. R ¹ , R ² , R ^A1 and R ^A2 may each independently have a substituent. A plurality of R ¹ 's may be the same or different, a plurality of R ² 's may be the same or different, when there are a plurality of R ^A1's , they may be the same or different, and when there are a plurality of R ^A2's , they may be the same or different.
[14] The resin composition according to any one of [1] to [13], wherein the component (A) contains a compound represented by the following formula:

[15] The resin composition according to any one of [1] to [14], wherein the component (B2) has a biphenyl skeleton.
[16] The resin composition according to any one of [1] to [15], wherein the dielectric constant of the cured product is 3.0 or less.
[17] The resin composition according to any one of [1] to [16], wherein the cured product has a dielectric tangent value of 0.0030 or less.
[18] The resin composition according to any one of [1] to [17], wherein the linear thermal expansion coefficient of the cured product in the range of 25°C to 80°C is 40 ppm/°C or less.
[19] The resin composition according to any one of [1] to [18], which is for use in an insulating layer of a printed wiring board.
[20] The resin composition according to any one of [1] to [19], which is for use in an interlayer insulating layer of a printed wiring board.
[21] A resin sheet comprising a support and a layer of the resin composition according to any one of [1] to [20] provided on the support.
[22] A printed wiring board comprising an insulating layer made of a cured product of the resin composition according to any one of [1] to [20].
[23] A semiconductor device comprising an insulating layer made of a cured product of the resin composition according to any one of [1] to [20].

The present invention provides a resin composition that exhibits excellent dielectric properties and produces a cured product that has good adhesion to a conductor layer and mechanical strength.

<Terminology>
As used herein, the term "optionally substituted" in reference to a compound or group means both the case where the hydrogen atoms of the compound or group are not substituted with substituents, and the case where some or all of the hydrogen atoms of the compound or group are substituted with substituents.

In this specification, unless otherwise specified, the term "substituent" means a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkyloxy group, an aryl group, an aryloxy group, an arylalkyl group, an arylalkoxy group, a monovalent heterocyclic group, an alkylidene group, an amino group, a silyl group, an acyl group, an acyloxy group, a carboxy group, a sulfo group, a cyano group, a nitro group, a hydroxy group, a mercapto group, and an oxo group.

Halogen atoms used as substituents include, for example, fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

The alkyl group used as a substituent may be either linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 1 to 14, even more preferably 1 to 12, even more preferably 1 to 6, and particularly preferably 1 to 3. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.

The number of carbon atoms in the cycloalkyl group used as a substituent is preferably 3 to 20, more preferably 3 to 12, and even more preferably 3 to 6. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

The alkoxy group used as a substituent may be either linear or branched. The number of carbon atoms in the alkoxy group is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, a sec-butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, and a decyloxy group.

The number of carbon atoms in the cycloalkyloxy group used as a substituent is preferably 3 to 20, more preferably 3 to 12, and even more preferably 3 to 6. Examples of the cycloalkyloxy group include a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, and a cyclohexyloxy group.

The aryl group used as a substituent is a group in which one hydrogen atom on the aromatic ring has been removed from an aromatic hydrocarbon. The number of carbon atoms in the aryl group used as a substituent is preferably 6 to 24, more preferably 6 to 18, even more preferably 6 to 14, and even more preferably 6 to 10. Examples of the aryl group include a phenyl group, a naphthyl group, and an anthracenyl group.

The number of carbon atoms in the aryloxy group used as a substituent is preferably 6 to 24, more preferably 6 to 18, even more preferably 6 to 14, and even more preferably 6 to 10. Examples of the aryloxy group used as a substituent include a phenoxy group, a 1-naphthyloxy group, and a 2-naphthyloxy group.

The number of carbon atoms in the arylalkyl group used as a substituent is preferably 7 to 25, more preferably 7 to 19, even more preferably 7 to 15, and even more preferably 7 to 11. Examples of the arylalkyl group include a phenyl-C ₁ to C ₁₂ alkyl group, a naphthyl-C ₁ to C ₁₂ alkyl group, and an anthracenyl-C ₁ to C ₁₂ alkyl group.

The number of carbon atoms in the arylalkoxy group used as a substituent is preferably 7 to 25, more preferably 7 to 19, even more preferably 7 to 15, and even more preferably 7 to 11. Examples of the arylalkoxy group include a phenyl-C ₁ to C ₁₂ alkoxy group and a naphthyl-C ₁ to C ₁₂ alkoxy group.

The monovalent heterocyclic group used as a substituent refers to a group in which one hydrogen atom has been removed from the heterocycle of a heterocyclic compound. The number of carbon atoms in the monovalent heterocyclic group is preferably 3 to 21, more preferably 3 to 15, and even more preferably 3 to 9. The monovalent heterocyclic group also includes a monovalent aromatic heterocyclic group (heteroaryl group). Examples of the monovalent heterocycle include a thienyl group, a pyrrolyl group, a furanyl group, a furyl group, a pyridyl group, a pyridazinyl group, a pyrimidyl group, a pyrazinyl group, a triazinyl group, a pyrrolidyl group, a piperidyl group, a quinolyl group, and an isoquinolyl group.

The alkylidene group used as a substituent refers to a group in which two hydrogen atoms have been removed from the same carbon atom of an alkane. The number of carbon atoms in the alkylidene group is preferably 1 to 20, more preferably 1 to 14, even more preferably 1 to 12, even more preferably 1 to 6, and particularly preferably 1 to 3. Examples of the alkylidene group include a methylidene group, an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, a sec-butylidene group, an isobutylidene group, a tert-butylidene group, a pentylidene group, a hexylidene group, a heptylidene group, an octylidene group, a nonylidene group, and a decylidene group.

The acyl group used as a substituent is a group represented by the formula -C(=O)-R (wherein R is an alkyl group or an aryl group). The alkyl group represented by R may be either linear or branched. Examples of the aryl group represented by R include a phenyl group, a naphthyl group, and an anthracenyl group. The number of carbon atoms in the acyl group is preferably 2 to 20, more preferably 2 to 13, and even more preferably 2 to 7. Examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, and a benzoyl group.

The acyloxy group used as a substituent is a group represented by the formula: -O-C(=O)-R (wherein R is an alkyl group or an aryl group). The alkyl group represented by R may be either linear or branched. Examples of the aryl group represented by R include a phenyl group, a naphthyl group, and an anthracenyl group. The number of carbon atoms in the acyloxy group is preferably 2 to 20, more preferably 2 to 13, and even more preferably 2 to 7. Examples of the acyloxy group include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a pivaloyloxy group, and a benzoyloxy group.

The above-mentioned substituents may further have a substituent (hereinafter, sometimes referred to as a "secondary substituent"). Unless otherwise specified, the secondary substituent may be the same as the above-mentioned substituent.

As used herein, the term "aromatic ring" refers to a ring that follows Hückel's rule, in which the number of electrons in the pi-electron system of the ring is 4n+2 (n is a natural number), and includes monocyclic aromatic rings and fused aromatic rings in which two or more monocyclic aromatic rings are fused together. The aromatic ring may be a carbocyclic or heterocyclic ring. Examples of aromatic rings include monocyclic aromatic rings such as a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an imidazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, and a pyrazine ring; condensed rings in which two or more monocyclic aromatic rings are condensed, such as a naphthalene ring, an anthracene ring, a benzofuran ring, an isobenzofuran ring, an indole ring, an isoindole ring, a benzothiophene ring, a benzimidazole ring, an indazole ring, a benzoxazole ring, a benzisoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, an acridine ring, a quinazoline ring, a cinnoline ring, and a phthalazine ring; and condensed rings in which one or more monocyclic aromatic rings are condensed to one or more monocyclic non-aromatic rings, such as an indane ring, a fluorene ring, and a tetralin ring.

In this specification, the term "non-aromatic ring" means a ring other than an aromatic ring, and includes a monocyclic non-aromatic ring and a fused non-aromatic ring in which two or more monocyclic non-aromatic rings are fused. The non-aromatic ring may be a carbocyclic ring or a heterocyclic ring. The non-aromatic ring may be a saturated or unsaturated ring. Examples of non-aromatic rings include a cycloalkane ring; a cycloalkene ring; a monocyclic non-aromatic heterocyclic ring (preferably 3 to 10 members) such as a pyrrolidine ring, a tetrahydrofuran ring, a dioxane ring, or a tetrahydropyran ring; and a bicyclic or higher fused non-aromatic carbocyclic ring (preferably 8 to 15 members) such as a norbornane ring, a decalin ring, an adamantane ring, or a tetrahydrodicyclopentadiene ring.

The present invention will be described in detail below based on its preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and can be modified as desired without departing from the scope of the claims of the present invention and their equivalents.

[Resin composition]
The resin composition of the present invention comprises (A) a benzocyclobutene resin, (B) a maleimide compound, and (C) an inorganic filler,
The component (B) is
(B1) a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to a nitrogen atom of the maleimide, and (B2) a maleimide compound having an aromatic ring directly bonded to a nitrogen atom of the maleimide, the maleimide compound having a molecular weight of 500 or more;
The present invention is characterized in that the compound is one or more selected from the following:

Benzocyclobutene resin produces an isomeric diene (orthoquinodimethane) when heated, and this diene undergoes a Diels-Alder type cycloaddition reaction, which can cure the resin. Benzocyclobutene resin is expected to produce a cured product with excellent dielectric properties, since the curing reaction does not produce highly polar functional groups such as hydroxyl groups. However, the present inventors have found that when such a cured product (insulating layer) is formed using this benzocyclobutene resin, the adhesiveness to the conductor layer may be poor, and the resulting cured product may have poor mechanical strength. It is presumed that the above reaction of benzocyclobutene resin requires high temperatures, and its reactivity in the presence of oxygen is poor, which makes it difficult to obtain the desired crosslinking properties and thermal history.

In contrast, the resin composition of the present invention, which uses a benzocyclobutene resin in combination with a maleimide compound having a specific structure and an inorganic filler, can provide a cured product that has good adhesion to a conductor layer and good mechanical strength while retaining the advantages of the excellent dielectric properties of the benzocyclobutene resin, such as low dielectric tangent and low dielectric constant. Furthermore, the present inventors have found that the resin composition of the present invention, which uses a benzocyclobutene resin in combination with a maleimide compound having a specific structure and an inorganic filler, also improves thermal properties. In this way, the present invention realizes a cured product that has good adhesion to a conductor layer, mechanical strength, and thermal properties while retaining the advantages of the excellent dielectric properties inherent to benzocyclobutene resin, and significantly contributes to the recent demand for high-speed transmission.

-(A) Benzocyclobutene resin-
The resin composition of the present invention contains a benzocyclobutene resin as component (A), which can provide a cured product (insulating layer) with excellent dielectric properties.

The structure of component (A) is not particularly limited as long as it contains a benzocyclobutene group that can generate an isomeric diene upon heating. In order to provide a cured product with good adhesion to the conductor layer and good mechanical strength in combination with components (B) and (C) described below, it is preferable that component (A) has two or more benzocyclobutene groups in one molecule.

In one embodiment, component (A) contains a compound represented by the following formula (A-1):

In formula (A-1),
R ¹ represents a divalent aliphatic group having an unsaturated bond;
L represents a single bond or a divalent linking group;
R ^A1 represents an alkyl group, a cyano group or a halogen atom;
R ^A2 represents an alkyl group, a trialkylsilyl group, an alkoxy group or a halogen atom;
nA1 represents an integer of 0 to 2;
nA2 represents an integer of 0 to 3;
nA3 represents 0 or 1. R ¹ , R ^A1 and R ^A2 may each independently have a substituent. A plurality of R ¹ may be the same or different, when there are a plurality of R ^A1 s, they may be the same or different, when there are a plurality of R ^{A2 s} , they may be the same or different.

The divalent group represented by ^R1 preferably has 1 to 3 unsaturated bonds, more preferably 1 or 2 unsaturated bonds, and even more preferably 1 unsaturated bond. The unsaturated bond may be a double bond or a triple bond, but is preferably a double bond. The divalent group represented by ^R1 is preferably an alkenylene group or an alkynylene group. The number of carbon atoms in the divalent group represented by ^R1 is preferably 2 to 10, more preferably 2 to 6 or 2 to 4. The number of carbon atoms in the above does not include the number of carbon atoms of the substituent.

The divalent linking group represented by L is not particularly limited as long as it is a divalent group consisting of one or more (e.g., 1 to 3000, 1 to 1000, 1 to 100, 1 to 50) skeleton atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, sulfur atoms, and silicon atoms, and may be, for example, a divalent group described as ^A12 in formula (B1-3) described later, or a siloxane skeleton. Among these, L is preferably a siloxane skeleton. Thus, in one embodiment, component (A) has a siloxane skeleton.

The number of carbon atoms in ^the alkyl group represented by R is preferably 1 to 10, more preferably 1 to 6, 1 to 4, or 1 to 3. The number of carbon atoms in the substituent is not included in the number of carbon atoms. The halogen atom represented by ^R is preferably a chlorine atom or a bromine atom.

The number of carbon atoms in the alkyl group and alkoxy group represented by ^R is preferably 1 to 10, more preferably 1 to 6, 1 to 4 or 1 to 3. The number of carbon atoms in the alkyl portion of the trialkylsilyl group represented by ^R is preferably 1 to 3, more preferably 1 or 2. The number of carbon atoms in the substituents is not included in the above number of carbon atoms. In addition, the halogen atom represented by ^R is preferably a chlorine atom or a bromine atom.

In combination with the components (B) and (C) described below, from the viewpoint of producing a cured product with good adhesion to the conductor layer, in formula (A-1), nA3 is preferably 1 and L is preferably a siloxane skeleton.

In a preferred embodiment, component (A) contains a compound represented by the following formula (A-2):

In formula (A-2),
R ¹ , R ^A1 , R ^A2 , nA1 and nA2 are as described in formula (A-1).
^R2 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an arylalkyl group, or an aryl group;
nA4 represents an integer of 1 to 10. ^R2 may have a substituent. A plurality of ^R2 may be the same or different.

The number of carbon atoms in the alkyl group represented by ^R2 is preferably 1 to 10, more preferably 1 to 6, 1 to 4, or 1 to 3. The number of carbon atoms in the cycloalkyl group represented by ^R2 is preferably 3 to 10, more preferably 4 to 6. The number of carbon atoms in the arylalkyl group represented by ^R2 is preferably 7 to 20, more preferably 7 to 15, or 7 to 12. The aryl moiety in the arylalkyl group is preferably a phenyl group. The number of carbon atoms in the aryl group represented by ^R2 is preferably 6 to 14, more preferably 6 to 10. The aryl group is preferably a phenyl group. The number of carbon atoms in the substituent is not included in the above number of carbon atoms.

R ¹ , R ^A1 , R ^A2 , nA1 and nA2 are as explained in formula (A-1). Among them, it is preferable that R ¹ is an alkenylene group having 2 to 4 carbon atoms, and nA1 and nA2 are 0.

In a particularly preferred embodiment, component (A) contains a compound represented by the following formula (A-3):

In formula (A-3), ^R2 and nA4 are as described in formula (A-2).

Component (A) can be prepared according to the procedures described in, for example, U.S. Pat. No. 4,812,588 and U.S. Pat. No. 5,138,081. Component (A) may also be a commercially available product. For example, the compound represented by formula (A-3) is the CYCLOTENE series manufactured by Dow Chemical Company, and "CYCLOTENE 3022" has the structure represented by the following formula:

As mentioned above, the benzocyclobutene group produces an isomeric diene, which undergoes a Diels-Alder type cycloaddition reaction. Therefore, in addition to the compounds (monomers) represented by the above formulas (A-1) to (A-3), component (A) may also contain dimers or polymers produced by the addition reaction of such compounds.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the (A) component are not particularly limited as long as the effects of the present invention are achieved in combination with the (B) and (C) components described below. In one embodiment, Mn is preferably 2000 or less, more preferably 1800 or less, and even more preferably 1600 or less, 1500 or less, 1400 or less, 1200 or less, or 1000 or less. In one embodiment, Mw is also in the above-mentioned preferred range. The lower limit of the molecular weight is not particularly limited, and may be, for example, 250 or more, 300 or more, 350 or more, etc. The Mw and Mn of the (A) component can be measured as polystyrene equivalent values by gel permeation chromatography (GPC).

From the viewpoint of realizing a cured product with excellent dielectric properties, the content of the (A) component in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, or 7% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass. The upper limit of the content of the (A) component is not particularly limited, but is preferably 50% by mass or less, more preferably 40% by mass or less, 35% by mass or less, or 30% by mass or less. Therefore, in a preferred embodiment, the content of the (A) component is 1% by mass or more and 50% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

-(B) Maleimide compound-
The resin composition of the present invention contains a maleimide compound as component (B), and the component (B) is a maleimide compound having a specific structure, specifically,
(B1) a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to a nitrogen atom of the maleimide, and (B2) a maleimide compound having an aromatic ring directly bonded to a nitrogen atom of the maleimide, the maleimide compound having a molecular weight of 500 or more;
The resin composition of the present invention is characterized in that the component (B2) is one or more selected from the following. In addition, when the component (B2) has a biphenyl skeleton in addition to an aromatic ring directly bonded to the nitrogen atom of the maleimide, the desired effect is achieved regardless of the molecular weight. Therefore, the resin composition of the present invention may use, as the component (B2), a maleimide compound having an aromatic ring directly bonded to the nitrogen atom of the maleimide and a biphenyl skeleton.

The term "directly" means that in the case of component (B1), there is no other group between the nitrogen atom of the maleimide and the aliphatic group having 5 or more carbon atoms, and in the case of component (B2), there is no other group between the nitrogen atom of the maleimide and the aromatic ring.

The resin composition of the present invention uses a combination of the above-mentioned component (A) and the specific structure of component (B), which allows the realization of a cured product that has excellent adhesion to the conductor layer, mechanical strength, and thermal properties while retaining the inherent advantage of the excellent dielectric properties of component (A).

Regardless of whether component (B) is component (B1) or component (B2), it is preferable that one molecule contains two or more maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups).

<Component (B1)>
The component (B1) is a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to a nitrogen atom of the maleimide. Such a maleimide compound can be obtained, for example, by subjecting a component containing an aliphatic amine compound (such as a diamine compound having a dimer acid skeleton), maleic anhydride, and, if necessary, a tetracarboxylic dianhydride to an imidization reaction.

In one embodiment, component (B1) includes a compound represented by the following formula (B1-1):

In formula (B1-1),
A ¹ represents an aliphatic group having 5 or more carbon atoms which may have a substituent;
L ¹ represents a single bond or a divalent linking group;
nB1 represents an integer of 0 to 20. When there are a plurality of ^A1's , they may be the same or different, and when there are a plurality of ^L1's , they may be the same or different.

The number of carbon atoms in the aliphatic group represented by ^A1 is 5 or more, and preferably 10 or more, 15 or more, or 20 or more. The upper limit of the number of carbon atoms is not particularly limited, and may be, for example, 100 or less, 80 or less, 60 or less, or 50 or less. The number of carbon atoms does not include the number of carbon atoms of the substituent.

In one embodiment, A ¹ is a divalent group represented by the following formula (B1-2).

In formula (B1-2),
A ¹¹ represents a single bond, an alkylene group, or an alkenylene group (preferably an alkylene group or an alkenylene group);
Ring ^Z1 represents a non-aromatic ring optionally having a group selected from an alkyl group and an alkenyl group (preferably a cycloalkane ring or cycloalkene ring optionally having a group selected from an alkyl group and an alkenyl group),
nB11 represents an integer of 0 to 3 (preferably 0 or 1, more preferably 1);
* indicates a bonding site. A ¹¹ and ring Z ¹ may each independently have a substituent. When there are a plurality of A ¹¹ , they may be the same or different, and when there are a plurality of rings Z ¹ , they may be the same or different.

Examples of the divalent linking group represented by ^L1 include divalent organic groups (preferably divalent ring-containing organic groups (e.g., aromatic or non-aromatic rings)) consisting of two or more (e.g., 2 to 3000, 2 to 1000, 2 to 100, or 2 to 50) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms, and among these, a divalent group represented by the following formula (B1-3) is preferred.

In formula (B1-3),
A ¹² represents a single bond or a divalent group having one or more (e.g., 1 to 3000, 1 to 1000, 1 to 100, or 1 to 50) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms;
R ^B1 and R ^B2 each independently represent a substituent;
nB12 represents 0 or 1;
nB13 and nB14 each independently represent an integer of 0 to 3 (preferably 0 or 1);
* indicates a binding site. When there are a plurality of R ^B1 , they may be the same or different, and when there are a plurality of R ^B2 , they may be the same or different.

When nB12 is 0, the divalent group represented by formula (B1-3) represents a divalent group having a structure represented by the following formula (B1-4), in which R ^B1 , nB13, and * are as explained in formula (B1-3).

In an embodiment in which nB12 in formula (B1-3) is 1, the divalent group represented by A ¹² is preferably a divalent group represented by the following formula (B1-5).

In formula (B1-5),
Y ¹ represents a single bond, an alkylene group, an alkenylene group, -O-, -CO-, -S-, -SO-, -SO ₂ -, -CONH-, -NHCO-, -COO-, or -OCO-;
Ring ^Z2 represents a non-aromatic ring which may have a substituent or an aromatic ring which may have a substituent;
nB15 represents an integer of 0 to 5 (preferably 0 to 3);
* indicates a bonding site. ^Y1 and ring ^Z2 may each independently have a substituent. When there are a plurality of ^Y1 , they may be the same or different, and when there are a plurality of rings ^Z2 , they may be the same or different.

Specific examples of the divalent group represented by ^A12 include, but are not limited to, _-CH2- , -CH( _CH3 )-, -CH( _CH2CH3 ) _- , -C( _CH3 ) _{2- ,} -C( _CH3 )( _CH2CH3 )-, -C _{( CH2CH3} ) _2- , -O-, -CO-, -S-, -SO-, and _-SO2- , as well as divalent organic groups represented by the following:

The weight average molecular weight (Mw) of the (B1) component is not particularly limited, but is preferably 150 to 50,000, more preferably 300 to 20,000. More specifically, in an embodiment where nB1 in formula (B1-1) is an integer of 1 or more, it is preferably 500 to 50,000, more preferably 1,000 to 20,000, and in an embodiment where nB1 is 0, it is preferably 150 to 5,000, more preferably 300 to 1,000. The Mw of the (B1) component can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

Furthermore, for the (B1) component, the functional group equivalent of the maleimide group is preferably 50 to 20,000 g/eq., more preferably 100 to 20,000 g/eq., and more specifically, in an embodiment in which nB1 in formula (B1-1) is an integer of 1 or more, it is preferably 300 g/eq. to 20,000 g/eq., more preferably 500 g/eq. to 10,000 g/eq., and in an embodiment in which nB1 is 0, it is preferably 50 g/eq. to 2,000 g/eq., more preferably 100 g/eq. to 1,000 g/eq., even more preferably 200 g/eq. to 600 g/eq., and particularly preferably 300 g/eq. to 400 g/eq.

In order to realize a cured product that is exceptionally excellent in adhesion to the conductor layer and mechanical strength when combined with component (A) and component (C) described below, it is preferable that component (B1) contains a maleimide compound having any of the following structures: the structure represented by formula (B1-6), the structure represented by formula (B1-7), or the structure represented by formula (B1-8).

In formula (B1-6), A ¹¹ and ring Z ¹ are as described above, the number of carbon atoms per block of A ¹¹ -ring Z ¹ -A ¹¹ is preferably 20 to 100 (more preferably 30 to 60 or 30 to 50), and it is particularly preferably a so-called dimer acid skeleton (C36 skeleton). nB16 represents an integer of 1 to 10.

In formula (B1-7), A ¹¹ , Y ¹ , ring Z ¹ , ring Z ² and nB15 are as described above, and the number of carbon atoms per block of A ¹¹ -ring Z ¹ -A ¹¹ is preferably 20 to 100 (more preferably 30 to 60 or 30 to 50), and it is particularly preferably a so-called dimer acid skeleton (C36 skeleton). In addition, a block consisting of nB15+1 Y1s and nB15 rings Z2 corresponds to the divalent group A ¹² described above, and is preferably a divalent group containing an oxygen atom. nB17 represents an integer of 1 to 10.

In formula (B1-8), A ¹¹ and ring Z ¹ are as described above, the number of carbon atoms per block of A ¹¹ -ring Z ¹ -A ¹¹ is preferably 20 to 100 (more preferably 30 to 60 or 30 to 50), and it is particularly preferably a so-called dimer acid skeleton (C36 skeleton). nB11 represents an integer of 0 to 10.

Commercially available maleimide compounds having the structure represented by formula (B1-6) include, for example, "BMI-3000J" and "BMI-5000" manufactured by Designer Molecules. Commercially available maleimide compounds having the structure represented by formula (B1-7) include, for example, "BMI-1400", "BMI-1500", and "BMI-1700" manufactured by Designer Molecules. Commercially available maleimide compounds having the structure represented by formula (B1-8) include, for example, "BMI-689" manufactured by Designer Molecules.

<Component (B2)>
The component (B2) is a maleimide compound having an aromatic ring directly bonded to the nitrogen atom of the maleimide, and having a molecular weight of at least 500. Such a maleimide compound can be obtained, for example, by subjecting a component containing an aromatic amine compound (such as an aromatic diamine compound) and maleic anhydride to an imidization reaction.

In one embodiment, component (B2) includes a compound represented by the following formula (B2-1):

In formula (B2-1),
Ring Ar ¹ represents an aromatic ring which may have a substituent;
^L2 represents a single bond or a divalent linking group;
nB2 represents an integer of 1 to 100. A plurality of rings Ar ¹ may be the same or different, and when a plurality of L ² are present, they may be the same or different.

The aromatic ring represented by ring Ar ¹ may be either a carbocyclic ring or a heterocyclic ring, but is more preferably a carbocyclic ring. The number of carbon atoms in the aromatic ring represented by ring Ar ¹ is preferably 3 to 20, more preferably 5 to 14 or 6 to 10. The number of carbon atoms does not include the number of carbon atoms of the substituent.

The divalent linking group represented by ^L2 is not particularly limited as long as it is a divalent group consisting of one or more (for example, 1 to 3000, 1 to 1000, 1 to 100, 1 to 50) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms, and examples thereof include the divalent groups described as ^A12 in the above-mentioned formula (B1-3).

In particular, in the combination of component (A) and component (C) described below, from the viewpoint of realizing a cured product with exceptionally excellent adhesion to the conductor layer and mechanical strength, ring Ar1 is preferably an aromatic carbon ring having 6 to 10 carbon atoms which may have a substituent (more preferably a benzene ring which may have a substituent), and ^L2 (when there are multiple L2, at least one ^L2 ) is preferably a divalent group having a biphenyl skeleton. Thus, in one embodiment, component (B2) has a biphenyl skeleton.

In the component (B2), the nitrogen atom of the maleimide is directly bonded to the aromatic ring. The bonding position of the maleimide to the aromatic ring may be any position based on ^L2 bonded to the aromatic ring. For example, when the aromatic ring is a benzene ring, the bonding position of the maleimide to the benzene ring may be any of the ortho, meta, and para positions based on ^L2 bonded to the benzene ring, but bonding to the para position is preferred from the viewpoint of obtaining the effects of the present invention.

In a preferred embodiment, component (B2) contains a compound represented by the following formula (B2-2):

In formula (B2-2),
R ^B3 , R ^B4 , R ^B5 and R ^B6 each independently represent a substituent;
nB21 represents an integer from 1 to 100;
nB22 and nB23 each independently represent an integer of 1 to 10;
nB24 and nB25 each independently represent an integer of 0 to 3;
Each of nB26 and nB27 independently represents an integer of 0 to 4. When there are a plurality of R ^B3 , they may be the same or different, and the same applies to R ^B4 , R ^B5 and R ^B6 .

nB21 is preferably 1 to 50, more preferably 1 to 20, and even more preferably 1 to 5.

nB22 and nB23 are each independently preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2.

nB24 and nB25 are each independently preferably an integer of 0 to 2, more preferably 0 or 1. When nB24 and nB25 are 1 or more, it is preferable that the substituents represented by R ^B3 and R ^B4 are each independently an alkyl group or an aryl group.

nB26 and nB27 are each independently preferably an integer of 0 to 2, more preferably 0 or 1. When nB26 and nB27 are 1 or more, it is preferable that the substituents represented by R ^B5 and R ^B6 are each independently an alkyl group or an aryl group.

Among them, nB26 and nB27 are preferably 0. Therefore, in a preferred embodiment, component (B2) contains a compound represented by the following formula (B2-3).

In formula (B2-3), R ^B3 , R ^B4 , nB21, nB22, nB23, nB24 and nB25 are as explained in formula (B2-2).

When the molecular weight of component (B2) has a molecular weight distribution, the weight average molecular weight (Mw) is 500 or more, preferably 550 or more. The upper limit of Mw is not particularly limited, but is preferably 5000 or less, more preferably 2500 or less. The Mw of component (B2) can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

For component (B2), the functional group equivalent of the maleimide group is preferably 50 g/eq. to 2000 g/eq., more preferably 100 g/eq. to 1000 g/eq., even more preferably 150 g/eq. to 500 g/eq., and particularly preferably 200 g/eq. to 300 g/eq.

In order to realize a cured product that is exceptionally excellent in adhesion to the conductor layer and mechanical strength when combined with component (A) and component (C) described below, it is preferable that component (B2) contains a maleimide compound having a structure represented by the following formula (B2-4).

In formula (B2-4), nB21 is as explained above.

Commercially available maleimide compounds having the structure represented by formula (B2-4) include, for example, "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd. As the (B2) component, compounds represented by formula (2-1) such as "BMI-4000" manufactured by Daiwa Kasei Co., Ltd. and "BMI-80" manufactured by Keiai Kasei Co., Ltd. may also be used.

The content of the (B) component in the resin composition is preferably 1% by mass or more, more preferably 3% by mass or more or 5% by mass or more, based on 100% by mass of the non-volatile components in the resin composition, from the viewpoint of realizing a cured product with good thermal properties as well as adhesion to the conductor layer and mechanical strength while retaining the advantage of the excellent dielectric properties inherent to the (A) component. The upper limit of the content of the (B) component is not particularly limited, but is preferably 30% by mass or less, more preferably 25% by mass or less or 20% by mass or less. Therefore, in a preferred embodiment, the content of the (B) component is 1% by mass or more and 30% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

From the viewpoint of obtaining the effects of the present invention more significantly, the blending ratio of the (B) component to the (A) component, i.e., the mass ratio of the (B) component/(A) component, is preferably 0.1 or more, more preferably 0.2 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.8 or more, or 1 or more, calculated on a non-volatile component basis. The upper limit of the mass ratio is not particularly limited, but may be, for example, 10 or less, 8 or less, 6 or less, or 5 or less.

-(C) Inorganic filler-
The resin composition of the present invention contains an inorganic filler as component (C).

The resin composition of the present invention uses the above-mentioned components (A) and (B) in combination with the above-mentioned component (C), which allows the realization of a cured product that has excellent adhesion to the conductor layer, mechanical strength, and thermal properties while retaining the inherent advantage of the excellent dielectric properties of component (A).

Examples of materials for component (C) include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. In addition, spherical silica is preferred as the silica. Component (C) may be used alone or in combination of two or more.

Examples of commercially available products of component (C) include "UFP-30" manufactured by Denka Chemical Industry Co., Ltd.; "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatechs Co., Ltd.; "UFP-30" manufactured by Denka Company; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs Co., Ltd.; and "DAW-03" and "FB-105FD" manufactured by Denka Company, Ltd.

The average particle size of the (C) component is not particularly limited, but is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less. The lower limit of the average particle size is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.07 μm or more, 0.1 μm or more, or 0.2 μm or more. The average particle size of the (C) component can be measured by a laser diffraction/scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is created on a volume basis using a laser diffraction/scattering particle size distribution measuring device, and the median diameter is taken as the average particle size. The measurement sample can be prepared by weighing 100 mg of the inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing it by ultrasonic waves for 10 minutes. The measurement sample was measured using a laser diffraction type particle size distribution measuring device with blue and red light source wavelengths and a flow cell method to measure the volumetric particle size distribution of the inorganic filler, and the average particle size was calculated as the median diameter from the obtained particle size distribution. An example of a laser diffraction type particle size distribution measuring device is the "LA-960" manufactured by Horiba, Ltd.

The specific surface area of component (C) is not particularly limited, but is preferably 0.1 m ² /g or more, more preferably 0.5 m ² /g or more, even more preferably 1 m ² /g or more, 3 m ² /g or more, or 5 m ² /g or more. The upper limit of the specific surface area is not particularly limited, but is preferably 100 m ² /g or less, more preferably 80 m ² /g or less, even more preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area of component (C) is obtained by adsorbing nitrogen gas to the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) according to the BET method, and calculating the specific surface area using the BET multipoint method.

The (C) component is preferably surface-treated with an appropriate surface treatment agent. By performing the surface treatment, the moisture resistance and dispersibility of the (C) component can be improved. Examples of the surface treatment agent include silane coupling agents such as vinyl silane coupling agents, epoxy silane coupling agents, styryl silane coupling agents, (meth)acrylic silane coupling agents, amino silane coupling agents, isocyanurate silane coupling agents, ureido silane coupling agents, mercapto silane coupling agents, isocyanate silane coupling agents, and acid anhydride silane coupling agents; non-silane coupling-alkoxysilane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane; and silazane compounds. The surface treatment agent may be used alone or in combination of two or more.

Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd.

From the viewpoint of improving the dispersibility of the inorganic filler, it is preferable that the degree of surface treatment with the surface treatment agent falls within a specified range. Specifically, it is preferable that 100% by mass of the inorganic filler is surface-treated with 0.2 to 5% by mass of the surface treatment agent.

The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and even more preferably 0.2 mg/m ² or more. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition or the melt viscosity in a sheet form, it is preferably 1.0 mg/m ² or less, more preferably 0.8 mg/m ² or less, and even more preferably 0.5 mg/m ² or less. The amount of carbon per unit surface area of the (C) component can be measured after the inorganic filler after the surface treatment is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with the surface treatment agent, and ultrasonic cleaning is performed at 25 ° C. for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer, such as "EMIA-320V" manufactured by Horiba, Ltd.

The content of the (C) component in the resin composition is preferably 30% by mass or more, more preferably 35% by mass or more or 40% by mass or more, and even more preferably 45% by mass or more or 50% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass, from the viewpoint of realizing a cured product with good thermal properties as well as adhesion to the conductor layer and mechanical strength while retaining the advantage of the excellent dielectric properties inherent to the (A) component. The upper limit of the content of the (C) component is not particularly limited, but is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less. Therefore, in a preferred embodiment, the content of the (C) component is 30% by mass or more and 80% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

From the viewpoint of obtaining the effects of the present invention more significantly, the blending ratio of the (C) component to the (A) component, i.e., the mass ratio of the (C) component/(A) component, is preferably 1 or more, more preferably 1.5 or more or 2 or more, and even more preferably 2.5 or more, 3 or more, 3.5 or more, 4 or more, 4.5 or more, or 5 or more, calculated on a non-volatile component basis. The upper limit of the mass ratio is not particularly limited, but may be, for example, 50 or less, 40 or less, or 30 or less.

The resin composition of the present invention, which contains a combination of components (A), (B), and (C), can realize a cured product that has excellent mechanical properties and thermal properties, as well as excellent adhesion to the conductor layer and mechanical strength, while retaining the advantage of the excellent dielectric properties inherent to component (A). Combining component (A) with only component (B) or only component (C) does not produce the above effect (see Comparative Example), but it has been confirmed that a specific effect is obtained when component (A) is combined with components (B) and (C).

-(D) Curable resin containing a phenylene ether skeleton-
The resin composition of the present invention may further comprise a curable resin containing a phenylene ether skeleton as component (D). By further comprising component (D), the effects of the present invention can be more significantly enjoyed.

The (D) component preferably contains a phenylene ether skeleton and further contains a radically polymerizable unsaturated group that contributes to the curing reaction. Examples of the radically polymerizable unsaturated group include a vinyl group, a vinylphenyl group, an acryloyl group, a methacryloyl group, a fumaroyl group, and a maleoyl group. The (D) component preferably has two or more radically polymerizable unsaturated groups.

In one embodiment, component (D) includes a compound represented by the following formula (D-1):

In formula (D-1),
X represents a monovalent group having a radically polymerizable unsaturated group,
^L3 represents a divalent linking group;
^R and ^R each independently represent a substituent.
nD11 and nD12 each independently represent an integer of 0 to 4;
nD1 and nD2 each independently represent an integer of 0 to 300, provided that at least one of them is an integer of 1 or more. A plurality of X's may be the same or different, when ^a plurality of R's may be the same or different, and when ^a plurality of R's may be the same or different.

The monovalent group represented by X is not particularly limited as long as it has a radically polymerizable unsaturated group, but from the viewpoint of being able to enjoy the effects of the present invention more effectively when it is combined with components (A) to (C) and blended, it is preferable that it is a monovalent group represented by the following formula (D-2).

In formula (D-2),
R ^D1 , R ^D2 and R ^D3 each independently represent a hydrogen atom or an alkyl group;
R ^D4 represents an alkylene group;
R ^D13 represents a substituent.
nD3 and nD4 each independently represent 0 or 1;
nD13 represents an integer of 0 to 4,
* indicates a binding site. R ^D1 , R ^D2 , R ^D3 and R ^D4 each may independently have a substituent. When there are a plurality of R ^D13 , they may be the same or different.

The number of carbon atoms in the alkyl group represented by R ^D1 , R ^D2 and R ^D3 is preferably 1 to 10, more preferably 1 to 6 or 1 to 4, and even more preferably 1 or 2. The number of carbon atoms does not include the number of carbon atoms of the substituent. Of these, R ^D1 is preferably a hydrogen atom or an alkyl group, and R ^D2 and R ^D3 are preferably hydrogen atoms.

The number of carbon atoms in the alkylene group represented by R ^D4 is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3. The number of carbon atoms does not include the number of carbon atoms of the substituent.

nD13 is preferably 0 to 2, more preferably 0 or 1. When nD13 is an integer of 1 or more, the substituent represented by R ^D13 is preferably an alkyl group.

When R ^D1 is a hydrogen atom, nD3 is preferably 0. When R ^D1 is an alkyl group, nD3 is preferably 1.

In addition, when nD3 is 0, nD4 is preferably 1, and when nD3 is 1, nD4 is preferably 0.

In formula (D-1), the divalent linking group represented by ^L3 is not particularly limited as long as it is a divalent group consisting of one or more (for example, 1 to 3000, 1 to 1000, 1 to 100, 1 to 50) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms, and examples thereof include the divalent groups described as ^A12 in formula (B1-3) above.

In formula (D-1), nD11 and nD12 are each independently preferably 1 to 4, more preferably 2 or 3, and even more preferably 2. When nD11 and nD12 are an integer of 1 or more, the substituents represented by R ^D11 and R ^D12 are preferably an alkyl group.

In formula (D-1), nD1 and nD2 are each independently preferably 1 or more, and preferably 100 or less, more preferably 50 or less, and even more preferably 20 or less or 10 or less.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the (D) component are not particularly limited as long as the effects of the present invention are achieved in combination with the (A) to (C) components. In one embodiment, Mn is preferably 2500 or less, more preferably 2200 or less, and even more preferably 2000 or less or 1900 or less. In one embodiment, Mw is also within the above-mentioned preferred range. The lower limit of the molecular weight is not particularly limited, and may be, for example, 500 or more, 700 or more, etc. The Mw and Mn of the (D) component can be measured as polystyrene equivalent values by gel permeation chromatography (GPC).

A preferred example of component (D) is a compound represented by the following formula (D-3):

In formula (D-3), R ^D4 , R ^D11 , R ^D12 , L ³ , nD1 and nD2 are as defined above.

Among these, ^L3 is preferably a divalent group represented by the following formula (D-4).

In formula (D-4),
R ^{and R} each independently represent an alkyl group or a phenyl group;
nD14 and nD15 each independently represent an integer of 0 to 4;
* indicates the binding site.

The number of carbon atoms in the alkyl group represented by R ^D14 and R ^D15 is preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 or 2. R ^D14 and R ^D15 are preferably alkyl groups.

nD14 and nD15 are each independently preferably 1 to 4, more preferably 2 or 3.

An example of the compound represented by formula (D-3) is the compound represented by the following formula (D-5). In the formula, nD1 and nD2 are as explained above. A commercially available product of the compound represented by formula (D-5) is, for example, "OPE-2St" manufactured by Mitsubishi Gas Chemical Company, Inc.

Another preferred example of component (D) is the compound represented by the following formula (D-6):

In formula (D-6), R ^D2 , R ^D11 , R ^D12 , R ^D13 , L ³ , nD1 and nD2 are as defined above.

Among these, L ³ is preferably selected from the group consisting of an alkylene group, an alkenylene group, -O-, -CO-, -CS-, -SO- and -SO ₂ -, more preferably an alkylene group, and further preferably an isopropylidene group (-C(CH ₃ ) ₂ -).

An example of the compound represented by formula (D-6) is the compound represented by the following formula (D-7). In the formula, nD1 and nD2 are as explained above. A commercially available product of the compound represented by formula (D-7) is, for example, "NORYL SA9000" manufactured by SABIC.

When the resin composition of the present invention contains the (D) component, the content of the (D) component in the resin composition is preferably 1% by mass or more, more preferably 3% by mass or more or 5% by mass or more, even more preferably 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more, when the non-volatile components in the resin composition are 100% by mass. The upper limit of the content of the (D) component is not particularly limited, but is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. Therefore, in a preferred embodiment, the content of the (D) component is 1% by mass or more and 40% by mass or less, when the non-volatile components in the resin composition are 100% by mass.

From the viewpoint of obtaining the effects of the present invention more significantly, the blending ratio of the (D) component to the (A) component, i.e., the mass ratio of the (D) component/(A) component, is preferably 0.1 or more, more preferably 0.2 or more, 0.3 or more, or 0.5 or more, and even more preferably 0.7 or more, 0.8 or more, 0.9 or more, 1 or more, 1.2 or more, 1.4 or more, or 1.5 or more, calculated on a non-volatile component basis. The upper limit of the mass ratio is not particularly limited, but may be, for example, 10 or less, 8 or less, 6 or less, or 5 or less.

-(E) High molecular weight component-
The resin composition of the present invention may further contain a high molecular weight component as component (E).

From the viewpoint of obtaining a cured product with even more excellent dielectric properties, the weight average molecular weight (Mw) of component (E) is preferably 5,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more. The upper limit of the Mw is not particularly limited, but is preferably 100,000 or less, more preferably 80,000 or less, and even more preferably 50,000 or less. The Mw of component (E) can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

Examples of component (E) include thermoplastic resins such as phenoxy resin, polyimide resin, polycarbonate resin, polyvinyl acetal resin, polyolefin resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polyetheretherketone resin, polystyrene resin, and polyester resin. Among these, it is preferable that component (E) contains at least one selected from phenoxy resin, polyimide resin, and polycarbonate resin, from the viewpoint of obtaining a cured product with excellent dielectric properties.

Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group.

Commercially available phenoxy resins include, for example, "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482" manufactured by Mitsubishi Chemical Corporation; and the like.

The polyimide resin may be a resin having an imide structure. Polyimide resins are generally obtained by an imidization reaction between a diamine compound and an acid anhydride. Commercially available polyimide resins may be used, such as "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd.

Polycarbonate resin is a resin having a carbonate structure. Examples of such resins include carbonate resins without reactive groups, hydroxyl group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxyl group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, urethane group-containing carbonate resins, and epoxy group-containing carbonate resins. Here, reactive groups refer to functional groups that can react with other components, such as hydroxyl groups, phenolic hydroxyl groups, carboxyl groups, acid anhydride groups, isocyanate groups, urethane groups, and epoxy groups.

Commercially available polycarbonate resins can be used. Examples of commercially available products include "FPC0220" and "FPC2136" manufactured by Mitsubishi Gas Chemical Co., Ltd., "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Chemicals Corporation, and "C-1090", "C-2090", and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd.

When the resin composition of the present invention contains the (E) component, the content of the (E) component in the resin composition is not particularly limited as long as it does not impair the effects of the present invention, but is preferably 0.1 mass% or more, 0.3 mass% or more, or 0.5 mass% or more, assuming that the non-volatile components in the resin composition are 100 mass%. The upper limit of the content of the (E) component is not particularly limited, but is preferably 10 mass% or less, more preferably 5 mass% or less, and even more preferably 3 mass% or less.

--(F) Polymerization initiator--
The resin composition of the present invention may further contain a polymerization initiator as the component (F).

Examples of component (F) include peroxides such as t-butylcumyl peroxide, t-butyl peroxyacetate, α,α'-di(t-butylperoxy)diisopropylbenzene, t-butyl peroxylaurate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneodecanoate, and t-butyl peroxybenzoate.

Commercially available products of component (F) include, for example, NOF Corp.'s "Perbutyl C," "Perbutyl A," "Perbutyl P," "Perbutyl L," "Perbutyl O," "Perbutyl ND," "Perbutyl Z," "Perhexyl D," "Percumyl P," and "Percumyl D."

When the resin composition of the present invention contains component (F), the content of component (F) is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, and is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

-Other ingredients-
The resin composition of the present invention may further contain an epoxy resin and an epoxy resin curing agent.

Epoxy resins include, for example, bixylenol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, tetraphenylethane type epoxy resins, etc. Epoxy resins may be used alone or in combination of two or more.

Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter referred to as "solid epoxy resins"). The resin composition of the present invention may contain only liquid epoxy resins, may contain only solid epoxy resins, or may contain a combination of liquid epoxy resins and solid epoxy resins.

Specific examples of liquid epoxy resins include DIC's "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins); Mitsubishi Chemical's "828US", "jER828EL", "825", and "Epicoat 828EL" (bisphenol A type epoxy resins); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F type epoxy resins); Mitsubishi Chemical's "jER152" (phenol novolac type epoxy resin); Mitsubishi Chemical's "630" and "630LSD" (glycidylamine type epoxy resins). epoxy resin); Nippon Steel & Sumitomo Metal Chemical's "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); Nagase ChemteX's "EX-721" (glycidyl ester type epoxy resin); Daicel's "Celloxide 2021P" (alicyclic epoxy resin with an ester skeleton); Daicel's "PB-3600" (epoxy resin with a butadiene structure); Nippon Steel & Sumitomo Metal Chemical's "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin), etc.

Specific examples of solid epoxy resins include DIC's "HP4032H" (naphthalene type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resin); DIC's "N-690" (cresol novolac type epoxy resin); DIC's "N-695" (cresol novolac type epoxy resin); DIC's "HP-7200HH", "HP-7200H", and "HP-7200" (dicyclopentadiene type epoxy resin). DIC Corporation's "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", and "HP6000" (naphthylene ether type epoxy resins); Nippon Kayaku Co., Ltd.'s "EPPN-502H" (trisphenol type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC7000L" (naphthol novolac type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC3000H", "NC3000", and "NC3000" (naphthol novolac type epoxy resins). 000L, "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX88" manufactured by Mitsubishi Chemical Corporation 00" (anthracene type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical; "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical.

The epoxy equivalent of the epoxy resin is preferably 50 g/eq. to 5000 g/eq., more preferably 50 g/eq. to 3000 g/eq., even more preferably 80 g/eq. to 2000 g/eq., and even more preferably 110 g/eq. to 1000 g/eq. The epoxy equivalent is the mass of the epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500. The Mw of the epoxy resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

When the resin composition of the present invention contains an epoxy resin, the content of the epoxy resin in the resin composition is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, 1% by mass or more, or 1.5% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, or 3% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

Epoxy resin curing agents include, for example, active ester curing agents, phenolic curing agents, naphthol curing agents, benzoxazine curing agents, cyanate ester curing agents, carbodiimide curing agents, amine curing agents, and acid anhydride curing agents. These may be used alone or in combination of two or more.

The content of the epoxy resin curing agent is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 10% by mass or less, and more preferably 5% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

The resin composition of the present invention may further contain any additive. Examples of such additives include curing accelerators such as phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators; organic fillers such as rubber particles; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; defoamers such as silicone-based defoamers, acrylic defoamers, fluorine-based defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; and triazole-based adhesion Examples of the additives include adhesion imparting agents such as tetrazole adhesion imparting agents and triazine adhesion imparting agents; antioxidants such as hindered phenol antioxidants and hindered amine antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester dispersants, polyoxyalkylene dispersants, acetylene dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers. These additives may be used alone or in combination of two or more. A person skilled in the art can set the appropriate amount of each ingredient.

In addition to the non-volatile components described above, the resin composition of the present invention may further contain any organic solvent as a volatile component. Any known organic solvent may be used as the organic solvent, and the type is not particularly limited. Examples of organic solvents include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. ether ester solvents; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. The organic solvents may be used alone or in combination of two or more.

The resin composition of the present invention can be produced, for example, by adding and mixing components (A), (B), and (C), and, if necessary, components (D), (E), and (F), an epoxy resin, an epoxy resin curing agent, other additives, and an organic solvent in any order and/or all at once in any preparation vessel. In addition, the temperature can be appropriately set during the process of adding and mixing each component, and heating and/or cooling can be performed temporarily or throughout. In addition, during or after the process of adding and mixing, the resin composition can be stirred or shaken using a stirring or shaking device such as a mixer to disperse it uniformly. In addition, degassing can be performed under low pressure conditions such as under vacuum at the same time as stirring or shaking.

As mentioned above, the resin composition of the present invention, which contains a combination of components (A), (B), and (C), retains the inherent advantage of component (A), i.e., the excellent dielectric properties, and produces a cured product that has excellent adhesion to the conductor layer, as well as excellent mechanical and thermal properties.

In one embodiment, the cured product of the resin composition of the present invention is characterized by a low dielectric constant (Dk). For example, when measured at 5.8 GHz and 23°C as described in the <Evaluation of Dielectric Properties> section below, the dielectric constant (Dk) of the cured product of the resin composition of the present invention can be preferably 3.0 or less, or 2.9 or less.

In one embodiment, the cured product of the resin composition of the present invention is characterized by a low dielectric loss tangent (Df). For example, when measured at 5.8 GHz and 23°C as described in the <Evaluation of Dielectric Properties> section below, the dielectric loss tangent (Df) of the cured product of the resin composition of the present invention can be preferably 0.0030 or less, 0.0029 or less, 0.0028 or less, or 0.0027 or less.

In one embodiment, the cured product of the resin composition of the present invention is characterized by good adhesion to the conductor layer. For example, the conductor adhesion strength measured by the method described in the <Evaluation of Conductor Adhesion> section below can be preferably 0.50 kgf/cm or more, 0.55 kgf/cm or more, or 0.60 kgf/cm or more.

In one embodiment, the cured product of the resin composition of the present invention is characterized by excellent thermal properties. For example, the linear thermal expansion coefficient in the range of 25°C to 80°C measured by the method described in the <Evaluation of Thermal Properties (Coefficient of Linear Thermal Expansion: CTE)> section below can be preferably 40 ppm/°C or less, 38 ppm/°C or less, 36 ppm/°C or less, or 35 ppm/°C or less.

In one embodiment, the cured product of the resin composition of the present invention is characterized by excellent mechanical strength. For example, the maximum stress measured by the method described in the section <Evaluation of mechanical properties (maximum stress and breaking elongation)> below can be preferably 90 MPa or more, 95 MPa or more, 100 MPa or more, 105 MPa or more, or 110 MPa or more. In addition, the breaking elongation can be preferably 1.4% or more, 1.5% or more, or 1.6% or more.

The resin composition of the present invention can be suitably used as a resin composition for insulating purposes, particularly as a resin composition for forming an insulating layer. Specifically, it can be suitably used as a resin composition for forming an insulating layer of a printed wiring board (resin composition for insulating layer of printed wiring board), and more suitably used as a resin composition for forming an interlayer insulating layer of a printed wiring board (resin composition for insulating interlayer of printed wiring board). Since the resin composition of the present invention provides an insulating layer with good component embedding properties, it can also be suitably used when the printed wiring board is a component-embedded circuit board. The resin composition of the present invention can also be suitably used as a resin composition for forming an insulating layer on which a conductor layer (including a rewiring layer) is provided (resin composition for insulating layer for forming a conductor layer). The resin composition of the present invention can further be used in a wide range of applications requiring a resin composition, such as a resin sheet, a sheet-like laminate material such as a prepreg, a solder resist, an underfill material, a die bonding material, a semiconductor encapsulant, a hole-filling resin, and a component embedding resin.

[Resin sheet]
The resin composition of the present invention can be used by coating in the form of a varnish, but from an industrial perspective, it is generally preferred to use the resin composition in the form of a sheet-like laminate material containing the resin composition.

The following resin sheets and prepregs are preferred as sheet-like laminate materials.

In one embodiment, the resin sheet comprises a support and a layer of a resin composition (hereinafter simply referred to as a "resin composition layer") provided on the support, and is characterized in that the resin composition layer is formed from the resin composition of the present invention.

The thickness of the resin composition layer is preferably 50 μm or less, more preferably 40 μm or less, from the viewpoint of making the printed wiring board thinner and being able to provide a cured product with excellent insulating properties even if the cured product of the resin composition is a thin film. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 5 μm or more, 10 μm or more, etc.

Examples of the support include films made of plastic materials, metal foils, and release paper, with films made of plastic materials and metal foils being preferred.

When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polycarbonate (PC), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. As the copper foil, a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

The support may be subjected to a matte treatment, a corona treatment, or an antistatic treatment on the surface to be bonded to the resin composition layer. A support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used as the support. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. The support with a release layer may be a commercially available product, such as "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Unipeel" manufactured by Unitika Limited, which are PET films having a release layer mainly composed of an alkyd resin-based release agent.

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When using a support with a release layer, it is preferable that the thickness of the entire support with the release layer is in the above range.

The support may also be a metal foil with a support substrate, which is a thin metal foil with a peelable support substrate laminated thereon. In one embodiment, the metal foil with a support substrate includes a support substrate, a release layer provided on the support substrate, and a metal foil provided on the release layer. When a metal foil with a support substrate is used as the support, the resin composition layer is provided on the metal foil.

In the metal foil with a supporting substrate, the material of the supporting substrate is not particularly limited, but examples thereof include copper foil, aluminum foil, stainless steel foil, titanium foil, copper alloy foil, etc. When copper foil is used as the supporting substrate, it may be electrolytic copper foil or rolled copper foil. In addition, the release layer is not particularly limited as long as it can release the metal foil from the supporting substrate, and examples thereof include an alloy layer of an element selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, and P; an organic coating, etc.

In the case of metal foil with a supporting substrate, the material of the metal foil is preferably, for example, copper foil or copper alloy foil.

In the metal foil with a supporting substrate, the thickness of the supporting substrate is not particularly limited, but is preferably in the range of 10 μm to 150 μm, and more preferably in the range of 10 μm to 100 μm. The thickness of the metal foil may be, for example, in the range of 0.1 μm to 10 μm.

In one embodiment, the resin sheet may further include an optional layer as necessary. Such an optional layer may be, for example, a protective film provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, it is possible to suppress adhesion of dirt and the like to the surface of the resin composition layer and scratches.

The resin sheet can be produced, for example, by preparing a resin varnish by dissolving the liquid resin composition in an organic solvent or by applying the resin varnish onto a support using a die coater or the like, and then drying the varnish to form a resin composition layer.

The organic solvent may be the same as the organic solvent described as a component of the resin composition. The organic solvent may be used alone or in combination of two or more kinds.

Drying may be performed by known methods such as heating or blowing hot air. There are no particular limitations on the drying conditions, but drying is performed so that the content of organic solvent in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Although it varies depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when using a resin composition or resin varnish containing 30% by mass to 60% by mass of organic solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

The resin sheet can be stored in a roll. If the resin sheet has a protective film, it can be used by peeling off the protective film.

In one embodiment, the prepreg is formed by impregnating a sheet-like fiber substrate with the resin composition of the present invention.

The sheet-like fiber substrate used for the prepreg is not particularly limited, and may be any commonly used substrate for prepregs, such as glass cloth, aramid nonwoven fabric, or liquid crystal polymer nonwoven fabric. From the viewpoint of making the printed wiring board thinner, the thickness of the sheet-like fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. There is no particular lower limit to the thickness of the sheet-like fiber substrate. It is usually 10 μm or more.

Prepregs can be manufactured by known methods such as the hot melt method and the solvent method.

The thickness of the prepreg can be in the same range as the resin composition layer in the resin sheet described above.

The sheet-like laminate material of the present invention can be suitably used to form an insulating layer of a printed wiring board (for an insulating layer of a printed wiring board), and can be even more suitably used to form an interlayer insulating layer of a printed wiring board (for an interlayer insulating layer of a printed wiring board).

[Printed wiring board]
The printed wiring board of the present invention includes an insulating layer made of a cured product of the resin composition of the present invention.

The printed wiring board can be produced, for example, by using the above-mentioned resin sheet by a method including the following steps (I) and (II).
(I) a step of laminating a resin sheet on an inner layer substrate so that a resin composition layer of the resin sheet is bonded to the inner layer substrate; and (II) a step of curing (e.g., thermally curing) the resin composition layer to form an insulating layer.

The "inner layer substrate" used in step (I) is a member that will be the substrate of the printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and the conductor layer may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate may be called an "inner layer circuit substrate." In addition, intermediate products on which an insulating layer and/or a conductor layer is to be formed during the manufacture of a printed wiring board are also included in the "inner layer substrate" of the present invention. When the printed wiring board is a component-embedded circuit board, an inner layer substrate with a component embedded may be used.

The lamination of the inner layer substrate and the resin sheet can be carried out, for example, by heat-pressing the resin sheet to the inner layer substrate from the support side. Examples of the member for heat-pressing the resin sheet to the inner layer substrate (hereinafter also referred to as the "heat-pressing member") include a heated metal plate (such as a SUS panel) or a metal roll (SUS roll). The heat-pressing member may be pressed directly onto the resin sheet, or may be pressed via an elastic material such as heat-resistant rubber so that the resin sheet can adequately follow the surface irregularities of the inner layer substrate.

The lamination of the inner layer substrate and the resin sheet may be performed by a vacuum lamination method. In the vacuum lamination method, the heat-pressure bonding temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heat-pressure bonding pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably in the range of 0.29MPa to 1.47MPa, and the heat-pressure bonding time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination may be performed under reduced pressure conditions, preferably at a pressure of 26.7hPa or less.

Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., and a batch-type vacuum pressure laminator.

After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example by pressing a heat-pressure bonding member from the support side. The pressing conditions for the smoothing treatment may be the same as the heat-pressure bonding conditions for the lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

The support may be removed between step (I) and step (II), or after step (II). When a metal foil is used as the support, the conductor layer may be formed using the metal foil without peeling off the support. When a metal foil with a supporting substrate is used as the support, the supporting substrate (and the peeling layer) may be peeled off. Then, the conductor layer can be formed using the metal foil.

In step (II), the resin composition layer is cured (e.g., thermally cured) to form an insulating layer made of a cured product of the resin composition. The curing conditions for the resin composition layer are not particularly limited, and conditions that are typically used when forming an insulating layer for a printed wiring board may be used.

For example, the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 120°C to 250°C, more preferably 150°C to 240°C, and even more preferably 180°C to 230°C. The curing time is preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and even more preferably 15 minutes to 120 minutes.

Before the resin composition layer is thermally cured, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 120°C, preferably 60°C to 115°C, and more preferably 70°C to 110°C for 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

When manufacturing a printed wiring board, the steps of (III) drilling holes in the insulating layer, (IV) roughening the insulating layer, and (V) forming a conductor layer may be further carried out. These steps (III) to (V) may be carried out according to various methods known to those skilled in the art that are used in the manufacture of printed wiring boards. When the support is removed after step (II), the removal of the support may be carried out between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Furthermore, the formation of the insulating layer and the conductor layer in steps (I) to (V) may be repeated as necessary to form a multilayer wiring board.

In another embodiment, the printed wiring board of the present invention can be manufactured using the above-mentioned prepreg. The manufacturing method is basically the same as when a resin sheet is used.

Step (III) is a step of drilling holes in the insulating layer, which allows holes such as via holes and through holes to be formed in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, etc., depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be appropriately determined depending on the design of the printed wiring board.

Step (IV) is a step of roughening the insulating layer. Usually, smears are also removed in this step (IV). The procedure and conditions of the roughening treatment are not particularly limited, and known procedures and conditions that are usually used when forming an insulating layer for a printed wiring board can be adopted. For example, the insulating layer can be roughened by carrying out a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order.

The swelling liquid used in the roughening treatment is not particularly limited, but includes an alkaline solution, a surfactant solution, etc., and is preferably an alkaline solution, and more preferably a sodium hydroxide solution or a potassium hydroxide solution. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. The swelling treatment using the swelling liquid is not particularly limited, but can be performed by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes, for example. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

The oxidizing agent used in the roughening treatment is not particularly limited, but examples thereof include an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment using an oxidizing agent such as an alkaline permanganate solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotech Japan.

The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan is an example.

Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, etc., it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

Step (V) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The conductor layer may be a single metal layer or an alloy layer, and examples of the alloy layer include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

The conductor layer may be a single-layer structure, or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

The thickness of the conductor layer depends on the desired printed wiring board design, but is generally between 3 μm and 35 μm, preferably between 5 μm and 30 μm.

In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer using a conventionally known technique such as a semi-additive method or a full-additive method, and from the viewpoint of ease of production, it is preferable to form the conductor layer by a semi-additive method. Below, an example of forming the conductor layer by a semi-additive method is shown.

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a portion of the plating seed layer corresponding to the desired wiring pattern. A metal layer is formed on the exposed plating seed layer by electrolytic plating, and the mask pattern is then removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, and a conductor layer having the desired wiring pattern can be formed.

In another embodiment, the conductor layer may be formed using a metal foil. When the conductor layer is formed using a metal foil, it is preferable to perform step (V) between steps (I) and (II). For example, after step (I), the support is removed, and a metal foil is laminated on the exposed surface of the resin composition layer. The lamination of the resin composition layer and the metal foil may be performed by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Thereafter, a conductor layer having a desired wiring pattern can be formed by a conventionally known technique such as a subtractive method or a modified semi-additive method using the metal foil on the insulating layer.

Metal foils can be manufactured by known methods such as electrolysis and rolling. Commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Nippon Mining & Metals Corporation, and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd.

Alternatively, as described above, if a metal foil or a metal foil with a supporting substrate is used as the support for the resin sheet, the conductor layer may be formed using the metal foil.

In addition, the resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer for forming a rewiring layer (resin composition for forming a rewiring layer) and as a resin composition for sealing a semiconductor chip (resin composition for sealing a semiconductor chip) when manufacturing a semiconductor chip package. Techniques for manufacturing semiconductor chip packages using resin compositions (resin sheets) are widely known in the art, and the resin composition and resin sheet of the present invention can be applied to any of these methods and techniques.

[Semiconductor device]
The semiconductor device of the present invention includes an insulating layer made of a cured product of the resin composition layer of the present invention. The semiconductor device of the present invention can be produced by using the printed wiring board or semiconductor package of the present invention.

Semiconductor devices include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft).

The present invention will be specifically explained below with reference to examples. The present invention is not limited to these examples. In the following, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Unless otherwise specified, the temperature and pressure conditions are room temperature (25°C) and atmospheric pressure (1 atm).

First, we will explain the various measurement and evaluation methods.

[Preparation of samples for measurement and evaluation]
1. Preparation of Cured Product for Evaluation The protective film was peeled off from the resin sheet produced in the Examples and Comparative Examples, and the resin composition layer was thermally cured by heating in a nitrogen atmosphere at 220° C. for 90 minutes. Thereafter, the support was peeled off to obtain a cured film made of a cured product of the resin composition.

2. Preparation of Evaluation Substrate (1) Copper Foil Pretreatment The shiny side of Mitsui Mining & Smelting Co., Ltd.'s "3EC-III" (electrolytic copper foil, 35 μm) was immersed in MEC Etch Bond "CZ-8201" manufactured by MEC Corporation to roughen the copper surface to a Ra value of 0.5 μm. The copper foil was then subjected to an anti-rust treatment (CL8300) and further to a heat treatment in an oven at 130° C. for 30 minutes. This resulted in a copper foil with a low surface roughness (hereinafter referred to as "CZ copper foil").

(2) Preparation of substrate The protective film was peeled off from the resin sheet prepared in the examples and comparative examples to expose the resin composition layer. Then, using a batch type vacuum pressure laminator ("MVLP-500" manufactured by Meiki Co., Ltd.), the resin sheet was laminated on both sides of a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, manufactured by Panasonic Corporation "R1515A") on which the exposed surface of the resin composition layer was formed, so that the resin sheet was bonded to the laminate. The lamination was performed by reducing the pressure for 30 seconds to adjust the air pressure to 13 hPa or less, and then pressing at 100 ° C. and a pressure of 0.74 MPa for 30 seconds. After the lamination, the support was peeled off from the resin sheet. Then, the treated surface of the CZ copper foil was laminated to the exposed surface of the resin composition layer under the same conditions as above. After the lamination treatment, the resin composition layer was thermally cured at 220° C. for 90 minutes to form a cured product (insulating layer). In this manner, an evaluation board having CZ copper foil laminated on both sides was produced.

<Evaluation of dielectric properties>
The dielectric properties were evaluated using the cured film for evaluation.
Specifically, the cured film for evaluation was cut into a width of 2 mm and a length of 80 mm to obtain a test piece. The dielectric constant (Dk value) and dielectric loss tangent (Df value) of the obtained test piece were measured by a cavity resonance perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C using an "HP8362B" manufactured by Agilent Technologies. Measurements were performed on three test pieces (n=3), and the average value was calculated. The dielectric properties of the cured product were evaluated according to the following evaluation criteria.

Dielectric property evaluation criteria:
○: The average dielectric constant is 3.0 or less, and the average dielectric tangent is 0.0030 or less (excellent dielectric properties)
×: Either or both of the average value of the dielectric constant and the average value of the dielectric tangent do not satisfy the above criteria (poor dielectric properties)

<Evaluation of Thermal Properties (Coefficient of Linear Thermal Expansion: CTE)>
The thermal properties were evaluated using the cured film for evaluation.
Specifically, the cured film for evaluation was cut into a width of 5 mm and a length of 15 mm to obtain a test piece. The obtained test piece was subjected to thermomechanical analysis by a tensile load method using a thermomechanical analyzer (Rigaku's "Thermo Plus TMA8310"). After mounting the test piece on the device, it was measured twice consecutively under the measurement conditions of a load of 1 g and a temperature rise rate of 5°C/min, and the average linear thermal expansion coefficient (ppm/°C) from 25°C to 80°C in the second measurement was calculated. Measurements were performed on three test pieces (n=3), and the average value was calculated. The thermal properties of the cured product were evaluated according to the following evaluation criteria.

Thermal Characterization Criteria:
○: Average linear thermal expansion coefficient is 40 ppm/°C or less (excellent thermal properties)
×: Average linear thermal expansion coefficient exceeds 40 ppm/°C (poor thermal properties)

<Evaluation of mechanical properties (maximum stress and breaking elongation)>
The mechanical properties of the cured film for evaluation were evaluated.
Specifically, the cured film for evaluation was cut into a dumbbell-shaped No. 1 test piece to obtain it. The obtained test piece was subjected to tensile strength measurement using a tensile tester "RTC-1250A" manufactured by Orientec Co., Ltd., and the maximum stress and breaking elongation at 23°C were measured. The measurement was carried out in accordance with JIS K7127. The measurement was carried out five times (n=5), and the average of the top three points was calculated. The mechanical properties of the cured product were evaluated according to the following evaluation criteria.

Mechanical property evaluation criteria:
○: The average maximum stress is 90 MPa or more, and the average breaking elongation is 1.4% or more (excellent mechanical properties)
×: Either or both of the average value of the maximum stress and the average value of the breaking elongation do not meet the above criteria (inferior mechanical properties)

<Evaluation of Conductor Adhesion>
The evaluation substrate was used to evaluate the conductor adhesion.
In detail, the prepared evaluation board was cut into small pieces of 150×30 mm. A cutter was used to make a 10 mm wide and 100 mm long cut in the copper foil portion of the small piece. Then, one end of the copper foil was peeled off and held with a gripper attached to a tensile tester described later, and the load [kgf/cm] when peeling 35 mm in the vertical direction at a speed of 50 mm/min at room temperature (normal temperature) was measured. For the measurement, a tensile tester (Autocom Universal Tester "AC-50C-SL" manufactured by TSE Co., Ltd.) was used. The measurement was performed in accordance with Japanese Industrial Standard JIS C6481. The load value obtained as a result of the measurement is hereinafter referred to as "conductor adhesion strength". The conductor adhesion was evaluated according to the following evaluation criteria.

Conductor adhesion evaluation criteria:
○: Conductor adhesion strength is 0.50 kgf/cm or more (excellent conductor adhesion)
×: The value of the conductor adhesion strength is less than 0.50 kgf/cm (poor conductor adhesion)

<Melt Viscosity Measurement>
The melt viscosity of the resin composition layer of the resin sheet produced in the examples and comparative examples was measured using a dynamic viscoelasticity measuring device ("Rheosol-G3000" manufactured by UBM Co., Ltd.). For 1 g of the sample resin composition, a parallel plate with a diameter of 18 mm was used to raise the temperature from a starting temperature of 60°C to 200°C at a heating rate of 5°C/min, and the dynamic viscoelasticity was measured under the measurement conditions of a measurement temperature interval of 2.5°C, a vibration of 1 Hz, and a strain of 5 deg, and the melt viscosity at 120°C was measured. The melt viscosity of the resin composition was evaluated according to the following evaluation criteria.

Melt Viscosity Evaluation Criteria:
Good: Melt viscosity value is less than 2500 poise (excellent resin flowability)
×: Melt viscosity value is 2500 poise or more (poor resin flow property)

Synthesis Example 1 (Synthesis of Polyimide Resin 1)
A 500 mL separable flask equipped with a water content receiver connected to a reflux condenser, a nitrogen inlet tube, and a stirrer was prepared. 20.3 g of 4,4'-oxydiphthalic anhydride (ODPA), 200 g of γ-butyrolactone, 20 g of toluene, and 29.6 g of 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane were added to this flask, and the mixture was stirred at 45°C for 2 hours under a nitrogen stream to carry out a reaction. Next, the reaction solution was heated and, while maintaining the temperature at about 160°C, condensed water was azeotropically removed together with toluene under a nitrogen stream. It was confirmed that a predetermined amount of water had accumulated in the water content receiver, and that no water was flowing out. After confirmation, the reaction solution was further heated and stirred at 200°C for 1 hour. The mixture was then cooled to obtain a polyimide solution (non-volatile content: 20% by mass) containing a polyimide resin having a 1,1,3-trimethylindane skeleton. The obtained polyimide resin had a repeating unit represented by the following formula (X1) and a repeating unit represented by the following formula (X2). The weight average molecular weight of the polyimide resin was 12,000.

--Examples 1-1 to 1-10, Reference Example 1-1, Comparative Examples 1-1 to 1-3--
Examples and comparative examples of embodiments in which the component (B1) is used as the component (B) are shown below.

[Example 1-1]
(1) Preparation of Resin Composition 10 parts of maleimide compound b1-1 ("BMI-3000J" manufactured by Designer Molecules) as component (B) and 28.6 parts (10 parts as non-volatile component) of benzocyclobutene resin a ("CYCLOTENE3022" manufactured by The Dow Chemical Company; number average molecular weight: 390, mesitylene solution containing 35% by mass of non-volatile component) as component (A) were dissolved in 10 parts of methyl ethyl ketone (MEK) by heating with stirring.

The maleimide compound b1-1 ("BMI-3000J") is a compound represented by the following structural formula. In the formula, n is an integer from 1 to 10.

The obtained solution was cooled to room temperature. Then, 29.2 parts (19 parts as non-volatile components) of a curable resin d1 ("OPE-2St" (oligophenylene ether-styrene resin) manufactured by Mitsubishi Gas Chemical Co., Ltd.; number average molecular weight: 1200, toluene solution containing 65% by mass of non-volatile components) as component (D) and 19 parts as non-volatile components of an inorganic filler c1 (spherical silica "SO-C2" manufactured by Admatechs Co., Ltd., surface-treated with an amine-based silane coupling agent "KBM573" manufactured by Shin-Etsu Chemical Co., Ltd. (average particle size: 0.5 μm, specific surface area: 5.8 m2 ⁾ as component (C) were added to the solution. 60 parts of hexanediaminetetraacetate (1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile components, weight average molecular weight of non-volatile components: 35,000), 3.3 parts (1 part as non-volatile components) of high molecular weight component e1 as component (E) ("YX6954BH30" manufactured by Mitsubishi Chemical Corporation; 1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile components, weight average molecular weight of non-volatile components: 35,000), and 0.05 parts of a curing accelerator as component (F) ("Perhexyl (registered trademark) D" manufactured by NOF Corporation) were added and mixed, and further dispersed uniformly in a high-speed rotating mixer. In this way, a varnish of a resin composition containing components (A) to (F) was prepared.

(2) Preparation of Resin Sheet As a support, a PET film ("Lumirror R80" manufactured by Toray Industries, Inc.; thickness 38 μm, softening point 130° C., hereinafter sometimes referred to as "release PET") whose one main surface had been release-treated with an alkyd resin-based release agent ("AL-5" manufactured by Lintec Corporation) was prepared.

The varnish of the resin composition prepared in (1) above was uniformly applied onto the release-treated surface of a release PET sheet using a die coater so that the thickness of the resin composition layer after drying would be 40 μm, and then dried for 3 minutes at 90° C. Thereby, a resin sheet including a support and a resin composition layer provided on the support was obtained.
Next, a polypropylene film (Oji F-Tex Co., Ltd. "Alphan MA-411", thickness 15 μm) was laminated as a protective film on the exposed surface of the resin composition layer (the surface not bonded to the release PET) so that the rough surface was bonded to the resin composition layer. This resulted in a resin sheet including a support, a resin composition layer provided on the support, and a protective film provided on the resin composition layer.

[Example 1-2]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that 1) the amount of benzocyclobutene resin a (in terms of non-volatile components) was changed from 10 parts to 25 parts, 2) the amount of maleimide compound b1-1 was changed from 10 parts to 5 parts, and 3) the amount of curable resin d1 (in terms of non-volatile components) was changed from 19 parts to 9 parts.

[Examples 1-3]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that 1) the amount of benzocyclobutene resin a (in terms of non-volatile components) was changed from 10 parts to 20 parts, 2) the amount of inorganic filler c1 was changed from 60 parts to 40 parts, and 3) the amount of curable resin d1 (in terms of non-volatile components) was changed from 19 parts to 29 parts.

[Examples 1 to 4]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-3, except that the inorganic filler c1 was changed to inorganic filler c2 (spherical silica "UFP-30" (average particle size: 0.3 μm, specific surface area 30.7 m ² /g) manufactured by Denka Co., Ltd., surface-treated with an amine-based silane coupling agent "KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.).

[Examples 1 to 5]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that the maleimide compound b1-1 was changed to the maleimide compound b1-2 ("BMI-1700" manufactured by Designer Molecules, Inc.).

The maleimide compound b1-2 ("BMI-1700") is a compound represented by the following structural formula. In the formula, n is an integer from 1 to 10.

[Examples 1 to 6]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that the maleimide compound b1-1 was changed to the maleimide compound b1-3 ("BMI-1500" manufactured by Designer Molecules, Inc.).

The maleimide compound b1-3 ("BMI-1500") is a compound represented by the following structural formula. In the formula, n is an integer from 1 to 10.

[Examples 1 to 7]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that the maleimide compound b1-1 was changed to the maleimide compound b1-4 ("BMI-689" manufactured by Designer Molecules, Inc.).

The maleimide compound b1-4 ("BMI-689") is a compound represented by the following structural formula:

[Examples 1 to 8]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that the high molecular weight component e1 was changed to the high molecular weight component e2 (polyimide resin 1 synthesized in Synthesis Example 1).

[Examples 1 to 9]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that the curable resin d1 was changed to the curable resin d2 (SABIC's "SA9000-111" (number average molecular weight 1850 to 1950)).

[Examples 1-10]
1) The amount of curable resin d1 (converted into non-volatile components) was changed from 19 parts to 14 parts, and 2) 2 parts of an epoxy resin ("NC3000" manufactured by Nippon Kayaku Co., Ltd., biphenyl type epoxy resin), 4.6 parts of a curing agent ("HPC-8000-65T" manufactured by DIC Corporation, active ester curing agent, toluene solution with a solid content of 65% by mass) (3 parts as non-volatile components), and 0.03 parts of a curing accelerator ("1B2PZ" manufactured by Shikoku Kasei Corporation, 1-benzyl-2-phenylimidazole) were blended. A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1.

[Reference Example 1-1]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that 1) benzocyclobutene resin a was not added, 2) the amount of maleimide compound b1-1 was changed from 10 parts to 30 parts, and 3) the amount of curable resin d1 (converted into non-volatile components) was changed from 19 parts to 9 parts.

[Comparative Example 1-1]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that 1) maleimide compound b1-1 was not added, 2) the amount of benzocyclobutene resin a (in terms of non-volatile components) was changed from 10 parts to 30 parts, and 3) the amount of curable resin d1 (in terms of non-volatile components) was changed from 19 parts to 9 parts.

[Comparative Example 1-2]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that the maleimide compound b1-1 was changed to the maleimide compound b' (Kei Kaisha "BMI-70", bis(3-ethyl-5 methyl-4-maleimidophenyl)methane).

[Comparative Example 1-3]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 1-1, except that 1) inorganic filler c1 was not added, 2) the amount of benzocyclobutene resin a (in terms of non-volatile components) was changed from 10 parts to 39 parts, 3) the amount of maleimide compound b1-1 was changed from 10 parts to 35 parts, and 4) the amount of curable resin d1 (in terms of non-volatile components) was changed from 19 parts to 25 parts.

The results of Examples 1-1 to 1-10, Reference Example 1-1, and Comparative Examples 1-1 to 1-3 are shown in Table 1.

--Examples 2-1 to 2-7, Reference Example 2-1, Comparative Examples 2-1 to 2-3--
Examples and comparative examples of embodiments in which component (B2) is used as component (B) are shown below.

[Example 2-1]
(1) Preparation of Resin Composition 28.6 parts (20 parts as nonvolatile component) of maleimide compound b2-1 as component (B) ("MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., a mixed solution of MEK/toluene with a nonvolatile content of 70%) and 28.6 parts (10 parts as nonvolatile component) of benzocyclobutene resin a as component (A) ("CYCLOTENE3022" manufactured by Dow Chemical Company; number average molecular weight: 390, mesitylene solution with a nonvolatile content of 35% by mass) were dissolved in 10 parts of methyl ethyl ketone (MEK) by heating with stirring.

The maleimide compound b2-1 ("MIR-3000-70MT") is a compound represented by the following structural formula. In the formula, e1 is an integer from 1 to 100.

The obtained solution was cooled to room temperature. Then, 13.8 parts (9 parts as non-volatile components) of a curable resin d1 ("OPE-2St" (oligophenylene ether-styrene resin) manufactured by Mitsubishi Gas Chemical Co., Ltd.; number average molecular weight: 1200, toluene solution containing 65% by mass of non-volatile components) as component (D) and 10.0 parts (9 parts as non-volatile components) of an inorganic filler c1 (spherical silica "SO-C2" manufactured by Admatechs Co., Ltd., surface-treated with an amine-based silane coupling agent "KBM573" manufactured by Shin-Etsu Chemical Co., Ltd. (average particle size: 0.5 μm, specific surface area: 5.8 m2 ⁾ as component (C) were added to the solution. 60 parts of hexanediaminetetraacetate (1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile components, weight average molecular weight of non-volatile components: 35,000), 3.3 parts (1 part as non-volatile components) of high molecular weight component e1 as component (E) ("YX6954BH30" manufactured by Mitsubishi Chemical Corporation; 1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile components, weight average molecular weight of non-volatile components: 35,000), and 0.05 parts of a curing accelerator as component (F) ("Perhexyl (registered trademark) D" manufactured by NOF Corporation) were added and mixed, and further dispersed uniformly in a high-speed rotating mixer. In this way, a varnish of a resin composition containing components (A) to (F) was prepared.

(2) Preparation of Resin Sheet A resin sheet was prepared in the same manner as in Example 1-1 using the varnish of the resin composition prepared in (1) above.

[Example 2-2]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-1, except that 1) the amount of benzocyclobutene resin a (in terms of non-volatile components) was changed from 10 parts to 25 parts, 2) the amount of maleimide compound b2-1 (in terms of non-volatile components) was changed from 20 parts to 10 parts, and 3) the amount of curable resin d1 (in terms of non-volatile components) was changed from 9 parts to 4 parts.

[Example 2-3]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-1, except that 1) the amount of benzocyclobutene resin a (in terms of non-volatile components) was changed from 10 parts to 20 parts, 2) the amount of inorganic filler c1 was changed from 60 parts to 40 parts, and 3) the amount of curable resin d1 (in terms of non-volatile components) was changed from 9 parts to 19 parts.

[Example 2-4]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-3, except that the inorganic filler c1 was changed to inorganic filler c2 (spherical silica "UFP-30" (average particle size: 0.3 μm, specific surface area 30.7 m ² /g) manufactured by Denka Co., Ltd., surface-treated with an amine-based silane coupling agent "KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.).

[Example 2-5]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-1, except that the high molecular weight component e1 was changed to the high molecular weight component e2 (polyimide resin 1 synthesized in Synthesis Example 1).

[Example 2-6]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-1, except that the curable resin d1 was changed to the curable resin d2 (SABIC's "SA9000-111" (number average molecular weight 1850 to 1950)).

[Example 2-7]
A resin composition was prepared in the same manner as in Example 2-1, except that 1) the amount of maleimide compound b2-1 (converted into non-volatile components) was changed from 20 parts to 15 parts, and 2) 2 parts of an epoxy resin ("NC3000" manufactured by Nippon Kayaku Co., Ltd., biphenyl type epoxy resin), 4.6 parts of a curing agent ("HPC-8000-65T" manufactured by DIC Corporation, active ester type curing agent, toluene solution with a solid content of 65% by mass) (3 parts as non-volatile components), and 0.03 parts of a curing accelerator ("1B2PZ" manufactured by Shikoku Kasei Corporation, 1-benzyl-2-phenylimidazole) were added. A resin sheet was produced in the same manner as in Example 2-1.

[Reference Example 2-1]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-1, except that 1) the benzocyclobutene resin a was not added, and 2) the amount of the maleimide compound b2-1 (in terms of non-volatile components) was changed from 20 parts to 30 parts.

[Comparative Example 2-1]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-1, except that 1) maleimide compound b2-1 was not added, 2) the amount of benzocyclobutene resin a (in terms of non-volatile components) was changed from 10 parts to 20 parts, and 3) the amount of curable resin d1 (in terms of non-volatile components) was changed from 9 parts to 19 parts.

[Comparative Example 2-2]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-1, except that the maleimide compound b2-1 was changed to the maleimide compound b' (Kei Kaisha "BMI-70", bis(3-ethyl-5 methyl-4-maleimidophenyl)methane).

[Comparative Example 2-3]
A resin composition was prepared and a resin sheet was produced in the same manner as in Example 2-1, except that 1) inorganic filler c1 was not added, 2) the amount of benzocyclobutene resin a (in terms of non-volatile components) was changed from 10 parts to 39 parts, 3) the amount of maleimide compound b2-1 (in terms of non-volatile components) was changed from 20 parts to 35 parts, and 4) the amount of curable resin d1 (in terms of non-volatile components) was changed from 9 parts to 25 parts.

The results of Examples 2-1 to 2-7, Reference Example 2-1, and Comparative Examples 2-1 to 2-3 are shown in Table 2.

Claims (24)

(A) benzocyclobutene resin,
(B) a maleimide compound,
(C) containing an inorganic filler,
The component (B) is
(B1) a compound represented by the following formula (B1-1) : and (B2) a maleimide compound having an aromatic ring directly bonded to a nitrogen atom of a maleimide, the maleimide compound having a biphenyl skeleton and a molecular weight of 500 or more:
The resin composition is one or more selected from the following.

(In formula (B1-1),
A ¹ represents an aliphatic group having 5 or more carbon atoms which may have a substituent;
L ¹ represents a single bond or a divalent linking group;
nB1 represents an integer of 0 to 20. When there are a plurality of ^A1's , they may be the same or different, and when there are a plurality of L1 ^'s , they may be the same or different. (A) benzocyclobutene resin,
(B) a maleimide compound,
(C) an inorganic filler ,
(D) Curable resin containing a phenylene ether skeleton
Including,
The component (B) is
(B1) a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to a nitrogen atom of the maleimide, and (B2) a maleimide compound having an aromatic ring directly bonded to a nitrogen atom of the maleimide, the maleimide compound having a molecular weight of 500 or more;
The resin composition is one or more selected from the following. The resin composition according to claim 2 , wherein the component (B1) contains a compound represented by the following formula (B1-1):

(In formula (B1-1),
A ¹ represents an aliphatic group having 5 or more carbon atoms which may have a substituent;
L ¹ represents a single bond or a divalent linking group;
nB1 represents an integer of 0 to 20. When there are a plurality of ^A1's , they may be the same or different, and when there are a plurality of ^L1's , they may be the same or different. The resin composition according to any one of claims 1 to 3 , wherein the component (B2) comprises a compound represented by the following formula (B2-1):

(In formula (B2-1),
Ring Ar ¹ represents an aromatic ring which may have a substituent;
^L2 represents a single bond or a divalent linking group;
nB2 represents an integer of 1 to 100. A plurality of rings ^Ar1 may be the same or different, and when a plurality of ^L2s are present, they may be the same or different. The resin composition according to any one of claims 1 to 4 , wherein the content of the component (C) is 30% by mass or more and 80% by mass or less, when the non-volatile components in the resin composition are 100% by mass. The resin composition according to any one of claims 1 to 5 , wherein the content of the component (A) is 1 mass% or more and 50 mass% or less, when the non-volatile components in the resin composition are 100 mass%. The resin composition according to any one of claims 1 to 6 , wherein component (A) has two or more benzocyclobutene groups and has a number average molecular weight (Mn) of 2000 or less. The resin composition according to claim 1 , further comprising (D) a curable resin having a phenylene ether skeleton. The resin composition according to claim 2 or 8 , wherein the component (D) comprises a compound represented by the following formula (D-1):

(In formula (D-1),
X represents a monovalent group having a radically polymerizable unsaturated group,
^L3 represents a divalent linking group;
^R and ^R each independently represent a substituent.
nD11 and nD12 each independently represent an integer of 0 to 4;
nD1 and nD2 each independently represent an integer from 0 to 300, provided that at least one of them is an integer of 1 or more. Multiple Xs may be the same or different, when there are multiple R ^D11s , they may be the same or different, and when there are multiple R ^D12s , they may be the same or different. The resin composition according to claim 2 , 8 or 9 , wherein the Mn of the component (D) is 2,500 or less. The resin composition according to any one of claims 1 to 10 , wherein the component (A) has a siloxane skeleton. The resin composition according to any one of claims 1 to 11 , wherein the content of the component (B) is 1 mass% or more and 30 mass% or less, when the non-volatile components in the resin composition are 100 mass%. The resin composition according to any one of claims 2 and 8 to 10 , wherein the content of the component (D) is 1 mass% or more and 40 mass% or less, when the non-volatile components in the resin composition are 100 mass%. The resin composition according to any one of claims 1 to 13 , wherein the component (A) comprises a compound represented by the following formula (A-2):

(In formula (A-2),
R ¹ represents a divalent aliphatic group having an unsaturated bond;
^R2 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an arylalkyl group, or an aryl group;
R ^A1 represents an alkyl group, a cyano group or a halogen atom;
R ^A2 represents an alkyl group, a trialkylsilyl group, an alkoxy group or a halogen atom;
nA1 represents an integer of 0 to 2;
nA2 represents an integer of 0 to 3;
nA4 represents an integer of 1 to 10. R ¹ , R ² , R ^A1 and R ^A2 may each independently have a substituent. A plurality of R ¹ 's may be the same or different, a plurality of R ² 's may be the same or different, when there are a plurality of R ^A1's , they may be the same or different, and when there are a plurality of R ^A2's , they may be the same or different. The resin composition according to any one of claims 1 to 14 , wherein the component (A) comprises a compound represented by the following formula:

The resin composition according to claim 2 or 3 , wherein the component (B2) has a biphenyl skeleton. The resin composition according to any one of claims 1 to 16 , wherein the cured product has a dielectric constant of 3.0 or less. The resin composition according to any one of claims 1 to 17 , wherein the cured product has a dielectric loss tangent of 0.0030 or less. The resin composition according to any one of claims 1 to 18 , wherein the linear thermal expansion coefficient of the cured product in the range of 25°C to 80°C is 40 ppm/°C or less. The resin composition according to any one of claims 1 to 19 , which is for use in an insulating layer of a printed wiring board. The resin composition according to any one of claims 1 to 20 , which is for use in an interlayer insulating layer of a printed wiring board. A resin sheet comprising a support and a layer of the resin composition according to any one of claims 1 to 21 provided on the support. A printed wiring board comprising an insulating layer made of a cured product of the resin composition according to any one of claims 1 to 21 . A semiconductor device comprising an insulating layer made of a cured product of the resin composition according to any one of claims 1 to 21 .