JP7600954B2 - Resin composition - Google Patents

Description

The present invention relates to a resin composition. It also relates to a resin sheet, a cured product, a printed wiring board, a semiconductor chip package, and a semiconductor device that use the resin composition.

Resin compositions containing a thermosetting resin such as an epoxy resin and its curing agent produce cured products with excellent insulation, heat resistance, adhesion, etc., and have been widely used as insulating materials for electronic components such as printed wiring boards and semiconductor chip packages. For example, the resin composition disclosed in Patent Document 1 is known as such a resin composition.

JP 2014-47318 A

As communication speeds have increased in recent years, insulating materials for electronic components are required to have a lower dielectric tangent in order to reduce transmission loss when they are used in high-frequency environments. In addition, it is desirable for insulating materials for electronic components to have high adhesion to conductor layers and conductor foils (hereinafter simply referred to as "conductor adhesion"), especially high conductor adhesion even after exposure to high-temperature and high-humidity environments.

In addition, as electronic components become smaller and more functional, insulating materials are becoming thinner, making them more susceptible to cracking and other defects. To prevent this, insulating materials are required to have excellent mechanical properties, specifically high elongation at break.

The objective of the present invention is to provide a novel resin composition that has a low dielectric tangent, exhibits good conductor adhesion even after exposure to a high-temperature, high-humidity environment, and can produce a cured product that exhibits good mechanical properties.

As a result of intensive research, the inventors discovered that the above problems can be solved by further combining a resin having an ethynyl group or an ethynylene group in a resin composition containing a thermosetting resin and a curing agent, and thus completed the present invention.

（式中、
Ｒ^１は、水素原子、置換基を有していてもよいアリール基、又は、置換基を有していてもよいアルキル基を表し、
環Ａｒ^１は、置換基を有していてもよい芳香環を表し、
ｎ１は、０又は１を表し、
＊は、結合手を表す。）
［４］ （Ｃ）成分が、下記一般式（Ｃ２）で表される構造単位を有する、［１］～［３］の何れかに記載の樹脂組成物。

（式中、
Ｒ^２は、（ｉ）１つ以上の芳香環を含有する２価の有機基、（ｉｉ）炭素原子数５以上の２価の脂肪族基、又は、（ｉｉｉ）シロキサン骨格を有する２価の基を表し、
Ｒ^３は、それぞれ独立に、１つ以上の芳香環を含有する４価の有機基を表し、
Ｒ^４は、それぞれ独立に、（ｉ）１つ以上の芳香環を含有する２価の有機基、又は、（ｉｉ）炭素原子数５以上の２価の脂肪族基を表し、
ｎ２は、０以上の数を表す。）
［５］ （Ｃ）成分の重量平均分子量が５００～５００００の範囲である、［１］～［４］の何れかに記載の樹脂組成物。
［６］ （Ｃ）成分の含有量が、樹脂組成物中の樹脂成分を１００質量％とした場合、１質量％以上である、［１］～［５］の何れかに記載の樹脂組成物。
［７］ さらに（Ｄ）無機充填材を含む、［１］～［６］の何れかに記載の樹脂組成物。
［８］ （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、５０質量％以上である、［７］に記載の樹脂組成物。
［９］ プリント配線板の絶縁層用である、［１］～［８］の何れかに記載の樹脂組成物。
［１０］ 半導体封止用である、［１］～［８］の何れかに記載の樹脂組成物。
［１１］ 支持体と、該支持体上に設けられた［１］～［１０］の何れかに記載の樹脂組成物の層とを含む、樹脂シート。
［１２］ 支持体が、熱可塑性樹脂フィルム又は金属箔である、［１１］に記載の樹脂シート。
［１３］ ［１］～［１０］の何れかに記載の樹脂組成物の硬化物。
［１４］ ［１］～［９］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。
［１５］ ［１］～［８］、［１０］の何れかに記載の樹脂組成物の硬化物からなる封止層を含む、半導体チップパッケージ。
［１６］ ［１４］に記載のプリント配線板又は［１５］に記載の半導体チップパッケージを含む、半導体装置。 That is, the present invention includes the following.
[1] A resin composition comprising (A) a thermosetting resin, (B) a curing agent, and (C) a resin having an ethynyl group or an ethynylene group.
[2] The resin composition according to [1], wherein the component (C) has an ethynyl group or an ethynylene group at an end of the molecule.
[3] The resin composition according to [1] or [2], wherein the molecular end of the component (C) is a structural unit represented by the following general formula (C1):

(Wherein,
R ¹ represents a hydrogen atom, an aryl group which may have a substituent, or an alkyl group which may have a substituent;
Ring Ar ¹ represents an aromatic ring which may have a substituent;
n1 represents 0 or 1;
* represents a bond.)
[4] The resin composition according to any one of [1] to [3], wherein the component (C) has a structural unit represented by the following general formula (C2):

(Wherein,
^R2 represents (i) a divalent organic group containing one or more aromatic rings, (ii) a divalent aliphatic group having 5 or more carbon atoms, or (iii) a divalent group having a siloxane skeleton;
Each ^R3 independently represents a tetravalent organic group containing one or more aromatic rings;
^R4 each independently represents (i) a divalent organic group containing one or more aromatic rings, or (ii) a divalent aliphatic group having 5 or more carbon atoms;
n2 represents a number equal to or greater than 0.
[5] The resin composition according to any one of [1] to [4], wherein the weight average molecular weight of the component (C) is in the range of 500 to 50,000.
[6] The resin composition according to any one of [1] to [5], wherein the content of the component (C) is 1 mass% or more, when the resin components in the resin composition are 100 mass%.
[7] The resin composition according to any one of [1] to [6], further comprising (D) an inorganic filler.
[8] The resin composition according to [7], wherein the content of the (D) component is 50% by mass or more, based on 100% by mass of non-volatile components in the resin composition.
[9] The resin composition according to any one of [1] to [8], which is for use in an insulating layer of a printed wiring board.
[10] The resin composition according to any one of [1] to [8], which is for semiconductor encapsulation.
[11] A resin sheet comprising a support and a layer of the resin composition according to any one of [1] to [10] provided on the support.
[12] The resin sheet according to [11], wherein the support is a thermoplastic resin film or a metal foil.
[13] A cured product of the resin composition according to any one of [1] to [10].
[14] A printed wiring board comprising an insulating layer made of a cured product of the resin composition according to any one of [1] to [9].
[15] A semiconductor chip package comprising an encapsulating layer made of a cured product of the resin composition according to any one of [1] to [8] and [10].
[16] A semiconductor device comprising the printed wiring board according to [14] or the semiconductor chip package according to [15].

The present invention provides a novel resin composition that has a low dielectric tangent, exhibits good conductor adhesion even after exposure to a high-temperature, high-humidity environment, and can produce a cured product that exhibits good mechanical properties.

<Terminology>
As used herein, the term "optionally substituted" in reference to a compound or group means both the case where none of the hydrogen atoms of the compound or group are substituted with a substituent, and the case where some or all of the hydrogen atoms of the compound or group are substituted with a substituent.

In this specification, unless otherwise specified, the term "substituent" means a halogen atom, an alkyl group, an alkenyl 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, a carboxy group, a sulfo group, a cyano group, a nitro group, a hydroxy group, a mercapto group, or an oxo group.

Examples of halogen atoms used as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The alkyl group used as a substituent may be either linear or branched. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3. The alkenyl group used as a substituent may be either linear or branched. The number of carbon atoms of the alkenyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 or 3. The number of carbon atoms of the cycloalkyl group used as a substituent is preferably 3 to 12, more preferably 3 to 6. The alkoxy group used as a substituent may be either linear or branched. The number of carbon atoms of the alkoxy group is preferably 1 to 12, more preferably 1 to 6. The number of carbon atoms of the cycloalkyloxy group used as a substituent is preferably 3 to 12, more preferably 3 to 6. The aryl group used as a substituent is a group obtained by removing one hydrogen atom on the aromatic ring from an aromatic hydrocarbon. The number of carbon atoms of the aryl group used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms of the aryloxy group used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms of the arylalkyl group used as a substituent is preferably 7 to 15, more preferably 7 to 11. The number of carbon atoms of the arylalkoxy group used as a substituent is preferably 7 to 15, more preferably 7 to 11. The monovalent heterocyclic group used as a substituent refers to a group in which one hydrogen atom is removed from the heterocycle of a heterocyclic compound. The number of carbon atoms of the monovalent heterocyclic group is preferably 3 to 15, more preferably 3 to 9. The alkylidene group used as a substituent refers to a group in which two hydrogen atoms are removed from the same carbon atom of an alkane. The number of carbon atoms of the alkylidene group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3. The above-mentioned substituents may further have a substituent (hereinafter sometimes referred to as a "secondary substituent"). Unless otherwise specified, the secondary substituents may be the same as those described above.

In this specification, the term "organic group" refers to a group containing at least carbon atoms as skeletal atoms, and may be linear, branched, or cyclic. In this specification, unless otherwise specified, the number of skeletal atoms of an organic group is preferably 1 to 3000, more preferably 1 to 1000, even more preferably 1 to 100, even more preferably 1 to 50, and particularly preferably 1 to 30 or 1 to 20. Examples of organic groups include groups consisting of one or more skeletal atoms (including at least a carbon atom) selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms.

In this specification, the term "aromatic ring" means a ring that follows the Huckel rule in which the number of electrons in the π-electron system on the ring is 4p+2 (p is a natural number), and includes a monocyclic aromatic ring and a fused polycyclic aromatic ring in which two or more monocyclic aromatic rings are fused. The aromatic ring may be an aromatic carbocyclic ring having only carbon atoms as ring-constituting atoms, or an aromatic heterocyclic ring having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms in addition to carbon atoms as ring-constituting atoms. In this specification, the number of carbon atoms in the aromatic ring is preferably 3 or more, more preferably 4 or more or 5 or more, and even more preferably 6 or more, unless otherwise specified, and the upper limit is preferably 24 or less, more preferably 18 or less or 14 or less, and even more preferably 10 or less. The number of carbon atoms does not include the number of carbon atoms of the substituent. 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; and condensed polycyclic aromatic rings in which two or more monocyclic aromatic rings are condensed, such as a naphthalene ring, an anthracene ring, a phenanthrene 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.

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 polycyclic 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 ring or an 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 fused polycyclic 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 with reference to preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and may 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 is characterized by comprising (A) a thermosetting resin, (B) a curing agent, and (C) a resin having an ethynyl group or an ethynylene group.

<(A) Thermosetting resin>
The resin composition of the present invention contains a thermosetting resin as component (A).

Examples of thermosetting resins include epoxy resins, benzocyclobutene resins, epoxy acrylate resins, urethane acrylate resins, urethane resins, cyanate resins, polyimide resins, benzoxazine resins, unsaturated polyester resins, phenolic resins, melamine resins, silicone resins, and phenoxy resins. Thermosetting resins may be used alone or in combination of two or more.

In particular, it is preferable that the thermosetting resin contains an epoxy resin, since in combination with the component (C) described below, a cured product excellent in dielectric properties, conductor adhesion, and mechanical properties can be obtained.

Examples of epoxy resins include bisphenol-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, and tetraphenylethane-type epoxy resins. Bisphenol-type epoxy resins refer to epoxy resins having a bisphenol structure, and examples thereof include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins. Biphenyl-type epoxy resin refers to an epoxy resin having a biphenyl structure, where the biphenyl structure may have a substituent such as an alkyl group, an alkoxy group, or an aryl group. Therefore, bixylenol-type epoxy resins and biphenyl aralkyl-type epoxy resins are also included in biphenyl-type epoxy resins. The epoxy resins may be used alone or in combination of two or more types.

The epoxy resin is preferably an aromatic epoxy resin. Here, an aromatic epoxy resin means an epoxy resin that has an aromatic ring in its molecule.

The epoxy resin preferably has two or more epoxy groups in one molecule. When the non-volatile components of the epoxy resin are taken as 100% by mass, the proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

There are two types of epoxy resins: those that are liquid at a temperature of 20°C (hereafter referred to as "liquid epoxy resins"), and those that are solid at a temperature of 20°C (hereafter referred to as "solid epoxy resins").

Preferably, the liquid epoxy resin has two or more epoxy groups in one molecule.

Preferred liquid epoxy resins are bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins such as alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, and epoxy resins having a butadiene structure.

Specific examples of liquid epoxy resins include DIC's "HP-4032", "HP-4032D", and "HP-4032SS" (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). bisphenol A epoxy resin); "ZX1059" (a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin) manufactured by Nippon Steel Chemical &Material; "EX-721" (glycidyl ester epoxy resin) manufactured by Nagase ChemteX; "Celloxide 2021P" (alicyclic epoxy resin with an ester structure) manufactured by Daicel; "PB-3600" (epoxy resin with a butadiene structure) manufactured by Daicel; "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane epoxy resin) manufactured by Nippon Steel Chemical & Material.

As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable.

Preferred solid epoxy resins are bixylenol type epoxy resins, naphthalene type epoxy resins, naphthalene type tetrafunctional epoxy resins, cresol novolac type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol type epoxy resins, biphenyl type epoxy resins, naphthylene ether type epoxy resins, anthracene type epoxy resins, bisphenol A type epoxy resins, bisphenol AF type epoxy resins, and tetraphenylethane type epoxy resins.

Specific examples of solid epoxy resins include DIC's "HP-4032H" (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 diene type epoxy resins); "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", and "HP6000" (naphthylene ether type epoxy resins) manufactured by DIC Corporation; "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", and "NC3000L" manufactured by Nippon Kayaku Co., Ltd. ","NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "Y Examples include "X8800" (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; and "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical.

The resin composition of the present invention may contain only liquid epoxy resin as the epoxy resin, may contain only solid epoxy resin, or may contain a combination of liquid epoxy resin and solid epoxy resin. When a combination of liquid epoxy resin and solid epoxy resin is used, the ratio by mass between them (liquid epoxy resin:solid epoxy resin) is preferably 1:0.01 to 1:50, more preferably 1:0.05 to 1:20, and even more preferably 1:0.1 to 1:10.

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).

In combination with the (C) component described later, from the viewpoint of being able to produce a cured product excellent in all of dielectric properties, conductor adhesion, and mechanical properties, the content of the (A) component in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more, 14% by mass or more, or 15% by mass or more, when the resin components in the resin composition are taken as 100% by mass. The upper limit of the content is not particularly limited and may be determined according to the properties required of the resin composition, but may be, for example, 60% by mass or less, 50% by mass or less, or 40% by mass or less. In the present invention, the "resin component" in the resin composition refers to the non-volatile components constituting the resin composition, excluding the inorganic filler described later.

In the resin composition of the present invention, when the non-volatile components of component (A) are taken as 100% by mass, the content of the epoxy resin is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 55% by mass or more, 60% by mass or more, 65% by mass or more, or 70% by mass or more. There is no particular upper limit to the content of the epoxy resin in component (A), and it may be 100% by mass, but it may also be, for example, 95% by mass or less, 90% by mass or less, etc.

<(B) Curing Agent>
The resin composition of the present invention contains a curing agent as component (B). Component (B) usually has the function of reacting with component (A) to cure the resin composition.

Examples of the (B) component include active ester-based curing agents, phenol-based curing agents, naphthol-based curing agents, acid anhydride-based curing agents, cyanate ester-based curing agents, carbodiimide-based curing agents, and amine-based curing agents. The (B) component may be used alone or in combination of two or more types.

In particular, in terms of being able to provide a cured product that is excellent in dielectric properties, conductor adhesion, and mechanical properties in combination with the (A) component and the (C) component described below, it is preferable that the (B) component contains one or more selected from the group consisting of active ester-based curing agents, phenol-based curing agents, and naphthol-based curing agents, and in terms of being able to provide a cured product that is particularly excellent in dielectric properties, it is preferable that the (B) component contains an active ester-based curing agent. Therefore, in one embodiment, the (B) component contains one or more selected from the group consisting of active ester-based curing agents, phenol-based curing agents, and naphthol-based curing agents, and more preferably contains an active ester-based curing agent.

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

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

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

Specific examples of preferred active ester-based hardeners include active ester-based hardeners containing a dicyclopentadiene-type diphenol structure, active ester-based hardeners containing a naphthalene structure, active ester-based hardeners containing an acetylated product of phenol novolac, and active ester-based hardeners containing a benzoylated product of phenol novolac. Among these, active ester-based hardeners containing a naphthalene structure and active ester-based hardeners containing a dicyclopentadiene-type diphenol structure are more preferred. The term "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

Commercially available active ester compounds include active ester compounds containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation); active ester compounds containing a naphthalene structure such as "EXB-8100L-65T", "EXB-8150-60T", and "EXB-8150-62T", Examples of active ester compounds containing phosphorus include "EXB9401" (manufactured by DIC Corporation), "DC808" (manufactured by Mitsubishi Chemical Corporation) which is an active ester compound that is an acetylated product of phenol novolac, "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) which is an active ester compound that is a benzoylated product of phenol novolac, and "PC1300-02-65MA" (manufactured by Air Water Inc.) which is an active ester compound containing a styryl group and a naphthalene structure.

From the viewpoint of heat resistance and water resistance, phenol-based and naphthol-based curing agents having a novolac structure are preferred. From the viewpoint of adhesion to the conductor layer, nitrogen-containing phenol-based and nitrogen-containing naphthol-based curing agents are preferred, and triazine skeleton-containing phenol-based and triazine skeleton-containing naphthol-based curing agents are more preferred.

Specific examples of phenol-based and naphthol-based hardeners include "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", and "SN-37" manufactured by Nippon Steel Chemical & Material Co., Ltd. 5" and "SN-395" manufactured by DIC Corporation; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165" manufactured by Gun-ei Chemical Co., Ltd.; "GDP-6115L", "GDP-6115H", and "ELPC75" manufactured by Gun-ei Chemical Co., Ltd.

Examples of acid anhydride curing agents include curing agents having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Examples of acid anhydrides include polymeric acid anhydrides such as biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and styrene-maleic acid resins in which styrene and maleic acid are copolymerized. Examples of commercially available acid anhydride-based hardeners include "MH-700" manufactured by New Japan Chemical Co., Ltd.

Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins have been partially converted to triazine. Specific examples of cyanate ester-based hardeners include Lonza Japan's "PT30" and "PT60" (phenol novolac-type multifunctional cyanate ester resins), "ULL-950S" (multifunctional cyanate ester resin), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been converted to triazine and formed into a trimer).

Specific examples of carbodiimide-based curing agents include Carbodilite (registered trademark) V-03 (carbodiimide group equivalent: 216 g/eq.), V-05 (carbodiimide group equivalent: 262 g/eq.), V-07 (carbodiimide group equivalent: 200 g/eq.), V-09 (carbodiimide group equivalent: 200 g/eq.), and Stavaxol (registered trademark) P (carbodiimide group equivalent: 302 g/eq.), all manufactured by Nisshinbo Chemical Co., Ltd.

Amine-based curing agents include curing agents having one or more amino groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, and aromatic amines. Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)-2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxyphenyl)-2,2'-dimethyl-4,4'-diaminobiphenyl. bis(4-aminophenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, and the like. Commercially available amine-based curing agents may be used, such as "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD A-A", "KAYAHARD A-B", and "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd., and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

In terms of being able to produce a cured product that is excellent in dielectric properties, conductor adhesion, and mechanical properties in combination with the (A) component and the (C) component described later, the content of the (B) component in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, assuming that the resin components in the resin composition are 100% by mass. The upper limit of the content is not particularly limited and may be determined according to the properties required of the resin composition, but may be, for example, 70% by mass or less, 60% by mass or less, or 55% by mass or less.

As described above, from the viewpoint of obtaining a cured product having excellent dielectric properties, it is preferable that the (B) component contains an active ester-based curing agent. When the resin composition of the present invention contains an active ester-based curing agent as the (B) component, the content of the active ester-based curing agent in the (B) component is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, 75% by mass or more, or 80% by mass or more, when the non-volatile components of the (B) component are taken as 100% by mass, from the viewpoint of obtaining a cured product having particularly excellent dielectric properties. The upper limit of the content of the active ester-based curing agent in the (B) component is not particularly limited, and may be 100% by mass, but may also be, for example, 95% by mass or less, 90% by mass or less, etc.

When the resin composition of the present invention contains an active ester-based curing agent as component (B), the mass ratio of the active ester-based curing agent to component (A) (active ester-based curing agent/component (A)) is preferably 0.5 or more, more preferably 0.6 or more, and even more preferably 0.8 or more, from the viewpoint of exhibiting particularly excellent dielectric properties. Here, a resin composition containing an active ester-based curing agent as a curing agent can realize a cured product with good dielectric properties, but if the content is increased to a level that can realize excellent dielectric properties, it is likely to result in a hard and brittle cured product, and therefore there is a problem that crack defects are likely to occur. In contrast, according to the resin composition of the present invention containing component (C) described later, even if an active ester-based curing agent is contained to a level that can realize excellent dielectric properties, a cured product exhibiting good mechanical properties can be obtained. For example, in the resin composition of the present invention, the mass ratio of the active ester-based curing agent to component (A) may be increased to 1 or more, 1.1 or more, or 1.2 or more. The upper limit of the mass ratio (active ester curing agent/component (A)) may be, for example, 2 or less, 1.9 or less, or 1.8 or less.

<(C) Resin Having Ethynyl Group or Ethynylene Group>
The resin composition of the present invention contains, as component (C), a resin having an ethynyl group or an ethynylene group (hereinafter, also simply referred to as an "ethynyl group-containing resin").

By including such component (C), the resin composition of the present invention can produce a cured product that has a low dielectric tangent, good conductor adhesion even after exposure to a high-temperature, high-humidity environment, and good mechanical properties.

Component (C) is a resin having an ethynyl group or an ethynylene group, and is characterized by having a group represented by the formula R ¹ -C≡C-. R ¹ will be described later, but when R ¹ is a hydrogen atom, it is said to have an ethynyl group, and when R ¹ is other than a hydrogen atom, it is said to have an ethynylene group.

In order to achieve the desired effect in combination with components (A) and (B), it is preferable that component (C) has an ethynyl group or an ethynylene group at its molecular end.

The (C) component preferably has multiple ethynyl or ethynylene groups in the molecule, for example, it preferably has ethynyl or ethynylene groups at both ends of the molecular chain. In one embodiment, the (C) component has ethynyl or ethynylene groups at both ends of the molecular chain.

In particular, from the viewpoint of being able to provide a cured product with even better dielectric tangent, conductor adhesion, and mechanical properties in combination with components (A) and (B), it is preferable that the molecular end of component (C) is a structural unit represented by the following general formula (C1) (hereinafter also referred to as "structural unit (C1)").

（式中、
Ｒ^１は、水素原子、置換基を有していてもよいアリール基、又は、置換基を有していてもよいアルキル基を表し、
環Ａｒ^１は、置換基を有していてもよい芳香環を表し、
ｎ１は、０又は１を表し、
＊は、結合手を表す。）

(Wherein,
R ¹ represents a hydrogen atom, an aryl group which may have a substituent, or an alkyl group which may have a substituent;
Ring Ar ¹ represents an aromatic ring which may have a substituent;
n1 represents 0 or 1;
* represents a bond.)

The aryl group in ^R1 refers to a monovalent group obtained by removing one hydrogen atom on an aromatic ring from an aromatic hydrocarbon. In order to realize a resin composition that, when combined with components (A) and (B), provides a cured product that is excellent in dielectric tangent, conductor adhesion, and mechanical properties, the number of carbon atoms in the aryl group is preferably 6 to 14, and more preferably 6 to 10. Examples of the aryl group include a phenyl group, a naphthyl group, and an anthracenyl group.

The alkyl group in R ¹ refers to a monovalent group obtained by removing one hydrogen atom from a saturated hydrocarbon, and may be either linear or branched. In order to realize a resin composition that, in combination with the (A) component and the (B) component, provides a cured product excellent in dielectric tangent, conductor adhesion, and mechanical properties, the number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 4, and even more 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, an octyl group, and a decyl group.

The substituents that the aryl group or alkyl group in R ¹ may have are as described above. Among them, from the viewpoint of realizing a resin composition that, in combination with the (A) component and the (B) component, provides a cured product that is excellent in all of dielectric tangent, conductor adhesion, and mechanical properties, one or more selected from a halogen atom, an alkyl group, and an aryl group are preferred, and one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms are more preferred.

In a preferred embodiment, R ¹ in general formula (C1) represents a hydrogen atom, an aryl group having 6 to 10 carbon atoms which may have a substituent, or an alkyl group having 1 to 3 carbon atoms which may have a substituent, and the substituent is one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms. In a more preferred embodiment, R ¹ in general formula (C1) represents a hydrogen atom, an aryl group having 6 carbon atoms (i.e., a phenyl group), or an alkyl group having 1 to 3 carbon atoms.

The aromatic ring in the ring Ar ¹ may be either an aromatic carbocyclic ring or an aromatic heterocyclic ring, but is preferably an aromatic carbocyclic ring from the viewpoint of obtaining the effects of the present invention. The number of carbon atoms in the aromatic carbocyclic ring is preferably 6 to 14, more preferably 6 to 10.

The substituents that the aromatic ring in ring Ar ¹ may have are as described above. Among them, from the viewpoint of realizing a resin composition that, in combination with component (A) and component (B), provides a cured product that is excellent in all of dielectric tangent, conductor adhesion, and mechanical properties, one or more selected from a halogen atom, an alkyl group, and an aryl group are preferred, and one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms are more preferred.

In a preferred embodiment, ring Ar ¹ in general formula (C1) is an aromatic carbon ring having 6 to 14 carbon atoms (more preferably a benzene ring or a naphthalene ring) which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

In general formula (C1), n1 represents 0 or 1.

The (C) component preferably has a plurality of structural units (C1) in the molecule, and for example, the (C) component preferably has the structural unit (C1) at both ends of its molecular chain. Thus, in one embodiment, both ends of the (C) component's molecular chain are structural units (C1).

In order to realize a resin composition that, in combination with the (A) and (B) components, provides a cured product that is excellent in dielectric tangent, conductor adhesion, and mechanical properties, the weight average molecular weight (Mw) of the (C) component is preferably 50,000 or less, more preferably 45,000 or less, and even more preferably 30,000 or less, 28,000 or less, 26,000 or less, or 25,000 or less. The lower limit of the Mw of the (C) component is not particularly limited, but is preferably 500 or more, 600 or more, or 700 or more, from the viewpoint of being able to enjoy the effects of the present invention more effectively. Therefore, in a preferred embodiment, the Mw of the (C) component is in the range of 500 to 50,000. The Mw of the (C) component can be measured as a polystyrene equivalent value by the GPC method.

As long as component (C) has an ethynyl group or an ethynylene group (preferably the structural unit (C1)), the structure of the remainder is not particularly limited, and may be appropriately determined so as to satisfy the preferred range of Mw described above, for example, by using one or more (e.g., 1 to 3000, 1 to 1000, 1 to 500) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, sulfur atoms, and silicon atoms. Below, we will explain the structure of component (C) that is particularly suitable from the perspective of realizing a resin composition that, when combined with components (A) and (B), provides a cured product that is even more excellent in terms of dielectric tangent, conductor adhesion, and mechanical properties.

In a preferred embodiment, component (C) has a structural unit represented by the following general formula (C2) (hereinafter also referred to as "structural unit (C2)").

（式中、
Ｒ^２は、（ｉ）１つ以上の芳香環を含有する２価の有機基、（ｉｉ）炭素原子数５以上の２価の脂肪族基、又は、（ｉｉｉ）シロキサン骨格を有する２価の基を表し、
Ｒ^３は、それぞれ独立に、１つ以上の芳香環を含有する４価の有機基を表し、
Ｒ^４は、それぞれ独立に、（ｉ）１つ以上の芳香環を含有する２価の有機基、又は、（ｉｉ）炭素原子数５以上の２価の脂肪族基を表し、
ｎ２は、０以上の数を表す。）

(Wherein,
^R2 represents (i) a divalent organic group containing one or more aromatic rings, (ii) a divalent aliphatic group having 5 or more carbon atoms, or (iii) a divalent group having a siloxane skeleton;
Each ^R3 independently represents a tetravalent organic group containing one or more aromatic rings;
^R4 each independently represents (i) a divalent organic group containing one or more aromatic rings, or (ii) a divalent aliphatic group having 5 or more carbon atoms;
n2 represents a number equal to or greater than 0.

In general formula (C2), ^R2 represents (i) a divalent organic group containing one or more aromatic rings, (ii) a divalent aliphatic group having 5 or more carbon atoms, or (iii) a divalent group having a siloxane skeleton.

When ^R2 represents (i) a divalent organic group containing one or more aromatic rings, the aromatic ring contained in the divalent organic group represented by ^R2 may be any of a monocyclic aromatic ring and a condensed polycyclic aromatic ring in which two or more monocyclic aromatic rings are condensed, as described above. In addition, the aromatic ring may be any of an aromatic carbon ring and an aromatic heterocycle. In particular, in combination with the (A) component and the (B) component, from the viewpoint of realizing a resin composition that provides a cured product excellent in dielectric tangent, conductor adhesion, and mechanical properties, the divalent organic group preferably contains one or more aromatic carbon rings (more preferably two or more, three or more, or four or more).

When R ² represents (i) a divalent organic group containing one or more aromatic rings, from the viewpoint of further enjoying the effects of the present invention, R ² is preferably a divalent group represented by the following general formula (C2-2i) (hereinafter also referred to as "divalent group (C2-2i)"):

（式中、
環Ａｒ^２１、環Ａｒ^２２、環Ａｒ^２３及び環Ａｒ^２４は、それぞれ独立に、置換基を有していてもよい芳香環を表し、
Ｌ^２１、Ｌ^２２及びＬ^２３は、それぞれ独立に、単結合、又は、２価の連結基を表し、
ｎ２１は、０以上の数を表し、
ｎ２２は、０又は１を表し、
ｎ２３は、０又は１を表す。）

(Wherein,
Ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ each independently represent an aromatic ring which may have a substituent;
L ²¹ , L ²² and L ²³ each independently represent a single bond or a divalent linking group;
n21 represents a number equal to or greater than 0;
n22 represents 0 or 1;
n23 represents 0 or 1.

Here, when n23 is 0, the divalent group (C2-2i) has a structure in which two bonds extend from ring Ar ²¹ (*-ring Ar ²¹ -*). When n23 is 1, the divalent group (C2-2i) has a structure represented by *-ring Ar ²¹ -L ²¹ -(ring Ar ²² -L ²² ) _n21 -(ring Ar ²³ -L ²³ ) _n22 -ring Ar ²⁴ -*.

The aromatic rings in ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ are as described above. In particular, from the viewpoint of obtaining the effects of the present invention, the aromatic rings in ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ are each independently an aromatic carbocyclic ring having 6 to 14 carbon atoms, and more preferably a benzene ring or a naphthalene ring.

The substituents which the aromatic rings in rings Ar ²¹ , Ar ²² , Ar ²³ and Ar ²⁴ may have are as described above. Among these, from the viewpoint of obtaining the effects of the present invention more preferably have one or more selected from a halogen atom, an alkyl group and an aryl group, and more preferably have one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 10 carbon atoms.

In a preferred embodiment, ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ in general formula (C2-2i) are each independently an aromatic carbon ring having 6 to 14 carbon atoms (more preferably a benzene ring or a naphthalene ring) which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

In formula (C2-2i), L ²¹ , L ²² and L ²³ each independently represent a single bond or a divalent linking group. The divalent linking group represented by L ²¹ , L ²² and L ²³ is preferably a divalent group having one or more (e.g., 1 to 3000, 1 to 1000, 1 to 100, 1 to 50) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, sulfur atoms and silicon atoms. Examples of divalent linking groups include _-SO2- , -CO-, -COO-, -O-, -S-, -O- _{C6H4 -O-} (wherein _-C6H4- represents a phenylene group), -O- _{C6H4 -} C( _CH3 ) ₂ - _C6H4 -O-, -COO-( _CH2 ) _q -OCO- (wherein q represents an integer of 1 to 20), -COO- _H2C - _HC (-O-C(=O) _-CH3 ) _-CH2- OCO-, _an alkylene group, an alkenylene group, an alkynylene group, an arylene group, a heteroarylene group, ^-NR0- (wherein ^R0 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), and -C(=O) ^-NR0- . The alkylene group may be linear or branched, and the number of carbon atoms is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 5 or 1 to 4. The alkenylene group may be linear or branched, and the number of carbon atoms is preferably 2 to 10, more preferably 2 to 6, and even more preferably 2 to 5. The number of carbon atoms of the arylene group is preferably 6 to 14, more preferably 6 to 10, and the number of carbon atoms of the heteroarylene group is preferably 3 to 9. The above-mentioned alkyl group, alkylene group, alkenylene group, alkynylene group, arylene group, and heteroarylene group may further have a substituent. The substituent is as described above, but among them, from the viewpoint of being able to enjoy the effects of the present invention more, one or more selected from a halogen atom, an alkyl group, and an aryl group are preferable, and one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms are more preferable.

In a preferred embodiment, L ²¹ , L ²² and L ²³ in general formula (C2-2i) each independently represent a single bond, -SO ₂ -, -CO-, -COO-, -O-, -S-, an alkylene group having 1 to 10 carbon atoms which may have a substituent, an alkenylene group having 2 to 10 carbon atoms which may have a substituent, -NR ⁰ - (wherein R ⁰ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), or -C(═O)-NR ⁰ -, more preferably a single bond, -O-, -S-, or an alkylene group having 1 to 6 carbon atoms which may have a substituent. Here, the substituent is preferably one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

In one embodiment, n22 and n23 are 1, the divalent linking group represented by L ²¹ and the divalent linking group represented by L ²³ are the same as each other, and the divalent linking group represented by L ²¹ and the divalent linking group represented by L ²² are different from each other. In a preferred embodiment, n22 and n23 are 1, L ²¹ and L ²³ are -O-, and L ²² is an alkylene group which may have a substituent. The preferred range of the number of carbon atoms of the alkylene group and the preferred type of the substituent are as described above.

In general formula (C2-2i), n21 represents a number of 0 or more, preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 4 or 1 to 3.

In a preferred embodiment, in formula (C2-2i),
n22 and n23 are 1;
Ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ each independently represent an aromatic carbon ring having 6 to 14 carbon atoms (more preferably a benzene ring or a naphthalene ring) which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
L ²¹ , L ²² and L ²³ each independently represent a single bond, -O-, -S-, or an alkylene group having 1 to 6 carbon atoms which may have a substituent, and the substituent is at least one selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
n21 represents a number from 1 to 5.

In a more preferred embodiment, in general formula (C2-2i),
n22 and n23 are 1;
Ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ each independently represent a benzene ring which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
L ²¹ and L ²³ represent -O-;
L ²² represents an alkylene group having 1 to 6 carbon atoms which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
n21 represents a number from 1 to 3.

When ^R2 (ii) represents a divalent aliphatic group having 5 or more carbon atoms, the aliphatic group may be either linear or branched, and may contain a ring structure. The number of carbon atoms in the aliphatic group is preferably 6 or more, more preferably 8 or more, 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 aliphatic group may contain, as a skeleton atom, one or more atoms selected from oxygen atoms, nitrogen atoms, sulfur atoms, and silicon atoms in addition to carbon atoms.

When R ² represents (ii) a divalent aliphatic group having 5 or more carbon atoms, from the viewpoint of further enjoying the effects of the present invention, R ² is preferably a divalent group represented by the following general formula (C2-2ii) (hereinafter also referred to as "divalent group (C2-2ii)").

（式中、
Ｒ^２１及びＲ^２３は、それぞれ独立に、単結合、置換基を有していてもよいアルキレン基、又は、置換基を有していてもよいアルケニレン基を表し、
環Ｒ^２２は、アルキル基及びアルケニル基からなる群から選択される置換基を有していてもよい非芳香環を表し、
ｎ２４は、０～３の数を表し、
＊は、結合手を表す。）

(Wherein,
R ²¹ and R ²³ each independently represent a single bond, an alkylene group which may have a substituent, or an alkenylene group which may have a substituent;
Ring R ²² represents a non-aromatic ring which may have a substituent selected from the group consisting of an alkyl group and an alkenyl group;
n24 represents a number from 0 to 3,
* represents a bond.)

The alkylene group in R ²¹ and R ²³ may be either linear or branched, and preferably has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and further preferably 1 to 10 or 1 to 8 carbon atoms.

The alkenylene group in R ²¹ and R ²³ may be either linear or branched, and preferably has 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and further preferably 2 to 10 or 2 to 8 carbon atoms.

The substituents that the alkylene group or alkenylene group in R ²¹ and R ²³ may have are as described above. Among them, from the viewpoint of obtaining the effects of the present invention more preferably has one or more selected from a halogen atom, an alkyl group, and an aryl group, and more preferably has one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

The non-aromatic ring in ring R ²² is as described above, and from the viewpoint of obtaining the effects of the present invention, it is preferably a cycloalkane ring or a cycloalkene ring. The number of carbon atoms in the cycloalkane ring or cycloalkene ring is preferably 3 to 12, more preferably 3 to 10, and even more preferably 3 to 8 or 4 to 8.

The alkyl group and alkenyl group as the substituent that the non-aromatic ring in ring R ²² may have are as described above. Among them, the number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 8, and the number of carbon atoms of the alkenyl group is preferably 2 to 10, more preferably 2 to 8.

In general formula (C2-2ii), n24 represents a number from 0 to 3, preferably 0 to 2, more preferably 0 or 1, and even more preferably 1.

In a preferred embodiment, in formula (C2-2ii),
n24 is 1,
R ²¹ and R ²³ each independently represent a single bond, an alkylene group having 1 to 8 carbon atoms which may have a substituent, or an alkenylene group having 2 to 8 carbon atoms which may have a substituent, wherein the substituent is one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
Ring R ²² represents a cycloalkane ring or cycloalkene ring having 4 to 8 carbon atoms, which may have one or more substituents selected from the group consisting of alkyl groups having 1 to 8 carbon atoms and alkenyl groups having 2 to 8 carbon atoms.

In a more preferred embodiment, in general formula (C2-2ii),
n24 is 1,
R ²¹ and R ²³ each represent an alkylene or alkenylene group having 8 carbon atoms, which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
Ring R22 represents a cyclohexane ring or a cyclohexene ring which may have one or more substituents selected from the group consisting of an alkyl group having 6 to 8 carbon atoms and an alkenyl group having 6 to 8 carbon atoms;
Or,
n24 is 1,
One of R ²¹ and R ²³ represents a single bond;
The other of R ²¹ and R ²³ represents an alkylene group having 1 to 3 carbon atoms which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
Ring R ²² represents a cyclohexane ring having 1 to 4 (preferably 2 to 4, more preferably 3) alkyl groups having 1 to 3 carbon atoms as a substituent. In the former case, the divalent group (C2-2ii) preferably has a C36 skeleton derived from dimer diamine.

When R ² represents (iii) a divalent group having a siloxane skeleton, from the viewpoint of further enjoying the effects of the present invention, R ² is preferably a divalent group represented by the following general formula (C2-2iii) (hereinafter also referred to as "divalent group (C2-2iii)").

（式中、
Ｒ^２４及びＲ^２５は、それぞれ独立に、置換基を有していてもよいアルキレン基を表し、
Ｒ^２６及びＲ^２７は、それぞれ独立に、水素原子、置換基を有していてもよいアルキル基、又は、置換基を有していてもよいアリール基を表し、
ｎ２５は、０以上の数を表す。）

(Wherein,
R ²⁴ and R ²⁵ each independently represent an alkylene group which may have a substituent;
R ²⁶ and R ²⁷ each independently represent a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group;
n25 represents a number equal to or greater than 0.

The alkylene group in R ²⁴ and R ²⁵ may be either linear or branched and preferably has 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6 or 1 to 4 carbon atoms.

The substituents that the alkylene group in R ²⁴ and R ²⁵ may have are as described above. Among them, from the viewpoint of obtaining the effects of the present invention, one or more selected from a halogen atom, an alkyl group, and an aryl group are preferable, and one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms are more preferable.

The alkyl group in R ²⁶ and R ²⁷ may be either linear or branched, and preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and further preferably 1 to 4 or 1 to 3 carbon atoms.

The aryl group in R ²⁶ and R ²⁷ preferably has 6 to 14 carbon atoms, and more preferably 6 to 10 carbon atoms.

The substituents that the alkyl group or aryl group in R ²⁶ and R ²⁷ may have are as described above. Among them, from the viewpoint of obtaining the effects of the present invention, one or more selected from a halogen atom, an alkyl group, and an aryl group are preferable, and one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms are more preferable.

In general formula (C2-2iii), n25 represents a number of 0 or more, and the range is not particularly limited. For example, it may be appropriately determined so that the Mw of component (C) falls within the above preferred range.

In a preferred embodiment, in formula (C2-2iii),
R ²⁴ and R ²⁵ each independently represent an alkylene group having 1 to 10 carbon atoms which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
R ²⁶ and R ²⁷ each independently represent an alkyl group having 1 to 3 carbon atoms which may have a substituent, or an aryl group having 6 to 10 carbon atoms which may have a substituent, wherein the substituent is one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
n25 represents a number such that the Mw of component (C) is in the range of 500 to 50000. With regard to n25, the more preferred range of the Mw of component (C) is as described above.

In formula (C2), each R ³ independently represents a tetravalent organic group containing one or more aromatic rings.

The aromatic ring contained in the tetravalent organic group represented by ^R3 may be, as described above, either a monocyclic aromatic ring or a condensed polycyclic aromatic ring in which two or more monocyclic aromatic rings are condensed. The aromatic ring may be either an aromatic carbon ring or an aromatic heterocycle. In particular, in combination with the (A) component and the (B) component, from the viewpoint of realizing a resin composition that provides a cured product excellent in dielectric tangent, conductor adhesion, and mechanical properties, the tetravalent organic group preferably contains one or more aromatic carbon rings (more preferably two or more, three or more, or four or more).

From the viewpoint of obtaining the effects of the present invention more effectively, R ³ is preferably a tetravalent group represented by the following general formula (C2-3) (hereinafter also referred to as "tetravalent group (C2-3)").

（式中、
環Ａｒ^３１、環Ａｒ^３２、環Ａｒ^３３及び環Ａｒ^３４は、それぞれ独立に、置換基を有していてもよい芳香環を表し、
Ｌ^３１、Ｌ^３２及びＬ^３３は、それぞれ独立に、単結合、又は、２価の連結基を表し、
ｎ３１は、０以上の数を表し、
ｎ３２は、０又は１を表し、
ｎ３３は、０又は１を表す。）

(Wherein,
Ring Ar ³¹ , ring Ar ³² , ring Ar ³³ and ring Ar ³⁴ each independently represent an aromatic ring which may have a substituent;
L ³¹ , L ³² and L ³³ each independently represent a single bond or a divalent linking group;
n31 represents a number equal to or greater than 0;
n32 represents 0 or 1;
n33 represents 0 or 1.

Here, when n33 is 0, the tetravalent group (C2-3) has a structure in which four bonds extend from ring Ar ³¹ ((*-)(*-)Ring Ar ³¹ (-*)(-*)). When n33 is 1, the tetravalent group (C2-3) has a structure represented by (*-)(*-)Ring Ar ³¹ -L ³¹ -(Ring Ar ³² -L ³² ) _n31 -(Ring Ar ³³ -L ³³ ) _n32 -Ring Ar ³⁴ (-*)(-*).

The aromatic rings in ring Ar ³¹ , ring Ar ³² , ring Ar ³³ and ring Ar ³⁴ , including preferred examples thereof, are the same as the aromatic rings in ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ^24. The substituents that the aromatic rings in ring Ar ³¹ , ring Ar ³² , ring Ar ³³ and ring Ar ³⁴ may have, including preferred examples thereof, are the same as the aromatic rings in ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ .

In a preferred embodiment, ring Ar ³¹ , ring Ar ³² , ring Ar ³³ and ring Ar ³⁴ in general formula (C2-3) are each independently an aromatic carbon ring having 6 to 14 carbon atoms (more preferably a benzene ring or a naphthalene ring) which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

The divalent linking groups represented by L ³¹ , L ³² and L ³³ are the same as the divalent linking groups represented by L ²¹ , L ²² and L ²³ described above, including preferred examples thereof and preferred examples of the substituents.

In a preferred embodiment, L ³¹ , L ³² and L ³³ in general formula (C2-3) each independently represent a single bond, -SO ₂ -, -CO-, -COO-, -O-, -S-, an alkylene group having 1 to 10 carbon atoms which may have a substituent, an alkenylene group having 2 to 10 carbon atoms which may have a substituent, -NR ⁰ - (wherein R ⁰ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), or -C(═O)-NR ⁰ -, more preferably a single bond, -O-, -S-, or an alkylene group having 1 to 6 carbon atoms which may have a substituent. Here, the substituent is preferably one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

In one embodiment, n32 and n33 are 1, the divalent linking group represented by L ³¹ and the divalent linking group represented by L ³³ are the same as each other, and the divalent linking group represented by L ³¹ and the divalent linking group represented by L ³² are different from each other. In a preferred embodiment, n32 and n33 are 1, L ³¹ and L ³³ are -O-, and L ³² is an alkylene group which may have a substituent. The preferred range of the number of carbon atoms of the alkylene group and the preferred type of the substituent are as described above.

In general formula (C2-3), n31 represents a number of 0 or more, preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 4 or 1 to 3.

In a preferred embodiment, in formula (C2-3),
n32 and n33 are 1;
Ring Ar ³¹ , ring Ar ³² , ring Ar ³³ and ring Ar ³⁴ each independently represent an aromatic carbon ring having 6 to 14 carbon atoms (more preferably a benzene ring or a naphthalene ring) which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
L ³¹ , L ³² and L ³³ each independently represent a single bond, -O-, -S-, or an alkylene group having 1 to 6 carbon atoms which may have a substituent, and the substituent is one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
n31 represents a number from 1 to 5.

In a more preferred embodiment, in formula (C2-3),
n32 and n33 are 1;
Ring Ar ³¹ , ring Ar ³² , ring Ar ³³ and ring Ar ³⁴ each independently represent a benzene ring which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
L ³¹ and L ³³ represent -O-;
L ³² represents an alkylene group having 1 to 6 carbon atoms which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
n31 represents a number from 1 to 3.

In formula (C2), each R ⁴ independently represents (i) a divalent organic group containing one or more aromatic rings, or (ii) a divalent aliphatic group having 5 or more carbon atoms.

When R ⁴ represents (i) a divalent organic group containing one or more aromatic rings, the divalent organic group is the same as the (i) divalent organic group containing one or more aromatic rings described above for R ^2. Suitable examples of the divalent organic group are as described above for the divalent group represented by general formula (C2-2i), i.e., the divalent group (C2-2i).

In a preferred embodiment, R ⁴ is a divalent group (C2-2i), where in general formula (C2-2i):
n22 and n23 are 1;
Ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ each independently represent an aromatic carbon ring having 6 to 14 carbon atoms (more preferably a benzene ring or a naphthalene ring) which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
L ²¹ , L ²² and L ²³ each independently represent a single bond, -O-, -S-, or an alkylene group having 1 to 6 carbon atoms which may have a substituent, and the substituent is at least one selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
n21 represents a number from 1 to 5.

In a more preferred embodiment, R ⁴ is a divalent group (C2-2i), where in general formula (C2-2i):
n22 and n23 are 1;
Ring Ar ²¹ , ring Ar ²² , ring Ar ²³ and ring Ar ²⁴ each independently represent a benzene ring which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
L ²¹ and L ²³ represent -O-;
L ²² represents an alkylene group having 1 to 6 carbon atoms which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
n21 represents a number from 1 to 3.

When R ⁴ represents (ii) a divalent aliphatic group having 5 or more carbon atoms, the divalent organic group is the same as the (ii) divalent aliphatic group having 5 or more carbon atoms described above for R ^2. Suitable examples of the divalent aliphatic group are as described above for the divalent group represented by general formula (C2-2ii), i.e., the divalent group (C2-2ii).

In a preferred embodiment, R ⁴ is a divalent group (C2-2ii), where in general formula (C2-2ii):
n24 is 1,
R ²¹ and R ²³ each independently represent a single bond, an alkylene group having 1 to 8 carbon atoms which may have a substituent, or an alkenylene group having 2 to 8 carbon atoms which may have a substituent, wherein the substituent is one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
Ring R ²² represents a cycloalkane ring or cycloalkene ring having 4 to 8 carbon atoms, which may have one or more substituents selected from the group consisting of alkyl groups having 1 to 8 carbon atoms and alkenyl groups having 2 to 8 carbon atoms.

In a more preferred embodiment, R ⁴ is a divalent group (C2-2ii), where in general formula (C2-2ii):
n24 is 1,
R ²¹ and R ²³ each represent an alkylene or alkenylene group having 8 carbon atoms, which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
Ring R22 represents a cyclohexane ring or a cyclohexene ring, which may have one or more substituents selected from the group consisting of an alkyl group having 6 to 8 carbon atoms and an alkenyl group having 6 to 8 carbon atoms; or
n24 is 1,
One of R ²¹ and R ²³ represents a single bond;
The other of R ²¹ and R ²³ represents an alkylene group having 1 to 3 carbon atoms which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
Ring R ²² represents a cyclohexane ring having 1 to 4 (preferably 2 to 4, more preferably 3) alkyl groups having 1 to 3 carbon atoms as a substituent. In the former case, the divalent group (C2-2ii) preferably has a C36 skeleton derived from dimer diamine.

In general formula (C2), n2 is a number equal to or greater than 0. There is no particular upper limit to n2 as long as the effects of the present invention are achieved, and it may be determined appropriately so that the Mw of component (C) falls within the preferred range described above. For example, n2 may be a number in the range of 0 to 100.

From the viewpoint of realizing a resin composition that provides a cured product excellent in dielectric tangent, conductor adhesion, and mechanical properties in combination with the (A) component and the (B) component, when n2 is 0, R ² preferably represents (ii) a divalent aliphatic group having 5 or more carbon atoms, or (iii) a divalent group having a siloxane skeleton, and more preferably the above divalent group (C2-2ii) or the above divalent group (C2-2iii). Suitable examples of these divalent groups (C2-2ii) and (C2-2iii) are as described above.

Furthermore, when n2 is not 0 (for example, when it is a number in the range of 1 to 100), R ² preferably represents (i) a divalent organic group containing one or more aromatic rings, or (ii) a divalent aliphatic group having 5 or more carbon atoms, and more preferably the above divalent group (C2-2i) or the above divalent group (C2-2ii). Suitable examples of these divalent groups (C2-2i) and (C2-2ii) are as described above. In such a case, R ³ and R ⁴ , including suitable examples thereof, are as described above.

In order to realize a resin composition that, when combined with components (A) and (B), provides a cured product that is superior in dielectric tangent, conductor adhesion, and mechanical properties, it is preferable that structural unit (C2) is a structural unit represented by the following general formula (C2') (hereinafter also referred to as "structural unit (C2')").

（式中、
Ｒ^２、Ｒ^４、ｎ２、環Ａｒ^３２、環Ａｒ^３３、Ｌ^３１、Ｌ^３２、Ｌ^３３、ｎ３１、ｎ３２及びｎ３３は先述のとおりであり、
Ｒ^３１及びＲ^３２は、それぞれ独立に、置換基を表し、
ｎ３４及びｎ３５は、それぞれ独立に、０～３の数を表す。）

(Wherein,
R ² , R ⁴ , n2, the ring Ar ³² , the ring Ar ³³ , L ³¹ , L ³² , L ³³ , n31, n32 and n33 are as defined above;
R ³¹ and R ³² each independently represent a substituent.
n34 and n35 each independently represent a number from 0 to 3.

In formula (C2'), R ² , R ⁴ , n2, ring Ar ³² , ring Ar ³³ , L ³¹ , L ³² , L ³³ , n31, n32 and n33 are as defined above.

When n2 is 0, ^R2 preferably represents (ii) a divalent aliphatic group having 5 or more carbon atoms, or (iii) a divalent group having a siloxane skeleton, and more preferably the above divalent group (C2-2ii) or the above divalent group (C2-2iii). Suitable examples of these divalent groups (C2-2ii) and (C2-2iii) are as described above.

When n2 is not 0 (for example, when it is a number in the range of 1 to 100), ^R2 preferably represents (i) a divalent organic group containing one or more aromatic rings, or (ii) a divalent aliphatic group having 5 or more carbon atoms, and more preferably the above divalent group (C2-2i) or the above divalent group (C2-2ii). Suitable examples of these divalent groups (C2-2i) and (C2-2ii) are as described above.

When n2 is not 0 (for example, when it is a number in the range of 1 to 100), the ring Ar ³² , the ring Ar ³³ , L ³¹ , L ³² , L ³³ , n31, n32 and n33 are as described above, and as explained above for the tetravalent group (C2-3),
n32 and n33 are 1;
Ring Ar ³² and ring Ar ³³ each independently represent an aromatic carbon ring having 6 to 14 carbon atoms (more preferably a benzene ring or a naphthalene ring) which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
L ³¹ , L ³² and L ³³ each independently represent a single bond, -O-, -S-, or an alkylene group having 1 to 6 carbon atoms which may have a substituent, and the substituent is one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
n31 preferably represents a number from 1 to 5;
n32 and n33 are 1;
Ring Ar ³² and ring Ar ³³ each independently represent a benzene ring which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
L ³¹ and L ³³ represent -O-;
L ³² represents an alkylene group having 1 to 6 carbon atoms which may have one or more substituents selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms;
More preferably, n31 represents a number from 1 to 3.

When n2 is not 0 (for example, when n2 is a number in the range of 1 to 100), R ⁴ is as described above, and is more preferably the above divalent group (C2-2i) or the above divalent group (C2-2ii). Suitable examples of these divalent groups (C2-2i) and (C2-2ii) are as described above.

The substituents represented by R ³¹ and R ³² (corresponding to the substituents which may be possessed by ring Ar ³¹ and ring Ar ³⁴ in general formula (C2-3)) are as described above, and among them, one or more selected from a halogen atom, an alkyl group, and an aryl group are preferable, and one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms are more preferable.

In a preferred embodiment, component (C) has the above structural unit (C1) at its molecular end and contains the above structural unit (C2) within its molecular chain.

The (C) component may have a structure in which the structural unit (C1) is directly bonded to both ends of the structural unit (C2). That is, the (C) component may have a structure containing only the structural unit (C1) and the structural unit (C2). Alternatively, the (C) component may contain other structural units in addition to the structural unit (C1) and the structural unit (C2), as long as the effects of the present invention are achieved. In the (C) component, the total content of the structural unit (C1) and the structural unit (C2) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, 80% by mass or more, or 90% by mass or more, when the entire molecular chain of the (C) component is taken as 100% by mass, and the upper limit may be 100% by mass.

An example of such other structural units is the structural unit represented by the following general formula (C3) (hereinafter also referred to as "structural unit (C3)").

（式中、
Ｒ^５は、４価の脂肪族基を表し、
Ｒ^６は、（ｉ）１つ以上の芳香環を含有する２価の有機基、又は、（ｉｉ）２価の脂肪族基を表す。）

(Wherein,
^R5 represents a tetravalent aliphatic group;
^R6 represents (i) a divalent organic group containing one or more aromatic rings, or (ii) a divalent aliphatic group.

The tetravalent aliphatic group represented by ^R5 may be either linear or branched, and may contain a ring structure. The number of carbon atoms in the aliphatic group is preferably 2 or more, 3 or more, 4 or more, or 6 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 aliphatic group may contain, as a skeleton atom, one or more atoms selected from an oxygen atom, a nitrogen atom, a sulfur atom, and a silicon atom in addition to a carbon atom.

The (i) divalent organic group containing one or more aromatic rings represented by R ⁶ , including suitable examples thereof, is the same as the (i) divalent organic group containing one or more aromatic rings represented by R ^2. The (ii) divalent aliphatic group represented by R ⁶ , including suitable examples thereof, is the same as the (ii) divalent aliphatic group having 5 or more carbon atoms represented by R ² , and may also be a divalent aliphatic group having 1 to 4 carbon atoms.

In terms of being able to provide a cured product that is excellent in dielectric properties, conductor adhesion, and mechanical properties in combination with the (A) component and the (B) component, the content of the (C) component in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, 4% by mass or more, or 5% by mass or more, assuming that the resin components in the resin composition are 100% by mass. The upper limit of the content is not particularly limited and may be determined according to the properties required of the resin composition, but may be, for example, 50% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less.

From the viewpoint of obtaining the effects of the present invention more effectively, when the total of the non-volatile components (A) and (B) in the resin composition is taken as 100% by mass, the content of the (C) component is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, 4% by mass or more, or 5% by mass or more. The upper limit of the content is not particularly limited and may be determined according to the properties required of the resin composition, but may be, for example, 60% by mass or less, 55% by mass or less, or 50% by mass or less.

The following is an example of the synthesis procedure for component (C).

In one embodiment, component (C) is
(c1) an aromatic carboxylic acid anhydride having an ethynyl group or an ethynylene group;
(c2) A reaction product (imidized product) with a diamine compound.

-(c1) Aromatic carboxylic acid anhydride having an ethynyl group or an ethynylene group-
The component (c1) is an aromatic carboxylic anhydride having an ethynyl group or an ethynylene group. The structure of the component (c1) is not particularly limited as long as it is an aromatic carboxylic anhydride having an ethynyl group or an ethynylene group, but a suitable example is an aromatic carboxylic anhydride represented by the following general formula (c1) (hereinafter, also referred to as "aromatic carboxylic anhydride (c1)"). By using the aromatic carboxylic anhydride (c1), the component (C) having the above structural unit (C1) can be synthesized.

（式中、Ｒ^１、環Ａｒ^１及びｎ^１は先述のとおりである。）

(In the formula, R ¹ , ring Ar ¹ and n ¹ are as defined above.)

For the aromatic carboxylic acid anhydride (c1), R ¹ , ring Ar ¹ and n ¹ may be appropriately determined so as to achieve the desired structure of the structural unit (C1) in the component (C). For example, such aromatic carboxylic anhydrides (c1) include 4-phenylethynylphthalic anhydride (hereinafter also referred to as "PEPA") which provides a structural unit (C1) in which R ¹ is a phenyl group, n1 is 0, and ring Ar ¹ is a benzene ring, 4-methylethynylphthalic anhydride which provides a structural unit (C1) in which R ¹ is a methyl group, n1 is 0, and ring Ar ¹ is a benzene ring, 4-ethynylphthalic anhydride which provides a structural unit (C1) in which R ¹ is a hydrogen atom, n1 is 0, and ring Ar ¹ is a benzene ring, and phenylethynyltrimellitic anhydride (hereinafter also referred to as "PETA") which provides a structural unit (C1) in which R ¹ is a phenyl group, n1 is 1, and ring Ar ¹ is a benzene ring. These various aromatic carboxylic anhydrides (c1) are available from various suppliers such as Tokyo Chemical Industry Co., Ltd. and Nexam Chemical Co., Ltd.

-(c2) Diamine compound-
The component (c2) is a diamine compound. The structure of the component (c2) is not particularly limited as long as it has two amino groups at the molecular chain terminals, but a suitable example is a diamine compound represented by the following general formula (c2) (hereinafter, also referred to as "diamine compound (c2)"). By using the diamine compound (c2), the component (C) having the above structural unit (C2) can be synthesized.

（式中、Ｒ^２、Ｒ^３、Ｒ^４及びｎ２は先述のとおりである。）

(In the formula, R ² , R ³ , R ⁴ and n2 are as defined above.)

For the component (c2), R ² , R ³ , R ⁴ and n2 may be appropriately determined so as to achieve the desired structure of the structural unit (C2) in the component (C). For example, as the diamine compound (c2), a diamine compound represented by the following general formula (c2-1) (hereinafter also referred to as "diamine compound (c2-1)") may be used to provide the structural unit (C2) in which n2 is 0.

（式中、Ｒ^２は先述のとおりである。）

(In the formula, ^R2 is as defined above.)

Specifically, when achieving a structural unit (C2) in which R ² is the above divalent group (C2-2i), a diamine compound having a structure in which amino groups are bonded to both ends of the above divalent group (C2-2i) may be used. For example, various benzenediamines such as 1,4-benzenediamine may be used to obtain a structural unit (C2) in which n23 is 0 and ring Ar ²¹ is a benzene ^ring , and various biphenyldiamines such as 4,4'-biphenyldiamine may be used to obtain a structural unit (C2) ⁱⁿ which n23 is 1, n21 and ⁿ²² are 0, ^ring Ar ²¹ and ring Ar ²⁴ are benzene rings, and L ^{21 is a} single bond. As a material that provides the structural unit (C2) in which ²² is a dimethylmethylene group (a branched alkylene group having 3 carbon atoms), 4,4'-[1,4-phenylenebis[(1-methylethylidene)-4,1-phenyleneoxy]]bisbenzeneamine (a compound represented by the following formula; hereinafter, also referred to as "BPPAN") may be used.

When achieving a structural unit (C2) in which R ² is the above divalent group (C2-2ii), a diamine compound having a structure in which amino groups are bonded to both terminals of the above divalent group (C2-2ii) may be used. For example, various alkylene diamines such as 1,6-hexamethylene diamine may be used as a structural unit (C2) in which n24 is 0 and R ²³ is an alkylene group. Dimer diamine may be used as a structural unit (C2) in which n24 is 1, R ²¹ and R ²³ are alkylene groups or alkenylene groups having 8 carbon atoms, and ring R ²² is a cyclohexane ring or cyclohexene ring having a substituent selected from the group consisting of alkyl groups and alkenyl groups having 6 to 8 carbon atoms. Isophorone diamine (hereinafter also referred to as "IPDA") may be used as a structural unit (C2) in which n24 is 1, one of R ²¹ and R ²³ is a single bond, the other is a methylene group, and ring R ²² is a cyclohexane ring having three methyl groups as substituents.

When achieving a structural unit (C2) in which R ² is the above-mentioned divalent group (C2-2iii), a diamine compound having a structure in which amino groups are bonded to both ends of the above-mentioned divalent group (C2-2iii) may be used. For example, various amino-modified silicone compounds such as "KF-8010", " ^X -22-161A ^" , "X-22-161B", "KF-8012", and "KF-8008" (all manufactured by Shin-Etsu Silicones Co., Ltd.) may be used to provide a structural unit (C2) in which R 24 and R 25 are alkylene groups, ^R26 and R27 are alkyl groups having 1 to 3 carbon atoms, and n25 is a number such that the weight average molecular weight of the (C) component is in the range of 500 to 50,000. As a structural unit (C2) in which ^R25 is an alkylene group, R26 and R27 are each independently an alkyl group or a phenyl group having 1 to 3 carbon atoms, and n25 is a number such that the weight average molecular weight of the component (C) is in the range of 500 to 50,000, various amino-modified silicone compounds such as "X-22-1660B-3" and "X-22-9409" (both manufactured by Shin-Etsu Silicones Co., Ltd.) may be used.

In addition, the diamine compound (c2) where n2 is not 0, for example, where n2 is in the range of 1 to 100, may be a reaction product (imidized product) of the above diamine compound (c2-1), an aromatic carboxylic dianhydride represented by the following general formula (c2-2-1) (hereinafter also referred to as "aromatic carboxylic dianhydride (c2-2-1)"), and a diamine compound represented by the following general formula (c2-2-2) (hereinafter also referred to as "diamine compound (c2-2-2)").

（式中、Ｒ^３は先述のとおりである。）

(In the formula, ^R3 is as defined above.)

（式中、Ｒ^４は先述のとおりである。）

(In the formula, ^R4 is as defined above.)

With regard to the aromatic carboxylic dianhydride (c2-2-1), when achieving a structural unit (C2) in which R ³ is the above-mentioned tetravalent group (C2-3), an aromatic carboxylic dianhydride having a structure in which both terminals of the above-mentioned tetravalent group (C2-3) are carboxylic acid anhydrides may be used. For example, various benzenetetracarboxylic dianhydrides such as 1,2,4,5-benzenetetracarboxylic dianhydride may be used to obtain a structural unit (C2) in which n33 is ⁰ and ring Ar ³¹ is a benzene ring. Various biphenyltetracarboxylic dianhydrides such as 3,3',4,4'-biphenyltetracarboxylic dianhydride may be used to obtain a structural unit (C2) in which n33 is 1, n31 and n32 are 0 ^, ring Ar ³¹ and ring Ar ³⁴ are benzene rings ^{, and L 31} is a single bond ^. As a material that provides the structural unit (C2) in which ³² is a dimethylmethylene group (a branched alkylene group having 3 carbon atoms), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (a compound represented by the following formula; hereinafter, also referred to as "BPADA") may be used.

The diamine compound (c2-1) is as described above. When achieving a structural unit (C2) in which n2 is not 0, as described above, R ² preferably represents (i) a divalent organic group containing one or more aromatic rings, or (ii) a divalent aliphatic group having 5 or more carbon atoms, and as the diamine compound (c2-1), a diamine compound having a structure in which amino groups are bonded to both ends of the above divalent group (C2-2i), or a diamine compound having a structure in which amino groups are bonded to both ends of the above divalent group (C2-2ii) can be preferably used. The same applies to the diamine compound (c2-2-2).

In addition, when ^R2 and ^R4 have the same structure in the structural unit (C2) in the target component (C), the diamine compound (c2-1) and the diamine compound (c2-2-2) may be the same. In such a case, the diamine compound (c2) may be a reaction product (imidized product) of the diamine compound (c2-1) and the aromatic carboxylic dianhydride (c2-2-1).

When synthesizing a component (C) containing, in addition to the structural units (C1) and (C2), another structural unit, for example, the above structural unit (C3), it is sufficient to blend, in addition to the aromatic carboxylic acid dianhydride represented by the above general formula (c2-2-1), an aliphatic carboxylic acid dianhydride in which R ³ in the formula is replaced by R ^5. For example, various alkane tetracarboxylic acid dianhydrides such as 1,1,6,6-hexane tetracarboxylic acid dianhydride, and various cycloalkane tetracarboxylic acid dianhydrides such as 1,2,4,5-cyclohexane tetracarboxylic acid dianhydride may be used.

When synthesizing the (C) component containing the structural unit (C2) where n2 is 0, it is sufficient to react the aromatic carboxylic anhydride (c1) with the diamine compound (c2-1). When synthesizing the (C) component containing the structural unit (C2) where n2 is not 0, such as a number in the range of 1 to 100, the diamine compound (c2-1), the aromatic carboxylic dianhydride (c2-2-1), and the diamine compound (c2-2-2) may be reacted to synthesize the diamine compound (c2), and then the resulting diamine compound (c2) may be reacted with the aromatic carboxylic anhydride (c1). Alternatively, the aromatic carboxylic anhydride (c1), the diamine compound (c2-1), the aromatic carboxylic dianhydride (c2-2-1), and the diamine compound (c2-2-2) may be mixed and then reacted. In this reaction, the degree of progress of imidization (dehydration cyclization) can be adjusted by changing the conditions such as the ratio of the amounts of each component, and the structure of the resulting component (C) (n2 in the structural unit (C2)) can be adjusted. Note that this reaction is not particularly limited as long as the desired structure of the component (C) is realized, and may be carried out using a process and conditions that are conventionally known for imidization reactions.

<(D) Inorganic filler>
The resin composition of the present invention may further contain an inorganic filler as component (D). By including component (D), the linear thermal expansion coefficient and the dielectric loss tangent can be further reduced.

Examples of materials for component (D) include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum silicate, 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 (D) may be used alone or in combination of two or more.

Examples of commercially available products of component (D) 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.; "DAW-03" and "FB-105FD" manufactured by Denka Company; "MGH-005" manufactured by Taiheiyo Cement Corporation; and "BA-S" manufactured by JGC Catalysts and Chemicals Co., Ltd.

The average particle size of the (D) 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 (D) 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 (D) 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 (D) 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 (D) component may be a non-hollow inorganic filler with a porosity of 0 volume % (preferably non-hollow silica), or a hollow inorganic filler with a porosity of more than 0 volume % (preferably hollow silica), or may contain both. The (D) component may contain only a non-hollow inorganic filler (preferably non-hollow silica), or may contain only a hollow inorganic filler (preferably hollow silica), or may contain a combination of a non-hollow inorganic filler (preferably non-hollow silica) and a hollow inorganic filler (preferably hollow silica). When the (D) component contains a hollow inorganic filler, it is preferable because it is easy to realize a resin composition that provides a cured product with a lower dielectric constant and better dielectric properties. The porosity of the hollow inorganic filler is preferably 10% by volume or more, more preferably 15% by volume or more, and even more preferably 20% by volume or more, and its upper limit is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less, 75% by volume or less, 70% by volume or less, 65% by volume or less, 60% by volume or less, 55% by volume or less, or 50% by volume or less. The porosity P (volume %) of the inorganic filler is defined as the volume-based ratio of the total volume of one or more voids present inside the particle to the total volume of the particle based on the outer surface of the particle (total volume of voids/volume of particle), and is calculated, for example, by the following formula (1) using the measured value D _M (g/cm ³ ) of the actual density of the inorganic filler and the theoretical value D _T (g/cm ³ ) of the material density of the material forming the inorganic filler.

The actual density of the inorganic filler can be measured, for example, using a true density measuring device. An example of a true density measuring device is the ULTRAPYCNOMETER 1000 manufactured by QUANTACROME. For example, nitrogen is used as the measurement gas.

The (D) component is preferably surface-treated with an appropriate surface treatment agent. By being surface-treated, the moisture resistance and dispersibility of the (D) component can be improved. Examples of the surface treatment agent include silane coupling agents such as vinyl-based silane coupling agents, epoxy-based silane coupling agents, styryl-based silane coupling agents, (meth)acrylic-based silane coupling agents, amino-based silane coupling agents, isocyanurate-based silane coupling agents, ureido-based silane coupling agents, mercapto-based silane coupling agents, isocyanate-based silane coupling agents, and acid anhydride-based 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 types.

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

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 (D) 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.

When the resin composition of the present invention contains component (D), the content of component (D) in the resin composition may be determined according to the properties required of the resin composition, but when the non-volatile components in the resin composition are taken as 100% by mass, it is, for example, 40% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 65% by mass or more or 70% by mass or more. The upper limit of the content of the inorganic filler is not particularly limited, but may be, for example, 90% by mass or less, 80% by mass or less, etc.

<(E) Organic filler>
The resin composition of the present invention may further contain an organic filler as the component (E).

The organic filler may be any organic filler that can be used when forming insulating materials for electronic components such as printed wiring boards and semiconductor chip packages, and examples of such organic fillers include rubber particles, polyamide fine particles, and silicone particles.

The rubber particles are not particularly limited as long as they are fine particles of resin that is insoluble and infusible in organic solvents by chemically crosslinking a resin that exhibits rubber elasticity, and examples of such particles include acrylonitrile butadiene rubber particles, butadiene rubber particles, and acrylic rubber particles. Specific examples of rubber particles include XER-91 (manufactured by Japan Synthetic Rubber Co., Ltd.), Staphyloid AC3355, AC3816, AC3816N, AC3832, AC4030, AC3364, and IM101 (all manufactured by Aica Kogyo Co., Ltd.), and Paraloid EXL2655 and EXL2602 (all manufactured by The Dow Chemical Company).

The average particle size of component (E) is preferably in the range of 0.005 μm to 1 μm, and more preferably in the range of 0.2 μm to 0.6 μm. The average particle size of component (E) can be measured using dynamic light scattering. For example, the organic filler is uniformly dispersed in a suitable organic solvent using ultrasound or the like, and a particle size distribution of the organic filler is created on a mass basis using a concentrated particle size analyzer (Otsuka Electronics Co., Ltd.'s "FPAR-1000"), and the median diameter is used as the average particle size.

When the resin composition of the present invention contains component (E), the content of component (E) in the resin composition is preferably 0.5% by mass, more preferably 1% by mass or more, 1.5% by mass or more, or 2% by mass or more, when the resin components in the resin composition are taken as 100% by mass, and the upper limit is preferably 10% by mass or less, more preferably 8% by mass or less, 6% by mass or less, or 5% by mass or less.

<(F) Curing Accelerator>
The resin composition of the present invention may further include a curing accelerator as component (F). By including the curing accelerator, the curing time and the curing temperature can be efficiently adjusted.

Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and peroxide-based curing accelerators. The curing accelerators may be used alone or in combination of two or more.

When the resin composition of the present invention contains the (F) component, the content of the (F) component in the resin composition is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and even more preferably 0.01% by mass or more, and is preferably 1% by mass or less, more preferably 0.8% by mass or less, 0.7% by mass or less, or 0.6% by mass or less, based on 100% by mass of the resin components in the resin composition.

<Optional Additives>
The resin composition of the present invention may further contain any additive. Examples of such additives include radically polymerizable resins having at least one radically polymerizable unsaturated group selected from a maleimide group, a vinyl group, an allyl group, a styryl group, a vinylphenyl group, an acryloyl group, a methacryloyl group, a fumaroyl group, and a maleoyl group; radical polymerization initiators such as a peroxide-based radical polymerization initiator and an azo-based radical polymerization initiator; thermoplastic resins such as phenoxy resins, polyvinyl acetal resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polyetheretherketone resins, and polyester resins; organometallic compounds such as organic copper compounds, organic zinc compounds, and organic cobalt 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; defoaming agents such as benzene-based defoaming agents, acrylic-based defoaming agents, fluorine-based defoaming agents, vinyl resin-based defoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; adhesion imparting agents such as triazole-based adhesion imparting agents, tetrazole-based adhesion imparting agents, triazine-based adhesion imparting agents; antioxidants such as hindered phenol-based antioxidants; fluorescent brightening agents such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds flame retardants such as inorganic flame retardants (e.g., antimony trioxide), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, cationic dispersants; and stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, carboxylic anhydride-based stabilizers. The content of such additives may be determined depending on the properties required for the resin composition.

<Organic solvent>
The resin composition of the present invention may further contain an organic solvent as a volatile component. Examples of the organic solvent 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. Examples of the organic solvent include ether ester solvents such as ethyl lactate, ethyl lactate, methyl 2-hydroxyisobutyrate, and the like; ester alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, diethylene glycol monobutyl ether (butyl carbitol), and the like; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and the like; sulfoxide solvents such as dimethyl sulfoxide, and the like; nitrile solvents such as acetonitrile, propionitrile, and the like; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane, and the like; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene, and the like. The organic solvent may be used alone or in combination of two or more kinds.

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), as well as other additives and organic solvents, 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 described above, the resin composition of the present invention, which contains a combination of components (A), (B), and (C), has a low dielectric tangent, exhibits good conductor adhesion even after exposure to a high-temperature, high-humidity environment, and can produce a cured product that exhibits good mechanical properties.

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 [Dielectric Properties] section below, the dielectric loss tangent (Df) of the cured product of the resin composition of the present invention can be preferably 0.01 or less, 0.008 or less, 0.006 or less, 0.005 or less, 0.004 or less, 0.003 or less, or 0.0025 or less.

In one embodiment, the cured product of the resin composition of the present invention exhibits a characteristic of high adhesion to a conductor. For example, when exposed to high temperature and humidity conditions of 130°C and 85% RH for 100 hours as described in the [Adhesion to conductor foil] section below, when the adhesion strength to the conductor foil before exposure to the high temperature and humidity conditions is S1 (kgf/cm) and the adhesion strength to the conductor foil after exposure to the high temperature and humidity conditions is S2 (kgf/cm), the difference between S1 and S2 (S1-S2) is preferably 0.35 kgf/cm or less, 0.34 kgf/cm or less, 0.32 kgf/cm or less, 0.3 kgf/cm or less, 0.28 kgf/cm or less, 0.26 kgf/cm or less, or 0.25 kgf/cm or less. In addition, the value of S2 is preferably 0.3 kgf/cm or more, 0.32 kgf/cm or more, 0.34 kgf/cm or more, 0.35 kgf/cm or more, 0.36 kgf/cm or more, 0.38 kgf/cm or more, or 0.4 kgf/cm or more.

In one embodiment, the cured product of the resin composition of the present invention is characterized by excellent mechanical properties (elongation at break). For example, when a tensile test is performed in accordance with JIS K7127 as described in the [Elongation at break] section below, the elongation at break of the cured product of the resin composition of the present invention can be preferably 1.5% or more, 1.6% or more, 1.8% or more, or 2% or more.

As described above, the resin composition of the present invention has a low dielectric loss tangent, exhibits good conductor adhesion even after exposure to a high-temperature and high-humidity environment, and produces a cured product exhibiting good mechanical properties. Therefore, the resin composition of the present invention 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 can be 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). The resin composition of the present invention can also be suitably used when the printed wiring board is a circuit board with built-in components. The resin composition of the present invention can also be suitably used as a resin composition for sealing a semiconductor chip (resin composition for semiconductor sealing), and can also be suitably used as a resin composition for a rewiring formation layer as an insulating layer for forming a rewiring layer (resin composition for rewiring formation 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 hole filling resin, and a component embedding resin.

[Sheet-like laminated materials (resin sheets, prepregs)]
The resin composition of the present invention can be used as it is, but it may also be used 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 includes 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 varies depending on the application, and may be appropriately determined depending on the application. For example, from the viewpoint of thinning the printed wiring board or semiconductor chip package, the thickness of the resin composition layer is preferably 200 μm or less, more preferably 150 μm or less, 120 μm or less, 100 μm or less, 80 μm or less, 60 μm or less, or 50 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but may usually be 1 μm or more, 5 μm or more, etc.

Examples of the support include a thermoplastic resin film, a metal foil, and a release paper, with a thermoplastic resin film and a metal foil being preferred. Thus, in a preferred embodiment, the support is a thermoplastic resin film or a metal foil.

When a thermoplastic resin film is used as the support, examples of the thermoplastic resin include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and 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.

When a metal foil is used as the support, a metal foil with a support substrate may be used, 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. Examples of such optional layers include 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 and scratches on the surface of the resin composition layer.

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 to 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 thinning printed wiring boards and semiconductor chip packages, 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 insulating layers of printed wiring boards), and can be more suitably used to form an interlayer insulating layer of a printed wiring board (for insulating interlayers of printed wiring boards). The sheet-like laminate material of the present invention can also be suitably used to encapsulate semiconductor chips (for semiconductor encapsulation), and can be suitably used for a rewiring formation layer as an insulating layer for forming a rewiring layer.

[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 circuit board with built-in components, an inner layer substrate with built-in components 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 140°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 140°C, preferably 60°C to 135°C, and more preferably 70°C to 130°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, in this step (IV), smear removal (desmear) is also performed. 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 of a printed wiring board can be adopted. For example, the insulating layer can be roughened by performing 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.

[Semiconductor chip package]
The semiconductor chip package of the present invention includes an encapsulation layer made of a cured product of the resin composition of the present invention. As described above, the semiconductor chip package of the present invention may also include an insulating layer (rewiring formation layer) for forming a rewiring layer made of a cured product of the resin composition of the present invention.

A semiconductor chip package can be manufactured, for example, by a method including the following steps (1) to (6) using the resin composition and resin sheet of the present invention. The resin composition and resin sheet of the present invention may be used to form the sealing layer in step (3) or the rewiring formation layer in step (5). An example of forming a sealing layer or a rewiring formation layer using a resin composition or a resin sheet will be shown below, but the technology for forming the sealing layer or the rewiring formation layer of a semiconductor chip package is publicly known, and a person skilled in the art can manufacture a semiconductor package using the resin composition and resin sheet of the present invention according to a publicly known technology.
(1) A step of laminating a temporary fixing film on a substrate;
(2) A step of temporarily fixing a semiconductor chip on a temporary fixing film;
(3) forming an encapsulation layer on the semiconductor chip;
(4) peeling the substrate and the temporary fixing film from the semiconductor chip;
(5) forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off; and (6) forming a rewiring layer as a conductor layer on the rewiring formation layer.

-Step (1)-
The material used for the substrate is not particularly limited. Examples of the substrate include a silicon wafer, a glass wafer, a glass substrate, a metal substrate such as copper, titanium, stainless steel, or cold-rolled steel plate (SPCC), a substrate in which glass fiber is impregnated with epoxy resin or the like and subjected to a heat curing treatment (e.g., an FR-4 substrate), and a substrate made of bismaleimide triazine resin (BT resin).

The material of the temporary fixing film is not particularly limited as long as it can be peeled off from the semiconductor chip in step (4) and can temporarily fix the semiconductor chip. Commercially available products can be used as the temporary fixing film. Examples of commercially available products include Riva Alpha manufactured by Nitto Denko Corporation.

-Step (2)-
The semiconductor chips can be temporarily fixed using known devices such as a flip chip bonder, a die bonder, etc. The layout and number of semiconductor chips can be appropriately set depending on the shape and size of the temporary fixing film, the number of semiconductor packages to be produced, etc., and for example, the semiconductor chips can be temporarily fixed by arranging them in a matrix shape of multiple rows and multiple columns.

-Step (3)-
A resin composition layer of the resin sheet of the present invention is laminated on a semiconductor chip, or the resin composition of the present invention is applied onto a semiconductor chip and cured (for example, thermally cured) to form an encapsulating layer.

For example, the semiconductor chip and the resin sheet can be laminated by removing the protective film of the resin sheet and then heat-pressing the resin sheet to the semiconductor chip from the support side. Examples of the member for heat-pressing the resin sheet to the semiconductor chip (hereinafter also referred to as the "heat-pressing member") include a heated metal plate (such as a SUS plate) or a metal roll (SUS roll). It is preferable to press the heat-pressing member through an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently follow the surface irregularities of the semiconductor chip, rather than pressing the heat-pressing member directly onto the resin sheet. The semiconductor chip and the resin sheet may be laminated by a vacuum lamination method, and the lamination conditions are the same as those described in relation to the manufacturing method of the printed wiring board, and the preferred ranges are also the same.

After lamination, the resin composition is thermally cured to form the sealing layer. The thermal curing conditions are the same as those described in relation to the method for manufacturing a printed wiring board.

The support of the resin sheet may be peeled off after the resin sheet is laminated on the semiconductor chip and thermally cured, or the support may be peeled off before the resin sheet is laminated on the semiconductor chip.

When the resin composition of the present invention is applied to form a sealing layer, the application conditions are the same as those for forming the resin composition layer described in relation to the resin sheet of the present invention, and the preferred ranges are also the same.

-Step (4)-
The method for peeling off the substrate and the temporary fixing film can be appropriately changed depending on the material of the temporary fixing film, and examples of the method include a method in which the temporary fixing film is heated and foamed (or expanded) to peel it off, and a method in which ultraviolet light is irradiated from the substrate side to reduce the adhesive strength of the temporary fixing film and then peeled off.

In the method of heating and foaming (or expanding) the temporary fixing film to peel it off, the heating conditions are usually 100 to 250° C. for 1 to 90 seconds or 5 to 15 minutes. In the method of irradiating the temporary fixing film from the substrate side with ultraviolet light to reduce the adhesive strength of the temporary fixing film to peel it off, the irradiation dose of ultraviolet light is usually 10 mJ/cm ² to 1000 mJ/cm ² .

-Step (5)-
The material for forming the rewiring formation layer (insulating layer) is not particularly limited as long as it has insulating properties when the rewiring formation layer (insulating layer) is formed, and from the viewpoint of ease of manufacturing the semiconductor chip package, ultraviolet curable resins and thermosetting resins are preferred. The rewiring formation layer may be formed using the resin composition or resin sheet of the present invention.

After forming the redistribution layer, via holes may be formed in the redistribution layer to connect the semiconductor chip to a conductor layer (described later). The via holes may be formed by a known method depending on the material of the redistribution layer.

-Step (6)-
The formation of the conductor layer on the rewiring formation layer may be carried out in the same manner as in step (V) described in relation to the method for producing a printed wiring board. Note that steps (5) and (6) may be repeated to alternately stack (build up) the conductor layer (rewiring layer) and the rewiring formation layer (insulating layer).

When manufacturing a semiconductor chip package, the steps of (7) forming a solder resist layer on the conductor layer (rewiring layer), (8) forming bumps, and (9) dicing and singulating a plurality of semiconductor chip packages into individual semiconductor chip packages may be further carried out. These steps may be carried out according to various methods used in the manufacture of semiconductor chip packages and known to those skilled in the art.

By forming a sealing layer and a rewiring formation layer using the resin composition and resin sheet of the present invention, which provide a cured product exhibiting excellent dielectric properties, a semiconductor chip package with extremely low transmission loss can be realized regardless of whether the semiconductor package is a fan-in (Fan-In) type package or a fan-out (Fan-Out) type package. In one embodiment, the semiconductor chip package of the present invention is a fan-out (Fan-Out) type package. The resin composition and resin sheet of the present invention can be applied regardless of whether the package is a fan-out type panel level package (FOPLP) or a fan-out type wafer level package (FOWLP). In one embodiment, the semiconductor package of the present invention is a fan-out type panel level package (FOPLP). In another embodiment, the semiconductor package of the present invention is a fan-out type wafer level package (FOWLP).

[Semiconductor device]
The semiconductor device of the present invention includes a 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 chip 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.

Synthesis Example 1: Preparation of Ethynyl Group-Containing Resin 1
A monomer composition obtained by mixing 46.5 g of BPADA, 50.4 g of BPPAN, 2.9 g of PEPA, and 40 g of toluene as a solvent in 400 g of N,N-dimethylacetamide (hereinafter also referred to as "DMAc") as a solvent was stirred and reacted at room temperature and atmospheric pressure for 3 hours. As a result, a polyamic acid solution was obtained.

The polyamic acid solution was then heated and, while maintained at approximately 160°C, the condensed water was azeotropically removed with toluene under a nitrogen stream. It was confirmed that a specified amount of water had accumulated in the moisture content receiver and that no water was leaking out. After confirmation, the reaction solution was further heated and stirred at 200°C for 1 hour. It was then cooled. This resulted in a varnish containing 20% by mass of ethynyl group-containing resin 1, which has a structure represented by the following formula, as a non-volatile component. The weight average molecular weight (Mw; polystyrene equivalent) of ethynyl group-containing resin 1 was approximately 17,000.

Synthesis Example 2: Preparation of Ethynyl Group-Containing Resin 2
A monomer composition obtained by mixing 46.5 g of BPADA, 50.4 g of BPPAN, 3.2 g of PETA, and 40 g of toluene as a solvent in 400 g of DMAc as a solvent was stirred and reacted at room temperature and atmospheric pressure for 3 hours, thereby obtaining a polyamic acid solution.

The obtained polyamic acid solution was subjected to dehydration cyclization (imidization) in the same manner as in Synthesis Example 1 to obtain a varnish containing 20 mass% of ethynyl group-containing resin 2 having the structure represented by the following formula as a non-volatile component. The weight average molecular weight (Mw; polystyrene equivalent) of ethynyl group-containing resin 2 was approximately 19,000.

Synthesis Example 3: Preparation of Ethynyl Group-Containing Resin 3
A monomer composition obtained by mixing 46.5 g of BPADA, 37.8 g of BPPAN, 12.8 g of dimer diamine (PRIAMINE 1075 manufactured by Croda Japan), 2.9 g of PEPA, and 40 g of toluene as a solvent in 400 g of DMAc as a solvent was stirred and reacted at room temperature and atmospheric pressure for 3 hours. As a result, a polyamic acid solution was obtained.

The obtained polyamic acid solution was subjected to dehydration cyclization (imidization) in the same manner as in Synthesis Example 1 to obtain a varnish containing 20 mass% of ethynyl group-containing resin 3 having the structure represented by the following formula as a non-volatile component. The weight average molecular weight (Mw; polystyrene equivalent) of ethynyl group-containing resin 3 was approximately 16,000.

Synthesis Example 4: Preparation of Ethynyl Group-Containing Resin 4
A monomer composition obtained by mixing 46.5 g of BPADA, 37.8 g of BPPAN, 4.1 g of IPDA, 3.2 g of PETA, and 40 g of toluene as a solvent in 400 g of DMAc as a solvent was stirred and reacted at room temperature and atmospheric pressure for 3 hours, thereby obtaining a polyamic acid solution.

The resulting polyamic acid solution was subjected to dehydration cyclization (imidization) in the same manner as in Synthesis Example 1 to obtain a varnish containing 20 mass% of ethynyl group-containing resin 4, which has the structure represented by the following formula, as a non-volatile component. The weight average molecular weight (Mw; polystyrene equivalent) of ethynyl group-containing resin 4 was approximately 15,000.

Synthesis Example 5: Preparation of Ethynyl Group-Containing Resin 5
A monomer composition obtained by mixing 30.0 g of dimer diamine (PRIAMINE 1075 manufactured by Croda Japan Co., Ltd.), 27.0 g of PEPA, and 150 g of toluene as a solvent in 250 g of DMAc as a solvent was stirred at room temperature and atmospheric pressure for 5 hours to cause a reaction.

10.0 g of p-toluenesulfonic acid monohydrate was then added, and the reaction solution was heated under reflux to cool and separate the azeotropic water and toluene, after which only the toluene was returned to the system and the dehydration reaction was carried out for 10 hours. After air cooling to room temperature, the mixture was concentrated under reduced pressure, and the brown solution was dissolved in 200 g of ethyl acetate and washed three times with 50 g of ion-exchanged water and three times with 50 g of 2% aqueous sodium hydrogen carbonate solution. Sodium sulfate was then added to dry the mixture, which was then concentrated under reduced pressure and the resulting reaction product was vacuum-dried at 80°C for 12 hours to obtain ethynyl group-containing resin 5 having the structure represented by the following formula:

Synthesis Example 6: Preparation of Ethynyl Group-Containing Resin 6
A monomer composition obtained by mixing 60.0 g of modified silicone oil ("X-22-1660B-3" manufactured by Shin-Etsu Silicone Co., Ltd.), 7.5 g of PETA, and 40 g of toluene as a solvent in 400 g of DMAc as a solvent was stirred and reacted at room temperature and atmospheric pressure for 3 hours.

The resulting polyamic acid solution was subjected to dehydration cyclization (imidization) in the same manner as in Synthesis Example 1 to obtain a varnish containing 20% by mass of ethynyl group-containing resin 6 (wherein R represents an alkylene group having 1 to 6 carbon atoms) as a non-volatile component, the resin having the structure represented by the following formula:

Synthesis Example 7 Preparation of Ethynyl Group-Free Resin 7
A monomer composition obtained by mixing 49.6 g of BPADA, 50.4 g of BPPAN, and 40 g of toluene as a solvent in 400 g of DMAc as a solvent was stirred and reacted at room temperature and atmospheric pressure for 3 hours, thereby obtaining a polyamic acid solution.

The obtained polyamic acid solution was subjected to dehydration cyclization (imidization) in the same manner as in Synthesis Example 1 to obtain a varnish containing 20 mass% of ethynyl-free resin 7 having the structure represented by the following formula as a non-volatile component. The weight average molecular weight (Mw; polystyrene equivalent) of ethynyl-free resin 7 was approximately 20,000.

[Example 1. Preparation of resin composition 1]
Five parts of a liquid epoxy resin ("ZX1059" manufactured by Nippon Steel Chemical & Material Co., Ltd., a 1:1 mixture (mass ratio) of bisphenol A type epoxy resin and bisphenol F type epoxy resin, epoxy equivalent: 169 g/eq) and 15 parts of a biphenyl type epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: approximately 290 g/eq) were heated and dissolved in 20 parts of toluene and 20 parts of MEK with stirring. The resulting solution was cooled to room temperature, and then mixed with 40 parts of an active ester curing agent ("HPC-8000-65T" manufactured by DIC Corporation, active group equivalent 223 g/eq, toluene solution with solid content of 65% by mass), 4 parts of a triazine skeleton-containing phenolic curing agent ("LA-3018-50P" manufactured by DIC Corporation, hydroxyl group equivalent approximately 151 g/eq, 2-methoxypropanol solution with solid content of 50%), 20 parts of the ethynyl group-containing resin 1 synthesized in Synthesis Example 1 (solution with solid content of 20% by mass), and an organic filler ("Paraloid" manufactured by The Dow Chemical Company). EXL2655"), 2 parts of a curing accelerator ("1B2PZ" manufactured by Shikoku Chemical Industry Co., Ltd., 1-benzyl-2-phenylimidazole, MEK solution with 10% solids), and 150 parts of an inorganic filler (spherical silica ("SO-C2" manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) surface-treated with an amine-based silane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.)) were mixed and uniformly dispersed in a high-speed rotating mixer to obtain resin composition 1.

[Example 2. Preparation of resin composition 2]
Resin composition 2 was obtained in the same manner as in Example 1, except that 40 parts of an active ester curing agent ("PC1300-02-65MA" manufactured by Air Water Corporation, active group equivalent 199, methyl amyl ketone solution with solid content of 65% by mass) was used instead of 40 parts of an active ester curing agent ("HPC-8000-65T" manufactured by DIC Corporation, active group equivalent 223, toluene solution with solid content of 65% by mass).

[Example 3. Preparation of resin composition 3]
Resin composition 3 was obtained in the same manner as in Example 1, except that 20 parts of the ethynyl group-containing resin 2 (20% by mass solution of solid content) synthesized in Synthesis Example 2 was used instead of 20 parts of the ethynyl group-containing resin 1 (20% by mass solution of solid content).

[Example 4. Preparation of resin composition 4]
Resin composition 4 was obtained in the same manner as in Example 1, except that 100 parts of the ethynyl group-containing resin 2 (20% by mass solution of solid content) synthesized in Synthesis Example 2 was used instead of 20 parts of the ethynyl group-containing resin 1 (20% by mass solution of solid content).

[Example 5. Preparation of resin composition 5]
Resin composition 5 was obtained in the same manner as in Example 1, except that 20 parts of the ethynyl group-containing resin 3 (20 mass% solids solution) synthesized in Synthesis Example 3 was used instead of 20 parts of the ethynyl group-containing resin 1 (20 mass% solids solution).

[Example 6. Preparation of resin composition 6]
Resin composition 6 was obtained in the same manner as in Example 1, except that 20 parts of ethynyl group-containing resin 4 (20 mass% solids solution) synthesized in Synthesis Example 4 was used instead of 20 parts of ethynyl group-containing resin 1 (20 mass% solids solution).

[Example 7. Preparation of resin composition 7]
Resin composition 7 was obtained in the same manner as in Example 1, except that 8 parts of ethynyl group-containing resin 5 (toluene solution with a solid content of 50% by mass) synthesized in Synthesis Example 5 was used instead of 20 parts of ethynyl group-containing resin 1 (solution with a solid content of 20% by mass).

[Example 8. Preparation of resin composition 8]
Resin composition 8 was obtained in the same manner as in Example 1, except that 20 parts of ethynyl group-containing resin 6 (20 mass% solids solution) synthesized in Synthesis Example 6 was used instead of 20 parts of ethynyl group-containing resin 1 (20 mass% solids solution).

[Example 9. Preparation of resin composition 9]
Resin composition 9 was obtained in the same manner as in Example 3, except that (i) the amount of inorganic filler (spherical silica ("SO-C2" manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) surface-treated with an amine-based silane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.)) was changed from 150 parts to 115 parts, and (ii) 28 parts of hollow aluminosilicate particles ("MGH-005" manufactured by Taiheiyo Cement Corporation, average particle size 1.6 μm, porosity 80% by volume) were added.

[Example 10. Preparation of resin composition 10]
Resin composition 10 was obtained in the same manner as in Example 3, except that (i) the amount of inorganic filler (spherical silica ("SO-C2" manufactured by Admatechs, average particle size 0.5 μm) surface-treated with an amine-based silane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.)) was changed from 150 parts to 115 parts, and (ii) 6.5 parts of hollow silica particles ("BA-S" manufactured by JGC Catalysts and Chemicals, average particle size 2.6 μm, porosity 25% by volume) were added.

[Comparative Example 1. Preparation of Comparative Resin Composition]
A comparative resin composition was obtained in the same manner as in Example 1, except that 20 parts of the ethynyl group-free resin (20 mass% solids solution) synthesized in Synthesis Example 7 was used instead of 20 parts of the ethynyl group-containing resin 1 (20 mass% solids solution).

[Preparation of resin sheet]
As a support, a polyethylene terephthalate film ("Lumirror R80" manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130° C.) that had been subjected to a release treatment with an alkyd resin-based release agent ("AL-5" manufactured by Lintec Corporation) was prepared.

Each of resin compositions 1 to 10 and the comparative resin composition was uniformly applied to a support using a die coater so that the thickness of the resin composition layer after drying was 30 μm, and the coating was dried at 70°C to 95°C for 3 minutes to form a resin composition layer on the support. Next, the rough surface of a polypropylene film (Oji F-Tex Co., Ltd. "Alphan MA-411", thickness 15 μm) was attached as a protective film to the surface of the resin composition layer that was not joined to the support. This resulted in a resin sheet A having a support, a resin composition layer, and a protective film in this order.

[Adhesion to plated conductor layer]
(1) Preparation of Inner Layer Board Both sides of a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, board thickness 0.4 mm, Panasonic Corporation "R1515A") on which an inner layer circuit was formed was etched by 1 μm with a microetching agent (Mech Corporation "CZ8101") to roughen the copper surface.

(2) Lamination of resin sheet The protective film was peeled off from the resin sheet A to expose the resin composition layer. Using a batch type vacuum pressure laminator (two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.), the resin composition layer was laminated on both sides of the inner layer substrate so that it was in contact with the inner layer substrate. 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 120°C and a pressure of 0.74 MPa for 30 seconds. Next, a heat press was performed at 100°C and a pressure of 0.5 MPa for 60 seconds.

(3) Thermal curing of resin composition layer The inner layer substrate with the resin sheet laminated thereon was then placed in an oven at 130° C. and heated for 30 minutes, and then transferred to an oven at 180° C. and heated for 30 minutes to thermally cure the resin composition layer and form an insulating layer. The support was then peeled off to obtain a cured substrate A having the insulating layer, the inner layer substrate, and the insulating layer in this order.

(4) Roughening Treatment A desmear treatment was carried out as a roughening treatment on the cured substrate A. As the desmear treatment, the following wet desmear treatment was carried out.

(Wet desmear treatment)
The cured substrate A was immersed in a swelling liquid (Atotech Japan's "Swelling Dip Securigant P", an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 5 minutes, then immersed in an oxidizing agent solution (Atotech Japan's "Concentrate Compact CP", an aqueous solution of potassium permanganate at a concentration of approximately 6% and sodium hydroxide at a concentration of approximately 4%) at 80°C for 15 minutes, and then immersed in a neutralizing liquid (Atotech Japan's "Reduction Solution Securigant P", an aqueous sulfuric acid solution) at 40°C for 5 minutes, and then dried at 80°C for 15 minutes.

(5) Formation of Conductive Layer According to the semi-additive method, a conductive layer was formed on the roughened surface of the insulating layer. That is, the substrate after the roughening treatment was immersed in an electroless plating solution containing _PdCl2 at 40 ° C for 5 minutes, and then immersed in an electroless copper plating solution at 25 ° C for 20 minutes. Next, after heating at 150 ° C for 30 minutes and performing an annealing treatment, an etching resist was formed, and a pattern was formed by etching. Then, copper sulfate electrolytic plating was performed to form a conductive layer having a thickness of 30 μm, and an annealing treatment was performed at 200 ° C for 60 minutes. The obtained substrate is called "evaluation substrate B".

(6) Evaluation of Adhesion with Plated Conductive Layer The peel strength of the insulating layer and the plated conductor layer was measured in accordance with the Japanese Industrial Standards (JIS C6481). Specifically, a cut was made in the conductor layer of evaluation board B, measuring 10 mm wide and 100 mm long, and one end of the cut was peeled off and held with a gripper. The load (kgf/cm) when 35 mm was peeled off in the vertical direction at a speed of 50 mm/min at room temperature was measured to determine the peel strength. A tensile tester ("AC-50C-SL" manufactured by TSE) was used for the measurement.

[Dielectric properties]
The protective film was peeled off from the resin sheet A produced in the examples and comparative examples, and the resin composition layer was thermally cured by heating at 200°C for 90 minutes, and then the support was peeled off. The obtained cured product was referred to as "evaluation cured product C". The evaluation cured product C was cut into a test piece having a width of 2 mm and a length of 80 mm. The dielectric tangent of the test piece was measured at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C by a cavity resonance perturbation method using an Agilent Technologies "HP8362B". Measurements were performed on three test pieces, and the average value was calculated.

[Elongation at break]
The cured product C for evaluation was subjected to a tensile test in accordance with Japanese Industrial Standards (JIS K7127) using a Tensilon universal testing machine ("RTC-1250A" manufactured by Orientec Co., Ltd.) to measure the elongation at break.

[Adhesion to conductor foil]
(1) Copper foil undercoat treatment The shiny side of Mitsui Mining & Smelting Co., Ltd.'s "3EC-III" (electrolytic copper foil, 35 μm) was immersed in MEC Etch Bond "CZ-8101" manufactured by MEC Corporation to roughen the copper surface (Ra value = 1 μm) and apply anti-rust treatment (CL8300). This copper foil is called CZ copper foil. It was then heated in an oven at 130°C for 30 minutes.

(2) Lamination of copper foil and formation of insulating layer The protective film was peeled off from each resin sheet A prepared in the examples and comparative examples, and a batch type vacuum pressure laminator ("MVLP-500" manufactured by Meiki Co., Ltd.) was used to bond the resin composition layer to a glass cloth substrate epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, manufactured by Panasonic Corporation "R1515A") formed with an inner layer circuit. The laminate was laminated on both sides of the laminate. The lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressing at 100 ° C. and a pressure of 0.74 MPa for 30 seconds. The release PET support was peeled off from the laminated resin sheet. The treated surface of the CZ copper foil was laminated on the resin composition layer under the same conditions as above. Then, the resin composition layer was cured under curing conditions of 200 ° C. and 90 minutes to form an insulating layer, thereby preparing a sample.

(3) Evaluation of adhesion to conductor foil - Measurement of adhesion to conductor foil (S1) before high temperature and high humidity environmental test (HAST) -
The prepared sample was cut into small pieces of 150 x 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, and one end of the copper foil was peeled off and held with a gripper (Autocom type testing machine, "AC-50C-SL", manufactured by TSE Corporation). An Instron universal testing machine was used to measure the load at room temperature in accordance with JIS C6481 when 35 mm was peeled off in the vertical direction at a speed of 50 mm/min.

- Measurement of adhesion (S2) with conductor foil after high temperature and high humidity environmental test (HAST) -
The prepared sample was subjected to a high temperature and high humidity environmental test for 100 hours under conditions of 130°C and 85% RH using a highly accelerated life tester ("PM422" manufactured by Kusumoto Chemicals Co., Ltd.). Thereafter, similarly to the measurement of adhesion S1, one end of the copper foil was peeled off and held with a gripper (Autocom type testing machine "AC-50C-SL" manufactured by TSE Corporation), and the load when 35 mm was peeled off in the vertical direction at room temperature at a speed of 50 mm/min was measured in accordance with JIS C6481 using an Instron universal testing machine.

The results of Examples 1 to 10 and Comparative Example 1 are shown in Table 1.

Claims (18)

A resin composition comprising (A) an epoxy resin , (B) a curing agent, and (C) a resin having an ethynyl group or an ethynylene group,
The molecular end of the component (C) is a structural unit represented by the following general formula (C1):
A resin composition, wherein the component (C) has a structural unit represented by the following general formula (C2) :

(Wherein,
R ¹ represents a hydrogen atom, an aryl group which may have a substituent, or an alkyl group which may have a substituent;
Ring Ar ¹ represents an aromatic ring which may have a substituent;
n1 represents 0 or 1;
* represents a bond.)

(Wherein,
R2 ^represents (i) a divalent organic group containing one or more aromatic rings, (ii) a divalent aliphatic group having 5 or more carbon atoms, or (iii) a divalent group having a siloxane skeleton;
^Each R3 independently represents a tetravalent organic group containing one or more aromatic rings;
R4 each independently represents (i) a divalent organic group containing one or more aromatic rings, or (ii) a divalent aliphatic group having 5 or more carbon atoms ^;
n2 represents a number equal to or greater than 0. In general formula (C1), R ¹ The resin composition according to claim 1 , wherein is an aryl group which may have a substituent, or an alkyl group which may have a substituent. In general formula (C2), R ² The resin composition according to claim 1 or 2, wherein (ii) is a divalent aliphatic group having 5 or more carbon atoms, or (iii) is a divalent group having a siloxane skeleton. The resin composition according to any one of claims 1 to 3, wherein the component (B) comprises a curing agent selected from the group consisting of active ester-based curing agents, phenol-based curing agents, naphthol-based curing agents, acid anhydride-based curing agents, cyanate ester-based curing agents, carbodiimide-based curing agents, and amine-based curing agents. The resin composition according to any one of claims 1 to 4, wherein the component (B) comprises an active ester-based curing agent. The resin composition according to claim 5, wherein a mass ratio of the active ester curing agent to the component (A) (active ester curing agent/component (A)) is 0.8 or more. The resin composition according to any one of claims 1 to 6 , wherein the weight average molecular weight of component (C) is in the range of 500 to 50,000. The resin composition according to any one of claims 1 to 7 , wherein the content of the component (C) is 1 mass% or more, based on 100 mass% of the resin components in the resin composition. The resin composition according to any one of claims 1 to 8 , further comprising (D) an inorganic filler. The resin composition according to claim 9 , wherein the content of the component (D) is 50% by mass or more, based on 100% by mass of non-volatile components in the resin composition. The resin composition according to any one of claims 1 to 10 , which is used for an insulating layer of a printed wiring board. The resin composition according to any one of claims 1 to 10 , which is used for semiconductor encapsulation. A resin sheet comprising a support and a layer of the resin composition according to any one of claims 1 to 12 provided on the support. The resin sheet according to claim 13 , wherein the support is a thermoplastic resin film or a metal foil. A cured product of the resin composition according to any one of claims 1 to 12 . 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 11 . A semiconductor chip package comprising an encapsulating layer made of a cured product of the resin composition according to any one of claims 1 to 10 and 12 . A semiconductor device comprising the printed wiring board according to claim 16 or the semiconductor chip package according to claim 17 .