TW202432533A - Resin composition - Google Patents

Abstract

A resin composition includes (A) an epoxy resin, (B) an active ester resin and (C) a maleimide compound. The component (C) contains (C1) a maleimide compound having a structural unit represented by the following formula (1). (In the formula (1), R1 each independently represents an alkyl group, one of R2 and R3 represents a hydrogen atom and the other represents a methyl group, one of R4 and R5 represents a hydrogen atom and the other represents a methyl group, RS1 each independently represents a substituent, X1 represents a monovalent group represented by the following formula (2), m1 represents an integer of 1 to 3, and m2 represents an integer of 0 or greater, where m1 and m2 satisfy m1+m2≤3, m3 represents an integer of 0 to 4, n represents an integer of 1 to 100, and * represents a bond.) (In formula (2), one of R6 and R7 represents a hydrogen atom and the other represents a methyl group, RS2 independently represents a substituent, m4 represents an integer of 0 to 5, and * represents a bond).

Description

Resin composition

The present invention relates to a resin composition and further to a resin sheet, a cured product, a circuit substrate and a semiconductor device.

Resin compositions containing epoxy resins and their hardeners can provide cured products with excellent insulation, heat resistance, and adhesion, and are therefore widely used as insulating materials for circuit boards such as printed wiring boards and redistribution boards for semiconductor chip packaging.

On the other hand, with the recent increase in communication speed, in order to reduce transmission loss when working in a high-frequency environment, the insulating material of the circuit board needs to have excellent dielectric properties (low dielectric tangent). As an insulating material with excellent dielectric properties, it is reported that a specific curing agent such as an active ester resin that can reduce and inhibit the generation of polar groups such as secondary hydroxyl groups in the curing reaction of epoxy resin is used (for example, patent documents 1 and 2). Prior art documents Patent documents

Patent document 1: Japanese Patent Publication No. 2019-157027 Patent document 2: Japanese Patent Publication No. 2020-94213.

[The problem that the invention wants to solve]

As a manufacturing technology for circuit boards, there is a known manufacturing method that utilizes a stacking method of alternately stacking insulating layers and conductive layers. As electronic devices become more functional, the number of layers stacked by stacking circuit boards tends to increase. As the number of layers increases, the generation of cracks or circuit deformation due to the difference in thermal expansion between the insulating layer and the conductive layer becomes a problem. In order to suppress such cracks or circuit deformation problems, it is desirable to suppress the thermal expansion coefficient of the formed insulating layer to a relatively low level.

In this regard, it was confirmed that if the active ester resin is blended to such an extent that good dielectric properties are achieved, the thermal expansion coefficient of the resulting insulating layer may increase.

Although there are reports that the thermal expansion coefficient can be reduced by adding a maleimide compound when forming an insulating layer of a circuit board (for example, paragraph 0052 of Japanese Patent Publication No. 2016-219640), the inventors of the present invention have found that when a maleimide compound is added to a resin composition containing an active ester resin, the dielectric tangent increases, and the effect of using the active ester resin is reduced, or the active ester resin does not contribute to the reduction of the thermal expansion coefficient at all.

The present invention provides a novel resin composition capable of producing a cured product having both good dielectric properties and a low thermal expansion coefficient.

[Means for Solving the Problem] The inventors of this case conducted intensive research and found that the above-mentioned problem can be solved by a resin composition having the following structure, thereby completing the present invention.

That is, the present invention comprises the following contents. [1] A resin composition comprising (A) an epoxy resin, (B) an active ester resin and (C) a maleimide compound, wherein the component (C) comprises (C1) a maleimide compound having a structural unit represented by the following formula (1): (In formula (1), ^R1 each independently represents an alkyl group, ^R2 , ^R3 , ^R4 and R5 each independently represents a hydrogen atom or a methyl group, and one of ^R2 and ^R3 represents a hydrogen atom and the other represents a methyl group, one of ^R4 and ^R5 represents a hydrogen atom and the other represents a methyl group, ^{RS1 each} independently represents a substituent, ^X1 represents a monovalent group represented by the following formula (2), m1 represents an integer of 1 to 3, m2 represents an integer greater than 0, and here, m1 and m2 satisfy m1+m2≤3, m3 represents an integer of 0 to 4, n represents an integer of 1 to 100, and * represents a bonding bond.) (In formula (2), ^R6 and ^R7 each independently represent a hydrogen atom or a methyl group, and one of ^R6 and ^R7 represents a hydrogen atom and the other represents a methyl group, ^Rs2 each independently represent a substituent, m4 represents an integer from 0 to 5, and * represents a bond.) [2] The resin composition according to [1], wherein the mass ratio of component (B) to component (A) [component (B)/component (A)] is 0.8 or more. [3] The resin composition according to [1] or [2], wherein the content of component (C) is 5 mass% or more, when the resin component in the resin composition is 100 mass%. [4] The resin composition according to any one of [1] to [3], wherein the content of component (C1) is 30% by mass or more, based on the total amount of component (C) (the total amount of component (C)) being 100% by mass. [5] The resin composition according to any one of [1] to [4], further comprising (E) an inorganic filler. [6] The resin composition according to [5], wherein the content of component (E) is 40% by mass or more, based on the non-volatile components in the resin composition being 100% by mass. [7] The resin composition according to any one of [1] to [6], further comprising: (F) a resin containing an aromatic ring and a free radical polymerizable unsaturated group. [8] A resin composition according to any one of [1] to [7], which is used as an insulating layer of a circuit board. [9] A resin sheet comprising a support and a layer of the resin composition according to any one of [1] to [8] disposed on the support. [10] A resin sheet according to [9], wherein the support is a thermoplastic resin film or a metal foil. [11] A cured product, which is a cured product of the resin composition according to any one of [1] to [8]. [12] A circuit board comprising an insulating layer formed by a cured product of the resin composition according to any one of [1] to [8]. [13] A semiconductor device comprising the circuit board according to [12]. [Effect of the Invention]

According to the present invention, a novel resin composition capable of providing a cured product having both good dielectric properties and a low thermal expansion coefficient can be provided.

[ Specific implementation method ] <Explanation of terms>

In the present specification, the phrase "may also have a substituent" with respect to a compound or a group refers to both the case where hydrogen atoms of the compound or group are not substituted by a substituent and the case where a part or all of the hydrogen atoms of the compound or group are substituted by a substituent.

In the present specification, unless otherwise specified, the term "substituent" means a halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an alkylthio group, a cycloalkylthio group, an aryl group, an aryloxy group, an arylthio group, an aralkyl group, an arylalkoxy group, a monovalent heterocyclic group, an alkylidene group, an acyl group, an acyloxy group, a hydroxyl group, an amino group, a silyl group, a carboxyl group, a sulfo group, a cyano group, a nitro group, a hydroxyl group, and a pendoxy group.

As the halogen atom which can be used as a substituent, for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be cited. The alkyl group which can be used as a substituent can be any of a straight chain or a branched chain. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 3. The alkenyl group which can be used as a substituent can be any of a straight chain or a branched chain. The number of carbon atoms of the alkenyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 or 3. The number of carbon atoms of the cycloalkyl group which can be used as a substituent is preferably 3 to 12, and more preferably 3 to 6. The alkoxy group which can be used as a substituent can be any of a straight chain or a branched chain. The number of carbon atoms of the alkoxy group is preferably 1 to 12, and more preferably 1 to 6. The number of carbon atoms of the cycloalkoxy group which can be used as a substituent is preferably 3 to 12, more preferably 3 to 6. The alkylthio group which can be used as a substituent may be either linear or branched. The number of carbon atoms of the alkylthio group is preferably 1 to 12, more preferably 1 to 6. The number of carbon atoms of the cycloalkylthio group which can be used as a substituent is preferably 3 to 12, more preferably 3 to 6. The number of carbon atoms of the aryl group which can be used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms of the aryloxy group which can be used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms of the arylthio group which can be used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms of the aralkyl group which can be used as a substituent is preferably 7 to 15, more preferably 7 to 11. The number of carbon atoms of the arylalkoxy group which can be used as a substituent is preferably 7 to 15, more preferably 7 to 11. The monovalent heterocyclic group which can be used as a substituent refers to a group formed by removing one hydrogen atom from the heterocyclic ring 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 monovalent heterocyclic group also includes a monovalent aromatic heterocyclic group (heteroaryl group). The alkylidene group which can be used as a substituent refers to a group formed by removing two hydrogen atoms 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 particularly preferably 1 to 3. The acyl group which can be used as a substituent refers to a group represented by the formula: -C(=O)-R (wherein R is an alkyl group or an aryl group). The alkyl group represented by R may be either linear or branched. The number of carbon atoms in the acyl group is preferably 2 to 13, more preferably 2 to 7. The acyloxy group that can be used as a substituent is a group represented by the formula: -O-C(=O)-R (wherein R has the same meaning as above). The number of carbon atoms in the acyloxy group is preferably 2 to 13, more preferably 2 to 7. The above-mentioned substituent may further have a substituent (sometimes referred to as a "secondary substituent"). As a secondary substituent, the same group as the above-mentioned substituent may be used unless otherwise specified.

In this specification, the term " _Cp - _Cq " (p and q are positive integers, satisfying p < q) means that the number of carbon atoms in the organic group described immediately after the term is p to q. For example, " _C1 - _C6 alkyl" means an alkyl group having 1 to 6 carbon atoms, and " _C6 - _C10 cycloalkyl" means a cycloalkyl group having 6 to 10 carbon atoms.

The present invention is described in detail below by showing embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and can be implemented with any changes within the scope of the patent application of the present invention and its equivalent scope.

[Resin composition] The resin composition of the present invention is characterized in that it comprises (A) an epoxy resin, (B) an active ester resin and (C) a maleimide compound, wherein the component (C) comprises: (C1) a maleimide compound having a structural unit represented by the following formula (1), (In formula (1), ^R1 each independently represents an alkyl group, ^R2 , ^R3 , ^R4 and R5 each independently represents a hydrogen atom or a methyl group, and one of ^R2 and ^R3 represents a hydrogen atom and the other represents a methyl group, one of ^R4 and ^R5 represents a hydrogen atom and the other represents a methyl group, ^{RS1 each} independently represents a substituent, ^X1 represents a monovalent group represented by the following formula (2), m1 represents an integer of 1 to 3, m2 represents an integer greater than 0, and here, m1 and m2 satisfy m1+m2≤3, m3 represents an integer of 0 to 4, n represents an integer of 1 to 100, and * represents a bonding bond.) (In formula (2), ^R6 and ^R7 each independently represent a hydrogen atom or a methyl group, and one of ^R6 and ^R7 represents a hydrogen atom and the other represents a methyl group, ^RS2 each independently represents a substituent, m4 represents an integer of 0 to 5, and * represents a bond.)

As described above, in order to suppress the occurrence of cracks or circuit deformation, the insulating material of the circuit substrate is expected to have a low thermal expansion coefficient. In addition, in order to reduce the transmission loss when working in a high-frequency environment, it is also required to exhibit good dielectric properties (low dielectric tangent). In this regard, it has been confirmed that after the active ester resin is added to a degree to achieve good dielectric properties, the thermal expansion coefficient of the resulting insulating material sometimes increases. Although it has been reported that maleimide compounds help to reduce the thermal expansion coefficient, the inventors of this case have found that if a maleimide compound is added to a resin composition containing an active ester resin, the dielectric tangent increases, the effect of using the active ester resin is reduced, or it does not contribute to the reduction of the thermal expansion coefficient in the first place.

On the other hand, according to the present invention, in combination with an epoxy resin and an active ester resin, a maleimide compound having a structural unit represented by the above formula (1) is used as a maleimide compound, and a cured product having a low thermal expansion coefficient can be provided while maintaining good dielectric properties. As described above, the significant contribution of the present invention is that a cured product having both good dielectric properties and a low thermal expansion coefficient can be provided, and a circuit substrate capable of suppressing cracks and circuit deformation when forming multi-layer wiring can be realized while effectively reducing transmission loss when operating in a high-frequency environment.

Hereinafter, each component will be described.

<(A) Epoxy resin> The resin composition of the present invention contains an epoxy resin as component (A).

Examples of the epoxy resin include bisphenol epoxy resins, dicyclopentadiene epoxy resins, trisphenol epoxy resins, naphthol novolac epoxy resins, phenol novolac epoxy resins, tert-butyl-catechol epoxy resins, naphthalene epoxy resins, naphthol epoxy resins, anthracene epoxy resins, glycidylamine epoxy resins, glycidyl ester epoxy resins, Cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, naphthyl ether type epoxy resin, trihydroxymethyl type epoxy resin, tetraphenylethane type epoxy resin. Bisphenol type epoxy resin refers to epoxy resin having a bisphenol structure, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin. Biphenyl type epoxy resin refers to epoxy resin having a biphenyl structure, wherein the biphenyl structure may have a substituent such as an alkyl group, an alkoxy group, an aryl group, etc. Therefore, biphenyl type epoxy resin and biphenyl aralkyl type epoxy resin are also included in the biphenyl type epoxy resin. The epoxy resin may be used alone or in combination of two or more.

As the epoxy resin, an aromatic epoxy resin is preferred. Here, the aromatic epoxy resin refers to an epoxy resin having an aromatic ring in its molecule.

The epoxy resin preferably has two or more epoxy groups in one molecule. When the non-volatile component of the epoxy resin is 100 mass %, the ratio of the epoxy resin having two or more epoxy groups in one molecule is preferably 50 mass % or more, more preferably 60 mass % or more, and further preferably 70 mass % or more.

Among epoxy resins, there are epoxy resins that are liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resin") and epoxy resins that are solid at a temperature of 20°C (hereinafter referred to as "solid epoxy resin").

As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

As the liquid epoxy resin, preferred are bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, aliphatic epoxy resins such as aliphatic epoxy resins having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resins having a butadiene structure.

Specific examples of liquid epoxy resins include: "HP-4032", "HP-4032-D", "HP-4032SS" (naphthalene-based epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "825", "EPIKOTE "828EL" (bisphenol A type epoxy resin); "jER807" and "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630" and "630LSD" (epoxypropylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; "EX-721" (epoxypropyl ester type epoxy resin) manufactured by Nagase ChemteX; "CELLOXIDE "2021P" manufactured by Daicellu Corporation (an epoxy resin with a butadiene structure); "ZX1658" and "ZX1658GS" manufactured by Nippon Steel Chemical Materials Co., Ltd. (liquid 1,4-epoxypropyl cyclohexane type epoxy resins), etc.

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

As the solid epoxy resin, preferred are bixylene type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthyl ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, and tetraphenylethane type epoxy resin.

Specific examples of solid epoxy resins include: "HP-4032H" manufactured by DIC Corporation (naphthalene-based epoxy resin); "HP-4700" and "HP-4710" manufactured by DIC Corporation (naphthalene-based tetrafunctional epoxy resin); "N-690" manufactured by DIC Corporation (cresol novolac-based epoxy resin); "N-695" manufactured by DIC Corporation (cresol novolac-based epoxy resin); "HP-7200HH", "HP-7200H", "HP-7200H" and "HP-7200H" manufactured by DIC Corporation. "00" (dicyclopentadiene type epoxy resin); "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthyl ether type epoxy resin) manufactured by DIC Corporation; "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC-7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC-3000H" manufactured by Nippon Kayaku Co., Ltd. , "NC-3000", "NC-3000L", "NC-3100" (biphenyl type epoxy resin); "ESN-475V" (naphthol type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; "ESN-485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX4000HK" (xylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation Epoxy resin); "YX8800" manufactured by Mitsubishi Chemical (anthracene type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd.; "YL7760" manufactured by Mitsubishi Chemical (bisphenol AF type epoxy resin); "YL7800" manufactured by Mitsubishi Chemical (fluorene type epoxy resin); "jER1010" manufactured by Mitsubishi Chemical (solid bisphenol A type epoxy resin); "jER1031S" manufactured by Mitsubishi Chemical (tetraphenylethane type epoxy resin), etc.

In the resin composition of the present invention, the epoxy resin may include only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. When a liquid epoxy resin and a solid epoxy resin are used in combination, their mass ratio (liquid epoxy resin: solid epoxy resin) is preferably 1:0.01 to 1:50, more preferably 1:0.05 to 1:20, and further 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., further preferably 80 g/eq. to 2000 g/eq., and further preferably 110 g/eq. to 1000 g/eq. The epoxy equivalent is the mass of the epoxy resin containing 1 equivalent of epoxy groups. The epoxy equivalent can be measured according to JIS K 7236.

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

In combination with the components (B) and (C) described later, from the viewpoint of providing a cured product that exhibits both good dielectric properties and a low thermal expansion coefficient and excellent mechanical properties, the content of the component (A) in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 12% by mass or more, 14% by mass or more, or 15% by mass or more, based on 100% by mass of the resin component in the resin composition. The upper limit of the content is not particularly limited and can be determined according to the properties required of the resin composition, and can 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" referred to in the resin composition refers to the components excluding the inorganic filler described below from the non-volatile components constituting the resin composition.

<(B) Active ester resin> The resin composition of the present invention contains an active ester resin as component (B).

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

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

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

From the viewpoint of being able to enjoy the effects of the present invention more, specific examples of preferred active ester resins include active ester resins containing a dicyclopentadiene diphenol structure, active ester resins containing a naphthalene structure, active ester resins containing acetylated novolac resins, and active ester resins containing benzoylated novolac resins. Among them, in combination with the component (C1) described later, active ester resins containing a naphthalene structure and active ester resins containing a dicyclopentadiene diphenol structure are more preferred from the viewpoint of being able to achieve a cured product that exhibits both better dielectric properties and a lower thermal expansion coefficient. The "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit composed of phenylene-dicyclopentylene-phenylene.

As the component (B), commercial products can be used. Examples of the commercial products include "EXB-9451", "EXB-9460", "EXB-9460S", "HPC-8000-65T", "HPC-8000H-65MT", and "HPC-8000L-65MT" (manufactured by DIC Corporation) as active ester resins containing a dicyclopentadiene-type diphenol structure; "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-65T", and "EXB-8150-65MT" (manufactured by DIC Corporation) as active ester resins containing a naphthalene structure. As an active ester resin containing phosphorus, "EXB9401" (manufactured by DIC Corporation) can be cited; as an active ester resin of an acetylated product of a linear phenolic resin, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be cited; as an active ester resin of a benzoylated product of a linear phenolic resin, "YLH1026", "YLH1030", "YLH1048" (manufactured by Mitsubishi Chemical Corporation) can be cited; as an active ester resin containing a styryl group and a naphthalene structure, "PC1300-02-65MA" (manufactured by Airwater Corporation) can be cited.

The component (B) may be used alone or in combination of two or more at any ratio.

The active ester group equivalent of component (B) is preferably 50 g/eq. to 500 g/eq., more preferably 50 g/eq. to 400 g/eq., and even more preferably 100 g/eq. to 300 g/eq. The active ester group equivalent is the mass of the active ester resin per 1 equivalent of active ester groups.

From the viewpoint of easily realizing a resin composition having good dielectric properties, when the resin component in the resin composition is set to 100 mass %, the content of the component (B) in the resin composition is preferably 10 mass % or more, more preferably 20 mass % or more, further preferably 25 mass % or more or 30 mass % or more. The upper limit of the content is not particularly limited and can be determined according to the properties required of the resin composition, for example, it can be 60 mass % or less, 55 mass % or less, or 50 mass % or less.

In the resin composition of the present invention, from the viewpoint of providing a cured product exhibiting good dielectric properties, the mass ratio of the component (B) to the component (A) (component (B)/component (A)) is preferably 0.6 or more, more preferably 0.8 or more, and further preferably 1 or more. As described above, the resin composition of the present invention using the component (C1) can provide a cured product exhibiting a low thermal expansion coefficient even when the component (B) is included to such an extent that excellent dielectric properties can be achieved. For example, in the resin composition of the present invention, the mass ratio of the component (B) to the component (A) can be increased to 1.1 or more or 1.2 or more. The upper limit of the mass ratio (component (B)/component (A)) can be, for example, 2 or less, 1.9 or less, 1.8 or less, etc.

<(C) Maleimide Compound> The resin composition of the present invention is characterized in that it contains a maleimide compound as the component (C), wherein the maleimide compound comprises: (C1) a maleimide compound having a structural unit represented by the following formula (1) (also referred to as "component (C1)" for short), (In formula (1), ^R1 each independently represents an alkyl group, ^R2 , ^R3 , ^R4 and R5 each independently represents a hydrogen atom or a methyl group, and one of ^R2 and ^R3 represents a hydrogen atom and the other represents a methyl group, one of ^R4 and ^R5 represents a hydrogen atom and the other represents a methyl group, ^{RS1 each} independently represents a substituent, ^X1 represents a monovalent group represented by the following formula (2), m1 represents an integer of 1 to 3, m2 represents an integer greater than 0, and here, m1 and m2 satisfy m1+m2≤3, m3 represents an integer of 0 to 4, n represents an integer of 1 to 100, and * represents a bonding bond.) (In formula (2), ^R6 and ^R7 each independently represent a hydrogen atom or a methyl group, and one of ^R6 and ^R7 represents a hydrogen atom and the other represents a methyl group, ^RS2 each independently represents a substituent, m4 represents an integer of 0 to 5, and * represents a bond.)

In formula (1), R ¹ independently represents an alkyl group. The alkyl group represented by R ¹ may be either a linear or branched chain. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 8, and further preferably 1 to 6, 1 to 4, or 1 to 3, from the viewpoint of achieving a cured product having good dielectric properties and a low thermal expansion coefficient in combination with the components (A) and (B).

In formula (1), one of ^R2 and ^R3 represents a hydrogen atom and the other represents a methyl group, and one of ^R4 and ^R5 represents a hydrogen atom and the other represents a methyl group. Thus, in combination with the components (A) and (B), a cured product having good dielectric properties and a low thermal expansion coefficient can be obtained.

In formula (1), R ^S1 each independently represents a substituent. As described above, the substituent represented by R ^S1 is preferably selected from at least one selected from halogen atoms, alkyl groups, alkoxy groups, alkylthio groups, cycloalkyl groups, cycloalkoxy groups, cycloalkylthio groups, aryl groups, aryloxy groups, arylthio groups, hydroxyl groups and alkyl groups, and more preferably selected from at least one selected from halogen atoms, alkyl groups, cycloalkyl groups, aryl groups and hydroxyl groups, among which alkyl groups are preferred. The number of carbon atoms of these substituents is firstly as described above, and preferred examples are also as described above.

In formula (1), ^X1 represents a monovalent group represented by the above formula (2).

In formula (2), one of ^R6 and ^R7 represents a hydrogen atom and the other represents a methyl group. Thus, in combination with the components (A) and (B), a cured product having good dielectric properties and a low thermal expansion coefficient can be obtained.

In formula (2), R ^S2 each independently represents a substituent. As described above, the substituent represented by R ^S2 is preferably selected from at least one selected from halogen atoms, alkyl groups, alkoxy groups, alkylthio groups, cycloalkyl groups, cycloalkoxy groups, cycloalkylthio groups, aryl groups, aryloxy groups, arylthio groups, hydroxyl groups and alkyl groups, and more preferably selected from at least one selected from halogen atoms, alkyl groups, cycloalkyl groups, aryl groups and hydroxyl groups, among which alkyl groups are preferred. The number of carbon atoms of these substituents is firstly as described above, and preferred examples are also as described above.

In formula (2), m4 represents an integer of 0 to 5. From the viewpoint of achieving a better effect of the present invention, m4 preferably represents an integer of 0 to 4, and more preferably represents an integer of 0 to 3.

In formula (1), m1 represents an integer of 1 to 3. From the viewpoint of achieving a better effect of the present invention, m1 preferably represents 1 or 2. In formula (1), R ¹ preferably binds to at least one of the 2-position, 3-position, 4-position, 5-position, or 6-position of the benzene ring to which R ¹ binds.

In formula (1), m2 represents an integer greater than 0. Here, m2 satisfies m1+m2≤3 in the relationship with m1.

In formula (1), m3 represents an integer of 0 to 4. From the viewpoint of achieving a better effect of the present invention, m3 preferably represents an integer of 0 to 3, and more preferably represents an integer of 0 to 2.

In formula (1), n represents an integer of 1 to 100. From the viewpoint of achieving a cured product having better dielectric properties and a lower thermal expansion coefficient in combination with the components (A) and (B), n preferably represents an integer of 1 to 90, more preferably an integer of 1 to 80, an integer of 1 to 60, or an integer of 1 to 50.

From the viewpoint of achieving a cured product exhibiting further improved dielectric properties and a further lower thermal expansion coefficient in combination with the components (A) and (B), examples of particularly preferred structural units represented by formula (1) are shown below.

In a preferred embodiment, in formula (1), ^R1 independently represents an alkyl group having 1 to 6 carbon atoms, one of ^R2 and ^R3 represents a hydrogen atom and the other represents a methyl group, one of ^R4 and ^R5 represents a hydrogen atom and the other represents a methyl group, ^RS1 independently represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group or a hydroxyl group, ^X1 represents a monovalent group represented by formula (2) above (in formula (2), one of ^R6 and ^R7 represents a hydrogen atom and the other represents a methyl group, ^RS2 independently represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group or a hydroxyl group, and m4 represents an integer of 0 to 3), m1 represents 1 or 2, m2 represents an integer greater than 0, and here, m1 and m2 satisfy m1+m2≤3, m3 represents an integer of 0 to 3, and n represents an integer of 1 to 90.

In a more preferred embodiment, in formula (1), ^R1 each independently represents an alkyl group having 1 to 3 carbon atoms, one of ^R2 and ^R3 represents a hydrogen atom and the other represents a methyl group, one of ^R4 and ^R5 represents a hydrogen atom and the other represents a methyl group, ^RS1 each independently represents an alkyl group having 1 to 6 carbon atoms, ^X1 represents a monovalent group represented by the above formula (2) (in formula (2), one of ^R6 and ^R7 represents a hydrogen atom and the other represents a methyl group, ^RS2 each independently represents an alkyl group having 1 to 6 carbon atoms, and m4 represents an integer of 0 to 3), m1 represents 1 or 2, m2 represents an integer greater than 0, wherein m1 and m2 satisfy m1+m2≤3, m3 represents an integer of 0 to 2, and n represents an integer of 1 to 80.

In a preferred embodiment, the component (C1) has a structure represented by the following formula (1-1).

(In formula (1-1), ^R1 , ^R2 , ^R3 , ^R4 , ^R5 , ^RS1 , ^X1 , m1, m2, m3 and n are the same as described above, ^XM1 represents a hydrogen atom or a monovalent group represented by the above formula (2), and ^XM2 represents a hydrogen atom, a monovalent group represented by the following formula (3) or a monovalent group represented by the following formula (4).)

(In formula (3), R ¹ and m1 are the same as above, and * represents a bonding bond.)

(In formula (4), R ¹ , X ¹ , and m1 are the same as above, and m5 represents an integer greater than 1. Here, m1 and m5 satisfy m1+m5≤4, and * represents a bonding bond.)

As described later, component (C1) can be synthesized by reacting an alkyl-substituted aniline compound with a divinylbenzene compound which may have a substituent and, if necessary, a monovinylbenzene compound which may have a substituent, to obtain an intermediate amine compound, with maleic anhydride to perform maleimidation.

In formula (1-1), when X ^M1 is a hydrogen atom, it represents a terminal structure derived from an aniline compound substituted with an alkyl group. In addition, when X ^M1 is a structure represented by formula (2), it represents a terminal structure formed by further bonding a structure derived from a monovinylbenzene compound which may also have a substituent to a structure derived from an aniline compound substituted with an alkyl group when a monovinylbenzene compound which may also have a substituent is used as a raw material.

In formula (1-1), when X ^M2 is a hydrogen atom, it indicates a terminal structure derived from a divinylbenzene compound which may also have a substituent. In addition, when X ^M2 is a structure represented by the above formula (3), it indicates a terminal structure derived from an aniline compound substituted with an alkyl group. Furthermore, when X ^M2 is a structure represented by the above formula (4), it indicates that, when a monovinylbenzene compound which may also have a substituent is used as a raw material, a terminal structure is formed by further bonding a structure derived from an aniline compound substituted with an alkyl group to a structure derived from an aniline compound substituted with an alkyl group.

Regarding ^R1 , R2, ^R3 , ^R4 , ^R5 , ^RS1 , ^X1 , m1, m2, m3 and n in these formulas (1-1), (2), (3) and ( ⁴ ), preferred examples and ranges thereof are as described for formula (1).

In formula (4), m5 represents an integer greater than 1, and here, m5 satisfies m1+m5≤4 in the relationship with m1.

From the viewpoint of achieving a cured product exhibiting better dielectric properties and lower thermal expansion coefficient in combination with the components (A) and (B), the number average molecular weight (Mn) of the component (C1) is preferably in the range of 350 to 2,000, more preferably in the range of 400 to 1,500, and the weight average molecular weight (Mw) thereof is preferably in the range of 400 to 500,000, more preferably in the range of 450 to 400,000. These Mn and Mw can be measured as polystyrene-converted values by the GPC method.

An example of the synthesis procedure of the component (C1) is shown below.

In one embodiment, component (C1) is a maleimide of an intermediate amine compound (x1) obtained by reacting an aniline compound (x1-1) substituted with an alkyl group and a divinylbenzene compound (x1-2) which may also have a substituent.

When the intermediate amine compound (x1) is obtained, in addition to the above-mentioned components (x1-1) and (x1-2), a monovinylbenzene compound (x1-3) which may have a substituent may be further reacted.

Therefore, in another embodiment, component (C1) is a maleimide of an intermediate amine compound (x1) obtained by reacting (x1-1) an aniline compound substituted with an alkyl group, (x1-2) a divinylbenzene compound which may also have a substituent, and (x1-3) a monovinylbenzene compound which may also have a substituent.

-(x1-1) Alkyl-substituted aniline compound- The component (x1-1) is an alkyl-substituted aniline compound, which is represented by the following formula (x1-1).

(wherein, R ¹ and m1 are the same as above.).

The component (x1-1) can be appropriately determined in order to achieve the structure of the target component (C1). The structure of the component (C1), that is, the structural unit represented by formula (1), and further, the preferred example of the structure represented by formula (1-1) is as described above. For example, as the aniline compound, when ^R1 in the target component (C1) is a _C1 - _C6 alkyl group and m1 is 1, mono- _C1 - _C6 alkylaniline can be used. In addition, when ^R1 in the target component (C1) is a _C1 - _C6 alkyl group and m1 is 3, tri- _C1 - _C6 alkylaniline can be used. From the viewpoint of smoothly synthesizing component (C1) in combination with component (x1-2) and component (x1-3), it is preferred that at least one carbon atom at the 2-, 4-, or 6-position of the benzene ring of component (x1-1) is unsubstituted.

-(x1-2) Divinylbenzene compound which may also have a substituent- The component (x1-2) is a divinylbenzene compound which may also have a substituent, and is represented by the following formula (x1-2).

(In the formula, ^RS1 and m3 are the same as above.)

The component (x1-2) can be appropriately determined in order to achieve the structure of the target component (C1). The structure of the component (C1), i.e., the structural unit represented by formula (1), and further, the preferred example of the structure represented by formula (1-1) is as described above. For example, as the divinylbenzene compound, when ^RS1 in the target component (C1) is a _C1 ~ _{C6 alkyl} group and m3 is 1, mono- _C1 ~C6 alkyl-divinylbenzene can be used. In addition, when ^RS1 in the target component (C1) is a _C1 ~ _C6 alkyl group and m1 is 2, di- _C1 ~C6 _alkyl -divinylbenzene can be used. In addition, when m3 in the target component (C1) is 0, divinylbenzene can be used.

-(x1-3) Monovinylbenzene compound which may also have a substituent- The component (x1-3) is a monovinylbenzene compound which may also have a substituent, and is represented by the following formula (x1-3).

(In the formula, ^RS2 and m4 are the same as above.)

The component (x1-3) can be appropriately determined in order to achieve the structure of the target component (C1). The structure of the component (C1), i.e., the structural unit represented by the formula (1), and further, the preferred example of the structure represented by the formula (1-1) is as described above. As described above, the component (x1-3) is an arbitrarily used raw material. When the m2 in the formula (1) or the formula (1-1) is 1 or more, the X ^M1 in the formula (1-1) is the one represented by the formula (2), and the X ^M2 in the formula (1-1) is the one represented by the formula (4), the component (x1-3) is used. For example, as the monovinylbenzene compound, when ^RS2 in the target component (C1) is a _C1 to C6 _alkyl group and m4 is 1, a mono- _C1 to _C6 alkyl-monovinylbenzene can be used. When ^RS2 in the target component (C1) is a _C1 - _C6 alkyl group and m4 is 2, di- _C1 - _C6 alkyl-monovinylbenzene may be used. When m4 in the target component (C1) is 0, monovinylbenzene may be used.

The above-mentioned component (x1-1) is reacted with the component (x1-2) and, if necessary, the component (x1-3) in the presence of an acid catalyst to obtain an intermediate amine compound (x1). In the above reaction, the vinyl group of the component (x1-2) or the component (x1-3) generates a carbon positive ion in the presence of an acid catalyst, which reacts and bonds with the unsubstituted carbon of the benzene ring of the component (x1-1).

The mixing ratio of the component (x1-1) to the component (x1-2) is preferably 0.1 to 10 mol, more preferably 0.2 to 3 mol, relative to 1 mol of the component (x1-1), from the viewpoint of achieving a cured product (C1) having both good dielectric properties and a low thermal expansion coefficient in combination with the components (A) and (B). In addition, when the component (x1-3) is used in combination, the component (x1-3) is preferably 0.1 to 10 mol, more preferably 0.2 to 3 mol, relative to 1 mol of the component (x1-1).

The reaction may be carried out in a solvent-free system without using a solvent, or in an organic solvent system using an organic solvent. Examples of the organic solvent used in the reaction include aromatic solvents such as toluene and xylene; halogenated aromatic solvents such as chlorobenzene; and ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. The organic solvent may be used alone or in combination of two or more.

As the acid catalyst used in the reaction, there can be cited, for example, inorganic acids such as phosphoric acid, hydrochloric acid, and sulfuric acid, organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, and fluoromethanesulfonic acid, solid acids such as activated clay, acid clay, silica alumina, zeolite, and strongly acidic ion exchange resins, and polyacids.

The reaction temperature is not particularly limited as long as the reaction proceeds, and may be, for example, 100 to 250° C. The reaction time is not particularly limited as long as the structure of the target intermediate amine compound (x1) is achieved, and may be, for example, 30 minutes to 48 hours.

The intermediate amine compound (x1) may be purified after the reaction. For example, after the reaction, a purification step such as filtration or distillation may be performed in order to remove the catalyst or excess starting materials from the system.

Thus, an intermediate amine compound having a structure represented by the following formula (x1) is obtained.

(In formula (x1), ^R1 , ^R2 , ^R3 , ^R4 , ^R5 , ^RS1 , ^X1 , m1, m2, m3 and n are the same as described above, ^XM1' represents a hydrogen atom or a monovalent group represented by the above formula (2), and ^XM2' represents a hydrogen atom, a monovalent group represented by the following formula (3') or a monovalent group represented by the following formula (4').)

(In formula (3'), R ¹ and m1 are the same as described above.)

(In formula (4'), R ¹ , X ¹ , m1, and m5 are the same as described above.)

Then, the obtained intermediate amine compound (x1) is reacted with maleic anhydride to perform maleimidation, thereby obtaining the component (C1).

The reaction of component (x1) with maleic anhydride can be carried out by a maleimidation reaction of an amine group known in the art using maleic anhydride. The reaction can be carried out in a solvent-free system without using a solvent, or in an organic solvent system with using an organic solvent. The types of organic solvents that can be used are the same as those described above with respect to the reactions of component (x1-1) with component (x1-2) and with component (x1-3).

The reaction temperature is not particularly limited as long as the reaction proceeds, and may be, for example, in the range of 0 to 100° C. In addition, the reaction time is not particularly limited as long as the target structure of the component (C1) is achieved, and may be, for example, in the range of 1 to 24 hours. After the reaction, a purification step such as washing with water or precision filtration may be performed.

The reaction can be carried out in the presence of a catalyst. Examples of the catalyst include acetates of nickel, cobalt, sodium, calcium, iron, lithium, and manganese, inorganic salts such as chlorides, bromides, sulfates, and nitrates, inorganic acids such as phosphoric acid, hydrochloric acid, and sulfuric acid, organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, and fluoromethanesulfonic acid, solid acids such as activated clay, acid clay, silica alumina, zeolite, and strongly acidic ion exchange resins, and polyacids.

Regarding the mixing ratio of the intermediate amine compound (x1) and maleic anhydride, from the viewpoint of achieving a component (C1) that provides a cured product having both good dielectric properties and a low thermal expansion coefficient in combination with the components (A) and (B), it is preferred that the ratio of the equivalent of maleic anhydride to the amine group equivalent of the intermediate amine compound (x1) is in the range of 1 to 5.

The resin composition of the present invention may contain (C2) other maleimide compounds as long as it contains the above-mentioned component (C1).

As the component (C2), there is no particular limitation on its type as long as it has one or more (preferably two or more) maleimide groups in one molecule. Examples of the component (C2) include: "BMI-3000J", "BMI-5000", "BMI-1400", "BMI-1500", "BMI-1700", "BMI-689" (all designer molecules). (1) a maleimide resin containing an aliphatic skeleton (preferably an aliphatic skeleton containing a cyclic structure having 10 or more carbon atoms, more preferably an aliphatic skeleton having 36 carbon atoms derived from dimer diamine) such as "SLK-6895" (manufactured by Shin-Etsu Chemical Co., Ltd.), "SLK-1500" (all manufactured by Shin-Etsu Chemical Co., Ltd.), etc.; (2) a maleimide resin containing an indane skeleton described in Japan Invention Society Publication No. 2020-500211; (3) a maleimide resin containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Yamato Chemical Co., Ltd.), and "BMI-80" (manufactured by KI Chemicals Co., Ltd.).

From the viewpoint of achieving a cured product having both good dielectric properties and a low thermal expansion coefficient in combination with the components (A) and (B), the content of the component (C1), i.e., the maleimide compound having the structural unit represented by the formula (1), in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 12% by mass or more, 14% by mass or more, 15% by mass or more, 16% by mass or more, 18% by mass or more, or 20% by mass or more, based on 100% by mass of the resin component in the resin composition. The upper limit of the content is not particularly limited and can be determined according to the properties required of the resin composition. From the viewpoint of achieving a cured product exhibiting better dielectric properties and a lower thermal expansion coefficient in combination with the components (A) and (B), the upper limit of the content is preferably 60% by mass or less, more preferably 50% by mass or less, and further preferably 45% by mass or less or 40% by mass or less.

When the resin composition of the present invention contains component (C2), i.e., other maleimide compounds, the content of component (C1) is preferably 30% by mass or more, more preferably 50% by mass or more, and further preferably 60% by mass or more, 70% by mass or more, or 80% by mass or more, when the total amount of component (C) (total of non-volatile components) is taken as 100% by mass. The upper limit of the content of component (C1) in the total amount of component (C) is not particularly limited, and may be 100% by mass, for example, 99% by mass or less, 98% by mass or less, 96% by mass or less, 95% by mass or less, etc.

In the resin composition of the present invention, the total content of the component (C) can be appropriately determined to satisfy the above-mentioned content of the component (C1) and the appropriate range of the content of the component (C1) in the total component (C). For example, when the resin component in the resin composition is 100% by mass, the total content of the component (C) in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 12% by mass or more, 14% by mass or more, 15% by mass or more, 16% by mass or more, 18% by mass or more, or 20% by mass or more. The upper limit of the content is not particularly limited and can be determined according to the properties required of the resin composition. From the viewpoint of achieving a cured product exhibiting better dielectric properties and a lower thermal expansion coefficient in combination with the components (A) and (B), the upper limit of the content is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less or 40% by mass or less.

<(D) Other hardeners> The resin composition of the present invention may further contain a hardener other than component (B) (also referred to as "other hardener") as component (D).

Examples of the component (D) include phenolic curing agents, naphthol curing agents, acid anhydride curing agents, cyanate curing agents, carbodiimide curing agents, and amine curing agents. The component (D) may be used alone or in combination of two or more.

As the phenolic hardener and the naphthol hardener, those having a phenolic structure are preferred from the viewpoint of heat resistance and water resistance. In addition, from the viewpoint of adhesion with the conductive layer, nitrogen-containing phenolic hardeners and nitrogen-containing naphthol hardeners are preferred, and phenolic hardeners containing a triazine skeleton and naphthol hardeners containing a triazine skeleton are more preferred.

Specific examples of phenolic hardeners and naphthol hardeners include: "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Chemicals; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", and "SN-375" manufactured by Nippon Steel Chemical Materials Co., Ltd. ", "SN-395"; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", "KA-1165" manufactured by DIC Corporation; "GDP-6115L", "GDP-6115H", "ELPC 75" and others manufactured by Qun-Yung Chemical Corporation.

Examples of the acid anhydride curing agent include those having one or more acid anhydride groups in one molecule. Specific examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, dihydrophthalic anhydride, and 1,2-dihydrophthalic anhydride. Benzophenone tetracarboxylic acid dianhydride, biphenyl tetracarboxylic acid dianhydride, naphthalene tetracarboxylic acid dianhydride, oxydiphthalic acid dianhydride, 3,3'-4,4'-diphenylsulfonate tetracarboxylic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(trimellitic anhydride ester), styrene-maleic acid resin obtained by copolymerization of styrene and maleic acid, etc. As commercially available products of anhydride-based hardeners, "MH-700" manufactured by Shin Nippon Rika Co., Ltd. can be cited.

Examples of the cyanate curing agent include 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-cyano)phenylpropane, 1,1-bis(4-cyanophenylmethane), bis(2,6-dimethylphenyl cyanate ... Difunctional cyanate resins such as (4-cyano-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanophenyl-1-(methylethylidene))benzene, bis(4-cyanophenyl)sulfide and bis(4-cyanophenyl)ether, polyfunctional cyanate resins derived from phenol novolac resins and cresol novolac resins, prepolymers obtained by triazinization of a part of these cyanate resins, etc. Specific examples of cyanate-based curing agents include "PT30" and "PT60" manufactured by Lonza Japan (novolak type multifunctional cyanate resins), "ULL-950S" (multifunctional cyanate resin), "BA230", and "BA230S75" (prepolymers obtained by triazine-forming a trimer with part or all of bisphenol A dicyanate), etc.

Specific examples of carbodiimide-based hardeners include carbodiimide (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.), and V-09 (carbodiimide group equivalent: 200 g/eq.) manufactured by Nisshinbo Chemical Co., Ltd.; and Stabaxol (registered trademark) P (carbodiimide group equivalent: 302 g/eq.) manufactured by Rhein Chemie Co., Ltd.

Examples of the amine-based curing agent include those having one or more amine groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, aromatic amines, and the like. Specific examples of the amine-based curing agent include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfonate, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfonate, 3,3'-diaminodiphenylsulfonate, metaphenylenediamine, metaphenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino- 4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-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, etc. As the amine-based hardener, commercially available products can be used, for example, "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD A-A", "KAYAHARD A-B", "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd. and "EPICURE W" manufactured by Mitsubishi Chemical Corporation.

When the resin composition of the present invention contains component (D), the content of component (D) in the resin composition can be determined according to the properties required of the resin composition, and when the resin component in the resin composition is set to 100% by mass, it is, for example, 0.1% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, and further preferably 3% by mass or more. The upper limit of the content of component (D) is not particularly limited, and can be, for example, 20% by mass or less, 15% by mass or less, 10% by mass or less, etc.

As described above, from the perspective of providing a cured product exhibiting good dielectric properties, the resin composition of the present invention includes an active ester resin, i.e., component (B). In the resin composition of the present invention, when the total of the non-volatile components of components (B) and (D) is 100% by mass, the content of component (B) is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, 75% by mass or more, or 80% by mass or more. The upper limit of the content of component (B) in the total of components (B) and (D) is not particularly limited, and may be 100% by mass, for example, 95% by mass or less, 90% by mass or less, etc.

<(E) Inorganic filler> The resin composition of the present invention may further contain an inorganic filler as the (E) component. By containing the (E) component, there is a tendency to further reduce the thermal expansion coefficient and dielectric tangent.

Examples of the material of the component (E) include silicon dioxide, aluminum oxide, 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, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among them, silicon dioxide is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. In addition, spherical silica is preferred as silica. Component (E) may be used alone or in combination of two or more.

Examples of commercially available products of the component (E) include "UFP-30" manufactured by Denki Kagaku Kogyo Co., Ltd.; "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical Materials Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatechs; "UFP-30" manufactured by Denka; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama Co., Ltd. NSS-5N"; "SC2500SQ", "SO-C4", "SO-C2", "SO-C1" manufactured by Yaduma; "DAW-03", "FB-105FD" manufactured by Denka; "Cellspheres" and "MGH-005" produced by Pacific Cement; "Esferique" and "BA-1" manufactured by Helio Catalytic Chemicals, etc.

The average particle size of the (E) component is not particularly limited, and is preferably less than 10 μm, more preferably less than 5 μm, and further preferably less than 3 μm, less than 2 μm, less than 1 μm or less than 0.7 μm. The lower limit of the average particle size is not particularly limited, and is preferably greater than 0.01 μm, more preferably greater than 0.05 μm, and further preferably greater than 0.07 μm, greater than 0.1 μm or greater than 0.2 μm. The average particle size of the (E) component can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler material can be prepared on a volume basis using a laser diffraction scattering particle size distribution measuring device, and the median particle size can be measured as the average particle size. The sample to be measured can be a sample obtained by weighing 100 mg of an inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the sample by ultrasonic wave for 10 minutes. For the sample to be measured, a laser diffraction particle size distribution measuring device is used, and the wavelength of the light source used is set to blue and red. The particle size distribution based on the volume of the inorganic filler is measured by a flow cell method, and the average particle size is calculated as the median particle size based on the obtained particle size distribution. Examples of laser diffraction particle size distribution measuring devices include "LA-960" manufactured by Horiba, Ltd.

The specific surface area of the component (E) is not particularly limited, but is preferably 0.1 m ² /g or more, more preferably 0.5 m ² /g or more, further 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, further 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 the component (E) is obtained by adsorbing nitrogen on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech) according to the BET method, and calculating the specific surface area using the BET multipoint method.

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

Commercially available products of the surface treatment agent include, for example, "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industries, Ltd., "KBM803" (3-butylenepropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industries, Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Industries, Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industries, Ltd., and "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Industries, Ltd.

From the viewpoint of improving the dispersibility of the inorganic filler, the degree of surface treatment with the surface treatment agent is preferably within a predetermined range. Specifically, it is preferred 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 using a 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/ ^m2 or more, more preferably 0.1 mg/ ^m2 or more, and further preferably 0.2 mg/ ^m2 or more. On the other hand, from the viewpoint of preventing the increase in the melt viscosity of the resin composition or the melt viscosity of the sheet form, it is preferably 1.0 mg/ ^m2 or less, more preferably 0.8 mg/ ^m2 or less, and further preferably 0.5 mg/ ^m2 or less. The amount of carbon per unit surface area of the (E) component can be measured after the surface-treated inorganic filler is cleaned 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 components, the amount of carbon per unit surface area of the inorganic filler is measured using a carbon analyzer. As a carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd. can be used.

When the resin composition of the present invention contains component (E), the content of component (E) in the resin composition can be, for example, 40% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more, 65% by mass or more, or 70% by mass or more, from the viewpoint of easily realizing a resin composition having a lower coefficient of thermal expansion, when the non-volatile components in the resin composition are set to 100% by mass. The upper limit of the content of the component (E) is not particularly limited, and can be, for example, 90% by mass or less, 85% by mass or less, etc.

<(F) Resin containing an aromatic ring and a free radical polymerizable unsaturated group> The resin composition of the present invention may further contain a resin containing an aromatic ring and a free radical polymerizable unsaturated group as the (F) component. By including the (F) component in combination with the (C1) component, a resin composition having a cured product exhibiting better dielectric properties can be achieved.

The aromatic ring contained in the (F) component may be an aromatic carbon ring or an aromatic heterocyclic ring. In addition, the aromatic ring may be a monocyclic aromatic ring, a condensed aromatic ring formed by condensing two or more monocyclic aromatic rings, or a condensed aromatic ring formed by condensing one or more monocyclic non-aromatic rings on one or more monocyclic aromatic rings. Examples of these aromatic rings include monocyclic aromatic rings such as a benzene ring and a pyridine ring; and condensed aromatic rings such as an indane ring, a fluorene ring, and a naphthalene ring. Among them, the aromatic ring is preferably an aromatic carbon ring. The number of carbon atoms in the aromatic carbon ring is preferably 6 or more and 10 or less.

The aromatic ring contained in the (F) component may also be bonded with a substituent. As described above, the substituent is preferably selected from one or more of a halogen atom, an alkyl group, an alkoxy group, an alkylthio group, a cycloalkyl group, an aryl group, an aryloxy group, an arylthio group, a hydroxyl group and a butyl group, from the viewpoint of being able to realize a resin composition that exhibits both good dielectric properties and a low thermal expansion coefficient in combination with the (C1) component. The number of substituents bonded to one aromatic ring may be 1 or more than 2. When the number of substituents is more than 2, these two or more substituents may be the same or different. Among them, the aromatic ring contained in the (F) component is preferably unbonded with a substituent or bonded with an alkyl group.

The number of aromatic rings contained in the component (F) is usually 1 or more, preferably 2 or more. When the component (F) contains two or more aromatic rings, these two or more aromatic rings may be the same or different.

The radical polymerizable unsaturated group contained in the component (F) means a group containing an unsaturated bond that is radical polymerizable. Examples of the radical polymerizable unsaturated group include a group containing an ethylenic double bond.

Examples of the free radical polymerizable unsaturated group include vinyl, allyl, vinylphenyl, acryl, methacryl, fumaric and maleic groups. The number of free radical polymerizable unsaturated groups contained in the component (F) is usually 1 or more, preferably 2 or more. When the component (F) contains 2 or more free radical polymerizable unsaturated groups, these 2 or more free radical polymerizable unsaturated groups may be the same or different.

Examples of the component (F) containing two or more aromatic rings and two or more radically polymerizable unsaturated groups include, in addition to the resins described below, "NE-V-1100-70T" manufactured by DIC Corporation (a resin containing a plurality of benzene rings and an allyl group).

Among them, the component (F) preferably contains a group represented by the following formula (F1).

.

(In formula (F1), ^RA1 , ^RA2 and ^RA3 each independently represent a hydrogen atom or an alkyl group; ^RA4 each independently represents an alkyl group; _ma1 represents 0 or 1; _ma2 represents an integer from 0 to 4; and * represents a bonding bond.)

In formula (F1), ^RA1 , ^RA2 and ^RA3 each independently represent a hydrogen atom or an alkyl group. The number of carbon atoms in the alkyl group is preferably 1 to 18, more preferably 1 to 12, further preferably 1 to 6, and further more preferably 1 to 2. The alkyl group may be any of a linear, branched, or cyclic group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a n-butyl group, and a tert-butyl group. Among them, ^RA1 is preferably a hydrogen atom or a methyl group, and ^RA2 and ^RA3 are preferably a hydrogen atom.

In formula (F1), R ^A4 each independently represents an alkyl group. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 2. The alkyl group may be any of a linear, branched, or cyclic group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a n-butyl group, and a t-butyl group. Among them, R ^A1 is preferably a methyl group.

In formula (F1), m _a1 represents 0 or 1. When ^RA1 is a hydrogen atom, m _a1 is preferably 0. When ^RA1 is an alkyl group, m _a1 is preferably 1.

In formula (F1), m _a2 represents an integer of 0 to 4. m _a2 is preferably 0 to 2.

The component (F) may contain one group represented by the formula (F1) per molecule, and preferably contains two or more groups represented by the formula (F1).

The component (F) is preferably a compound containing a polyphenylene ether skeleton. Examples of the component (F) containing a polyphenylene ether skeleton include a compound represented by the following formula (F2).

.

(In formula (F2), ^L1 represents a divalent linking group; ^RB11 , ^RB12 , ^RB13 , ^RB21 , ^RB22 and ^RB23 each independently represent a hydrogen atom or an alkyl group; ^RB14 , ^RB15 , ^RB24 and ^RB25 each independently represent an alkyl group; ^RB16 and ^RB26 each independently represent an alkylene group; _mb11 and _mb21 each independently represent 0 or 1; _mb12 , _mb13 , _mb22 and _mb23 each independently represent an integer from 0 to 4; _mb14 and _mb24 each independently represent an integer from 0 to 300; _mb15 and _mb25 each independently represent 0 or 1.)

In formula (F2), ^L1 represents a divalent linking group. Examples of the divalent linking group include alkylene, alkenylene, arylene, alkylarylene, heteroarylene, -O-, -NH-, ^-NRx- , -CO-, -CS-, -SO-, _-SO2- , -C(=O)O-, -NHC(=O)-, -NC(=O)N-, -NHC(=O)O-, -C(=O)-, -S-, and groups combining these groups in plurality. ^Rx represents a alkyl group having 1 to 12 carbon atoms. The number of carbon atoms in ^L1 is usually 60 or less, more preferably 48 or less, further preferably 36 or less, and further more preferably 24 or less.

In formula (F2), ^RB11 , ^RB12 , ^RB13 , RB21, ^RB22 and ^RB23 each independently represent a hydrogen atom or an alkyl group. ^RB11 , ^RB12 , ^{RB13 , RB21, RB22 and RB23 may have the same meanings as RA1, RA2 and RA3 in formula (F1). Among them, RB11 and RB21 are preferably hydrogen atoms or methyl groups ,} and ^RB12 , ^RB13 , ^RB22 and ^RB23 are preferably hydrogen atoms.

In formula (F2), R ^B14 , R ^B15 , R ^B24 and R ^B25 each independently represent an alkyl group. R ^B14 , R ^B15 , R ^B24 and R ^B25 may have the same meaning as R ^A4 in formula (F1). Among them, R ^B14 , R ^B15 , R ^B24 and R ^B25 are preferably methyl groups.

In formula (F2), R ^B16 and R ^B26 each independently represent an alkylene group. The number of carbon atoms in the alkylene group is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3. The alkylene group is preferably a linear alkylene group, and more preferably a methylene group.

In formula (F2), m _b11 and m _b21 independently represent 0 or 1.

In formula (F2), m _b12 , m _b13 , m _b22 and m _b23 each independently represent an integer of 0 to 4. m _b12 , m _b13 , m _b22 and m _b23 are preferably 1 to 4, more preferably 2 to 3, and particularly preferably 2.

In formula (F2), m _b14 and m _b24 each independently represent an integer of 0 to 300. Specifically, m _b14 and m _b24 are usually 0 or more, preferably 1 or more, and usually 300 or less, preferably 100 or less, more preferably 50 or less, further preferably 20 or less, and further more preferably 10 or less.

In formula (F2), m _b15 and m _b25 each independently represent 0 or 1. When m _b11 is 0, m _b15 is preferably 1; when m _b11 is 1, m _b15 is preferably 0. In addition, when m _b21 is 0, m _b25 is preferably 1; when m _b21 is 1, m _b25 is preferably 0.

If a preferable example of the compound represented by formula (F2) is given, the compound represented by the following formula (F3) can be mentioned.

.

(In formula (F3), ^L2 represents a divalent linking group; R ^C15 and R ^C25 each independently represent an alkyl group; R ^C16 and R ^C26 each independently represent an alkylene group; m _C14 and m _C24 each independently represent an integer of 0 to 300.)

In formula (F3), ^L2 represents a divalent linking group. ^L2 may have the same meaning as ^L1 in formula (F2). Among them, ^L2 is preferably a divalent group represented by the following formula (F3-1).

.

(In formula (F3-1), ^XF1 to ^XF8 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group. * represents a bonding bond.)

In formula (F3), R ^C15 and R ^C25 each independently represent an alkyl group. R ^C15 and R ^C25 may have the same meaning as R ^A4 in formula (F1). Among them, R ^C15 and R ^C25 are preferably methyl groups.

In formula (F3), R ^C16 and R ^C26 each independently represent an alkylene group. R ^C16 and R ^C26 may have the same meanings as R ^B16 and R ^B26 in formula (F2). Among them, R ^C16 and R ^C26 are more preferably methylene groups.

In formula (F3), m _c14 and m _c24 each independently represent an integer of 0 to 300. m _c14 and m _c24 may have the same meanings as m _b14 and m _b24 in formula (F2). In formula (F3), preferably, a structure in which one of m _c14 and m _c24 is 0 is excluded.

As the compound represented by formula (F3), for example, the compound represented by the following formula (F4) can be cited. In formula (F4), m _c14 and m _c24 represent the same numbers as the corresponding symbols in formula (F3). The compound represented by formula (F4) can be obtained as "OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd.

.

Another preferred example of the compound represented by formula (F2) is a compound represented by the following formula (F5).

.

(In formula (F5), L ³ represents a divalent linking group; R ^D11 and R ^D21 each independently represent a hydrogen atom or an alkyl group; R ^D14 , R ^D15 , R ^D24 and R ^D25 each independently represent an alkyl group; m _d14 and m _d24 each independently represent an integer of 0 to 300.)

In formula (F5), ^L3 represents a divalent linking group. ^L3 may have the same meaning as ^L1 in formula ( _F2 ). ^L3 is preferably selected from any one of alkylene, alkenylene, -O-, ^-NRx- , -CO-, -CS-, -SO-, and -SO2-, preferably alkylene, and particularly preferably isopropylene (-C(CH3) _2- ).

In formula (F5), R ^D11 and R ^D21 each independently represent a hydrogen atom or an alkyl group. R ^D11 and R ^D21 may have the same meanings as R ^B11 and R ^B21 in formula (F2). Preferably, R ^D11 and R ^D21 are methyl groups.

In formula (F5), R ^D14 , R ^D15 , R ^D24 and R ^D25 each independently represent an alkyl group. R ^D14 , R ^D15 , R ^D24 and R ^D25 may have the same meaning as R ^A4 in formula (F1). Among them, R ^D14 , R ^D15 , R ^D24 and R ^D25 are preferably methyl groups.

In formula (F5), m _d14 and m _d24 each independently represent an integer of 0 to 300. m _d14 and m _d24 may have the same meanings as m _b14 and m _b24 in formula (F2). In addition, the total of m _b14 and m _b24 is preferably 2 or more.

Examples of the compound represented by formula (F5) include the compound represented by the following formula (F6). In formula (F6), L ³ , m _d14 and m _d24 have the same meanings as the corresponding symbols in formula (F5). The compound represented by formula (F4) can be obtained as "NORYL SA9000" manufactured by SABIC.

.

Another preferred example of the component (F) is a polymer containing a structural unit represented by the following formula (F7).

.

(In formula (F7), ^RE1 , ^RE2 and ^RE3 each independently represent a hydrogen atom or an alkyl group; ^RE4 each independently represents an alkyl group; ^RE5 , ^RE6 and ^RE7 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; _me1 represents 0 or 1; _me2 represents an integer from 0 to 4; * represents a bonding bond.)

In formula (F7), ^RE1 , ^RE2 and ^RE3 each independently represent a hydrogen atom or an alkyl group. ^RE1 , ^RE2 and ^RE3 may have the same meanings as ^RA1 , ^RA2 and ^RA3 in formula (F1). Among them, ^RE1 , ^RE2 and ^RA3 are preferably hydrogen atoms.

In formula (F7), ^RE4 each independently represents an alkyl group. ^RE4 may have the same meaning as ^RA4 in formula (F1).

In formula (F7), ^RE5 , ^RE6 and ^RE7 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Among them, ^RE5 , ^RE6 and ^RE7 are preferably a hydrogen atom.

In formula (F7), _me1 represents 0 or 1, preferably 0.

In formula (F7), _me2 represents an integer from 0 to 4, preferably 0.

The molar content of the structural unit represented by formula (F7) is preferably within a specific range relative to 100 mol% of the total of all structural units contained in the polymer containing the structural unit represented by formula (F7). Specifically, the molar content of the structural unit represented by formula (F7) is preferably 2 mol% to 95 mol%, more preferably 8 mol% to 81 mol%. In addition, the average number of the structural units represented by formula (F7) contained in one molecule of the above-mentioned polymer is preferably 1 to 160, more preferably 3 to 140.

The polymer including the structural unit represented by formula (F7) may further include an arbitrary structural unit in combination with the structural unit represented by formula (F7). Examples of the arbitrary structural unit include the structural unit represented by the following formula (F7-1).

.

(In formula (F7-1), ^RE8 , ^RE9 and ^RE10 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. ^ArE1 represents an aryl group which may have a substituent. As the substituent possessed by ^ArE1 , an alkyl group having 1 to 6 carbon atoms can be mentioned. * represents a bonding bond.)

As a polymer containing a structural unit represented by formula (F7), for example, a copolymer containing a structural unit represented by the following formula (F8), a structural unit represented by the following formula (F8-1), and a structural unit represented by the following formula (F8-2) can be cited. In formula (F8), formula (F8-1), and formula (F8-2), * represents a bond. In the copolymer, the molar content of the structural unit represented by formula (F8), the structural unit represented by formula (F8-1), and the structural unit represented by formula (F8-2) is 8 mol% to 54 mol%, 0 mol% to 92 mol%, and 0 mol% to 89 mol%, respectively. In addition, the average number of the structural unit represented by formula (F8), the structural unit represented by formula (F8-1), and the structural unit represented by formula (F8-2) contained in one molecule of the copolymer is 1 to 160, 0 to 350, and 0 to 270, respectively. The copolymer is available as "ODV-XET (X03)", "ODV-XET (X04)" and "ODV-XET (X05)" manufactured by Nippon Steel Chemical Materials Co., Ltd.

.

The component (F) may be used alone or in combination of two or more at any ratio.

The free radical polymerizable unsaturated group equivalent of the component (F) is preferably 250 g/eq. to 1200 g/eq., and more preferably 300 g/eq. to 1100 g/eq. The free radical polymerizable unsaturated group equivalent represents the mass of the component (F) per 1 equivalent of the free radical polymerizable unsaturated group. When the free radical polymerizable unsaturated group equivalent of the component (F) is within the above range, the effect of the present invention can be significantly obtained.

The Mw of the component (F) is preferably 1000 to 40000, more preferably 1500 to 35000. The Mw of the component (F) can be measured as a value in terms of polystyrene by a GPC method.

When the component (F) is contained, from the viewpoint of being able to provide a resin composition having a cured product exhibiting better dielectric properties and a lower thermal expansion coefficient in combination with the component (C1), the content of the component (F) in the resin composition is preferably 2% by mass or more, more preferably 4% by mass or more, further preferably 5% by mass or more, 6% by mass or more, or 8% by mass or more, based on 100% by mass of the resin component in the resin composition, and the upper limit thereof is preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 15% by mass or less.

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

As the organic filler, an organic filler containing a rubber component can be widely used. As the rubber component contained in the organic filler, for example, organic silicon-based elastomers such as polydimethylsiloxane; olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychloroprene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, ethylene-propylene-butylene terpolymer; thermoplastic elastomers such as acrylic thermoplastic elastomers such as polypropyl (meth)acrylate, polybutyl (meth)acrylate, polycyclohexyl (meth)acrylate, polyoctyl (meth)acrylate, etc. can be cited. The rubber component may further contain an organic silicon rubber such as polyorganosiloxane rubber. The rubber component contained in the rubber particles may have a Tg of, for example, 0°C or less, preferably -10°C or less, more preferably -20°C or less, and even more preferably -30°C or less.

In one embodiment, the organic filler material is a core-shell type rubber particle formed by "a core particle containing the rubber component listed above" and "a shell formed by graft copolymerizing a monomer component copolymerizable with the rubber component contained in the core particle". The core-shell type here does not necessarily refer to only those in which the core particle and the shell can be clearly distinguished, but also includes those in which the boundary between the core particle and the shell is unclear, and the core particle may not be completely covered by the shell.

Specific examples of the organic filler containing a rubber component include: "CHT" manufactured by Cheil Industries; "B602" manufactured by UMGABS; "PARALOID EXL-2602", "PARALOID EXL-2603", "PARALOID EXL-2655", "PARALOID EXL-2311", "PARALOID-EXL2313", "PARALOID EXL-2315", "PARALOID KM-330", "PARALOID KM-336P", "PARALOID KCZ-201" manufactured by Dow; "Metablen C-223A", "Metablen E-901", "Metablen S-2001", "Metablen W-450A", "Metablen "KANE ACE M-511", "KANE ACE M-600", "KANE ACE M-400", "KANE ACE M-580", "KANE ACE MR-01" manufactured by KANEKA, "STAPHYLOID AC3355", "STAPHYLOID AC3816", "STAPHYLOID AC3832", "STAPHYLOID AC4030", "STAPHYLOID AC3364" manufactured by AICA Industries, etc. These are core-shell type rubber particles.

When the component (G) is contained, the content of the component (G) in the resin composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and further preferably 2% by mass or more, with the resin component in the resin composition being 100% by mass. The upper limit of the content 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.

<(H) Hardening accelerator> The resin composition of the present invention may contain a hardening accelerator as the (H) component.

Examples of the component (H) include phosphorus-based hardening accelerators, amine-based hardening accelerators, imidazole-based hardening accelerators, guanidine-based hardening accelerators, metal-based hardening accelerators, and peroxide-based hardening accelerators. The hardening accelerators may be used alone or in combination of two or more.

When the resin composition of the present invention contains component (H), the content of component (H) in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more, with the upper limit being preferably 3% by mass or less, more preferably 2.5% by mass or less or 2% by mass or less, based on the resin component in the resin composition being 100% by mass.

<Optional additives> The resin composition of the present invention may further contain any additives. Examples of such additives include: free radical polymerization initiators such as peroxide-based free radical polymerization initiators and azo-based free radical polymerization initiators; thermoplastic resins such as phenoxy resins, polyvinyl alcohol acetal resins, polysulfide resins, polyethersulfide resins, polyetheretherketone resins, and polyester resins; organic metal compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, Colorants such as crystal violet, titanium oxide, and carbon black; inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as organic silicon leveling agents and acrylic polymer leveling agents; thickeners such as Benton (bentonite) and montmorillonite; defoaming agents such as organic silicon defoaming agents, acrylic defoaming agents, fluorine defoaming agents, and vinyl resin defoaming agents; UV absorbers such as benzotriazole UV absorbers; adhesives such as urea silane adhesion improvers; adhesion enhancers such as triazole-based adhesion enhancers, tetrazole-based adhesion enhancers, and triazine-based adhesion enhancers; antioxidants such as hindered phenol-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and organic silicon-based surfactants; phosphorus-based flame retardants (such as phosphate compounds, phosphazene compounds, phosphinic acid compounds, and red phosphorus), nitrogen-based flame retardants (such as melamine sulfate), Flame retardants such as halogen flame retardants, inorganic flame retardants (such as antimony trioxide); dispersants such as phosphate dispersants, polyoxyalkylene dispersants, acetylene dispersants, organic silicon dispersants, anionic dispersants, cationic dispersants; borate stabilizers, titanium stabilizers, aluminum stabilizers, zirconate stabilizers, isocyanate stabilizers, carboxylic acid stabilizers, carboxylic anhydride stabilizers, etc. The content of the additives can be determined according to the properties required by 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 solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol ethyl ether acetate. Ether ester solvents such as acetate), γ-butyrolactone, and methyl methoxypropionate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene, etc. Organic solvents may be used alone or in combination of two or more.

The resin composition of the present invention can be produced, for example, by the following method: adding component (A), component (B), component (C1), and, if necessary, component (C2), component (D), component (E), component (F), component (G), component (H), and other additives or organic solvents to any preparation container in any order and/or in part or in whole at the same time and mixing. In addition, during the process of adding and mixing the components, the temperature can be appropriately set, and heating and/or cooling can be performed temporarily or all the time. In addition, during or after the process of adding and mixing, the resin composition can be stirred or shaken, for example, using a stirring device such as a mixer or a shaking device, so as to be uniformly dispersed. Alternatively, defoaming may be performed under low pressure conditions such as vacuum while stirring or vibrating.

As described above, the resin composition of the present invention containing the component (C1) in combination with the components (A) and (B) can provide a cured product having both good dielectric properties and a low thermal expansion coefficient. Furthermore, the resin composition of the present invention containing the component (C1) in combination with the components (A) and (B) can provide a cured product having good adhesion to the coated conductor layer and good heat resistance.

In one embodiment, the cured product of the resin composition of the present invention exhibits a low dielectric tangent (Df). For example, as described in the "Measurement of Dielectric Tangent" column described later, when measured at 5.8 GHz and 23°C, the dielectric tangent (Df) of the cured product of the resin composition of the present invention can be preferably 0.0035 or less, 0.0034 or less, 0.0032 or less, 0.003 or less, 0.0028 or less, or 0.0026 or less.

In one embodiment, the cured product of the resin composition of the present invention has a low thermal expansion coefficient. For example, as described in the column <Measurement of glass transition temperature (Tg) and average linear thermal expansion coefficient (CTE)> described later, when measured under the measurement condition of a temperature increase rate of 5°C/min from 25°C to 250°C, the average linear thermal expansion coefficient (CTE [25-150°C]) in the range of 25°C to 150°C can be preferably 25 ppm/°C or less, 24 ppm/°C or less, 23 ppm/°C or less, or 22 ppm/°C or less. In addition, the average linear thermal expansion coefficient (CTE [150-240°C]) in the range of 150°C to 240°C can be preferably 70 ppm/°C or less, 65 ppm/°C or less, 60 ppm/°C or less, or 55 ppm/°C or less.

In one embodiment, the cured product of the resin composition of the present invention exhibits a characteristic of high adhesion to the coated conductor layer. For example, as described in the <Measurement of peel strength of coated conductor layer> column described later, when the coated conductor layer is formed, the adhesion strength to the coated conductor layer is preferably 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.

As described above, the resin composition of the present invention can provide a cured product that exhibits both good dielectric properties and a low thermal expansion coefficient. Therefore, the resin composition of the present invention can be used as a resin composition for forming an insulating layer of a printed wiring board (resin composition for insulating layer of a printed wiring board), and more preferably as a resin composition for forming an interlayer insulating layer of a printed wiring board (resin composition for interlayer insulating layer of a printed wiring board). The resin composition of the present invention can also be used in the case where the printed wiring board is a component-built-in wiring board. The resin composition of the present invention can also be used as a resin composition for forming an insulating layer of a redistribution substrate for semiconductor packaging (resin composition for insulating layer of redistribution substrate). It should be noted that in the present invention, a printed wiring board and a redistribution substrate are also collectively referred to as a "circuit substrate", and therefore, the resin composition of the present invention can be used as an insulating layer of a circuit substrate.

The resin composition of the present invention can be widely used in resin sheets, prepreg and other sheet-like lamination materials, solder resists, bottom filling materials, chip bonding materials, hole filling resins, sealing resins, component embedding resins and other uses requiring resin compositions.

[Sheet-like laminated material (resin sheet, prepreg)] The resin composition of the present invention can be used directly or in the form of a sheet-like laminated material containing the resin composition.

As the sheet-like lamination material, the resin sheets and prepregs shown below are preferred.

In one embodiment, the resin sheet is characterized in that it includes a support body and a layer of a resin composition disposed on the support body (hereinafter, referred to as "resin composition layer"), and the resin composition layer is formed of the resin composition of the present invention.

The thickness of the resin composition layer has different preferred values depending on the application and can be appropriately determined according to the application. For example, from the perspective of thinning a printed wiring board or a semiconductor package, the thickness of the resin composition layer is preferably 100 μm or less, 80 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, and is usually 1 μm or more, 5 μm or more, etc.

As the support, for example, a thermoplastic resin film, a metal foil, and a release paper can be cited, preferably a thermoplastic resin film and a metal foil. Therefore, in a preferred embodiment, the support is a thermoplastic resin film or a metal foil.

When a thermoplastic resin film is used as a support, the thermoplastic resin includes polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylic polymers such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

When a metal foil is used as a support, examples of the metal foil include copper foil and aluminum foil, and copper foil is preferred. The copper foil may be a foil made of copper alone or an alloy of copper and other metals (such as tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

The surface of the support body that is bonded to the resin composition layer may be subjected to matte treatment, corona treatment, or antistatic treatment. In addition, a support body with a release layer having a release layer on the surface that is bonded to the resin composition layer may be used. Examples of release agents used in the release layer of the support body with a release layer include at least one release agent selected from alkyd resins, polyolefin resins, polyurethane resins, and organic silicone resins. The support body with a release layer can use commercially available products, for example, PET film having a release layer with an alkyd resin release agent as the main component, such as "SK-1", "AL-5", and "AL-7" manufactured by Lintec, "Lumirror T60" manufactured by Toray, "Purex" manufactured by Teijin, and "Unipeel" manufactured by Unitika.

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

When a metal foil is used as a support, a metal foil with a support substrate in which a peelable support substrate is bonded to a thin metal foil can be used. In one embodiment, the metal foil with a support substrate includes a support substrate, a peeling layer provided on the support substrate, and a metal foil provided on the peeling layer. When the metal foil with a support substrate is used as a 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, and 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, as for the peeling layer, as long as the metal foil can be peeled off from the supporting substrate, there is no particular limitation, and examples thereof include alloy layers of elements selected from Cr, Ni, Co, Fe, Mo, Ti, W, and P; organic films, etc.

In the 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, more preferably in the range of 10 μm to 100 μm. In addition, 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 arbitrary layer as required. As the arbitrary layer, for example, a protective film provided on the surface of the resin composition layer that is not bonded to the support body (i.e., the surface on the opposite side of the support body) can be cited. The thickness of the protective film is not particularly limited, and may be, for example, 1 μm to 40 μm. By stacking the protective film, it is possible to prevent dirt from being attached to the surface of the resin composition layer or causing damage.

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

As the organic solvent, the same organic solvents as those explained as the components of the resin composition can be cited. The organic solvent may be used alone or in combination of two or more.

Drying can be carried out by known methods such as heating and hot air blowing. The drying conditions are not particularly limited, and the drying is carried out in a manner such that the content of the organic solvent in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. The drying conditions also vary depending on the boiling point of the organic solvent in the resin composition or resin varnish. For example, when a resin composition or resin varnish containing 30% by mass to 60% by mass of an organic solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 minutes to 10 minutes.

The resin sheet can be stored in a roll shape. 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 the resin composition of the present invention into a sheet-like fiber substrate.

The sheet-like fiber substrate used for the prepreg is not particularly limited, and glass cloth, aromatic polyamide non-woven fabric, liquid crystal polymer non-woven fabric, etc., which are commonly used materials for prepreg substrates, can be used. From the perspective of thinning the printed wiring board or semiconductor chip packaging, the thickness of the sheet-like fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, further preferably 30 μm or less, and particularly preferably 20 μm or less. The lower limit of the thickness of the sheet-like fiber substrate is not particularly limited. It is usually 10 μm or more.

The prepreg can be produced by a known method such as a hot melt method or a solvent method.

The thickness of the prepreg may be in the same range as that of the resin composition layer in the above-mentioned resin sheet.

The sheet-like laminating material of the present invention can be used to form an insulating layer of a printed wiring board (for an insulating layer of a printed wiring board), and can be more preferably used to form an interlayer insulating layer of a printed wiring board (for an interlayer insulating layer of a printed wiring board). The sheet-like laminating material of the present invention can also be used to form an insulating layer of a redistribution substrate of a semiconductor package (for an insulating layer of a redistribution substrate). That is, the sheet-like laminating material of the present invention can be used to form an insulating layer of a circuit substrate.

[Circuit board] The resin composition of the present invention can be used to form an insulating layer of a circuit board. The present invention also provides the circuit board, i.e., a circuit board including an insulating layer formed by a cured product of the resin composition of the present invention.

<Printed wiring board> In one embodiment, the circuit substrate of the present invention is a printed wiring board.

For example, a printed wiring board can be manufactured using the above-mentioned resin sheet by a method comprising the following steps (I) and (II): (I) a step of stacking the resin sheet layer on the inner substrate in such a manner that the resin composition layer of the resin sheet is bonded to the inner substrate; (II) a step of hardening (e.g., thermally hardening) the resin composition layer to form an insulating layer.

The "inner layer substrate" used in step (I) is a component that becomes the substrate of the printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, and the like. In addition, the substrate may have a conductive layer on one or both sides thereof, and the conductive layer may be patterned. An inner layer substrate having a conductive layer (circuit) formed on one or both sides of the substrate is sometimes referred to as an "inner layer circuit substrate." In addition, when manufacturing a printed wiring board, an intermediate product to be further formed with an insulating layer and/or a conductive layer is also included in the "inner layer substrate" described in the present invention. In the case where the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components can be used.

The inner substrate and the resin sheet can be stacked, for example, by heating and pressing the resin sheet onto the inner substrate from the support body side. As a member for heating and pressing the resin sheet onto the inner substrate (hereinafter also referred to as a "heating and pressing member"), for example, a heated metal plate (SUS end plate, etc.) or a metal roller (SUS roller) can be cited. It should be noted that the heating and pressing member can be directly pressed onto the resin sheet, or it can be pressed through an elastic material such as heat-resistant rubber so that the resin sheet fully follows the surface unevenness of the inner substrate.

The lamination of the inner substrate and the resin sheet can be performed by vacuum lamination. In the vacuum lamination, the heating and pressing temperature is preferably 60°C to 160°C, more preferably 80°C to 140°C, the heating and pressing pressure is preferably 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the heating and pressing time is preferably 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination can be preferably performed under reduced pressure conditions with a pressure of less than 26.7hPa.

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

After lamination, the laminated resin sheets can be smoothed under normal pressure (atmospheric pressure), for example, by pressing the heat-pressing member from the support body side. The pressing conditions for the smoothing treatment can be the same as the heat-pressing conditions for the lamination described above. The smoothing treatment can be performed using a commercially available lamination press. It should be noted that the lamination and smoothing treatment can be performed continuously using the commercially available vacuum lamination press described above.

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 conductive 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. Furthermore, the conductive layer may be formed using the metal foil.

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

For example, the heat curing conditions of the resin composition layer vary depending on the type of the resin composition, but in one embodiment, the curing temperature is preferably 140° C. to 250° C., more preferably 150° C. to 240° C., and further preferably 180° C. to 230° C. The curing time is preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and further preferably 15 minutes to 120 minutes.

Before the resin composition layer is heat-hardened, the resin composition layer may be preheated at a temperature lower than the hardening temperature. For example, before the resin composition layer is heat-hardened, the resin composition layer may be preheated at a temperature of 50°C to 140°C, preferably 60°C to 135°C, more preferably 70°C to 130°C for more than 5 minutes, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and further preferably 15 minutes to 100 minutes.

When manufacturing a printed wiring board, (III) a step of opening holes in the insulating layer, (IV) a step of roughening the insulating layer, and (V) a step of forming a conductive layer may be further performed. These steps (III) to (V) may be performed by various methods known to those skilled in the art in the art to which the invention belongs for use in the manufacture of printed wiring boards. It should be noted that when the support is removed after step (II), the removal of the support may be performed between step (II) and step (III), between step (III) and step (IV), or between step (IV) and step (V). In addition, as needed, the formation of the insulating layer and the conductive layer in steps (I) to (V) can be repeated to form a multi-layer wiring board.

In other embodiments, the printed wiring board of the present invention can be manufactured using the above-mentioned prepreg. The manufacturing method is basically the same as that of the case of using a resin sheet.

Step (III) is a step of opening holes in the insulating layer, thereby forming holes such as through holes and vias in the insulating layer. Step (III) can be performed, for example, using a drill, laser, plasma, etc., depending on the composition of the resin composition used in forming the insulating layer. The size and shape of the hole can be appropriately determined according to the design of the printed wiring board.

Step (IV) is a step of roughening the insulating layer. Usually, in this step (IV), stain removal (decontamination) is also performed. The order and conditions of the roughening treatment are not particularly limited, and the known order and conditions commonly used when forming the insulating layer of the printed wiring board can be adopted. For example, the insulating layer can be roughened by sequentially performing swelling treatment using a swelling liquid, roughening treatment using an oxidizing agent, and neutralization treatment using a neutralizing liquid.

The swelling liquid used in the roughening treatment is not particularly limited, and an alkaline solution, a surfactant solution, etc. can be cited. An alkaline solution is preferred, and a sodium hydroxide solution and a potassium hydroxide solution are more preferred as the alkaline solution. Commercially available swelling liquids include, for example, "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan Co., Ltd. The swelling treatment using the swelling liquid is not particularly limited, and can be performed, for example, by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 minute to 20 minutes. From the viewpoint of controlling the swelling of the resin of the insulating layer to an appropriate level, it is preferred 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, and an alkaline permanganate solution prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide can be cited. The roughening treatment using an oxidizing agent such as an alkaline permanganate solution is preferably performed by immersing the insulating layer in the oxidizing agent solution heated to 60°C to 100°C for 10 minutes to 30 minutes. In addition, the concentration of the permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. As commercially available oxidizing agents, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Atotech Japan Co., Ltd. can be cited.

The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and commercially available products include, for example, "Reduction Solution Securiganth P" manufactured by Atotech Japan Co., Ltd.

The treatment with the neutralizing solution can be performed by immersing the surface roughened with the oxidizing agent in the neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the perspective of operability, it is preferred to immerse the surface roughened with the oxidizing agent in the neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

Step (V) is a step of forming a conductive layer, and the conductive layer is formed on the insulating layer. The conductive material used for the conductive layer is not particularly limited. In a preferred embodiment, the conductive layer contains one or more metals selected from gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The conductive layer can be a single metal layer or an alloy layer. As an alloy layer, for example, a layer formed of an alloy of two or more metals selected from the above metals (for example, nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy) can be cited. Among them, from the viewpoints of versatility of conductor layer formation, cost, ease of pattern formation, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel-chromium alloy, copper-nickel alloy, or 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 nickel-chromium alloy is more preferred, and a single metal layer of copper is more preferred.

The conductive layer may be a single-layer structure or a multi-layer structure in which two or more single metal layers or alloy layers formed of different types of metals or alloys are stacked. In the case where the conductive layer is 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 nickel-chromium alloy.

The thickness of the conductor layer varies depending on the desired design of the printed wiring board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

In one embodiment, the conductive layer can be formed by plating. From the viewpoint of facilitating the formation of fine wiring, it is preferably formed by a semi-additive method. An example of forming a conductive layer by a semi-additive method is shown below.

First, a coating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed coating seed layer to expose a portion of the coating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed coating seed layer by electrolytic plating, the mask pattern is removed. Then, the unnecessary coating seed layer is removed by etching, etc., so that a conductive layer having a desired wiring pattern can be formed.

In other embodiments, the conductive layer may be formed using a metal foil. When the conductive layer is formed using a metal foil, it is preferred to perform step (V) between step (I) and step (II). For example, after step (I), the support is removed and the metal foil is laminated on the surface of the exposed resin composition layer. The lamination of the resin composition layer and the metal foil may be performed by vacuum lamination. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form the insulating layer. Then, by utilizing the metal foil on the insulating layer, a conductive layer having a desired wiring pattern can be formed by a conventionally known technique such as a modified semi-additive process.

The metal foil can be produced by a known method such as electrolysis or rolling. Commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Nippon Mining & Metals Co., Ltd., and 3EC-III foil and TP-III foil manufactured by Mitsui Metals & Mining Co., Ltd.

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

<Rewiring substrate for semiconductor package> In one embodiment, the circuit substrate of the present invention is a rewiring substrate (rewiring layer) for a semiconductor package. The following is an explanation in conjunction with a method for manufacturing a semiconductor package.

The semiconductor package includes an insulating layer formed of a cured product of the resin composition of the present invention as an insulating layer of a redistribution board. In addition, the semiconductor package may also include a sealing layer formed of a cured product of the resin composition of the present invention.

The semiconductor package can be manufactured, for example, using the resin composition or resin sheet of the present invention by a method comprising the following steps (1) to (6). The resin composition or resin sheet of the present invention can be used to form the redistribution formation layer (for forming the insulating layer of the redistribution substrate) of step (5) or the sealing layer of step (3). The following is an example of using a resin composition or a resin sheet to form a redistribution forming layer or a sealing layer, but the technology for forming a redistribution forming layer or a sealing layer of a semiconductor package is well known. If a person has general knowledge in the technical field to which the invention belongs, the resin composition or resin sheet of the present invention can be used to manufacture a semiconductor package according to the known technology; (1) a step of stacking a temporary fixing film on a substrate, (2) a step of temporarily fixing a semiconductor chip on the temporary fixing film, (3) a step of forming a sealing layer on the semiconductor chip, (4) a step of peeling off the substrate and the temporary fixing film from the semiconductor chip, (5) A step of forming a redistribution layer as an insulating layer on the surface of the semiconductor chip from which the substrate and the temporary fixing film are peeled off, and (6) A step of forming a redistribution layer as a conductive layer on the redistribution layer.

-Step (1)- The material used in the substrate is not particularly limited. Examples of the substrate include: semiconductor wafers such as silicon wafers; glass wafers; glass substrates; metal substrates such as copper, titanium, stainless steel, and cold-rolled steel sheets (SPCC); substrates formed by impregnating glass fibers with epoxy resins and heat-curing treatment (e.g., FR-4 substrates); substrates formed of dimaleimide triazine resins (BT resins), etc.

The temporary fixing film is not particularly limited in material as long as it can be peeled off from the semiconductor chip in step (4) and can temporarily fix the semiconductor chip. The temporary fixing film can be a commercial product. Examples of commercial products include REVALPHA manufactured by Nitto Denko Corporation.

-Step (2)- The temporary fixation of the semiconductor chip can be performed using a known device such as a flip chip bonder or a die bonder. The layout and number of semiconductor chips can be appropriately set according to the shape and size of the temporary fixation film, the target production number of semiconductor packages, etc. For example, they can be arranged in a matrix of multiple rows and columns for temporary fixation.

-Step (3)- Layer the resin composition of the resin sheet of the present invention on the semiconductor chip, or apply the resin composition of the present invention on the semiconductor chip and harden it (for example, thermally harden it) to form a sealing layer.

For example, the semiconductor chip and the resin sheet can be stacked by heating and pressing the resin sheet onto the semiconductor chip from the support body side after removing the protective film of the resin sheet. As a component for heating and pressing the resin sheet onto the semiconductor chip (hereinafter also referred to as a "heating and pressing component"), for example, a heated metal plate (SUS end plate, etc.) or a metal roller (SUS roller) can be cited. It should be noted that it is preferred that the heating and pressing component is not directly pressed onto the resin sheet, but is pressed via an elastic material such as heat-resistant rubber so that the resin sheet can fully follow the surface unevenness of the semiconductor chip. The lamination of the semiconductor chip and the resin sheet can also be carried out by vacuum lamination. The lamination conditions are the same as those described in the method for producing a printed wiring board, and the preferred range is also the same.

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

The support of the resin sheet can be peeled off after the resin sheet is stacked on the semiconductor chip and thermally hardened, or the support can be peeled off before the resin sheet is stacked on the semiconductor chip.

When the resin composition of the present invention is applied to form a sealant layer, the application conditions are the same as those for forming the resin composition layer described with respect to the resin sheet of the present invention, and the preferred range is also the same.

-Step (4)- The method of peeling off the substrate and the temporary fixing film can be appropriately changed according to the material of the temporary fixing film, and examples thereof include a method of peeling off the temporary fixing film by heating and foaming (or expanding) the temporary fixing film, and a method of peeling off the temporary fixing film by irradiating ultraviolet rays from the substrate side to reduce the adhesion of the temporary fixing film.

In the method of peeling by heating and foaming (or expanding) the temporary fixing film, the heating condition is usually 100 to 250°C for 1 to 90 seconds or 5 to 15 minutes. In the method of peeling by irradiating ultraviolet rays from the substrate side to reduce the adhesion of the temporary fixing film, the irradiation amount of ultraviolet rays is usually 10 mJ/ ^cm2 to 1000 mJ/ ^cm2 .

-Step (5)- The resin composition and resin sheet of the present invention are used to form a redistribution formation layer (insulating layer of the redistribution substrate).

After the redistribution formation layer is formed, a through hole may be formed in the redistribution formation layer in order to connect the semiconductor chip to the conductor layer described later. The through hole may be formed by a known method depending on the material of the redistribution formation layer.

-Step (6)- The formation of the conductor layer on the redistribution formation layer can be carried out in the same manner as step (V) described in the method for manufacturing a printed wiring board. It should be noted that steps (5) and (6) can be repeated to alternately overlap (stack) the conductor layer (redistribution layer) and the redistribution formation layer (insulation layer).

When manufacturing semiconductor packages, further steps may be performed: (7) forming a solder resist layer on a conductor layer (rewiring layer), (8) forming bumps, and (9) cutting a plurality of semiconductor packages into individual semiconductor packages for singulation. These steps may be performed according to various methods known to those skilled in the art in the art to which the invention belongs in the manufacture of semiconductor packages.

By using the resin composition and resin sheet of the present invention that can provide a hardened material that exhibits both good dielectric properties and a low thermal expansion coefficient to form a redistribution forming layer (insulating layer), a semiconductor package with extremely low transmission loss can be achieved without worrying about cracks and circuit deformation, regardless of whether the semiconductor package is a fan-in package or a fan-out package. In one embodiment, the semiconductor package of the present invention is a fan-out package. The resin composition and resin sheet of the present invention are applicable to both fan-out panel-level packaging (FOPLP) and fan-out wafer-level packaging (FOWLP). In one embodiment, the semiconductor package of the present invention is a fan-out panel level package (FOPLP) or a fan-out wafer level package (FOWLP).

[Semiconductor device] The semiconductor device of the present invention includes a layer formed of a cured product of the resin composition layer of the present invention. The semiconductor device of the present invention can be manufactured using the circuit substrate of the present invention.

As semiconductor devices, various semiconductor devices used in electrical products (e.g., computers, mobile phones, digital cameras, and televisions) and transportation vehicles (e.g., motorcycles, cars, trains, ships, and airplanes) can be cited .

The present invention is specifically described below by showing examples. However, the present invention is not limited to the following examples. It should be noted that, hereinafter, "parts" and "%" indicating quantity refer to "parts by mass" and "% by mass" respectively, unless otherwise expressly stated.

<Synthesis Example 1: Synthesis of maleimide compound A> (I) Synthesis of intermediate amine compound In a flask equipped with a thermometer, a condenser, a Dean-Stark trap and a stirrer, add 242.4 g (2.0 mol) of 2-ethylaniline, 242 g of xylene and 80 g of activated clay, and raise the temperature to 130°C while stirring, and keep it for 30 minutes. Then, add 272.0 g of DVB-810 (a mixture of divinylbenzene/ethylstyrene (divinylbenzene/ethylstyrene = 81/19 (mol)%), manufactured by Nippon Steel Chemical Materials Co., Ltd.) dropwise over 2 hours, and react for 1 hour in this state. Then, raise the temperature to 190°C over 6 hours and keep it for 10 hours. After the reaction, the mixture was cooled to 100°C with air, diluted with 300 g of toluene, the activated clay was removed by filtration, and low molecular weight substances such as the solvent and unreacted products were removed by distillation under reduced pressure to obtain an intermediate amine compound. The amine equivalent of the intermediate amine compound is 214 g/equivalent.

(II) Maleimidation In a 2L flask equipped with a thermometer, a condenser, a Dean-Stark trap and a stirrer, 117.7 g (1.2 mol) of maleic anhydride and 700 g of toluene were added and stirred at room temperature. Then, a mixed solution of 214 g (1 equivalent) of the intermediate amine compound (c-1) and 175 g of DMF was added dropwise over 1 hour, and then reacted for 2 hours. 37.1 g of p-toluenesulfonic acid monohydrate was added to the reaction solution, and the mixture was heated to 115°C. After cooling and separating the azeotropic water and toluene under reflux, only toluene was returned to the system, and a dehydration reaction was carried out for 5 hours. After air cooling to room temperature, the mixture was neutralized with 49% NaOH. Then, toluene and water were removed by distillation under reduced pressure at 60°C, and 600 g of MEK (methyl ethyl ketone) was added to the DMF solution remaining in the flask. After the solution was heated to 60°C, 200 g of ion exchange water was used for three separation treatments to remove the salt in the solution. Sodium sulfate was then added for drying, and the reaction product obtained by reduced pressure concentration was vacuum dried at 80°C to obtain maleimide compound A. The obtained maleimide compound A has a structural unit in which ^R1 in the above formula (1) is an ethyl group, one of ^R2 and ^R3 is a hydrogen atom and the other is a methyl group, one of ^R4 and ^R5 is a hydrogen atom and the other is a methyl group, m1=1, m1+m2≤3, and m3=0 (here, with respect to ^X1 , in formula (2), one of ^R6 and ^R7 is a hydrogen atom and the other is a methyl group, ^RS2 is an ethyl group, and m4=1), and has a number average molecular weight (Mn) of about 580 and a weight average molecular weight (Mw) of about 720.

<Synthesis Example 2: Synthesis of Maleimide Compound B> According to Synthesis Example 1 of Japan Invention Publication No. 2020-500211, a MEK solution of maleimide compound B represented by the following formula (M) was prepared (non-volatile component 62% by mass). The Mw/Mn of maleimide compound B is 1.81, and t'' in formula (M) is 1.47.

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<Synthesis Example 3: Synthesis of Active Ester Resin A> In a flask equipped with a thermometer, a dropping funnel, a condenser, a separatory tube, and a stirrer, 203.0 g of isophthalic acid dichloride (the molar number of acyl chloride group: 2.0 mol) and 1400 g of toluene were added, and the system was replaced with nitrogen under reduced pressure to dissolve. Then, 113.9 g (0.67 mol) of o-phenylphenol and 240 g of dihydroxynaphthalene having a benzyl group (the molar number of phenolic hydroxyl group: 1.33 mol) were added, and the system was replaced with nitrogen under reduced pressure to dissolve. Then, 0.70 g of tetrabutylammonium bromide is dissolved, and while nitrogen is purged, the system is controlled at below 60°C, and 400 g of a 20% aqueous sodium hydroxide solution is added dropwise over 3 hours. Then, stirring is continued for 1.0 hour under this condition. After the reaction is completed, the liquid is allowed to stand and the aqueous layer is removed. Furthermore, water is added to the toluene layer in which the reactants are dissolved, and the mixture is stirred for 15 minutes, and the liquid is allowed to stand and the aqueous layer is removed. This operation is repeated until the pH value of the aqueous layer reaches 7. Then, the water is removed by dehydration by decantation to obtain an active ester resin A (an active ester resin containing a naphthalene structure) in a toluene solution state with a non-volatile component of 65% by mass. The active ester equivalent of the obtained active ester resin A is 238g/eq.

<Synthesis Example 4: Synthesis of Vinyl Resin A> According to Example 1 of International Publication No. 2017/115813, 3.0 mol (390.6 g) of divinylbenzene, 1.8 mol (229.4 g) of ethylvinylbenzene, 10.2 mol (1066.3 g) of styrene, and 15.0 mol (1532.0 g) of n-propyl acetate were added to a 5.0 L reactor, and 600 mmol of diethyl ether complex of boron trifluoride was added at 70°C, and the reaction was carried out for 4 hours. After the polymerization solution was stopped with an aqueous sodium bicarbonate solution, the oil layer was washed 3 times with pure water, and the polymer was recovered by decompression devolatileation at 60°C. The obtained substance was weighed, and it was confirmed that 896.7 g of vinyl resin A was obtained. The Mw of vinyl resin A is 41300.

[Examples 1 to 9, Comparative Examples 1 to 4] (1) Preparation of resin composition The components were weighed according to the formulation described in Table 1, and then 10 parts of MEK and 10 parts of cyclohexanone were mixed and uniformly dispersed using a high-speed rotary mixer to obtain a resin composition (resin varnish).

(2) Production of resin sheet As a support, a polyethylene terephthalate film ("AL5" manufactured by Lintec Corporation, thickness 38μm) having a release layer was prepared. The obtained resin varnish was evenly applied to the release layer of the support so that the thickness of the resin composition layer after drying was 40μm. Then, the resin composition was dried at 80℃ to 100℃ (average 90℃) for 4 minutes to obtain a resin sheet having a layered structure of resin composition layer/support.

<Determination of dielectric tangent> The resin sheets obtained in the examples and comparative examples were heated in an oven at 190°C for 90 minutes to cure the resin composition layer. Then, the support was peeled off to obtain a cured product of the resin composition layer. The cured product was cut into pieces with a length of 80 mm and a width of 2 mm as a cured product for evaluation.

For each evaluation cured product, the dielectric tangent value (Df value) was measured by the cavity resonance perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23° C. using “HP8362B” manufactured by Agilent Technologies. The measurement was performed on two test pieces, and the average value was calculated.

<Measurement of glass transition temperature (Tg) and mean linear thermal expansion coefficient (CTE)> The resin sheets obtained in the examples and comparative examples were heated in an oven at 190°C for 90 minutes to harden the resin composition layer. Then, the hardened resin composition layer was obtained by peeling it from the support. The hardened material was cut into pieces with a length of 20 mm and a width of 6 mm to prepare hardened materials for evaluation.

For each evaluation cured product, the glass transition temperature (Tg) was measured under the measurement condition of a temperature increase rate of 5°C/min from 25°C to 250°C using a TMA apparatus manufactured by Rigaku Corporation. In addition, the average linear thermal expansion coefficient in the range from 25°C to 150°C (CTE [25-150°C]; ppm/°C) and the average linear thermal expansion coefficient in the range from 150°C to 240°C (CTE [150-240°C]; ppm/°C) were measured. The same test piece was measured twice, and the second value was recorded.

<Measurement of the peel strength of the coated conductor layer> (1) Preparation of the inner layer substrate The copper surface of a glass cloth-based epoxy double-sided copper-clad laminate (copper foil thickness 18μm, substrate thickness 0.4mm, "R1515A" manufactured by Panasonic) with an inner layer circuit formed on both sides was etched to 1μm using a micro-etchant ("CZ8101" manufactured by MEC) to roughen the copper surface.

(2) Lamination of resin sheets Using a batch vacuum pressure laminating press (Nikko-Materials, two-stage stacking laminating press "CVP700"), the resin sheets obtained in the examples and comparative examples were laminated on both sides of the inner substrate in such a way that the resin composition layer was in contact with the inner substrate. Lamination was performed by reducing the pressure for 30 seconds to adjust the air pressure to below 13 hPa, and then pressing at 120°C and a pressure of 0.74 MPa for 30 seconds. Then, smoothing was performed by hot pressing at 100°C and a pressure of 0.5 MPa for 60 seconds.

(3) Thermal curing of the resin composition layer Then, the inner substrate with the resin sheet stacked on it is placed in an oven at 130°C and heated for 30 minutes, and then transferred to an oven at 170°C and heated for 30 minutes to thermally cure the resin composition layer and form an insulating layer. Then, the support is peeled off to obtain a cured substrate A having a structure of insulating layer/inner substrate/insulating layer.

(4) Roughening treatment The hardened substrate A is subjected to a decontamination treatment as a roughening treatment. As a decontamination treatment, the following wet decontamination treatment was performed; (Wet decontamination treatment) The hardened substrate was immersed in a swelling solution ("Swelling Dip Securiganth P" manufactured by Atotech Japan, an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 5 minutes, then immersed in an oxidizing solution ("Concentrate Compact CP" manufactured by Atotech Japan, an aqueous solution of potassium permanganate with a concentration of about 6% and sodium hydroxide with a concentration of about 4%) at 80°C for 20 minutes, and finally immersed in a neutralizing solution ("Reduction Solution Securiganth P" manufactured by Atotech Japan, an aqueous solution of sulfuric acid) at 40°C for 5 minutes. Then, dried at 80°C for 15 minutes. The resulting substrate is called a roughened substrate.

(5) Formation of Conductive Layer A conductive layer was formed on the surface of the roughened substrate by a semi-additive method. That is, the roughened substrate 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. After annealing at 150°C for 30 minutes, an anti-etching layer was formed, and a pattern was formed by etching. Thereafter, copper sulfate electroplating was performed to form a conductive layer with a thickness of 25 μm, and annealing was performed at 190°C for 60 minutes. The resulting substrate is referred to as evaluation substrate A.

(6) Determination of the peel strength of the coated conductor layer The peel strength of the coated conductor layer was measured in accordance with Japanese Industrial Standards (JIS C 6481). Specifically, a cut of 10 mm in width and 100 mm in length was made on the conductor layer of the evaluation substrate A, one end of the cut was peeled off and clamped with a clamp, and 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. A tensile tester ("AC-50C-SL" manufactured by TSE) was used for the measurement.

<Evaluation of stain removability> For the above-mentioned hardened substrate A, a _CO2 laser processing machine (LK-2K212/2C) manufactured by Viamechanics was used to process the insulating layer under the conditions of a frequency of 2000 Hz, a pulse width of 3 microseconds, an output power of 0.95 W, and a shot number of 3 to form a through hole with a top diameter (diameter) of 50 μm in the surface of the insulating layer and a diameter of 50 μm in the bottom surface of the insulating layer, thereby obtaining an evaluation substrate B.

The insulating layer surface of the evaluation substrate B was immersed in a swelling solution ("Swelling Dip Securiganth P" manufactured by Atotech Japan) at 60°C for 10 minutes, then immersed in an oxidizing agent solution ("Concentrate Compact P" manufactured by Atotech Japan, an aqueous solution of potassium permanganate with a concentration of about 6% and sodium hydroxide with a concentration of about 4%) at 80°C for 25 minutes, and finally immersed in a neutralizing solution ("Reduction Solution Securiganth P" manufactured by Atotech Japan) at 40°C for 5 minutes.

The bottom of the through-hole was observed using a scanning electron microscope (SEM), and the maximum stain length from the wall surface at the bottom of the through-hole was measured based on the image obtained. Evaluation was performed according to the following criteria; ○: Maximum stain length is less than 5μm ×: Maximum stain length is more than 5μm.

The results of Examples 1 to 9 and Comparative Examples 1 to 4 are shown in Table 1.

It should be noted that the details of each component listed in Table 1 are as follows: (A) Epoxy resin ・ZX1059: Functional group equivalent weight 169 g/eq, manufactured by Nippon Steel Chemical Materials Co., Ltd., 1:1 mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin ・HP-4032-SS: Functional group equivalent weight 144 g/eq, manufactured by DIC Corporation, naphthalene type epoxy resin ・NC-3000L: Functional group equivalent weight 269 g/eq, manufactured by Nippon Kayaku Co., Ltd., biphenyl type epoxy resin (B) Active ester resin ・HPC-8150-62T: Functional group equivalent weight 223, toluene solution with a non-volatile content of 61.5 mass%, manufactured by DIC Corporation, active ester resin with a naphthalene structure ・HPC-8000L-65MT: Functional group equivalent weight 229 、Toluene/MEK solution with a non-volatile content of 65% by mass, manufactured by DIC Corporation, an active ester resin containing a dicyclopentadiene-type diphenol structure ・Active ester resin A: active ester resin synthesized in Synthesis Example 3 (C) Maleimide compound ・Maleimide compound A: maleimide compound synthesized in Synthesis Example 1 ・Maleimide compound B: maleimide compound synthesized in Synthesis Example 2 ・MIR-3000-70MT: toluene/MEK solution with a non-volatile content of 70% by mass, manufactured by Nippon Kayaku Co., Ltd., a maleimide compound having a structure represented by the following formula and containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group (wherein n is 1 to 100)・SLK-6895: Shin-Etsu Chemical Co., Ltd., maleimide compound containing an aliphatic skeleton ・SLK-1500: Shin-Etsu Chemical Co., Ltd., maleimide compound containing an aliphatic skeleton (D) Other hardeners ・LA-3018-50P: 1-methoxy-2-propanol solution with a functional group equivalent of 151 and a non-volatile content of 50% by mass, DIC Corporation, a phenolic hardener containing a triazine skeleton (E) Inorganic filler ・SO-C2: Spherical silica surface-treated with an amino-based silane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.5μm, specific surface area ^5.8m2 /g, manufactured by Yaduma Co., Ltd. (F) Resin containing an aromatic ring and a free radical polymerizable unsaturated group ・OPE-2St-1200: a toluene solution containing 65% by mass of non-volatile components, manufactured by Mitsubishi Gas Chemical Co., Ltd. Vinyl resin A: the vinyl resin synthesized in Synthesis Example 4 ・NE-V-1100-70T: a toluene solution containing 70% by mass of non-volatile components, manufactured by DIC Corporation (G) Organic filler ・EXL-2655: manufactured by Dow Chemical Company, an organic filler containing a rubber component (H) Curing accelerator ・1B2PZ: manufactured by Shikoku Chemical Industries, Ltd., an imidazole-based curing accelerator.

Claims (13)

A resin composition comprising (A) an epoxy resin, (B) an active ester resin and (C) a maleimide compound, wherein the component (C) comprises: (C1) a maleimide compound having a structural unit represented by the following formula (1), In formula (1), ^R1 independently represents an alkyl group, ^R2 , ^R3 , ^R4 and ^R5 independently represent a hydrogen atom or a methyl group, and one of ^R2 and ^R3 represents a hydrogen atom and the other represents a methyl group, one of ^R4 and ^R5 represents a hydrogen atom and the other represents a methyl group, ^RS1 independently represents a substituent, ^X1 represents a monovalent group represented by the following formula (2), m1 represents an integer of 1 to 3, m2 represents an integer greater than 0, wherein m1 and m2 satisfy m1+m2≤3, m3 represents an integer of 0 to 4, n represents an integer of 1 to 100, and * represents a bonding bond; In formula (2), ^R6 and ^R7 each independently represent a hydrogen atom or a methyl group, and one of ^R6 and ^R7 represents a hydrogen atom and the other represents a methyl group, R ^S2 each independently represents a substituent, m4 represents an integer of 0 to 5, and * represents a bond. The resin composition according to claim 1, wherein the mass ratio of the component (B) to the component (A), that is, the component (B)/the component (A) is 0.8 or more. The resin composition as described in claim 1, wherein the content of component (C) is 5% by mass or more when the resin component in the resin composition is 100% by mass. The resin composition according to claim 1, wherein the content of the component (C1) is 30% by mass or more, when the total amount of the component (C) is 100% by mass. The resin composition according to claim 1, further comprising (E) an inorganic filler. The resin composition according to claim 5, wherein the content of the component (E) is 40% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass. The resin composition as described in claim 1, further comprising: (F) a resin containing an aromatic ring and a free radical polymerizable unsaturated group. The resin composition as claimed in claim 1 is used as an insulating layer of a circuit substrate. A resin sheet comprises a support and a layer of the resin composition according to any one of claims 1 to 8 disposed on the support. The resin sheet as described in claim 9, wherein the support body is a thermoplastic resin film or a metal foil. A cured product, which is a cured product of the resin composition according to any one of claims 1 to 8. A circuit board comprising an insulating layer formed of a cured product of the resin composition according to any one of claims 1 to 8. A semiconductor device comprising a circuit substrate as described in claim 12.