JP7552124B2 - Resin composition - Google Patents

Description

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

A known manufacturing technique for printed wiring boards is a build-up method in which insulating layers and conductor layers are alternately stacked. In build-up manufacturing methods, the insulating layers are generally formed by curing a resin composition. An example of such a resin composition is the resin composition disclosed in Patent Document 1.

JP 2019-66792 A

The cured product formed by curing the resin composition can be used as an insulating layer for the printed wiring board of a semiconductor device. For this reason, it is required that the dielectric properties (dielectric constant and dielectric tangent) of the cured product be low. In addition, it is desirable that the insulating layer formed from this cured product has excellent peel strength between the conductor layer even if the roughness of the insulating layer surface is small, and also has a high glass transition temperature in order to have excellent heat resistance.

The present invention has been devised in view of the above problems, and aims to provide a resin composition capable of producing a cured product having low dielectric properties, excellent peel strength even with a small surface roughness, and a high glass transition temperature; a resin sheet having a resin composition layer containing the resin composition; a printed wiring board including an insulating layer formed of a cured product of the resin composition; and a semiconductor device including the printed wiring board.

As a result of intensive research into solving the above problems, the inventors discovered that the above problems could be solved by using (A) a polyether ether ketone compound having a maleimide group, (B) an epoxy resin, and (C) an active ester-based curing agent, and thus completed the present invention.

That is, the present invention includes the following.
[1] (A) a polyether ether ketone compound having a maleimide group,
A resin composition comprising: (B) an epoxy resin; and (C) an active ester-based curing agent.
[2] The resin composition according to [1], wherein the number average molecular weight of the (A) component is 10,000 or less.
[3] The resin composition according to [1] or [2], wherein the component (A) has a maleimide group at a terminal.
[4] The resin composition according to any one of [1] to [3], wherein the content of the component (A) is 5% by mass or more and 60% by mass or less, when the resin components in the resin composition are 100% by mass.
[5] The resin composition according to any one of [1] to [4], wherein the component (B) contains a naphthol-type epoxy resin.
[6] The resin composition according to any one of [1] to [5], wherein the component (C) is at least one selected from the group consisting of a dicyclopentadiene-type active ester curing agent and a naphthalene-type active ester curing agent containing a naphthalene structure.
[7] The resin composition according to any one of [1] to [6], further comprising (D) a resin having a polymerizable unsaturated group.
[8] The resin composition according to [7], wherein the component (D) is a resin containing a maleimide group and an aromatic ring.
[9] The resin composition according to any one of [1] to [8], further comprising (E) an inorganic filler.
[10] The resin composition according to [9], wherein the content of the (E) component is 40% by mass or more and 65% by mass or less, when the total amount of non-volatile components in the resin composition is 100% by mass.
[11] The resin composition according to any one of [1] to [10], which is for forming an insulating layer.
[12] The resin composition according to any one of [1] to [11], which is for forming an insulating layer for forming a conductor layer.
[13] A resin sheet comprising a support and a resin composition layer provided on the support, the resin composition layer comprising the resin composition according to any one of [1] to [12].
[14] A printed wiring board comprising an insulating layer formed from a cured product of the resin composition according to any one of [1] to [12].
[15] A semiconductor device comprising the printed wiring board according to [14].

The present invention provides a resin composition capable of producing a cured product having low dielectric properties, excellent peel strength even with a small surface roughness, and a high glass transition temperature; a resin sheet having a resin composition layer containing the resin composition; a printed wiring board including an insulating layer formed of a cured product of the resin composition; and a semiconductor device including the printed wiring board.

The present invention will be described below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be modified as desired without departing from the scope of the claims of the present invention and their equivalents.

[Resin composition]
The resin composition of the present invention includes (A) a polyether ether ketone compound having a maleimide group, (B) an epoxy resin, and (C) an active ester curing agent. With such a resin composition, it is possible to obtain a cured product having low dielectric properties, excellent peel strength even with a small surface roughness, and a high glass transition temperature.

The resin composition may further contain optional components such as (D) a resin containing a radically polymerizable unsaturated group, (E) an inorganic filler, (F) a curing agent, (G) a curing accelerator, and (H) other additives, as necessary.

<(A) Polyether ether ketone compound having maleimide group>
The resin composition contains a polyether ether ketone compound having a maleimide group as component (A). The maleimide group is represented by the following formula (A-1). By including component (A) in the resin composition, a cured product having a high glass transition temperature can be obtained.

Component (A) may be a compound having a maleimide group and a polyether ether ketone (PEEK) structure. Each molecule of component (A) preferably has one or more maleimide groups, more preferably two or more, preferably ten or less, more preferably five or less, and even more preferably three or less. From the viewpoint of obtaining a cured product with excellent dielectric properties, it is preferable for the maleimide group to have a maleimide group at the end of component (A), and more preferably to have a maleimide group at both ends.

式（Ａ－２）中、Ａｒ^１、Ａｒ^２、Ａｒ^３、Ａｒ^４、及びＡｒ^５は、それぞれ独立に２価の芳香族炭化水素基を表す。ｎは２～５０の整数を表す。＊は結合手を表す。 The component (A) has a polyether ether ketone structure. The polyether ether ketone structure preferably has a structure represented by the following formula (A-2).

In formula (A-2), Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , and Ar ⁵ each independently represent a divalent aromatic hydrocarbon group, n represents an integer of 2 to 50, and * represents a bond.

An aromatic hydrocarbon group refers to a hydrocarbon group that contains an aromatic ring. However, the aromatic hydrocarbon group does not necessarily have to be composed of only aromatic rings, and may contain a chain structure or an alicyclic hydrocarbon group as part of it, and the aromatic ring may be monocyclic, polycyclic, or heterocyclic.

Examples of divalent aromatic hydrocarbon groups include arylene groups, aralkylene groups, and groups having an arylene-alkylene-arylene structure.

As the arylene group, an arylene group having 6 to 30 carbon atoms is preferable, an arylene group having 6 to 20 carbon atoms is more preferable, and an arylene group having 6 to 10 carbon atoms is even more preferable. Examples of such arylene groups include a phenylene group, a naphthylene group, an anthracenylene group, and a biphenylene group.

As the aralkylene group, an aralkylene group having 7 to 30 carbon atoms is preferable, an aralkylene group having 7 to 20 carbon atoms is more preferable, and an aralkylene group having 7 to 15 carbon atoms is even more preferable. Examples of such an aralkylene group include a benzylene group and a group having a biphenylene-methylene structure.

式中、「＊」は結合手を表す。 The arylene in the group having an arylene-alkylene-arylene structure is the same as the arylene group described above. As the alkylene, an alkylene group having 1 to 10 carbon atoms is preferable, an alkylene group having 1 to 6 carbon atoms is more preferable, and an alkylene group having 1 to 3 carbon atoms is even more preferable. Examples of such alkylene include methylene, ethylene, and propylene. The alkylene may have a substituent. Examples of the substituent include an alkyl group having 1 to 3 carbon atoms; a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom; and a halogenated alkyl group. An alkyl group having 1 to 3 carbon atoms and a halogenated alkyl group are preferable, a methyl group and a trifluoromethyl group are more preferable, and a methyl group is even more preferable. Specific examples of the group having such an arylene-alkylene-arylene structure include structures represented by the following formulas (1) and (2). Among them, a group represented by formula (1) is preferable.

In the formula, "*" represents a bond.

Among these, Ar ¹ , Ar ² , Ar ⁴ , and Ar ⁵ are preferably an arylene group or a group having an arylene-alkylene-arylene structure, more preferably an arylene group, and even more preferably a phenylene group. Ar ³ is preferably an arylene group or a group having an arylene-alkylene-arylene structure, more preferably a group having an arylene-alkylene-arylene structure, and even more preferably a group having a phenylene-dimethylmethylene-phenylene structure (a group represented by formula (1)).

n represents an integer from 2 to 50, preferably an integer from 3 to 40, more preferably an integer from 4 to 30, and even more preferably an integer from 5 to 20.

Specific examples of the structure represented by formula (A-2) include structures represented by the following formulas (A1) to (A2), but are not limited thereto (in the formulas, * represents a bond).

n1 and n2 are the same as n in formula (A-2).

式中、Ｄ^１及びＤ^２は、それぞれ独立に単結合又は２価の連結基を表す。Ａｒ^１１、Ａｒ^１２、Ａｒ^１４、及びＡｒ^１５は、それぞれ独立に式（Ａ－２）中のＡｒ^１、Ａｒ^２、Ａｒ^４、及びＡｒ^５と同じである。Ａｒ^１３は、それぞれ独立に式（Ａ－２）中のＡｒ^３と同じである。ｍは式（Ａ－２）中のｎと同じである。 The component (A) is preferably a compound represented by the following formula (A-3).

In the formula, ^D1 and ^D2 each independently represent a single bond or a divalent linking group. ^Ar11 , ^Ar12 , ^Ar14 , and ^Ar15 each independently represent ^Ar1 , ^Ar2 , ^Ar4 , and ^Ar5 in formula (A-2). ^Ar13 each independently represent ^Ar3 in formula (A-2). m is the same as n in formula (A-2).

^D1 and ^D2 each independently represent a single bond or a divalent linking group. Examples of the divalent linking group include a divalent hydrocarbon group, a divalent heterocyclic group, a carbonyl group, an ether bond, an ester bond, a carbonate bond, an amide bond, an imide bond, and a group in which a plurality of these are linked together. The divalent hydrocarbon group includes a divalent aliphatic hydrocarbon group and a divalent aromatic hydrocarbon group.

Examples of divalent aliphatic hydrocarbon groups include linear or branched alkylene groups having 1 to 18 carbon atoms, and linear or branched alkenylene groups having 2 to 18 carbon atoms. Examples of linear or branched alkylene groups having 1 to 18 carbon atoms include methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene groups. Examples of linear or branched alkenylene groups having 2 to 18 carbon atoms include vinylene, 1-methylvinylene, propenylene, 1-butenylene, and 2-butenylene groups.

Examples of divalent alicyclic hydrocarbon groups include divalent alicyclic hydrocarbon groups having 3 to 18 carbon atoms, such as cycloalkylene groups (including cycloalkylidene groups) such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylidene groups.

Examples of divalent aromatic hydrocarbon groups include arylene groups having 6 to 14 carbon atoms, such as 1,2-phenylene group, 1,4-phenylene group, 1,3-phenylene group, 4,4'-biphenylene group, 3,3'-biphenylene group, 2,6-naphthylene group, 2,7-naphthylene group, 1,8-naphthylene group, and anthracenylene group.

The heterocycle constituting the divalent heterocyclic group includes an aromatic heterocycle and a non-aromatic heterocycle. The heterocycle may be a 3- to 10-membered ring having a carbon atom and at least one heteroatom as atoms constituting the ring, or a condensed ring thereof. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. The heterocycle is preferably a 3- to 10-membered ring, more preferably a 4- to 6-membered ring. Examples of heterocyclic rings constituting the divalent heterocyclic group include three-membered rings such as an oxirane ring; four-membered rings such as an oxetane ring; five-membered rings such as a furan ring, a tetrahydrofuran ring, an oxazole ring, an isoxazole ring, a γ-butyrolactone ring, a thiophene ring, a thiazole ring, an isothiazole ring, a thiadiazole ring, a pyrrole ring, a pyrrolidine ring, a pyrazole ring, an imidazole ring, and a triazole ring; six-membered rings such as a 4-oxo-4H-pyran ring, a tetrahydropyran ring, a morpholine ring, a 4-oxo-4H-thiopyran ring, an isocyanuric ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a piperidine ring, and a piperazine ring; a 3-oxatricyclo[4.3.1.1 ^4,8 ]undecane-2-one ring, a 3-oxatricyclo[4.2.1.0 ^4,8 ]nonan-2-one ring and the like bridged rings; and condensed rings such as a benzofuran ring, an isobenzofuran ring, a 4-oxo-4H-chromene ring, a chroman ring, an isochroman ring, a benzothiophene ring, an indole ring, an indoline ring, a quinoline ring, an acridine ring, a naphthyridine ring, a quinazoline ring, and a purine ring. A divalent heterocyclic group is a group obtained by removing two hydrogen atoms from the structural formula of the above heterocycle.

Among these, from the viewpoint of obtaining the effects of the present invention significantly, ^D1 and ^D2 preferably represent a divalent aromatic hydrocarbon group, more preferably an arylene group having 6 to 16 carbon atoms, further preferably a 1,2-phenylene group, a 1,4-phenylene group, a 1,3-phenylene group, a 4,4'-biphenylene group, a 3,3'-biphenylene group, a 2,6-naphthylene group, a 2,7-naphthylene group, a 1,8-naphthylene group, or an anthracenylene group, and particularly preferably a 1,2-phenylene group, a 1,4-phenylene group, or a 1,3-phenylene group.

Specific examples of the component (A) include the following, but the invention is not limited to these: In the following formula, na and nb each independently represent an integer of 2 to 50.

The component (A) may be a commercially available product or may be synthesized by a known method. The component (A) may be synthesized, for example, by using the synthesis method described in Polymer 1989, p. 978. The component (A) may be used alone or in combination of two or more types.

From the viewpoint of obtaining a cured product having low dielectric properties and excellent adhesion to copper foil, the weight average molecular weight of the (A) component is preferably 1,000 or more, more preferably 1,200 or more, and even more preferably 1,400 or more, and is preferably 10,000 or less, more preferably 7,500 or less, and even more preferably 5,000 or less.
The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a polystyrene equivalent value.

From the viewpoint of obtaining a cured product having low dielectric properties and excellent adhesion to copper foil, the number average molecular weight of the (A) component is preferably 1,000 or more, more preferably 1,200 or more, and even more preferably 1,400 or more, and is preferably 10,000 or less, more preferably 7,500 or less, and even more preferably 5,000 or less.
The number average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a polystyrene equivalent value.

From the viewpoint of obtaining a cured product having low dielectric properties and excellent adhesion to copper foil, the content of the component (A) is preferably 1 mass % or more, more preferably 3 mass % or more, and even more preferably 5 mass % or more, and is preferably 25 mass % or less, more preferably 20 mass % or less, and even more preferably 15 mass % or less, based on 100 mass % of the non-volatile components in the resin composition.
In the present invention, the content of each component in the resin composition is a value when the non-volatile components in the resin composition are taken as 100 mass %, unless otherwise specified.

From the viewpoint of obtaining a cured product with low dielectric properties and excellent adhesion to copper foil, the content of component (A) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, and is preferably 60% by mass or less, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, when the resin component in the resin composition is taken as 100% by mass. The resin component refers to the non-volatile components in the resin composition excluding inorganic filler (E).

<(B) Epoxy Resin>
The resin composition contains an epoxy resin as component (B). By including the epoxy resin (B) in the resin composition, it is possible to obtain a cured product having low dielectric properties and excellent peel strength.

Examples of component (B) include bixylenol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, tetraphenylethane type epoxy resins, etc. Of these, naphthol-type epoxy resins are preferred as component (B) from the viewpoint of achieving significant effects of the present invention.

The resin composition preferably contains, as component (B), an epoxy resin having two or more epoxy groups in one molecule. From the viewpoint of significantly obtaining the desired effects of the present invention, the ratio of the epoxy resin having two or more epoxy groups in one molecule to 100% by mass of the non-volatile components of component (B) is preferably 20% by mass or more, more preferably 30% by mass or more, and particularly preferably 40% by mass or more.

Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition may contain only liquid epoxy resins, only solid epoxy resins, or a combination of liquid epoxy resins and solid epoxy resins as component (B), but from the viewpoint of significantly achieving the desired effects of the present invention, it is preferable to contain only solid epoxy resins.

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

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

Specific examples of solid epoxy resins include DIC's "HP4032H" (naphthalene type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resin); DIC's "N-690" (cresol novolac type epoxy resin); DIC's "N-695" (cresol novolac type epoxy resin); DIC's "HP-7200", "HP-7200HH", and "HP-7200H" (dicyclopentadiene ether type epoxy resins); DIC Corporation's "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", and "HP6000" (naphthylene ether type epoxy resins); Nippon Kayaku Co., Ltd.'s "EPPN-502H" (trisphenol type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC7000L" (naphthol novolac type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC3000H", "NC3000", and "NC3000L" ","NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; " Examples of such epoxy resins include "YX8800" (anthracene type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical; "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical; and "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical. These may be used alone or in combination of two or more types.

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

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

Specific examples of liquid epoxy resins include DIC's "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins); Mitsubishi Chemical's "828US", "jER828EL", "825", and "Epicoat 828EL" (bisphenol A type epoxy resins); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F type epoxy resins); Mitsubishi Chemical's "jER152" (phenol novolac type epoxy resin); and Mitsubishi Chemical's "630" and "630LSD" (glycidylamine type epoxy resins). ); "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical &Material; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX; "Celloxide 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel; "PB-3600" (epoxy resin having a butadiene structure) manufactured by Daicel; "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Material. These may be used alone or in combination of two or more types.

When a liquid epoxy resin and a solid epoxy resin are used in combination as component (B), the ratio by mass (liquid epoxy resin:solid epoxy resin) is preferably 1:1 to 1:20, more preferably 1:1.5 to 1:15, and particularly preferably 1:2 to 1:10. When the ratio by mass of the liquid epoxy resin and the solid epoxy resin is within this range, the desired effects of the present invention can be significantly obtained. Furthermore, when used in the form of a resin sheet, appropriate adhesion is usually obtained. Furthermore, when used in the form of a resin sheet, sufficient flexibility is usually obtained, improving handling. Furthermore, a cured product having sufficient breaking strength can usually be obtained.

The epoxy equivalent of component (B) is preferably 50 g/eq. to 5000 g/eq., more preferably 50 g/eq. to 3000 g/eq., even more preferably 80 g/eq. to 2000 g/eq., and even more preferably 110 g/eq. to 1000 g/eq. Within this range, the crosslink density of the cured product of the resin composition layer is sufficient, resulting in an insulating layer with small surface roughness. The epoxy equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of component (B) is preferably 100 to 5,000, more preferably 200 to 3,000, and even more preferably 250 to 1,500, from the viewpoint of significantly achieving the desired effects of the present invention.

The content of component (B) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on 100% by mass of the non-volatile components in the resin composition, from the viewpoint of obtaining an insulating layer that exhibits good mechanical strength and insulating reliability. The upper limit of the epoxy resin content is preferably 30% by mass or less, more preferably 25% by mass or less, and particularly preferably 20% by mass or less, from the viewpoint of significantly obtaining the desired effects of the present invention.

From the viewpoint of obtaining an insulating layer that exhibits good mechanical strength and insulating reliability, the content of component (B) is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more, and is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, assuming that the resin component in the resin composition is 100% by mass.

<(C) Active ester curing agent>
The resin composition contains an active ester-based curing agent (C). By using the active ester-based curing agent, the dielectric properties can be improved, and the peel strength becomes excellent. The component (C) may be used alone or in combination of two or more kinds.

(C) As the active ester-based curing agent, generally, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are preferably used. The active ester-based curing agent is preferably one obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester-based curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester-based curing agent 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 phenol compounds or naphthol compounds include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refer to diphenol compounds obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

Specific examples of the (C) component include dicyclopentadiene-type active ester-based curing agents, naphthalene-type active ester-based curing agents containing a naphthalene structure, active ester-based curing agents containing an acetylated product of phenol novolac, and active ester-based curing agents containing a benzoylated product of phenol novolac. Among these, the (C) component is more preferably one or more selected from dicyclopentadiene-type active ester-based curing agents and naphthalene-type active ester-based curing agents containing a naphthalene structure, and is even more preferably a naphthalene-type active ester-based curing agent containing a naphthalene structure. As the dicyclopentadiene-type active ester-based curing agent, an active ester-based curing agent containing a dicyclopentadiene-type diphenol structure is preferred. The "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

(C) Commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-65TM", and "EXB-8000L-65TM" (manufactured by DIC Corporation) as active ester curing agents containing a dicyclopentadiene-type diphenol structure; and "EXB9416-70BK", "EXB-8100L-65T", "EXB-8150L-65T", "EXB-8150-65T", "HPC-8150-60T", "HPC-8150-62T" (manufactured by DIC Corporation) and "PC1300-02-65T" (air) as naphthalene-type active ester curing agents containing a naphthalene structure.・Water Co., Ltd.); "DC808" (Mitsubishi Chemical Corporation) as an active ester-based hardener containing acetylated phenol novolac; "YLH1026" (Mitsubishi Chemical Corporation) as an active ester-based hardener containing benzoylated phenol novolac; "DC808" (Mitsubishi Chemical Corporation) as an active ester-based hardener that is an acetylated phenol novolac; "YLH1026" (Mitsubishi Chemical Corporation), "YLH1030" (Mitsubishi Chemical Corporation), "YLH1048" (Mitsubishi Chemical Corporation) as active ester-based hardener that is a benzoylated phenol novolac; "EXB-8500-65T" (DIC Corporation); and the like.

The active ester group equivalent of the (C) active ester curing agent 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., from the viewpoint of being able to reduce the dielectric tangent and obtaining a cured product with excellent adhesion. The active ester group equivalent is the mass of the active ester curing agent containing one equivalent of active ester groups.

The ratio of the amount of (B) epoxy resin to the amount of (C) active ester curing agent is the ratio of [total number of active groups of active ester curing agent]/[total number of epoxy groups of epoxy resin], which is preferably 0.01 or more, more preferably 0.3 or more, even more preferably 0.5 or more, and preferably 5 or less, more preferably 3 or less, even more preferably 2 or less. Here, the "number of epoxy groups of epoxy resin" is the total value obtained by dividing the mass of the non-volatile components of epoxy resin present in the resin composition by the epoxy equivalent. Also, the "number of active groups of active ester curing agent" is the total value obtained by dividing the mass of the non-volatile components of active ester curing agent present in the resin composition by the active ester group equivalent. By setting the ratio of the amount of epoxy resin to the active ester curing agent within this range, it is possible to obtain the effects of the present invention significantly.

The content of the (C) active ester curing agent is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on 100% by mass of the non-volatile components in the resin composition, from the viewpoint of obtaining a cured product with low dielectric properties and excellent peel strength. The upper limit is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less.

The content of (C) active ester curing agent is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more, based on 100% by mass of the resin component in the resin composition, from the viewpoint of obtaining a cured product with low dielectric properties and excellent peel strength, and is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less.

<(D) Resin containing radically polymerizable unsaturated group>
In addition to the above-mentioned components, the resin composition may contain (D) a resin containing a radically polymerizable unsaturated group as an optional component. By including (D) a resin containing a radically polymerizable unsaturated group in the resin composition, a cured product having low dielectric properties and excellent peel strength can be obtained. The (D) component does not include components (A) to (C).

The radically polymerizable unsaturated group contained in component (D) represents a group containing an unsaturated bond exhibiting radical polymerizability. Examples of this radically polymerizable unsaturated group include a group containing an ethylenic double bond. Component (D) containing such a radically polymerizable unsaturated group can cause radical polymerization by heat or active energy rays, thereby curing the resin composition.

Examples of radically polymerizable unsaturated groups include maleimide groups, vinyl groups, vinylphenyl groups, acryloyl groups, methacryloyl groups, fumaroyl groups, maleoyl groups, benzocyclobutene groups, and allyl groups. Among these, the maleimide group is preferred as component (D) from the viewpoint of obtaining the effects of the present invention more significantly. The number of radically polymerizable unsaturated groups contained in component (D) is usually 1 or more, and preferably 2 or more. When component (D) contains two or more radically polymerizable unsaturated groups, the two or more radically polymerizable unsaturated groups may be the same or different.

The (D) component is preferably a resin containing an aromatic ring in the molecule. Therefore, the (D) component is preferably a resin containing an aromatic ring and a radically polymerizable unsaturated group. The aromatic ring contained in the (D) component may be an aromatic carbon ring or an aromatic heterocycle. The aromatic ring may be a monocyclic aromatic ring, a condensed aromatic ring in which two or more monocyclic aromatic rings are condensed, or a condensed aromatic ring in which one or more monocyclic non-aromatic rings are condensed to 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 these, the aromatic ring is preferably an aromatic carbon ring. The number of carbon atoms in the aromatic carbon ring is preferably 6 to 10.

The aromatic ring contained in component (D) may have a substituent bonded thereto. The number of substituents bonded to one aromatic ring may be one or more. When the number of substituents is two or more, the two or more substituents may be the same or different.

Examples of the substituent include an alkyl group, an alkyloxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, a cycloalkyl group, a halogen atom, a hydroxyl group, and a mercapto group.

The number of carbon atoms in the alkyl group is preferably 1 to 10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a t-butyl group.

The number of carbon atoms in the alkyloxy group is preferably 1 to 10. Examples of the alkyloxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

The number of carbon atoms in the alkylthio group is preferably 1 to 10. Examples of the alkylthio group include a methylthio group, an ethylthio group, a propylthio group, and a butylthio group.

The number of carbon atoms in the aryl group is preferably 6 to 10. Examples of the aryl group include a phenyl group and a naphthyl group.

The number of carbon atoms in the aryloxy group is preferably 6 to 10. Examples of the aryloxy group include a phenyloxy group and a naphthyloxy group.

The number of carbon atoms in the arylthio group is preferably 6 to 10. Examples of the arylthio group include a phenylthio group and a naphthylthio group.

The number of carbon atoms in the cycloalkyl group is preferably 3 to 10. Examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.

Examples of halogen atoms include fluorine atoms, chlorine atoms, and iodine atoms.

In particular, it is preferable that the aromatic ring contained in component (D) has no substituents or has an alkyl group bonded thereto.

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

Component (D) may be used alone or in combination of two or more types.

A preferred embodiment of component (D) is a resin containing a maleimide group. It is preferable that the resin containing a maleimide group further contains an aromatic ring. Since the resin containing a maleimide group is a resin belonging to component (D), those corresponding to component (A) are excluded. The resin containing a maleimide group may be used alone or in combination of two or more types.

Examples of resins containing maleimide groups include
(D-1) a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to a nitrogen atom of a maleimide group,
(D-2) a maleimide compound having an aromatic ring directly bonded to the nitrogen atom of the maleimide group, and (D-3) a maleimide compound containing a trimethylindane skeleton.
It is preferable that the compound is one or more selected from the following:

The term "directly" means that in the case of component (D-1), there is no other group between the nitrogen atom of the maleimide group and the aliphatic group having 5 or more carbon atoms, and in the case of component (D-2), there is no other group between the nitrogen atom of the maleimide group and the aromatic ring.

Component (D-1) is a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to the nitrogen atom of the maleimide. Component (D-1) can be obtained, for example, by imidization reaction of a component containing an aliphatic amine compound (such as a diamine compound having a dimer acid skeleton), maleic anhydride, and, if necessary, tetracarboxylic dianhydride.

Examples of aliphatic groups having 5 or more carbon atoms include alkyl groups, alkylene groups, and alkenylene groups.

The number of carbon atoms in an alkyl group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This alkyl group may be linear, branched, or cyclic, and linear is preferred. Examples of such alkyl groups include pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups. An alkyl group having 5 or more carbon atoms may be present as a substituent of an alkylene group having 5 or more carbon atoms.

The number of carbon atoms in an alkylene group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This alkylene group may be linear, branched, or cyclic, and linear is preferred. Here, the concept of a cyclic alkylene group includes a group consisting of only a cyclic alkylene group and a group containing both a linear alkylene group and a cyclic alkylene group. Examples of such alkylene groups include a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tridecylene group, a heptadecylene group, a hexatriacontylene group, a group having an octylene-cyclohexylene structure, a group having an octylene-cyclohexylene-octylene structure, and a group having a propylene-cyclohexylene-octylene structure.

The number of carbon atoms in an alkenylene group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This alkenylene group may be linear, branched, or cyclic, and linear is preferred. Here, the concept of a cyclic alkenylene group includes cases where the alkenylene group is composed only of a cyclic alkenylene group and cases where the alkenylene group contains both a linear alkenylene group and a cyclic alkenylene group. Examples of such alkenylene groups include pentynylene, hexynylene, heptylenylene, octynylene, nonynylene, decynylene, undecynylene, dodecynylene, tridecynylene, heptadecynylene, hexatriacontinylene, groups having an octynylene-cyclohexynylene structure, groups having an octynylene-cyclohexynylene-octynylene structure, and groups having a propynylene-cyclohexynylene-octynylene structure.

一般式（Ｄ－１－１）中、Ｍは置換基を有していてもよい炭素原子数が５以上の２価の脂肪族基を表し、Ｌは単結合又は２価の連結基を表す。 The component (D-1) is preferably a compound represented by the following formula (D-1-1).

In formula (D-1-1), M represents a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, and L represents a single bond or a divalent linking group.

M represents a divalent aliphatic group having 5 or more carbon atoms, which may have a substituent. The number of carbon atoms in the divalent aliphatic group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This aliphatic group may be linear, branched, or cyclic, and linear is preferred. Here, the concept of a cyclic aliphatic group includes a case in which the group is composed only of a cyclic aliphatic group, and a case in which the group contains both a linear aliphatic group and a cyclic aliphatic group. Examples of the divalent aliphatic group include an alkylene group, an alkenylene group, and the like. The alkylene group and the alkenylene group are as described above.

Examples of the substituent of M include a halogen atom, -OH, -O-C _1-10 alkyl group, -N(C _1-10 alkyl group) ₂ , C _1-10 alkyl group, C _2-30 alkenyl group, C _2-30 alkynyl group, C _6-10 aryl group, -NH ₂ , -CN, -C(O)O-C _1-10 alkyl group, -COOH, -C(O)H, -NO _2, and the like. Here, the term "C _x-y " (x and y are positive integers, and x<y) indicates that the number of carbon atoms in the organic group described immediately after this term is x to y. For example, the expression "C _1-10 alkyl group" indicates an alkyl group having 1 to 10 carbon atoms. These substituents may be bonded to each other to form a ring, and the ring structure also includes a spiro ring and a fused ring. The substituent is preferably an alkyl group having 5 or more carbon atoms.

L represents a single bond or a divalent linking group. Examples of the divalent linking group include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, -C(=O)-, -C(=O)-O-, -NR ⁰ - (R ⁰ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms), an oxygen atom, a sulfur atom, C(=O)NR ⁰ -, a divalent group derived from phthalimide, a divalent group derived from pyromellitic diimide, and a group consisting of a combination of two or more of these divalent groups. The alkylene group, the alkenylene group, the alkynylene group, the arylene group, the divalent group derived from phthalimide, the divalent group derived from pyromellitic diimide, and a group consisting of a combination of two or more of these divalent groups may have an alkyl group having 5 or more carbon atoms as a substituent. The divalent group derived from phthalimide represents a divalent group derived from phthalimide, and specifically, is a group represented by the general formula (D-1-2). The divalent group derived from pyromellitic diimide refers to a divalent group derived from pyromellitic diimide, specifically, a group represented by general formula (D-1-3), in which "*" represents a bond.

The alkylene group as the divalent linking group in L is preferably an alkylene group having 1 to 50 carbon atoms, more preferably an alkylene group having 1 to 45 carbon atoms, and particularly preferably an alkylene group having 1 to 40 carbon atoms. This alkylene group may be linear, branched, or cyclic. Examples of such alkylene groups include methylethylene, cyclohexylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, heptadecylene, hexatriacontylene, groups having an octylene-cyclohexylene structure, groups having an octylene-cyclohexylene-octylene structure, and groups having a propylene-cyclohexylene-octylene structure.

The alkenylene group as the divalent linking group in L is preferably an alkenylene group having 2 to 50 carbon atoms, more preferably an alkenylene group having 2 to 45 carbon atoms, and particularly preferably an alkenylene group having 2 to 40 carbon atoms. This alkenylene group may be linear, branched, or cyclic. Examples of such alkenylene groups include a methylethylenylene group, a cyclohexenylene group, a pentenylene group, a hexenylene group, a heptenylene group, and an octenylene group.

The alkynylene group as the divalent linking group in L is preferably an alkynylene group having 2 to 50 carbon atoms, more preferably an alkynylene group having 2 to 45 carbon atoms, and particularly preferably an alkynylene group having 2 to 40 carbon atoms. This alkynylene group may be linear, branched, or cyclic. Examples of such alkynylene groups include a methylethynylene group, a cyclohexynylene group, a pentynylene group, a hexynylene group, a heptynylene group, and an octynylene group.

The arylene group as the divalent linking group in L is preferably an arylene group having 6 to 24 carbon atoms, more preferably an arylene group having 6 to 18 carbon atoms, even more preferably an arylene group having 6 to 14 carbon atoms, and even more preferably an arylene group having 6 to 10 carbon atoms. Examples of the arylene group include a phenylene group, a naphthylene group, and an anthracenylene group.

The divalent linking groups in L, that is, alkylene groups, alkenylene groups, alkynylene groups, and arylene groups, may have a substituent. The substituent is the same as the substituent of M in general formula (B2-1-1), and is preferably an alkyl group having 5 or more carbon atoms.

Examples of groups consisting of a combination of two or more divalent groups in L include a divalent group consisting of a combination of an alkylene group, a divalent group derived from phthalimide, and an oxygen atom; a divalent group consisting of a combination of a divalent group derived from phthalimide, an oxygen atom, an arylene group, and an alkylene group; a divalent group consisting of a combination of an alkylene group and a divalent group derived from pyromellitic diimide; and the like. A group consisting of a combination of two or more divalent groups may form a ring such as a condensed ring by the combination of the respective groups. In addition, a group consisting of a combination of two or more divalent groups may have a repeating unit number of 1 to 10.

Among these, L in general formula (D-1-1) is preferably an oxygen atom, an arylene group having 6 to 24 carbon atoms which may have a substituent, an alkylene group having 1 to 50 carbon atoms which may have a substituent, an alkyl group having 5 or more carbon atoms, a divalent group derived from phthalimide, a divalent group derived from pyromellitic diimide, or a divalent group consisting of a combination of two or more of these groups. Among them, as L, an alkylene group; a divalent group having a structure of an alkylene group-phthalimide-derived divalent group-oxygen atom-phthalimide-derived divalent group; a divalent group having a structure of an alkylene group-phthalimide-derived divalent group-oxygen atom-arylene group-alkylene group-arylene group-oxygen atom-phthalimide-derived divalent group; a divalent group having a structure of an alkylene-pyromellitic acid diimide-derived divalent group; a divalent group having a structure of an alkynylene group-phthalimide-derived divalent group-oxygen atom-phthalimide-derived divalent group; a divalent group having a structure of an alkynylene group-phthalimide-derived divalent group-oxygen atom-arylene group-alkynylene group-arylene group-oxygen atom-phthalimide-derived divalent group; a divalent group having a structure of a divalent group having ...

一般式（Ｄ－１－４）中、Ｍ^１はそれぞれ独立に置換基を有していてもよい炭素原子数が５以上の２価の脂肪族基を表し、Ｚはそれぞれ独立に置換基を有していてもよい炭素原子数が５以上の２価の脂肪族基又は置換基を有していてもよい芳香環を有する２価の基を表す。ｔは１～１０の整数を表す。 The maleimide resin represented by the general formula (D-1-1) is preferably a maleimide resin represented by the general formula (D-1-4).

In formula (D-1-4), M ¹ 's each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, Z's each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent or a divalent group having an aromatic ring which may have a substituent, and t represents an integer from 1 to 10.

Each ^M1 independently represents a divalent aliphatic group having 5 or more carbon atoms which may have a substituent. ^M1 is the same as M in formula (D-1-1).

Each Z independently represents a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, or a divalent group having an aromatic ring which may have a substituent. Examples of the divalent aliphatic group in Z include an alkylene group and an alkenylene group. The divalent aliphatic group may be linear, branched, or cyclic, and among these, a cyclic divalent aliphatic group having 5 or more carbon atoms which may have a substituent is preferred.

The number of carbon atoms in the alkylene group is preferably 6 or more, more preferably 8 or more, and preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. Examples of such alkylene groups include groups having an octylene-cyclohexylene structure, groups having an octylene-cyclohexylene-octylene structure, and groups having a propylene-cyclohexylene-octylene structure.

The number of carbon atoms in an alkenylene group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This alkenylene group may be linear, branched, or cyclic, and linear is preferred. Here, the concept of a cyclic alkenylene group includes cases where the alkenylene group is composed only of a cyclic alkenylene group and cases where the alkenylene group contains both a linear alkenylene group and a cyclic alkenylene group. Examples of such alkenylene groups include pentynylene, hexynylene, heptylenylene, octynylene, nonynylene, decynylene, undecynylene, dodecynylene, tridecynylene, heptadecynylene, hexatriacontinylene, groups having an octynylene-cyclohexynylene structure, groups having an octynylene-cyclohexynylene-octynylene structure, and groups having a propynylene-cyclohexynylene-octynylene structure.

Examples of the aromatic ring in the divalent group having an aromatic ring represented by Z include a benzene ring, a naphthalene ring, an anthracene ring, a phthalimide ring, a pyromellitic diimide ring, and an aromatic heterocycle, and the like are mentioned, with a benzene ring, a phthalimide ring, and a pyromellitic diimide ring being preferred. That is, the divalent group having an aromatic ring is preferably a divalent group having a benzene ring which may have a substituent, a divalent group having a phthalimide ring which may have a substituent, or a divalent group having a pyromellitic diimide ring which may have a substituent. Examples of the divalent group having an aromatic ring include a group consisting of a combination of a divalent group derived from phthalimide and an oxygen atom; a group consisting of a combination of a divalent group derived from phthalimide, an oxygen atom, an arylene group, and an alkylene group; a group consisting of a combination of an alkylene group and a divalent group derived from pyromellitic diimide; a divalent group derived from pyromellitic diimide; a group consisting of a combination of a divalent group derived from phthalimide and an alkylene group; and the like. The above arylene group is the same as the arylene group in the divalent linking group represented by L in general formula (D-1-1).

The alkylene group and the divalent group having an aromatic ring represented by Z may have a substituent. The substituent is the same as the substituent that M in general formula (D-1-1) may have.

Specific examples of the group represented by Z include the following groups: In the formula, "*" represents a bond.

一般式（Ｄ－１－５）中、Ｍ^２及びＭ^３はそれぞれ独立に置換基を有していてもよい炭素原子数が５以上の２価の脂肪族基を表し、Ｒ^４０はそれぞれ独立に、酸素原子、アリーレン基、アルキレン基、又はこれらの基の２以上の組み合わせからなる２価の基を表す。ｔ１は１～１０の整数を表す。
一般式（Ｄ－１－６）中、Ｍ^４、Ｍ^６及びＭ^７はそれぞれ独立に置換基を有していてもよい炭素原子数が５以上の脂肪族基を表し、Ｍ^５はそれぞれ独立に置換基を有していてもよい芳香環を有する２価の基を表し、Ｒ^４１及びＲ^４２はそれぞれ独立に炭素原子数が５以上のアルキル基を表す。ｔ２は０～１０の整数を表し、ｕ１及びｕ２はそれぞれ独立に０～４の整数を表す。 The compound represented by general formula (D-1-1) is preferably any one of a compound represented by general formula (D-1-5) and a compound represented by general formula (D-1-6).

In formula (D-1-5), ^M2 and ^M3 each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, ^R40 each independently represent an oxygen atom, an arylene group, an alkylene group, or a divalent group consisting of a combination of two or more of these groups, and t1 represents an integer from 1 to 10.
In formula (D-1-6), ^M4 , ^M6 , and ^M7 each independently represent an aliphatic group having 5 or more carbon atoms which may have a substituent, ^M5 each independently represent a divalent group having an aromatic ring which may have a substituent, ^R41 and ^R each independently represent an alkyl group having 5 or more carbon atoms, t2 represents an integer of 0 to 10, and u1 and u2 each independently represent an integer of 0 to 4.

^M2 and ^M3 each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent. ^M2 and ^M3 are the same as the divalent aliphatic group having 5 or more carbon atoms represented by M in general formula (D-1-1), and are preferably a hexatriacontinylene group or a hexatriacontylene group.

Each R ⁴⁰ independently represents an oxygen atom, an arylene group, an alkylene group, or a group consisting of a combination of two or more of these divalent groups. The arylene group and the alkylene group are the same as the arylene group and the alkylene group in the divalent linking group represented by L in the general formula (D-1-1). R ⁴⁰ is preferably a group consisting of a combination of two or more of the divalent groups or an oxygen atom.

Examples of the group consisting of a combination of two or more divalent groups in ^R40 include a combination of an oxygen atom, an arylene group, and an alkylene group. Specific examples of the group consisting of a combination of two or more divalent groups include the following groups. In the formula, "*" represents a bond.

^M4 , ^M6 , and ^M7 each independently represent an aliphatic group having 5 or more carbon atoms which may have a substituent. ^M4 , ^M6 , and ^M7 are the same as the aliphatic group having 5 or more carbon atoms which may have a substituent represented by M in formula (D-1-1), and are preferably a hexylene group, a heptylene group, an octylene group, a nonylene group, or a decylene group, and more preferably an octylene group.

M ⁵ each independently represents a divalent group having an aromatic ring which may have a substituent. M ⁵ is the same as the divalent group having an aromatic ring which may have a substituent represented by Z in the general formula (D-1-4), and is preferably a group consisting of a combination of an alkylene group and a divalent group derived from pyromellitic diimide; a group consisting of a combination of a divalent group derived from phthalimide and an alkylene group, and more preferably a group consisting of a combination of an alkylene group and a divalent group derived from pyromellitic diimide. The arylene group and alkylene group are the same as the arylene group and alkylene group in the divalent linking group represented by L in the general formula (D-1-1).

Specific examples of the group represented by ^M5 include the following groups: In the formula, "*" represents a bond.

R ⁴¹ and R ⁴² each independently represent an alkyl group having 5 or more carbon atoms. R ⁴¹ and R ⁴² are the same as the alkyl group having 5 or more carbon atoms described above, and are preferably a hexyl group, a heptyl group, an octyl group, a nonyl group, or a decyl group, and more preferably a hexyl group or an octyl group.

u1 and u2 each independently represent an integer from 1 to 15, preferably an integer from 1 to 10.

Specific examples of the component (D-1) include the following compounds (Di) to (D-iii), but are not limited to these specific examples. In the formula, v represents an integer of 1 to 10.

Specific examples of the (D-1) component include "BMI1500" (compound of formula (D-i)), "BMI1700" (compound of formula (D-ii)), and "BMI689" (compound of formula (D-iii)), all manufactured by Designor Molecules.

The weight average molecular weight (Mw) of component (D-1) is preferably 150 to 5,000, and more preferably 300 to 2,500.

From the viewpoint of significantly achieving the desired effects of the present invention, the maleimide group equivalent of the (D-1) component is preferably 50 g/eq. to 2000 g/eq., more preferably 100 g/eq. to 1000 g/eq., and even more preferably 150 g/eq. to 500 g/eq. The maleimide group equivalent is the mass of the (D-1) component containing one equivalent of maleimide groups.

Component (D-2) is a maleimide compound having an aromatic ring directly bonded to the nitrogen atom of the maleimide. Component (D-2) can be obtained, for example, by subjecting a component containing an aromatic amine compound (such as an aromatic diamine compound) and maleic anhydride to an imidization reaction.

The aromatic ring may be a carbocyclic or heterocyclic ring. Examples of the aromatic ring include monocyclic aromatic rings such as a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an imidazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, and a pyrazine ring; condensed rings in which two or more monocyclic aromatic rings are condensed, such as a naphthalene ring, an anthracene ring, a benzofuran ring, an isobenzofuran ring, an indole ring, an isoindole ring, a benzothiophene ring, a benzimidazole ring, an indazole ring, a benzoxazole ring, a benzisoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, an acridine ring, a quinazoline ring, a cinnoline ring, and a phthalazine ring; and condensed rings in which one or more monocyclic aromatic rings, such as an indane ring, a fluorene ring, and a tetralin ring, are condensed to one or more monocyclic non-aromatic rings. Among these, the aromatic ring is preferably a monocyclic aromatic ring, and more preferably a benzene ring.

The component (D-2) is preferably a compound represented by the following formula (D-2-1).

In the formula, R ^c 's each independently represent a substituent; X ^c 's each independently represent a single bond, an alkylene group, an alkenylene group, -O-, -CO-, -S-, -SO-, -SO ₂ -, -CONH-, -NHCO-, -COO-, or -OCO- (preferably a single bond or an alkylene group); Z ^c 's each independently represent a non-aromatic ring which may have a substituent, or an aromatic ring which may have a substituent (preferably an aromatic ring which may have a substituent, particularly preferably an aromatic ring which may have a substituent); s represents an integer of 1 or more (preferably an integer of 1 to 100, more preferably an integer of 1 to 50, and even more preferably an integer of 1 to 20); t1's each independently represent 0 or an integer of 1 or more; and u's each independently represent an integer of 0 to 2 (preferably 0).] are particularly preferably maleimide compounds represented by the formulae (D-2-2) to (D-2-5):

式中、Ｒ^ｃ１、Ｒ^ｃ２及びＲ^ｃ３は、それぞれ独立して、アルキル基を示し；Ｘ^ｃ１及びＸ^ｃ２は、それぞれ独立して、単結合又はアルキレン基を示し；ｓは、１以上の整数（好ましくは１～１００の整数、より好ましくは１～５０の整数、さらに好ましくは１～２０の整数）を示し；ｔ’は、１～５の整数を示し；ｖ１、ｖ２及びｖ３は、それぞれ独立して、０～２の整数（好ましくは０）を示す。なお、ｓ単位、ｔ単位、ｔ’単位、ｖ単位、ｖ１単位、ｖ２単位及びｖ３単位は、それぞれ、単位毎に同一であってもよいし、異なっていてもよい。

In the formula, R ^c1 , R ^c2 and R ^c3 each independently represent an alkyl group; X ^c1 and X ^c2 each independently represent a single bond or an alkylene group; s represents an integer of 1 or more (preferably an integer of 1 to 100, more preferably an integer of 1 to 50, and even more preferably an integer of 1 to 20); t' represents an integer of 1 to 5; and v1, v2 and v3 each independently represent an integer of 0 to 2 (preferably 0). Note that the s unit, t unit, t' unit, v unit, v1 unit, v2 unit and v3 unit may be the same or different for each unit.

式中、Ｒ^３１及びＲ^３６はマレイミド基を表し、Ｒ^３２、Ｒ^３３、Ｒ^３４及びＲ^３５は、それぞれ独立に水素原子、アルキル基、又はアリール基を表し、Ｄはそれぞれ独立に２価の芳香族基を表す。ｍ１及びｍ２はそれぞれ独立に１～１０の整数を表し、ａは１～１００の整数を表す。 In another embodiment, the component (D-2) preferably has a structure represented by the following formula (D-2-6).

In the formula, R ³¹ and R ³⁶ represent a maleimide group, R ³² , R ³³ , R ³⁴ and R ³⁵ each independently represent a hydrogen atom, an alkyl group or an aryl group, and D each independently represents a divalent aromatic group. m1 and m2 each independently represent an integer of 1 to 10, and a represents an integer of 1 to 100.

In formula (D-2-6), R ³² , R ³³ , R ³⁴ and R ³⁵ each independently represent a hydrogen atom, an alkyl group or an aryl group, and preferably a hydrogen atom.

As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, an alkyl group having 1 to 6 carbon atoms is more preferable, and an alkyl group having 1 to 3 carbon atoms is even more preferable. The alkyl group may be linear, branched, or cyclic. Examples of such alkyl groups include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and an isopropyl group.

The aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 15 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms. The aryl group may be a single ring or a condensed ring. Examples of such aryl groups include a phenyl group, a naphthyl group, and an anthracenyl group.

The alkyl group and the aryl group may have a substituent. The substituent is not particularly limited, and examples thereof include a halogen atom, -OH, -O-C _1-6 alkyl group, -N(C _1-10 alkyl group) ₂ , C _1-10 alkyl group, C _6-10 aryl group, -NH ₂ , -CN, -C(O)O-C _1-10 alkyl group, -COOH, -C(O)H, and -NO _2. Here, the term "C _p-q " (p and q are positive integers, and p<q is satisfied) indicates that the number of carbon atoms in the organic group described immediately after this term is p to q. For example, the expression "C _1-10 alkyl group" indicates an alkyl group having 1 to 10 carbon atoms. These substituents may be bonded to each other to form a ring, and the ring structure also includes a spiro ring and a fused ring.

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

D in formula (D-2-6) represents a divalent aromatic group. Examples of the divalent aromatic group include a phenylene group, a naphthylene group, an anthracenylene group, an aralkyl group, a biphenylene group, and a biphenylaralkyl group. Among them, a biphenylene group and a biphenylaralkyl group are preferred, and a biphenylene group is more preferred. The divalent aromatic group may have a substituent. The substituent is the same as the substituent that the alkyl group represented by R ³² in formula (D-2-6) may have.

m1 and m2 each independently represent an integer from 1 to 10, preferably 1 to 6, more preferably 1 to 3, even more preferably 1 to 2, and even more preferably 1.

a represents an integer from 1 to 100, preferably from 1 to 50, more preferably from 1 to 20, and even more preferably from 1 to 5.

式中、Ｒ^３７及びＲ^３８はマレイミド基を表す。ａ１は１～１００の整数を表す。 The component (D-2) is preferably a resin represented by formula (D-2-7).

In the formula, R ³⁷ and R ³⁸ each represent a maleimide group, and a1 represents an integer of 1 to 100.

a1 is the same as a in formula (D-2-6), and the preferred range is also the same.

Commercially available products of component (D-2) include, for example, "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd.; "BMI-50P" manufactured by KI Kasei Co., Ltd.; "BMI-1000", "BMI-1000H", "BMI-1100", "BMI-1100H", "BMI-4000", and "BMI-5100" manufactured by Daiwa Kasei Kogyo Co., Ltd.; "BMI-4,4'-BPE", "BMI-70" manufactured by KI Kasei Co., Ltd., and "BMI-80" manufactured by KI Kasei Co., Ltd.

The weight average molecular weight (Mw) of component (D-2) is preferably 150 to 5,000, more preferably 300 to 2,500.

The functional group equivalent of the maleimide group in component (D-2) is preferably 50 g/eq. to 2000 g/eq., more preferably 100 g/eq. to 1000 g/eq., even more preferably 150 g/eq. to 500 g/eq., and particularly preferably 200 g/eq. to 300 g/eq.

The component (D-3) is a maleimide compound containing a trimethylindane skeleton. The trimethylindane skeleton is the skeleton shown in the following formula (D-3-1).

The benzene ring contained in the trimethylindane skeleton may have a substituent bonded thereto, for example, an alkyl group, an alkyloxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, a cycloalkyl group, a halogen atom, a hydroxyl group, and a mercapto group.
The number of carbon atoms in the alkyl group is preferably 1 to 10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a t-butyl group.
The number of carbon atoms in the alkyloxy group is preferably 1 to 10. Examples of the alkyloxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
The number of carbon atoms in the alkylthio group is preferably 1 to 10. Examples of the alkylthio group include a methylthio group, an ethylthio group, a propylthio group, and a butylthio group.
The number of carbon atoms in the aryl group is preferably 6 to 10. Examples of the aryl group include a phenyl group and a naphthyl group.
The number of carbon atoms in the aryloxy group is preferably 6 to 10. Examples of the aryloxy group include a phenyloxy group and a naphthyloxy group.
The number of carbon atoms in the arylthio group is preferably 6 to 10. Examples of the arylthio group include a phenylthio group and a naphthylthio group.
The number of carbon atoms in the cycloalkyl group is preferably 3 to 10. Examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and an iodine atom.

Among the above-mentioned substituents, the hydrogen atoms of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group may be substituted with halogen atoms.

The number of substituents bonded to one benzene ring contained in the trimethylindane skeleton may be 1 or 2 or more. The number of substituents bonded to a benzene ring contained in the trimethylindane skeleton is usually 0 to 3. When the number of substituents is 2 or more, the 2 or more substituents may be the same or different. In particular, it is preferable that no substituents are bonded to the benzene ring contained in the trimethylindane skeleton.

The number of trimethylindane structures contained in one molecule of component (D-3) may be 1 or 2 or more. The upper limit may be, for example, 10 or less, 8 or less, 7 or less, or 6 or less.

The (D-3) component preferably further contains an aromatic ring skeleton in addition to the above-mentioned trimethylindane skeleton. The number of ring carbon atoms of the aromatic ring skeleton is preferably 6 to 10. Examples of aromatic ring skeletons include a benzene ring skeleton and a naphthalene ring skeleton. The number of the aromatic ring skeletons contained in one molecule of the (D-3) component is preferably 1 or more, more preferably 2 or more, and preferably 6 or less, more preferably 4 or less, and particularly preferably 3 or less. When the (D-3) component contains two or more aromatic ring skeletons in addition to the trimethylindane skeleton, the aromatic ring skeletons may be the same or different.

The aromatic ring contained in the aromatic ring skeleton may have a substituent bonded thereto. Examples of the substituent include the substituents described above as the substituents that may be bonded to the benzene ring contained in the trimethylindane skeleton, and a nitro group. The number of substituents bonded to one aromatic ring may be 1 or 2 or more. The number of substituents bonded to an aromatic ring is usually 0 to 4. When the number of substituents is 2 or more, the 2 or more substituents may be the same or different.

The (D-3) component preferably further contains a divalent aliphatic hydrocarbon group in addition to the above-mentioned trimethylindane skeleton. In particular, when the (D-3) component contains an aromatic ring skeleton other than the benzene ring contained in the trimethylindane skeleton, the (D-3) component preferably contains a divalent aliphatic hydrocarbon group. In this case, the divalent aliphatic hydrocarbon group preferably connects between the benzene ring and the aromatic ring skeleton contained in the trimethylindane skeleton. In addition, the divalent aliphatic hydrocarbon group preferably connects between the aromatic ring skeletons.

The number of carbon atoms in the divalent aliphatic hydrocarbon group is preferably 1 or more, and preferably 12 or less, more preferably 8 or less, and particularly preferably 5 or less. As the divalent aliphatic hydrocarbon group, an alkylene group as a saturated aliphatic hydrocarbon group is more preferable. Examples of the divalent aliphatic hydrocarbon group include linear alkylene groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups; and branched alkylene groups such as ethylidene (-CH(CH ₃ )-), propylidene (-CH(CH ₂ CH ₃ )-), isopropylidene (-C(CH ₃ ) ₂ -), ethylmethylmethylene (-C(CH ₃ )(CH ₂ CH ₃ )-), and diethylmethylene (-C(CH ₂ CH ₃ ) ₂ -). (B2-3) When the maleimide compound containing a trimethylindane skeleton contains two or more divalent aliphatic hydrocarbon groups in addition to the trimethylindane skeleton, those divalent aliphatic hydrocarbon groups may be the same or different.

The component (D-3) preferably contains a structure represented by the following formula (D-3-2): The entire component (D-3) may have the structure represented by formula (D-3-2), or a portion of the component (D-3) may have the structure represented by formula (D-3-2).

(In the formula, Ar ^a1 represents a divalent aromatic hydrocarbon group which may have a substituent; each R ^a1 independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group; each R ^a2 independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group; R ^a3 each independently represents a divalent aliphatic hydrocarbon group; n _a1 represents a positive integer; n _a2 each independently represents an integer of 0 to 4; n _a3 each independently represents an integer of 0 to 3. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of ^{R a1} may be substituted with a halogen atom. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of R ^a2 may be substituted with a halogen atom. When _{n a2} is 2 to 4, R ^a1 may be the same or different within the same ring. When n _a3 is 2 to 3, R ^a2 may be the same or different within the same ring.)

In formula (D-3-2), Ar ^a1 represents a divalent aromatic hydrocarbon group which may have a substituent. The number of carbon atoms in this divalent aromatic hydrocarbon group is preferably 6 or more, preferably 20 or less, more preferably 16 or less. Examples of the divalent aromatic hydrocarbon group include a phenylene group and a naphthylene group. Examples of the substituent that the divalent aromatic hydrocarbon group may have include an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group, and a mercapto group. The hydrogen atom of each substituent may be further substituted with a halogen atom. Specific examples of these substituents include the same examples as the substituents that may be bonded to the benzene ring contained in the trimethylindane skeleton. When the divalent aromatic hydrocarbon group has a substituent, the number of the substituents is preferably 1 to 4. When the divalent aromatic hydrocarbon group has two or more substituents, the two or more substituents may be the same or different. Among them, Ar ^a1 is preferably a divalent aromatic hydrocarbon group having no substituent.

In formula (D-3-2), R ^a1 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. The hydrogen atoms of the alkyl group, the alkyloxy group, the alkylthio group, the aryl group, the aryloxy group, the arylthio group, and the cycloalkyl group may be substituted with a halogen atom. Specific examples of these groups include the same examples as the substituents that may be bonded to the benzene ring contained in the trimethylindane skeleton. Among them, R ^a1 is more preferably one or more groups selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms, and is particularly preferably an alkyl group having 1 to 4 carbon atoms.

In formula (D-3-2), R ^a2 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group. The hydrogen atoms of the alkyl group, the alkyloxy group, the alkylthio group, the aryl group, the aryloxy group, the arylthio group, and the cycloalkyl group may be substituted with a halogen atom. Specific examples of these groups include the same examples as the substituents that may be bonded to the benzene ring contained in the trimethylindane skeleton. Among them, R ^a2 is more preferably one or more groups selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

In formula (D-3-2), each R ^a3 independently represents a divalent aliphatic hydrocarbon group. The preferred range of the divalent aliphatic hydrocarbon group is as described above.

In formula (D-3-2), n _a1 represents a positive integer. n _a1 is preferably 1 or more and is preferably 10 or less, and more preferably 8 or less.

In formula (D-3-2), n _a2 each independently represents an integer of 0 to 4. n _a2 is preferably 2 or 3, more preferably 2. Multiple n _a2 may be different, but are preferably the same. When n _a2 is 2 or more, multiple R ^a1 may be the same or different within the same ring.

In formula (D-3-2), n _a3 each independently represents an integer of 0 to 3. Multiple n _a3 may be different, but are preferably the same. n _a3 is preferably 0.

（式中、Ｒ^ｂ１は、それぞれ独立に、炭素原子数１～１０のアルキル基、炭素原子数１～１０のアルキルオキシ基、炭素原子数１～１０のアルキルチオ基、炭素原子数６～１０のアリール基、炭素原子数６～１０のアリールオキシ基、炭素原子数６～１０のアリールチオ基、炭素原子数３～１０のシクロアルキル基、ハロゲン原子、ニトロ基、水酸基、又は、メルカプト基を表し；Ｒ^ｂ２は、それぞれ独立に、炭素原子数１～１０のアルキル基、炭素原子数１～１０のアルキルオキシ基、炭素原子数１～１０のアルキルチオ基、炭素原子数６～１０のアリール基、炭素原子数６～１０のアリールオキシ基、炭素原子数６～１０のアリールチオ基、炭素原子数３～１０のシクロアルキル基、ハロゲン原子、水酸基、又は、メルカプト基を表し；ｎ_ｂ１は、正の整数を表し；ｎ_ｂ２は、それぞれ独立に、０～４の整数を表し；ｎ_ｂ３は、それぞれ独立に、０～３の整数を表す。Ｒ^ｂ１のアルキル基、アルキルオキシ基、アルキルチオ基、アリール基、アリールオキシ基、アリールチオ基、及びシクロアルキル基の水素原子は、ハロゲン原子で置換されていてもよい。Ｒ^ｂ２のアルキル基、アルキルオキシ基、アルキルチオ基、アリール基、アリールオキシ基、アリールチオ基、及びシクロアルキル基の水素原子は、ハロゲン原子で置換されていてもよい。ｎ_ｂ２が２～４の場合、Ｒ^ｂ１は、同一環内で同じであってもよく異なっていてもよい。ｎ_ｂ３が２～３の場合、Ｒ^ｂ２は、同一環内で同じであってもよく異なっていてもよい。） It is particularly preferable that the component (D-3) contains a structure represented by the following formula (D-3-3): The entire component (D-3) may have the structure represented by formula (D-3-3), or a portion of the component (D-3) may have the structure represented by formula (D-3-3).

(In the formula, R ^b1 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group; R ^b2 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group; n _b1 represents a positive integer; n _b2 each independently represents an integer of 0 to 4; _b3 each independently represents an integer of 0 to 3. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of ^{R b1} may be substituted with a halogen atom. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of R ^b2 may be substituted with a halogen atom. When n _b2 is 2 to 4, R ^b1 may be the same or different in the same ring. When n _b3 is 2 to 3, R ^b2 may be the same or different in the same ring.)

In formula (D-3-3), R ^b1 , R ^b2 , n _b1 , n _b2 and n _b3 are the same as R ^a1 , R ^a2 , n _a1 , n _a2 and n _a3 in formula (D-3-2), respectively.

式（Ｄ－３－４）において、Ｒ^ｃ１、Ｒ^ｃ２、ｎ_ｃ２及びｎ_ｃ３は、それぞれ、式（Ｄ－３－２）におけるＲ^ａ１、Ｒ^ａ２、ｎ_ａ２及びｎ_ａ３と同じである。また、式（Ｄ－３－４）において、ｎ_ｃ１は、繰り返し単位数であり、１～２０の整数を表す。さらに、式（Ｄ－３－４）において、＊は、結合手を表す。例えば、（Ｄ－３）成分は、式（Ｄ－３－２）において、ｎ_ａ２が３以下であり、且つ、マレイミド基が結合するベンゼン環のマレイミド基に対するオルト位及びパラ位のうち、２つ以上に、Ｒ^ａ１が結合していない場合に、式（Ｄ－３－２）で表される構造に組み合わせて前記の式（Ｄ－３－４）で表される構造を含みうる。また、例えば、（Ｄ－３）成分は、式（Ｄ－３－３）において、ｎ_ｂ２が３以下であり、且つ、マレイミド基が結合するベンゼン環のマレイミド基に対するオルト位及びパラ位のうち、２つ以上に、Ｒ^ｂ１が結合していない場合に、式（Ｄ－３－３）で表される構造に組み合わせて前記の式（Ｄ－３－４）で表される構造を含みうる。 The component (D-3) may further contain a structure represented by the following formula (D-3-4).

In formula (D-3-4), R ^c1 , R ^c2 , n _c2 and n _c3 are the same as R ^a1 , R ^a2 , n _a2 and n _a3 in formula (D-3-2) , respectively. In formula (D-3-4), n _c1 is the number of repeating units and represents an integer of 1 to 20. In formula (D-3-4) , * represents a bond. For example, in formula (D-3-2), when n _a2 is 3 or less and R ^a1 is not bonded to two or more of the ortho and para positions relative to the maleimide group of the benzene ring to which the maleimide group is bonded, the (D-3) component may include a structure represented by formula (D-3-4) in combination with the structure represented by formula (D-3-2). Furthermore, for example, when n _b2 is 3 or less in formula (D-3-3) and R b1 is not bonded to two or more of the ortho-positions and para-positions relative to the maleimide group of the benzene ring to which the ^maleimide group is bonded, the component (D-3) can contain a structure represented by formula (D-3-4) in combination with the structure represented by formula (D-3-3).

The (D-3) component may be used alone or in any combination of two or more types in any ratio.

The maleimide group equivalent of the (D-3) component is preferably 50 g/eq. or more, more preferably 100 g/eq. or more, particularly preferably 200 g/eq. or more, and is preferably 2000 g/eq. or less, more preferably 1000 g/eq. or less, particularly preferably 800 g/eq. or less. The maleimide group equivalent represents the mass of the maleimide compound per equivalent of maleimide group. When the maleimide group equivalent of the (D-3) component is within the above range, the effects of the present invention can be significantly obtained.

There are no particular limitations on the method for producing component (D-3). Component (D-3) can be produced, for example, by the method described in Japan Institute of Invention and Innovation's Technical Journal No. 2020-500211. According to the production method described in Japan Institute of Invention and Innovation's Technical Journal No. 2020-500211, it is possible to obtain a maleimide compound having a distribution in the number of repeating units of the trimethylindane skeleton. The maleimide compound obtained by this method contains a structure represented by the following formula (D-3-5). Therefore, component (D-3) may contain a maleimide compound containing a structure represented by formula (D-3-5).

(wherein, R ¹ 's each independently represent an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group; R ² 's each independently represent an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group; n ₁ 's each independently represent an average number of repeating units of 0.95 to 10.0; n ₂ 's each independently represent an integer of 0 to 4; Each of n 2 and _{n 3} independently represents an integer of 0 to 3. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of R ¹ may be substituted with a halogen atom. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of R ² may be substituted with a halogen atom. When n ₂ is 2 to 4, R ¹ may be the same or different in the same ring. When n ₃ is 2 to 3, R ² may be the same or different in the same ring.)

In formula (D-3-5), R ¹ , R ² , n ₂ and n ₃ are the same as R ^a1 , R ^a2 , n _a2 and n _a3 in formula (D-3-2), respectively.

In formula (D-3-5), n ₁ represents the average number of repeating units, and its range is 0.95 to 10.0. According to the manufacturing method described in the Japan Institute of Invention and Innovation Disclosure Technical Bulletin No. 2020-500211, a group of maleimide compounds containing a structure represented by formula (D-3-5) can be obtained. As can be seen from the fact that the average number of repeating units n ₁ in formula (D-3-5) can be smaller than 1.00, the maleimide compound containing the structure represented by formula (D-3-5) thus obtained can contain a maleimide compound having a trimethylindane skeleton repeating unit number of 0. Therefore, the maleimide compound containing the structure represented by formula (D-3-5) can be purified to obtain the (D-3) component by removing the maleimide compound having a trimethylindane skeleton repeating unit number of 0, and the resin composition may contain only the obtained (D-3) component. However, even if a maleimide compound having a trimethylindane skeleton repeating unit number of 0 is contained in the resin composition, the effect of the present invention can be obtained. In addition, when purification is omitted, costs can be reduced. Therefore, it is preferable that the resin composition contains a maleimide compound having a structure represented by formula (D-3-5) without excluding a maleimide compound having a trimethylindane skeleton with a repeating unit number of 0.

In formula (D-3-5), the average number of repeating units _n1 is preferably 0.95 or more, more preferably 0.98 or more, even more preferably 1.0 or more, particularly preferably 1.1 or more, and is preferably 10.0 or less, more preferably 8.0 or less, even more preferably 7.0 or less, particularly preferably 6.0 or less. When the average number of repeating units _n1 is within the above range, the effects of the present invention can be significantly obtained. In particular, the glass transition temperature of the resin composition can be effectively increased.

Examples of the structure represented by formula (D-3-5) include the following:

The maleimide compound containing the structure represented by formula (D-3-5) may further contain the structure represented by formula (D-3-4) above. For example, the maleimide compound containing the structure represented by formula (D-3-5) may contain the structure represented by formula (D-3-4) in combination with the structure represented by formula (D-3-5) when _n2 is 3 or less and ^R1 is not bonded to two or more of the ortho-positions and para-positions relative to the maleimide group of the benzene ring to which the maleimide group is bonded in formula (D-3-5) .

The maleimide compound containing the structure represented by formula (D-3-5) preferably has a molecular weight distribution Mw/Mn calculated from gel permeation chromatography (GPC) measurement within a specific range. The molecular weight distribution is a value obtained by dividing the weight average molecular weight Mw by the number average molecular weight Mn, and is expressed as "Mw/Mn". Specifically, the molecular weight distribution Mw/Mn of the maleimide compound containing the structure represented by formula (D-3-5) is preferably 1.0 to 4.0, more preferably 1.1 to 3.8, even more preferably 1.2 to 3.6, and particularly preferably 1.3 to 3.4. When the molecular weight distribution Mw/Mn of the maleimide compound containing the structure represented by formula (D-3-5) is within the above range, the effects of the present invention can be significantly obtained.

Of the maleimide compounds containing a structure represented by formula (D-3-5), the amount of the maleimide compound having an average repeating unit number n ₁ of 0 is preferably in a specific range. When the GPC measurement of the maleimide compound containing a structure represented by formula (D-3-5) is performed, the amount of the maleimide compound having an average repeating unit number n ₁ of 0 can be expressed in area % based on the results of the GPC measurement. In detail, in the chromatogram obtained by the GPC measurement, the amount of the maleimide compound having an average repeating unit number n ₁ of 0 can be expressed by the ratio (area %) of the area of the peak of the maleimide compound having an average repeating unit number n 1 of 0 to the total area of the peak of the maleimide compound containing a structure represented by formula (D-3-5). Specifically, the amount of the maleimide compound having an average repeating unit number n ₁ of 0 is preferably 32 area % or less, more preferably 30 area % or less, and even more preferably 28 area % or less, relative to the total amount of the maleimide compound containing a structure represented by formula (D- _3-5) (100 area %). When the amount of the maleimide compound in which the average number of repeating units _n1 is 0 is within the above range, the effects of the present invention can be significantly obtained.

The maleimide group equivalent of the maleimide compound containing the structure represented by formula (D-3-5) is preferably in the same range as the maleimide group equivalent of the above-mentioned component (D-3). When the maleimide group equivalent of the maleimide compound containing the structure represented by formula (D-3-5) is in the above range, the effects of the present invention can be significantly obtained.

From the viewpoint of obtaining a cured product with low dielectric properties and excellent peel strength, the content of component (D) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, and is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of non-volatile components in the resin composition.

From the viewpoint of obtaining a cured product with low dielectric properties and excellent peel strength, the content of component (D) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, assuming that the resin components in the resin composition are 100% by mass.

<(E) Inorganic filler>
The resin composition may contain an inorganic filler (E) as an optional component in addition to the above-mentioned components. By including the inorganic filler (E) in the resin composition, a cured product having excellent dielectric properties can be obtained. It becomes possible to obtain things.

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

(E) Commercially available inorganic fillers include, for example, "UFP-30" manufactured by Denka Chemical Industry Co., Ltd.; "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatechs Co., Ltd.; "UFP-30" manufactured by Denka Company, Ltd.; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "SC2500SQ", "SO-C4", "SO-C2", "SO-C1", and "SC2050-SXF" manufactured by Admatechs Co., Ltd.

(E) From the viewpoint of significantly obtaining the desired effects of the present invention, the average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, particularly preferably 0.1 μm or more, and is preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less.

(E) The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on the Mie scattering theory. Specifically, a particle size distribution of the inorganic filler is created on a volume basis using a laser diffraction/scattering particle size distribution measuring device, and the median diameter is used as the average particle size. The measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing it ultrasonically for 10 minutes. The measurement sample is measured using a laser diffraction particle size distribution measuring device with blue and red light source wavelengths, and the volume-based particle size distribution of the inorganic filler is measured using a flow cell method, and the average particle size is calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution measuring devices include the "LA-960" manufactured by Horiba, Ltd. and the "SALD-2200" manufactured by Shimadzu Corporation.

From the viewpoint of significantly obtaining the desired effects of the present invention, the specific surface area of the (E) inorganic filler is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, and particularly preferably 3 m ² /g or more. There is no particular upper limit, but it is preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area is obtained by measuring the specific surface area of the inorganic filler using a BET fully automatic specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.), adsorbing nitrogen gas onto the surface of a sample, and calculating the specific surface area using the BET multipoint method.

(E) The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include fluorine-containing silane coupling agents such as 3,3,3-trifluoropropyltrimethoxysilane; aminosilane coupling agents such as 3-aminopropyltriethoxysilane, N-phenyl-8-aminooctyl-trimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane; epoxysilane coupling agents such as 3-glycidoxypropyltrimethoxysilane; mercaptosilane coupling agents such as 3-mercaptopropyltrimethoxysilane; silane coupling agents; alkoxysilanes such as phenyltrimethoxysilane; organosilazane compounds such as hexamethyldisilazane; titanate coupling agents, and the like. The surface treatment agent may be used alone or in any combination of two or more.

Examples of commercially available surface treatment agents include Shin-Etsu Chemical's "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical's "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical's "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical's "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical's "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical's "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical's "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical's "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

From the viewpoint of improving the dispersibility of the inorganic filler, it is preferable that the degree of surface treatment with the surface treatment agent falls within a specified range. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated with 0.2 parts by mass to 5 parts by mass of the surface treatment agent, more preferably with 0.2 parts by mass to 3 parts by mass, and more preferably with 0.3 parts by mass to 2 parts by mass.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and even more preferably 0.2 mg/m ² or more. On the other hand, from the viewpoint of suppressing the increase in the melt viscosity of the resin varnish and the melt viscosity in the sheet form, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and even more preferably 0.5 mg/m ² or less.

(E) The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solids, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. An example of a carbon analyzer that can be used is the "EMIA-320V" manufactured by Horiba, Ltd.

The content of (E) inorganic filler is preferably 40% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, and preferably 75% by mass or less, preferably 70% by mass or less, preferably 65% by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass, from the viewpoint of obtaining a remarkable effect of the present invention.

<(F) Curing Agent>
In addition to the above-mentioned components, the resin composition may further contain a curing agent (F) as an optional component. However, the active ester-based curing agent (C) is not included in the curing agent (F). Examples of the curing agent (F) include a phenol-based curing agent, a naphthol-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, and a carbodiimide-based curing agent. Among them, from the viewpoint of improving the insulation reliability, the curing agent (F) is preferably one or more of a phenol-based curing agent, a naphthol-based curing agent, a cyanate ester-based curing agent, and a carbodiimide-based curing agent, more preferably one of a phenol-based curing agent and a naphthol-based curing agent, and further preferably includes a phenol-based curing agent. The curing agent (F) may be used alone or in combination of two or more.

As the phenol-based hardener and naphthol-based hardener, from the viewpoint of heat resistance and water resistance, a phenol-based hardener having a novolac structure or a naphthol-based hardener having a novolac structure is preferred. Also, from the viewpoint of adhesion to the conductor layer, a nitrogen-containing phenol-based hardener is preferred, and a triazine skeleton-containing phenol-based hardener is more preferred.

Specific examples of phenol-based and naphthol-based curing agents include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Kasei Co., Ltd., "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd., "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN-495V", "SN375", and "SN395" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA3018-50P", and "EXB-9500" manufactured by DIC Corporation.

Specific examples of benzoxazine-based curing agents include "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "P-d" and "F-a" manufactured by Shikoku Chemical Industry Co., Ltd.

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

Specific examples of carbodiimide-based curing agents include "V-03" and "V-07" manufactured by Nisshinbo Chemical Co., Ltd.

When the curing agent is contained as the (F) component, the ratio of the amount of the epoxy resin to the (B) active ester curing agent and the (F) curing agent is preferably in the range of 1:0.01 to 1:5, more preferably 1:0.3 to 1:3, and even more preferably 1:0.5 to 1:2, in terms of the ratio of [total number of epoxy groups in the epoxy resin]:[total number of active groups in the (B) active ester curing agent and the (F) curing agent]. Here, the "number of epoxy groups in the epoxy resin" refers to the total value obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition by the epoxy equivalent. In addition, the "number of active groups in the (B) active ester curing agent and the (F) curing agent" refers to the total value obtained by dividing the mass of the non-volatile components of the active ester curing agent and the curing agent present in the resin composition by the active group equivalent. By setting the ratio of the amount of the epoxy resin to the (B) component and the (F) component within such range, the effect of the present invention can be obtained significantly.

When a curing agent is contained as the (F) component, the ratio of the amount of the epoxy resin to all of the (F) curing agents is preferably in the range of 1:0.01 to 1:1, more preferably 1:0.03 to 1:0.5, and even more preferably 1:0.05 to 1:0.3, in terms of the ratio of [total number of epoxy groups in the epoxy resin]:[total number of active groups in the (F) curing agent]. Here, the "number of active groups in the (F) curing agent" refers to the total value of all values obtained by dividing the mass of the non-volatile components of the (F) curing agent present in the resin composition by the active group equivalent. By setting the ratio of the amount of the epoxy resin to the curing agent as the (F) component within this range, the effects of the present invention can be obtained significantly.

From the viewpoint of significantly obtaining the desired effect of the present invention, the content of the (F) curing agent is preferably 1% by mass or more, more preferably 1.5% by mass or more, and even more preferably 2% by mass or more, assuming that the non-volatile components in the resin composition are 100% by mass. The upper limit is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less.

From the viewpoint of significantly obtaining the desired effect of the present invention, the content of the (F) curing agent is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, and is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, when the resin component in the resin composition is taken as 100% by mass.

<(G) Curing Accelerator>
In addition to the above-mentioned components, the resin composition may further contain, as an optional component, a curing accelerator as component (G).

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

Examples of phosphorus-based curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, etc., with triphenylphosphine and tetrabutylphosphonium decanoate being preferred.

Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.

Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4 -diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl Examples of the imidazole compounds include 1-dodecyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and adducts of imidazole compounds and epoxy resins, with 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole being preferred.

Commercially available imidazole curing accelerators may be used, such as "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Examples of guanidine-based curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene. Examples include o[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide, and dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are preferred.

Metal-based curing accelerators include, for example, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organocopper complexes such as copper (II) acetylacetonate, organozinc complexes such as zinc (II) acetylacetonate, organoiron complexes such as iron (III) acetylacetonate, organonickel complexes such as nickel (II) acetylacetonate, and organomanganese complexes such as manganese (II) acetylacetonate. Organometallic salts include, for example, zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

From the viewpoint of significantly obtaining the desired effect of the present invention, the content of component (G) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, and is preferably 3% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of non-volatile components in the resin composition.

From the viewpoint of significantly obtaining the desired effect of the present invention, the content of component (G) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of the resin component in the resin composition.

<(H) Other Additives>
The resin composition may further contain other additives as optional components in addition to the above-mentioned components. Examples of such additives include thermoplastic resins, elastomers, organic fillers, thickeners, defoamers, leveling agents, adhesion promoters, flame retardants, etc. These may be used alone or in combination of two or more in any ratio.

The resin composition can be produced, for example, by mixing the above-mentioned components in any order. In addition, during the process of mixing each component, heating and/or cooling may be performed by appropriately adjusting the temperature. In addition, each component may be uniformly dispersed by stirring using a stirring device such as a mixer during or after mixing. Furthermore, the resin composition may be subjected to a degassing treatment as necessary.

<Physical properties and applications of resin composition>
Since the resin composition contains a combination of the (A) component, the (B) component, and the (C) component, it is possible to obtain a cured product that has low dielectric properties, excellent peel strength even with a small surface roughness, and a high glass transition temperature.

The cured product obtained by thermally curing the resin composition at 200°C for 90 minutes has a low dielectric constant Dk. Therefore, when an insulating layer is formed with this cured product, an insulating layer with a low dielectric constant can be obtained. For example, the dielectric constant Dk of the cured product obtained by curing the resin composition under the conditions described in the examples below is preferably 3.0 or less, more preferably 2.9 or less, and even more preferably 2.8 or less. The lower limit of the dielectric constant Dk of the cured product is not particularly limited, but can be 0.1 or more. The dielectric constant of the cured product can be measured by the method described in the examples.

The cured product obtained by thermally curing the resin composition at 200°C for 90 minutes has a low dielectric loss tangent. Therefore, when an insulating layer is formed from this cured product, an insulating layer with a low dielectric loss tangent can be obtained. For example, the dielectric loss tangent Df of the cured product obtained by curing the resin composition under the conditions described in the examples described later is preferably 0.010 or less, more preferably 0.005 or less, and even more preferably 0.004 or less. The lower limit of the dielectric loss tangent Df of the cured product is not particularly limited, but may be 0.001 or more. The dielectric loss tangent of the cured product can be measured by the method described in the examples.

The cured product obtained by thermally curing the resin composition at 200°C for 90 minutes can increase the plating peel strength between the resin composition and the plating. Therefore, when an insulating layer is formed from this cured product, an insulating layer with high peel strength between the insulating layer and the conductor layer can be obtained. For example, when an insulating layer and a plated conductor layer are formed by the method described in the examples below, the peel strength between the insulating layer and the conductor layer can be preferably 0.2 kgf/cm or more, more preferably 0.3 kgf/cm or more, and particularly preferably 0.4 kgf/cm or more. The upper limit of the adhesion is not particularly limited, but can be, for example, 10.0 kgf/cm or less. The peel strength can be measured by the method described in the examples.

The resin composition is thermally cured at 200°C for 90 minutes to produce a cured product with a small arithmetic mean roughness (Ra) on the surface after roughening treatment. Therefore, an insulating layer with a small arithmetic mean roughness (Ra) on the surface after roughening treatment can be obtained. The arithmetic mean roughness (Ra) is preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 50 nm or less. The lower limit is not particularly limited, but may be 1 nm or more. The arithmetic mean roughness (Ra) can be measured according to the method described in the examples below.

The cured product obtained by thermally curing the resin composition at 200°C for 90 minutes exhibits the characteristic of a high glass transition temperature. Therefore, when an insulating layer is formed from this cured product , an insulating layer having a high glass transition temperature and excellent heat resistance can be obtained. The glass transition temperature is preferably 140°C or higher, more preferably 145°C or higher, and even more preferably 150°C or higher. The upper limit is not particularly limited, but may be 300°C or lower. The glass transition temperature can be measured according to the method described in the examples below.

The resin composition according to one embodiment of the present invention is suitable as a resin composition for insulating applications, and is particularly suitable as a resin composition for forming an insulating layer. Thus, for example, the resin composition is suitable as a resin composition for forming an insulating layer of a printed wiring board (a resin composition for forming an insulating layer of a printed wiring board). The resin composition is also suitable as a resin composition for forming an insulating layer (a resin composition for forming an insulating layer for forming a conductor layer) for forming a conductor layer (including a rewiring layer) formed on an insulating layer. The resin composition can also be used in a wide range of applications in which the resin composition can be used, such as resin sheets, sheet-like laminate materials such as prepregs, solder resists, underfill materials, die bonding materials, semiconductor encapsulants, hole-filling resins, component-embedding resins, multi-chip packages, package-on-packages, wafer-level packages, panel-level packages, and systems-in-packages.

Furthermore, for example, when a semiconductor chip package is manufactured through the following steps (1) to (6), the resin composition according to the present embodiment is also suitable as a resin composition for forming a rewiring formation layer as an insulating layer for forming a rewiring layer (resin composition for forming a rewiring formation layer) and as a resin composition for sealing a semiconductor chip (resin composition for sealing a semiconductor chip). When a semiconductor chip package is manufactured, a rewiring layer may be further formed on the sealing layer.
(1) A step of laminating a temporary fixing film on a substrate;
(2) A step of temporarily fixing a semiconductor chip on a temporary fixing film;
(3) forming an encapsulation layer on the semiconductor chip;
(4) peeling the substrate and the temporary fixing film from the semiconductor chip;
(5) forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off; and (6) forming a rewiring layer as a conductor layer on the rewiring formation layer.

The above-mentioned resin composition can also be used when the printed wiring board is a circuit board with built-in components.

[Resin sheet]
The resin sheet of the present invention includes a support and a resin composition layer formed from the resin composition of the present invention provided on the support.

The thickness of the resin composition layer is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less, from the viewpoint of making the printed wiring board thinner and being able to provide a cured product with excellent insulating properties even if the cured product of the resin composition is a thin film. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 5 μm or more.

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

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

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

The support may be subjected to a matte treatment, corona treatment, or antistatic treatment on the surface that is to be bonded to the resin composition layer.

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

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

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

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

Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone. The organic solvents may be used alone or in combination of two or more.

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

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

[Printed wiring board]
A printed wiring board according to one embodiment of the present invention includes an insulating layer formed of a cured product obtained by curing the above-described resin composition.

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

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

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

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

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

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

The support may be removed between steps (I) and (II), or after step (II).

In step (II), the resin composition layer is cured to form an insulating layer made of a cured product of the resin composition. The curing conditions for the resin composition layer are not particularly limited, and the conditions employed for forming an insulating layer of a printed wiring board may be used. The resin composition layer may be cured by irradiation with active energy rays such as ultraviolet rays, but is usually thermally cured by heating.

For example, the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

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

The method for producing a printed wiring board may further include (III) a step of drilling holes in the insulating layer, (IV) a step of roughening the insulating layer, and (V) a step of forming a conductor layer. 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). Furthermore, the formation of the insulating layer and the conductor layer in steps (I) to (V) may be repeated as necessary to form a multilayer wiring board.

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

Step (IV) is a step of roughening the insulating layer. Usually, smears are also removed in this step (IV). The procedure and conditions of the roughening treatment are not particularly limited. For example, the insulating layer can be roughened by carrying out a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid in this order.

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

The oxidizing agent used in the roughening treatment may be, for example, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment using an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include, for example, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotech Japan.

The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product is, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, etc., it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

In one embodiment, the arithmetic mean roughness Ra of the insulating layer surface after the roughening treatment is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. The lower limit is not particularly limited, and may be, for example, 1 nm or more, 2 nm or more, etc. The root mean square roughness (Rq) of the insulating layer surface after the roughening treatment is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. The lower limit is not particularly limited, and may be, for example, 1 nm or more, 2 nm or more, etc. The arithmetic mean roughness (Ra) and root mean square roughness (Rq) of the insulating layer surface can be measured using a non-contact surface roughness meter.

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

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

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

The conductor layer is preferably formed by plating. For example, the surface of the insulating layer can be plated by a semi-additive method, a full-additive method, or the like to form a conductor layer having a desired wiring pattern. From the viewpoint of ease of production, it is preferable to form the conductor layer by a semi-additive method. Below, an example of forming a conductor layer by a semi-additive method is shown.

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

[Semiconductor device]
A semiconductor device according to an embodiment of the present invention includes the above-mentioned printed wiring board. This semiconductor device can be manufactured using the above-mentioned printed wiring board.

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

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the following examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, the operations described below were carried out in an environment of normal temperature and pressure, unless otherwise specified.

<Preparation of Maleimide Resin A>
An MEK solution (non-volatile content 70% by mass) of maleimide resin A synthesized by the method described in Synthesis Example 1 of Japan Institute of Invention and Innovation Disclosure Technical Journal Publication No. 2020-500211 was prepared. This maleimide resin A has a structure represented by the following formula.

When the FD-MS spectrum of maleimide resin A is measured, peaks at M+=560, 718, and 876 are confirmed. These peaks correspond to the cases where _n1 is 0, 1, and 2, respectively. Furthermore, when maleimide resin A is analyzed by GPC and the value of the number of repeating units _n1 of the indane skeleton portion is calculated based on the number average molecular weight, _n1 =1.47, and the molecular weight distribution (Mw/Mn)=1.81. Furthermore, the content of maleimide resins in which the average number of repeating units _n1 is 0 is 26.5 area % in the total amount (100 area %) of maleimide resin A.

The FD-MS spectrum of the maleimide resin A was measured using the following measuring device and under the following measuring conditions.
(FD-MS spectrum measuring device and measuring conditions)
Measurement device: JMS-T100GC AccuTOF
Measurement conditions Measurement range: m/z = 4.00 to 2000.00
Rate of change: 51.2mA/min
Final current value: 45mA
Cathode voltage: -10 kV
Recording interval: 0.07 sec

The GPC of the maleimide resin A was measured using the following measuring device and under the following measuring conditions.
Measuring device: “HLC-8320 GPC” manufactured by Tosoh Corporation
Columns: Tosoh Corporation guard column "HXL-L", Tosoh Corporation "TSK-GEL G2000HXL", Tosoh Corporation "TSK-GEL G2000HXL", Tosoh Corporation "TSK-GEL G3000HXL", and Tosoh Corporation "TSK-GEL G4000HXL"
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation "GPC Workstation EcoSEC-WorkStation"
Measurement conditions: Column temperature 40°C
Developing solvent: Tetrahydrofuran
Flow rate: 1.0 ml/min. Standard: Monodisperse polystyrene with a known molecular weight is used in accordance with the measurement manual for the aforementioned "GPC Workstation EcoSEC-WorkStation."
Sample: A tetrahydrofuran solution of 1.0% by mass, calculated as the non-volatile component of the maleimide compound, filtered through a microfilter (50 μl).

The molecular weight distribution of the maleimide resin A (weight average molecular weight (Mw)/number average molecular weight (Mn)) and the average number of repeating units "n ₁ " contributing to the indane skeleton in the maleimide resin are calculated from the GPC chart obtained by the GPC measurement. The average number of repeating units "n ₁ " is calculated based on the number average molecular weight (Mn). Specifically, for compounds in which n ₁ is 0 to 4, the theoretical molecular weight and the measured molecular weight in GPC are plotted on a scatter diagram, and an approximate straight line is drawn. Then, the number average molecular weight (Mn) is obtained from the point indicated by the measured value Mn (1) on this straight line, and the average number of repeating units "n ₁ " is calculated. Furthermore, based on the results of the GPC measurement, the content ratio (area %) of maleimide resins in which the average number of repeating units n ₁ is 0 in the total amount of maleimide resin A (100 area %) is calculated. For details, refer to the Japan Institute of Invention and Innovation Disclosure Technical Bulletin No. 2020-500211.

<Synthesis of PEEK (polyether ether ketone) compound A>
31.443 g of 4,4'-difluorobenzophenone, 27.419 g of bisphenol A , 29.894 g of anhydrous potassium carbonate, 180 mL of N-methylpyrrolidone, and 90 mL of toluene were placed in a 500 mL flask (three-neck) equipped with a stirring device, an argon inlet tube, and a Dean-Stark apparatus, and heated under an argon atmosphere with stirring to reflux the toluene at 130-140°C for 4 hours. The mixture was then further heated to 170-180°C to distill off the toluene. Stirring was continued for 10 hours at 170-180°C, and the mixture was then returned to room temperature to obtain Product 1.

5.233 g of 4-aminophenol, 6.628 g of anhydrous potassium carbonate, 18 mL of N-methylpyrrolidone, and 90 mL of toluene were added to the flask containing Product 1, and the mixture was again heated under stirring in an argon atmosphere to reflux the toluene at 130-140°C for 3 hours. The mixture was then heated to 170-180°C to distill off the toluene, and stirring was continued for another 4 hours while maintaining the temperature. The mixture was then cooled to room temperature, and the reaction liquid was added to 5000 mL of methanol and filtered to obtain a powdered solid. This powdered solid was repeatedly washed with methanol and water, and then dried at 100°C for 8 hours to obtain 37.461 g of a powdered solid (Diamine-A).

In a 500 mL flask (three-necked) equipped with a stirrer and an argon inlet tube, 0.878 g of Diamine-A, 4.943 g of maleic anhydride, and 240 mL of N-methylpyrrolidone were placed and stirred at room temperature for 18 hours under an argon atmosphere. Then, 8.576 g of acetic anhydride and 0.689 g of sodium acetate were added and stirred at 60 ° C. for 6 hours. After the reaction solution was returned to room temperature, the reaction solution was added to 5000 mL of methanol to obtain a powdery solid. This powdery solid was repeatedly washed with methanol and water, and then dried at 100 ° C. for 8 hours to obtain 28.434 g of PEEK compound A represented by the following formula. The number average molecular weight of PEEK compound A calculated by GPC measurement was 2230.

[Example 1]
14 parts of PEEK compound A, 20 parts of naphthalene type epoxy resin ("ESN475V" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent of about 332 g/eq.), 30 parts of active ester type curing agent ("HPC-8000-65T" manufactured by DIC Corporation, active group equivalent of 223, toluene solution with solid content of 65 mass %), 60 parts of inorganic filler (spherical silica ("SO-C2" manufactured by Admatechs Co., Ltd., average particle size of 0.5 μm, specific surface area of 5.8 m ² /g) surface-treated with amine type alkoxysilane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.5 parts of curing accelerator ("1B2PZ" manufactured by Shikoku Kasei Co., Ltd., 2-phenyl-1-benzyl-1H-imidazole) were mixed and uniformly dispersed using a high-speed rotating mixer to obtain a resin varnish.

A polyethylene terephthalate film with a release layer ("AL5" manufactured by Lintec Corporation, thickness 38 μm) was prepared as a support. The resin varnish was uniformly applied onto the release layer of this support so that the thickness of the resin composition layer after drying would be 40 μm. The resin varnish was then dried at 80°C to 100°C (average 90°C) for 4 minutes to obtain a resin sheet including a support and a resin composition layer.

[Example 2]
In Example 1, 30 parts of an active ester curing agent (DIC Corporation's "HPC-8000-65T", active group equivalent 223, toluene solution with solid content of 65% by mass) was changed to 30 parts of an active ester curing agent (DIC Corporation's "HPC-8150-62T", active group equivalent 229, toluene solution with solid content of 62% by mass).
A resin varnish and a resin sheet were obtained in the same manner as in Example 1 except for the above.

[Example 3]
In Example 2,
The amount of PEEK Compound A was changed from 14 parts to 10.5 parts.
Furthermore, 5 parts of a radical polymerizable compound (biphenylaralkyl type maleimide compound ("MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., maleimide group equivalent: 275 g/eq., MEK/toluene mixed solution with non-volatile content of 70%)) was used.
A resin varnish and a resin sheet were obtained in the same manner as in Example 2 except for the above.

[Example 4]
In Example 2,
The amount of PEEK Compound A was changed from 14 parts to 12.6 parts.
Furthermore, 2 parts of a radical polymerizable compound ("BMI-1500" manufactured by Designor Molecular Systems, Inc., maleimide group equivalent weight 750 g/eq.) was used.
A resin varnish and a resin sheet were obtained in the same manner as in Example 2 except for the above.

[Example 5]
In Example 2,
The amount of active ester curing agent (DIC Corporation's "HPC-8150-62T", active group equivalent 229, toluene solution with solid content of 62% by mass) was changed from 30 parts to 25 parts.
The amount of the curing accelerator (Shikoku Kasei Corporation's "1B2PZ", 2-phenyl-1-benzyl-1H-imidazole) was changed from 0.5 parts to 0.1 parts.
Furthermore, 5 parts of a triazine skeleton-containing cresol novolak-based hardener ("LA3018-50P" manufactured by DIC Corporation, hydroxyl equivalent 151, 1-methoxy-2-propanol solution with 50% non-volatile components) was used.
A resin varnish and a resin sheet were obtained in the same manner as in Example 2 except for the above.

[Example 6]
In Example 2,
The amount of PEEK Compound A was changed from 14 parts to 10.5 parts.
Furthermore, 5 parts of a MEK solution of maleimide resin A (70% by mass of non-volatile components) was used.
A resin varnish and a resin sheet were obtained in the same manner as in Example 2 except for the above.

[Example 7]
In Example 1, 30 parts of the active ester curing agent (DIC Corporation's "HPC-8000-65T", active group equivalent 223, toluene solution with solid content of 65% by mass) was changed to 30 parts of an active ester curing agent containing a naphthalene structure (Air Water Corporation's "PC1300-02-65MA", active group equivalent 200, methyl amyl ketone solution with solid content of 65% by mass).
A resin varnish and a resin sheet were obtained in the same manner as in Example 1 except for the above.

[Comparative Example 1]
In Example 2,
Without using 14 parts of PEEK compound A,
The amount of inorganic filler (spherical silica (Admatechs' SO-C2, average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical's KBM573)) was changed from 60 parts to 45 parts.
A resin varnish and a resin sheet were obtained in the same manner as in Example 2 except for the above.

[Comparative Example 2]
In Example 3,
Without using 10.5 parts of PEEK compound A,
The amount of the radical polymerizable compound (biphenylaralkyl-type maleimide compound ("MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., maleimide group equivalent: 275 g/eq., MEK/toluene mixed solution with nonvolatile content of 70%)) was changed from 5 parts to 20 parts.
A resin varnish and a resin sheet were obtained in the same manner as in Example 3 except for the above.

[Comparative Example 3]
In Example 4,
Without using 12.6 parts of PEEK compound A,
The amount of the radical polymerizable compound ("BMI-1500" manufactured by Designor Molecules, maleimide group equivalent: 750 g/eq.) was changed from 2 parts to 14 parts.
A resin varnish and a resin sheet were obtained in the same manner as in Example 4 except for the above.

[Measurement of dielectric properties (dielectric constant and dielectric tangent)]
The resin sheets prepared in the examples and comparative examples were heated at 200°C for 90 minutes to heat-cure the resin composition layer. The support was then peeled off to obtain "resin composition cured product A". The resin composition cured product A was cut into a test piece having a width of 2 mm and a length of 80 mm. The dielectric constant Dk and dielectric loss tangent Df of the test piece were measured at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C using an Agilent Technologies "HP8362B" by a cavity resonance perturbation method. Measurements were performed on three test pieces, and the average values are shown in the table below.

[Measurement of plating peel strength]
(1) Surface preparation of inner layer circuit board:
As an inner layer circuit board, a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, Panasonic "R1515A") having inner layer circuits (copper foil) on both sides was prepared. Both sides of this inner layer circuit board were etched by 1 μm using MEC "CZ8101" to roughen the copper surface.

(2) Lamination of resin sheet:
The resin sheet was laminated on both sides of the inner layer circuit board using a batch type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator, CVP700). This lamination was performed so that the resin composition layer of the resin sheet was in contact with the inner layer circuit board. This lamination was also performed by reducing the pressure for 30 seconds to 13 hPa or less, and pressing at 130°C and a pressure of 0.74 MPa for 45 seconds. Next, a heat press was performed at 120°C and a pressure of 0.5 MPa for 75 seconds.

(3) Curing of resin composition:
The laminated resin sheet and the inner layer circuit board were heated at 130° C. for 30 minutes, and then heated at 170° C. for 30 minutes to harden the resin composition and form an insulating layer. Thereafter, the support was peeled off to obtain a laminated substrate having the insulating layer, the inner layer circuit board, and the insulating layer in this order.

(4) Roughening treatment:
The laminated substrate was immersed in a swelling liquid (Swelling Dip Securigant P (aqueous solution of glycol ethers and sodium hydroxide) containing diethylene glycol monobutyl ether, manufactured by Atotech Japan) at 60° C. for 10 minutes. Next, the laminated substrate was immersed in a roughening liquid (Concentrate Compact P (aqueous solution of KMnO ₄ : 60 g/L, NaOH: 40 g/L) manufactured by Atotech Japan) at 80° C. for 20 minutes. Thereafter, the laminated substrate was immersed in a neutralizing liquid (Reduction Showreusin Securigant P (aqueous solution of sulfuric acid) manufactured by Atotech Japan) at 40° C. for 5 minutes. The laminated substrate was then dried at 80° C. for 30 minutes to obtain "Evaluation Substrate A".

(5) Semi-additive plating:
Evaluation substrate A 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 that, it was heated at 150°C for 30 minutes and annealed. After that, an etching resist was formed, and a pattern was formed by etching. Then, copper sulfate electrolytic plating was performed to form a conductor layer with a thickness of 20 μm. Next, an annealing treatment was performed at 200°C for 60 minutes to obtain "evaluation substrate B".

(6) Measurement of plating peel strength:
A cut was made in the conductor layer of evaluation board B, surrounding a rectangular portion having a width of 10 mm and a length of 100 mm. One end of the rectangular portion was peeled off and gripped with a gripper (Autocom type testing machine "AC-50C-SL" manufactured by TSE Corporation). The rectangular portion was peeled off in the vertical direction at room temperature at a speed of 50 mm/min using the gripper, and the load (kgf/cm) when 35 mm had been peeled off was measured as the plating peel strength.

[Measurement of surface roughness Ra]
The arithmetic mean roughness Ra of the surface of the insulating layer of the evaluation substrate A was measured. The measurement was performed using a non-contact surface roughness meter (WYKO NT3300 manufactured by Veeco Instruments) in VSI mode with a 50x lens and a measurement range of 121 μm × 92 μm. This measurement was performed at 10 measurement points, and the average values are shown in the table below.

[Measurement of glass transition temperature]
The cured resin composition A was cut into a test piece having a width of about 5 mm and a length of about 15 mm, and a thermomechanical analysis was performed by a tensile load method using a dynamic viscoelasticity measuring device (EXSTAR6000, manufactured by SII Nano Technology Co., Ltd.). After mounting the test piece on the device, the measurement was performed under the measurement conditions of a load of 200 mN and a heating rate of 2°C/min. The peak top of the obtained tan δ was calculated as the glass transition temperature (°C).

＊表中、（Ａ）成分の含有量は、樹脂組成物中の樹脂成分を１００質量％とした場合の（Ａ）成分の含有量を表す。（Ｅ）成分の含有量は、樹脂組成物中の不揮発成分を１００質量％とした場合の（Ｅ）成分の含有量を表す。（Ｃ）成分／（Ｂ）成分は、［活性エステル系硬化剤の活性基の合計数］／［エポキシ樹脂のエポキシ基の合計数］の比率を表し、ここで［エポキシ樹脂のエポキシ基の合計数］とは、樹脂組成物中に存在するエポキシ樹脂の不揮発成分の質量をエポキシ当量で除した値を全て合計した値であり、［活性エステル系硬化剤の活性基の合計数」とは、樹脂組成物中に存在する活性エステル系硬化剤の不揮発成分の質量を活性エステル基当量で除した値を全て合計した値である。

*In the table, the content of the (A) component represents the content of the (A) component when the resin component in the resin composition is 100% by mass. The content of the (E) component represents the content of the (E) component when the non-volatile component in the resin composition is 100% by mass. The (C) component/(B) component represents the ratio of [total number of active groups of the active ester curing agent]/[total number of epoxy groups of the epoxy resin], where [total number of epoxy groups of the epoxy resin] is the total value obtained by dividing the mass of the non-volatile component of the epoxy resin present in the resin composition by the epoxy equivalent, and [total number of active groups of the active ester curing agent] is the total value obtained by dividing the mass of the non-volatile component of the active ester curing agent present in the resin composition by the active ester group equivalent .

Claims (14)

(A) a polyether ether ketone compound having a maleimide group,
(B) an epoxy resin,
(C) an active ester curing agent; and (E) an inorganic filler,
The content of the component (A) is 1% by mass or more and 25% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass,
The content of the (B) component is 5% by mass or more and 30% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass,
The content of the component (C) is 1% by mass or more and 30% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass,
A resin composition, wherein the content of the component (E) is 40% by mass or more and 65% by mass or less, when the total amount of non-volatile components in the resin composition is 100% by mass. The resin composition according to claim 1, wherein the number average molecular weight of component (A) is 10,000 or less. The resin composition according to claim 1 or 2, wherein component (A) has a maleimide group at the end. The resin composition according to any one of claims 1 to 3, in which the content of component (A) is 5% by mass or more and 60% by mass or less, assuming that the resin component, which is the non-volatile component in the resin composition excluding the inorganic filler, is 100% by mass. The resin composition according to any one of claims 1 to 4, wherein component (B) contains a naphthol-type epoxy resin. The resin composition according to any one of claims 1 to 5, wherein component (C) is at least one selected from dicyclopentadiene-type active ester-based curing agents and naphthalene-type active ester-based curing agents containing a naphthalene structure. the quantitative ratio of component (B) to component (C) is, as a ratio of the total number of active groups in component (C) to the total number of epoxy groups in component (B), 0.01 or more and 5 or less ;
The total number of epoxy groups in the component (B) is a value obtained by dividing the mass of the non-volatile components of the component (B) present in the resin composition by the epoxy equivalent, and
The total number of active groups of the component (C) is a value obtained by dividing the mass of the non-volatile component (C) present in the resin composition by the active ester group equivalent. The resin composition according to any one of claims 1 to 6. The resin composition according to any one of claims 1 to 7, further comprising (D) a resin having a polymerizable unsaturated group different from component (A). The resin composition according to claim 8, wherein component (D) is a resin containing a maleimide group and an aromatic ring. The resin composition according to any one of claims 1 to 9, which is used to form an insulating layer. The resin composition according to any one of claims 1 to 10, which is a resin composition for forming an insulating layer when a conductor layer is formed on an insulating layer . A resin sheet comprising a support and a resin composition layer provided on the support, the resin composition comprising the resin composition according to any one of claims 1 to 11. A printed wiring board comprising an insulating layer formed from a cured product of the resin composition according to any one of claims 1 to 11. A semiconductor device including the printed wiring board according to claim 13.