JP7803333B2 - resin composition - Google Patents

Description

The present invention relates to a resin composition, as well as a cured product, resin sheet, circuit board, and semiconductor device obtained using the resin composition.

Circuit boards, such as printed wiring boards and rewiring boards for semiconductor chip packages, are provided with insulating layers. Insulating layers are generally formed by curing a resin composition. The insulating layers of circuit boards are required to exhibit good dielectric properties (low dielectric constant, low dielectric loss tangent) to reduce transmission loss when operating in a high-frequency environment.
As a resin material that provides a cured product exhibiting good dielectric properties, for example, a resin composition containing a maleimide resin has been reported (Patent Document 1).

JP 2012-116941 A

As disclosed in Patent Document 1, while resin compositions containing maleimide resins generally produce cured products with good dielectric properties, they tend to be prone to cracking after desmearing. Furthermore, because maleimide resins typically have a high softening point, cured products of resin compositions containing maleimide resins tend to be brittle and have poor mechanical properties.

The present invention aims to provide a resin composition that exhibits good dielectric properties and can produce a cured product with good mechanical properties, specifically high elongation at break and excellent crack resistance, as well as a cured product obtained using the resin composition, and a resin sheet, circuit board, and semiconductor device that include the resin composition.

The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by a resin composition containing, in combination with a maleimide resin, a compound having a specific structure and a thermosetting resin other than a maleimide resin, and have completed the present invention.
That is, the present invention includes the following.

[1] (A) Compound A represented by the following formula (A-1):
(In formula (A-1),
X represents a divalent group represented by the following formula (A-2) or a divalent group represented by the following formula (A-3):
(In formula (A-2),
R ¹¹ and R ¹² each independently represent a divalent aromatic group which may have a substituent;
Each L ¹¹ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹¹ and L ¹¹ may be bonded together to form a ring.
a represents a number ranging from 0 to 5.
(In formula (A-3),
R ¹³ and R ¹⁴ each independently represent a divalent aromatic group which may have a substituent;
^L12 represents a group represented by formula (A-4).
b and c each independently represent a number ranging from 0 to 5.
(In formula (A-4),
R ¹⁵ and R ¹⁶ each independently represent a divalent aromatic group which may have a substituent;
Each L ¹³ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹⁵ and L ¹³ may be bonded together to form a ring.
d represents a number ranging from 0 to 5.
(B) maleimide resin, and (C) thermosetting resin (excluding maleimide resin).
A resin composition comprising:
[2] The resin composition according to [1], wherein R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ in formula (A-2) and formula (A-3) each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent.
[3] The resin composition according to [1] or [2], wherein R ¹⁵ and R ¹⁶ in formula (A-4) each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent.
[4] The resin composition according to any one of [1] to [3], wherein L ¹¹ in formula (A-2) each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a divalent aromatic group which may have a substituent, a carbonyl group, or a sulfonyl group.
[5] The resin composition according to any one of [1] to [4], wherein L ¹¹ in formula (A-2) each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group.
[6] The resin composition according to any one of [1] to [5], wherein X in formula (A-1) is a group represented by the following formula (A-5):
(In formula (A-5),
Each Rs independently represents a substituent.
L ²¹ each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group, and when L ²¹ is a divalent aliphatic group which may have a substituent, L ²¹ and the benzene ring on the left side may be bonded together to form a ring,
n1 and n2 each independently represent a number ranging from 0 to 4;
m represents a number ranging from 0 to 5;
"*" represents a bond.)
[7] The resin composition according to any one of [1] to [6], wherein the content of the component (A) is 2% by mass or more and 12% by mass or less when the resin component in the resin composition is 100% by mass.
[8] When the resin component in the resin composition is 100% by mass, the content of the (B) component is 20% by mass or more and 75% by mass or less. The resin composition according to any one of [1] to [7].
[9] The resin composition according to any one of [1] to [8], wherein the component (C) includes one or more resins selected from the group consisting of epoxy resins, phenolic resins, and terminal double bond resins.
[10] When the resin component in the resin composition is 100% by mass, the thermosetting resin (C) is 10% by mass or more and 50% by mass or less. [1] The resin composition according to any one of [1] to [9].
[11] The resin composition according to any one of [1] to [10], further comprising (D) a thermoplastic resin.
[12] The resin composition according to any one of [1] to [11], further comprising (E) an inorganic filler.
[13] The resin composition according to [12], wherein the content of the component (E) is 50% by mass or more when the nonvolatile components in the resin composition are 100% by mass.
[14] The resin composition according to any one of [1] to [13], which is for use in an insulating layer of a circuit board.
[15] A cured product of the resin composition according to any one of [1] to [13].
[16] A resin sheet comprising a support and a layer of the resin composition according to any one of [1] to [13] provided on the support.
[17] The resin sheet according to [16], wherein the support is a thermoplastic resin film or a metal foil.
[18] A circuit board comprising an insulating layer made of a cured product of the resin composition according to any one of [1] to [13].
[19] A semiconductor device comprising the circuit board according to [18].

The resin composition of the present invention can provide a cured product that exhibits good dielectric properties and good mechanical properties, specifically high elongation at break and excellent crack resistance, as well as cured products, resin sheets, circuit boards, and semiconductor devices obtained using the resin composition.

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 can be modified and implemented as desired without departing from the scope of the claims and their equivalents.

As used herein, the term "optionally substituted" when referring to a compound or group means both cases where the hydrogen atoms of the compound or group are not substituted with substituents, and cases where some or all of the hydrogen atoms of the compound or group are substituted with substituents.

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

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

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

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

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

The alkenyl group used as a substituent is a monovalent unsaturated hydrocarbon group having one carbon-carbon double bond, and may be either linear or branched. The alkenyl group preferably has 2 to 20 carbon atoms, more preferably 2 to 12, and even more preferably 2 to 6. Examples of the alkenyl group include vinyl, allyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, and decenyl groups.

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

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

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

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

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

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

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

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

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

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

As used herein, the term "aromatic ring" refers to a ring conforming to Hückel's rule, in which the number of electrons in the π-electron system of the ring is 4p+2 (p is a natural number). An aromatic ring may be an aromatic carbocyclic ring containing only carbon atoms as ring constituent atoms, or an aromatic heterocyclic ring containing heteroatoms such as oxygen, nitrogen, and sulfur atoms in addition to carbon atoms as ring constituent atoms. The aromatic ring is preferably an aromatic carbocyclic ring. Furthermore, aromatic rings such as aromatic carbocyclic rings are preferably 5- to 14-membered aromatic rings, more preferably 6- to 14-membered aromatic rings, and even more preferably 6- to 10-membered aromatic rings. Specific examples of suitable aromatic carbocyclic rings include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. A benzene ring or a naphthalene ring is more preferred, and a benzene ring is particularly preferred.

As used herein, the term "non-aromatic ring" refers to a ring other than an aromatic ring that has aromaticity throughout the ring. The non-aromatic ring may be a non-aromatic carbocyclic ring having only carbon atoms as ring-constituting atoms, or a non-aromatic heterocyclic ring having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms as ring-constituting atoms in addition to carbon atoms. The non-aromatic ring is preferably a non-aromatic carbocyclic ring. The non-aromatic ring may be a saturated ring or an unsaturated ring. The non-aromatic ring is preferably a 3- to 21-membered non-aromatic ring, more preferably a 4- to 17-membered non-aromatic ring, and even more preferably a 5- to 14-membered non-aromatic ring. Specific preferred examples of the non-aromatic ring (non-aromatic carbocycle) include monocyclic non-aromatic saturated carbocycles such as a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, and a cyclooctane ring; monocyclic non-aromatic unsaturated carbocycles such as a cyclobutene ring, a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, a cyclooctene ring, a cyclopentadiene ring, and a cyclohexadiene ring; bicyclo[2.2.1]heptane ring (norbornane ring), bicyclo[4.4.0]decane ring (decalin ring), bicyclo[5.3.0]decane ring, bicyclo[4.3.0]nonane ring (hydrindane ring), bicyclo[3.2.1]octane ring, bicyclo[5.4.0]undecane ring, bicyclo[3.3.0]octane ring, bicyclo[3.3.1]nonane ring, tricyclo[5.2.1.0 ^2,6 and bicyclic or higher non-aromatic saturated carbocyclic rings such as a bicyclo[ ^2.2.1 ]hept- ^2- ene ring (norbornene ring), a bicyclo[2.2.2]oct-2-ene ring, and a bicyclo[4.4.0]dec-2-ene ring. The non-aromatic ring may be a non-aromatic ring partially fused with an aromatic ring. Examples of the non-aromatic ring partially condensed with an aromatic ring include an indane ring, an indene ring, a tetralin ring, a 1,2-dihydronaphthalene ring, a 1,4-dihydronaphthalene ring, a fluorene ring, a 9,10-dihydroanthracene ring, and a 9,10-dihydrophenanthrene ring.

[Resin composition]
The resin composition of the present invention contains (A) a compound represented by formula (A-1) described below, (B) a maleimide resin, and (C) a thermosetting resin (excluding maleimide resins). In the present invention, by using the specific compound represented by formula (A-1) in combination with the maleimide resin, it is possible to obtain a cured product that has excellent crack resistance after a desmear treatment, and by further containing a thermosetting resin (excluding maleimide resins), it is possible to obtain a cured product that has good mechanical properties, specifically, high elongation at break.

The resin composition may contain optional components in addition to the above-mentioned components (A) to (C). Examples of optional components include (D) thermoplastic resin, (E) inorganic filler, (F) radical reaction initiator, (G) curing accelerator, and other additives. Each component contained in the resin composition is described in detail below.

[(A) Compound represented by formula (A-1)]
The resin composition of the present invention contains, as component (A), a compound represented by the following formula (A-1):

(In formula (A-1),
X represents a divalent group represented by the following formula (A-2) or a divalent group represented by the following formula (A-3):

(In formula (A-2),
R ¹¹ and R ¹² each independently represent a divalent aromatic group which may have a substituent;
Each L ¹¹ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹¹ and L ¹¹ may be bonded together to form a ring.
a represents a number ranging from 0 to 5.

(In formula (A-3),
R ¹³ and R ¹⁴ each independently represent a divalent aromatic group which may have a substituent;
^L12 represents a group represented by formula (A-4).
b and c each independently represent a number ranging from 0 to 5.

(In formula (A-4),
R ¹⁵ and R ¹⁶ each independently represent a divalent aromatic group which may have a substituent;
Each L ¹³ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹⁵ and L ¹³ may be bonded together to form a ring.
d represents a number ranging from 0 to 5.

The component (A) of the present invention functions as a crosslinking agent for the maleimide resin (B). The resin composition of the present invention, which contains the component (A) in combination with the maleimide resin, can produce a cured product that exhibits excellent crack resistance. The component (A) may be used alone or in combination of two or more types.

In formula (A-1), X represents a divalent group represented by formula (A-2) or a divalent group represented by formula (A-3).

In formula (A-2), R ¹¹ and R ¹² each independently represent a divalent aromatic group which may have a substituent. A divalent aromatic group refers to a group obtained by removing two hydrogen atoms from the aromatic ring of an aromatic compound. Examples of the divalent aromatic group which may have a substituent include an arylene group which may have a substituent and a heteroarylene group which may have a substituent. The number of carbon atoms in the divalent aromatic group is preferably 3 or more, more preferably 4 or more or 5 or more, and even more preferably 6 or more, and the upper limit is preferably 30 or less, more preferably 24 or less, even more preferably 18 or less or 14 or less, and particularly preferably 10 or less. The number of carbon atoms does not include the number of carbon atoms of the substituent.

In a preferred embodiment, the divalent aromatic groups represented by R ¹¹ and R ¹² are each independently an optionally substituted phenylene group; an optionally substituted naphthylene group; an optionally substituted phenylene-fluorenylidene-phenylene group; or an optionally substituted biphenylene group; more preferably an optionally substituted phenylene group or an optionally substituted naphthylene group, with an optionally substituted phenylene group being particularly preferred. When the divalent aromatic group has a substituent, the substituent is as described above, but among these, one or more selected from the group consisting of an alkyl group, an alkenyl group, and a hydroxy group are preferred, and one or more selected from the group consisting of a methyl group, an allyl group, and a hydroxy group are more preferred.

In formula (A-2), ^L11 each independently represent a single bond or a divalent linking group which may have a substituent. Examples of the divalent linking group which may have a substituent include a divalent organic group consisting of one or more (e.g., 1 to 3,000, 1 to 1,000, 1 to 100, or 1 to 50) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms, and an oxygen atom, a carbonyl group, a sulfonyl group, a divalent aliphatic group which may have a substituent, or a divalent aromatic group which may have a substituent is preferred.

In a preferred embodiment, each L ¹¹ independently represents a single bond, an optionally substituted divalent aliphatic group, an oxygen atom, an optionally substituted divalent aromatic group, a carbonyl group, or a sulfonyl group.

Examples of the divalent aliphatic group for ^L11 include an alkylene group, a cycloalkylene group, an alkenylene group, a cycloalkenylene group, and an alkapolyenylene group (the number of double bonds is preferably 2 to 10, more preferably 2 to 6, even more preferably 2 to 4, and still more preferably 2). Of these, an alkylene group, a cycloalkylene group, an alkenylene group, and a cycloalkenylene group are preferred, an alkylene group and a cycloalkylene group are more preferred, and a cycloalkylene group is even more preferred.

The alkylene group for ^L11 may be linear or branched, and preferably has 1 to 12 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 4. The number of carbon atoms does not include the number of carbon atoms of the substituent. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a 2-propylene group, a 1,1-dimethyl-3-methylpropylene group, a butylene group, a pentylene group, and a hexylene group.

The number of carbon atoms of the cycloalkylene group for ^L11 is preferably 3 to 15, more preferably 3 to 12, and even more preferably 3 to 10. The number of carbon atoms of the substituent is not included in this number of carbon atoms. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a decahydronaphthalene group, a norbornanylene group, a dicyclopentanylene group, and an adamantanylene group, with a dicyclopentanylene group being preferred.

The alkenylene group for ^L11 may be linear or branched, and preferably has 2 to 12 carbon atoms, more preferably 2 to 6, and even more preferably 2 to 4. The number of carbon atoms does not include the number of carbon atoms of substituents. Examples of the alkenylene group include an ethenylene group, a propenylene group, a butenylene group, a pentenylene group, and a hexenylene group.

The number of carbon atoms in the cycloalkenylene group for ^L11 is preferably 3 to 15, more preferably 3 to 12, and even more preferably 3 to 10. The number of carbon atoms in the substituent is not included in this number of carbon atoms. Examples of the cycloalkenylene group include a cyclopropenylene group, a cyclobutenylene group, a cyclopentenylene group, a cyclohexenylene group, and a norbornenylene group.

Examples of the divalent aromatic group for L ¹¹ include an arylene group and a heteroarylene group, and an arylene group is preferred.

The number of carbon atoms in the arylene group in ^L11 is preferably 6 to 24, more preferably 6 to 18, and even more preferably 6 to 14. The number of carbon atoms in the substituent is not included in this number of carbon atoms. Examples of the arylene group include a phenylene group, a naphthylene group, an anthracenylene group, a fluorenediyl group (e.g., a 9H-fluorene-9,9-diyl group), a fluorenylidene group, a phenanthrenediyl group, an indanediyl group, and a pyrenediyl group, with a phenylene group and a fluorenylidene group being preferred.

The number of carbon atoms of the heteroarylene group for ^L11 is preferably 3 to 21, more preferably 3 to 15, and even more preferably 3 to 9. The number of carbon atoms of the substituent is not included in this number of carbon atoms. Examples of the heteroarylene group include a pyrrolediyl group, a furandiyl group, a thiophenediyl group, a pyridinediyl group, a pyridazinediyl group, a pyrimidinediyl group, a pyrazinediyl group, a triazinediyl group, a piperidinediyl group, a triazolediyl group, a purinediyl group, a carbazolediyl group, a quinolinediyl group, and an isoquinolinediyl group.

^R11 and ^L11 may be bonded together to form a ring. In this case, ^L11 is preferably a divalent aliphatic group which may have a substituent, and more preferably an alkylene group which may have a substituent. When ^R11 and ^L11 are bonded together to form a ring, it is preferable that a phenylene group and a cyclopentylene group are bonded together to form an indane ring.

Preferably, L ¹¹ each independently represents a single bond, an optionally substituted divalent aliphatic group, an oxygen atom, an optionally substituted divalent aromatic group, a carbonyl group, or a sulfonyl group, more preferably a single bond, an optionally substituted divalent aliphatic group, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group, and more preferably a single bond, an oxygen atom, a carbonyl group, a sulfonyl group, an optionally substituted alkylene group having 1 to 12 carbon atoms, or an optionally substituted cycloalkylene group having 3 to 15 carbon atoms, or an optionally substituted arylene group having 6 to 24 carbon atoms. The substituents that ^{L 11} may have are as described above, but are preferably one or more selected from the group consisting of alkyl groups, alkenyl groups, and hydroxy groups, and more preferably one or more selected from the group consisting of methyl groups, allyl groups, and hydroxy groups.

In formula (A-2), a represents a number ranging from 0 to 5, preferably from 0 to 4, more preferably from 0 to 3 or from 0 to 2.

In formula (A-3), R ¹³ and R ¹⁴ each independently represent a divalent aromatic group which may have a substituent. The divalent aromatic group may be the same as the divalent aromatic group represented by R ¹¹ and R ¹² in formula (A-2). In a preferred embodiment, the divalent aromatic groups represented by R ¹³ and R ¹⁴ are each independently a phenylene group which may have a substituent, or a naphthylene group which may have a substituent, more preferably a phenylene group which may have a substituent. When the divalent aromatic group has a substituent, the substituent is as described above, but among them, one or more selected from the group consisting of an alkyl group, an alkenyl group, and a hydroxy group are preferred, and one or more selected from the group consisting of a methyl group, an allyl group, and a hydroxy group are more preferred.

In formula (A-3), L ¹² represents a group represented by formula (A-4).

In formula (A-4), R ¹⁵ and R ¹⁶ each independently represent a divalent aromatic group which may have a substituent. The divalent aromatic groups represented by ^{R 15} and R ¹⁶ may be the same as the divalent aromatic groups represented by R ¹¹ and R ¹² in formula (A-2). In a preferred embodiment, the divalent aromatic group represented by R ¹⁵ and R ¹⁶ is a phenylene group which may have a substituent, or a naphthylene group which may have a substituent, and more preferably a phenylene group which may have a substituent. When the divalent aromatic group has a substituent, the substituent is as described above, and among them, one or more selected from the group consisting of an alkyl group, an alkenyl group, and a hydroxy group are preferred, and one or more selected from the group consisting of a methyl group, an allyl group, and a hydroxy group are more preferred.

In formula (A-4), L ¹³ each independently represents a single bond or a divalent linking group which may have a substituent. The divalent linking group in ^{L 13} may be the same as the divalent linking group in L ¹¹ in formula (A-2). In a preferred embodiment, the divalent linking group represented by L ¹³ is an alkylene group having 1 to 12 carbon atoms which may have a substituent. The substituent which L ¹³ may have is as described above, and may be the same as the substituent which L ¹¹ may have.

In formula (A-4), d represents a number ranging from 0 to 5, preferably 0 to 4, more preferably 0 to 3 or 0 to 2. ^{R 15} and L ¹³ may be bonded together to form a ring. In this case, L ¹³ is preferably a divalent aliphatic group which may have a substituent, and more preferably an alkylene group which may have a substituent. In addition, when R ¹⁵ and L ¹³ are bonded together to form a ring, it is preferable that a phenylene group and a cyclopentylene group are bonded together to form an indane ring.

In formula (A-3), b and c each independently represent a number ranging from 0 to 5, preferably from 0 to 4, more preferably from 0 to 3 or from 0 to 2.

In particular, from the viewpoint of being able to realize a resin composition that, in combination with components (B) and (C), exhibits good dielectric properties and also good mechanical properties (high elongation at break) and provides a cured product with excellent crack resistance, when X is a divalent group represented by formula (A-2), the divalent group represented by formula (A-2), i.e., X, is preferably a divalent group represented by formula (A-5) below. From the same viewpoint, when X is a divalent group represented by formula (A-3), L ¹² in formula (A-3), i.e., the divalent group represented by formula (A-4), is preferably a divalent group represented by formula (A-5) below.

(In formula (A-5),
Each Rs independently represents a substituent.
L ²¹ each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group, and when L ²¹ is a divalent aliphatic group which may have a substituent, L ²¹ and the benzene ring on the left side may be bonded together to form a ring,
n1 and n2 each independently represent a number ranging from 0 to 4;
m represents a number ranging from 0 to 5;
"*" represents a bond.)

Each Rs independently represents a substituent. The substituents are as described above, but among them, one or more selected from the group consisting of alkyl groups, alkenyl groups, and hydroxy groups are preferred, and one or more selected from the group consisting of methyl groups, allyl groups, and hydroxy groups are more preferred.

L ²¹ each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group, and more preferably a single bond, an oxygen atom, a carbonyl group, a sulfonyl group, an alkylene group having 1 to 12 carbon atoms which may have a substituent, a cycloalkylene group having 3 to 15 carbon atoms which may have a substituent, or an arylene group having 6 to 24 carbon atoms which may have a substituent. The substituent that L ²¹ may have is as described above, and among these, one or more selected from the group consisting of an alkyl group, an alkenyl group, and a hydroxy group are preferred, and one or more selected from the group consisting of a methyl group, an allyl group, and a hydroxy group are more preferred.

When ^L21 is a divalent aliphatic group which may have a substituent, ^L21 and the left-side benzene ring may be bonded together to form a ring, in which case it is preferable that the cyclopentylene group and the left-side benzene ring be bonded to form an indane ring.

n1 and n2 each independently represent a number ranging from 0 to 4, preferably 0 to 4, more preferably 0 to 3 or 0 to 2.

m represents a number ranging from 0 to 5, preferably 0 to 4, more preferably 0 to 3, or 0 to 2. From the perspective of better enjoying the effects of the present invention, it is particularly preferable that m be 1 or 2.

In one particularly preferred embodiment from the viewpoint of further enjoying the effects of the present invention,
X in formula (A-1) represents a divalent group represented by formula (A-2):
R ¹¹ and R ¹² each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent;
L ¹¹ each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group;
a represents a number ranging from 0 to 5, and R ¹¹ and L ¹¹ may be bonded together to form a ring. Among these, the divalent group represented by formula (A-2) is preferably a divalent group represented by formula (A-5). In such an embodiment, suitable types of substituents are as described above.

In another embodiment that is particularly preferable from the viewpoint of further enjoying the effects of the present invention,
X in formula (A-1) represents a divalent group represented by formula (A-3):
R ¹³ and R ¹⁴ each independently represent a phenylene group which may have a substituent;
b and c each independently represent a number ranging from 0 to 5;
L ¹² is a group represented by formula (A-4),
R ¹⁵ and R ¹⁶ each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent;
L ¹³ each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group;
d represents a number ranging from 0 to 5, and R ¹⁵ and L ¹³ may be bonded together to form a ring. Among these, the divalent group represented by formula (A-4) is preferably a divalent group represented by formula (A-5). In such an embodiment, suitable types of substituents are as described above.

The component (A) is, for example,
1) 1-phenyl-1-propene-3-halide,
2) dihydric phenol compounds,
can be obtained by a condensation reaction.

1-Phenyl-1-propene-3-halides are compounds in which a halogen is bonded to the three ends of 1-phenyl-1-propene. Examples of such compounds include 3-bromo-1-phenyl-1-propene.

A divalent phenol compound is a compound in which the phenol moiety of the compound can react with 1-phenyl-1-propene-3-halide and can constitute X in formula (A-1). Examples of such compounds include various bisphenol compounds such as 4,4'-methylenebis(2,6-dimethylphenol), 4,4'-(9-fluorenylidene)diphenol, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxybenzophenone, bisphenol A, bisphenol F, 2,2'-diallylbisphenol A, and bisphenol S; various biphenyl compounds such as 4,4'-dihydroxybiphenyl; dihydroxyaryl compounds such as 2,7-naphthalenediol; and polyphenylene ether compounds having hydroxy groups at both ends.

A base may be used in the condensation reaction. Examples of bases include alkali metal hydroxides such as sodium hydroxide (caustic soda) and potassium hydroxide; and tertiary amines such as triethylamine, pyridine, and N,N-diisopropylethylamine. A single base may be used alone, or two or more bases may be used in combination.

The condensation reaction may be carried out in a solvent-free system without using a solvent, or in an organic solvent system using an organic solvent. Examples of organic solvents include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; acetate-based solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; carbitol-based solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; and amide-based solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. These organic solvents may be used alone or in combination.

The reaction temperature may be, for example, in the range of 0 to 80°C. The reaction time may be, for example, in the range of 30 minutes to 24 hours.

After the reaction is complete, if necessary, a purification step such as water washing or microfiltration may be carried out to remove by-product salts and excess starting materials from the system. Specifically, an amount of water necessary to dissolve the by-product salts is added and stirred, and the aqueous layer is then discarded. The organic layer is then dried, and if necessary, the organic solvent is distilled off to obtain the compound of the present invention. The organic solvent may also be used as is as a solvent for the resin composition without being completely removed.

When combined with components (B) and (C), the resin composition exhibits good dielectric properties. Furthermore, the incorporation of the alkylene ether skeleton of (A) into the curing system reduces the rigidity of the maleimide, ensuring flexibility. This results in a resin composition that exhibits good mechanical properties (high elongation at break) and produces a cured product with excellent crack resistance. From this perspective, the content of component (A) in the resin composition, taken as 100% by mass of the resin components in the resin composition, is preferably 2% or 3% by mass or more, more preferably 5% by mass or more, even more preferably 7% by mass or more, still more preferably 7.5% by mass or more, or 8% by mass or more. The upper limit is preferably 15% by mass or less, more preferably 12% by mass or less, even more preferably 11% by mass or less, 10% by mass or less, or 9.5% by mass or less. Therefore, in one embodiment, the content of component (A) is 2% by mass or more and 12% by mass or less, taken as 100% by mass of the resin components in the resin composition.

In the present invention, the term "resin component" used in reference to a resin composition refers to the non-volatile components constituting the resin composition, excluding the inorganic filler described below.

[(B) Maleimide resin]
The resin composition of the present invention contains a maleimide resin as component (B).

There are no particular restrictions on the type of maleimide resin, as long as it contains one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) per molecule. Component (B) may be used alone or in combination of two or more.

Component (B) may be an aromatic maleimide resin having a maleimide group directly bonded to an aromatic ring, or an aliphatic maleimide resin not having a maleimide group directly bonded to an aromatic ring. When component (B) contains an aliphatic maleimide resin, the aliphatic maleimide resin preferably contains a maleimide resin having a carbon skeleton derived from a dimer acid. When component (B) contains an aromatic maleimide resin, the aromatic maleimide resin preferably contains a maleimide resin having one or more skeletons selected from a biphenyl skeleton and an indane skeleton. Therefore, component (B) preferably contains a maleimide resin having one or more skeletons selected from a carbon skeleton derived from a dimer acid, a biphenyl skeleton, and an indane skeleton.

A carbon skeleton derived from a dimer acid refers to a carbon skeleton obtained by removing the two terminal carboxyl groups (—COOH) of a dimer acid, or a carbon skeleton obtained by replacing the two terminal carboxyl groups (—COOH) with methylene groups (—CH ₂ —). Dimer acids are known compounds obtained by dimerizing unsaturated fatty acids (preferably those having 11 to 22 carbon atoms, more preferably those having 14 to 20 carbon atoms, and particularly preferably those having 18 carbon atoms), and their industrial production process is largely standardized in the industry. Dimer acids are readily available, particularly those whose main component is a 36-carbon dimer acid obtained by dimerizing an 18-carbon unsaturated fatty acid, such as oleic acid or linoleic acid, which are inexpensive and readily available. Furthermore, dimer acids may contain arbitrary amounts of monomer acid, trimer acid, other polymerized fatty acids, etc., depending on the production method, degree of purification, etc. Furthermore, although double bonds remain after the polymerization reaction of unsaturated fatty acids, in this specification, hydrogenated products obtained by further hydrogenation to reduce the degree of unsaturation are also included in the term dimer acid.

The maleimide resin having a carbon skeleton derived from a dimer acid preferably includes a maleimide resin represented by the following formula (B1):

(In formula (B1),
n ₁ + 1 Xs each independently represent a divalent organic group consisting of five or more skeletal atoms selected from carbon atoms, nitrogen atoms (not forming an imide), oxygen atoms, and sulfur atoms, and non-skeletal atoms selected from hydrogen atoms and halogen atoms, and at least one of the n + 1 Xs represents a divalent hydrocarbon group derived from a dimer acid;
n Y's _each independently represent a tetravalent organic group consisting of five or more skeletal atoms selected from carbon atoms, nitrogen atoms (not forming an imide), oxygen atoms, and sulfur atoms, and non-skeletal atoms selected from hydrogen atoms and halogen atoms;
_n1 represents an integer of 0 or 1 or more.

In formula (B1), n ₁ + 1 Xs each independently represent a divalent organic group consisting of 5 or more (preferably 5 to 200, more preferably 5 to 100, and even more preferably 5 to 50) skeletal atoms selected from carbon atoms, nitrogen atoms (not forming imides), oxygen atoms, and sulfur atoms, and non-skeletal atoms selected from hydrogen atoms and halogen atoms, and at least one of the n + 1 Xs represents a divalent hydrocarbon group derived from a dimer acid.

The divalent hydrocarbon group derived from a dimer acid means a divalent hydrocarbon group obtained by removing the two terminal carboxy groups (—COOH) of a dimer acid, or a divalent hydrocarbon group obtained by replacing the two terminal carboxy groups (—COOH) with methylene groups (—CH ₂ —).

The n ₁ + 1 Xs may have a divalent organic group other than a divalent hydrocarbon group derived from a dimer acid, but when the n ₁ + 1 Xs are taken as 100 mol %, it is preferable that 30 mol % or more of them are divalent hydrocarbon groups derived from a dimer acid, more preferably 60 mol % or more of them are divalent hydrocarbon groups derived from a dimer acid, even more preferably 90 mol % or more of them are divalent hydrocarbon groups derived from a dimer acid, and even more preferably that (all) the n ₁ + 1 Xs are divalent hydrocarbon groups derived from a dimer acid.

The divalent organic group other than the divalent hydrocarbon group derived from a dimer acid in the n ₁ +1 Xs may be a divalent organic group without an aromatic ring, or may be a divalent organic group with an aromatic ring.

In formula (B1), _n1 Ys each independently represent a tetravalent organic group consisting of five or more (preferably 5 to 200, more preferably 5 to 100, and even more preferably 5 to 50) skeletal atoms selected from carbon atoms, nitrogen atoms (not forming imides), oxygen atoms, and sulfur atoms, and non-skeletal atoms selected from hydrogen atoms and halogen atoms. The tetravalent organic group represented by Y may be a tetravalent organic group without an aromatic ring, or may be a tetravalent organic group with an aromatic ring.

In one embodiment, the tetravalent organic group represented by Y is preferably a tetravalent group selected from the following formulae (Y1) to (Y5):

(In formulas (Y1) to (Y5),
ring Y ¹¹ , ring Y ²¹ , ring Y ²² , ring Y ³¹ , ring Y ³² , ring Y ³³ , ring Y ⁴¹ , ring Y ⁴² , ring Y ⁴³ , ring Y ⁴⁴ , ring Y ⁵¹ , ring Y ⁵² , ring Y ⁵³ , ring Y ⁵⁴ and ring Y ⁵⁵ each independently represent an aromatic ring which may have a substituent or a non-aromatic ring which may have a substituent;
Y ^2a , Y ^3a , Y ^3b , Y ^4a , Y ^4b , Y ^4c , Y ^5a , Y ^5b , Y ^5c and Y ^5d each independently represent a single bond, —C(R ^y ) ₂ —, —O—, —CO—, —S—, —SO—, —SO ₂ —, —CONH—, or —NHCO—;
R ^y 's each independently represent a hydrogen atom or an alkyl group which may be substituted with a halogen atom, or two R ^y's bonded to the same carbon atom are bonded together to form a non-aromatic ring which may have a substituent;
* indicates a binding site;
The two bonding sites on the same ring represented by * are bonding sites to two adjacent carbon atoms on the ring.)

In formulae (Y1) to (Y5), ring Y ¹¹ , ring Y ²¹ , ring Y ²² , ring Y ³¹ , ring Y ³² , ring Y ³³ , ring Y ⁴¹ , ring Y ⁴² , ring Y ⁴³ , ring Y ⁴⁴ , ring Y ⁵¹ , ring Y ⁵² , ring Y ⁵³ , ring Y ⁵⁴ and ring Y ⁵⁵ each independently represent an aromatic ring which may have a substituent or a non-aromatic ring which may have a substituent. These cyclic structures are preferably aromatic rings which may have a substituent, more preferably benzene rings which may have a substituent, and even more preferably benzene rings which may be substituted with an alkyl group.

Substituents that ring Y ¹¹ , ring Y ²¹ , ring Y ²² , ring Y ³¹ , ring Y ³² , ring Y ³³ , ring Y ⁴¹ , ring Y ⁴² , ring Y ⁴³ , ring Y ⁴⁴ , ring Y ⁵¹ , ring ^{Y 52 ,} ring Y ⁵³ , ring Y 54 and ring Y ⁵⁵ may have are not particularly limited, and examples thereof include a halogen atom, —NO ₂ , —CN, —COH, —OH, —SH, —NH ₂ , —COOH, —R ^c , —COR ^c , —OR ^c , —SR ^c , —SOR ^c , —SO ₂ R ^c , —NHR ^c , —NR ^c ₂ , —COOR ^c , —OCOR ^c , —CONH ₂ , —CONHR ^c , —CONR ^c ₂ , —NHCOR ^c and the like (wherein R ^c is as defined above).
It is a aryl group.

In formulae (Y1) to (Y5), Y ^2a , Y ^3a , Y ^3b , Y ^4a , Y ^4b , Y ^4c , Y ^5a , Y ^5b , Y ^5c and Y ^5d each independently represent a single bond, —C(R ^y ) ₂ —, —O—, —CO—, —S—, —SO—, —SO ₂ —, —CONH—, or —NHCO—, and in one embodiment, preferably a single bond, —C(R ^y ) ₂ —, or —O—.

Each R ^y independently represents a hydrogen atom or an alkyl group which may be substituted with a halogen atom, or two R ^ys bonded to the same carbon atom bond together to form a non-aromatic ring which may have a substituent. The alkyl group may be the same as the alkyl group in R ^c . Each R ^y independently represents preferably a hydrogen atom or an alkyl group which may be substituted with a halogen atom; more preferably a hydrogen atom or a methyl group which may be substituted with a halogen atom; even more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group; particularly preferably a hydrogen atom or a methyl group.

The substituent that R ^y may have is not particularly limited, and examples thereof include monovalent substituents such as halogen atoms, -NO ₂ , -CN, -COH, -OH, -SH, -NH ₂ , -COOH, -R ^c , -COR ^c , -OR ^c , -SR ^c , -SOR ^c , -SO ₂ R ^c , -NHR ^c , -NR ^c ₂ , -COOR ^c , -OCOR ^c , -CONH ₂ , -CONHR ^c , -CONR ^c ₂ , and -NHCOR ^c (wherein R ^c is as defined above).

In formula (B1), _n1 represents 0 or an integer of 1 or more, preferably 0 or an integer of 1 to 10, and more preferably 0.

One type of maleimide resin having a carbon skeleton derived from dimer acid may be used alone, or two or more types may be used in combination.

Commercially available maleimide resins with a carbon skeleton derived from dimer acid include, for example, "BMI-689," "BMI-1500," "BMI-1700," and "BMI-3000J" manufactured by Designer Molecules, Inc., and "SLK-6895-T90" manufactured by Shin-Etsu Chemical Co., Ltd.

An example of an aromatic maleimide resin is a maleimide resin represented by formula (B2).

(In formula (B2),
R ¹⁰ each independently represents a hydrogen atom or an alkyl group optionally substituted with a halogen atom;
each ring D independently represents an aromatic carbocyclic ring which may have a substituent;
_n2 represents an integer of 1 or more;
The _n2 units may be the same or different for each unit.

In formula (B2), R ¹⁰ each independently represents a hydrogen atom or an alkyl group optionally substituted with a halogen atom. The alkyl group may be the same as the alkyl group in R ^c . ^{R 10} each independently preferably represents a hydrogen atom or an alkyl group; more preferably represents a hydrogen atom or a methyl group; and even more preferably represents a hydrogen atom.

In formula (B2), each ring D independently represents an aromatic carbocycle which may have a substituent. The aromatic carbocycle may be the same as the aromatic carbocycle described in the section on the ^aromatic rings in ring Y ¹¹ , ring Y ²¹ , ring Y ²² , ring Y ³¹ , ring Y ³² , ring Y ³³ , ^{ring Y 41 ,} ring Y ⁴² , ring Y ⁴³ , ring Y ⁴⁴ , ring Y ⁵¹ , ring Y ⁵² , ring Y 53 , ring Y 54 and ring Y ⁵⁵ . Furthermore, the "substituent" in ring D may be ^{the same as the substituent in the "optionally substituted aromatic ring" in, for example, ring Y 11 , ring Y 21 , ring Y 22 , ring Y 31 , ring Y 32 , ring} Y ³³ , ring Y ⁴¹ , ring Y ⁴² , ring Y ⁴³ , ring Y ⁴⁴ , ring Y 51 , ring Y 52 , ring Y 53 , ring Y 54 and ring Y ^55. Ring D preferably represents an optionally substituted benzene ring; more preferably represents a benzene ring optionally substituted with a group selected from an alkyl group and an aryl group; particularly preferably represents an (unsubstituted) benzene ring.

In formula (B2), _n2 represents an integer of 1 or more, and is preferably an integer of 1 to 10.

The maleimide resin having a biphenyl skeleton preferably includes a maleimide resin represented by the following formula (B3):

(In formula (B3),
R ²⁰ each independently represents a hydrogen atom or an alkyl group optionally substituted with a halogen atom;
Ring E, ring F, and ring G each independently represent an aromatic carbocyclic ring which may have a substituent;
_n3 represents an integer of 1 or more;
The _n3 units may be the same or different for each unit.

In formula (B3), ^R20 each independently represents a hydrogen atom or an alkyl group optionally substituted with a halogen atom. The alkyl group may be the same as the alkyl group in ^Rc . ^R20 each independently represents preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

In formula (B3), ring E, ring F, and ring G each independently represent an aromatic carbocycle which may have a substituent. The aromatic carbocycle may be the same ^{as the aromatic carbocycle described in the section on the aromatic rings in ring Y 11 , ring Y 21 , ring Y 22 , ring Y 31 , ring Y 32 , ring Y 33 , ring} Y ⁴¹ , ring Y ⁴² , ring Y ⁴³ , ring Y ⁴⁴ , ring Y ⁵¹ , ring Y 52 , ring Y ⁵³ , ring Y 54, and ring Y ^55. Ring E, ring F, and ring G are preferably benzene rings which may have a substituent, more preferably benzene rings which may be substituted with a group selected from an alkyl group and an aryl group, and even more preferably (unsubstituted) benzene rings.

Substituents that ring E, ring F, and ring G may have are not particularly limited, and examples thereof include monovalent substituents such as halogen atoms, -NO ₂ , -CN, -COH, -OH, -SH, -NH ₂ , -COOH, -R ^c , -COR ^c , -OR ^c , -SR ^c , -SOR ^c , -SO ₂ R ^c , -NHR ^c , -NR ^c ₂ , -COOR ^c , -OCOR ^c , -CONH ₂ , -CONHR ^c , -CONR ^c ₂ , and -NHCOR ^c (wherein R ^c is as defined above).

In formula (B3), _n3 represents an integer of 1 or more, and is preferably an integer of 1 to 10.

Commercially available maleimide resins with a biphenyl skeleton include, for example, "MIR-3000-70MT" and "MIR-5000-60T" manufactured by Nippon Kayaku Co., Ltd.

One type of maleimide resin having a biphenyl skeleton may be used alone, or two or more types may be used in combination.

The maleimide resin having an indane skeleton preferably includes a maleimide resin represented by the following formula (B4):

(In formula (B4),
Each R ³⁰ independently represents an alkyl group;
Ring H and ring I each independently represent an aromatic carbocyclic ring which may have a substituent;
_n4 represents an integer of 1 or more;
The _n4 units may be the same or different for each unit.

In formula (B4), each R ³⁰ independently represents an ^alkyl group, and preferably represents a methyl group.

In formula (B4), each ring H independently represents an aromatic ring which may have a substituent. Ring H is preferably a benzene ring which may have a substituent, more preferably a benzene ring which may have a substituent, and even more preferably a benzene ring substituted with an alkyl group.

In formula (B4), each ring I independently represents an aromatic ring which may have a substituent. Ring I is preferably a benzene ring which may have a substituent, more preferably a benzene ring which may be substituted with an alkyl group, and even more preferably an (unsubstituted) benzene ring.

Substituents that Ring H and Ring I may have are not particularly limited, and examples thereof include monovalent substituents such as halogen atoms, -NO ₂ , -CN, -COH, -OH, -SH, -NH ₂ , -COOH, -R ^c , -COR ^c , -OR ^c , -SR ^c , -SOR ^c , -SO ₂ R ^c , -NHR ^{c ,} -NR ^c ₂ , -COOR ^c , -OCOR c , -CONH ₂ , -CONHR ^c , -CONR ^c ₂ , and -NHCOR ^c (wherein R ^c is as defined above).

In formula (B4), _n4 represents an integer of 1 or more, and is preferably an integer of 1 to 20.

Maleimide resins having an indane skeleton can be produced, for example, using the method described in Japan Institute of Invention and Innovation's Technical Bulletin No. 2020-500211 or a method equivalent thereto.

One type of maleimide resin having an indane skeleton may be used alone, or two or more types may be used in combination.

The maleimide group equivalent of component (B) is preferably 50 g/eq. or more, more preferably 100 g/eq. or more, even more preferably 150 g/eq. or more, 200 g/eq. or more, 250 g/eq. or more, or 300 g/eq. or more, and its upper limit is preferably 2,000 g/eq. or less, more preferably 1,000 g/eq. or less, even more preferably 800 g/eq. or less, 600 g/eq. or less, 500 g/eq. or less, or 450 g/eq. or less. The maleimide group equivalent is the mass of component (B) per 1 molar equivalent of maleimide groups.

The molecular weight of component (B) is preferably less than 5,000, more preferably less than 3,000, even more preferably less than 2,000, less than 1,500, less than 1,200, or less than 1,000. There is no particular lower limit, but it can be, for example, 300 or more, 400 or more, or 500 or more.

In order to realize a resin composition that, when combined with components (A) and (C), exhibits good dielectric properties, good mechanical properties (high elongation at break), and produces a cured product with excellent crack resistance, the content of component (B) in the resin composition, relative to 100% by mass of the resin components in the resin composition, is preferably 20% by mass or 30% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more or 50% by mass or more. The upper limit of the content is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less or 65% by mass or less. Therefore, in one embodiment, relative to 100% by mass of the resin components in the resin composition, the content of component (B) is 20% by mass or more and 75% by mass or less.

From the viewpoint of being able to realize a resin composition that, when combined with component (C), exhibits even better dielectric properties, even better mechanical properties (high elongation at break), and produces a cured product with even more excellent crack resistance, the mass ratio of component (A) to component (B) (component (A)/component (B)) is preferably 0.02 or more, more preferably 0.04, even more preferably 0.06 or more or 0.08 or more, still more preferably 0.1 or more, 0.12 or more, or 0.14 or more, with the upper limit being preferably 0.4 or less, more preferably 0.3 or less, even more preferably 0.25 or less or 0.2 or less.

[(C) Thermosetting resin]
The resin composition of the present invention contains a thermosetting resin as component (C). The thermosetting resin as component (C) does not contain a maleimide resin.

Examples of component (C) include epoxy resins, phenolic resins, benzoxazine resins, active ester resins, cyanate ester resins, carbodiimide resins, amine resins, acid anhydride resins, and terminal double bond resins. The thermosetting resin may be used alone or in combination of two or more types in any ratio. Among these, from the viewpoint of being able to further enjoy the effects of the present invention, one or more types selected from the group consisting of epoxy resins, phenolic resins, and terminal double bond resins are preferred.
Phenol resins, naphthol resins, benzoxazine resins, active ester resins, cyanate ester resins, carbodiimide resins, amine resins, and acid anhydride resins also function as curing agents for epoxy resins, and are collectively referred to as epoxy resin curing agents.

-Epoxy resin-
The type of epoxy resin is not particularly limited as long as it has one or more (preferably two or more) epoxy groups per molecule. Examples of epoxy resins include bisphenol-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins. Bisphenol-type epoxy resins refer to epoxy resins having a bisphenol structure, such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins. Biphenyl-type epoxy resins refer to epoxy resins having a biphenyl structure, where the biphenyl structure may have a substituent such as an alkyl group, an alkoxy group, or an aryl group. Therefore, bixylenol-type epoxy resins and biphenylaralkyl-type epoxy resins are also included in biphenyl-type epoxy resins.

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

Preferably, the liquid epoxy resin is one having two or more epoxy groups per molecule.

Preferred liquid epoxy resins include glycerol-type epoxy resins, 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 with an ester skeleton, cyclohexanedimethanol-type epoxy resins, cycloaliphatic glycidyl ethers, and epoxy resins with a butadiene structure.

Specific examples of liquid epoxy resins include Nagase ChemteX's "EX-992L," Mitsubishi Chemical's "YX7400," and DIC's "HP4032," "HP4032D," and "HP4032SS" (naphthalene-type epoxy resins); Mitsubishi Chemical's "828US," "828EL," and "825" (bisphenol A-type epoxy resins); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F-type epoxy resins); "jER152" (phenol novolac type epoxy resin) manufactured by Ryo Chemical Co., Ltd.; "630", "630LSD", and "604" (glycidylamine type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycirol type epoxy resin) manufactured by ADEKA Corporation; "EP-3950L" and "EP-3980S" (glycidylamine type epoxy resins) manufactured by ADEKA Corporation; "EP-4088S" (dicyclopentadiene type epoxy resin) manufactured by ADEKA Corporation. ); "ZX1059" (a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EX-721" (glycidyl ester epoxy resin) manufactured by Nagase ChemteX Corporation; "EX-991L" (an epoxy resin containing an alkyleneoxy skeleton and a butadiene skeleton) manufactured by Nagase ChemteX Corporation; "Celloxide 2021P" (an alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation; Daicel Examples include "PB-3600" manufactured by Nippon Soda Co., Ltd., "JP-100" and "JP-200" (epoxy resins with a butadiene structure); "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane-type epoxy resins) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EG-280" (fluorene structure-containing epoxy resin) manufactured by Osaka Gas Chemicals Co., Ltd.; and "EX-201" (cyclic aliphatic glycidyl ether) manufactured by Nagase ChemteX Corporation.

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

Preferred solid epoxy resins include bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol novolac-type 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, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, and phenolphthalimidine-type epoxy resins.

Specific examples of solid epoxy resins include DIC Corporation's "HP4032H" (naphthalene-type epoxy resin); DIC Corporation's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resin); DIC Corporation's "N-690" (cresol novolac-type epoxy resin); DIC Corporation's "N-695" (cresol novolac-type epoxy resin); DIC Corporation's "HP-7200," "HP-7200HH," "HP-7200H," and "HP-7200L" (dicyclopentadiene-type epoxy resin); DIC Corporation's "EXA-7311" and "E XA-7311-G3, EXA-7311-G4, EXA-7311-G4S, HP-6000, HP-6000L (naphthylene ether type epoxy resin); Nippon Kayaku's "EPPN-502H" (trisphenol type epoxy resin); Nippon Kayaku's "NC7000L" (naphthol novolac type epoxy resin); Nippon Kayaku's "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin); Nippon Steel Chemical & Material's "ESN475V" "ESN4100V" (naphthalene-type epoxy resin); "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", and "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation. Examples include "YX7700" (phenol aralkyl type epoxy resin) manufactured by Osaka Gas Chemicals Co., Ltd.; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. These may be used alone or in combination of two or more.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the mass ratio between them (liquid epoxy resin:solid epoxy resin) is preferably 10:1 to 1:50, more preferably 5:1 to 1:20, even more preferably 2:1 to 1:10, and particularly preferably 1:1 to 1:3.

The epoxy equivalent of the epoxy resin is preferably 50 g/eq. to 5,000 g/eq., more preferably 60 g/eq. to 2,000 g/eq., even more preferably 70 g/eq. to 1,000 g/eq., and even more preferably 80 g/eq. to 500 g/eq. The epoxy equivalent is the mass of resin per equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

The weight-average molecular weight of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight-average molecular weight of the resin can be measured as a polystyrene-equivalent value using gel permeation chromatography (GPC).

-Phenol resin-
The phenolic resin may be a compound having one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring per molecule. Phenolic resins are sometimes referred to as "phenolic curing agents" because, when combined with an epoxy resin, they can react with the epoxy resin to cure the resin composition. From the viewpoint of achieving the effects of the present invention more significantly, the phenolic resin is preferably a phenolic resin having a novolac structure. Furthermore, from the viewpoint of adhesion, nitrogen-containing phenolic resins are preferred, and triazine skeleton-containing phenolic resins are more preferred. Of these, triazine skeleton-containing phenolic novolac resins are preferred from the viewpoint of achieving the effects of the present invention more significantly. Specific examples of phenolic resins include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-375", and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; and "LA-7052", "LA-7054", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", "TD-2090-60M", and "KA-1163" manufactured by DIC Corporation.

- Cyanate ester resin -
The cyanate ester resin may be a compound having one or more, preferably two or more, cyanate groups in one molecule. When combined with an epoxy resin, the cyanate ester resin reacts with the epoxy resin to cure the resin composition, and is therefore sometimes called a "cyanate ester curing agent." Examples of cyanate ester resins 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-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate ester resins include "PT30" and "PT60" manufactured by Lonza (both of which are phenol novolac-type multifunctional cyanate resins), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine-converted to form a trimer).

- Active ester resin -
As the activated ester resin, compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are generally preferred. When combined with an epoxy resin, activated ester resins can react with the epoxy resin to cure the resin composition, and are therefore sometimes referred to as "active ester curing agents." The activated ester resin is preferably one obtained by the condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound with a hydroxy compound and/or a thiol compound. From the perspective of improving heat resistance, activated ester resins obtained from a carboxylic acid compound and a hydroxy compound are preferred, and activated ester resins obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound are more preferred. As the carboxylic acid compound, either an aromatic carboxylic acid compound or an aliphatic carboxylic acid compound may be used, and examples thereof include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, and halides thereof. Examples of aromatic hydroxy compounds include (i) polyaddition products of unsaturated aliphatic cyclic compounds containing two double bonds per molecule with phenols, (ii) various bisphenol compounds, (iii) aromatic polyols having two or more hydroxy groups bonded to a carbon atom on an aromatic ring, and (iv) aromatic monools having one hydroxy group bonded to a carbon atom on an aromatic ring. Examples of polyaddition products of unsaturated aliphatic cyclic compounds with phenols include polyaddition products of unsaturated aliphatic cyclic compounds such as dicyclopentadiene, tetrahydroindene, norbornadiene, limonene, and vinylcyclohexene with phenols that may have a substituent (e.g., phenol, cresol, xylenol, ethylphenol, propylphenol, vinylphenol, allylphenol, phenylphenol, benzylphenol, and halophenols), and specific examples thereof include dicyclopentadiene-phenol polyaddition products. Examples of bisphenol compounds include bisphenol A, bisphenol F, bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, and bisphenol M. Examples of aromatic polyols having two or more hydroxy groups bonded to carbon atoms on an aromatic ring include hydroquinone, resorcinol, catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, and phenol novolak. Examples of aromatic monools having one hydroxy group bonded to a carbon atom on an aromatic ring include phenol, cresol, xylenol, ethylphenol, propylphenol, vinylphenol, allylphenol, phenylphenol, benzylphenol, halophenols, naphthol, methylnaphthol, dimethylnaphthol, ethylnaphthol, propylnaphthol, vinylnaphthol, allylnaphthol, phenylnaphthol, benzylnaphthol, and halonaphthol.

Specific examples of active ester resins include dicyclopentadiene-type active ester resins, naphthalene-type active ester resins containing a naphthalene structure, active ester resins containing an acetylated phenol novolac, active ester resins containing a benzoylated phenol novolac, and active ester resins containing a styryl group and a naphthalene structure. Among these, at least one selected from dicyclopentadiene-type active ester resins and naphthalene-type active ester resins is more preferred. As dicyclopentadiene-type active ester resins, active ester resins containing a dicyclopentadiene-type diphenol structure are preferred.

Commercially available activated ester resins include, for example, activated ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB9451," "EXB9460," "EXB9460S," "EXB-8000L," "EXB-8000L-65M," "EXB-8000L-65TM," "HPC-8000L-65TM," "HPC-8000L-65T," "HPC-8000," "HPC-8000-65T," "HPC-8000H," and "HPC-8000H-65TM" (manufactured by DIC Corporation); activated ester resins containing a naphthalene structure such as "HP-B-8151-62T," "EXB-8100L-65T," and "EXB-8150-60T"; Examples include "EXB-8150-62T," "EXB-9416-70BK," "HPC-8150-60T," "HPC-8150-62T," and "EXB-8" (manufactured by DIC Corporation); a phosphorus-containing activated ester resin such as "EXB9401" (manufactured by DIC Corporation); an activated ester resin that is an acetylated product of phenol novolac such as "DC808" (manufactured by Mitsubishi Chemical Corporation); activated ester resins that are benzoylated products of phenol novolac such as "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation); and an activated ester resin containing a styryl group and a naphthalene structure such as "PC1300-02-65MA" (manufactured by Air Water Inc.).

- Carbodiimide resin -
As the carbodiimide resin, a compound having one or more, preferably two or more, carbodiimide structures in one molecule can be used. When combined with an epoxy resin, a carbodiimide resin can react with the epoxy resin to cure the resin composition, and therefore is sometimes called a "carbodiimide curing agent." Specific examples of carbodiimide resins include aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexane-bis(methylene-t-butylcarbodiimide); aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide); poly(phenylenecarbodiimide), poly(naphthalenecarbodiimide), and the like. Examples of polycarbodiimides include aromatic polycarbodiimides such as poly(methylenebis(methylphenylene)carbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide]. Commercially available carbodiimide resins include, for example, "Carbodilite V-02B,""CarbodiliteV-03,""CarbodiliteV-04K,""CarbodiliteV-07," and "Carbodilite V-09," manufactured by Nisshinbo Chemical Inc.; and "Stavaxol P,""StavaxolP400," and "Hykasil 510," manufactured by Lanxess AG.

-Acid anhydride resin-
As the acid anhydride resin, a compound having one or more, preferably two or more, acid anhydride groups in one molecule can be used. When combined with an epoxy group, an acid anhydride resin can react with the epoxy resin to cure the resin composition, and therefore is sometimes called an "acid anhydride curing agent." Specific examples of acid anhydride resins include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Examples of suitable acid anhydrides include hydrates, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymeric acid anhydrides such as styrene-maleic acid resins in which styrene and maleic acid are copolymerized. Examples of commercially available acid anhydride resins include "HNA-100", "MH-700", "MTA-15", "DDSA", and "OSA" manufactured by New Japan Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" and "HN-5500" manufactured by Resonac; and "EF-30", "EF-40", "EF-60", and "EF-80" manufactured by Cray Valley Chemical Industries, Ltd.

- Amine resin -
As the amine resin, a compound having one or more, preferably two or more, amino groups in one molecule can be used. When combined with an epoxy group, the amine resin can react with the epoxy resin to cure the resin composition, and therefore is sometimes called an "amine-based curing agent." Examples of the amine resin include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. The amine resin is preferably a primary amine or secondary amine, with primary amines being more preferred. Specific examples of amine resins include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxyphenyl)propanol. Examples of suitable bis(4-aminophenoxy)biphenyl include bis(4-aminophenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, and bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine resins include, for example, "SEIKACURE-S" manufactured by Seika Corporation; "KAYABOND C-200S,""KAYABONDC-100,""KAYAHARDA-A,""KAYAHARDA-B," and "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd.; "EPICURE W" manufactured by Mitsubishi Chemical Corporation; and "DTDA" manufactured by Sumitomo Seika Chemicals Co., Ltd.

- Benzoxazine resin -
Benzoxazine resins, when combined with epoxy resins, can react with the epoxy resin to cure the resin composition, and are therefore sometimes referred to as "benzoxazine-based curing agents." Specific examples of benzoxazine resins include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation; "HFB2006M" manufactured by Showa Highpolymer Co., Ltd.; and "P-d" and "F-a" manufactured by Shikoku Chemicals Corporation.

Thiol resins are sometimes called "thiol-based curing agents" because when combined with epoxy resins, they react with the epoxy resin to harden the resin composition. Examples of thiol resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

-Terminal double bond resin-
The terminal double bond resin is a radical polymerizable resin having an ethylenically unsaturated group having one or more (preferably two or more) carbon-carbon double bonds per molecule, or a radical polymerizable group containing an ethylenically unsaturated bond at the molecular end. Examples of the radical polymerizable group include one or more groups selected from a vinyl group, a propenyl group (1-propenyl group), an allyl group (2-propenyl group), a styryl group, a vinylphenyl group, an acryloyl group, and a methacryloyl group. Of these, from the viewpoint of being able to more effectively enjoy the effects of the present invention, one or more groups selected from a vinyl group, an allyl group, and a styryl group are preferred. Of these, from the viewpoint of being able to more easily enjoy the effects of the present invention, the terminal double bond resin is preferably an allyl resin, a vinyl resin, or a styryl resin.

Allyl resins are compounds containing one or more, preferably two or more, allyl groups. Examples of allyl resins include aromatic carboxylic acid allyl ester compounds such as diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, and diallyl 2,3-naphthalenecarboxylate; isocyanuric acid allyl ester compounds such as 1,3,5-triallyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; epoxy-containing aromatic allyl compounds such as 2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane; benzoxazine-containing aromatic allyl compounds such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane; ether-containing aromatic allyl compounds such as 1,3,5-triallyl ether benzene; and allyl silane compounds such as diallyldiphenylsilane. Commercially available allyl radical polymerizable compounds include "TAIC" (1,3,5-triallyl isocyanurate) manufactured by Nippon Kasei Chemical Industry Co., Ltd., "DAD" (diallyl diphenate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd., "TRIAM-705" (triallyl trimellitate) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., "DAND" (2,3-diallyl naphthalenecarboxylate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd., "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane manufactured by Shikoku Chemical Industry Co., Ltd., "RE-810NM" (2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane) manufactured by Nippon Kayaku Co., Ltd., and "DA-MGIC" (1,3-diallyl-5-glycidyl isocyanurate) manufactured by Shikoku Chemical Industry Co., Ltd.

Examples of vinyl resins include trialkenyl isocyanurate compounds such as triallyl isocyanurate, polybutadiene resins whose repeating units are 1,2-butadiene, cis-1,4-butadiene, or trans-1,4-butadiene, and vinylbenzyl compounds such as styrene and divinylbenzene, which have vinylbenzyl groups in the molecule.

The styryl resin may be a monomer or oligomer, and is not particularly limited as long as it contains one or more (preferably two or more) styryl or vinylphenyl groups per molecule. Examples of styryl resins include "OPE-2St," "OPE-2St 1200," and "OPE-2St 2200" (all manufactured by Mitsubishi Gas Chemical Company, Inc.). Examples of styryl resins include styrene monomers, as well as homopolymers of aromatic divinyl compounds such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl)ether, as well as copolymers of these aromatic divinyl compounds with aromatic monovinyl compounds such as styrene, vinyltoluene, ethylstyrene, and vinylnaphthalene.

In order to realize a resin composition that, when combined with components (A) and (B), exhibits good dielectric properties, good mechanical properties (high elongation at break), and produces a cured product with excellent crack resistance, the content of component (C) in the resin composition, based on 100% by mass of the resin components in the resin composition, is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and even more preferably 20% by mass or more. The upper limit of the content is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less or 35% by mass or less. Therefore, in one embodiment, based on 100% by mass of the resin components in the resin composition, the content of component (C) is 10% by mass or more and 50% by mass or less.

From the perspective of achieving a resin composition that exhibits good dielectric properties, good mechanical properties (high elongation at break), and produces a cured product with excellent crack resistance, when the resin components in the resin composition are taken as 100% by mass, the total content of components (A), (B), and (C) is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 85% by mass or more or 90% by mass or more; the upper limit is not particularly limited, and can be, for example, 99.8% by mass or less, 99.5% by mass or less, or 99% by mass or less.

[(D) Thermoplastic resin]
The resin composition of the present invention may contain a thermoplastic resin as the component (D).

Examples of component (D) include polystyrene resin, oxazoline group-containing resin, polyimide resin, phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyamide-imide resin, polyetherimide resin, polysulfone resin, polyether sulfone resin, polyphenylene ether resin, polycarbonate resin, polyether ether ketone resin, and polyester resin.

In one embodiment, component (D) preferably contains one or more resins selected from the group consisting of polystyrene resins, oxazoline group-containing resins, polyimide resins, and phenoxy resins, more preferably one or more resins selected from the group consisting of polyimide resins and phenoxy resins, and particularly preferably phenoxy resins. Furthermore, component (D) may be used alone or in combination of two or more resins.

Commercially available polystyrene resins may be used, including hydrogenated styrene-based thermoplastic elastomers "H1041," "Tuftec H1043," "Tuftec P2000," and "Tuftec MP10" (manufactured by Asahi Kasei Corporation); epoxidized styrene-butadiene thermoplastic elastomers "Epofriend AT501" and "CT310" (manufactured by Daicel Corporation); modified styrene-based elastomer with hydroxyl groups "Septon HG252" (manufactured by Kuraray Co., Ltd.); modified styrene-based elastomer with carboxyl groups "Tuftec N503M," modified styrene-based elastomer with amino groups "Tuftec N501," modified styrene-based elastomer with acid anhydride groups "Tuftec M1913" (manufactured by Asahi Kasei Corporation); and unmodified styrene-based elastomer "Septon S8104" (manufactured by Kuraray Co., Ltd.).

Examples of oxazoline group-containing resins include 2-isopropenyl-2-oxazoline, 5-methyl-2-isopropenyl-2-oxazoline, 4,4-dimethyl-2-isopropenyl-2-oxazoline, 4-methyl-2-isopropenyl-2-oxazoline, 4,4,5-trimethyl-2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline, 5-methyl-2-vinyl-2-oxazoline, 4,4-dimethyl-2-vinyl-2-oxazoline, and 4-methyl-2-vinyl-2-oxazoline. They are obtained by polymerizing addition-polymerizable oxazoline compounds (vinyloxazoline skeleton-containing monomers) such as 4,4,5-trimethyl-2-vinyl-2-oxazoline and 4,4,5-trimethyl-2-vinyl-2-oxazoline, and may be copolymerized with other monomers, such as styrene-based monomers such as styrene, α-methylstyrene, 4-methylstyrene, 3-methylstyrene, 2-methylstyrene, 4-ethylstyrene, 4-tert-butylstyrene, p-divinylbenzene, and m-divinylbenzene, as needed. A specific example of an oxazoline group-containing resin is "PX-3-RP-61" manufactured by Nippon Shokubai Co., Ltd.

Specific examples of polyimide resins include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd., and "PIAD200" manufactured by Arakawa Chemical Co., Ltd.

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

Specific examples of phenoxy resins include Mitsubishi Chemical Corporation's "1256" and "4250" (both phenoxy resins containing a bisphenol A skeleton); Mitsubishi Chemical Corporation's "YX8100" (phenoxy resin containing a bisphenol S skeleton); Mitsubishi Chemical Corporation's "YX6954" (phenoxy resin containing a bisphenolacetophenone skeleton), Nippon Steel Chemical & Material Co., Ltd.'s "FX280" and "FX293," and Mitsubishi Chemical Corporation's "YX7200B35," "YL7500BH30," "YX6954BH30," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," and "YL7482."

Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, with polyvinyl butyral resins being preferred. Specific examples of polyvinyl acetal resins include the S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemical Co., Ltd.

Examples of polyolefin resins include ethylene copolymer resins such as low-density polyethylene, very low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; and polyolefin polymers such as polypropylene and ethylene-propylene block copolymer.

Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxyl group-containing polybutadiene resins, phenolic hydroxyl group-containing polybutadiene resins, carboxyl group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, isocyanate group-containing polybutadiene resins, urethane group-containing polybutadiene resins, and polyphenylene ether-polybutadiene resins.

Specific examples of polyamide-imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins also include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imides) manufactured by Resonac Corporation.

Specific examples of polyethersulfone resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

Specific examples of polyphenylene ether resins include "NORYL SA90" manufactured by SABIC. Specific examples of polyetherimide resins include "Ultem" manufactured by GE.

Examples of polycarbonate resins include hydroxyl group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxyl group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, and urethane group-containing carbonate resins. Specific examples of polycarbonate resins include Mitsubishi Gas Chemical Company's "FPC0220," Asahi Kasei Corporation's "T6002" and "T6001" (polycarbonate diols), and Kuraray Co., Ltd.'s "C-1090," "C-2090," and "C-3090" (polycarbonate diols). Specific examples of polyether ether ketone resins include Sumitomo Chemical Company's "Sumiploy K."

Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

The content of component (D) in the resin composition, relative to the resin components in the resin composition taken as 100% by mass, is, for example, 0% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, 1% by mass or more, 2% by mass or more, or 3% by mass or more; the upper limit of the content is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, 15% by mass or less, or 10% by mass or less.

[(E) Inorganic filler]
The resin composition of the present invention may contain an inorganic filler as the component (E).

Examples of inorganic fillers include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum silicate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred. These inorganic fillers may be used alone or in combination.

Commercially available inorganic fillers include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C," "YA050C," "YA050C-MJE," "YA010C," "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30," "DAW-03," and "FB-105FD" manufactured by Denka Co., Ltd.; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "CellSpheres" and "MGH-005" manufactured by Taiheiyo Cement Corporation; and "Sfereek" and "BA-1" manufactured by JGC Catalysts and Chemicals Co., Ltd.

The average particle size of the inorganic filler is not particularly limited, but is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less. The lower limit of the average particle size is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.07 μm or more, 0.1 μm or more, or 0.2 μm or more.
The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on 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 the mixture 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 used, using a flow cell system to measure the volume-based particle size distribution of the inorganic filler, and the average particle size is calculated as the median diameter from the obtained particle size distribution. An example of a laser diffraction particle size distribution measuring device is the "LA-960" manufactured by Horiba, Ltd.

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

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

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

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

The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/ ^m² or more, more preferably 0.1 mg/ ^m² or more, and even more preferably 0.2 mg/ ^m² or more. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition or the melt viscosity in a sheet form, the amount of carbon per unit surface area of the (E) component is preferably 1.0 mg/ ^m² or less, more preferably 0.8 mg/ ^m² or less, and even more preferably 0.5 mg/ ^m² or less. The amount of carbon per unit surface area of the (E) component can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with the surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer, such as the "EMIA-320V" manufactured by Horiba, Ltd.

From the viewpoint of achieving a resin composition that, when combined with components (A) to (C), exhibits good dielectric properties, as well as good mechanical properties (high elongation at break), and produces a cured product with excellent crack resistance, the content of component (E) in the resin composition is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, based on 100% by mass of the non-volatile components in the resin composition. The upper limit of the content is preferably 85% by mass or less, more preferably 80% by mass or less.

[(F) Radical Polymerization Initiator]
The resin composition of the present invention may contain a radical polymerization initiator as the component (F).

Examples of component (F) include a thermal polymerization initiator that generates free radicals upon heating and a photopolymerization initiator that generates free radicals upon light irradiation. Of these, a thermal polymerization initiator is preferred from the perspective of being able to fully enjoy the effects of the present invention. Component (F) may be used alone or in any combination of two or more types.

Examples of component (F) include peroxide-based radical polymerization initiators and azo-based radical polymerization initiators. Among these, peroxide-based radical polymerization initiators are preferred.

Peroxide-based radical polymerization initiators include, for example, hydroperoxide compounds such as 1,1,3,3-tetramethylbutyl hydroperoxide; dialkyl peroxide compounds such as tert-butylcumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, dicumyl peroxide, 1,4-bis(1-tert-butylperoxy-1-methylethyl)benzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; and diacyl peroxide compounds such as dilauroyl peroxide, didecanoyl peroxide, dicyclohexyl peroxydicarbonate, and bis(4-tert-butylcyclohexyl)peroxydicarbonate. peroxyester compounds such as tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyneodecanoate, tert-hexylperoxyisopropyl monocarbonate, tert-butyl peroxylaurate, (1,1-dimethylpropyl) 2-ethylperhexanoate, tert-butyl 2-ethylperhexanoate, tert-butyl 3,5,5-trimethylperhexanoate, tert-butylperoxy-2-ethylhexyl monocarbonate, and tert-butylperoxymaleic acid; and the like.

Examples of azo radical polymerization initiators include azonitrile compounds such as 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, and 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile; 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide], 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide], and 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide]. azo amide compounds such as 2,2'-azobis[2-methyl-N-[2-(1-hydroxybutyl)]-propionamide], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide], 2,2'-azobis(2-methylpropionamide) dihydrate, 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(N-cyclohexyl-2-methylpropionamide); alkyl azo compounds such as 2,2'-azobis(2,4,4-trimethylpentane) and 2,2'-azobis(2-methylpropane); and the like.

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

The content of component (F) in the resin composition is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and even more preferably 1.5% by mass or less, based on 100% by mass of the resin components in the resin composition. The lower limit of the content is not particularly limited, but may be, for example, 0% by mass or more, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, or 0.8% by mass or more, based on 100% by mass of the resin components in the resin composition.

[(G) Curing accelerator]
The resin composition of the present invention may contain a curing accelerator as the component (G).

Examples of component (G) include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators. Amine-based curing accelerators, imidazole-based curing accelerators, and metal-based curing accelerators are preferred, and either amine-based curing accelerators or imidazole-based curing accelerators are more preferred. Component (B) 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, and butyltriphenylphosphonium thiocyanate, 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 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-4,5-dihydroxymethylimidazole, Examples of the imidazole compounds include phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole are preferred.

Commercially available imidazole-based curing accelerators may be used, such as "P200-H50" manufactured by Mitsubishi Chemical Corporation and "1B2PZ" manufactured by Shikoku Chemicals 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 2[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, with dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene being 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. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

The content of component (G) in the resin composition is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and preferably 2% by mass or less, more preferably 1% by mass or less, based on 100% by mass of the resin components in the resin composition.

[Other additives]
The resin composition of the present invention may further contain other additives as optional components in addition to the above-mentioned components. Examples of other additives include organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone leveling agents and acrylic polymer leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone antifoaming agents, acrylic antifoaming agents, fluorine-based antifoaming agents, and vinyl resin antifoaming agents; ultraviolet absorbers such as benzotriazole ultraviolet absorbers; adhesion improvers such as urea silane; adhesion imparters such as triazole adhesion imparters, tetrazole adhesion imparters, and triazine adhesion imparters; and antioxidants such as hindered phenol antioxidants. surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers; photopolymerization initiation aids such as tertiary amines; and photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones.
The other additives may be used singly or in combination of two or more.

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

The amount of solvent is not particularly limited, but when all components in the resin composition are taken as 100% by mass, it may be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or even 0% by mass.

[Method of producing resin composition]
The resin composition of the present invention can be produced, for example, by mixing components that can be contained in the resin composition. The above-mentioned components may be mixed in part or all at the same time, or may be mixed sequentially. During the process of mixing each component, the temperature may be appropriately set, and thus heating and/or cooling may be performed temporarily or throughout. Furthermore, stirring or shaking may be performed during the process of mixing each component.

[Characteristics of resin composition]
The cured product of the resin composition of the present invention can have a low dielectric loss tangent. Therefore, when an insulating layer is formed using this cured product, an insulating layer with a low dielectric loss tangent can be obtained. The dielectric loss tangent of the cured product of the resin composition is preferably 0.003 or less, more preferably 0.0028 or less, and even more preferably 0.0025 or less. There is no particular lower limit, but it can be 0.0001 or more. The dielectric loss tangent can be measured by the method described in the examples below.

The cured product of the resin composition of the present invention exhibits the characteristic of high elongation at break. Therefore, when an insulating layer is formed using this cured product, an insulating layer with excellent mechanical strength can be obtained. The elongation at break of the cured product of the resin composition is preferably 1.4% or more, more preferably 1.5% or more, 1.6% or more, 1.8% or more, or 2% or more. The upper limit is not particularly limited, but can be, for example, 10% or less. The elongation at break can be measured by the method described in the examples below.

The cured product of the resin composition of the present invention exhibits excellent crack resistance. Therefore, when an insulating layer is formed using this cured product, an insulating layer with excellent crack resistance can be obtained. Specifically, the resin composition is laminated onto an inner layer substrate on which a wiring pattern has been formed, and then thermally cured to obtain a cured product. The surface of the cured product is roughened to obtain a sample. 100 sections on the pattern of the inner layer substrate of the sample are checked for cracks along the pattern shape, and the number of sections on the pattern without cracks is counted. The percentage of crack-free sections out of the 100 sections is calculated as the "yield." In this case, the yield is preferably 40% or more, more preferably 60% or more, and even more preferably 80% or more. Crack resistance can be measured by the method described in the Examples below.

[Uses of resin composition]
The resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer of a printed wiring board (resin composition for an insulating layer of a printed wiring board), and more suitably used as a resin composition for forming an interlayer insulating layer of a printed wiring board (resin composition for an interlayer insulating layer of a printed wiring board). The resin composition of the present invention can also be suitably used when the printed wiring board is a circuit board with built-in components. The resin composition of the present invention can also be suitably used as a resin composition for forming an insulating layer of a rewiring board for a semiconductor package (resin composition for an insulating layer of a rewiring board). In the present invention, printed wiring boards and rewiring boards are collectively referred to as "circuit boards," and therefore the resin composition of the present invention can be suitably used for the insulating layer of a circuit board.

The resin composition of the present invention can also be used in a wide range of applications requiring a resin composition, such as sheet-like laminate materials such as resin sheets and prepregs, solder resists, underfill materials, die bonding materials, hole-filling resins, sealing resins, and component-embedding resins.

[Sheet-like laminated material]
The resin composition may be used by applying it in the form of a varnish, but from an industrial perspective, it is preferable to use it in the form of a sheet-like laminate material containing the resin composition.

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

In one embodiment, the resin sheet includes a support and a resin composition layer provided on the support. The resin composition layer is formed from the resin composition described above. Therefore, the resin composition layer typically contains a resin composition, and preferably contains only a resin composition.

The thickness of the resin composition layer is preferably 50 μm or less, more preferably 40 μm or less, from the perspective of achieving a thinner film and being able to provide a cured product with excellent insulating properties even when thin. The lower limit of the thickness of the resin composition layer is not particularly limited, but may be 5 μm or more, 10 μm or more, etc.

Examples of the support include thermoplastic resin film, metal foil, and release paper, with thermoplastic resin film and metal foil being preferred.

When a thermoplastic resin film is used as the support, examples of thermoplastic resins include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimides. 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. The copper foil may be a foil made of the single metal copper, or a foil made of an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

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

The support may be a support with a release layer, which has a release layer on the surface that bonds with the resin composition layer. Examples of release agents 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. Commercially available products may be used as the support with a release layer, including PET films with a release layer primarily composed of an alkyd resin-based release agent, such as "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Uni-Peel" manufactured by Unitika Ltd.

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 overall thickness of the support with a release layer be in the above range.

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

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

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

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

In one embodiment, the resin sheet may further include an optional layer, if necessary. Examples of such optional layers include a protective film conforming 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 a protective film, it is possible to prevent dust from adhering to the surface of the resin composition layer and scratches from occurring.

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

Solvents include those similar to those described as components of the resin composition. One type of solvent may be used alone, or two or more types may be used in combination.

Drying may be carried out by heating, blowing hot air, or other methods. Drying conditions are not particularly limited, but drying is typically carried out so that the solvent content in the resin composition layer is 10% by mass or less, and preferably 5% by mass or less. While this varies depending on the boiling point of the solvent in the resin composition, for example, when using a resin composition containing 30% to 60% by mass of solvent, a 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 rolled up. If the resin sheet has a protective film, it can usually be used by peeling off the protective film.

In one embodiment, the prepreg is formed by impregnating a sheet-like fiber substrate with the resin composition according to this embodiment.

The sheet-like fiber substrate used for the prepreg can be, for example, a commonly used prepreg substrate such as glass cloth, aramid nonwoven fabric, or liquid crystal polymer nonwoven fabric. From the perspective of achieving a thin sheet, the thickness of the sheet-like fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. There is no particular lower limit to the thickness of the sheet-like fiber substrate, and it is usually 10 μm or more.

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

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

The sheet-like laminate material can be suitably used to form insulating layers of printed wiring boards (for insulating layers of printed wiring boards), and can be even more suitably used to form interlayer insulating layers of printed wiring boards (for insulating layers of printed wiring boards). The sheet-like laminate material of the present invention can also be suitably used to form insulating layers of rewiring boards for semiconductor packages (for insulating layers of rewiring boards). In other words, the sheet-like laminate material of the present invention can be suitably used as an insulating layer for circuit boards.

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

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

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 the resin composition layer of the resin sheet is bonded to the inner layer substrate; and (II) a step of curing (e.g., thermally curing) the resin composition layer to form an insulating layer.

The "inner layer substrate" used in step (I) refers to a component that will become the substrate of a printed wiring board, and examples include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may also have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer substrate with a conductor layer (circuit) formed on one or both sides of the substrate is sometimes referred to as an "inner layer circuit board." Furthermore, the term "inner layer substrate" used in this invention also includes intermediate products on which insulating layers and/or conductor layers are to be further formed during the manufacture of a printed wiring board. When the printed wiring board is a component-embedded circuit board, an inner layer substrate with embedded components may be used.

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

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

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

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

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

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

For example, the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 140°C to 250°C, more preferably 150°C to 240°C, and even more preferably 160°C to 230°C. The curing time is preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and even more preferably 15 minutes to 120 minutes.

Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 140°C, preferably 60°C to 135°C, and more preferably 70°C to 130°C for 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

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

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

Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (III) may be performed using, for example, a drill, 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 determined appropriately depending on the design of the printed wiring board.

Step (IV) is a step in which the insulating layer is roughened. Typically, smear removal (desmearing) is also performed in this step (IV). The roughening treatment procedures and conditions are not particularly limited, and known procedures and conditions commonly used in forming insulating layers for printed wiring boards can be used. For example, the insulating layer can be roughened by performing a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid, in that order.

The swelling liquid used in the roughening treatment is not particularly limited, but examples include alkaline solutions and surfactant solutions. Alkaline solutions are preferred, with sodium hydroxide and potassium hydroxide solutions being more preferred. Commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. The swelling treatment using a swelling liquid is not particularly limited, but can be carried out by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes, for example. To keep swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

The oxidizing agent used in the roughening treatment is not particularly limited, but examples include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as 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% to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP," "Concentrate Compact P," and "Dosing Solution Securigans P" manufactured by Atotech Japan.

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

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

Step (V) is a step of forming a conductor layer, in which 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. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, from the standpoint 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 have a single-layer structure, or a multi-layer structure consisting of two or more single-metal or alloy layers made of different types of metals or alloys. If 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 nickel-chromium alloy.

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

In one embodiment, the conductor layer may be formed by plating. From the perspective of facilitating the formation of fine wiring, it is preferable to form it by a semi-additive method. Below, an example of forming a conductor layer by a semi-additive method is shown.

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing 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. Unnecessary plating seed layer is then removed by etching or other methods, forming a conductor layer with the desired wiring pattern.

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

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

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

<Rewiring substrate for semiconductor package>
In one embodiment, the circuit board of the present invention is a rewiring substrate (rewiring layer) of a semiconductor package. Hereinafter, a method for manufacturing a semiconductor package will be described.

The semiconductor package includes an insulating layer made of a cured product of the resin composition of the present invention as an insulating layer of the rewiring substrate. The semiconductor package may also include a sealing layer made of a cured product of the resin composition of the present invention.

A semiconductor package can be manufactured, for example, by a method including the following steps (1) to (6) using the resin composition and resin sheet of the present invention. The resin composition and resin sheet of the present invention can be used to form a rewiring formation layer (insulating layer for forming a rewiring substrate) in step (5) or a sealing layer in step (3). An example of forming a rewiring formation layer or a sealing layer using a resin composition or a resin sheet will be shown below. However, techniques for forming a rewiring formation layer or a sealing layer for a semiconductor package are known, and a person skilled in the art can manufacture a semiconductor package using the resin composition and resin sheet of the present invention according to known techniques.
(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.

-Process (1)-
The material used for the substrate is not particularly limited, and examples of the substrate include semiconductor wafers such as silicon wafers, glass wafers, glass substrates, metal substrates such as copper, titanium, stainless steel, and cold-rolled steel plate (SPCC), substrates in which glass fibers are impregnated with epoxy resin or the like and subjected to a thermosetting treatment (e.g., FR-4 substrates), and substrates made of bismaleimide triazine resin (BT resin).

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

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

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

For example, lamination of a semiconductor chip and a resin sheet can be achieved by removing the protective film from the resin sheet and then thermocompressing the resin sheet to the semiconductor chip from the support side. Examples of a member for thermocompressing the resin sheet to the semiconductor chip (hereinafter also referred to as a "thermocompression member") include a heated metal plate (such as a stainless steel plate) or a metal roll (such as a stainless steel roll). It is preferable to press the thermocompression member not directly onto the resin sheet, but rather via an elastic material such as heat-resistant rubber, so that the resin sheet can adequately conform to the surface irregularities of the semiconductor chip. The semiconductor chip and resin sheet can also be laminated using a vacuum lamination method. The lamination conditions and preferred ranges are the same as those described in connection with the manufacturing method of a printed wiring board.

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

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

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

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

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

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

After forming the redistribution layer, via holes may be formed in the redistribution layer to establish interlayer connections between the semiconductor chip and the conductor layer described below. The via holes may be formed using known methods depending on the material of the redistribution layer.

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

When manufacturing a semiconductor package, the following steps may be further performed: (7) forming a solder resist layer on the conductor layer (rewiring layer), (8) forming bumps, and (9) dicing multiple semiconductor packages into individual semiconductor packages. These steps may be performed according to various methods known to those skilled in the art that are used in the manufacture of semiconductor packages.

By forming a rewiring formation layer (insulating layer) using the resin composition and resin sheet of the present invention, which can produce a cured product exhibiting excellent dielectric properties, excellent mechanical properties, and crack resistance, it is possible to realize a semiconductor package with extremely low transmission loss without worrying about cracks, regardless of whether the semiconductor package is a fan-in (Fan-In) package or a fan-out (Fan-Out) package. In one embodiment, the semiconductor package of the present invention is a fan-out (Fan-Out) package. The resin composition and resin sheet of the present invention can be applied to both fan-out panel level packages (FOPLPs) and fan-out wafer level packages (FOWLPs). In one embodiment, the semiconductor package of the present invention is a fan-out panel level package (FOPLP) or a fan-out wafer level package (FOWLP).

[Semiconductor device]
The semiconductor device of the present invention includes a layer made of a cured product of the resin composition layer of the present invention. The semiconductor device of the present invention can be produced using the circuit board of the present invention.

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

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

(Synthesis Example 1: Synthesis of Resin A)
10 g of 4,4'-methylenebis(2,6-dimethylphenol) was dissolved in 390 mL of tetrahydrofuran, and 15 g of 3-bromo-1-phenyl-1-propene was added, followed by cooling to 0°C. 3.4 g of sodium hydride was added, and the mixture was stirred overnight at room temperature under a nitrogen gas atmosphere. Water was added to the reaction mixture, the tetrahydrofuran was removed by concentration under reduced pressure, dichloromethane was added, and the organic layer was washed with water and saturated brine and dried over anhydrous sodium sulfate. After filtering off the desiccant, the mixture was concentrated under reduced pressure to obtain 15 g of the target resin A as white crystals. This resin A has the structure represented by the following formula:

(Synthesis Example 2: Synthesis of Maleimide B)
An MEK solution (70% by mass of nonvolatile components) of maleimide B (Mw/Mn = 1.81, t'' = 1.47 (mainly 1, 2, or 3)) synthesized by the method described in Synthesis Example 1 of the Japan Institute of Invention and Innovation's Technical Journal Disclosure No. 2020-500211 was prepared. This maleimide B has a structure represented by the following formula:

(Synthesis Example 3: Synthesis of vinyl resin C)
3.0 mol (390.6 g) of divinylbenzene, 1.8 mol (229.4 g) of ethylvinylbenzene, 10.2 mol (1066.3 g) of styrene, and 15.0 mol (1532.0 g) of n-propyl acetate were charged into a 5.0 L reactor, and 600 mmol of a boron trifluoride diethyl ether complex was added at 70 ° C. The reaction was allowed to proceed for 4 hours. After the polymerization solution was terminated with an aqueous sodium bicarbonate solution, the oil layer was washed three times with pure water, and the mixture was subjected to vacuum devolatilization at 60 ° C. to recover the polymer. The resulting product was weighed, and it was confirmed that 896.7 g of vinyl resin C was obtained. The weight average molecular weight (Mw) of vinyl resin C was 41,300.

(Examples 1 to 13, Comparative Examples 1 to 3)
(Preparation of resin varnish)
Each component was weighed out in the number of parts by mass shown in Table 1, and then mixed with 10 parts of MEK and 2 parts of cyclohexanone, and the mixture was uniformly dispersed using a high-speed rotating mixer to obtain a resin varnish.

The details of each component listed in Table 1 are as follows.
(A) Compound represented by formula (A-1) Resin A: Synthesized in Synthesis Example 1 (B) Maleimide resin MIR-3000-70MT: functional group equivalent weight 275, toluene solution with 70% nonvolatile content by mass, manufactured by Nippon Kayaku Co., Ltd. Maleimide B: Synthesized in Synthesis Example 2 SLK-6895-T90: functional group equivalent weight 345, toluene solution with 90% nonvolatile content by mass, manufactured by Shin-Etsu Chemical Co., Ltd. (C) Thermosetting resins: LA-3018-50P: functional group equivalent weight 151, 1-methoxy-2-propanol solution with 50% nonvolatile content by mass, manufactured by DIC Corporation; HP-4032-SS: functional group equivalent weight 144, manufactured by DIC Corporation; HPC-8000-65T: functional group equivalent weight 223, toluene solution with 62% nonvolatile content, manufactured by DIC Corporation; V-03: functional group equivalent weight 216, toluene solution with 50% nonvolatile content by mass, manufactured by Nisshinbo Chemical Inc.; DAD: functional group equivalent weight 161, manufactured by Nisshoku Techno Fine Chemical Co., Ltd.; Vinyl resin C: toluene solution (50% nonvolatile content by mass) synthesized in Synthesis Example 3
OPE-2St: toluene solution with functional group equivalent of 590 and non-volatile content of 65% by mass, manufactured by Mitsubishi Gas Chemical Co., Ltd. (D) Thermoplastic resins P2000: styrene butadiene elastomer, manufactured by Asahi Kasei Corporation PIAD200: polyimide resin, mixed solution of cyclohexanone, dimethyl glycol, and methylcyclohexane with non-volatile content of 30% by mass, manufactured by Arakawa Chemical Co., Ltd. YX7553BH30: phenoxy resin, 1:1 solution of MEK and cyclohexanone with non-volatile content of 30% by mass, manufactured by Mitsubishi Chemical Corporation (E) Inorganic filler SO-C2: spherical silica surface-treated with an amine-based alkoxysilane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size of 0.5 μm, specific surface area of 5.8 m ² /g, manufactured by Admatechs Co., Ltd. (F) Radical polymerization initiator Perhexyl D: manufactured by NOF Corporation (G) Curing accelerator 1B2PZ: Shikoku Chemicals Corporation

<Test Example 1: Measurement of dielectric loss tangent (Df)>
(1) Preparation of Resin Sheet A with a Resin Composition Layer Thickness of 40 μm A polyethylene terephthalate film ("AL5" manufactured by Lintec Corporation, thickness 38 μm) with a release layer was prepared as a support. The varnish-like resin compositions obtained in the Examples and Comparative Examples were uniformly applied to the release layer of this support so that the thickness of the resin composition layer after drying would be 40 μm. The resin composition was then dried at 80°C to 100°C (average 90°C) for 2 minutes to obtain a resin sheet A including a support and a resin composition layer.
(2) Preparation of Cured Product The obtained resin sheet A was cured for 90 minutes in an oven at 190° C. The support was peeled off from the resin sheet A taken out of the oven to obtain a cured product of the resin composition layer.
(3) Measurement of Dielectric Loss Tangent (Df) The cured product was cut into a piece of 80 mm long and 2 mm wide, and the dielectric loss tangent (Df value) was measured by the cavity resonance perturbation method using an "HP8362B" manufactured by Agilent Technologies at a measurement frequency of 5.8 GHz and measurement temperatures of 23° C. and 90° C. Measurement was performed on two test pieces, and the average was calculated.

<Test Example 2: Measurement of elongation at break>
The cured product obtained in Test Example 1 (2) was subjected to tensile strength measurement using an Orientec tensile tester "RTC-1250A" to measure the strength at break and elongation at break at 23°C. The measurement was carried out in accordance with JIS K7127. The measurement was carried out five times, and the average of the top three points was calculated.

<Test Example 3: Evaluation of crack resistance>
(1) Lamination of Resin Sheet An inner layer substrate ("MCL-E700G" manufactured by Resonac Corporation, conductor layer thickness 35 μm, total thickness 0.4 mm, residual copper ratio 40%) having circuit conductors (copper) formed on both sides with an L/S = 8 μm/8 μm wiring pattern was prepared. Resin sheets were laminated to both sides of this inner layer substrate so that the resin composition layer was in contact with the inner layer substrate. This lamination was performed using a vacuum pressure laminator ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.) by vacuum suction at a temperature of 120°C for 30 seconds, followed by pressing from above the support via heat-resistant rubber at a temperature of 120°C and a pressure of 7.0 kg/cm2 for ³⁰ seconds. Next, pressing was performed for 60 seconds under atmospheric pressure at a temperature of 120°C and a pressure of 5.5 kg/ ^cm2 using an SUS end plate.
(2) Thermal curing of resin composition layer The resin composition layer was thermally cured by heating at 130°C for 30 minutes and then at 170°C for 30 minutes to obtain an insulating layer as a cured product layer made of a cured product of the resin composition. Thereafter, the support was peeled off to obtain a sample substrate having a layer structure of insulating layer/internal layer substrate/insulating layer.
(3) Roughening Treatment The insulating layer of the sample substrate was subjected to roughening treatment. Specifically, the sample substrate was immersed in a swelling solution, Swelling Dip Securigant P (manufactured by Atotech Japan), at 60°C for 10 minutes. Next, the sample substrate was immersed in a roughening solution, Concentrate Compact P (aqueous solution of KMnO4: 60 g/L, NaOH: 40 g/L) (manufactured by Atotech Japan), at 80°C for 20 minutes. Finally, the sample substrate was immersed in a neutralizing solution, Reduction Solution Securigant P (manufactured by Atotech Japan), at 40°C for 5 minutes.
(4) Crack Evaluation The surface of the insulating layer after the roughening treatment was observed on the L/S pattern of the inner layer substrate. The surface of 100 inner layer substrates was checked for cracks along the pattern shape, and the percentage of the number of portions on the pattern where cracks did not occur was counted. This percentage was calculated as the "yield." The calculated yield was then scored according to the following criteria.
1 point: 0% or more but less than 20%.
2 points: 20% or more but less than 40%.
3 points: 40% or more but less than 60%.
4 points: 60% or more but less than 80%.
5 points: 80% or more.
A score of 4 or more was evaluated as ⊚, a score of 3 was evaluated as "○", and a score of 2 or less was evaluated as "×".

Claims (23)

(A) A compound represented by the following formula (A-1):
(In formula (A-1),
X represents a divalent group represented by the following formula (A-2) or a divalent group represented by the following formula (A-3):
(In formula (A-2),
R ¹¹ and R ¹² each independently represent a divalent aromatic group which may have a substituent;
Each L ¹¹ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹¹ and L ¹¹ may be bonded together to form a ring.
a represents a number ranging from 0 to 5.
(In formula (A-3),
R ¹³ and R ¹⁴ each independently represent a divalent aromatic group which may have a substituent;
^L12 represents a group represented by formula (A-4).
b and c each independently represent a number ranging from 0 to 5.
(In formula (A-4),
R ¹⁵ and R ¹⁶ each independently represent a divalent aromatic group which may have a substituent;
Each L ¹³ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹⁵ and L ¹³ may be bonded together to form a ring.
d represents a number ranging from 0 to 5.
(B) maleimide resin, and (C) thermosetting resin (excluding maleimide resin).
Contains
The component (A) is 2 to 15% by mass when the resin component in the resin composition is 100% by mass,
The (B) component is 20 to 80% by mass when the resin component in the resin composition is 100% by mass,
A resin composition in which the component (C) is 5 to 60% by mass when the resin component in the resin composition is 100% by mass . (A) A compound represented by the following formula (A-1):
(In formula (A-1),
X represents a divalent group represented by the following formula (A-5):
(In formula (A-5),
Each Rs independently represents a substituent.
L ²¹ each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group, and when L ²¹ is a divalent aliphatic group which may have a substituent, L ²¹ and the benzene ring on the left side may be bonded together to form a ring,
n1 and n2 each independently represent a number ranging from 0 to 4;
m represents a number ranging from 1 to 5;
"*" represents a bond.)
(B) maleimide resin, and (C) thermosetting resin (excluding maleimide resin).
Contains
The component (A) is 2 to 15% by mass when the resin component in the resin composition is 100% by mass,
The (B) component is 20 to 80% by mass when the resin component in the resin composition is 100% by mass,
A resin composition in which the component (C) is 5 to 60% by mass when the resin component in the resin composition is 100% by mass . (A) A compound represented by the following formula (A-1):
(In formula (A-1),
X represents a divalent group represented by the following formula (A-2) or a divalent group represented by the following formula (A-3):
(In formula (A-2),
R ¹¹ and R ¹² each independently represent a divalent aromatic group which may have a substituent;
Each L ¹¹ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹¹ and L ¹¹ may be bonded together to form a ring.
a represents a number ranging from 0 to 5.
(In formula (A-3),
R ¹³ and R ¹⁴ each independently represent a divalent aromatic group which may have a substituent;
^L12 represents a group represented by formula (A-4).
b and c each independently represent a number ranging from 0 to 5.
(In formula (A-4),
R ¹⁵ and R ¹⁶ each independently represent a divalent aromatic group which may have a substituent;
Each L ¹³ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹⁵ and L ¹³ may be bonded together to form a ring.
d represents a number ranging from 0 to 5.
(B) maleimide resin, and (C) thermosetting resin (excluding maleimide resin).
Contains
The component (A) is 2 to 15% by mass when the resin component in the resin composition is 100% by mass,
The (B) component is 20 to 80% by mass when the resin component in the resin composition is 100% by mass,
A resin composition for an insulating layer of a circuit board, wherein the component (C) is 5 to 60% by mass when the resin component in the resin composition is 100% by mass . (A) A compound represented by the following formula (A-1):
(In formula (A-1),
X represents a divalent group represented by the following formula (A-2) or a divalent group represented by the following formula (A-3):
(In formula (A-2),
R ¹¹ and R ¹² each independently represent a divalent aromatic group which may have a substituent;
Each L ¹¹ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹¹ and L ¹¹ may be bonded together to form a ring.
a represents a number ranging from 0 to 5.
(In formula (A-3),
R ¹³ and R ¹⁴ each independently represent a divalent aromatic group which may have a substituent;
^L12 represents a group represented by formula (A-4).
b and c each independently represent a number ranging from 0 to 5.
(In formula (A-4),
R ¹⁵ and R ¹⁶ each independently represent a divalent aromatic group which may have a substituent;
Each L ¹³ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹⁵ and L ¹³ may be bonded together to form a ring.
d represents a number ranging from 0 to 5.
(B) maleimide resin, and (C) thermosetting resin (excluding maleimide resin).
Contains
The component (A) is 2 to 15% by mass when the resin component in the resin composition is 100% by mass,
The (B) component is 20 to 80% by mass when the resin component in the resin composition is 100% by mass,
The component (C) is 5 to 60% by mass when the resin component in the resin composition is 100% by mass,
A resin composition in which the mass ratio of the component (A) to the component (B) (component (A)/component (B)) is 0.4 or less . (A) A compound represented by the following formula (A-1):
(In formula (A-1),
X represents a divalent group represented by the following formula (A-2) or a divalent group represented by the following formula (A-3):
(In formula (A-2),
R ¹¹ and R ¹² each independently represent a divalent aromatic group which may have a substituent;
Each L ¹¹ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹¹ and L ¹¹ may be bonded together to form a ring.
a represents a number ranging from 0 to 5.
(In formula (A-3),
R ¹³ and R ¹⁴ each independently represent a divalent aromatic group which may have a substituent;
^L12 represents a group represented by formula (A-4).
b and c each independently represent a number ranging from 0 to 5.
(In formula (A-4),
R ¹⁵ and R ¹⁶ each independently represent a divalent aromatic group which may have a substituent;
Each L ¹³ independently represents a single bond or a divalent linking group which may have a substituent, and R ¹⁵ and L ¹³ may be bonded together to form a ring.
d represents a number ranging from 0 to 5.
(B) maleimide resin, and (C) thermosetting resin (excluding maleimide resin).
Contains
The component (C) contains one or more resins selected from the group consisting of epoxy resins, phenolic resins, and terminal double bond resins,
The component (A) is 2 to 15% by mass when the resin component in the resin composition is 100% by mass,
The (B) component is 20 to 80% by mass when the resin component in the resin composition is 100% by mass,
A resin composition in which the component (C) is 5 to 60% by mass when the resin component in the resin composition is 100% by mass . The resin composition according to any one of claims 1 and 3 to 5, wherein R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ in formula (A-2) and formula ( A-3) each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent. The resin composition according to any one of claims 1 and 3 to 5, wherein R ¹⁵ and R ¹⁶ in formula (A- 4) each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent. The resin composition according to any one of claims 1 and 3 to 5, wherein L ¹¹ in formula (A -2) each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a divalent aromatic group which may have a substituent, a carbonyl group, or a sulfonyl group. The resin composition according to any one of claims 1 and 3 to 5, wherein L ¹¹ in formula (A -2 ) each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group. The resin composition according to any one of claims 1 and 3 to 5 , wherein X in formula (A-1) is a group represented by the following formula (A-5):
(In formula (A-5),
Each Rs independently represents a substituent.
L ²¹ each independently represents a single bond, a divalent aliphatic group which may have a substituent, an oxygen atom, a phenylene group, a fluorenylidene group, a carbonyl group, or a sulfonyl group, and when L ²¹ is a divalent aliphatic group which may have a substituent, L ²¹ and the benzene ring on the left side may be bonded together to form a ring,
n1 and n2 each independently represent a number ranging from 0 to 4;
m represents a number ranging from 0 to 5;
"*" represents a bond.) The resin composition according to any one of claims 1 to 5 , wherein the content of component (A) is 2% by mass or more and 12% by mass or less, when the resin component in the resin composition is 100% by mass. The resin composition according to any one of claims 1 to 5 , wherein the content of component (B) is 20% by mass or more and 75% by mass or less, when the resin component in the resin composition is 100% by mass. The resin composition according to any one of claims 1 to 4 , wherein the component (C) comprises at least one resin selected from the group consisting of epoxy resins, phenolic resins, and terminal double bond resins. The resin composition according to any one of claims 1 to 5 , wherein the content of component (C) is 10% by mass or more and 50% by mass or less, when the resin component in the resin composition is 100% by mass. The resin composition according to any one of claims 1 to 5 , further comprising (D) a thermoplastic resin. The resin composition according to any one of claims 1 to 5 , further comprising (E) an inorganic filler. The resin composition according to claim 16 , wherein the content of component (E) is 50% by mass or more when the nonvolatile components in the resin composition are 100% by mass. The resin composition according to any one of claims 1 to 5, which is used for an insulating layer of a circuit board. A cured product of the resin composition according to any one of claims 1 to 5 . A resin sheet comprising a support and a layer of the resin composition according to any one of claims 1 to 5 provided on the support. The resin sheet according to claim 20 , wherein the support is a thermoplastic resin film or a metal foil. A circuit board comprising an insulating layer made of a cured product of the resin composition according to any one of claims 1 to 5 . A semiconductor device comprising the circuit board according to claim 22 .