TWI900531B - Resin composition - Google Patents

Abstract

The present invention provides a resin composition capable of controlling the unevenness generated when laminating a resin composition; a resin sheet containing the resin composition; a printed wiring board having an insulating layer formed using the resin composition; and a semiconductor device. The present invention provides a solution to this problem by providing a resin composition comprising (A) an epoxy resin and (B) an active ester compound having at least one of the groups represented by the following formulae (1) to (3). In the formulae, * represents a bond. n represents an integer from 1 to 5.

Description

Resin composition

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

In the manufacturing technology of printed wiring boards, there is a known manufacturing method that uses an assembly method in which insulating layers and conductive layers are alternately stacked.

Regarding insulating materials for printed wiring boards used in such insulating layers, for example, Patent Document 1 discloses a resin composition. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application No. 2018-199797

[The problem that the invention aims to solve]

Insulating layers are generally formed by depositing and thermally curing a resin composition onto a substrate. The inventors of the present invention conducted extensive research and found that depositing a resin composition containing conventional resin compositions to form an insulating layer reduces surface uniformity and easily produces unevenness (post-deposition unevenness). Such unevenness on the insulating layer surface can impair the ability to form wiring within the insulating layer.

The present invention is to provide a resin composition that suppresses unevenness during lamination; a resin sheet containing the resin composition; a printed wiring board having an insulating layer formed using the resin composition; and a semiconductor device. [Means for Solving the Problem]

The inventors of the present invention have devoted themselves to research and review on the above-mentioned issues and found that the above-mentioned issues can be solved by making the active ester compound containing a specific group, which ultimately led to the completion of the present invention.

That is, the present invention includes the following contents. [1] A resin composition comprising: (A) an epoxy resin, and (B) at least one active ester compound having a group represented by the following formulae (1) to (3). (In the formula, * represents a bond. In formula (3), n represents an integer from 1 to 5.) [2] The resin composition of [1], wherein component (B) is an active ester compound represented by the following general formula (b-1). (In general formula (b-1), Ar ¹¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3); Ar ¹² each independently represents a divalent aromatic hydrocarbon group which may have a substituent; Ar ¹³ each independently represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aliphatic hydrocarbon group which may have a substituent, an oxygen atom, a sulfur atom, or a divalent group formed by a combination thereof. a represents an integer from 1 to 6, and b represents an integer from 0 to 10.) [3] The resin composition of [2], wherein Ar ¹³ in general formula (b-1) each independently represents a divalent aromatic hydrocarbon group which may have a substituent and a divalent group combined with an oxygen atom. [4] The resin composition according to any one of [1] to [3], wherein the component (B) is an active ester compound represented by the following general formula (b-3). (In general formula (b-3), Ar ³¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3). a2 represents an integer from 1 to 6, c2 represents an integer from 1 to 5, and d each independently represents an integer from 0 to 6.) [5] The resin composition of any one of [1] to [4], further comprising (C) an inorganic filler. [6] The resin composition of any one of [1] to [5], which is used for forming an insulating layer. [7] The resin composition of any one of [1] to [6], which is used for forming an insulating layer for forming a conductive layer. [8] A resin sheet comprising a support and a resin composition layer disposed on the support comprising the resin composition of any one of [1] to [7]. [9] A printed wiring board comprising an insulating layer formed by a cured product of the resin composition of any one of [1] to [7]. [10] A semiconductor device comprising the printed wiring board of [9]. [Effects of the Invention]

According to the present invention, a resin composition having uneven lamination resulting from lamination of the resin composition can be provided; a resin sheet comprising the resin composition; a printed wiring board having an insulating layer formed from a cured product of the resin composition; and a semiconductor device. [Embodiments of the Invention]

The present invention is described below in detail with reference to its preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and can be arbitrarily modified and implemented without departing from the scope of the patent application of the present invention and its equivalents.

[Resin Composition] The resin composition of the present invention comprises (A) an epoxy resin and (B) at least one active ester compound having a group represented by the following formulas (1) to (3). By incorporating component (B) into the resin composition, unevenness after lamination, which occurs when a resin composition layer containing the resin composition is laminated, can be suppressed. Furthermore, the present invention generally produces a cured product having excellent plating peel strength, copper foil adhesion, and copper foil adhesion after HAST, and furthermore, low dielectric properties and a low arithmetic average roughness (Ra). (In the formula, * represents a key. In formula (3), n represents an integer from 1 to 5.)

The resin composition may further contain optional components in addition to components (A) and (B). Optional components include (C) inorganic fillers, (D) hardeners, (E) curing accelerators, and (F) other additives. The following describes each component of the resin composition in detail.

<(A) Epoxy Resin> The resin composition contains an epoxy resin (A) as component (A). Component (A) includes, for example, bis(xylenol) epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, bisphenol AF epoxy resins, dicyclopentadiene epoxy resins, tris(phenoxy)phenol epoxy resins, naphthol novolac epoxy resins, phenol novolac epoxy resins, tert-butylbenzene epoxy resins, naphthalene epoxy resins, naphthol epoxy resins, and anthracene 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 with a butadiene structure, aliphatic epoxy resins, heterocyclic epoxy resins, spirocyclic epoxy resins, oxalic acid-type epoxy resins, oxalic acid-dimethanol-type epoxy resins, naphthyl ether-type epoxy resins, trihydroxymethyl-type epoxy resins, tetraphenylethane-type epoxy resins, etc. Epoxy resins may be used alone or in combination of two or more.

The resin composition preferably includes an epoxy resin having two or more epoxy groups per molecule as the epoxy resin (A). To significantly achieve the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the non-volatile component of the epoxy resin (A) is preferably 50% by mass or greater, more preferably 60% by mass or greater, and particularly preferably 70% by mass or greater.

Epoxy resins include those that are liquid at 20°C (hereinafter referred to as "liquid epoxy resins") and those that are solid at 20°C (hereinafter referred to as "solid epoxy resins"). The resin composition, as component (A), may contain only the liquid epoxy resin, only the solid epoxy resin, or a combination of the liquid and solid epoxy resins. However, from the perspective of significantly achieving the desired effects of the present invention, it is preferred to contain only the solid epoxy resin.

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

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

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

As for liquid epoxy resins, those having two or more epoxy groups in one molecule are preferred.

As for liquid 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, glycidylamine-type epoxy resins, phenol novolac-type epoxy resins, aliphatic epoxy resins with an ester skeleton, oxalic acid epoxy resins, oxalic acid dimethanol-type epoxy resins, glycidylamine-type epoxy resins, and epoxy resins with a butadiene structure are preferred, with naphthalene-type epoxy resins being even more preferred.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene-based epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "825", and "EPIKOTE" manufactured by Mitsubishi Chemical Corporation; 828EL" (bisphenol A epoxy resin); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F epoxy resin); Mitsubishi Chemical's "jER152" (phenol novolac epoxy resin); Mitsubishi Chemical's "630" and "630LSD" (glycidylamine epoxy resin); Nippon Steel Chemicals & Materials' "ZX1059" (a mixture of bisphenol A and bisphenol F epoxy resins); Nagase Examples include Chemtex's "EX-721" (a glycidyl ester epoxy resin); Daicel's "CELLOXIDE 2021P" (an ester-based epoxy resin); Daicel's "PB-3600" (an epoxy resin with a butadiene structure); and Nippon Steel Chemicals & Materials' "ZX1658" and "ZX1658GS" (liquid 1,4-glycidyl cyclohexane epoxy resins). These can be used alone or in combination.

Regarding component (A), when a liquid epoxy resin and a solid epoxy resin are used in combination, the mass ratio (liquid epoxy resin:solid epoxy resin) is preferably 1:1 to 1:20, more preferably 1:1.5 to 1:15, and particularly preferably 1:2 to 1:10. By maintaining the mass ratio of the liquid epoxy resin to the solid epoxy resin within this range, the desired effects of the present invention are significantly achieved. Furthermore, when used in the form of a resin sheet, moderate adhesion is achieved. Furthermore, when used in the form of a resin sheet, sufficient flexibility is achieved, and absorbency is improved. Furthermore, a cured product with sufficient breaking strength is generally obtained.

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

The weight-average molecular weight (Mw) of component (A) is preferably 100-5000, more preferably 200-3000, and even more preferably 250-1500 to significantly achieve the desired effects of the present invention. The weight-average molecular weight of the resin is measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

From the perspective of achieving an insulating layer exhibiting excellent mechanical strength and insulation reliability, the content of component (A) is preferably 1% by mass or greater, more preferably 5% by mass or greater, and even more preferably 10% by mass or greater, based on 100% by mass of the non-volatile components in the resin composition. The upper limit of the epoxy resin content is preferably 25% by mass or less, more preferably 20% by mass or less, and particularly preferably 15% by mass or less, from the perspective of significantly achieving the desired effects of the present invention. In addition, in the present invention, the content of each component in the resin composition is based on 100% by mass of the non-volatile components in the resin composition, unless otherwise specified.

<(B) Active ester compound having at least one group represented by the following formulas (1) to (3)> The resin composition contains at least one active ester compound having a group represented by the following formulas (1) to (3) as component (B). By including component (B) in the resin composition, the occurrence of unevenness after lamination can be suppressed. Furthermore, by including component (B) in the resin composition, a cured product having excellent plating peel strength, copper foil adhesion, and copper foil adhesion after HAST can generally be obtained, thereby having low dielectric properties and a low arithmetic average roughness (Ra).

(In the formula, * represents a key. In formula (3), n represents an integer from 1 to 5.)

Component (B) has at least one of the groups represented by formulae (1) to (3) and can be a compound having an active ester site capable of reacting with component (A). Component (B) preferably has at least one of the groups represented by formulae (1) to (3) at its terminal end. Component (B) may have different or identical groups at both terminals.

The group represented by formula (1) may be a group derived from cresol as shown below. The methyl group in the group represented by formula (1) is preferably bonded to any of the vicinal, meta, and para positions relative to the oxygen atom, and is more preferably bonded to the vicinal position.

The group represented by formula (2) may be a group derived from phenylphenol as shown below. The phenyl group in the group represented by formula (2) is preferably bonded to the oxygen atom of the phenol site at any of the vicinal, meta, and para positions, and more preferably at the vicinal position.

The group represented by formula (3) may be a group derived from styrenated phenol as shown below. The styrene moiety in the group represented by formula (3) is preferably bonded to the oxygen atom of the phenol moiety at any of the vicinal, meta, and para positions, and more preferably at the vicinal position.

In formula (3), n represents an integer from 1 to 5, preferably an integer from 1 to 3, and more preferably an integer from 1 to 2. (In the formula, n1 is the same as n in formula (3).) Component (B) is preferably a compound represented by the following general formula (b-1). (In general formula (b-1), Ar ¹¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3); Ar ¹² each independently represents a divalent aromatic hydrocarbon group which may have a substituent; Ar ¹³ each independently represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aliphatic hydrocarbon group which may have a substituent, an oxygen atom, a sulfur atom, or a divalent group composed of a combination thereof; a represents an integer from 1 to 6; and b represents an integer from 0 to 10.)

In general formula (b-1), Ar ¹¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3). The groups represented by formulas (1) to (3) are as described above. Among them, the group represented by formula (1) and the group represented by formula (2) are preferred.

In general formula (b-1), Ar ^<12> each independently represents a divalent aromatic hydrocarbon group optionally having a substituent. Examples of divalent aromatic hydrocarbon groups include arylene groups and arylene alkyl groups, with arylene groups being preferred. Arylene groups are preferably arylene groups having 6 to 30 carbon atoms, more preferably arylene groups having 6 to 20 carbon atoms, and even more preferably arylene groups having 6 to 10 carbon atoms. Examples of such arylene groups include phenylene groups, naphthyl groups, anthracenyl groups, and biphenylene groups. Aralkylene groups are preferably arylene groups having 7 to 30 carbon atoms, more preferably arylene groups having 7 to 20 carbon atoms, and even more preferably arylene groups having 7 to 15 carbon atoms. Among these, phenylene groups are particularly preferred.

In general formula (b-1), Ar ^<13> each independently represents a divalent aromatic alkyl group optionally having a substituent, a divalent aliphatic alkyl group optionally having a substituent, an oxygen atom, a sulfur atom, or a divalent group formed by a combination thereof, preferably a divalent group formed by a combination thereof. The divalent aromatic alkyl group is the same as the divalent aromatic alkyl group represented by Ar ^<12> .

The divalent aliphatic hydrocarbon group is preferably a divalent saturated aliphatic hydrocarbon group, preferably an alkylene group or a cycloalkylene group, and more preferably a cycloalkylene group.

The alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and even more preferably an alkylene group having 1 to 3 carbon atoms. Examples of the alkylene group include methylene, ethylene, propylene, 1-methylmethylene, 1,1-dimethylmethylene, 1-methylethylene, 1,1-dimethylethylene, 1,2-dimethylethylene, butylene, 1-methylpropylene, 2-methylpropylene, pentylene, and hexylene.

The cycloalkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and even more preferably 5 to 10 carbon atoms. Examples of the cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl, and cycloheptyl.

The divalent groups formed by such combinations are preferably divalent aromatic hydrocarbon groups optionally having substituents and divalent groups combined with oxygen atoms. More preferred are divalent aromatic hydrocarbon groups optionally having one or more substituents and divalent groups alternately combined with one or more oxygen atoms. Even more preferred are naphthyl groups optionally having one or more substituents and divalent groups alternately combined with one or more oxygen atoms. Therefore, naphthoxy groups optionally having substituents are even more preferred.

The divalent aromatic alkyl group represented by ^Ar12 , the divalent aromatic alkyl group represented by ^Ar13 , and the divalent aliphatic alkyl group may have a substituent. The number of substituents may be one or more. Examples of substituents include aryl groups having 6 to 20 carbon atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, and halogen atoms. Substituents may be present alone or in combination of two or more.

Examples of the aryl group having 6 to 20 carbon atoms include benzyl, phenyl, naphthyl, anthracenyl, tolyl, and xylyl, with benzyl being preferred.

Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, 1,2-dimethylpropyl, n-hexyl, isohexyl, n-nonyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclononyl.

Examples of the alkoxy group having 1 to 10 carbon atoms include methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, 2-ethylhexyloxy, octyloxy, and nonyloxy.

Halogen atoms include fluorine, chlorine, bromine, and iodine. The aforementioned substituents may further have substituents (hereinafter referred to as "secondary substituents"). Unless otherwise specified, the secondary substituents may be the same as those described above.

In general formula (b-1), a represents an integer of 1 to 6, preferably an integer of 1 to 5, and more preferably an integer of 1 to 3. Furthermore, when the compound represented by general formula (b-1) is an oligomer or polymer, a represents the average value thereof.

In general formula (b-1), b represents an integer from 0 to 10, preferably an integer from 0 to 5, more preferably an integer from 0 to 3, and even more preferably 0. Furthermore, when the compound represented by general formula (b-1) is an oligomer or polymer, b represents the average value thereof.

The component (B) is preferably a compound represented by the general formula (b-2). (In general formula (b-2), Ar ²¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3); Ar ²² each independently represents a divalent aromatic hydrocarbon group which may have a substituent; and Ar ²³ each independently represents a divalent aromatic hydrocarbon group which may have a substituent. a1 represents an integer from 1 to 6, and c1 represents an integer from 1 to 5.)

Ar ²¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3). The groups represented by formulas (1) to (3) are as described above. Among them, the group represented by formula (1) and the group represented by formula (2) are preferred.

Ar ²² each independently represents a divalent aromatic alkyl group which may have a substituent. Ar ²² is the same as Ar ¹² in general formula (b-1).

Ar ²³ each independently represents a divalent aromatic alkyl group which may have a substituent. Ar ²³ is the same as the divalent aromatic alkyl group which may have a substituent as Ar ¹³ in general formula (b-1).

In general formula (b-2), a1 represents an integer from 1 to 6. a1 is the same as a in general formula (b-1).

In general formula (b-2), c1 represents an integer from 1 to 5. Preferably, c1 represents an integer from 1 to 4, and more preferably, c1 represents an integer from 1 to 3.

The component (B) is preferably a compound represented by the general formula (b-3). (In general formula (b-3), Ar ^<31> each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3). a<2> represents an integer from 1 to 6, c<2> represents an integer from 1 to 5, and d each independently represents an integer from 0 to 6.)

Ar ³¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3). The groups represented by formulas (1) to (3) are as described above. Among them, the group represented by formula (1) and the group represented by formula (2) are preferred.

In general formula (b-3), a2 represents an integer from 1 to 6. a2 is the same as a in general formula (b-1).

In general formula (b-3), c2 represents an integer from 1 to 5. c2 is the same as c1 in general formula (b-2).

In general formula (b-3), d each independently represents an integer from 0 to 6. Preferably, d represents an integer from 1 to 5, and more preferably, represents an integer from 1 to 4.

Component (B) can be synthesized by a known method, for example, the method described in the following examples. Component (B) can be synthesized, for example, by the method described in International Publication No. 2018/235424 or International Publication No. 2018/235425.

The weight average molecular weight of component (B) is preferably 150 or greater, more preferably 200 or greater, and even more preferably 250 or greater, from the viewpoint of significantly achieving the effects of the present invention. It is preferably 4000 or less, more preferably 3000 or less, and even more preferably 2500 or less. The weight average molecular weight of component (B) is the weight average molecular weight in terms of polystyrene as measured by colloid permeation chromatography (GPC).

From the perspective of significantly achieving the effects of the present invention, the active ester equivalent (unsaturated bond equivalent) of component (B) is preferably 50 g/eq or greater, more preferably 100 g/eq or greater, and even more preferably 150 g/eq., and preferably 2000 g/eq or less, more preferably 1000 g/eq or less, and even more preferably 500 g/eq or less. The active ester equivalent is the mass of component (B) containing one equivalent of unsaturated bonds.

The molar ratio of component (A) to component (B) is preferably in the range of 1:0.01 to 1:20, more preferably 1:0.1 to 1:10, and even more preferably 1:0.5 to 1:5, calculated as the ratio of [total number of epoxy groups in component (A)]:[total number of active ester groups in component (B)]. Here, the "total number of epoxy groups in component (A)" refers to the total mass of the nonvolatile components in component (A) present in the resin composition divided by the epoxy equivalent. Furthermore, the "total number of active ester groups in component (B)" refers to the total mass of the nonvolatile components in component (B) present in the resin composition divided by the active ester equivalent. By setting the quantitative ratio of component (A) to component (B) within this range, the effects of the present invention can be remarkably achieved.

From the viewpoint of suppressing the occurrence of unevenness after lamination, the content of component (B) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, relative to 100% by mass of the non-volatile components in the resin composition.

<(C) Inorganic Filler> In addition to the above components, the resin composition may optionally contain an inorganic filler as component (C). The use of the inorganic filler (C) can improve the dielectric and insulating properties of the cured resin composition.

Inorganic fillers are made of inorganic compounds. Examples of inorganic filler materials include silicon oxide, aluminum oxide, glass, phillipse, silicate, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron hydroxide, aluminum hydroxide, manganese hydroxide, aluminum borate, strontium carbonate, strontium titanium oxide, calcium titanium oxide, magnesium titanium oxide, bismuth titanium oxide, titanium oxide, zirconium oxide, barium titanium oxide, barium zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silicon oxide is particularly suitable. Examples of silicon oxide include amorphous silicon oxide, molten silicon oxide, crystalline silicon oxide, synthetic silicon oxide, and hollow silicon oxide. Spherical silicon oxide is particularly preferred. (C) Inorganic fillers may be used singly or in combination of two or more.

Commercially available products of component (C) include, for example, "UFP-30" manufactured by Denka; "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Corporation; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatechs; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama; and "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs.

The specific surface area of component (C) is preferably 1 ^m² /g or greater, more preferably 2 ^m² /g or greater, and particularly preferably 3 ^m² /g or greater. While there is no particular upper limit, it is preferably 60 ^m² /g or less, 50 ^m² /g or less, or 40 ^m² /g or less. The specific surface area is calculated using the BET multipoint method using a specific surface area measuring device (Macsorb HM-1210, manufactured by Mountech) by adsorbing nitrogen gas onto the sample surface.

The average particle size of component (C) is preferably 0.01 μm or more, more preferably 0.05 μm or more, particularly preferably 0.1 μm or more, and preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less, in order to remarkably obtain the desired effects of the present invention.

The average particle size of component (C) can be measured by a laser diffraction and scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be made on a volume basis using a laser diffraction and scattering particle size distribution measuring device, and the median diameter is used as the average particle size for measurement. The measurement sample can be 100 mg of inorganic filler and 10 g of methyl ethyl ketone weighed into a small glass bottle and dispersed by ultrasonic waves for 10 minutes. The measurement sample is measured using a laser diffraction particle size distribution measuring device, and the wavelength of the light source used is divided into blue and red. The volume-based particle size distribution of component (C) is measured using a flow cell method, and the average particle size is calculated from the obtained particle size distribution as the median diameter. Examples of laser diffraction particle size distribution measuring devices include the LA-960 manufactured by Horiba, Ltd.

Component (C) is preferably treated with a surface treatment agent to improve moisture resistance and dispersibility. Examples of surface treatment agents include vinyl silane coupling agents, (meth)acrylic coupling agents, fluorinated silane coupling agents, amino silane coupling agents, epoxy silane coupling agents, alkyl silane coupling agents, silane coupling agents, alkoxy silanes, organosilazane compounds, and titanium salt coupling agents. Among these, vinyl silane coupling agents, (meth)acrylic coupling agents, and amino silane coupling agents are preferred for significantly achieving the effects of the present invention. Surface treatment agents may be used singly or in combination of two or more.

As for commercially available surface treatment agents, for example, Shin-Etsu Chemical Co., Ltd.'s "KBM1003" (vinyl triethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM503" (3-methacryloyloxypropyl triethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropoxytrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-butylene propyl trimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyl "KBM-103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM-4803" (long-chain epoxy-type silane coupling agent), Shin-Etsu Chemical Co., Ltd. "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane), etc.

From the perspective of improving the dispersibility of the inorganic filler, it is best to maintain the degree of surface treatment with the surface treatment agent within a predetermined range. Specifically, for 100 parts by weight of the inorganic filler, it is best to treat the surface with 0.2 to 5 parts by weight of the surface treatment agent, more preferably 0.2 to 3 parts by weight, and even more preferably 0.3 to 2 parts by weight.

The degree of surface treatment with a surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. To improve 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 greater, more preferably 0.1 mg/ ^m² or greater, and even more preferably 0.2 mg/ ^m² or greater. On the other hand, to prevent an increase in the melt viscosity of the resin composition or the melt viscosity of the sheet form, the amount of carbon per unit surface area is preferably 1 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 an inorganic filler can be measured by washing the surface-treated inorganic filler with a solvent, such as methyl ethyl ketone (MEK). Specifically, a sufficient amount of MEK is added to the surface-treated inorganic filler and ultrasonically washed at 25°C for 5 minutes. After removing the supernatant and drying the solid components, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. A suitable carbon analyzer is the EMIA-320V manufactured by Horiba, Ltd.

From the perspective of significantly achieving the effects of the present invention, the content of the inorganic filler is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

<(D) Hardener> In addition to the above components, the resin composition may optionally contain a hardener as component (D). However, this excludes components equivalent to component (B).

As the curing agent (D), a compound that can cure the resin composition together with component (A) can be used. Examples include active ester curing agents, which are not equivalent to component (B), phenol curing agents, benzoxazine curing agents, carbodiimide curing agents, acid anhydride curing agents, amine curing agents, cyanate curing agents, maleimide curing agents, and polyphenylene ether curing agents (styrene curing agents). Among these, phenol curing agents, carbodiimide curing agents, maleimide curing agents, and polyphenylene ether curing agents are particularly preferred in terms of achieving the effects of the present invention.

Active ester hardeners include those having one or more active ester groups per molecule. Preferred active ester hardeners include compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxylamine esters, and esters of heterocyclic hydroxyl compounds. Preferred active ester hardeners are those obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound with a hydroxyl compound and/or a thiol compound. In particular, from the perspective of improved heat resistance, active ester hardeners obtained from a carboxylic acid compound and a hydroxyl compound are preferred, and those obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound are even more preferred.

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

As for the phenol compound or naphthol compound, for example, hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, hydroquinone, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, 1,3,5-benzenetriol, 1,2,4-benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolac, etc. Here, the term "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

Preferred examples of active ester hardeners include active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing acetylated phenol novolacs, and active ester compounds containing benzoylated phenol novolacs. Among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are particularly preferred. The term "dicyclopentadiene-type diphenol structure" refers to a divalent structure consisting of phenylene-dicyclopentadiene-phenylene.

As for commercially available active ester curing agents, active ester compounds containing a dicyclopentadiene-type diphenol structure include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", "HPC-8000H", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L-65TM", (manufactured by DIC Corporation); active ester compounds containing a naphthalene structure include "HPC-8150-62T", "EXB-8100L-65T", "EXB-8150L-65T", "EXB9416-70BK", " HPC-8900-70BK" (manufactured by DIC Corporation); examples of active ester compounds of acetylated phenol novolacs include "DC808" (manufactured by Mitsubishi Chemical Corporation); examples of active ester compounds of benzoylated phenol novolacs include "YLH1026" (manufactured by Mitsubishi Chemical Corporation); examples of active ester hardeners of acetylated phenol novolacs include "DC808" (manufactured by Mitsubishi Chemical Corporation); examples of active ester hardeners of benzoylated phenol novolacs include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), etc.

Examples of phenolic hardeners include those containing one or more, preferably two or more, hydroxyl groups bonded to aromatic rings (such as benzene rings and naphthalene rings) per molecule. Compounds containing hydroxyl groups bonded to benzene rings are particularly preferred. Furthermore, from the perspective of heat resistance and water resistance, phenolic hardeners with a novolac structure are preferred. Furthermore, from the perspective of adhesion, nitrogen-containing phenolic hardeners are preferred, with phenolic hardeners containing a triazine skeleton being even more preferred. In particular, from the perspective of achieving high heat resistance, water resistance, and adhesion, phenolic novolac hardeners containing a triazine skeleton are preferred.

Specific examples of phenol-based hardeners and naphthol-based hardeners include "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Chemicals; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku; and "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", "SN-375", and "SN-375" manufactured by Nippon Steel Chemicals & Materials. SN-395"; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", "KA-1165" manufactured by DIC Corporation; "GDP-6115L", "GDP-6115H", "ELPC75" and others manufactured by Qunrong Chemical Co., Ltd.

Specific examples of benzoxazine-based hardeners include "HFB2006M" manufactured by Showa Highpolymer Co., Ltd., "P-d," "F-a," and "ALP-d" manufactured by Shikoku Chemical Industries, Ltd., and "ODA-BOZ" manufactured by JFE Chemicals.

Specific examples of carbodiimide-based hardeners include "V-03," "V-05," and "V-07" manufactured by Nisshinbo Chemical Co., Ltd.; and Stabaxol® (registered trademark) P manufactured by LAN-CHEMI.

As for the acid anhydride curing agent, there are those having one or more acid anhydride groups in one molecule. Specific examples of the acid anhydride curing agent include anhydrous phthalic acid, anhydrous tetrahydrophthalic acid, anhydrous hexahydrophthalic acid, anhydrous methyltetrahydrophthalic acid, anhydrous 4-methylhexahydrophthalic acid, anhydrous methylhexahydrophthalic acid, methylnadic anhydride, hydrogenated methylnadic anhydride, anhydrous trialkyltetrahydrophthalic acid, anhydrous dodecenylsuccinic acid, 5-(2,5-dioxytetrahydro-3-pyranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, anhydrous trimellitic acid, anhydrous pyromellitic acid, and the like. Polymer-type acid anhydrides such as formic acid, benzophenonetetracarboxylic acid dianhydrous, biphenyltetracarboxylic acid dianhydrous, naphthalenetetracarboxylic acid dianhydrous, oxydiphthalic acid dianhydrous, 3,3'-4,4'-diphenylsulfoniumtetracarboxylic acid dianhydrous, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxy-3-pyranyl)-naphtho[1,2-c]furan-1,3-dione, ethylene glycol bis(trimellitic anhydride ester), and styrene-maleic acid resin copolymerized with styrene and maleic acid can also be used. Commercially available acid anhydride hardeners can also be used, such as "MH-700" manufactured by Shin Nippon Rika Co., Ltd.

Amine-based hardeners include those having one or more amino groups per molecule, such as aliphatic amines, polyether amines, alicyclic amines, and aromatic amines. Aromatic amines are preferred from the perspective of achieving the desired effects of the present invention. Amine-based hardeners are preferably primary or secondary amines, with primary amines being more preferred. Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfonyl, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfonyl, 3,3'-diaminodiphenylsulfonyl, m-phenylenediamine, m-xylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-aminobenzidine), -4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfonium, bis(4-(3-aminophenoxy)phenyl)sulfonium, etc. Amine hardeners that can be used are commercially available products, such as "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD A-A", "KAYAHARD A-B", and "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd., and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

Cyanate curing agents include bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylenediphenyl 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)sulfide, and bis(4-cyanatephenyl)ether; multifunctional cyanate resins derived from phenol novolac and cresol novolac; partially triazine-containing prepolymers of these cyanate resins; etc. Specific examples of cyanate-based hardeners include "PT30" and "PT60" manufactured by Lonza Japan (both phenol novolac-type multifunctional cyanate resins); "ULL-950S" (a multifunctional cyanate resin); "BA230" and "BA230S75" (prepolymers of bisphenol A dicyanate partially or fully triazinated to form trimers); and so on.

Maleimide-based curing agents are compounds containing a maleimide group represented by the following formula (D-1) in their molecules. Maleimide-based curing agents may be used alone or in combination of two or more.

The number of maleimide groups per molecule of the maleimide-based hardener is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, preferably 10 or less, even more preferably 6 or less, and particularly preferably 3 or less, in order to remarkably achieve the desired effects of the present invention.

From the perspective of significantly achieving the desired effects of the present invention, the maleimide-based hardener preferably has either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and more preferably has both an aliphatic hydrocarbon group and an aromatic hydrocarbon group.

The aliphatic alkyl group is preferably a divalent aliphatic alkyl group, more preferably a divalent saturated aliphatic alkyl group, and even more preferably an alkylene group. The alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, even more preferably an alkylene group having 1 to 3 carbon atoms, and particularly preferably a methylene group.

Aromatic alkyl groups are preferably monovalent and divalent aromatic alkyl groups, with aryl groups and arylene groups being more preferred. Among arylene groups, arylene groups having 6 to 30 carbon atoms are preferred, arylene groups having 6 to 20 carbon atoms are more preferred, and arylene groups having 6 to 10 carbon atoms are even more preferred. Examples of such arylene groups include phenylene, naphthyl, anthracenyl, aralkyl, biphenylene, and biphenyl aralkyl groups. Among them, phenylene, aralkyl, biphenylene, and biphenyl aralkyl groups are preferred, with phenylene, aralkyl, and biphenylene being even more preferred. Among aryl groups, aryl groups having 6 to 30 carbon atoms are preferred, aryl groups having 6 to 20 carbon atoms are even more preferred, and aryl groups having 6 to 10 carbon atoms are even more preferred, with phenyl being particularly preferred.

In maleimide-based curing agents, in order to significantly achieve the desired effects of the present invention, it is preferred that the nitrogen atom of the maleimide group be directly bonded to a monovalent or divalent aromatic hydrocarbon group. Here, "directly" means that there is no other group between the nitrogen atom of the maleimide group and the aromatic hydrocarbon group.

The maleimide-based curing agent is preferably one having a structure represented by the following formula (D-2). In formula (D-2), R ³¹ and R ³⁶ represent a maleimide group, R ³² , R ³³ , R ³⁴ , and R ³⁵ each independently represent a hydrogen atom, an alkyl group, or an aryl group, and D each independently represents a divalent aromatic group. m1 and m2 each independently represent an integer from 1 to 10, and a represents an integer from 1 to 100.

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

Alkyl groups preferably have 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. Alkyl groups may be linear, branched, or cyclic. Examples of such alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, and isopropyl.

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

Alkyl and aryl groups may have substituents. Examples of substituents include halogen atoms, -OH, _-OC1-6 alkyl, -N( _C1-10 alkyl) ₂ , _C1-10 alkyl, _C6-10 aryl, _-NH2 , -CN, -C(O) _OC1-10 alkyl, -COOH, -C(O)H, and _-NO2 . The term " _Cpq " (p and q are positive integers, satisfying p < q) indicates that the organic group following the term has p to q carbon atoms. For example, " _C1-10 alkyl" indicates an alkyl group with 1 to 10 carbon atoms. These substituents may also be bonded to form rings, including spirocyclic or condensed ring structures.

D in formula (D-2) represents a divalent aromatic group. Examples of divalent aromatic groups include phenylene, naphthylene, anthracenylene, aralkylene, biphenylene, and biphenylaralkylene. Biphenylene and biphenylaralkylene are preferred, with biphenylene being more preferred. The divalent aromatic group may have a substituent. The substituents are the same as those that may be present in the alkyl group represented by ^R in general formula (D-2).

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

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

As the maleimide-based hardener, the resin represented by formula (D-3) is preferred. In formula (D-3), R ³⁷ and R ³⁸ represent a maleimide group. a1 represents an integer from 1 to 100.

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

Such maleimide-based hardeners can be commercially available products. Examples of commercially available products include "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd.

In another embodiment of the maleimide-based curing agent, the maleimide-based curing agent is a compound having at least one maleimide group in the molecule.

In this maleimide-based curing agent, the aliphatic group having 5 or more carbon atoms is preferably directly bonded to the nitrogen atom of the maleimide group. Examples of the aliphatic group having 5 or more carbon atoms include alkyl, alkylene, and alkenylene groups.

The number of maleimide groups per molecule of the maleimide-based hardener may be 1, preferably 2 or more, more preferably 10 or less, even more preferably 6 or less, and particularly preferably 3 or less. The effects of the present invention can be significantly achieved by using a maleimide-based hardener having 2 or more maleimide groups per molecule.

The maleimide-based curing agent is preferably represented by the following general formula (D-4). In the general formula (D-4), M represents a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, and L represents a single bond or a divalent linking group.

M represents a divalent aliphatic group having 5 or more carbon atoms, which may have a substituent. The divalent aliphatic group having 5 or more carbon atoms preferably has 6 or more carbon atoms, more preferably 8 or more carbon atoms, and preferably 50 or less carbon atoms, more preferably 45 or less carbon atoms, and even more preferably 40 or less carbon atoms. Examples of divalent aliphatic groups include alkylene groups and alkenylene groups. The substituents of M are the same as those of the ^alkyl group represented by R in general formula (D-2), and the substituents are preferably alkyl groups having 5 or more carbon atoms.

L represents a single bond or a divalent linking group. Examples of divalent linking groups include alkylene groups, alkenylene groups, alkynylene groups, arylene groups, -C(=O)-, -C(=O)-O-, -NR ⁰ - (R ⁰ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), an oxygen atom, a sulfur atom, C(=O)NR ⁰ -, a divalent group derived from phthalimide, a divalent group derived from pyromellitic acid diimide, and a group composed of two or more such divalent groups. Alkylene groups, alkenylene groups, alkynylene groups, arylene groups, a divalent group derived from phthalimide, a divalent group derived from pyromellitic acid diimide, and a group composed of two or more such divalent groups may have an alkyl group having 5 or more carbon atoms as a substituent. The divalent group derived from phthalimide refers to a divalent group derived from phthalimide, specifically a group represented by general formula (D-5). The divalent group derived from pyromellitic acid diimide refers to a divalent group derived from pyromellitic acid diimide, specifically a group represented by general formula (D-6). In the formula, "*" represents a bond.

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

The divalent alkenylene group serving as a linking group in L is preferably an alkenylene group having 2 to 20 carbon atoms, more preferably an alkenylene group having 2 to 15 carbon atoms, and particularly preferably an alkenylene group having 2 to 10 carbon atoms. This alkenylene group may be in the form of a straight chain, a branched chain, or a ring. Examples of such alkenylene groups include methylvinylene, cyclohexenylene, pentenylene, hexenylene, heptenylene, and octenylene.

The divalent alkynyl group serving as a linking group in L is preferably an alkynyl group having 2 to 20 carbon atoms, more preferably an alkynyl group having 2 to 15 carbon atoms, and particularly preferably an alkynyl group having 2 to 10 carbon atoms. This alkynyl group may be in the form of a straight chain, a branched chain, or a ring. Examples of such alkynyl groups include methylethynyl, cyclohexynyl, pentynyl, hexynyl, heptynyl, and octynyl.

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

The divalent linking group in L, which is an alkylene group, alkenylene group, alkynylene group, or arylene group, may have a substituent. The substituents are the same as those for the alkyl group represented by R ³² in general formula (D-2), preferably an alkyl group having 5 or more carbon atoms.

Examples of groups formed by combining two or more divalent groups in L include an alkylene group, a divalent group derived from phthalimide, and an oxygen atom; a divalent group formed by combining a divalent group derived from phthalimide, an oxygen atom, an arylene group, and an alkylene group; and a divalent group formed by combining an alkylene group and a divalent group derived from pyromellitic acid diimide. Groups formed by combining two or more divalent groups can form a ring such as a condensed ring by combining the groups. Furthermore, groups formed by combining two or more divalent groups can have a repeating unit number of 1 to 10.

Among them, L in the general formula (D-4) is preferably an oxygen atom, an aryl group having 6 to 24 carbon atoms which may have a substituent, an alkylene group having 1 to 50 carbon atoms which may have a substituent, an alkyl group having 5 or more carbon atoms, a divalent group derived from phthalimide, a divalent group derived from pyromellitic acid diimide, or a divalent group consisting of a combination of two or more of these groups. Among them, L is an alkylene group; a divalent group having a structure of alkylene group-divalent group derived from phthalimide-oxygen atom-divalent group derived from phthalimide; a divalent group having a structure of alkylene group-divalent group derived from phthalimide-oxygen atom-arylene group-alkylene group-arylene group-oxygen atom-divalent group derived from phthalimide; and more preferably, a divalent group having a structure of alkylene group-divalent group derived from pyromellitic acid diimide.

The maleimide-based hardener represented by the general formula (D-4) is preferably represented by the general formula (D-7). In general formula (D-7), M1 ^'s each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, and Z's each independently represent an alkylene group having 5 or more carbon atoms which may have a substituent, or a divalent group having an aromatic ring which may have a substituent. t represents an integer from 1 to 10.

^M1 each independently represents a divalent aliphatic group having 5 or more carbon atoms which may have a substituent. ^M1 is the same as M in the general formula (D-4) and represents an alkylene group or an alkenylene group.

Each Z independently represents an alkylene group having 5 or more carbon atoms, which may have a substituent, or a divalent group having an aromatic ring, which may have a substituent. The alkylene group in Z may be any of chain, branched chain, and cyclic forms, with cyclic alkylene groups having 5 or more carbon atoms, which may have a substituent, being preferred. The number of carbon atoms in the alkylene group is preferably 6 or more, more preferably 8 or more, more preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. Examples of such alkylene groups include groups having an octylene-cyclohexene structure, a group having an octylene-cyclohexene-octylene structure, and a group having a propylene-cyclohexene-octylene structure.

Examples of the aromatic ring in the divalent group having an aromatic ring represented by Z include a benzene ring, a naphthalene ring, an anthracene ring, a phthalimide ring, a pyromellitic acid diimide ring, and an aromatic heterocycle. A benzene ring, a phthalimide ring, and a pyromellitic acid diimide ring are preferred. Specifically, examples of the divalent group having an aromatic ring include a divalent group having a benzene ring which may have a substituent, a divalent group having a phthalimide ring which may have a substituent, and a divalent group having a pyromellitic acid diimide ring which may have a substituent. Examples of the divalent group having an aromatic ring include a group formed by combining a divalent group derived from phthalimide and an oxygen atom; a group formed by combining a divalent group derived from phthalimide, an oxygen atom, an arylene group, and an alkylene group; a group formed by combining an alkylene group and a divalent group derived from pyromellitic acid diimide; a divalent group derived from pyromellitic acid diimide; and a group formed by combining a divalent group derived from phthalimide and an alkylene group. These arylene and alkylene groups are the same as the arylene and alkylene groups in the divalent linking group represented by L in general formula (F-4).

The alkylene group and the divalent group having an aromatic ring represented by Z may have a substituent. The substituents are the same as those of the alkyl group represented by R ³² in the general formula (D-2).

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

The maleimide-based curing agent represented by the general formula (D-4) is preferably any one of the maleimide-based curing agent represented by the general formula (D-8) and the maleimide-based curing agent represented by the general formula (D-9). In general formula (D-8), ^M2 and ^M3 each independently represent a divalent aliphatic group having 5 or more carbon atoms that may have a substituent, and ^R40 each independently represents an oxygen atom, an arylene group, an alkylene group, or a divalent group formed by a combination of two or more of these groups. t1 represents an integer from 1 to 10. In general formula (D-9), ^M4 , ^M6 , and ^M7 each independently represent a divalent aliphatic group having 5 or more carbon atoms that may have a substituent, ^M5 each independently represents a divalent group having an aromatic ring that may have a substituent, and ^R41 and ^R42 each independently represent an alkyl group having 5 or more carbon atoms. t2 represents an integer from 0 to 10, and u1 and u2 each independently represent an integer from 0 to 4.

^M2 and ^M3 each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent. ^M2 and ^M3 are the same as the divalent aliphatic group having 5 or more carbon atoms represented by M in general formula (D-4), and represent an alkylene group or an alkenylene group, preferably a hexatriacontyl group or a hexatriacontyl group.

R ^<40> each independently represents an oxygen atom, an arylene group, an alkylene group, or a group composed of two or more divalent groups. The arylene group and alkylene group are the same as the arylene group and alkylene group in the divalent linking group represented by L in general formula (F-4). R ^<40> is preferably a group composed of two or more divalent groups or an oxygen atom.

Examples of the group formed by combining two or more divalent groups in R ⁴⁰ include combinations of oxygen atoms, arylene groups, and alkylene groups. Specific examples of the group formed by combining two or more divalent groups include the following groups. In the formula, "*" represents a bond.

M ⁴ , M ⁶ , and M ⁷ each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent. M ⁴ , M ⁶ , and M ⁷ are the same as the divalent aliphatic group having 5 or more carbon atoms which may have a substituent represented by M in general formula (D-4), and represent an alkylene group or an alkenylene group, preferably a hexylene group, a heptylene group, an octylene group, a nonylene group, or a decylene group, with an octylene group being more preferred.

^M5 each independently represents a divalent group having an aromatic ring that may have a substituent. ^M5 is the same as the divalent group having an aromatic ring that may have a substituent represented by Z in general formula (D-7), and is a group formed by combining an alkylene group and a divalent group derived from pyromellitic diimide; preferably, a group formed by combining a divalent group derived from phthalimide and an alkylene group; and more preferably, a group formed by combining an alkylene group and a divalent group derived from pyromellitic diimide. The above-mentioned arylene group and alkylene group are the same as the arylene group and alkylene group in the divalent linking group represented by L in general formula (D-4).

Specific examples of the group represented by M ⁵ include the following groups: Wherein, "*" represents a bond.

^R41 and ^R42 each independently represent an alkyl group having 5 or more carbon atoms. ^R41 and ^R42 are the same as the alkyl group having 5 or more carbon atoms described above, preferably hexyl, heptyl, octyl, nonyl, or decyl, with hexyl and octyl being more preferred.

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

Specific examples of maleimide-based curing agents include the following compounds (D1) to (D3). However, maleimide-based curing agents are not limited to these specific examples. Wherein, v represents an integer from 1 to 10.

Specific examples of maleimide-based curing agents include "BMI1500" (compound of formula (D1)), "BMI1700" (compound of formula (D2)), and "BMI689" (compound of formula (D3)) manufactured by DMI Corporation.

To significantly achieve the desired effects of the present invention, the maleimide equivalent weight of the maleimide-based hardener is preferably 50 g/eq. to 2000 g/eq., more preferably 100 g/eq. to 1000 g/eq., and even more preferably 150 g/eq. to 500 g/eq. The maleimide equivalent weight is the mass of the maleimide-based hardener containing one equivalent of maleimide groups.

Polyphenylene ether-based hardeners contain vinylphenyl groups. These vinylphenyl groups have the following structure: (＊indicates a keystroke.)

From the perspective of obtaining a cured product with low dielectric loss, polyphenylene ether-based curing agents preferably have two or more vinylphenyl groups per molecule.

From the perspective of obtaining a cured product with low dielectric loss, polyphenylene ether-based curing agents preferably have a cyclic structure. A divalent cyclic group is preferred. The divalent cyclic group may contain either an aliphatic cyclic group or an aromatic cyclic group. Furthermore, the divalent cyclic group may be present in multiples.

In order to significantly achieve the desired effects of the present invention, the divalent cyclic group is preferably 3 or more members, more preferably 4 or more members, and even more preferably 5 or more members, and preferably 20 or less members, more preferably 15 or less members, and even more preferably 10 or less members. Furthermore, the divalent cyclic group may have a monocyclic or polycyclic structure.

The rings in the divalent cyclic groups may have heteroatoms in addition to carbon atoms to form the ring skeleton. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms, with oxygen atoms being preferred. The heteroatoms are present in one, two, or more heteroatoms in the aforementioned rings.

Specific examples of the divalent cyclic group include the following divalent groups (i) and (ii). (In the divalent groups (i) and (ii), ^R51 , ^R52 , ^R55 , ^R56 , ^R57 , ^R61 , and ^R62 each independently represent a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group; and ^R53 , ^R54 , ^R58 , ^R59 , and ^R60 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group.)

Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. Examples of alkyl groups having 6 or fewer carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl, with methyl being preferred. ^R51 , ^R52 , ^R55 , ^R56 , ^R57 , ^R61 , and ^R62 are preferably methyl. ^R53 , ^R54 , ^R58 , ^R59 , and ^R60 are preferably hydrogen or methyl.

Furthermore, the divalent cyclic group may be combined with plural divalent cyclic groups. Specific examples of the combination of divalent cyclic groups include the divalent cyclic group represented by the following formula (D4). (In formula (D4), R ⁷¹ , R ⁷² , R ⁷⁵ , R ⁷⁶ , R ⁷⁷ , R ⁸¹ , R ⁸² , R ⁸⁵ , and R ⁸⁶ each independently represent a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group; R ⁷³ , R ⁷⁴ , R ⁷⁸ , R ⁷⁹ , R ⁸⁰ , R ⁸³ , and R ⁸⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. d1 and d2 represent integers from 0 to 300. However, the case where one of d1 and d2 is 0 is excluded.)

R ⁷¹ , R ⁷² , R ⁸⁵ , and R ⁸⁶ are the same as R ⁵¹ in formula (i). R ⁷³ , R ⁷⁴ , R ⁸³ , and R ⁸⁴ are the same as R ⁵³ in formula (i). ^{R 75} , R ⁷⁶ , R ⁷⁷ , R ⁸¹ , and R ⁸² are the same as R ⁵⁵ in formula (ii). R ⁷⁸ , R ⁷⁹ , and R ⁸⁰ are the same as R ⁵⁸ in formula (ii).

d1 and d2 represent integers from 0 to 300. However, this excludes the case where either d1 or d2 is 0. Preferably, d1 and d2 represent integers from 1 to 100, more preferably from 1 to 50, and even more preferably from 1 to 10. d1 and d2 may be the same or different.

The divalent cyclic group may have a substituent. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, an aryl group, an arylalkyl group, a silyl group, an acyl group, an acyloxy group, a carboxyl group, a sulfonic acid group, a cyano group, a nitro group, a hydroxyl group, a hydroxyl group, and a pendoxy group. An alkyl group is preferred.

The vinylphenyl group can be directly bonded to a divalent cyclic group or through a divalent linking group. Examples of divalent linking groups include alkylene groups, alkenylene groups, arylene groups, heteroarylene groups, -C(=O)O-, -O-, -NHC(=O)-, -NC(=O)N-, -NHC(=O)O-, -C(=O)-, -S-, -SO-, and -NH-, and combinations of these groups are also possible. Alkylene groups are preferably those with 1 to 10 carbon atoms, more preferably those with 1 to 6 carbon atoms, and even more preferably those with 1 to 5 carbon atoms or those with 1 to 4 carbon atoms. Alkylene groups can be linear, branched, or cyclic. Examples of such alkylene groups include methylene, ethylene, propylene, butylene, pentylene, hexylene, and 1,1-dimethylethylene, with methylene, ethylene, and 1,1-dimethylethylene being preferred. Alkenylene groups are preferably alkenylene groups having 2 to 10 carbon atoms, more preferably alkenylene groups having 2 to 6 carbon atoms, and even more preferably alkenylene groups having 2 to 5 carbon atoms. Arylene and heteroarylene groups are preferably arylene or heteroarylene groups having 6 to 20 carbon atoms, and even more preferably arylene or heteroarylene groups having 6 to 10 carbon atoms. Divalent linking groups are preferably alkylene groups, with methylene being more preferred.

The polyphenylene ether-based curing agent is preferably represented by the following formula (D-10). (In formula (D-10), ^R91 and ^R92 each independently represent a divalent linking group. Ring B1 represents a divalent cyclic group.)

^R91 and ^R92 each independently represent a divalent linking group. The divalent linking group is the same as the divalent linking group described above.

Ring B1 represents a divalent cyclic group. Ring B1 is the same as the above-mentioned divalent cyclic group.

Ring B1 may have a substituent. The substituent is the same as the substituent that the aforementioned divalent cyclic group may have.

Although specific examples of polyphenylene ether-based curing agents are shown below, the present invention is not limited thereto. (q1 is the same as d1 in formula (D4), and q2 is the same as d2 in formula (D4).

Commercially available polyphenylene ether-based curing agents can be used, for example, "OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd. Polyphenylene ether-based curing agents may be used alone or in combination of two or more.

To significantly achieve the desired effects of the present invention, the number average molecular weight of the polyphenylene ether-based hardener is preferably 3000 or less, more preferably 2500 or less, and even more preferably 2000 or less or 1500 or less. The lower limit is preferably 100 or more, more preferably 300 or more, and even more preferably 500 or more or 1000 or more. The number average molecular weight is the polystyrene-equivalent number average molecular weight measured by gel permeation chromatography (GPC).

From the viewpoint of significantly achieving the effects of the present invention, the content of the hardener (D) is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

When the number of epoxy groups in component (A) is 1, the number of active groups in the hardener (D) is preferably 0.1 or greater, more preferably 0.2 or greater, even more preferably 0.3 or greater, preferably 2 or less, more preferably 1.8 or less, even more preferably 1.6 or less, and particularly preferably 1.4 or less. Here, the "active group number of the hardener (D)" refers to the total value obtained by dividing the mass of the non-volatile components of the hardener (D) in the resin composition by the active group equivalent. By setting the active group number of the hardener (D) within the aforementioned range when the number of epoxy groups in component (A) is 1, the desired effects of the present invention can be significantly achieved.

<(E) Hardening Accelerator> In addition to the above components, the resin composition may optionally contain a hardening accelerator as component (E).

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

Phosphorus-based hardening accelerators include, for example, 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.

As amine-based hardening accelerators, there can be mentioned trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc., with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.

As for the imidazole hardening accelerator, for example, 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-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole 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 cyanuric acid adduct, 2-phenylimidazole cyanuric acid adduct, 2-phenyl-4,5-dihydroxy Imidazole compounds such as methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and adducts of imidazole compounds with epoxy resins, preferably 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

As the imidazole-based hardening accelerator, a commercially available product may be used, for example, "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Guanidine-based hardening accelerators include, for example, 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, 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, 1-(o-tolyl)biguanidine, etc., with dicyanamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene being preferred.

Examples of metal hardening accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the organometallic complex include organic cobalt complexes such as cobalt (II) acetylacetylacetone and cobalt (III) acetylacetylacetone, organic copper complexes such as copper (II) acetylacetylacetone, organic zinc complexes such as zinc (II) acetylacetylacetone, organic iron complexes such as iron (III) acetylacetylacetone, organic nickel complexes such as nickel (II) acetylacetylacetone, and organic manganese complexes such as manganese (II) acetylacetylacetone. Examples of the organic metal salt include zinc octylate, tin octylate, zinc cycloalkanoate, cobalt cycloalkanoate, tin stearate, and zinc stearate.

In order to significantly achieve the desired effects of the present invention, the content of component (E) is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.03% by mass or more, based on 100% by mass of the non-volatile components in the resin composition, and is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less.

<(F) Other Additives> In addition to the above-mentioned components, the resin composition may optionally contain other additives. Examples of such additives include thermoplastic resins, flame retardants, thickeners, defoamers, leveling agents, and adhesion enhancers. These additives may be used singly or in combination. The respective amounts can be appropriately determined by those skilled in the art.

The method for preparing the resin composition of the present invention is not particularly limited, but examples thereof include a method in which a solvent is added to the blending components as needed, and the mixture is mixed and dispersed using a rotary mixer or the like.

<Resin Composition Properties and Applications> The resin composition contains component (A) and component (B). This composition suppresses the occurrence of unevenness during the lamination of resin composition layers containing the resin composition. Furthermore, the present invention generally produces a cured product that exhibits excellent coating peel strength, copper foil adhesion, and copper foil adhesion after HAST, and exhibits low dielectric properties and a low arithmetic average roughness (Ra).

The resin composition exhibits properties that suppress the occurrence of unevenness during the lamination of resin composition layers containing the resin composition. Specifically, this is achieved by following the method described in the Examples below. In this case, no unevenness is typically observed, resulting in a completely uniform surface. Details of the evaluation of unevenness after lamination can be determined using the method described in the Examples below.

The resin composition is heat-cured at 130°C for 30 minutes, followed by 170°C for 30 minutes. The resulting surface roughening treatment typically results in a low arithmetic average roughness (Ra). Therefore, the cured product provides an insulating layer with a low arithmetic average roughness. The arithmetic average roughness is preferably 300 nm or less, more preferably 250 nm or less, and even more preferably 200 nm or less. The lower limit of the arithmetic average roughness can be 30 nm or greater. The arithmetic average roughness (Ra) can be measured using the method described in the Examples below.

A cured product obtained by heat-curing a resin composition at 190°C for 90 minutes typically exhibits low dielectric properties (dielectric loss). Therefore, the cured product provides an insulating layer with low dielectric loss. The dielectric loss is preferably 0.005 or less, more preferably 0.004 or less, and even more preferably 0.003 or less. The lower limit of the dielectric loss can be 0.0001 or greater. Dielectric loss can be measured according to the method described in the Examples below.

A cured product obtained by heat-curing the resin composition at 130°C for 30 minutes, then at 170°C for 30 minutes, and then at 200°C for 90 minutes generally exhibits excellent peel strength against the conductive layer formed by coating (coated conductive layer). Therefore, the cured product provides an insulating layer with excellent peel strength against the coated conductive layer. The peel strength is preferably 0.3 kgf/cm or greater, more preferably 0.35 kgf/cm or greater, and even more preferably 0.4 kgf/cm or greater. The upper limit of the peel strength can be 10 kgf/cm or less. The peel strength of the coated conductive layer can be measured according to the method described in the Examples below.

A cured resin composition heat-cured at 130°C for 30 minutes, then at 170°C for 30 minutes, and then at 200°C for 90 minutes typically exhibits excellent peel strength (copper foil adhesion) with copper foil. Therefore, the cured product has an insulating layer with excellent peel strength with copper foil. The peel strength is preferably 0.3 kgf/cm or greater, more preferably 0.4 kgf/cm or greater, and even more preferably 0.5 kgf/cm or greater. The upper limit of the peel strength can be 10 kgf/cm or less. Copper foil adhesion can be measured according to the method described in the Examples below.

A cured product that is heat-cured at 130°C for 30 minutes and then at 170°C for 30 minutes typically exhibits excellent peel strength (copper foil adhesion after HAST) with a copper foil after a HAST test (130°C, 85% RH, 100 hours). Therefore, the cured product has an insulating layer with excellent peel strength with the copper foil after HAST. The copper foil adhesion after HAST is preferably 0.15 kgf/cm or greater, more preferably 0.2 kgf/cm or greater, and even more preferably 0.25 kgf/cm or greater. The upper limit of the copper foil adhesion after HAST can be 10 kgf/cm or less. The copper foil adhesion after HAST can be measured according to the method described in the examples below.

The resin composition of the present invention can suppress the occurrence of unevenness during the lamination of resin layers containing the resin composition. Therefore, the resin composition of the present invention is suitable for use as a resin composition for insulating purposes. Specifically, it is suitable for use as a resin composition for forming a conductive layer (including a redistribution layer) on an insulating layer (a resin composition for forming an insulating layer for forming a conductive layer).

Furthermore, in the multilayer printed wiring board described later, it is suitable for use as a resin composition for forming an insulating layer of the multilayer printed wiring board (resin composition for forming an insulating layer of a multilayer printed wiring board) and a resin composition for forming an interlayer insulating layer of the printed wiring board (resin composition for forming an interlayer insulating layer of a printed wiring board).

Furthermore, for example, when a semiconductor chip package is manufactured through the following steps (1) to (6), the resin composition of the present invention is suitable for use as a resin composition for a redistribution forming layer (resin composition for forming a redistribution forming layer) for forming an insulating layer of a redistribution layer, and as a resin composition for sealing a semiconductor chip (resin composition for sealing a semiconductor chip). When a semiconductor chip package is manufactured, a redistribution layer can also be further formed on the sealing layer. (1) laminating a temporary fixing film on a substrate, (2) temporarily fixing a semiconductor chip on the temporary fixing film, (3) forming a sealing layer on the semiconductor chip, (4) peeling the substrate and the temporary fixing film from the semiconductor chip, (5) forming a redistribution layer as an insulating layer on the surface of the substrate and the temporary fixing film from which the semiconductor chip has been peeled, and (6) forming a redistribution layer as a conductive layer on the redistribution layer.

[Resin Sheet] The resin sheet of the present invention comprises a support and a resin composition layer formed from the resin composition of the present invention disposed on the support.

The thickness of the resin composition layer is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less, from the perspective of providing a cured product with excellent insulation properties, even when the printed wiring board is thinned and the cured product of the resin composition is a thin film. The lower limit of the thickness of the resin composition layer is not particularly limited, but is generally 5 μm or more.

As for the support, there can be mentioned, for example, a film made of a plastic material, a metal foil, and a release paper, with a film made of a plastic material and a metal foil being preferred.

When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter referred to as "PET") and polyethylene naphthalate (hereinafter referred to as "PEN"), polycarbonate (hereinafter referred to as "PC"), acrylic esters such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, with polyethylene terephthalate being particularly preferred due to its low cost.

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

The surface of the support system that contacts the resin composition layer may be subjected to matte treatment, corona treatment, or anti-static treatment.

Furthermore, the support may be a support having a release layer attached to the surface thereof that contacts the resin composition layer. Examples of release agents used in the release layer of the support may include at least one selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. The support for the release layer may be a commercially available product, for example, a PET film having a release layer mainly composed of an alkyd resin-based release agent. Examples include "SK-1," "AL-5," and "AL-7" manufactured by LINTEC, "Lumirror T60" manufactured by Toray Industries, "Purex" manufactured by Teijin, and "unipeel" manufactured by UNITIKA.

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

In one embodiment, the resin sheet may further include an optional layer as needed. Examples of such an optional layer include a protective film disposed on the surface of the resin composition layer not bonded to the support (i.e., the surface opposite the support) and conforming to the support. The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. The addition of the protective film can suppress the adhesion of dust and other substances to the surface of the resin composition layer and prevent scratches.

Resin sheets can be produced, for example, by dissolving a resin composition in an organic solvent to prepare a resin paint, applying the resin paint onto a support using a die coater, and drying the resin composition layer.

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

Drying can be carried out by known methods such as heating or blowing hot air. Drying conditions are not particularly limited, but the resin composition layer should be dried to a concentration of 10% by mass or less, preferably 5% by mass or less of the organic solvent. This depends on the boiling point of the organic solvent in the resin coating. For example, when using a resin coating containing 30% to 60% by mass of an organic solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

Resin sheets can be rolled into a roll for storage. If the resin sheet has a protective film, the film can be removed before use.

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

A printed wiring board can be produced, for example, by using the above-described resin sheet and then performing the following steps (I) and (II). (I) Laminating the resin composition layer of the resin sheet on the inner substrate so that the resin composition layer is bonded to the inner substrate (II) Thermally curing the resin composition layer to form an insulating layer

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

Lamination of the inner substrate and the resin sheet can be achieved, for example, by heat-pressing the resin sheet onto the inner substrate from the support side. Examples of the member heat-pressing the resin sheet onto the inner substrate (hereinafter referred to as the "heat-pressing member") include a heated metal plate (such as a SUS mirror) or a metal roller (such as a SUS roller). Furthermore, rather than directly pressing the heat-pressing member onto the resin sheet, it is preferable to apply pressure via an elastic material such as heat-resistant rubber, allowing the resin sheet to adequately follow the surface irregularities of the inner substrate.

Lamination of the inner substrate and the resin sheet can be performed using a vacuum lamination method. In this method, the heat-pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C. The heat-pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa. The heat-pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination is preferably performed 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 Manufacturing Co., Ltd., the vacuum applicator manufactured by NIKKO Materials Co., Ltd., and the batch vacuum pressure laminator.

After lamination, the deposited resin sheet can be smoothed under normal pressure (atmospheric pressure) by applying pressure from the support side using a heated pressing member, for example. The smoothing pressure conditions can be the same as those used for the lamination process described above. The smoothing process can be performed using a commercially available laminator. Furthermore, lamination and smoothing can be performed continuously using the aforementioned commercially available vacuum laminator.

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

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

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

Before heat-hardening the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, before heat-hardening the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 120°C (preferably 60°C to 115°C, and more preferably 70°C to 110°C) for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes).

During the manufacture of a printed wiring board, a step (III) of opening holes in the insulating layer, a step (IV) of roughening the insulating layer, and a step (V) of forming a conductive layer may be further performed. These steps (III) to (V) may be performed using various methods known to those skilled in the art of printed wiring board manufacturing. Furthermore, when the support is removed after step (II), the removal of the support may be performed between step (II) and step (III), between step (III) and step (IV), or between step (IV) and step (V). Furthermore, if necessary, the steps (II) to (V) of forming the insulating layer and the conductive layer may be repeated to form a multi-layer wiring board.

Step (III) involves drilling holes in the insulating layer, thereby forming vias, through-holes, and other through-holes in the insulating layer. Step (III) can also be performed using methods such as drilling, laser cutting, or plasma drilling, depending on the composition of the resin used to form the insulating layer. The size and shape of the through-holes can be appropriately determined based on the design of the printed wiring board.

Step (IV) is a step of roughening the insulating layer. Usually, stains are also removed in this step (IV). The procedure and conditions for the roughening treatment are not particularly limited, and the well-known procedures and conditions generally used when forming the insulating layer of the printed wiring board can be adopted. For example, the insulating layer is roughened by performing swelling treatment with a swelling liquid, roughening treatment with an oxidizing agent, and neutralization treatment with a neutralizing liquid in sequence. The swelling liquid used in the roughening treatment is not particularly limited, and alkaline solutions, surfactant solutions, etc. can be cited. Alkaline solutions are preferred, and sodium hydroxide solutions and potassium hydroxide solutions are more preferred. Examples of commercially available swelling fluids include "Swelling Dip Securiganth P," "Swelling Dip Securiganth SBU," and "Swelling Dip Securigant P" manufactured by Atotech Japan. The swelling treatment using the swelling fluid is not particularly limited; for example, it can be performed by immersing the insulating layer in a swelling fluid at 30°C to 90°C for 1 to 20 minutes. To moderately suppress swelling of the resin in the insulating layer, immersing the insulating layer in a swelling fluid at 40°C to 80°C for 5 to 15 minutes is preferred. The oxidizing agent used in the roughening treatment is not particularly limited. An example of such an oxidizing agent is an alkaline permanganic acid solution prepared by dissolving potassium permanganate or sodium permanganate in an aqueous sodium hydroxide solution. The roughening treatment using an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in the oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganic acid solution is preferably 5% to 10% by mass. Commercially available oxidizing agents include alkaline permanganic acid solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Atotech Japan. The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution. A commercially available example is "Reduction Solution Securiganth P" manufactured by Atotech Japan. Treatment with the neutralizing solution can be performed by immersing the surface roughened with an oxidizing agent in the neutralizing solution at 30°C to 80°C for 1 to 30 minutes. For workability, immersing the surface roughened with an oxidizing agent in the neutralizing solution at 40°C to 70°C for 5 to 20 minutes is preferred.

In one embodiment, the arithmetic average roughness (Ra) of the insulating layer surface after the roughening treatment is preferably 300 nm or less, more preferably 250 nm or less, and even more preferably 200 nm or less. The lower limit is not particularly limited, but is preferably 30 nm or greater, more preferably 40 nm or greater, and even more preferably 50 nm or greater. The arithmetic average roughness (Ra) of the insulating layer surface can be measured using a non-contact surface roughness meter.

Step (V) is a step of forming a conductive layer, which is formed on the insulating layer. The conductive material used in the conductive layer is not particularly limited. In a preferred embodiment, the conductive layer includes 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 conductive layer can be a single metal layer or an alloy layer. As for the alloy layer, for example, a layer formed from an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy) can be used. Among them, from the perspective of versatility of conductive layer formation, 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 nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy is preferred; a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of nickel-chromium alloy is more preferred; and a single metal layer of copper is even more preferred.

The conductive layer may be a single layer structure or a multiple layer structure comprising two or more stacked single metal layers or alloy layers composed of different types of metals or alloys. When the conductive layer is a multiple 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 3μm to 35μm, preferably 5μm to 30μm.

In one embodiment, the conductive layer can be formed by plating. For example, plating on the surface of the insulating layer using conventionally known techniques such as semi-additive and fully additive processes can form a conductive layer having a desired wiring pattern. From the perspective of manufacturing simplicity, formation using a semi-additive process is preferred. The following illustrates an example of forming a conductive layer using a semi-additive process.

First, a seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the seed layer by exposing a portion of the layer corresponding to the desired wiring pattern. A metal layer is formed on the exposed seed layer by electrolytic plating, and the mask pattern is removed. The unneeded seed layer can then be removed by etching, etc., to form a conductive layer with the desired wiring pattern.

[Semiconductor Device] The semiconductor device of the present invention includes the printed wiring board of the present invention. The semiconductor device of the present invention can be manufactured using the printed wiring board of the present invention.

In terms of semiconductor devices, various semiconductor devices can be cited, such as those used in electronic products (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft).

The semiconductor device of the present invention is manufactured by mounting a component (semiconductor chip) on the conductive area of a printed wiring board. The so-called "conductive area" is "the area where electrical signals are transmitted within the printed wiring board," and this area can be either surface or embedded. Furthermore, the semiconductor chip is not particularly limited as long as it is an electrical circuit element made of semiconductors.

The semiconductor chip mounting method used in semiconductor device manufacturing is not particularly limited as long as the semiconductor chip can operate effectively. Specifically, wire bonding, flip-chip, bumpless underlay (BBUL), anisotropic conductive film (ACF), and non-conductive film (NCF) methods are examples. Here, "BBUL" refers to a method in which the semiconductor chip is directly embedded in a recessed portion of a printed wiring board, connecting the semiconductor chip to the wiring on the printed wiring board.

[Example]

Hereinafter, the present invention will be described in more detail with reference to the embodiments, but the present invention is not limited to these embodiments. In addition, in the following description, unless otherwise indicated, "parts" and "%" represent "parts by mass" and "% by mass" respectively.

<Synthesis Example 1: Synthesis of Active Ester Compound (B-1)> In a flask equipped with a thermometer, dropping funnel, cooling tube, separatory tube, and stirrer, 320 g (2.0 mol) of 2,7-dihydroxynaphthalene, 184 g (1.7 mol) of benzyl alcohol, and 5.0 g of p-toluenesulfonic acid monohydrate were placed. The mixture was stirred at room temperature while nitrogen was blown in. The temperature was then raised to 150°C, and the mixture was stirred for 4 hours while distilling off the generated water. After the reaction, 900 g of methyl isobutyl ketone and 5.4 g of a 20% aqueous sodium hydroxide solution were added for neutralization. The aqueous layer was removed by separation and the mixture was washed three times with 280 g of water. The methyl isobutyl ketone was removed under reduced pressure to obtain 460 g of a benzyl-modified naphthalene compound (A-1). The obtained benzyl-modified naphthalene compound (A-1) was a black solid with a hydroxyl equivalent of 180 g/equivalent.

In a flask equipped with a thermometer, dropping funnel, cooling tube, separatory tube, and stirrer, 203.0 g of isophthalic acid chloride (2.0 mol of acid chloride group) and 1400 g of toluene were placed, and the reaction system was purged with nitrogen under reduced pressure to dissolve the mixture. Next, 72.4 g (0.67 mol) of o-cresol and 240 g of the benzyl-modified naphthalene compound (A-1) (1.33 mol of phenolic hydroxyl group) were added, and the reaction system was purged with nitrogen to dissolve the mixture. Subsequently, 0.70 g of tetrabutylammonium bromide was dissolved, and while nitrogen purging was applied, the reaction system was kept below 60°C, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. Then, stirring was continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand for separation and the aqueous layer was removed. Furthermore, the reactants were dissolved and the toluene layer was added to water and stirred for 15 minutes. The mixture was allowed to stand for separation and the aqueous layer was removed. This operation was repeated until the pH of the aqueous layer reached 7. Then, the water was removed by dehydration using a decanter to obtain the active ester compound (B-1) in a toluene solution with a non-volatile content of 65% by mass. The active ester equivalent of the obtained active ester compound (B-1) was 238 g/eq.

<Synthesis Example 2: Synthesis of Active Ester Compound (B-2)> In a flask equipped with a thermometer, dropping funnel, cooling tube, separatory tube, and stirrer, 203.0 g of isophthalic acid chloride (2.0 mol of acid chloride group) and 1400 g of toluene were placed, and the reaction system was purged with nitrogen under reduced pressure to dissolve the mixture. Next, 113.9 g (0.67 mol) of o-phenylphenol and 240 g of the benzyl-modified naphthalene compound (A-1) (1.33 mol of phenolic hydroxyl group) were added, and the reaction system was purged with nitrogen under reduced pressure to dissolve the mixture. Next, 0.70 g of tetrabutylammonium bromide was dissolved, and while nitrogen was purged, the reaction system was kept below 60°C. 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. Stirring was continued under these conditions for 1.0 hour. After the reaction was complete, the mixture was allowed to stand for separation, and the aqueous layer was removed. Furthermore, the reactants were dissolved and the toluene layer was added to water, stirred for 15 minutes, allowed to stand for separation, and the aqueous layer was removed. This process was repeated until the pH of the aqueous layer reached 7. The solution was then dehydrated using a decanter to obtain the active ester compound (B-2) as a toluene solution containing 65% by mass of non-volatile matter. The active ester equivalent of the resulting active ester compound (B-2) was 206 g/eq.

<Synthesis Example 3: Synthesis of Active Ester Compound (B-3)> In a flask equipped with a thermometer, dropping funnel, cooling tube, separatory tube, and stirrer, 203.0 g of isophthalic acid chloride (2.0 mol of acid chloride group) and 1400 g of toluene were placed, and the reaction system was purged with nitrogen under reduced pressure to dissolve the mixture. Next, 132.7 g (0.67 mol) of styrenated phenol and 240 g of benzyl-modified naphthalene compound (A-1) (1.33 mol of phenolic hydroxyl group) were added and dissolved under reduced pressure. Next, 0.70 g of tetrabutylammonium bromide was dissolved, and while nitrogen was purged, the reaction system was kept below 60°C. 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. Stirring was continued under these conditions for 1.0 hour. After the reaction was complete, the mixture was allowed to stand for separation, and the aqueous layer was removed. Furthermore, the reactants were dissolved and the toluene layer was added to water, stirred for 15 minutes, allowed to stand for separation, and the aqueous layer was removed. This process was repeated until the pH of the aqueous layer reached 7. The solution was then dehydrated using a decanter to obtain the active ester compound (B-3) as a toluene solution containing 65% by mass of non-volatile matter. The active ester equivalent of the resulting active ester compound (B-3) was 259 g/eq.

Active ester compounds (B-1) to (B-3) were identified as follows. The identification results indicate that active ester compound (B-1) is a compound having a general formula (b-3) in which Ar ³¹ has a group represented by formula (1), active ester compound (B-2) is a compound having a general formula (b-3) in which Ar ³¹ has a group represented by formula (2), and active ester compound (B-3) is a compound having a general formula (b-3) in which Ar ³¹ has a group represented by formula (3) (n = 1 to 5).

<Example 1: Preparation of Resin Composition 1> 3 parts of the epoxy resin "ESN475V" (manufactured by Nippon Steel Chemicals & Materials Co., Ltd., epoxy equivalent: approximately 330 g/eq.) as component (A) and 7 parts of the epoxy resin "HP-4032-SS" (manufactured by DIC Corporation, epoxy equivalent: approximately 144 g/eq.) as component (A) were dissolved in 10 parts of methyl ethyl ketone (MEK) to obtain epoxy resin solution A. To this epoxy resin solution A, 25 parts of an active ester compound (B-1) as component (B), 65 parts of spherical silica (average particle size 0.77 μm, Admatechs "SO-C2") surface-treated with an amine-based alkoxysilane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) (hereinafter also referred to as "inorganic filler A"), and 0.2 parts of an imidazole compound "1B2PZ" (manufactured by Shikoku Chemical Co., Ltd.) as component (E) were added and uniformly dispersed using a high-speed rotary mixer to prepare resin coating A. Inorganic filler A had an average particle size of 0.5 μm and a specific surface area of 5.9 ^m² /g.

<Example 2: Preparation of Resin Composition 2> In Example 1, 25 parts of active ester compound (B-1) was replaced with 25 parts of active ester compound (B-2). Apart from the above, resin composition 2 was prepared in the same manner as in Example 1.

<Example 3: Preparation of Resin Composition 3> In Example 1, 25 parts of active ester compound (B-1) was replaced with 25 parts of active ester compound (B-3). Apart from the above, resin composition 3 was prepared in the same manner as in Example 1.

<Example 4: Preparation of Resin Composition 4> In Example 1, the amount of active ester compound (B-1) was changed from 25 parts to 22 parts, the amount of imidazole compound (1B2PZ manufactured by Shikoku Chemical Industries, Ltd.) was changed from 0.2 parts to 0.02 parts, and two parts of triazine-containing cresol novolac resin (DIC "LA-3018-50P", a 50% solids solution in methoxypropanol) and one part of carbodiimide resin (Nisseibo Chemicals "V-03", an active group equivalent of approximately 216, a 50% solids solution in toluene) were used. Apart from the above, Resin Composition 4 was prepared in the same manner as in Example 1.

<Example 5: Preparation of Resin Composition 5> In Example 2, the amount of active ester compound (B-2) was changed from 25 parts to 22 parts, the amount of imidazole compound (1B2PZ manufactured by Shikoku Chemicals Co., Ltd.) was changed from 0.2 parts to 0.02 parts, and two parts of triazine-containing cresol novolac resin (DIC "LA-3018-50P", a 50% solids solution in methoxypropanol) and one part of carbodiimide resin (Nisseibo Chemicals "V-03", an active group equivalent of approximately 216, a 50% solids solution in toluene) were used. Apart from the above, Resin Composition 5 was prepared in the same manner as in Example 2.

<Example 6: Preparation of Resin Composition 6> In Example 3, the amount of the active ester compound (B-3) was changed from 25 parts to 22 parts, the amount of the imidazole compound (1B2PZ manufactured by Shikoku Chemical Industries, Ltd.) was changed from 0.2 parts to 0.02 parts, and two parts of a triazine-containing cresol novolac resin (DIC's "LA-3018-50P," a 50% solids solution in methoxypropanol) and one part of a carbodiimide resin (Nisseibo Chemicals' "V-03," an active group equivalent of approximately 216, a 50% solids solution in toluene) were used. Apart from the above, Resin Composition 6 was prepared in the same manner as in Example 3.

<Example 7: Preparation of Resin Composition 7> In Example 1, the amount of active ester compound (B-1) was changed from 25 parts to 22 parts, the amount of imidazole compound (1B2PZ manufactured by Shikoku Chemical Industries, Ltd.) was changed from 0.2 parts to 0.02 parts, and 2 parts of triazine-containing cresol novolac resin (DIC "LA-3018-50P", a 50% solids solution in methoxypropanol) and 2 parts of vinylbenzyl resin (Mitsubishi Gas Chemical Co., Ltd. "OPE-2St", a 65% solids solution in toluene) were used. Apart from the above, Resin Composition 7 was prepared in the same manner as in Example 1.

<Example 8: Preparation of Resin Composition 8> In Example 7, two parts of vinylbenzyl resin ("OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd., a 65% solids solution in toluene) were replaced with two parts of maleimide resin ("MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., a 70% solids solution in toluene/MEK). Other than the above, Resin Composition 8 was prepared in the same manner as in Example 7.

<Example 9: Preparation of Resin Composition 9> In Example 7, 2 parts of vinylbenzyl resin ("OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd., a 65% solids solution in toluene) were replaced with 1 part of maleimide resin ("BMI-689" manufactured by DMI). Other than the above, Resin Composition 9 was prepared in the same manner as in Example 7.

<Example 10: Preparation of Resin Composition 10> In Example 7, 2 parts of vinylbenzyl resin ("OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd., a 65% solids solution in toluene) were replaced with 1 part of maleimide resin ("BMI-1500" manufactured by DMI). Other than the above, resin composition 10 was prepared in the same manner as in Example 7.

<Comparative Example 1: Preparation of Resin Composition 11> In Example 1, 25 parts of the active ester compound (B-1) was replaced with 25 parts of another hardener (an active ester hardener, DIC Corporation's "HPC8150-62T," a 62% solids solution in toluene). Apart from the above, Resin Composition 11 was prepared in the same manner as in Example 1.

<Comparative Example 2: Preparation of Resin Composition 12> In Example 1, 25 parts of the active ester compound (B-1) was replaced with 23 parts of another hardener (an active ester-based hardener, DIC Corporation's "HPC8000-65T," a 65% solids solution in toluene). Apart from the above, Resin Composition 12 was prepared in the same manner as in Example 1.

<Comparative Example 3: Preparation of Resin Composition 13> In Example 4, 22 parts of the active ester compound (B-1) was replaced with 22 parts of a different hardener (active ester hardener, DIC Corporation's "HPC8150-62T," a 62% solids toluene solution). Apart from the above, Resin Composition 13 was prepared in the same manner as in Example 4.

<Comparative Example 4: Preparation of Resin Composition 14> In Example 3, 22 parts of the active ester compound (B-2) was replaced with 21 parts of another hardener (an active ester-based hardener, DIC Corporation's "HPC8000-65T," a 65% solids solution in toluene). Apart from the above, Resin Composition 14 was prepared in the same manner as in Example 3.

<Evaluation of unevenness after lamination, determination of arithmetic mean roughness, and peel strength of coated conductive layer> (1) Preparation of resin sheet A having a resin composition layer thickness of 40 μm As a support, a polyethylene terephthalate film ("AL5" manufactured by LINTEC, thickness 38 μm) having a release layer was prepared. The resin composition obtained in the examples and comparative examples was uniformly coated on the release layer of this support so that the resin composition layer had a thickness of 40 μm after drying. The resin composition was then dried at 80°C to 100°C (average 90°C) for 4 minutes to obtain a resin sheet A comprising a support and a resin composition layer.

(2) Preparation of the inner layer substrate A copper laminate (copper foil thickness 18μm, substrate thickness 0.4mm, Panasonic "R1515A") with an epoxy resin-coated glass cloth substrate on which the inner layer circuit is formed is etched to a depth of 1μm on both sides using a micro-etchant (MEC "CZ8101") to roughen the copper surface.

(3) Lamination of Resin Sheet A Using a batch vacuum press laminator (Nikko-Materials, 2-platform assembly laminator "CVP700"), the resin composition layer was laminated on both sides of the inner substrate in such a way that the resin composition layer was in contact with the inner substrate. Lamination was performed by decompressing for 30 seconds to adjust the air pressure to below 13hPa, and then pressing at 120°C and 0.74MPa for 30 seconds. Then, hot pressing was performed at 100°C and 0.5MPa for 60 seconds.

(4) Thermal curing of the resin composition layer Then, the inner substrate layered with the resin sheet A is placed in an oven at 130°C and heated for 30 minutes. Then, it is moved to an oven at 170°C and heated for 30 minutes to thermally cure the resin composition layer and form an insulating layer. The support is then peeled off to obtain a cured substrate A having an insulating layer, an inner substrate, and an insulating layer in this order.

(5) Evaluation of unevenness after lamination On both sides of the cured substrate A, the surface uniformity of the portion where the resin sheet A was laminated (the surface opposite to the laminated plate) was visually observed and evaluated as follows. 0: No unevenness was observed at all, exhibiting a completely uniform surface. ×: Unevenness was observed in the portion where the resin sheet was laminated.

(6) Roughening Treatment Electroless copper plating is performed on the hardened substrate A as a roughening treatment. The electroless copper plating treatment is performed by the following wet electroless copper plating process.

(Wet Electroless Copper Plating) The cured substrate A was immersed in a swelling solution (Atotech Japan's "Concentrate Compact P," an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 5 minutes. It was then immersed in an oxidizing solution (Atotech Japan's "Concentrate Compact CP," an aqueous solution of approximately 6% potassium permanganate and approximately 4% sodium hydroxide) at 80°C for 20 minutes. The substrate was then immersed in a neutralizing solution (Atotech Japan's "Reduction Solution Securiganth P," an aqueous solution of sulfuric acid) at 40°C for 5 minutes and dried at 80°C for 15 minutes.

(7) Measurement of the arithmetic mean roughness (Ra) of the insulating layer surface after roughening treatment The arithmetic mean roughness (Ra) of the insulating layer surface after roughening treatment was determined using a non-contact surface roughness meter (WYKO NT3300 manufactured by Bruker) in VSI mode with a 50x lens and a measurement range of 121μm × 92μm. The measurement was performed by taking the average value of 10 points.

(8) Formation of the Conductive Layer A conductive layer was formed on the roughened surface of the insulating layer by a semi-additive method. That is, the roughened substrate was immersed in an electroless plating solution containing _PdCl2 at 40°C for 5 minutes, and then immersed in an electroless copper plating solution at 25°C for 20 minutes. Subsequently, after annealing at 150°C for 30 minutes, an etching resist was formed, and a pattern was formed by etching. Then, copper sulfate electrolytic plating was performed to form a conductive layer with a thickness of 25μm, and annealing was performed at 190°C for 60 minutes. The resulting substrate is referred to as "Evaluation Substrate B".

(9) Determination of the peeling strength of the coated conductive layer The peeling strength of the insulating layer and the conductive layer was measured in accordance with the Japanese Industrial Standard (JIS C6481). Specifically, a 10 mm wide and 100 mm long cut was made in the conductive layer of the evaluation substrate B. This end was peeled off and clamped with a clamp. The load (kgf/cm) when the layer was peeled off 35 mm in the vertical direction at a speed of 50 mm/min at room temperature was measured to obtain the peeling strength. A tensile testing machine ("AC-50C-SL" manufactured by TSE Corporation) was used for the measurement.

<Evaluation of Dielectric Properties> Dielectric properties were evaluated by measuring the dielectric loss (Df). Specifically, the following procedure was used to prepare a cured product B for evaluation and measure the dielectric loss (Df).

Resin sheet A obtained in the Examples and Comparative Examples was oven-cured at 190°C for 90 minutes. After removing the resin sheet A from the oven, the support was peeled off to obtain a cured product containing the resin composition layer. This cured product was cut into 80 mm long and 2 mm wide sections, designated as cured product B for evaluation.

For each evaluation cured product B, the dielectric loss (Df value) was measured using an Agilent Technologies "HP8362B" using the cavity resonance perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. Two test pieces were used for the measurement, and the average value was calculated.

<Measurement of Copper Foil Adhesion (Peel Strength)> (1) Preparation of Adhesion Evaluation Substrate For the inner substrate, a copper laminate (copper foil thickness 18μm, substrate thickness 0.8mm, Panasonic "R1515A") was prepared on both sides of a glass cloth substrate with copper foil on the surface. The copper foil on the surface of this inner substrate was completely etched away. Then, it was dried at 190°C for 30 minutes.

Using a batch vacuum pressure laminator (Nikko Materials, dual-platform assembly laminator "CVP700"), the resin sheet A obtained in the above-described examples and comparative examples was laminated on both sides of the inner substrate, with the resin composition layer bonded to the inner substrate. Lamination was performed by decompressing the pressure for 30 seconds to below 13 hPa, followed by pressing at 100°C and 0.74 MPa for 30 seconds.

The laminated resin sheet A is then smoothed by heat pressing at 100°C and 0.5 MPa for 60 seconds under atmospheric pressure. The support is then peeled off, yielding an "intermediate composite body I" comprising, in order, the resin composition layer, the inner substrate, and the resin composition layer.

Separately, a glossy copper foil (35 μm thick, "3EC-III" manufactured by Mitsui Metals) was prepared. The glossy surface of this copper foil was roughened by etching it with a micro-etching agent ("CZ8101" manufactured by MEC Corporation) to a depth of 1 μm. The resulting copper foil is referred to as "roughened copper foil."

This roughened copper foil is laminated onto both surfaces of intermediate composite body I, with the roughened surface of the copper foil bonding to the resin composition layer of intermediate composite body I. This lamination is performed under the same conditions as the aforementioned lamination of the resin sheet onto the inner substrate. This yields "intermediate composite body II," which sequentially comprises the roughened copper foil, the resin composition layer, the inner substrate, the resin composition layer, and the roughened copper foil.

This intermediate composite II was placed in an oven at 100°C for 30 minutes, then moved to a 170°C oven and heated for another 30 minutes. After being removed from the oven and brought to room temperature, it was further placed in an oven at 200°C for an additional 90 minutes. This allowed the resin composition layer to thermally cure, resulting in "evaluation substrate C," which sequentially consisted of a roughened copper foil, an insulating layer (the cured resin composition layer), an inner substrate, an insulating layer (the cured resin composition layer), and a roughened copper foil. In this evaluation substrate C, the roughened copper foil served as the conductive layer.

(2) Measurement of Copper Foil Adhesion (Peel Strength) Using the aforementioned evaluation substrate C, the peel strength between the roughened copper foil and the insulating layer was measured. This peel strength measurement was performed in accordance with JIS C6481. Specifically, the peel strength measurement was performed using the following procedure.

A rectangular cut with a width of 10 mm and a length of 100 mm was made on the roughened copper foil of the evaluation substrate C. One end of this rectangular portion was peeled off and clamped with a clamp (Autocom testing machine "AC-50C-SL" manufactured by TSE). The rectangular portion was peeled vertically over a length of 35 mm, and the load (kgf/cm) during this peeling was measured as the peeling strength. The peeling was performed at room temperature at a speed of 50 mm/min. Furthermore, after the HAST test (130°C, 85% humidity, 100 hours), the copper foil adhesion (peeling strength) was measured again.

In Examples 1 to 10, even when the components (C) to (E) were not included, the results were confirmed to be similar to those of the above examples, although there were differences in degree.

Claims (10)

A resin composition comprising: (A) an epoxy resin, and (B) at least one active ester compound having a group represented by the following formulae (1) to (3), wherein component (B) comprises an active ester compound represented by the following general formula (b-1), wherein the content of component (A) is such that, when the non-volatile components in the resin composition are taken as 100% by mass, it is from 1% to 25% by mass, and the content of component (B) is such that, when the non-volatile components in the resin composition are taken as 100% by mass, it is from 5% to 30% by mass. In the formula, * represents a key; in formula (3), n represents an integer from 1 to 5 In general formula (b-1), Ar ¹¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3); Ar ¹² each independently represents a divalent aromatic hydrocarbon group which may have a substituent; Ar ¹³ each independently represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aliphatic hydrocarbon group which may have a substituent, an oxygen atom, a sulfur atom, or a divalent group composed of a combination thereof; a represents an integer from 1 to 6; and b represents an integer from 0 to 10. The resin composition of claim 1, wherein Ar ¹³ in the general formula (b-1) each independently represents a divalent aromatic hydrocarbon group which may have a substituent and a divalent group combined with an oxygen atom. The resin composition of claim 1, wherein component (B) is an active ester compound represented by the following general formula (b-3): In general formula (b-3), Ar ³¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3); a2 represents an integer from 1 to 6, c2 represents an integer from 1 to 5, and d each independently represents an integer from 0 to 6. The resin composition of claim 1, further comprising (C) an inorganic filler. The resin composition of claim 1 is used to form an insulating layer. The resin composition of claim 1 is used to form an insulating layer of a conductive layer. A resin sheet comprising a support and a resin composition layer disposed on the support and comprising the resin composition according to any one of claims 1 to 6. A printed wiring board comprising an insulating layer formed by a cured product of the resin composition according to any one of claims 1 to 6. A semiconductor device comprising the printed wiring board of claim 8. An active ester compound represented by the following general formula (b-1), In general formula (b-1), Ar ¹¹ each independently represents a group represented by formula (1), a group represented by formula (2), or a group represented by formula (3), wherein * represents a bond; in formula (3), n represents an integer of 1 to 5, Ar ¹² each independently represents a divalent aromatic hydrocarbon group which may have a substituent, Ar ¹³ each independently represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aliphatic hydrocarbon group which may have a substituent, an oxygen atom, a sulfur atom, or a divalent group formed by a combination thereof; a represents an integer of 1 to 6, and b represents an integer of 0 to 10.