resin composition

Abstract

To provide a novel resin composition that incorporates a composition contributing to excellent dielectric properties, while yielding a cured product that exhibits excellent crack resistance and also demonstrates excellent adhesion to a conductor layer when exposed to high-temperature and high-humidity environments.SOLUTION: A resin composition comprises (A) polyphenylene ether particles, (B) an epoxy resin, (C) a curing agent, and (D) an inorganic filler.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to resin compositions, and more particularly to resin sheets, cured products, circuit boards, and semiconductor devices. [Background technology]

[0002] Resin compositions containing epoxy resins and their curing agents have been widely used as insulating materials for circuit boards such as printed circuit boards and redistribution boards for semiconductor chip packages, because they produce cured products with excellent insulation, heat resistance, and adhesion.

[0003] On the other hand, with the recent increase in communication speeds, insulating materials for circuit boards require insulating materials with excellent dielectric properties (low dielectric loss tangent) to reduce transmission loss when operating in high-frequency environments. Insulating materials with excellent dielectric properties are known to employ specific compositions, such as using specific curing agents, including active ester-based curing agents that can reduce or suppress the generation of polar groups like secondary hydroxyl groups during the curing reaction of epoxy resins, or incorporating a high proportion of inorganic fillers (for example, Patent Documents 1-3). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-157027 [Patent Document 2] Japanese Patent Publication No. 2020-94213 [Patent Document 3] Japanese Patent Publication No. 2020-152780 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, when an insulating layer was formed using a conventional resin composition that contributes to good dielectric properties in the manufacturing of circuit boards, the resulting insulating layer tended to crack easily after desmearing.

[0006] In the process of studying to improve crack resistance, the inventors of the present invention confirmed that crack resistance can be improved somewhat by adding organic particles. However, when adding organic particles in an amount sufficient to improve crack resistance, problems occurred such as deterioration of dielectric properties and thus reduction of the desired effects, or deterioration of adhesion to the conductor layer when exposed to a high-temperature and high-humidity environment.

[0007] An object of the present invention is to provide a novel resin composition that can provide a cured product that exhibits good crack resistance and good adhesion to a conductor layer when exposed to a high-temperature and high-humidity environment, even when adopting a composition that contributes to good dielectric properties.

Means for Solving the Problems

[0008] As a result of intensive studies, the inventors of the present invention found that the above problems can be solved by a resin composition having the following configuration, and thus completed the present invention.

[0009] That is, the present invention includes the following content. [1] A resin composition containing (A) polyphenylene ether particles, (B) an epoxy resin, (C) a curing agent, and (D) an inorganic filler. [2] The resin composition according to [1], wherein the average particle size of component (A) is 5 μm or less. [3] (A) The 90% particle size D of component 90 is 2 μm or less, and the resin composition according to [1] or [2]. [4] The resin composition according to any one of [1] to [3], wherein the content of component (A) is 0.5% by mass or more when the resin component of the resin composition is 100% by mass. [5] (C) The component contains at least one curing agent selected from the group consisting of (C-1) an active ester-based curing agent, a cyanate ester-based curing agent, and a carbodiimide-based curing agent, and the resin composition according to any one of [1] to [4]. [6] The resin composition according to [5], wherein the mass ratio of component (C-1) to component (B) ((C-1) / (B)) is 1 or more. [7] (B) The resin composition according to any one of [1] to [6], wherein the content of component (B) is 5% by mass or more when the total resin component of the resin composition is considered to be 100% by mass. [8] The resin composition according to any one of [1] to [7], wherein the content of component (D) is 40% by mass or more when the nonvolatile components of the resin composition are taken as 100% by mass. [9] (A) A resin composition according to any one of [1] to [8], wherein component (A) is an emulsion polymer or a suspension polymer.

[10] (A) A resin composition according to any one of [1] to [9], wherein component (A) is insoluble in the solvent.

[11] A resin composition according to any one of [1] to

[10] , for use as an insulating layer for a circuit board.

[12] A resin sheet comprising a support and a layer of any of the resin compositions described in [1] to

[11] provided on the support.

[13] The resin sheet according to

[12] , wherein the support is a thermoplastic resin film or a metal foil.

[14] A cured product of any of the resin compositions described in [1] to

[11] .

[15] A circuit board comprising an insulating layer made of a cured resin composition described in any of [1] to

[11] .

[16] A semiconductor device including the circuit board described in

[15] . [Effects of the Invention]

[0010] According to the present invention, even when employing a composition that contributes to good dielectric properties, it is possible to provide a novel resin composition that can produce a cured product that exhibits good crack resistance and good adhesion to a conductive layer when exposed to a high-temperature, high-humidity environment. [Modes for carrying out the invention]

[0011] <Explanation of Terms> In this specification, the term “may have substituents” with respect to a compound or group means both cases where the hydrogen atoms of the compound or group are not substituted with substituents, and cases where some or all of the hydrogen atoms of the compound or group are substituted with substituents.

[0012] In this specification, the term "substituent" means, unless otherwise specified, a halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxy group, a cycloalkyloxy group, an alkylthio group, a cycloalkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylalkoxy group, a monovalent heterocyclic group, an alkylidene group, an acyl group, an acyloxy group, a hydroxyl group, an amino group, a silyl group, a carboxyl group, a sulfo group, a cyano group, a nitro group, a mercapto group, and an oxo group.

[0013] Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. The alkyl group used as a substituent may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3. The alkenyl group used as a substituent may be linear or branched. The number of carbon atoms in the alkenyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 or 3. The number of carbon atoms in the cycloalkyl group used as a substituent is preferably 3 to 12, more preferably 3 to 6. The alkoxy group used as a substituent may be linear or branched. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6. The number of carbon atoms in the cycloalkyloxy group used as a substituent is preferably 3 to 12, more preferably 3 to 6. The alkylthio group used as a substituent may be linear or branched. The number of carbon atoms in the alkylthio group is preferably 1 to 12, more preferably 1 to 6. The number of carbon atoms in the cycloalkylthio group used as a substituent is preferably 3 to 12, more preferably 3 to 6. The number of carbon atoms in the aryl group used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms in the aryloxy group used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms in the arylthio group used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms in the arylalkyl group used as a substituent is preferably 7 to 15, more preferably 7 to 11. The number of carbon atoms in the arylalkoxy group used as a substituent is preferably 7 to 15, more preferably 7 to 11. A monovalent heterocyclic group used as a substituent refers to a group obtained by removing one hydrogen atom from the heterocycle of a heterocyclic compound. The number of carbon atoms in the monovalent heterocyclic group is preferably 3 to 15, more preferably 3 to 9. The monovalent heterocyclic group also includes a monovalent aromatic heterocyclic group (heteroaryl group). An alkylidene group used as a substituent is a group formed by removing two hydrogen atoms from the same carbon atom of an alkane.The alkylidene group preferably has 1 to 12 carbon atoms, more preferably 1 to 6, and particularly preferably 1 to 3. The acyl group used as a substituent is a group represented by the formula -C(=O)-R (wherein R is an alkyl group or an aryl group). The alkyl group represented by R may be linear or branched. The acyl group preferably has 2 to 13 carbon atoms, more preferably 2 to 7. The acyloxy group used as a substituent is a group represented by the formula -OC(=O)-R (wherein R is the same as above). The acyloxy group preferably has 2 to 13 carbon atoms, more preferably 2 to 7. The substituents described above may have further substituents (sometimes referred to as "secondary substituents"). Unless otherwise specified, the same substituents as described above may be used as secondary substituents.

[0014] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and may be implemented with modifications as appropriate without departing from the scope of the claims and equivalents of the present invention.

[0015] [Resin composition] The resin composition of the present invention comprises (A) polyphenylene ether particles, (B) epoxy resin, (C) curing agent, and (D) inorganic filler.

[0016] As mentioned above, when an insulating layer was formed in the manufacturing of a circuit board using a conventional resin composition that contributes to good dielectric properties (for example, a resin composition employing a specific composition, such as using a specific curing agent such as an active ester-based curing agent that can reduce or suppress the generation of polar groups such as secondary hydroxyl groups in the curing reaction of epoxy resin, or a resin composition that incorporates a high amount of inorganic filler), the resulting insulating layer tended to crack easily after desmearing.

[0017] In the process of investigating ways to improve crack resistance, the inventors confirmed that adding organic particles could improve crack resistance to some extent. However, they found that adding organic particles in an amount sufficient to improve crack resistance resulted in problems such as deterioration of dielectric properties, which negated the desired effect, and deterioration of adhesion with the conductor layer when exposed to high temperature and high humidity environments.

[0018] In contrast, according to the present invention, which uses polyphenylene ether particles as an organic filler in a resin composition containing epoxy resin, a curing agent, and an inorganic filler, even when a specific composition that contributes to good dielectric properties is adopted, it is possible to produce a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high temperature and high humidity environment. Furthermore, it has been confirmed that an insulating layer with little unevenness and good surface flatness can be realized regardless of the surface pattern of the substrate (surface unevenness pattern caused by recesses such as degas holes and protrusions such as surface circuits).

[0019] The following describes each component.

[0020] <(A) Polyphenylene ether particles> The resin composition of the present invention contains polyphenylene ether particles as component (A). This makes it possible to obtain a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high temperature and high humidity environment, even when a specific composition that contributes to good dielectric properties is adopted in a resin composition containing epoxy resin, a curing agent and an inorganic filler.

[0021] In this specification, the term "polyphenylene ether particles" refers to granular material made of a material containing at least a compound having a polyphenylene ether structure (hereinafter also simply referred to as "polyphenylene ether compound"). The polyphenylene ether particles may be solid particles made of a material containing at least a polyphenylene ether compound, hollow particles having a shell portion made of a material containing at least a polyphenylene ether compound and a hollow portion surrounded by the shell portion, or mixtures thereof.

[0022] Even when employing a specific composition that contributes to good dielectric properties, from the viewpoint of producing a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high-temperature, high-humidity environment, the content of the polyphenylene ether compound in the material constituting component (A) is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more. The upper limit of the content is not particularly limited and may be 100% by mass. The polyphenylene ether compound may be used alone or in combination of two or more types.

[0023] From the viewpoint of more effectively enjoying the effects of the present invention, it is preferable that the polyphenylene ether compound includes a polyphenylene ether structure comprising multiple constituent units represented by the following formula (1).

[0024] [ka] (In the formula, Each R independently represents a halogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aryl group, an optionally substituted amino group, a nitro group, or a carboxyl group. m represents an integer between 0 and 4.

[0025] The alkyl or alkoxy group in R may be linear or branched, and its number of carbon atoms is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4 or 1 to 3. The number of carbon atoms does not include the number of carbon atoms of substituents.

[0026] The number of carbon atoms in the aryl group in R is preferably 6 to 14, more preferably 6 to 10. This number of carbon atoms does not include the number of carbon atoms in substituents.

[0027] As mentioned above, the substituents that the monovalent group represented by R may have are halogen atoms, alkyl groups, alkoxy groups, or aryl groups. The number of carbon atoms of these substituents, as well as other preferred examples, are as mentioned above.

[0028] In formula (1), m represents an integer between 0 and 4, preferably an integer between 0 and 3, and more preferably an integer between 1 and 3.

[0029] Even when employing a specific composition that contributes to good dielectric properties, from the viewpoint of producing a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high-temperature, high-humidity environment, a polyphenylene ether structure containing one or more selected from the group consisting of 2,6-disubstituted-1,4-phenylene ether units, 2,5-disubstituted-1,4-phenylene ether units, and 2,3,6-trisubstituted-1,4-phenylene ether units is preferred, and among these, a polyphenylene ether structure containing multiple 2,6-disubstituted-1,4-phenylene ether units is preferred (where the substituents at the 2,6 positions, 2,5 positions, and 2,3,6 positions correspond to R in formula (1)).

[0030] Specific examples of suitable polyphenylene ether structures include poly(2,6-dialkyl-1,4-phenylene ether) structures, poly(2-alkyl-6-aryl-1,4-phenylene ether) structures, poly(2,6-diaryl-1,4-phenylene ether) structures, poly(2,6-dihalo-1,4-phenylene ether) structures, and poly(2,6-disubstituted-1,4-phenylene ether) structures; polyphenylene ether structures containing multiple 2,6-disubstituted-1,4-phenylene ether units, such as copolymer structures of 2,6-disubstituted phenols with other phenol compounds (for example, 2,5-disubstituted phenols such as 2,5-dialkylphenol, 2-alkyl-5-arylphenol, 2,5-diarylphenol, etc., and 2,3,6-trisubstituted phenols such as 2,3,6-trialkylphenol, 2,3,6-trihalophenol, etc.), and coupling reaction products of 2,6-disubstituted phenols with biphenol compounds or bisphenol compounds.

[0031] The compound having the polyphenylene ether structure described above, i.e., the polyphenylene ether compound, may have other structures as long as it has a polyphenylene ether structure. Such other structures are not particularly limited as long as they do not hinder the effects of the present invention, and include any structure that can react with the terminal groups of the polyphenylene ether structure to form a molecule of the polyphenylene ether compound together with the polyphenylene ether structure. Examples include structures derived from crosslinkable monomers or monofunctional monomers that can react with the terminal groups of the polyphenylene ether structure.

[0032] Examples of the above-mentioned crosslinkable monomers include polyfunctional (meth)acrylic acid esters such as ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and glycerin tri(meth)acrylate; polyfunctional acrylamide derivatives such as N,N'-methylenebis(meth)acrylamide and N,N'-ethylenebis(meth)acrylamide; polyfunctional allyl derivatives such as diallylamine and tetraallyloxyethane; and aromatic crosslinkable monomers such as divinylbenzene, divinylnaphthalene, and diallyl phthalate.

[0033] Examples of the monofunctional monomers mentioned above include alkyl(meth)acrylic acid esters with 1 to 16 carbon atoms, such as methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, and cetyl(meth)acrylate; aromatic monofunctional monomers such as styrene, α-methylstyrene, ethyl vinylbenzene, vinyltoluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, vinyl biphenyl, and vinylnaphthalene; dicarboxylic acid ester monomers such as dimethyl maleate, diethyl fumarate, dimethyl fumarate, and diethyl fumarate; maleic anhydride; N-vinylcarbazole; and (meth)acrylonitrile.

[0034] If the polyphenylene ether compound has a structure derived from the above-mentioned crosslinkable monomer or monofunctional monomer, the polyphenylene ether compound may be prepared by reacting a starting compound having a polyphenylene ether structure with one or more other starting compounds selected from the group consisting of the above-mentioned crosslinkable monomer and monofunctional monomer. In such a case, when the total of the starting compound having a polyphenylene ether structure and the other starting compounds is 100 parts by mass, it is preferable to use the starting compound having a polyphenylene ether structure in an amount of preferably 20 parts by mass or more, more preferably 40 parts by mass or more, 50 parts by mass or more, 55 parts by mass or more, or 60 parts by mass or more.

[0035] The raw material compound having a polyphenylene ether structure is not particularly limited as long as it has a polyphenylene ether structure, but preferred examples from the viewpoint of enjoying the effects of the present invention include homopolymers or copolymers of phenol compounds selected from the group consisting of 2,6-disubstituted phenols, 2,5-disubstituted phenols, and 2,3,6-trisubstituted phenols; and coupling reaction products of a phenol compound selected from the group consisting of 2,6-disubstituted phenols, 2,5-disubstituted phenols, and 2,3,6-trisubstituted phenols with a biphenol compound or bisphenol compound. Furthermore, the number average molecular weight (Mn) of the raw material compound having a polyphenylene ether structure is preferably in the range of 500 to 4000. Here, the Mn of the raw material compound is the polystyrene-based Mn measured by gel permeation chromatography (GPC). Commercially available starting compounds having such a polyphenylene ether structure may be used, for example, "OPE-2St" manufactured by Mitsubishi Gas Chemical Corporation and "NORYL" manufactured by SABIC Corporation (both containing multiple 2,6-dialkyl-1,4-phenylene ether units).

[0036] (A) The materials constituting component (A) may include other components in addition to the polyphenylene ether compound described above, as long as they do not hinder the effects of the present invention.

[0037] Other such components include, for example, non-crosslinkable polymers, dispersion stabilizers, surfactants, and polymerization initiators. These other components may be used individually or in combination of two or more.

[0038] Examples of non-crosslinkable polymers include one or more selected from the group consisting of polyolefins, styrene-based polymers, (meth)acrylic acid-based polymers, and styrene-(meth)acrylic acid-based polymers. Examples of polyolefins include polyethylene, polypropylene, and poly-α-olefin. Examples of styrene-based polymers include polystyrene, styrene-acrylonitrile copolymer, and acrylonitrile-butadiene-styrene copolymer. Examples of (meth)acrylic acid-based polymers include polymethyl (meth)acrylate, polyethyl (meth)acrylate, polybutyl (meth)acrylate, and polypropyl (meth)acrylate. Examples of styrene-(meth)acrylic acid-based polymers include styrene-methyl (meth)acrylate copolymer, styrene-ethyl (meth)acrylate copolymer, styrene-butyl (meth)acrylate copolymer, and styrene-propyl (meth)acrylate copolymer.

[0039] Examples of dispersion stabilizers include polyvinyl alcohol, polycarboxylic acids, celluloses (hydroxyethylcellulose, carboxymethylcellulose, etc.), and polyvinylpyrrolidone. Other examples of dispersion stabilizers include inorganic water-soluble polymer compounds such as sodium tripolyphosphate; phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate; pyrophosphates such as calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate, and zinc pyrophosphate; and poorly water-soluble inorganic compounds such as calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, and colloidal silica.

[0040] Various surfactants may be used, including anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

[0041] Examples of polymerization initiators include organic peroxides such as lauroyl peroxide, benzoyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butyl peroxy-2-ethylhexanoate, and di-t-butyl peroxide; and azo compounds such as 2,2'-azobisisobutyronitrile, 1,1'-azobiscyclohexanecarbonitride, and 2,2'-azobis(2,4-dimethylvaleronitrile).

[0042] (A) The content of other components, i.e., components other than the polyphenylene ether compound, in the material constituting component (A) is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. The lower limit of the content is not particularly limited and may be 0% by mass, but may also be 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, etc.

[0043] Even when employing a specific composition that contributes to good dielectric properties, from the viewpoint of producing a cured product that exhibits even better crack resistance and better adhesion to the conductive layer when exposed to a high-temperature, high-humidity environment, the average particle size of component (A) is preferably 5 μm or less, more preferably 4 μm or less, even more preferably 3 μm or less, even more preferably 2 μm or less, 1.5 μm or less, or 1 μm or less, and its lower limit is preferably 0.1 μm or more, 0.2 μm or more, or 0.3 μm or more.

[0044] In this specification, the average particle size of component (A) is defined as the median diameter (50% particle size D) based on volume. 50 This refers to the average particle size of component (A). The average particle size of component (A) can be measured by the laser diffraction-scattering method based on Mie scattering theory. Specifically, a volume-based particle size distribution of component (A) is created using a laser diffraction-scattering particle size distribution analyzer, and the particle size at which the integrated distribution value is 50% (median diameter, 50% particle size D) is determined. 50The average particle size can be measured. For the measurement sample, 100 mg of component (A) and 10 g of methyl ethyl ketone can be weighed into a vial and dispersed using ultrasound for 10 minutes. Examples of laser diffraction particle size distribution analyzers include the "LA-960" manufactured by Horiba, Ltd.

[0045] In particular, from the viewpoint of producing a cured product that exhibits exceptionally good crack resistance and exceptionally good adhesion to the conductive layer when exposed to high temperature and high humidity environments, component (A) 90% particle size D 90 The particle size is preferably 2 μm or less, more preferably 1.5 μm or less, even more preferably 1.4 μm or less, 1.2 μm or less, or 1 μm or less, with a lower limit of preferably 0.1 μm or more, 0.2 μm or more, or 0.3 μm or more. Here, the 90% particle size D of component (A) 90 As mentioned earlier regarding the average particle size, this refers to the particle size at which the cumulative distribution value of component (A) becomes 90% when the particle size distribution of component (A) is created on a volume basis. 90% particle size D of component (A) 90 This can be measured in the same way as the average particle size.

[0046] The method for producing component (A) is not particularly limited, and conventionally known methods for producing resin particles may be used. As mentioned above, component (A) may be either solid particles or hollow particles. If component (A) is a solid particle, it may be produced by any method, such as (1) preparing a material containing at least a polyphenylene ether compound, melt-kneading it as necessary, and then crushing and disintegrating it to obtain granular material of a predetermined shape and size, or (2) solution polymerizing a raw material compound having a polyphenylene ether structure with the above-mentioned crosslinkable monomer or monofunctional monomer, and then mixing it with a poor solvent to precipitate particles. If component (A) is a hollow particle, it may be produced by any method, such as reacting a raw material compound having a polyphenylene ether structure with the above-mentioned crosslinkable monomer or monofunctional monomer in an aqueous medium in the presence of a non-reactive oily solvent to obtain particles containing the non-reactive oily solvent in their pores, and then removing the non-reactive oily solvent to obtain hollow particles. Furthermore, commercially available polyphenylene ether compounds may be used when producing component (A), which is a solid particle. Examples include "Lupiace" from Mitsubishi Engineering Plastics Corporation and "Zylon" from Asahi Kasei Corporation. As mentioned above, in addition to these polyphenylene ether compounds, other components such as non-crosslinkable polymers may be used when producing component (A).

[0047] The following is an example of a method for producing component (A) as hollow particles.

[0048] First, a raw material compound having a polyphenylene ether structure is reacted with the above-mentioned crosslinkable monomer or monofunctional monomer in an aqueous medium in the presence of a non-reactive oily solvent. The reaction is carried out by emulsion polymerization or suspension polymerization, with the non-reactive oily solvent containing the above-mentioned raw material compound etc. as the oil phase and the aqueous medium as the aqueous phase. Therefore, in one embodiment, component (A) used in the present invention is an emulsion polymer or a suspension polymer.

[0049] In such a reaction, preferably, an oil phase containing a starting compound having a polyphenylene ether structure, a crosslinkable monomer or monofunctional monomer, and a non-reactive oily solvent is added to an aqueous phase containing an aqueous medium and dispersed, and then heated to carry out the polymerization reaction.

[0050] Examples of aqueous media include water, and mixed media of water and lower alcohols (methanol, ethanol, etc.). The amount of aqueous media used is not particularly limited as long as the emulsion polymerization or suspension polymerization reaction proceeds appropriately, but is preferably in the range of 100 to 5000 parts by mass, and more preferably in the range of 150 to 2000 parts by mass, per 100 parts by mass of the oil phase.

[0051] The non-reactive oily solvent is an oily solvent that does not exhibit chemical reactivity with any of the raw material compounds having a polyphenylene ether structure, crosslinkable monomers, or monofunctional monomers, and acts as a hollowing agent that gives hollow spaces to the particles. The non-reactive oily solvent is not particularly limited, but examples include heptane, hexane, toluene, cyclohexane, methyl acetate, ethyl acetate, methyl ethyl ketone, chloroform, and carbon tetrachloride. Oily solvents with a boiling point of less than 100°C are preferred because they are easily removed from the hollow particles. From the viewpoint of easily obtaining hollow particles, the amount of non-reactive oily solvent used is preferably in the range of 20 to 250 parts by mass per 100 parts by mass of the total amount of the raw material compounds having a polyphenylene ether structure, crosslinkable monomers, and monofunctional monomers.

[0052] Dispersion can be carried out using any dispersion method, as long as the oil phase can be present in droplet form in the aqueous phase. For example, a dispersion method using a homomixer or homogenizer may be employed.

[0053] During such dispersion, other components such as the aforementioned non-crosslinked polymer and dispersion stabilizers may be added. For example, by using a non-crosslinked polymer, the phase separation between the polyphenylene ether compound produced in the polymerization reaction and the non-reactive oily solvent is promoted, which facilitates the formation of the shell portion and tends to make it easier to produce component (A) as hollow particles. The amounts of these other components used are as described above, but may be determined as appropriate depending on the purpose.

[0054] The polymerization temperature is not particularly limited as long as it allows the polymerization of the raw material compound to proceed, but is preferably in the range of 30°C to 80°C. The polymerization time is not particularly limited as long as it allows the polymerization of the raw material compound to proceed and the desired polyphenylene ether compound to be obtained, but is preferably in the range of 1 hour to 48 hours.

[0055] It is preferable to perform post-heating after the polymerization reaction. The temperature of the post-heating is not particularly limited as long as the desired hollow particles are obtained, but is preferably in the range of 70°C to 120°C, and the post-heating time is preferably in the range of 1 hour to 24 hours.

[0056] (A) A commercially available product may be used as component (A). For example, a product having the above-mentioned suitable composition and dimensions is "XX-6655Z" manufactured by Sekisui Chemical Co., Ltd. (hollow polyphenylene ether particles, average particle size 0.4 μm, 90% particle size D 90 (less than 1 μm), "XX-6714Z" (solid polyphenylene ether particles, average particle size 0.7 μm, 90% particle size D 90 Examples include (less than 1 μm).

[0057] Even when a specific composition that contributes to good dielectric properties is adopted, the content of component (A) in the resin composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, 1.5% by mass or more, 2% by mass or more, or 2.5% by mass or more, and even more preferably 3% by mass or more, 3.5% by mass or more, 4% by mass or more, or 4.5% by mass or more, when the total resin component in the resin composition is considered as 100% by mass. The upper limit of this content is preferably 35% by mass or less, more preferably 30% by mass or less, 25% by mass or less, or 20% by mass or less, from the viewpoint of easily realizing an insulating layer that exhibits good crack resistance and good adhesion to the conductive layer after exposure to a high temperature and high humidity environment, while also exhibiting good surface flatness with little unevenness, regardless of the surface pattern of the substrate.

[0058] In the present invention, the term "resin component" in reference to a resin composition refers to the non-volatile components constituting the resin composition, excluding the inorganic filler (D) described later.

[0059] In particular, from the viewpoint of providing a cured product with outstanding crack resistance and adhesion to the conductor layer after exposure to a high-temperature, high-humidity environment, when the total of (B) epoxy resin and (C-1) one or more curing agents selected from the group consisting of active ester curing agents, cyanate ester curing agents, and carbodiimide curing agents is 100 parts by mass, the content of component (A) is preferably 2.2 parts by mass or more, more preferably 2.5 parts by mass or more, and even more preferably 3 parts by mass or more, 3.5 parts by mass or more, or 4 parts by mass or more. The upper limit of this content is preferably 38 parts by mass or less, more preferably 35 parts by mass or less, 30 parts by mass or less, or 25 parts by mass or less, from the viewpoint of easily realizing an insulating layer that exhibits good crack resistance and good adhesion to the conductor layer after exposure to a high-temperature, high-humidity environment, while also exhibiting outstanding surface flatness with little unevenness regardless of the surface pattern of the substrate.

[0060] <(B) Epoxy resin> The resin composition of the present invention contains an epoxy resin as component (B).

[0061] Examples of epoxy resins include bisphenol-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro-ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins. Bisphenol-type epoxy resins refer to epoxy resins having a bisphenol structure, and examples include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins. Biphenyl-type epoxy resins refer to epoxy resins having a biphenyl structure, where the biphenyl structure may have substituents such as alkyl groups, alkoxy groups, or aryl groups. Therefore, bixylenol-type epoxy resins and biphenylaralkyl-type epoxy resins are also included in biphenyl-type epoxy resins. Epoxy resins may be used individually or in combination of two or more types.

[0062] As the epoxy resin, aromatic epoxy resins are preferred. Here, aromatic epoxy resins refer to epoxy resins that have an aromatic ring in their molecule.

[0063] The epoxy resin preferably has two or more epoxy groups in one molecule. When the non-volatile components of the epoxy resin are considered to be 100% by mass, the proportion of epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

[0064] Epoxy resins include liquid epoxy resins at 20°C (hereinafter referred to as "liquid epoxy resins") and solid epoxy resins at 20°C (hereinafter referred to as "solid epoxy resins").

[0065] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0066] Preferred liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resins such as alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resins having a butadiene structure.

[0067] Specific examples of liquid epoxy resins include DIC's "HP-4032," "HP-4032D," and "HP-4032SS" (naphthalene-type epoxy resin); Mitsubishi Chemical's "828US," "jER828EL," "825," and "Epicote 828EL" (bisphenol A-type epoxy resin); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F-type epoxy resin); Mitsubishi Chemical's "jER152" (phenol novolac-type epoxy resin); and Mitsubishi Chemical's "630" and "630LSD" (glycidylamine-type epoxy resin). Examples of resins include: "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Co., Ltd.; "Celoxide 2021P" (alicyclic epoxy resin with an ester skeleton) manufactured by Daicel Corporation; "PB-3600" (epoxy resin with a butadiene structure) manufactured by Daicel Corporation; and "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.

[0068] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups per molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups per molecule is more preferred.

[0069] Preferred solid epoxy resins include bixylenol-type epoxy resin, naphthalene-type epoxy resin, naphthalene-type tetrafunctional epoxy resin, cresol novolac-type epoxy resin, dicyclopentadiene-type epoxy resin, trisphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthylene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, and tetraphenylethane-type epoxy resin.

[0070] Specific examples of solid epoxy resins include DIC's "HP-4032H" (naphthalene-type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC's "N-690" (cresol novolac-type epoxy resin); DIC's "N-695" (cresol novolac-type epoxy resin); DIC's "HP-7200HH", "HP-7200H", and "HP-7200" (dicyclopenta Diene-type epoxy resins: DIC Corporation's "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether-type epoxy resin); Nippon Kayaku Co., Ltd.'s "EPPN-502H" (trisphenol-type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC7000L" (naphthol novolac-type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC3000H", "NC3000", "NC3000L" "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; Examples include "YX8800" (anthracene-type epoxy resin); "PG-100" and "CG-500" from Osaka Gas Chemical Co., Ltd.; "YL7760" (bisphenol AF-type epoxy resin) from Mitsubishi Chemical Corporation; "YL7800" (fluorene-type epoxy resin) from Mitsubishi Chemical Corporation; "jER1010" (solid bisphenol A-type epoxy resin) from Mitsubishi Chemical Corporation; and "jER1031S" (tetraphenylethane-type epoxy resin) from Mitsubishi Chemical Corporation.

[0071] The resin composition of the present invention may contain only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. When a combination of a liquid epoxy resin and a solid epoxy resin is used, their mass ratio (liquid epoxy resin:solid epoxy resin) is preferably 1:0.01 to 1:50, more preferably 1:0.05 to 1:20, and even more preferably 1:0.1 to 1:10.

[0072] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 5000 g / eq., more preferably 50 g / eq. to 3000 g / eq., even more preferably 80 g / eq. to 2000 g / eq., and even more preferably 110 g / eq. to 1000 g / eq. The epoxy equivalent is the mass of the epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0073] The weight-average molecular weight (Mw) of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500. The Mw of the epoxy resin can be measured as a polystyrene equivalent value by the GPC method.

[0074] In combination with component (A) described above, and components (C) and (D) described later, from the viewpoint of producing a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high-temperature, high-humidity environment, the content of component (B) in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more, 14% by mass or more, or 15% by mass or more, when the total resin components in the resin composition are considered as 100% by mass. The upper limit of the content is not particularly limited and may be determined according to the properties required of the resin composition, but for example, it may be 60% by mass or less, 55% by mass or less, or 50% by mass or less.

[0075] <(C) Hardener> The resin composition of the present invention contains a curing agent as component (C).

[0076] Examples of component (C) include active ester curing agents, cyanate ester curing agents, carbodiimide curing agents, phenol curing agents, naphthol curing agents, acid anhydride curing agents, and amine curing agents. Component (C) may be used alone or in combination of two or more types.

[0077] By using a specific curing agent that can reduce or suppress the generation of polar groups such as secondary hydroxyl groups during the curing reaction of epoxy resins, it is possible to achieve a resin composition that exhibits good dielectric properties. Examples of curing agents that contribute to such good dielectric properties include active ester curing agents, cyanate ester curing agents, and carbodiimide curing agents.

[0078] As mentioned above, when an insulating layer was formed using a specific composition that contributes to good dielectric properties in the manufacturing of circuit boards, the resulting insulating layer tended to crack easily after desmearing. We confirmed that crack resistance could be improved somewhat by adding organic particles, but we found that adding organic particles in an amount sufficient to improve crack resistance resulted in a deterioration of dielectric properties, which reduced the desired effect, and also caused problems such as poor adhesion to the conductor layer when exposed to high temperature and high humidity environments. Furthermore, we confirmed that the deterioration of adhesion to the conductor layer after exposure to high temperature and high humidity environments becomes more pronounced when a high concentration of specific curing agents, such as active ester-based curing agents, is used to obtain even better dielectric properties.

[0079] In contrast, according to the present invention using component (A) described above, even when employing a specific composition that contributes to good dielectric properties, it is possible to produce a cured product that exhibits good crack resistance and good adhesion to the conductor layer when exposed to a high-temperature, high-humidity environment.

[0080] Therefore, in one embodiment, component (C) comprises one or more curing agents selected from the group consisting of (C-1) active ester curing agents, cyanate ester curing agents, and carbodiimide curing agents. The resin composition of the present invention is advantageous because it is possible to obtain a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high temperature and high humidity environment, while enjoying the excellent effect inherently provided by such (C-1) component (contributing to good dielectric properties).

[0081] -Activated ester-based curing agent- As the active ester curing agent, a compound having one or more active ester groups in one molecule can be used. Among these, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are preferred as the active ester curing agent. The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent derived from a carboxylic acid compound is preferred, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is more preferred, and an active ester curing agent obtained from a carboxylic acid compound and an aromatic hydroxy compound is even more preferred.

[0082] As the carboxylic acid compound, either an aromatic carboxylic acid compound or an aliphatic carboxylic acid may be used, for example, benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc.

[0083] Examples of aromatic hydroxy compounds include (i) polyaddition products of unsaturated aliphatic cyclic compounds containing two double bonds in one molecule and phenols, (ii) various bisphenol compounds, (iii) aromatic polyols in which two or more hydroxyl groups are bonded to a carbon atom on an aromatic ring, and (iv) aromatic monools in which one hydroxyl group is bonded to a carbon atom on an aromatic ring. Examples of polyaddition products of unsaturated aliphatic cyclic compounds and phenols include polyaddition products of unsaturated aliphatic cyclic compounds such as dicyclopentadiene, tetrahydroindene, norbornadiene, limonene, and vinylcyclohexene with phenols that may have substituents (e.g., phenol, cresol, xylenol, ethylphenol, propylphenol, vinylphenol, allylphenol, phenylphenol, benzylphenol, halophenol, etc.), and specifically, for example, dicyclopentadiene-phenol polyadditions. Examples of bisphenol compounds include bisphenol A, bisphenol F, bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, and bisphenol M. Examples of aromatic polyols, in which two or more hydroxyl groups are bonded to a carbon atom on an aromatic ring, include hydroquinone, resorcinol, catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, and phenol novolac. Examples of aromatic monools, in which one hydroxyl group is bonded to a carbon atom on an aromatic ring, include phenol, cresol, xylenol, ethylphenol, propylphenol, vinylphenol, allylphenol, phenylphenol, benzylphenol, halophenol, naphthol, methylnaphthol, dimethylnaphthol, ethylnaphthol, propylnaphthol, vinylnaphthol, allylnaphthol, phenylnaphthol, benzylnaphthol, and halonaphthol.

[0084] Suitable examples of active ester curing agents include active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing an acetylated phenol novolac, and active ester compounds containing a benzoylated phenol novolac. Among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are more preferred from the viewpoint of providing good dielectric properties in combination with components (A), (B), and (D) described later. "Dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentalene-phenylene.

[0085] Commercially available active ester curing agents include, as active ester resins containing a dicyclopentadiene-type diphenol structure, "EXB-9451", "EXB-9460", "EXB-9460S", "HPC-8000-65T", "HPC-8000H-65TM", and "HPC-8000L-65TM" (manufactured by DIC Corporation); and as active ester resins containing a naphthalene structure, "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-60T", and "HPC-8150-62T". Examples include "HP-B-8151-62T" and "HP-C-8151-62T" (manufactured by DIC Corporation); "EXB9401" (manufactured by DIC Corporation) as a phosphorus-containing active ester resin; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin that is an acetylated phenol novolac; "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester resins that are benzoylated phenol novolacs; and "PC1300-02-65MA" (manufactured by Air Water Corporation) as an active ester resin containing a styryl group and a naphthalene structure.

[0086] -Cyanate ester-based hardening agent- Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl) thioether, and bis(4-cyanatephenyl) ether; polyfunctional cyanate resins derived from phenol novolacs and cresol novolacs, etc.; and prepolymers in which these cyanate resins are partially triazined.

[0087] Specific examples of cyanate ester-based curing agents include "PT30" and "PT60" (phenol novolac type polyfunctional cyanate ester resin), "ULL-950S" (polyfunctional cyanate ester resin), "BA230", and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazined and trimerized), all manufactured by Lonza Japan.

[0088] -Carbodiimide-based hardener- Carbodiimide-based curing agents are compounds having one or more, preferably two or more, carbodiimide groups (-N=C=N-) in one molecule. Specific examples of carbodiimide-based curing agents include Carbodilite® V-03 (carbodiimide group equivalent: 216 g / eq.), V-05 (carbodiimide group equivalent: 262 g / eq.), V-07 (carbodiimide group equivalent: 200 g / eq.), V-09 (carbodiimide group equivalent: 200 g / eq.) manufactured by Nisshinbo Chemical Co., Ltd., and Stavaxol® P (carbodiimide group equivalent: 302 g / eq.) manufactured by Rhein Chemie.

[0089] In the resin composition of the present invention, component (C) may include curing agents other than component (C-1). For example, component (C) may include one or more curing agents selected from the group consisting of (C-2) phenol-based curing agents, naphthol-based curing agents, acid anhydride-based curing agents, and amine-based curing agents.

[0090] -Phenol-based curing agents and naphthol-based curing agents- From the viewpoint of heat resistance and water resistance, phenolic and naphthol-based curing agents are preferred if they have a novolac structure. Furthermore, from the viewpoint of adhesion to the conductive layer, nitrogen-containing phenolic and nitrogen-containing naphthol-based curing agents are preferred, and triazine skeleton-containing phenolic and triazine skeleton-containing naphthol-based curing agents are more preferred. From the viewpoint of achieving an insulating layer with good heat resistance, water resistance, and adhesion to the conductive layer, phenolic and naphthol-based curing agents having both a triazine skeleton and a novolac structure are particularly preferred.

[0091] Specific examples of phenol-based and naphthol-based curing agents include, for example, "MEH-7700," "MEH-7810," "MEH-7851," and "MEH-8000H" from Meiwa Kasei Co., Ltd.; "NHN," "CBN," and "GPH" from Nippon Kayaku Co., Ltd.; and "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-495V," and "SN-37" from Nippon Steel Chemical & Material Co., Ltd. Examples include "5", "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" from DIC Corporation, and "GDP-6115L", "GDP-6115H", "ELPC75" from Gun-ei Chemical Co., Ltd.

[0092] -Acid anhydride curing agent- Examples of acid anhydride-based curing agents include curing agents having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride-based curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexen-1,2-dicarboxylic acid anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenone tetracarboxylic acid di Examples of acid anhydrides include anhydrides, biphenyltetracarboxylic acid dianhydride, naphthalenetetracarboxylic acid dianhydride, oxydiphthalic acid dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymer-type acid anhydrides such as styrene-maleic acid resin copolymerized with styrene and maleic acid. A commercially available acid anhydride-based curing agent is "MH-700" manufactured by Shin Nippon Rika Co., Ltd.

[0093] -Amine-based curing agent- Examples of amine-based curing agents include curing agents having one or more amino groups in one molecule, such as aliphatic amines, polyetheramines, alicyclic amines, and aromatic amines. Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxy Examples include bis(4-(4-aminophenoxy)phenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Commercial amine-based curing agents may also be used, such as "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD AA", "KAYAHARD AB", and "KAYAHARD AS" from Nippon Kayaku Co., Ltd., and "Epicure W" from Mitsubishi Chemical Corporation.

[0094] From the viewpoint of easily realizing a resin composition that provides good dielectric properties in combination with component (A), component (B), and component (D) described later, the content of component (C) in the resin composition is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, 35% by mass or more, or 40% by mass or more, when the total resin components in the resin composition are considered to be 100% by mass. The upper limit of the content is not particularly limited and may be determined according to the properties required of the resin composition, but for example it may be 80% by mass or less, 75% by mass or less, 70% by mass or less, or 65% by mass or less.

[0095] From the viewpoint of realizing a resin composition that provides good dielectric properties in combination with component (A), component (B), and component (D) described later, the content of component (C-1) in component (C) is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 85% by mass or more, 90% by mass or more, or 95% by mass or more, when the nonvolatile component of component (C) is taken as 100% by mass. The upper limit of the content is not particularly limited and may be 100% by mass, but may be, for example, 99.5% by mass or less, 99% by mass or less, etc.

[0096] In the resin composition of the present invention, the mass ratio of component (C-1) to component (B) ((C-1) / (B) component) is preferably 1 or more, more preferably 1.1 or more, and even more preferably 1.2 or more or 1.4 or more, from the viewpoint of obtaining a cured product with excellent dielectric properties. As described above, the resin composition of the present invention using component (A) can produce a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high temperature and high humidity environment, even when containing component (C-1) to an extent that enables the realization of excellent dielectric properties. For example, in the resin composition of the present invention, the mass ratio of component (C-1) to component (B) may be increased to 1.5 or more, 1.6 or more, or 1.7 or more. The upper limit of the mass ratio ((B) / (A) component) may be, for example, 2.5 or less, 2.4 or less, 2.2 or less, 2 or less, etc.

[0097] <(D) Inorganic filler> The resin composition of the present invention contains an inorganic filler as component (D). By including component (D), the linear thermal expansion coefficient and dielectric loss tangent can be further reduced.

[0098] Examples of materials for component (D) include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum silicate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred as silica. Component (D) may be used alone or in combination of two or more types.

[0099] Examples of commercially available components of (D) include "UFP-30" from Denka Chemical Industry Co., Ltd.; "SP60-05" and "SP507-05" from Nippon Steel Chemical & Material Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" from Admatex Co., Ltd.; "UFP-30" from Denka Co., Ltd.; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" from Tokuyama Corporation; "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" from Admatex Co., Ltd.; "DAW-03" and "FB-105FD" from Denka Co., Ltd.; "Selfiers" and "MGH-005" from Taiheiyo Cement Corporation; and "Esferique" and "BA-1" from JGC Catalytic Chemical Co., Ltd.

[0100] (D) component's average particle size is not particularly limited, but preferably 10 μm or less, more preferably 5 μm or less, still more preferably 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less. The lower limit of the average particle size is not particularly limited, but preferably 0.01 μm or more, more preferably 0.05 μm or more, still more preferably 0.07 μm or more, 0.1 μm or more, or 0.2 μm or more. The average particle size of (D) component is the median diameter (50% particle size D 50 ) based on volume, and can be measured in the same way as the average particle size of (A) component.

[0101] (D) component's specific surface area is not particularly limited, but preferably 0.1 m 2 / g or more, more preferably 0.5 m 2 / g or more, still more preferably 1 m 2 / g or more, 3 m 2 / g or more, or 5 m 2 / g or more. The upper limit of the specific surface area is not particularly limited, but preferably 100 m 2 / g or less, more preferably 80 m 2 / g or less, still more preferably 60 m 2 / g or less, 50 m 2 / g or less, or 40 m 2 / g or less. The specific surface area of (D) component can be obtained by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) according to the BET method and calculating the specific surface area using the BET multi-point method.

[0102] Component (D) is preferably surface-treated with an appropriate surface treatment agent. Surface treatment can improve the moisture resistance and dispersibility of component (D). Examples of surface treatment agents include silane coupling agents such as vinyl silane coupling agents, epoxy silane coupling agents, styryl silane coupling agents, (meth)acrylic silane coupling agents, amino silane coupling agents, isocyanurate silane coupling agents, ureido silane coupling agents, mercapto silane coupling agents, isocyanate silane coupling agents, and acid anhydride silane coupling agents; non-silane coupling alkoxysilane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane; and silazane compounds. The surface treatment agent may be used alone or in combination of two or more types.

[0103] Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane), "KBE903" (3-aminopropyltriethoxysilane), "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), and "SZ-31" (hexamethyldisilazane), all manufactured by Shin-Etsu Chemical Co., Ltd.

[0104] From the viewpoint of improving the dispersibility of component (D), the degree of surface treatment by the surface treatment agent is preferably within a predetermined range. Specifically, it is preferable that 100% by mass of the inorganic filler is surface-treated with 0.2 to 5% by mass of the surface treatment agent.

[0105] The degree of surface treatment by a surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler should be 0.02 mg / m². 2 The above is preferred, and 0.1 mg / m² 2 The above is more preferable, 0.2 mg / m² 2The above is even more preferable. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition and the melt viscosity in sheet form, 1.0 mg / m² 2 The following is preferred: 0.8 mg / m² 2 The following is more preferable: 0.5 mg / m² 2 The following is even more preferable: The amount of carbon per unit surface area of ​​component (D) can be measured after cleaning the inorganic filler with a solvent (e.g., methyl ethyl ketone (MEK)) after surface treatment. Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solids, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. As a carbon analyzer, a Horiba "EMIA-320V" or the like can be used.

[0106] From the viewpoint of facilitating the realization of a resin composition that yields even better dielectric properties in combination with components (A) to (C), the content of component (D) in the resin composition is, for example, 40% by mass or more, preferably 50% by mass or more, when the non-volatile components in the resin composition are considered to be 100% by mass. As mentioned above, according to the present invention using component (A), even when a specific composition that contributes to good dielectric properties is adopted, it is possible to produce a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high temperature and high humidity environment. For example, in the resin composition of the present invention, the content of component (D) may be increased to 60% by mass or more, 65% by mass or more, or 70% by mass or more. The upper limit of the content of component (D) is not particularly limited, but may be, for example, 90% by mass or less, 85% by mass or less.

[0107] <(E) Radical polymerizable resin> The resin composition of the present invention may also contain a radical polymerizable resin as component (E).

[0108] The type of radical polymerizable resin is not particularly limited, as long as it has one or more (preferably two or more) radical polymerizable unsaturated groups per molecule. Examples of radical polymerizable resins include resins having one or more radical polymerizable unsaturated groups selected from maleimide groups, vinyl groups, allyl groups, styryl groups, vinylphenyl groups, acryloyl groups, methacryloyl groups, fumaroyl groups, and maleoil groups. Among these, from the viewpoint of obtaining a cured product that exhibits even better dielectric properties, it is preferable that the radical polymerizable resin be one or more selected from maleimide resins, (meth)acrylic resins, and styryl resins.

[0109] The type of maleimide resin is not particularly limited, as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl groups) per molecule. Examples of maleimide resins include: (1) maleimide resins containing an aliphatic skeleton (preferably an aliphatic skeleton with 36 carbon atoms derived from dimer amine) such as "BMI-3000J", "BMI-5000", "BMI-1400", "BMI-1500", "BMI-1700", and "BMI-689" (all manufactured by Designer Molecules), and "SLK6895-T90" (manufactured by Shin-Etsu Chemical Co., Ltd.); (2) maleimide resins containing an indan skeleton as described in the Japan Institute of Invention and Innovation, Technical Report No. 2020-500211; and (3) maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Yamato Kasei Co., Ltd.), and "BMI-80" (manufactured by Kei-I Kasei Co., Ltd.).

[0110] The type of (meth)acrylic resin is not particularly limited as long as it has one or more (preferably two or more) (meth)acryloyl groups in one molecule, and may be a monomer or oligomer. Here, the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups. Examples of methacrylic resins include (meth)acrylate monomers, as well as (meth)acrylic resins such as "A-DOG" (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "NPDGA", "FM-400", "R-687", "THE-330", "PET-30", and "DPHA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0111] The type of styryl resin is not particularly limited as long as it has one or more (preferably two or more) styryl groups or vinylphenyl groups in one molecule, and may be a monomer or oligomer. Examples of styryl resins include styrene monomer, as well as styryl resins such as "OPE-2St," "OPE-2St 1200," and "OPE-2St 2200" (all manufactured by Mitsubishi Gas Chemical Company).

[0112] If the resin composition of the present invention contains component (E), the content of component (E) in the resin composition may be determined according to the properties required for the resin composition. However, if the total resin components in the resin composition are considered as 100% by mass, then for example, it is 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, 0.6% by mass or more, 0.8% by mass or more, or 1% by mass or more. The upper limit of the content of component (E) is not particularly limited, but for example, it may be 15% by mass or less, 10% by mass or less, 8% by mass or less, etc.

[0113] <(F) Curing accelerator> The resin composition of the present invention may also contain a curing accelerator as component (F).

[0114] Examples of component (F) include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and peroxide-based curing accelerators. The curing accelerator may be used alone or in combination of two or more types.

[0115] When the resin composition of the present invention contains component (F), the content of component (F) in the resin composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, preferably 2% by mass or less, more preferably 1.5% by mass or less, or 1% by mass or less, when the total amount of resin components in the resin composition is 100% by mass.

[0116] <(G)Thermoplastic resin> The resin composition of the present invention may also contain a thermoplastic resin as component (G).

[0117] Examples of thermoplastic resins include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polycarbonate resin, polyetheretherketone resin, and polyester resin. Thermoplastic resins may be used individually or in combination of two or more types.

[0118] The polystyrene equivalent Mw of the thermoplastic resin is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, and even more preferably in the range of 20,000 to 60,000. The polystyrene equivalent Mw of the thermoplastic resin is measured by the GPC method. Specifically, the weight-average molecular weight of the thermoplastic resin in polystyrene equivalent can be measured using a Shimadzu LC-9A / RID-6A measuring device, a Showa Denko Shodex K-800P / K-804L / K-804L column, and chloroform or the like as the mobile phase, at a column temperature of 40°C, and can be calculated using a calibration curve for standard polystyrene.

[0119] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The ends of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Phenoxy resins may be used alone or in combination of two or more types. Specific examples of phenoxy resins include "1256" and "4250" (both phenoxy resins containing a bisphenol A skeleton), "YX8100" (phenoxy resin containing a bisphenol S skeleton), and "YX6954" (phenoxy resin containing a bisphenol acetophenone skeleton), all manufactured by Mitsubishi Chemical Corporation. Other examples include "FX280" and "FX293" from Nippon Steel Chemical & Material Corporation, and "YX7553," "YL6794," "YL7213," "YL7290," and "YL7482" from Mitsubishi Chemical Corporation.

[0120] Examples of polyvinyl acetal resins include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of polyvinyl acetal resins include, for example, Denka's "Denka Butyral 4000-2," "Denka Butyral 5000-A," "Denka Butyral 6000-C," and "Denka Butyral 6000-EP," and Sekisui Chemical's Esrec BH series, BX series, KS series, BL series, and BM series.

[0121] As the polyimide resin, a resin having an imide structure (preferably a cyclic imide structure) can be used. For example, an imidized compound of an acid anhydride and a diamine compound or a diisocyanate compound may be used.

[0122] The acid anhydride used to prepare the polyimide resin is not particularly limited, but tetracarboxylic anhydrides are preferred, for example, aromatic tetracarboxylic dianhydrides and aliphatic tetracarboxylic dianhydrides, with aromatic tetracarboxylic dianhydrides being preferred. Examples of aromatic tetracarboxylic dianhydrides include benzenetetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, anthracenetetracarboxylic dianhydride, and diphthalic acid dianhydride, with diphthalic acid dianhydride being preferred. The diphthalic acid dianhydride is not particularly limited as long as it is a compound containing two phthalic anhydride structures in the molecule, and each benzene ring in the phthalic anhydride structure may optionally have 1 to 3 substituents. The two phthalic anhydride structures in the diphthalic acid dianhydride may be directly bonded, or they may be bonded via a linker structure having 1 to 100 skeletal atoms selected from the group consisting of carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms. An example of a "linker structure" in diphthalic acid dianhydride is -[R e -Ph] me -R e -[Ph-R e ] ne A divalent group represented by - is an example. In this formula, R eEach independently represents a single bond, -(substituted or unsubstituted alkylene group)-, -O-, -S-, -CO-, -SO2-, -CONH-, -NHCO-, -COO-, or -OCO-; me and ne independently represent an integer from 0 to 2 (preferably 0 or 1). In this specification, unless otherwise specified, "Ph" represents a 1,4-phenylene group, a 1,3-phenylene group, or a 1,2-phenylene group. Specific examples of linker structures include -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH(CH3)-, -C(CH3)2-, -O-, -CO-, -SO2-, -Ph-, -O-Ph-O-, -O-Ph-SO2-Ph-O-, -O-Ph-C(CH3)2-Ph-O-, etc.Examples of diphthalic acid dianhydrides include 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3',4,4'-diphenylethertetracarboxylic acid dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid dianhydride, and 2,3,3',4'-biphenyltetracarboxylic acid dianhydride. Rubonic acid dianhydride, 2,3,3',4'-benzophenonetetracarboxylic acid dianhydride, 2,3,3',4'-diphenylethertetracarboxylic acid dianhydride, 2,3,3',4'-diphenylsulfonetetracarboxylic acid dianhydride, 2,2'-bis(3,4-dicarboxyphenoxyphenyl)sulfone dianhydride, 4,4'-oxydiphthalic acid anhydride, methylene-4,4'-diphthalic acid dianhydride, 1,1-ethynylidene-4 ,4'-diphthalic acid dianhydride, 2,2-propyridene-4,4'-diphthalic acid dianhydride, 1,2-ethylene-4,4'-diphthalic acid dianhydride, 1,3-trimethylene-4,4'-diphthalic acid dianhydride, 1,4-tetramethylene-4,4'-diphthalic acid dianhydride, 1,5-pentamethylene-4,4'-diphthalic acid dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenyl)benzene dianhydride Examples include bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic acid dianhydride.

[0123] The diamine compounds used to prepare the polyimide resin are not particularly limited as long as they are compounds having two amino groups in their molecule. Examples include aliphatic diamine compounds and aromatic diamine compounds. Examples of aliphatic diamine compounds include linear aliphatic diamine compounds such as 1,2-ethylenediamine and 1,10-diaminodecane; branched aliphatic diamine compounds such as 1,2-diamino-2-methylpropane and 2-methyl-1,5-diaminopentane; alicyclic diamine compounds such as 1,3-bis(aminomethyl)cyclohexane and 4,4'-methylenebis(cyclohexylamine); and dimer amines, with dimer amines being preferred. Dimer amines refer to diamine compounds obtained by substituting the two terminal carboxylic acid groups (-COOH) of a dimer acid with aminomethyl groups (-CH2-NH2) or amino groups (-NH2). Examples of aromatic diamine compounds include phenylenediamine compounds, naphthalenediamine compounds, and dianiline compounds, with dianiline compounds being preferred. A dianiline compound refers to a compound containing two aniline structures in its molecule. Each benzene ring in the aniline structure may optionally have 1 to 3 substituents. The two aniline structures in a dianiline compound may be directly bonded, or they may be bonded via a linker structure having 1 to 100 skeletal atoms selected from the group consisting of carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of "linker structures" in dianiline compounds include -NHCO-, -CONH-, -OCO-, -COO-, -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -CH=CH-, -O-, -S-, -CO-, -SO2-, -NH-, Examples include -Ph-, -Ph-Ph-, -C(CH3)2-Ph-C(CH3)2-, -O-Ph-O-, -O-Ph-Ph-O-, -O-Ph-SO2-Ph-O-, -O-Ph-C(CH3)2-Ph-O-, -Ph-CO-O-Ph-, -C(CH3)2-Ph-C(CH3)2-, the group represented by formula (e-1) below, the group represented by (e-2), and groups consisting of combinations thereof. In formulas (e-1) and (e-2), "*" represents a bond.

[0124] [ka]

[0125] Examples of dianiline compounds include 4,4'-diamino-2,2'-ditrifluoromethyl-1,1'-biphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4-aminophenyl 4-aminobenzoate, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-aminophenyl)propane, 4,4'-(hexafluoroisopropylidene)dianiline, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenyl Examples include [(((((4-aminophenoxy)phenyl)]hexafluoropropane, α,α-bis[4-(4-aminophenoxy)phenyl]-1,3-diisopropylbenzene, α,α-bis[4-(4-aminophenoxy)phenyl]-1,4-diisopropylbenzene, 4,4'-(9-fluorenylidene)dianiline, 2,2-bis(3-methyl-4-aminophenyl)propane, 2,2-bis(3-methyl-4-aminophenyl)benzene, 4,4'-diamino-3,3'-dimethyl-1,1'-biphenyl, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 9,9'-bis(3-methyl-4-aminophenyl)fluorene, and 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindan. The diamine compound may be used individually or in combination of two or more types.

[0126] The diisocyanate compound used to prepare the polyimide resin is not particularly limited as long as it is a compound having two isocyanate groups in its molecule. Examples include aliphatic diisocyanate compounds and aromatic diisocyanate compounds. Examples of aliphatic diisocyanate compounds include linear aliphatic diisocyanate compounds such as 1,4-butane diisocyanate and 1,6-hexane diisocyanate; branched aliphatic diisocyanate compounds such as 2,2,4-trimethylhexamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate; and alicyclic diisocyanate compounds such as norbornane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. Examples of aromatic diisocyanate compounds include tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, and o-tolidine diisocyanate. As described above, the diisocyanate compound only needs to have two isocyanate groups in its molecule. For example, a diisocyanate compound having a urethane bond, obtained by reacting the above-mentioned diisocyanate compound with a diol compound, may be used. The diol compound is not particularly limited as long as it has two hydroxyl groups in its molecule. For example, diol compounds having a saturated or unsaturated aliphatic skeleton (e.g., alkylene skeleton, alkenylene skeleton, alkapolienyl group) (the bifunctional hydroxyl-terminated polybutadiene described later is one example); aromatic diol compounds having an aromatic skeleton such as biphenol compounds, bisphenol compounds, and polyarylene ethers having terminal hydroxyl groups may be used.

[0127] Therefore, in one preferred embodiment, the polyimide resin is an imidide of an acid anhydride and a diamine compound. In another preferred embodiment, the polyimide resin is an imidide of an acid anhydride and a diisocyanate compound. The terminal functional groups of the polyimide resin may be modified by reacting with the above-mentioned diol compound or the like.

[0128] Other specific examples of polyimide resins include "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shin Nippon Rika Co., Ltd. Other specific examples of polyimide resins include linear polyimides obtained by reacting a bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (as described in Japanese Patent Publication No. 2006-37083), and modified polyimides containing a polysiloxane skeleton (as described in Japanese Patent Publication No. 2002-12667 and Japanese Patent Publication No. 2000-319386, etc.).

[0129] Specific examples of polyamide-imide resins include "Viromax HR11NN" and "Viromax HR16NN" manufactured by Toyobo Co., Ltd. Other specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300," which contain a polysiloxane skeleton, manufactured by Hitachi Chemical Co., Ltd.

[0130] Specific examples of polyethersulfone resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0131] Specific examples of polysulfone resins include Solvay Advanced Polymers' polysulfones "P1700" and "P3500".

[0132] When the resin composition of the present invention contains component (G), the content of component (G) in the resin composition may be determined according to the properties required for the resin composition. However, when the total resin components in the resin composition are considered as 100% by mass, for example, it is 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, 0.6% by mass or more, or 0.8% by mass or more. The upper limit of the content of component (G) is not particularly limited, but may be, for example, 15% by mass or less, 10% by mass or less, 8% by mass or less, 6% by mass or less, etc.

[0133] <Optional additives> The resin composition of the present invention may further contain any additives. Such additives include, for example, radical polymerization initiators such as peroxide-based radical polymerization initiators and azo-based radical polymerization initiators; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; organic fillers other than component (A) (e.g., rubber particles; however, when the total amount of organic fillers is 100 parts by mass, component (A) is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, 90 parts by mass or more, or 95 parts by mass or more); colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentonite and montmorillonite; defoaming agents such as silicone-based defoaming agents, acrylic-based defoaming agents, fluorine-based defoaming agents, and vinyl resin-based defoaming agents; Examples of adhesives include: UV absorbers such as nzotriazole-based UV absorbers; adhesion improvers such as urea silane; adhesion fertilizers such as triazole-based adhesion fertilizers, tetrazole-based adhesion fertilizers, and triazine-based adhesion fertilizers; antioxidants such as hindered phenol-based antioxidants; fluorescent whitening agents such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; and stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic acid anhydride-based stabilizers. The amount of such additives may be determined according to the properties required of the resin composition.

[0134] <organic solvents> The resin composition of the present invention may further contain an organic solvent as a volatile component. Examples of organic solvents include: ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; and 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples include ether ester solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. Organic solvents may be used individually or in combination of two or more.

[0135] The resin composition of the present invention can be manufactured, for example, by adding components (A), (B), (C), (D), and optionally components (E), (F), (G), other additives and organic solvents, in any order and / or some or all at the same time, and mixing them in any preparation container. The temperature can be set appropriately during the process of adding and mixing each component, and heating and / or cooling may be performed temporarily or throughout the process. In addition, during or after the process of adding and mixing, the resin composition may be stirred or shaken using, for example, a stirring device such as a mixer or a shaking device to disperse it uniformly. Degassing may be performed simultaneously with stirring or shaking under low pressure conditions such as vacuum.

[0136] Furthermore, even if the resin composition of the present invention contains an organic solvent, component (A) is insoluble in the organic solvent and is also miscible with other components, including components (B) and (C), so that suitable dimensions such as the average particle size can be maintained. Therefore, in one embodiment, component (A) is insoluble in the solvent.

[0137] As described above, the resin composition of the present invention, which includes component (A) in combination with components (B) to (D), can produce a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high-temperature, high-humidity environment, even when a specific composition that contributes to good dielectric properties is adopted. Furthermore, it can realize an insulating layer with little unevenness and good surface flatness, regardless of the surface pattern of the substrate (surface unevenness pattern caused by recesses such as degass holes and protrusions such as surface circuits).

[0138] In one embodiment, the cured product of the resin composition of the present invention exhibits a low dielectric loss tangent (Df). For example, as described in the [Test Example 1: Measurement of Dielectric Loss Tangent (Df)] section below, when measured at 5.8 GHz and 23°C, the dielectric loss tangent (Df) of the cured product of the resin composition of the present invention can preferably be 0.006 or less, 0.005 or less, 0.004 or less, 0.0038 or less, 0.0036 or less, 0.0034 or less, 0.0032 or less, or 0.003 or less.

[0139] In one embodiment, the cured product of the resin composition of the present invention exhibits high adhesion to the conductive layer. For example, as described in the section [Test Example 3: Measurement of copper foil peel strength after high temperature and high humidity environment test (HAST)] below, when exposed to high temperature and high humidity conditions of 130°C and 85%RH for 100 hours, the adhesion strength to the conductive foil after exposure to high temperature and high humidity conditions is preferably 0.35 kgf / cm or more, 0.4 kgf / cm or more, 0.42 kgf / cm or more, 0.44 kgf / cm or more, and 0.45 kgf / cm or more.

[0140] As described above, even when employing a specific composition that contributes to good dielectric properties, the resin composition of the present invention can produce a cured product that exhibits good crack resistance and good adhesion to the conductive layer when exposed to a high-temperature, high-humidity environment. Furthermore, it can realize an insulating layer with little unevenness and good surface flatness, regardless of the surface pattern of the substrate. Therefore, the resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer of a printed wiring board (resin composition for the insulating layer of a printed wiring board), and more suitably used as a resin composition for forming an interlayer insulating layer of a printed wiring board (resin composition for the insulating edge layer of an insulating layer of a printed wiring board). The resin composition of the present invention can also be suitably used when the printed wiring board is a circuit board with embedded components. The resin composition of the present invention can also be suitably used as a resin composition for forming an insulating layer of a redistribution substrate for a semiconductor package (resin composition for the insulating layer of a redistribution substrate). In this invention, printed wiring boards and redistribution substrates are collectively referred to as "circuit boards," and therefore the resin composition of the present invention can be suitably used for the insulating layer of a circuit board.

[0141] The resin composition of the present invention can be used in a wide range of applications where a resin composition is required, such as sheet-like laminated materials like resin sheets and prepregs, solder resists, underfill materials, die bonding materials, hole-filling resins, sealing resins, and component embedding resins.

[0142] [Sheet-like laminated materials (resin sheets, prepregs)] The resin composition of the present invention can be used as is, or it may be used in the form of a sheet-like laminated material containing the resin composition.

[0143] As sheet-like laminated materials, the following resin sheets and prepregs are preferred.

[0144] In one embodiment, the resin sheet comprises a support and a layer of a resin composition provided on the support (hereinafter simply referred to as the "resin composition layer"), characterized in that the resin composition layer is formed from the resin composition of the present invention.

[0145] The optimal thickness of the resin composition layer varies depending on the application and may be determined appropriately according to the application. For example, from the viewpoint of thinning printed circuit boards and semiconductor packages, the thickness of the resin composition layer is preferably 100 μm or less, 80 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 1 μm or more, 5 μm or more, etc.

[0146] Examples of support materials include thermoplastic resin films, metal foils, and release paper, with thermoplastic resin films and metal foils being preferred. Therefore, in one preferred embodiment, the support material is a thermoplastic resin film or a metal foil.

[0147] When using a thermoplastic resin film as a support, examples of thermoplastic resins include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetylcellulose (TAC), polyether sulfide (PES), polyether ketones, and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0148] When using metal foil as a support, examples of metal foil include copper foil and aluminum foil, with copper foil being preferred. As for copper foil, foil made of single-metal copper may be used, or foil made of an alloy of copper with another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

[0149] The support may have a matte finish, corona treatment, or antistatic treatment applied to the surface that bonds with the resin composition layer. Alternatively, a support with a release layer may be used, which has a release layer on the surface that bonds with the resin composition layer. Examples of release agents used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available support with a release layer may be used, for example, PET films having a release layer mainly composed of an alkyd resin-based release agent, such as "SK-1", "AL-5", and "AL-7" from Lintec Corporation, "Lumirror T60" from Toray Industries, Inc., "Purex" from Teijin Corporation, and "Unipeel" from Unitika Corporation.

[0150] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When using a support with a release layer, it is preferable that the overall thickness of the support with the release layer is within the above range.

[0151] When using metal foil as a support, a metal foil with a support substrate, which is formed by laminating a peelable support substrate onto a thin metal foil, may be used. In one embodiment, the metal foil with a support substrate includes a support substrate, a release layer provided on the support substrate, and a metal foil provided on the release layer. When using metal foil with a support substrate as a support, the resin composition layer is provided on the metal foil.

[0152] In a metal foil with a support substrate, the material of the support substrate is not particularly limited, but examples include copper foil, aluminum foil, stainless steel foil, titanium foil, copper alloy foil, etc. When copper foil is used as the support substrate, it may be electrolytic copper foil or rolled copper foil. Furthermore, the release layer is not particularly limited as long as it can be used to peel the metal foil from the support substrate, and examples include an alloy layer of elements selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, and P; an organic coating, etc.

[0153] In a metal foil with a support substrate, the material of the metal foil is preferably, for example, copper foil or copper alloy foil.

[0154] In a metal foil with a support substrate, the thickness of the support substrate is not particularly limited, but is preferably in the range of 10 μm to 150 μm, and more preferably in the range of 10 μm to 100 μm. The thickness of the metal foil may be, for example, in the range of 0.1 μm to 10 μm.

[0155] In one embodiment, the resin sheet may further include any additional layer as needed. Such an additional layer may be, for example, a protective film provided on the side of the resin composition layer that is not bonded to the support (i.e., the side opposite to the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, the adhesion of dust and other debris to the surface of the resin composition layer and scratches can be suppressed.

[0156] Resin sheets can be manufactured, for example, by applying a resin varnish prepared by directly using a liquid resin composition or by dissolving the resin composition in an organic solvent, coating it onto a support using a die coater or the like, and then drying it to form a resin composition layer.

[0157] Examples of organic solvents include those similar to those described as components of the resin composition. Organic solvents may be used individually or in combination of two or more.

[0158] Drying may be carried out by known methods such as heating or blowing hot air. The drying conditions are not particularly limited, but the resin composition layer should be dried so that the content of the organic solvent in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when using a resin composition or resin varnish containing 30% to 60% by mass of organic solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0159] Resin sheets can be stored by rolling them up. If the resin sheet has a protective film, it can be used after removing the protective film.

[0160] In one embodiment, the prepreg is formed by impregnating a sheet-like fibrous substrate with the resin composition of the present invention.

[0161] The sheet-like fibrous substrate used for the prepreg is not particularly limited, and commonly used prepreg substrates such as glass cloth, aramid nonwoven fabric, and liquid crystal polymer nonwoven fabric can be used. From the viewpoint of thinning printed circuit boards and semiconductor chip packages, the thickness of the sheet-like fibrous substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. The lower limit of the thickness of the sheet-like fibrous substrate is not particularly limited, but is usually 10 μm or more.

[0162] Prepregs can be manufactured by known methods such as the hot melt method and the solvent method.

[0163] The thickness of the prepreg can be within the same range as the resin composition layer in the resin sheet described above.

[0164] The sheet-like laminated material of the present invention can be suitably used to form an insulating layer of a printed circuit board (for the insulating layer of a printed circuit board), and more suitably used to form an interlayer insulating layer of a printed circuit board (for the insulating edge layer of a printed circuit board). The sheet-like laminated material of the present invention can also be suitably used to form an insulating layer of a redistribution substrate for a semiconductor package (for the insulating layer of a redistribution substrate). In other words, the sheet-like laminated material of the present invention can be suitably used as an insulating layer for a circuit board.

[0165] [Circuit board] The resin composition of the present invention can be used to form an insulating layer on a circuit board. The present invention also provides such a circuit board, that is, a circuit board including an insulating layer made of a cured product of the resin composition of the present invention.

[0166] <Printed wiring board> In one embodiment, the circuit board of the present invention is a printed wiring board.

[0167] Printed circuit boards can be manufactured, for example, using the above-mentioned resin sheet by a method including the following steps (I) and (II). (I) A process of laminating a resin sheet onto an inner layer substrate such that the resin composition layer of the resin sheet is bonded to the inner layer substrate. (II) A step of curing (e.g., thermal curing) the resin composition layer to form an insulating layer.

[0168] The "internal layer substrate" used in process (I) is a material that serves as the substrate for a printed wiring board, and examples include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, etc. The substrate may also have a conductive layer on one or both sides, and this conductive layer may be patterned. An internal layer substrate in which a conductive layer (circuit) is formed on one or both sides of the substrate is sometimes called an "internal layer circuit board." Furthermore, an intermediate product on which an insulating layer and / or a conductive layer is to be formed during the manufacturing of a printed wiring board is also included in the "internal layer substrate" as defined in this invention. If the printed wiring board is a circuit board with embedded components, an internal layer substrate with embedded components may be used.

[0169] The lamination of the inner layer substrate and the resin sheet can be performed, for example, by heating and pressing the resin sheet onto the inner layer substrate from the support side. Examples of the heating and pressing member used to heat and press the resin sheet onto the inner layer substrate (hereinafter also referred to as the "heat pressing member") include a heated metal plate (such as a SUS end plate) or a metal roll (such as a SUS roll). The heating and pressing member may be pressed directly onto the resin sheet, or it may be pressed via an elastic material such as heat-resistant rubber so that the resin sheet can adequately follow the surface irregularities of the inner layer substrate.

[0170] Lamination of the inner layer substrate and the resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the heat-pressure temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heat-pressure 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, and the heat-pressure time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination may preferably be carried out under reduced pressure conditions of 26.7 hPa or less.

[0171] Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include vacuum pressure laminators manufactured by Meiki Seisakusho Co., Ltd., vacuum applicators manufactured by Nikko Materials Co., Ltd., and batch-type vacuum pressure laminators.

[0172] After lamination, the laminated resin sheets may be smoothed by pressing a heat-sealing member from the support side under normal pressure (atmospheric pressure). The pressing conditions for the smoothing process can be the same as the heat-sealing conditions for lamination. The smoothing process can be performed using a commercially available laminator. Lamination and smoothing may be performed continuously using the commercially available vacuum laminator mentioned above.

[0173] The support may be removed between steps (I) and (II), or after step (II). If a metal foil is used as the support, the conductive layer may be formed using the metal foil without peeling off the support. If a metal foil with a support substrate is used as the support, the support substrate (and release layer) should be peeled off. Then, the conductive layer can be formed using the metal foil.

[0174] In step (II), the resin composition layer is cured (e.g., by thermal curing) to form an insulating layer made of the cured resin composition. The curing conditions for the resin composition layer are not particularly limited, and conditions commonly used when forming an insulating layer for a printed circuit board may be used.

[0175] For example, the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 140°C to 250°C, more preferably 150°C to 240°C, and even more preferably 180°C to 230°C. The curing time can be preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and even more preferably 15 minutes to 120 minutes.

[0176] Prior to thermal curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermal curing the resin composition layer, it may be preheated at a temperature of 50°C to 140°C, preferably 60°C to 135°C, more preferably 70°C to 130°C for 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.

[0177] In manufacturing printed circuit boards, the following steps may be further performed: (III) drilling holes in the insulating layer, (IV) roughening the insulating layer, and (V) forming the conductor layer. These steps (III) through (V) may be carried out according to various methods known to those skilled in the art that are used in the manufacture of printed circuit boards. If the support is removed after step (II), the removal of the support may be carried out between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Furthermore, if necessary, the formation of the insulating layer and the conductor layer in steps (I) through (V) may be repeated to form a multilayer circuit board.

[0178] In other embodiments, the printed circuit board of the present invention can be manufactured using the prepreg described above. The manufacturing method is basically the same as when a resin sheet is used.

[0179] Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (III) may be carried out using, for example, a drill, laser, plasma, etc., depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be appropriately determined according to the design of the printed circuit board.

[0180] Step (IV) is a process for roughening the insulating layer. Typically, smear removal (desmear) is also performed in this step (IV). The procedure and conditions for the roughening process are not particularly limited, and known procedures and conditions commonly used when forming the insulating layer of a printed circuit board can be adopted. For example, the insulating layer can be roughened by performing swelling treatment with a swelling solution, roughening treatment with an oxidizing agent, and neutralization treatment with a neutralizing solution in this order.

[0181] The swelling solution used for the roughening treatment is not particularly limited, but examples include alkaline solutions and surfactant solutions, and is preferably an alkaline solution, with sodium hydroxide solution and potassium hydroxide solution being more preferred. Examples of commercially available swelling solutions include "Swelling Dip Securing P" and "Swelling Dip Securing SBU" manufactured by Atotec Japan. The swelling treatment with the swelling solution is not particularly limited, but can be carried out, for example, by immersing the insulating layer in a swelling solution at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling solution at 40°C to 80°C for 5 to 15 minutes.

[0182] The oxidizing agent used for the roughening treatment is not particularly limited, but examples include an alkaline permanganate solution obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. The roughening treatment with an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. Furthermore, the concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Attec Japan.

[0183] Furthermore, an acidic aqueous solution is preferred as the neutralizing solution used in the roughening treatment. A commercially available example is "Reduction Solution Securigant P" manufactured by Attec Japan.

[0184] The neutralization treatment can be carried out by immersing the treated surface, which has been roughened with an oxidizing agent, in a neutralization solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, it is preferable to immerse the object, which has been roughened with an oxidizing agent, in a neutralization solution at 40°C to 70°C for 5 to 20 minutes.

[0185] Step (V) is a step of forming a conductive layer, in which a conductive layer is formed on an insulating layer. The conductive material used for the conductive layer is not particularly limited. In a preferred embodiment, the conductive layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductive layer may be a single-metal layer or an alloy layer, and examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). In particular, from the viewpoint of versatility in conductor layer formation, cost, and ease of patterning, single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy are preferred, single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy are more preferred, and single metal layers of copper are even more preferred.

[0186] The conductive layer may be a single-layer structure, or it may be a multi-layer structure in which two or more single-metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductive layer is a multi-layer structure, the layer in contact with the insulating layer is preferably a single-metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

[0187] The thickness of the conductor layer depends on the desired printed circuit board design, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0188] In one embodiment, the conductor layer may be formed by plating. From the viewpoint of facilitating the formation of fine wiring, it is preferable to form it by a semi-additive method. An example of forming the conductor layer by a semi-additive method is shown below.

[0189] First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. After forming a metal layer on the exposed plating seed layer by electroplating, the mask pattern is removed. Subsequently, the unnecessary plating seed layer can be removed by etching or other means to form a conductor layer having the desired wiring pattern.

[0190] In other embodiments, the conductor layer may be formed using metal foil. When forming the conductor layer using metal foil, step (V) is preferably performed between steps (I) and (II). For example, after step (I), the support is removed and the metal foil is laminated onto the surface of the exposed resin composition layer. The lamination of the resin composition layer and the metal foil may be carried out by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Subsequently, the metal foil on the insulating layer can be used to form a conductor layer having a desired wiring pattern by conventional known techniques such as the modified semi-additive method.

[0191] Metal foils can be manufactured by known methods such as electrolysis and rolling. Examples of commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Metals, and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd.

[0192] Alternatively, as mentioned above, if a metal foil or a metal foil with a support substrate is used as the support for the resin sheet, the conductive layer may be formed using the metal foil.

[0193] <Semiconductor package redistribution substrate> In one embodiment, the circuit board of the present invention is a redistribution substrate (redistribution layer) for a semiconductor package. The following description will be based on the manufacturing method of the semiconductor package.

[0194] The semiconductor package includes an insulating layer made of a cured product of the resin composition of the present invention as an insulating layer of the redistribution substrate. The semiconductor package may also include a sealing layer made of a cured product of the resin composition of the present invention.

[0195] A semiconductor package can be manufactured, for example, using the resin composition and resin sheet of the present invention by a method including the following steps (1) to (6). The resin composition and resin sheet of the present invention may be used to form the redistribution layer (insulating layer for forming a redistribution substrate) in step (5) or the sealing layer in step (3). An example of forming a redistribution layer and a sealing layer using the resin composition and resin sheet is shown below, but the techniques for forming redistribution layers and sealing layers of semiconductor packages are well known, and those skilled in the art can manufacture semiconductor packages using the resin composition and resin sheet of the present invention in accordance with known techniques. (1) A step of laminating a temporary fixing film onto the substrate, (2) A step of temporarily fixing the semiconductor chip onto a temporary fixing film, (3) A step of forming a sealing layer on a semiconductor chip, (4) Steps to peel off the substrate and temporary fixing film from the semiconductor chip, (5) A step of forming a rewiring layer as an insulating layer on the surface from which the substrate and temporary fixing film of the semiconductor chip have been peeled off, and (6) Step of forming a redistribution layer as a conductor layer on the redistribution formation layer.

[0196] -Process (1)- The material used for the substrate is not particularly limited. Examples of substrates include semiconductor wafers such as silicon wafers; glass wafers; glass substrates; metal substrates such as copper, titanium, stainless steel, and cold-rolled steel sheets (SPCC); substrates made by impregnating glass fibers with epoxy resin and heat-curing them (e.g., FR-4 substrates); and substrates made of bismaleimidotriazine resin (BT resin).

[0197] The temporary fixing film is not limited in material as long as it can be peeled off from the semiconductor chip in step (4) and temporarily fix the semiconductor chip. Commercially available temporary fixing films can be used. Examples of commercially available products include Riva Alpha manufactured by Nitto Denko Corporation.

[0198] -Process (2)- Temporary fixing of semiconductor chips can be performed using known devices such as flip-chip bonders and die bonders. The layout and number of semiconductor chips can be appropriately set according to the shape and size of the temporary fixing film, the number of semiconductor packages to be produced, etc. For example, they can be temporarily fixed in a matrix arrangement with multiple rows and multiple columns.

[0199] -Process (3)- The resin composition layer of the resin sheet of the present invention is laminated onto a semiconductor chip, or the resin composition of the present invention is applied onto a semiconductor chip and cured (e.g., by heat curing) to form a sealing layer.

[0200] For example, lamination of a semiconductor chip and a resin sheet can be performed by removing the protective film from the resin sheet and then heating and pressing the resin sheet onto the semiconductor chip from the support side. Examples of the heating and pressing member used to heat and press the resin sheet onto the semiconductor chip (hereinafter also referred to as the "heating and pressing member") include a heated metal plate (such as a SUS end plate) or a metal roll (such as a SUS roll). It is preferable to press the resin sheet via an elastic material such as heat-resistant rubber, rather than directly pressing the heating and pressing member onto the resin sheet, so that the resin sheet can adequately follow the surface irregularities of the semiconductor chip. Lamination of the semiconductor chip and the resin sheet may also be carried out by a vacuum lamination method, and the lamination conditions are the same as those described in relation to the manufacturing method of printed circuit boards, and the preferred range is also the same.

[0201] After lamination, the resin composition is heat-cured to form a sealing layer. The heat-curing conditions are the same as those described in relation to the manufacturing method of printed circuit boards.

[0202] The resin sheet support may be peeled off after the resin sheet has been laminated onto the semiconductor chip and heat-cured, or the support may be peeled off before the resin sheet has been laminated onto the semiconductor chip.

[0203] When applying the resin composition of the present invention to form a sealing layer, the application conditions are the same as those for forming the resin composition layer described in relation to the resin sheet of the present invention, and the preferred ranges are also the same.

[0204] -Process (4)- The method for peeling off the substrate and the temporary fixing film can be appropriately changed depending on the material of the temporary fixing film, etc. Examples include a method of peeling off the temporary fixing film by heating and foaming (or expanding) it, and a method of peeling off the temporary fixing film by irradiating it with ultraviolet light from the substrate side to reduce the adhesive strength of the temporary fixing film.

[0205] In the method of peeling off a temporary fixing film by heating and foaming (or expanding) it, the heating conditions are usually 100-250°C for 1-90 seconds or 5-15 minutes. In the method of peeling off a temporary fixing film by irradiating it with ultraviolet light from the substrate side to reduce its adhesive strength, the amount of ultraviolet light irradiated is usually 10 mJ / cm². 2 ~1000 mJ / cm 2 That is the case.

[0206] -Process (5)- The present invention provides a resin composition and resin sheet used to form a rewiring layer (an insulating layer for a rewiring substrate).

[0207] After forming the redistribution layer, via holes may be formed in the redistribution layer to interlayer connect the semiconductor chip with the conductor layer described later. The via holes may be formed by known methods depending on the material of the redistribution layer.

[0208] -Process (6)- The formation of the conductor layer on the rewiring layer may be carried out in the same manner as in step (V) described in relation to the manufacturing method of a printed circuit board. Alternatively, steps (5) and (6) may be repeated to alternately stack the conductor layer (rewiring layer) and the rewiring layer (insulating layer) (build-up).

[0209] In manufacturing a semiconductor package, the following steps may be further performed: (7) forming a solder resist layer on a conductor layer (redistribution layer), (8) forming bumps, and (9) dicing multiple semiconductor packages into individual semiconductor packages to form individual pieces. These steps may be carried out in accordance with various methods known to those skilled in the art that are used in the manufacture of semiconductor packages.

[0210] The present invention provides a resin composition and resin sheet that exhibit excellent dielectric properties, good crack resistance, and good adhesion to the conductor layer when exposed to high temperature and high humidity environments. By forming a redistribution layer (insulating layer) using these resin compositions and resin sheets, it is possible to realize a semiconductor package with extremely low transmission loss, regardless of whether it is a fan-in or fan-out type package, without concerns about a decrease in conductor adhesion. In one embodiment, the semiconductor package of the present invention is a fan-out type package. The resin composition and resin sheet of the present invention can be applied to fan-out panel-level packages (FOPLPs) and fan-out wafer-level packages (FOWLPs). In one embodiment, the semiconductor package of the present invention is a fan-out panel-level package (FOPLP) or a fan-out wafer-level package (FOWLP).

[0211] [Semiconductor device] The semiconductor device of the present invention includes a layer made of a cured product of the resin composition layer of the present invention. The semiconductor device of the present invention can be manufactured using the circuit board of the present invention.

[0212] Examples of semiconductor devices include various types of semiconductor devices used in electrical products (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft). [Examples]

[0213] The present invention will be described in detail below with reference to examples. The present invention is not limited to these examples. In the following, "parts" and "%" refer to "parts by mass" and "mass%" respectively, unless otherwise specified. Unless otherwise specified, the temperature and pressure conditions are room temperature (25°C) and atmospheric pressure (1 atm).

[0214] <Synthesis Example 1: Synthesis of Fine Particle A> Polyphenylene ether resin (Lupiace LN91, manufactured by Mitsubishi Engineering Plastics Corporation) was crushed in methanol solvent using a homomixer (HM-300 model, manufactured by AS ONE Corporation) at 25°C, 8000 rpm, and for 4 hours. The methanol solvent was then dried off, and the polyphenylene ether (PPE) powder was recovered by sieving it through a JIS test sieve with a mesh size of 12 μm. 198 parts of toluene and 3 parts of polystyrene (Polystyrene Japan Co., Ltd. "SX-300") were placed in a flask and stirred to dissolve the polystyrene. Next, 50 parts of pre-prepared PPE powder were added and stirred for 2 hours to obtain a dispersion of PPE particles (20% by mass). This was then used to make fine particles A (average particle size 1.2 μm, 90% particle size D 90 (This was defined as less than 1.8 μm.)

[0215] <Synthesis Example 2: Synthesis of Maleimide Compound B> A MEK solution of maleimide compound B (70% by mass of non-volatile components) was synthesized according to the method described in Synthesis Example 1 of the Japan Institute of Invention and Innovation, Technical Report No. 2020-500211.

[0216] <Synthesis Example 3: Synthesis of Polyimide Resin C> In a flask equipped with a stirrer, thermometer, and condenser, 271.7 parts of propylene glycol methyl ether acetate (PGMAc), 14.1 parts (0.064 mol) of isophorone diisocyanate (IPDI), and 112.2 parts (0.03 mol) of polybutadiene with OH groups at both ends (G-3000, manufactured by Nippon Soda Co., Ltd., hydroxyl value: 30 mg KOH / g) were supplied. The mixed solution was heated to 50°C and held at this temperature for 1 hour. Next, after confirming that the amount of isocyanate groups was below a predetermined value, 145.2 parts (0.09 mol) of oligophenylene ether resin containing phenolic hydroxyl groups at both ends (SA90-100, manufactured by Sabic, hydroxyl equivalent: 807 g / mol) and 1 part (0.003 mol) of benzophenone tetracarboxylic dianhydride (BTDA) were added to the mixed solution. Subsequently, the mixed solution was heated to 140°C and the reaction was continued for 4 hours. Characteristic absorption was measured by infrared spectroscopy, and the characteristic absorption of the isocyanate group was 2270 cm⁻¹. -1 The reaction was terminated after confirming that the absorption peak had completely disappeared and the increase in viscosity had subsided. In this manner, polyimide resin C having a structure in which the molecular ends are sealed with phenolic resin (oligophenylene ether resin containing phenolic hydroxyl groups at both ends) was synthesized. The non-volatile content was 50% by mass.

[0217] <Synthesis Example 4: Synthesis of Polyimide Resin D> A 500 mL separable flask was prepared, equipped with a moisture meter connected to a reflux condenser, a nitrogen inlet tube, and a stirrer. 20.3 g of 4,4'-oxydiphthalic anhydride (ODPA), 200 g of γ-butyrolactone, 20 g of toluene, and 29.6 g of 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindan were added to this flask, and the reaction was carried out by stirring at 45°C for 2 hours under a nitrogen stream. Next, the reaction solution was heated and maintained at approximately 160°C, while azeotropically removing the condensed water with toluene under a nitrogen stream. It was confirmed that the predetermined amount of water had accumulated in the moisture meter and that no further water leakage was observed. After confirmation, the reaction solution was further heated and stirred at 200°C for 1 hour. Subsequently, the solution was cooled to obtain a solution containing polyimide resin D having a 1,1,3-trimethylindan skeleton (20% by mass of non-volatile components). The obtained polyimide resin D had repeating units represented by the following formula (X1) and the following formula (X2). The weight-average molecular weight of polyimide resin D was 12,000.

[0218] [ka]

[0219] [Example 1] (1) Preparation of resin composition Twelve parts of biphenyl-type epoxy resin (NC3000, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent approximately 269 g / eq.) and six parts of bisphenol-type epoxy resin (ZX1059, manufactured by Nippon Steel Chemical & Material Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent approximately 169 g / eq.) were heated and dissolved in 40 parts of methyl ethyl ketone while stirring. This mixture was then cooled to room temperature to prepare the epoxy resin solution. This epoxy resin dissolution composition contains hollow PPE particles (Sekisui Chemical Co., Ltd. "XX-6655Z", average particle size 0.4 μm, 90% particle size D) 903 parts (less than 1 μm), 50 parts of activated ester curing agent (DIC Corporation's "HPC-8151-62T", activated ester group equivalent approximately 240 g / eq., toluene solution with non-volatile component content of 62% by mass), and spherical silica (Admatex Corporation's "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m²) surface-treated with silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM-573"). 2 A resin composition was prepared by mixing 150 parts of triazine skeleton (1 / g), 4 parts of triazine skeleton-containing phenolic curing agent (DIC Corporation's "LA-3018-50P", active group equivalent of approximately 151 g / eq., 2-methoxypropanol solution with 50% non-volatile content), 0.5 parts of imidazole curing accelerator (Shikoku Chemicals Co., Ltd.'s "1B2PZ", 1-benzyl-2-phenylimidazole), and 2 parts of phenoxy resin (Mitsubishi Chemical Corporation's "YX7553BH30", a 1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile content), and uniformly dispersing them in a high-speed rotary mixer.

[0220] (2) Manufacturing of resin sheets A polyethylene terephthalate film (AL5, manufactured by Lintec Corporation, 38 μm thick) with a release layer was prepared as a support. The resin composition prepared in (1) above was uniformly applied to the release layer of this support so that the thickness of the resin composition layer after drying was 40 μm. The resin composition was then dried at 80°C to 100°C (average 90°C) for 4 minutes to obtain a resin sheet having a resin composition layer / support layer structure.

[0221] [Example 2] Except for the following changes, a resin composition was prepared in the same manner as in Example 1 to obtain a resin sheet: (1) the amount of hollow PPE particles (Sekisui Chemical Co., Ltd. "XX-6655Z") was changed from 3 parts to 20 parts; (2) the amount of spherical silica surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-573") (Admatex Co., Ltd. "SO-C2") was changed from 150 parts to 200 parts; (3) an additional 5 parts of styryl resin (Mitsubishi Gas Chemical Co., Ltd. "OPE-2St 2200", a toluene solution with a non-volatile content of 65%) was used; and (4) an additional 4 parts of a carbodiimide-based curing agent (Nisshinbo Chemical Co., Ltd. "V-03", an active group equivalent of approximately 216 g / eq., a toluene solution with a non-volatile content of 50%) was used.

[0222] [Example 3] (1) Instead of hollow PPE particles (“XX-6655Z” manufactured by Sekisui Plastics Co., Ltd.), solid PPE particles (“XX-6714Z” manufactured by Sekisui Plastics Co., Ltd., average particle size 0.7 μm, 90% particle size D 90 (1) Three parts of a toluene solution with an active ester group equivalent of approximately 223 g / eq. and a non-volatile component content of 65% were used instead of the active ester curing agent (DIC Corporation's "HPC-8151-62T"). (2) Fifty parts of an active ester curing agent (DIC Corporation's "HPC-8000-65T", an active ester group equivalent of approximately 223 g / eq., and a non-volatile component content of 65%) were used. (3) Six parts of the imide resin C obtained in Synthesis Example 3 were used in addition. (4) Carbodiimide curing agent (Japanese Except for the addition of 4 parts of a toluene solution of Seibo Chemical Co., Ltd.'s "V-03" (active group equivalent of approximately 216 g / eq., non-volatile component content of 50%), and the change in the amount of spherical silica (Admatex Co., Ltd.'s "SO-C2") surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM-573") from 150 parts to 160 parts, a resin composition was prepared in the same manner as in Example 1 to obtain a resin sheet.

[0223] [Example 4] Except for (1) using 3 parts of solid PPE particles (Sekisui Chemical Co., Ltd. "XX-6714Z", average particle size 0.7 μm) instead of hollow PPE particles (Sekisui Chemical Co., Ltd. "XX-6655Z"), (2) further using 3 parts of bismaleimide compound (DMI Corporation "BMI-1500"), and (3) changing the amount of spherical silica (Admatex Corporation "SO-C2") surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-573") from 150 parts to 160 parts, a resin composition was prepared and a resin sheet was obtained in the same manner as in Example 1.

[0224] [Example 5] Except for (1) changing the amount of hollow PPE particles (XX-6655Z manufactured by Sekisui Chemical Co., Ltd.) from 3 parts to 1 part, (2) replacing 6 parts of bisphenol type epoxy resin (ZX1059 manufactured by Nippon Steel Chemical & Material Co., Ltd.) with 6 parts of bisphenol A type epoxy resin (828EL manufactured by Mitsubishi Chemical Corporation, epoxy equivalent approximately 180), and (3) further using 5 parts of maleimide compound B obtained in Synthesis Example 2, a resin composition was prepared in the same manner as in Example 1, and a resin sheet was obtained.

[0225] [Example 6] (1) Instead of 6 parts of bisphenol type epoxy resin ("ZX1059" manufactured by Nippon Steel Chemical & Material Co., Ltd.), 6 parts of bisphenol A type epoxy resin ("828EL" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent approximately 180) were used. (2) Instead of 50 parts of activated ester curing agent ("HPC-8151-62T" manufactured by DIC Corporation), 50 parts of activated ester curing agent ("HPC-8000-65T" manufactured by DIC Corporation, activated ester group equivalent approximately 223 g / eq., toluene solution with 65% non-volatile component content) were used. (3) Instead of 150 parts of spherical silica ("SO-C2" manufactured by Admatex Co., Ltd.) surface-treated with silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.), spherical silica ("UFP-30" manufactured by Denka Co., Ltd., average particle size 0.3 μm, specific surface area 30.7 m²) were used. 2 / g, carbon content per unit surface area: 0.22 mg / m² 2Except for using 70 parts of (4) the amount of phenoxy resin (YX7553BH30 manufactured by Mitsubishi Chemical Corporation) being changed from 2 parts to 10 parts, the resin composition was prepared in the same manner as in Example 1, and a resin sheet was obtained.

[0226] [Example 7] (1) The amount of active ester curing agent (DIC Corporation's "HPC-8000-65T") was changed from 50 parts to 10 parts, (2) an additional 20 parts of cyanate ester curing agent (Lonza Japan Corporation's "BA230S75", a prepolymer of bisphenol A dicyanate, with a cyanate equivalent of approximately 232 g / eq., and a MEK solution with a non-volatile component content of 75% by mass) were used, (3) a triazine skeleton-containing phenol curing agent (DIC Corporation's "LA-3018-50P") (4) Instead of 4 parts of a 2-methoxypropanol solution with an active group equivalent of approximately 151 g / eq. and a non-volatile content of 50%, 4 parts of a carbodiimide-based curing agent (Nisshinbo Chemical Co., Ltd. "V-03", an active group equivalent of approximately 216 g / eq. and a toluene solution with a non-volatile content of 50%) were used. 2 Except for using 120 parts of (g) and substituting 0.5 parts of (5) imidazole-based curing accelerator (Shikoku Chemicals, Ltd. "1B2PZ", 1-benzyl-2-phenylimidazole) with 1 part of a 1% by mass MEK solution of cobalt(III) acetylacetonate (Tokyo Chemical Industries, Ltd.), a resin composition was prepared in the same manner as in Example 6 to obtain a resin sheet.

[0227] [Example 8] A resin composition was prepared in the same manner as in Example 1, except that 15 parts of fine particles A prepared in Synthesis Example 1 were used instead of 3 parts of hollow PPE particles (XX-6655Z manufactured by Sekisui Chemical Co., Ltd.), and a resin sheet was obtained.

[0228] [Example 9] A resin composition was prepared in the same manner as in Example 1, except that 6 parts of polyimide resin D obtained in Synthesis Example 4 were used instead of 2 parts of phenoxy resin (Mitsubishi Chemical Corporation's "YX7553BH30," a 1:1 solution of MEK and cyclohexanone with 30% by mass of nonvolatile components). A resin sheet was obtained.

[0229] [Comparative Example 1] A resin composition was prepared in the same manner as in Example 1, except that three parts of hollow PPE particles (XX-6655Z, manufactured by Sekisui Chemical Co., Ltd.) were not used, and a resin sheet was obtained.

[0230] [Comparative Example 2] A resin composition was prepared in the same manner as in Example 1, except that three parts of rubber particles (Aica Industries' "Stafiloid AC3816N", average particle size 0.3 μm) were used instead of three parts of hollow PPE particles (Sekisui Chemical Co., Ltd.'s "XX-6655Z"), and a resin sheet was obtained.

[0231] [Comparative Example 3] A resin composition was prepared in the same manner as in Example 1, except that three parts of acrylic particles (MX-80H3wT, average particle size 0.8 μm, manufactured by Soken Chemical Co., Ltd.) were used instead of three parts of hollow PPE particles (XX-6655Z, manufactured by Sekisui Chemical Co., Ltd.), and a resin sheet was obtained.

[0232] [Comparative Example 4] A resin composition was prepared in the same manner as in Example 1, except that three parts of styrene particles (SX-500H, average particle size 5.0 μm, manufactured by Soken Chemical Co., Ltd.) were used instead of three parts of hollow PPE particles (XX-6655Z, manufactured by Sekisui Chemical Co., Ltd.), and a resin sheet was obtained.

[0233] [Comparative Example 5] A resin composition was prepared in the same manner as in Example 6, except that three parts of hollow PPE particles (XX-6655Z, manufactured by Sekisui Chemical Co., Ltd.) were not used, and a resin sheet was obtained.

[0234] [Comparative Example 6] A resin composition was prepared in the same manner as in Example 7, except that three parts of hollow PPE particles (XX-6655Z, manufactured by Sekisui Chemical Co., Ltd.) were not used, and a resin sheet was obtained.

[0235] <Various evaluation tests> [Test Example 1: Measurement of Dielectric Loss Tangent (Df)] The resin sheets prepared in the examples and comparative examples were heated at 200°C for 90 minutes to heat-cur the resin composition layer, and then the support was peeled off to obtain a cured film formed from the cured resin composition. The cured film was cut to a width of 2 mm and a length of 80 mm to obtain cured product A for evaluation.

[0236] The dielectric loss tangent (Df value) of the obtained cured sample A was measured using the cavity resonance perturbation method with an Agilent Technologies HP8362B at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. Measurements were performed on three test specimens, and the average value was calculated.

[0237] [Test Example 2: Evaluation of cracks after desmear treatment (roughening treatment)] As the inner layer substrate, a core material (Hitachi Chemical Co., Ltd. "E705GR", thickness 400 μm) with circular copper pads (copper thickness 35 μm) having a diameter of 350 μm formed in a grid pattern at intervals of 400 μm so that the residual copper ratio becomes 60% was prepared. Then, the resin sheets produced in the examples and comparative examples were laminated on both sides of the inner layer substrate using a batch type vacuum pressure laminator (Nitto Materials Co., Ltd. 2-stage build-up laminator "CVP700") so that the resin composition layer was joined to the inner layer substrate. The lamination was carried out by reducing the pressure for 30 seconds to make the atmospheric pressure 13 hPa or less and then pressure bonding at a temperature of 100 °C and a pressure of 0.74 MPa for 30 seconds. Next, it was put into an oven at 130 °C and heated for 30 minutes, and then transferred to an oven at 170 °C and heated for 30 minutes to thermally cure the resin composition layer to form an insulating layer. After peeling the support to expose the insulating layer, the obtained substrate was immersed in a swelling liquid (Atotech Japan Co., Ltd. "Swelling Dip. Security Gun P") at 60 °C for 10 minutes, then immersed in a roughening liquid (Atotech Japan Co., Ltd. "Concentrate. Compact P", aqueous solution of KMnO4: 60 g / L, NaOH: 40 g / L) at 80 °C for 30 minutes, and finally immersed in a neutralizing liquid (Atotech Japan Co., Ltd. "Reduction Solution. Security Gun P") at 40 °C for 5 minutes. Regarding the processed circuit board, 100 copper pad portions were observed to confirm the presence or absence of cracks in the insulating layer, and evaluation was performed according to the following evaluation criteria.

[0238] Evaluation criteria for crack resistance: 〇: When the number of cracks is 10 or less △: When the number of cracks is more than 10 and 20 or less ×: When the number of cracks is more than 20

[0239] [Test Example 3: Measurement of copper foil peel strength after high temperature and high humidity environment test (HAST)] (1) Substrate treatment of copper foil The glossy surface of the "3EC-III" (electrolytic copper foil, 35 μm) manufactured by Mitsui Kinzoku Kogyo Co., Ltd. was etched by 1 μm with a micro-etching agent ("CZ8101" manufactured by Meck Co., Ltd.) to roughen the copper surface, and then rust prevention treatment (CL8300) was performed. Furthermore, heat treatment was carried out in an oven at 130 °C for 30 minutes. This copper foil is called CZ copper foil.

[0240] (2) Preparation of inner layer substrate Both sides of a glass cloth base epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, "R1515A" manufactured by Panasonic Corporation) on which inner layer circuits were formed were etched by 1 μm with a micro-etching agent ("CZ8101" manufactured by Meck Co., Ltd.) to roughen the copper surface.

[0241] (3) Fabrication of evaluation substrate The resin sheets obtained in the examples and comparative examples were laminated on both sides of the inner layer substrate using a batch type vacuum pressure laminator ("CVP700", a two-stage build-up laminator manufactured by Nichco Materials Co., Ltd.) such that the resin composition layer was in contact with the inner layer substrate. Lamination was carried out by reducing the pressure for 30 seconds to adjust the air pressure to 13 hPa or less, and then pressure bonding at 120 °C and a pressure of 0.74 MPa for 30 seconds. Subsequently, heat pressing was performed at 100 °C and a pressure of 0.5 MPa for 60 seconds to smooth it. After smoothing, the support was peeled off. The treated surface of the CZ copper foil was laminated on the exposed resin composition layer under the same conditions as above. Then, an evaluation substrate having a structure of CZ copper foil / insulating layer / inner layer substrate / insulating layer / CZ copper foil was fabricated by curing the resin composition layer under curing conditions of 200 °C for 90 minutes to form an insulating layer.

[0242] (4) Measurement of copper foil peel strength after HAST The obtained evaluation substrates were subjected to a high-temperature, high-humidity environment test for 100 hours at 130°C and 85%RH using an accelerated life testing apparatus (PM422, manufactured by Kusumoto Kasei Co., Ltd.). After HAST, the evaluation substrates were cut into 150 × 30 mm pieces. A cutter was used to make a 10 mm wide, 100 mm long incision in the copper foil portion of each piece. One end of the incision was peeled off and the piece was grasped with a grip on a tensile testing machine (AC-50C-SL, manufactured by TSE Corporation). The load [kgf / cm] was measured when 35 mm was peeled off vertically at a speed of 50 mm / min at room temperature. The obtained load value was defined as the copper foil peel strength after HAST. The measurement was performed in accordance with JIS C6481.

[0243] [Test Example 4: Evaluation of Undulation] As the inner layer substrate, a core material (Hitachi Chemical Industries, Ltd. "E705GR", thickness 400 μm, copper thickness 35 μm) was prepared, in which circular degassing holes with a diameter of 200 μm were formed in a grid pattern at 2 mm intervals. The resin sheets obtained in the examples and comparative examples were then laminated on both sides of the inner layer substrate using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd. 2-stage build-up laminator "CVP700") so that the resin composition layer was bonded to the inner layer substrate. Lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing at a temperature of 100°C and a pressure of 0.74 MPa for 30 seconds. The resin composition layer was then cured to form an insulating layer by placing it in a 130°C oven and heating for 30 minutes, and then transferring it to a 170°C oven and heating for another 30 minutes. After peeling off the support to expose the insulating layer, the height of the top and bottom of the insulating layer was measured using a non-contact surface roughness meter (WYKO NT3300, B. In Instruments) and evaluated according to the following criteria. Undulation was defined as the difference (μm) between the height of the top and bottom of the insulating layer.

[0244] Criteria for evaluating undulation: ○: When the undulation is 2 μm or less △: When the undulation is greater than 2 μm but less than or equal to 3 μm. ×: When the undulation is greater than 3 μm

[0245] The results for Examples 1-9 and Comparative Examples 1-6 are shown in Table 1.

[0246] [Table 1]

Claims

1. A resin composition comprising (A) polyphenylene ether particles, (B) epoxy resin, (C) curing agent, and (D) inorganic filler, 90% particle size D of component (A) ９０ It is 1.5 μm or less, A resin composition in which the content of component (A) is 0.5% by mass or more and 35% by mass or less, when the total resin component of the resin composition is taken as 100% by mass.

2. The resin composition according to claim 1, wherein the average particle size of component (A) is 5 μm or less.

3. The resin composition according to claim 1, wherein component (C) comprises one or more curing agents selected from the group consisting of (C-1) active ester curing agents, cyanate ester curing agents, and carbodiimide curing agents.

4. The resin composition according to claim 1, wherein the mass ratio of component (C-1) to component (B) (component (C-1) / component (B)) is 1 or more.

5. The resin composition according to claim 1, wherein the content of component (B) is 5% by mass or more when the total resin component of the resin composition is 100% by mass.

6. The resin composition according to claim 1, wherein the content of component (D) is 40% by mass or more when the nonvolatile components of the resin composition are taken as 100% by mass.

7. The resin composition according to claim 1, wherein component (A) is an emulsion polymer or a suspension polymer.

8. The resin composition according to claim 1, wherein component (A) is insoluble in the solvent.

9. The resin composition according to claim 1, for use as an insulating layer for a circuit board.

10. A resin sheet comprising a support and a layer of the resin composition according to any one of claims 1 to 9 provided on the support.

11. The resin sheet according to claim 10, wherein the support is a thermoplastic resin film or a metal foil.

12. A cured product of the resin composition according to any one of claims 1 to 9.

13. A circuit board comprising an insulating layer made of a cured product of the resin composition according to any one of claims 1 to 9.

14. A semiconductor device comprising the circuit board described in claim 13.

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