resin composition

Abstract

The present invention provides a resin composition that can produce an insulating layer with low dielectric loss tangent, excellent crack resistance, and excellent foaming resistance. The solution of the present invention is a resin composition comprising (A) an organic filler material comprising a polymer containing specific repeating units, and (B) a curable resin, wherein the average particle size of the organic filler material (A) is 5 μm or less.

Description

Technical Field

[0001] This invention relates to resin compositions, and sheet-like laminates, resin sheets, circuit boards, semiconductor wafer packages, and semiconductor devices using the resin compositions. Prior Technology

[0002] Insulating layers are typically provided in circuit boards and semiconductor wafer packages. For example, in printed wiring boards, which are a type of circuit board, interlayer insulating layers are sometimes provided as insulating layers. Furthermore, for example, in semiconductor wafer packages, rewiring forming layers are sometimes provided as insulating layers. These insulating layers are typically formed from a cured material obtained by curing a resin composition.

[0003] [Previous Technical Documents] [Patent Literature] Patent Document 1: Japanese Patent Application Publication No. 2020-23714 Patent Document 2: Japanese Patent Application Publication No. 2020-83966 Patent Document 3: Japanese Patent Application Publication No. 2020-136542 Patent document 4: Japanese Patent No. 6859897. Summary of the Invention

[0004] [The problem the invention aims to solve]

[0005] In recent years, with the increasing density of wiring in circuit boards and semiconductor wafer packaging, there is a demand for improving the crack resistance of insulating layers. To improve crack resistance, the inventors have experimented with using organic filler materials. In cured compositions containing suitable organic filler materials, the organic filler material functions as a stress-relieving component, thus promising to improve crack resistance.

[0006] However, the inventors conducted research and found that for resin compositions containing organic filler materials, there are the following first and second problems.

[0007] First, when using conventional organic fillers as stress-relieving components, the dielectric loss tangent of the hardened material sometimes increases, leading to greater transport losses. Furthermore, while some organic fillers, such as polystyrene particles, can improve crack resistance and reduce the dielectric loss tangent, they tend to blister during the reflow process. Here, blistering refers to the phenomenon of the conductor layer bulging and expanding during reflow.

[0008] Therefore, the first objective of the present invention is to provide: a resin composition capable of producing an insulating layer with low dielectric loss tangent, excellent crack resistance and foaming resistance; a sheet-like laminate containing the resin composition and a resin sheet; a circuit board containing a cured copy of the resin composition, a semiconductor wafer package, and a semiconductor device.

[0009] Second, when conventional organic filler materials are used as stress-relieving components, the dielectric loss tangent of the cured resin composition tends to have poor temperature stability at high temperatures. Specifically, the dielectric loss tangent of the cured material at high temperatures tends to be significantly higher than that of the cured material at room temperature. Circuit boards and semiconductor wafer packages typically generate heat during use. Therefore, when using cured materials with a significantly increased dielectric loss tangent at high temperatures, as mentioned above, transmission losses may sometimes increase at high temperatures. Furthermore, when conventional organic filler materials are used, the insulation reliability of the insulating layer tends to be poor.

[0010] Therefore, the second objective of the present invention is to provide: a resin composition that provides an insulating layer with excellent crack resistance, high temperature stability at high temperatures with a dielectric loss tangent, and excellent insulation reliability; a sheet-like laminate containing the resin composition and a resin sheet; a circuit board containing a cured copy of the resin composition; a semiconductor wafer package; and a semiconductor device. [Methods used to solve problems]

[0011] The inventors conducted diligent research to understand the aforementioned problems. As a result, the inventors discovered that the following resin composition can solve the aforementioned problems; the resin composition comprises: (A) an organic filler material containing a polymer with specific repeating units and (B) a curable resin, wherein the average particle size of the organic filler material (A) is within a specific range; thus, the present invention was completed. That is, the present invention comprises the following.

[0012] <1> A resin composition comprising: (A) an organic filler material comprising a polymer containing repeating units as shown in formula (1) below, and (B) a curable resin, (A) The average particle size of the organic filler material is less than 5 μm. [Chemical Formula 1] (in equation (1), Ra independently represents either a hydrogen atom or a monovalent saturated hydrocarbon group. Rb represents a hydrogen atom or a monovalent hydrocarbon group that may have substituents. <2> like <1> The described resin composition further includes (C) an inorganic filler material; <3> like <1> or <2> The resin composition described herein, wherein (B) the curable resin comprises one or more selected from epoxy resin, phenolic resin, reactive ester resin, cyanate ester resin, (meth)acrylic resin, styrene resin, acrylic resin, and maleimide resin; <4> like <1> ~ <3> The resin composition described in any one of the following, wherein particles of organic filler material (A) are contained in the shell portion exposed on the surface of the particles of organic filler material (A), The aforementioned shell portion comprises a polymer containing repeating units as shown in formula (1); <5> like <1> ~ <4> The resin composition described in any one of the following, wherein (A) the average particle size of the organic filler material is less than 1 μm; <6> like <1> ~ <5> The resin composition described in any one of the following, wherein (B) the curing resin comprises an active ester resin; <7> like <1> ~ <6> The resin composition described in any one of the following, wherein, The rate of increase of Df(100℃) relative to Df(25℃) is less than 20%. Df(25℃) represents the dielectric loss tangent at 25℃ of the cured material obtained by heat-treating the resin composition at 200℃ for 90 minutes. Df(100℃) represents the dielectric loss tangent at 100℃ of the cured material obtained by heat-treating the resin composition at 200℃ for 90 minutes; <8> like <1> ~ <7> The resin composition described in any one of the following, wherein, relative to 100% by mass of the non-volatile components of the resin composition, the amount of (A) organic filler material is 0.2% by mass or more and 5% by mass or less; <9> like <1> ~ <8> The resin composition described in any one of the following is used to form an insulating layer; <10> A hardened substance, which is <1> ~ <9> The hardened product of the resin composition described in any one of them; <11> A sheet-like laminated material, comprising <1> ~ <9> The resin composition described in any one of them; <12> A resin sheet comprising a support and a resin composition layer formed on the support. The resin composition layer includes <1> ~ <9> The resin composition described in any one of them; <13> A circuit board comprising <1> ~ <9> The hardened product of the resin composition described in any one of them; <14> A semiconductor wafer package comprising <1> ~ <9> The hardened product of the resin composition described in any one of them; <15> A semiconductor device having <13> The circuit board described; <16> A semiconductor device having <14> The semiconductor wafer packaging described herein.

[0013] Specifically, from the perspective of solving the first problem, the following is expected: <i-1>A resin composition comprising: (A) an organic filler material comprising a polymer containing repeating units of the aforementioned formula (1), and (B) a curable resin. (A) The average particle size of the organic filler material is less than 5 μm; <i-2>like <i-1>The described resin composition further includes (C) an inorganic filler material; <i-3>like <i-1>or <i-2>The resin composition described herein, wherein (B) the curable resin comprises one or more selected from epoxy resin, phenolic resin, reactive ester resin, cyanate ester resin, (meth)acrylic resin, styrene resin, acrylic resin, and maleimide resin; <i-4>like <i-1> ~ <i-3>The resin composition described in any one of the following, wherein particles of organic filler material (A) are contained in the shell portion exposed on the surface of the particles of organic filler material (A), The aforementioned shell portion comprises a polymer containing repeating units as shown in formula (1); <i-5>like <i-1> ~ <i-4>The resin composition described in any one of the following, wherein (A) the average particle size of the organic filler material is less than 1 μm; <i-6>like <i-1> ~ <i-5>The resin composition described in any one of the following is used to form an insulating layer; <i-7>A hardened substance, which is <i-1> ~ <i-6>The hardened product of the resin composition described in any one of them; <i-8>A sheet-like laminated material, comprising <i-1> ~ <i-6>The resin composition described in any one of them; <i-9>A resin sheet comprising a support and a resin composition layer formed on the support. The resin composition layer includes <i-1> ~ <i-6>The resin composition described in any one of them; <i-10>A circuit board comprising <i-1> ~ <i-6>The hardened product of the resin composition described in any one of them; <i-11>A semiconductor wafer package comprising <i-1> ~ <i-6>The hardened product of the resin composition described in any one of them; <i-12>A semiconductor device having <i-10>The circuit board or described <i-11>The semiconductor wafer packaging described herein.

[0014] Furthermore, from the perspective of solving the second problem, the following content is preferred: <ii-1>A resin composition comprising: (A) an organic filler material comprising a polymer containing repeating units of the aforementioned formula (1), and (B) a curable resin. (A) The average particle size of the organic filler material is less than 5 μm; <ii-2>like <ii-1>The described resin composition further includes (C) an inorganic filler material; <ii-3>like <ii-1>or <ii-2>The resin composition described herein, wherein (B) the curable resin comprises one or more selected from epoxy resin, phenolic resin, reactive ester resin, cyanate ester resin, (meth)acrylic resin, styrene resin, acrylic resin, and maleimide resin; <ii-4>like <ii-1> ~ <ii-3>The resin composition described in any one of the following, wherein particles of organic filler material (A) are contained in the shell portion exposed on the surface of the particles of organic filler material (A), The aforementioned shell portion comprises a polymer containing repeating units as shown in formula (1); <ii-5>like <ii-1> ~ <ii-4>The resin composition described in any one of the following, wherein (B) the curing resin comprises an active ester resin; <ii-6>like <ii-1> ~ <ii-5>The resin composition described in any one of the following, wherein, The rate of increase of Df(100℃) relative to Df(25℃) is less than 20%. Df(25℃) represents the dielectric loss tangent at 25℃ of the cured material obtained by heat-treating the resin composition at 200℃ for 90 minutes. Df(100℃) represents the dielectric loss tangent at 100℃ of the cured material obtained by heat-treating the resin composition at 200℃ for 90 minutes; <ii-7>like <ii-1> ~ <ii-6>The resin composition described in any one of the following, wherein, relative to 100% by mass of the non-volatile components of the resin composition, the amount of (A) organic filler material is 0.2% by mass or more and 5% by mass or less; <ii-8>like <ii-1> ~ <ii-7>The resin composition described in any one of the following is used to form an insulating layer; <ii-9>A hardened substance, which is as follows <ii-1> ~ <ii-8>The hardened product of the resin composition described in any one of them; <ii-10>A sheet-like laminated material, containing <ii-1> ~ <ii-8>The resin composition described in any one of them; <ii-11>A resin sheet comprising a support and a resin composition layer formed on the support. The resin composition layer includes <ii-1> ~ <ii-8>The resin composition described in any one of them; <ii-12>A circuit board comprising <ii-1> ~ <ii-8>The hardened product of the resin composition described in any one of them; <ii-13>A semiconductor wafer package comprising <ii-1> ~ <ii-8>The hardened product of the resin composition described in any one of them; <ii-14>A semiconductor device having <ii-12>The circuit board or described <ii-13>The semiconductor wafer packaging described herein. [Invention Effects]

[0015] According to the resin composition of the present invention, at least one of the following first and second effects can be obtained: First, according to the present invention, it is possible to provide: a resin composition capable of producing an insulating layer with low dielectric loss tangent, excellent crack resistance and blister resistance; a sheet-like laminate containing the resin composition and a resin sheet; a circuit board containing the cured resin composition, a semiconductor wafer package, and a semiconductor device; Second, according to the present invention, it is possible to provide: a resin composition that provides an insulating layer with excellent crack resistance, high temperature stability at high temperatures with a dielectric loss tangent, and excellent insulation reliability; a sheet-like laminate containing the resin composition and a resin sheet; a circuit board containing the cured resin composition, a semiconductor wafer package, and a semiconductor device. Simple Explanation of the Diagram

[0016] [Figure 1] is a schematic cross-sectional view of a fan-out type WLP, which is an example of a semiconductor wafer package, according to one embodiment of the present invention. Implementation

[0017] Hereinafter, embodiments and examples of the present invention will be described. However, the present invention is not limited to the embodiments and examples shown below, and may be implemented in any way without departing from the scope of the claims and their equivalents.

[0018] In the following description, the term "(meth)acrylic acid" includes acrylic acid, methacrylic acid, and combinations thereof. Furthermore, the term "(meth)acrylate" includes acrylates, methacrylates, and combinations thereof.

[0019] In the following explanation, the term "dielectric constant" refers to the relative permittivity.

[0020] <Summary of the resin composition of the first embodiment> The resin composition of the first embodiment of the present invention comprises (A) an organic filler and (B) a curable resin. The (A) organic filler comprises a polymer containing repeating units as shown in formula (1). Moreover, the (A) organic filler has an average particle size within a specific range. Hereinafter, the polymer containing repeating units as shown in formula (1) will be appropriately referred to as "polymer (1)".

[0021] [Chemical Formula 2] (in equation (1), Ra independently represents either a hydrogen atom or a monovalent saturated hydrocarbon group. Rb represents a hydrogen atom or a monovalent hydrocarbon group that may have substituents.

[0022] According to the resin composition of the first embodiment, an insulating layer with low dielectric loss tangent, excellent crack resistance, and excellent foaming resistance can be obtained. Furthermore, this insulating layer typically possesses a low relative permittivity.

[0023] [] <Regarding the organic filler material of the first embodiment (A)> The resin composition of the first embodiment of the present invention includes an organic filler material (A) as component (A). The organic filler material (A) exists in the resin composition in a particulate form and is typically contained in the cured material in a state that maintains the particulate form.

[0024] (A) The organic filler material comprises a polymer (1) containing repeating units as shown in formula (1). The (A) organic filler material containing polymer (1) generally plays a role in relieving stress in the cured resin composition, thus improving the crack resistance of the cured material. In addition, the cured material generally has low polarity, thus reducing dielectric properties such as dielectric loss tangent.

[0025] [Chemical Formula 3] .

[0026] In formula (1), Ra independently represents either a hydrogen atom or a monovalent saturated hydrocarbon group. The monovalent saturated hydrocarbon group can be a chain hydrocarbon group without a ring structure or a cyclic hydrocarbon group containing a ring structure. Preferably, the monovalent saturated hydrocarbon group is an alkyl group. Furthermore, the number of carbon atoms in the monovalent saturated hydrocarbon group as Ra is typically 1 or more, typically 12 or less, preferably 8 or less, and particularly preferably 6 or less. Examples of preferred monovalent saturated hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl; and cycloalkyl groups such as cyclohexyl. Preferably, Ra is a hydrogen atom.

[0027] In formula (1), Rb represents a hydrogen atom or a monovalent hydrocarbon group that may have substituents. The monovalent hydrocarbon group can be a chain hydrocarbon group without a ring structure or a cyclic hydrocarbon group containing a ring structure. Furthermore, the monovalent hydrocarbon group can be a saturated hydrocarbon group or an unsaturated hydrocarbon group. Moreover, the monovalent hydrocarbon group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The number of carbon atoms in the monovalent hydrocarbon group as Rb is usually 1 or more, usually 18 or less, preferably 12 or less, more preferably 8 or less, and particularly preferably 6 or less. Examples of preferred monovalent hydrocarbon groups include: alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl; alkenyl groups such as vinyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl and naphthyl; and alkylaryl groups such as methylphenyl and ethylphenyl.

[0028] The monovalent hydrocarbon group of Rb can have substituents. The phrase "may have substituents" refers to both the case where the hydrogen atoms of the hydrocarbon group are not substituted by a substituent and the case where some or all of the hydrogen atoms of the hydrocarbon group are substituted by a substituent. Examples of substituents include: halogen atoms, alkoxy groups, cycloalkyloxy groups, aryloxy groups, arylalkoxy groups, monovalent heterocyclic groups, amino groups, silylalkyl groups, acetyl groups, acetyloxy groups, carboxyl groups, sulfonyl groups, cyano groups, nitro groups, hydroxyl groups, mercapto groups, and oxo groups. Among these, hydroxyl and carboxyl groups are preferred, and carboxyl groups are particularly preferred.

[0029] In the foregoing, Rb is preferably a monovalent cyclic hydrocarbon group that may have substituents, more preferably an aryl group that may have hydroxyl, carboxyl or alkyl groups, even more preferably an aryl group that may have hydroxyl or carboxyl groups, even more preferably an aryl group that may have carboxyl groups, even more preferably an unsubstituted aryl group, and particularly preferably a phenyl group.

[0030] As an example of the repeating unit shown in equation (1), the structures shown in equations (1-1) to (1-5) can be cited below. Among them, the repeating unit shown in equation (1-1) and the repeating unit shown in equation (1-5) are preferred.

[0031] [] [Chemical Formula 4] .

[0032] Polymer (1) preferably contains a large amount of repeating units as shown in formula (1), or may contain only repeating units as shown in formula (1). The amount of repeating units as shown in formula (1) is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, particularly preferably 90% by mass or more, and usually less than 100% by mass, relative to 100% by mass of the total mass of polymer (1).

[0033] Polymer (1) can be a homopolymer or a copolymer. Therefore, polymer (1) can be a homopolymer containing only one type of repeating unit as shown in formula (1), or a copolymer containing two or more types of repeating units as shown in formula (1). Furthermore, polymer (1) can be a copolymer containing repeating units as shown in formula (1) and any combination of repeating units not represented by formula (1).

[0034] When polymer (1) is a copolymer containing any repeating unit, the repeating unit may have a structure formed by polymerizing any monomer. Examples of any monomer include: methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, glycidyl methacrylate, etc.; (meth)acrylic acid; N-substituted maleimide, N-phenylmaleimide, etc.; maleimide; α,β-unsaturated carboxylic acid, maleic acid, itaconic acid, etc. Any monomer may be used alone or in combination. Therefore, polymer (1) may contain only one repeating unit or may contain a combination of two or more repeating units.

[0035] The amount of any repeating unit in polymer (1) is preferably small. The amount of any repeating unit is preferably less than 70% by mass, more preferably less than 50% by mass, further preferably less than 30% by mass, particularly preferably less than 10% by mass, and may also be 0% by mass, relative to 100% by mass of the total mass of polymer (1).

[0036] The glass transition temperature of polymer (1) is preferably above 20°C, more preferably above 50°C, particularly preferably above 80°C, preferably below 180°C, more preferably below 150°C, and particularly preferably below 120°C. The glass transition temperature of polymer (1) can be determined by DSC (differential scanning calorimetry) at a heating rate of 10°C / min.

[0037] (A) The organic filler material preferably contains a large amount of polymer (1), but may also contain only polymer (1). The amount of polymer (1) relative to 100% by mass of (A) organic filler material is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, particularly preferably 90% by mass or more, and usually less than 100% by mass.

[0038] In the organic filler material (A), any component may be included in combination with polymer (1). Examples of any component other than polymer (1) that may be included in the organic filler material (A) include, for example, any polymer. Examples of any polymer include, for example, acrylic polymers such as poly(methyl)acrylate, poly(ethyl)acrylate, poly(propyl)acrylate, poly(butyl)acrylate, poly(cyclohexyl)methacrylate, and poly(octyl)methacrylate; and polysiloxane polymers such as polydimethylsiloxane. Any component may be used alone or in combination of two or more.

[0039] (A) The amount of any component in the organic filler material is preferably small. Relative to 100% by mass of (A) organic filler material, the amount of any component that (A) organic filler material may contain is preferably 70% by mass or less, more preferably 50% by mass or less, further preferably 30% by mass or less, particularly preferably 10% by mass or less, or may be 0% by mass.

[0040] For particles of organic filler material (A), the particle may have a uniform composition or a non-uniform composition. When distinguishing the components contained in a particle of organic filler material (A) based on its composition, the particle is typically contained in a shell portion exposed on the particle's surface. This shell portion corresponds to the outermost layer of the particle of organic filler material (A). Therefore, a particle of organic filler material (A) with a uniform composition can be understood as the particle being entirely formed by a shell portion. Furthermore, a particle of organic filler material (A) with a non-uniform composition may have a shell portion and a core portion formed within the shell portion. In this case, the particle of organic filler material (A) may further contain arbitrary portions within the core portion, or arbitrary portions between the shell portion and the core portion. Here, the shell portion and the core portion may not be explicitly distinguished, and the boundary between them may be unclear. Further, the core portion may be covered by the shell portion, or it may not be completely covered. Further, the particle of organic filler material (A) may have a hollow portion within the shell portion.

[0041] From the viewpoint of significantly maximizing the effects of the present invention, the aforementioned shell portion preferably contains polymer (1). The shell portion preferably contains a large amount of polymer (1), but may also contain only polymer (1). The range of the amount of polymer (1) relative to 100% by mass of the shell portion can be the same as the range of the amount of polymer (1) relative to 100% by mass of the (A) organic filler material described above. When the shell portion contains polymer (1), the aggregation of particles of the (A) organic filler material can be effectively suppressed, thus effectively utilizing the effects brought about by the (A) organic filler material. Furthermore, particularly when the particle composition of the (A) organic filler material includes both the shell portion and the core portion, the degree of freedom in the composition of the core portion covered by the shell portion can be increased.

[0042] Regarding commercially available organic filler materials (A) containing the aforementioned polymer (1), examples of organic filler materials with an average particle size of 1 μm or less include: "SEP-03T3", "SEP-03T3A", "SSD-001T", "SEP-03T4", "SEP-03T3AB", "SEP-03T3AC", and "SEP-03T3AD" manufactured by Negami Kogyo Co., Ltd.; Sekisui Chemicals Co., Ltd. Examples of organic fillers with average particle sizes greater than 1 μm include: AICA Industries' "XX-6283Z", "XX-6288Z", "XX-6145Z", "XX-6229Z", "XX-6283Z", "XX-6214Z (hollow polystyrene)", and "XX-6430Z (hollow polystyrene)"; AICA Industries' "PS-050-1" and "PS-050-2"; and Morimoto Chemical's "SB-25N". Furthermore, examples of organic fillers with average particle sizes greater than 1 μm include: AICA Industries' "GS-0305" (average particle size 3 μm); Morimoto Chemical's "SB-25" (average particle size 2.5 μm); and Soken Chemical's "SX-130H" (average particle size 1.3 μm).

[0043] (A) Organic filler materials can be used alone or in combination of two or more.

[0044] (A) The organic filler material has an average particle size within a specific range. Specifically, the average particle size of (A) the organic filler material is typically 5 μm or less, preferably 3 μm or less, and particularly preferably 1 μm or less. When the average particle size of (A) the organic filler material is as small as described above, not only can the dielectric loss tangent and crack resistance be improved, but also the blistering resistance can be improved. Details are as follows. Cured products containing organic filler material containing polymer (1) have historically tended to have low adhesion between the insulating layer and the conductor layer serving as the substrate. Therefore, conventionally, when a conductor layer is formed on an insulating layer formed using the cured product and a reflow treatment is performed, the insulating layer peels off from the conductor layer serving as the substrate, and the conductor layer on the insulating layer tends to bulge, thus easily generating blistering. In contrast, in the first embodiment of the present invention, by using (A) the organic filler material having an average particle size within a specific range, excellent crack resistance and dielectric properties are achieved, while blistering suppression is realized. The ability to suppress foaming by controlling the average particle size of the organic filler material (A) is an effect first discovered by the inventors, and can be said to be an effect unexpected from conventional technical knowledge. There is no particular limitation on the lower limit of the average particle size of the organic filler material (A), for example, it can be 0.01 μm or more, 0.05 μm or more, 0.1 μm or more, etc.

[0045] The average particle size of the organic filler material (A) can be measured using a laser diffraction particle size distribution measuring device (e.g., the "SALD-2100" manufactured by Shimadzu Corporation). Using this measuring device, the volume average particle size can be measured as the average particle size of the organic filler material (A). The measurement can be performed by dispersing the organic filler material (A) in an organic solvent that does not dissolve the organic filler material (A). As the organic solvent, to suppress the aggregation of the organic filler material (A), a low-polarity or medium-polarity solvent is typically used; toluene or tetrahydrofuran (THF) is preferred.

[0046] (A) Organic filler materials may or may not require surface treatment. Examples of surface treatment agents for (A) organic filler materials include: inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid; carboxylic acids such as acetic acid, propionic acid, butyric acid, and acrylic acid; sulfonic acids such as p-toluenesulfonic acid, ethylsulfonic acid, and dodecylbenzenesulfonic acid; organic acids such as polyoxyethylene alkyl ether phosphates; silane coupling agents such as tetraethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, 3-(meth)propenyloxypropyltrimethoxysilane, and 8-(meth)propenyloxyoctyltrimethoxysilane; and isocyanate compounds such as ethyl isocyanate. A single surface treatment agent may be used, or two or more may be used in combination.

[0047] The amount of (A) organic filler material contained in the resin composition of the first embodiment of the present invention is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, more preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of (A) organic filler material is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thereby generally reduce the relative permittivity of the insulating layer.

[0048] The amount of (A) organic filler material included in the resin composition of the first embodiment of the present invention is preferably 0.2% by mass or more, more preferably 1% by mass or more, particularly preferably 2% by mass or more, more preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less, relative to 100% by mass of the resin content of the resin composition. The resin content of the resin composition refers to the content from which (C) inorganic filler material has been removed from the non-volatile components of the resin composition. When the amount of (A) organic filler material is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thereby generally reduces the relative permittivity of the insulating layer.

[0049] [] <Regarding the first embodiment (B) curing resin> The resin composition of the first embodiment of the present invention comprises a curable resin (B) as component (B). The curable resin (B) does not contain any substances belonging to component (A) described above. The curable resin (B) may be a thermosetting resin, a photosetting resin, or a combination thereof. Furthermore, a single curable resin may be used, or two or more may be used in combination.

[0050] Examples of curable resins include epoxy resins, phenolic resins, reactive ester resins, cyanate ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, thiol resins, and free radical polymerizable resins. Curable resins can be used alone or in combination of two or more.

[0051] In particular, from the viewpoint of achieving significant effects of the present invention, it is preferable to use an "epoxy resin" in combination with a "resin that can react with the epoxy resin to harden the resin composition." Hereinafter, the resin that can react with the epoxy resin to harden the resin composition is sometimes referred to as a "hardener." Examples of hardeners include: phenolic resins, reactive ester resins, cyanate ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. Among hardeners, phenolic resins, reactive ester resins, cyanate ester resins, and carbodiimide resins are preferred. Furthermore, a single hardener may be used, or two or more may be used in combination.

[0052] Epoxy resin is a curable resin containing epoxy groups. Examples of epoxy resins include: bixylenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butylcatechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, and cresol novolac. Epoxy resins include novolac type, phenolic alkyl type, biphenyl type, linear aliphatic epoxy resin, butadiene-structured epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, spirocyclic epoxy resin, cyclohexane type, cyclohexanediol type, naphthyl ether type, tris(hydroxymethyl) type, tetraphenylethane type, isocyanurate type, and phenol phthalimidine type epoxy resin, etc. Epoxy resins can be used alone or in combination of two or more.

[0053] From the perspective of obtaining a cured product with excellent heat resistance, epoxy resins containing aromatic structures are preferable. Aromatic structures refer to chemical structures generally defined as aromatic, and also include polycyclic aromatics and aromatic heterocycles. Examples of epoxy resins containing aromatic structures include: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol phenolic varnish type epoxy resin, phenolic phenolic varnish type epoxy resin, tert-butylcatechol type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, bixylenol type epoxy resin, glycidylamine type epoxy resin with aromatic structures, and glycidylamine type epoxy resin with aromatic structures. Ester-type epoxy resins, cresol-phenolic varnish-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins with aromatic structures, butadiene-type epoxy resins with aromatic structures, alicyclic epoxy resins with aromatic structures, heterocyclic epoxy resins, spirocyclic epoxy resins with aromatic structures, cyclohexane-diethanol-type epoxy resins with aromatic structures, naphthyl ether-type epoxy resins, tris(hydroxymethyl)-type epoxy resins with aromatic structures, and tetraphenylethane-type epoxy resins with aromatic structures, etc.

[0054] In (B) curable resins, epoxy resins are preferably epoxy resins containing two or more epoxy groups per molecule. The proportion of epoxy resins containing two or more epoxy groups per molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more, relative to 100% by mass of the non-volatile components of the epoxy resin.

[0055] Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter sometimes referred to as "solid epoxy resins"). In a resin composition, the epoxy resin may consist only of liquid epoxy resin, or it may consist only of solid epoxy resin; preferably, it comprises a combination of liquid and solid epoxy resins.

[0056] As a liquid epoxy resin, it is preferable to be a liquid epoxy resin having two or more epoxy groups in one molecule.

[0057] As liquid epoxy resins, 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, phenolic varnish type epoxy resin, alicyclic epoxy resin with ester skeleton, cyclohexane type epoxy resin, cyclohexanediethanol type epoxy resin, and epoxy resin with butadiene structure are preferred.

[0058] Specific examples of liquid epoxy resins include: DIC's "HP4032", "HP4032D", and "HP4032SS" (naphthalene-type epoxy resin); and Mitsubishi Chemical's "828US", "828EL", "jER828EL", "825", and "EPIKOTE". 828EL (Bisphenol A type epoxy resin); "jER807" and "1750" (Bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (Phenolic varnish type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", and "604" (Glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (Glycidyl ester type epoxy resin) manufactured by ADEKA Corporation; "EP-3950L" and "EP-3980S" (Glycidylamine type epoxy resin) manufactured by ADEKA Corporation; "EP-4088S" (Dicyclopentadiene type epoxy resin) manufactured by ADEKA Corporation; "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; Nagase ChemteX's "EX-721" (glycidyl ester type epoxy resin); Daicel's "Celloxide 2021P" (alicyclic epoxy resin with an ester skeleton); Daicel's "PB-3600"; Nippon Soda's "JP-100" and "JP-200" (epoxy resins with a butadiene structure); and Nippon Steel Chemical Materials' "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin), etc. These can be used alone or in combination of two or more.

[0059] As a solid epoxy resin, it is preferable to be a solid epoxy resin having three or more epoxy groups per molecule, and more preferably an aromatic solid epoxy resin having three or more epoxy groups per molecule.

[0060] As solid epoxy resins, the preferred types are xylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol phenolic varnish-type epoxy resins, cresol phenolic varnish-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthyl ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, and phenol benzopyrrolidone-type epoxy resins.

[0061] Specific examples of solid epoxy resins include: DIC's "HP4032H" (naphthalene-type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC's "N-690" (cresol-phenolic varnish type epoxy resin); DIC's "N-695" (cresol-phenolic varnish type epoxy resin); DIC's "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene type epoxy resins); and DIC's "EXA-7311", "EXA-7311-G3", and "EXA..." -7311-G4, EXA-7311-G4S, HP6000 (naphthyl ether type epoxy resin); EPPN-502H (triphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; NC7000L (naphthol phenolic varnish type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; NC3000H, NC3000, NC3000L, NC3000FH, NC3100 (biphenyl type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; ESN475V, ESN4100V (naphthalene type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; ESN485 (naphthol type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd. "ESN375" (dihydroxynaphthalene type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", and "YL7890" manufactured by Mitsubishi Chemical Corporation. (Bis(xylenol) type epoxy resin); Mitsubishi Chemical Corporation's "YL6121" (biphenyl type epoxy resin); Mitsubishi Chemical Corporation's "YX8800" (anthracene type epoxy resin); Mitsubishi Chemical Corporation's "YX7700" (phenolic alkyl type epoxy resin); Osaka Gas Chemical Co., Ltd.'s "PG-100" and "CG-500"; Mitsubishi Chemical Corporation's "YX7760" (bisphenol AF type epoxy resin); Mitsubishi Chemical Corporation's "YL7800" (fluorene type epoxy resin); Mitsubishi Chemical Corporation's "jER1010" (bisphenol A type epoxy resin); Mitsubishi Chemical Corporation's "jER1031S" (tetraphenylethane type epoxy resin); Nippon Kayaku Co., Ltd.'s "WHR991S" (phenol benzopyrrolidone type epoxy resin), etc. These can be used alone or in combination.

[0062] When liquid epoxy resin and solid epoxy resin are used in combination, the mass ratio (liquid epoxy resin: solid epoxy resin) is preferably 20:1 to 1:20, more preferably 10:1 to 1:10, and particularly preferably 7:1 to 1:7.

[0063] The epoxy equivalent of epoxy resin is preferably 50 g / eq. to 5000 g / eq., more preferably 60 g / eq. to 3000 g / eq., further preferably 80 g / eq. to 2000 g / eq., and particularly preferably 110 g / eq. to 1000 g / eq. Epoxy equivalent represents the mass of resin corresponding to one equivalent of epoxy groups. This epoxy equivalent can be determined according to JIS K7236.

[0064] The weight-average molecular weight (Mw) of epoxy resin is preferably 100–5000, more preferably 250–3000, and even more preferably 400–1500. The weight-average molecular weight of epoxy resin can be determined by gel permeation chromatography (GPC) as a value converted from polystyrene.

[0065] The amount of epoxy resin in the resin composition is preferably 1% or more by mass, more preferably 2% or more by mass, particularly preferably 5% or more by mass, more preferably 50% or less by mass, more preferably 40% or less by mass, and particularly preferably 30% or less by mass, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of epoxy resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and foaming resistance of the insulating layer, and thus can generally reduce the relative permittivity of the insulating layer.

[0066] The amount of epoxy resin in the resin composition, relative to 100% by mass of the resin content of the resin composition, is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, preferably 80% by mass or less, more preferably 70% by mass or less, and particularly preferably 60% by mass or less. When the amount of epoxy resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and foaming resistance of the insulating layer, and thus generally can reduce the relative permittivity of the insulating layer.

[0067] As phenolic resins, compounds having one or more, preferably two or more, hydroxyl groups bonded to aromatic rings such as benzene or naphthalene rings in one molecule can be used. When combined with epoxy resins, phenolic resins can react with the epoxy resins to harden the resin composition; therefore, they are sometimes called "phenolic curing agents." From the viewpoint of heat resistance and water resistance, phenolic resins with a novolac structure are preferred. Furthermore, from the viewpoint of adhesion, nitrogen-containing phenolic resins are preferred, and phenolic resins containing a triazine skeleton are even more preferred. Among these, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, phenolic novolac resins containing a triazine skeleton are preferred. Specific examples of phenolic resins include: MEH-7700, MEH-7810, MEH-7851 manufactured by Meiwa Kasei Corporation; NHN, CBN, GPH manufactured by Nippon Kayaku Co., Ltd.; SN-170, SN-180, SN-190, SN-475, SN-485, SN-495, SN-375, SN-395 manufactured by Nippon Steel Chemical Materials Co., Ltd.; and LA-7052, LA-7054, LA-3018, LA-3018-50P, LA-1356, TD2090, TD-2090-60M manufactured by DIC Corporation.

[0068] The amount of phenolic resin in the resin composition, relative to 100% by mass of the non-volatile components of the resin composition, is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less. When the amount of phenolic resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally reduce the relative permittivity of the insulating layer.

[0069] The amount of phenolic resin in the resin composition, relative to 100% by mass of the resin content of the resin composition, is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 3% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less. When the amount of phenolic resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally can reduce the relative permittivity of the insulating layer.

[0070] As reactive ester resins, compounds with two or more highly reactive ester groups in one molecule, such as phenolic esters, thiophenolic esters, N-hydroxyamine esters, and heterocyclic hydroxyl compounds, are generally preferred. When combined with epoxy resins, reactive ester resins can react with the epoxy resins to harden the resin composition; therefore, they are sometimes called "reactive ester-based curing agents." These reactive ester resins are preferably compounds obtained through the condensation reaction of carboxylic acid compounds and / or thiocarboxylic acid compounds with hydroxyl compounds and / or thiols. Especially from the viewpoint of improving heat resistance, reactive ester resins obtained from carboxylic acid compounds and hydroxyl compounds are preferred, and reactive ester resins obtained from carboxylic acid compounds and phenolic compounds and / or naphthol compounds are even more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenolic or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthol, 1,6-dihydroxynaphthol, 2,6-dihydroxynaphthol, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, pyroglucinol, dicyclopentadiene-type diphenol compounds, and phenolic novolac resins. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

[0071] Specifically, the preferred active ester resins are dicyclopentadiene-type active ester resins, naphthalene-type active ester resins containing a naphthalene structure, acetylated active ester resins containing phenolic varnish resins, and benzoylated active ester resins containing phenolic varnish resins. More preferably, they are selected from at least one of dicyclopentadiene-type and naphthalene-type active ester resins. As a dicyclopentadiene-type active ester resin, it is preferable to be an active ester resin containing a dicyclopentadiene-type diphenol structure.

[0072] Commercially available reactive ester resins include, for example, reactive ester resins containing a dicyclopentadiene-type bisphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation); and reactive ester resins containing a naphthalene structure such as "HP-B-8151-62T", "EXB-8100L-65T", "EXB-8150-60T", and "EXB..." Examples of active ester resins include "-8150-62T", "EXB-9416-70BK", "HPC-8150-60T", "HPC-8150-62T", and "EXB-8" (manufactured by DIC Corporation); phosphorus-containing active ester resins include "EXB9401" (manufactured by DIC Corporation); acetylated active ester resins used as phenolic varnish resins include "DC808" (manufactured by Mitsubishi Chemical Corporation); benzoyl active ester resins used as phenolic varnish resins include "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation); and active ester resins containing styrene and naphthalene structures include "PC1300-02-65MA" (manufactured by AIR&WATER Corporation).

[0073] The amount of active ester resin in the resin composition is preferably 1% or more by mass, more preferably 3% or more by mass, particularly preferably 5% or more by mass, more preferably 40% or less by mass, more preferably 30% or less by mass, and particularly preferably 20% or less by mass, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of active ester resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and foaming resistance of the insulating layer, and thus generally reduce the relative permittivity of the insulating layer.

[0074] The amount of active ester resin in the resin composition is preferably 1% or more by mass, more preferably 5% or more by mass, particularly preferably 10% or more by mass, more preferably 80% or less by mass, more preferably 70% or less by mass, and particularly preferably 60% or less by mass, relative to 100% of the resin content of the resin composition. When the amount of active ester resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus can generally reduce the relative permittivity of the insulating layer.

[0075] As cyanate ester resins, compounds having one or more, preferably two or more, cyanate ester groups per molecule can be used. When combined with epoxy resins, cyanate ester resins can react with the epoxy resins to harden the resin composition, and are therefore sometimes called "cyanate ester-based curing agents". Examples of difunctional cyanate resins include: bisphenol A dicyanate, polyphenol cyanate (oligomeric (3-methylene-1,5-phenyl cyanate)), 4,4'-methylene bis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate-phenyl)propane, 1,1-bis(4-cyanate-phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate-phenyl-1-(methylethylidene))benzene, bis(4-cyanate-phenyl) sulfide, and bis(4-cyanate-phenyl) ether; polyfunctional cyanate resins derived from phenolic varnish resins and cresol varnish resins; and prepolymers obtained by triazineization of some of these cyanate resins. Specific examples of cyanate ester resins include Lonza Japan's "PT30" and "PT60" (both phenolic varnish-type multifunctional cyanate ester resins), "BA230", and "BA230S75" (prepolymers in which some or all of the bisphenol A dicyanate is triazineized to form a trimer).

[0076] The amount of cyanate resin in the resin composition is preferably 1% or more by mass, more preferably 3% or more by mass, particularly preferably 5% or more by mass, more preferably 40% or less by mass, more preferably 30% or less by mass, and particularly preferably 20% or less by mass, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of cyanate resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally reduce the relative permittivity of the insulating layer.

[0077] The amount of cyanate resin in the resin composition is preferably 1% or more by mass, more preferably 5% or more by mass, particularly preferably 10% or more by mass, more preferably 60% or less by mass, more preferably 50% or less by mass, and particularly preferably 40% or less by mass, relative to 100% of the resin content of the resin composition. When the amount of cyanate resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally reduce the relative permittivity of the insulating layer.

[0078] As a carbodiimide resin, compounds having one or more, preferably two or more, carbodiimide structures within one molecule can be used. When combined with epoxy resins, carbodiimide resins can react with the epoxy resins to harden the resin composition; therefore, they are sometimes called "carbodiimide-based curing agents." Specific examples of carbodiimide resins include aliphatic bis(tert-butylcarbodiimide) and cyclohexanebis(methylene-tert-butylcarbodiimide); aromatic bis(xylylcarbodiimide) and other bis(carbodiimides); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylcarbodiimide, poly(methylene biscyclohexylcarbodiimide), and poly(isophoronecarbodiimide); poly(phenylcarbodiimide), poly(phenylcarbodiimide), etc. Polycarbodiimides, including naphthylcarbodiimide, poly(methylenecarbodiimide), poly(methyldiisopropylphenylcarbodiimide), poly(triethylphenylcarbodiimide), poly(diethylphenylcarbodiimide), poly(triisopropylphenylcarbodiimide), poly(diisopropylphenylcarbodiimide), poly(xylylcarbodiimide), poly(tetramethylxylylcarbodiimide), poly(methylenediphenylcarbodiimide), poly[methylenebis(methylphenyl)carbodiimide], and other aromatic polycarbodiimides. Commercially available carbodiimide resins include, for example: "CARBODILITE V-02B", "CARBODILITE V-03", "CARBODILITE V-04K", "CARBODILITE V-07" and "CARBODILITE V-09" manufactured by Nisshinbo Chemical Co., Ltd.; and "Stabaxol P", "Stabaxol P400" and "Hycasyl 510" manufactured by Rhein-Chemie Co., Ltd.

[0079] The amount of carbodiimide resin in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, more preferably 10% by mass or less, more preferably 8% by mass or less, and particularly preferably 5% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of carbodiimide resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus can generally reduce the relative permittivity of the insulating layer.

[0080] The amount of carbodiimide resin in the resin composition, relative to 100% by mass of the resin content of the resin composition, is preferably 0.1% by mass or more, more preferably 1% by mass or more, particularly preferably 2% by mass or more, preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less. When the amount of carbodiimide resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally can reduce the relative permittivity of the insulating layer.

[0081] As anhydride resins, compounds having one or more, preferably two or more, anhydride groups per molecule can be used. When combined with epoxy resins, anhydride resins can react with the epoxy resins to harden the resin composition; therefore, they are sometimes called "anhydride-based curing agents." Specific examples of anhydride resins include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and diphenylmethyl... Polymer-type anhydrides such as ketone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxobis(phthalic acid) dianhydride, 3,3'-4,4'-diphenyltrimethyltetracarboxylic 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(trimethoxybenzoic acid ester), and styrene-maleic acid resin obtained by copolymerizing styrene with maleic acid. Commercially available anhydride resins include, for example: "HNA-100", "MH-700", "MTA-15", "DDSA", and "OSA" manufactured by Shin Nippon Rika Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Co., Ltd.; "HN-2200" and "HN-5500" manufactured by Hitachi Chemical Co., Ltd.; and "EF-30", "EF-40", "EF-60", and "EF-80" manufactured by Cray Valley Co., Ltd.

[0082] As amine resins, compounds having one or more, preferably two or more, amine groups in one molecule can be used. When combined with epoxy resins, amine resins can react with the epoxy resins to harden the resin composition; therefore, they are sometimes called "amine curing agents." Examples of amine resins include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. Amine resins are preferably primary or secondary amines, and more preferably primary amines. Specific examples of amine resins include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-phenylenediamine, 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-hydroxybenzyl) 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl) benzoxide, bis(4-(3-aminophenoxy)phenyl) benzoxide, etc. Commercially available amine resins include, for example: SEIKA's "SEIKACURE-S"; Nippon Kayaku Co., Ltd.'s "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD AA", "KAYAHARD AB", and "KAYAHARD AS"; Mitsubishi Chemical Co., Ltd.'s "Epicure W"; and Sumitomo Seika Co., Ltd.'s "DTDA".

[0083] When benzoxazine resins are combined with epoxy resins, they can react with the epoxy resins to harden the resin composition; therefore, they are sometimes called "benzoxazine-based hardeners." Specific examples of benzoxazine resins include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Co., Ltd.; "HFB2006M" manufactured by Showa Polymer Co., Ltd.; and "Pd" and "Fa" manufactured by Shikoku Chemical Industry Co., Ltd.

[0084] When combined with epoxy resins, thiol resins can react with the epoxy resins to harden the resin composition; therefore, they are sometimes called "thiol-based curing agents." Examples of thiol resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

[0085] The active group equivalent of the hardener is preferably 50 g / eq. to 3000 g / eq., more preferably 100 g / eq. to 1000 g / eq., further preferably 100 g / eq. to 500 g / eq., and particularly preferably 100 g / eq. to 300 g / eq. The active group equivalent is the mass of hardener corresponding to 1 equivalent of active group.

[0086] When the number of epoxy groups in the epoxy resin is set to 1, the number of active groups in the curing agent is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.5 or more, preferably 5.0 or less, more preferably 4.0 or less, and particularly preferably 3.0 or less. "The number of epoxy groups in the epoxy resin" refers to the sum of all values ​​obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition by the epoxy equivalent. Furthermore, "the number of active groups in the curing agent" refers to the sum of all values ​​obtained by dividing the mass of the non-volatile components of the curing agent present in the resin composition by the active group equivalent.

[0087] The amount of hardener in the resin composition is preferably 1% or more by mass, more preferably 5% or more by mass, particularly preferably 10% or more by mass, more preferably 50% or less by mass, more preferably 40% or less by mass, and particularly preferably 30% or less by mass, relative to 100% of the non-volatile components of the resin composition. When the amount of hardener is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally reduce the relative permittivity of the insulating layer.

[0088] The amount of hardener in the resin composition, relative to 100% by mass of the resin content, is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, preferably 90% by mass or less, more preferably 80% by mass or less, and particularly preferably 70% by mass or less. When the amount of hardener is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally reduce the relative permittivity of the insulating layer.

[0089] As a free radical polymerizable resin, a compound having an vinyl unsaturated bond can be used. Therefore, a free radical polymerizable resin can have a free radical polymerizable group containing an vinyl unsaturated bond. Examples of free radical polymerizable groups include unsaturated hydrocarbon groups such as vinyl, allyl, 1-propenyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, and 4-vinylphenyl; and α,β-unsaturated carbonyl groups such as acrylonitrile, methacrylonitrile, and maleimino (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl). The number of free radical polymerizable groups contained in one molecule of the free radical polymerizable resin can be one, preferably two or more. A single free radical polymerizable resin can be used, or two or more can be used in combination. Examples of preferred free radical polymerizable resins include (meth)acrylic resin, styrene resin, acrylonitrile resin, and maleimino resin.

[0090] (Meth)acrylic resin can be a compound having one or more, preferably two or more (meth)acrylic groups in one molecule. (Meth)acrylic resin can be a monomer or an oligomer. The term "(meth)acrylic" can include acrylonitrile, methacrylic, and combinations thereof. Examples of (meth)acrylate resins include, for example, cyclohexane-1,4-diethanol di(meth)acrylate, cyclohexane-1,3-diethanol di(meth)acrylate, tricyclodecane-diethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and other low molecular weight (molecular weight less than 1000) aliphatic (meth)acrylate compounds; dioxanediol di(meth)acrylate, 3,6-dioxane-1,8-octanediol... Low molecular weight (molecular weight less than 1000) ether-containing (meth)acrylate compounds such as di(meth)acrylate, 3,6,9-trioxaundecane-1,11-diol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 9,9-bis[4-(2-propenyloxyethoxy)phenyl]fluorene, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, etc.; low molecular weight (molecular weight less than 1000) isocyanurate-containing (meth)acrylate compounds such as tri(3-hydroxypropyl)isocyanurate tri(meth)acrylate, tri(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, etc.; high molecular weight (molecular weight greater than 1000) acrylate compounds such as (meth)acrylate-modified polyphenylene ether resin, etc. In addition, commercially available (meth)acrylic resins include, for example: "A-DOG" manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; "DCP" and "DCP-A" manufactured by Kyoei Chemical Co., Ltd.; "NPDGA", "FM-400", "R-604", "R-684", "R-687", "THE-330", "PET-30", and "DPHA" manufactured by Nippon Kayaku Co., Ltd.; and "SA9000" and "SA9000-111" manufactured by SABIC Innovative Plastics.

[0091] Styrene-based resins can be compounds having one or more, preferably two or more, styrene or vinylphenyl groups in one molecule. Styrene-based resins can be monomers or oligomers. Examples of styrene-based resins include: low molecular weight (molecular weight less than 1000) styrene compounds such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl) ether; and high molecular weight (molecular weight 1000 or more) styrene compounds such as vinylbenzyl-modified polyphenylene ether resin and styrene-divinylbenzene copolymer. Furthermore, commercially available styrene-based resins include, for example, "OPE-2St," "OPE-2St 1200," and "OPE-2St 2200" manufactured by Mitsubishi Gas Chemical Co., Ltd.

[0092] Acrylic resins can be compounds having one or more, preferably two or more, propenyl groups in one molecule. Acrylic resins can be monomers or oligomers. The aforementioned propenyl group can include 1-propenyl, 2-propenyl (i.e., allyl), and combinations thereof. Examples of acrylic resins include: diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, diallyl 2,3-naphthalenedicarboxylate, and other aromatic carboxylic acid allyl ester compounds; 1,3,5-triallyl isocyanurate, 1,3-diallyl-5-glycidyl isocyanurate, and other isocyanurate allyl ester compounds; 2,2-bis[ Aromatic allyl compounds containing epoxy groups, such as 3-allyl-4-(glycidyloxy)phenyl]propane; aromatic allyl compounds containing benzoxazine, such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazine-3-yl)phenyl]methane; aromatic allyl compounds containing ethers, such as 1,3,5-triallyl ether benzene; and allyl silane compounds, such as diallyl diphenylsilane. Examples of commercially available acrylic resins include: TAIC (1,3,5-triallyl isocyanurate) manufactured by Nippon Chemical Co., Ltd., and Nisshoku Techno Fine Chemicals. The following resins are used: "DAD" (dallyl dibenzoate) manufactured by [Company Name], "TRIAM-705" (triallyl trimellitate) manufactured by Wako Pure Chemical Industries, "DAND" (dallyl 2,3-naphthoic acid) manufactured by Nippon Distillation Industries, "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane) manufactured by Shikoku Chemical Industries, "RE-810NM" (2,2-bis[3-allyl-4-(glycidoxy)phenyl]propane) manufactured by Nippon Chemical Industries, and "DA-MGIC" (1,3-diallyl-5-glycidyl isocyanurate) manufactured by Shikoku Chemical Industries. Furthermore, as a propylene-based resin, a resin containing hydroxyl groups bonded to an aromatic ring can be used, for example, a resin shown in formula (b1) below. Thus, acrylic resins containing hydroxyl groups bonded to aromatic rings can function not only as free radical polymerizable resins, but also as phenolic curing agents.

[0093] [Chemical Formula 5] .

[0094] Maleimide resins can be compounds having one or more, preferably two or more, maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl) in one molecule. Maleimide resins can be monomers or oligomers. Examples of commercially available maleimide resins include: "BMI-3000J", "BMI-5000", "BMI-1400", "BMI-1500", "BMI-1700", and "BMI-689" (all are designer molecules). Maleimide resins containing an aliphatic backbone of 36 carbon atoms derived from dimer diamines, etc.; maleimide resins containing an indane backbone as described in Japan Invention Association Publication No. 2020-500211; and maleimide resins containing an aromatic ring backbone 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 KI Kasei Co., Ltd.).

[0095] The equivalent amount of vinyl unsaturated bonds in free radical polymerizable resins is preferably 20 g / eq. to 3000 g / eq., more preferably 50 g / eq. to 2500 g / eq., further preferably 70 g / eq. to 2000 g / eq., and particularly preferably 90 g / eq. to 1500 g / eq. The vinyl unsaturated bond equivalent indicates the mass of free radical polymerizable resin per 1 equivalent of vinyl unsaturated bonds.

[0096] The weight-average molecular weight (Mw) of the free radical polymerizable resin is preferably below 40,000, more preferably below 10,000, further preferably below 5,000, and particularly preferably below 3,000. There is no particular limitation on the lower limit; for example, it can be above 150. The weight-average molecular weight of the free radical polymerizable resin can be determined using gel permeation chromatography (GPC) as a value converted from polystyrene.

[0097] The amount of free radical polymerizable resin in the resin composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, more preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 1% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of free radical polymerizable resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally reduce the relative permittivity of the insulating layer.

[0098] The amount of free radical polymerizable resin in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of free radical polymerizable resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus can generally reduce the relative permittivity of the insulating layer.

[0099] In the above, (B) the curing resin preferably comprises one or more resins selected from the group consisting of epoxy resins, phenolic resins, reactive ester resins, cyanate ester resins, (meth)acrylic resins, styrene resins, acrylic resins, and maleimide resins. In this case, the total amount of resins selected from the aforementioned group is preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably 90% by mass or more, and usually less than 100% by mass relative to 100% by mass of the curing resin in (B). When the curing resin in (B) comprises such a preferred resin, the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer can be effectively improved, and consequently, the relative permittivity of the insulating layer can generally be reduced.

[0100] The amount of (B) curable resin in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, more preferably 80% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of (B) curable resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thereby generally reduce the relative permittivity of the insulating layer.

[0101] The amount of (B) curable resin in the resin composition is preferably 50% by mass or more, more preferably 60% by mass or more, particularly preferably 70% by mass or more, more preferably 98% by mass or less, more preferably 96% by mass or less, and particularly preferably 94% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of (B) curable resin is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and foaming resistance of the sodium sulfonate insulating layer, and thus can generally reduce the relative permittivity of the insulating layer.

[0102] <Regarding the inorganic filler material of the first embodiment (C)> The resin composition of the first embodiment of the present invention may further include (C) inorganic filler material as an optional component. The (C) inorganic filler material, as component (C), does not contain substances belonging to components (A) to (B) above. The (C) inorganic filler material is generally included in the resin composition in a particulate state.

[0103] Inorganic compounds are used as the inorganic filler material in (C). Examples of inorganic filler materials in (C) include: silicon dioxide, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silicon dioxide and alumina are preferred, and silicon dioxide is particularly preferred. Examples of silicon dioxide include: amorphous silicon dioxide, fused silicon dioxide, crystalline silicon dioxide, synthetic silicon dioxide, and hollow silicon dioxide. Furthermore, spherical silicon dioxide is preferred as the silicon dioxide. (C) Inorganic filler materials may be used alone or in combination of two or more.

[0104] (C) Inorganic fillers can be classified into hollow inorganic fillers with internal pores and solid inorganic fillers without internal pores. As (C) inorganic fillers, hollow inorganic fillers can be used alone, solid inorganic fillers can be used alone, or a combination of hollow and solid inorganic fillers can be used. When using hollow inorganic fillers, the relative permittivity of the cured resin composition is generally reduced.

[0105] Hollow inorganic fillers typically have a porosity greater than 0% by volume due to their porous nature. From the viewpoint of reducing the relative permittivity of the insulating layer of the cured resin-containing material, a porosity of 5% by volume or more is preferable for hollow inorganic fillers, more preferably 10% by volume or more, and particularly preferably 15% by volume or more. Furthermore, from the viewpoint of the mechanical strength of the cured resin-containing material, a porosity of 95% by volume or less is preferable for hollow inorganic fillers, more preferably 90% by volume or less, and particularly preferably 85% by volume or less.

[0106] The porosity P (volume %) of a particle is defined as a volume-based ratio (total volume of pores / volume of particle) of the total volume of one or more pores present within the particle relative to the volume of the particle as a whole relative to its outer surface. This porosity P can be calculated using the measured actual density of the particle, DM (g / cm³), and the theoretical density of the material forming the particle, DT (g / cm³), using the following formula (X1).

[0107] [] [Mathematical Expression 1] .

[0108] Hollow inorganic filler materials can be manufactured, for example, by the methods described in Japanese Patent No. 5940188 and Japanese Patent No. 5864299, or by following the methods therein.

[0109] Commercially available products as (C) inorganic filler materials include: "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical Materials Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", "YA010C", "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30", "DAW-03", and "FB-105FD" manufactured by DENKA Co., Ltd.; "SILFIL NSS-3N", "SILFIL NSS-4N", and "SILFIL NSS-5N" manufactured by Tokuyama Co., Ltd.; "CellSpheres" manufactured by Taiheiyo-Cement Co., Ltd.; and "ESPRIQUE" manufactured by Nippon Chemicals Co., Ltd.

[0110] (C) The average particle size of the inorganic filler material is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less, from the viewpoint of significantly obtaining the desired effect of the present invention.

[0111] (C) The average particle size of inorganic filler materials can be determined by laser diffraction scattering based on the Mie scattering theory. Specifically, a laser diffraction particle size distribution measuring device can be used to prepare the particle size distribution of the inorganic filler material on a volume basis, and the median particle size can be used as the average particle size for measurement. The sample to be measured can be obtained by weighing 100 mg of inorganic filler material and 10 g of methyl ethyl ketone into a tube and dispersing it ultrasonically for 10 minutes. For the sample to be measured, a laser diffraction particle size distribution measuring device is used, with blue and red light source wavelengths, and the volume-based particle size distribution of the inorganic filler material is measured in a flow cell manner. The average particle size is calculated based on the obtained particle size distribution as the median particle size. Examples of laser diffraction particle size distribution measuring devices include the "LA-960" manufactured by Horiba Manufacturing Co., Ltd.

[0112] (C) From the viewpoint of significantly achieving the desired effect of the present invention, the specific surface area of ​​the inorganic filler material is preferably 0.1 m² / g or more, more preferably 0.5 m² / g or more, further preferably 1 m² / g or more, particularly preferably 3 m² / g or more, preferably 100 m² / g or less, more preferably 70 m² / g or less, further preferably 50 m² / g or less, and particularly preferably 40 m² / g or less. The specific surface area of ​​the inorganic filler material can be obtained as follows: according to the BET method, nitrogen gas is adsorbed onto the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech), and the specific surface area is calculated using the BET multi-point method.

[0113] From the perspective of improving moisture resistance and dispersibility, (C) inorganic filler materials are preferably treated with surface treatment agents. Examples of surface treatment agents include: fluorosilane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, etc. A single surface treatment agent can be used, or two or more can be used in any combination.

[0114] Commercially available surface treatment agents include, for example: KBM403 (3-epoxypropoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., KBM803 (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., KBE903 (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., KBM573 (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., SZ-31 (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., KBM103 (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., KBM-4803 (long-chain epoxy silane coupling agent) manufactured by Shin-Etsu Chemical Industry Co., Ltd., and KBM-7103 (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0115] From the perspective of improving the dispersibility of inorganic fillers, the degree of surface treatment using surface treatment agents is preferably within a specified range. Specifically, it is preferable that 100% by mass of the inorganic filler is surface treated with 0.2% to 5% by mass of a surface treatment agent, more preferably with 0.2% to 3% by mass, and even more preferably with 0.3% to 2% by mass.

[0116] The degree of surface treatment using surface treatment agents can be evaluated by the carbon content per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the carbon content per unit surface area of ​​the inorganic filler is preferably 0.02 mg / m² or more, more preferably 0.1 mg / m² or more, and even more preferably 0.2 mg / m² or more. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition, it is preferably 1.0 mg / m² or less, more preferably 0.8 mg / m² or less, and even more preferably 0.5 mg / m² or less.

[0117] (C) The carbon content per unit surface area of ​​the inorganic filler material can be determined after cleaning the surface-treated inorganic filler material with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, sufficient MEK is added as a solvent to the surface-treated inorganic filler material, and the mixture is ultrasonically cleaned at 25°C for 5 minutes. After removing the supernatant and drying the solid components, the carbon content per unit surface area of ​​the inorganic filler material can be determined using a carbon analyzer. A carbon analyzer such as the "EMIA-320V" manufactured by Horiba Manufacturing Co., Ltd. can be used.

[0118] The amount of inorganic filler (C) in the resin composition, relative to 100% by mass of the non-volatile components of the resin composition, can be 0% by mass or more than 0% by mass, preferably 10% by mass or more, more preferably 20% by mass or more, particularly preferably 30% by mass or more, preferably 94% by mass or less, more preferably 90% by mass or less, particularly preferably 80% by mass or less. When the amount of inorganic filler (C) is within the aforementioned range, it can effectively improve the dielectric loss tangent, crack resistance, and blistering resistance of the insulating layer, and thus generally reduce the relative permittivity of the insulating layer.

[0119] <Regarding the (D) hardening accelerator of the first embodiment> The resin composition of the first embodiment of the present invention may further include (D) a curing accelerator as an optional component. The (D) curing accelerator, as component (D), does not contain substances belonging to components (A) to (C) above. The (D) curing accelerator functions as a curing catalyst that promotes the curing of the (B) curable resin.

[0120] As a (D) curing accelerator, an appropriate curing accelerator can be used depending on the type of (B) curable resin. For example, when the (B) curable resin contains epoxy resin, examples of (D) curing accelerators that can promote the curing of the epoxy resin include: phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, amine-based curing accelerators, etc. A single (D) curing accelerator can be used, or two or more can be used in combination.

[0121] Examples of phosphorus-based hardening accelerators include: tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitictate, tetrabutylphosphonium hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, di-tert-butyldimethylphosphonium tetraphenylborate, and other aliphatic phosphonium salts; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, and p-methylphosphonium bromide. Aromatic phosphonium salts of phenyltriphenylphosphonium tetratolylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetratolylborate, triphenylethylphosphonium tetraphenylborate, tri(3-methylphenyl)ethylphosphonium tetraphenylborate, tri(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, etc.; aromatic phosphine-borane complexes of triphenylphosphine-triphenylborane, etc.; aromatic phosphine-quinone addition reactants of triphenylphosphine-p-benzoquinone, etc.; tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, etc. Aliphatic phosphines such as di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine; dibutylphenylphosphine, di-tert-butylphenylphosphine, methyl diphenylphosphine, ethyl diphenylphosphine, butyl diphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tri(4-ethylphenyl)phosphine, tri(4-propylphenyl)phosphine, tri(4-isopropylphenyl)phosphine, tri(4-butylphenyl)phosphine, tri(4-tert-butylphenyl)phosphine, tri(2,4-dimethylphenyl)phosphine, tri(2,5-dimethylphenyl)phosphine, tri(2 Aromatic phosphines such as 6-dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphine)ethane, 1,3-bis(diphenylphosphine)propane, 1,4-bis(diphenylphosphine)butane, 1,2-bis(diphenylphosphine)acetylene, and 2,2'-bis(diphenylphosphine)diphenyl ether.

[0122] Examples of urea-based hardening accelerators include: 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. Aromatic dimethylureas such as 1-dimethylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-epenylphenyl)bis(N',N'-dimethylurea), N,N-(4-methyl-1,3-epenylphenyl)bis(N',N'-dimethylurea)[toluenebisdimethylurea], etc.

[0123] Examples of guanidine-based hardening promoters include: dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, 1-(o-tolyl)biguanidine, etc.

[0124] Examples of imidazole-based hardening accelerators include: 2-methylimidazolium, 2-undecylimidazolium, 2-heptadecylimidazolium, 1,2-dimethylimidazolium, 2-ethyl-4-methylimidazolium, 1,2-dimethylimidazolium, 2-ethyl-4-methylimidazolium, 2-phenylimidazolium, 2-phenyl-4-methylimidazolium, 1-benzyl-2-methylimidazolium, 1-benzyl-2-phenylimidazolium, 1-cyanoethyl-2-methylimidazolium, 1-cyanoethyl-2-undecylimidazolium, 1-cyanoethyl-2-ethyl-4-methylimidazolium, 1-cyanoethyl-2-phenylimidazolium, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolium-(1')] [Ethyl-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-triazine isocyanuric acid adduct, 2-phenylimidazolyl isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazolium, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline and other imidazole compounds and adducts of imidazole compounds with epoxy resins. Commercially available imidazole-based hardening accelerators include, for example: "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" manufactured by Shikoku Chemical Co., Ltd.; and "P200-H50" manufactured by Mitsubishi Chemical Co., Ltd.

[0125] Examples of organometallic hardening accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt(II) and cobalt(III) acetoacetone, organocopper complexes such as copper(II) acetoacetone, organozinc complexes such as zinc(II) acetoacetone, organoiron complexes such as iron(III) acetoacetone, organonickel complexes such as nickel(II) acetoacetone, and organomanganese complexes such as manganese(II) acetoacetone. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0126] Examples of amine-based hardening accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. Commercially available products can be used as amine-based hardening accelerators, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0127] The amount of (D) curing accelerator in the resin composition, relative to 100% by mass of the non-volatile components of the resin composition, may be 0% by mass or more than 0% by mass, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, particularly preferably 0.05% by mass or more, preferably less than 1.0% by mass, more preferably less than 0.5% by mass, and particularly preferably less than 0.2% by mass.

[0128] The amount of (D) curing accelerator in the resin composition, relative to 100% by mass of the resin component of the resin composition, may be 0% by mass or more than 0% by mass, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, particularly preferably 0.1% by mass or more, preferably 2.0% by mass or less, more preferably 1.0% by mass or less, particularly preferably 0.5% by mass or less.

[0129] [] <Regarding the (E) thermoplastic resin of the first embodiment> The resin composition of the first embodiment of the present invention may further include (E) thermoplastic resin as an arbitrary component. The (E) thermoplastic resin, as component (E), does not contain substances belonging to components (A) to (D) above.

[0130] Examples of (E) thermoplastic resins include: phenoxy resins, polyimide resins, polyvinyl alcohol acetal resins, polyolefin resins, polybutadiene resins, polyamide-imide resins, polyether-imide resins, polyurethane resins, polyphenylene ether resins, polycarbonate resins, polyether ether ketone resins, polyester resins, etc. (E) thermoplastic resins can be used alone or in combination of two or more.

[0131] Examples of phenoxy resins include those having one or more skeletons selected from the following: bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, phenolic skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal end of the phenoxy resin may have any functional group such as phenolic hydroxyl group or epoxy group. Specific examples of phenoxy resins include: Mitsubishi Chemical's "1256" and "4250" (both phenoxy resins containing a bisphenol A backbone); Mitsubishi Chemical's "YX8100" (phenoxy resin containing a bisphenol S backbone); Mitsubishi Chemical's "YX6954" (phenoxy resin containing a bisphenol acetophenone backbone); Nippon Steel & Sumitomo Chemical's "FX280" and "FX293"; and Mitsubishi Chemical's "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", "YL7482", and "YL7891BH30", etc.

[0132] Specific examples of polyimide resins include Shin-Etsu Chemical Co., Ltd.'s "SLK-6100", Shin Nippon Rikka Co., Ltd.'s "RIKACOAT SN20" and "RIKACOAT PN20".

[0133] Examples of polyvinyl alcohol acetal resins include polyvinyl alcohol formaldehyde resin and polyvinyl alcohol butyral resin, with polyvinyl alcohol butyral resin being preferred. Specific examples of polyvinyl alcohol acetal resins include: "Denka Butyral 4000-2", "Denka Butyral 5000-A", "Denka Butyral 6000-C", and "Denka Butyral 6000-EP" manufactured by Denka Kogyo Co., Ltd.; and the S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemicals Co., Ltd., etc.

[0134] Examples of polyolefin resins include: low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, and other ethylene-based copolymer resins; polyolefin polymers such as polypropylene and ethylene-propylene block copolymers.

[0135] Examples of polybutadiene resins include: resins containing a hydrogenated polybutadiene backbone, hydroxyl-containing polybutadiene resins, phenolic hydroxyl-containing polybutadiene resins, carboxyl-containing polybutadiene resins, acid anhydride-containing polybutadiene resins, epoxy-containing polybutadiene resins, isocyanate-containing polybutadiene resins, urethane-containing polybutadiene resins, and polyphenylene ether-polybutadiene resins.

[0136] Specific examples of polyamide-imide resins include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. Other specific examples of polyamide-imide resins include modified polyamides such as "KS9100" and "KS9300" (polyamide-imide containing a polysiloxane backbone) manufactured by Hitachi Chemical Co., Ltd.

[0137] Specific examples of polyether resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0138] Specific examples of polyurethane resins include "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0139] Specific examples of polyphenylene oxide resins include SABIC's "NORYL SA90". Specific examples of polyetherimide resins include GE's "ULTEM".

[0140] Examples of polycarbonate resins include: hydroxyl-containing carbonate resins, phenolic hydroxyl-containing carbonate resins, carboxyl-containing carbonate resins, anhydride-containing carbonate resins, isocyanate-containing carbonate resins, and aminocarbamate-containing carbonate resins. Specific examples of polycarbonate resins include "FPC0220" manufactured by Mitsubishi Gas Chemical Co., Ltd., "T6002" and "T6001" (polycarbonate diol) manufactured by Asahi Kasei Chemical Co., Ltd., and "C-1090," "C-2090," and "C-3090" (polycarbonate diol) manufactured by Kuraray Co., Ltd. Specific examples of polyetheretherketone (PEEK) resins include "SUMIPLOY K" manufactured by Sumitomo Chemical Co., Ltd.

[0141] Examples of polyester resins include: polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polypropylene terephthalate resin, polypropylene naphthalate resin, and polycyclohexanedimethyl terephthalate resin.

[0142] (E) The weight-average molecular weight (Mw) of the thermoplastic resin is preferably greater than 5,000, more preferably greater than 8,000, further preferably greater than 10,000, particularly preferably greater than 20,000, preferably less than 100,000, more preferably less than 70,000, further preferably less than 60,000, and particularly preferably less than 50,000. (E) The weight-average molecular weight of the thermoplastic resin can be determined by gel permeation chromatography (GPC) as a value converted from polystyrene.

[0143] The amount of (E) thermoplastic resin in the resin composition, relative to 100% by mass of the non-volatile components of the resin composition, may be 0% by mass or more than 0% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, preferably less than 20% by mass, more preferably less than 10% by mass, and particularly preferably less than 5% by mass.

[0144] The amount of (E) thermoplastic resin in the resin composition, relative to 100% by mass of the resin component of the resin composition, may be 0% by mass or more than 0% by mass, preferably 0.1% by mass or more, more preferably 1% by mass or more, particularly preferably 2% by mass or more, preferably less than 30% by mass, more preferably less than 20% by mass, and particularly preferably less than 10% by mass.

[0145] <Regarding the first embodiment (F) any additive> The resin composition of the first embodiment of the present invention may further include any additive (F) as any non-volatile component. Among the additives (F) that are component (F), substances belonging to components (A) to (E) above are not included. Examples of (F) arbitrary additives include: free radical polymerization initiators such as peroxide-based free radical polymerization initiators and azo-based free radical polymerization initiators; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; homogenizing agents such as polysiloxane-based homogenizers and acrylic polymer-based homogenizers; thickeners such as Benton and montmorillonite; defoamers such as polysiloxane-based defoamers, acrylic defoamers, fluorinated defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion enhancers such as ureasilane; triazole-based adhesion promoters and tetraazole-based adhesion promoters. Adhesion enhancers such as adhesion enhancers and triazine adhesion enhancers; antioxidants such as hindered phenolic antioxidants; fluorescent whitening agents such as zirconia derivatives; surfactants such as fluorine surfactants and polysiloxane surfactants; flame retardants such as phosphorus flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphonic acid compounds, red phosphorus), nitrogen flame retardants (e.g., melamine sulfate), halogen flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester dispersants, polyoxyethylene dispersants, alkyne dispersants, polysiloxane dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate ester stabilizers, titanate stabilizers, aluminate stabilizers, zirconate stabilizers, isocyanate stabilizers, carboxylic acid stabilizers, and carboxylic anhydride stabilizers. (F) Any additive may be used alone or in combination of two or more.

[0146] <Regarding the solvent (G) of the first embodiment> In the resin composition of the first embodiment of the present invention, it may be further combined with non-volatile components such as components (A) to (F) to include solvent (G) as an arbitrary volatile component. Organic solvents are typically used as solvent (G). 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, diphenyl ether, and anisole; 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, and diethylene glycol ethyl ether acetate. Ether ester solvents such as acetate, γ-butyrolactone, and methyl methoxypropionate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); acetylamine solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; arginine 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. (G) Solvents may be used alone or in combination of two or more.

[0147] (G) The amount of solvent is not particularly limited. When all components in the resin composition are set to 100% by mass, it can be 60% or less by mass, 40% or less by mass, 30% or less by mass, 20% or less by mass, 15% or less by mass, 10% or less by mass, etc., or it can be 0% by mass.

[0148] <Method for manufacturing the resin composition of the first embodiment> The resin composition of the first embodiment of the present invention can be manufactured, for example, by mixing components that may be included in the resin composition. Some or all of the aforementioned components may be mixed simultaneously, or they may be mixed sequentially. During the mixing of the components, the temperature can be appropriately set, so heating and / or cooling can be performed temporarily or continuously. Furthermore, stirring or agitation can be performed during the mixing of the components.

[0149] <Characteristics of the resin composition in the first embodiment> A cured product is obtained by curing the resin composition according to the first embodiment of the present invention. During the curing process, heat is typically applied to the resin composition. Therefore, volatile components such as solvent (G) typically contained in the resin composition may volatilize due to the heat during curing, but non-volatile components such as components (A) to (F) do not volatilize due to the heat during curing. Therefore, the cured product of the resin composition may contain non-volatile components of the resin composition or their reaction products.

[0150] The cured resin composition of the first embodiment of the present invention can have a low dielectric loss tangent. Therefore, when an insulating layer is formed using this cured composition, an insulating layer with a low dielectric loss tangent can be obtained. The dielectric loss tangent of the cured resin composition is preferably 0.040 or less, more preferably 0.030 or less, and particularly preferably 0.020 or less. There is no particular limitation on the lower limit; for example, it can be 0.0001 or more. The dielectric loss tangent of the cured composition can be determined using the method described in <Experimental Example I-1: Determination of Relative Permittivity (Dk) and Dielectric Loss Tangent (Df)> of the embodiments described later.

[0151] The cured resin composition of the first embodiment of the present invention exhibits excellent crack resistance. Therefore, when an insulating layer is formed using this cured composition, an insulating layer with excellent crack resistance can be obtained. For example, when evaluating crack resistance using the method described in <Test Example I-2: Evaluation of Crack Resistance> of the embodiments described later, a yield rate of 40% or more (good), 60% or more (better), and 80% or more (particularly good) can be achieved. Generally, a higher yield rate indicates better crack resistance.

[0152] The cured resin composition of the first embodiment of the present invention exhibits excellent foaming resistance. Therefore, when an insulating layer is formed using this cured composition, foaming during reflow can be suppressed. For example, when evaluated using the method described in <Test Example I-3: Evaluation of Foaming Resistance> of the embodiments described later, abnormalities such as expansion of the conductor layer formed on the insulating layer containing the resin composition can be suppressed.

[0153] The cured resin composition of the first embodiment of the present invention typically has a low relative permittivity. Therefore, when an insulating layer is formed using this cured composition, an insulating layer with a low relative permittivity can be obtained. The relative permittivity of the cured resin composition is preferably 4.0 or less, more preferably 3.8 or less, and particularly preferably 3.5 or less. There is no particular limitation on the lower limit; for example, it can be 0.1 or more. The relative permittivity of the cured composition can be measured using the method described in <Experimental Example I-1: Determination of Relative Permittivity (Dk) and Dielectric Loss Tangent (Df)> in the embodiments described later.

[0154] <Summary of the resin composition of the second embodiment> The resin composition of the second embodiment of the present invention comprises (A) an organic filler and (B) a curable resin. The (A) organic filler comprises a polymer (1) containing repeating units of formula (1). Furthermore, the (A) organic filler has an average particle size within a specific range.

[0155] [Chemical Formula 6] (in equation (1), Ra independently represents either a hydrogen atom or a monovalent saturated hydrocarbon group. Rb represents a hydrogen atom or a monovalent hydrocarbon group that may have substituents.

[0156] According to the resin composition of the second embodiment, an insulating layer with excellent crack resistance, high-temperature stability at high temperatures, and excellent insulation reliability can be obtained. Furthermore, this insulating layer can typically be a layer with low dielectric properties such as relative permittivity and dielectric loss tangent.

[0157] <Regarding the organic filler material of the second embodiment (A)> The resin composition of the second embodiment of the present invention includes an organic filler material (A) as component (A). This organic filler material (A) exists in the resin composition in a particulate form and is typically included in the cured material while maintaining its particulate form. The organic filler material (A) can be used alone or in combination of two or more. The same material as the organic filler material (A) described in the first embodiment can be used as the organic filler material (A). Therefore, the scope of the organic filler material (A) in the second embodiment can be the same as the scope of the organic filler material (A) in the first embodiment.

[0158] Therefore, the polymer (1) in the second embodiment can be the same as the polymer (1) described in the first embodiment. Furthermore, the amount of polymer (1) contained in the organic filler material of the second embodiment (A) can be the same as the amount of polymer (1) contained in the organic filler material of the first embodiment (A). Furthermore, the types and amounts of any components that can be contained in the organic filler material of the second embodiment (A) can be the same as the types and amounts of any components that can be contained in the organic filler material of the first embodiment (A). Furthermore, the organic filler material of the second embodiment (A) can also include portions such as a shell and a core. The portions such as a shell and a core that can be contained in the organic filler material of the second embodiment (A) can be the same as the portions such as a core and a shell that can be contained in the organic filler material of the first embodiment (A). Furthermore, the range of the average particle size of the organic filler material of the second embodiment (A) can be the same as the range of the average particle size of the organic filler material of the first embodiment (A). Furthermore, the organic filler material of the second embodiment (A) can also be treated with a surface treatment agent. The surface treatment agent for the organic filler material in the second embodiment (A) can be the same as the surface treatment agent for the organic filler material in the first embodiment (A).

[0159] Organic filler material (A) containing polymer (1) can generally play a role in mitigating stress in the cured form of resin composition, thus improving the crack resistance of the cured form. Furthermore, cured forms containing organic filler material containing polymer (1) have historically tended to have poor temperature stability and insulation reliability at high temperatures with dielectric loss tangent. In contrast, in the second embodiment of the present invention, by using organic filler material (A) with an average particle size within a specific range, temperature stability and insulation reliability at high temperatures with dielectric loss tangent can be improved. Therefore, by forming an insulating layer using the cured form of the resin composition of the second embodiment, an insulating layer with excellent crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability can be obtained. The ability to maintain high crack resistance while simultaneously improving temperature stability and insulation reliability at high temperatures with dielectric loss tangent when the average particle size of organic filler material (A) is an effect first discovered by the inventors and is an effect unexpected by conventional technical knowledge. Furthermore, the hardened material typically exhibits low polarity, thus reducing dielectric properties such as dielectric loss tangent.

[0160] The range of the amount of (A) organic filler material contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of (A) organic filler material contained in the resin composition of the first embodiment.

[0161] In a particularly desirable state, the amount of (A) organic filler material contained in the resin composition of the second embodiment of the present invention is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, preferably 5% by mass or less, more preferably 4.5% by mass or less, and particularly preferably 4% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of (A) organic filler material is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0162] In a particularly desirable state, the amount of (A) organic filler material contained in the resin composition of the second embodiment of the present invention is preferably 0.5% by mass or more, more preferably 1% by mass or more, particularly preferably 3% by mass or more, preferably 25% by mass or less, more preferably 20% by mass or less, and particularly preferably 15% by mass or less, relative to 100% by mass of the resin composition. The resin composition of the resin composition, as described above, represents the composition after removing (C) inorganic filler material from the non-volatile components of the resin composition. When the amount of (A) organic filler material is within the aforementioned range, the insulation layer exhibits particularly good crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability, thereby generally reducing the relative permittivity and dielectric loss tangent.

[0163] <Regarding the (B) curing resin of the second embodiment> The resin composition of the second embodiment of the present invention comprises a curable resin (B) as component (B). The curable resin (B) does not contain any substance belonging to component (A) described above. The curable resin (B) can be used alone or in combination of two or more. As the curable resin (B) of the second embodiment, the same substance as the curable resin (B) described in the first embodiment can be used. Therefore, the scope of the curable resin (B) of the second embodiment can be the same as the scope of the curable resin (B) of the first embodiment.

[0164] Therefore, the curable resin of the second embodiment (B) may also include epoxy resin. The epoxy resin of the second embodiment can be the same substance as the epoxy resin of the first embodiment. The range of the amount of epoxy resin contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of epoxy resin contained in the resin composition of the first embodiment.

[0165] In the particularly desirable state, the amount of epoxy resin in the resin composition of the second embodiment is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 5% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of epoxy resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0166] In the particularly desirable state, the amount of epoxy resin in the resin composition of the second embodiment is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, more preferably 60% by mass or less, more preferably 50% by mass or less, and particularly preferably 40% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of epoxy resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0167] Furthermore, the curable resin of the second embodiment (B) may also contain a phenolic resin. The same substance as the phenolic resin of the first embodiment can be used as the phenolic resin of the second embodiment. The range of the amount of phenolic resin contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of phenolic resin contained in the resin composition of the first embodiment.

[0168] In the particularly desirable state, the amount of phenolic resin in the resin composition of the second embodiment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, more preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of phenolic resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0169] In the particularly desirable state, the amount of phenolic resin in the resin composition of the second embodiment is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 3% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of phenolic resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0170] Furthermore, the curable resin of the second embodiment (B) may also include an active ester resin. The active ester resin of the second embodiment can be the same substance as the active ester resin of the first embodiment. The range of the amount of active ester resin included in the resin composition of the second embodiment may be the same as or different from the range of the amount of active ester resin included in the resin composition of the first embodiment.

[0171] In the particularly desirable state, the amount of active ester resin in the resin composition of the second embodiment is preferably 1% by mass or more, more preferably 5% by mass or more, particularly preferably 10% by mass or more, more preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of active ester resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0172] In the particularly desirable state, the amount of active ester resin in the resin composition of the second embodiment is preferably 10% by mass or more, more preferably 20% by mass or more, particularly preferably 30% by mass or more, preferably 80% by mass or less, more preferably 70% by mass or less, and particularly preferably 60% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of active ester resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0173] Furthermore, the curable resin of the second embodiment (B) may also contain a cyanate ester resin. The same substance as the cyanate ester resin of the first embodiment can be used as the cyanate ester resin of the second embodiment. The range of the amount of cyanate ester resin contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of cyanate ester resin contained in the resin composition of the first embodiment.

[0174] Furthermore, the curable resin of the second embodiment (B) may also include a carbodiimide resin. The same substance as the carbodiimide resin of the first embodiment can be used as the carbodiimide resin of the second embodiment. The range of the amount of carbodiimide resin included in the resin composition of the second embodiment may be the same as or different from the range of the amount of carbodiimide resin included in the resin composition of the first embodiment.

[0175] In the particularly desirable state, the amount of carbodiimide resin in the resin composition of the second embodiment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, more preferably 10% by mass or less, more preferably 8% by mass or less, and particularly preferably 5% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of carbodiimide resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0176] In the particularly desirable state, the amount of carbodiimide resin in the resin composition of the second embodiment is preferably 0.1% by mass or more, more preferably 1% by mass or more, particularly preferably 2% by mass or more, more preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of carbodiimide resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0177] Furthermore, the curable resin of the second embodiment (B) may also contain curing agents other than those described above. As the curing agent of the second embodiment, the same substance as the curing agent of the first embodiment can be used. The ratio of the number of active groups of the curing agent, such as phenolic resin, reactive ester resin, cyanate ester resin, carbodiimide resin, acid anhydride resin, amine resin, benzoxazine resin, and thiol resin, to the number of epoxy groups of the epoxy resin can be the same as in the first embodiment. That is, in the resin composition of the second embodiment, the range of the number of active groups of the curing agent when the number of epoxy groups of the epoxy resin is set to 1 can be within the same range as described in the first embodiment.

[0178] The range of the amount of curing agent contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of curing agent contained in the resin composition of the first embodiment.

[0179] In the particularly desirable state, the amount of curing agent in the resin composition of the second embodiment is preferably 1% by mass or more, more preferably 5% by mass or more, particularly preferably 10% by mass or more, more preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of curing agent is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0180] In the particularly desirable state, the amount of curing agent in the resin composition of the second embodiment is preferably 10% by mass or more, more preferably 30% by mass or more, particularly preferably 50% by mass or more, preferably 90% by mass or less, more preferably 80% by mass or less, and particularly preferably 70% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of curing agent is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0181] Furthermore, the curable resin of the second embodiment (B) may also include a free radical polymerizable resin. The same substance as the free radical polymerizable resin of the first embodiment can be used as the free radical polymerizable resin. The range of the amount of free radical polymerizable resin included in the resin composition of the second embodiment may be the same as or different from the range of the amount of free radical polymerizable resin included in the resin composition of the first embodiment.

[0182] In the particularly desirable state, the amount of free radical polymerizable resin in the resin composition of the second embodiment is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.3% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 1% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of free radical polymerizable resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0183] In the particularly desirable state, the amount of free radical polymerizable resin in the resin composition of the second embodiment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of free radical polymerizable resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0184] In the above, the curable resin of the second embodiment (B) preferably comprises, like the curable resin of the first embodiment (B), one or more selected from the group consisting of epoxy resin, phenolic resin, reactive ester resin, cyanate ester resin, (meth)acrylic resin, styrene resin, acrylic resin, and maleimide resin. In this case, the total amount of resin selected from the aforementioned group can be the same as the range described in the first embodiment. In a particularly desirable case, the total amount of resin selected from the aforementioned group relative to 100% by mass of the curable resin of (B) is preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably 90% by mass or more, preferably 100% by mass or less, more preferably 98% by mass or less, and particularly preferably 96% by mass or less. When the curable resin of (B) comprises such a preferred resin, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and consequently, the relative permittivity and dielectric loss tangent are generally reduced.

[0185] The range of the amount of (B) curable resin contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of (B) curable resin contained in the resin composition of the first embodiment.

[0186] In the particularly desirable state, the amount of (B) curable resin in the resin composition of the second embodiment is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, preferably 60% by mass or less, more preferably 50% by mass or less, and particularly preferably 40% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition. When the amount of (B) curable resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0187] In the particularly desirable state, the amount of (B) curable resin in the resin composition of the second embodiment is preferably 50% by mass or more, more preferably 60% by mass or more, particularly preferably 70% by mass or more, preferably 98% by mass or less, more preferably 96% by mass or less, and particularly preferably 94% by mass or less, relative to 100% by mass of the resin content of the resin composition. When the amount of (B) curable resin is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0188] <Regarding the inorganic filler material of the second embodiment (C)> The resin composition of the second embodiment of the present invention may further include (C) inorganic filler material as an optional component. The (C) inorganic filler material, as component (C), does not contain substances belonging to components (A) to (B) described above. The (C) inorganic filler material is generally contained in the resin composition in a particle state. One (C) inorganic filler material may be used alone, or two or more may be used in combination. As the (C) inorganic filler material of the second embodiment, the same material as the (C) inorganic filler material described in the first embodiment may be used. Therefore, the scope of the (C) inorganic filler material of the second embodiment may be the same as the scope of the (C) inorganic filler material of the first embodiment.

[0189] The range of the amount of inorganic filler (C) in the resin composition of the second embodiment can be the same as or different from the range of the amount of inorganic filler (C) in the resin composition of the first embodiment. In a particularly desirable form, the amount of inorganic filler (C) in the resin composition of the second embodiment, relative to 100% by mass of the non-volatile components of the resin composition, can be 0% by mass or more than 0% by mass, preferably 40% by mass or more, more preferably 50% by mass or more, particularly preferably 60% by mass or more, preferably 94% by mass or less, more preferably 90% by mass or less, and particularly preferably 85% by mass or less. When the amount of inorganic filler (C) is within the aforementioned range, the crack resistance, temperature stability at high temperatures with dielectric loss tangent, and insulation reliability of the insulating layer are particularly good, and the relative permittivity and dielectric loss tangent are generally reduced.

[0190] <Regarding the (D) hardening accelerator of the second embodiment> The resin composition of the second embodiment of the present invention may further include a (D) curing accelerator as an optional component. The (D) curing accelerator, as component (D), does not contain substances belonging to components (A) to (C) described above. The (D) curing accelerator may be used alone or in combination of two or more. The same substance as the (D) curing accelerator described in the first embodiment may be used as the (D) curing accelerator in the second embodiment. Therefore, the scope of the (D) curing accelerator in the second embodiment may be the same as the scope of the (D) curing accelerator in the first embodiment.

[0191] The range of the amount of (D) curing accelerator contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of (D) curing accelerator contained in the resin composition of the first embodiment.

[0192] In the particularly desirable state, the amount of (D) curing accelerator in the resin composition of the second embodiment, relative to 100% by mass of the non-volatile components of the resin composition, can be 0% by mass or more than 0% by mass, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, particularly preferably 0.03% by mass or more, preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less.

[0193] In the particularly desirable state, the amount of (D) curing accelerator in the resin composition of the second embodiment, relative to 100% by mass of the resin component of the resin composition, can be 0% by mass or more than 0% by mass, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, particularly preferably 0.1% by mass or more, preferably 2.0% by mass or less, more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less.

[0194] <Regarding the second embodiment (E) thermoplastic resin> The resin composition of the second embodiment of the present invention may further include (E) thermoplastic resin as an optional component. The (E) thermoplastic resin, as component (E), does not contain substances belonging to components (A) to (D) described above. The (E) thermoplastic resin may be used alone or in combination of two or more. The same substance as the (E) thermoplastic resin described in the first embodiment may be used as the (E) thermoplastic resin of the second embodiment. Therefore, the scope of the (E) thermoplastic resin of the second embodiment may be the same as the scope of the (E) thermoplastic resin of the first embodiment.

[0195] The range of the amount of (E) thermoplastic resin contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of (E) thermoplastic resin contained in the resin composition of the first embodiment.

[0196] In the particularly desirable state, the amount of (E) thermoplastic resin in the resin composition of the second embodiment, relative to 100% by mass of the non-volatile components of the resin composition, can be 0% by mass or more than 0% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

[0197] In the particularly desirable state, the amount of (E) thermoplastic resin in the resin composition of the second embodiment, relative to 100% by mass of the resin content of the resin composition, can be 0% by mass or more than 0% by mass, preferably 0.1% by mass or more, more preferably 1% by mass or more, particularly preferably 2% by mass or more, preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less.

[0198] <Regarding the second embodiment (F) any additive> The resin composition of the second embodiment of the present invention may further include any additive (F) as any non-volatile component. Among the additives (F) that are components (F), substances belonging to components (A) to (E) above are not included. Any additive (F) may be used alone or in combination of two or more. As the additives (F) of the second embodiment, the same substances as those described in the first embodiment may be used. Therefore, the scope of the additives (F) of the second embodiment may be the same as the scope of the additives (F) of the first embodiment.

[0199] <Regarding the solvent (G) of the second embodiment> In the resin composition of the second embodiment of the present invention, solvent (G) may be further included as an arbitrary volatile component in combination with non-volatile components such as components (A) to (F) described above. Solvent (G) may be used alone or in combination of two or more. As the solvent (G) of the second embodiment, the same solvent as the solvent (G) described in the first embodiment may be used. Therefore, the range of solvents (G) of the second embodiment may be the same as the range of solvents (G) of the first embodiment.

[0200] The range of the amount of solvent (G) contained in the resin composition of the second embodiment may be the same as or different from the range of the amount of solvent (G) contained in the resin composition of the first embodiment.

[0201] <Method for manufacturing the resin composition of the second embodiment> The resin composition of the second embodiment of the present invention can be manufactured, for example, in the same manner as the resin composition of the first embodiment, by mixing the components that may be included in the resin composition.

[0202] <Characteristics of the resin composition in the second embodiment> A cured product can be obtained by curing the resin composition according to the second embodiment of the present invention. During the curing process, heat is typically applied to the resin composition. Therefore, volatile components such as solvent (G) typically contained in the resin composition may volatilize due to the heat during curing, but non-volatile components such as components (A) to (F) may not volatilize due to the heat during curing. Therefore, the cured product of the resin composition may contain non-volatile components of the resin composition or their reaction products.

[0203] For the cured resin composition of the second embodiment of the present invention, excellent temperature stability at high temperatures with a dielectric loss tangent is achieved. Therefore, the increase in the dielectric loss tangent of the cured material in a high-temperature environment can be suppressed. Consequently, the rate of increase of the dielectric loss tangent Df(100°C) of the cured material at 100°C relative to the dielectric loss tangent Df(25°C) of the cured material at 25°C can be reduced. Specifically, the range of the aforementioned rate of increase is generally 0% or more, generally less than 20%, preferably 19% or less, and more preferably 18% or less. When an insulating layer is formed using a cured material with such a low rate of increase of the dielectric loss tangent at high temperatures, an insulating layer with excellent temperature stability at high temperatures with a dielectric loss tangent can be obtained.

[0204] The aforementioned rate of rise of the dielectric loss tangent of the hardened material can be determined by the following formula (X): Rate of increase = {Df(100℃) - Df(25℃)} / Df(25℃) (X) (In formula (X), Df(25℃) represents the dielectric loss tangent at 25℃ of the cured material obtained by heat-treating the resin composition at 200℃ for 90 minutes, and Df(100℃) represents the dielectric loss tangent at 100℃ of the cured material obtained by heat-treating the resin composition at 200℃ for 90 minutes.) The dielectric loss tangent of the hardened material can be measured using the method described in <Experimental Example II-1: Determination of Relative Permittivity (Dk) and Dielectric Loss Tangent (Df)> in the examples described later.

[0205] The cured resin composition of the second embodiment of the present invention exhibits excellent crack resistance. Therefore, when this cured composition is used to form an insulating layer, an insulating layer with excellent crack resistance can be obtained. For example, when the crack resistance is evaluated using the method described in <Test Example I-2: Evaluation of Crack Resistance> of the embodiments described later, the yield is preferably 40% or more, more preferably 60% or more, and particularly preferably 80% or more. Generally, the higher the yield value, the better the crack resistance.

[0206] The cured resin composition of the second embodiment of the present invention exhibits excellent insulation reliability. Therefore, when an insulating layer is formed using this cured composition, an insulating layer with excellent insulation reliability can be obtained. For example, when evaluating insulation reliability using the method described in <Test Example II-3: Evaluation of Insulation Reliability> of the embodiments described later, it is preferable that the number of samples with both the initial resistance value and the HAST resistance value being 1.0 × 10⁶ Ω or higher is 5 or higher, more preferably 6 or higher, and particularly preferably 7.

[0207] The cured resin composition of the second embodiment of the present invention generally has a low dielectric loss tangent. Therefore, when an insulating layer is formed using this cured composition, an insulating layer with a low dielectric loss tangent can be obtained. The dielectric loss tangent of the cured resin composition at 25°C is preferably 0.040 or less, more preferably 0.035 or less, and particularly preferably 0.030 or less. There is no particular limitation on the lower limit; for example, it can be 0.0001 or more. Furthermore, the dielectric loss tangent of the cured resin composition at 100°C is preferably 0.050 or less, more preferably 0.040 or less, and particularly preferably 0.035 or less. There is no particular limitation on the lower limit; for example, it can be 0.0001 or more. The dielectric loss tangent of the cured composition can be measured using the method described in <Experimental Example II-1: Determination of Relative Permittivity (Dk) and Dielectric Loss Tangent (Df)> of the embodiments described later.

[0208] The cured resin composition of the second embodiment of the present invention typically has a low relative permittivity. Therefore, when an insulating layer is formed using this cured composition, an insulating layer with a low relative permittivity can be obtained. The relative permittivity of the cured resin composition at 25°C is preferably 4.0 or less, more preferably 3.8 or less, and particularly preferably 3.5 or less. There is no particular limitation on the lower limit; for example, it can be 0.1 or more. The relative permittivity of the cured composition can be measured using the method described in <Experimental Example II-1: Determination of Relative Permittivity (Dk) and Dielectric Loss Tangent (Df)> of the embodiments described later.

[0209] <Uses of the resin composition of the first and second embodiments> In the following description, "resin composition" refers to both the resin composition of the first embodiment and the resin composition of the second embodiment. The resin composition can be used for insulating purposes, and is particularly preferred as a resin composition for forming an insulating layer (resin composition for forming an insulating layer). For example, the resin composition of this embodiment is preferably used as a resin composition for forming an insulating layer for a semiconductor wafer package (resin composition for an insulating layer of a semiconductor wafer package) and as a resin composition for forming an insulating layer for a circuit board (including a printed wiring board) (resin composition for an insulating layer of a circuit board). In particular, the resin composition is preferably used to form an interlayer insulating layer disposed between conductor layers.

[0210] Examples of semiconductor wafer packaging include: FC-CSP, MIS-BGA packaging, ETS-BGA packaging, fan-out WLP (Wafer Level Package), fan-in WLP, fan-out PLP (Panel Level Package), and fan-in PLP.

[0211] In addition, the aforementioned resin composition can also be used as an underfill material, for example, as a material for MUF (Molding Under Filling) used after a semiconductor wafer is attached to a substrate.

[0212] Furthermore, the aforementioned resin composition can be used in a wide range of applications employing resin compositions, such as resin sheets, prepregs and other sheet-like laminated materials, solder resists, wafer bonding materials, semiconductor sealing materials, hole-filling resins, and component embedding resins.

[0213] <Sheet-like laminated materials> The resin composition can be applied as a varnish, but industrially it is preferred to use it as a sheet-like laminate containing the resin composition.

[0214] As a sheet-like laminated material, resin sheets and prepregs as shown below are preferred.

[0215] In one embodiment, the resin sheet includes a support and a resin composition layer disposed on the support. The resin composition layer is formed using the aforementioned resin composition. Therefore, the resin composition layer typically contains a resin composition, and preferably contains only a resin composition.

[0216] From the viewpoint of achieving thinner profiles and from the viewpoint that resin compositions can provide a cured material with excellent insulation even when thin, it is preferable that the thickness of the resin composition layer is 50 μm or less, and more preferably 40 μm or less. There is no particular limitation on the lower limit of the resin composition layer thickness; it can be 5 μm or more, 10 μm or more, etc.

[0217] Examples of supports include films, metal foils, and release paper made of plastic materials, with films and metal foils made of plastic materials being preferred.

[0218] When using a film formed of a plastic material as a support, examples of plastic materials include: polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), acrylics such as polycarbonate (hereinafter sometimes abbreviated as "PC") and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetin (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0219] When using metal foil as a support, examples of metal foils include copper foil and aluminum foil, with copper foil being preferred. Copper foil can be used as the support, either as a single metal such as copper or as an alloy of copper with other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0220] The surfaces of the support that are bonded to the resin composition layer can be treated with matte finish, corona treatment, and antistatic treatment.

[0221] As a support, a support with a release layer can be used on the surface bonded to the resin composition layer. Examples of release agents for the release layer of the support with the release layer include, for example, one or more release agents selected from alkyd resins, polyolefin resins, urethane resins, and polysiloxane resins. Commercially available products can be used as the support with the release layer, such as PET films having a release layer with an alkyd resin-based release agent as the main component, namely, Lintec's "SK-1", "AL-5", and "AL-7", Toray's "Lumirror T60", Teijin's "Purex", and UNITIKA's "Unipeel".

[0222] There is no particular limitation on the thickness of the support, but it is preferably in the range of 5μm to 75μm, and more preferably in the range of 10μm to 60μm. Furthermore, 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-mentioned range.

[0223] In one embodiment, the resin sheet may further comprise any layer as needed. Examples of such arbitrary layers include, for instance, a protective film, selected according to the support, disposed on the side of the resin composition layer that is not in contact with the support (i.e., the side opposite to the support). The thickness of the protective film is not particularly limited, for example, from 1 μm to 40 μm. By laminating the protective film, it is possible to suppress the adhesion of dust and other contaminants to the surface of the resin composition layer, or to suppress damage to the surface of the resin composition layer.

[0224] Resin sheets can be manufactured, for example, by directly coating a liquid (varnish-like) resin composition onto a support using a die coater or similar machine, or by dissolving the resin composition in a solvent to prepare a liquid (varnish-like) resin composition and coating the resin composition onto a support using a die coater or similar machine, and then drying it to form a resin composition layer.

[0225] As an organic solvent, examples can be made that are the same solvents described as components of the resin. A single solvent may be used, or two or more may be used in combination.

[0226] Drying can be carried out using methods such as heating or blowing hot air. There are no particular restrictions on drying conditions; drying is typically carried out when the solvent content in the resin composition layer is typically 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the solvent in the resin composition, for example, when using a resin composition containing 30% to 60% by mass of solvent, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0227] Resin sheets can be stored by rolling them into rolls. When resin sheets have a protective film, they can usually be used by peeling off the protective film.

[0228] In one embodiment, the prepreg is formed by impregnating the resin composition of this embodiment into a sheet fiber substrate.

[0229] The sheet fiber substrate used in prepregs can be made of materials commonly used as prepreg substrates, such as glass cloth, aromatic polyamide nonwoven fabric, and liquid crystal polymer nonwoven fabric. From the viewpoint of thinness, the thickness of the sheet fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, further preferably 30 μm or less, and particularly preferably 20 μm or less. There is no particular limitation on the lower limit of the thickness of the sheet fiber substrate, which is usually 10 μm or more.

[0230] Prepregs can be manufactured using methods such as hot-melt method and solvent method.

[0231] The thickness of the prepreg can be the same range as the resin composition layer in the resin sheet described above.

[0232] Sheet-like laminated materials are preferably used, for example, in the manufacture of semiconductor wafer packages to form insulating layers (insulating resin sheets for semiconductor wafer packages). Examples of suitable semiconductor wafer packages include, for instance, fan-out type WLP, fan-in type WLP, fan-out type PLP, and fan-in type PLP. Furthermore, sheet-like laminated materials can be used, for example, to form insulating layers for circuit boards (insulating resin sheets for circuit boards). Further, sheet-like laminated materials can be used as materials for MUFs (Multilayer Insulators) used after connecting semiconductor wafers to substrates. In particular, sheet-like laminated materials are preferably used to form interlayer insulating layers.

[0233] <Circuit substrate> One embodiment of the circuit board of the present invention includes a cured resin composition. Typically, the circuit board includes an insulating layer formed from the cured resin composition. The insulating layer includes the cured resin composition described above, preferably only the cured resin composition described above. This circuit board can be manufactured, for example, by a manufacturing method including the following steps (I) and (II): (I) The step of forming a resin composition layer on the inner substrate; (II) The step of hardening the resin composition layer to form an insulating layer.

[0234] The "inner layer substrate" used in step (I) refers to a component that serves as the substrate of a circuit board, such as glass epoxy resin substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. Furthermore, this substrate may have conductive layers on one or both sides, and these conductive layers may be patterned. Sometimes, an inner layer substrate with conductive layers (circuit) formed on one or both sides of the substrate is referred to as an "inner layer circuit board." Additionally, intermediate components for which insulating layers and / or conductive layers are to be further formed during the manufacturing of the circuit board are also included in the aforementioned "inner layer substrate." When the circuit board is a circuit board with built-in components, an inner layer substrate with built-in components can be used.

[0235] When patterning the conductor layer of the inner substrate, from the viewpoint of fully utilizing its excellent crack resistance, the minimum linewidth / line spacing ratio of the conductor layer is preferably small. "Linewidth" refers to the circuit width of the conductor layer, and "line spacing" refers to the interval between circuits. The minimum linewidth / line spacing ratio is preferably 20 / 20 μm or less (i.e., a pitch of 40 μm or less), more preferably 15 / 15 μm or less, and even more preferably 10 / 10 μm or less. The lower limit can be, for example, 0.5 / 0.5 μm or more. The spacing can be uniform or non-uniform throughout the conductor layer. The minimum spacing of the conductor layer can be, for example, 40 μm or less, 36 μm or less, or 30 μm or less.

[0236] The formation of the resin composition layer on the inner substrate can be achieved, for example, by laminating the inner substrate and the resin sheet. The lamination of the inner substrate and the resin sheet can be achieved, for example, by heat-pressing the resin sheet onto the inner substrate from the support side. Examples of components for heat-pressing the resin sheet onto the inner substrate (hereinafter also referred to as "heat-pressing components") include, for example, heated metal plates (SUS end plates, etc.) or metal rollers (SUS rollers). Preferably, the heat-pressing component is not directly pressed onto the resin sheet, but rather pressed through an elastic material such as heat-resistant rubber, so that the resin sheet fully follows the surface irregularities of the inner substrate.

[0237] The lamination of the inner substrate and the resin sheet can be carried out by vacuum lamination. In vacuum lamination, the heating and pressing temperature is preferably 60℃~160℃, more preferably 80℃~140℃; the heating and pressing pressure is preferably 0.098MPa~1.77MPa, more preferably 0.29MPa~1.47MPa; and the heating and pressing time is preferably 20 seconds~400 seconds, more preferably 30 seconds~300 seconds. Lamination is preferably carried out under reduced pressure conditions below 26.7 hPa.

[0238] Lamination can be performed using commercially available vacuum laminators. Examples of commercially available vacuum laminators include: vacuum pressure laminators manufactured by Meiki Manufacturing Co., Ltd., vacuum dressing machines manufactured by Nikko-Materials Co., Ltd., and intermittent vacuum pressure laminators.

[0239] After lamination, the heated pressing member is pressed under normal pressure (atmospheric pressure), for example, from the support side, thereby performing a smoothing treatment on the laminated resin sheet. The pressing conditions for the smoothing treatment can be set to the same conditions as the heated pressing conditions for the lamination described above. The smoothing treatment can be performed using a commercially available laminator. Alternatively, lamination and smoothing treatment can be performed continuously using the aforementioned commercially available vacuum laminator.

[0240] The support can be removed between step (I) and step (II), or after step (II).

[0241] In step (II), the resin composition layer is cured to form an insulating layer formed from the cured resin composition. The curing of the resin composition layer can be performed using methods suitable for resin compositions, such as thermosetting or photosetting. Specific curing conditions for the resin composition layer can be those commonly used when forming insulating layers for circuit boards.

[0242] When using a thermosetting resin composition, the curing of the resin composition can be performed as thermosetting. Therefore, in this case, step (II) may include thermosetting the resin composition layer. The thermosetting conditions of the resin composition layer may vary depending on the type of resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. Furthermore, the curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0243] Furthermore, when heat-curing the resin composition layer, the manufacturing method of the circuit board preferably includes preheating the resin composition layer at a temperature lower than the curing temperature before heat curing. For example, before heat curing the resin composition layer, the resin composition layer may be preheated at a temperature of typically 50°C to 150°C, preferably 60°C to 140°C, more preferably 70°C to 130°C for typically 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.

[0244] On the other hand, when using a photocurable resin composition, the curing of the resin composition can be performed as photocuring. Therefore, in this case, step (II) may include photocuring the resin composition layer. The photocuring conditions of the resin composition may vary depending on the type of resin composition. For example, the resin composition layer of the irradiated portion can be photocured by irradiating it with active light. Examples of active light include ultraviolet light, visible light, electron beams, X-rays, etc., with ultraviolet light being particularly preferred. The irradiation amount of ultraviolet light is, for example, 10 mJ / cm² to 1000 mJ / cm². When using a resin sheet with a support, exposure can be performed through the support or after the support has been peeled off.

[0245] In exposure processing, active light can be irradiated onto a resin composition layer through a patterned mask. Among the exposure methods using masks, there are contact exposure methods where the mask is in contact with the workpiece for exposure, and non-contact exposure methods where parallel light is used for exposure without contact. Either method can be used.

[0246] Step (II) can also be included in the development process after exposure. The development process removes the uncured portions (unexposed areas) and forms a pattern on the cured layer. Development is usually performed by wet development. In wet development, safe, stable, and easy-to-handle developers such as alkaline aqueous solutions, aqueous developers, and organic solvents can be used as the developer. Among these, a development step using an alkaline aqueous solution is preferred. As the development method, methods such as spraying, shaking immersion, brushing, and scraping can be employed.

[0247] Furthermore, during the photocuring of the resin composition layer, a post-baking treatment can be performed as needed after photocuring and development. Examples of post-baking treatments include ultraviolet irradiation using a high-pressure mercury lamp and heat treatment using a clean oven. Ultraviolet irradiation treatment can be performed, for example, at an irradiation dose of approximately 0.05 J / cm² to 10 J / cm². Additionally, heat treatment is preferably performed, for example, at 150°C to 250°C for 20 to 180 minutes, and more preferably at 160°C to 230°C for 30 to 120 minutes.

[0248] In manufacturing the circuit board, steps (III) of opening holes in the insulating layer, (IV) of roughening the insulating layer, and (V) of forming a conductor layer can be further performed. These steps (III) to (V) can be performed according to various methods known to those skilled in the art in the art for manufacturing the circuit board. Furthermore, when the support is removed after step (II), the removal of the support can be performed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). In addition, the formation of the insulating layer and conductor layer in steps (I) to (V) can be repeated as needed to form a circuit board with a multilayer structure, such as a multilayer printed wiring board.

[0249] In other embodiments, the circuit board can be manufactured using the aforementioned prepreg. The manufacturing method is essentially the same as when using resin sheets.

[0250] Step (III) is the step of creating holes in the insulating layer, thereby forming vias, through-holes, and other holes in the insulating layer. Step (III) can be carried out using tools such as drills, lasers, or plasma, depending on the composition of the resin used in the formation of the insulating layer. The size and shape of the holes can be appropriately determined according to the design of the circuit board.

[0251] Step (IV) is a roughening process for the insulating layer. Typically, smear removal is also performed in step (IV). Therefore, the aforementioned roughening process is sometimes referred to as "smear removal." The steps and conditions for the roughening process are not particularly limited, and known steps and conditions commonly used in forming the insulating layer of a circuit board can be employed. For example, the insulating layer can be roughened sequentially by performing a swelling treatment using a swelling solution, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing solution.

[0252] Examples of swelling solutions used in roughening treatments include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solution or potassium hydroxide solution is particularly preferable. Commercially available swelling solutions include, for example, "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by ATOTECH JAPAN. Swelling treatment using a swelling solution can be performed, 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 controlling the resin swelling of the insulating layer at 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.

[0253] Examples of oxidants used in roughening treatments include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment based on oxidants such as alkaline permanganate solutions is preferably performed by immersing the insulating layer in an oxidant 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. Commercially available oxidants include, for example, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Ammet Japan Co., Ltd.

[0254] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution. Commercially available examples include "Reduction Solution Securiganth P" manufactured by Ammet Japan Co., Ltd. The treatment based on the neutralizing solution can be performed by immersing the surface that has undergone oxidant-based roughening treatment in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From an operability perspective, it is preferable to immerse the object that has undergone oxidant-based roughening treatment in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0255] Step (V) is the step of forming a conductor layer. A conductor layer is formed on the insulating layer. There are no particular limitations on the conductor material used in the conductor layer. In a preferred embodiment, the conductor layer comprises one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer can be a single metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). From the viewpoints of versatility, cost, and ease of patterning in conductor layer formation, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of nickel-chromium, copper-nickel, or copper-titanium alloys, is preferred. More preferably, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of nickel-chromium alloys, is even more preferred. A single metal layer of copper is further preferred.

[0256] The conductor layer can be a single-layer structure or a multi-layer structure consisting of two or more single-metal or alloy layers made of different types of metals or alloys. When the conductor 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.

[0257] The thickness of the conductor layer depends on the desired circuit board design, typically 3μm to 35μm, preferably 5μm to 30μm.

[0258] In one embodiment, the conductor layer can be formed by plating. For example, known techniques such as semi-additive and fully additive methods can be used to plate the surface of the insulating layer to form a conductor layer with the desired wiring pattern. From the viewpoint of ease of manufacture, the semi-additive method is preferred. An example of forming a conductor layer using the semi-additive method is shown below.

[0259] First, a seed layer is formed on the surface of an insulating layer using electroless plating. Next, a masking pattern is formed on the formed seed layer, corresponding to the desired wiring pattern, exposing a portion of the seed layer. A metal layer is formed on the exposed seed layer using electrolytic plating, and then the masking pattern is removed. Finally, the unwanted seed layer is removed using etching or the like, forming a conductor layer with the desired wiring pattern.

[0260] In other embodiments, the conductor layer can be formed using metal foil. When using metal foil to form the conductor layer, step (V) is preferably performed between steps (I) and (II). For example, after step (I), the support is removed, and metal foil is laminated onto the surface of the exposed resin composition layer. The lamination of the resin composition layer and the metal foil can be performed by vacuum lamination. The lamination conditions can be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Then, using the metal foil on the insulating layer, a conductor layer with the desired wiring pattern can be formed using existing known techniques such as subtractive processing or modified semi-additive processing.

[0261] Metal foil can be manufactured using known methods such as electrolysis and rolling. Commercially available metal foils include, for example, HLP foil and JXUT-III foil manufactured by JX Minerals & Metals Corporation, and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Metals Corporation.

[0262] Semiconductor wafer packaging One embodiment of the semiconductor wafer package of the present invention includes a cured resin composition. Typically, the semiconductor wafer package includes an insulating layer formed from the cured resin composition. The insulating layer includes the cured resin composition described above, preferably only the cured resin composition described above. Examples of such semiconductor wafer packages include the one described below.

[0263] The semiconductor wafer package of the first example includes the aforementioned circuit substrate and a semiconductor wafer mounted on the circuit substrate. This semiconductor wafer package can be manufactured by bonding the semiconductor wafer to the circuit substrate.

[0264] Regarding the bonding conditions between the circuit board and the semiconductor wafer, any conditions that allow for conductive connection between the terminal electrodes of the semiconductor wafer and the circuit wiring of the circuit board can be used. For example, conditions used in flip-chip mounting of semiconductor wafers can be employed. Furthermore, for example, bonding between the semiconductor wafer and the circuit board can be achieved via an insulating adhesive.

[0265] As an example of a bonding method, one can cite the method of pressing a semiconductor wafer onto a circuit board. As for the pressing conditions, the pressing temperature is usually in the range of 120°C to 240°C (preferably in the range of 130°C to 200°C, more preferably in the range of 140°C to 180°C), and the pressing time is usually in the range of 1 second to 60 seconds (preferably in the range of 5 seconds to 30 seconds).

[0266] In addition, as another example of a bonding method, a method of bonding a semiconductor wafer to a circuit board by reflow can be cited. The reflow conditions can be in the range of 120°C to 300°C.

[0267] After the semiconductor wafer is bonded to the circuit board, it can be filled with a molding underfill material. The above-described resin composition can be used as the molding underfill material.

[0268] The semiconductor wafer package of the second example includes a semiconductor wafer and an insulating layer formed from a cured resin composition. Examples of semiconductor wafer packages of the second example include fan-out type WLP and fan-out type PLP.

[0269] Figure 1 is a schematic cross-sectional view of a fan-out type WLP, which is an example of a semiconductor wafer package according to one embodiment of the present invention. As shown in Figure 1, the semiconductor wafer package 100 of the fan-out type WLP includes: a semiconductor wafer 110; a sealing layer 120 formed to cover the periphery of the semiconductor wafer 110; a redistribution layer 130, which is an insulating layer disposed on the side of the semiconductor wafer 110 opposite to the sealing layer 120; a redistribution layer 140, which is a conductor layer; a solder mask layer 150; and bumps 160.

[0270] Such semiconductor wafer packaging manufacturing methods include: (A) The step of laminating a temporary fixation film on a substrate; (B) The step of temporarily fixing the semiconductor wafer onto the temporary fixing film; (C) The step of forming a sealing layer on a semiconductor wafer; (D) The step of peeling the substrate and temporary fixing film from the semiconductor wafer; (E) The step of forming a rewiring layer on the surface of a semiconductor wafer where the substrate and temporary fixing film have been stripped; (F) The step of forming a rewiring layer as a conductor layer on the rewiring forming layer; and (G) The step of forming a solder resist layer on the rewiring layer. Furthermore, the above-described semiconductor wafer package manufacturing method may include: (H) The step of cutting multiple semiconductor wafer packages into individual semiconductor wafer packages to achieve monolithic packaging.

[0271] (Step (A)) Step (A) is the step of laminating a temporary fixing film on the substrate. The lamination conditions of the substrate and the temporary fixing film can be the same as the lamination conditions of the substrate and the resin sheet in the method of manufacturing a circuit board.

[0272] Examples of substrates include: silicon wafers; glass wafers; glass substrates; metal substrates such as copper, titanium, stainless steel, and cold-rolled steel sheets (SPCC); substrates such as FR-4 substrates obtained by infiltrating glass fibers with epoxy resin and then subjecting them to thermosetting treatment; substrates formed from bismaleimide triazine resins such as BT resin; and so on.

[0273] Temporary fixation films can be made of any material that can be peeled off from a semiconductor wafer and temporarily fix the semiconductor wafer. Commercially available examples include "REVALPHA" manufactured by Nitto Denko Corporation.

[0274] (Step (B)) Step (B) is the step of temporarily fixing the semiconductor wafer onto the temporary fixing film. Temporary fixing of the semiconductor wafer can be performed using devices such as flip chip bonders or die bonders. The layout and number of semiconductor wafers can be appropriately set according to the shape and size of the temporary fixing film, the production quantity of the target semiconductor wafer package, etc. For example, the semiconductor wafers can be arranged in a matrix of multiple rows and columns for temporary fixing.

[0275] (Step (C)) Step (C) is the step of forming a sealing layer on the semiconductor wafer. The sealing layer may be formed, for example, from a photosensitive resin composition or a thermosetting resin composition. The sealing layer may be formed using a cured form of the resin composition of the embodiment described above. The sealing layer can generally be formed by a method comprising the steps of forming a resin composition layer on the semiconductor wafer and curing the resin composition layer to form the sealing layer.

[0276] (Step (D)) Step (D) is the step of peeling the substrate and the temporary fixing film from the semiconductor wafer. Ideally, the peeling method should be suitable for the material of the temporary fixing film. Examples of peeling methods include heating, foaming, or expanding the temporary fixing film. Another example is peeling by irradiating the temporary fixing film with ultraviolet light through the substrate, thereby reducing the adhesion of the temporary fixing film.

[0277] If the substrate and temporary fixing film are peeled off from the semiconductor wafer as described above, the surface of the sealing layer is exposed. A method for manufacturing a semiconductor wafer package may include grinding the exposed surface of the sealing layer. Grinding improves the smoothness of the sealing layer surface.

[0278] (Step (E)) Step (E) is the step of forming a rewiring layer as an insulating layer on the surface of the semiconductor wafer where the substrate and temporary fixing film have been stripped. Typically, this rewiring layer is formed on the semiconductor wafer and the sealing layer. The rewiring layer can be formed using a cured resin composition of the embodiment described above. The rewiring layer can generally be formed using a method that includes the steps of forming a resin composition layer on the semiconductor wafer and curing the resin composition layer to form the rewiring layer. The formation of the resin composition layer on the semiconductor wafer can be performed, for example, by a method identical to the method for forming a resin composition layer on an inner substrate described in the aforementioned circuit board manufacturing method, except that a semiconductor wafer is used to replace the inner substrate.

[0279] After forming a resin composition layer on a semiconductor wafer, the resin composition layer is cured to obtain a rewiring layer, which is an insulating layer containing the cured resin composition. The curing conditions of the resin composition layer can be the same as those used in the method for manufacturing a circuit board. When thermally curing the resin composition layer, a preheating treatment can be performed on the resin composition layer at a temperature lower than the curing temperature before thermal curing. The preheating treatment conditions can be the same as those used in the preheating treatment method for manufacturing a circuit board. Typically, after forming the rewiring layer, holes are formed in the rewiring layer to connect the semiconductor wafer to the rewiring layer.

[0280] (Step (F)) Step (F) is the step of forming a rewiring layer as a conductor layer on the rewiring forming layer. The method of forming the rewiring layer on the rewiring forming layer can be the same as the method of forming a conductor layer on an insulating layer in the circuit board manufacturing method. In addition, steps (E) and (F) can be repeated to alternately deposit (stack) the rewiring layer and the rewiring forming layer.

[0281] (Step (G)) Step (G) is the step of forming a solder mask layer on the rewiring layer. The solder mask layer can be made of any insulating material. From the viewpoint of ease of manufacturing semiconductor wafer packages, photosensitive resin compositions and thermosetting resin compositions are preferred. The solder mask layer can also be formed using a cured form of the resin composition described in the above embodiments.

[0282] Furthermore, in step (G), bump machining can be performed as needed to form bumps. Bump machining can be performed using methods such as solder balls or solder plating. Additionally, the formation of through-holes during bump machining can be performed in the same manner as in step (E).

[0283] (Step (H)) In addition to steps (A) to (G), the method for manufacturing a semiconductor wafer package may also include step (H). Step (H) is a step of monolithicization, in which multiple semiconductor wafer packages are cut into individual semiconductor wafer packages. The method for cutting the semiconductor wafer packages into individual semiconductor wafer packages is not particularly limited.

[0284] Semiconductor Devices Semiconductor devices include the aforementioned circuit board or semiconductor wafer package. Examples of semiconductor devices include various semiconductor devices used in electrical products (such as computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical devices, and televisions) and vehicles (such as motorcycles, automobiles, trams, ships, and airplanes). [Example]

[0285] The following examples illustrate the invention in detail. However, the invention is not limited to the following examples. In the following description, unless otherwise specified, "parts" and "%" refer to "parts by mass" and "% by mass," respectively. Furthermore, the temperature and pressure conditions, unless otherwise specified, are room temperature (25°C) and atmospheric pressure (1 atm). In the following description, "L / S" also represents the line width / spacing ratio of the wiring diagram.

[0286] <Synthesis example 1> In a 1L reaction vessel equipped with a thermometer, stirrer, and condenser, 410g of methanol, 48.0g of sodium hydroxide, and 205.0g of biphenol were added. While monitoring for exothermic heating, 91.8g of allyl chloride was added dropwise over 3 hours at 40°C. The temperature was then raised to the methanol reflux temperature (approximately 60°C) for 4 hours for allyl etherification. After washing with water to remove salt, the temperature was raised to 180°C for 10 hours for a transfer reaction. Following the transfer reaction, the temperature was lowered to 100°C, and 205.0g of butanol was added to dissolve the resin. Then, 70.5g of potassium hydroxide was added, and a propyleneation reaction was carried out at 115°C for 6 hours. The resin was then washed with water and concentrated to obtain the propylene-based resin shown in formula (b1) (propylene matrix of biphenol, hydroxyl equivalent 133g / eq.).

[0287] <Description of Example Group I> <Example I-1> While stirring, 20 parts of biphenyl-type epoxy resin (NC3000L manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent approximately 269 g / eq.) and 10 parts of bisphenol-type epoxy resin (ZX1059 manufactured by Nippon Steel Chemical Materials Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent approximately 169 g / eq.) were heated and dissolved in 25 parts of naphtha solvent to obtain a solution. The solution was cooled to room temperature to prepare the epoxy resin solution composition.

[0288] The epoxy resin solution contains 5 parts of polystyrene microparticles (SEP-03T3 manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm), 100 parts of an active ester compound (HPC-8150-62T manufactured by DIC Co., Ltd., with an active ester equivalent of approximately 220 g / eq. and a non-volatile component content of 62% by mass in toluene solution), and a phenolic curing agent containing a triazine skeleton (LA-3018-50P manufactured by DIC Co., Ltd., with an active group equivalent of approximately 15%). 10 parts of a 2-methoxypropanol solution with 1 g / eq. and 50% non-volatile content, 15 parts of a carbodiimide-based curing agent (Nisshinbo Chemical Co., Ltd. "V-03", active group equivalent of about 216 g / eq., toluene solution with 50% non-volatile content), 300 parts of spherical silica (Yaduma Co., Ltd. "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m² / g) surface-treated with silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-573"), 0.2 parts of curing accelerator (4-dimethylaminopyridine (DMAP)), and 10 parts of phenoxy resin (Mitsubishi Chemical Co., Ltd. "YX7553BH30", a 1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile content) were uniformly dispersed using a high-speed rotary mixer to prepare a resin composition.

[0289] <Example I-2> The amount of polystyrene microparticles (SEP-03T3 manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm) was increased from 5 parts to 20 parts. Furthermore, instead of 100 parts of the active ester compound (HPC-8150-62T manufactured by DIC Co., Ltd., an active ester equivalent of approximately 220 g / eq., and a toluene solution with a non-volatile content of 62% by mass), 100 parts of the active ester compound (HPC-8000-65T manufactured by DIC Co., Ltd., an active ester equivalent of approximately 223 g / eq., and a toluene solution with a non-volatile content of 65%) was used. Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0290] <Example I-3> Five parts of polystyrene microparticles (SEP-03T3, manufactured by Negami Kogyo Co., Ltd., average particle size 0.3 μm) were replaced with five parts of polystyrene / acrylic acid copolymer microparticles (SEP-03T3A, manufactured by Negami Kogyo Co., Ltd., average particle size 0.3 μm). Furthermore, the amount of spherical silica particles (SO-C2, manufactured by Yatuma Co., Ltd., average particle size 0.5 μm, specific surface area 5.8 m² / g) surface-treated with a silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) was reduced from 300 parts to 210 parts. Further, six parts of hollow aluminosilicate particles (MG-005, manufactured by Pacific Cement Co., Ltd., hollow inorganic filler, average particle size 1.6 μm, porosity 80% by volume) were added to the resin composition. Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0291] <Example I-4> Five parts of polystyrene microparticles (SEP-03T3 manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm) were replaced with five parts of polystyrene microparticles (XX-6283Z manufactured by Sekisui Kasei Co., Ltd., with an average particle size of 0.3 μm). Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0292] <Example I-5> Five parts of polystyrene microparticles (SEP-03T3 manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm) were replaced with five parts of carboxyl-treated polystyrene microparticles (XX-6288Z manufactured by Sekisui Kasei Co., Ltd., with an average particle size of 0.3 μm). Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0293] <Example I-6> Five parts of polystyrene microparticles (SEP-03T3 manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm) were replaced with five parts of polystyrene microparticles (GS-0305 manufactured by AICA Kogyo Co., Ltd., with an average particle size of 3.0 μm). Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0294] <Example I-7> Five parts of polystyrene microparticles (SEP-03T3 manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm) were replaced with five parts of polyethylene microparticles (SB-25 manufactured by Morimoto Chemical Co., Ltd., with an average particle size of 2.5 μm). Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0295] <Example I-8> The following materials were used instead of 20 parts of biphenyl-type epoxy resin (NC3000L manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent approximately 269 g / eq.) and 10 parts of bisphenol-type epoxy resin (ZX1059 manufactured by Nippon Steel Chemical Materials Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent approximately 169 g / eq.), and 20 parts of naphthalene-type epoxy resin (HP-4032-SS manufactured by DIC Co., Ltd., 1,6-bis(glycidoxy)naphthalene, epoxy equivalent approximately 145 g / eq.) and 10 parts of xylenol-type epoxy resin (YX4000H manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent 190 g / eq.). Then, 3 parts of biphenyl alkylphenol varnish-type maleimide (MIR-3000-70MT manufactured by Nippon Kayaku Co., Ltd., a MEK / toluene mixed solution with a non-volatile component rate of 70%) were added to the resin composition. Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0296] <Example I-9> Three parts of biphenyl aryl phenolic varnish-type maleimide (MIR-3000-70MT, manufactured by Nippon Kayaku Co., Ltd., a MEK / toluene mixed solution with 70% non-volatile components) were replaced with five parts of vinyl benzyl modified polyphenylene ether (OPE-2St 2200, manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with 65% non-volatile components). Except for the above, the resin composition was prepared in the same manner as in Examples I-8.

[0297] <Example I-10> Five parts of polystyrene microparticles (SEP-03T3, manufactured by Negami Kogyo Co., Ltd., average particle size 0.3 μm) were replaced with three parts of polystyrene / acrylic acid copolymer microparticles (SEP-03T3A, manufactured by Negami Kogyo Co., Ltd., average particle size 0.3 μm) and two parts of polystyrene microparticles (XX-6283Z, manufactured by Sekisui Kasei Co., Ltd., average particle size 0.3 μm). Furthermore, three parts of the propylene-based resin obtained in Synthesis Example 1 were used instead of three parts of the biphenyl alkylphenol varnish-type maleimide (MIR-3000-70MT, manufactured by Nippon Kayaku Co., Ltd., MEK / toluene mixed solution with 70% non-volatile content). Except for the above, the resin composition was prepared in the same manner as in Examples I-8.

[0298] <Example I-11> The following formulation was used instead of 100 parts of an active ester compound (DIC Corporation's "HPC-8150-62T", a toluene solution with an active ester equivalent of approximately 220 g / eq. and a non-volatile component percentage of 62% by mass), 10 parts of a phenolic curing agent containing a triazine skeleton (DIC Corporation's "LA-3018-50P", a 2-methoxypropanol solution with an active group equivalent of approximately 151 g / eq. and a non-volatile component percentage of 50%), and 15 parts of a carbodiimide curing agent (Nisshinbo Chemical Co., Ltd.'s "V-03", a toluene solution with an active group equivalent of approximately 216 g / eq. and a non-volatile component percentage of 50%), and 40 parts of a phenolic varnish-type phenolic curing agent (DIC Corporation's "TD-2090", a solution with an active group equivalent of approximately 105 g / eq. and a non-volatile component percentage of 60%). Furthermore, the amount of spherical silica (SO-C2, average particle size 0.5 μm, specific surface area 5.8 m² / g), which had been surface-treated with a silane coupling agent (KBM-573, Shin-Etsu Chemical Co., Ltd.), was reduced from 300 parts to 50 parts. Further, 0.2 parts of the curing accelerator (4-dimethylaminopyridine (DMAP)) were replaced with 0.1 parts of an imidazole-based curing accelerator (1B2PZ, 1-benzyl-2-phenylimidazolium, Shikoku Chemical Co., Ltd.). Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0299] <Example I-12> The following formulation was used instead of the active ester compound (DIC Corporation's "HPC-8150-62T", a toluene solution with an active ester equivalent of approximately 220 g / eq. and a non-volatile content of 62% by mass): 100 parts; a phenolic curing agent containing a triazine skeleton (DIC Corporation's "LA-3018-50P", a 2-methoxypropanol solution with an active ester equivalent of approximately 151 g / eq. and a non-volatile content of 50%): 2-methoxypropanol solution; and a carbodiimide curing agent (Nisshinbo Chemical Co., Ltd.'s "V-03", a toluene solution with an active ester equivalent of approximately 216 g / eq. and a non-volatile content of 50%): 15 parts; and a prepolymer of bisphenol A dicyanate (Lonza Japan's "Primaset"). 20 parts of a MEK solution containing BA230S75 (approximately 232 g / eq. of cyanate ester equivalent and 75% by mass of non-volatile components) were prepared. Furthermore, the amount of spherical silica (SO-C2, average particle size 0.5 μm, specific surface area 5.8 m² / g) surface-treated with a silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) was reduced from 300 parts to 60 parts. Further, 0.01 parts of cobalt(III) acetone (Co(III)AcAc, manufactured by Tokyo Chemical Co., Ltd.) were added to the resin composition. Except for the above, the resin composition was prepared in the same manner as in Example I-1.

[0300] <Comparative Example I-1> The resin composition was prepared in the same manner as in Example I-1, except that polystyrene microparticles (SEP-03T3 manufactured by Neage Kogyo Co., Ltd., with an average particle size of 0.3 μm) were not used.

[0301] <Comparative Example I-2> Five parts of core-shell structured rubber particles (AICA Industrial Co., Ltd.'s "STAPHYLOID AC3816N", with an acrylic resin core and a polymethyl methacrylate resin shell, average particle size 0.3 μm) were used instead of polystyrene microparticles (SEP-03T3, manufactured by Negami Kogyo Co., Ltd.). Biphenyl alkylphenol varnish-type maleimide (MIR-3000-70MT, manufactured by Nippon Kayaku Co., Ltd., a MEK / toluene mixture with a 70% non-volatile content) was not used. Except for the above, the resin composition was prepared in the same manner as in Examples I-8.

[0302] <Comparative Example I-3> Five parts of polystyrene particles (G-800T, Negami Kogyo Co., Ltd., average particle size 0.3 μm) were used instead of five parts of polystyrene microparticles (SEP-03T3, Negami Kogyo Co., Ltd., average particle size 6.0 μm). Furthermore, biphenyl alkylphenol varnish-type maleimide (MIR-3000-70MT, Nippon Kayaku Co., Ltd., MEK / toluene mixed solution with 70% non-volatile component) was not used. Except for the above, the resin composition was prepared in the same manner as in Examples I-8.

[0303] <Comparative Example I-4> The resin composition was prepared in the same manner as in Examples I-12, except that polystyrene microparticles (SEP-03T3 manufactured by Neage Kogyo Co., Ltd., with an average particle size of 0.3 μm) were not used.

[0304] Manufacturing of Resin Sheets As a support, a polyethylene terephthalate film (Lintec Corporation "AL5", thickness 38 μm) with a release layer was prepared. The resin composition obtained in the above-described examples and comparative examples was uniformly coated onto the release layer of this support, so that the thickness of the dried resin composition layer was 40 μm. Then, the resin composition was dried at 80°C to 100°C (average 90°C) for 4 minutes to obtain a resin sheet comprising the support and the resin composition layer.

[0305] <Experimental Example I-1: Determination of Relative Permittivity (Dk) and Dielectric Loss Tangent (Df)> The aforementioned resin sheet was heated at 200°C for 90 minutes to thermally harden the resin composition layer. The support was then peeled off, thereby obtaining a hardened film formed from the hardened resin composition. The hardened film was cut into pieces with a width of 2 mm and a length of 80 mm to obtain hardened material A for evaluation.

[0306] For the obtained evaluation hardened material A, the relative permittivity (Dk) and dielectric loss tangent (Df) were measured using an Agilent Technologies HP8362B instrument with resonant cavity perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23 °C. Measurements were performed on three samples, and the average values ​​were calculated.

[0307] <Experimental Example I-2: Evaluation of Crack Resistance> (1) Lamination of resin sheets: An inner layer substrate (Hitachi Chemical Co., Ltd. "MCL-E700G", conductor layer thickness 35μm, total thickness 0.4mm, residual copper ratio 40%) with circuit conductors (copper) formed on both sides as a wiring pattern of L / S=8μm / 8μm) was prepared. Resin sheets were laminated to both sides of this inner layer substrate by bonding resin composition layers to the inner layer substrate. The lamination was performed as follows: using a vacuum pressure laminator (Mingki Manufacturing Co., Ltd. "MVLP-500"), after vacuuming for 30 seconds at 120°C, the material was pressed from a support body for 30 seconds at 120°C and 7.0 kg / cm² pressure using heat-resistant rubber. Next, under atmospheric pressure, SUS end plates were used for 60 seconds at 120°C and 5.5 kg / cm² pressure.

[0308] (2) Thermosetting of the resin composition layer: The resin composition layer was heated at 130°C for 30 minutes, followed by heating at 170°C for 30 minutes to thermally harden it, resulting in an insulating layer formed from the hardened resin composition. The support was then peeled off to obtain a sample substrate with a layer structure of insulating layer / inner substrate / insulating layer.

[0309] (3) Roughening treatment: The insulating layer of the sample substrate was roughened. Specifically, the sample substrate was immersed in Swelling Dip Securiganth P manufactured by Amtec Japan Co., Ltd. at 60°C for 10 minutes as a swelling solution. Next, it was immersed in Concentrate Compact P (an aqueous solution of KMnO4: 60 g / L and NaOH: 40 g / L) manufactured by Amtec Japan Co., Ltd. as a roughening solution at 80°C for 20 minutes. Finally, it was immersed in Reduction solution Securiganth P manufactured by Amtec Japan Co., Ltd. as a neutralizing solution at 40°C for 5 minutes.

[0310] (4) Evaluation of cracks: After roughening the surface of the insulating layer, observe portions of the wiring pattern on the inner layer substrate. Check for cracks (fissures) on the surface of the insulating layer by examining the pattern shape of 100 inner layer substrates, and count the proportion of patterns without cracks. Calculate this proportion as the "yield rate". Furthermore, score the calculated yield rate according to the following criteria: 1 point: 0% or higher and less than 20% 2 points: 20% or more but less than 40% 3 points: 40% or higher but less than 60% 4 points: 60% or higher but less than 80% 5 points: above 80% Rating 5 points or above as "○", 3-4 points as "△", and 2 points or below as "×".

[0311] <Experimental Example I-3: Evaluation of Foaming Resistance> (1) Substrate treatment of the internal substrate: As the inner layer substrate, a double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, Panasonic "R1515A") was prepared on a glass cloth substrate with copper foil on both sides. The copper foil on the surface of the inner layer substrate was etched using a micro-etching agent (MEC "CZ8101") at a copper etching depth of 1 μm to roughen the surface. Then, it was dried at 190°C for 30 minutes.

[0312] (2) Lamination and curing of resin sheets: Using an intermittent vacuum pressure laminator (Nikko-Materials 2-Stage Buildup Laminator "CVP700"), resin sheets were laminated onto both sides of the inner layer substrate by bonding the resin composition layer to the aforementioned inner layer substrate. This lamination was performed as follows: after a 30-second decompression to bring the pressure below 13 hPa, pressing was carried out for 30 seconds at a temperature of 100°C and a pressure of 0.74 MPa. Next, the laminated resin sheet was hot-pressed for 60 seconds at atmospheric pressure, 100°C, and a pressure of 0.5 MPa to smooth it.

[0313] The resin composition layer is heated in an oven at 130°C for 30 minutes, and then transferred to an oven at 170°C for another 30 minutes to thermally harden it, resulting in an insulating layer formed from the hardened resin composition. The support is then peeled off to obtain an intermediate substrate with a layer structure of insulating layer / inner substrate / insulating layer.

[0314] (3) Roughening treatment: The intermediate substrate was immersed in Swelling Dip Securiganth P manufactured by Amtec Japan Co., Ltd. at 60°C for 10 minutes as a swelling solution. Next, it was immersed in Concentrate Compact P (an aqueous solution of KMnO4: 60 g / L and NaOH: 40 g / L) manufactured by Amtec Japan Co., Ltd. as a roughening solution at 80°C for 20 minutes. Then, it was immersed in Reduction Solution Securiganth P manufactured by Amtec Japan Co., Ltd. as a neutralizing solution at 40°C for 5 minutes. The resulting intermediate substrate was used as evaluation substrate A.

[0315] (4) Plating using a semi-additive process: To form a circuit on the surface of the insulating layer, evaluation substrate A was immersed in an electroless plating solution containing PdCl₂, followed by immersion in an electroless copper plating solution. After annealing at 150°C for 30 minutes, a resist layer was formed, and an etched pattern was formed. Then, copper sulfate electrolytic plating was performed to form a conductor layer with a thickness of 30 ± 5 μm. Next, annealing was performed at 180°C for 60 minutes. Thus, evaluation substrate B was obtained as a circuit substrate having a conductor layer on an insulating layer.

[0316] (5) Evaluation of expansion during the reflux step: The evaluation substrate B was cut to obtain small pieces of 100mm × 50mm. These small pieces were subjected to a reflow test five times using a reflow apparatus (HAS-6116, Antom Ltd., Japan) that reproduces the peak temperature of 260°C (reflow temperature profile according to IPC / JEDEC J-STD-020C). The aforementioned test was performed on five small pieces, and the pieces were visually observed after the test. Based on the visual observation results, blister resistance was rated "×" if three or more small pieces showed abnormalities such as conductor layer expansion. Furthermore, blister resistance was rated "△" if one or two small pieces showed abnormalities such as conductor layer expansion. Finally, blister resistance was rated "○" if no abnormalities were found in any of the small pieces.

[0317] <Results regarding Example Group I> The results of Examples I-1 to I-12 and Comparative Examples I-1 to I-4 described above are shown in Tables 1 to 3 below. In the tables below, "Compound 1" refers to the acrylic resin manufactured in Synthesis Example 1.

[0318]

[0319]

[0320]

[0321] <Description of Example Group II> <Example II-1> While stirring, 20 parts of biphenyl-type epoxy resin (NC3000L manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent approximately 269 g / eq.) and 10 parts of bisphenol-type epoxy resin (ZX1059 manufactured by Nippon Steel Chemical Materials Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent approximately 169 g / eq.) were heated and dissolved in 25 parts of naphtha solvent to obtain a solution. The solution was cooled to room temperature to prepare the epoxy resin solution composition.

[0322] The epoxy resin solution contains 5 parts of polystyrene microparticles (SEP-03T3 manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm), an active ester compound (HPC-8150-62T manufactured by DIC Co., Ltd., with an active ester equivalent of approximately 220 g / eq. and a non-volatile component content of 62% by mass in toluene solution). 100 parts of a phenolic curing agent containing a triazine skeleton (DIC Corporation's "LA-3018-50P", active group equivalent approximately 151 g / eq., 50% non-volatile component in a 2-methoxypropanol solution), 10 parts of a carbodiimide curing agent (Nisshinbo Chemical Co., Ltd.'s "V-03", active group equivalent approximately 216 g / eq., 50% non-volatile component in a toluene solution), and 15 parts of spherical silica (Yaduma Corporation's "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m² / g) surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM-573"). 300 parts of a resin composition were prepared by uniformly dispersing the following ingredients: a curing accelerator (4-dimethylaminopyridine (DMAP)) and a phenoxy resin (Mitsubishi Chemical Co., Ltd. "YX7553BH30", a 1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile components) using a high-speed rotary mixer.

[0323] <Example II-2> The amount of polystyrene microparticles (SEP-03T3 manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm) was increased from 5 parts to 15 parts. Furthermore, instead of 100 parts of the active ester compound (HPC-8150-62T manufactured by DIC Co., Ltd., an active ester equivalent of approximately 220 g / eq., and a toluene solution with a non-volatile content of 62% by mass), 100 parts of the active ester compound (HPC-8000-65T manufactured by DIC Co., Ltd., an active ester equivalent of approximately 223 g / eq., and a toluene solution with a non-volatile content of 65%) was used. Except for the above, the resin composition was prepared in the same manner as in Example II-1.

[0324] <Example II-3> Five parts of polystyrene microparticles (SEP-03T3, manufactured by Negami Kogyo Co., Ltd., average particle size 0.3 μm) were replaced with five parts of polystyrene / acrylic acid copolymer microparticles (SEP-03T3A, manufactured by Negami Kogyo Co., Ltd., average particle size 0.3 μm). Furthermore, the amount of spherical silica particles (SO-C2, manufactured by Yatuma Co., Ltd., average particle size 0.5 μm, specific surface area 5.8 m² / g) surface-treated with a silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) was reduced from 300 parts to 210 parts. In addition, six parts of hollow aluminosilicate particles (MG-005, manufactured by Pacific Cement Co., Ltd., hollow inorganic filler, average particle size 1.6 μm, porosity 80% by volume) were added to the resin composition. Except for the above, the resin composition was prepared in the same manner as in Example II-1.

[0325] <Example II-4> Five parts of polystyrene microparticles (SEP-03T3, manufactured by Negami Kogyo Co., Ltd., with an average particle size of 0.3 μm) were replaced with five parts of carboxyl-treated polystyrene microparticles (XX-6288Z, manufactured by Sekisui Kasei Co., Ltd., with an average particle size of 0.3 μm). Furthermore, three parts of a biphenyl alkylphenol varnish-type maleimide (MIR-3000-70MT, manufactured by Nippon Kayaku Co., Ltd., a MEK / toluene mixed solution with a non-volatile component content of 70%) were added to the resin composition. Except for the above, the resin composition was prepared in the same manner as in Example II-1.

[0326] <Example II-5> Five parts of polystyrene microparticles (SEP-03T3, manufactured by Negami Kogyo Co., Ltd., average particle size 0.3 μm) were replaced with five parts of polystyrene microparticles (GS-0305, manufactured by AICA Kogyo Co., Ltd., average particle size 3.0 μm). Furthermore, ten parts of bisphenol-type epoxy resin (ZX1059, manufactured by Nippon Steel Chemical Materials Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent approximately 169 g / eq.) were replaced with ten parts of naphthalene-type epoxy resin (HP-4032-SS, manufactured by DIC Co., Ltd., 1,6-bis(glycidoxy)naphthalene, epoxy equivalent approximately 145 g / eq.). Further, five parts of vinyl benzyl-modified polyphenylene ether (OPE-2St 2200, manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with a non-volatile content of 65%) were added to the resin composition. Except for the above, the resin composition was prepared in the same manner as in Example II-1.

[0327] <Example II-6> Five parts of polystyrene microparticles (AICA Kogyo Co., Ltd. "GS-0305", average particle size 3.0 μm) were replaced with five parts of polyethylene microparticles (Morimura Chemical Co., Ltd. "SB-25", average particle size 2.5 μm). Furthermore, five parts of vinyl benzyl-modified polyphenylene ether (Mitsubishi Gas Chemical Co., Ltd. "OPE-2St 2200", toluene solution with 65% non-volatile content) were replaced with three parts of the acrylic resin obtained in Synthesis Example 1. Except for the above, the resin composition was prepared in the same manner as in Examples II-5.

[0328] <Example II-7> Five parts of polystyrene microparticles (AICA Kogyo Co., Ltd. "GS-0305", average particle size 3.0 μm) were replaced with five parts of polystyrene microparticles (Negami Kogyo Co., Ltd. "SEP-03T3", average particle size 0.3 μm). Furthermore, the amount of the active ester compound (DIC Co., Ltd. "HPC-8150-62T", active ester equivalent approximately 220 g / eq., toluene solution with 62% by mass of non-volatile components) was reduced from 100 parts to 80 parts. Further, the amount of spherical silica (Yaduma Co., Ltd. "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m² / g) surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-573") was reduced from 300 parts to 250 parts. Except for the above, the resin composition was prepared in the same manner as in Examples II-5.

[0329] <Comparative Example II-1> The resin composition was prepared in the same manner as in Example II-1, except that polystyrene microparticles (SEP-03T3 manufactured by Neage Kogyo Co., Ltd., with an average particle size of 0.3 μm) were not used.

[0330] <Comparative Example II-2> Five parts of core-shell structured rubber particles (STAPHYLOID AC3816N manufactured by AICA Industries Co., Ltd., with an average particle size of 0.3 μm) were used instead of five parts of polystyrene microparticles (SEP-03T3 manufactured by Neage Kogyo Co., Ltd., with an average particle size of 0.3 μm). In addition, 20 parts of biphenyl-type epoxy resin (NC3000L manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent approximately 269 g / eq.) and 10 parts of bisphenol-type epoxy resin (ZX1059 manufactured by Nippon Steel Chemical Materials Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent approximately 169 g / eq.) were replaced with naphthalene-type epoxy resin (HP-4032-SS manufactured by DIC Co., Ltd., 1,6-bis(glycidoxy)naphthalene, epoxy equivalent approximately 145 g / eq.) and 10 parts of bixylenol-type epoxy resin (YX4000H manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent 190 g / eq.). Except for the above, the resin composition was prepared in the same manner as in Example II-1.

[0331] <Comparative Example II-3> Five parts of polystyrene particles (“STAPHYLOID AC3816N” manufactured by AICA Industries, Inc., with an average particle size of 0.3 μm) were used instead of five parts of rubber particles. Five parts of polystyrene particles (“G-800T” manufactured by Negami Industries, Inc., with an average particle size of 6.0 μm) were used instead of five parts of rubber particles (“STAPHYLOID AC3816N” manufactured by AICA Industries, Inc., with an average particle size of 0.3 μm). Except for the above, the resin composition was prepared in the same manner as in Comparative Example II-2.

[0332] Manufacturing of Resin Sheets As a support, a polyethylene terephthalate film (Lintec Corporation "AL5", thickness 38 μm) with a release layer was prepared. The resin composition obtained in the above-described examples and comparative examples was uniformly coated onto the release layer of this support, so that the thickness of the dried resin composition layer was 40 μm. Then, the resin composition was dried at 80°C to 100°C (average 90°C) for 4 minutes to obtain a resin sheet comprising the support and the resin composition layer.

[0333] <Experimental Example II-1: Determination of Relative Permittivity (Dk) and Dielectric Loss Tangent (Df)> The aforementioned resin sheet was heated at 200°C for 90 minutes to thermally harden the resin composition layer. The support was then peeled off, thereby obtaining a hardened film formed from the hardened resin composition. The hardened film was cut into 62mm × 75mm pieces to obtain hardened material A for evaluation.

[0334] For the obtained evaluation hardened material A, the dielectric loss tangent and relative permittivity were measured at a measurement frequency of 10 GHz using an EM Labs CR-710 resonator. The dielectric loss tangent was measured at 25 °C and 100 °C. Furthermore, the relative permittivity was measured at 25 °C.

[0335] Calculate the rate of increase of the dielectric loss tangent Df(100℃) at 100℃ relative to the dielectric loss tangent Df(25℃) at 25℃: {Df(100℃) - Df(25℃)} / Df(25℃). If this rate of increase is less than 20%, the temperature stability of the dielectric loss tangent at high temperature is determined to be "0". Furthermore, if the rate of increase is greater than 20%, the temperature stability of the dielectric loss tangent at high temperature is determined to be "×".

[0336] <Experimental Example II-2: Evaluation of Crack Resistance> The formation and cracking of the insulating layer using the resin composition manufactured in each example and comparative example were evaluated by the method described in <Test Example I-2: Evaluation of Crack Resistance> in the description of relevant Example Group I.

[0337] <Experimental Example II-3: Evaluation of Insulation Reliability> Resin sheets were laminated onto TAB tape (used in tape automated bonding) with L / S = 20 μm / 20 μm using an intermittent vacuum laminator (Nichigo-Morton VP160). After peeling off the support, the resin composition layer was hardened by heating at 180°C for 90 minutes in an intermittent oven, resulting in a sample with a layer structure of TAB tape / insulation layer. The resistivity of the insulation layer was measured at 7 locations. The measured resistivity of the insulation layer is referred to as the "initial resistivity".

[0338] Next, a HAST test was conducted, in which the sample was placed in a HAST testing machine (manufactured by Kusumoto Chemical Co., Ltd., "ETAC PM422") at 130°C and 85% Rh for 100 hours. After the HAST test, the resistance value of the insulation layer of the sample was measured at 7 locations. The resistance value of the insulation layer measured in this way is called the "HAST resistance value".

[0339] The insulation performance is judged based on a resistance value of 1.0 × 10⁶ Ω or higher, which is considered good, and a resistance value less than 1.0 × 10⁶ Ω, which is considered poor. Furthermore, based on this standard, insulation reliability is evaluated using the following criteria: ○: Samples with good insulation properties at 6 or more locations showed both initial and HAST resistance values; △: Five samples showed good insulation, with both initial and HAST resistance values. ×: The initial resistance value and the resistance value after HAST are both of the less than 5 points of the sample with good insulation.

[0340] <Results regarding Example Group II> The results of Examples II-1 to II-7 and Comparative Examples II-1 to II-3 described above are shown in Tables 4 and 5 below.

[0341]

[0342]

[0343] 100: Semiconductor wafer packaging 110: Semiconductor wafers 120: Sealing layer 130: Rewiring Forming Layer 140: Re-wiring layer 150: Solder mask layer 160: Bump < / ii-1> < / ii-1> < / ii-1> < / ii-1> < / ii-1> < / ii-1> < / ii-1> < / ii-1> < / ii-1> < / ii-1> < / i-1> < / i-1> < / i-1> < / i-1> < / i-1> < / i-1> < / i-1> < / i-1>

Claims

1. A resin composition comprising: (A) an organic filler material comprising a polymer containing repeating units as shown in formula (1) below, and (B) a curable resin, wherein (A) the organic filler material has an average particle size of 5 μm or less, and (B) the curable resin comprises an active ester resin, wherein in formula (1), Ra independently represents a hydrogen atom or a monovalent saturated hydrocarbon group, and Rb represents a monovalent aromatic hydrocarbon group that may have substituents.

2. The resin composition as claimed in claim 1, wherein, It further includes (C) inorganic filler materials.

3. The resin composition as claimed in claim 1, wherein, (B) The curing resin comprises one or more selected from epoxy resin, phenolic resin, cyanate ester resin, (meth)acrylic resin, styrene resin, acrylic resin, and maleimide resin.

4. The resin composition as claimed in claim 1, wherein, (A) The particles of the organic filler material are contained in the shell portion exposed on the surface of the particles of the (A) organic filler material, the shell portion containing a polymer containing the repeating unit shown in the aforementioned formula (1).

5. The resin composition as claimed in claim 1, wherein, (A) The average particle size of the organic filler material is less than 1 μm.

6. The resin composition as claimed in claim 1, wherein, The rate of increase of Df(100℃) relative to Df(25℃) is less than 20%. Df(25℃) represents the dielectric loss tangent at 25℃ of the cured material obtained by heat-treating the resin composition at 200℃ for 90 minutes. Df(100℃) represents the dielectric loss tangent at 100℃ of the cured material obtained by heat-treating the resin composition at 200℃ for 90 minutes.

7. The resin composition as claimed in claim 1, wherein, The amount of organic filler material is 0.2% to 5% by mass relative to 100% by mass of the non-volatile components of the resin composition.

8. The resin composition of claim 1, which is used to form an insulating layer.

9. A cured material, which is a cured material of the resin composition of any one of claims 1 to 8.

10. A sheet-like laminated material comprising a resin composition as claimed in any one of claims 1 to 8.

11. A resin sheet comprising a support and a resin composition layer formed on the support, the resin composition layer comprising a resin composition as claimed in any one of claims 1 to 8.

12. A circuit board comprising a cured form of a resin composition as claimed in any one of claims 1 to 8.

13. A semiconductor wafer package comprising a cured form of a resin composition as claimed in any one of claims 1 to 8.

14. A semiconductor device having a circuit board as claimed in claim 12.

15. A semiconductor device comprising a semiconductor wafer package as claimed in claim 13.

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