Resin sheet for forming insulation layer of semiconductor package substrate

Abstract

To provide a resin sheet from which a cured product that has low melt viscosity, low dielectric loss tangent and dielectric constant, good crack resistance and excellent smear removability can be obtained.SOLUTION: A resin sheet for forming an insulation layer of a semiconductor package substrate has a support, and a resin composition layer provided on the support, wherein the resin composition layer contains (A) a radical polymerizable group-containing compound having a carbodiimide structure, (B) one or more antioxidants selected from a phenolic antioxidant and a sulfuric antioxidant, (C) a thermosetting resin, and (D) an inorganic filler.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin sheet for forming an insulating layer of a semiconductor package substrate, and further to a resin sheet, a printed wiring board, and a semiconductor device obtained by using the resin composition. [Background technology]

[0002] A known manufacturing technique for printed wiring boards is a build-up method in which insulating layers and conductor layers are alternately stacked. In build-up manufacturing methods, the insulating layers are generally formed by curing a resin composition. For example, Patent Document 1 discloses a resin composition containing an epoxy resin, an active ester compound, an inorganic filler, and an antioxidant. Furthermore, Patent Document 2 discloses a technique for forming an insulating layer by curing a resin composition containing a carbodiimide compound. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-68335 [Patent Document 2] International Publication No. 2023 / 027013 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for finer wiring due to improved functionality of electronic components. To achieve even finer wiring, a resin composition that provides an insulating layer with a low melt viscosity, dielectric loss tangent, and dielectric constant (relative permittivity) is required. There is also a demand for a resin composition that provides an insulating layer with good crack resistance and excellent smear removal properties. However, at the current stage, it is not yet possible to satisfy all of these requirements. Hereinafter, the dielectric loss tangent and relative permittivity may be collectively referred to as dielectric properties.

[0005] An object of the present invention is to provide a resin sheet that can give a cured product having a low melt viscosity, a low dielectric loss tangent and dielectric constant, good crack resistance, and excellent smear removal properties. [Means for solving the problem]

[0006] As a result of intensive research conducted by the present inventors in order to achieve the objects of the present invention, they have found that by using a resin composition layer containing (A) a radically polymerizable group-containing compound having a carbodiimide structure, (B) one or more antioxidants selected from phenolic antioxidants and sulfur-based antioxidants, (C) a thermosetting resin, and (D) an inorganic filler, it is possible to obtain a cured product that has a low dielectric tangent and dielectric constant, good crack resistance and embeddability, and excellent smear removability, and have thereby completed the present invention.

[0007] That is, the present invention includes the following. [1] A film having a support and a resin composition layer provided on the support, The resin composition layer comprises: (A) a radical polymerizable group-containing compound having a carbodiimide structure; (B) one or more antioxidants selected from phenol-based antioxidants and sulfur-based antioxidants; (C) thermosetting resins, and (D) A resin sheet for forming an insulating layer of a semiconductor package substrate, comprising an inorganic filler. [2] The resin sheet for forming an insulating layer of a semiconductor package substrate according to [1], wherein the content of component (A) is 0.1% by mass or more and 25% by mass or less, when the resin component of the resin composition layer is 100% by mass. [3] The resin sheet for forming an insulating layer of a semiconductor package substrate according to [1] or [2], wherein the content of component (B) is 0.1% by mass or more and 10% by mass or less, when the resin component of the resin composition layer is 100% by mass. [4] A resin sheet for forming an insulating layer of a semiconductor package substrate according to any one of [1] to [3], wherein the content of component (C) is 50% by mass or more and 98% by mass or less, when the resin component of the resin composition layer is 100% by mass. [5] The resin sheet for forming an insulating layer of a semiconductor package substrate according to any one of [1] to [4], wherein the content of component (D) is 45% by mass or more and 85% by mass or less, when the non-volatile components of the resin composition layer are 100% by mass. [6] The resin sheet for forming an insulating layer of a semiconductor package substrate according to any one of [1] to [5], wherein the melt viscosity of the resin composition layer is 3000 poise or less. [7] A semiconductor chip package substrate comprising an insulating layer made of a cured product of the resin composition layer of the resin sheet for forming an insulating layer of a semiconductor package substrate according to any one of [1] to [6]. [8] A semiconductor device comprising the semiconductor chip package substrate according to [7]. [Effects of the Invention]

[0008] According to the present invention, it is possible to obtain a resin sheet which can give a cured product having a low melt viscosity, a low dielectric loss tangent and dielectric constant, good crack resistance, and excellent smear removal properties. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below with reference to preferred embodiments thereof. However, the present invention is not limited to the following embodiments and examples, and can be implemented with any modifications within the scope of the claims of the present invention and their equivalents.

[0010] [Resin sheet for forming insulating layers on semiconductor package substrates] The resin sheet for forming an insulating layer of a semiconductor package substrate of the present invention has a support and a resin composition layer provided on the support, the resin composition layer containing (A) a radically polymerizable group-containing compound having a carbodiimide structure, (B) one or more antioxidants selected from phenolic antioxidants and sulfur-based antioxidants, (C) a thermosetting resin, and (D) an inorganic filler. This resin sheet makes it possible to obtain a cured product with low melt viscosity, low dielectric tangent and dielectric constant, good crack resistance, and excellent smear removal properties.

[0011] The resin sheet for forming an insulating layer of a semiconductor chip package substrate of the present invention is useful for use as an insulating layer in semiconductor package substrates. Examples of semiconductor package substrates include FC-CSP, MIS-BGA package, ETS-BGA package, fan-out type WLP (Wafer Level Package), fan-in type WLP, fan-out type PLP (Panel Level Package), and fan-in type PLP. Hereinafter, the "resin sheet for forming an insulating layer of a semiconductor package substrate" may be simply referred to as the "resin sheet."

[0012] <Support> The resin sheet has a support, and the support is bonded to one surface of the resin composition layer. Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferred.

[0013] When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0014] When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0015] The surface of the support that is to be bonded to the resin composition layer may be subjected to a matte treatment, a corona treatment, or an antistatic treatment.

[0016] The support may also be a support with a release layer, which has a release layer on the surface that bonds to the resin composition layer. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available products may also be used as the support with a release layer, including, for example, "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Uni-Peel" manufactured by Unitika Limited, which are PET films having a release layer primarily composed of an alkyd resin-based release agent.

[0017] The thickness of the support is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, and is preferably 75 μm or less, more preferably 60 μm or less, even more preferably 50 μm or less. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is within the above range.

[0018] <Resin composition layer> The resin sheet has a resin composition layer and is provided on a support. The insulating layer can be formed by thermally curing the resin composition layer. Typically, the insulating layer contains a cured product of the resin composition layer, and preferably contains only a cured product of the resin composition layer. The resin composition layer contains (A) a radically polymerizable group-containing compound having a carbodiimide structure, (B) one or more antioxidants selected from phenolic antioxidants and sulfur-based antioxidants, (C) a thermosetting resin, and (D) an inorganic filler. The resin composition layer may further contain (E) a polymer component, (F) a curing accelerator, (G) other additives, and (H) a solvent, as necessary.

[0019] In the present invention, unless otherwise specified, the content of each component in the resin composition layer is a value when the nonvolatile components in the resin composition layer are 100 mass %, and the nonvolatile components refer to all nonvolatile components in the resin composition layer excluding the solvent. Furthermore, in the present invention, the resin components in the resin composition layer refer to the nonvolatile components of the resin composition layer excluding the (D) inorganic filler.

[0020] -(A) Radical polymerizable group-containing compound having a carbodiimide structure- The resin composition layer contains, as component (A), a radical-polymerizable group-containing compound having a carbodiimide structure (A). By including component (A) in the resin composition layer, it becomes possible to increase the solubility in alkaline solutions and improve smear removal while maintaining a low dielectric tangent and a low dielectric constant.

[0021] The (A) radically polymerizable group-containing compound having a carbodiimide structure is a compound having one or more carbodiimide structures (-N=C=N-) and one or more radically polymerizable groups in one molecule. The (A) component may further have one or more urethane bonds (-O-CO-NH-) in one molecule. Two or more carbodiimide structures, two or more radically polymerizable groups, and two or more urethane bonds may be present in one molecule. When an epoxy resin is included as the (C) thermosetting resin described below, the (A) component may react with the epoxy resin to cure it. The (A) component may be used alone or in combination of two or more.

[0022] The radical polymerizable group is a group having a radically polymerizable ethylenically unsaturated bond. Examples of the radical polymerizable group 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 acryloyl, methacryloyl, and maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl). The radical polymerizable group is preferably present at the terminal of component (A).

[0023] The component (A) preferably contains a structural unit represented by the following formula (A-1) in addition to the radical polymerizable group. [ka] In formula (A-1), Y represents a divalent hydrocarbon group which may have a substituent.

[0024] In formula (A-1), Y represents a divalent hydrocarbon group which may have a substituent. The divalent hydrocarbon group represented by Y usually has 1 or more carbon atoms, preferably 2 or more carbon atoms, and usually 30 or less carbon atoms. The divalent hydrocarbon group may be a divalent saturated hydrocarbon group or a divalent unsaturated hydrocarbon group. Unless otherwise specified, a divalent unsaturated hydrocarbon group represents a hydrocarbon group having at least one carbon-carbon double bond, carbon-carbon triple bond, or aromatic hydrocarbon ring, and includes linear, branched, and cyclic groups.

[0025] Preferred divalent hydrocarbon groups for Y include, for example, alkylene groups, cycloalkylene groups, arylene groups, and groups formed by combining these groups.

[0026] The number of carbon atoms in the alkylene group for Y is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. The number of carbon atoms does not include the number of carbon atoms of the substituent. Suitable examples of the alkylene group include a methylene group, an ethylene group, a propylene group, and a butylene group.

[0027] The number of carbon atoms in the cycloalkylene group for Y is preferably 3 to 20, more preferably 3 to 12, and even more preferably 3 to 6. The number of carbon atoms in the substituent is not included in this number of carbon atoms. Suitable examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, and a cyclohexylene group.

[0028] The arylene group for Y represents a group obtained by removing two hydrogen atoms on an aromatic ring from an aromatic hydrocarbon. The number of carbon atoms in the arylene group is preferably 6 to 24, more preferably 6 to 18, even more preferably 6 to 14, and still more preferably 6 to 10. The number of carbon atoms does not include the number of carbon atoms of substituents. Suitable examples of the arylene group include a phenylene group, a naphthylene group, and an anthracenylene group.

[0029] The substituent for Y is not particularly limited, and examples thereof include a halogen atom, an alkyl-oxy group, an alkenyl-oxy group, an aryl-oxy group, an alkyl-oxy-carbonyl group, an alkenyl-oxy-carbonyl group, an aryl-oxy-carbonyl group, an alkyl-carbonyl-oxy group, an alkenyl-carbonyl-oxy group, an aryl-carbonyl-oxy group, etc. Among these, it is preferable that the divalent hydrocarbon group for Y has no substituent.

[0030] More preferably, Y represents a divalent saturated hydrocarbon group of 2 to 30 carbon atoms which may have a substituent, or a divalent unsaturated hydrocarbon group of 2 to 30 carbon atoms which may have a substituent. Even more preferably, Y represents a divalent saturated hydrocarbon group of 2 to 30 carbon atoms which may have a substituent and has a ring structure (for example, a ring structure selected from a cycloalkane ring, a benzene ring, and a naphthalene ring), or a divalent unsaturated hydrocarbon group of 2 to 30 carbon atoms which may have a substituent and has a ring structure (for example, a ring structure selected from a cycloalkane ring, a benzene ring, and a naphthalene ring).

[0031] Y in formula (A-1) preferably represents a divalent group represented by the following formula (A-2). [ka] In formula (A-2), Y a , Y b and Y c are each independently a single bond or C(R y )2;R yeach independently represents a hydrogen atom or a methyl group; ring Y 1 and ring Y 2 each independently represents an optionally substituted cycloalkane ring having 4 to 10 carbon atoms, an optionally substituted benzene ring, or an optionally substituted naphthalene ring; n y represents 0 or 1; * represents a binding site.

[0032] In formula (A-2), Y a , Y b and Y c are each independently a single bond or C(R y )2. Preferably, Y a and Y c is a single bond and Y b is C(R y )2. R y are each independently a hydrogen atom or a methyl group, and are preferably a hydrogen atom.

[0033] In formula (A-2), ring Y 1 and ring Y 2 each independently represents a cycloalkane ring having 4 to 10 carbon atoms which may have a substituent, a benzene ring which may have a substituent, or a naphthalene ring which may have a substituent. 1 and ring Y 2 each independently represents a cycloalkane ring having 4 to 10 carbon atoms, which may have a substituent. Examples of the cycloalkane ring having 4 to 10 carbon atoms include monocyclic saturated hydrocarbon rings such as a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclononane ring, and a cyclodecane ring; bicyclic saturated hydrocarbon rings such as a bicyclo[2.2.1]heptane ring (norbornane ring), a bicyclo[4.4.0]decane ring (decalin ring), a bicyclo[5.3.0]decane ring, a bicyclo[4.3.0]nonane ring (hydrindane ring), a bicyclo[3.3.0]octane ring, and a bicyclo[3.3.1]nonane ring; 2,6 ] Decane ring (tetrahydrodicyclopentadiene ring), tricyclo[3.3.1.13,7 ] A tricyclic saturated hydrocarbon ring such as a decane ring (adamantane ring) is preferred. 1 and ring Y 2 each independently represents a cyclohexane ring which may have a substituent. The substituents on the cycloalkane ring, benzene ring and naphthalene ring are not particularly limited, and examples thereof include a halogen atom, an alkyl group, an alkenyl group, an aryl group, an aryl-alkyl group (an alkyl group substituted with an aryl group), an alkyl-aryl group (an aryl group substituted with an alkyl group), an alkyl-oxy group, an alkenyl-oxy group, an aryl-oxy group, an alkyl-oxy-carbonyl group, an alkenyl-oxy-carbonyl group, an aryl-oxy-carbonyl group, an alkyl-carbonyl-oxy group, an alkenyl-carbonyl-oxy group, and an aryl-carbonyl-oxy group. Among these, the ring Y 1 and ring Y 2 is particularly preferably an unsubstituted cyclohexane ring.

[0034] Specific examples of Y include divalent groups represented by formulae (Y1) to (Y14), and the divalent group represented by formula (Y1) is particularly preferred. In formulae (Y1) to (Y14), * indicates a bonding site. [ka]

[0035] In a preferred example, the proportion of the structural unit represented by formula (A-1) contained in component (A) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, particularly preferably 80% by mass or more, and may even be 90% by mass or more, relative to 100% by mass of the total molecular mass of component (A).

[0036] The component (A) is preferably a compound represented by formula (A-3). [ka] In formula (A-3), each R independently represents a hydrogen atom or a methyl group;1 each independently represents a carbonyl group, a methylene group, a phenylene group, or a phenylene-methylene group; X 2 each independently represents a divalent saturated hydrocarbon group having 2 to 4 carbon atoms; each Z independently represents a divalent saturated hydrocarbon group having 2 to 300 carbon atoms which may have a substituent, or a divalent unsaturated hydrocarbon group having 2 to 300 carbon atoms which may have a substituent; each a independently represents 0 or an integer of 1 or more; each b independently represents b≦1; each c independently represents c≦1 or more; d independently represents 0 or d≦1 or more; and each Y independently represents the above-mentioned group. The a units, b units, c units, and d units may be the same or different for each unit.

[0037] In formula (A-3), each R independently represents a hydrogen atom or a methyl group.

[0038] In formula (A-3), X 1 are each independently a carbonyl group, a methylene group, a phenylene group, or a phenylene-methylene group (the bonding direction is not particularly limited, but it is preferable that the phenylene side is bonded to C in "RC"). Preferably, X 1 are each independently a methylene group or a carbonyl group. The phenylene-methylene group includes a 1,2-phenylene-methylene group, a 1,3-phenylene-methylene group, and a 1,4-phenylene-methylene group.

[0039] In formula (A-3), X 2 are each independently a divalent saturated hydrocarbon group having 2 to 4 carbon atoms. The divalent saturated hydrocarbon group may be linear, branched, or cyclic. Specific examples of the divalent saturated hydrocarbon group having 2 to 4 carbon atoms include linear alkylene groups having 2 to 4 carbon atoms, such as an ethylene group, a trimethylene group, and a tetramethylene group; and branched alkylene groups having 2 to 4 carbon atoms, such as an ethylidene group, a propylidene group, an isopropylidene group, and an ethylmethylmethylene group. X 2In one embodiment, each independently represents preferably a divalent saturated hydrocarbon group having 2 or 3 carbon atoms, and more preferably an ethylene group (—CH 2 —CH 2 —).

[0040] In formula (A-3), each Z independently represents a divalent saturated hydrocarbon group of 2 to 300 carbon atoms, which may have a substituent, or a divalent unsaturated hydrocarbon group of 2 to 300 carbon atoms, which may have a substituent. Preferably, each Z independently represents a divalent saturated hydrocarbon group of 2 to 300 carbon atoms, or a divalent unsaturated hydrocarbon group of 2 to 300 carbon atoms. More preferably, each Z independently represents a divalent hydrocarbon group of 300 or less carbon atoms, which has a structural unit selected from the group consisting of formulae (Z1) to (Z8) below. Even more preferably, each Z independently represents a divalent hydrocarbon group of 300 or less carbon atoms, which is composed of a structural unit selected from the group consisting of formulae (Z1) to (Z8). [ka]

[0041] It is more preferable that Z each independently represent a divalent hydrocarbon group having 300 or less carbon atoms and having a structural unit represented by formula (Z1); it is even more preferable that Z represent a divalent hydrocarbon group having 300 or less carbon atoms and consisting of a structural unit selected from formulas (Z1) to (Z8) and having at least a structural unit represented by formula (Z1). Of these, it is particularly preferable that Z represent a divalent hydrocarbon group having 300 or less carbon atoms and represented by the following formula (Z-1). [ka] (In formula (Z-1), n z indicates an integer of 1 or more; * indicates a binding site.)

[0042] In formula (A-3), each a independently represents 0 or an integer of 1 or more, preferably 0 or an integer of 1 to 10, and more preferably 0 or 1.

[0043] In formula (A-3), b represents the average degree of polymerization of the carbodiimide group. Each b independently represents b≦1 or more, preferably an integer of 1 or more, more preferably an integer of 1 to 100, and even more preferably an integer of 1 to 100, 1 to 10, or an integer of 1 to 10.

[0044] In formula (A-3), c represents the average degree of polymerization of the divalent saturated hydrocarbon group of 2 to 300 carbon atoms, which may have a substituent, represented by Z. Each c independently represents c≦1 or more, and is preferably an integer of 1 or more, more preferably 1 to 100, still more preferably an integer of 1 to 100, 1 to 10, an integer of 1 to 10, or 1.

[0045] In formula (A-3), d represents the average degree of polymerization of the group represented by Z with the polycarbodiimide. Each d is independently 0 or d≦1 or greater, preferably 0 or an integer of 1 to 100, more preferably 0 or an integer of 1 to 100, and even more preferably 0 or an integer of 1 to 10.

[0046] Due to its manufacturing method, component (A) may contain isocyanate groups (-N=C=O) in the molecule. The content of isocyanate groups in component (A) (also referred to as the "NCO content") is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, still more preferably 2% by mass or less, and particularly preferably 1% by mass or less or 0.5% by mass or less.

[0047] Specific examples of the component (A) include compounds represented by the following formulas (S1) to (S5). However, the component (A) is not limited to these specific examples. In the formulas, b' is the same as b in formula (A-3), d' is the same as d in formula (A-3), and e' is the same as c in formula (A-3). Note that in formula (S3), only 1,2-addition structural units are shown as e' units, but 1,4-addition structural units (cis, trans) are also included. [ka]

[0048] Component (A) can be prepared by a conventionally known method. One known method involves, for example, mixing and stirring a diisocyanate compound such as dicyclohexylmethane-4,4'-diisocyanate with a carbodiimidization catalyst such as 3-methyl-1-phenyl-2-phospholene-1-oxide to carry out a carbodiimidization reaction to obtain an isocyanate-terminated polycarbodiimide. The resulting isocyanate-terminated polycarbodiimide is then reacted with a compound having a radical polymerizable group such as a (meth)acryloyl group, and, if necessary, with other polymerizable compounds such as polybutadiene having hydroxyl groups at both ends. The reaction temperature, reaction time, and other parameters can be appropriately determined by those skilled in the art.

[0049] The weight average molecular weight of component (A) is preferably 500 or more, more preferably 600 or more, even more preferably 700 or more, even more preferably 800 or more, even more preferably 900 or more, and even more preferably 1000 or more, and is preferably 10,000 or less, more preferably 8,000 or less, even more preferably 7,000 or less, and even more preferably 6,000 or less. The weight average molecular weight of component (A) can be measured by gel permeation chromatography (GPC) (polystyrene equivalent).

[0050] The content of component (A) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, when the non-volatile components in the resin composition layer are taken as 100% by mass.

[0051] The content of component (A) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, and is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, when the resin component in the resin composition layer is taken as 100% by mass.

[0052] -(B) one or more antioxidants selected from phenol-based antioxidants and sulfur-based antioxidants- The resin composition layer contains, as component (B), one or more antioxidants selected from (B) phenol-based antioxidants and sulfur-based antioxidants. This component (B) does not include those corresponding to the aforementioned component (A). The inclusion of component (B) in the resin composition layer reduces the degree of crosslinking during curing, thereby alleviating stress in the cured product. As a result, it is possible to suppress the occurrence of cracks in the cured product. Furthermore, the inclusion of component (B) in the resin composition layer reduces the melt viscosity of the resin composition layer, thereby improving embeddability and suppressing an increase in the dielectric loss tangent. One type of component (B) may be used alone, or two or more types may be used in combination.

[0053] The phenolic antioxidant is an antioxidant having a phenolic hydroxy group in the molecule, and is preferably a hindered phenolic antioxidant. The phenolic antioxidant preferably has a group represented by the following formula (B-1): [ka] In formula (B-1), R 1 and R 2 each independently represents a hydrogen atom or a hydrocarbon group.

[0054] R 1 The hydrocarbon group represented by is a monovalent hydrocarbon group. The number of carbon atoms in the hydrocarbon group is usually 1 or more, preferably 2 or more, more preferably 3 or more, and is preferably 12 or less, more preferably 8 or less, and even more preferably 6 or less.

[0055] R 1The hydrocarbon group represented by may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof. The aliphatic hydrocarbon group may be a saturated aliphatic hydrocarbon group, or an unsaturated aliphatic hydrocarbon group. Furthermore, the aliphatic hydrocarbon group may be a linear or branched chain hydrocarbon group, a cyclic hydrocarbon group (i.e., an alicyclic hydrocarbon group), or a combination of a chain hydrocarbon group and a cyclic hydrocarbon group. Among these, an aliphatic hydrocarbon group is preferred, a saturated aliphatic hydrocarbon group is more preferred, and a branched or cyclic aliphatic hydrocarbon group is even more preferred.

[0056] R 1 Preferred specific examples of the hydrocarbon group represented by R include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, and heptyl; and cycloalkyl groups such as cyclopentyl and cyclohexyl. When the hindered phenol compound contains two or more groups represented by formula (B-1) in one molecule, R 1 may be the same or different.

[0057] In formula (B-1), R 2 represents a hydrogen atom or a hydrocarbon group. 2 The range of R 1 The range can be the same as that of R 1 and R 2 and may be the same or different, provided that in the group represented by formula (B-1), R 1 and R 2 At least one of R is a hydrocarbon group. 1 and R 2 Preferably, both of the groups are hydrocarbon groups.

[0058] The phenolic antioxidant may contain only one group represented by formula (B-1) in one molecule, or may contain two or more groups represented by formula (B-1). When one molecule of the phenolic antioxidant contains two or more groups represented by formula (B-1), the groups represented by formula (B-1) may be the same or different.

[0059] The phenolic antioxidant preferably contains an aliphatic hydrocarbon group in combination with the group represented by formula (B-1). Examples of the aliphatic hydrocarbon group include alkyl groups such as methyl and ethyl groups; and alkylene groups such as methylene and ethylene groups. The group represented by formula (B-1) is preferably bonded to the aliphatic hydrocarbon group.

[0060] Examples of phenolic antioxidants include 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 4,4',4''-(1-methylpropanyl-3-ylidene)tris(6-tert-butyl-m-cresol), 6,6'-di-tert-butyl-4,4'-butylidene-m-cresol, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethyl ethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 2,2-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, N,N'-bis-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionylhexamethylenediamine, and the like.

[0061] The phenolic antioxidant may be a commercially available product, such as "AO-20," "AO-30," "AO-40," "AO-50," "AO-60," "AO-60G," "AO-80," or "AO-330" manufactured by ADEKA Corporation; or "HP-300" manufactured by Kawaguchi Chemical Industry Co., Ltd.

[0062] The sulfur-based antioxidant can be an antioxidant having a sulfur atom in the molecule, and may contain only one sulfur atom or two or more sulfur atoms in one molecule.

[0063] The sulfur-based antioxidant preferably contains, in addition to sulfur atoms, an ester bond (—O—C(═O)—) and an aliphatic hydrocarbon group. Examples of the aliphatic hydrocarbon group include an alkyl group. The alkyl group is preferably a long-chain alkyl group, and the number of carbon atoms in the alkyl group is preferably 5 or more, more preferably 8 or more, and even more preferably 10 or more, and preferably 30 or less, more preferably 20 or less, and even more preferably 15 or less.

[0064] The sulfur-based antioxidant is preferably either a thiol-based antioxidant or a thioether-based antioxidant, and from the viewpoint of controlling the reactivity in the system, a thioether-based antioxidant is more preferred.

[0065] Examples of sulfur-based antioxidants include 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diyl bis[3-(dodecylthio)propionate], di(tridecyl)-3,3′-thiodipropionate, thiododecyl-3,3′-thiodipropionate, and thiodiethylenebis[3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate].

[0066] The sulfur-based antioxidant may be a commercially available product, such as "AO-412S," "AO-503," or "AO-26" manufactured by ADEKA Corporation; "Irganox PS800," "Irganox 1726," or "Irganox 1035" manufactured by BASF Japan Ltd.

[0067] The content of component (B) is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, and is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, and 0.8% by mass or less, when the non-volatile components in the resin composition layer are taken as 100% by mass.

[0068] The content of component (B), when the resin component in the resin composition layer is taken as 100% by mass, is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, even more preferably 0.2% by mass or more, 0.5% by mass or more, 1% by mass or more, or 1.5% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0069] When the content of the (A) component when the nonvolatile components in the resin composition layer are taken as 100% by mass is defined as a, and the content of the (B) component when the nonvolatile components in the resin composition layer are taken as 100% by mass is defined as b, a / b is preferably 100 or less, more preferably 80 or less, even more preferably 70 or less, 50 or less, 30 or less, 10 or less, or 5 or less, and is preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 1 or more, 1.5 or more, or 2 or more. By adjusting the (A) and (B) components so that a / b falls within this range, it is possible to obtain a cured product that has a low melt viscosity, low dielectric tangent and dielectric constant, good crack resistance, and excellent smear removability.

[0070] -(C)Thermosetting resin- The resin composition layer contains a (C) thermosetting resin as the (C) component. The (C) thermosetting resin as the (C) component excludes those corresponding to the (A) and (B) components. The (C) thermosetting resin is not particularly limited in type as long as it can be cured by heat. One type of (C) thermosetting resin may be used alone, or two or more types may be used in combination.

[0071] Examples of the (C) thermosetting resin include epoxy resins, radical polymerizable resins, phenolic resins, cyanate resins, active ester resins, carbodiimide resins (excluding those corresponding to component (A)), acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. One type of thermosetting resin may be used alone, or two or more types may be used in combination.

[0072] From the viewpoint of significantly achieving the effects of the present invention, it is preferable to use the (C) thermosetting resin in combination with an epoxy resin and a resin capable of reacting with the epoxy resin to cure the resin composition layer. Hereinafter, a resin capable of reacting with an epoxy resin to cure the resin composition layer may be referred to as a "curing agent." Examples of curing agents include phenolic resins, cyanate resins, active ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. Among these, phenolic resins and active ester resins are preferred as curing agents. One type of curing agent may be used alone, or two or more types may be used in combination. In one embodiment, the thermosetting resin includes an epoxy resin and a phenolic resin.

[0073] Epoxy resins are thermosetting resins having epoxy groups. Examples of epoxy resins include tetramethylbisphenol type epoxy resins (bixylenol type epoxy resins), biphenyl type epoxy resins, naphthalene type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, Examples of the epoxy resin include glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, phenol aralkyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexane dimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, isocyanurate-type epoxy resins, and phenolphthalimidine-type epoxy resins. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0074] The thermosetting resin (C) preferably contains an epoxy resin having two or more epoxy groups per molecule, and the proportion of the epoxy resin having 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, based on 100% by mass of the non-volatile components of the epoxy resin.

[0075] Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition layer may contain only a liquid epoxy resin as the epoxy resin, or may contain only a solid epoxy resin, or may contain a combination of a liquid epoxy resin and a solid epoxy resin.

[0076] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0077] Preferred liquid epoxy resins are bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexanedimethanol type epoxy resins, and epoxy resins having a butadiene structure, more preferred are glycidyl amine type epoxy resins, bisphenol A type epoxy resins, and bisphenol F type epoxy resins, and even more preferred are naphthalene type epoxy resins, bisphenol A type epoxy resins, and bisphenol F type epoxy resins.

[0078] Specific examples of liquid epoxy resins include "HP4032," "HP4032D," and "HP4032SS" (naphthalene-type epoxy resins) manufactured by DIC Corporation; "828US," "828EL," "jER828EL," "825," and "Epikote 828EL" (bisphenol A-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630," "630LSD," and "604" (glycidylamine-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycirol-type epoxy resin) manufactured by ADEKA Corporation; and "EP-3950L" and "EP-3980S" (glycidylamine-type epoxy resins) manufactured by ADEKA Corporation. epoxy resins); "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 & Material Co., Ltd.; "EX-721" (glycidyl ester-type epoxy resin) manufactured by Nagase ChemteX Corporation; "Celloxide 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation; "PB-3600" manufactured by Daicel Corporation; "JP-100" and "JP-200" (epoxy resins having a butadiene structure (epoxidized polybutadiene resin) manufactured by Nippon Soda Co., Ltd.); and "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd. These may be used alone or in combination of two or more.

[0079] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferred.

[0080] Preferred solid epoxy resins include tetramethylbisphenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol novolac-type epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, and phenolphthalimidine-type epoxy resins, with biphenyl-type epoxy resins being more preferred.

[0081] Specific examples of solid epoxy resins include DIC Corporation's "HP4032H" (naphthalene-type epoxy resin); DIC Corporation's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC Corporation's "N-690" (cresol novolac-type epoxy resin); DIC Corporation's "N-695" (cresol novolac-type epoxy resin); DIC Corporation's "HP-7200," "HP-7200HH," "HP-7200H," and "HP-7200L" (dicyclopentadiene-type epoxy resins); and DIC Corporation's "EXA-7311." "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V", "ESN4" manufactured by Nippon Steel Chemical & Material Co., Ltd. 100V" (naphthalene-type epoxy resin); "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", and "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "Y" manufactured by Mitsubishi Chemical Corporation Examples include "X7700" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YX7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.These may be used alone or in combination of two or more.

[0082] When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the mass ratio thereof (liquid epoxy resin:solid epoxy resin) is preferably 1:0.01 to 1:20, more preferably 1:0.05 to 1:10, and particularly preferably 1:0.1 to 1:7.

[0083] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 3,000 g / eq., even more preferably 80 g / eq. to 2,000 g / eq., and particularly preferably 110 g / eq. to 1,000 g / eq. The epoxy equivalent represents the mass of the resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0084] The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0085] The content of the epoxy resin as the (C) thermosetting resin is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, assuming that the non-volatile components in the resin composition layer are 100% by mass.

[0086] The content of the epoxy resin as the (C) thermosetting resin is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more, and is preferably 50% by mass or less, more preferably 45% by mass or less, and particularly preferably 40% by mass or less, when the resin component in the resin composition layer is taken as 100% by mass.

[0087] The radical polymerizable resin as component (C) is not particularly limited in type, as long as it has one or more (preferably two or more) radical polymerizable unsaturated groups in one molecule. Examples of the radical polymerizable resin include resins having one or more radical polymerizable unsaturated groups selected from maleimide, vinyl, allyl, styryl, vinylphenyl, acryloyl, methacryloyl, fumaroyl, and maleoyl groups. Among these, from the viewpoint of significantly achieving the effects of the present invention, maleimide resins, (meth)acrylic resins, and styrene resins are preferred as the radical polymerizable resin.

[0088] The type of maleimide resin is not particularly limited as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) in one molecule. Examples of maleimide resins include: (1) maleimide resins containing an aliphatic skeleton (preferably an aliphatic skeleton having 36 carbon atoms derived from dimer diamine), such as "BMI-3000J," "BMI-5000," "BMI-1400," "BMI-1500," "BMI-1700," and "BMI-689" (all manufactured by Designer Molecules Inc.), and "SLK6895-T90" (manufactured by Shin-Etsu Chemical Co., Ltd.); (2) maleimide resins containing an indane skeleton, as described in the Japan Institute of Invention and Innovation's Technical Journal Disclosure No. 2020-500211; and (3) maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Daiwa Kasei Co., Ltd.), and "BMI-80" (manufactured by Keiai Kasei Co., Ltd.).

[0089] The (meth)acrylic resin may be a monomer or an oligomer, and may be any type, as long as it has one or more (preferably two or more) (meth)acryloyl groups in one molecule. Here, the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups. Examples of methacrylic resins include (meth)acrylate monomers, as well as (meth)acrylic resins such as "A-DOG" (manufactured by Shin-Nakamura Chemical Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "NPDGA," "FM-400," "R-687," "THE-330," "PET-30," "SA9000" (manufactured by SABIC), and "DPHA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0090] The styrene resin is, for example, a compound having one or more, preferably two or more, vinyl groups directly bonded to an aromatic carbon atom. Examples of the styrene resin 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 resins such as vinylbenzyl-modified polyphenylene ether resin and styrene-divinylbenzene copolymer. Examples of commercially available styrene resins include "ODV-XET(X03)", "ODV-XET(X04)", and "ODV-XET(X05)" (styrene-divinylbenzene copolymers) manufactured by Nippon Steel Chemical & Material Co., Ltd., and "OPE-2St 1200" and "OPE-2St 2200" (vinylbenzyl-modified polyphenylene ether resins) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0091] The content of the radically polymerizable resin as the (C) thermosetting resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, when the non-volatile components in the resin composition layer are taken as 100% by mass.

[0092] The content of the radical polymerizable resin as the (C) thermosetting resin is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, and is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less, when the resin component in the resin composition layer is taken as 100% by mass.

[0093] The phenolic resin may be a compound having one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring per molecule. When combined with an epoxy resin, the phenolic resin may react with the epoxy resin to harden the resin composition layer, and is therefore sometimes referred to as a "phenolic curing agent." From the viewpoint of achieving the remarkable effects of the present invention, the phenolic resin is preferably a phenolic resin having a novolac structure. Furthermore, from the viewpoint of adhesion, nitrogen-containing phenolic resins are preferred, and triazine skeleton-containing phenolic resins are more preferred. Of these, triazine skeleton-containing phenolic novolac resins are preferred from the viewpoint of achieving the remarkable effects of the present invention. Specific examples of phenolic resins include "MEH-7700," "MEH-7810," and "MEH-7851" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-375," and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; and "LA-7052," "LA-7054," "LA-3018," "LA-3018-50P," "LA-1356," "TD2090," "TD-2090-60M," and "KA-1163" manufactured by DIC Corporation.

[0094] As the active ester resin, compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are generally preferred. When combined with an epoxy resin, active ester resins can react with the epoxy resin to cure the resin composition layer, and are therefore sometimes referred to as "active ester curing agents." The active ester resin is preferably one obtained by the condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving resistance to high-temperature reflow blistering, active ester resins obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester resins obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound are 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 phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0095] Specifically, the active ester resin is preferably a dicyclopentadiene-type active ester resin, a naphthalene-type active ester resin containing a naphthalene structure, an active ester resin containing an acetylated product of phenol novolac, or an active ester resin containing a benzoylated product of phenol novolac, and among these, at least one selected from a dicyclopentadiene-type active ester resin and a naphthalene-type active ester resin is more preferred. As the dicyclopentadiene-type active ester resin, an active ester resin containing a dicyclopentadiene-type diphenol structure is preferred.

[0096] Commercially available active ester resins include, for example, activated ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000L-65T", "HPC-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation); activated ester resins containing a naphthalene structure such as "HP-B-8151-62T", "EXB-8100L-65T", and "EXB-8150-60T"; Examples of such active ester resins include "EXB-8150-62T," "EXB-9416-70BK," "HPC-8150-60T," "HPC-8150-62T," and "EXB-8" (manufactured by DIC Corporation); "EXB9401" (manufactured by DIC Corporation) as a phosphorus-containing active ester resin; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin which is an acetylated product of phenol novolac; "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester resins which are benzoylated products of phenol novolac; and "PC1300-02-65MA" (manufactured by Air Water Inc.) as an active ester resin containing a styryl group and a naphthalene structure.

[0097] The cyanate resin may be a compound having one or more, preferably two or more, cyanate groups in one molecule. When combined with an epoxy resin, the cyanate resin reacts with the epoxy resin to harden the resin composition layer, and therefore is sometimes called a "cyanate-based curing agent." Examples of cyanate resins include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, and bis(4-cyanatephenyl)ether; multifunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate resins include "PT30" and "PT60" manufactured by Lonza (both of which are phenol novolac-type multifunctional cyanate resins), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine-converted to form a trimer).

[0098] The carbodiimide resin (excluding those corresponding to component (A)) may be a compound having one or more, preferably two or more, carbodiimide structures in one molecule and having no radical polymerizable group. When combined with an epoxy resin, the carbodiimide resin reacts with the epoxy resin to harden the resin composition layer, and therefore is sometimes called a "carbodiimide-based curing agent."

[0099] Specific examples of carbodiimide resins include aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexanebis(methylene-t-butylcarbodiimide); aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide); poly(phenylenecarbodiimide), poly(naphthalenecarbodiimide); Examples of polycarbodiimides include aromatic polycarbodiimides such as poly(methylenediphenylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide].

[0100] 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 Inc.; and "Stavaxol P," "Stavaxol P100," "Stavaxol P400," and "Hykasil 510" manufactured by Lanxess AG.

[0101] As the acid anhydride resin, a compound having one or more, preferably two or more, acid anhydride groups in one molecule can be used. When combined with an epoxy group, the acid anhydride resin can react with the epoxy resin to harden the resin composition layer, and therefore is sometimes called an "acid anhydride curing agent." Specific examples of acid anhydride resins include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic anhydride. Examples of suitable anhydrides include hydrates, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymeric anhydrides such as styrene-maleic acid resin, which is a copolymer of styrene and maleic acid. Commercially available acid anhydride resins include, for example, "HNA-100," "MH-700," "MTA-15," "DDSA," and "OSA" manufactured by New Japan Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" and "HN-5500" manufactured by Resonac Corporation; and "EF-30," "EF-40," "EF-60," and "EF-80" manufactured by Cray Valley Chemical Industries, Ltd.

[0102] The amine resin may be a compound having one or more, preferably two or more, amino groups in one molecule. When combined with an epoxy group, the amine resin may react with the epoxy resin to harden the resin composition layer, and is therefore sometimes referred to as an "amine-based curing agent." Examples of the amine resin include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. The amine resin is preferably a primary amine or secondary amine, with primary amines being more preferred. Specific examples of amine resins include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxyphenyl)propionate. Examples of suitable bis(4-aminophenoxy)benzene include bis(4-aminophenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, and bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine resins include, for example, "SEIKACURE-S" manufactured by Seika Corporation; "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD AA," "KAYAHARD AB," and "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd.; "Epicure W" manufactured by Mitsubishi Chemical Corporation; and "DTDA" manufactured by Sumitomo Seika Chemicals Co., Ltd.

[0103] Benzoxazine resins, when combined with epoxy resins, can react with the epoxy resin to cure the resin composition layer, and are therefore sometimes referred to as "benzoxazine-based curing agents." Specific examples of benzoxazine resins include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation; "HFB2006M" manufactured by Showa Polymer Co., Ltd.; and "Pd" and "Fa" manufactured by Shikoku Chemicals Corporation.

[0104] Thiol resins, when combined with epoxy resins, can react with the epoxy resin to harden the resin composition layer, and are therefore sometimes referred to as "thiol-based curing agents." Examples of thiol resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

[0105] The active group equivalent of the curing agent is preferably 50 g / eq. to 3000 g / eq., more preferably 100 g / eq. to 1000 g / eq., still more 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 the curing agent per equivalent of the active group.

[0106] The weight average molecular weight (Mw) of the curing agent is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0107] When the number of epoxy groups in the epoxy resin is taken as 1, the number of active groups in the curing agent is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and preferably 5 or less, more preferably 3 or less, and particularly preferably 2 or less. The "number of epoxy groups in the epoxy resin" refers to the total value obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition layer by the epoxy equivalent. Furthermore, the "number of active groups in the curing agent" refers to the total value obtained by dividing the mass of the non-volatile components of the curing agent present in the resin composition layer by the active group equivalent.

[0108] The content of the curing agent as (C) thermosetting resin is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 23% by mass or less, when the non-volatile components in the resin composition layer are taken as 100% by mass.

[0109] The content of the curing agent as (C) thermosetting resin is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, and preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 50% by mass or less, when the resin component in the resin composition layer is 100% by mass.

[0110] The content of the (C) thermosetting resin is preferably 50% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more, and is preferably 65% ​​by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less, or 40% by mass or less, when the non-volatile components in the resin composition layer are taken as 100% by mass.

[0111] The content of the (C) thermosetting resin is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, and is preferably 98% by mass or less, more preferably 93% by mass or less, and even more preferably 90% by mass or less, assuming that the resin component in the resin composition layer is 100% by mass.

[0112] The total content of the (A), (B), and (C) components is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more, and is preferably 55% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less, 40% by mass or less, or 35% by mass or less, assuming that the non-volatile components in the resin composition layer are 100% by mass.

[0113] -(D) Inorganic filler- The resin composition layer contains an inorganic filler (D) as the component (D). By using a resin composition layer containing the component (D), a cured product with a low dielectric loss tangent can be obtained. The inorganic filler (D) may be used alone or in a combination of two or more types in any ratio.

[0114] The (D) inorganic filler is contained in the resin composition layer in the form of particles. An inorganic compound is used as the (D) inorganic filler material. Examples of (D) inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Furthermore, spherical silica is preferred.

[0115] (D) Examples of commercially available inorganic fillers include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C," "YA050C," "YA050C-MJE," "YA010C," "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30," "DAW-03," and "FB-105FD" manufactured by Denka Company, Limited; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "CellSpheres" and "MGH-005" manufactured by Taiheiyo Cement Corporation; and "Sfereek" and "BA-1" manufactured by JGC Catalysts and Chemicals Co., Ltd.

[0116] The average particle size of the (D) inorganic filler is not particularly limited, but is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, still more preferably 2 μm or less, and particularly preferably 1.5 μm or less. The lower limit of the average particle size of the (D) inorganic filler is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and particularly preferably 0.2 μm or more.

[0117] (D) The average particle size of inorganic fillers can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a volumetric particle size distribution of the inorganic filler is created using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture ultrasonically for 10 minutes. The volumetric particle size distribution of the inorganic filler was measured using a laser diffraction particle size distribution analyzer with blue and red wavelength light sources using a flow cell system, and the average particle size was calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution analyzers include the LA-960 manufactured by Horiba, Ltd.

[0118] The specific surface area of ​​the (D) inorganic filler is not particularly limited, but is preferably 0.1 m2 / g or more, more preferably 0.5m 2 / g or more, more preferably 1m 2 / g or more, particularly preferably 3m 2 The upper limit of the specific surface area of ​​the (D) inorganic filler is not particularly limited, but is preferably 100 m 2 / g or less, more preferably 70m 2 / g or less, more preferably 50m 2 / g or less, and even more preferably 30m 2 / g or less, particularly preferably 10m 2 The specific surface area of ​​the inorganic filler is obtained by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) according to the BET method, and then calculating the specific surface area using the BET multipoint method.

[0119] (D) The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a mercaptosilane coupling agent, a silane coupling agent, an alkoxysilane, an organosilazane compound, and a titanate coupling agent. The surface treatment agent may be used alone or in any combination of two or more.

[0120] Examples of commercially available surface treatment agents include Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd.'s "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical Co., Ltd.'s "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

[0121] The degree of surface treatment with the surface treatment agent is preferably within a predetermined range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably 0.2% to 3% by mass, and even more preferably 0.3% to 2% by mass.

[0122] The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler is set to 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2 More preferably, 0.2 mg / m or more 2 On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition layer or the melt viscosity in the form of a sheet, it is more preferable that the melt viscosity is 1.0 mg / m 2 Preferably less than 0.8 mg / m 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred:

[0123] (D) The amount of carbon per unit surface area of ​​the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. An "EMIA-320V" manufactured by Horiba, Ltd., or the like can be used as the carbon analyzer.

[0124] The content of the (D) inorganic filler is preferably 45% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, 60% by mass or more, or 65% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition layer, and the upper limit is preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.

[0125] -(E) Polymer component- The resin composition layer may contain a polymer component (E) as the component (E). The polymer component (E) as the component (E) excludes components (A) to (D). By including the component (E) in the resin composition layer, stress in the resin composition layer is alleviated, and as a result, a cured product with superior crack resistance can be obtained. The component (E) may be used singly or in combination of two or more types.

[0126] Component (E) can be one having a high weight-average molecular weight, such as polyimide resin, phenoxy resin, polyimide resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin, polyester resin, etc.

[0127] The weight average molecular weight (Mw) of component (E) is preferably greater than 5,000, more preferably 8,000 or more, even more preferably 10,000 or more, and particularly preferably 20,000 or more; and is preferably 100,000 or less, more preferably 70,000 or less, even more preferably 60,000 or less, and particularly preferably 50,000 or less.

[0128] The polyimide resin may be a resin having an imide structure, and generally includes those obtained by an imidization reaction between a diamine compound and an acid anhydride.

[0129] The diamine compound for preparing the polyimide resin is not particularly limited, but examples thereof include aliphatic diamine compounds and aromatic diamine compounds.

[0130] Examples of the aliphatic diamine compound include linear aliphatic diamine compounds such as 1,2-ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-hexamethylenediamine, 1,5-diaminopentane, and 1,10-diaminodecane; branched aliphatic diamine compounds such as 1,2-diamino-2-methylpropane, 2,3-diamino-2,3-butane, and 2-methyl-1,5-diaminopentane; alicyclic diamine compounds such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, and 4,4'-methylenebis(cyclohexylamine); and dimer acid diamines (hereinafter also referred to as "dimer diamines"). The dimer acid diamine refers to a diamine compound obtained by substituting two terminal carboxylic acid groups (-COOH) of a dimer acid with an aminomethyl group (-CH2-NH2) or an amino group (-NH2). Dimer acid is a known compound obtained by dimerizing an unsaturated fatty acid (preferably one having 11 to 22 carbon atoms, particularly preferably one having 18 carbon atoms), and its industrial production process is largely standardized in the industry.

[0131] Examples of the aromatic diamine compound include a phenylenediamine compound, a naphthalenediamine compound, and a dianiline compound.

[0132] The phenylenediamine compound refers to a compound consisting of a benzene ring having two amino groups, and further, the benzene ring here may have 1 to 3 optional substituents. The substituents here are not particularly limited. Specific examples of the phenylenediamine compound include 1,4-phenylenediamine, 1,2-phenylenediamine, 1,3-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,5-diaminobiphenyl, and 2,4,5,6-tetrafluoro-1,3-phenylenediamine.

[0133] The naphthalene diamine compound refers to a compound consisting of a naphthalene ring having two amino groups, and the naphthalene ring may have 1 to 3 optional substituents. The substituents are not particularly limited. Specific examples of the naphthalene diamine compound include 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,6-diaminonaphthalene, and 2,3-diaminonaphthalene.

[0134] A dianiline compound refers to a compound containing two aniline structures in the molecule, and each of the two benzene rings in the two aniline structures may further have one to three optional substituents. The substituents are not particularly limited. The two aniline structures in the dianiline compound may be bonded via a direct bond and / or one or two linker structures having 1 to 100 skeletal atoms selected from carbon, oxygen, sulfur, and nitrogen atoms. Dianiline compounds also include those in which two aniline structures are bonded via two bonds.

[0135] Specific examples of the "linker structure" in the dianiline compound include -NHCO-, -CONH-, -OCO-, -COO-, -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -CH=CH-, -O-, -S-, and -CO- , -SO2-, -NH-, -Ph-, -Ph-Ph-, -C(CH3)2-Ph-C(CH3)2-, -O-Ph-O-, -O-Ph-Ph-O-, -O-Ph-SO2-Ph-O-, -O-Ph-C(CH3)2-Ph-O-, -C(CH3)2-Ph-C(CH3)2-, groups represented by the following formulas (I) and (II), and groups consisting of combinations thereof. In this specification, "Ph" represents a 1,4-phenylene group, a 1,3-phenylene group, or a 1,2-phenylene group. [ka]

[0136] In one embodiment, specific examples of the dianiline compound include 4,4'-diamino-2,2'-ditrifluoromethyl-1,1'-biphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4-aminophenyl 4-aminobenzoate, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-aminophenyl)propane, 4,4'-(hexafluoroisopropylidene)dianiline, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-

[0033] 4,4'-(9-fluorenylidene)dianiline, 2,2-bis(3-methyl-4-aminophenyl)propane, 2,2-bis(3-methyl-4-aminophenyl)benzene, 4,4'-diamino-3,3'-dimethyl-1,1'-biphenyl, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 9,9'-bis(3-methyl-4-aminophenyl)fluorene, 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane, and the like.

[0137] The diamine compound may be a commercially available product or may be synthesized by a known method. The diamine compound may be used alone or in combination of two or more.

[0138] The acid anhydride used to prepare the polyimide resin is not particularly limited, but in a preferred embodiment, it is an aromatic tetracarboxylic dianhydride, such as benzenetetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, anthracenetetracarboxylic dianhydride, or diphthalic dianhydride, preferably diphthalic dianhydride.

[0139] Benzenetetracarboxylic dianhydride means a dianhydride of benzene having four carboxy groups, and further, the benzene ring here may have 1 to 3 optional substituents, such as a halogen atom, a cyano group, and -X 330 -R 330 (The same definition as in the following formula (E-1)) is preferred. Specific examples of the benzenetetracarboxylic dianhydride include pyromellitic dianhydride and 1,2,3,4-benzenetetracarboxylic dianhydride.

[0140] Naphthalenetetracarboxylic dianhydride refers to a dianhydride of naphthalene having four carboxy groups, and the naphthalene ring here may optionally have 1 to 3 substituents, such as halogen atoms, cyano groups, and -X 330 -R 330 (The same definition as in formula (E-1) below.) Specific examples of naphthalenetetracarboxylic dianhydride include 1,4,5,8-naphthalenetetracarboxylic dianhydride and 2,3,6,7-naphthalenetetracarboxylic dianhydride.

[0141] Anthracenetetracarboxylic dianhydride refers to a dianhydride of anthracene having four carboxy groups, and the anthracene ring here may optionally have 1 to 3 substituents, such as halogen atoms, cyano groups, and -X 330 -R 330(The same definition as in the following formula (E-1)) is preferred. Specific examples of the anthracenetetracarboxylic dianhydride include 2,3,6,7-anthracenetetracarboxylic dianhydride.

[0142] Diphthalic dianhydride refers to a compound containing two phthalic anhydrides in the molecule, and each of the two benzene rings in the two phthalic anhydrides may have one to three optional substituents. The substituents include halogen atoms, cyano groups, and -X 330 -R 330 (the same as the definition of formula (E-1) below). The two phthalic anhydrides in the diphthalic dianhydride may be bonded to each other by a direct bond or via a linker structure having 1 to 100 skeletal atoms selected from carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.

[0143] An example of the diphthalic dianhydride is a compound represented by formula (E-1). [ka] (In the formula, R 11 and R 12 are each independently a halogen atom, a cyano group, a nitro group, or -X 13 -R 13 indicates, X 13 are each independently a single bond, -NR 13’ -, -O-, -S-, -CO-, -SO2-, -NR 13’ CO-, -CONR 13’ -, -OCO-, or -COO-; R 13 each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group, R 13’ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkenyl group, Y represents a single bond or a linker structure having 1 to 100 skeletal atoms selected from carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms; n1 and m1 each independently represent an integer of 0 to 3.

[0144] Y is preferably a linker structure having 1 to 100 skeletal atoms selected from carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms. n1 and m1 are preferably 0.

[0145] The "linker structure" in Y has 1 to 100 skeletal atoms selected from carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms. The "linker structure" is preferably -[A-Ph] a -A-[Ph-A] b - (wherein each A independently represents a single bond, -(substituted or unsubstituted alkylene group)-, -O-, -S-, -CO-, -SO2-, -CONH-, -NHCO-, -COO-, or -OCO-, and each a and b independently represents an integer of 0 to 2 (preferably 0 or 1).)

[0146] Specific examples of the "linker structure" for Y include -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH(CH3)-, -C(CH3)2-, -O-, -CO-, -SO2-, -Ph-, -O-Ph-O-, -O-Ph-SO2-Ph-O-, -O-Ph-C(CH3)2-Ph-O-, etc., with -O-Ph-C(CH3)2-Ph-O- being preferred.

[0147] Specific examples of diphthalic dianhydrides include 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, and 2,3,3',4'-biphenyltetracarboxylic dianhydride. carboxylic acid dianhydride, 2,3,3',4'-benzophenonetetracarboxylic acid dianhydride, 2,3,3',4'-diphenylethertetracarboxylic acid dianhydride, 2,3,3',4'-diphenylsulfonetetracarboxylic acid dianhydride, 2,2'-bis(3,4-dicarboxyphenoxyphenyl)sulfone dianhydride, methylene-4,4'-diphthalic acid dianhydride, 1,1-ethynylidene-4,4'-diphthalic acid dianhydride, 2,2-propanol Pyridene-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,3- Examples include bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic dianhydride (BPADA), and 4,4'-oxydiphthalic anhydride.

[0148] The acid anhydride may be commercially available or may be synthesized by a known method or a method similar thereto. The acid anhydride may be used alone or in combination of two or more.

[0149] The polyimide resin can be prepared by a conventionally known method. For example, a method of heating a mixture of a diamine compound, an acid anhydride, and a solvent to cause a reaction is exemplified. The amount of the diamine compound mixed is, for example, usually 0.5 to 1.5 molar equivalents, preferably 0.9 to 1.1 molar equivalents, relative to the acid anhydride.

[0150] Commercially available polyimide resins can be used, including "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd.

[0151] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenolacetophenone, novolac, biphenyl, fluorene, dicyclopentadiene, norbornene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both of which are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; and "YL7500BH30," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," "YL7482," and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation.

[0152] Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, with polyvinyl butyral resins being preferred. Specific examples of polyvinyl acetal resins include S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemical Co., Ltd.

[0153] Examples of polyolefin resins include ethylene copolymer resins such as low-density polyethylene, very low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; and polyolefin polymers such as polypropylene and ethylene-propylene block copolymer.

[0154] Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxy group-containing polybutadiene resins, phenolic hydroxy group-containing polybutadiene resins, carboxy group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, isocyanate group-containing polybutadiene resins, urethane group-containing polybutadiene resins, and polyphenylene ether-polybutadiene resins.

[0155] Specific examples of polyamide-imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins also include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imides) manufactured by Resonac Corporation.

[0156] A specific example of the polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0157] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0158] A specific example of the polyphenylene ether resin is NORYL SA90 manufactured by SABIC, etc. A specific example of the polyetherimide resin is ULTEM manufactured by GE, etc.

[0159] Examples of polycarbonate resins include hydroxyl group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxyl group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, and urethane group-containing carbonate resins. Specific examples of polycarbonate resins include "FPC0220" manufactured by Mitsubishi Gas Chemical Company, Inc., "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd. Specific examples of polyether ether ketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd.

[0160] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

[0161] The thermoplastic resin (E) may be an organic filler that is insoluble in the solvent described below and exists in the form of particles in the resin composition layer. Examples of the organic filler include rubber particles, polyamide fine particles, silicone particles, and core-shell particles, with rubber particles being preferred.

[0162] Examples of the rubber component contained in the rubber particles include olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychlorobutadiene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, and ethylene-propylene-butene terpolymer; and acrylic-based thermoplastic elastomers such as poly(propyl meth)acrylate, poly(butyl meth)acrylate, poly(cyclohexyl meth)acrylate, and poly(octyl meth)acrylate. Preferred are olefin-based thermoplastic elastomers, and more preferably styrene-butadiene copolymers. Furthermore, silicone-based rubbers such as polyorganosiloxane rubbers may be mixed into the rubber component. The rubber component contained in the rubber particles has a glass transition temperature of, for example, 0°C or lower, preferably -10°C or lower, more preferably -20°C or lower, and even more preferably -30°C or lower.

[0163] As the rubber particles, commercially available products may be used, such as "EXL2655" manufactured by Dow Chemical Japan, and "AC3401N" and "AC3816N" manufactured by Aica Kogyo Co., Ltd.

[0164] Core-shell particles are particulate organic fillers consisting of a core particle containing a rubber component as described above and one or more shell layers covering the core particle. Furthermore, the core-shell particles are preferably core-shell graft copolymer particles consisting of a core particle containing a rubber component as described above and a shell formed by graft copolymerization of a monomer component copolymerizable with the rubber component contained in the core particle. The term "core-shell" as used here does not necessarily refer only to particles in which the core particle and the shell are clearly distinguishable, but also includes particles in which the boundary between the core particle and the shell is unclear, and the core particle does not necessarily have to be completely covered by the shell.

[0165] The rubber component is preferably contained in the core-shell graft copolymer particles in an amount of 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more. The upper limit of the rubber component content in the core-shell graft copolymer particles is not particularly limited, but from the viewpoint of sufficiently covering the core particles with the shell portion, it is preferably, for example, 95% by mass or less, and more preferably 90% by mass.

[0166] Examples of monomer components that form the shell portion of the core-shell graft copolymer particles include (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, and glycidyl (meth)acrylate; (meth)acrylic acid; N-substituted maleimides such as N-methylmaleimide and N-phenylmaleimide; maleimide; α,β-unsaturated carboxylic acids such as maleic acid and itaconic acid; aromatic vinyl compounds such as styrene, 4-vinyltoluene, and α-methylstyrene; and (meth)acrylonitrile, among which (meth)acrylic acid esters are preferred, and methyl (meth)acrylate is more preferred.

[0167] Commercially available core-shell graft copolymer particles include, for example, "CHT" manufactured by Samsung SDI; "B602" manufactured by Techno UMG; "Paraloid EXL2602," "Paraloid EXL2603," "Paraloid EXL2655," "Paraloid EXL2311," "Paraloid EXL2313," "Paraloid EXL2315," "Paraloid KM330," "Paraloid KM336P," and "Paraloid KCZ201" manufactured by Dow Chemical Japan; "Metablen C-223A," "Metablen E-901," "Metablen S-2001," "Metablen W-450A," and "Metablen SRK-200" manufactured by Mitsubishi Rayon; and "Kane Ace M-511," "Kane Ace M-600," "Kane Ace M-400," "Kane Ace M-580," and "Kane Ace MR-01" manufactured by Kaneka Corporation. These may be used alone or in combination of two or more.

[0168] The average particle size (average primary particle size) of the core-shell graft copolymer particles is not particularly limited, but is preferably 20 nm or more, more preferably 50 nm or more, even more preferably 80 nm or more, particularly preferably 100 nm or more, and preferably 5,000 nm or less, more preferably 2,000 nm or less, even more preferably 1,000 nm or less, particularly preferably 500 nm or less. The average particle size (average primary particle size) of the core-shell graft copolymer particles can be measured using a zeta potential particle size distribution analyzer or the like.

[0169] The content of component (E) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less, assuming that the non-volatile components of the resin composition layer are 100% by mass.

[0170] The content of component (E) is preferably 1% by mass or more, more preferably 1.5% by mass or more, even more preferably 2% by mass or more, and preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 5% by mass or less, assuming that the resin component of the resin composition layer is 100% by mass.

[0171] -(F) Curing accelerator- The resin composition layer may contain a curing accelerator (F) as the component (F). The curing accelerator (F) as the component (F) does not include those corresponding to the above-mentioned components (A) to (E). The curing accelerator (F) functions as a curing catalyst that accelerates the curing of the epoxy resin in the component (C).

[0172] As the (F) curing accelerator, a compound that accelerates the curing of the epoxy resin can be used. Examples of such (F) curing accelerators include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. One type of (F) curing accelerator may be used alone, or two or more types may be used in combination.

[0173] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium tetra-p-tolylborate. aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone adducts such as triphenylphosphine-p-benzoquinone adduct; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine aromatic phosphines such as benzene, 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(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether;

[0174] Examples of the urea-based curing accelerator 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 toluene bis(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-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea].

[0175] Examples of guanidine curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0176] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct Examples of imidazole compounds include 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. Commercially available imidazole curing accelerators include "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 Chemicals Corporation; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0177] Examples of metal-based curing 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 organic cobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron complexes such as iron(III) acetylacetonate, organic nickel complexes such as nickel(II) acetylacetonate, and organic manganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0178] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. Commercially available amine curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0179] The content of the (F) curing accelerator is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, even more preferably 0.01% by mass or more, or 0.05% by mass or more, and is preferably 1.5% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, based on 100% by mass of the non-volatile components in the resin composition layer.

[0180] The content of the (F) curing accelerator is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more, and is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, when the resin component in the resin composition layer is taken as 100% by mass.

[0181] -(G) Other additives- The resin composition layer may contain (G) other additives as an optional non-volatile component. Examples of (G) other additives include elastomers (excluding those corresponding to component (E)); 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 oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; triazole-based adhesion promoters, Examples of the additives include adhesion promoters such as tetrazole-based adhesion promoters and triazine-based adhesion promoters; antioxidants such as hindered phenol-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic acid anhydride-based stabilizers; photopolymerization initiator aids such as tertiary amines; photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones; and antioxidants (excluding those corresponding to component (B)). (G) Other additives may be used alone or in combination of two or more.

[0182] -(H) Solvent- The resin composition layer may further contain a (H) solvent as an optional volatile component in addition to the nonvolatile components (A) to (G) described above. An organic solvent is typically used as the (H) solvent. Examples of the organic solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of suitable solvents include ether ester solvents such as ethyl acetate; 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); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. The (H) solvent may be used singly or in combination of two or more.

[0183] The amount of (H) solvent is not particularly limited, but may be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or even 0% by mass, relative to 100% by mass of all components of the resin composition layer.

[0184] The thickness of the resin composition layer is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 55 μm or less, from the viewpoint of reducing the thickness of the printed wiring board and providing a cured product with excellent insulating properties even when the cured product of the resin composition layer is thin. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 5 μm or more, 10 μm or more, etc.

[0185] <Protective film> The resin sheet may optionally include a protective film conforming to the support as another layer. The protective film is provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). By laminating the protective film on the resin sheet, adhesion of dust and the like to the surface of the resin composition layer and scratches can be suppressed.

[0186] Examples of the protective film include films made of plastic materials, metal foils, and release papers, with films made of plastic materials and metal foils being preferred.

[0187] When a film made of a plastic material is used as the protective film, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0188] When a metal foil is used as the protective film, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0189] The surface of the protective film that is to be bonded to the resin composition layer may be subjected to a matte treatment, a corona treatment, or an antistatic treatment.

[0190] The protective film may also be a protective film with a release layer, which has a release layer on the surface that bonds to the resin composition layer. Examples of the release agent used in the release layer of the protective film with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available protective films with a release layer may be used, including, for example, "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation, "Lumirror T60," "Lumirror R80," and "Lumirror" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Uni-Peel" manufactured by Unitika Limited, which are PET films having a release layer primarily composed of an alkyd resin-based release agent.

[0191] The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. When the protective film has a multi-layer structure such as a protective film with a release layer, it is preferable that the thickness of the entire protective film is in this range.

[0192] <Method of manufacturing resin sheet> The resin sheet can be produced, for example, by preparing a resin varnish by dissolving the components contained in the resin composition layer in a solvent, applying this resin varnish to a support using a die coater or the like, and then drying it to form a resin composition layer.

[0193] The solvent may be the same as the solvent explained as a component of the resin composition layer, and one type of solvent may be used alone, or two or more types may be used in combination.

[0194] Drying may be carried out by heating, blowing hot air, or the like. Drying conditions are not particularly limited, but drying is usually carried out so that the solvent content in the resin composition layer becomes 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 a resin composition containing 30% by mass to 60% by mass of solvent is used, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0195] The resin sheet can be stored in a rolled state. When the resin sheet has a protective film, it can usually be used by peeling off the protective film.

[0196] <Physical properties of resin sheet> Since the resin composition layer in the resin sheet of the present invention contains a combination of components (A) to (D), the cured product of the resin composition layer exhibits the characteristic of a low dielectric loss tangent. This results in an insulating layer with a low dielectric loss tangent. The dielectric loss tangent of the cured product heat-cured at 190°C for 90 minutes is preferably 0.0050 or less, more preferably 0.0045 or less, even more preferably 0.004 or less, and particularly preferably 0.003 or less. There is no particular restriction on the lower limit, and it can be, for example, 0.0010 or more. The dielectric loss tangent can be measured by the method described in the Examples below.

[0197] Since the resin composition layer in the resin sheet of the present invention contains a combination of components (A) to (D), the cured resin composition layer exhibits the characteristic of a low relative dielectric constant. This results in an insulating layer with a low relative dielectric constant. The relative dielectric constant of the cured product is preferably 3.5 or less, more preferably 3.4 or less, and even more preferably 3.3 or less. There is no particular lower limit, and it can be, for example, 0.1 or more. The relative dielectric constant can be measured by the method described in the Examples below.

[0198] The resin composition layer exhibits the characteristic of low melt viscosity (minimum melt viscosity). This results in an insulating layer with excellent embeddability. The melt viscosity is measured, for example, using a dynamic viscoelasticity measuring device under the following measurement conditions: a temperature rise rate of 5°C / min, a measurement temperature interval of 2.5°C, and a vibration frequency of 1 Hz when measured in a temperature range of 60°C to 200°C. The melt viscosity measured in a temperature range of 60°C to 200°C is preferably 4000 poise or less, 3500 poise or less, and more preferably 3000 poise or less. There is no particular lower limit, but it can be 10 poise or more. The melt viscosity can be measured by the method described in the examples below.

[0199] The cured product obtained by curing the resin composition layer at 130°C for 30 minutes and then at 170°C for 30 minutes exhibits the property that smears generated during via hole formation are easily removed (excellent smear removability). That is, an insulating layer with good smear removability is obtained. Because of the excellent smear removability, the maximum smear length measured from the wall surface side of the bottom of the via hole is preferably less than 5 μm, more preferably 3 μm or less, and even more preferably less than 3 μm. The lower limit is not particularly limited, but may be 0.01 μm or more. The smear removability can be measured by the method described in the examples below.

[0200] A cured product obtained by curing a resin composition layer at 130°C for 30 minutes and then at 170°C for 30 minutes exhibits the property of being able to suppress the occurrence of cracks after desmearing (roughening treatment). This results in an insulating layer with excellent crack resistance. Specifically, after producing a circuit board and performing desmearing, 100 copper pads on the circuit board are observed, and preferably 20 or less cracks are found, more preferably 10 or less. The crack resistance can be evaluated by the method described in the Examples below.

[0201] [Semiconductor package substrate and its manufacturing method] The semiconductor chip package of the present invention includes a circuit board and a semiconductor chip mounted on the circuit board, and the circuit board includes an insulating layer formed from a cured product of the resin composition layer in the resin sheet of the present invention. This semiconductor chip package can be produced by bonding the semiconductor chip to the circuit board. The circuit board will be described later.

[0202] The bonding conditions are not particularly limited as long as the terminal electrodes of the semiconductor chip are conductively connected to the circuit wiring of the circuit board, and known conditions used in flip-chip mounting of semiconductor chips may be used. Alternatively, the semiconductor chip and the circuit board may be bonded via an insulating adhesive.

[0203] In a preferred embodiment, the semiconductor chip is pressure-bonded to the circuit board under pressure conditions such as a pressure-bonding temperature in the range of 120°C to 240°C (preferably 130°C to 200°C, more preferably 140°C to 180°C) and a pressure-bonding time in the range of 1 second to 60 seconds (preferably 5 seconds to 30 seconds).

[0204] In another preferred embodiment, the semiconductor chip is bonded to the circuit board by reflow. The reflow conditions can be, for example, in the range of 120°C to 300°C.

[0205] After bonding the semiconductor chip to the circuit board, it is also possible to obtain a semiconductor chip package by, for example, filling the semiconductor chip with a mold underfill material. The method of filling with a mold underfill material can be carried out by a known method.

[0206] The circuit board includes an insulating layer formed from a cured product of the resin composition layer in the resin sheet of the present invention. This circuit board can be produced, for example, by a production method including the following steps (I) and (II). (I) A step of laminating a resin sheet on an inner layer substrate so that the resin composition layer of the resin sheet is bonded to the inner layer substrate. (II) A step of curing the resin composition layer to form an insulating layer.

[0207] The "inner layer substrate" used in step (I) is a member that will become the substrate of a circuit board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate is sometimes referred to as an "inner layer circuit board." Furthermore, intermediate products on which an insulating layer and / or a conductor layer is to be further formed during the production of a 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 may be used.

[0208] The inner layer substrate and the resin sheet can be laminated, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of a member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter also referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS plate) or a metal roll (such as a SUS roll). Note that rather than pressing the thermocompression bonding member directly onto the resin sheet, it is preferable to press it via an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently conform to the surface irregularities of the inner layer substrate.

[0209] The lamination of the inner layer substrate and the resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, the thermocompression pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. The lamination is preferably carried out under reduced pressure conditions of 26.7hPa or less.

[0210] The lamination can be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch vacuum pressure laminator.

[0211] After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression conditions for lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

[0212] The support may be removed between step (I) and step (II), or may be removed after step (II).

[0213] In step (II), the resin composition layer is cured to form an insulating layer made of a cured product of the resin composition layer. The resin composition layer is usually cured by thermal curing. Specific curing conditions for the resin composition layer may be those typically used when forming an insulating layer for a printed wiring board.

[0214] For example, the thermal curing conditions for the resin composition layer vary depending on the types of components contained in the resin composition layer, but in one embodiment, the curing temperature is preferably 120° C. to 240° C., more preferably 150° C. to 220° C., and even more preferably 170° C. to 210° C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0215] Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 150°C, preferably 60°C to 140°C, more preferably 70°C to 130°C for 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

[0216] When manufacturing a circuit board, the following steps may be further performed: (III) drilling holes in the insulating layer, (IV) roughening the insulating layer, and (V) forming a conductor layer. These steps (III) to (V) may be performed according to various methods known to those skilled in the art and used in manufacturing circuit boards. When the support is removed after step (II), the removal of the support may be performed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Furthermore, if necessary, the formation of the insulating layer and the conductor layer in steps (I) to (V) may be repeated to form a multilayer wiring board.

[0217] Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, or the like, depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be determined appropriately depending on the design of the printed wiring board.

[0218] Step (IV) is a step of roughening the insulating layer. Typically, smear removal is also performed in this step (IV). The roughening treatment procedure and conditions are not particularly limited, and known procedures and conditions commonly used in forming insulating layers for printed wiring boards can be adopted. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order.

[0219] Examples of swelling liquids used in the roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Examples of the alkaline solution include sodium hydroxide solution and potassium hydroxide solution. Examples of commercially available swelling liquids include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan. Swelling treatment using a swelling liquid can be performed by immersing the insulating layer in the swelling liquid at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in the swelling liquid at 40°C to 80°C for 5 to 15 minutes.

[0220] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0221] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan can be cited. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, a preferred method is to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0222] In one embodiment, the arithmetic mean roughness (Ra) of the insulating layer surface after the roughening treatment is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. There is no particular limitation on the lower limit and it can be, for example, 1 nm or more, 2 nm or more, etc. Furthermore, the root mean square roughness (Rq) of the insulating layer surface after the roughening treatment is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. There is no particular limitation on the lower limit and it can be, for example, 1 nm or more, 2 nm or more, etc. The arithmetic mean roughness (Ra) and root mean square roughness (Rq) of the insulating layer surface can be measured using a non-contact surface roughness meter.

[0223] Step (V) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

[0224] The conductor layer may have a single layer structure, or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

[0225] The thickness of the conductor layer depends on the desired design of the printed wiring board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0226] In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer using a conventionally known technique such as a semi-additive method or a full-additive method. From the viewpoint of ease of production, the semi-additive method is preferred. An example of forming a conductor layer using a semi-additive method will be described below.

[0227] First, a plating seed layer is formed on the surface of an insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, thereby forming a conductor layer having the desired wiring pattern.

[0228] In another embodiment, the conductor layer may be formed using a metal foil. When a metal foil is used 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 a metal foil is laminated on the exposed surface of the resin composition layer. The resin composition layer and the metal foil may be laminated by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Thereafter, a conductor layer having a desired wiring pattern can be formed using the metal foil on the insulating layer by a conventionally known technique such as a subtractive method or a modified semi-additive method.

[0229] The metal foil can be produced by a known method such as an electrolytic method, a rolling method, etc. Examples of commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Nippon Mining & Smelting Co., Ltd., and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd.

[0230] [Semiconductor Devices] Semiconductor devices that can be equipped with the semiconductor chip package of the present invention include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft). [Example]

[0231] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. In the following, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Unless otherwise specified, the temperature conditions are room temperature (23°C), and unless otherwise specified, the pressure conditions are atmospheric pressure (1 atm).

[0232] <Synthesis Example 1: Synthesis of a radical polymerizable group-containing compound having a carbodiimide structure> 100 parts by mass of dicyclohexylmethane-4,4'-diisocyanate (HMDI) and 0.5 parts by mass of 3-methyl-1-phenyl-2-phospholene-1-oxide as a carbodiimidization catalyst were placed in a reaction vessel equipped with a reflux condenser and a stirrer, and the mixture was stirred and mixed under a nitrogen stream at 185°C for 24 hours to carry out a carbodiimidization reaction, yielding an isocyanate-terminated polycarbodiimide. IR spectroscopy of the obtained isocyanate-terminated polycarbodiimide revealed a peak at a wavelength of 2150cm. -1 Absorption peaks due to carbodiimide groups were confirmed before and after the measurement. The terminal NCO content was 8.19 mass %, and the average degree of polymerization of the carbodiimide groups determined by the above measurement method was 3.5.

[0233] Next, 8.8 parts by mass of ethylene glycol monoacrylate was added to the isocyanate-terminated polycarbodiimide at 150°C under a nitrogen stream, and the mixture was heated to 180°C and stirred for 2 hours to react.-1 After confirming that the absorption peak of the isocyanate group had disappeared, the reaction product was removed from the reaction vessel and cooled to room temperature to obtain a pale yellow, transparent, solid polycarbodiimide compound (a radically polymerizable group-containing compound having a carbodiimide structure; the main component is the compound of the above formula (S1); b' means the average degree of polymerization of the carbodiimide group). [ka]

[0234] <Synthesis Example 2: Synthesis of a compound containing a radical polymerizable group having a carbodiimide structure> In Synthesis Example 1, 8.8 parts of ethylene glycol monoacrylate was changed to 8.8 parts of ethylene glycol monoallyl ether. A solid polycarbodiimide compound (a radically polymerizable group-containing compound having a carbodiimide structure; the main component is the compound of formula (S2) above; b' is the same as above) was obtained in the same manner as in Synthesis Example 1, except for the above points. [ka]

[0235] <Synthesis Example 3: Synthesis of a compound containing a radical polymerizable group having a carbodiimide structure> To the isocyanate-terminated polycarbodiimide obtained in the same manner as in Synthesis Example 1, 8.8 parts by mass of ethylene glycol monoacrylate and 4 parts by mass of polybutadiene ("G-1000" manufactured by Nippon Soda Co., Ltd., number average molecular weight 1400, 1,2-addition structural unit 85% or more, trans-1,4-addition structural unit 15% or less) were added, and the mixture was heated to 180°C and stirred and mixed for 2 hours to react. After confirming that the absorption peak of the isocyanate group at a wavelength of 2200 to 2300 cm-1 had disappeared by IR spectrum measurement, the reaction product was removed from the reaction vessel and cooled to room temperature to obtain a pale yellow, transparent, solid polycarbodiimide compound (a radically polymerizable group-containing compound having a carbodiimide structure; the main component is the compound of the above formula (S3); b' is the same as above. d' means the average degree of polymerization of the combined units of polybutadiene and polycarbodiimide. e' means the average degree of polymerization of the butadiene units corresponding to the above number average molecular weight. Although only 1,2-addition structural units are shown as e' units, 1,4-addition structural units (cis, trans) are also included). [ka]

[0236] <Synthesis Example 4: Synthesis of Maleimide A> An MEK solution (62% by mass of non-volatile components) of a maleimide compound synthesized by the method described in Synthesis Example 1 of Japan Institute of Invention and Innovation Technical Bulletin No. 2020-500211 was prepared. This maleimide compound has a structure represented by the following formula (1) (Mw / Mn=1.81, t''=1.47 (mainly 1, 2, or 3)). [ka]

[0237] <Synthesis Example 5: Synthesis of Polyimide B> A 500 mL separable flask was prepared, equipped with a water content receiver connected to a reflux condenser, a nitrogen inlet tube, and a stirrer. 20.3 g of 4,4'-oxydiphthalic anhydride (ODPA), 200 g of γ-butyrolactone, 20 g of toluene, and 29.6 g of 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane were added to the flask and stirred at 45°C for 2 hours under a nitrogen stream. The reaction solution was then heated and maintained at approximately 160°C, while the condensed water was azeotropically removed with toluene under a nitrogen stream. It was confirmed that the specified amount of water had accumulated in the water content receiver and that no water was leaking out. After confirmation, the reaction solution was further heated and stirred at 200°C for 1 hour. The mixture was then cooled to obtain a polyimide solution (non-volatile content: 20% by mass) containing a polyimide resin having a 1,1,3-trimethylindane skeleton. The obtained polyimide resin had a repeating unit represented by the following formula (X1) and a repeating unit represented by the following formula (X2). The weight-average molecular weight of the polyimide resin was 12,000. [ka]

[0238] <Production of resin varnish> Each component was weighed out in the number of parts by mass shown in the table below, and then mixed with 10 parts of MEK and 10 parts of cyclohexanone. The mixture was uniformly dispersed using a high-speed rotating mixer to obtain a resin varnish. [Table 1]

[0239] Details of each component listed in the table are as follows: (A) Radical polymerizable compound having a carbodiimide structure Synthesis Example 1: Radical polymerizable group-containing compound having a carbodiimide structure synthesized in Synthesis Example 1 Synthesis Example 2: Radical polymerizable group-containing compound having a carbodiimide structure synthesized in Synthesis Example 2 Synthesis Example 3: Radical polymerizable group-containing compound having a carbodiimide structure synthesized in Synthesis Example 3 (B) Antioxidants AO-330: Phenolic antioxidant, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene, manufactured by ADEKA Corporation AO-20: Phenolic antioxidant, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, manufactured by ADEKA Corporation HP-300: Phenolic antioxidant, N,N'-bis-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionylhexamethylenediamine, manufactured by Kawaguchi Chemical Industry Co., Ltd. AO-503: Thioether antioxidant, di(tridecyl)-3,3'-thiodipropionate, manufactured by ADEKA Corporation (C) Thermosetting resin HP-4032-SS: Naphthalene-type epoxy resin, epoxy equivalent weight 144g / eq., manufactured by DIC Corporation NC-3000-L: Biphenyl type epoxy resin, epoxy equivalent 269g / eq., manufactured by Nippon Kayaku Co., Ltd. ZX-1059: 1:1 mixture of bisphenol A epoxy resin and bisphenol F epoxy resin, epoxy equivalent 169g / eq., manufactured by Nippon Steel Chemical & Material Co., Ltd. HPC-8150-62T: Activated ester resin with naphthalene structure, epoxy equivalent weight 223g / eq., non-volatile content 65% by mass in toluene solution, manufactured by DIC Corporation HPC-8000L-65MT: Active ester resin containing dicyclopentadiene-type diphenol structure, epoxy equivalent weight 229g / eq., MEK-toluene mixed solution with 65% solids, manufactured by DIC Corporation LA-3018-50P: Triazine skeleton-containing phenolic resin, 1-methoxy-2-propanol solution with 50% non-volatile content, manufactured by DIC Corporation BA230S75: Prepolymer of bisphenol A dicyanate, functional group equivalent weight 232 g / eq., MEK solution with non-volatile content of 75% by mass, manufactured by Lonza V03: Carbodiimide resin, functional group equivalent weight 216 g / eq., toluene solution with non-volatile content of 50% by mass, manufactured by Nisshinbo Chemical Inc. Stabaxol P100: Carbodiimide resin, functional group equivalent weight 272g / eq., manufactured by LANXESS Maleimide A: Synthesized in Synthesis Example 4 SA9000: Methacrylate-modified polyphenylene ether, manufactured by SABIC ODV-XET-X04: Polystyrene resin, toluene solution with 50% non-volatile content, manufactured by Nippon Steel Chemical & Material Co., Ltd. (D) Inorganic filler SO-C2: Spherical silica surface-treated with an amine-based alkoxysilane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.5 μm, specific surface area 5.8 m 2 / g, manufactured by Admatechs Co., Ltd. UFP-30: Spherical silica surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical Co., Ltd.'s "KBM573"), with an average particle size of 0.3 μm and a specific surface area of ​​5.8 m 2 / g, manufactured by Denka (E) Polymer component YX7553BH30: Phenoxy resin, 1:1 solution of MEK and cyclohexanone with 30% non-volatile content, weight average molecular weight 35,000, manufactured by Mitsubishi Chemical Corporation Polyimide B: Synthesized in Synthesis Example 5 AC3816N: Staphyloid, manufactured by AICA Kogyo Co., Ltd. (F) Curing accelerator Perhexyl D: NOF Corporation 1B2PZ: Shikoku Chemicals Corporation Co(III): Metal catalyst, manufactured by Tokyo Chemical Industry Co., Ltd. (G) Other additives JP-360: Phosphorus-based antioxidant, manufactured by Johoku Chemical Co., Ltd. ANTAGE 3C: Amine antioxidant, manufactured by Kawaguchi Chemical Industry Co., Ltd.

[0240] <Preparation of Resin Sheet Having Resin Composition Layer of 40 μm Thick> A polyethylene terephthalate film ("AL5" manufactured by Lintec Corporation, thickness 38 μm) with a release layer was prepared as a support. The resin varnishes obtained in the Examples and Comparative Examples were uniformly applied onto the release layer of this support so that the thickness of the resin composition layer after drying would be 40 μm. Thereafter, the resin composition was dried at 80°C to 100°C (average 90°C) for 2 minutes to obtain a resin sheet including the support and the resin composition layer.

[0241] <Measurement of dielectric constant and dielectric loss tangent (dielectric properties)> (1) Preparation of the cured product The resin sheets obtained in the examples and comparative examples were cured for 90 minutes in an oven at 190° C. The resin sheets were taken out of the oven and the support was peeled off to obtain cured resin composition layers.

[0242] (2) Measurement of dielectric constant and dielectric loss tangent The cured product was cut into a piece of 80 mm long and 2 mm wide, and the dielectric constant and dielectric loss tangent (Dk and Df values) were measured using an Agilent Technologies HP8362B by the cavity resonance perturbation method at a measurement frequency of 5.8 GHz and measurement temperatures of 23°C and 90°C. Measurements were performed on two test pieces, and the average was calculated.

[0243] <Melt viscosity measurement> A portion of the resin composition layer was peeled off from the resin sheet, and the melt viscosity was measured using a dynamic viscoelasticity measuring device (Rheosol-G3000 manufactured by UBM). Using parallel plates with a diameter of 18 mm, 1 g of the resin composition layer was heated from a starting temperature of 60°C to 200°C at a heating rate of 5°C / min, and the dynamic viscoelasticity was measured under the following measurement conditions: measurement interval temperature 2.5°C, frequency 1 Hz, and strain 5°C, and the minimum melt viscosity (poise) was calculated.

[0244] <Evaluation of smear removal> (1) Surface preparation for interior substrates A glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness: 18 μm, substrate thickness: 0.8 mm, Panasonic "R1515A") was prepared as the inner layer substrate. The copper foil on the surface of this inner layer substrate was roughened by etching using a microetching agent (MEC "CZ8101") to remove 1 μm of copper. The substrate was then dried at 190°C for 30 minutes.

[0245] (2) Lamination and hardening of resin sheets The resin sheets obtained in the examples and comparative examples were laminated onto both sides of the inner layer substrate using a batch-type vacuum pressure laminator (a two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.) so that the resin composition layer was bonded to the inner layer substrate. This lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, and then pressing at a temperature of 100°C and a pressure of 0.74 MPa for 30 seconds.

[0246] The laminated resin sheet was then heat-pressed at atmospheric pressure at 100°C under a pressure of 0.5 MPa for 60 seconds to smooth it, and then placed in a 130°C oven and heated for 30 minutes, and then transferred to a 170°C oven and heated for 30 minutes.

[0247] (3) Formation of via holes Using a CO2 laser processing machine (LK-2K212 / 2C) manufactured by Via Mechanics, the insulating layer was processed under the conditions of a frequency of 2000 Hz, a pulse width of 3 μs, an output of 0.95 W, and a shot count of 3, to form via holes with a top diameter of 50 μm on the insulating layer surface and a diameter of 40 μm on the insulating layer bottom surface. After that, the support was peeled off.

[0248] (4) Roughening treatment The inner layer substrate was immersed in a swelling solution, Swelling Dip Securiganth P (manufactured by Atotech Japan), at 60°C for 10 minutes. Next, it was immersed in a roughening solution, Concentrate Compact P (aqueous solution of KMnO4: 60 g / L, NaOH: 40 g / L) (manufactured by Atotech Japan), at 80°C for 20 minutes. Finally, it was immersed in a neutralizing solution, Reduction Solution Securiganth P (manufactured by Atotech Japan), at 40°C for 5 minutes. The resulting substrate was designated evaluation substrate A.

[0249] (5) Evaluation of residue (smear) at the bottom of via holes The periphery of the bottom of the via hole was observed with a scanning electron microscope (SEM), and the maximum smear length from the wall surface of the bottom of the via hole was measured from the obtained image and evaluated according to the following criteria. ◎: Maximum smear length is less than 3 μm ○: Maximum smear length is 3 μm or more and less than 5 μm ×: Maximum smear length is 5 μm or more

[0250] <Evaluation of cracks after desmear treatment (roughening treatment)> The resin sheets obtained in the Examples and Comparative Examples were laminated to both sides of a core material (Resonac Corporation "E705GR", 400 μm thick) consisting of 350 μm diameter circular copper pads (35 μm copper thickness) arranged in a grid pattern at 400 μm intervals to achieve a residual copper ratio of 60%. Using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator "CVP700"), the resin composition layer was bonded to both sides of the inner layer substrate. This lamination was carried out by reducing the pressure to 13 hPa or less for 30 seconds, followed by pressure bonding at 100°C and 0.74 MPa for 30 seconds. The resulting sheet was placed in a 130°C oven for 30 minutes, then transferred to a 170°C oven for 30 minutes. The support layer was then peeled off, and the resulting circuit board was immersed in a swelling solution, Securiganth P (manufactured by Atotech Japan), at 60°C for 10 minutes. Next, the circuit board was immersed in a roughening solution, Concentrate Compact P (aqueous solution of 60 g / L KMnO4 and 40 g / L NaOH) (manufactured by Atotech Japan), at 80°C for 30 minutes. Finally, the circuit board was immersed in a neutralizing solution, Securiganth P (manufactured by Atotech Japan), at 40°C for 5 minutes. One hundred copper pads on the roughening-treated circuit board were observed to check for cracks in the resin composition layer and evaluated according to the following criteria. ○: If there are 10 or fewer cracks △: More than 10 but less than 20 cracks ×: More than 20 cracks

[0251] [Table 2]

Claims

1. A support and a resin composition layer provided on the support, The resin composition layer comprises: (A) a radical polymerizable group-containing compound having a carbodiimide structure; (B) one or more antioxidants selected from phenol-based antioxidants and sulfur-based antioxidants; (C) a thermosetting resin, and (D) A resin sheet for forming an insulating layer of a semiconductor package substrate, comprising an inorganic filler.

2. 2. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein the content of the component (A) is 0.1% by mass or more and 25% by mass or less, when the resin component of the resin composition layer is 100% by mass.

3. 2. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein the content of the component (B) is 0.1% by mass or more and 10% by mass or less, when the resin component of the resin composition layer is 100% by mass.

4. 2. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein the content of the component (C) is 50% by mass or more and 98% by mass or less, when the resin component of the resin composition layer is 100% by mass.

5. 2. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein the content of the component (D) is 45% by mass or more and 85% by mass or less, when the non-volatile components of the resin composition layer are 100% by mass.

6. 2. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein the resin composition layer has a melt viscosity of 3000 poise or less.

7. A semiconductor chip package substrate comprising an insulating layer made of a cured product of the resin composition layer of the resin sheet for forming an insulating layer of a semiconductor package substrate according to any one of claims 1 to 6.

8. A semiconductor device comprising the semiconductor chip package substrate according to claim 7.

Images