Resin sheet for forming insulating layer of semiconductor package substrate

Abstract

The present invention addresses the problem of providing a resin sheet for forming an insulating layer of a semiconductor package substrate, said resin sheet being capable of obtaining a cured product having a high glass transition temperature, suppressed occurrence of a halo phenomenon, good crack resistance, and excellent flame retardancy. [Solution] A resin sheet for forming an insulating layer of a semiconductor package substrate, the resin sheet having a support body and a resin composition layer provided on the support body, the resin composition layer contains (A) a radically polymerizable group-containing compound having a carbodiimide structure, (B) a flame retardant having a crosslinkable functional group, and (C) a thermosetting resin.

Description

Technical Field

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

[0002] As a manufacturing technology for printed wiring boards, a stacking method is known, in which insulating layers and conductive layers are alternately stacked. In stacking methods, the insulating layer is generally formed by curing a resin composition. For example, Patent Document 1 discloses a technology for forming an insulating layer by curing a resin composition containing a carbodiimide compound.

[0003] Prior art literature Patent Literature Patent Document 1: International Publication No. 2023 / 027013 Summary of the Invention

[0004] Technical issues to be solved by the invention In recent years, the increased functionality of electronic components has led to a demand for higher wiring densities in circuit boards. To achieve this further, the mechanical strength, flame retardancy, and crack resistance of the insulating layer need to be further improved. To improve mechanical strength, increasing the glass transition temperature of the insulating layer and suppressing the haloing phenomenon are possible approaches.

[0005] The halo phenomenon refers to the discoloration of the resin in the insulating layer around the through-hole. This halo phenomenon is generally caused by the degradation of the resin around the through-hole. Furthermore, if the insulating layer that has developed the halo phenomenon is subjected to a roughening treatment, the resin in the portion of the insulating layer where the halo phenomenon has occurred (hereinafter sometimes referred to as the "halo portion") may be corroded during the roughening treatment, causing interlayer delamination between the insulating layer and the inner substrate, and deteriorating the mechanical strength.

[0006] An object of the present invention is to provide a resin sheet capable of obtaining a cured product having a high glass transition temperature, suppressed occurrence of a halo phenomenon, and excellent crack resistance.

[0007] Means for solving technical problems In order to achieve the subject of the present invention, the present inventors conducted in-depth research and found that by using (A) a compound containing a free radical polymerizable group having a carbodiimide structure, (B) a flame retardant having a cross-linking functional group, and (C) a thermosetting resin, a cured product with a high glass transition temperature, suppressed halo phenomenon, and good crack resistance can be obtained, thereby completing the present invention.

[0008] That is, the present invention includes the following contents. [1] A resin sheet for forming an insulating layer of a semiconductor package substrate, comprising 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) a flame retardant having a crosslinkable functional group, and (C) Thermosetting resin. [2] The resin sheet for forming an insulating layer of a semiconductor package substrate according to [1], further comprising (D) an inorganic filler. [3] The resin sheet for forming an insulating layer of a semiconductor package substrate according to [1] or [2], further comprising (E) a radically polymerizable group-containing compound that does not have a carbodiimide structure. [4] The 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 (A) is 0.1% by mass or more and 15% by mass or less, when the non-volatile matter 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 (B) is 0.01% by mass or more and 3% by mass or less, when the non-volatile matter of the resin composition layer is 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 content of component (C) is 10% by mass or more and 40% by mass or less, when the non-volatile matter of the resin composition layer is set to 100% by mass. [7] The resin sheet for forming an insulating layer of a semiconductor package substrate according to any one of [2] to [6], wherein the content of the component (D) is 45% by mass or more and 85% by mass or less, when the non-volatile matter of the resin composition layer is set to 100% by mass. [8] The resin sheet for forming an insulating layer of a semiconductor package substrate according to any one of [3] to [7], wherein the content of the component (E) is 0.1% by mass or more and 20% by mass or less, when the non-volatile matter of the resin composition layer is set to 100% by mass. [9] A semiconductor chip package substrate comprising an insulating layer formed from a cured product of a resin composition layer of a resin sheet for forming an insulating layer of a semiconductor package substrate according to any one of [1] to [8].

[10] A semiconductor device comprising the semiconductor chip package substrate described in [9]. Effects of the Invention

[0009] According to the present invention, a resin sheet can be obtained that can produce a cured product having a high glass transition temperature, suppressed halo phenomenon, and excellent crack resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a cross-sectional view schematically showing an insulating layer obtained by curing a resin composition layer together with an inner layer substrate. Figure 2 It is a plan view schematically showing the surface of the insulating layer opposite to the conductor layer, which is obtained by curing the resin composition layer. Figure 3 This is a cross-sectional view schematically showing an insulating layer obtained by curing a resin composition layer and subjected to a roughening treatment, together with an inner layer substrate. DETAILED DESCRIPTION

[0011] Hereinafter, the present invention will be described in detail based on its preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and can be implemented with arbitrary modifications without departing from the scope of the claims and their equivalents.

[0012] [Resin sheet for forming an insulating layer of a semiconductor package substrate] The resin sheet for forming an insulating layer of a semiconductor package substrate of the present invention comprises a support and a resin composition layer disposed on the support. The resin composition layer comprises (A) a compound having a carbodiimide structure and containing a free radical polymerizable group, (B) a flame retardant having a crosslinkable functional group, (C) a thermosetting resin, and (D) an inorganic filler. This resin sheet can produce a cured product having a high glass transition temperature, suppressed haloing, and excellent crack resistance. Furthermore, the cured product generally exhibits excellent flame retardancy.

[0013] The resin sheet for forming an insulating layer on a semiconductor chip package substrate of the present invention is useful as an insulating layer for a semiconductor package substrate. Examples of semiconductor package substrates include FC-CSP, MIS-BGA packages, ETS-BGA packages, fan-out (WLP) (Wafer Level Package), fan-in (WLP), fan-out (PLP) (Panel Level Package), and fan-in (PLP). Hereinafter, the "resin sheet for forming an insulating layer on a semiconductor package substrate" may be simply referred to as the "resin sheet."

[0014] <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 films made of plastic materials, metal foils, and release paper, with films made of plastic materials and metal foils being preferred.

[0015] When a film formed of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes referred to as "PET") and polyethylene naphthalate (hereinafter sometimes referred to as "PEN"), polycarbonate (hereinafter sometimes referred to as "PC"), acrylic polymers such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0016] 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 copper alone or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0017] The surface of the support to be in contact with the resin composition layer may be subjected to matte treatment, corona treatment, or antistatic treatment.

[0018] In addition, as the support, a support with a release layer having a release layer on the surface bonded to the resin composition layer can be used. As the release agent used in the release layer of the support with a release layer, for example, one or more release agents selected from alkyd resins, polyolefin resins, polyurethane resins and silicone resins can be mentioned. The support with a release layer can use commercially available products, for example: "SK-1", "AL-5", and "AL-7" manufactured by Lintec, which are PET films having a release layer with an alkyd resin-based release agent as a main component; "Lumirror T60" manufactured by Toray Industries, Ltd.; "Purex" manufactured by Teijin Co., Ltd.; "Unipeel" manufactured by Unitika Co., Ltd., etc.

[0019] The thickness of the support is not particularly limited, but is preferably 1 μm or greater, more preferably 5 μm or greater, and even more preferably 10 μm or greater, and is preferably 75 μm or less, more preferably 60 μm or less, and even more preferably 50 μm or less. When a support with a release layer is used, the overall thickness of the support with the release layer is preferably within the above range.

[0020] <Resin Composition Layer> The resin sheet has a resin composition layer and is arranged on a support. The insulating layer can be formed by thermally curing the resin composition layer. Typically, the insulating layer comprises a cured product of the resin composition layer, preferably only comprises a cured product of the resin composition layer. The resin composition layer comprises (A) a compound containing a free radical polymerizable group having a carbodiimide structure, (B) a flame retardant having a crosslinkable functional group, and (C) a thermosetting resin. As needed, the resin composition layer may further comprise (D) an inorganic filler, (E) a compound containing a free radical polymerizable group without a carbodiimide structure, (F) a thermoplastic resin, (G) a stress relaxation material, (H) a free radical polymerization initiator, (I) a curing accelerator, (J) other additives, and (K) a solvent.

[0021] In the present invention, unless otherwise specified, the content of each component in the resin composition layer is the value when the non-volatile component in the resin composition layer is set to 100% by mass. The non-volatile component refers to the total non-volatile components of the components constituting the resin composition layer, excluding the solvent (K) described below. Furthermore, in the present invention, the resin component in the resin composition layer refers to the component excluding the inorganic filler from the non-volatile components of the resin composition layer.

[0022] -(A) Compounds containing a radically polymerizable group and having a carbodiimide structure- The resin composition layer contains (A) a radical polymerizable group-containing compound having a carbodiimide structure as the component (A). The component (A) may be used alone or in combination of two or more.

[0023] (A) The compound containing a free radical polymerizable group having a carbodiimide structure refers to a compound having one or more carbodiimide structures (-N=C=N-) and one or more free radical polymerizable groups in one molecule. Component (A) may further have one or more carbamate bonds (-O-CO-NH-) in one molecule. The carbodiimide structure, the free radical polymerizable group and the carbamate bond may each have two or more in one molecule. In the case of containing an epoxy resin as the (C) thermosetting resin described below, component (A) sometimes has a function of reacting with the epoxy resin to cure it. Component (A) may be used alone or in combination of two or more.

[0024] A radical polymerizable group refers to 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 (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl). The radical polymerizable group is preferably present at the end of component (A).

[0025] The component (A) preferably contains a structural unit represented by the following formula (A-1) in addition to the radical polymerizable group. [Chemical Formula 1] In formula (A-1), Y represents a divalent hydrocarbon group which may have a substituent.

[0026] In formula (A-1), Y represents a divalent hydrocarbon group optionally having a substituent. The number of carbon atoms in the divalent hydrocarbon group in Y is usually 1 or more, preferably 2 or more, and usually 30 or less. The divalent hydrocarbon group may be a divalent saturated hydrocarbon group or a divalent unsaturated hydrocarbon group. Unless otherwise specified, the 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 any of linear, branched, and cyclic hydrocarbon groups.

[0027] Preferred examples of the divalent hydrocarbon group for Y include an alkylene group, a cycloalkylene group, an arylene group, and a combination thereof.

[0028] The number of carbon atoms in the alkylene group in Y is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6, 1 to 4, or 1 to 3. This number of carbon atoms does not include the number of carbon atoms in the substituent. Preferred examples of the alkylene group include methylene, ethylene, propylene, and butylene.

[0029] The number of carbon atoms in the cycloalkylene group in Y is preferably 3 to 20, more preferably 3 to 12, and even more preferably 3 to 6. This number of carbon atoms does not include the number of carbon atoms in the substituent. Preferred examples of the cycloalkylene group include cyclopropylene, cyclobutylene, cyclopentylene, and cyclohexylene.

[0030] The arylene group in Y represents a group formed by removing two hydrogen atoms from an aromatic hydrocarbon ring. The arylene group preferably has 6 to 24 carbon atoms, more preferably 6 to 18, and even more preferably 6 to 14 or 6 to 10 carbon atoms. This number of carbon atoms does not include the number of carbon atoms in the substituent. Preferred examples of the arylene group include phenylene, naphthylene, and anthracene.

[0031] The substituent in 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, and an aryl-carbonyl-oxy group. The divalent hydrocarbon group in Y preferably has no substituent.

[0032] More preferably, Y represents a divalent saturated hydrocarbon group having 2 to 30 carbon atoms, which may have a substituent, or a divalent unsaturated hydrocarbon group having 2 to 30 carbon atoms, which may have a substituent. Still more preferably, Y represents a divalent saturated hydrocarbon group having 2 to 30 carbon atoms, which may have a substituent and has a ring structure (e.g., a ring structure selected from a cycloalkane ring, a benzene ring, and a naphthalene ring), or a divalent unsaturated hydrocarbon group having 2 to 30 carbon atoms, which may have a substituent and has a ring structure (e.g., a ring structure selected from a cycloalkane ring, a benzene ring, and a naphthalene ring).

[0033] Y in formula (A-1) preferably represents a divalent group represented by the following formula (A-2). [Chemical Formula 2] In formula (A-2), Y a 、Y b and Y c Each independently represents a single bond or C(R y )2; R y Each independently represents a hydrogen atom or a methyl group; Ring Y 1 and Y 2 Each independently represents a cycloalkane ring having 4 to 10 carbon atoms and optionally having a substituent, a benzene ring optionally having a substituent, or a naphthalene ring optionally having a substituent; n y Indicates 0 or 1; * indicates the binding site.

[0034] In formula (A-2), Y a 、Y b and Y c Each independently represents a single bond or C(R y )2. Preferably, Y a and Y c is a single bond and Y b Represents C(R y )2. R y Each independently represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom.

[0035] In formula (A-2), ring Y 1 and Ring Y 2 Each independently represents a cycloalkane ring having 4 to 10 carbon atoms and optionally having a substituent, a benzene ring having an optional substituent, or a naphthalene ring having an optional 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 cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, and cyclodecane ring; bicyclic saturated hydrocarbon rings such as bicyclo[2.2.1]heptane ring (norbornane ring), bicyclo[4.4.0]decane ring (decalin ring), bicyclo[5.3.0]decane ring, bicyclo[4.3.0]nonane ring (hexahydroindan ring), bicyclo[3.3.0]octane ring, and bicyclo[3.3.1]nonane ring; and tricyclic saturated hydrocarbon rings such as tricyclo[5.2.1.0 2,6 ] decane ring (tetrahydrodicyclopentadiene ring), tricyclic [3.3.1.1 3,7 ] decane ring (adamantane ring) and other tricyclic saturated hydrocarbon rings. More preferably, ring Y 1 and Ring Y 2 Each independently represents a cyclohexane ring optionally having a substituent. As substituents in the cycloalkane ring, benzene ring and naphthalene ring, there are no particular limitations, and examples thereof include halogen atoms, alkyl groups, alkenyl groups, aryl groups, aryl-alkyl groups (alkyl groups substituted with aryl groups), alkyl-aryl groups (aryl groups substituted with alkyl groups), alkyl-oxy groups, alkenyl-oxy groups, aryl-oxy groups, alkyl-oxy-carbonyl groups, alkenyl-oxy-carbonyl groups, aryl-oxy-carbonyl groups, alkyl-carbonyl-oxy groups, alkenyl-carbonyl-oxy groups, aryl-carbonyl-oxy groups, etc. Among them, ring Y 1 and Ring Y 2 An unsubstituted cyclohexane ring is particularly preferred.

[0036] Specific examples of Y include divalent groups represented by formulae (Y1) to (Y14), and a divalent group represented by formula (Y1) is particularly preferred. In formulae (Y1) to (Y14), * represents a bonding site. [Chemical Formula 3]

[0037] In a preferred example, the proportion of the structural unit represented by formula (A-1) contained in the component (A) is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, particularly preferably 80% by mass or more, and may be 90% by mass or more, relative to 100% by mass of the total mass of the molecules of the component (A).

[0038] (A) The component is preferably a compound represented by formula (A-3). [Chemical Formula 4] In formula (A-3), R each independently represents a hydrogen atom or a methyl group; X1 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; Z each independently represents a divalent saturated hydrocarbon group having 2 to 300 carbon atoms, which may be substituted, or a divalent unsaturated hydrocarbon group having 2 to 300 carbon atoms, which may be substituted; a each independently represents an integer of 0 or 1 or greater; b each independently represents an integer of 1 or greater; c each independently represents an integer of 1 or greater; d each represents 0 or 1 or greater; and Y each independently represents the above-mentioned groups. Units a, b, c, and d may be the same or different.

[0039] In formula (A-3), R each independently represents a hydrogen atom or a methyl group.

[0040] In formula (A-3), X 1 Each independently represents a carbonyl group, a methylene group, a phenylene group, or a phenylene-methylene group (the bonding direction is not particularly limited, but the phenylene side is preferably bonded to the C in "RC"). Preferably, X 1 Each independently represents a methylene group or a carbonyl group. Phenylene-methylene groups include 1,2-phenylene-methylene, 1,3-phenylene-methylene, and 1,4-phenylene-methylene.

[0041] In formula (A-3), X 2 Each independently represents 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 ethylene, trimethylene, and tetramethylene; and branched alkylene groups having 2 to 4 carbon atoms, such as ethylidene, propylidene, isopropylidene, and ethylmethylmethylene. In one embodiment, X 2 Each of them is independently preferably a divalent saturated hydrocarbon group having 2 or 3 carbon atoms, and more preferably an ethylene group (-CH2-CH2-).

[0042] In formula (A-3), Z each 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. Preferably, Z each independently represents a divalent saturated hydrocarbon group having 2 to 300 carbon atoms, or a divalent unsaturated hydrocarbon group having 2 to 300 carbon atoms. More preferably, Z each independently represents a divalent hydrocarbon group having 300 or less carbon atoms, which has a structural unit selected from the following formulas (Z1) to (Z8). Even more preferably, Z each independently represents a divalent hydrocarbon group having 300 or less carbon atoms, which is formed from a structural unit selected from the following formulas (Z1) to (Z8). [Chemical Formula 5]

[0043] Z more preferably each independently represents a divalent hydrocarbon group having 300 or less carbon atoms and having a structural unit represented by formula (Z1); further preferably, it represents a divalent hydrocarbon group having 300 or less carbon atoms formed from structural units selected from formulae (Z1) to (Z8) and having at least a structural unit represented by formula (Z1). Among them, Z particularly preferably represents a divalent hydrocarbon group having 300 or less carbon atoms represented by the following formula (Z-1). [Chemical Formula 6] (In formula (Z-1), n z represents an integer greater than 1; * represents a binding site.)

[0044] In formula (A-3), a each independently represents an integer of 0 or 1 or greater, preferably 0 or an integer of 1 to 10, and more preferably 0 or 1.

[0045] In formula (A-3), b represents the average degree of polymerization of the carbodiimide group. Each b independently represents 1 or more, preferably an integer of 1 or more, more preferably 1 to 100, further preferably an integer of 1 to 100, 1 to 10, or 1 to 10.

[0046] In formula (A-3), c represents the average degree of polymerization of the optionally substituted divalent saturated hydrocarbon group having 2 to 300 carbon atoms represented by Z. Each c independently represents 1 or more, preferably an integer of 1 or more, more preferably 1 to 100, further preferably an integer of 1 to 100, 1 to 10, an integer of 1 to 10, or 1.

[0047] In formula (A-3), d represents the average degree of polymerization of the group represented by Z and the polycarbodiimide. d is independently 0 or 1 or greater, preferably 0 or an integer of 1 to 100, more preferably 0 or an integer of 1 to 100, further preferably 0 or an integer of 1 to 10.

[0048] Component (A) may contain an isocyanate group (-N=C=O) in the molecule depending on its production method. The isocyanate group content (also referred to as "NCO content") in component (A) is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1% by mass or less, or 0.5% by mass or less.

[0049] Specific examples of component (A) include the compounds shown in the following (S1) to (S5). However, component (A) is not limited to these specific examples. In the formula, 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). It should be noted that in formula (S5), the e' unit only represents a 1,2-addition structural unit, but also includes a 1,4-addition structural unit (cis, trans). [Chemical Formula 7]

[0050] (A) component can be prepared by a method known in the past. As a known method, for example, by mixing and stirring the diisocyanate compounds such as dicyclohexylmethane -4,4'- diisocyanate and the carbodiimidization catalysts such as 3-methyl -1-phenyl-2-phosphole -1- oxide, thereby carrying out carbodiimidization reaction to obtain isocyanate-terminated polycarbodiimide. Then, the obtained isocyanate-terminated polycarbodiimide, the compound with the free radical polymerizable groups such as (meth) acryloyl and the two-terminal hydroxy polybutadiene used as needed are reacted. If it is a person skilled in the art, reaction temperature, reaction time, etc. can be appropriately set.

[0051] 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, 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, even more preferably 6,000 or less. The weight average molecular weight of component (A) can be measured by gel permeation chromatography (GPC) (polystyrene conversion).

[0052] From the perspective of increasing the glass transition temperature, the carbodiimide equivalent of component (A) is preferably 150 g / eq. or greater, more preferably 200 g / eq. or greater, and even more preferably 250 g / eq. or greater, and is preferably 1000 g / eq. or less, more preferably 800 g / eq. or less, and even more preferably 600 g / eq. or less. The carbodiimide equivalent represents the mass of the resin per equivalent of carbodiimide groups.

[0053] When the non-volatile component in the resin composition layer is set to 100 mass%, the content of component (A) is preferably 0.1 mass% or more, more preferably 0.3 mass% or more, further preferably 0.4 mass% or more, preferably 15 mass% or less, further preferably 10 mass% or less, and further preferably 8 mass% or less.

[0054] When the resin component in the resin composition layer is set to 100% by mass, the content of component (A) is preferably 1% by mass or more, more preferably 1.5% by mass or more, further preferably 2% by mass or more, preferably 20% by mass or less, more preferably 15% by mass or less, further preferably 10% by mass or less.

[0055] -(B) Flame retardant having a crosslinkable functional group- The resin composition layer contains (B) a flame retardant having a crosslinkable functional group as component (B). The flame retardant having a crosslinkable functional group (B) as component (B) does not include substances belonging to component (A). By including the flame retardant having a crosslinkable functional group (B) in the resin composition layer, the flame retardancy can be improved, the decrease in the glass transition temperature of the cured product of the resin composition layer can be suppressed, and the occurrence of the halo phenomenon can be suppressed. The flame retardant having a crosslinkable functional group (B) can be used alone or in combination of two or more.

[0056] A crosslinkable functional group is a functional group that can form a crosslinked structure by irradiation with light such as heat or ultraviolet rays, and component (B) has a crosslinkable functional group. Therefore, the crosslinking density of the resin composition layer containing component (B) increases during curing. It is believed that as the crosslinking density of the cured product increases, oxygen in the cured product becomes difficult to penetrate, resulting in the inhibition of oxidation of metals such as copper foil, which serves as the base of the insulating layer, and the occurrence of the halo phenomenon is suppressed. It is also believed that when the crosslinking density of the cured product increases, the glass transition temperature also increases.

[0057] As the flame retardant (B) having a crosslinkable functional group, a flame retardant having one or more crosslinkable functional groups per molecule can be used. A flame retardant having one or more crosslinkable functional groups per molecule is sufficient, and may also have two or more crosslinkable functional groups. The upper limit of the number of crosslinkable functional groups that can be present in a molecule is not particularly limited, and may be 10 or less.

[0058] As a crosslinkable functional group, any functional group capable of crosslinking with a curable component such as an epoxy resin may be used. Examples thereof include: hydroxyl groups; unsaturated hydrocarbon groups such as vinyl groups, allyl groups, 1-propenyl groups, 3-cyclohexenyl groups, 3-cyclopentenyl groups, 2-vinylphenyl groups, 3-vinylphenyl groups, and 4-vinylphenyl groups; and α,β-unsaturated carbonyl groups such as acryloyl groups, methacryloyl groups, acryloyloxy groups, methacryloyloxy groups, and maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups). Preferably, any one of hydroxyl groups, vinyl groups, acryloyl groups, and methacryloyl groups is used, more preferably any one of hydroxyl groups and vinyl groups, and even more preferably hydroxyl groups. The crosslinkable functional group is preferably present at the end of component (B).

[0059] Examples of the component (B) include phosphorus-based flame retardants having a cross-linking functional group, such as phosphazene compounds having a cross-linking functional group, phosphates having a cross-linking functional group, phosphate esters having a cross-linking functional group, polyphosphates having a cross-linking functional group, phosphinates having a cross-linking functional group, phosphinates having a cross-linking functional group, phosphonates having a cross-linking functional group, and phosphonates having a cross-linking functional group; aliphatic amine compounds having a cross-linking functional group, and aromatic amine compounds having a cross-linking functional group. , nitrogen-based flame retardants with cross-linking functional groups such as nitrogen-containing heterocyclic compounds with cross-linking functional groups, urea compounds with cross-linking functional groups, etc.; hexabromobenzene with cross-linking functional groups, chlorinated paraffin with cross-linking functional groups, brominated polycarbonate resins with cross-linking functional groups, brominated epoxy resins with cross-linking functional groups, brominated phenoxy resins with cross-linking functional groups, brominated polyphenylene ether resins with cross-linking functional groups, brominated polystyrene resins with cross-linking functional groups, brominated benzyl polyacrylate resins with cross-linking functional groups, etc. halogen-based flame retardants with cross-linking functional groups, etc.

[0060] Among them, as component (B), from the viewpoint of significantly achieving the effects of the present invention, a phosphorus-based flame retardant having a crosslinkable functional group is preferred, any of a phosphazene compound having a crosslinkable functional group and a phosphate ester having a crosslinkable functional group is more preferred, and a phosphate ester having a crosslinkable functional group is further preferred.

[0061] The component (B) is preferably any one of a compound represented by the following formula (B-1) and a compound represented by the following formula (B-2). [Chemical Formula 8] In formula (B-1), R 1b and R 2b Each independently represents an alkyl group, an alkoxy group, an aryl group, an aryloxy group or a crosslinkable functional group, R3b represents a crosslinkable functional group, a divalent hydrocarbon group, a monovalent hydrocarbon group, or a monovalent group formed by a combination thereof, R 1 and R 2 They can combine with each other to form a ring. In formula (B-2), R 11b Each independently represents a cross-linking functional group, R 12b Each independently represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 6 carbon atoms. n1 represents an integer of 3 to 25, m1 represents an integer of 1 to 5, and m2 represents an integer of 0 to 5.

[0062] In formula (B-1), R 1 and R 2 Each independently represents an alkyl group, an alkoxy group, an aryl group, an aryloxy group, or a crosslinkable functional group. The crosslinkable functional group is as described above.

[0063] As the alkyl group, an alkyl group having 1 to 20 carbon atoms is preferred, an alkyl group having 1 to 15 carbon atoms is more preferred, and an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 3 carbon atoms is further preferred. This number of carbon atoms does not include the carbon atoms of the substituents described below. The alkyl group may be any of linear, branched, or cyclic. Examples of the alkyl group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, sec-butyl, and tert-butyl. Among these, the alkyl group is preferably methyl or ethyl, and more preferably ethyl.

[0064] As the alkoxy group, an alkoxy group having 1 to 20 carbon atoms is preferred, an alkoxy group having 1 to 15 carbon atoms is more preferred, and an alkoxy group having 1 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms is further preferred. This number of carbon atoms does not include the carbon atoms of the substituents described below. The alkoxy group may be any of linear, branched, or cyclic. Examples of the alkoxy group include methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, 2-butoxy, tert-butoxy, 1-pentyloxy, 2-pentyloxy, 3-pentyloxy, 2,2-dimethylpropoxy, 2-ethylpropoxy, 3,3-dimethylpropoxy, 1,1-dimethylpropoxy, cyclopentyloxy, 1-hexyloxy, 2-hexyloxy, 3-hexyloxy, and 4-methylpentyloxy. Among them, as the alkoxy group, methoxy and ethoxy are preferred, and ethoxy is more preferred.

[0065] The aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 15 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms. This number of carbon atoms does not include the carbon atoms of the substituents described below. Examples of the aryl group include phenyl and naphthyl. Among them, phenyl is preferred.

[0066] As the aryloxy group, an aryloxy group having 6 to 20 carbon atoms is preferred, an aryloxy group having 6 to 15 carbon atoms is more preferred, and an aryloxy group having 6 to 10 carbon atoms is further preferred. The number of carbon atoms does not include the number of carbon atoms of the substituents described later. Examples of the aryloxy group include phenoxy, 4-methylphenoxy, 3-methylphenoxy, 2-methylphenoxy, 2,6-dimethylphenoxy, 2,4-dimethylphenoxy, 2,3-dimethylphenoxy, 2,4,6-trimethylphenoxy, 4-isopropylphenoxy, 2-isopropylphenoxy, 3-isopropylphenoxy, 4-isobutylphenoxy, 2-isobutylphenoxy, 3-isobutylphenoxy, 4-tert-butylphenoxy, 2-tert-butylphenoxy, 3-tert-butylphenoxy, 2,6-di-tert-butylphenoxy, 2,4-di-tert-butylphenoxy, 2,3-di-tert-butylphenoxy, 2-methyl-4-tert-butylphenoxy, 2-methyl-6-tert-butylphenoxy, 4-methyl-2-tert-butylphenoxy, etc. Among them, as the aryloxy group, phenoxy is preferred.

[0067] R 1 and R 2 The alkyl group, alkoxy group, aryl group and aryloxy group shown may optionally have substituents. There is no particular limitation on the substituents, and examples thereof include a halogen atom, -O-C 1-6 alkyl group, -N(C 1-10 alkyl)2, C 1-10 alkyl group, C 6-10 aryl group, -NH2, -CN, -C(O)O-C 1-10 alkyl group, -COOH, -C(O)H, -NO2, etc. In addition, the substituent may also be a crosslinkable functional group. Here, the term "C p-q " (p and q are positive integers satisfying p < q) means that the number of carbon atoms of the organic group described immediately after this term is p to q. For example, the expression "C 1-10 alkyl group" means an alkyl group having 1 to 10 carbon atoms. These substituents may combine with each other to form a ring, and the ring structure also includes a spiro ring or a fused ring.

[0068] The above-mentioned substituents may further have substituents (hereinafter sometimes referred to as "secondary substituents"). As the secondary substituents, the same groups as the above-mentioned substituents can be used as long as there is no particular description.

[0069] R 1 and R 2 may combine with each other to form a ring. The ring structure that R 1 and R 2 can form also includes a spiro ring and a fused ring. Examples of the ring structure include a group shown by the following formula (B-1a), etc. In the formula (B-1a), * represents the bonding site to the phosphorus atom. [Chemical Formula 9]

[0070] In formula (B-1), R 3 It represents a crosslinkable functional group, a divalent hydrocarbon group, a monovalent hydrocarbon group, or a monovalent group formed by combining them.

[0071] The monovalent hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and further preferably 1 to 10 carbon atoms and 1 to 6 carbon atoms. The number of carbon atoms does not include the number of carbon atoms of the substituent. The monovalent hydrocarbon group may be any of linear, branched, and cyclic. Examples of the monovalent hydrocarbon group include monovalent aliphatic hydrocarbon groups and monovalent aromatic hydrocarbon groups, preferably monovalent aromatic hydrocarbon groups. The monovalent hydrocarbon group may be any of monovalent saturated hydrocarbon groups and monovalent unsaturated hydrocarbon groups, preferably monovalent unsaturated hydrocarbon groups. Specific examples of the monovalent hydrocarbon group include alkyl groups, alkenyl groups, aryl groups, and the like. Regarding the alkyl group and the aryl group, they are the same as R in formula (B-1). 1 The alkyl and aryl groups shown are the same.

[0072] Examples of the alkenyl group include ethenyl, propenyl, butenyl, and pentenyl.

[0073] The monovalent hydrocarbon group may have a substituent. The substituent and R in formula (B-1) 1 The substituents optionally possessed are the same. Among them, the substituent optionally possessed by the monovalent hydrocarbon group is preferably a crosslinkable functional group, more preferably a hydroxyl group.

[0074] The divalent hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and even more preferably 1 to 10 carbon atoms and 1 to 6 carbon atoms. The divalent hydrocarbon group may be any of linear, branched, and cyclic. Examples of the divalent hydrocarbon group include divalent aliphatic hydrocarbon groups and divalent aromatic hydrocarbon groups, with divalent aliphatic hydrocarbon groups being preferred. The divalent hydrocarbon group may be any of divalent saturated hydrocarbon groups and divalent unsaturated hydrocarbon groups, with divalent saturated hydrocarbon groups being preferred. Specific examples of the divalent hydrocarbon group include alkylene groups, alkenylene groups, and arylene groups.

[0075] Examples of the alkylene group include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, and decylene, and a methylene group is preferred.

[0076] Examples of the alkenylene group include vinylene, propenylene, butenylene, pentenylene, hexenylene, heptenylene, octenylene, nonenylene, and decenylene.

[0077] Examples of the arylene group include a phenylene group and a naphthylene group.

[0078] The divalent hydrocarbon group may have a substituent. The substituent and R in formula (B-1) 1 The substituents that may be possessed are the same. Among them, the substituent that the divalent hydrocarbon group may possess is preferably a crosslinkable functional group, and more preferably a hydroxyl group.

[0079] As the monovalent group formed by combining these, a monovalent group formed by combining a monovalent hydrocarbon group and a crosslinkable functional group; a monovalent group formed by combining a crosslinkable functional group, a monovalent hydrocarbon group and an oxygen atom; and a monovalent group formed by combining a divalent hydrocarbon group and a crosslinkable functional group are preferred. More preferred are any of a monovalent group formed by combining a monovalent hydrocarbon group and a crosslinkable functional group and a monovalent group formed by combining a divalent hydrocarbon group and a crosslinkable functional group.

[0080] Specific examples of the monovalent group formed by combining these groups include groups represented by the following formulae (Ba) to (Bb): wherein * represents a bonding site to a phosphorus atom. [Chemical Formula 10]

[0081] The compound represented by formula (B-1) is preferably a compound represented by formula (B-1-1). [Chemical Formula 11] In formula (B-1-1), R 21b It represents a crosslinkable functional group, a divalent hydrocarbon group, a monovalent hydrocarbon group, or a monovalent group formed by combining them.

[0082] In formula (B-1-1), R 31 represents a crosslinkable functional group, a divalent hydrocarbon group, a monovalent hydrocarbon group, or a monovalent group formed by a combination thereof, and R in formula (B-1) 3b same.

[0083] Examples of the compound represented by formula (B-1) include, but are not limited to, the following compounds (B1) to (B6). In the formula, Et represents an ethyl group. [Chemical Formula 12]

[0084] In formula (B-2), R 11b Each independently represents a crosslinkable functional group, and the crosslinkable functional group is as described above.

[0085] In formula (B-2), R 12b Each independently represents a hydrogen atom, a hydroxyl group or an alkyl group. 1bThe alkyl groups shown are identical.

[0086] In formula (B-2), n1 represents an integer of 3 to 25, preferably an integer of 3 to 15, more preferably an integer of 3 to 10, and further preferably 3.

[0087] In formula (B-2), m1 represents an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1.

[0088] In formula (B-2), m2 represents an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 0 or 1.

[0089] Examples of the compound represented by formula (B-2) include the compound (B7) exemplified below, but the compound is not limited thereto. [Chemical Formula 13]

[0090] Component (B) can be a commercially available product. Examples of commercially available products include "HCA-HQ-HST" manufactured by Sanko Co., Ltd., "FP700-TP" manufactured by Fushimi Pharmaceutical Co., Ltd., "V5," "V7," "API-09," "MC-2," and "MC-4" manufactured by Katayama Chemical Co., Ltd., and "SPH-100" manufactured by Otsuka Chemical Co., Ltd.

[0091] From the viewpoint of improving flame retardancy, when the resin component in the resin composition layer is set to 100% by mass, the content of phosphorus atoms is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and further preferably 0.03% by mass or more. The upper limit is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and further preferably 0.3% by mass or less. Here, "phosphorus atom content" is the concept of the content of phosphorus atoms contained in (A) component to (H) component other than (B) component, in addition to the phosphorus atoms contained in (B) component.

[0092] When the non-volatile component of the resin composition layer is set to 100 mass%, the content of the component (B) is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, further preferably 0.1 mass% or more, preferably 3 mass% or less, more preferably 2 mass% or less, further preferably 1 mass% or less.

[0093] When the resin component of the resin composition layer is set to 100 mass%, the content of the component (B) is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, further preferably 0.1 mass% or more, preferably 3 mass% or less, more preferably 2 mass% or less, further preferably 1 mass% or less.

[0094] When the content of the component (A) when the resin component of the resin composition layer is 100% by mass is a, and the content of the component (B) when the resin component of the resin composition layer is 100% by mass is b, from the viewpoint of obtaining a cured product having a high glass transition temperature and excellent flame retardancy, a / b is preferably 1 or more, more preferably 2 or more, further preferably 3 or more, preferably 25 or less, more preferably 20 or less, and further preferably 15 or less.

[0095] -(C) Thermosetting resin- The resin composition layer contains a thermosetting resin (C) as component (C). The thermosetting resin (C) as component (C) does not include components (A) to (B). The type of thermosetting resin (C) is not particularly limited as long as it can be cured by heat. The thermosetting resin (C) may be used alone or in combination of two or more.

[0096] Examples of the thermosetting resin (C) include epoxy resins, phenolic resins, cyanate resins, active ester resins, carbodiimide resins (excluding those in component (A)), acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. The thermosetting resins may be used alone or in combination of two or more.

[0097] From the viewpoint of significantly obtaining the effect of the present invention, (C) thermosetting resin is preferably used in combination with an epoxy resin and a resin capable of reacting with the epoxy resin to cure the resin composition layer. Hereinafter, the resin capable of reacting with the epoxy resin to cure the resin composition layer is sometimes referred to as a "curing agent". As a curing agent, for example, phenolic resins, cyanate resins, active ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, thiol resins, etc. can be cited. Among them, as a curing agent, phenolic resins and active ester resins are preferred. One curing agent can be used alone or in combination of two or more. In one embodiment, the thermosetting resin comprises an epoxy resin, an active ester resin, and a phenolic resin.

[0098] Epoxy resin is a thermosetting resin having an epoxy group. Examples of epoxy resins include tetramethylbisphenol epoxy resin (biphenyl epoxy resin), biphenyl epoxy resin, naphthalene epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AF epoxy resin, dicyclopentadiene epoxy resin, trisphenol epoxy resin, naphthol novolac epoxy resin, phenol novolac epoxy resin, tert-butyl-catechol epoxy resin, naphthol epoxy resin, anthracene epoxy resin, glycidylamine epoxy resin, glycidyl ester epoxy resin. The epoxy resins include epoxy resins of the type butyl epoxy resin, ...

[0099] The (C) thermosetting resin preferably includes an epoxy resin having two or more epoxy groups per molecule as an epoxy resin. The proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the non-volatile component of the epoxy resin is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0100] Epoxy resins include those that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and those that are solid at 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition layer may contain only a liquid epoxy resin, only a solid epoxy resin, or a combination of liquid and solid epoxy resins as the epoxy resin.

[0101] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0102] As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resin having a butadiene structure are preferred. Glycidyl amine type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin are more preferred, and naphthalene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin are further preferred.

[0103] 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" manufactured by Mitsubishi Chemical Corporation; "828EL" (bisphenol A type epoxy resin); "jER807" and "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD" and "604" (glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (GLYCIROL type epoxy resin) manufactured by ADEKA Corporation; "EP-3950L" and "EP-3980S" (glycidylamine type epoxy resin) manufactured by ADEKA Corporation; "EP-4088S" (dicyclopentadiene type epoxy resin) manufactured by ADEKA Corporation; "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemicals Co., Ltd.; Nagase Examples include ChemteX's "EX-721" (glycidyl ester epoxy resin); Daicel's "CELLOXIDE 2021P" (aliphatic epoxy resin with an ester skeleton); Daicel's "PB-3600" and Nippon Soda's "JP-100" and "JP-200" (epoxy resins with a butadiene structure (epoxidized polybutadiene resins); and Nippon Steel Chemicals' "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane epoxy resins). These can be used alone or in combination.

[0104] The solid epoxy resin is preferably a solid epoxy resin having three or more epoxy groups in one molecule, and more preferably an aromatic solid epoxy resin having three or more epoxy groups in one molecule.

[0105] As solid epoxy resins, preferred are 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, naphthyl ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, and phenol benzopyrrolidone-type epoxy resins, preferably biphenyl-type epoxy resins.

[0106] Specific examples of solid epoxy resins include "HP4032H" (naphthalene-type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" (cresol novolac-type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac-type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene-type epoxy resins) manufactured by DIC Corporation; and "HP-7200HH" and "HP-7200H" manufactured by DIC Corporation. "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthyl ether type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "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" and "ESN4100V" (naphthalene-type epoxy resins) manufactured by Japan Materials Corporation; "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemicals; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemicals; "YX4000H", "YX4000", "YX4000HK", and "YL7890" (bimethylol-type epoxy resins) 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 "YX7700" (phenol aralkyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "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; "WHR991S" (phenol benzopyrrolidone type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. These may be used alone or in combination of two or more.

[0107] 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.

[0108] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 5000 g / eq., more preferably 60 g / eq. to 3000 g / eq., further preferably 80 g / eq. to 2000 g / eq., and particularly preferably 110 g / eq. to 1000 g / eq. The epoxy equivalent represents the mass of the resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K 7236.

[0109] The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500. The weight average molecular weight of the resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0110] The content of the epoxy resin as the thermosetting resin (C) is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, when the non-volatile component in the resin composition layer is 100% by mass, and is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, and 15% by mass or less.

[0111] The content of the epoxy resin as the thermosetting resin (C) is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, or 40% by mass or more, and is preferably 65% ​​by mass or less, more preferably 60% by mass or less, and particularly preferably 55% by mass or less, based on 100% by mass of the resin component in the resin composition layer.

[0112] As the phenolic resin, a compound having one or more, preferably two or more, hydroxyl groups bound to aromatic rings such as a benzene ring or a naphthalene ring in one molecule can be used. When combined with an epoxy resin, the phenolic resin can react with the epoxy resin to solidify the resin composition layer, and is therefore sometimes referred to as a "phenolic curing agent". From the viewpoint of significantly obtaining the effects of the present invention, the phenolic resin is preferably a phenolic resin having a phenolic structure. In addition, from the viewpoint of close adhesion, nitrogen-containing phenolic resins are preferred, and phenolic resins containing a triazine skeleton are more preferred. Among them, from the viewpoint of significantly obtaining the effects of the present invention, linear phenolic resins containing a triazine skeleton are preferred. Specific examples of phenolic resins include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Chemicals 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 Chemicals 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.

[0113] As active ester resin, it is generally preferred to use esters of phenolic esters, thiophenolic esters, N-hydroxylamine esters, heterocyclic hydroxy compounds, etc., which have ester groups with more than two high reactive activities in one molecule. Active ester resin can react with epoxy resin and solidify the resin composition layer when combined with epoxy resin, so it is sometimes referred to as "active ester curing agent". The active ester resin is preferably a resin 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 the high-temperature reflow soldering expansion resistance, the active ester resin obtained by a carboxylic acid compound and a hydroxy compound is preferably, and the active ester resin obtained by a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferably. As the carboxylic acid compound, for example, benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc. can be mentioned. Examples of the phenolic compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, pyrogallol, dicyclopentadiene-type diphenolic compounds, and novolac resins. Here, the term "dicyclopentadiene-type diphenolic compound" refers to a diphenolic compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

[0114] Specifically, preferred active ester resins include dicyclopentadiene-type active ester resins, naphthalene-type active ester resins containing a naphthalene structure, active ester resins containing acetylated products of novolac resins, and active ester resins containing benzoylated products of novolac resins. Among these, at least one selected from dicyclopentadiene-type active ester resins and naphthalene-type active ester resins is more preferred. As the dicyclopentadiene-type active ester resin, an active ester resin containing a dicyclopentadiene-type diphenol structure is preferred.

[0115] As commercially available active ester resins, for example, as active ester curing agents containing a dicyclopentadiene-type diphenol structure, there are "EXB9451", "EXB9460", "EXB9460S", "HPC-8000L-65TM", "HPC-8000-65T", "EXB-8000H", and "EXB-8000L-65TM" (manufactured by DIC Corporation); as active ester curing agents containing a naphthalene structure, there are "EXB-9416-70BK", "EXB-8100L-65T", "HPC-8150-62T", "EXB-8150L-65T", "EXB-8100L-65T", and "EXB-8100L-65T". XB-8" (manufactured by DIC Corporation); as an active ester curing agent containing phosphorus, "EXB9401" (manufactured by DIC Corporation) can be cited, and as an active ester curing agent containing an acetylated product of a linear phenolic resin, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be cited; as an active ester curing agent containing a benzoylated product of a linear phenolic resin, "YLH1026", "YLH1030", "YLH1048" (manufactured by Mitsubishi Chemical Corporation), and "EXB-8500-65T" (manufactured by DIC Corporation) can be cited; as an active ester curing agent containing a styryl group and a naphthalene structure, "PC1300-02-65T" and "PC1300-02-65MA" (manufactured by Air Water Corporation) can be cited, etc.

[0116] As the cyanate resin, a compound having one or more, preferably two or more, cyanate groups per molecule can be used. When combined with an epoxy resin, a cyanate resin can react with the epoxy resin to cure the resin composition layer, and is therefore sometimes referred to as a "cyanate curing agent." Examples of the cyanate resin include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenylcyanate), 4,4'-ethylenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylene))benzene, bis(4-cyanatephenyl)sulfide, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac resins and cresol novolac resins; and prepolymers in which a portion of these cyanate resins is triazinated. Specific examples of cyanate resins include "PT30" and "PT60" manufactured by Arxada (both are novolac-type multifunctional cyanate resins), "BA230" and "BA230S75" (prepolymers obtained by triazine-forming a trimer of bisphenol A dicyanate in part or in its entirety) and the like.

[0117] As the carbodiimide resin (excluding the substance included in component (A)), a compound having one or more, preferably two or more, carbodiimide structures per molecule and no free radical polymerizable groups can be used. When combined with an epoxy resin, a carbodiimide resin can react with the epoxy resin to cure the resin composition layer, and is therefore sometimes referred to as a "carbodiimide-based curing agent."

[0118] Specific examples of the carbodiimide resin include: aliphatic biscarbodiimides such as tetramethylene-bis(tert-butylcarbodiimide) and cyclohexanebis(methylene-tert-butylcarbodiimide); aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide); poly(phenylenecarbodiimide), poly( Aromatic polycarbodiimides such as poly(naphthylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide] are also included.

[0119] Examples of commercially available carbodiimide resins include "CARBODILITE V-02B," "CARBODILITE V-03," "CARBODILITE V-04K," "CARBODILITE V-07," and "CARBODILITE V-09" manufactured by Nisshinbo Chemical Co., Ltd.

[0120] 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 the acid anhydride resin is combined with the epoxy resin, it can react with the epoxy resin to cure the resin composition layer, so it is sometimes called an "acid anhydride curing agent". Specific examples of the acid anhydride resin include: phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, diphenyl Polymer-type acid anhydrides such as ketone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), styrene-maleic acid resin obtained by copolymerization of styrene and maleic acid, etc. Commercially available products of the acid anhydride resin include, for example, "HNA-100", "MH-700", "MTA-15", "DDSA", and "OSA" manufactured by Shin Nippon Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" and "HN-5500" manufactured by Lisenoco; and "EF-30", "EF-40", "EF-60", and "EF-80" manufactured by Cray Valley Corporation.

[0121] Examples of amine resins include compounds having one or more, preferably two or more, amino groups per molecule. Amine resins, when combined with epoxy resins, react with the epoxy resin to cure the resin composition layer and are therefore sometimes referred to as "amine curing agents." Examples of amine resins include aliphatic amines, polyetheramines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. Amine resins are preferably primary or secondary amines, more preferably primary amines. Specific examples of the amine resin include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-xylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxy phenyl)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, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Examples of commercially available amine resins include “SEIKA CURE-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.

[0122] 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 Co., Ltd.; "HFB2006M" manufactured by Showa High Molecular Co., Ltd.; and "Pd" and "Fa" manufactured by Shikoku Chemicals Co., Ltd.

[0123] When combined with an epoxy resin, a thiol resin can react with the epoxy resin to cure the resin composition layer, and is therefore sometimes referred to as a "thiol-based curing agent." Examples of thiol resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

[0124] The active group equivalent weight of the curing agent is preferably 50 g / eq. to 3000 g / eq., more preferably 100 g / eq. to 1000 g / eq., further preferably 100 g / eq. to 500 g / eq., and particularly preferably 100 g / eq. to 300 g / eq. The active group equivalent weight is the mass of the curing agent per equivalent of active groups.

[0125] The weight average molecular weight (Mw) of the curing agent is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500. The weight average molecular weight of the resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0126] When the number of epoxy groups in the epoxy resin is set to 1, the number of active groups in the curing agent is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, 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 sum of all values ​​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 sum of all values ​​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.

[0127] When the non-volatile component in the resin composition layer is set to 100 mass%, the content of the curing agent as the thermosetting resin (C) is preferably 1 mass% or more, more preferably 2 mass% or more, further preferably 3 mass% or more, preferably 40 mass% or less, more preferably 35 mass% or less, and further preferably 30 mass% or less.

[0128] When the resin component in the resin composition layer is set to 100% by mass, the content of the curing agent as the thermosetting resin (C) is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, further preferably 40% by mass or less.

[0129] When the non-volatile component in the resin composition layer is set to 100 mass%, the content of the (C) thermosetting resin is preferably 10 mass% or more, more preferably 15 mass% or more, further preferably 20 mass% or more, preferably 40 mass% or less, more preferably 35 mass% or less, and further preferably 30 mass% or less.

[0130] When the resin component in the resin composition layer is set to 100 mass%, the content of the (C) thermosetting resin is preferably 10 mass% or more, more preferably 20 mass% or more, and even more preferably 30 mass% or more, and is preferably 98 mass% or less, more preferably 93 mass% or less, and even more preferably 90 mass% or less.

[0131] When the non-volatile component in the resin composition layer is set to 100% by mass, the total content of component (A), component (B) and component (C) is preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more, and is preferably 100% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, and 40% by mass or less.

[0132] -(D) Inorganic filler- The resin composition layer may contain an inorganic filler (D) as the component (D). The inorganic filler (D) may be used alone or in combination of two or more at any ratio.

[0133] (D) The inorganic filler is contained in the resin composition layer in the form of particles. As the material of the inorganic filler (D), an inorganic compound is used. As the material of the inorganic filler (D), for example, silica, aluminum oxide, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate, calcium zirconate, zirconium phosphate and zirconium tungstate phosphate, etc. Among them, silica is particularly preferred. As silica, for example, amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica, etc. can be mentioned. In addition, spherical silica is preferred as silica.

[0134] Examples of commercially available inorganic fillers (D) include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemicals; "YC100C," "YA050C," "YA050C-MJE," "YA010C," "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Yaduma; "UFP-30," "DAW-03," and "FB-105FD" manufactured by Denka; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama; and "CellSpheres" and "MGH-005" manufactured by Pacific Cement.

[0135] The average particle size of the inorganic filler (D) is not particularly limited, but is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, even more preferably 2 μm or less, and particularly preferably 1.5 μm or less. The lower limit of the average particle size of the inorganic filler (D) 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.

[0136] (D) The average particle size of the inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, it can be measured in the following manner: using a laser diffraction scattering particle size distribution measuring device, the particle size distribution of the inorganic filler is made on a volume basis, and the median particle size is used as the average particle size. The sample can be measured using a sample obtained in the following manner: 100 mg of inorganic filler and 10 g of methyl ethyl ketone are weighed into a vial and dispersed for 10 minutes using ultrasound. For the measurement sample, a laser diffraction particle size distribution measuring device is used, the wavelength of the light source is set to blue and red, and the particle size distribution of the volume basis of the inorganic filler is measured in a flow cell manner, and the average particle size is calculated from the obtained particle size distribution as the median particle size. As a laser diffraction particle size distribution measuring device, for example, "LA-960" manufactured by Horiba, Ltd. can be cited.

[0137] (D) The specific surface area of ​​the inorganic filler is not particularly limited, but is preferably 0.1 m 2 / g or more, more preferably 0.5m 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 inorganic filler (D) 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, more preferably 30m 2 / g or less, particularly preferably 10m 2 The specific surface area of ​​the inorganic filler can be obtained by adsorbing nitrogen on the sample surface using a specific surface area measuring apparatus (Macsorb HM-1210 manufactured by Mountech) according to the BET method and calculating the specific surface area using the BET multipoint method.

[0138] From the viewpoint of improving moisture resistance and dispersibility, the (D) inorganic filler is preferably treated with a surface treatment agent. Examples of the surface treatment agent include fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, and titanate coupling agents. The surface treatment agent may be used alone or in any combination of two or more.

[0139] Examples of commercially available surface treatment agents include “KBM403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM803” (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBE903” (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM573” (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “SZ-31” (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM103” (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM-4803” (long-chain epoxy-type silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd., and “KBM-7103” (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.

[0140] From the viewpoint of improving the dispersibility of the inorganic filler, the degree of surface treatment by the surface treatment agent is preferably within a specified range. 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.

[0141] The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler is preferably 0.02 mg / m 2 More than 0.1 mg / m 2 More preferably, 0.2 mg / m 2On the other hand, from the viewpoint of preventing the increase in the melt viscosity of the resin composition layer or the melt viscosity of the sheet form, it is preferably 1.0 mg / m 2 Below, more preferably 0.8 mg / m 2 Below, more preferably 0.5 mg / m 2 the following.

[0142] (D) The amount of carbon per unit surface area of ​​the inorganic filler can be measured after the surface-treated inorganic filler is cleaned with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK is added as a solvent to the inorganic filler 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 component, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. As a carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd. can be used.

[0143] When the non-volatile component in the resin composition layer is set to 100% by mass, the content of the (D) inorganic filler is preferably 45% by mass or more, more preferably 50% by mass or more, further preferably 55% by mass or more, 60% by mass or more, or 65% by mass or more. The upper limit is preferably 85% by mass or less, more preferably 80% by mass or less, and further preferably 75% by mass or less.

[0144] -(E) Radically polymerizable group-containing compound not having a carbodiimide structure- The resin composition layer may contain (E) a compound containing a free radical polymerizable group that does not have a carbodiimide structure as the (E) component. The (E) compound containing a free radical polymerizable group that does not have a carbodiimide structure as the (E) component does not include substances belonging to the above-mentioned (A) to (D) components. (E) A compound containing a free radical polymerizable group that does not have a carbodiimide structure refers to a compound that contains one or more free radical polymerizable groups in one molecule but does not have a carbodiimide structure (-N=C=N-). The (E) component may be used alone or in combination of two or more. From the viewpoint of improving flame retardancy, the resin composition preferably contains the (E) component.

[0145] The component (E) may have two or more radical polymerizable groups in one molecule. The radical polymerizable groups are as described above.

[0146] In the first embodiment, the component (E) preferably comprises a thermoplastic resin having two or more free radical polymerizable groups (e.g., a number average molecular weight of 800 or more). The thermoplastic resin is not particularly limited, and examples thereof include phenoxy resins, polyvinyl acetal resins, polystyrene resins, polyethylene resins, polypropylene resins, polybutadiene resins, polyimide resins, polyamide-imide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polyetheretherketone resins, and polyester resins. In this embodiment, the component (E) comprises a modified resin of these resins having two or more free radical polymerizable groups.

[0147] In the first embodiment, component (E) more preferably includes a resin selected from a modified polyphenylene ether resin having two or more free radical polymerizable groups and a modified polystyrene resin having two or more free radical polymerizable groups, further preferably includes a modified polyphenylene ether resin having two or more free radical polymerizable groups, and more preferably includes a resin represented by formula (E-1). [Chemical Formula 14] In formula (E-1), R b Each independently represents a hydrogen atom or a methyl group; X b Each independently represents a carbonyl group, a methylene group, a phenylene group, or a phenylene-methylene group (the bonding direction is not particularly limited, preferably the phenylene side is bonded to "R b -C”); R 11 and R 12 Each independently represents an alkyl group; R 13 、R 14 、R 21 、R 22 、R 23 and R 24 Each independently represents a hydrogen atom or an alkyl group; A represents a single bond, -C(R c )2-, -O-, -CO-, -S-, -SO- or -SO2-; R c Each independently represents a hydrogen atom or an alkyl group; p represents 0 or 1; q and r each independently represent an integer greater than 1. The q unit and the r unit may be the same or different.

[0148] R b Each independently represents a hydrogen atom or a methyl group. b Each independently represents a carbonyl group, a methylene group, a phenylene group, or a phenylene-methylene group (the bonding direction is not particularly limited, preferably the phenylene side is bonded to "R b -C" is combined), preferably carbonyl or phenylene-methylene.

[0149] R11 and R 12 Each independently represents an alkyl group, preferably a methyl group. 13 and R 14 R each independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom. 21 and R 22 Each independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group, more preferably a methyl group. 23 and R 24 Each independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.

[0150] A represents a single bond, -C(R c )2-, -O-, -CO-, -S-, -SO- or -SO2-, preferably a single bond, -C(R c )2- or -O-. R c Each independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group. p represents 0 or 1, preferably 1. q and r each independently represent an integer of 1 or more, preferably an integer of 1 to 200, more preferably an integer of 1 to 100.

[0151] The radical polymerizable group equivalent of the component (E) in the first embodiment is preferably 300 g / eq. to 2500 g / eq., more preferably 400 g / eq. to 2000 g / eq. The radical polymerizable group equivalent represents the mass of the resin (compound) per 1 equivalent of the radical polymerizable group.

[0152] The number average molecular weight of the component (E) in the first embodiment is preferably 800 to 10000, more preferably 900 to 5000. The number average molecular weight of the resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0153] Examples of commercially available products of the component (E) in the first embodiment include "OPE-2St 1200" and "OPE-2St 2200" (vinylbenzyl-modified polyphenylene ether resins) manufactured by Mitsubishi Gas Chemical Co., Ltd.; and "SA9000" and "SA9000-111" (methacrylic acid-modified polyphenylene ether resins) manufactured by SABIC.

[0154] In the second embodiment, the component (E) contains a low molecular weight compound (e.g., a molecular weight of less than 800) having two or more free radical polymerizable groups. Examples of such compounds include polyfunctional (meth)acryloyl group-containing compounds having a molecular weight of less than 800, polyfunctional vinylaryl group-containing compounds having a molecular weight of less than 800, and polyfunctional allyl group-containing compounds having a molecular weight of less than 800.

[0155] The polyfunctional (meth)acryloyl group-containing compound having a molecular weight of less than 800 is a compound having two or more (meth)acryloyl groups. Examples of the polyfunctional (meth)acryloyl group-containing compound having a molecular weight of less than 800 include aliphatic (meth)acrylates such as cyclohexane-1,4-dimethanol di(meth)acrylate, cyclohexane-1,3-dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, glycerol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate. Ester compounds; ether-containing (meth)acrylate compounds such as dioxanediol di(meth)acrylate, 3,6-dioxa-1,8-octanediol di(meth)acrylate, 3,6,9-trioxaundecane-1,11-diol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, etc.; isocyanurate-containing (meth)acrylate compounds such as tris(3-hydroxypropyl)isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, etc. Commercially available products of polyfunctional (meth)acryloyl group-containing compounds having a molecular weight of less than 800 include, for example, "A-DOG" (dioxanediol diacrylate) manufactured by Shin-Nakamura Chemical Industry Co., Ltd., "DCP-A" (tricyclodecane dimethanol diacrylate) and "DCP" (tricyclodecane dimethanol dimethacrylate) manufactured by Kyoeisha Chemical Co., Ltd., "KAYARA DR-684" (tricyclodecane dimethanol diacrylate) and "KAYARAD R-604" (dioxanediol diacrylate) manufactured by Nippon Kayaku Co., Ltd.

[0156] A polyfunctional vinylaryl group-containing compound having a molecular weight of less than 800 is a compound having two or more vinylaryl groups. Examples of polyfunctional vinylaryl group-containing compounds having a molecular weight of less than 800 include 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl)ether.

[0157] The compound containing a polyfunctional allyl group having a molecular weight of less than 800 is a compound having two or more allyl groups. Examples of the compound containing a polyfunctional allyl group having a molecular weight of less than 800 include aromatic carboxylic acid allyl ester compounds such as diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, and diallyl 2,3-naphthalenedicarboxylate; isocyanuric acid allyl ester compounds such as 1,3,5-triallyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; and 2,2-bis[3- Aromatic allyl compounds containing epoxy groups such as allyl-4-(glycidyloxy)phenyl]propane; aromatic allyl compounds containing benzoxazine such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane; aromatic allyl compounds containing ethers such as 1,3,5-triallyl etherbenzene; allylsilane compounds such as diallyldiphenylsilane. Commercially available products containing polyfunctional allyl groups with a molecular weight of less than 800 include "TAIC" (1,3,5-triallyl isocyanurate) manufactured by Nippon Chemical Industry Co., Ltd. and Nisshoku Techno Fine Chemicals Co., Ltd. "DAD" (diallyl diphenyldicarboxylate) manufactured by Fujifilm Wako Pure Chemical Co., Ltd., "TRIAM-705" (triallyl trimellitate) manufactured by Fujifilm Wako Pure Chemical Co., Ltd., "DAND" (diallyl 2,3-naphthoate) manufactured by Nichikyu Tech Fine Chemicals Co., Ltd., "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane) manufactured by Shikoku Chemical Co., Ltd., "RE-810NM" (2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane) manufactured by Nippon Kayaku Co., Ltd., and "DA-MGIC" (1,3-diallyl-5-glycidyl isocyanurate) manufactured by Shikoku Chemical Co., Ltd.

[0158] The radical polymerizable group equivalent of the component (E) in the second embodiment is preferably 30 g / eq. to 400 g / eq., more preferably 50 g / eq. to 300 g / eq., and even more preferably 75 g / eq. to 200 g / eq.

[0159] The molecular weight of the component (E) in the second embodiment is preferably 100 to 700, more preferably 200 to 400, and even more preferably 250 to 500.

[0160] In the third embodiment, component (E) preferably comprises a maleimide compound having a partial structure represented by formula (E-2). The maleimide compound refers to a compound containing at least one maleimide group (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl) per molecule. The number of maleimide groups per molecule of the maleimide compound in the third embodiment is preferably 2 or more, particularly preferably 2. [Chemical Formula 15] In the formula, ring E represents a monocyclic alkane ring or a monocyclic alkene ring optionally having a substituent; i and j each independently represent an integer of 0 or 1 or greater, and the total of i and j is 6 or greater; * represents a bonding site.

[0161] A monocycloalkane ring refers to a monocyclic aliphatic saturated hydrocarbon ring. The monocycloalkane ring is preferably a monocycloalkane ring having 4 to 14 carbon atoms, more preferably a monocycloalkane ring having 4 to 10 carbon atoms, and particularly preferably a monocycloalkane ring having 5 or 6 carbon atoms. Examples of the monocycloalkane ring include a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, and a cyclooctane ring. A monocycloalkene ring refers to a monocyclic aliphatic unsaturated hydrocarbon ring having at least one carbon-carbon double bond. The monocycloalkene ring is preferably a monocycloalkene ring having 4 to 14 carbon atoms, more preferably a monocycloalkene ring having 4 to 10 carbon atoms, and particularly preferably a monocycloalkene ring having 5 or 6 carbon atoms. Examples of the monocycloalkene ring include a cyclobutene ring, a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, a cyclooctene ring, a cyclopentadiene ring, and a cyclohexadiene ring.

[0162] Examples of the substituent of the monocyclic alkane ring and the monocyclic alkene ring include the same substituents as the substituents that Y in the formula (A-1) may have.

[0163] Ring E represents a monocyclic alkane ring optionally having a substituent or a monocyclic alkene ring optionally having a substituent. Ring E is preferably a monocyclic alkane ring optionally substituted with a group selected from an alkyl group and an alkenyl group; or a monocyclic alkene ring optionally substituted with a group selected from an alkyl group and an alkenyl group. Ring E is more preferably a monocyclic alkane ring optionally substituted with a group selected from an alkyl group having 1 to 14 carbon atoms and an alkenyl group having 2 to 14 carbon atoms; or a monocyclic alkene ring optionally substituted with a group selected from an alkyl group having 1 to 14 carbon atoms and an alkenyl group having 2 to 14 carbon atoms.

[0164] i and j each independently represent an integer of 0 or 1 or greater, and the total of i and j is 6 or greater (preferably 8 or greater, more preferably 10 or greater). i and j each independently represent an integer of 0 to 20, and the total of i and j is 6 or greater (preferably 8 or greater, more preferably 10 or greater). i and j each independently represent an integer of 1 to 20, and the total of i and j is 6 or greater (preferably 8 or greater, more preferably 10 or greater). i and j each independently represent an integer of 5 to 10. i and j are particularly preferably 8.

[0165] In the third embodiment, it is particularly preferred that the component (B) contains a maleimide compound represented by formula (E-3). [Chemical Formula 16] Where R 1 Each independently represents a substituent; Ring F each independently represents an aromatic ring optionally having a substituent; D 1 and D 2 Each independently represents a single bond, -C(R x )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, -NHCO-, -COO- or -OCO-; R x Each independently represents a hydrogen atom or an alkyl group; e each independently represents 0 or 1; f each independently represents an integer of 0 or 1 or greater; g each independently represents 0, 1, or 2; m represents an integer of 0 or 1 or greater; other symbols have the same meanings as described above. For the f unit, g unit, and m unit, each unit may be the same or different.

[0166] An aromatic ring refers to a ring that follows Huckel's rule and has 4p+2 electrons (p is a natural number) in the π electron system on the ring. The aromatic ring may be an aromatic carbocyclic ring having only carbon atoms as ring atoms, or an aromatic heterocyclic ring having, in addition to carbon atoms, heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms. In one embodiment, an aromatic carbocyclic ring is preferred. In one embodiment, the aromatic ring is preferably an aromatic ring of 5 to 14 members, more preferably an aromatic ring of 6 to 14 members, and further preferably an aromatic ring of 6 to 10 members. Preferred specific examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and the like, more preferably a benzene ring or a naphthalene ring, and particularly preferably a benzene ring.

[0167] As R 1 The substituents in and the substituents on the aromatic ring are the same as the substituents which Y in formula (A-1) may have.

[0168] Ring F each independently represents an aromatic ring optionally having a substituent, and is preferably a benzene ring optionally substituted with a group selected from an alkyl group.1 and D 2 Each independently represents a single bond, -C(R x )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, -NHCO-, -COO- or -OCO-, preferably a single bond, -C(R x )2- or -O-. R x Each of the following independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group. Each of the following independently represents 0 or 1, preferably 0. Each of the following independently represents an integer of 0 or 1 or greater, preferably 0, 1, 2 or 3, more preferably 0, 1 or 2. Each of the following independently represents 0, 1 or 2, preferably 0. Each of the following independently represents an integer of 0 or 1 or greater, preferably 0.

[0169] The partial structure represented by formula (E-4) contained in formula (E-3) is not particularly limited, and examples thereof include partial structures represented by formulas (Ea) to (Ec). [Chemical Formula 17] In the formula, * represents a binding site, and other symbols have the same meanings as above. [Chemical Formula 18] In the formula, * represents the binding site.

[0170] The radical polymerizable group equivalent weight of the component (E) in the third embodiment is preferably 200 g / eq. to 2500 g / eq., more preferably 250 g / eq. to 2000 g / eq., and even more preferably 300 g / eq. to 1500 g / eq. The radical polymerizable group equivalent weight of the component (E) represents the mass of the resin per 1 equivalent of the radical polymerizable group.

[0171] The weight average molecular weight of the component (E) in the third embodiment is preferably 400 to 100,000, more preferably 500 to 7,000, and particularly preferably 600 to 5,000.

[0172] Examples of commercially available products of the component (E) in the third embodiment include “BMI-689,” “BMI-1500,” “BMI-1700,” and “BMI-3000J” manufactured by Designer Molecules Inc. and “SLK-6895-T90” manufactured by Shin-Etsu Chemical Co., Ltd.

[0173] In the fourth embodiment, the component (E) preferably contains a maleimide compound represented by formula (E-5). [Chemical Formula 19] Where R 2 Each independently represents a hydrogen atom or an alkyl group; Ring L, Ring M and Ring N each independently represent an aromatic ring optionally having a substituent; Z 1 Each independently represents a single bond, -C(R z )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH- or -NHCO-; R z Each independently represents a hydrogen atom or an alkyl group; s represents an integer greater than or equal to 1; t each independently represents 0 or 1; and u each independently represents 0, 1, 2, or 3. The s unit and the u unit may be the same or different.

[0174] R 2 Each independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.

[0175] Ring L, ring M and ring N each independently represent an aromatic ring optionally having a substituent, preferably a benzene ring optionally having a substituent, more preferably a benzene ring optionally substituted with a group selected from an alkyl group and an aryl group, and particularly preferably an (unsubstituted) benzene ring.

[0176] Z 1 Each independently represents a single bond, -C(R z )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH- or -NHCO-, preferably a single bond, -C(R z )2- or -O-, more preferably a single bond or -C(R z )2-, particularly preferably a single bond. z Each independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.

[0177] s represents an integer of 1 or greater, preferably an integer of 1 to 10. t each independently represents 0 or 1, preferably 1. u each independently represents 0, 1, 2 or 3, preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 1.

[0178] The radical polymerizable group equivalent of the component (E) in the fourth embodiment is preferably 150 g / eq. to 1000 g / eq., and more preferably 200 g / eq. to 500 g / eq.

[0179] The weight average molecular weight of the component (E) in the fourth embodiment is preferably 100 to 10,000, more preferably 150 to 5,000, and particularly preferably 200 to 3,000.

[0180] Examples of commercially available products of the component (E) in the fourth embodiment include "MIR-3000-70MT" and "MIR-5000-60T" manufactured by Nippon Kayaku Co., Ltd.

[0181] The component (E) may contain any one of the suitable thermoplastic resin in the first embodiment, the suitable compound in the second embodiment, the suitable maleimide compound in the third embodiment, and the suitable maleimide compound in the fourth embodiment alone, or may contain two or more of them in combination at any ratio.

[0182] The radical polymerizable group equivalent of the component (E) is preferably 30 g / eq. to 2500 g / eq., particularly preferably 75 g / eq. to 2000 g / eq.

[0183] When the non-volatile component in the resin composition layer is set to 100 mass%, the content of the component (E) is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, further preferably 1 mass% or more, preferably 20 mass% or less, more preferably 15 mass% or less, further preferably 10 mass% or less.

[0184] When the resin component in the resin composition layer is 100% by mass, the content of the component (E) is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, preferably 60% by mass or less, more preferably 50% by mass or less, further preferably 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less.

[0185] When the content of the (E) component when the resin component in the resin composition layer is 100% by mass is e, and the content of the (A) component when the resin component in the resin composition layer is 100% by mass is a, e / a is preferably 0.1 or more, more preferably 0.5 or more, further preferably 0.8 or more, preferably 10 or less, more preferably 8 or less, further preferably 5 or less, or 3 or less.

[0186] -(F)Thermoplastic resin- The resin composition layer may contain a thermoplastic resin (F) as the component (F). The thermoplastic resin (F) as the component (F) does not include those included in the above-mentioned components (A) to (E). The component (F) may be used alone or in combination of two or more.

[0187] Examples of the (F) thermoplastic resin include polyimide resins, phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyamide-imide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, and polyester resins.

[0188] Specific examples of the polyimide resin include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., and "RIKACOAT SN20" and "RIKACOAT PN20" manufactured by Shin Nippon Chemical Co., Ltd.

[0189] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeletons, bisphenol F skeletons, bisphenol S skeletons, bisphenol acetophenone skeletons, phenolic skeletons, biphenyl skeletons, fluorene skeletons, dicyclopentadiene skeletons, norbornene skeletons, naphthalene skeletons, anthracene skeletons, adamantane skeletons, terpene skeletons, and trimethylcyclohexane skeletons. The termini of the phenoxy resins may be any functional group such as a phenolic hydroxyl group or an epoxy group.

[0190] Specific examples of phenoxy resins include: "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (a phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (a phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel Chemicals; "YX7200B35", "YL7500BH30", "YX6954BH30", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482" manufactured by Mitsubishi Chemical Corporation.

[0191] Examples of the polyvinyl acetal resin include polyvinyl formal resin and polyvinyl butyral resin, preferably polyvinyl butyral resin. Specific examples of the polyvinyl acetal resin 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.

[0192] Examples of the polyolefin resin include ethylene copolymer resins such as low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, and ethylene-methyl acrylate copolymers; and polyolefin polymers such as polypropylene and ethylene-propylene block copolymers.

[0193] Examples of the polybutadiene resin include resins containing a hydrogenated polybutadiene skeleton, polybutadiene resins containing a hydroxyl group, polybutadiene resins containing a phenolic hydroxyl group, polybutadiene resins containing a carboxyl group, polybutadiene resins containing an acid anhydride group, polybutadiene resins containing an epoxy group, polybutadiene resins containing an isocyanate group, polybutadiene resins containing a urethane group, and polyphenylene ether-polybutadiene resins.

[0194] Specific examples of polyamide-imide resins include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polyamide-imides containing a polysiloxane skeleton) manufactured by Lisenoco Co., Ltd.

[0195] Specific examples of the polyethersulfone resin include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. and the like.

[0196] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers. Specific examples of polyphenylene ether resins include "NORYL SA90" manufactured by SABIC. Specific examples of polyetherimide resins include "Ultem" manufactured by GE.

[0197] 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 Co., Ltd., "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 polyetheretherketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd.

[0198] Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

[0199] The weight average molecular weight (Mw) of the (F) thermoplastic resin is preferably 5,000 or more, more preferably 8,000 or more, further 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, further preferably 60,000 or less, and particularly preferably 50,000 or less.

[0200] When the non-volatile component in the resin composition layer is set to 100 mass%, the content of the (F) thermoplastic resin is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, and even more preferably 0.8 mass% or more, and is preferably 3 mass% or less, more preferably 2 mass% or less, and even more preferably 1.5 mass% or less.

[0201] When the resin component in the resin composition layer is set to 100 mass%, the content of the (F) thermoplastic resin is preferably 1 mass% or more, more preferably 2 mass% or more, and even more preferably 3 mass% or more, and is preferably 15 mass% or less, more preferably 10 mass% or less, and even more preferably 8 mass% or less.

[0202] -(G) Stress Relaxation Materials- The resin composition layer may contain a stress relaxation material (G) as the component (G). The stress relaxation material (G) as the component (G) does not include any of the components (A) to (F) described above. The component (G) may be used alone or in combination of two or more.

[0203] The (G) stress relaxation material refers to a flexible resin and may be a particulate resin component (particulate stress relaxation material) that maintains a particle form in the resin composition layer, or a non-particulate resin component (non-particulate stress relaxation material) that tends to be mixed or dissolved in the resin composition layer. The material may contain only one or both of these. The resin component forming the stress relaxation material may be a resin that exhibits rubber elasticity on its own or exhibits rubber elasticity through reaction with other components. Examples of the resin exhibiting rubber elasticity include resins that exhibit an elastic modulus of 1 GPa or less in a tensile test at 25°C and 40% RH in accordance with Japanese Industrial Standards (JIS K7161).

[0204] The particle-shaped stress relaxation material is preferably spherical. In addition, the particle-shaped stress relaxation material may be a hollow particle having a hole inside the particle, or a non-hollow particle having no hole inside the particle. The hollow particle may be a single hollow particle having only one hole inside the particle, or a multi-hollow particle having multiple holes inside the particle.

[0205] The particulate stress relaxation material is, for example, rubber particles containing a rubber component, preferably rubber particles containing the following as the rubber component: silicone elastomers such as polydimethylsiloxane; olefin thermoplastic elastomers such as polybutadiene, polyisoprene, polychloroprene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-butadiene terpolymer, and ethylene-propylene-butylene terpolymer; and thermoplastic elastomers such as acrylic thermoplastic elastomers such as polypropyl (meth)acrylate, polybutyl (meth)acrylate, polycyclohexyl (meth)acrylate, and polyoctyl (meth)acrylate. Furthermore, silicone rubbers such as polyorganosiloxane rubber may be mixed into the rubber component. The glass transition temperature of the rubber component contained in the rubber particles is, for example, 0°C or lower, preferably -10°C or lower, more preferably -20°C or lower, and further preferably -30°C or lower.

[0206] The particulate stress relaxation material preferably comprises core-shell rubber particles. Core-shell rubber particles are particulate stress relaxation materials formed from a core particle containing the rubber component listed above and a shell portion covering the core particle with one or more layers. Furthermore, the core-shell rubber particles are preferably core-shell graft copolymer rubber particles formed from a core particle containing the rubber component listed above and a shell portion formed by graft copolymerization of a monomer component copolymerizable with the rubber component contained in the core particle. The core-shell type mentioned here does not necessarily refer only to those in which the core particle and shell portion are clearly distinguishable, but also includes those in which the boundary between the core particle and shell portion is unclear, and the core particle may not be completely covered by the shell portion.

[0207] The rubber component preferably comprises 40% by mass or more of the core-shell rubber particles, 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 rubber particles is not particularly limited, but is preferably 95% by mass or less, or 90% by mass or less, for example, from the perspective of sufficiently covering the core particles with the shell portion.

[0208] The monomer components forming the shell of the core-shell rubber particles include, for example, (meth)acrylates 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 these, (meth)acrylates are preferred, and methyl (meth)acrylate is more preferred. Note that "(meth)acrylic acid" refers to either methacrylic acid or acrylic acid.

[0209] Examples of commercially available core-shell rubber particles include "CHT" manufactured by Samsung SDI; "B602" manufactured by TechnoUMG; "PARALOID EXL-2602," "PARALOID EXL-2603," "PARALOID EXL-2655," "PARALOID EXL-2311," "PARALOID EXL2313," "PARALOID XL-2315," "PARALOID KM-330," "PARALOID KM-336P," and "PARALOID KCZ-201" manufactured by The Dow Chemical Company of Japan; "Metablen C-223A," "Metablen E-901," "Metablen S-2001," "Metablen W-450A," and "Metablen SRK-200" manufactured by Mitsubishi Rayon Co., Ltd.; and "Kane Ace M-511," "Kane Ace M-600," and "Kane Ace M-600" manufactured by Kaneka. AceM-400", "Kane Ace M-580", "Kane Ace MR-01"; "AC3401N", "AC3816N" made by Gantsu Chemical Co., Ltd.

[0210] The average particle size (average primary particle size) of the particulate stress relaxation material is not particularly limited, but is preferably 20 nm or greater, more preferably 30 nm or greater, and even more preferably 50 nm or greater. The upper limit of the average particle size (average primary particle size) of the particulate stress relaxation material is not particularly limited, but is preferably 10,000 nm or less, more preferably 5,000 nm or less, and even more preferably 1,000 nm or less. The average particle size (average primary particle size) of the particulate stress relaxation material can be measured using a zeta potential particle size distribution analyzer or the like.

[0211] The non-particulate stress relaxation material preferably comprises a resin having one or more structures selected from the group consisting of a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, and a polycarbonate structure. It is more preferred that the material comprises a resin having one or more structures selected from the group consisting of a polybutadiene structure and a polycarbonate structure. It is particularly preferred that the material comprises a resin having a polybutadiene structure and a phenolic hydroxyl group (a phenolic hydroxyl group-containing polybutadiene resin) or a resin having a polycarbonate structure (a polycarbonate resin). The term "(meth)acrylate" refers to both methacrylate and acrylate.

[0212] The polybutadiene structure includes not only structures formed by polymerizing butadiene butadiene, but also structures formed by hydrogenating the same structure. Furthermore, the polybutadiene structure may be partially or entirely hydrogenated. Furthermore, the polybutadiene structure may be included in the main chain or in the side chain of the stress relaxation material molecule.

[0213] Preferred examples of polybutadiene resins include resins containing a hydrogenated polybutadiene skeleton, polybutadiene resins containing hydroxyl groups, polybutadiene resins containing phenolic hydroxyl groups, polybutadiene resins containing carboxyl groups, polybutadiene resins containing acid anhydride groups, polybutadiene resins containing epoxy groups, polybutadiene resins containing isocyanate groups, and polybutadiene resins containing urethane groups. Among these, polybutadiene resins containing phenolic hydroxyl groups and polybutadiene resins containing epoxy groups are more preferred, and polybutadiene resins containing phenolic hydroxyl groups are particularly preferred. Here, "resin containing a hydrogenated polybutadiene skeleton" refers to a resin in which at least a portion of the polybutadiene skeleton is hydrogenated, and does not necessarily mean a resin in which the polybutadiene skeleton is completely hydrogenated. Examples of resins containing a hydrogenated polybutadiene skeleton include epoxy resins containing a hydrogenated polybutadiene skeleton. Preferred examples of polybutadiene resins containing phenolic hydroxyl groups include resins made from hydroxyl-terminated polybutadiene, diisocyanate compounds, and phenolic hydroxyl-containing resins. Examples of the hydroxyl-terminated polybutadiene and diisocyanate compounds include the same compounds exemplified below. Examples of phenolic hydroxyl-containing resins include cresol novolac resins.

[0214] Specific examples of the polybutadiene resin include "PB-3600" (polybutadiene containing an epoxy group) manufactured by Daicel Corporation, "JP-100" and "JP-200" (polybutadiene containing an epoxy group) manufactured by Nippon Soda Co., Ltd., "Ricon 657" (polybutadiene containing an epoxy group) manufactured by Cray Valley Co., Ltd., "Ricon 130MA8", "Ricon 130MA13", "Ricon 130MA20", "Ricon 131MA5", "Ricon 131MA10", "Ricon 131MA17", "Ricon 131MA20", "Ricon 131MA5" and "Ricon 131MA10" manufactured by Daicel Corporation. 184MA6" (polybutadiene containing an acid anhydride group), "GQ-1000" (polybutadiene into which hydroxyl groups and carboxyl groups are introduced), "G-1000", "G-2000", and "G-3000" (polybutadiene containing hydroxyl groups at both ends) manufactured by Nippon Soda Co., Ltd.), "GI-1000", "GI-2000", and "GI-3000" (hydrogenated polybutadiene containing hydroxyl groups at both ends), "PB3600" and "PB4700" (polybutadiene skeleton epoxy compounds) manufactured by Daicel Corporation, "Epofriend A1005", "Epofriend A1010", and "Epofriend A1020" (epoxy compounds of styrene, butadiene, and styrene block copolymers), "FCA-061L" (hydrogenated polybutadiene skeleton epoxy compound), and "R-45EPT" (polybutadiene skeleton epoxy compound) manufactured by Nagase ChemteX Co., Ltd.

[0215] In addition, as an example of a preferred polybutadiene resin, a linear polyimide (polyimide described in Japanese Patent Application Laid-Open No. 2006-37083 and International Publication No. 2008 / 153208) made from hydroxyl-terminated polybutadiene, a diisocyanate compound, and a polyacid or its anhydride can also be mentioned. The polybutadiene structure content of this polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. For details of this polyimide resin, reference can be made to the descriptions in Japanese Patent Application Laid-Open No. 2006-37083 and International Publication No. 2008 / 153208, the contents of which are incorporated into this specification.

[0216] The number average molecular weight of the hydroxyl-terminated polybutadiene is preferably 500 to 5000, more preferably 800 to 3500. The hydroxyl equivalent weight of the hydroxyl-terminated polybutadiene is preferably 250 to 5000 g / eq., more preferably 1000 to 3000 g / eq.

[0217] Examples of diisocyanate compounds include aromatic diisocyanates such as toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene diisocyanate, and diphenylmethane diisocyanate; aliphatic diisocyanates such as hexamethylene diisocyanate; and alicyclic diisocyanates such as isophorone diisocyanate. Among these, aromatic diisocyanates are preferred, and toluene-2,4-diisocyanate is more preferred.

[0218] Examples of the polybasic acid or its anhydride include ethylene glycol bis(trimellitic acid), pyromellitic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, naphthalenetetracarboxylic acid, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-cyclohexene-1,2-dicarboxylic acid, and 3,3'-4,4'-diphenylsulfonetetracarboxylic acid, and their anhydrides; tribasic acids such as trimellitic acid and cyclohexanetricarboxylic acid, and their anhydrides; and 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furyl)-naphtho(1,2-C)furan-1,3-dione.

[0219] The polybutadiene resin may contain a polystyrene structure having a structure obtained by polymerizing styrene.

[0220] Specific examples of the resin having a polystyrene structure in the molecule, i.e., the polystyrene resin, include: styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-butadiene-butylene-styrene block copolymer (SBBS), styrene-butadiene diblock copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-butadiene random copolymer, etc.

[0221] Commercially available polystyrene resins may be used, and examples thereof include hydrogenated styrene-based thermoplastic elastomers "H1041," "Tuftec H1043," "Tuftec P2000," and "Tuftec MP10" (manufactured by Asahi Kasei Corporation); epoxidized styrene-butadiene thermoplastic elastomers "Epofriend AT501" and "CT310" (manufactured by Daicel Corporation); modified styrene-based elastomers "SEPTON HG252" (manufactured by Kuraray Co., Ltd.) having hydroxyl groups; modified styrene-based elastomers "Tuftec N503M" (manufactured by Carboxyl groups), modified styrene-based elastomers "Tuftec N501" (manufactured by Amino groups), and modified styrene-based elastomers "Tuftec M1913" (manufactured by Asahi Kasei Corporation); and unmodified styrene-based elastomers "SEPTON S8104" (manufactured by Kuraray Co., Ltd.). Component (C) may be used alone or in combination of two or more.

[0222] The polysiloxane structure is a structure containing siloxane bonds, and is contained in silicone rubber, for example. The polysiloxane structure may be contained in the main chain or in the side chain of the stress relaxation material molecule.

[0223] Specific examples of resins having a polysiloxane structure in the molecule, i.e., polysiloxane resins, include "SMP-2006", "SMP-2003PGMEA", "SMP-5005PGMEA" manufactured by Shin-Etsu Silicone Co., Ltd., and linear polyimides made from amino-terminated polysiloxane and tetrabasic acid anhydride (International Publication No. 2010 / 053185).

[0224] The poly(meth)acrylate structure is formed by polymerizing acrylic acid or acrylic acid ester, and also includes a structure formed by polymerizing methacrylic acid or methacrylic acid ester. The (meth)acrylate structure may be included in the main chain or in the side chain of the stress relaxation material molecule.

[0225] Preferred examples of the resin having a poly(meth)acrylate structure in the molecule, i.e., the poly(meth)acrylate resin, include: poly(meth)acrylate resins containing hydroxyl groups, poly(meth)acrylate resins containing phenolic hydroxyl groups, poly(meth)acrylate resins containing carboxyl groups, poly(meth)acrylate resins containing acid anhydride groups, poly(meth)acrylate resins containing epoxy groups, poly(meth)acrylate resins containing isocyanate groups, poly(meth)acrylate resins containing urethane groups, and the like.

[0226] Specific examples of poly(meth)acrylate resins include: TEISANRESIN "SG-70L", "SG-708-6", "WS-023", "SG-700AS", "SG-280TEA" manufactured by Nagase ChemteX (an acrylate copolymer resin containing a carboxyl group, having an acid value of 5 to 34 mgKOH / g, a weight-average molecular weight of 400,000 to 900,000, and a Tg of -30°C to 5°C), "SG-80H", "SG-80H-3", and "SG-P3" (an acrylate copolymer resin containing an epoxy group, having an epoxy equivalent of 4761 to 14285 g / eq, and a weight-average molecular weight of 350,000). ~850,000, Tg is 11℃~12℃), "SG-600TEA", "SG-790" (hydroxyl-containing acrylate copolymer resin, hydroxyl value is 20~40mgKOH / g, weight average molecular weight is 500,000~1.2 million, Tg is -37℃~-32℃), "ME-2000", "W-116.3" (carboxyl-containing acrylate copolymer resin), "W-197C" (hydroxyl-containing acrylate copolymer resin), "KG-25", "KG-3000" (epoxy-containing acrylate copolymer resin) manufactured by Negami Industries, Ltd., etc.

[0227] The polyalkylene structure preferably has a predetermined number of carbon atoms. The specific number of carbon atoms in the polyalkylene structure is preferably 2 or more, more preferably 3 or more, particularly preferably 5 or more, and preferably 15 or less, more preferably 10 or less, and particularly preferably 6 or less. Furthermore, the polyalkylene structure may be included in the main chain or in a side chain in the stress relaxation material molecule.

[0228] The polyalkyleneoxy structure preferably has a predetermined number of carbon atoms. Specifically, the number of carbon atoms in the polyalkyleneoxy structure is preferably 2 or more, preferably 3 or more, more preferably 5 or more, preferably 15 or less, more preferably 10 or less, and particularly preferably 6 or less. The polyalkyleneoxy structure may be included in the main chain or in a side chain in the stress relaxation material molecule.

[0229] Specific examples of resins having a polyalkylene structure in the molecule, i.e., polyalkylene resins, and resins having a polyalkyleneoxy structure in the molecule, i.e., polyalkyleneoxy resins, include: "PTXG-1000" and "PTXG-1800" manufactured by Asahi Kasei Fibers Corporation, "YX-7180" (a resin containing an alkylene structure having an ether bond) manufactured by Mitsubishi Chemical Corporation, "EXA-4850-150", "EXA-4816", and "EXA-4822" manufactured by DIC Corporation, "EP-4000", "EP-4003", "EP-4010", and "EP-4011" manufactured by ADEKA Corporation, "BEO-60E" and "BPO-20E" manufactured by Shin Nippon Chemical Co., Ltd., and "YL7175" and "YL7410" manufactured by Mitsubishi Chemical Corporation.

[0230] The polyisoprene structure may be contained in the main chain or in the side chain of the stress relaxation material molecule. Specific examples of polyisoprene resins having a polyisoprene structure in the molecule include "KL-610" and "KL-613" manufactured by Kuraray Co., Ltd.

[0231] The polyisobutylene structure may be contained in the main chain or in the side chain of the stress relaxation material molecule. Specific examples of resins having a polyisobutylene structure in the molecule, i.e., polyisobutylene resins, include "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer) manufactured by Kaneka Corporation.

[0232] The polycarbonate structure may be contained in the main chain or in the side chain of the stress relaxation material molecule.

[0233] Preferred examples of resins having a polycarbonate structure in their molecules, i.e., polycarbonate resins, include polycarbonate resins containing hydroxyl groups, polycarbonate resins containing phenolic hydroxyl groups, polycarbonate resins containing carboxyl groups, polycarbonate resins containing acid anhydride groups, polycarbonate resins containing epoxy groups, polycarbonate resins containing isocyanate groups, and polycarbonate resins containing carbamate groups.

[0234] Specific examples of the polycarbonate resin include "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.

[0235] Preferred examples of polycarbonate resins include linear polyimides made from hydroxyl-terminated polycarbonates, diisocyanate compounds, and polyacids or their anhydrides. These linear polyimides have both a urethane structure and a polycarbonate structure. The polycarbonate content of these polyimide resins is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. For details of these polyimide resins, please refer to International Publication No. 2016 / 129541, the contents of which are incorporated herein by reference.

[0236] The number average molecular weight of the hydroxyl-terminated polycarbonate is preferably 500 to 5000, more preferably 1000 to 3000. The hydroxyl equivalent weight of the hydroxyl-terminated polycarbonate is preferably 250 to 1250.

[0237] The non-granular stress relaxation material preferably further has an imide structure. The imide structure can improve the heat resistance of the non-granular stress relaxation material and effectively improve the crack resistance.

[0238] The chemical structure of the non-particulate stress relaxation material may be any of linear, branched, and cyclic structures, but is preferably linear.

[0239] The non-granular stress relaxation material preferably further comprises a functional group reactive with the epoxy resin. The functional group also includes a reactive group that is activated upon heating. The presence of the functional group in the non-granular stress relaxation material can enhance the mechanical strength of the cured product of the resin composition.

[0240] Examples of the functional group include a carboxyl group, a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a carbamate group. Among these, from the viewpoint of significantly achieving the effects of the present invention, the functional group preferably contains one or more functional groups selected from the group consisting of a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a carbamate group, and a phenolic hydroxyl group is particularly preferred.

[0241] The non-particulate stress relaxation material may be used alone or in combination of two or more.

[0242] The specific number average molecular weight Mn of the non-particulate stress relaxation material is preferably 500 or greater, more preferably 800 or greater, even more preferably 1,000 or greater, and particularly preferably 1,200 or greater. It is preferably 100,000 or less, more preferably 50,000 or less, and particularly preferably 10,000 or less. The number average molecular weight Mn of the non-particulate stress relaxation material is a polystyrene-equivalent number average molecular weight measured using GPC (gel permeation chromatography).

[0243] When the non-particulate stress relaxation material has a functional group, the functional group equivalent weight of the non-particulate stress relaxation material is preferably 100 g / eq. or more, more preferably 200 g / eq. or more, even more preferably 1,000 g / eq. or more, and particularly preferably 2,500 g / eq. or more. It is preferably 50,000 g / eq. or less, more preferably 30,000 g / eq. or less, even more preferably 10,000 g / eq. or less, and particularly preferably 5,000 g / eq. or less. The functional group equivalent weight is the number of grams of resin containing one gram equivalent of functional groups. For example, the epoxy group equivalent weight can be measured according to JIS K7236. Alternatively, the hydroxyl group equivalent weight can be calculated by dividing the molecular weight of KOH by the hydroxyl value measured according to JIS K1557-1.

[0244] The glass transition temperature (Tg) of the (G) stress relaxation material is preferably 20° C. or lower, more preferably 10° C. or lower, and even more preferably 0° C. or lower.

[0245] When the non-volatile component in the resin composition layer is 100 mass%, the content of the stress relaxation material (G) is preferably 0.1 mass% or more, more preferably 0.3 mass% or more, even more preferably 0.5 mass% or more, and preferably 3 mass% or less, more preferably 2 mass% or less, and even more preferably 1.5 mass% or less.

[0246] When the resin component in the resin composition layer is 100% by mass, the content of the (G) stress relaxation material is preferably 1% by mass or more, more preferably 1.5% by mass or more, even more preferably 2% by mass or more, and is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less.

[0247] <(H) Radical Polymerization Initiator> The resin composition layer may further contain a (H) radical polymerization initiator as the (H) component. The (H) radical polymerization initiator as the (H) component does not include substances belonging to the above-mentioned components (A) to (G). The (H) radical polymerization initiator may be, for example, a thermal polymerization initiator that generates free radicals when heated. The (H) radical polymerization initiator may be a polymerization initiator for the radical polymerizable groups contained in the (A) and (E) components. The (H) radical polymerization initiator may be used alone or in any combination of two or more.

[0248] (H) Radical polymerization initiators include, for example, peroxide-based radical polymerization initiators and azo-based radical polymerization initiators. Among them, peroxide-based radical polymerization initiators are preferred.

[0249] Examples of the peroxide-based radical polymerization initiator include hydroperoxide compounds such as 1,1,3,3-tetramethylbutyl hydroperoxide; dialkyl peroxide compounds such as tert-butylcumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, dicumyl peroxide, 1,4-bis(1-tert-butylperoxy-1-methylethyl)benzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; dilauroyl peroxide, didecanoyl peroxide, dicyclohexyl peroxydicarbonate, and bis(4-tert-butylcyclohexyl)peroxydicarbonate. Peroxy diacyl compounds such as oxydicarbonates; peroxy ester compounds such as tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl monocarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyneodecanoate, tert-hexyl peroxyisopropyl monocarbonate, tert-butyl peroxylaurate, 1,1-dimethylpropyl 2-ethylperoxyhexanoate, tert-butyl 2-ethylperoxyhexanoate, tert-butyl 3,5,5-trimethylperoxyhexanoate, tert-butyl peroxy-2-ethylhexyl monocarbonate, and tert-butyl peroxymaleate; etc.

[0250] Examples of the azo radical polymerization initiator include azo nitrile compounds such as 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, and 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile; 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide], 2,2'-azobis[2-methyl-N-[1,1-bis( Azoamide compounds such as 2,2'-azobis[2-methyl-N-[2-(1-hydroxybutyl)]-propionamide], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide], 2,2'-azobis(2-methylpropionamide) dihydrate, 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(N-cyclohexyl-2-methylpropionamide); alkylazo compounds such as 2,2'-azobis(2,4,4-trimethylpentane) and 2,2'-azobis(2-methylpropane); and the like.

[0251] Examples of commercially available products of the radical polymerization initiator (H) include "PERBUTYL C", "PERBUTYL A", "PERBUTYL P", "PERBUTYL L", "PERBUTYL O", "PERBUTYL ND", "PERBUTYL Z", "PERBUTYL I", "PERCUMYL P", "PERCUMYL D", "PERHEXYL D", "PERHEXYL A", "PERHEXYL I", "PERHEXYL Z", "PERHEXYL ND", "PERHEXYL O", and "PERHEXYL PV" manufactured by NOF Corporation.

[0252] When the non-volatile component in the resin composition layer is set to 100 mass%, the content of the (H) radical polymerization initiator is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, further preferably 0.1 mass% or more, preferably 1.5 mass% or less, more preferably 1 mass% or less, and further preferably 0.5 mass% or less.

[0253] When the resin component in the resin composition layer is set to 100 mass%, the content of the (H) radical polymerization initiator is preferably 0.1 mass% or more, more preferably 0.3 mass% or more, further preferably 0.5 mass% or more, preferably 3 mass% or less, more preferably 1.5 mass% or less, and further preferably 1 mass% or less.

[0254] <(I) Curing Accelerator> The resin composition layer may contain (I) a curing accelerator as component (I). The (I) curing accelerator as component (I) does not include any of the aforementioned components (A) to (H). The (I) curing accelerator functions as a curing catalyst that accelerates the curing of the epoxy resin in component (C).

[0255] As the curing accelerator (I), a compound that accelerates the curing of epoxy resins can be used. Examples of such curing accelerators (I) 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 of the curing accelerators (I) can be used alone, or two or more can be used in combination.

[0256] Phosphorus curing accelerators include, for example, tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitic acid salt, tetrabutylphosphonium hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, di-tert-butyldimethylphosphonium tetraphenylborate and other aliphatic phosphonium salts; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, para-methyl Aromatic phosphonium salts such as phenyltriphenylphosphonium tetra-p-tolyl borate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolyl borate, 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 addition reactants such as triphenylphosphine-p-benzoquinone addition reactants; tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butylphosphine aliphatic phosphines such as 2-butyl-2-butenyl phosphine, di-tert-butyl-3-methyl-2-butenyl phosphine, tricyclohexyl phosphine; dibutylphenyl phosphine, di-tert-butylphenyl phosphine, methyldiphenyl phosphine, ethyldiphenyl phosphine, butyldiphenyl phosphine, diphenylcyclohexyl phosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tri(4-ethylphenyl)phosphine, tri(4-propylphenyl)phosphine, tri(4-isopropylphenyl)phosphine, tri(4-butylphenyl)phosphine, tri(4-tert-butylphenyl)phosphine, tri(2,4-dimethylphenyl)phosphine, tri(2,5-dimethylphenyl)phosphine, tri(2,6-dimethylphenyl)phosphine Aromatic phosphines such as 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 are also included.

[0257] 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, Aromatic dimethylureas such as 1-dimethylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluenebisdimethylurea].

[0258] Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, and 1-(o-tolyl)biguanidine.

[0259] 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, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1' )]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline and other imidazole compounds, and adducts of imidazole compounds with epoxy resins. Commercially available imidazole curing accelerators include, for example, "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" manufactured by Shikoku Chemical Industry Co., Ltd.; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0260] Examples of metallic 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 organocobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate; organocopper complexes such as copper (II) acetylacetonate; organozinc complexes such as zinc (II) acetylacetonate; organoiron complexes such as iron (III) acetylacetonate; organonickel complexes such as nickel (II) acetylacetonate; and organomanganese complexes such as manganese (II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0261] Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine; 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. Commercially available amine-based curing accelerators may be used, and examples thereof include "MY-25" manufactured by Ajinomoto Fine Technologies Co., Ltd.

[0262] When the non-volatile component in the resin composition layer is 100% by mass, the content of the curing accelerator (I) is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, further preferably 0.01% by mass or more and 0.05% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, further preferably 3% by mass or less, 2% by mass or less, 1% by mass or less, or 0.5% by mass or less.

[0263] When the resin component in the resin composition layer is 100% by mass, the content of the curing accelerator (I) is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, further preferably 0.3% by mass or more, preferably 10% by mass or less, more preferably 9% by mass or less, further preferably 5% by mass or less, 3% by mass or less, or 1% by mass or less.

[0264] <(J) Other additives> The resin composition layer may contain (J) other additives as any non-volatile components. Examples of (J) other additives include: organometallic compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone leveling agents and acrylic polymer leveling agents; thickeners such as Benton (bentonite) and montmorillonite; defoaming agents such as silicone defoaming agents, acrylic defoaming agents, fluorine defoaming agents, and vinyl resin defoaming agents; ultraviolet absorbers such as benzotriazole ultraviolet absorbers; adhesion enhancers such as urea silane; triazole adhesion imparting agents, tetrazole adhesion imparting agents, and triazine adhesion imparting agents. Adhesion-imparting agents such as pre-adhesives; antioxidants such as hindered phenol-based antioxidants; fluorescent whitening agents such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; dispersants such as phosphate-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers; photopolymerization initiation aids such as tertiary amines; photosensitizers such as pyrazolines, anthracenes, coumarins, xanthones, and thioxanthones; antioxidants; and flame retardants (excluding those included in component (B)). (J) Other additives may be used alone or in combination of two or more.

[0265] <(K)Solvent> The resin composition layer may further contain (K) a solvent as an arbitrary volatile component in combination with the non-volatile components such as the above-mentioned (A) to (J) components. As the (K) solvent, an organic solvent is generally used. Examples of the organic solvent include: ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, and carbitol acetate. Ether ester solvents such as acetate, γ-butyrolactone, and methyl methoxypropionate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); 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; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (K) The solvent may be used alone or in combination of two or more.

[0266] The amount of the solvent (K) is not particularly limited and 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 0% by mass relative to 100% by mass of all components of the resin composition layer.

[0267] From the perspective of achieving thinner printed wiring boards and providing a cured product having excellent insulating properties even when the cured product of the resin composition layer is a thin film, 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. The lower limit of the thickness of the resin composition layer is not particularly limited, but can generally be 5 μm or more, 10 μm or more, or the like.

[0268] <Protective film> If necessary, the resin sheet may include a protective film based on the support as an additional 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 to the support). By laminating the protective film on the resin sheet, it is possible to prevent the surface of the resin composition layer from being attached to garbage or otherwise damaged.

[0269] Examples of the protective film include films made of plastic materials, metal foils, and release papers, and films made of plastic materials and metal foils are preferred.

[0270] When a film formed of a plastic material is used as the protective film, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes referred to as "PET") and polyethylene naphthalate (hereinafter sometimes referred to as "PEN"), polycarbonate (hereinafter sometimes referred to as "PC"), acrylic polymers such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0271] 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 copper alone or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0272] The surface of the protective film that contacts the resin composition layer may be subjected to matte treatment, corona treatment, or antistatic treatment.

[0273] In addition, as the protective film, a protective film with a release layer having a release layer on the surface bonded to the resin composition layer can be used. As the release agent used in the release layer of the protective film with a release layer, for example, one or more release agents selected from alkyd resins, polyolefin resins, polyurethane resins and silicone resins can be mentioned. The protective film with a release layer can be a commercially available product, for example, a PET film having a release layer with an alkyd resin-based release agent as the main component, i.e., "SK-1", "AL-5", "AL-7" manufactured by Lintec, "Lumirror T60", "Lumirror R80", "Lumirror" manufactured by Toray Industries, "Purex" manufactured by Teijin, "Unipeel" manufactured by Unitika, etc.

[0274] The thickness of the protective film is not particularly limited, and 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, the thickness of the entire protective film is preferably within the above range.

[0275] <Method for 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 the resin varnish on a support using a die coater or the like, and drying to form the resin composition layer.

[0276] Examples of the solvent include the same solvents as those described as components of the resin composition layer. The solvents may be used alone or in combination of two or more.

[0277] Drying can be carried out by heating, blowing hot air, or the like. Drying conditions are not particularly limited, but drying is performed so that the content of the solvent in the resin composition layer is generally 10% by mass or less, preferably 5% by mass or less. Drying conditions also vary depending on the boiling point of the solvent in the resin composition. For example, when using a resin composition containing 30% to 60% by mass of a solvent, the resin composition layer can be formed by drying at 50° C. to 150° C. for 3 to 10 minutes.

[0278] The resin sheet can be stored in a roll. When the resin sheet has a protective film, it can usually be used by peeling off the protective film.

[0279] <Physical Properties of Resin Sheet> By curing the resin composition layer, an insulating layer formed from the cured resin composition layer can be obtained. Forming through-holes in this insulating layer and roughening it can suppress the halo phenomenon. These effects are described below with reference to the accompanying drawings.

[0280] Figure 1 This is a cross-sectional view schematically showing an insulating layer 100 obtained by curing the resin composition layer of the resin sheet of the present invention together with an inner layer substrate 200. Figure 1 , a cross section of the insulating layer 100 is shown, which is obtained by cutting the insulating layer 100 along a plane that passes through the center 120C of the bottom 120 of the through-hole 110 and is parallel to the thickness direction of the insulating layer 100 .

[0281] like Figure 1 As shown, the insulating layer 100 is a layer obtained by curing a resin composition layer formed on the inner layer substrate 200 including the conductor layer 210, and is formed from the cured product of the resin composition layer. Furthermore, a through hole 110 is formed in the insulating layer 100. The through hole 110 is typically formed in a tapered shape (straight taper shape), that is, the diameter increases as it approaches the surface 100U of the insulating layer 100 opposite the conductor layer 210, and the diameter decreases as it approaches the conductor layer 210. Ideally, the through hole 110 is formed in a columnar shape having a constant diameter in the thickness direction of the insulating layer 100. The through hole 110 is typically formed by irradiating the surface 100U of the insulating layer 100 opposite the conductor layer 210 with a laser to remove a portion of the insulating layer 100.

[0282] The bottom of the through-hole 110 on the conductor layer 210 side is appropriately referred to as the "through-hole bottom" and is indicated by the symbol 120. Moreover, the diameter of the through-hole bottom 120 is referred to as the bottom diameter Lb. In addition, the opening of the through-hole 110 formed on the side opposite to the conductor layer 210 is appropriately referred to as the "through-hole top" and is indicated by the symbol 130. Moreover, the diameter of the through-hole top 130 is referred to as the top diameter Lt. Usually, the planar shape of the through-hole bottom 120 and the through-hole top 130 as viewed from the thickness direction of the insulating layer 100 is formed into a circle, but it can also be an ellipse. In the case where the planar shape of the through-hole bottom 120 and the through-hole top 130 is an ellipse, the bottom diameter Lb and the top diameter Lt respectively represent the major diameter of the above-mentioned ellipse.

[0283] At this time, the closer the taper ratio Lb / Lt (%), obtained by dividing the bottom diameter Lb by the top diameter Lt, is to 100%, the better the shape of the through hole 110. Using the resin composition layer of the present invention makes it easy to control the shape of the through hole 110, and thus, a through hole 110 with a taper ratio Lb / Lt close to 100% can be achieved.

[0284] For example, in the case where an insulating layer 100 is obtained by curing a resin composition layer by heating it at 100°C for 30 minutes and then heating it at 180°C for 30 minutes, and a through hole 110 having a top diameter Lt of approximately 50 μm is formed by irradiating it with a CO2 laser under the conditions of a mask diameter of 2.0 mm, a pulse width of 6 μs, an energy (output power) of 4 W / shot, a shot number of 2, and a burst mode (2 kHz), the taper ratio Lb / Lt of the through hole 110 is preferably 75% to 100%, more preferably 80% to 100%, and particularly preferably 85% to 100%.

[0285] The taper ratio Lb / Lt of the through hole 110 can be calculated from the bottom diameter Lb and the top diameter Lt of the through hole 110. Furthermore, the bottom diameter Lb and the top diameter Lt of the through hole 110 can be measured by cutting the insulating layer 100 using a FIB (focused ion beam) to reveal a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the through hole bottom 120, and then observing the cross section using an electron microscope.

[0286] Figure 2 The insulating layer 100 and the conductive layer 210 ( Figure 2 A top view of the surface 100U on the opposite side (not shown).

[0287] like Figure 2As shown, when observing the insulating layer 100 having the through-hole 110 formed therein, a discolored portion 140 of the insulating layer 100 may be observed around the through-hole 110. This discolored portion 140 may be formed due to degradation of the resin when forming the through-hole 110, and is usually formed continuously from the through-hole 110. In addition, in many cases, the discolored portion 140 is a whitened portion.

[0288] Figure 3 This is a cross-sectional view schematically showing the roughened insulating layer 100 obtained by curing the resin composition layer of the resin sheet of the present invention together with the inner layer substrate 200. Figure 3 , a cross section of the insulating layer 100 is shown, which is obtained by cutting the insulating layer 100 along a plane that passes through the center 120C of the through-hole bottom 120 of the through-hole 110 and is parallel to the thickness direction of the insulating layer 100 .

[0289] like Figure 3 As shown, if the insulating layer 100 having the through-hole 110 formed therein is subjected to a roughening process, a halo phenomenon may occur, whereby the insulating layer 100 in the discolored portion 140 is peeled off from the conductive layer 210, forming a gap 160 that is continuous from the edge 150 of the through-hole bottom 120. This gap 160 is typically formed by erosion of the discolored portion 140 during the roughening process.

[0290] In the present invention, since the resin composition layer contains components (A) to (C), the halo phenomenon can be suppressed. Therefore, the insulation layer 100 can be prevented from peeling off from the conductive layer 210, and the size of the gap 160 can be reduced.

[0291] The edge 150 of the through-hole bottom 120 is equivalent to the edge portion of the inner peripheral side of the gap portion 160. Therefore, the distance Wb from the edge 150 of the through-hole bottom 120 to the end portion 170 on the outer peripheral side of the gap portion 160 (that is, the end portion on the side farther from the center 120C of the through-hole bottom 120) is equivalent to the dimension of the gap portion 160 in the in-plane direction. Here, the in-plane direction refers to the direction perpendicular to the thickness direction of the insulating layer 100. In addition, in the following description, the above-mentioned distance Wb is sometimes referred to as the halo distance Wb of the through-hole 110 from the edge 150 of the through-hole bottom 120. The halo distance Wb from the edge 150 of the through-hole bottom 120 can be used to evaluate the degree of suppression of the halo phenomenon. Specifically, the smaller the halo distance Wb from the edge 150 of the through-hole bottom 120, the more effectively the halo phenomenon can be suppressed.

[0292] For example, an insulating layer 100 obtained by curing a resin composition layer by heating it at 100°C for 30 minutes and then heating it at 180°C for 30 minutes is irradiated with a CO2 laser under the conditions of a mask diameter of 2.0 mm, a pulse width of 6 μs, an energy of 4 W / shot, a shot count of 2, and a burst mode (2 kHz) to form a through hole 110 having a top diameter Lt of approximately 50 μm. The insulating layer 100 is then immersed in a swelling solution at 60°C for 10 minutes, then immersed in an oxidizing agent solution at 80°C for 20 minutes, then immersed in a neutralizing solution at 40°C for 5 minutes, and then dried at 80°C for 15 minutes.

[0293] The halo distance Wb from the edge 150 of the through-hole bottom 120 can be measured as follows: using FIB (focused ion beam), the insulating layer 100 is cut to reveal a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the through-hole bottom 120, and then the cross section is observed with an electron microscope.

[0294] Furthermore, the use of the resin composition layer in the resin sheet of the present invention facilitates control of the shape of through-holes 110 in insulating layer 100 before roughening. This generally makes it possible to easily control the shape of through-holes 110 even after roughening. Consequently, even after roughening, the shape of through-holes 110 can be maintained to the same high quality as before roughening. Consequently, the use of the resin composition layer in the resin sheet of the present invention allows for through-holes 110 with a taper ratio Lb / Lt approaching 100% to be achieved in the insulating layer after roughening.

[0295] For example, an insulating layer 100 obtained by curing a resin composition layer by heating it at 100°C for 30 minutes and then heating it at 180°C for 30 minutes is irradiated with a CO2 laser under conditions of a mask diameter of 2.0 mm, a pulse width of 6 μs, an energy of 4 W / shot, a shot count of 2, and a burst mode (2 kHz) to form through-holes 110 with a top diameter Lt of approximately 50 μm. The insulating layer 100 is then immersed in a swelling solution at 60°C for 10 minutes, then immersed in an oxidizing agent solution at 80°C for 20 minutes, then immersed in a neutralizing solution at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. Using the resin composition of the present invention, the through-holes 110 formed in the insulating layer 100 thus obtained preferably have a taper ratio Lb / Lt of 76% to 100%, more preferably 80% to 100%, and particularly preferably 85% to 100%.

[0296] The taper ratio Lb / Lt of the through hole 110 can be calculated from the bottom diameter Lb and the top diameter Lt of the through hole 110. Furthermore, the bottom diameter Lb and the top diameter Lt of the through hole 110 can be measured by cutting the insulating layer 100 using a FIB (focused ion beam) to reveal a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the through hole bottom 120, and then observing the cross section using an electron microscope.

[0297] Furthermore, by using the resin sheet of the present invention, the formation of the discolored portion 140 when forming the through hole 110 can be suppressed. Figure 2 As shown, the size of the discoloration portion 140 can be reduced, and ideally, can be eliminated. The size of the discoloration portion 140 can be evaluated using the halo distance Wt of the through-hole 110 from the edge 180 of the through-hole top 130.

[0298] Edge 180 of through-hole top 130 corresponds to the inner peripheral edge of discoloration portion 140. A halo distance Wt from edge 180 of through-hole top 130 represents the distance from edge 180 of through-hole top 130 to edge 190 of the outer peripheral edge of discoloration portion 140. The smaller the halo distance Wt from edge 180 of through-hole top 130, the more effectively the formation of discoloration portion 140 can be suppressed.

[0299] The halo distance Wt from the edge 180 of the via top 130 can be measured by observation with an optical microscope.

[0300] In addition, according to the research of the present inventors, it is clear that, generally, the larger the diameter of the through-hole 110, the more likely the size of the discoloration portion 140 is to become larger. Therefore, the ratio of the size of the discoloration portion 140 to the diameter of the through-hole 110 can be used to evaluate the degree of suppression of the formation of the discoloration portion 140. For example, the halo ratio Ht relative to the top radius Lt / 2 of the through-hole 110 can be used for evaluation. Here, the top radius Lt / 2 of the through-hole 110 refers to the radius of the through-hole top 130 of the through-hole 110. In addition, the halo ratio Ht relative to the top radius Lt / 2 of the through-hole 110 is the ratio obtained by dividing the halo distance Wt from the edge 180 of the through-hole top 130 by the top radius Lt / 2 of the through-hole 110. The smaller the halo ratio Ht relative to the top radius Lt / 2 of the through-hole 110, the more effectively the formation of the discoloration portion 140 can be suppressed.

[0301] For example, for the insulating layer 100 obtained by heating the resin composition layer at 100°C for 30 minutes and then heating it at 180°C for 30 minutes to cure it, when a CO2 laser is irradiated under the conditions of a mask diameter of 2.0 mm, a pulse width of 6 μs, an energy of 4 W / shot, an shot number of 2, and a burst mode (2 kHz), and a through hole 110 with a top diameter Lt of approximately 50 μm is formed, the halo ratio Ht of the through hole 110 relative to the top radius Lt / 2 can be preferably less than 70%, more preferably less than 50%, and even more preferably less than 35%.

[0302] The halo ratio Ht of the through hole 110 relative to the top radius Lt / 2 may be calculated from the top diameter Lt of the through hole 110 and the halo distance Wt of the through hole 110 from the edge 180 of the through hole 130 .

[0303] During the manufacturing process of a semiconductor chip package substrate, the through-hole 110 is typically formed in a state where no additional conductive layer (not shown) is provided on the surface 100U of the insulating layer 100 opposite the conductive layer 210. Therefore, if the manufacturing process of the semiconductor chip package substrate is understood, the following structure can be clearly recognized: the through-hole bottom 120 is present on the conductive layer 210 side, and the through-hole top 130 is open on the side opposite the conductive layer 210. However, in the completed semiconductor chip package substrate, there may be a case where the conductive layer is provided on both sides of the insulating layer 100. In this case, it may be difficult to distinguish the through-hole bottom 120 from the through-hole top 130 based on their positional relationship with the conductive layer. However, the top diameter Lt of the through-hole top 130 is typically larger than the bottom diameter Lb of the through-hole bottom 120. Therefore, in the aforementioned case, the through-hole bottom 120 and the through-hole top 130 can be distinguished by the size of the diameter.

[0304] Since the resin composition layer in the resin sheet of the present invention includes components (A) to (C), the cured product of the resin composition layer exhibits a high glass transition temperature (Tg). Therefore, an insulating layer with a high glass transition temperature is obtained. The glass transition temperature of the cured product of the resin composition layer is preferably 130°C or higher, more preferably 140°C or higher, and even more preferably 150°C or higher. The upper limit of the glass transition temperature of the cured product is not particularly limited and may be 300°C or lower. The glass transition temperature can be measured by the method described in the Examples below.

[0305] The cured resin composition layer exhibits the property of suppressing the formation of cracks after desmearing (roughening). This results in an insulating layer with excellent crack resistance. Specifically, after preparing a circuit substrate and performing a desmearing treatment, the circuit substrate is observed and evaluated for the presence of cracks according to JIS K5600-5-6. The crack rate is preferably less than 15%, more preferably less than 5%, and even more preferably less than 5%. Crack resistance can be evaluated using the method described in the Examples below.

[0306] The cured product of the resin composition layer generally exhibits excellent flame retardancy. Therefore, the cured product provides an insulating layer with excellent flame retardancy. Regarding flame retardancy, a flame retardancy test in accordance with the UL94 standard is performed, preferably with a rating of "V-1," more preferably "V-0" or higher. Flame retardancy can be measured by the method described in the Examples below.

[0307] [Semiconductor package substrate and manufacturing method thereof] The semiconductor chip package of the present invention includes a circuit substrate and a semiconductor chip mounted on the circuit substrate. The circuit substrate includes an insulating layer formed from a cured product of the resin composition layer in the resin sheet of the present invention. The semiconductor chip package can be manufactured by bonding the semiconductor chip to the circuit substrate. The circuit substrate is described below.

[0308] As long as the terminal electrodes of the semiconductor chip are connected to the circuit wiring of the circuit substrate by conductors, the bonding conditions are not particularly limited, and the known conditions used in flip-chip mounting of the semiconductor chip can be used. In addition, the semiconductor chip and the circuit substrate can also be bonded via an insulating adhesive.

[0309] A preferred embodiment is to press-bond the semiconductor chip to the circuit board. The pressing conditions include, for example, a pressing 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 pressing time in the range of 1 second to 60 seconds (preferably 5 seconds to 30 seconds).

[0310] In another preferred embodiment, the semiconductor chip is bonded to the circuit board by reflow soldering. The reflow soldering conditions can be set to a range of 120°C to 300°C, for example.

[0311] After the semiconductor chip is bonded to the circuit board, the semiconductor chip may be filled with a mold underfill material, for example, to obtain a semiconductor chip package. The method of filling with the mold underfill material can be implemented using a known method.

[0312] 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 the 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.

[0313] The "inner substrate" used in step (I) is a component of a substrate that forms a circuit substrate, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. In addition, the substrate may have a conductor layer on one or both sides thereof, and the conductor layer may also be patterned. An inner substrate having a conductor layer (circuit) formed on one or both sides of a substrate is sometimes referred to as an "inner circuit substrate". In addition, when manufacturing a circuit substrate, an intermediate product to be further formed with an insulating layer and / or a conductor layer is also included in the aforementioned "inner substrate". When the circuit substrate is a circuit board with built-in components, an inner substrate with built-in components may also be used.

[0314] The inner substrate and the resin sheet can be laminated, for example, by heat-pressing the resin sheet onto the inner substrate from the support side. As a member for heat-pressing the resin sheet onto the inner substrate (hereinafter also referred to as a "heat-pressing member"), for example, a heated metal plate (SUS end plate, etc.) or a metal roller (SUS roller, etc.) can be cited. It should be noted that the heat-pressing member is not directly pressed onto the resin sheet, but is pressed via an elastic material such as heat-resistant rubber so that the resin sheet fully follows the surface unevenness of the inner substrate.

[0315] The inner substrate and the resin sheet can be laminated by vacuum lamination. In vacuum lamination, the heating and pressing temperature is preferably 60°C to 160°C, more preferably 80°C to 140°C, the heating and pressing pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1.47 MPa, and the heating and pressing time is preferably 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

[0316] Lamination can be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Manufacturing Co., Ltd., a vacuum laminator manufactured by Nikko Materials Co., Ltd., and a batch vacuum pressure laminator.

[0317] After lamination, the laminated resin sheets can be smoothed under normal pressure (atmospheric pressure), for example, by pressing a heat-pressing member from the support side. The pressing conditions for the smoothing treatment can be the same as the heat-pressing conditions for the lamination. The smoothing treatment can be performed using a commercially available laminator. It should be noted that the lamination and smoothing treatment can be performed continuously using the commercially available vacuum laminator.

[0318] The support may be removed between step (I) and step (II), or may be removed after step (II).

[0319] In step (II), the resin composition layer is cured to form an insulating layer formed from a cured product of the resin composition layer. The curing of the resin composition layer is usually performed by thermal curing. The specific curing conditions of the resin composition layer can use the conditions commonly used when forming an insulating layer of a printed wiring board.

[0320] For example, the thermal curing conditions of the resin composition layer vary depending on the types of components contained in the resin composition layer. 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.

[0321] Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, before 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.

[0322] When manufacturing a circuit substrate, the process of (III) opening a hole in the insulating layer, the process of (IV) roughening the insulating layer, and the process of (V) forming a conductor layer can be further implemented. These processes (III) to (V) can be implemented according to various methods known to those skilled in the art used in the manufacture of the circuit substrate. It should be noted that when the support body is removed after process (II), the removal of the support body can be implemented between process (II) and process (III), between process (III) and process (IV), or between process (IV) and process (V). In addition, as needed, the formation of the insulating layer and the conductor layer of process (I) to process (V) can also be repeatedly implemented to form a multilayer wiring board.

[0323] Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as through holes and through holes in the insulating layer. Step (III) can be carried out using, for example, a drill, laser, plasma, etc., depending on the composition of the resin composition used when forming the insulating layer. The size and shape of the holes can be appropriately determined according to the design of the printed wiring board.

[0324] Step (IV) is a step of roughening the insulating layer. Typically, contamination removal is also performed in step (IV). The steps and conditions for the roughening treatment are not particularly limited, and known steps and conditions commonly used in forming the insulating layer of a printed wiring board can be employed. For example, the insulating layer can be roughened by sequentially performing a swelling treatment using a swelling solution, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing solution.

[0325] As the swelling liquid used in the roughening treatment, for example, an alkaline solution, a surfactant solution, etc. can be mentioned, preferably an alkaline solution, and as the alkaline solution, a sodium hydroxide solution or a potassium hydroxide solution is more preferable. As commercially available swelling liquids, for example, "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan Co., Ltd. can be mentioned. The swelling treatment using the swelling liquid can be carried out, for example, by immersing the insulating layer in the swelling liquid at 30°C to 90°C for 1 minute to 20 minutes. From the viewpoint of controlling the swelling of the resin of the insulating layer to an appropriate level, it is preferred to immerse the insulating layer in the swelling liquid at 40°C to 80°C for 5 minutes to 15 minutes.

[0326] As the oxidizing agent used in the roughening treatment, an alkaline permanganate solution formed by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide can be cited. The roughening treatment using an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 minutes to 30 minutes. In addition, the concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. As commercially available oxidizing agents, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Atotech Japan Co., Ltd. can be cited.

[0327] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution. Commercially available products include, for example, "Reduction Solution Securiganth P" manufactured by Atotech Japan Co., Ltd. Treatment with the neutralizing solution can be performed by immersing the surface roughened with an oxidizing agent in the neutralizing solution at a temperature of 30°C to 80°C for 5 to 30 minutes. For ease of use, immersing the surface roughened with an oxidizing agent in the neutralizing solution at a temperature of 40°C to 70°C for 5 to 20 minutes is preferred.

[0328] In one embodiment, the arithmetic mean roughness (Ra) of the insulating layer surface after roughening treatment is preferably less than 500nm, more preferably less than 400nm, and more preferably less than 300nm. The lower limit is not particularly limited, for example, it can be more than 1nm, more than 2nm, etc. In addition, the root mean square roughness (Rq) of the insulating layer surface after roughening treatment is preferably less than 500nm, more preferably less than 400nm, and more preferably less than 300nm. The lower limit is not particularly limited, for example, it can be more than 1nm, more than 2nm, 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.

[0329] Step (V) is a step of forming a conductor layer, in which a conductor layer is formed on the insulating layer. The conductor material used in the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer comprises one or more metals selected from 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. As the alloy layer, for example, a layer formed by an alloy of two or more metals selected from the above metals (e.g., nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy) can be mentioned. Among them, from the viewpoints of versatility, cost, ease of pattern formation, etc. of the formation of the conductor layer, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper or an alloy layer of nickel-chromium alloy, copper-nickel alloy or copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper or an alloy layer of nickel-chromium alloy is more preferred, and a single metal layer of copper is further preferred.

[0330] The conductor layer may have a single-layer structure or a multilayer structure in which two or more single metal layers or alloy layers composed of different types of metals or alloys are stacked. When the conductor layer has a multilayer 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.

[0331] 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.

[0332] In one embodiment, the conductor layer can be formed by plating. For example, the surface of the insulating layer can be plated using conventionally known techniques such as a semi-additive process or a fully additive process to form a conductor layer having a desired wiring pattern. From the perspective of ease of production, the semi-additive process is preferred. An example of forming a conductor layer using the semi-additive process is shown below.

[0333] First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer in accordance with the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. The unnecessary plating seed layer is then removed by etching or other methods, thereby forming a conductor layer having the desired wiring pattern.

[0334] In other embodiments, the conductor layer can be formed using metal foil. When using metal foil to form the conductor layer, it is preferred to implement process (V) between process (I) and process (II). For example, after process (I), the support is removed and a metal foil is laminated on the surface of the exposed resin composition layer. The lamination of the resin composition layer and the metal foil can be implemented by a vacuum lamination method. The lamination conditions can be the same as those described for process (I). Then, process (II) is implemented to form an insulating layer. Then, utilizing the metal foil on the insulating layer, a conductor layer with a desired wiring pattern can be formed by conventionally known techniques such as a subtractive process and a modified semi-additive process.

[0335] Metal foil can be produced by known methods such as electrolysis and rolling. Commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Metals, and 3EC-III foil and TP-III foil manufactured by Mitsui Mining and Co., Ltd.

[0336] [Semiconductor devices] Examples of semiconductor devices in which the semiconductor chip package of the present invention is to be installed include various semiconductor devices used in electrical products (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, and televisions, etc.) and vehicles (e.g., motorcycles, cars, trams, ships, and airplanes, etc.). Example

[0337] The present invention is described in detail below using examples. The present invention is not limited to these examples. It should be noted that, unless otherwise specified, "parts" and "%" indicating quantities refer to "parts by mass" and "% by mass," respectively. Unless otherwise specified, the temperature is room temperature (23°C), and the pressure is atmospheric pressure (1 atm).

[0338] The present invention is described in detail below using examples. The present invention is not limited to these examples. It should be noted that, unless otherwise specified, "parts" and "%" indicating quantities refer to "parts by mass" and "% by mass," respectively. Unless otherwise specified, the temperature is room temperature (23°C), and the pressure is atmospheric pressure (1 atm).

[0339] <Synthesis example 1> 100 parts by mass of dicyclohexylmethane-4,4'-diisocyanate (HMDI) and 0.5 parts by mass of 3-methyl-1-phenyl-2-phosphine-1-oxide as a carbodiimidization catalyst were added to a reaction vessel equipped with a reflux tube and a stirrer. The mixture was stirred and mixed at 185°C for 24 hours under a nitrogen flow to perform a carbodiimidization reaction to obtain an isocyanate-terminated polycarbodiimide. The obtained isocyanate-terminated polycarbodiimide was measured by IR spectroscopy and confirmed to have a wavelength of 2150 cm -1 The absorption peaks based on carbodiimide groups are shown on the left and right. The terminal NCO content was 8.19% by mass, and the average polymerization degree of the carbodiimide groups determined by the above-mentioned measurement method was 3.5.

[0340] Next, 8.8 parts by mass of ethylene glycol monoacrylate was added to the isocyanate-terminated polycarbodiimide at 150°C under nitrogen flow, and the mixture was heated to 180°C and stirred for 2 hours to react. IR spectroscopy was performed to confirm the presence of IR at a wavelength of 2200 to 2300 cm -1 After the absorption peak of the isocyanate group disappears, the reaction product is taken out from the reaction container and cooled to room temperature to obtain a light yellow transparent solid polycarbodiimide compound (a compound containing free radical polymerizable groups having a carbodiimide structure; the main component is the compound of the above formula (S1); b' refers to the average degree of polymerization of the carbodiimide group.). [Chemical Formula 20]

[0341] <Synthesis example 2> A solid polycarbodiimide compound (a compound having a carbodiimide structure and containing a radically polymerizable group; the main component being the compound of the above formula (S2); b' having the same meaning as above) was obtained in the same manner as in Synthesis Example 1 except that ethylene glycol monoallyl ether was used instead of ethylene glycol monoacrylate. [Chemical Formula 21]

[0342] <Synthesis example 3> A solid polycarbodiimide compound (a compound having a carbodiimide structure and containing a radically polymerizable group; the main component being the compound of the above formula (S3); b' having the same meaning as above) was obtained in the same manner as in Synthesis Example 1 except that ethylene glycol methacrylate was used instead of ethylene glycol monoacrylate. [Chemical Formula 22]

[0343] <Synthesis example 4> A solid polycarbodiimide compound (a compound having a carbodiimide structure and containing a radically polymerizable group; the main component being the compound of the above formula (S4); b' having the same meaning as above) was obtained in the same manner as in Synthesis Example 1 except that ethylene glycol monoacrylate was replaced with allyl alcohol. [Chemical Formula 23]

[0344] <Synthesis example 5> 8.8 parts by mass of ethylene glycol monoacrylate and 4 parts by mass of hydroxyl-terminated polybutadiene ("G-1000" manufactured by Nippon Soda Co., Ltd., number average molecular weight 1400, 85% or more of 1,2-addition structural unit, 15% or less of trans-1,4-addition structural unit) were added to the isocyanate-terminated polycarbodiimide obtained by the same method as in Synthesis Example 1, and the mixture was heated to 180°C and stirred for 2 hours to react. IR spectroscopy confirmed that the wavelength of the reaction was 2200 to 2300 cm -1 After the absorption peak of the isocyanate group disappears, the reaction product is taken out from the reaction vessel and cooled to room temperature to obtain a light yellow transparent solid polycarbodiimide compound (a compound containing a free radical polymerizable group having a carbodiimide structure; the main component is the compound of the above formula (S5); b' has the same meaning as above. D' refers to the average degree of polymerization of the combined units of polybutadiene and polycarbodiimide. E' refers to the average degree of polymerization of the butadiene unit equivalent to the above number average molecular weight. As the e' unit, only 1,2-addition structural units are indicated, but 1,4-addition structural units (cis, trans) are also included.). [Chemical Formula 24]

[0345] <Example 1> 25 parts of bisphenol A epoxy resin ("828US" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 180 g / eq.) and 25 parts of biphenyl epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of about 269 g / eq.) were dissolved in 50 parts of solvent naphtha while stirring and heating, and then cooled to room temperature. To this mixed solution, 270 parts of spherical silica (average particle size 0.5 μm, “SO-C2” manufactured by Yaduma Co., Ltd.) surface-treated with an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts of methacrylate butadiene styrene rubber particles (“EXL-2655” manufactured by Dow Chemical Japan Co., Ltd.), and 0.5 parts of a flame retardant having a crosslinkable functional group (“HCA-HQ-HST” manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm, phenolic hydroxyl equivalent weight of approximately 162 g / eq.) were added, and the mixture was kneaded on a triple roll mill to be uniformly dispersed. The roller dispersion was mixed with 14 parts of a phenolic curing agent containing a triazine skeleton ("LA-3018-50P" manufactured by DIC Corporation, a 1-methoxy-2-propanol solution with a hydroxyl group equivalent of about 151 g / eq. and a solid content of 50%), 40 parts of an active ester compound ("HPC-8000-65T" manufactured by DIC Corporation, a toluene solution with an active group equivalent of about 223 g / eq. and a non-volatile content of 65% by mass), 20 parts of a phenoxy resin ("YX6954BH30" manufactured by Mitsubishi Chemical Corporation, a mixed solution of MEK and cyclohexanone with a solid content of 30%), and styrene-modified polyphenylene ether resin ("OPE-2St" manufactured by Mitsubishi Gas Chemical Corporation). 15.4 parts of a polyol (aqueous mixture of 1,200 and 2,000 mmol / l) (number average molecular weight 1200, a toluene solution with a solid content of 65%), 12 parts of a compound containing a free radical polymerizable group having a carbodiimide structure (the compound obtained in Synthesis Example 1, a toluene solution with a solid content of 50%), 6 parts of a curing accelerator ("DMAP", 4-dimethylaminopyridine, a MEK solution with a solid content of 5% by mass), and 5 parts of an organic peroxide ("PERBUTYL C" manufactured by NOF Corporation, a MEK solution with a solid content of 20%) were uniformly dispersed using a high-speed rotary mixer to prepare a varnish-like resin composition.

[0346] The flame retardant having a crosslinkable functional group ("HCA-HQ-HST" manufactured by Sanko Co., Ltd.) has the following structural formula. [Chemical Formula 25]

[0347] As a support, a PET film ("Lumirror R80" manufactured by Toray Industries, Ltd., 38 μm thick) was prepared, which had been subjected to a release treatment using an alkyd resin-based release agent ("AL-5" manufactured by Lintec). A varnish-like resin composition was evenly applied to the release layer of the support so that the thickness of the resin composition layer after drying was 40 μm. The film was then dried at 80-120°C (average 100°C) for 5 minutes to produce a resin sheet having a resin composition layer thickness of 40 μm.

[0348] Separately, a resin sheet having a resin composition layer having a thickness of 80 μm after drying was prepared by the same method as the method for preparing the resin sheet having a resin composition layer having a thickness of 40 μm.

[0349] <Example 2> In Example 1, 12 parts of a compound containing a free radical polymerizing group having a carbodiimide structure (the compound obtained in Synthesis Example 1, a toluene solution with a solid content of 50%) are changed to 12 parts of a compound containing a free radical polymerizing group having a carbodiimide structure (the compound obtained in Synthesis Example 2, a toluene solution with a solid content of 50%). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0350] <Example 3> In Example 1, 12 parts of a compound containing a free radical polymerizing group having a carbodiimide structure (the compound obtained in Synthesis Example 1, a toluene solution with a solid content of 50%) are changed to 12 parts of a compound containing a free radical polymerizing group having a carbodiimide structure (the compound obtained in Synthesis Example 3, a toluene solution with a solid content of 50%). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0351] <Example 4> In Example 1, 12 parts of a compound containing a free radical polymerizing group having a carbodiimide structure (the compound obtained in Synthesis Example 1, a toluene solution with a solid content of 50%) are changed to 12 parts of a compound containing a free radical polymerizing group having a carbodiimide structure (the compound obtained in Synthesis Example 4, a toluene solution with a solid content of 50%). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0352] <Example 5> In Example 1, 12 parts of a compound containing a free radical polymerizing group having a carbodiimide structure (the compound obtained in Synthesis Example 1, a toluene solution with a solid content of 50%) are changed to 12 parts of a compound containing a free radical polymerizing group having a carbodiimide structure (the compound obtained in Synthesis Example 5, a toluene solution with a solid content of 50%). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0353] <Example 6> In Example 1, 1) The amount of the compound having a carbodiimide structure and containing a radical polymerizable group (the compound obtained in Synthesis Example 5, a toluene solution having a solid content of 50%) was changed from 12 parts to 6 parts, 2) 6 parts of a polycarbodiimide compound having no radical polymerizable group ("V-03" manufactured by Nisshinbo Chemical Co., Ltd., a toluene solution having a solid content of 50%) were further used. Except for the above matters, the same procedure as in Example 1 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0354] <Example 7> In Example 1, 1) 12 parts of the compound having a carbodiimide structure and containing a free radical polymerizable group (the compound obtained in Synthesis Example 1, a toluene solution with a solid content of 50%) were replaced with 12 parts of the compound having a carbodiimide structure and containing a free radical polymerizable group (the compound obtained in Synthesis Example 5, a toluene solution with a solid content of 50%). 2) 25 parts of a biphenyl epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent weight of approximately 269 g / eq.) were replaced with 25 parts of a naphthalene epoxy resin ("HP-4032SS" manufactured by DIC Corporation, epoxy equivalent weight of approximately 144 g / eq.). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0355] <Example 8> In Example 5, 25 parts of biphenyl epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent weight about 269 g / eq.) The amount was changed to 25 parts of a bimethylol-type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight: approximately 185 g / eq.). Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0356] <Example 9> In Example 5, 1) 14 parts of a phenolic curing agent containing a triazine skeleton ("LA-3018-50P" manufactured by DIC Corporation, hydroxyl equivalent of about 151 g / eq., 1-methoxy-2-propanol solution of 50% solid content) were not used. 2) The amount of the active ester compound ("HPC-8000-65T" manufactured by DIC Corporation, active group equivalent weight approximately 223 g / eq., 65% by mass of nonvolatile matter, toluene solution) was changed from 40 parts to 20 parts, 3) The amount of curing accelerator (DMAP, 4-dimethylaminopyridine, 5% solid content MEK solution) was changed from 6 parts to 0.4 parts, 4) 12 parts of a prepolymer of bisphenol A diisocyanate ("BA230S75" manufactured by Arxada, cyanate equivalent weight about 235 g / eq., MEK solution with a solid content of 75%) were used. 5) 5 parts of a novolac-type multifunctional cyanate ester resin ("PT30" manufactured by Arxada, cyanate equivalent weight about 124 g / eq., 80% solid content MEK solution) were used. 6) 4 parts of an organometallic catalyst ("cobalt (III) acetylacetonate" manufactured by Tokyo Chemical Industry Co., Ltd., a 1% solid content MEK solution) was used. Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0357] <Example 10> In Example 5, 15.4 parts of styrene-modified polyphenylene ether resin ("OPE-2St 1200 (number average molecular weight 1200)" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with a solid content of 65%) are replaced with 11.1 parts of bismaleimide resin ("SLK-6895-T90" manufactured by Shin-Etsu Chemical Co., Ltd., a toluene solution with a maleimide equivalent of approximately 345 g / eq. and a solid content of 90%). Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0358] <Example 11> In Example 5, 15.4 parts of styrene-modified polyphenylene ether resin ("OPE-2St 1200 (number average molecular weight 1200)" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with a solid content of 65%) are replaced with 14.3 parts of biphenyl aralkyl-type multifunctional maleimide resin ("MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., a mixed solution of MEK and toluene with a maleimide equivalent of approximately 393 g / eq. and a solid content of 70%). Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0359] <Example 12> In Example 5, 0.5 parts of a flame retardant having a crosslinkable functional group (“HCA-HQ-HST” manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm, phenolic hydroxyl equivalent of approximately 162 g / eq.) was changed to 0.5 parts of a flame retardant having a crosslinkable functional group (“FP700-TP” manufactured by Fushimi Pharmaceutical Industry Co., Ltd., a phosphorus-based flame retardant containing ethylenically unsaturated bonds, phosphorus content 0.127, ethylenically unsaturated bond equivalent 488 g / eq.). Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0360] The flame retardant having a crosslinkable functional group ("FP700-TP" manufactured by Fushimi Pharmaceutical Industry Co., Ltd.) has the following structural formula. [Chemical Formula 26]

[0361] <Example 13> In Example 5, 0.5 parts of a flame retardant having a crosslinkable functional group ("HCA-HQ-HST" manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm, phenolic hydroxyl equivalent of approximately 162 g / eq.) is changed to 0.5 parts of a flame retardant having a crosslinkable functional group ("V5" manufactured by Katayama Chemical Industry Co., Ltd., a phosphorus-based flame retardant containing ethylenically unsaturated bonds, phosphorus content 0.128, ethylenically unsaturated bond equivalent 242 g / eq.). Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0362] The flame retardant having a crosslinkable functional group ("V5" manufactured by Katayama Chemical Industry Co., Ltd.) has the following structural formula. [Chemical Formula 27]

[0363] <Example 14> In Example 5, 1) The amount of styrene-modified polyphenylene ether resin ("OPE-2St 1200 (number average molecular weight 1200)" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with a solid content of 65%) was changed from 15.4 parts to 46.2 parts. 2) The amount of bisphenol A epoxy resin ("828US" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight approximately 180 g / eq.) was changed from 25 parts to 18 parts. 3) The amount of biphenyl epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent weight approximately 269 g / eq.) was changed from 25 parts to 18 parts. 4) The amount of the active ester compound ("HPC-8000-65T" manufactured by DIC Corporation, active group equivalent weight of approximately 223 g / eq., toluene solution containing 65% by mass of nonvolatile matter) was changed from 40 parts to 30 parts. Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0364] <Example 15> In Example 5, 1) The amount of styrene-modified polyphenylene ether resin ("OPE-2St 1200 (number average molecular weight 1200)" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with a solid content of 65%) was changed from 15.4 parts to 77.9 parts. 2) The amount of bisphenol A epoxy resin ("828US" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight approximately 180 g / eq.) was changed from 25 parts to 11 parts. 3) The amount of biphenyl epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent weight approximately 269 g / eq.) was changed from 25 parts to 11 parts. 4) The amount of the active ester compound ("HPC-8000-65T" manufactured by DIC Corporation, active group equivalent weight of approximately 223 g / eq., toluene solution containing 65% by mass of nonvolatile matter) was changed from 40 parts to 20 parts. Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0365] <Example 16> In Example 5, 1) Change the amount of solvent naphtha from 50 parts to 25 parts, 2) 270 parts of spherical silica (average particle size 0.5 μm, “SO-C2” manufactured by Yaduma Co., Ltd.) surface-treated with an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) were not used. Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0366] <Example 17> In Example 5, 1) 15.4 parts of styrene-modified polyphenylene ether resin ("OPE-2St 1200 (number average molecular weight 1200)" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution having a solid content of 65%) were used without using 2) The amount of spherical silica (average particle size 0.5 μm, “SO-C2” manufactured by Yaduma Co., Ltd.) surface-treated with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) was changed from 270 parts to 250 parts. Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0367] <Example 18> In Example 17, 0.5 parts of a flame retardant having a crosslinkable functional group (“HCA-HQ-HST” manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm, phenolic hydroxyl equivalent of approximately 162 g / eq.) was changed to 0.5 parts of a flame retardant having a crosslinkable functional group (“SPH-100” manufactured by Otsuka Chemical Co., Ltd., a phosphorus-based flame retardant containing hydroxyl groups, phosphorus content 0.125, phenolic hydroxyl equivalent of approximately 249 g / eq.). Except for the above matters, the same procedure as in Example 17 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0368] <Comparative Example 1> In Example 1, 12 parts of a compound having a carbodiimide structure and containing a free radical polymerizing group (the compound obtained in Synthesis Example 1, a toluene solution with a solid content of 50%) are changed to 12 parts of a carbodiimide compound not having a free radical polymerizing group ("V-03" manufactured by Nisshinbo Chemical Co., Ltd., a toluene solution with a solid content of 50%). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0369] <Comparative Example 2> In Example 5, 0.5 parts of a flame retardant having a crosslinkable functional group ("HCA-HQ-HST" manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm, phenolic hydroxyl equivalent weight approximately 162 g / eq.) was not used. Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet.

[0370] <Comparative Example 3> In Example 5, 0.5 parts of a flame retardant having a crosslinkable functional group (“HCA-HQ-HST” manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm, phenolic hydroxyl equivalent weight of approximately 162 g / eq.) was replaced with 0.5 parts of a flame retardant not having a crosslinkable functional group (“FP-100” manufactured by Fushimi Pharmaceutical Industry Co., Ltd., phosphorus content 0.134, compound with the following structure). Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet. [Chemical Formula 28]

[0371] <Comparative Example 4> In Example 5, 0.5 parts of a flame retardant having a crosslinkable functional group ("HCA-HQ-HST" manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm, phenolic hydroxyl equivalent of approximately 162 g / eq.) was replaced with 0.5 parts of a flame retardant not having a crosslinkable functional group ("PX-200" manufactured by Daihachi Chemical Industry Co., Ltd., phosphorus content 0.09, compound of the following structure). Except for the above matters, the same procedure as in Example 5 was carried out to obtain a varnish-like resin composition and a resin sheet. [Chemical Formula 29]

[0372] <Comparative Example 5> 270 parts of spherical silica (average particle size 0.5 μm, “SO-C2” manufactured by Yaduma Co., Ltd.) surface-treated with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts of methacrylate butadiene styrene rubber particles (“EXL-2655” manufactured by Dow Chemical Japan Co., Ltd.), and a flame retardant having a crosslinkable functional group (“HCA-HQ-HST” manufactured by Sanko Co., Ltd., 10-(2,5- 0.5 parts of (1,2-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm, phenolic hydroxyl equivalent of approximately 162 g / eq.), 76.9 parts of styrene-modified polyphenylene ether resin ("OPE-2St1200 (number average molecular weight 1200)" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with a solid content of 65%), and 60 parts of solvent naphtha were kneaded on a triple roll mill to achieve uniform dispersion. The roller dispersion was mixed with 20 parts of a phenoxy resin ("YX6954BH30" manufactured by Mitsubishi Chemical Corporation, a mixed solution of MEK and cyclohexanone with a solid content of 30%), 33.3 parts of a bismaleimide resin ("SLK-6895-T90" manufactured by Shin-Etsu Chemical Co., Ltd., a maleimide equivalent of about 345 g / eq., a toluene solution with a solid content of 90%), 14.3 parts of a biphenyl aralkyl type polyfunctional maleimide resin ("MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., a maleimide equivalent of about 393 g / eq.), 12 parts of a polycarbodiimide compound (the compound obtained in Synthesis Example 5, a toluene solution with a solid content of 50%), 6 parts of a curing accelerator ("DMAP", 4-dimethylaminopyridine, a MEK solution with a solid content of 5% by mass), and 10 parts of an organic peroxide ("PERBUTYL" manufactured by NOF Corporation). C ", 20% solid content of MEK solution) 5 parts, with a high-speed rotary mixer uniformly dispersed to prepare a varnish-like resin composition. The resin sheet was prepared in the same manner as in Example 1.

[0373] <Test Example 1: Measurement of Glass Transition Temperature (Tg)> (1) Preparation of Cured Material for Evaluation The resin sheets having a 40 μm-thick dried resin composition layer prepared in Examples and Comparative Examples were heated at 200° C. for 90 minutes to thermally cure the resin composition layer, and then the support was peeled off. The resulting cured product was referred to as a “cured product for evaluation.”

[0374] (2) Determination of glass transition temperature The cured product for evaluation was cut into test pieces approximately 5 mm wide and 15 mm long. Thermomechanical analysis was performed using a thermomechanical analyzer (Rigaku Corporation, "Thermo Plus TMA8310") using the tensile loading method. The test piece was mounted in the apparatus and measured twice under the conditions of a 1 g load and a heating rate of 5°C / minute. The glass transition temperature was obtained during the second measurement.

[0375] <Test Example 2: Measurement of flame retardancy> (1) Preparation of a resin sheet having a thickness of 80 μm of the dried resin composition layer Resin sheets having a thickness of 80 μm of the dried resin composition layer prepared in Examples and Comparative Examples were prepared.

[0376] (2) Preparation of substrate A copper-clad laminate ("679FG," manufactured by Nikko-Norco) with etched copper foil (substrate thickness 0.2 mm, halogen-free core material) was heated in a 190°C oven for 30 minutes and then cooled to room temperature. Using a batch vacuum press laminator (Nikko-materials, two-stage stack laminator "CVP700"), 80 μm thick resin sheets were laminated on both sides of the substrate, with the resin composition layer in contact with the substrate. Lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, followed by pressing at 100°C and 0.74 MPa for 30 seconds.

[0377] (3) Thermal curing of the resin composition layer After laminating the resin sheets, the support was peeled off and the resin composition layer was heated at 200°C for 90 minutes to thermally cure and form an insulating layer. This produced a substrate having a layered structure of insulating layer / substrate / insulating layer. The resulting substrate having a layered structure of insulating layer / substrate / insulating layer is referred to as "Substrate A."

[0378] (4) Preparation of evaluation substrate The resulting substrate A was cut into pieces measuring 12.7 mm wide and 127 mm long. The cut surface was then polished with sandpaper (#1200) and then with sandpaper (#2800). This produced a substrate for flame retardancy testing. This substrate for flame retardancy testing is referred to as "evaluation substrate A."

[0379] (5) Evaluation of flame retardancy The obtained evaluation substrate A was subjected to a flame retardancy test (flame resistance test) in accordance with the UL94 standard. As a result of the flame retardancy test, if the evaluation substrate A continued to burn for 30 seconds or more after 10 seconds of flame exposure, it was evaluated as "×", indicating poor flame resistance. If the flame retardancy test substrate did not continue to burn for 30 seconds or more after 10 seconds of flame exposure, it was evaluated as either "V-0" or "V-1" in accordance with the UL94 standard.

[0380] <Test Example 3: Evaluation of Crack Resistance> (1) Preparation of a resin sheet having a thickness of 40 μm of the dried resin composition layer Resin sheets having a thickness of 40 μm of the dried resin composition layer prepared in Examples and Comparative Examples were prepared.

[0381] (2) Base treatment of inner layer circuit board A glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, Panasonic "R1766") with an inner layer circuit formed thereon was etched 1.0 μm on both sides using "CZ8101" manufactured by MEC Corporation to roughen the copper surface.

[0382] (3) Lamination of resin sheets The resin sheet prepared in (1) was laminated onto both sides of the inner layer circuit substrate treated in (2) using a batch vacuum press laminator (Nikko-materials, two-stage stack laminator "CVP700"), so that the resin composition layer and the inner layer circuit substrate were bonded. The lamination process was carried out by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing at 100°C and a pressure of 0.74 MPa for 30 seconds. Subsequently, hot pressing was performed at 100°C and a pressure of 0.5 MPa for 60 seconds.

[0383] (4) Curing of resin composition After the resin sheets were stacked, the resin composition layer was thermally cured at 100° C. for 30 minutes and then at 180° C. for 30 minutes to form an insulating layer. Thereafter, the support was peeled off to expose the insulating layer.

[0384] (5) Roughening treatment The inner layer circuit substrate with the insulating layer exposed was immersed in a swelling solution ("Swelling DipSecuriganth P" manufactured by Atotech Japan, an aqueous sodium hydroxide solution containing diethylene glycol monobutyl ether) at 60°C for 10 minutes, then immersed in an oxidizing agent ("Concentrate Compact CP" manufactured by Atotech Japan, an aqueous solution with a potassium permanganate concentration of about 6% by mass and a sodium hydroxide concentration of about 4% by mass) at 80°C for 20 minutes, and finally immersed in a neutralizing solution ("Reduction Solution Securiganth P" manufactured by Atotech Japan, an aqueous solution of hydroxylamine sulfate) at 40°C for 5 minutes. Then, it was dried at 80°C for 15 minutes. The resulting substrate was referred to as "evaluation substrate B".

[0385] (6) Evaluation of crack resistance According to JIS K 5600-5-6, cuts were made in a checkerboard pattern on the evaluation substrate B, and the evaluation substrate B was observed for cracks using an optical microscope. Specifically, cuts were made in a grid pattern at 1 mm intervals on the cured coating of the evaluation substrate B to form 10 coating slices in the vertical direction and 10 in the horizontal direction, for a total of 100 coating slices. Here, the coating slice represents each part of the cured coating divided by the cuts. These 100 coating slices were observed using an optical microscope, and the number of coating slices with cracks was counted. Based on the ratio of the number of coating slices with cracks to the total number of 100 coating slices, the crack resistance was evaluated according to the following evaluation criteria. ○: Almost no cracks were found on the evaluation substrate B (less than 5%) △: There are some cracks on the evaluation substrate B (5% or more and less than 15%) ×: There are many cracks on the evaluation substrate B (15% or more)

[0386] <Test Example 4: Evaluation of the Halo Phenomenon> (1) Preparation of a resin sheet having a thickness of 40 μm of the dried resin composition layer Resin sheets having a thickness of 40 μm of the dried resin composition layer prepared in Examples and Comparative Examples were prepared.

[0387] (2) Base treatment of inner layer circuit board A glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, Panasonic "R1766") with an inner layer circuit formed thereon was etched 0.5 μm on both sides using "CZ8201" manufactured by MEC to roughen the copper surface.

[0388] (3) Lamination of resin sheets The inner layer circuit board treated in step (2) was laminated on both sides using a batch vacuum press laminator (Nikko-materials, two-stage stack laminator, "CVP700") so that the resin composition layer and the inner layer circuit board were bonded. The lamination process was performed by reducing the pressure to 13 hPa or less for 30 seconds, followed by pressing at 100°C and a pressure of 0.74 MPa for 30 seconds. Subsequently, hot pressing was performed at 100°C and a pressure of 0.5 MPa for 60 seconds.

[0389] (4) Curing of the resin composition layer After the resin sheets were stacked, the resin composition layer was thermally cured at 100° C. for 30 minutes and then at 180° C. for 30 minutes to form an insulating layer.

[0390] (5) Formation of through-holes A CO2 laser processing machine ("LC-2E21B / 1C" manufactured by Via Machine Co., Ltd.) was used to form an opening in the insulating layer with a support attached under the conditions of a mask diameter of 2.0 mm, a pulse width of 6 μs at a frequency of 2000 Hz, an output power of 4 W, and a shot number of 2. The support was then peeled off to expose the insulating layer. The top diameter (diameter) of the opening in the surface of the insulating layer was 50 μm. It should be noted that the depth of the opening was determined by measuring the difference between the deepest part of the non-processed portion and the processed portion of the insulating layer from a cross-sectional observation image and calculating the difference.

[0391] (6) Roughening treatment The inner layer circuit board with the insulating layer exposed due to the through-holes was immersed in a swelling solution ("Swelling Dip Securiganth P" manufactured by Atotech Japan, an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 10 minutes. It was then immersed in an oxidizing solution ("Concentrate Compact CP" manufactured by Atotech Japan, an aqueous solution of approximately 6% potassium permanganate and approximately 4% sodium hydroxide) at 80°C for 20 minutes. Finally, it was immersed in a neutralizing solution ("Reduction Solution Securiganth P" manufactured by Atotech Japan, an aqueous solution of sulfuric acid) at 40°C for 5 minutes and then dried at 80°C for 15 minutes. This was designated "Evaluation Substrate C."

[0392] (7) Determination of through-hole diameter after decontamination treatment Cross-sectional observation of the evaluation substrate C was performed using a FIB-SEM hybrid instrument (SII Nano Technology, Inc., "SMI3050SE"). Specifically, a FIB (focused ion beam) was used to cut a vertical cross-section of the laser via hole, and the via hole diameter after desmear treatment was measured from the cross-sectional SEM image. For each sample, the via hole top diameter after desmear treatment was measured from cross-sectional SEM images of five randomly selected locations, and the average value was used as the via hole top diameter Lt (μm).

[0393] (8) Determination of halo distance after roughening treatment The evaluation substrate C was observed using an optical microscope ("KH8700" manufactured by Hirox Corporation). Specifically, an optical microscope (CCD) was used to observe the insulating layer around the through-hole from the upper part of the evaluation substrate C. The observation was performed by aligning the focus of the optical microscope on the top of the through-hole. As a result of the observation, a ring-shaped halo portion that was continuous from the edge of the through-hole top of the through-hole and in which the insulating layer was discolored to white could be seen around the through-hole. Thus, from the observed image, the radius r1 of the through-hole top of the through-hole (equivalent to the inner radius of the halo portion) and the outer radius r2 of the halo portion were measured, and the difference r2-r1 between the radius r2 and the radius r1 was calculated as the halo distance from the edge of the through-hole top at the measurement location.

[0394] The above measurement was performed on five randomly selected through-holes, and the average value of the halo distances of the five through-holes was used as the halo distance Wt (μm) from the edge of the through-hole top of the sample.

[0395] Calculate the halo ratio Ht (the ratio of the halo distance Wt from the edge of the top of the through-hole after roughening treatment to the radius of the top of the through-hole (Lt / 2) after roughening treatment (Wt / (Lt / 2)). If the halo ratio Ht is less than 35%, it is judged as "◎"; if the halo ratio Ht is greater than 35% and less than 50%, it is judged as "○"; if the halo ratio Ht is greater than 50% and less than 70%, it is judged as "△"; if the halo ratio Ht is greater than 70%, it is judged as "×".

[0396] [Table 1](Table 1) [Table 2]@Table 2@ [Table 3] (Table 3) * In the table, the content of each component indicates the content when the non-volatile component in the resin composition layer is taken as 100% by mass.

Claims

1. A resin sheet for forming an insulating layer of a semiconductor package substrate, wherein: 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) a flame retardant having a crosslinkable functional group, and (C) Thermosetting resin.

2. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein It further contains (D) an inorganic filler.

3. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein (E) A radical polymerizable group-containing compound having no carbodiimide structure is further included.

4. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein When the nonvolatile matter of the resin composition layer is 100 mass %, the content of the component (A) is 0.1 mass % or more and 15 mass % or less.

5. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein When the nonvolatile matter of the resin composition layer is 100 mass %, the content of the component (B) is 0.01 mass % or more and 3 mass % or less.

6. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 1, wherein When the nonvolatile matter of the resin composition layer is 100 mass %, the content of the component (C) is 10 mass % or more and 40 mass % or less.

7. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 2, wherein When the nonvolatile matter of the resin composition layer is 100 mass %, content of the component (D) is 45 mass % or more and 85 mass % or less.

8. The resin sheet for forming an insulating layer of a semiconductor package substrate according to claim 3, wherein When the nonvolatile matter of the resin composition layer is 100 mass %, content of the (E) component is 0.1 mass % or more and 20 mass % or less.

9. A semiconductor chip packaging substrate, wherein: A semiconductor package substrate comprising an insulating layer formed of a cured product of a resin composition layer of a resin sheet for forming an insulating layer according to any one of claims 1 to 8.

10. A semiconductor device, wherein: A semiconductor chip package substrate comprising the semiconductor chip package substrate according to claim 9.

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