Manufacturing method of resin film and printed wiring board

Abstract

This invention provides a method for manufacturing a resin sheet and a printed circuit board having a resin composition layer that provides a cured material with excellent dielectric properties, conductor adhesion, and mechanical properties. The resin sheet of this invention comprises a support and a resin composition layer disposed on the support. The resin composition layer includes (A) benzocyclobutene resin, (B) an inorganic filler, and (C) a free radical polymerizable resin. The oxygen permeability α of the resin composition layer, when cured at 220°C for 90 minutes, is 70 cc / m²·day or less. The oxygen permeability β of the resin sheet, when cured at 220°C for 90 minutes, is 40 cc / m²·day or less. Here, the oxygen permeability α and oxygen permeability β are measured according to JIS K7126-2:2006 (isobaric method) at 23°C and 0%RH.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a resin sheet and a printed wiring board. Furthermore, it relates to a printed wiring board and a semiconductor device obtained using a resin composition layer derived from the resin sheet. [Previous Technology]

[0002] As a manufacturing technology for printed circuit boards, there are known manufacturing methods that utilize an additive layering approach, where insulating layers and conductor layers are alternately overlapped. As an insulating material for the printed circuit board used in these insulating layers, there are known resin compositions, such as those described in Patent Document 1. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2005-220270 [Summary of the Invention]

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

[0005] Among the curable resins used as insulating materials, resins containing benzocyclobutene groups (hereinafter also referred to as "benzocyclobutene resins") are known. Since the benzocyclobutene group is a reactive functional group with low polarity, the cured products of benzocyclobutene resins generally have excellent dielectric properties.

[0006] However, after review, the inventors learned that the cured resin composition layer containing benzocyclobutene resin has poor adhesion to conductor materials (e.g., copper) and poor mechanical properties.

[0007] The objective of this invention is to provide a method for manufacturing a resin film comprising a resin composition layer of a cured material that exhibits excellent dielectric properties, excellent conductor adhesion, and excellent mechanical properties, and a printed circuit board. [Means for solving the objective]

[0008] As a result of active research conducted by the inventors to solve the above-mentioned problems, it was discovered that in a resin sheet having a support and a resin composition layer, the resin composition layer comprises a combination of (A) benzocyclobutene resin, (B) an inorganic filler material, and (C) a free radical polymerizable resin. Furthermore, by adjusting the oxygen permeability of the hardened resin composition layer or resin sheet to a specific value or below, the above-mentioned problems can be solved, and thus the present invention was completed.

[0009] That is, the present invention includes the following. [1] A resin sheet having a support and a resin composition layer disposed on the support, wherein the resin composition layer comprises (A) benzocyclobutene resin, (B) an inorganic filler and (C) a free radical polymerizable resin, wherein the oxygen permeability α of the resin composition layer is 70 cc / m2·day or less when cured under conditions at 220°C for 90 minutes, and the oxygen permeability β of the resin sheet is 40 cc / m2·day or less when cured under conditions at 220°C for 90 minutes, wherein the oxygen permeability α and the oxygen permeability β are measured values ​​measured at 23°C and 0%RH according to JIS K7126-2:2006 (isobaric method). [2] The resin film of [1] wherein the content of component (B) is 30% or more and 80% or less when the non-volatile component in the resin composition is set to 100% by mass. [3] The resin film of [1] or [2], wherein the content of component (A) is 3% by mass or more and 40% by mass or less when the non-volatile components in the resin composition are set to 100% by mass. [4] The resin sheet of any one of [1] to [3], wherein component (A) is a compound having two or more benzocyclobutene groups in its molecule, and the number average molecular weight (Mn) of component (A) is 2000 or less. [5] The resin sheet of any one of [1] to [4], wherein component (C) is selected from one or more of maleimide resin, (meth)acrylic resin and styrene resin. [6] The resin sheet of any one of [1] to [5], wherein the aforementioned support system is selected from a single-layer resin film, a plurality of-layer resin films, a metal foil, a release paper and a composite film comprising a support substrate and a metal foil. [7] A resin sheet of any one of [1] to [6], wherein component (A) has a siloxane backbone. [8] The resin sheet of any one of [1] to [7], wherein component (A) comprises a compound represented by the following formula (A-2), (in formula (A-2), R1 represents a divalent aliphatic group having an unsaturated bond, R2 represents a hydrogen atom, alkyl, cycloalkyl, arylalkyl or aryl, RA1 represents an alkyl, cyano or halogen atom, RA2 represents an alkyl, trialkylsilyl, alkoxy or halogen atom, nA1 represents an integer from 0 to 2, nA2 represents an integer from 0 to 3, nA4 represents an integer from 1 to 10, R1, R2, RA1 and RA2 may each independently have substituents, a plurality of R1 may be the same or different, a plurality of R2 may be the same or different, when RA1 is a plurality, they may be the same or different, when RA2 is a plurality, they may be the same or different). [9] A resin sheet of any one of [1] to [8], wherein component (A) comprises a compound represented by the following formula.

[10] A resin sheet of any one of [1] to [9], wherein the dielectric constant of the hardened portion of the aforementioned resin composition layer is 3.0 or less.

[11] A resin sheet of any one of [1] to

[10] , wherein the dielectric loss tangent of the hardened portion of the aforementioned resin composition layer is 0.0030 or less.

[12] A resin sheet of any one of [1] to

[11] , wherein the hardened portion of the aforementioned resin composition layer is exposed during the aforementioned oxygen permeability β measurement.

[13] A resin sheet of any one of [1] to

[12] is used as an insulating layer for a printed circuit board.

[14] A method for manufacturing a printed circuit board includes the following steps: (1) preparing a resin sheet having a support and a resin composition layer disposed on the support, wherein one side of the resin composition is exposed; (2) depositing the resin sheet on the substrate in such a way as to deposit the resin composition layer on the substrate of the printed circuit board; and (3) curing the resin sheet deposited on the substrate in a state in which the support does not peel off from the resin composition layer, wherein the resin composition layer comprises (A) benzocyclobutene resin, (B) inorganic filler and (C) free radical polymerizable resin, wherein the oxygen permeability α of the resin composition layer measured under conditions of 220°C for 90 minutes is 70 cc / m2·day or less, and the oxygen permeability β of the resin sheet exposed on one side of the resin composition layer measured under conditions of 220°C for 90 minutes is 40 cc / m2·day or less. Here, oxygen permeability α and oxygen permeability β are measured values ​​according to JIS K7126-2:2006 (isobaric method) at 23°C and 0%RH. [Effects of the invention].

[0010] According to the present invention, a method for manufacturing a resin sheet having a resin composition layer of a cured material with excellent dielectric properties, conductor adhesion and mechanical properties and a printed wiring board can be provided.

Implementation Method

[0011] <Terminology Explanation>

[0012] In this specification, the term "may have substituents" for a compound or base means both the case where the hydrogen atoms of the compound or base are not substituted by substituents and the case where some or all of the compound or base are substituted by substituents.

[0013] In this specification, the term "substituent" means, unless otherwise specified, a halogen atom, alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, arylalkyl, arylalkoxy, monovalent heterocyclic group, alkylene group, amino group, silyl, acetyl, acetoxy, carboxyl, sulfonyl, cyano, nitro, hydroxyl, mercapto, and oxo group.

[0014] Halogen atoms used as substituents include, for example, fluorine atoms, chlorine atoms, bromine atoms and iodine atoms.

[0015] The alkyl group used as a substituent may be either straight-chain or branched. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 14, even more preferably 1 to 12, still more preferably 1 to 6, and particularly preferably 1 to 3. Examples of such alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, dibutyl, isobutyl, tributyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl.

[0016] The cycloalkyl group used as a substituent preferably has 3 to 20 carbon atoms, more preferably 3 to 12, and even more preferably 3 to 6. Examples of such cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0017] The alkoxy group used as a substituent can be either linear or branched. The number of carbon atoms in the alkoxy group is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. Examples of such alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, dibutoxy, isobutoxy, tributoxy, pentoxy, hexoxy, heptoxy, octoxy, nonoxy, and decoxy.

[0018] The number of carbon atoms in the cycloalkoxy group used as a substituent is preferably 3 to 20, more preferably 3 to 12, and even more preferably 3 to 6. Examples of such cycloalkoxy groups include cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexoxy.

[0019] The aryl group used as a substituent is a group formed by removing one hydrogen atom from an aromatic ring of an aromatic hydrocarbon. The number of carbon atoms in the aryl group used as a substituent is preferably 6 to 24, more preferably 6 to 18, even more preferably 6 to 14, and still more preferably 6 to 10. Examples of such aryl groups include phenyl, naphthyl, and anthracene.

[0020] The number of carbon atoms in the aryloxy group used as a substituent is preferably 6 to 24, more preferably 6 to 18, even more preferably 6 to 14, and still more preferably 6 to 10. Examples of aryloxy groups used as substituents include phenoxy, 1-naphthoxy, and 2-naphthoxy.

[0021] The number of carbon atoms in the aryl alkyl group used as a substituent is preferably 7 to 25, more preferably 7 to 19, even more preferably 7 to 15, and still more preferably 7 to 11. Examples of such aryl alkyl groups are, for example, phenyl-C1 to C12 alkyl, naphthyl-C1 to C12 alkyl, and anthracene-C1 to C12 alkyl.

[0022] The number of carbon atoms of the arylalkoxy group used as a substituent is preferably 7 to 25, more preferably 7 to 19, even more preferably 7 to 15, and still more preferably 7 to 11. Examples of such arylalkoxy groups are, for example, phenyl-C1 to C12 alkoxy and naphthyl-C1 to C12 alkoxy.

[0023] A monovalent heterocyclic group used as a substituent refers to a group in which one hydrogen atom is removed from the heterocycle of a heterocyclic compound. The monovalent heterocyclic group preferably has 3 to 21 carbon atoms, more preferably 3 to 15, and even more preferably 3 to 9. The monovalent heterocyclic group also includes monovalent aromatic heterocyclic groups (heteroaryl). Examples of such monovalent heterocycles include, for example, thiopheneyl, pyrrolyl, furanyl, fyryl, pyridinyl, pyrimidinyl, pyrazinyl, triazinyl, pyrrolidinyl, piperidinyl, quinolinyl, and isoquinolinyl.

[0024] An alkylene group used as a substituent refers to a group from which two hydrogen atoms are removed from the same carbon atom of an alkane. The number of carbon atoms in an alkylene group is preferably 1 to 20, more preferably 1 to 14, even more preferably 1 to 12, still more preferably 1 to 6, and particularly preferably 1 to 3. Examples of such alkylene groups include methylene, ethylene, propylene, isopropylene, butylene, dibutylene, isobutylene, tributylene, pentylene, hexylene, heptylene, octylene, nonylene, and decylene.

[0025] The acetyl group used as a substituent refers to a group represented by the formula: -C(=O)-R (where R is an alkyl or aryl group). The alkyl group represented by R can be either linear or branched. Examples of aryl groups represented by R include phenyl, naphthyl, and anthracene. The number of carbon atoms in the acetyl group is preferably 2 to 20, more preferably 2 to 13, and even more preferably 2 to 7. Examples of acetyl groups include acetyl, propionic, butyl, isobutyl, tert-pentaylyl, and benzoyl.

[0026] The acetylation group used as a substituent refers to a group represented by the formula: -OC(=O)-R (where R is an alkyl or aryl group). The alkyl group represented by R can be either linear or branched. Examples of aryl groups represented by R include phenyl, naphthyl, and anthracene. The number of carbon atoms in the acetylation group is preferably 2 to 20, more preferably 2 to 13, and even more preferably 2 to 7. Examples of acetylation groups include ethoxy, propoxy, butoxy, isobutoxy, pentaacetoxy, and benzoyloxy.

[0027] The above-mentioned substituent may further have substituents (hereinafter sometimes referred to as "secondary substituents"). As secondary substituents, the same substituents as those described above may be used unless otherwise specified.

[0028] In this specification, the term "aromatic ring" refers to a ring that conforms to Hückel's law and contains 4n+2 electrons (n ​​is a natural number) in its π-electron system. This includes monocyclic aromatic rings and condensed aromatic rings formed by the condensation of two or more monocyclic aromatic rings. Aromatic rings can be carbon rings or heterocyclic rings. Examples of aromatic rings include monocyclic aromatic rings such as benzene rings, furan rings, thiophene rings, pyrrole rings, pyrazole rings, oxazole rings, isoxazole rings, thiazole rings, imidazole rings, pyridine rings, pyrazine rings, pyrimidine rings, and darazine rings; condensation rings formed by the condensation of two or more monocyclic aromatic rings such as naphthyl rings, anthracene rings, benzofuran rings, isobenzofuran rings, indole rings, isoindole rings, benzothiophene rings, benzimidazole rings, imidazole rings, benzoxazole rings, benzoisoxazole rings, benzothiazole rings, quinoline rings, isoquinoline rings, quinoxoline rings, acridine rings, quinazoline rings, borazolin rings, and pteridine rings; and condensation rings formed by the condensation of one or more monocyclic aromatic rings with one or more monocyclic non-aromatic rings, such as indanium rings, fumonisin rings, and tetrahydronaphthyl rings.

[0029] In this specification, the term "non-aromatic ring" refers to a ring other than an aromatic ring, including monocyclic non-aromatic rings and condensed non-aromatic rings formed by the condensation of two or more monocyclic non-aromatic rings. The non-aromatic ring can be a carbocyclic ring or a heterocyclic ring. The non-aromatic ring can be a saturated ring or an unsaturated ring. Examples of non-aromatic rings include, for example, cycloalkanes; cycloalkenes; monocyclic non-aromatic heterocycles such as pyrrolidine rings, tetrahydrofuran rings, dioxane rings, and tetrahydropyran rings (preferably 3 to 10 members); and condensed non-aromatic carbocyclic rings of two or more rings such as norbornene rings, decahydronaphthalene rings, adamantane rings, and tetrahydrodicyclopentadiene rings (preferably 8 to 15 members).

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments and examples, and can be arbitrarily modified without departing from the scope of the claims and their equivalents.

[0031] [Resin Sheet] The resin sheet of the present invention comprises a support and a resin composition layer disposed on the support, the resin composition layer comprising (A) benzocyclobutene resin, (B) an inorganic filler, and (C) a free radical polymerizable resin. The oxygen permeability α of the resin composition layer in the resin sheet of the present invention, measured under conditions of 220°C for 90 minutes of curing, is 70 cc / m²·day or less, and the oxygen permeability β of the resin sheet, measured under conditions of 220°C for 90 minutes of curing, is 40 cc / m²·day or less. Here, the oxygen permeability α and oxygen permeability β are measured according to JIS K7126-2:2006 (isobaric method) at 23°C and 0%RH.

[0032] Benzocyclobutene resin is heated to produce an isomer diene (o-quinone dimethane), which is then cured by a Diels-Alder type cyclization addition reaction. Since the curing reaction does not produce highly polar functional groups such as hydroxyl groups, benzocyclobutene resin is expected to produce cured products with excellent dielectric properties. However, according to the inventors' research, it has been found that resin compositions containing benzocyclobutene resin exhibit poor conductor adhesion and mechanical properties after curing (insulating layer). Regarding the above-mentioned reaction of benzocyclobutene resin, in addition to requiring high temperatures, its reactivity is lacking in the presence of oxygen, thus it is presumed to be affected by thermal history and difficulty in obtaining the desired crosslinking properties or degree of crosslinking. In contrast, according to the resin sheet of the present invention, which contains benzocyclobutene resin in combination with inorganic fillers and free radical polymerizable resin, and whose oxygen permeability as a resin composition layer or as a resin sheet is within a specific range after curing, cured products with excellent conductor adhesion and mechanical properties can be obtained. Furthermore, based on the resin sheet of the present invention that satisfies the aforementioned specific composition and oxygen permeability conditions, a cured material with improved dielectric properties such as dielectric constant and dielectric loss tangent can be obtained. In addition, the inventors have found that the insulation performance is also improved with the resin sheet of the present invention. Therefore, the present invention achieves a cured material that retains or even enhances the excellent dielectric properties inherent in benzocyclobutene resin, while also exhibiting good insulation properties, such as conductor adhesion and mechanical properties, making a significant contribution to the requirements of today's high-speed transmission.

[0033] As described above, the resin sheet of the present invention is characterized by having a support and a resin composition layer disposed on the support. The resin composition layer comprises (A) benzocyclobutene resin, (B) inorganic filler and (C) free radical polymerizable resin. After curing, the oxygen permeability α of the resin composition layer and the oxygen permeability β of the resin sheet are within a specific range.

[0034] Details of the support and resin composition layers will be described later. First, we will explain the oxygen permeability α and β.

[0035] -Oxygen permeability α- Oxygen permeability α refers to the oxygen permeability of the cured resin composition layer. The oxygen permeability α of the resin composition layer of the resin sheet of the present invention, measured under curing conditions of 220°C and 90 minutes, is less than 70 cc / m2·day.

[0036] Based on the viewpoint of obtaining a cured material exhibiting excellent dielectric properties, excellent conductor adhesion, and excellent mechanical properties, the oxygen permeability α is preferably 68 cc / m²·day or less, more preferably 66 cc / m²·day or less, or 65 cc / m²·day or less. The lower limit of the oxygen permeability α is not particularly limited, but it is generally 1 cc / m²·day or more, 5 cc / m²·day or more, 10 cc / m²·day or more, etc.

[0037] The oxygen permeability α can be measured according to the steps described in the "Determination of Oxygen Permeability" section below, and is measured on the resin composition layer exposed on both main surfaces after curing at 220°C for 90 minutes. Therefore, when measuring the oxygen permeability α, both surfaces of the cured resin composition layer are exposed. Furthermore, the oxygen permeability α can be adjusted by changing the composition and thickness of the resin composition layer. It is preferable to cure the resin composition layer together with the support.

[0038] -Oxygen permeability β- Oxygen permeability β relates to the oxygen permeability of the cured resin sheet. The oxygen permeability β of the resin sheet of the present invention, measured under conditions of 220°C and 90 minutes of curing, is less than 40 cc / m2·day.

[0039] Based on the viewpoint of obtaining a hardened material exhibiting excellent dielectric properties, conductor adhesion, and mechanical properties, the oxygen permeability β is preferably 38 cc / m²·day or less, more preferably 36 cc / m²·day or less, 35 cc / m²·day or less, 34 cc / m²·day or less, 32 cc / m²·day or less, or 30 cc / m²·day or less. The lower limit of the oxygen permeability β is not particularly limited and may be 0 cc / m²·day.

[0040] The oxygen permeability β can be measured according to the steps described in the "Determination of Oxygen Permeability" section below, after curing at 220°C for 90 minutes on a resin sheet. When measuring the oxygen permeability β on a resin sheet with a protective film, the measurement is performed on a resin sheet with one side of the resin composition layer (cured material) exposed after the protective film is peeled off. Therefore, when measuring the oxygen permeability β, the cured side of the resin composition layer is exposed. The oxygen permeability β can be adjusted by changing the composition and thickness of the resin composition layer, the composition, type, and thickness of the support, etc.

[0041] Based on the viewpoint of obtaining a cured material exhibiting excellent dielectric properties as well as excellent conductor adhesion and mechanical properties, it is important that both oxygen permeability α and β satisfy the above conditions. Even if only one of oxygen permeability α and β satisfies the above conditions, the effects of the present invention cannot be obtained.

[0042] Hereinafter, the support, resin composition layer and the like used in the resin sheet of the present invention will be described.

[0043] <Support> The support is not particularly limited as long as the oxygen permeability β condition is achieved in combination with the resin composition layers described below. The support is preferably selected from, for example, a single-layer resin film, multiple-layer resin films, metal foil, release paper, and composite films including a support substrate and a metal foil.

[0044] Examples of single-layer resin films include single-layer films made of plastic materials. Examples of plastic materials include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetin cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide.

[0045] An example of a multilayer resin film is a multilayer film obtained by integrally overlapping one or more of the single-layer resin films described above. Other materials may be interposed between the two overlapping single-layer resin films in the multilayer resin film. Examples of such interposed materials include inorganic fillers, deoxidizers, desiccants, and ultraviolet absorbers.

[0046] Examples of metal foils include copper foil and aluminum foil. Copper foil can be made of copper as a single metal or an alloy of copper with other metals (such as tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0047] In the composite film comprising a supporting substrate and a metal foil, the supporting substrate is not particularly limited, as long as it can support the metal foil, for example, a resin film, a metal film, etc. As for the resin film used as the supporting substrate, examples include the aforementioned single-layer or multi-layer resin films, and as for the metal film used as the supporting substrate, examples include films made of metals such as copper, aluminum, stainless steel, titanium, and copper alloys. Furthermore, in the composite film, the material used for the metal foil is preferably, for example, copper foil or copper alloy foil. The composite film may include a release layer between the supporting substrate and the metal foil. The release layer is not particularly limited as long as it can peel the metal foil from the supporting substrate, for example, an alloy layer selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, and P; an organic coating film, etc. In the resin sheet of the present invention, when the composite film is used as the support, the resin composition layer can be disposed on the metal foil or on the supporting substrate. When the resin composition layer is disposed on the metal foil, it is advantageous because the metal foil can be used to form a conductor layer. In composite films, the exposed surface of the metal foil is also better roughened to ensure good fixation of the hardened resin composition layer formed on it.

[0048] The support may also be treated with a matte finish, corona treatment, or antistatic treatment on one or both sides. These treated surfaces are usually formed on the surfaces that are bonded to the resin composition layers.

[0049] The support may also have a release layer on one or both sides. Examples of release agents used in the release layer include one or more selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available products can be used for the support with the release layer, such as LINTEC's "SK-1", "AL-5", and "AL-7", Toray Industries' "LUMIRROR T60", Teijin Corporation's "PUREX", and UNITIKA Corporation's "UNIPEEL", which have a release layer of PET film with an alkyd resin-based release agent as the main component.

[0050] The thickness of the support is not particularly limited as long as it meets the oxygen permeability β condition described above in combination with the resin composition layers. Appropriate thickness varies depending on the type of support, but preferably 5 μm or more, more preferably 8 μm or more, 10 μm or more, 12 μm or more, 14 μm or more, or 15 μm or more, and even more preferably 20 μm or more, 25 μm or more, 30 μm or more, or 35 μm or more. The upper limit is preferably 150 μm or less, more preferably 140 μm or less, 120 μm or less, 100 μm or less, or 80 μm or less. Furthermore, when using a support with an attached release layer, the total thickness of the support with the release layer is preferably within the above-mentioned range.

[0051] <Resin Composition Layer> In the resin sheet of the present invention, the resin composition layer includes (A) benzocyclobutene resin, (B) inorganic filler and (C) free radical polymerizable resin.

[0052] As mentioned above, the resin sheet of the present invention can achieve a hardened material with excellent dielectric properties, conductor adhesion and mechanical properties by making the resin composition layer combination contain (A) benzocyclobutene resin, (B) inorganic filler and (C) free radical polymerizable resin, and satisfying the above conditions of oxygen permeability α and β.

[0053] The following describes the resin composition that constitutes the resin composition layer.

[0054] The resin composition constituting the resin composition layer includes (A) benzocyclobutene resin, (B) inorganic filler, and (C) free radical polymerizable resin. The resin composition may further include one or more components selected from (D) thermoplastic resin, (E) curing accelerator, epoxy resin, epoxy resin curing agent, other additives, or organic solvents.

[0055] -(A) Benzocyclobutene resin- In this invention, the resin composition includes benzocyclobutene resin as component (A). This allows for the acquisition of a cured material (insulating layer) with excellent dielectric properties. Component (A) can be used alone or in combination of two or more.

[0056] Component (A) is not particularly limited as long as it contains a benzocyclobutenyl group that can generate an isomerized diene by heating. When combined with components (B) and (C) described below, from the viewpoint of obtaining a cured product with excellent dielectric properties, conductor adhesion, and mechanical properties, component (A) preferably contains a compound having two or more benzocyclobutenyl groups in its molecule. Furthermore, in the combination of component (A) with components (B) and (C) described below, from the viewpoint of obtaining a cured product with excellent dielectric properties, conductor adhesion, and mechanical properties, component (A) preferably has unsaturated groups other than benzocyclobutenyl groups.

[0057] In one embodiment, component (A) comprises a compound represented by the following formula (A-1).

[0058]

[0059] In formula (A-1), R1 represents a divalent aliphatic group with an unsaturated bond, L represents a single bond or a divalent linkage group, RA1 represents an alkyl, cyano or halogen atom, RA2 represents an alkyl, trialkylsilyl, alkoxy or halogen atom, nA1 represents an integer from 0 to 2, nA2 represents an integer from 0 to 3, nA3 represents 0 or 1, R1, RA1 and RA2 can each independently have substituents, multiple R1s can be the same or different, when RA1 is multiple, they can be the same or different, when RA2 is multiple, they can be the same or different, multiple nA1s can be the same or different, multiple nA2s can be the same or different.

[0060] The divalent group represented by R1 preferably has 1 to 3 unsaturated bonds, more preferably 1 or 2, and even more preferably 1. The unsaturated bonds can be double or triple bonds, but are preferably double bonds. The divalent group represented by R1 is preferably alkenyl or alkyl. The number of carbon atoms in the divalent group represented by R1 is preferably 2 to 10, more preferably 2 to 6 or 2 to 4. The above number of carbon atoms does not include the number of carbon atoms in the substituents.

[0061] As the divalent linker represented by L, it is not particularly limited if it is a divalent group formed by one or more (e.g., 1 to 3000, 1 to 1000, 1 to 100, 1 to 50) skeletal atoms selected from carbon, oxygen, nitrogen, sulfur, and silicon atoms. For example, it can be a divalent group formed by one or more (e.g., 1 to 3000, 1 to 1000, 1 to 100, 1 to 50) skeletal atoms selected from carbon, oxygen, nitrogen, and sulfur atoms, or it can be a siloxane skeleton. Preferably, L is a siloxane skeleton. Therefore, in one embodiment, component (A) has a siloxane skeleton.

[0062] The alkyl group represented by RA1 preferably has 1 to 10 carbon atoms, 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 of the substituents. The halogen atom represented by RA1 is preferably a chlorine atom or a bromine atom.

[0063] The number of carbon atoms in the alkyl and alkoxy groups represented by RA2 is preferably 1 to 10, more preferably 1 to 6, 1 to 4, or 1 to 3. The number of carbon atoms in the alkyl portion of the trialkylsilyl group represented by RA2 is preferably 1 to 3, more preferably 1 or 2. The above-mentioned number of carbon atoms does not include the number of carbon atoms in the substituents. Furthermore, the halogen atom represented by RA2 is preferably a chlorine atom or a bromine atom.

[0064] In the combination with components (B) and (C) described below, based on the viewpoint of obtaining a hardened material with maintained or improved dielectric properties, and based on the viewpoint of obtaining a hardened material with excellent conductor adhesion and mechanical properties, in formula (A-1), nA3 is preferably 1, and L is preferably a siloxane skeleton.

[0065] In a preferred embodiment, component (A) comprises a compound represented by the following formula (A-2).

[0066]

[0067] In formula (A-2), R1, RA1, RA2, nA1, and nA2 are as described in formula (A-1), R2 represents a hydrogen atom, alkyl, cycloalkyl, arylalkyl, or aryl group, and nA4 represents an integer from 1 to 10. R2 may have substituents. Multiple R2s may be the same or different.

[0068] The alkyl group represented by R2 preferably has 1 to 10 carbon atoms, more preferably 1 to 6, 1 to 4, or 1 to 3. The cycloalkyl group represented by R2 preferably has 3 to 10 carbon atoms, more preferably 4 to 6. The arylalkyl group represented by R2 preferably has 7 to 20 carbon atoms, more preferably 7 to 15 or 7 to 12. The aryl portion of the arylalkyl group is preferably phenyl. The aryl group represented by R2 preferably has 6 to 14 carbon atoms, more preferably 6 to 10. The aryl group is preferably phenyl. The above carbon atom numbers do not include the carbon atom numbers of substituents.

[0069] R1, RA1, RA2, nA1 and nA2 are as described in formula (A-1), wherein preferably R1 is an alkenyl group having 2 to 4 carbon atoms, and nA1 and nA2 are 0.

[0070] In a preferred embodiment, component (A) comprises a compound represented by the following formula (A-3).

[0071]

[0072] In formula (A-3), R2 and nA4 are as explained in formula (A-2).

[0073] Component (A) can be prepared according to the procedures described in, for example, U.S. Patent No. 4,812,588 and U.S. Patent No. 5,138,081. Furthermore, commercially available products can be used as component (A), for example, the CYCLOTENE (registered trademark) series manufactured by Dow Chemical Company, as a compound represented by formula (A-3). Based on the view that the oxygen permeability after curing is limited to below the aforementioned specific value, the 3000 series of dry-etching CYCLOTENE (registered trademark) is preferred among the CYCLOTENE (registered trademark) series. The non-volatile components contained in "CYCLOTENE (registered trademark) 3022" manufactured by Dow Chemical Company are expressed by the following formula.

[0074]

[0075] As mentioned above, the benzocyclobutenyl group produces an isomer diene, which triggers a Diels-Alder type cyclization addition reaction. Therefore, component (A) can be a compound (monomer) represented by the above formulas (A-1) to (A-3), or a dimer or polymer produced by the addition reaction of the compound, or a mixture thereof.

[0076] The weight average molecular weight (Mw) or number average molecular weight (Mn) of component (A) is not particularly limited as long as it can exert the effects of the present invention when combined with components (B) and (C) described below. In one embodiment, Mn is preferably 2000 or less, more preferably 1800 or less, and even more preferably 1600 or less, 1500 or less, 1400 or less, 1200 or less, or 1000 or less. In one embodiment, Mw is also within the above-mentioned preferred range. The lower limit of this molecular weight is not particularly limited, for example, it can be set to 250 or more, 300 or more, 350 or more, etc. The Mw or Mn of component (A) is determined by gel permeation chromatography (GPC) using values ​​converted to polystyrene. Therefore, in a preferred embodiment, component (A) comprises a compound having two or more benzocyclobutenyl groups in its molecule, and the number average molecular weight (Mn) of component (A) is 2000 or less.

[0077] The content of component (A) in the resin composition, based on the viewpoint of achieving a cured product with maintained or improved dielectric properties, is preferably 3% or more, 4% or more, 5% or more, or 7% or more when the non-volatile component in the resin composition is set to 100% by mass. There is no particular limitation on the upper limit of the content of component (A). Based on the viewpoint of obtaining a cured product with oxygen permeability within the above-mentioned range, it is preferably 40% or less, 35% or less, 30% or less, or 25% or less. Therefore, in a preferred embodiment, the content of component (A), when the non-volatile component in the resin composition is set to 100% by mass, is 3% or more and 40% or less by mass.

[0078] The content of component (A) in the resin composition, based on the viewpoint of achieving a cured product with maintained or improved dielectric properties, is preferably 6% or more, 8% or more, 10% or more, or 14% or more when the resin component in the resin composition is set to 100% by mass. The resin component in the resin composition refers to the component other than the inorganic filler (B) among the non-volatile components in the resin composition. There is no particular upper limit to the content of component (A), but for example, it is 90% or less. Based on the viewpoint of obtaining a cured product with low oxygen permeability, it is preferably 80% or less or 70% or less. Therefore, in a preferred embodiment, the content of component (A), when the resin component in the resin composition is set to 100% by mass, is 6% or more and 80% or less by mass.

[0079] -(B) Inorganic filler- In this invention, the resin composition includes an inorganic filler as component (B).

[0080] The present invention relates to a resin composition in which, in addition to component (A) described above, component (B) and component (C) described below are combined, and as described above, the resin composition layer and resin sheet satisfy both of the oxygen permeability α and β conditions, thereby achieving a cured product with excellent dielectric properties, conductor adhesion and mechanical properties. Furthermore, by including component (B) in the resin composition, a cured product with excellent thermal properties (e.g., coefficient of linear thermal expansion) can be obtained.

[0081] Examples of component (B) include, for example, silicon oxide, 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 titanate, barium zirconate, calcium zirconium phosphate, and zirconium tungstate phosphate. Among these, silicon oxide is particularly preferred. Examples of silicon oxide include, for example, amorphous silicon oxide, molten silicon oxide, crystalline silicon oxide, synthetic silicon oxide, and hollow silicon oxide. Spherical silicon oxide is preferred as the silicon oxide. Component (B) may be used alone or in combination of two or more.

[0082] Commercially available products as component (B) include, for example, “UFP-30” manufactured by Denka Chemical Industries, Ltd.; “SP60-05” and “SP507-05” manufactured by Nippon Steel Chemical & Materials Co., Ltd.; “YC100C”, “YA050C”, “YA050C-MJE”, and “YA010C” manufactured by ADMATECHS Co., Ltd.; “UFP-30” manufactured by DENKA Co., Ltd.; “SILFILL NSS-3N”, “SILFILL NSS-4N”, and “SILFILL NSS-5N” manufactured by Tokuyama Co., Ltd.; “SC2500SQ”, “SO-C4”, “SO-C2”, and “SO-C1” manufactured by ADMATECHS Co., Ltd.; and “DAW-30” and “FB-105FD” manufactured by DENKA Co., Ltd.

[0083] (B) The average particle size of the component is not particularly limited, but it is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less. The lower limit of the average particle size is not particularly limited, but it is preferably 0.01 μm or more, more preferably 0.05 μm or more, and even more preferably 0.07 μm or more, 0.1 μm or more, or 0.2 μm or more. The average particle size of the component (B) can be determined based on the Mie scattering theory using laser diffraction. Specifically, a laser diffraction particle size distribution measuring device can be used to prepare the particle size distribution of the inorganic filler based on volume, and the median diameter can be used as the average particle size for measurement. The sample for measurement can be prepared by measuring 100 mg of inorganic filler and 10 g of methyl ethyl ketone into an ampoule and dispersing it ultrasonically for 10 minutes. The sample was measured using a laser diffraction particle size distribution measuring device. The light source wavelength was set to blue and red, and the particle size distribution of the inorganic filler was measured in a flow cell manner based on a volume reference. The average particle size was calculated from the obtained particle size distribution as the median diameter. An example of a laser diffraction particle size distribution measuring device is the "LA-960" manufactured by Horiba Manufacturing Co., Ltd.

[0084] The specific surface area of ​​component (B) is not particularly limited, but is preferably 0.1 m² / g or more, more preferably 0.5 m² / g or more, and even more preferably 1 m² / g or more, 3 m² / g or more, or 5 m² / g or more. The upper limit of this specific surface area is not particularly limited, but is preferably 100 m² / g or less, more preferably 80 m² / g or less, and even more preferably 60 m² / g or less, 50 m² / g or less, or 40 m² / g or less. The specific surface area of ​​component (B) can be obtained by using the BET method, employing a specific surface area measuring device (Macsorb HM-1210 manufactured by Mauntech Co., Ltd.) to adsorb nitrogen onto the sample surface, and calculating the specific surface area using the BET multi-point method.

[0085] (B) Component is preferably surface-treated with a suitable surface treatment agent. Surface treatment improves the moisture resistance and dispersibility of component (B). Examples of surface treatment agents include silane coupling agents such as vinyl silane coupling agents, epoxy silane coupling agents, styrene silane coupling agents, (meth)acrylic acid silane coupling agents, amino silane coupling agents, isocyanurate silane coupling agents, urea silane coupling agents, thiol silane coupling agents, isocyanate silane coupling agents, and anhydride silane coupling agents; non-silane coupling-alkoxy silane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane; and silazane compounds. One surface treatment agent may be used alone, or two or more may be used in combination.

[0086] Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., and "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0087] The degree of surface treatment using the surface treatment agent is preferably limited to a specific range, based on the viewpoint of improving the dispersibility of inorganic fillers. Specifically, 100% by mass of the inorganic filler is preferably surface treated with 0.2 to 5% by mass of the surface treatment agent.

[0088] The degree of surface treatment using the surface treatment agent can be evaluated by the carbon content per unit surface area of ​​the inorganic filler. Based on the viewpoint of improving the dispersibility of the inorganic filler, the carbon content per unit surface area of ​​the inorganic filler is preferably 0.02 mg / m² or more, more preferably 0.1 mg / m² or more, and even more preferably 0.2 mg / m² or more. On the other hand, based on the viewpoint of preventing an increase in the melt viscosity of the resin composition and the melt viscosity of the flake morphology, it is preferably 1.0 mg / m² or less, more preferably 0.8 mg / m² or less, and even more preferably 0.5 mg / m² or less. (B) The carbon content per unit surface area of ​​the component can be determined by washing the surface-treated inorganic filler with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the surface-treated inorganic filler, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solids, the carbon content per unit surface area of ​​the inorganic filler is determined using a carbon analyzer. For example, the "EMIA-320V" manufactured by Horiba Seisakusho Co., Ltd. can be used as the carbon analyzer.

[0089] The content of component (B) in the resin composition, based on the viewpoint of obtaining a cured product with excellent dielectric properties, conductor adhesion, and mechanical properties, is preferably 30% by mass or more, and more preferably 35% by mass or more, when the non-volatile component in the resin composition is set to 100% by mass. There is no particular upper limit to the content of component (B), but it is preferably 80% by mass or less, and more preferably 75% by mass or less. Therefore, in a preferred embodiment, the content of component (B), when the non-volatile component in the resin composition is set to 100% by mass, is 30% by mass or more and 80% by mass or less.

[0090] From the viewpoint that the effects of the present invention can be enjoyed more significantly, the ratio of component (B) to component (A), i.e., the mass ratio of component (B) to component (A), is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2.0 or more when converted to non-volatile components. There is no particular limitation on the upper limit of the mass ratio, and it may be, for example, 50 or less, 40 or less, or 30 or less.

[0091] Based on the viewpoint that the effects of the present invention can be enjoyed more significantly, the ratio of component (B) to components (A) and (C), i.e., the mass ratio of component (B) / {(A) + (C)}, is preferably 0.5 or more when converted to non-volatile components. There is no particular upper limit to the mass ratio, for example, it can be 25 or less.

[0092] -(C) Free Radical Polymerizing Resin- In this invention, the resin composition includes a free radical polymerizing resin as component (C). However, component (C) does not have a benzocyclobutene group, unlike component (A). That is, component (C) is not equivalent to component (A).

[0093] The resin composition of the present invention, in addition to the above-mentioned component (A), also combines the above-mentioned component (C) and component (B), and the above-mentioned resin composition layer and resin sheet satisfy the above-mentioned conditions of oxygen permeability α and β, thereby achieving a hardened material with excellent dielectric properties, conductor adhesion and mechanical properties.

[0094] (C) Component has a free radical polymerizable unsaturated group in the molecule. Component (C) can be used alone or in combination of two or more.

[0095] As for component (C), it is not particularly limited as long as the molecule has a free radical polymerizable unsaturated group. In combination with components (A) and (B), based on the viewpoint of obtaining a hardened material with excellent dielectric properties, conductor adhesion and mechanical properties, component (C) preferably includes a compound having one or more free radical polymerizable unsaturated groups selected from vinyl, allyl, styrene, vinylphenyl, acrylonitrile and methacryl, maleimino, fumarate and maleyl. More preferably, it includes a compound containing one or more compounds selected from allyl, styrene, vinylphenyl, acrylonitrile and methacryl.

[0096] Therefore, component (C) is preferably selected from at least one of maleimide resin, styrene resin, (meth)acrylic resin, allyl resin and butadiene resin, more preferably selected from one or more of maleimide resin, (meth)acrylic resin and styrene resin, and even more preferably any one of maleimide resin and styrene resin.

[0097] (C) The composition is preferably a compound containing two or more free radical polymerizable unsaturated groups in the molecule. There is no particular limit on the upper limit, and it can be set to 10 or less, etc.

[0098] The maleimide resin molecule contains a maleimide group represented by the following formula (C-1).

[0099] The number of maleimide moles in each molecule of maleimide resin is preferably 2 or more, more preferably 3 or more, more preferably 10 or less, more preferably 6 or less, and even more preferably 3 or less, based on the viewpoint of significantly obtaining the expected effects of the present invention.

[0100] Maleimine resin, based on the viewpoint of significantly obtaining the expected effects of the present invention, preferably has either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, more preferably has both an aliphatic hydrocarbon group and an aromatic hydrocarbon group.

[0101] As an aliphatic hydrocarbon group, it is preferably a divalent aliphatic hydrocarbon group, more preferably a divalent saturated aliphatic hydrocarbon group, and even more preferably an alkyl group. As an alkyl group, it is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, even more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

[0102] The aromatic hydrocarbon group is preferably a monovalent or divalent aromatic hydrocarbon group, more preferably an aryl or an aryl group. As an aryl group, it is preferably an aryl group with 6 to 30 carbon atoms, more preferably an aryl group with 6 to 20 carbon atoms, and even more preferably an aryl group with 6 to 10 carbon atoms. Examples of such aryl groups include, for example, phenyl, naphthyl, anthraceneyl, aralkyl, biphenyl, biphenylaralkyl, etc., among which phenyl, aralkyl, biphenyl, and biphenylaralkyl are preferred, and phenyl, aralkyl, and biphenyl are even more preferred. As an aryl group, it is preferably an aryl group with 6 to 30 carbon atoms, more preferably an aryl group with 6 to 20 carbon atoms, and even more preferably an aryl group with 6 to 10 carbon atoms, and particularly preferably a phenyl group.

[0103] In maleimide resins, from the viewpoint of significantly achieving the intended effects of the present invention, the nitrogen atom of the maleimide group is preferably directly bonded to a monovalent or divalent aromatic hydrocarbon group. Here, "directly" means that there are no other groups between the nitrogen atom of the maleimide group and the aromatic hydrocarbon group.

[0104] Maleimide resin preferably includes, for example, a compound represented by the following formula (C-2).

[0105] In formula (C-2), R31 and R36 represent maleimine groups, R32, R33, R34 and R35 independently represent hydrogen atoms, alkyl groups or aryl groups, and D independently represents divalent aromatic hydrocarbon groups. m1 and m2 independently represent integers from 1 to 10, and a represents integers from 1 to 100.

[0106] In formula (C-2), R32, R33, R34 and R35 each independently represent a hydrogen atom, an alkyl group or an aryl group, preferably a hydrogen atom.

[0107] The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably an alkyl group having 1 to 3 carbon atoms. The alkyl group can be straight-chain, branched, or cyclic. Examples of such alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, etc.

[0108] The aryl group is preferably an aryl group with 6 to 20 carbon atoms, more preferably an aryl group with 6 to 15 carbon atoms, and even more preferably an aryl group with 6 to 10 carbon atoms. The aryl group can be a monocyclic ring or a condensed ring. Examples of such aryl groups include phenyl, naphthyl, anthracene, etc.

[0109] Alkyl and aryl groups may have substituents. There are no particular limitations on the substituents; any of the aforementioned types are acceptable, but examples include halogen atoms, -OH, -O-C1-6 alkyl, -N(C1-10 alkyl)2, C1-10 alkyl, C6-10 aryl, -NH2, -CN, -C(O)O-C1-10 alkyl, -COOH, -C(O)H, -NO2, etc. Here, the term "Cp-q" (where p and q are positive integers, satisfying p < q) indicates that the number of carbon atoms in the organogroup immediately following the term is p to q. For example, "C1-10 alkyl" indicates an alkyl group with 1 to 10 carbon atoms. These substituents can bond together to form rings, including spirocyclic and condensed ring structures.

[0110] In formula (C-2), D represents a divalent aromatic group. Examples of divalent aromatic groups include, for example, pentylene, pentylenaphthalene, pentylethracene, aralkyl, pentylene-biphenyl, and biphenylaralkyl, with pentylene-biphenyl and biphenylaralkyl being preferred, and pentylene-biphenyl being even more preferred. The divalent aromatic group may have substituents. The substituents are the same as those that may be present on the alkyl group represented by R32 in formula (C-2).

[0111] m1 and m2 represent integers from 1 to 10, preferably from 1 to 6, even more preferably from 1 to 3, even more preferably from 1 to 2, and even more preferably from 1.

[0112] a represents an integer from 1 to 100, preferably from 1 to 50, more preferably from 1 to 20, and even more preferably from 1 to 5.

[0113] The maleimide resin preferably comprises a compound represented by formula (C-3). In formula (C-3), R37 and R38 represent maleimide groups. a1 represents an integer from 1 to 100.

[0114] a1 is the same as a in formula (C-2), and the preferred range is also the same.

[0115] Maleimine resin can be commercially available. Examples of commercially available products include "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd.

[0116] Maleimide resin preferably comprises a compound containing at least one of an alkyl group having 5 or more carbon atoms and an enyl group having 5 or more carbon atoms.

[0117] The alkyl group having 5 or more carbon atoms preferably has 6 or more carbon atoms, more preferably 8 or more, more preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. The alkyl group can be linear, branched, or cyclic, with linear being preferred. Examples of such alkyl groups include pentyl, hexyl, heptyl, octyl, nonyl, and decyl. The alkyl group having 5 or more carbon atoms may have an alkyl group having 5 or more carbon atoms as a substituent. The alkyl group having 5 or more carbon atoms may be an alkenyl group or a polyalkenyl group (preferably with 2 double bonds).

[0118] The carbon number of the alkyl group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, more preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. The alkyl group can be linear, branched, or cyclic, with linear being preferred. Here, the term "cyclic alkyl group" includes cases consisting solely of cyclic alkyl groups and cases including both linear and cyclic alkyl groups. Examples of such alkyl groups include, for instance, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, heptadecanyl, hexadecyl, octyl, octylcyclohexyl, octylcyclohexyl-octyl, propyl-cyclohexyl-octyl, etc. Alkyl groups with 5 or more carbon atoms can be part of an enylene group or a polyalkylene group (preferably with 2 double bonds).

[0119] Maleimide resin, based on the viewpoint of significantly achieving the expected effects of the present invention, also preferably includes compounds containing alkyl groups having 5 or more carbon atoms and alkyl groups having 5 or more carbon atoms.

[0120] Alkyl groups having 5 or more carbon atoms and alkyl groups having 5 or more carbon atoms can also bond together to form rings, including spirocyclic and condensed rings. Examples of rings formed by mutual bonding include cyclohexane rings.

[0121] Alkyl groups having 5 or more carbon atoms and alkyl groups having 5 or more carbon atoms preferably do not have substituents, but may also have substituents. Substituents are as described above, and preferred examples include unsaturated hydrocarbon groups, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, halogen atoms, etc. Substituents may be present individually or in combination of two or more.

[0122] The maleimide resin preferably comprises a compound in which an alkyl group having 5 or more carbon atoms and an alkyl group having 5 or more carbon atoms are directly bonded to the nitrogen atom of the maleimide group.

[0123] In one embodiment, the maleimide resin includes a compound represented by the following general formula (C-4). In the general formula (C-4), M represents a divalent aliphatic hydrocarbon group having 5 or more carbon atoms and substituents, and L represents a single bond or a divalent linker.

[0124] M represents a divalent aliphatic hydrocarbon group of an alkyl group having 5 or more carbon atoms that may have substituents. Preferably, M represents an alkyl group, an alkenyl group, or an alkylpolyalkenyl group (more preferably with 2 double bonds) having 5 or more carbon atoms that may have substituents. The alkyl group of M is the same as the aforementioned alkyl groups having 5 or more carbon atoms. As a substituent of M, it is the same as the substituent that may be present in the aforementioned alkyl groups having 5 or more carbon atoms and alkyl groups having 5 or more carbon atoms, and the substituent is preferably an alkyl group having 5 or more carbon atoms.

[0125] L represents a single bond or a divalent linkage. Examples of divalent linkages include alkyl, alkenyl, alkynyl, aryl, -C(=O)-, -C(=O)-O-, -NR0- (R0 is a hydrogen atom and an alkyl group with 1 to 3 carbon atoms), oxygen atom, sulfur atom, C(=O)NR0-, divalent groups derived from phthalamide, divalent groups derived from pyromellitic acid diimide, and groups formed by combinations of two or more of these divalent groups. Alkenyl, alkenyl, alkynyl, aryl, divalent groups derived from phthalamide, divalent groups derived from pyromellitic acid diimide, and groups formed by combinations of two or more of these divalent groups may contain an alkyl group with 5 or more carbon atoms as a substituent. The divalent group derived from phthalamide represents a divalent group derived from phthalamide, specifically represented by the general formula (C-5). The divalent group derived from pyromellitic diimide represents a divalent group derived from pyromellitic diimide, specifically represented by the general formula (C-6). In the formula, "✽" represents a bond.

[0126]

[0127]

[0128] The alkyl group that forms the divalent linker in L is preferably an alkyl group with 1 to 50 carbon atoms, more preferably an alkyl group with 1 to 45 carbon atoms, and particularly preferably an alkyl group with 1 to 40 carbon atoms. This alkyl group can be linear, branched, or cyclic. Examples of such alkyl groups include, for example, methyl ethyl, cyclohexyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, heptadecanyl, hexadecyl, octyl, octyl-cyclohexyl-octyl, octyl-cyclohexyl-octyl, propyl-cyclohexyl-octyl, etc.

[0129] The alkenyl group, which is the divalent linker in L, is preferably an alkenyl group with 2 to 20 carbon atoms, more preferably an alkenyl group with 2 to 15 carbon atoms, and particularly preferably an alkenyl group with 2 to 10 carbon atoms. This alkenyl group can be linear, branched, or cyclic. Examples of such alkenyl groups include, for example, methylalkenylene, alkenylcyclohexenyl, alkenylpentenyl, alkenylhexenyl, alkenylheptenyl, alkenyloctenyl, etc.

[0130] The alkynyl group, which is the divalent linker in L, is preferably an alkynyl group with 2 to 20 carbon atoms, more preferably an alkynyl group with 2 to 15 carbon atoms, and particularly preferably an alkynyl group with 2 to 10 carbon atoms. This alkynyl group can be any of straight-chain, branched-chain, or cyclic. Examples of such alkynyl groups include, for instance, methyl-alkynyl, cyclohexynyl, pentynyl, hexynyl, heptyynyl, and octyynyl.

[0131] The aryl group that forms the divalent linker in L is preferably an aryl group with 6 to 24 carbon atoms, more preferably an aryl group with 6 to 18 carbon atoms, even more preferably an aryl group with 6 to 14 carbon atoms, and even more preferably an aryl group with 6 to 10 carbon atoms. Examples of aryl groups include, for example, phenyl, naphthyl, and anthraceneyl.

[0132] The alkyl, alkenyl, ynyl, and aryl groups that form the divalent linker in L may also have substituents. As substituents, they are the same as those that may be present in the alkyl groups having 5 or more carbon atoms and the alkyl groups having 5 or more carbon atoms, and preferably are alkyl groups having 5 or more carbon atoms.

[0133] Examples of a group consisting of two or more divalent groups in L include a divalent group consisting of an alkyl group, a divalent group derived from phthalimide, and an oxygen atom; a divalent group consisting of a divalent group derived from phthalimide, an oxygen atom, an aryl group, and an alkyl group; a divalent group consisting of an alkyl group and a divalent group derived from pyromellitic acid diimide; etc. A group consisting of two or more divalent groups can also form a ring such as a condensation ring through the combination of these groups. Furthermore, a group consisting of two or more divalent groups can have a repeating unit number of 1 to 10.

[0134] Wherein, L in the general formula (C-4) is preferably an oxygen atom, an aryl group having 6 to 24 carbon atoms that may have substituents, an alkyl group having 1 to 50 carbon atoms that may have substituents, an alkyl group having 5 or more carbon atoms, a divalent group derived from phthalimide, a divalent group derived from pyromellitic acid diimide, or a divalent group composed of two or more of such groups. Wherein, L is preferably an alkyl group; a divalent group having the structure of an alkyl group - a divalent group derived from phthalimide - an oxygen atom - a divalent group derived from phthalimide; a divalent group having the structure of an alkyl group - a divalent group derived from phthalimide - an oxygen atom - an aryl group - an alkyl group - an aryl group - an oxygen atom - a divalent group derived from phthalimide; a divalent group having the structure of an alkyl group - a divalent group derived from pyromellitic acid diimide.

[0135] Compounds represented by general formula (C-4) preferably include compounds represented by general formula (C-7). In general formula (C-7), M1 independently represents a divalent aliphatic hydrocarbon group containing an alkyl group having 5 or more carbon atoms that may have substituents, and Z independently represents a divalent group containing an alkyl group having 5 or more carbon atoms that may have substituents or an aromatic ring that may have substituents. t represents an integer from 1 to 10.

[0136] M1 independently represents a divalent aliphatic hydrocarbon group comprising an alkyl group having 5 or more carbon atoms that may have substituents. Preferably, M1 independently represents an alkyl group, an alkenyl group, or an alkylpolyenyl group having 5 or more carbon atoms that may have substituents (more preferably having 2 double bonds). M1 is more preferably the same as M in the general formula (C-4).

[0137] Z independently represents a divalent group having an alkyl group having 5 or more carbon atoms that may have substituents, or an aromatic ring that may have substituents. The alkyl group in Z can be chain-like, branched-chain, or cyclic, with a preference for a cyclic form, i.e., a cyclic alkyl group having 5 or more carbon atoms that may have substituents. The number of carbon atoms in the alkyl group is preferably 6 or more, more preferably 8 or more, more preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. Examples of such alkyl groups include those having an octyl-cyclohexyl structure, an octyl-cyclohexyl-octyl structure, and an propyl-cyclohexyl-octyl structure.

[0138] The aromatic ring in the divalent group having an aromatic ring represented by Z can be, as described above, for example, a benzene ring, a naphthalene ring, an anthracene ring, an o-phthalimide ring, a pyromellitic acid diimide ring, an aromatic heterocycle, etc., preferably a benzene ring, an o-phthalimide ring, or a pyromellitic acid diimide ring. That is, the divalent group having an aromatic ring is preferably a divalent group having a benzene ring that may have substituents, a divalent group having an o-phthalimide ring that may have substituents, or a divalent group having a pyromellitic acid diimide ring that may have substituents. Examples of divalent groups having an aromatic ring include groups formed by a combination of a divalent group derived from phthalimide and an oxygen atom; groups formed by a combination of a divalent group derived from phthalimide, an oxygen atom, an aryl group, and an alkyl group; groups formed by a combination of an alkyl group and a divalent group derived from pyromellitic acid diimide; groups derived from pyromellitic acid diimide; groups formed by a combination of a divalent group derived from phthalimide and an alkyl group; etc. The aforementioned aryl and alkyl groups are the same as the aryl and alkyl groups in the divalent linked groups represented by L in general formula (C-4).

[0139] The divalent group represented by Z, which has an alkyl group and an aromatic ring, may have substituents. As substituents, they are the same as those that may be present in alkyl groups having 5 or more carbon atoms and alkyl groups having 5 or more carbon atoms.

[0140] Specific examples of the basis for Z representation can be exemplified by the following basis. In the formula, "✽" represents a bond.

[0141]

[0142]

[0143] The compound represented by general formula (C-4) is preferably either the compound represented by general formula (C-8) or the compound represented by general formula (C-9).

[0144] In general formula (C-8), M2 and M3 each independently represent a divalent aliphatic hydrocarbon group containing an alkyl group with 5 or more carbon atoms that may have substituents, and R40 each independently represent an oxygen atom, an aryl group, an alkyl group, or a divalent group composed of two or more of such groups. t1 represents an integer from 1 to 10.

[0145] In general formula (C-9), M4, M6, and M7 each independently represent a divalent aliphatic hydrocarbon group containing an alkyl group with 5 or more carbon atoms that may have substituents; M5 each independently represents a divalent group containing an aromatic ring that may have substituents; R41 and R42 each independently represent an alkyl group with 5 or more carbon atoms. t2 represents an integer from 0 to 10, and u1 and u2 each independently represent an integer from 0 to 4.

[0146] M2 and M3 each independently represent a divalent aliphatic hydrocarbon group containing a substituent alkyl group having 5 or more carbon atoms. Preferably, M2 and M3 each independently represent a substituent alkyl group, subenyl group, or alkylpolyenyl group having 5 or more carbon atoms (more preferably with 2 double bonds). M2 and M3 are more preferably the same as the substituent alkyl group having 5 or more carbon atoms represented by M in general formula (C-4), and more preferably subhexadecyl.

[0147] R40 independently represents an oxygen atom, an aryl group, an alkyl group, or a combination of two or more divalent groups. The aryl group and alkyl group are the same as the aryl group and alkyl group represented by L in the general formula (C-4). R40 is preferably a group or an oxygen atom composed of two or more divalent groups.

[0148] Examples of groups formed by combining two or more divalent groups in R40 include combinations of oxygen atoms, aryl groups, and alkyl groups. Specific examples of groups formed by combining two or more divalent groups are given below. In the formula, "✽" represents a bond.

[0149] M4, M6, and M7 each independently represent a divalent aliphatic hydrocarbon group containing 5 or more carbon atoms that may have substituents. Preferably, M4, M6, and M7 each independently represent an alkyl, alkenyl, or alkylpolyalkenyl group (more preferably with 2 double bonds) containing 5 or more carbon atoms that may have substituents. M4, M6, and M7 are the same as the alkyl group containing 5 or more carbon atoms that may have substituents represented by M in general formula (C-4), preferably hexyl, heptyl, octyl, nonyl, decyl, and more preferably octyl.

[0150] M5 independently represents a divalent group having an aromatic ring that may have substituents. M5 is the same as the divalent group having an aromatic ring that may have substituents represented by Z in general formula (C-7), preferably a group formed by a combination of an alkyl group and a divalent group derived from pyromellitic acid diimide; a group formed by a combination of a divalent group derived from phthalic acid diimide and an alkyl group, more preferably a group formed by a combination of an alkyl group and a divalent group derived from pyromellitic acid diimide. The above-mentioned aryl and alkyl groups are the same as the aryl and alkyl groups in the divalent linked group represented by L in general formula (C-4).

[0151] A specific example of the basis for M5 representation can be the following basis. In the formula, "✽" represents a bond.

[0152] R41 and R42 each independently represent an alkyl group having 5 or more carbon atoms. R41 and R42 are the same as the alkyl groups having 5 or more carbon atoms mentioned above, preferably hexyl, heptyl, octyl, nonyl, decyl, and more preferably hexyl or octyl.

[0153] u1 and u2 represent integers from 1 to 15 respectively, preferably integers from 1 to 10.

[0154] Specific examples of maleimide resins include the following compounds (C1) to (C3). However, maleimide resins are not limited to these specific examples. In the formula, n represents an integer from 1 to 10.

[0155]

[0156]

[0157]

[0158] Specific examples of maleimide resins include “BMI1500” (a compound of formula (C1)), “BMI1700” (a compound of formula (C2)), and “BMI689” (a compound of formula (C3)) manufactured by Designer Molecules.

[0159] Based on the viewpoint of significantly achieving the expected effects of the present invention, the maleimide equivalent of the maleimide resin is preferably 50 g / eq. to 2000 g / eq., more preferably 100 g / eq. to 1000 g / eq., and even more preferably 150 g / eq. to 500 g / eq. The maleimide equivalent refers to the mass of a compound containing 1 equivalent of maleimide groups.

[0160] The styrene resin has one or more groups selected from styrene and vinylphenyl in its molecule, preferably vinylphenyl. Vinylphenyl is a group having the following structure (✽ indicates a bond).

[0161] Styrene resin, from the viewpoint of obtaining a cured material with low dielectric loss tangent, preferably has two or more vinylphenyl groups.

[0162] Styrene resin, from the viewpoint of obtaining a cured product with low dielectric loss tangent, preferably has a cyclic structure. The cyclic structure is preferably a divalent cyclic group. The divalent group can be a non-aromatic ring, for example, either a cyclic group containing an alicyclic structure or a cyclic group containing an aromatic ring structure. Furthermore, there can be a plurality of divalent cyclic groups.

[0163] The divalent cyclic group, based on the viewpoint of significantly achieving the expected effects of the present invention, preferably has 3 or more rings, more preferably 4 or more rings, even more preferably 5 or more rings, preferably 20 or fewer rings, more preferably 15 or fewer rings, and even more preferably 10 or fewer rings. Furthermore, the divalent cyclic group can be a monocyclic structure or a multicyclic structure.

[0164] The ring in the divalent cyclic group may have a ring skeleton composed of heteroatoms other than carbon atoms. Examples of heteroatoms include oxygen atoms, sulfur atoms, nitrogen atoms, etc., with oxygen atoms being preferred. There may be one heteroatom or two or more heteroatoms in the aforementioned ring.

[0165] Specific examples of divalent cyclic groups are the divalent groups (xii) or (xiii) below. (In divalent groups (xii) and (xiii), R51, R52, R55, R56, R57, R61 and R62 independently represent halogen atoms, alkyl groups with 6 or fewer carbon atoms or phenyl groups, respectively; R53, R54, R58, R59 and R60 represent hydrogen atoms, halogen atoms, alkyl groups with 6 or fewer carbon atoms or phenyl groups, respectively).

[0166] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. Alkyl groups with 6 or fewer carbon atoms include, for example, methyl, ethyl, propyl, butyl, pentyl, and hexyl, with methyl being preferred. R51, R52, R55, R56, R57, R61, and R62 preferably represent methyl. R53, R54, R58, R59, and R60 are preferably hydrogen atoms or methyl groups.

[0167] In addition, a plurality of divalent cyclic groups can be combined. As a specific example of combining divalent cyclic groups, a divalent cyclic group (divalent group (a)) represented by the following formula (C4) is given. (In formula (C4), R71, R72, R75, R76, R77, R81, R82, R85 and R86 each independently represent a halogen atom, an alkyl group or phenyl group with 6 or fewer carbon atoms, and R73, R74, R78, R79, R80, R83 and R84 each independently represent a hydrogen atom, a halogen atom, an alkyl group or phenyl group with 6 or fewer carbon atoms. d1 and d2 represent integers from 0 to 300. However, this does not apply if either d1 or d2 is 0).

[0168] R71, R72, R85 and R86 are the same as R51 in equation (xii). R73, R74, R83 and R84 are the same as R53 in equation (xii). R75, R76, R77, R81 and R82 are the same as R55 in equation (xiii). R78, R79 and R80 are the same as R58 in equation (xiii).

[0169] d1 and d2 represent integers from 0 to 300. However, this does not apply if either d1 or d2 is 0. It is preferable for d1 and d2 to represent integers from 1 to 100, more preferably integers from 1 to 50, and even more preferably integers from 1 to 10. d1 and d2 may be the same or different.

[0170] The divalent cyclic group may have substituents. Examples of substituents include halogen atoms, alkyl groups, alkoxy groups, aryl groups, arylalkyl groups, silyl groups, acetyl groups, acetoxy groups, carboxyl groups, sulfonyl groups, cyano groups, nitro groups, hydroxyl groups, mercapto groups, oxo groups, etc., with alkyl groups being preferred.

[0171] The vinylphenyl group can be directly bonded to a divalent cyclic group or bonded via a divalent linker. Examples of divalent linkers include alkyl, alkenyl, aryl, heteroaryl, -C(=O)O-, -O-, -NHC(=O)-, -NC(=O)N-, -NHC(=O)O-, -C(=O)-, -S-, -SO-, -NH-, etc., or combinations thereof. Preferably, the alkyl group is an alkyl group with 1 to 10 carbon atoms, more preferably an alkyl group with 1 to 6 carbon atoms, and even more preferably an alkyl group with 1 to 5 carbon atoms or an alkyl group with 1 to 4 carbon atoms. The alkyl group can be linear, branched, or cyclic. Examples of such alkyl groups include methylene, ethyl, propyl, butyl, pentyl, hexyl, and 1,1-dimethylethyl, with methylene, ethyl, and 1,1-dimethylethyl being preferred. Alkenyl groups are preferably alkenyl groups with 2 to 10 carbon atoms, more preferably alkenyl groups with 2 to 6 carbon atoms, and even more preferably alkenyl groups with 2 to 5 carbon atoms. Aryl or heteroaryl groups are preferably aryl or heteroaryl groups with 6 to 20 carbon atoms, and even more preferably aryl or heteroaryl groups with 6 to 10 carbon atoms. As a divalent linker, an alkyl group is preferred, with methylene being the most preferred.

[0172] The styrene resin preferably comprises a compound represented by the following formula (C-10). (In formula (C-10), R91 and R92 each independently represent a divalent linker. Cycle B1 represents a divalent cyclic group).

[0173] R91 and R92 independently represent divalent linkages. Divalent linkages are the same as those described above.

[0174] Cycle B1 represents a divalent cyclic group. Cycle B is the same as the divalent cyclic group described above.

[0175] Cyclone B1 may have substituents. The substituents are the same as those that may be present in the divalent cyclic group described above.

[0176] The following shows specific examples of styrene resin, but the present invention is not limited thereto. (q1 is the same as d1 in formula (C4), and q2 is the same as d2 in formula (C4).

[0177] Commercially available styrene resins can be used, such as "OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd. Styrene resins can be used alone or in combination of two or more types.

[0178] The number average molecular weight of the styrene resin, based on the viewpoint of significantly achieving the expected effects of the present invention, is preferably 3000 or less, more preferably 2500 or less, and even more preferably 2000 or less and 1500 or less. The lower limit is preferably 100 or more, more preferably 300 or more, and even more preferably 500 or more and 1000 or more. The number average molecular weight is the number average molecular weight of polystyrene determined using a gel permeation chromatography (GPC) instrument.

[0179] (Meth)acrylic resins comprise compounds having an acrylonitrile and a methacrylic group in their molecules. As a (meth)acrylic resin, from the viewpoint of significantly achieving the intended effects of the present invention, it is preferable to comprise compounds having two or more (meth)acrylic groups per molecule. The term "(meth)acrylic" is a general term for acrylonitrile and methacrylic.

[0180] (Meth)acrylic resin, from the viewpoint of significantly achieving the intended effects of the present invention, preferably has a cyclic structure. The cyclic structure is preferably a divalent cyclic group. The divalent cyclic group can be a non-aromatic ring, such as either a cyclic group containing an alicyclic structure or a cyclic group containing an aromatic ring structure. Among these, from the viewpoint of significantly achieving the intended effects of the present invention, a cyclic group containing an alicyclic structure is preferred.

[0181] The divalent cyclic group, based on the viewpoint of significantly achieving the expected effects of the present invention, preferably has 3 or more rings, more preferably 4 or more rings, even more preferably 5 or more rings, preferably 20 or fewer rings, more preferably 15 or fewer rings, and even more preferably 10 or fewer rings. Furthermore, the divalent cyclic group can be a monocyclic structure or a multicyclic structure.

[0182] The ring in the divalent cyclic group may be composed of heteroatoms other than carbon atoms, forming the ring skeleton. Examples of heteroatoms include oxygen atoms, sulfur atoms, nitrogen atoms, etc., with oxygen atoms being preferred. There may be one or more heteroatoms in the aforementioned ring.

[0183] Specific examples of divalent cyclic groups are the following divalent groups (i) to (xi). Among them, (x) or (xi) is preferred as a divalent cyclic group.

[0184] The divalent cyclic group may have substituents. Examples of such substituents include halogen atoms, alkyl groups, alkoxy groups, aryl groups, arylalkyl groups, silyl groups, acetyl groups, acetoxy groups, carboxyl groups, sulfonyl groups, cyano groups, nitro groups, hydroxyl groups, mercapto groups, oxo groups, etc., with alkyl groups being preferred.

[0185] The (meth)acrylic acid group can be directly bonded to a divalent cyclic group or bonded via a divalent linker. Examples of divalent linkers include alkyl, alkenyl, aryl, heteroaryl, -C(=O)O-, -O-, -NHC(=O)-, -NC(=O)N-, -NHC(=O)O-, -C(=O)-, -S-, -SO-, -NH-, etc., or combinations thereof. Preferably, the alkyl group is an alkyl group with 1 to 10 carbon atoms, more preferably an alkyl group with 1 to 6 carbon atoms, and even more preferably an alkyl group with 1 to 5 carbon atoms or an alkyl group with 1 to 4 carbon atoms. The alkyl group can be straight-chain, branched, or cyclic. Examples of such alkyl groups include methylene, ethyl, propyl, butyl, pentyl, hexyl, and 1,1-dimethylethyl, with methylene, ethyl, and 1,1-dimethylethyl being preferred. Alkenyl groups are preferably alkenyl groups with 2 to 10 carbon atoms, more preferably alkenyl groups with 2 to 6 carbon atoms, and even more preferably alkenyl groups with 2 to 5 carbon atoms. Aryl or heterocyclic groups are preferably aryl or heterocyclic groups with 6 to 20 carbon atoms, and even more preferably aryl or heterocyclic groups with 6 to 10 carbon atoms. Divalent linkages are preferably alkyl groups, with methylene and 1,1-dimethylethyl being preferred.

[0186] (Meth)acrylic resin preferably comprises a compound represented by the following formula (C-11). (In formula (C-11), R101 and R104 independently represent acrylonitrile or methacrylonitrile, respectively, and R102 and R103 independently represent divalent linkages. Cyclone B2 represents a divalent cyclic group).

[0187] R101 and R104 respectively represent acrylonitrile or methacrylonitrile, preferably acrylonitrile.

[0188] R102 and R103 each independently represent divalent linkages. The divalent linkages are the same as the divalent linkages that can be bonded to (meth)acrylic acid.

[0189] Cycle B2 represents a divalent cyclic group. Cycle B2 is the same as the divalent cyclic group described above. Cycle B2 may have substituents. The substituents are the same as those that may be present in the divalent cyclic group described above.

[0190] Specific examples of (meth)acrylic resins are as follows, but the present invention is not limited thereto.

[0191] (Meth)acrylic resins can be commercially available products, such as "A-DOG" manufactured by Shin-Nakamura Chemical Industry Co., Ltd., "DCP-A" manufactured by Kyoei Chemical Co., Ltd., "NPDGA", "FM-400", "R-687", "THE-330", "PET-30", "DPHA" manufactured by Nippon Kayaku Co., Ltd., and "NK ESTER DCP" manufactured by Shin-Nakamura Chemical Industry Co., Ltd.

[0192] The (meth)acrylic acid resin has a (meth)acrylic acid equivalent that, based on the viewpoint of significantly achieving the intended effects of the present invention, 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. The (meth)acrylic acid equivalent is the mass of a compound containing 1 equivalent of (meth)acrylic acid.

[0193] The allyl resin has at least one allyl group in its molecule. More preferably, the allyl resin has two or more allyl groups in one molecule. There is no particular upper limit, but it is more preferably 10 or less, and more preferably 5 or less.

[0194] Furthermore, the allyl resin, based on the viewpoint of significantly achieving the expected effects of the present invention, preferably has one of the following in addition to allyl: a benzoxazine ring, a phenolic ring, an isocyanurate ring, an epoxy group, and a carboxylic acid derivative having a cyclic structure.

[0195] The allyl resin having a benzoxazine ring is preferably bonded to either the nitrogen atom of the benzoxazine ring or the benzene ring, and more preferably to the nitrogen atom.

[0196] Allyl resin having a phenolic ring, for example, cresol resin containing allyl, phenolic varnish-type phenolic resin containing allyl, cresol varnish resin containing allyl, etc.

[0197] Preferably, in an allyl resin having an isocyanurate structure, the nitrogen atom of the isocyanurate group is directly bonded to the allyl group. Examples of allyl resins having an isocyanurate structure include allyl isocyanate, diallyl isocyanate, and triallyl isocyanate.

[0198] It is preferable that the allyl resin having epoxy groups contains two or more epoxy groups per molecule. Furthermore, the allyl resin having epoxy groups preferably has an aromatic structure; when using two or more allyl resins having epoxy groups, it is even more preferable that at least one has an aromatic structure. An aromatic structure is generally defined as an aromatic chemical structure, and also includes polycyclic aromatics and aromatic heterocycles. The allyl resin having epoxy groups preferably has a bisphenol structure; examples of bisphenol structures include bisphenol A, bisphenol F, and bisphenol AF.

[0199] As an allyl resin having a carboxylic acid derivative with a cyclic structure, it is preferably an allyl carboxylic acid having a cyclic structure. The cyclic structure can be a non-aromatic ring, such as either a cyclic group containing an alicyclic structure or a cyclic group containing an aromatic ring structure. Furthermore, the cyclic group, excluding carbon atoms, can have heteroatoms forming the ring skeleton. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms, with nitrogen atoms being preferred. One heteroatom or two or more heteroatoms may be present in the aforementioned ring.

[0200] Examples of carboxylic acids having a cyclic structure include isocyanuric acid, biphenyl dicarboxylic acid, phthalic acid, and cyclohexanedicarboxylic acid. Examples of allyl resins having carboxylic acid derivatives containing a cyclic structure include allyl isocyanurate, diallyl isocyanurate, triallyl isocyanurate, diallyl biphenyl, allyl biphenyl, o-diallyl phthalate, p-diallyl phthalate, p-diallyl terephthalate, allyl cyclohexanedicarboxylate, and diallyl cyclohexanedicarboxylate.

[0201] Allyl resins can be commercially available. Examples of commercially available products include: Meiwa Chemical Co., Ltd.'s "MEH-8000H" and "MEH-8005" (allyl resins with phenolic rings); Nippon Kayaku Co., Ltd.'s "RE-810NM" (allyl resins with epoxy groups); Shikoku Chemical Industry Co., Ltd.'s "ALP-d" (allyl resins with benzoxazine rings); Shikoku Chemical Industry Co., Ltd.'s "L-DAIC" (allyl resins with isocyanuric acid rings); Nippon Kayaku Co., Ltd.'s "TAIC" (allyl resins with isocyanuric acid rings (tallyl isocyanurate)); Osaka Soda Co., Ltd.'s "MDAC" (allyl resins with cyclohexane dicarboxylic acid derivatives); Nippon Chutsu Technology Fine Chemicals Co., Ltd.'s "DAD" (diallyl biphenyl phthalate); and Osaka Soda Co., Ltd.'s "DAISO DAP monomer" (o-diallyl phthalate), etc.

[0202] The allyl equivalent of the allyl resin, based on the viewpoint of significantly achieving the expected effects of the present invention, is preferably 20 g / eq. to 1000 g / eq., more preferably 50 g / eq. to 500 g / eq., and even more preferably 100 g / eq. to 300 g / eq. The allyl equivalent refers to the mass of a compound containing 1 allyl equivalent.

[0203] The butadiene resin has a butadiene backbone. The polybutadiene structure may be contained in the main chain or in the side chain. Furthermore, the polybutadiene structure may be partially or completely hydrogenated. As a butadiene resin, it is more preferably a resin selected from one or more resins of the group consisting of a hydrogenated polybutadiene backbone, a hydroxyl-containing butadiene resin, a phenolic hydroxyl-containing butadiene resin, a carboxyl-containing butadiene resin, an anhydride-containing butadiene resin, an epoxy-containing butadiene resin, an isocyanate-containing butadiene resin, and a carbamate-containing butadiene resin.

[0204] Specific examples of butadiene resins include "JP-100" manufactured by Nippon Soda Corporation, and "Ricon100", "Ricon150", "Ricon130MA8", "Ricon130MA13", "Ricon130MA20", "Ricon131MA5", "Ricon131MA10", "Ricon131MA17", "Ricon131MA20", and "Ricon 184MA6" manufactured by CRAY VALLEY Corporation.

[0205] As for the content of component (C), based on the viewpoint of improving the expected effect of the present invention, when the non-volatile component in the resin composition is set to 100% by mass, it is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less.

[0206] As for the content of component (C), based on the viewpoint of improving the expected effect of the present invention, when the resin component in the resin composition is set to 100% by mass, it is preferably 2% by mass or more, more preferably 10% by mass or more, even more preferably 16% by mass or more, preferably 90% by mass or less, even more preferably 87% by mass or less, and even more preferably 85% by mass or less.

[0207] The resin sheet of the present invention, which comprises a resin composition layer containing components (A), (B), and (C) and satisfies both the oxygen permeability α and β conditions described above, can achieve a cured material that retains or enhances the excellent dielectric properties inherent in component (A) and exhibits excellent conductor adhesion and mechanical properties. A resin composition layer comprising only component (B) or only component (C) in component (A) cannot achieve the aforementioned effects even if both oxygen permeability α and β conditions are met. It has been confirmed that when components (B) and (C) are combined and formulated in component (A) and both oxygen permeability α and β conditions are met, a unique effect can be obtained.

[0208] -(D) Thermoplastic resin- In this invention, the resin composition may further include thermoplastic resin as component (D).

[0209] Examples of component (D) include, for example, phenoxy resin, polyimide resin, polycarbonate resin, polyvinyl acetal resin, polyolefin resin, polyamide-imide resin, polyether-imide resin, polyurethane resin, polyether-urethane resin, polyphenylene ether resin, polyether ether ketone resin, polystyrene resin, polyester resin, etc. Among these, from the viewpoint of obtaining a cured material with excellent dielectric properties, component (D) is preferably selected from one or more of phenoxy resin, polyimide resin, and polycarbonate resin. From the viewpoint of obtaining a cured material with excellent mechanical properties, such as sufficient elongation at break, polyimide resin is more preferably used.

[0210] Examples of phenoxy resins include those having one or more skeletons selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, phenolic varnish skeleton, biphenyl skeleton, fumonisin skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal group of the phenoxy resin may also be any functional group such as a phenolic hydroxyl group or an epoxy group.

[0211] Commercially available phenoxy resins include, for example, Mitsubishi Chemical's "1256" and "4250" (both phenoxy resins containing a bisphenol A backbone); Mitsubishi Chemical's "YX8100" (phenoxy resin containing a bisphenol S backbone); Mitsubishi Chemical's "YX6954" (phenoxy resin containing a bisphenol acetophenone backbone); Nippon Steel Chemical & Materials Co., Ltd.'s "FX280" and "FX293"; Mitsubishi Chemical's "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482"; etc.

[0212] Polyimide resins can be resins having a amide structure. Polyimide resins are generally obtained by amide-imidization reaction of a diamine compound with an acid anhydride. Commercially available polyimide resins can be used, for example, "RIKACOTE SN20" and "RIKACOTE PN20" manufactured by Shin Nippon Rika Co., Ltd. Furthermore, as polyimide resins, thermoplastic resin d or its modified form in the solution prepared in <Synthesis Example 1> (Synthesis of a solution of thermoplastic resin d) described later can be used.

[0213] Polycarbonate resin is a resin having a carbonate structure. Examples of such resins include carbonate resins without the reactive groups described below, hydroxyl-containing carbonate resins, phenolic hydroxyl-containing carbonate resins, carboxyl-containing carbonate resins, acid anhydride-containing carbonate resins, isocyanate-containing carbonate resins, carbamate-containing carbonate resins, and epoxy-containing carbonate resins. The term "reactive group" here refers to a functional group that can react with other components such as hydroxyl, phenolic hydroxyl, carboxyl, acid anhydride, isocyanate, carbamate, and epoxy groups.

[0214] Commercially available polycarbonate resins can be used. Examples of commercially available products include "FPC0220" and "FPC2136" manufactured by Mitsubishi Gas Chemical Co., Ltd., "T6002" and "T6001" (polycarbonate diol) manufactured by Asahi Kasei Chemical Co., Ltd., and "C-1090", "C-2090", and "C-3090" (polycarbonate diol) manufactured by KURARAY Co., Ltd.

[0215] The weight-average molecular weight (Mw) of component (D) is preferably 5000 or more, more preferably 8000 or more, and even more preferably 10000 or more, based on the viewpoint of obtaining a cured product with superior mechanical properties such as elongation at break. There is no particular upper limit to this Mw, but it is preferably 100000 or less, more preferably 80000 or less, and even more preferably 50000 or less. The Mw of component (D) can be determined as a polystyrene equivalent value by gel permeation chromatography (GPC).

[0216] When the resin composition contains component (D), the content of component (D) in the resin composition is not particularly limited as long as it does not excessively hinder the effect of the present invention. However, when the non-volatile component in the resin composition is set to 100% by mass, it can be 0.1% by mass or more, 0.3% by mass or more, or 0.5% by mass or more. Based on the viewpoint of obtaining a cured product with better mechanical properties, such as elongation at break, the lower limit of the content of component (D) is preferably 0.7% by mass or more, 0.8% by mass or more, or 1.0% by mass or more. The upper limit of the content of component (D) is not particularly limited, but it is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less.

[0217] -(E) Curing Accelerator- In this invention, the resin composition may further include a curing accelerator as component (E). A typical example of a curing accelerator as component (E) is a peroxide-based curing accelerator.

[0218] As a component (E), examples include peroxides such as tert-butyl cumene peroxide, tert-butyl peracetate, α,α'-di(tert-butylperoxy)diisopropylbenzene, tert-butyl peroxylaurate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyneodecanate, and tributyl peroxybenzoate.

[0219] Commercially available products that are ingredients (E) include, for example, "PERBUTYL (registered trademark) C", "PERBUTYL (registered trademark) A", "PERBUTYL (registered trademark) P", "PERBUTYL (registered trademark) L", "PERBUTYL (registered trademark) O", "PERBUTYL (registered trademark) ND", "PERBUTYL (registered trademark) Z", "PERHEXYL (registered trademark) D", "PERCUMYL (registered trademark) P", "PERCUMYL (registered trademark) D", etc., manufactured by Nippon Oil Company.

[0220] When the resin composition contains component (E), the content of component (E) is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, more preferably 0.05% by mass or more, preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less, when the non-volatile component in the resin composition is set to 100% by mass.

[0221] -Other Components- In this invention, the resin composition may further include epoxy resin and epoxy resin curing agent.

[0222] Examples of epoxy resins include, for example, xylenol-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, bisphenol AF-type epoxy resin, dicyclopentadiene-type epoxy resin, triphenol-type epoxy resin, naphthol phenolic varnish-type epoxy resin, phenolic phenolic varnish-type epoxy resin, tributylcatechol-type epoxy resin, naphthalene-type epoxy resin, naphthol-type epoxy resin, anthracene-type epoxy resin, glycidylamine-type epoxy resin, glycidyl ester-type epoxy resin, cresol phenolic varnish-type epoxy resin, biphenyl-type epoxy resin, chain aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spirocyclic rings, cyclohexane-type epoxy resin, cyclohexanediethanol-type epoxy resin, naphthyl ether-type epoxy resin, tris(hydroxymethyl)-type epoxy resin, tetraphenylethane-type epoxy resin, etc. Epoxy resin can be used alone or in combination of two or more types.

[0223] Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter referred to as "solid epoxy resins"). The resin composition for the resin sheets of the present invention may contain only liquid epoxy resin, may contain only solid epoxy resin, or may combine liquid epoxy resin and solid epoxy resin.

[0224] Specific examples of liquid epoxy resins include DIC's "HP4032", "HP4032D", and "HP-4032-SS" (naphthalene-type epoxy resin); Mitsubishi Chemical's "828US", "jER828EL", "825", and "EPICOTE 828EL" (bisphenol A type epoxy resin); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F type epoxy resin); Mitsubishi Chemical's "jER152" (phenolic varnish type epoxy resin); Mitsubishi Chemical's "630" and "630LSD" (glycidylamine type epoxy resin); Nippon Steel Chemical & Materials Co., Ltd.'s "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); NAGASE CHEMTEX's "EX-721" (glycidyl ester type epoxy resin); DAICL's "CELLOXIDE 2021P" (alicyclic epoxy resin with an ester skeleton); DAICL's "PB-3600" (epoxy resin with a butadiene structure); and Nippon Steel Chemical & Materials Co., Ltd.'s "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin), etc.

[0225] Specific examples of solid epoxy resins include DIC's "HP4032H" (naphthalene-type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC's "N-690" (cresol phenolic varnish type epoxy resin); DIC's "N-695" (cresol phenolic varnish type epoxy resin); and DIC's "HP-7200HH", "HP-7200H", and "H" P-7200 (dicyclopentadiene type epoxy resin); DIC's EXA-7311, EXA-7311-G3, EXA-7311-G4, EXA-7311-G4S, and HP6000 (naphthalene ether type epoxy resin); Nippon Kayaku Co., Ltd.'s EPPN-502H (triphenol type epoxy resin); Nippon Kayaku Co., Ltd.'s NC7000L (naphthol phenolic varnish epoxy resin); Nippon Kayaku Co., Ltd.'s NC3000 "H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel Chemical & Materials Co., Ltd.; "ESN485" (naphthol phenolic varnish type epoxy resin) manufactured by Nippon Steel Chemical & Materials Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YX4000HK" (bi-xylenol type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd. Anthracene epoxy resin; YX8800 (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; PG-100 and CG-500 manufactured by Osaka Gas Chemical Co., Ltd.; YL7760 (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; YL7800 (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; jER1010 (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; jER1031S (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation, etc.

[0226] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 5000 g / eq., more preferably 50 g / eq. to 3000 g / eq., even more preferably 80 g / eq. to 2000 g / eq., and still more preferably 110 g / eq. to 1000 g / eq. The epoxy equivalent is the mass of a compound containing 1 equivalent of epoxy groups. This epoxy equivalent can be determined according to JIS K7236.

[0227] The weight average molecular weight (Mw) of the epoxy resin is preferably 100~5000, more preferably 250~3000, and even more preferably 400~1500. The Mw of the epoxy resin can be determined by gel permeation chromatography (GPC) using a value converted from polystyrene.

[0228] When the resin composition contains epoxy resin, the content of epoxy resin in the resin composition, when the non-volatile component in the resin composition is set to 100% by mass, is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, 1% by mass or more, or 1.5% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, or 3% by mass or less.

[0229] Examples of epoxy resin curing agents include reactive ester-based curing agents, phenol-based curing agents, naphthol-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, carbodiimide-based curing agents, amine-based curing agents, and acid anhydride-based curing agents. One of these can be used alone, or two or more can be used in combination.

[0230] The content of epoxy resin hardener is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, preferably 10% by mass or less, and even more preferably 5% by mass or less, when the non-volatile component in the resin composition is set to 100% by mass.

[0231] The resin composition may further contain any additives. Examples of such additives include, for instance, peroxide-based curing accelerators other than those mentioned above, such as phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators; organic fillers such as rubber particles; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, biphenyl pyrogallol, and phenothiazine; leveling agents such as silica-based leveling agents and acrylic polymer-based leveling agents; tackifiers such as bentonite and montmorillonite; defoamers such as silica-based defoamers, acrylic defoamers, fluorine-based defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion enhancers such as ureasilane; and triazole-based adhesion enhancers. Adhesion enhancers, including tetrazolium-based adhesion enhancers and triazine-based adhesion enhancers; antioxidants, including hindered phenolic antioxidants and hindered amine antioxidants; fluorescent whitening agents, including diphenylethylene derivatives; surfactants, including fluorine-based surfactants and silica-based surfactants; flame retardants, including phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphonic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants, including phosphate ester dispersants, polyoxyethylene dispersants, acetylene dispersants, silica-based dispersants, anionic dispersants, and cationic dispersants; and stabilizers, including borate ester stabilizers, titanate stabilizers, aluminate stabilizers, zirconate stabilizers, isocyanate amine stabilizers, carboxylic acid stabilizers, and carboxylic anhydride stabilizers. These additives can be used alone or in combination of two or more. The content of each additive can be set appropriately by those skilled in this art.

[0232] In addition to the non-volatile components mentioned above, the resin composition of the present invention may further contain any organic solvent as a volatile component. Conventional organic solvents may be appropriately used, and their types are not particularly limited. Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; and ethers such as 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diethylene glycol acetate, γ-butyrolactone, and methyl methoxypropionate. Ester solvents; ester-alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether-alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); acetylamine solvents such as N,N-dimethylformamide, N,N-dimethylacetylamine, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. Organic solvents can be used alone or in combination of two or more.

[0233] The resin composition of the present invention can be manufactured by, for example, adding and mixing components (A), (B), (C), and, as needed, components (D), (E), epoxy resin, epoxy resin hardener, other additives, and organic solvent in any mixing container in any order and / or partially or all simultaneously. Furthermore, during the addition and mixing of the components, the temperature can be appropriately set, and heating and / or cooling can be performed temporarily or continuously. During or after the addition and mixing, the resin composition can also be stirred or vibrated using a stirring device or oscillating device such as a mixer to achieve uniform dispersion. Simultaneously with stirring or vibrating, degassing can also be performed under low-pressure conditions such as vacuum.

[0234] The resin sheet of the present invention can be manufactured by, for example, by preparing the above-mentioned resin composition, directly applying the liquid resin composition or preparing a resin varnish in which the resin composition is dissolved in an organic solvent, applying it onto a support using a die applicator or the like, and then drying it to form a resin composition layer. When preparing the resin varnish, the above-mentioned organic solvent can be used.

[0235] Drying can be carried out by conventional methods such as heating or hot air blowing. There are no particular restrictions on drying conditions, but drying should be carried out until the organic solvent content in the resin composition layer is less than 10% by mass, preferably less than 5% by mass. Although it varies depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when using a resin composition or resin varnish containing 15% to 60% by mass of organic solvent, a resin composition layer can be formed by drying at 50°C to 150°C for 1 to 10 minutes.

[0236] In the resin sheet of the present invention, the thickness of the resin composition layer is preferably 100 μm or less, and more preferably 80 μm or less, based on the viewpoint of thinning printed circuit boards. The lower limit of the resin composition layer thickness is not particularly limited, and can usually be set to 5 μm or more, 10 μm or more, etc.

[0237] <Any Layer> The resin sheet of the present invention may also contain any layer. Examples of such any layer include, for example, a protective film, a barrier film, or a metal foil. The material of the protective film, barrier film, or metal foil is preferably any one of the materials listed above for the support. The any layer is preferably peelable from the resin sheet. The any layer is preferably located on the surface of the resin sheet that is not bonded to the support of the resin composition layer (i.e., the side opposite to the support), thereby suppressing the adhesion of dust or scratches to the surface of the resin composition layer. The thickness of the any layer is not particularly limited, for example, it can be 1 μm to 100 μm.

[0238] The resin sheet can be wound into a roll for storage. When the resin sheet has a protective film, barrier film, metal foil, or other arbitrary layer, it can be used by peeling off such arbitrary layer.

[0239] The resin sheet of the present invention can be suitably used to form an insulating layer of a printed wiring board (for insulating layer of printed wiring board), and more suitably used to form an interlayer insulating layer of a printed wiring board (for interlayer insulating layer of printed wiring board). Since the resin sheet of the present invention can obtain an insulating layer with good component embedding properties, it can be suitably used even when the printed wiring board is a circuit board with built-in components. The resin sheet of the present invention can also be suitably used to form an insulating layer on which a conductor layer (including a rewiring layer) is disposed (for forming an insulating layer of a conductor layer). The resin sheet of the present invention can further be used in a wide range of applications such as solder resist, underfill material, die bond material, semiconductor sealant, via filling resin, and component embedding resin.

[0240] In one embodiment, the cured product formed using the resin sheet of the present invention exhibits a low dielectric constant (Dk). For example, when measured at 5.8 GHz and 23°C as described in the <Dielectric Properties Evaluation> section below, the dielectric constant (Dk) of the cured product of the resin composition layer of the resin sheet of the present invention is preferably set to 3.0 or less or 2.9 or less.

[0241] In one embodiment, the cured product formed using the resin sheet of the present invention exhibits a low dielectric loss tangent (Df). For example, when measured at 5.8 GHz and 23°C as described in the <Dielectric Properties Evaluation> section below, the dielectric loss tangent (Df) of the cured product of the resin composition layer of the resin sheet of the present invention is preferably set to 0.0030 or less, 0.0029 or less, or 0.0028 or less.

[0242] In one embodiment, the hardened product formed using the resin sheet of the present invention exhibits excellent conductor adhesion. For example, the conductor adhesion strength measured by the method described in the <Conductor Adhesion Evaluation> section below can preferably be set to 0.50 kgf / cm or more, 0.52 kgf / cm or more, or 0.54 kgf / cm or more.

[0243] In one embodiment, the hardened product formed using the resin sheet of the present invention exhibits excellent mechanical properties. For example, the maximum point stress measured by the method described in the <Mechanical Properties (Maximum Point Stress and Elongation at Break) Evaluation> section below is preferably set to 100 MPa or more, 101 MPa or more, 102 MPa or more, or 105 MPa or more. Furthermore, the elongation at break is preferably set to 1.4% or more or 1.5% or more.

[0244] In one embodiment, the cured product formed using the resin sheet of the present invention tends to exhibit excellent insulation reliability. For example, when performing a HAST test at 130°C and 85%RH using the method described in the <Insulation Reliability Evaluation> section below, it is preferable that the insulation resistance value after 300 hours is set to be more than 50% of the initial insulation resistance value, more preferably 51% or more of the initial insulation resistance value or 52% or more of the initial insulation resistance value.

[0245] [Printed Wiring Board] A printed wiring board can be manufactured using the resin sheet of the present invention. In this case, the printed wiring board includes an insulating layer formed by a hardened material of the resin composition layer in the resin sheet of the present invention.

[0246] The printed wiring board may, for example, use the above-mentioned resin sheet and be manufactured by a method including the steps (I) and (II) below. (I) A step of depositing a resin sheet on an inner substrate in such a way that the resin composition layer of the resin sheet is bonded to the inner substrate. (II) A step of curing the resin composition layer (e.g., thermosetting) to form an insulating layer.

[0247] The "inner layer substrate" used in step (I) is a component that becomes the substrate of the printed wiring board, such as a glass epoxy board, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, etc. Furthermore, the substrate may have a conductor layer on one or both sides, and the conductor layer may also be patterned. An inner layer substrate with a conductor layer (circuit) formed on one or both sides of the substrate is sometimes called an "inner layer circuit board". Intermediate materials for forming an insulating layer and / or a conductor layer during the manufacture of the printed wiring board are also included in the "inner layer substrate" as referred to in this invention. When the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components may also be used.

[0248] The lamination of the inner layer substrate and the resin sheet can be performed, for example, by heating and pressing the resin sheet onto the inner layer substrate from the support side. Examples of components for heating and pressing the resin sheet onto the inner layer substrate (hereinafter also referred to as "heat-pressing components") include, for example, a heated metal plate (SUS mirror plate, etc.) or a metal roller (SUS roller). Furthermore, the heat-pressing components can be applied directly to the resin sheet, or the resin sheet can be pressed through an elastic material such as heat-resistant rubber, in a manner that allows the resin sheet to fully follow the surface irregularities of the inner layer substrate.

[0249] The lamination of the inner layer substrate and the resin sheet can be performed by vacuum lamination. In vacuum lamination, the heating-pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C; the heating-pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa; and the heating-pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination can preferably be performed under reduced pressure conditions below 26.7 hPa.

[0250] Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include, for example, a vacuum pressure laminator manufactured by Meiki Manufacturing Co., Ltd., a vacuum dressing machine manufactured by NIKKO Materials Co., Ltd., and a batch vacuum pressure laminator.

[0251] After lamination, the laminated resin sheet can be smoothed by applying pressure from the support side, for example, under normal pressure (atmospheric pressure), by heating and pressing the bonding member. The pressure conditions for smoothing can be the same as the heating and pressing conditions for lamination described above. Smoothing can be performed using a commercially available laminator. Furthermore, lamination and smoothing can be performed continuously using the aforementioned commercially available vacuum laminator.

[0252] The support may be removed between steps (I) and (II), but it is preferable to remove or peel it off after step (II).

[0253] One of the preferred embodiments of the manufacturing method of the printed wiring board is as follows. A method for manufacturing a printed circuit board includes the following steps: (1) preparing a resin sheet having a support and a resin composition layer disposed on the support, wherein one side of the resin composition is exposed; (2) depositing the resin sheet on the substrate in such a way as to deposit the resin composition layer on the substrate of the printed circuit board; and (3) curing the resin sheet deposited on the substrate in a state in which the support does not peel off from the resin composition layer, wherein the resin composition layer comprises (A) benzocyclobutene resin, (B) inorganic filler and (C) free radical polymerizable resin, wherein the oxygen permeability α of the resin composition layer measured under conditions of 220°C for 90 minutes is 70 cc / m2·day or less, and the oxygen permeability β of the resin sheet exposed on one side of the resin composition layer measured under conditions of 220°C for 90 minutes is 40 cc / m2·day or less, wherein the oxygen permeability α and the oxygen permeability β are based on JIS. K7126-2:2006 (isobaric method), measured values ​​at 23℃ and 0%RH.

[0254] When using metal foil as a support, the conductor layer can be formed using the metal foil without peeling off the support. Furthermore, when using metal foil with an attached support substrate as a support, only the support substrate (and release layer) needs to be peeled off. Moreover, the conductor layer can be formed using metal foil.

[0255] In step (II), the resin composition layer is cured (e.g., thermosetting) to form an insulating layer made of the cured resin composition. The curing conditions of the resin composition layer are not particularly limited, and conditions commonly used when forming an insulating layer for a printed wiring board can be used.

[0256] For example, the thermosetting conditions of the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 120°C to 250°C, more preferably 150°C to 240°C, and even more preferably 180°C to 230°C. The curing time is preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and even more preferably 15 minutes to 120 minutes.

[0257] Before heat curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, before heat curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 120°C, preferably 60°C to 115°C, more preferably 70°C to 110°C for at least 5 minutes, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

[0258] When manufacturing a printed wiring board, steps (III) of drilling holes in the insulating layer, (IV) of roughening the insulating layer, and (V) of forming the conductor layer may also be performed. These steps (III) to (V) should be performed according to various methods known to those skilled in the art for manufacturing printed wiring boards. Furthermore, when removing the support after step (II), the removal of the support may be performed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Moreover, if necessary, the formation of the insulating layer and conductor layer in steps (I) to (V) may be repeated to form a multilayer wiring board.

[0259] Step (III) is the drilling step of the insulating layer, thereby forming holes such as through holes and perforations in the insulating layer. Step (III) is carried out using, for example, a drill bit, laser, plasma, etc., depending on the composition of the resin composition used to form the insulating layer. The size and shape of the holes can be appropriately determined according to the design of the printed circuit board.

[0260] Step (IV) is a step of roughening the insulating layer. Usually, in this step (IV), residue removal is also performed. There are no particular restrictions on the order and conditions of the roughening treatment, and the conventional order and conditions usually used when forming the insulating layer of a printed wiring board can be adopted. For example, the insulating layer can be roughened by performing swelling treatment with a swelling solution, roughening treatment with an oxidizing agent, and neutralization treatment with a neutralizing solution in sequence.

[0261] The swelling solution used for the roughening treatment is not particularly limited, but examples include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solution and potassium hydroxide solution are more preferred as alkaline solutions. Commercially available swelling solutions include, for example, "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Corporation of Japan. The swelling treatment with the swelling solution is not particularly limited and can be carried out, for example, by immersing the insulating layer in a swelling solution at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the insulating resin to an appropriate degree, it is preferable to immerse the insulating layer in a swelling solution at 40°C to 80°C for 5 to 15 minutes.

[0262] The oxidant used for the roughening treatment is not particularly limited, but examples include, for instance, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. For the roughening treatment using an oxidant such as an alkaline permanganate solution, it is preferable to immerse the insulating layer in an oxidant solution heated to 60°C to 100°C for 10 to 30 minutes. Furthermore, the concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Examples of commercially available oxidants include, for instance, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Atotech Co., Ltd. of Japan.

[0263] Furthermore, the neutralizing solution used for the roughening treatment is preferably an acidic aqueous solution, such as "Reduction Solution Securiganth P" manufactured by Atotech Co., Ltd. of Japan.

[0264] The neutralization treatment can be carried out by immersing the treated surface roughened by the oxidant in a neutralization solution at 30°C to 80°C for 5 to 30 minutes. For workability and other considerations, it is preferable to immerse the object roughened by the oxidant in a neutralization solution at 40°C to 70°C for 5 to 20 minutes.

[0265] Step (V) is the step of forming a conductor layer, which 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 the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer can be a single metal layer or an alloy layer. For example, an alloy layer may be formed from an alloy of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). From the perspectives of the versatility, cost, and ease of patterning of conductor layer formation, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of nickel-chromium 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 even more preferred. A single metal layer of copper is also preferred.

[0266] The conductor layer may be a single-layer structure or a multi-layer structure consisting of two or more single metal layers or alloy layers made of different kinds of metals or alloys. When the conductor layer is a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc or titanium or an alloy layer of nickel-chromium alloy.

[0267] The thickness of the conductor layer depends on the required printed wiring board design, but is generally 3μm~35μm, preferably 5μm~30μm.

[0268] In one embodiment, the conductor layer can be formed by plating. For example, by plating the surface of the insulating layer using conventional techniques such as the semi-additive method or the full-additive method, a conductor layer with the desired wiring pattern can be formed. From the viewpoint of ease of manufacturing, it is preferable to form it by the semi-additive method. The following shows an example of forming a conductor layer by the semi-additive method.

[0269] First, a seed layer is formed on the surface of the insulating layer by electroless plating. Then, a masking pattern is formed on the formed seed layer, exposing a portion of the seed layer corresponding to the desired wiring pattern. After forming a metal layer on the exposed seed layer by electrolytic plating, the masking pattern is removed. Subsequently, the unwanted seed layer is removed by etching or the like, and a conductor layer with the desired wiring pattern can be formed.

[0270] In another embodiment, the conductor layer can be formed using metal foil. When forming the conductor layer using metal foil, step (V) is preferably performed between steps (I) and (II). For example, after step (I), the support is removed, and the metal foil is deposited on the exposed surface of the resin composition layer. The deposition of the resin composition layer and the metal foil can be performed by vacuum lamination. The deposition conditions can be the same as those described in step (I). Next, an insulating layer is formed by performing step (II). Subsequently, using the metal foil on the insulating layer, a conductor layer with the desired wiring pattern can be formed by conventional techniques such as subtraction and modified semi-addition.

[0271] Metal foil can be manufactured by conventional methods such as electrolysis and rolling. Examples of commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Minerals & Metals Corporation, and 3EC-III foil and TP-III foil manufactured by Mitsui Minerals & Metals Corporation.

[0272] Alternatively, when a metal foil or a metal foil with a supporting substrate is used as a support for the resin sheet, the conductor layer system is formed using the metal foil as described above.

[0273] Furthermore, the resin composition layer used in the resin sheet of the present invention can also be appropriately used as a resin composition layer for forming an insulating layer for forming a rewiring layer (resin composition layer for forming a rewiring layer) and a resin composition layer for sealing a semiconductor wafer (resin composition layer for sealing a semiconductor wafer) during the manufacture of semiconductor wafer packages. The technique of manufacturing semiconductor wafer packages using resin composition layers (resin sheets) is well known in the art, and the resin sheet or resin composition layer of the present invention can also be applied to any method or technique.

[0274] [Semiconductor Device] The semiconductor device may be manufactured in a manner comprising an insulating layer formed by a hardened resin composition layer of the resin sheet of the present invention. The semiconductor device may be manufactured using the aforementioned printed circuit board or semiconductor package.

[0275] Examples of semiconductor devices include various semiconductor devices used in electrical products (such as computers, mobile phones, digital cameras, and televisions) and vehicles (such as locomotives, automobiles, trams, ships, and airplanes). [Example]

[0276] Hereinafter, the present invention will be specifically described by way of examples. The present invention is not limited to these examples. In the following, "parts" and "%" to indicate quantity, unless otherwise stated, mean "parts by mass" and "% by mass," respectively. In particular, the temperature and pressure conditions when no temperature is specified are room temperature (25°C) and atmospheric pressure (1 atm).

[0277] First, various measurement and evaluation methods will be explained.

[0278] [Preparation of Samples for Measurement and Evaluation] 1. Preparation of Hardened Material for Evaluation: The protective film of a resin sheet A with a protective film prepared in the Examples and Comparative Examples is peeled off to expose one side of the resin composition layer. The resin composition layer is then rapidly heated at 220°C for 90 minutes under a nitrogen atmosphere to thermally harden it. This yields a resin sheet B consisting of a support and the hardened material disposed on the support. Furthermore, a portion of the resin sheet B is cut out, and by peeling off the support, both sides of the resin composition layer are exposed, resulting in a film-like hardened material C formed from the hardened resin composition layer.

[0279] 2. Fabrication of the substrate for the first evaluation (1) Substrate treatment of copper foil: The glossy surface of "3EC-III" (electrolytic copper foil, 35μm) manufactured by Mitsui Metal Mining Co., Ltd. was immersed in Mec Etch Bond "CZ-8201" manufactured by MEC Co., Ltd. to roughen the surface of the copper to Ra value of 0.5μm. Next, a rust prevention treatment (CL8300) was performed, and then the copper foil was heated in an oven at 130°C for 30 minutes. In this way, a copper foil with a low surface roughness (hereinafter referred to as "CZ copper foil") was obtained.

[0280] (2) Substrate fabrication: The protective film of the resin sheet A with protective film fabricated in the Examples and Comparative Examples was peeled off to expose one side of the resin composition layer. Then, a batch vacuum pressure laminator ("MVLP-500" manufactured by Meiki Co., Ltd.) was used to laminate the exposed resin composition layer onto both sides of the laminated board by bonding the exposed side of the resin composition layer to the epoxy resin double-sided copper-clad laminate (copper foil thickness 18μm, substrate thickness 0.4mm, "R1515A" manufactured by PANASONIC Co., Ltd.) on which the inner layer circuit is formed. The lamination process was carried out by depressurizing for 30 seconds, adjusting the air pressure to below 13hPa, and pressing at 100°C and 0.74MPa for 30 seconds. After the lamination process, the support was peeled off from the resin sheet. Then, the exposed side of the resin composition layer was laminated with the CZ copper foil under the same conditions as described above. After lamination, the resin composition layer is thermo-cured at 220°C for 90 minutes to form a hardened material (insulating layer). This process is then performed on a substrate D with CZ copper foil on both surface layers.

[0281] 3. Preparation of the substrate for the second evaluation: A propylene oxide film with comb-shaped electrodes (line / spacing: 15μm / 15μm) is formed on one side. The protective film of a resin sheet A with a self-adhesive protective film is peeled off, exposing one side of the resin composition layer. Then, using a batch vacuum pressure laminator ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.), the exposed side of the resin composition layer is laminated to the circuit forming side (electrode forming side) of the propylene oxide film. The lamination is performed by depressurizing the pressure to below 13 hPa for 30 seconds, and then pressing at 100°C and 0.74 MPa for 30 seconds. Subsequently, the resin composition layer is hardened by heating at 100°C for 30 minutes and then at 220°C for 90 minutes under nitrogen atmosphere. Thus, a substrate E having a propylene oxide film and a resin composition layer disposed on the propylene oxide film is produced.

[0282] <Determination of Oxygen Transmission Rate> The oxygen transmission rate of resin sheet B and cured material C was measured. An oxygen transmission rate measuring apparatus (MOCON "OX-TRAN 2 / 21") was used, and the measurement was performed at 23°C and 0%RH according to teJIS K7126-2:2006 (isobaric method). The oxygen transmission rate of resin sheet B is "oxygen transmission rate β", and the oxygen transmission rate of cured material C is "oxygen transmission rate α". Furthermore, the oxygen transmission rate of the support used in the fabrication of resin sheet A with a protective film was measured in the same manner as described above. The oxygen transmission rates of each support used in the examples and comparative examples are shown below. Oxygen transmission rate of support A: 40 cc / m²·day Oxygen transmission rate of support B: 0.1 cc / m²·day Oxygen transmission rate of support C: 0.1 cc / m²·day

[0283] <Evaluation of Dielectric Properties> The dielectric properties were evaluated using hardened material C. Specifically, hardened material C was cut into test pieces 2 mm wide and 80 mm long. For the obtained test pieces, the dielectric constant (Dk value) and dielectric loss tangent (Df value) were measured using an Agilent Technologies HP8362B instrument at a measurement frequency of 5.8 GHz and a measurement temperature of 23 °C via the cavity resonance perturbation method. Three test pieces (n=3) were measured, and their average values ​​were calculated. The dielectric properties of hardened material C were evaluated according to the following evaluation criteria.

[0284] Dielectric property evaluation criteria: ○: The average dielectric constant is 3.0 or less, and the average dielectric loss tangent is 0.0030 or less (excellent dielectric properties) ×: One or both of the average dielectric constant and the average dielectric loss tangent do not meet the above criteria (poor dielectric properties)

[0285] <Evaluation of Conductor Adhesion> Conductor adhesion is evaluated using evaluation substrate D. Specifically, evaluation substrate D is cut into small pieces of 150×30mm. A 10mm wide and 100mm long slit is cut into the copper foil portion of each small piece using a cutter. Then, one end of the copper foil is peeled off, held in place by the clamps provided with the tensile testing instrument described below, and the load [kgf / cm] when pulled vertically 35mm at a speed of 50mm / min is measured at room temperature. The measurement is performed using a tensile testing instrument (TSE Autocom universal testing instrument "AC-50C-SL"). The measurement is conducted according to Japanese Industrial Standard JIS C6481. The load value obtained from the measurement results is referred to below as "conductor adhesion strength". Conductor adhesion is evaluated according to the following evaluation criteria.

[0286] Conductor Adhesion Evaluation Criteria: ○: Conductor adhesion strength value is 0.50 kgf / cm or higher (excellent conductor adhesion) ×: Conductor adhesion strength value is less than 0.50 kgf / cm (poor conductor adhesion)

[0287] <Evaluation of Mechanical Properties (Maximum Point Stress and Elongation at Break)> Mechanical properties were evaluated using hardened material C. Specifically, hardened material C was cut into dumbbell-shaped pieces (No. 1) to obtain test specimens. The tensile strength of the obtained test specimens was measured using a tensile testing machine (RTC-1250A, manufactured by Oriental Technology Co., Ltd.) at a test speed of 5 mm / min. The elongation at break and maximum point stress at 23°C were also measured. The measurements were performed according to JIS K7127. Five measurements were performed (n=5), and the average of the first three measurements was calculated. The mechanical properties of the hardened material were evaluated according to the following evaluation criteria.

[0288] Mechanical property evaluation criteria: ○: The average value of the elongation at break is 1.4% or more and the average value of the maximum point stress is 100 MPa or more (excellent mechanical properties) ×: One or both of the average value of the maximum point stress and the average value of the elongation at break do not meet the above criteria (poor mechanical properties)

[0289] <Evaluation of Insulation Reliability> The insulation reliability is evaluated using substrate E. Specifically, firstly, the initial insulation resistance value of substrate E is measured. Then, substrate E is placed in a high-temperature, high-humidity bath at 130°C and 85% humidity, and a voltage of 3.3V is applied for 300 hours. A HAST test is then performed inside the bath at 130°C and 85%RH. The insulation resistance value of substrate E after 300 hours is measured and evaluated using the following criteria.

[0290] Insulation reliability evaluation criteria: ○: The insulation resistance value after 300 hours exceeds 50% of the initial insulation resistance value (excellent insulation reliability) ×: The insulation resistance value after 300 hours is less than 50% of the initial insulation resistance value (poor insulation reliability)

[0291] <Synthesis Example 1> (Solution Synthesis of Thermoplastic Resin d) A 500 mL separable flask connected to a reflux condenser, a moisture metering receiver, a nitrogen inlet tube, and a stirrer was prepared. 20.3 g of 4,4'-oxyphthalic anhydride (ODPA), 200 g of γ-butyrolactone, 20 g of toluene, and 29.6 g of 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindene were added to the flask, and the mixture was stirred at 45°C for 2 hours under nitrogen. Next, the reaction solution was heated and maintained at approximately 160°C, and azeotropically reacted with toluene under a nitrogen stream to remove condensate. A specific amount of water was accumulated in the moisture metering receiver, and no more water was observed flowing out. After confirmation, the reaction solution was further heated and stirred at 200°C for 1 hour. The solution was then cooled to obtain a solution (20% by mass of non-volatile components) containing a thermoplastic resin having a 1,1,3-trimethylindene backbone (hereinafter also referred to as "thermoplastic resin d"). The obtained thermoplastic resin d is a polyimide compound having repeating units represented by the following formula (X1) and repeating units represented by the following formula (X2). The weight average molecular weight of the aforementioned thermoplastic resin d is 12,000.

[0292]

[0293]

[0294] -Examples 1 to 6, Comparative Examples 1 to 5- Hereinafter, examples and comparative examples are shown for resin sheets containing a resin composition layer and a support containing a component selected from component (A), component (B) and component (C).

[0295] [Example 1] (1) Preparation of the resin composition constituting the resin composition layer: 28.6 parts (20 parts based on non-volatile components) of free radical polymerizable resin c1 (MIR-3000-70MT manufactured by Nippon Kayaku Co., Ltd.; a MEK / toluene mixed solution with 70% by mass of non-volatile components) as component (C), and 28.6 parts (10 parts based on non-volatile components) of benzocyclobutene resin a (CYCLOTEN (registered trademark) 3022 manufactured by Dow Chemical Co., Ltd.; number average molecular weight: 390, a trimethylbenzene solution with 35% by mass of non-volatile components) as component (A) were stirred and heated to dissolve. A solution was thus obtained.

[0296] Furthermore, the non-volatile components contained in the free radical polymerizable resin c1 ("MIR-3000-70MT") are represented by the following structural formula. In the formula, e1 is an integer from 1 to 100.

[0297]

[0298] Cool the resulting solution to room temperature. Subsequently, 13.8 parts (9 parts based on non-volatile components) of free radical polymerizable resin c2 (OPE-2St (oligophenyl ether styrene resin) manufactured by Mitsubishi Gas Chemical Co., Ltd.; number average molecular weight: 1200, toluene solution with 65% by mass of non-volatile components) as component (C), 60 parts of inorganic filler b (Spherical silica "SO-C2" manufactured by ADMATECHS Co., Ltd. with surface treated with amine silane coupling agent "KBM573" manufactured by Shin-Etsu Chemical Co., Ltd., average particle size: 0.5 μm, specific surface area: 5.8 m2 / g) as component (B), 5 parts of thermoplastic resin d (1 part based on non-volatile components) as component (D), and 0.05 parts of curing accelerator e (PERHEXYL (registered trademark) D manufactured by Nippon Oil Co., Ltd.) as component (E) were added to the solution and mixed, and then uniformly dispersed using a high-speed rotary mixer. A dispersion was thus obtained. Therefore, a resin varnish containing components (A) to (E) is prepared (non-volatile component content: 69% by mass).

[0299] (2) Fabrication of a resin sheet with a protective film: As support A, a PET film (Toray Industries' "Lumirror R80"; thickness 38 μm, softening point 130°C) is prepared on one side by demolding with an alkyd resin-based release agent (LINTEC's "AL-5"). The total thickness of support A is 38 μm.

[0300] The resin varnish of the resin composition prepared in (1) above is uniformly coated on the demolding surface of the support A using a die-cutting applicator, so that the thickness of the dried resin composition layer is 40 μm, and dried at 90°C for 3 minutes. Thereby, a resin sheet comprising the support A and the resin composition layer disposed on the support A is obtained.

[0301] Next, on the exposed surface of the resin composition layer (the surface not bonded to the support A), the support A, which serves as a protective film, is laminated to the resin composition layer in such a way that its demolding treatment surface is bonded to the resin composition layer. In this way, a resin sheet comprising a support, a resin composition layer disposed on the support, and a protective film disposed on the resin composition layer is obtained. The resin sheet thus obtained is generally referred to as "resin sheet A with a protective film".

[0302] [Example 2] Except that 1) the amount of benzocyclobutene resin a was changed from 28.6 parts to 38.5 parts (25 parts based on non-volatile components), 2) the amount of free radical polymerizable resin c1 was changed from 28.6 parts to 0 parts (i.e., not mixed), and the amount of free radical polymerizable resin c2 was changed from 13.8 parts to 21.5 parts (14 parts based on non-volatile components), the resin varnish was prepared in the same manner as in Example 1, and resin sheets were made using support A.

[0303] [Example 3] Except that 1) the amount of inorganic filler b was changed from 60 parts to 40 parts, 2) the amount of free radical polymerizable resin c1 was changed from 28.6 parts to 42.9 parts (19 parts based on non-volatile components), and the amount of free radical polymerizable resin c2 was changed from 13.8 parts to 29.2 parts (14 parts based on non-volatile components), the resin varnish was prepared in the same manner as in Example 1, and resin sheets were made using support A.

[0304] [Example 4] Except that support A was replaced with support B, the resin varnish was prepared in the same manner as in Example 3, and a resin sheet was made using support B. As support B, a PET film (Mitsubishi Chemical Corporation "TECHBARRIER (registered trademark) HX"; thickness 38 μm) with a 300 nm silicon oxide vapor deposited layer was formed on one of the main surfaces of a PET film (Toray Industries "Lumirror R80"; thickness 38 μm). The total thickness of support B was 53 μm.

[0305] [Example 5] Except that support A was replaced with support C, the resin varnish was prepared in the same manner as in Example 3, and a resin sheet was made using support C. Support C was prepared as follows. First, a metal-coated film (layer composition: 38 μm thick PET film / 2 μm thick water-soluble resin layer / 1000 nm thick copper layer) was prepared, identical to the metal-coated film described in Example 1 of Japanese Patent No. 5500074. Next, an alkyd-based release treatment (LINTEC "AL-5") was performed on the exposed surface of the PET film of the metal-coated film. The total thickness of the support C obtained in this way was 41 μm.

[0306] [Example 6] Except that 1) the amount of inorganic filler b was changed from 60 parts to 50 parts, 2) the amount of free radical polymerizable resin c1 was changed from 28.6 parts to 0 parts (i.e., not mixed), and the amount of free radical polymerizable resin c2 was changed from 13.8 parts to 15.4 parts (10 parts based on non-volatile components), 3) the amount of thermoplastic resin d was changed from 5 parts to 150 parts (30 parts based on non-volatile components), and 4) the support A was changed to support B, the resin varnish was prepared in the same manner as in Example 1, and the resin sheet was made using support B.

[0307] [Comparative Example 1] Except that 1) the amount of free radical polymerizable resin c1 was changed from 28.6 parts to 0 parts (i.e., not mixed), and the amount of free radical polymerizable resin c2 was changed from 13.8 parts to 0 parts (i.e., not mixed) (i.e., component (C) was not used), and 3) the amount of thermoplastic resin d was changed from 5 parts to 150 parts (30 parts based on non-volatile components), the resin varnish was prepared in the same manner as in Example 1, and resin sheets were made using support A.

[0308] [Comparative Example 2] Except that 1) the amount of inorganic filler b was changed from 60 parts to 40 parts, 2) the amount of free radical polymerizable resin c1 was changed from 28.6 parts to 0 parts (i.e., not mixed), and the amount of free radical polymerizable resin c2 was changed from 13.8 parts to 15.4 parts (10 parts based on non-volatile components), and 3) the amount of thermoplastic resin d was changed from 5 parts to 200 parts (40 parts based on non-volatile components), the resin varnish was prepared in the same manner as in Example 1, and resin sheets were made using support A.

[0309] [Comparative Example 3] Except that 1) the amount of benzocyclobutene resin a was changed from 28.6 parts to 85.7 parts (30 parts based on non-volatile components) and 2) the amount of inorganic filler b was changed from 40 parts to 20 parts, the resin varnish was prepared in the same manner as in Comparative Example 2, and resin sheets were made using support A.

[0310] [Comparative Example 4] Except that the support A was changed to support B, the resin varnish was prepared in the same manner as in Comparative Example 3, and the resin sheet was made using support B.

[0311] [Comparative Example 5] Except that the support B was changed to the support A, the resin varnish was prepared in the same manner as in Example 6, and the resin sheet was made using the support A.

[0312] The results of Examples 1 to 6 and Comparative Examples 1 to 5 are shown in Table 1 and Table 2.

[0313]

[0314]

Claims

1. A resin sheet comprising a support and a resin composition layer disposed on the support, wherein the resin composition layer comprises (A) a compound having two or more benzocyclobutene groups in its molecule, (B) an inorganic filler, and (C) a resin having free radical polymerizable unsaturated groups in its molecule, wherein the number average molecular weight (Mn) of the (A) component is 2000 or less, and the oxygen permeability α of the aforementioned resin composition layer, when cured under conditions at 220°C for 90 minutes, is 70 cc / m². day or less, and the oxygen permeability β of the aforementioned resin sheet, when cured under conditions at 220°C for 90 minutes, is 40 cc / m². day or less, wherein the oxygen permeability α and oxygen permeability β are measured values ​​according to JIS K7126-2:2006 (isobaric method) at 23°C and 0%RH.

2. The resin film of claim 1, wherein the content of component (B) is 30% or more and 80% or less when the non-volatile components in the resin composition are set to 100% by mass.

3. The resin film of claim 1, wherein the content of component (A) is 3% by mass or more and 40% by mass or less when the non-volatile components in the resin composition are set to 100% by mass.

4. The resin sheet of claim 1, wherein component (C) is selected from one or more of resins having maleimide groups, resins having acrylamide groups, resins having methacrylic groups, and resins having styrene groups.

5. The resin sheet of claim 1, wherein the aforementioned support system is selected from single-layer resin film, multiple-layer resin film, metal foil, release paper and composite film including support substrate and metal foil.

6. The resin sheet of claim 1, wherein component (A) has a siloxane backbone.

7. The resin sheet of claim 1, wherein component (A) comprises a compound represented by the following formula (A-2), 7. (In formula (A-2), R1 represents a divalent aliphatic group with an unsaturated bond, R2 represents a hydrogen atom, alkyl, cycloalkyl, arylalkyl or aryl, RA1 represents an alkyl, cyano or halogen atom, RA2 represents an alkyl, trialkylsilyl, alkoxy or halogen atom, nA1 represents an integer from 0 to 2, nA2 represents an integer from 0 to 3, nA4 represents an integer from 1 to 10, R1, R2, RA1 and RA2 may each have substituents independently, multiple R1s may be the same or different, multiple R2s may be the same or different, when RA1 is multiple, they may be the same or different, when RA2 is multiple, they may be the same or different).

8. The resin sheet of claim 1, wherein component (A) comprises a compound represented by the following formula, 9. The resin sheet of claim 1, wherein the dielectric constant of the hardened resin composition layer is 3.0 or less.

10. The resin sheet of claim 1, wherein the dielectric loss tangent of the hardened resin composition layer is 0.0030 or less.

11. The resin sheet of claim 1, wherein, during the aforementioned determination of oxygen permeability β, the hardened side of the aforementioned resin composition layer is exposed.

12. The resin sheet as requested in item 1 is used as an insulating layer for printed circuit boards.

13. A method for manufacturing a printed wiring board, comprising the following steps: (1) preparing a resin sheet having a support and a resin composition layer disposed on the support, wherein one side of the resin composition is exposed; (2) depositing the resin sheet on the substrate such that the resin composition layer is deposited on the substrate of the printed wiring board; and (3) curing the resin sheet deposited on the substrate in a state in which the support does not peel off from the resin composition layer, wherein the resin composition layer comprises (A) a compound having two or more benzocyclobutene groups in its molecule, (B) an inorganic filler and (C) a resin having free radical polymerizable unsaturated groups in its molecule, wherein the number average molecular weight (Mn) of the (A) component is 2000 or less, and the oxygen permeability α of the resin composition layer measured when cured at 220°C for 90 minutes is 70 cc / m2. For days below, the oxygen permeability β of the resin sheet exposed on one side of the aforementioned resin composition layer was measured at 220°C for 90 minutes and was 40cc / m2. For days below, the oxygen permeability α and oxygen permeability β were measured according to JIS K7126-2:2006 (isobaric method) at 23°C and 0%RH.