TWI879891B - Resin flakes - Google Patents

Abstract

[Topic] To provide a resin sheet or the like which can obtain a cured product having a low dielectric tangent and excellent insulation reliability. [Solution] A resin sheet having a support and a resin composition layer disposed on the support and containing a resin composition, wherein the oxygen permeability of the support measured by a method in accordance with JIS K7126 is 20 cc/m ² ·day or less in an environment of 23°C and 50% RH, the amount of solvent contained in the resin composition layer is 5 mass % or less, and the resin composition contains either (A-1) a volatile epoxy resin or (B) a free radical polymerizable resin.

Description

Resin flakes

The present invention relates to a resin sheet, a printed wiring board formed using the resin sheet, a semiconductor device, and a method for manufacturing the printed wiring board.

As a manufacturing technology for printed wiring boards, there is a known manufacturing method in which an insulating layer and a conductive layer are alternately stacked on an inner circuit substrate. Generally, the insulating layer is formed by curing a resin composition.

For example, Patent Document 1 describes a resin composition containing a liquid epoxy resin, a solid epoxy resin, an active ester hardener, and an inorganic filler. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2020-029494

[The problem that the invention wants to solve]

However, in recent years, when manufacturing multi-layer printed wiring boards, the cured resin composition used to form the insulating layer is required to have a lower dielectric tangent.

In order to reduce the dielectric tangent, it is considered to include a component that reduces the dielectric tangent in the resin composition. The inventors of the present invention have examined and found that if oxygen is present during the thermal curing of the resin composition layer, the crosslinking of the component that reduces the dielectric tangent will be hindered by oxygen and the curing reaction of the resin composition will be hindered. In addition, if the epoxy resin evaporates during the thermal curing of the resin composition layer, the crosslinkable component is reduced and the curing reaction is hindered. As a result, it was found that the crosslinking density of the cured product of the resin composition layer becomes lower, and even if the dielectric tangent can be reduced, the insulation reliability of the cured product of the resin composition layer becomes poor.

The subject of the present invention is to provide a resin sheet that can obtain a cured product with low dielectric tangent and excellent insulation reliability; a printed wiring board having an insulation layer formed using the resin sheet; a semiconductor device; and a method for manufacturing a printed wiring board. [Means for solving the subject]

The inventors of the present invention have actively studied and found that the use of a specific support and setting the solvent content in the resin composition forming the resin composition layer within a specific range, and the inclusion of either (A-1) a volatile epoxy resin or (B) a free radical polymerizable resin in the resin composition can solve the above-mentioned problem and complete the present invention. That is, the present invention includes the following contents.

[1] A resin sheet comprising a support and a resin composition layer disposed on the support, wherein the oxygen permeability of the support measured by a method in accordance with JIS K7126 is 20 cc/ ^m2 ·day or less in an environment of 23°C and 50% RH, the amount of solvent contained in the resin composition layer is 5 mass % or less, and the resin composition contains any one of (A-1) a volatile epoxy resin and (B) a free radical polymerizable resin. [2] The resin sheet as described in [1], wherein the water vapor transmission rate of the support measured by the method according to JIS K7129 in an environment of 40°C and 90% RH is 20 g/ ^m2 ·day or less. [3] The resin sheet as described in [1] or [2], wherein the total content of the component (A-1) and the component (B) is 1 mass % to 20 mass % when the resin component is 100 mass %. [4] The resin sheet as described in any one of [1] to [3], wherein the total content of the component (A-1), the component (B) and the solvent is 1 mass % to 20 mass % when the resin component is 100 mass %. [5] A resin sheet as described in any one of [1] to [4], wherein the resin composition further contains (C) an inorganic filler. [6] A resin sheet as described in [5], wherein the content of component (C) is 50% by mass or more when the non-volatile components in the resin composition are set to 100% by mass. [7] A printed wiring board comprising an insulating layer formed by a cured product of a resin composition layer of the resin sheet as described in any one of [1] to [6]. [8] A semiconductor device comprising the printed wiring board as described in [7]. [9] A method for manufacturing a printed wiring board, comprising the following steps in order: (I) laminating a resin sheet as described in any one of [1] to [6] on an inner substrate so that the resin composition layer is bonded to the inner substrate, (II) thermally curing the resin composition layer to form an insulating layer, and (III) peeling off the support. [Effects of the Invention]

The present invention can provide a resin sheet that can obtain a cured product with low dielectric tangent and excellent insulation reliability; a printed wiring board having an insulation layer formed using the resin sheet; a semiconductor device; and a method for manufacturing a printed wiring board.

The following is a detailed description of the resin sheet of the present invention, a printed wiring board having an insulating layer formed using the resin sheet, a semiconductor device, and a method for manufacturing the printed wiring board.

[Resin sheet] The resin sheet of the present invention is a resin sheet having a support and a resin composition layer disposed on the support and containing a resin composition, wherein the oxygen permeability of the support measured by the method according to JIS K7126 is 20cc/ ^m2 ·day or less in an environment of 23°C and 50%RH, the amount of solvent contained in the resin composition layer is 5% by mass or less, and the resin composition contains any one of (A-1) a volatile epoxy resin and (B) a free radical polymerizable resin.

The cured product of the resin composition layer formed by using the resin sheet of the present invention has a low dielectric tangent and excellent insulation reliability. In addition, the present invention can obtain a cured product with excellent adhesion between the normal copper foil and the copper foil after HAST. The following is a detailed description of each layer constituting the resin sheet.

<Support> The resin sheet of the present invention has a support. The oxygen permeability of the support measured by the method according to JIS K7126 is less than 20cc/ ^m2 ·day in an environment of 23°C and 50%RH. During the thermal curing of the resin composition layer, if oxygen exists in the resin composition layer, it will hinder the curing reaction of the resin composition. In addition, the volatile epoxy resin may pass through the support with a high oxygen permeability, so due to the volatility of the epoxy resin during the thermal curing of the resin composition layer, there may be a decrease in the cross-linkable components. As a result, the cross-linking density of the cured product of the resin composition layer becomes low, and the insulation reliability becomes poor. The resin sheet of the present invention has a support having an oxygen permeability of 20cc/ ^m2 ·day or less in an environment of 23°C and 50%RH as measured by the method of JIS K7126, which can inhibit oxygen from penetrating into the resin composition layer through the support. In addition, since the support has an oxygen permeability of 20cc/ ^m2 ·day or less in an environment of 23°C and 50%RH, the volatility of the epoxy resin contained in the resin composition layer can be inhibited, and the cross-linking density of the cured product of the resin composition layer can be increased. Therefore, it is possible to obtain an insulating layer with a low dielectric tangent and excellent insulation reliability.

From the viewpoint of obtaining an insulating layer with low dielectric tangent and excellent insulation reliability, the oxygen permeability of the support is 20cc/ ^m2 ·day or less, preferably 18cc/m2·day or less, more preferably 15cc/ ^m2 ·day or less, 10cc/ ^m2 ·day or less, 5cc/ ^m2 ·day or less, 3cc/ ^m2 ·day or less, or 1cc/ ^m2 ·day or less in an environment of 23° ^{C and} 50%RH. The lower limit is preferably 0cc/ ^m2 ·day or more, more preferably 0.01cc/ ^m2 ·day or more, 0.05cc/ ^m2 ·day or more. Here, %RH indicates relative humidity.

The specific method for measuring the oxygen permeability of the support is to use an oxygen permeability measuring device (manufactured by MOCON, OX-TRAN2/21) and measure it in an environment of 23°C and 50%RH in accordance with JIS K7126 (isobaric method).

From the viewpoint of obtaining an insulating layer with low dielectric tangent and excellent insulation reliability, the water vapor permeability of the support is preferably 20 g/m ² ·day or less, preferably 18 g/m ^{2·day or less, more preferably 15 g/m 2} ·day or less, 10 g/m ² ·day or less, 5 g/m ² ·day or less, 3 g/m ² ·day or less, or 1 g/m ² ·day or less at 40°C and 90%RH. The lower limit is preferably 0 g/m ² ·day or more, more preferably 0.01 g/m ² ·day ^or more, or 0.05 g/m ² ·day or more.

The water vapor permeability of the support can be specifically measured using a water vapor permeability measuring device (PERMATRAN-W3/34 manufactured by MOCON) in an environment of 40°C and 90%RH in accordance with JIS K7129.

As a support, a support having an oxygen permeability of 20cc/ ^m2 ·day or less in an environment of 23°C and 50%RH as measured by a method in accordance with JIS K7126 can be used. Examples of such a support include a substrate having an oxygen permeability of 20cc/ ^m2 ·day or less, a support having a release layer laminated on a substrate, a support having a barrier layer laminated on a substrate, and a support having a release layer, a substrate, and a barrier layer laminated in this order. In addition, in the case of a support body of a barrier layer or a release layer laminated on a substrate, the oxygen permeability of the substrate does not need to be less than 20cc/ ^m2 ·day. It is sufficient that the oxygen permeability of the support body of the barrier layer or the release layer laminated on the substrate is less than 20cc/ ^m2 ·day.

As the substrate, for example, a film made of a plastic material, a metal foil, and a release paper can be cited, and a film made of a plastic material and a metal foil are preferred.

When a film made of a plastic material is used as the substrate, the plastic material includes, for example, polyesters such as polyethylene terephthalate (hereinafter also referred to as "PET") and polyethylene naphthalate (hereinafter also referred to as "PEN"), polycarbonate (hereinafter also referred to as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and polyethylene terephthalate is more preferred.

When a metal foil is used as the substrate, examples of the metal foil include copper foil and aluminum foil, and copper foil is preferred. The copper foil may be a foil made of a single metal such as copper, or may be a foil made of an alloy of copper and other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

In addition, as the substrate, a release layer substrate having a release layer on the surface bonded to the resin composition layer can also be used. As a release agent for the release layer of the substrate attached with the release layer, for example, at least one release agent selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins can be cited. The substrate attached with the release layer can also use a commercial product.

The thickness of the substrate is not particularly limited, but is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more, and preferably 75 μm or less, more preferably 60 μm or less, and even more preferably 50 μm or less. In addition, when a release-type substrate is used, the thickness of the release-type substrate as a whole is preferably within the above range.

The support may also have a barrier layer. By having a barrier layer, it becomes possible to suppress the penetration of oxygen and water vapor. As the barrier layer, for example, inorganic films, organic films, etc. can be cited. As the inorganic film, for example, metal foils such as aluminum and copper; silicon dioxide vapor-deposited films; silicon nitride films; silicon oxide films; magnesium oxide films, etc. can be cited. In addition, as the organic film, polyvinyl alcohol films, ethylene-vinyl alcohol copolymer films, polyvinylidene chloride films, etc. can be cited. The barrier layer may be composed of a plurality of barrier layers, and may also be composed of an inorganic film and an organic film.

As a method for forming an inorganic film, for example, there can be cited a chemical vapor deposition method using heat, plasma, ultraviolet rays, etc.; a physical vapor growth method using evaporation, sputtering, etc. As a method for forming an organic film, for example, it can be formed by coating an organic compound on a substrate using a coating device such as a die coater, a notch wheel coater, a gravure coater, a coating rod coater, etc.

From the viewpoint of remarkably obtaining the effect of the present invention, the thickness of the barrier layer is preferably 0.05 μm or more, more preferably 0.1 μm or more, and even more preferably 0.15 μm or more, and is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less.

The support can also bond the substrate and the barrier layer through the bonding layer. As an adhesive that can be used for the bonding layer, one that can bond the substrate and the barrier layer can be used. As such an adhesive, for example, an active energy ray curing type adhesive that can be cured by active energy rays such as water-based, solvent-based, hot melt-based, and ultraviolet rays can be cited.

From the viewpoint of remarkably obtaining the effect of the present invention, the thickness of the adhesive layer is preferably 0.1 μm or more, more preferably 0.3 μm or more, and even more preferably 0.5 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 5 μm or less.

The support may also have a release layer. By having a release layer, the support and the resin composition layer can be easily peeled off. As a release agent that can be used for the release layer, for example, one or more release agents selected from the group consisting of alkyd release agents, silicone release agents, urethane release agents, and olefin release agents can be cited. Among them, from the perspective of significantly obtaining the effect of the present invention, alkyd release agents are preferred.

From the viewpoint of remarkably obtaining the effect of the present invention, the thickness of the release layer is preferably 10 nm or more, more preferably 30 nm or more, and even more preferably 50 nm or more, and is preferably 1000 nm or less, more preferably 500 nm or less, and even more preferably 300 nm or less.

From the viewpoint of remarkably obtaining the effect of the present invention, the total thickness of the support is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more, and is preferably 80 μm or less, more preferably 70 μm or less, and even more preferably 60 μm or less.

The support system may also be subjected to a matte treatment, a corona treatment, or an antistatic treatment on the surface of the substrate that is bonded to the resin composition layer.

<Resin composition layer> The resin sheet has a resin composition layer containing a resin composition, the amount of solvent contained in the resin composition layer is 5% by mass or less, and the resin composition contains either (A-1) a volatile epoxy resin or (B) a radical polymerizable resin. By setting the amount of solvent contained in the resin composition layer to 5% by mass or less, the residual solvent in the cured product of the resin composition layer can be suppressed, so that the molecular spacing in the cured product is expanded, and the reduction of the crosslinking density can be suppressed. As a result, ion migration is not easily caused, and the cured product has excellent insulation reliability. In addition, it can also suppress the swelling of the copper wiring pattern caused by the volatilization of the solvent.

From the perspective of reducing the dielectric tangent, the resin composition contains any one of the components (A-1) and (B). The resin composition may further contain (A-2) epoxy resin other than the (A-1) component, (C) inorganic filler, (D) organic filler, (E) hardener, (F) hardening accelerator, (G) polymerization initiator, (H) thermoplastic resin, (I) flame retardant, and (J) other additives as needed. The following is a detailed description of each component contained in the resin composition. In addition, in this specification, the components (A-1) and (A-2) are collectively referred to as (A) epoxy resin.

-(A-1) Volatile epoxy resin- The resin composition may also contain (A-1) volatile epoxy resin as the (A-1) component. However, the resin composition does not contain the (B) component. By making the resin composition contain the (A-1) volatile epoxy resin, the melt viscosity of the resin composition can be reduced. Thereby, even if the (C) inorganic filler described later is contained in a large amount to reduce the dielectric tangent, the increase in the melt viscosity of the resin composition layer can be suppressed. The (A-1) component can be used alone or in combination of two or more.

The determination of volatile epoxy resins is to use a thermogravimetric differential thermal analyzer (TG-DTA device) to measure the weight loss rate caused by heating from 30℃ to 550℃ in air at 10℃/min. The epoxy resins with a weight loss rate of 3% by mass or more at 200℃ are defined as volatile epoxy resins. The specific method for determining volatile epoxy resin is to weigh about 10 mg of epoxy resin (mass before heating) in an aluminum sample pan, and in an uncovered open state, heat the sample from 30°C to 550°C at a rate of 10°C/min in an environment with an air flow rate of 200mL/min, and measure the weight (mass) of the sample at each temperature. The weight loss rate at 200°C is calculated using the following formula from the obtained results. Weight loss rate at 200°C (mass %) = 100×(mass before heating - mass at 200°C)/mass before heating

From the viewpoint of obtaining the desired effect of the present invention, the weight reduction rate of the volatile epoxy resin (A-1) at 200°C is preferably 3 mass% or more, more preferably 3.5 mass% or more, and even more preferably 4 mass% or more, and is preferably 20 mass% or less, more preferably 15 mass% or less, and even more preferably 10 mass% or less.

From the viewpoint of obtaining the desired effect of the present invention, the component (A-1) preferably has one or more epoxy groups in one molecule, more preferably two or more epoxy groups in one molecule, and even more preferably three or more epoxy groups in one molecule. From the viewpoint of remarkably obtaining the desired effect of the present invention, the ratio of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more, based on 100% by mass of the nonvolatile component of the component (A-1).

The component (A-1) includes a component (A-1) that is liquid at 20° C. and a component (A-1) that is solid at 20° C. The component (A-1) is preferably a liquid component in order to obtain the desired effect of the present invention.

As component (A-1), the aforementioned epoxy resin having a weight reduction rate of 3 mass % or more can be used. As such an epoxy resin, it is preferred to have a cyclic skeleton. As the cyclic structure, an alicyclic structure, an aromatic cyclic structure, etc. can be cited. As the alicyclic structure, a cyclohexane ring, a cyclopentane ring, a cycloheptane ring, a cyclooctane ring, etc. can be cited, and a cyclohexane ring is preferred. As the aromatic ring structure, a benzene ring, a naphthalene ring, an anthracene ring, etc. can be cited, and a benzene ring is preferred.

Specific examples of the component (A-1) include "ZX1658GS" manufactured by Nippon Steel & Sumitomo Metal Chemicals (liquid 1,4-epoxypropyl cyclohexane type epoxy resin); "EX-721" manufactured by Nagase ChemteX (liquid diglycidyl phthalate type epoxy resin); "CELLOXIDE 2021P" manufactured by Daicel (aliphatic epoxy resin having an ester skeleton); and "ZX1658" manufactured by Nippon Steel & Sumitomo Metal Chemicals (liquid 1,4-epoxypropyl cyclohexane type epoxy resin). These may be used alone or in combination of two or more.

The epoxy equivalent of the component (A-1) is preferably 50 g/eq. to 5000 g/eq., more preferably 50 g/eq. to 3000 g/eq., still more preferably 80 g/eq. to 2000 g/eq., and still more preferably 110 g/eq. to 1000 g/eq. Within this range, the crosslinking density of the cured product of the resin composition layer becomes sufficient, and an insulating layer with a small surface roughness can be obtained. The epoxy equivalent is the mass of the epoxy resin containing 1 equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

The weight average molecular weight (Mw) of the component (A-1) is preferably 100 to 5000, more preferably 200 to 3000, and even more preferably 250 to 1500 from the viewpoint of significantly obtaining the desired effect of the present invention. The weight average molecular weight of the resin can be measured as a value converted to polystyrene by gel permeation chromatography (GPC).

The content of component (A-1) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, from the viewpoint of obtaining good mechanical strength and an insulating layer showing insulation reliability, when the non-volatile components in the resin composition are set to 100% by mass. The upper limit of the content of the epoxy resin is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less, from the viewpoint of significantly obtaining the desired effect of the present invention. In addition, in the present invention, the content of each component in the resin composition is the value when the non-volatile components in the resin composition are set to 100% by mass, unless otherwise specifically stated.

-(A-2) Epoxy resin other than component (A-1) - The resin composition may further contain an epoxy resin other than component (A-2) (A-1) as an optional component. Component (A-2) refers to an epoxy resin having a weight loss rate of less than 3% by mass at 200°C.

Examples of the component (A-2) include bixylene type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, Glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spirocyclic epoxy resin, oxalicyclic epoxy resin, oxalicyclic alcohol type epoxy resin, naphthyl ether type epoxy resin, trihydroxymethyl type epoxy resin, tetraphenylethane type epoxy resin, etc. The epoxy resin may be used alone or in combination of two or more.

As component (A-2), it is preferred to include an epoxy resin having two or more epoxy groups in one molecule. From the viewpoint of significantly obtaining the desired effect of the present invention, the ratio of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more, relative to 100% by mass of the non-volatile component of component (A-2).

The component (A-2) includes an epoxy resin that is liquid at 20°C (hereinafter referred to as "liquid epoxy resin") and an epoxy resin that is solid at 20°C (hereinafter referred to as "solid epoxy resin"). The component (A-2) may include only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. From the perspective of significantly obtaining the desired effect of the present invention, a combination of a liquid epoxy resin and a solid epoxy resin is preferred.

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

As the solid epoxy resin, preferred are biphenyl type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, The epoxy resin may be a naphthyl ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, or tetraphenylethane type epoxy resin, and more preferably a naphthalene type tetrafunctional epoxy resin, a naphthol type epoxy resin, a biphenyl type epoxy resin, or a bisphenol AF type epoxy resin.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene-based epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene-based tetrafunctional epoxy resin) manufactured by DIC Corporation; "N-690" (cresol-phenolic epoxy resin) manufactured by DIC Corporation; "N-695" (cresol-phenolic epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", and "HP-7200H" ( "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthyl ether type epoxy resin) manufactured by DIC Corporation; "EPPN-502H" (triphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", " NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.; "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX4000HK" (xylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation "YX8800" manufactured by Mitsubishi Chemical (anthracene-type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd.; "YL7760" manufactured by Mitsubishi Chemical (bisphenol AF-type epoxy resin); "YL7800" manufactured by Mitsubishi Chemical (fluorene-type epoxy resin); "jER1010" manufactured by Mitsubishi Chemical (solid bisphenol A-type epoxy resin); "jER1031S" manufactured by Mitsubishi Chemical (tetraphenylethane-type epoxy resin), etc. These can be used alone or in combination of two or more.

The liquid epoxy resin is preferably one having two or more epoxy groups in one molecule.

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

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene-based epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "825", and "Epikote" manufactured by Mitsubishi Chemical Corporation. "828EL" (bisphenol A type epoxy resin); "jER807" and "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical; "630" and "630LSD" (glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical; "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.; "PB-3600" (epoxy resin with butadiene structure) manufactured by Daicel Co., Ltd., etc. These can be used alone or in combination of two or more.

When a liquid epoxy resin and a solid epoxy resin are used in combination as component (A-2), the mass ratio of the liquid epoxy resin and the solid epoxy resin is preferably 1:1 to 1:20, more preferably 1:1.5 to 1:15, and particularly preferably 1:2 to 1:10. By making the mass ratio of the liquid epoxy resin to the solid epoxy resin within the above range, the desired effect of the present invention can be significantly obtained. In addition, when it is usually used in the form of a resin sheet, moderate adhesion can be obtained. In addition, when it is usually used in the form of a resin sheet, sufficient flexibility can be obtained and the operability is improved. Furthermore, a hardened material having sufficient breaking strength can usually be obtained.

The epoxy equivalent of the component (A-2) is preferably 50 g/eq. to 5000 g/eq., more preferably 50 g/eq. to 3000 g/eq., still more preferably 80 g/eq. to 2000 g/eq., and still more preferably 110 g/eq. to 1000 g/eq. Within this range, the crosslinking density of the cured product of the resin composition layer becomes sufficient, and an insulating layer with a small surface roughness can be obtained.

The weight average molecular weight (Mw) of the component (A-2) is preferably 100 to 5,000, more preferably 200 to 3,000, and even more preferably 250 to 1,500, from the viewpoint of significantly obtaining the desired effect of the present invention.

The content of the component (A-2) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, from the viewpoint of obtaining good mechanical strength and an insulating layer showing insulation reliability, when the non-volatile components in the resin composition are set to 100% by mass. The upper limit of the content of the epoxy resin is preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less, from the viewpoint of significantly obtaining the desired effect of the present invention.

When the component (A-1) and the component (A-2) are used in combination, the quantitative ratio (component (A-1) : component (A-2)) is preferably 1:1 to 1:20, more preferably 1:1.5 to 1:15, and particularly preferably 1:2 to 1:10 in terms of mass ratio in order to significantly obtain the effect of the present invention.

-(B) Radical polymerizable resin- The resin composition contains (B) radical polymerizable resin as (B) component. However, this does not apply to the case where the resin composition contains (A-1) component. By containing (B) radical polymerizable resin in the resin composition, it is possible to obtain a cured product with a low dielectric tangent.

As component (B), a resin having a free radical polymerizable unsaturated group can be used. The so-called free radical polymerizable group refers to a group having an ethylene double bond that is hardenable by irradiation with active energy rays such as ultraviolet rays or by heat. Examples of such a group include vinyl, vinylphenyl, acryl, and methacryl, maleimide, fumaric, and maleic groups, preferably at least one selected from vinylphenyl, acryl, and methacryl. Here, acryl and methacryl are also collectively referred to as "(meth)acryl". In addition, the so-called vinylphenyl is a group having the structure shown below.

From the viewpoint of obtaining a cured product having a low dielectric tangent, the component (B) preferably has two or more free radical polymerizable unsaturated groups per molecule.

From the viewpoint of obtaining a cured product with a low dielectric tangent, the component (B) preferably has a cyclic structure. The cyclic structure is preferably a divalent cyclic group. The divalent cyclic group may be any of a cyclic group containing an alicyclic structure and a cyclic group containing an aromatic cyclic structure. In addition, it may have a plurality of divalent cyclic groups.

From the viewpoint of remarkably obtaining the desired effect of the present invention, the divalent cyclic group is preferably 3-membered or more, more preferably 4-membered or more, and even more preferably 5-membered or more, and preferably 20-membered or less, more preferably 15-membered or less, and even more preferably 10-membered or less. In addition, the divalent cyclic group may be a monocyclic structure or a polycyclic structure.

The ring in the divalent cyclic group may have a heteroatom other than carbon atoms to form the skeleton of the ring. Examples of the heteroatom include oxygen atoms, sulfur atoms, and nitrogen atoms, and oxygen atoms are preferred. The ring may have one heteroatom or two or more heteroatoms.

Specific examples of the divalent cyclic group include the following divalent groups (i) to (xiii). (In the divalent groups (xii) and (xiii), R ¹ , R ² , R ⁵ , R ⁶ , R ⁷ , R ¹¹ , and R ¹² each independently represent a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group; and R ³ , R ⁴ , R ⁸ , R ⁹ , and R ¹⁰ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group).

Examples of the halogen atom include fluorine, chlorine, bromine and iodine. Examples of the alkyl group having 6 or less carbon atoms include methyl, ethyl, propyl, butyl, pentyl and hexyl, preferably methyl. ^R1 , ^R2 , ^R5 , ^R6 , ^R7 , ^R11 and ^R12 preferably represent methyl. ^R3 , ^R4 , ^R8 , ^R9 and ^R10 preferably represent hydrogen or methyl.

Furthermore, the divalent cyclic group may be a combination of plural divalent cyclic groups. As a specific example of a combination of divalent cyclic groups, a divalent cyclic group represented by the following formula (a) (divalent group (a)) can be cited. (In formula (a), R ²¹ , R ²² , R ²⁵ , R ²⁶ , R ²⁷ , R ³¹ , R ³² , R ³⁵ and R ³⁶ each independently represent a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group; R ²³ , R ²⁴ , R ²⁸ , R ²⁹ , R ³⁰ , R ³³ and R ³⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. n and m represent integers of 0 to 300, except when one of n and m is 0).

R ²¹ , R ²² , R ³⁵ and R ³⁶ are the same as R ¹ in the divalent group (xii). R ²³ , R ²⁴ , R ³³ and R ³⁴ are the same as R ³ in the divalent group (xii). R ²⁵ , R ²⁶ , R ²⁷ , R ³¹ and R ³² are the same as R ⁵ in the formula (xiii). R ²⁸ , R ²⁹ and R ³⁰ are the same as R ⁸ in the formula (xiii).

n and m represent integers from 0 to 300. However, this excludes the case where one of n and m is 0. n and m preferably represent integers from 1 to 100, more preferably represent integers from 1 to 50, and even more preferably represent integers from 1 to 10. n and m may be the same or different.

The divalent cyclic group is preferably a divalent group (x), a divalent group (xi), or a divalent group (a), and more preferably a divalent group (x) or a divalent group (a).

The divalent cyclic group may have a substituent. Examples of such a substituent include a halogen atom, an alkyl group, an alkoxy group, an aryl group, an arylalkyl group, a silyl group, an acyl group, an acyloxy group, a carboxyl group, a sulfo group, a cyano group, a nitro group, a hydroxyl group, a hydroxyl group, and a pendoxy group. An alkyl group is preferred.

The free radical polymerizable unsaturated group may be directly bonded to the divalent cyclic group or may be bonded through a divalent linking group. Examples of the divalent linking group include alkylene groups, alkenylene groups, arylene groups, heteroarylene groups, -C(=O)O-, -O-, -NHC(=O)-, -NC(=O)N-, -NHC(=O)O-, -C(=O)-, -S-, -SO-, -NH-, etc., and may also be a group in which a plurality of these groups are combined. As the alkylene group, an alkylene group having 1 to 10 carbon atoms is preferred, an alkylene group having 1 to 6 carbon atoms is more preferred, an alkylene group having 1 to 5 carbon atoms, or an alkylene group having 1 to 4 carbon atoms is further preferred. The alkylene group may be any of a straight chain, a branched chain, and a cyclic chain. Examples of such alkylene groups include methylene, vinyl, propyl, butyl, pentyl, hexyl, and 1,1-dimethylvinyl, and methylene, vinyl, and 1,1-dimethylvinyl are preferred. Alkenylene groups are preferably alkenylene groups having 2 to 10 carbon atoms, more preferably alkenylene groups having 2 to 6 carbon atoms, and still more preferably alkenylene groups having 2 to 5 carbon atoms. Arylene groups and heteroaryl groups are preferably arylene groups or heteroaryl groups having 6 to 20 carbon atoms, and more preferably arylene groups or heteroaryl groups having 6 to 10 carbon atoms. Alkylene groups are preferred as divalent linking groups, and methylene and 1,1-dimethylvinyl are preferred.

The component (B) is preferably represented by the following formula (1). (In formula (1), R ⁵¹ and R ⁵⁴ each independently represent a free radical polymerizable unsaturated group, R ⁵² and R ⁵³ each independently represent a divalent linking group. Ring B represents a divalent cyclic group).

R ⁵¹ and R ⁵⁴ each independently represent a radical polymerizable unsaturated group, preferably a vinylphenyl group or a (meth)acryloyl group.

^R52 and ^R53 each independently represent a divalent linking group. The divalent linking group is the same as the divalent linking group described above.

Ring B represents a divalent cyclic group. Ring B is the same as the above-mentioned divalent cyclic group.

Ring B may have a substituent. The substituent is the same as the substituent that the above-mentioned divalent cyclic group may have.

Specific examples of the component (B) are shown below, but the present invention is not limited thereto. (n1 is the same as n in formula (a), and m1 is the same as m in formula (a)).

As the component (B), commercial products may be used, for example, "OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd., "A-DOG" manufactured by Shin-Nakamura Chemical Co., Ltd., "DCP-A" manufactured by Kyoeisha Chemical Co., Ltd., etc. The component (B) may be used alone or in combination of two or more.

The number average molecular weight of the component (B) is preferably 3000 or less, more preferably 2500 or less, further preferably 2000 or less, and 1500 or less, from the viewpoint of significantly obtaining the desired effect of the present invention. The lower limit is preferably 100 or more, more preferably 300 or more, further preferably 500 or more, and 1000 or more. The number average molecular weight is a polystyrene-converted number average molecular weight measured by gel permeation chromatography (GPC).

From the viewpoint of significantly obtaining the effect of the present invention, the content of component (B) 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, when the non-volatile components in the resin composition are set to 100% by mass. The upper limit is preferably 30% by mass or less, more preferably 15% by mass or less, and even more preferably 5% by mass or less.

From the viewpoint of remarkably obtaining the effect of the present invention, the total content of the component (A-1) and the component (B) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 4% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, when the resin component is 100% by mass. Here, the resin component refers to the component after removing the (C) inorganic filler and the (D) organic filler.

From the viewpoint of remarkably obtaining the effect of the present invention, the total content of the component (A-1), the component (B), and the solvent contained in the resin composition layer is preferably 1 mass % or more, more preferably 3 mass % or more, and even more preferably 5 mass % or more, and is preferably 25 mass % or less, more preferably 20 mass % or less, and even more preferably 15 mass % or less, when the resin component is 100 mass %.

-(C) Inorganic filler- The resin composition may further contain (C) an inorganic filler as an optional component.

As the material of the inorganic filler, an inorganic compound is used. Examples of the material of the inorganic filler include silicon dioxide, 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, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among them, silicon dioxide is particularly suitable. Examples of silicon dioxide include amorphous silicon dioxide, molten silicon dioxide, crystalline silicon dioxide, synthetic silicon dioxide, and hollow silicon dioxide. In addition, spherical silicon dioxide is preferred as silicon dioxide. Component (C) may be used alone or in combination of two or more.

Examples of commercially available products of the component (C) include "UFP-30" manufactured by Denka; "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Corporation; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatechs; "SILFIL NSS-3N", "SILFIL NSS-4N", and "SILFIL NSS-5N" manufactured by Tokuyama; and "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs.

From the viewpoint of remarkably obtaining the desired effect of the present invention, the average particle size of the component (C) is preferably 0.01 μm or more, more preferably 0.05 μm or more, particularly preferably 0.1 μm or more, preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less.

The average particle size of component (C) can be measured by laser diffraction and scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be made on a volume basis using a laser diffraction and scattering particle size distribution measuring device, and the median diameter can be used as the average particle size for measurement. The measurement sample can be 100 mg of the inorganic filler and 10 g of methyl ethyl ketone weighed into a small glass bottle and dispersed by ultrasonic waves for 10 minutes. The sample to be measured is a laser diffraction particle size distribution measuring device, and the wavelength of the light source used is set to light blue and red. The particle size distribution of (C) the inorganic filler based on the volume is measured by a flow cell method, and the average particle size is calculated from the obtained particle size distribution as the median diameter. Examples of laser diffraction particle size distribution measuring devices include "LA-960" manufactured by Horiba, Ltd.

The specific surface area of the component (C) is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, and particularly preferably 3 m ² /g or more, from the viewpoint of significantly obtaining the desired effect of the present invention. The upper limit is not particularly limited, but is preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area is obtained by using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech) according to the BET method, adsorbing nitrogen on the surface of the sample, and calculating the specific surface area using the BET multipoint method.

From the viewpoint of improving moisture resistance and dispersibility, component (C) is preferably treated with a surface treatment agent. Examples of the surface treatment agent include fluorine-containing silane coupling agents, aminosilane-based coupling agents, epoxysilane-based coupling agents, butylsilane-based coupling agents, silane-based coupling agents, alkoxysilanes, organic silazane compounds, and titanium ester-based coupling agents. The surface treatment agent may be used alone or in combination of two or more.

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

The degree of surface treatment by the surface treatment agent is preferably limited to a specific range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 0.2 to 5 parts by weight of the surface treatment agent is preferably used for surface treatment per 100 parts by weight of the inorganic filler, more preferably 0.2 to 3 parts by weight, and even more preferably 0.3 to 2 parts by weight.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and even more preferably 0.2 mg/m ² or more. On the other hand, from the viewpoint of suppressing the increase in the melt viscosity of the resin varnish and the melt viscosity in the form of a sheet, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and even more preferably 0.5 mg/m ² or less.

The amount of carbon per unit surface area of the (C) component can be measured after the surface-treated inorganic filler is cleaned with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After the supernatant is removed and the solid components are dried, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As a carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd. can be used.

From the viewpoint of lowering the dielectric tangent, the content of the component (C) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, and is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, when the non-volatile components in the resin composition are set to 100% by mass.

When the content (mass %) of the component (C) is c and the content (mass %) of the component (A-1) is a1, c/a1 is preferably 10 or more, more preferably 20 or more, further preferably 30 or more, preferably 90 or less, more preferably 85 or less, and further preferably 80 or less, from the viewpoint of remarkably obtaining the effect of the present invention.

Furthermore, when the content (mass %) of the component (B) in the case where the non-volatile components in the resin composition are set to 100 mass % is set to b, c/b is preferably 30 or more, more preferably 40 or more, further preferably 50 or more, preferably 80 or less, more preferably 70 or less, and further preferably 60 or less from the viewpoint of remarkably obtaining the effect of the present invention.

-(D) Organic filler- The photosensitive resin composition may further contain (D) an organic filler as an optional component. Since the (D) organic filler exhibits flexibility, it can disperse the stress of the cured product of the resin composition, and as a result, the insulation reliability can be improved.

Examples of the component (D) include urethane fine particles, rubber particles, polyamide fine particles, and silicone particles.

As the urethane fine particles, commercially available products may be used, for example, "MM-101SW", "MM-101SWA", "MM-101SM", "MM-101SMA", "MM-110SMA" and the like manufactured by Negami Industries, Ltd. may be cited.

As the rubber particles, any rubber particles may be used as long as they are microparticles of a resin that is insoluble and infusible in an organic solvent and is chemically crosslinked on a resin that exhibits rubber elasticity. Preferred examples of the rubber particles include core-shell rubber particles, crosslinked acrylonitrile butadiene rubber particles, crosslinked styrene butadiene rubber particles, and acrylic rubber particles. Core-shell rubber particles are rubber particles having a core layer and a shell layer, and may have, for example, a two-layer structure in which the outer shell layer is composed of a glassy polymer and the inner core layer is composed of a rubbery polymer, or a three-layer structure in which the outer shell layer is composed of a glassy polymer, the middle layer is composed of a rubbery polymer, and the core layer is composed of a glassy polymer. The glassy polymer layer is composed of, for example, a polymer of methyl methacrylate, and the rubbery polymer layer is composed of, for example, a butyl acrylate polymer (butyl rubber). Two or more types of rubber particles may be used in combination. As specific examples of core-shell rubber particles, there are "IM401-4-14" manufactured by Aica Industries; "AC3832", "AC3816N", "AC3401N", "IM-401 modified 7-17" manufactured by Ganz Chemicals; "METABLEN KW-4426" manufactured by Mitsubishi Rayon Corporation, etc. As specific examples of cross-linked acrylonitrile butadiene rubber (NBR) particles, there are "XER-91" manufactured by JSR Corporation (average particle size 0.5μm), etc. As specific examples of cross-linked styrene butadiene rubber (SBR) particles, there are "XSK-500" manufactured by JSR Corporation (average particle size 0.5μm), etc. Specific examples of acrylic rubber particles include "METABLEN W300A" (average particle size 0.1 μm) and "W450A" (average particle size 0.2 μm) manufactured by Mitsubishi Rayon Corporation.

As polyamide microparticles, microparticles of 50 μm or less of a resin having an amide bond can be used, for example, aliphatic polyamides such as nylon, aromatic polyamides such as kevlar, polyamide imide, etc. As polyamide microparticles, commercially available products can also be used, for example, "VESTOSINT 2070" manufactured by Daicel Huls Co., Ltd.; "SP500" manufactured by Toray Co., Ltd., etc. can be cited.

The average particle size of the component (D) is preferably 0.005 μm or more, more preferably 0.2 μm or more, preferably 1 μm or less, and more preferably 0.6 μm or less. The average particle size of the component (D) can be measured using a dynamic light scattering method. The average particle size of the component (D) can be determined, for example, by uniformly dispersing the organic filler in an appropriate organic solvent by ultrasound or the like, and using a high-concentration particle size analyzer (e.g., FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.) to obtain a particle size distribution of the organic filler based on mass, and using the median diameter as the average particle size for measurement.

From the viewpoint of remarkably obtaining the effect of the present invention, the content of the component (D) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, further preferably 0.1% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 1% by mass or less, when the non-volatile components of the resin composition are taken as 100% by mass.

-(E) Hardener- The resin composition may further contain (E) hardener as an optional component. The (E) component generally has a function of reacting with the (A) component to harden the resin composition. The (E) component may be used alone or in combination of two or more at any ratio.

As the component (E), a compound that can react with the component (A) to cure the resin composition can be used, for example, active ester hardeners, phenol hardeners, benzoxazine hardeners, carbodiimide hardeners, acid anhydride hardeners, amine hardeners, cyanate hardeners, etc. Among them, from the viewpoint of significantly obtaining the effect of the present invention, any one of active ester hardeners, phenol hardeners, benzoxazine hardeners, and carbodiimide hardeners is preferred, and any one of active ester hardeners, phenol hardeners, and carbodiimide hardeners is more preferred.

As active ester curing agents, curing agents having one or more active ester groups in one molecule can be cited. Among them, preferred active ester curing agents are compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxylamine esters, and esters of heterocyclic hydroxyl compounds. The active ester curing agent is preferably obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound with a hydroxyl compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxyl compound is preferred, and an active ester curing agent obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred.

Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

Examples of the phenol compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, reduced phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxydiphenyl ketone, trihydroxydiphenyl ketone, tetrahydroxydiphenyl ketone, phloroglucinol, pyrogallol, dicyclopentadiene-type diphenol compounds, and phenol novolac. Here, the so-called "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

Preferred specific examples of active ester curing agents include active ester compounds containing a dicyclopentadiene diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing acetylated phenol novolacs, and active ester compounds containing benzoylated phenol novolacs. Among them, more preferred are active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene diphenol structure. The so-called "dicyclopentadiene diphenol structure" refers to a divalent structure composed of phenylene-dicyclopentylene-phenylene.

Commercially available products of active ester-based hardeners include, as active ester compounds containing a dicyclopentadiene-type diphenol structure, "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", "HPC-8000H", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L", and "EXB-8000L-65TM" (manufactured by DIC Corporation); as active ester compounds containing a naphthalene structure, "HPC-8150-60T", "HPC-8150-62T", "EXB-8150-65T", "EXB-8100L-65T", "EXB-815 0L-65T", "EXB9416-70BK" (manufactured by DIC Corporation); as an active ester compound containing acetylated phenol novolac, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be cited; as an active ester compound containing benzoylated phenol novolac, "YLH1026" (manufactured by Mitsubishi Chemical Corporation) can be cited; as an active ester curing agent belonging to acetylated phenol novolac, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be cited; as an active ester curing agent belonging to benzoylated phenol novolac, "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), "YLH1048" (manufactured by Mitsubishi Chemical Corporation) can be cited; etc.

As phenolic hardeners, there can be cited hardeners having one or more, preferably two or more, hydroxyl groups bonded to aromatic rings (benzene rings, naphthalene rings, etc.) in one molecule. Among them, compounds having a hydroxyl group bonded to a benzene ring are preferred. In addition, from the viewpoint of heat resistance and water resistance, phenolic hardeners having a novolac structure are preferred. In addition, from the viewpoint of adhesion, nitrogen-containing phenolic hardeners are preferred, and phenolic hardeners containing a triazine skeleton are more preferred. In particular, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, phenolic novolac hardeners containing a triazine skeleton are preferred.

Specific examples of phenolic hardeners and naphthol hardeners include "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Chemicals; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", "SN-375", and "SN-475" manufactured by Nippon Steel & Sumitomo Chemicals Co., Ltd. "SN-395" manufactured by DIC Corporation; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", "KA-1165"; "GDP-6115L", "GDP-6115H", "ELPC75" manufactured by Qun Rong Chemical Corporation, etc.

Specific examples of benzoxazine-based hardeners include "ODA-BOZ" manufactured by JFE Chemical, "HFB2006M" manufactured by Showa High Molecular Co., Ltd., and "P-d" and "F-a" manufactured by Shikoku Chemical Industries, Ltd.

Specific examples of carbodiimide-based hardeners include "V-03", "V-05", and "V-07" manufactured by Nisshinbo Chemical Co., Ltd. and Stabaxol (registered trademark) P manufactured by Rhein Chemie Co., Ltd.

Examples of the acid anhydride curing agent include those having one or more acid anhydride groups in one molecule. Specific examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecene succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, benzene Acid anhydrides of polymer type such as pyrotetracarboxylic acid dianhydride, benzophenonetetracarboxylic acid dianhydride, biphenyltetracarboxylic acid dianhydride, naphthalenetetracarboxylic acid dianhydride, oxydiphthalic acid dianhydride, 3,3'-4,4'-diphenylsulfonatetetracarboxylic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, ethylene glycol bis(trimellitic acid anhydride ester), styrene-maleic acid resin obtained by copolymerization of styrene and maleic acid, etc. Acid anhydride type hardeners may also be commercially available products, for example, "MH-700" manufactured by Shin Nippon Rika Co., Ltd., etc.

As the amine-based hardener, there can be mentioned hardeners having one or more amine groups in one molecule, for example, aliphatic amines, polyether amines, alicyclic amines, aromatic amines, etc. Among them, aromatic amines are preferred from the viewpoint of achieving the desired effect of the present invention. The amine-based hardener is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfonate, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfonate, 3,3'-diaminodiphenylsulfonate, m-phenylenediamine, m-phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diphenylamine, 2,2'-dimethyl-4,4'-diphenylamine, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino bis(4-aminophenoxy)phenyl)sulfone, bis(4-(4-aminophenoxy)phenyl)sulfone, and the like. Amine hardeners that can be used are commercially available products, for example, "KAYABOND C-200S", "KAYABOND C-100", "Kayahard A-A", "Kayahard A-B", "Kayahard A-S" manufactured by Nippon Kayaku Co., Ltd., "Epicure W" manufactured by Mitsubishi Chemical Corporation, etc.

Examples of the cyanate curing agent include bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethyl)propane, and oligo(3-methylene-1,5-phenylene cyanate). Bifunctional cyanate resins such as bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)sulfide, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; prepolymers of these cyanate resins after triazine treatment; etc. Specific examples of cyanate-based hardeners include "PT30" and "PT60" manufactured by Lonza Japan (both are phenol novolac-type multifunctional cyanate resins); "ULL-950S" (multifunctional cyanate resin); "BA230" and "BA230S75" (prepolymers in which bisphenol A dicyanate is partially or completely triazinated to become a trimer); etc.

(E) From the viewpoint of remarkably obtaining the effect of the present invention, the content of the hardener is preferably 1 mass % or more, more preferably 5 mass % or more, and even more preferably 10 mass % or more, and is preferably 25 mass % or less, more preferably 20 mass % or less, and even more preferably 15 mass % or less, when the non-volatile components in the resin composition are taken as 100 mass %.

When the number of epoxy groups of the component (A) is 1, the number of active groups of the curing agent (E) is preferably 0.1 or more, more preferably 0.3 or more, and even more preferably 0.5 or more, and preferably 2 or less, more preferably 1.8 or less, and even more preferably 1.5 or less. Here, the "number of epoxy groups of the component (A)" is the total value of all values obtained by dividing the mass of the non-volatile components of the component (A) present in the resin composition by the epoxy equivalent. In addition, the "number of active groups of the curing agent (E)" is the total value of all values obtained by dividing the mass of the non-volatile components of the curing agent (E) present in the resin composition by the active group equivalent. When the number of epoxy groups in the component (A) is set to 1, the number of active groups in the curing agent (E) is within the above range, and the desired effect of the present invention can be significantly obtained.

When the number of epoxy groups of the component (A-1) is 1, the number of active groups of the curing agent (E) is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, and preferably 15 or less, more preferably 10 or less, and even more preferably 8 or less. Here, the "number of epoxy groups of the component (A-1)" is the total value of all values obtained by dividing the mass of the non-volatile components of the component (A-1) present in the resin composition by the epoxy equivalent. When the number of active groups of the curing agent (E) is within the above range when the number of epoxy groups of the component (A-1) is 1, the desired effect of the present invention can be significantly obtained.

-(F) Hardening accelerator- In addition to the above-mentioned components, the resin composition may further contain (F) a hardening accelerator as an optional component.

Examples of the hardening accelerator include phosphorus-based hardening accelerators, amine-based hardening accelerators, imidazole-based hardening accelerators, guanidine-based hardening accelerators, and metal-based hardening accelerators. Among them, phosphorus-based hardening accelerators, amine-based hardening accelerators, imidazole-based hardening accelerators, and metal-based hardening accelerators are preferred, and amine-based hardening accelerators, imidazole-based hardening accelerators, and metal-based hardening accelerators are more preferred. The hardening accelerators may be used alone or in combination of two or more.

Examples of the phosphorus-based hardening accelerator include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium salts, tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate, among which triphenylphosphine and tetrabutylphosphonium decanoate are preferred.

Examples of the amine-based hardening accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. Preferred are 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene.

Examples of the imidazole-based hardening accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6 -[2'-Undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazolyl isocyanuric acid adduct, 2-phenyl-4,5-dihydroxy Imidazole compounds such as methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and adducts of imidazole compounds with epoxy resins, preferably 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

As the imidazole-based hardening accelerator, a commercially available product may be used, for example, "P200-H50" manufactured by Mitsubishi Chemical Corporation.

As the guanidine-based hardening accelerator, for example, there can be mentioned dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0 ]dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-tolylbiguanidine, 1-phenylbiguanidine, 1-(o-tolyl)biguanidine, etc., preferably dicyanamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene.

Examples of the metal hardening accelerator include organic metal complexes or organic metal salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the organometallic complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, organic zinc complexes such as zinc (II) acetylacetonate, organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc cycloalkanoate, cobalt cycloalkanoate, tin stearate, zinc stearate and the like.

From the viewpoint of remarkably obtaining the desired effect of the present invention, the content of the component (F) is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, and is preferably 0.3% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

-(G) Polymerization initiator- In addition to the above components, the resin composition may further contain a (G) polymerization initiator as an optional component. The (G) component generally has a function of promoting the crosslinking of the free radical polymerizable unsaturated groups in the (B) component. The (G) component may be used alone or in combination of two or more.

Examples of the polymerization initiator (G) include peroxides such as t-butyl peroxide isopropylbenzene, t-butyl peroxyacetate, α,α'-di(t-butylperoxy)diisopropylbenzene, t-butyl peroxylaurate, t-butylperoxy-2-hexanoate, t-butyl peroxyneodecanoate, and t-butyl peroxybenzoate.

Examples of commercially available products of the (G) polymerization initiator include "Perbutyl C", "Perbutyl A", "Perbutyl P", "Perbutyl L", "Perbutyl O", "Perbutyl ND", "Perbutyl Z", "Percumyl P", and "Percumyl D" manufactured by NOF Corporation.

(G) From the viewpoint of remarkably obtaining the desired effect of the present invention, the content of the polymerization initiator is preferably 0.01 mass % or more, more preferably 0.02 mass % or more, and even more preferably 0.03 mass % or more, and is preferably 0.3 mass % or less, more preferably 0.2 mass % or less, and even more preferably 0.1 mass % or less, when the non-volatile components in the resin composition are taken as 100 mass %.

-(H) Thermoplastic resin- In addition to the above-mentioned components, the resin composition may further contain (H) thermoplastic resin as an optional component.

Examples of the thermoplastic resin as the component (H) include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyimide resins, polyamide imide resins, polyether imide resins, polysulfide resins, polyethersulfide resins, polycarbonate resins, polyetheretherketone resins, polyester resins, etc. Among them, phenoxy resins are preferred from the viewpoint of significantly obtaining the desired effect of the present invention. The thermoplastic resins may be used alone or in combination of two or more.

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

Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical (both are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical (a phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical (a phenoxy resin containing a bisphenol acetophenone skeleton); and "Phenoxy 1256" and "Phenoxy 1250" manufactured by Mitsubishi Chemical (both are phenoxy resins containing a bisphenol A skeleton). "FX280" and "FX293" manufactured by the company; "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482" manufactured by Mitsubishi Chemical Corporation; etc.

Examples of the polyvinyl acetal resin include polyvinyl formaldehyde resin and polyvinyl butyral resin, and polyvinyl butyral resin is preferred. Specific examples of the polyvinyl acetal resin include "Denka Butyral 4000-2", "Denka Butyral 5000-A", "Denka Butyral 6000-C", and "Denka Butyral 6000-EP" manufactured by Denki Kagaku Kogyo Co., Ltd.; Eslek BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemical Kogyo Co., Ltd.; and the like.

Specific examples of polyimide resins include "Rikacoat SN20" and "Rikacoat PN20" manufactured by Shin Nippon Rika Co., Ltd. Specific examples of polyimide resins include modified polyimides such as bifunctional hydroxyl-terminated polybutadiene, linear polyimide obtained by reacting a diisocyanate compound and a tetrahydrofuran anhydride (polyimide described in Japanese Patent Application Laid-Open No. 2006-37083), and polyimide containing a polysiloxane skeleton (polyimide described in Japanese Patent Application Laid-Open No. 2002-12667 and Japanese Patent Application Laid-Open No. 2000-319386).

Specific examples of polyamide imide resins include "Bylomax HR11NN" and "Bylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide imide resins include modified polyamide imides such as "KS9100" and "KS9300" (polyamide imide containing a polysiloxane skeleton) manufactured by Hitachi Chemical Co., Ltd.

As a specific example of the polyether sulphate resin, "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. and the like can be cited.

As specific examples of the polysulfone resin, polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers Inc. can be cited.

(H) The weight average molecular weight (Mw) of the thermoplastic resin is preferably 8,000 or more, more preferably 10,000 or more, particularly preferably 20,000 or more, and is preferably 70,000 or less, more preferably 60,000 or less, and particularly preferably 50,000 or less, from the viewpoint of significantly obtaining the desired effect of the present invention.

(H) From the viewpoint of remarkably obtaining the desired effect of the present invention, the content of the thermoplastic resin is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, and is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

-(I) Flame retardant- In addition to the above-mentioned components, the resin composition may further contain (I) a flame retardant as an optional component.

(I) As the flame retardant, for example, phosphazene compounds, organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, polysilicon flame retardants, metal hydroxides, etc. can be cited, and phosphazene compounds are preferred. The flame retardant may be used alone or in combination of two or more.

The phosphazene compound is not particularly limited as long as it is a cyclic compound containing nitrogen and phosphorus as constituent elements, but the phosphazene compound is preferably a phosphazene compound having a phenolic hydroxyl group.

Specific examples of phosphazene compounds include "SPH-100", "SPS-100", "SPB-100", "SPE-100" manufactured by Otsuka Chemical Co., Ltd., "FP-100", "FP-110", "FP-300", "FP-400" manufactured by Fushimi Pharmaceutical Co., Ltd., and the like. Preferably, "SPH-100" manufactured by Otsuka Chemical Co., Ltd. is used.

As flame retardants other than phosphazene compounds, commercially available products may be used, for example, "HCA-HQ" manufactured by Sanko Co., Ltd., "PX-200" manufactured by Daihachi Chemical Industry Co., Ltd. As flame retardants, those that are not easily hydrolyzed are preferred, for example, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxo-10-phosphaphenanthrene-10-oxide is preferred.

(I) From the viewpoint of significantly obtaining the effect of the present invention, the content of the flame retardant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, when the non-volatile components in the resin composition are set to 100% by mass. The upper limit is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less.

-(J) Other additives- In addition to the above-mentioned components, the resin composition may further contain other additives as arbitrary components. Examples of such additives include resin additives such as thickeners, defoamers, leveling agents, and adhesion-imparting agents. These additives may be used alone or in combination of two or more. Those having ordinary knowledge in the field of the present invention may appropriately set the content of each.

The method for preparing the resin composition is not particularly limited, and examples thereof include a method of mixing and dispersing the compounding components and a solvent added as needed using a rotary mixer or the like.

The thickness of the resin composition layer is preferably 100 μm or less, more preferably 70 μm or less, and even more preferably 60 μm or less, and 50 μm or less, from the viewpoint of thinning the printed wiring board and providing a cured product of the resin composition with excellent insulation even in the form of a thin film. The lower limit of the thickness of the resin composition layer is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more.

<Other layers> In one embodiment, the resin sheet may further include other layers as needed. As the other layers, for example, there can be cited a protective film of a substrate of a support provided on a surface of the resin composition layer that is not bonded to the support (i.e., the surface on the opposite side to the support). The thickness of the protective film is not particularly limited, but for example, is 1 μm to 40 μm. By laminating the protective film, the adhesion or damage of dust, etc. on the surface of the resin composition layer can be suppressed.

<Manufacturing method of resin sheet> The resin sheet of the present invention can be manufactured by, for example, preparing a resin varnish in which a resin composition is dissolved in a solvent such as an organic solvent, applying the resin varnish on a support using a die coater, and further drying the resin varnish so that the amount of the solvent contained in the resin composition layer becomes 5% by mass or less to form a resin composition layer.

The amount of the solvent contained in the resin composition layer is 5 mass % or less, preferably 3 mass % or less, and more preferably 2.5 mass % or less. The lower limit is not particularly limited, but can be 0 mass % or more, 0.1 mass % or more, etc.

The amount of solvent contained in the resin composition layer (residual solvent) is determined by measuring the mass of the support, the initial mass of the resin sheet, and the mass of the resin sheet after drying, and is calculated using the following formula. Residual solvent (mass %) = 100 × (initial mass of resin sheet - dried mass of resin sheet) / (initial mass of resin sheet - mass of support)

Specifically, the support is cut into 10cm×10cm, and the weight (mass) is measured using an electronic balance. The resin sheet with the support and the resin composition layer is cut into 10cm×10cm, and the initial mass is measured using an electronic balance. Then, the resin sheet is placed on a metal mesh, heated in an oven pre-set to 130°C for 15 minutes, moved to a dryer and left for 30 minutes, and cooled to room temperature. After that, the dry mass of the resin sheet is measured using an electronic balance. The mass of the support, the initial mass of the resin sheet, and the mass of the resin sheet after drying are obtained using the above formula.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetates such as ethyl acetate, butyl acetate, celoxylate acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as celoxylate and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone. The organic solvent may be used alone or in combination of two or more.

Drying can be carried out by known methods such as heating and hot air blowing. Although the drying conditions vary depending on the boiling point of the organic solvent in the resin varnish, for example, in the case of using a resin varnish containing 30% to 60% by mass of an organic solvent, by drying it at 50°C to 150°C for 3 minutes to 10 minutes, a resin composition layer with a solvent amount of less than 5% by mass can be formed. As an average drying temperature, it is preferably above 91°C, more preferably above 93°C, and even more preferably above 95°C. Although there is no particular upper limit, it can be set to below 200°C, below 150°C, etc. The drying time is preferably 1 minute or longer, more preferably 2 minutes or longer, and even more preferably 3 minutes or longer, and is preferably 10 minutes or shorter, more preferably 8 minutes or shorter, and even more preferably 7 minutes or shorter.

The resin sheet can be stored in a roll. If the resin sheet has a protective film, the resin sheet can be used by peeling off the protective film.

<Physical properties and uses of resin sheets> The cured product after the resin composition layer was heat-cured at 190°C for 90 minutes showed the characteristic of low dielectric tangent. Therefore, the aforementioned cured product can obtain an insulating layer with low dielectric tangent. As for the dielectric tangent, it is preferably less than 0.005, more preferably less than 0.0045, and more preferably less than 0.003. On the other hand, the lower limit of the dielectric tangent is not particularly limited and can be set to 0.0001 or more. The evaluation of the aforementioned dielectric tangent can be measured according to the method described in the embodiment described later.

The resin composition layer is heat-cured at 100°C for 30 minutes and then at 180°C for 90 minutes. The cured material shows excellent insulation reliability. Therefore, the aforementioned cured material can obtain an insulation layer with excellent insulation reliability. As insulation reliability, the insulation resistance value after the HAST test exceeds 50% of the initial insulation resistance value before the HAST test in a 300-hour HAST test at 130°C and 85%RH. The insulation reliability can be evaluated according to the method described in the embodiment described below.

After the resin composition layer is heat-cured at 190°C for 90 minutes, the cured product generally shows excellent adhesion to the copper foil. Therefore, the aforementioned cured product can obtain an insulating layer with excellent adhesion to the copper foil. As for the adhesion, it is preferably above 0.5kgf/cm, more preferably above 0.55kgf/cm, and even more preferably above 0.6kgf/cm. On the other hand, the upper limit of the adhesion is not particularly limited, but can be set to 5kgf/cm or less. The evaluation of the aforementioned adhesion can be measured according to the method described in the embodiment described later.

After the resin composition layer is heat-cured at 190°C for 90 minutes, the cured product usually shows excellent adhesion to the copper foil in a HAST test at 130°C and 85% RH for 100 hours. Therefore, the aforementioned cured product can obtain an insulating layer with excellent adhesion to the copper foil after the HAST test. As for the adhesion after the HAST test, it is preferably above 0.2kgf/cm, more preferably above 0.35kgf/cm, and even more preferably above 0.4kgf/cm. On the other hand, the upper limit value of the adhesion after the HAST test is not particularly limited, but can be set to 5kgf/cm or less. The evaluation of the adhesion after the aforementioned HAST test can be measured according to the method described in the embodiment described later.

The resin sheet of the present invention can obtain an insulating layer having excellent insulation reliability while reducing dielectric tangent. Therefore, the resin sheet of the present invention can be suitably used as a resin sheet for insulation purposes. Specifically, it can be suitably used as a resin sheet for forming an insulating layer, and the insulating layer is a resin sheet for forming a conductive layer (including a redistribution layer) on the insulating layer (resin sheet for forming an insulating layer for forming a conductive layer).

Furthermore, it can be suitably used as a resin sheet for forming an insulating layer of a multilayer printed wiring board (resin sheet for forming insulating layer of a multilayer printed wiring board) and a resin sheet for forming an interlayer insulating layer of a printed wiring board (resin sheet for forming interlayer insulating layer of a printed wiring board) in a multilayer printed wiring board described later.

In addition, for example, in the case of manufacturing a semiconductor chip package through the following steps (1) to (6), the resin sheet of the present invention can be used as a resin sheet for forming a redistribution layer (resin sheet for forming a redistribution layer) for forming an insulating layer of a redistribution layer, and a resin sheet for sealing a semiconductor chip (resin sheet for sealing a semiconductor chip). When manufacturing a semiconductor chip package, a redistribution layer can also be further formed on the sealing layer. (1) a step of laminating a temporary fixing film on a substrate, (2) a step of temporarily fixing a semiconductor chip on the temporary fixing film, (3) a step of forming a sealing layer on the semiconductor chip, (4) a step of peeling the substrate and the temporary fixing film from the semiconductor chip, (5) a step of forming a redistribution layer as an insulating layer on the surface of the semiconductor chip after the substrate and the temporary fixing film are peeled off, and (6) a step of forming a redistribution layer as a conductive layer on the redistribution layer

In addition, the resin sheet of the present invention can obtain an insulating layer with good component embedding properties, so it can also be suitably used in the case where the printed wiring board is a component-built-in circuit board.

[Printed wiring board] The printed wiring board of the present invention includes an insulating layer formed by a cured product of the resin composition of the present invention.

A printed wiring board can be produced, for example, using the above-mentioned resin sheet by a method comprising the following steps (I), (II) and (III) in sequence. (I) A step of laminating the resin sheet on the inner substrate so that the resin composition layer is bonded to the inner substrate, (II) A step of thermally curing the resin composition layer to form an insulating layer, (III) A step of peeling off the support

The so-called "inner layer substrate" used in step (I) is a component that becomes the substrate of the printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. In addition, the substrate may have a conductive layer on one or both sides thereof, and the conductive layer may also be patterned. An inner layer substrate having a conductive layer (circuit) formed on one or both sides of the substrate is also referred to as an "inner layer circuit substrate." In addition, when manufacturing a printed wiring board, an intermediate product that further requires the formation of an insulating layer and/or a conductive layer is also included in the "inner layer substrate" referred to in the present invention. In the case where the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components can be used.

The inner substrate and the resin sheet can be laminated, for example, by heat-pressing the resin sheet to the inner substrate from the support body side. As a component for heat-pressing the resin sheet to the inner substrate (hereinafter, also referred to as a "heat-pressing component"), for example, a heated metal plate (SUS mirror plate, etc.) or a metal roller (SUS roller) can be cited. In addition, instead of directly pressing the heat-pressing component to the resin sheet, it is better to press it through an elastic material such as heat-resistant rubber so that the resin sheet can fully follow the surface unevenness of the inner substrate.

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

The lamination can be performed by a commercially available vacuum laminating press. Examples of commercially available vacuum laminating presses include a vacuum press made by Meiki Seisakusho Co., Ltd., a vacuum applicator made by Nikko-Materials Co., Ltd., and a batch vacuum press.

After lamination, the laminated resin sheet can be smoothed by, for example, pressing the heated and pressed member from the support side under normal pressure (atmospheric pressure). The pressing conditions for the smoothing treatment can be set to the same conditions as the heated and pressed conditions for the above-mentioned lamination. The smoothing treatment can be performed by a commercially available lamination press. In addition, the lamination and smoothing treatment can also be performed continuously using the above-mentioned commercially available vacuum lamination press.

In step (II), the resin composition layer is thermally cured to form an insulating layer. The thermal curing conditions of the resin composition layer are not particularly limited, and the conditions generally used when forming an insulating layer of a printed wiring board can be used.

For example, although the heat curing conditions of the resin composition layer vary depending on the type of the resin composition, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

Before the resin composition layer is heat-hardened, the resin composition layer may be pre-heated at a temperature lower than the hardening temperature. For example, before the resin composition layer is heat-hardened, the resin composition layer may be pre-heated at a temperature of 50°C to 120°C (preferably 60°C to 115°C, more preferably 70°C to 110°C) for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes).

Since the insulating layer is formed by the cured product of the resin composition of the present invention, the thickness of the insulating layer can be made thinner. The thickness of the insulating layer is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less, or 10 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, and can usually be set to 1 μm or more, 5 μm or more, etc.

After step (II) is completed, from the perspective of reducing the dielectric tangent and obtaining an insulating layer with excellent insulation reliability, the support body is peeled off in step (III).

When manufacturing a printed wiring board, it is also possible to further implement a step (IV) of opening a hole in the insulating layer, a step (V) of roughening the insulating layer, and a step (VI) of forming a conductive layer. These steps (IV) and even step (VI) can be implemented according to various methods known to those skilled in the art of the present invention used in the manufacture of printed wiring boards. Steps (IV) to (V) can be performed before or after step (III). Usually, step (IV) is usually performed after step (III). In addition, the formation of the insulating layer and the conductive layer of steps (II) to (V) can be repeated as needed to form a multi-layer wiring board.

Step (IV) is a step of opening a hole in the insulating layer, thereby forming a via hole, a through-hole, or the like in the insulating layer. Step (IV) can also be performed using, for example, a drill, a laser, or plasma, depending on the composition of the resin composition used in forming the insulating layer. The size or shape of the hole can also be appropriately determined according to the design of the printed wiring board.

Step (V) is a step of roughening the insulating layer. Usually, in this step (V), the scum is also removed. The steps and conditions of the roughening treatment are not particularly limited, and the known steps and conditions commonly used when forming the insulating layer of the printed wiring board can be adopted. For example, the roughening treatment of the insulating layer can be carried out in sequence by swelling treatment with a swelling liquid, roughening treatment with an oxidizing agent, and neutralization treatment with a neutralizing liquid. The swelling liquid used in the roughening treatment is not particularly limited, and an alkaline solution, a surfactant solution, etc. can be cited. An alkaline solution is preferred, and a sodium hydroxide solution and a potassium hydroxide solution are more preferred as the alkaline solution. As commercially available swelling liquids, for example, "Swelling Dip Securiganth P", "Swelling Dip Securiganth SBU", "Swelling Dip Securiganth P" and the like manufactured by Atotech JAPAN can be cited. The swelling treatment performed by the swelling liquid is not particularly limited, and for example, it can be performed by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate degree, it is preferred to immerse the insulating layer in a swelling solution at 40°C to 80°C for 5 to 15 minutes. The oxidizing agent used in the roughening treatment is not particularly limited, and for example, an alkaline permanganic acid solution obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide can be cited. The roughening treatment performed using an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. In addition, the concentration of permanganate in the alkaline permanganic acid solution is preferably 5 mass% to 10 mass%. As commercially available oxidizing agents, for example, alkaline permanganic acid solutions such as "Concentrate Compact CP" and "Dosing Solution Security P" manufactured by Atotech JAPAN can be cited. In addition, as a neutralizing solution used in the roughening treatment, it is preferably an acidic aqueous solution, and as a commercial product, for example, "Reduction solution Securiganth P" manufactured by Atotech JAPAN can be cited. The treatment with the neutralizing solution can be performed by immersing the treated surface that has been roughened by the oxidizing agent in the neutralizing solution at 30°C to 80°C for 1 minute to 30 minutes. From the viewpoint of workability, a method in which the object roughened with an oxidizing agent is immersed in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes is preferred.

In one embodiment, the arithmetic average roughness (Ra) of the insulating layer surface after the roughening treatment is preferably 300 nm or less, more preferably 250 nm or less, and even more preferably 200 nm or less. The lower limit is not particularly limited, but is preferably 30 nm or more, more preferably 40 nm or more, and even more preferably 50 nm or more. The arithmetic average roughness (Ra) of the insulating layer surface can be measured using a non-contact surface roughness meter.

Step (VI) is a step of forming a conductive layer, and the conductive layer is formed on the insulating layer. The conductive material used in the conductive layer is not particularly limited. In a suitable embodiment, the conductive layer includes one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The conductive layer may be a single metal layer or an alloy layer. As the alloy layer, for example, a layer formed of an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy) can be cited. Among them, from the viewpoint of versatility, cost, ease of patterning, etc. of forming the conductive layer, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy is preferred; a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel-chromium alloy is more preferred; and a single metal layer of copper is even more preferred.

The conductive layer may be a single layer structure, or a composite structure of a single metal layer or two or more alloy layers composed of different types of metals or alloys. In the case where the conductive layer is a composite structure, the layer connected to the insulating layer is preferably a single metal layer of chromium, zinc or titanium, or an alloy layer of nickel-chromium alloy.

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

In one embodiment, the conductive layer can also be formed by plating. For example, a conductive layer having a desired wiring pattern can be formed by plating on the surface of the insulating layer using a known technique such as a semi-additive method or a full-additive method. From the perspective of manufacturing simplicity, it is preferably formed by a semi-additive method. The following is an example of forming a conductive layer by a semi-additive method.

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Then, a mask pattern is formed on the formed plating seed layer to expose a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. After that, the unnecessary plating seed layer can be removed by etching, etc., to form a conductor layer with the desired wiring pattern.

[Semiconductor device] The semiconductor device of the present invention includes the printed wiring board of the present invention. The semiconductor device of the present invention can be manufactured using the printed wiring board of the present invention.

As semiconductor devices, there can be cited various semiconductor devices provided to electric appliances (for example, computers, mobile phones, digital cameras, and televisions) and transportation vehicles (for example, motorcycles, cars, trains, ships, and aircrafts).

The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) on the conductive part of a printed wiring board. The so-called "conductive part" refers to the "part of the printed wiring board that transmits electrical signals", and the location can be on the surface or embedded in any position. In addition, there is no special restriction if the semiconductor chip is a circuit component made of semiconductor.

The semiconductor chip mounting method when manufacturing semiconductor devices is not particularly limited if the semiconductor chip can effectively produce functions. Specifically, there are wire bonding mounting methods, flip chip mounting methods, mounting methods using bumpless build-up layers (BBUL), mounting methods using anisotropic conductive films (ACF), and mounting methods using non-conductive films (NCF). Here, the so-called "mounting method using bumpless build-up layers (BBUL)" refers to "a mounting method in which a semiconductor chip is directly buried in a recess of a printed wiring board to connect the semiconductor chip to the wiring on the printed wiring board." [Example]

The present invention is specifically described below by way of examples, but the present invention is not limited to these examples. In addition, in the following descriptions, "parts" and "%" represent "parts by mass" and "% by mass" respectively, unless otherwise specified. In addition, unless otherwise specified, the analysis is performed at room temperature and atmospheric pressure.

<Measurement method of oxygen permeability> The oxygen permeability of the support was measured using an oxygen permeability measuring device (MOCON, OX-TRAN2/21) in accordance with JIS K7126 (isobaric method) at 23°C and 50%RH.

<Measurement method of water vapor permeability> The water vapor permeability of the support was measured using a water vapor permeability measuring device (PERMATRAN-W3/34 manufactured by MOCON) in accordance with JIS K7129 at 40°C and 90% RH.

<Determination of weight loss at 200°C> The weight loss at 200°C was determined using "TG/DTA EXSTAR6300" manufactured by Hitachi High-Tech Science Corporation. Specifically, approximately 10 mg of epoxy resin was weighed in an aluminum sample pan, and the sample was exposed without a lid, and the temperature was raised from 30°C to 550°C at a rate of 10°C/min in an environment with an air flow rate of 200 mL/min. The weight of the sample was measured at each temperature. The weight loss at 200°C was calculated from the obtained results using the following formula. Weight loss at 200°C (mass %) = 100 × (mass before heating - mass at 200°C) / mass before heating

<Method for determining the amount of solvent contained in the resin composition layer> (1) Determination of the mass of the support Cut the support into 10 cm × 10 cm pieces and measure the weight using an electronic balance. The measurement was performed on 3 samples, and the average value was determined as the mass of the support.

(2) Mass measurement of resin sheet The resin sheet with the support and the resin component layer was cut into 10 cm × 10 cm pieces, and the initial mass was measured using an electronic balance. Then, the resin sheet was placed on a metal mesh, heated in an oven pre-set to 130°C for 15 minutes, moved to a dryer and left for 30 minutes, and cooled to room temperature. After that, the dry mass of the resin sheet was measured using an electronic balance. The initial mass and dry mass were measured for 3 samples, and the average value was used. The amount of solvent contained in the resin component layer (residual solvent amount) was calculated using the following formula. Residual solvent amount (mass %) = 100 × (initial mass of resin sheet - dry mass of resin sheet) / (initial mass of resin sheet - mass of support)

<Preparation of Resin Composition 1> 10 parts of bisphenol A epoxy resin ("828EL" manufactured by Mitsubishi Chemical, epoxy equivalent of about 180 g/eq.), 20 parts of bisphenol AF epoxy resin ("YX7760" manufactured by Mitsubishi Chemical, epoxy equivalent of about 238 g/eq.), 25 parts of biphenyl epoxy resin ("NC-3000-L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of about 269 g/eq.), and 1,4-epoxypropyl cyclohexane epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., epoxy equivalent of about 200 g/eq.) as a volatile epoxy resin were mixed. 7 parts of "ZX1658GS" manufactured by Otsuka Chemical Co., Ltd., epoxy equivalent of about 135 g/eq., weight loss rate at 200°C measured by TG-DTA apparatus is 7.2%), 3 parts of phosphazene resin ("SPS-100" manufactured by Otsuka Chemical Co., Ltd.), 10 parts of phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Co., Ltd., a 1:1 solution of MEK and cyclohexanone with a solid content of 30 mass%) were stirred and dissolved in 20 parts of MEK and 40 parts of solvent naphtha while heating. After cooling to room temperature, 86 parts of active ester type hardener (DIC "EXB9416-70BK", active group equivalent of about 330g/eq., non-volatile matter 70% by mass methyl isobutyl ketone solution), 10 parts of phenol type hardener (DIC "LA3018-50P", active group equivalent of about 151g/eq., 2-methoxypropanol solution with 50% solid content), and naphthol type hardener (Nippon Steel Sumitomo Metal Chemical Co., Ltd. "SN395", active group equivalent of about 107g/eq.) were mixed. 2 parts, a carbodiimide hardener ("V-03" manufactured by Nisshinbo Chemical Co., Ltd., active group equivalent of about 216 g/eq., toluene solution with a solid content of 50% by mass), 10 parts, a hardening accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass), 8 parts, and 400 parts of spherical silica (average particle size 0.5 μm, specific surface area 5.8 m ² /g, "SO-C2" manufactured by Admatechs Co., Ltd.) surface-treated with a phenylaminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) were uniformly dispersed with a high-speed rotary mixer and filtered with a cartridge filter ("SHP100" manufactured by ROKITECHNO Co., Ltd.) to prepare a resin composition 1.

<Preparation of Resin Composition 2> In the preparation of resin composition 1, 1) the amount of biphenyl type epoxy resin ("NC-3000-L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of about 269g/eq.) was changed from 25 parts to 20 parts, 2) the liquid 1,4-epoxypropyl cyclohexane type epoxy resin ("ZX1658" manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.) which is a volatile epoxy resin was changed to GS", epoxy equivalent of about 135g/eq., weight loss rate of 7.2% at 200°C as measured by TG-DTA device) was changed to 12 parts of (meth)acrylate ("NK Ester A-DOG" manufactured by Shin-Nakamura Chemical Industry Co., Ltd., molecular weight 326), which is a free radical polymerizable resin, and 0.2 parts of polymerization initiator ("Perbutyl C" manufactured by NOF Corporation) were further used. Except for the above matters, resin composition 2 was prepared in the same manner as the preparation method of resin composition 1.

<Preparation of Resin Composition 3> In the preparation of resin composition 1, 1) the amount of biphenyl type epoxy resin ("NC-3000-L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of about 269g/eq.) was changed from 25 parts to 10 parts, 2) 10 parts of modified naphthalene type epoxy resin ("ESN-475V" manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., epoxy equivalent of about 330g/eq.) were used, 3) 5 parts of (meth)acrylate ("NK Ester A-DOG" manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight 326) belonging to a free radical polymerizable resin were used, 4) 0.2 parts of polymerization initiator ("Perbutyl C" manufactured by NOF Corporation) were used. Except for the above matters, resin composition 3 was prepared in the same manner as the method for preparing resin composition 1.

＜Preparation of resin composition 4＞ 10 parts of bisphenol AF type epoxy resin ("YX7760" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 238), 10 parts of biphenyl type epoxy resin ("NC-3000-L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of about 269 g/eq.), 20 parts of modified naphthalene type epoxy resin ("ESN-475V" manufactured by Nippon Steel & Sumitomo Chemical Corporation, epoxy equivalent of about 330 g/eq.), 7 parts of dimethylphenol type epoxy resin ("YX4000H" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 190 g/eq.), naphthalene type tetrafunctional epoxy resin ("HP-4710" manufactured by DIC Corporation, epoxy equivalent of about 170 g/eq.) were added. 3 parts, a liquid 1,4-epoxypropyl cyclohexane type epoxy resin ("ZX1658GS" manufactured by Nippon Steel & Sumitomo Metal Chemicals Co., Ltd., epoxy equivalent of about 135 g/eq., weight loss rate of 7.2% at 200°C as measured by TG-DTA apparatus) 7 parts, and a phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Co., Ltd., a 1:1 solution of MEK and cyclohexanone with a solid content of 30% by mass) 10 parts were dissolved in 20 parts of MEK and 40 parts of naphtha solvent while stirring. After cooling to room temperature, 5 parts of (meth)acrylate ("NK Ester A-DOG" manufactured by Shin-Nakamura Chemical Industry Co., Ltd., molecular weight 326) as a free radical polymerizable resin, 94 parts of active ester curing agent ("HPC8000-65T" manufactured by DIC Corporation, toluene solution with an active group equivalent of about 223 g/eq. and a non-volatile matter content of 65% by mass), 5 parts of phenol curing agent ("LA3018-50P" manufactured by DIC Corporation, 2-methoxypropanol solution with an active group equivalent of about 151 g/eq. and a solid content of 50%), and benzoxazine curing agent (JFE 3 parts of "ODA-BOZ" manufactured by Chemical Co., Ltd., a 50% solid content in MEK solution, benzoxazine ring equivalent of about 218 g/eq.), 10 parts of carbodiimide curing agent ("V-03" manufactured by Nisshinbo Chemical Co., Ltd., active group equivalent of about 216 g/eq., a 50% solid content in toluene solution), 4 parts of curing accelerator 1-benzyl-2-phenylimidazole ("1B2PZ" manufactured by Shikoku Chemical Co., Ltd.), a 10% solid content in methyl ethyl ketone solution), and a polymerization initiator ("Perbutyl C") 0.2 parts, rubber particles ("IM401-4-14" manufactured by Aica Industries, core-shell rubber particles with a core of polybutadiene and a shell of a copolymer of styrene and divinylbenzene) 2 parts, flame retardant ("HCA-HQ-HST" manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxo-10-phosphaphenanthrene-10-oxide, average particle size 1.5 μm) 3 parts, spherical silica surface-treated with a phenylaminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) (average particle size 0.5 μm, specific surface area 5.8 ^m2 /g, 400 parts of "SO-C2" manufactured by Admatechs) were added and uniformly dispersed with a high-speed rotary mixer, and then filtered with a cartridge filter ("SHP100" manufactured by ROKITECHNO) to prepare a resin composition 4.

<Preparation of Resin Composition 5> In the preparation of Resin Composition 1, 7 parts of liquid 1,4-epoxypropyl cyclohexane type epoxy resin ("ZX1658GS" manufactured by Nippon Steel & Sumitomo Metal Chemicals Co., Ltd., epoxy equivalent of about 135 g/eq., weight loss rate at 200°C measured by TG-DTA apparatus is 7.2%) were replaced with 7 parts of liquid diglycidyl phthalate ether type epoxy resin ("EX-721" manufactured by Nagase ChemteX, epoxy equivalent of about 154 g/eq., weight loss rate at 200°C measured by TG-DTA apparatus is 4.2%). Except for the above matters, resin composition 5 is prepared in the same manner as the method for preparing resin composition 1.

<Resin composition 6> Resin composition 6 was prepared in the same manner as Resin composition 2 except that 12 parts of (meth)acrylate ("NK Ester A-DOG" manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight 326) which is a free radical polymerizable resin was replaced with 20 parts of styrene-modified polyphenylene ether resin ("OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd., number average molecular weight 1200, a toluene solution containing 60% nonvolatile matter by mass) which is a free radical polymerizable resin.

The components used in resin compositions 1 to 6 and their blending amounts are shown in the following table.

<Example 1> A resin composition 1 was applied to a support 1 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment was performed, and on the other side a PET film with a thickness of 12 μm with a 300 nm silica vapor-deposited layer was laminated via a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) so that the thickness of the resin composition after drying would be 40 μm, and dried at 80 to 120°C (average 100°C) for 6 minutes. The amount of solvent contained in the resin composition layer at this time was 2.5 mass %. Next, a polypropylene film with a thickness of 15 μm is laminated on the surface of the resin composition layer and rolled up. The rolled resin sheet is slit with a width of 507 mm to obtain a sheet-like resin sheet 1 with a size of 507 mm×336 mm.

<Example 2> Resin composition 1 in Example 1 is replaced with resin composition 2. Except for the above matters, the same procedure as in Example 1 is followed to obtain resin sheet 2. The solvent contained in the resin composition layer is 2.6 mass %.

<Example 3> Resin composition 1 in Example 1 is replaced with resin composition 3. Except for the above matters, the same procedure as Example 1 is carried out to obtain resin sheet 3. The solvent contained in the resin composition layer is 2.5 mass %.

<Example 4> Resin composition 1 in Example 1 is replaced with resin composition 4. Except for the above matters, the same procedure as Example 1 is carried out to obtain resin sheet 4. The solvent contained in the resin composition layer is 2.3 mass %.

<Example 5> Resin composition 1 in Example 1 is replaced with resin composition 5. Except for the above matters, the same procedure as Example 1 is carried out to obtain resin sheet 5. The amount of solvent contained in the resin composition layer is 2.5 mass %.

<Example 6> Resin composition 1 in Example 1 is replaced with resin composition 6. Except for the above matters, the same procedure as in Example 1 is carried out to obtain resin sheet 6. The amount of solvent contained in the resin composition layer is 2.7 mass %.

<Example 7> In Example 1, support 1 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and on the other side a PET film with a thickness of 12 μm having a 300 nm silicon dioxide vapor-deposited layer is laminated via a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is changed to support 2 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and on the other side a 2 μm thick organic barrier layer (polyvinyl alcohol) is coated (total thickness 40 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 12 g/m ² ·day)). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a resin sheet 7. The amount of the solvent contained in the resin composition layer was 2.5 mass %.

<Example 8> In Example 1, support 1 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and a PET film with a thickness of 12 μm having a 300 nm silicon dioxide vapor-deposited layer is laminated to the other side through a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is changed to support 3 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and a 2 μm thick organic barrier layer (ethylene-vinyl alcohol copolymer) is coated on the other side (total thickness 40 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 11 g/m ² ·day)). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a resin sheet 8. The amount of the solvent contained in the resin composition layer was 2.5 mass %.

<Example 9> In Example 1, support 1 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and a PET film with a thickness of 12 μm having a 300 nm silicon dioxide vapor-deposited layer is laminated to the other side via a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is changed to support 4 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and a 2 μm thick organic barrier layer (polyvinylidene chloride) is coated on the other side (total thickness 40 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 5.0 g/m ² ·day)). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a resin sheet 9. The amount of the solvent contained in the resin composition layer was 2.5 mass %.

<Example 10> The support 1 in Example 1 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and a PET film with a thickness of 12 μm with a 300 nm silicon dioxide vapor-deposited layer is laminated on the other side through a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is changed to a support 5 (a PEN film with a thickness of 25 μm, on one side of which an alkyd release treatment is performed (total thickness 25 μm, oxygen permeability 14 cc/m ² ·day, water vapor permeability 5.6 g/m ² ·day)). Except for the above matters, the same procedures as in Example 1 are followed to obtain a resin sheet 10. The amount of solvent contained in the resin composition layer was 2.5 mass %.

<Example 11> The support 1 in Example 1 (a PET film with a thickness of 38 μm, one side of which is subjected to an alkyd release treatment, and a PET film with a thickness of 12 μm with a 300 nm silica vapor-deposited layer formed on the other side through a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is changed to support 6 (a PEN film with a thickness of 38 μm, one side of which is subjected to an alkyd release treatment (total thickness 38 μm, oxygen permeability 10 cc/m ² ·day, water vapor permeability 3.8 g/m ² ·day)). Except for the above matters, the same procedures as in Example 1 are followed to obtain a resin sheet 11. The amount of solvent contained in the resin composition layer was 2.5 mass %.

<Example 12> The support 1 in Example 1 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and a PET film with a thickness of 12 μm and a 300 nm silicon dioxide vapor-deposited layer is laminated on the other side via a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is changed to a support 7 (a film with a metal film described in Example 1 of Patent No. 5500074, on the PET side of which an alkyd release treatment is performed (total thickness 41 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 0.5 g/m ² ·day)). Except for the above matters, the same process as in Example 1 was carried out to obtain a resin sheet 12. The amount of the solvent contained in the resin composition layer was 2.5 mass %.

<Example 13> The support 1 in Example 1 (a PET film with a thickness of 38 μm, on one side of which an alkyd release treatment is performed, and a PET film with a thickness of 12 μm and a 300 nm silicon dioxide vapor-deposited layer is formed on the other side via a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is changed to a support 8 (a film with a metal film described in Example 1 of Patent No. 5500074, on the metal film side of which an alkyd release treatment is performed (total thickness 41 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 0.5 g/m ² ·day)). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a resin sheet 13. The amount of the solvent contained in the resin composition layer was 2.5 mass %.

<Example 14> The support 1 in Example 1 (a PET film with a thickness of 38 μm, subjected to alkyd release treatment on one side, and a PET film with a thickness of 12 μm with a 300 nm silica vapor-deposited layer bonded to the other side via a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is replaced with a support 9 (total thickness 18 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 0.1 g/m ² ·day)). Except for the above matters, the same procedure as in Example 1 is followed to obtain a resin sheet 14. The amount of the solvent contained in the resin composition layer is 2.5 mass %.

<Comparative Example 1> The support 1 in Example 1 (a PET film with a thickness of 38 μm, one side of which is subjected to an alkyd release treatment, and a PET film with a thickness of 12 μm having a 300 nm silicon dioxide vapor-deposited layer formed on the other side via a 3 μm thick adhesive layer (total thickness 53 μm, oxygen permeability 0.1 cc/m ² ·day, water vapor permeability 1.2 g/m ² ·day)) is changed to a support 10 (a PET film subjected to an alkyd release treatment (thickness 38 μm, oxygen permeability 40 cc/m ² ·day, water vapor permeability 15 g/m ² ·day). Except for the above matters, the same procedure as in Example 1 was carried out to obtain a resin sheet 15. The amount of the solvent contained in the resin composition layer was 2.5 mass %.

<Comparative Example 2> The resin composition 1 in Comparative Example 1 was changed to resin composition 2. Except for the above matters, the same procedure as in Comparative Example 1 was followed to obtain a resin sheet 16. The amount of solvent contained in the resin composition layer was 2.6 mass %.

<Comparative Example 3> Resin composition 1 in Example 1 was changed to resin composition 3, and the drying conditions were changed from 80-120°C (average 100°C) for 6 minutes to 80-100°C (average 90°C) for 4 minutes. Except for the above matters, the same process as Example 1 was carried out to obtain a resin sheet 17. The solvent content of the solvent contained in the resin composition layer was 5.1 mass %.

<Determination of copper foil adhesion> (1) Sample preparation The glossy surface of electrolytic copper foil (Mitsui Metal & Mining Co., Ltd. "3EC-III", thickness 35μm) was immersed in a micro-etching agent (MEC "CZ-8101") to roughen the copper surface (Ra value = 1μm), and then a rust-proofing solution (MEC "CL8300") was used to perform rust-proofing. The obtained copper foil is called CZ copper foil. In addition, it was heated in an oven at 130°C for 30 minutes.

As the inner circuit substrate, a glass cloth substrate epoxy resin double-sided copper sheet laminate with an inner circuit formed thereon was prepared (copper foil thickness 18μm, substrate thickness 0.4mm, "R1515A" manufactured by Panasonic). Then, resin sheets 1 to 17 were laminated on both sides of the inner circuit substrate using a batch vacuum pressure laminating press ("MVLP-500" manufactured by Meiki Seisakusho) so that the resin composition layer was bonded to the inner circuit substrate. The lamination was performed by depressurizing for 30 seconds to reduce the air pressure to 13hPa or less, and then pressing for 30 seconds at 100°C and a pressure of 0.74MPa. After lamination, the support is peeled off. On the exposed resin composition layer, the treated surface of the CZ copper foil is laminated under the same conditions as above. Afterwards, the resin composition layer is cured at 190°C for 90 minutes to form an insulating layer, thereby producing a sample having a structure of CZ copper foil/insulating layer/inner circuit board/insulating layer/CZ copper foil.

(2) Measurement of copper foil adhesion before high temperature and high humidity environment test (HAST) (Adhesion 1) The prepared sample was cut into small pieces of 150×30 mm. A cutter was used to cut a 10 mm wide and 100 mm long section on the copper foil portion of the small piece. One end of the copper foil in the longitudinal direction was peeled off and clamped with a clamp ("AC-50C-SL" manufactured by TSE). The load when peeling 35 mm vertically at a speed of 50 mm/min at room temperature was measured using an Instron universal testing machine in accordance with JIS C6481. The load measured in this way is called "Adhesion 1".

(3) Determination of copper foil adhesion after high temperature and high humidity environment test (HAST) (Adhesion 2) The prepared samples were cut into small pieces of 150×30 mm. A cutter was used to cut a 10 mm wide and 100 mm long section on the copper foil portion of the small piece. A high temperature and high humidity environment test was performed for 100 hours at 130°C and 85% RH using a highly accelerated life tester ("PM422" manufactured by Kusumoto Chemicals). After that, peel off one end of the copper foil in the length direction, clamp it with a clamp ("AC-50C-SL" manufactured by TSE), and use an Instron universal testing machine to measure the load when peeling 35mm in the vertical direction at a speed of 50mm/minute at room temperature in accordance with JIS C6481. The load measured in this way is called "Adhesion 2". In addition, Adhesion 2 is evaluated according to the following standards. ◎: 0.4kgf/cm or more and no bulging ○: 0.2kgf/cm or more, less than 0.4kgf/cm, and no bulging ×: less than 0.2kgf/cm, or 0.2kgf/cm or more but bulging

<Determination of dielectric tangent> (1) Preparation of evaluation cured product A 15 μm thick polypropylene film was peeled off from resin sheets 1 to 17, and the support used in each example and comparative example was laminated in such a way that the release surface was connected to the resin composition. The lamination was carried out by decompressing for 30 seconds to reduce the pressure to 13 hPa or less, and then pressing for 30 seconds at 100°C and a pressure of 0.74 MPa. After lamination, the resin composition layer was placed in an oven at 190°C and cured for 90 minutes to thermally cure. After thermal curing, the support on both sides of the resin composition layer was peeled off to obtain a thin sheet-like cured product. The hardened material obtained is called "hardened material for evaluation".

(2) Measurement of dielectric tangent The evaluation hardened material was cut into 80 mm in length and 2 mm in width as the evaluation sample. For this evaluation sample, the dielectric tangent was measured by the cavity resonance perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C using the "HP8362B" manufactured by Agilent Technologies. The measurement was performed on two evaluation samples and the average value was calculated. In addition, the average value of the dielectric tangent obtained was evaluated based on the following criteria. ◎: 0.0030 or less ○: greater than 0.0030 and less than 0.0050 ×: 0.0050 or more

<Evaluation of insulation reliability> (1) Preparation of evaluation laminate Prepare an amide film having a comb-tooth electrode (line/gap = 15μm/15μm). Use a batch vacuum pressure laminating press ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.) to laminate the resin sheets 1 to 17 so that the resin composition layer is bonded to the circuit forming surface of the amide film. Lamination is performed by depressurizing for 30 seconds to reduce the pressure to 13hPa or less, and then pressing for 30 seconds at 100°C and a pressure of 0.74MPa. Thereafter, the film was heated at 100°C for 30 minutes and then at 180°C for 90 minutes to obtain an evaluation layer.

(2) Evaluation of insulation reliability After measuring the initial insulation resistance of the evaluation laminate, place it in a high temperature and high humidity tank at 130°C and 85% humidity, charge it with a voltage of 3.3V, and perform a HAST test in the tank at 130°C and 85%RH for 300 hours. Measure the insulation resistance of the evaluation laminate after 300 hours and evaluate it according to the following criteria. 0: The insulation resistance after 300 hours exceeds 50% of the initial insulation resistance. ×: The insulation resistance after 300 hours is less than 50% of the initial insulation resistance.

Although the adhesion 1 and adhesion 2 measurements were performed in Comparative Example 3, bulging was observed at the interface between the insulating layer and the CZ copper foil.

In each example, it was confirmed that even when the component (A-2), the component (C) to the component (I) were not contained, the same results as those of the above examples could be obtained, although there were differences in degree.

Claims (7)

A resin sheet comprising a support and a resin composition layer disposed on the support, wherein the oxygen permeability of the support measured by a method in accordance with JIS K7126 is 20 cc/m ² ·day or less in an environment of 23°C and 50% RH, the amount of solvent contained in the resin composition layer is 5% by mass or less, the resin composition comprises (A-1) a volatile epoxy resin, (A-2) an epoxy resin having a weight loss rate of less than 3% by mass at 200°C, and (C) an inorganic filler, The content of the component (A-1) is 0.1% by mass or more and 10% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. The content of the component (A-2) is 1% by mass or more and 40% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. The content of the component (C) is 50% by mass or more, based on 100% by mass of the non-volatile components in the resin composition. The resin sheet as claimed in claim 1 further comprises (B) a radical polymerizable resin, wherein the total content of the component (A-1) and the component (B) is 1 mass % to 20 mass % when the resin component is 100 mass %. The resin sheet as claimed in claim 1, wherein the water vapor transmission rate of the support measured by the method according to JIS K7129 is 20 g/ ^m2 ·day or less in an environment of 40°C and 90%RH. The resin sheet as claimed in claim 2, wherein the total content of the component (A-1), the component (B), and the solvent is 1 mass % or more and 20 mass % or less when the resin component is 100 mass %. A printed wiring board comprises an insulating layer formed by curing a resin composition layer of the resin sheet as recited in claim 1. A semiconductor device includes a printed wiring board as described in claim 5. A method for manufacturing a printed wiring board comprises the following steps in sequence: (I) laminating a resin sheet as described in any one of claims 1 to 4 on an inner substrate in such a manner that the resin composition layer is bonded to the inner substrate, (II) thermally curing the resin composition layer to form an insulating layer, and (III) peeling off the support.