Thermosetting resin sheet

Abstract

To provide a thermosetting resin sheet or the like that can produce a cured product with low dielectric loss tangent, elongation, and an arithmetic mean roughness (Ra) that ensures adhesion with solder resist. [Solution] A thermosetting resin sheet comprising a support and a resin composition layer provided on the support, wherein the resin composition layer comprises (A) a compound represented by formula (1), (B) an epoxy resin, and (C) an inorganic filler, and the content of component (C) is 40% by mass or more when the non-volatile components in the resin composition layer are taken as 100% by mass. [Formula 1] TIFF2026114944000009.tif35170...(1)

Description

[Technical Field]

[0001] This invention relates to a thermosetting resin sheet. Furthermore, it relates to a circuit board and a semiconductor device using the thermosetting resin sheet. [Background technology]

[0002] As a manufacturing technique for circuit boards such as printed wiring boards, a build-up method is known in which insulating layers and conductive layers are stacked alternately. In the build-up method, the insulating layer is generally formed by curing a resin composition layer in a thermosetting resin sheet (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-15858 [Overview of the project] [Problems that the invention aims to solve]

[0004] In recent years, with the increasing sophistication of circuit boards, there has been a demand to lower the dielectric loss tangent of the insulating layer. One possible method to lower the dielectric loss tangent is to include a large amount of curing accelerator.

[0005] However, if a large amount of curing accelerator is included, the self-assembly of the epoxy resin will progress, increasing the crosslinking density and potentially worsening the elongation. In addition, including a large amount of curing accelerator can increase the amount of hydrophobic components in the resin composition layer, making desmearing more difficult. This can result in a lower arithmetic mean roughness on the surface of the insulating layer. Normally, a solder resist is provided as a protective film on the outermost layer of circuit boards such as printed wiring boards, but if the arithmetic mean roughness of the insulating layer surface is low, the adhesion between the insulating layer and the solder resist may be poor.

[0006] The present invention was conceived in view of the above problems, and it is possible to obtain a cured product having a low dielectric tangent and showing an arithmetic mean roughness (Ra) capable of ensuring an elongation rate and adhesion to a solder resist. A thermosetting resin sheet; a circuit board including a cured product of a resin composition layer of the thermosetting resin sheet; and a semiconductor device including the circuit board; are provided with the aim of achieving the above.

Means for Solving the Problems

[0007] As a result of intensive studies on the above problems, the present inventors have found that the above problems can be solved by containing the component (A) described below instead of the conventional curing accelerator, and have completed the present invention. <000??92> That is, the present invention includes the following content. [1] A thermosetting resin sheet including a support and a resin composition layer provided on the support, where the resin composition layer [[ID=1??]] (A) a compound represented by the formula (1), (B) an epoxy resin, and (C) an inorganic filler, and a thermosetting resin sheet in which the content of the component (C) is 40% by mass or more when the non-volatile components in the resin composition layer are 100% by mass. <000??101>

Chemical formula

[10] Furthermore, a thermosetting resin sheet according to any one of [1] to [9], comprising (G) an organic filler.

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

[10] , wherein the dielectric loss tangent of the cured product obtained by heat-curing the resin composition layer at 200°C for 90 minutes is 0.0050 or less.

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

[11] , wherein the elongation of the cured product obtained by heat-curing the resin composition layer at 200°C for 90 minutes is 1.5% or more, as measured in accordance with JIS K6251.

[13] A thermosetting resin sheet as described in any of [1] to

[12] , for use in semiconductor encapsulation.

[14] A thermosetting resin sheet as described in any of [1] to

[13] , for use as an interlayer insulating layer.

[15] A circuit board comprising an insulating layer formed of a cured product of a resin composition layer of a thermosetting resin sheet described in any of [1] to

[14] .

[16]

[15] A semiconductor device including the circuit board described above. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a thermosetting resin sheet that can produce a cured product with low dielectric loss tangent, elongation, and an arithmetic mean roughness (Ra) that can ensure adhesion with solder resist; a circuit board containing a cured product of the resin composition layer of the thermosetting resin sheet; and a semiconductor device containing the circuit board. [Modes for carrying out the invention]

[0010] The present invention will be described below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be modified and implemented without departing from the scope of the claims and their equivalents.

[0011] [Thermosetting resin sheet] The thermosetting resin sheet of the present invention comprises a support and a resin composition layer provided on the support, wherein the resin composition layer comprises (A) a compound represented by formula (1), (B) an epoxy resin, and (C) an inorganic filler, and the content of component (C) is 40% by mass or more when the non-volatile components in the resin composition layer are taken as 100% by mass. With this configuration, it is possible to obtain a cured product that exhibits a low dielectric loss tangent, elongation, and an arithmetic mean roughness (Ra) that ensures adhesion with solder resist. In addition, it is usually possible to obtain a cured product that exhibits excellent adhesion with the conductor layer after HAST testing (high-accelerated lifetime testing under high-temperature and high-humidity environments). Hereinafter, the thermosetting resin sheet may be simply referred to as "resin sheet".

[0012] The resin sheet may comprise other layers in addition to the support and resin composition layers. Each layer of the resin sheet will be described in detail below.

[0013] <Support> The resin sheet is provided with a support. Examples of the support include a film made of plastic material, a metal foil, and a release paper, with a film made of plastic material and a metal foil being preferred.

[0014] When using a plastic film as a support, examples of plastic materials include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetylcellulose (TAC), polyether sulfide (PES), polyether ketones, and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0015] When using metal foil as a support, examples of metal foil include copper foil and aluminum foil, with copper foil being preferred. As for copper foil, foil made of single-metal copper may be used, or foil made of an alloy of copper with another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

[0016] The support may have surface treatments such as matte finish, corona treatment, or antistatic treatment applied to the surface that bonds with the resin composition layer.

[0017] As the support, a support with a release layer may be used, which has a release layer on the surface that is bonded to the resin composition layer. Examples of release agents used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd-based release agents, polyolefin-based release agents, urethane-based release agents, and silicone-based release agents. Commercially available products may be used as the support with a release layer, for example, PET films having a release layer mainly composed of a silicone-based release agent or an alkyd resin-based release agent, such as "PET501010", "SK-1", "AL-5", and "AL-7" from Lintec Corporation; "Lumirror T60" from Toray Industries, Inc.; "Purex" from Teijin Ltd.; and "Unipeel" from Unitika Corporation.

[0018] The thickness of the support is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, preferably 75 μm or less, more preferably 60 μm or less, and even more preferably 50 μm or less. When using a support with a release layer, it is preferable that the overall thickness of the support with the release layer is within the above range.

[0019] <Resin composition layer> The resin sheet comprises a resin composition layer, which is provided on a support. The insulating layer can be formed by thermal curing the resin composition layer. Typically, the insulating layer includes a cured product of the resin composition layer, preferably consisting solely of a cured product of the resin composition layer.

[0020] The resin composition layer comprises (A) a compound represented by formula (1), (B) an epoxy resin, and (C) an inorganic filler, wherein the content of component (C) is 40% by mass or more, when the non-volatile components in the resin composition layer are taken as 100% by mass.

[0021] The resin composition layer may contain other components in combination with components (A) to (C). Examples of other components include (D) curing agents, (E) polymer resins, (F) radical polymerizable resins, (G) organic fillers, (H) curing accelerators (excluding those corresponding to component (A)), (I) any additives, and (J) solvents. Each component contained in the resin composition layer will be described in detail below.

[0022] In this invention, unless otherwise specified, the content of each component in the resin composition layer is the value when the non-volatile component in the resin composition layer is taken as 100% by mass, and the non-volatile component refers to the components of the resin composition layer other than the solvent described later. Furthermore, in this invention, the resin component of the resin composition layer refers to the components of the resin composition layer excluding the inorganic filler from the non-volatile components.

[0023] -(A) Compound represented by formula (1)- The resin composition layer contains a compound represented by formula (1) as component (A). By including component (A), a cured product can be obtained that exhibits a low dielectric loss tangent and an arithmetic mean roughness (Ra) that ensures elongation and adhesion with the solder resist. [ka] ...(1)

[0024] Component (A) has an imidazole structure and a hydroxyphenyl group, and therefore has excellent compatibility with resin components having aromatic rings and polar solvents, and can dissolve well in epoxy resin (B) and solvent (J). Accordingly, when the resin sheet of the present invention is manufactured using a solvent, the resin sheet can be easily manufactured.

[0025] Component (A) has a structure in which a hydroxyphenyl group is substituted at the 2-position of the imidazole structure that reacts with the epoxy group. In addition to forming coordinate bonds and hydrogen bonds with oxygen atoms, nitrogen atoms, and hydroxyl groups on the surface of the adherend due to the imidazole structure, the hydroxyphenyl group can also participate in hydrogen bonding, resulting in stronger interaction with the adherend and improving adhesion and bonding properties. Consequently, it exhibits excellent adhesion to solder resists and circuit-forming materials such as copper.

[0026] When the non-volatile components in the resin composition layer are assumed to be 100% by mass, the mass ratio of component (A) to component (D), described later, is preferably 100:0.1 to 100:40, more preferably 100:0.5 to 100:30, even more preferably 100:1 to 100:20, 100:1.5 to 100:15, 100:1.8 to 100:12, or 100:2 to 100:10, with component (D) set to 100 (component (D):component (A)). By adjusting the mass ratio of component (A) to component (D) to fall within this range, it is possible to sufficiently obtain the reaction-promoting effect of component (A) on component (D) while preventing excessive self-polymerization reactions of the epoxy resin by component (A), resulting in a crosslinking density within an appropriate range for the resulting cured product. Therefore, it tends to be possible to obtain cured products with superior heat resistance and mechanical strength.

[0027] (A) The content of component (A) is preferably 0.005% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, 0.15% by mass or more, or 0.2% by mass or more, when the nonvolatile components in the resin composition layer are considered to be 100% by mass or more, based on the viewpoint of obtaining sufficient curability. Furthermore, from the viewpoint of maintaining an appropriate curing rate and maintaining the uniformity of the cured layer, it is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 4% by mass or less, 3% by mass or less, or 2% by mass or less.

[0028] (A) The content of component (A) is preferably 0.005% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, 0.15% by mass or more, or 0.2% by mass or more, when the resin component in the resin composition layer is considered to be 100% by mass, from the viewpoint of obtaining sufficient curability. Furthermore, from the viewpoint of maintaining an appropriate curing rate and maintaining the uniformity of the cured layer, it is preferably 25% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, 10% by mass or less, or 8% by mass or less.

[0029] -(B) Epoxy resin- The resin composition layer contains epoxy resin (B) as component (B). This epoxy resin (B) as component (B) excludes any components that would be considered component (A). By including epoxy resin (B), a cured product exhibiting good mechanical strength and insulation reliability can be obtained. Epoxy resin (B) may be used alone or in combination of two or more types.

[0030] (B) Examples of epoxy resins include bixylenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, and glycidyl ester type epoxy resin. Examples include epoxy resins, glycidylcyclohexane type epoxy resins, alkyl diglycidyl ether type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiroring-containing epoxy resins, cyclohexane type epoxy resins, cyclohexanedimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, tetraphenylethane type epoxy resins, phenolphthaleimidine type epoxy resins, and the like.

[0031] The resin composition layer preferably contains an epoxy resin having two or more epoxy groups per molecule as component (B). From the viewpoint of significantly obtaining the desired effects of the present invention, the ratio of the epoxy resin having two or more epoxy groups per molecule to 100% by mass of the epoxy resin (B) is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0032] (B) Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition layer may contain only liquid epoxy resin as component (B), or only solid epoxy resin, but from the viewpoint of significantly obtaining the effects of the present invention, it is preferable to contain a combination of liquid epoxy resin and solid epoxy resin.

[0033] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0034] The liquid epoxy resins that are preferred are bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, glycidylamine type epoxy resin, and epoxy resin having a butadiene structure, glycidylcyclohexane type epoxy resin, phenolphthaleimidine type epoxy resin, alkyl diglycidyl ether type epoxy resin, epoxy resin having a butadiene structure, and resorcinol type epoxy resin, with bisphenol A type epoxy resin, bisphenol F type epoxy resin, and naphthalene type epoxy resin being more preferred.

[0035] Specific examples of liquid epoxy resins include DIC's "HP4032," "HP4032D," and "HP4032SS" (naphthalene-type epoxy resin); Mitsubishi Chemical's "828US," "jER828EL," "825," and "Epicote 828EL" (bisphenol A-type epoxy resin); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F-type epoxy resin); Mitsubishi Chemical's "jER152" (phenol novolac-type epoxy resin); Mitsubishi Chemical's "630" and "630LSD" (glycidylamine-type epoxy resin); and Nippon Steel Chemical & Material's "ZX1059" (a mixture of bisphenol A-type epoxy resin and bisphenol F-type epoxy resin). Examples include "EX-721" (glycidyl ester type epoxy resin) from Nagase ChemteX Corporation; "Celoxide 2021P" (alicyclic epoxy resin with an ester skeleton) from Daicel Corporation; "PB-3600" (epoxy resin with a butadiene structure) from Daicel Corporation; "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) from Nippon Steel Chemical & Material Co., Ltd.; "YED216D" (alkyl diglycidyl ether type epoxy resin) from Mitsubishi Chemical Corporation; "YD-8125G" (bisphenol A type epoxy resin) from Nippon Steel Chemical & Material Co., Ltd.; and "EX-201" (resorcinol type epoxy resin) from Nagase ChemteX Corporation. These can be used individually or in combination of two or more types.

[0036] As for the solid epoxy resin, a solid epoxy resin having two or more epoxy groups per molecule is preferred, a solid epoxy resin having three or more epoxy groups per molecule is more preferred, and an aromatic solid epoxy resin having three or more epoxy groups per molecule is even more preferred.

[0037] Preferred solid epoxy resins include bixylenol-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, naphthylene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, and tetraphenylethane-type epoxy resin. Naphthol novolac-type epoxy resin and biphenyl-type epoxy resin are more preferred, with biphenyl-type epoxy resin being even more preferred.

[0038] Specific examples of solid epoxy resins include DIC's "HP4032H" (naphthalene-type epoxy resin), "HP-4700", "HP-4710" (naphthalene-type tetrafunctional epoxy resin), "N-690" (cresol novolac-type epoxy resin), "N-695" (cresol novolac-type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (dicyclopentadiene-type epoxy resin), and "EXA-731" 1", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000", "HP6000L" (naphthylene ether type epoxy resin); Nippon Kayaku Co., Ltd.'s "EPPN-502H" (trisphenol type epoxy resin), "NC7000L" (naphthol novolac type epoxy resin), "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); Nippon Steel Chemical & Material's "ESN475V", "ESN4100V" (naphthalene-type epoxy resin), "ESN485" (naphthol novolac-type epoxy resin), "ESN4100-VEK75" (naphthol aralkyl-type epoxy resin); Mitsubishi Chemical's "YX4000H", "YL6121" (biphenyl-type epoxy resin), "YX4000HK" (bixylenol-type epoxy resin), "YX8800" (anthracene-type epoxy resin) Examples of xylyl resins include "PG-100" and "CG-500" from Osaka Gas Chemical Co., Ltd., and "YL7760" (bisphenol AF type epoxy resin), "YL7800" (fluorene type epoxy resin), "jER1010" (solid bisphenol A type epoxy resin), and "jER1031S" (tetraphenylethane type epoxy resin) from Mitsubishi Chemical Corporation; as well as "WHR-991S" (phenolphthalein type epoxy resin) from Nippon Kayaku Co., Ltd. These may be used individually or in combination of two or more types.

[0039] (B) When a liquid epoxy resin and a solid epoxy resin are used in combination as component, their mass ratio (liquid epoxy resin:solid epoxy resin) is preferably 1:0.1 to 1:20, more preferably 1:0.15 to 1:10, and particularly preferably 1:0.2 to 1:5.

[0040] (B) component has an epoxy equivalent weight preferably of 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 even more preferably 110 g / eq. to 1000 g / eq. When within this range, a cured product with a sufficient crosslink density of the cured resin composition layer can be obtained. The epoxy equivalent weight is the mass of an epoxy resin containing 1 equivalent of epoxy groups. This epoxy equivalent weight can be measured according to JIS K7236.

[0041] (B) component has a weight average molecular weight (Mw) preferably of 100 to 5000, more preferably 150 to 3000, still more preferably 200 to 1500, from the viewpoint of significantly obtaining the desired effects of the present invention. The weight average molecular weight of the epoxy resin is the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) method.

[0042] (B) component content, from the viewpoint of obtaining a cured product showing good mechanical strength and insulation reliability, when the non-volatile components in the resin composition layer are 100% by mass, is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more. The upper limit is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 18% by mass or less.

[0043] (B) component content, from the viewpoint of obtaining a cured product showing good mechanical strength and insulation reliability, when the resin components in the resin composition layer are 100% by mass, is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 25% by mass or more. The upper limit is preferably 50% by mass or less, more preferably 48% by mass or less, still more preferably 45% by mass or less, or 43% by mass or less.

[0044] Let M be the content of component (A) when the non-volatile components in the resin composition layer are 100% by mass [[ID=Assuming that the non-volatile components in the resin composition layer are 100% by mass, the content of component (B) is M B When this is the case, M A / M B However, it is preferably 0.001 or more, more preferably 0.005 or more, even more preferably 0.01 or more, or 0.03 or more, preferably 1 or less, more preferably 0.5 or less, even more preferably 0.3 or less, or 0.1 or less. A / M B By adjusting the ratio of components (A) and (B) so that the value falls within this range, the effects of the present invention can be significantly obtained.

[0045] -(C)Inorganic filler- The resin composition layer contains (C) an inorganic filler as component (C). By including (C) an inorganic filler in the resin composition layer, it is possible to obtain a cured product with a low dielectric loss tangent. (C) an inorganic filler is usually included in the resin composition layer in granular form. Component (C) may be used alone or in combination of two or more types.

[0046] (C) The inorganic filler content is 40% by mass or more, preferably 45% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, 60% by mass or more, or 65% by mass or more, from the viewpoint of obtaining a cured product with a low dielectric loss tangent, when the nonvolatile components in the resin composition layer are taken as 100% by mass. The upper limit is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, or 75% by mass or less.

[0047] (C) Inorganic compounds are used as the material for the inorganic filler. (C) Examples of materials for the inorganic filler include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred as the silica.

[0048] (C) Examples of commercially available inorganic fillers include "SP60-05" and "SP507-05" from Nippon Steel Chemical & Material Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", "YA010C", "SC2500SQ", "SO-C4", "SO-C2", "SO-C1", and "SO-C6" from Admatex Co., Ltd.; "UFP-30", "DAW-03", and "FB-105FD" from Denka Co., Ltd.; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" from Tokuyama Corporation; and "Cellspheres MGH-005" from Taiheiyo Cement Corporation.

[0049] (C) The average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, 0.2 μm or more, or 0.3 μm or more, preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less.

[0050] (C) The average particle size of inorganic fillers can be measured by the laser diffraction-scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be created on a volume basis using a laser diffraction-scattering particle size distribution analyzer, and the average particle size can be measured by taking the median diameter as the average particle size. A sample can be used in which 100 mg of inorganic filler and 10 g of methyl ethyl ketone (MEK) are weighed into a vial and dispersed using ultrasound for 10 minutes. The sample can be measured using a laser diffraction-type particle size distribution analyzer with blue and red light source wavelengths, and the volume-based particle size distribution of the inorganic filler can be measured using a flow cell method. The average particle size can then be calculated as the median diameter from the obtained particle size distribution. An example of a laser diffraction-type particle size distribution analyzer is the "LA-960" manufactured by Horiba, Ltd.

[0051] (C) The BET specific surface area of ​​the inorganic filler is preferably 0.1 m². 2 / g or more, more preferably 0.5m 2 / g or more, more preferably 1m 2 It is 100m or more / g, preferably 100m 2 / g or less, more preferably 70m 2 / g or less, more preferably 40m 2 It is less than / g.

[0052] (C) The specific surface area of ​​inorganic fillers can be measured by adsorbing nitrogen gas onto the sample surface using a specific surface area measuring device (Macsorb HM-1210, manufactured by Mountec Co., Ltd.) according to the BET method, and then calculating the specific surface area using the BET multipoint method.

[0053] (C) The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of surface treatment agents include fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, etc. The surface treatment agent may be used alone or in any combination of two or more types.

[0054] Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane), "KBE903" (3-aminopropyltriethoxysilane), "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), "SZ-31" (hexamethyldisilazane), "KBM103" (phenyltrimethoxysilane), "KBM-4803" (long-chain epoxy-type silane coupling agent), and "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane), all manufactured by Shin-Etsu Chemical Co., Ltd.

[0055] From the viewpoint of improving the dispersibility of the inorganic filler, the degree of surface treatment by the surface treatment agent is preferably within a specific range. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably with 0.2% to 3% by mass of the surface treatment agent, and even more preferably with 0.3% to 2% by mass of the surface treatment agent.

[0056] The degree of surface treatment by a 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 should be 0.02 mg / m². 2 The above is preferred, and 0.1 mg / m² 2 The above is more preferable, 0.2 mg / m² 2 The above is even more preferable. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition layer, 1.0 mg / m 2 The following is preferred: 0.8 mg / m² 2 The following is more preferable: 0.5 mg / m² 2 The following are even more preferable.

[0057] (C) The amount of carbon per unit surface area of ​​an inorganic filler can be measured after cleaning the inorganic filler with a solvent (e.g., methyl ethyl ketone) following surface treatment. Specifically, a sufficient amount of methyl ethyl ketone is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solids, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. A carbon analyzer such as the "EMIA-320V" manufactured by Horiba, Ltd. can be used.

[0058] Furthermore, the degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit mass of the inorganic filler. The amount of carbon per unit mass of the inorganic filler is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and also preferably 1.0% by mass or less, more preferably 0.8% by mass or less, and even more preferably 0.5% by mass or less. (C) The amount of carbon per unit mass of the inorganic filler can be measured using a carbon analyzer, just like the amount of carbon per unit surface area of ​​the inorganic filler.

[0059] -(D) Hardener- The resin composition layer may contain, as an optional component, a curing agent (D) as component (D). This curing agent (D) as component (D) excludes those corresponding to components (A) to (C). Component (D) usually has the function of curing the resin composition layer by reacting with component (B). Component (D) may be used alone, or two or more types may be used in any ratio.

[0060] Component (D) can be a compound that reacts with component (B) to cure the resin composition layer, and examples include active ester curing agents, phenol curing agents, benzoxazine curing agents, carbodiimide curing agents, acid anhydride curing agents, amine curing agents, and cyanate ester curing agents. In particular, component (D) preferably contains any of the active ester curing agent, phenol curing agent, and carbodiimide curing agent.

[0061] Examples of active ester curing agents include those having one or more active ester groups in one molecule. Among these, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are preferred as active ester curing agents. The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. Particularly from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy 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.

[0062] Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0063] Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolac. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by the condensation of two phenol molecules with one dicyclopentadiene molecule.

[0064] Preferred examples of active ester curing agents include dicyclopentadiene-type active ester curing agents, naphthalene-type active ester curing agents containing a naphthalene structure, active ester curing agents containing an acetylated phenol novolac, active ester curing agents containing a benzoylated phenol novolac, active ester curing agents that are acetylated phenol novolacs, and active ester curing agents containing a styryl group and a naphthalene structure. As for dicyclopentadiene-type active ester curing agents, active ester curing agents containing a dicyclopentadiene-type diphenol structure are preferred. "Dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene. Among these, it is preferable to include dicyclopentadiene-type active ester curing agents as active ester curing agents.

[0065] Commercially available active ester curing agents include, as active ester curing agents containing a dicyclopentadiene-type diphenol structure, "EXB9451", "EXB9460", "EXB9460S", "HPC-8000L-65TM", "HPC-8000-65T", "EXB-8000H", and "EXB-8000L-65TM" (manufactured by DIC); and as active ester curing agents containing a naphthalene structure, "EXB-9416-70BK", "EXB-8100L-65T", "HPC-8150-62T", "EXB-8150L-65T", "EXB-8100L-65T", and "EXB-8" (manufactured by DIC). Examples of phosphorus-containing active ester curing agents include "EXB9401" (manufactured by DIC Corporation), "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester curing agent containing an acetylated phenol novolac, "YLH1026", "YLH1030", "YLH1048" (manufactured by Mitsubishi Chemical Corporation) and "EXB-8500-65T" (manufactured by DIC Corporation) as active ester curing agents containing a styryl group and a naphthalene structure include "PC1300-02-65T" and "PC1300-02-65MA" (manufactured by Air Water Corporation).

[0066] Examples of phenolic curing agents include those having one or more, preferably two or more, hydroxyl groups bonded to aromatic rings (benzene rings, naphthalene rings, etc.) per molecule. Among these, compounds having hydroxyl groups bonded to benzene rings are preferred. Furthermore, from the viewpoint of heat resistance and water resistance, phenolic curing agents having a novolac structure are preferred. Moreover, from the viewpoint of adhesion, nitrogen-containing phenolic curing agents are preferred, and triazine skeleton-containing phenolic curing agents are more preferred. In particular, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, triazine skeleton-containing phenol novolac curing agents are preferred.

[0067] Specific examples of phenol-based and naphthol-based curing agents include "MEH-7700," "MEH-7810," and "MEH-8000H" from Meiwa Kasei Co., Ltd.; "NHN," "CBN," and "GPH" from Nippon Kayaku Co., Ltd.; and "SN-170," "SN-180," "SN-190," "SN-475," "SN-495," "SN-495V," "SN-375," and "SN-395" from Nippon Steel Chemical & Material Co., Ltd. Examples include DIC Corporation's "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165"; and Gun-ei Chemical Co., Ltd.'s "GDP-6115L", "GDP-6115H", and "ELPC75".

[0068] Specific examples of carbodiimide-based curing agents include "V-03," "V-05," "V-07," and "V-11S" manufactured by Nisshinbo Chemical Co., Ltd., and Stavaxol® P manufactured by Rhein Chemie Co., Ltd.

[0069] Specific examples of benzoxazine-based curing agents include "ODA-BOZ" from JFE Chemical Corporation, "HFB2006M" from Showa Polymer Co., Ltd., and "Pd" and "Fa" from Shikoku Chemicals Co., Ltd.

[0070] Examples of acid anhydride-based curing agents include those having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride-based curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexen-1,2-dicarboxylic acid anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenone. Examples of acid anhydrides include tetracarboxylic dianhydrides, biphenyltetracarboxylic dianhydrides, naphthalenetetracarboxylic dianhydrides, oxydiphthalic acid dianhydrides, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydrides, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymer-type acid anhydrides such as styrene-maleic acid resin obtained by copolymerizing styrene and maleic acid. Commercially available acid anhydride-based curing agents may also be used, such as "MH-700" manufactured by Shin Nippon Rika Co., Ltd.

[0071] Examples of amine-based curing agents include curing agents having one or more amino groups in one molecule, such as aliphatic amines, polyetheramines, alicyclic amines, and aromatic amines. Among these, aromatic amines are preferred from the viewpoint of achieving the desired effects of the present invention. The amine-based curing agent 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), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxy Examples include bis(4-(4-aminophenoxy)phenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Commercial amine-based curing agents may also be used, such as "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD AA", "KAYAHARD AB", and "KAYAHARD AS" from Nippon Kayaku Co., Ltd.; and "Epicure W" from Mitsubishi Chemical Corporation.

[0072] Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl) thioether, and bis(4-cyanatephenyl) ether; polyfunctional cyanate resins derived from phenol novolacs and cresol novolacs, etc.; and prepolymers in which these cyanate resins are partially triazined. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (both phenol novolac type polyfunctional cyanate ester resins) manufactured by Lonza Japan Co., Ltd.; "ULL-950S" (polyfunctional cyanate ester resin); "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazined and trimerized); and others.

[0073] When the number of epoxy groups in component (B) is set to 1, the number of active groups in the curing agent (D) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. Here, "number of epoxy groups in component (B)" is the sum of all values ​​obtained by dividing the mass of the nonvolatile components of component (B) present in the resin composition layer by the epoxy equivalent. Also, "number of active groups in the curing agent (D)" is the sum of all values ​​obtained by dividing the mass of the nonvolatile components of the curing agent (D) present in the resin composition layer by the active group equivalent.

[0074] (D) The content of the curing agent is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, or 5% by mass or more, when the nonvolatile components in the resin composition layer are considered to be 100% by mass.

[0075] (D) The content of the curing agent is preferably 5% by mass or more, more preferably 8% by mass or more, even more preferably 10% by mass or more, 15% by mass or more, or 20% by mass or more, when the resin component in the resin composition layer is considered to be 100% by mass, and preferably 60% by mass or less, more preferably 58% by mass or less, even more preferably 55% by mass or less, or 50% by mass or less.

[0076] -(E) Polymer resin- The resin composition layer may contain a polymer resin as component (E). This polymer resin as component (E) does not include those corresponding to components (A) to (D) described above. The polymer resin (E) may be used alone or in combination of two or more types.

[0077] (E) The polymer resin typically has a weight-average molecular weight greater than that of (B) the epoxy resin, and can exert the effect of reducing the elastic modulus of the cured resin composition layer. The specific weight-average molecular weight of (E) the polymer resin is usually greater than 5,000, preferably 8,000 or more, more preferably 10,000 or more, even more preferably 12,000 or more, 20,000 or more, or 30,000 or more, preferably 100,000 or less, more preferably 70,000 or less, particularly preferably 60,000 or less, or 50,000 or less. The weight-average molecular weight of (E) the polymer resin can be measured as a polystyrene equivalent value by gel permeation chromatography (GPC).

[0078] (E) As the polymer resin, for example, as component (E-1), a polymer resin with an elastic modulus of 1 GPa or less measured in accordance with JIS K6251 is included. The polymer resin with an elastic modulus of 1 GPa or less measured in accordance with JIS K6251 does not include those corresponding to components (A) to (D) described above. The polymer resin with an elastic modulus of 1 GPa or less measured in accordance with JIS K6251 may be used alone or in combination of two or more types. The elastic modulus of component (E-1) measured in accordance with JIS K6251 is 1 GPa or less, preferably 0.8 GPa or less, more preferably 0.7 GPa or less, even more preferably 0.6 GPa or less, 0.5 GPa or less, 0.4 GPa or less, or 0.3 GPa or less. There is no particular limit to the lower limit, but it may be 0.0001 GPa or more.

[0079] The elastic modulus of component (E-1) can be measured as follows: Component (E-1) is cut into a dumbbell shape according to the tensile strength type 5 specified in JIS K6251 to obtain a sample for measuring the coefficient of linear thermal expansion. A tensile test is performed on this sample using a universal testing machine (Shimadzu Autograph AGS-X-5kN) with a load cell of 50N and a test speed of 5mm / min to measure the elastic modulus.

[0080] Component (E-1) is an amorphous component that is soluble in a solvent and is either a component with rubber elasticity or a component that exhibits rubber elasticity when polymerized with other components. As a resin exhibiting rubber elasticity, it is a resin that exhibits an elastic modulus of 1 GPa or less when subjected to a tensile test in accordance with the Japanese Industrial Standard (JIS K6251). As component (E-1), a compound having one or more structures selected from polybutadiene structure, polysiloxane structure, poly(meth)acrylate structure, polyalkylene structure, polyalkylene oxy structure, polyisoprene structure, polyisobutylene structure, polyester structure, and polycarbonate structure in its molecule is preferred. Furthermore, a compound having one or more structures selected from the group consisting of polybutadiene structure, poly(meth)acrylate structure, polyalkylene oxy structure, polyisoprene structure, polyester structure, and polycarbonate structure in its molecule is even more preferred. Furthermore, a compound having one or more structures selected from the group consisting of polybutadiene structure, polyester structure, and polycarbonate structure in its molecule is particularly preferred. "(Meth)acrylate" is a term that encompasses methacrylate, acrylate, and combinations thereof. These structures may be included in the main chain or side chain of the (E-1) component molecule.

[0081] An example of component (E-1) is a resin containing a polybutadiene structure. The polybutadiene structure may be included in the main chain or in the side chain. The polybutadiene structure may be partially or entirely hydrogenated. A resin containing a polybutadiene structure is sometimes called a polybutadiene resin. Examples of polybutadiene resins include Clay Valley's "Ricon 130MA8," "Ricon 130MA13," "Ricon 130MA20," "Ricon 131MA5," "Ricon 131MA10," "Ricon 131MA17," "Ricon 131MA20," and "Ricon 184MA6" (acid anhydride group-containing polybutadiene); Nippon Soda's "GQ-1000" (hydroxyl group and carboxyl group-introduced polybutadiene), "G-1000," "G-2000," and "G-3000" (hydroxyl group polybutadiene at both ends), "GI-1000," "GI-2000," and "GI-3000" (hydroxyl group hydrogenated polybutadiene at both ends); and Nagase ChemteX's "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin). Examples of polybutadiene resins include hydroxyl-terminated polybutadiene, diisocyanate compounds, and linear polyimides derived from tetrabasic acid anhydrides (polyimides described in Japanese Patent Publication No. 2006-37083 and International Publication No. 2008 / 153208), and phenolic hydroxyl-containing butadiene. The butadiene structure content of the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. Details of the polyimide resin can be found in Japanese Patent Publication No. 2006-37083 and International Publication No. 2008 / 153208, and this information is incorporated herein by reference.

[0082] Another example of component (E-1) is a resin containing a poly(meth)acrylate structure. Resins containing a poly(meth)acrylate structure are sometimes called poly(meth)acrylic resins. Examples of poly(meth)acrylic resins include Teisan Resin from Nagase ChemteX Corporation and "ME-2000", "W-116.3", "W-197C", "KG-25", and "KG-3000" from Negami Kogyo Co., Ltd.

[0083] (E-1) Another example of component is a resin containing a polycarbonate structure. A resin containing a polycarbonate structure is sometimes called a polycarbonate resin. Examples of polycarbonate resins include "T6002" and "T6001" (polycarbonate diols) from Asahi Kasei Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) from Kuraray Co., Ltd. Linear polyimides made from hydroxyl-terminated polycarbonates, diisocyanate compounds, and tetrabasic acid anhydrides can also be used. The content of the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. Details of the polyimide resin can be found in International Publication No. 2016 / 129541, which is incorporated herein by reference.

[0084] (E-1) Another example of component is a resin containing a polysiloxane structure. Resins containing a polysiloxane structure are sometimes called siloxane resins. Examples of siloxane resins include "SMP-2006", "SMP-2003PGMEA", and "SMP-5005PGMEA" manufactured by Shin-Etsu Silicone Co., Ltd., as well as linear polyimides made from amine-terminated polysiloxanes and tetrabasic acid anhydrides (International Publication No. 2010 / 053185, Japanese Patent Publication No. 2002-12667 and Japanese Patent Publication No. 2000-319386, etc.).

[0085] Another example of component (E-1) is a resin containing a polyalkylene structure or a polyalkylene oxy structure. A resin containing a polyalkylene structure is sometimes called a polyalkylene resin, and a resin containing a polyalkylene oxy structure is sometimes called a polyalkylene oxy resin. The polyalkylene oxy structure preferably has 2 to 15 carbon atoms, more preferably has 3 to 10 carbon atoms, and even more preferably has 5 to 6 carbon atoms. Specific examples of polyalkylene resins and polyalkylene oxy resins include "PTXG-1000" and "PTXG-1800" manufactured by Asahi Kasei Fibers Co., Ltd.

[0086] Another example of component (E-1) is a resin containing a polyisoprene structure. A resin containing a polyisoprene structure is sometimes called a polyisoprene resin. Examples of polyisoprene resins include "KL-610" and "KL613" manufactured by Kuraray Co., Ltd.

[0087] Another example of component (E-1) is a resin containing a polyisobutylene structure. A resin containing a polyisobutylene structure is sometimes called a polyisobutylene resin. Examples of polyisobutylene resins include Kaneka Corporation's "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer).

[0088] Another example of component (E-1) is a resin containing a polyester structure. A resin containing a polyester structure is sometimes called a polyester resin. Examples of polyester resins include "Byron 600", "Byron 560", "Byron 230", "Byron GK-360", and "Byron BX-1001" from Toyobo Co., Ltd., and "LP-035", "LP-011", "TP-220", "TP-249", and "SP-185" from Mitsubishi Chemical Corporation.

[0089] Component (E-1) preferably has a radical polymerizable group at one end, and more preferably has radical polymerizable groups at both ends. Examples of radical polymerizable groups that component (E-1) may have at its ends include vinyl groups, allyl groups, vinylphenyl groups, and (meth)acryloyl groups. If component (E-1) contains two or more radical polymerizable groups, these two or more radical polymerizable groups may be the same or different. Among these, the radical polymerizable group that component (E-1) may have at its ends is preferably a (meth)acryloyl group.

[0090] Component (E-1) preferably has a functional group that can react with epoxy resin (B). The functional group that can react with epoxy resin (B) includes functional groups that appear upon heating. In one embodiment, the functional group that can react with epoxy resin (B) may be one or more functional groups selected from the group consisting of hydroxyl groups, carboxyl groups, acid anhydride groups, phenolic hydroxyl groups, epoxy groups, isocyanate groups, and urethane groups. Among these, hydroxyl groups, acid anhydride groups, phenolic hydroxyl groups, epoxy groups, isocyanate groups, and urethane groups are preferred as the functional group, hydroxyl groups, acid anhydride groups, phenolic hydroxyl groups, and epoxy groups are more preferred, and phenolic hydroxyl groups are particularly preferred. However, when an epoxy group is included as a functional group, the weight-average molecular weight (Mw) of component (E-1) is preferably greater than 5,000.

[0091] Component (E-1) preferably has a large number-average molecular weight. The specific number-average molecular weight (Mn) of component (E-1) is preferably 1,000 or more, more preferably 1,500 or more, even more preferably 3,000 or more, and particularly preferably 5,000 or more. The upper limit is preferably 1,000,000 or less, more preferably 900,000 or less. The number-average molecular weight (Mn) is the number-average molecular weight on a polystyrene basis measured using GPC (gel permeation chromatography).

[0092] The specific glass transition temperature (Tg) of component (E-1) is preferably 30°C or lower, more preferably 20°C or lower, even more preferably 10°C or lower, or 5°C or lower, preferably -60°C or higher, more preferably -50°C or higher, even more preferably -45°C or higher, -40°C or higher, -35°C or higher, -30°C or higher, -25°C or higher, -20°C or higher, -15°C or higher, or -10°C or higher.

[0093] (E) Examples of polymer resins include (E-2) thermoplastic resin as component (E-2). (E-2) thermoplastic resin does not include components (A) to (D) and component (E-1) mentioned above. (E-2) thermoplastic resin may be used alone or in combination of two or more types.

[0094] (E-2) Examples of thermoplastic resins include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polyimide resin, polyamide-imide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polyetheretherketone resin, polyester resin, etc. (E-2) A single thermoplastic resin may be used, or two or more types may be used in combination. (E-2) Phenoxy resin is preferred as the thermoplastic resin.

[0095] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal end of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Specific examples of phenoxy resins include "1256" and "4250" (both phenoxy resins containing a bisphenol A skeleton) manufactured by Mitsubishi Chemical Corporation; "YX8100" (phenoxy resin containing a bisphenol S skeleton) manufactured by Mitsubishi Chemical Corporation; "YX6954" (phenoxy resin containing a bisphenol acetophenone skeleton) manufactured by Mitsubishi Chemical Corporation; "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd.; and "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", "YL7482", and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation.

[0096] Specific examples of polyimide resins include "PIAD200" manufactured by Arakawa Chemical Co., Ltd., "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., and "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shin-Nippon Rika Co., Ltd. Specific examples of these polyimide resins also include modified polyimide resins such as linear polyimide resins obtained by reacting a bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (polyimide resin described in Japanese Patent Publication No. 2006-37083), and polysiloxane skeleton-containing polyimide resins (polyimide resins described in Japanese Patent Publication No. 2002-12667 and Japanese Patent Publication No. 2000-319386, etc.).

[0097] Examples of polyvinyl acetal resins include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of polyvinyl acetal resins include S-Rec BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, BM series, etc., manufactured by Sekisui Chemical Co., Ltd.

[0098] Examples of polyolefin resins include ethylene-based copolymer resins such as low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; and polyolefin polymers such as polypropylene and ethylene-propylene block copolymer.

[0099] Specific examples of polyamide-imide resins include "Viromax HR11NN" and "Viromax HR16NN" manufactured by Toyobo Co., Ltd. Other specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imide) manufactured by Resonaq Corporation.

[0100] Specific examples of polyethersulfone resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0101] Specific examples of polysulfone resins include Solvay Advanced Polymers' polysulfones "P1700" and "P3500".

[0102] The polyphenylene ether resin may be a copolymer of polyphenylene ether and polybutadiene. Specific examples of polyetherimide resins include GE's "Ultem," among others.

[0103] (E) The content of the polymer resin is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, preferably 15% by mass or less, more preferably 13% by mass or less, even more preferably 10% by mass or less, 8% by mass or less, 5% by mass or less, or 3% by mass or less, when the nonvolatile components of the resin composition layer are taken as 100% by mass.

[0104] (E) The polymer resin content is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, when the resin components in the resin composition layer are considered to be 100% by mass.

[0105] The content of component (A) when the non-volatile components in the resin composition layer are taken as 100% by mass is M. A Assuming that the non-volatile components in the resin composition layer are 100% by mass, the content of component (E) is M E When this is the case, M A / M E However, it is preferably 0.005 or more, more preferably 0.01 or more, even more preferably 0.05 or more, or 0.1 or more, preferably 3 or less, more preferably 1 or less, even more preferably 0.8 or less, or 0.5 or less. A / M E The effects of the present invention can be significantly obtained by adjusting the ratio of components (A) and (E) so that the result falls within the specified range.

[0106] -(F) Radical polymerizable resin- The resin composition layer may contain a radical polymerizable resin as component (F). This radical polymerizable resin as component (F) does not include those corresponding to components (A) to (E) described above. A radical polymerizable resin means a resin having one or more (preferably two or more) radical polymerizable unsaturated groups per molecule. The radical polymerizable resin (F) may be used alone or in combination of two or more types.

[0107] Examples of radical polymerizable unsaturated groups include one or more selected from maleimide group, vinyl group, styryl group, vinylphenyl group, allyl group, acryloyl group, methacryloyl group, fumaroyl group, and maleoil group. In particular, the radical polymerizable unsaturated group preferably has any of the maleimide group, styryl group, vinylphenyl group, vinyl group, allyl group, styryl group, acryloyl group, and methacryloyl group, and more preferably has either a maleimide group or a vinylphenyl group. Therefore, as the (F) radical polymerizable resin, from the viewpoint of significantly obtaining the effects of the present invention, it is preferable to include any of the maleimide resin, (meth)acrylic resin, allyl resin, and vinyl resin, and more preferably to include a maleimide resin.

[0108] The type of maleimide resin is not particularly limited, as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl groups) per molecule. Examples of maleimide resins include (1) "BMI-3000J", "BMI-5000", "BMI-1400", "BMI-1500", "BMI-1700", and "BMI-689" (all from Designer Molecules). Examples include maleimide resins containing an aliphatic skeleton (preferably an aliphatic skeleton with 36 carbon atoms derived from dimeramine), such as "SLK6895-T90" (manufactured by Shin-Etsu Chemical Co., Ltd.) and "BMI-TMH" (manufactured by Yamato Chemical Co., Ltd.); (2) Maleimide resins containing an indan skeleton as described in the Japan Institute of Invention and Innovation, Technical Report No. 2020-500211; and (3) Maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" and "MIR-5000-60T" (both manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" and "BMI-2300" (both manufactured by Yamato Chemical Co., Ltd.), and "BMI-70" and "BMI-80" (both manufactured by Kei-I Chemical Co., Ltd.).

[0109] The type of (meth)acrylic resin is not particularly limited as long as it has one or more (preferably two or more) (meth)acryloyl groups in one molecule, and may be a monomer or oligomer. Here, the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups. Examples of methacrylic resins include (meth)acrylate monomers, as well as (meth)acrylic resins such as "A-DOG" (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "SA9000" (manufactured by SABIC Corporation), "NPDGA", "FM-400", "R-604", "R-684", "THE-330", "PET-30", "DPHA", and "DPCA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0110] Allyl resins are compounds having, for example, one or more, preferably two or more allyl groups. Examples of allyl resins include aromatic carboxylic acid allyl ester compounds such as diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylic acid, and diallyl 2,3-naphthalenecarboxylic acid; isocyanuric acid allyl ester compounds such as 1,3,5-trialyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; epoxy-containing aromatic allyl compounds such as 2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane; benzoxazine-containing aromatic allyl compounds such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazine-3-yl)phenyl]methane; ether-containing aromatic allyl compounds such as 1,3,5-trialyl etherbenzene; and allyl silane compounds such as diallyldiphenylsilane.

[0111] Examples of commercially available allyl resins include "TAIC" (1,3,5-trialyl isocyanurate) from Nippon Chemical Industries, Ltd., "DAD" (diallyl diphenate) from Nichishoku Techno Fine Chemicals Co., Ltd., "TRIAM-705" (trialyl trimellitate) from Fujifilm Wako Pure Chemical Corporation, "DAND" (2,3-naphthalenecarboxylate diallyl) from Nichishoku Techno Fine Chemicals Co., Ltd., "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazine-3-yl)phenyl]methane) from Shikoku Chemicals, Ltd., "RE-810NM" (2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane) from Nippon Kayaku Co., Ltd., and "DA-MGIC" (1,3-diallyl-5-glycidyl isocyanurate) from Shikoku Chemicals, Ltd.

[0112] As long as a vinyl resin has one or more (preferably two or more) vinyl groups in one molecule, its type is not particularly limited, and the concept of vinyl resin also includes resins containing styryl groups and vinylphenyl groups that contain vinyl groups. For example, a vinyl resin may also be called a styrene resin if it has a styryl group that has one or more, preferably two or more vinyl groups directly bonded to an aromatic carbon atom. Examples of vinyl resins include low molecular weight (molecular weight less than 1000) styrene compounds such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl) ether; high molecular weight (molecular weight 1000 or more) styrene resins such as vinylbenzyl-modified polyphenylene ether resins and styrene-divinylbenzene copolymers; and styrene compounds having either a phenylpyrimidine skeleton or a 1,1-diphenylcyclohexane skeleton. Examples of commercially available vinyl resins and styrene resins include "ODV-XET(X03)", "ODV-XET(X04)", and "ODV-XET(X05)" (styrene-divinylbenzene copolymer) from Nippon Steel Chemical & Material Co., Ltd., and "OPE-2St 1200" and "OPE-2St 2200" (vinylbenzyl-modified polyphenylene ether resin) from Mitsubishi Gas Chemical Co., Ltd.

[0113] (F) The weight-average molecular weight of the radical polymerizable resin is preferably 5,000 or less, more preferably 4,000 or less, and even more preferably 3,000 or less. The lower limit may be, for example, 150 or more. (F) The weight-average molecular weight of the radical polymerizable resin can be measured as a polystyrene equivalent value by gel permeation chromatography (GPC).

[0114] (F) The content of the radical polymerizable resin is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, preferably 15% by mass or less, more preferably 13% by mass or less, even more preferably 10% by mass or less, 5% by mass or less, or 3% by mass or less, when the nonvolatile components in the resin composition layer are taken as 100% by mass.

[0115] (F) The content of the radical polymerizable resin is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 43% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less, when the total resin component in the resin composition layer is considered to be 100% by mass.

[0116] The content of component (A) when the non-volatile components in the resin composition layer are taken as 100% by mass is M. A Assuming that the non-volatile components in the resin composition layer are 100% by mass, the content of component (F) is M F When this is the case, M A / M F However, it is preferably 0.005 or more, more preferably 0.01 or more, even more preferably 0.02 or more, 0.05 or more, or 0.1 or more, and preferably 0.8 or less, more preferably 0.75 or less, even more preferably 0.7 or less, 0.65 or less, 0.6 or less, or 0.5 or less. A / M F By adjusting the ratio of components (A) and (F) so that the value falls within this range, the effects of the present invention can be significantly obtained.

[0117] -(G)Organic filler- The resin composition layer may contain, as an optional component, (G) component, an organic filler (G). This organic filler (G) component does not include those corresponding to components (A) to (F) described above. The organic filler (G) is usually immiscible with resin components other than the organic filler (G) and is included in the resin composition layer in granular form. It also does not dissolve in solvents and is included in the cured product while maintaining its granular state. By including the organic filler (G) in the resin composition layer, it is possible to improve the adhesion between it and the conductive layer after the HAST test. The organic filler (G) may be used alone or in combination of two or more types.

[0118] (G) As the organic filler, particles of organic material may be used. (G) As the organic material contained in the organic filler, rubber components are preferred. Examples of rubber components include silicone elastomers such as polydimethylsiloxane; olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychlorobutadiene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, ethylene-propylene-butene terpolymer; and thermoplastic elastomers such as acrylic-based thermoplastic elastomers such as propyl poly(meth)acrylate, butyl poly(meth)acrylate, cyclohexyl poly(meth)acrylate, and octyl poly(meth)acrylate. Furthermore, silicone-based rubbers such as polyorganosiloxane rubber may be mixed with the rubber component. The rubber component contained in the rubber particles has a glass transition temperature of, for example, 0°C or lower, preferably -10°C or lower, more preferably -20°C or lower, and even more preferably -30°C or lower.

[0119] (G) The organic filler may be a core-shell type rubber particle consisting of core particles containing the rubber components listed above and a shell portion formed by graft copolymerization of monomer components copolymerizable with the rubber components contained in the core particles. Here, "core-shell type" does not necessarily refer only to those in which the core particles and shell portion can be clearly distinguished, but also includes those in which the boundary between the core particles and shell portion is unclear, and the core particles do not have to be completely covered by the shell portion.

[0120] (G)Specific examples of organic fillers include, for example, "CHT" from Samsung SDI; "B602" from Techno UMG; "Paraloid EXL-2602", "Paraloid EXL-2603", "Paraloid EXL-2655", "Paraloid EXL-2311", "Paraloid-EXL2313", "Paraloid EXL-2315", "Paraloid KM-330", "Paraloid KM-336P", "Paraloid KCZ-201" from Dow Corporation; and "Metablen C-223A", "Metablen E-901", "Metablen" from Mitsubishi Rayon Corporation. Examples include the "S-2001", "Metablen W-450A", "Metablen SRK-200", Kaneka Corporation's "Kaneace M-511", "Kaneace M-600", "Kaneace M-400", "Kaneace M-580", "Kaneace MR-01", and Aica Kogyo Co., Ltd.'s "Stafiloid AC3355", "Stafiloid AC3816", "Stafiloid AC3816N", "Stafiloid AC3832", "Stafiloid AC4030", "Stafiloid AC3364", "AC3401N", and "AC3401".

[0121] (G) The content of the organic filler is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less, when the nonvolatile components in the resin composition layer are taken as 100% by mass.

[0122] (G) The content of the organic filler is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 10% by mass or less, more preferably 9% by mass or less, and even more preferably 8% by mass or less, when the resin component in the resin composition layer is taken as 100% by mass.

[0123] The content of component (A) when the non-volatile components in the resin composition layer are taken as 100% by mass is M. A Assuming that the non-volatile components in the resin composition layer are 100% by mass, the content of component (G) is M G When this is the case, M G / M A However, it is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 0.8 or more, or 1.2 or more, or 1.5 or more, preferably 50 or less, more preferably 40 or less, even more preferably 30 or less, 15 or less, 12 or less, 10 or less, 8 or less, 6 or less, or 5 or less.

[0124] The content of component (B) when the non-volatile component in the resin composition layer is taken as 100% by mass is M. A When this is the case, M G / M B However, it is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.08 or more, or 0.09 or more, 0.1 or more, or 0.12 or more, and preferably 1 or less, more preferably 0.8 or less, even more preferably 0.6 or less, 0.5 or less, 0.4 or less, or 0.3 or less.

[0125] The content of component (C) when the non-volatile component in the resin composition layer is taken as 100% by mass is M A When this is the case, M G / M C However, it is preferably 0.001 or more, more preferably 0.005 or more, even more preferably 0.01 or more, or 0.03 or more, preferably 1 or less, more preferably 0.5 or less, even more preferably 0.3 or less, 0.2 or less, or 0.1 or less.

[0126] -(H) Curing accelerator - The resin composition layer may contain (H) a curing accelerator (excluding those corresponding to component (A)) as an optional component. The curing accelerator (H) as component (H) does not include those corresponding to components (A) to (G) described above.

[0127] (H) Examples of curing accelerators include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, amine-based curing accelerators, etc. (H) A single type of curing accelerator may be used, or two or more types may be used in combination.

[0128] Examples of phosphorus-based curing accelerators include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium) pyromelitate, tetrabutylphosphonium hydrogen hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium bromide. Aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone addition products such as triphenylphosphine-p-benzoquinone addition products; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine Examples include aromatic phosphines such as tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether.

[0129] Examples of urea-based curing accelerators include aliphatic dimethylureas such as 1,1-dimethylurea, 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. Aromatic dimethylureas such as toluenebisdimethylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluenebisdimethylurea] are examples.

[0130] Examples of guanidine-based curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0131] Examples of imidazole-based curing accelerators 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-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct, 2-phenylimidazole isocyanurate adduct Examples of imidazole compounds include 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. Examples of commercially available imidazole-based curing accelerators include "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" from Shikoku Chemicals, Inc., and "P200-H50" from Mitsubishi Chemical Corporation.

[0132] Examples of metal-based hardening accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, and organomanganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0133] Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. Commercially available amine-based curing accelerators may also be used, such as "MY-25" manufactured by Ajinomoto Fine Techno Co., Ltd.

[0134] (H) The content of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, even more preferably 0.05% by mass or more, preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0.1% by mass or less, when the nonvolatile components in the resin composition layer are considered to be 100% by mass.

[0135] (H) The content of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, when the resin component in the resin composition layer is considered to be 100% by mass.

[0136] -(I) Other additives- In addition to the components described above, the resin composition layer may also contain (I) other additives as non-volatile components. Examples of such additives include: radical polymerization initiators; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentonite and montmorillonite; defoaming agents such as silicone-based defoaming agents, acrylic-based defoaming agents, fluorine-based defoaming agents, and vinyl resin-based defoaming agents; and UV absorbers such as benzotriazole-based UV absorbers. Examples of additives include: agents; adhesion improvers such as urea silane; adhesion improvers such as triazole-based adhesion improvers, tetrazole-based adhesion improvers, and triazine-based adhesion improvers; antioxidants such as hindered phenol-based antioxidants; fluorescent whitening agents such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic acid anhydride-based stabilizers. (I) Other additives may be used individually or in combination of two or more in any ratio. (I) The content of other additives can be appropriately determined by a person skilled in the art.

[0137] -(J) Solvent- The resin composition layer may contain any solvent as a volatile component in addition to the non-volatile component described above. (J) Any known solvent can be used as appropriate, and the type is not particularly limited, but an organic solvent is preferred. (J) Examples of solvents include: ketone solvents such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methoxypropio Examples include ether ester solvents such as methyl phosphate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (J) The solvent may be used alone or in combination of two or more in any ratio.

[0138] (J) The amount of solvent may be, for example, 60% by mass or less, 55% by mass or less, 50% by mass or less, or 45% by mass or less, or 20% by mass or more, 25% by mass or more, or 30% by mass or more, based on 100% by mass of all components in the resin composition layer.

[0139] The content of component (A) when the non-volatile components in the resin composition layer are taken as 100% by mass is M. A Assuming that the total components in the resin composition layer are 100% by mass, the (J) solvent content is M J When this is the case, M A / M J Preferably, it is 0.001 or more, more preferably 0.005 or more, even more preferably 0.01 or more, or 0.015 or more, preferably 0.03 or less, more preferably 0.028 or less, and even more preferably 0.025 or less.

[0140] From the viewpoint of thinning, the thickness of the resin composition layer is preferably 100 μm or less, more preferably 75 μm or less, and even more preferably 55 μm or less. The lower limit of the thickness of the resin composition layer may be, for example, 1 μm or more, 3 μm or more, 5 μm or more, etc.

[0141] <Other layers> The resin sheet may include other layers as needed. For example, the resin sheet may include a protective film similar to a support that protects the resin composition layer. The protective film is usually provided on the side of the resin composition layer that is not bonded to the support (i.e., the side opposite to the support). Therefore, it is preferable that the thermosetting resin sheet includes the support, the resin composition layer, and the protective film in that order. The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. When a protective film is provided, the adhesion of dust and scratches to the surface of the resin composition layer can be suppressed.

[0142] <Method for manufacturing thermosetting resin sheets> Thermosetting resin sheets can be manufactured, for example, by a method that includes forming a resin composition layer on a support. Specifically, a thermosetting resin sheet may be manufactured by preparing a liquid (varnish-like) resin composition (resin varnish) by using a liquid (varnish-like) resin composition containing component (A) as is, or by mixing a solvent with a resin composition containing component (A) to prepare a liquid (varnish-like) resin composition (resin varnish), applying this to a support, and further drying it as necessary to form a resin composition layer. As the solvent, the same solvent as described for the components of the resin composition layer may be used.

[0143] The resin composition can be applied using a coating device such as a die coater. Drying can be carried out by drying methods such as heating or hot air blowing. The drying conditions are not particularly limited, but the solvent content in the resin composition layer is usually 10% by mass or less, preferably 5% by mass or less. Although this may vary depending on the boiling point of the solvent, for example, when using a resin composition containing 30% to 60% by mass of solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0144] The manufactured thermosetting resin sheets can be stored by rolling them up. If the thermosetting resin sheets have a protective film, they can usually be used after removing the protective film.

[0145] <Physical properties and applications of thermosetting resin sheets> Since the resin composition layer in the thermosetting resin sheet of the present invention contains component (A), even if a large amount of component (C) is included, it is possible to obtain a cured product that exhibits excellent dielectric loss tangent and elongation, and an arithmetic mean roughness (Ra) that ensures adhesion with the solder resist. Furthermore, it is usually possible to obtain a cured product that exhibits excellent adhesion with the conductive layer after HAST testing.

[0146] A cured product obtained by heat-curing a resin composition layer at 200°C for 90 minutes exhibits the characteristic of a low dielectric loss tangent. Therefore, the cured product provides an insulating layer with a low dielectric loss tangent. The dielectric loss tangent is preferably 0.0050 or less, more preferably 0.0045 or less, even more preferably 0.004 or less, 0.0035 or less, or 0.0030 or less. There is no particular lower limit, but it can be 0.0001 or more, etc. The dielectric loss tangent can be measured by the method described in the examples below.

[0147] The surface of a cured product obtained by heat-curing a resin composition layer at 130°C for 30 minutes, and then at 170°C for 30 minutes, is roughened, and the roughened surface exhibits the characteristic of having an arithmetic mean roughness (Ra) that ensures adhesion with the solder resist. Therefore, the cured product provides an insulating layer that exhibits an arithmetic mean roughness (Ra) that ensures adhesion with the solder resist. The arithmetic mean roughness (Ra) of the roughened surface is preferably greater than 50 nm, more preferably 100 nm or more, even more preferably 120 nm or more, or 130 nm or more. The upper limit is preferably 500 nm or less, more preferably 450 nm or less, even more preferably 400 nm or less, 300 nm or less, or 200 nm or less. The arithmetic mean roughness (Ra) of the roughened surface can be measured according to the method described in the examples below.

[0148] A cured product obtained by heat-curing a resin composition layer at 200°C for 90 minutes exhibits the characteristic of high elongation. Therefore, the cured product provides an insulating layer with high elongation. The elongation was measured in accordance with JIS K6251 and can be determined by the elongation at the breaking point. The elongation (elongation at the breaking point) is preferably 1.0% or more, more preferably 1.05% or more, even more preferably 1.1% or more, 1.15% or more, 1.2% or more, 1.25% or more, 1.3% or more, 1.35% or more, 1.4% or more, 1.45% or more, 1.5% or more, or 1.55% or more. There is no particular upper limit, but it may be 5.0% or less, etc. The elongation can be measured by the method described in the examples below.

[0149] The cured product obtained by heat-curing the resin composition layer at 130°C for 30 minutes, followed by 170°C for 30 minutes, typically exhibits excellent adhesion to the conductor layer (sputtered copper) after the HAST test. Therefore, the cured product provides an insulating layer with excellent adhesion to the conductor layer (sputtered copper) after the HAST test. Adhesion can be evaluated by peel strength. The adhesion to the conductor layer (sputtered copper) after the HAST test is preferably 0.20 kgf / cm or higher, more preferably 0.30 kgf / cm or higher, and even more preferably 0.31 kgf / cm. There is no particular upper limit, but it can be 10 kgf / cm or the like. The adhesion to the conductor layer (sputtered copper) after the HAST test can be measured by the method described in the examples below.

[0150] Since the resin composition layer in the thermosetting resin sheet of the present invention contains component (A), even if a large amount of component (C) is included, it is possible to obtain a cured product that exhibits excellent dielectric loss tangent and elongation, and an arithmetic mean roughness (Ra) that ensures adhesion with solder resist. Therefore, the thermosetting resin sheet of the present invention can be suitably used as a thermosetting resin sheet (thermosetting resin sheet for sealing) for sealing electronic devices such as organic EL devices and semiconductors, and in particular, it can be suitably used as a thermosetting resin sheet (thermosetting resin sheet for semiconductor sealing), and preferably as a thermosetting resin sheet (thermosetting resin sheet for semiconductor chip sealing).

[0151] Furthermore, the thermosetting resin sheet can be used as an insulating layer in addition to its sealing applications. For example, the aforementioned thermosetting resin sheet can be suitably used as a thermosetting resin sheet for forming an insulating layer (thermosetting resin sheet for insulating layer), and in particular, it can be suitably used as a thermosetting resin sheet for forming an insulating layer of a circuit board (including printed wiring boards and semiconductor chip packages) (thermosetting resin sheet for insulating layer of circuit boards), and as a thermosetting resin sheet for forming an interlayer insulating layer of a circuit board (thermosetting resin sheet for interlayer insulating layer of circuit boards).

[0152] Furthermore, the resin composition layer may be used as an underfill material, for example, as a material for MUF (Molding Under Filling) used after connecting a semiconductor chip to a substrate.

[0153] [Circuit board] A circuit board according to one embodiment of the present invention includes an insulating layer formed from a cured product of the resin composition layer of the thermosetting resin sheet described above. The insulating layer may consist only of the cured product of the resin composition layer. The thickness of the insulating layer is not particularly limited and can be, for example, in the same range as the thickness of the resin composition layer of the thermosetting resin sheet. Furthermore, the insulating layer can usually have properties similar to those of the cured product of the resin composition layer described above.

[0154] Preferably, the circuit board comprises an inner layer substrate, and the insulating layer is provided on this inner layer substrate. The circuit board may also comprise a conductive layer. For example, a conductive layer may be provided on the insulating layer. An example of a preferred method for manufacturing a circuit board will be described below.

[0155] A preferred example of a method for manufacturing a circuit board is: Step (I) of forming a resin composition layer on an inner layer substrate, (II) A step of curing the resin composition layer and Includes.

[0156] An "internal layer substrate" is a material that serves as the base for a circuit board, and examples include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, etc. An internal layer substrate may have a conductive layer on one or both sides. The conductive layer on the internal layer substrate may be patterned. An internal layer substrate in which a conductive layer (circuit) is formed on one or both sides of the substrate is sometimes called an "internal layer circuit board." Furthermore, intermediate products on which an insulating layer and / or a conductive layer is to be formed during the manufacturing of a circuit board are also included in the term "internal layer substrate." In addition, an internal layer substrate with embedded components may be used.

[0157] The formation of a resin composition layer on an inner layer substrate is carried out using the thermosetting resin sheet of the present invention. The method for forming a resin composition layer using the thermosetting resin sheet of the present invention usually involves laminating the thermosetting resin sheet and the inner layer substrate. The lamination of the thermosetting resin sheet and the inner layer substrate is carried out so that the resin composition layer of the thermosetting resin sheet and the inner layer substrate are joined. This lamination may be carried out, for example, by heating and pressing the thermosetting resin sheet onto the inner layer substrate from the support side. Examples of a member for heating and pressing the thermosetting resin sheet onto the inner layer substrate (hereinafter also referred to as the "heat-pressing member") include a heated metal plate (such as a SUS end plate) or a metal roll (such as a SUS roll). It is preferable to press the thermosetting resin sheet via an elastic material such as heat-resistant rubber, rather than directly pressing the heat-pressing member onto the thermosetting resin sheet, so that the thermosetting resin sheet can sufficiently follow the surface irregularities of the inner layer substrate.

[0158] Lamination of the inner layer substrate and the thermosetting resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the heat-pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heat-pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa, and the heat-pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

[0159] Lamination may be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include vacuum pressure laminators manufactured by Meiki Seisakusho Co., Ltd., vacuum applicators manufactured by Nikko Materials Co., Ltd., and batch-type vacuum pressure laminators.

[0160] The method for manufacturing a circuit board may include, after lamination, a smoothing treatment of the thermosetting resin sheet by, for example, pressing a heat-pressure bonding member from the support side under normal pressure (atmospheric pressure). The pressing conditions for the smoothing treatment may be the same as the conditions for the heat-pressure bonding of the lamination. The smoothing treatment can be performed using a commercially available laminator. Lamination and smoothing may be performed continuously using the commercially available vacuum laminator.

[0161] The method for manufacturing a circuit board according to this example includes a step (II) in which a resin composition layer is cured after step (I). By curing the resin composition layer in step (II), an insulating layer containing the cured resin composition layer can be formed.

[0162] The resin composition layer is cured by thermal curing. The thermal curing conditions for the resin composition layer may vary depending on the type of components contained in the resin composition layer. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time may be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0163] The method for manufacturing a circuit board may include preheating the resin composition layer at a temperature lower than the curing temperature before the resin composition layer is heat-cured. For example, prior to heat-curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 150°C, preferably 60°C to 140°C, more preferably 70°C to 130°C for 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes. Preheating is usually performed after step (I). Also, if a smoothing treatment is performed after lamination of the inner layer substrate and the thermosetting resin sheet, preheating may usually be performed after the smoothing treatment.

[0164] A method for manufacturing a circuit board may include a step of peeling off the support of the thermosetting resin sheet after lamination of the inner layer substrate and the thermosetting resin sheet. The peeling off of the support may be performed between step (I) and step (II), or after step (II). Furthermore, if the method for manufacturing a circuit board includes a step of forming holes in the insulating layer (III), a step of roughening the insulating layer (IV), and a step of forming a conductor layer (V), as described later, the peeling off of the support may be performed between step (II) and step (III), between step (III) and step (IV), or between step (IV) and step (V).

[0165] The method for manufacturing a circuit board may include a step (III) after step (II) in which holes such as via holes and through holes are formed in the insulating layer. The method for forming the holes can be selected according to factors such as the composition of the components contained in the resin composition layer used to form the insulating layer. For example, holes may be formed by processing methods such as drilling, laser processing, and plasma processing, with laser processing being preferred. For example, holes may be formed by irradiating the insulating layer with laser light after peeling off the support, or by irradiating the insulating layer with laser light through the support. The dimensions and shape of the holes may be appropriately determined according to the design of the circuit board.

[0166] A method for manufacturing a circuit board may include a step (IV) of roughening the insulating layer. The roughening treatment can roughen the surface of the insulating layer. Furthermore, the roughening treatment can remove smear (resin residue) from the insulating layer. For this reason, this roughening treatment is sometimes called "desmear treatment". For example, if holes are formed in step (III), smear may be formed inside those holes, so it is preferable to perform the roughening treatment in step (IV) after step (III) to remove the aforementioned smear.

[0167] The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions commonly used when forming the insulating layer of a circuit board can be employed. For example, the roughening treatment may be carried out by applying swelling treatment with a swelling solution, oxidation treatment with an oxidizing agent, and neutralization treatment with a neutralizing solution to the insulating layer in this order, or a dry desmear treatment using plasma or the like may be performed.

[0168] Examples of swelling solutions used for roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solution and potassium hydroxide solution are more preferred as the alkaline solution. Examples of commercially available swelling solutions include "Swelling Dip Securigant P" and "Swelling Dip Securigant SBU" manufactured by Atotec Japan. Swelling treatment with a swelling solution can be carried out, for example, by immersing the insulating layer in a swelling solution at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling solution at 40°C to 80°C for 5 to 15 minutes.

[0169] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. The oxidation treatment with an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. Furthermore, the concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotec Japan.

[0170] As the neutralizing solution used for roughening treatment, an acidic aqueous solution is preferred, and a commercially available example is "Reduction Solution Securigant P" manufactured by Attec Japan. Neutralization treatment with a neutralizing solution can be carried out by immersing the treated surface, which has been oxidized with an oxidizing agent, in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the viewpoint of workability, it is preferable to immerse the object that has been oxidized with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0171] Dry desmear treatment can be carried out, for example, by introducing a gas into a plasma generator and using the generated plasma to treat the hardened layer (insulating layer). There are no particular restrictions on the method of generating the plasma, and examples include microwave plasma generated by microwaves, high-frequency plasma using high-frequency waves, atmospheric pressure plasma generated under atmospheric pressure, and vacuum plasma generated under vacuum, with vacuum plasma generated under vacuum being preferred.

[0172] The type of gas used for plasma formation (the type of gas that is plasma-formed) is not particularly limited as long as it can roughen the surface of the hardened layer (and remove smears formed in holes as needed). For example, it is preferable to use a gas containing fluorine atoms, or a gas containing either N2 or O2. Examples of gases containing fluorine atoms include F2, CF4, C2F6, and SF6. In this case, in addition to a gas containing fluorine atoms, N2, and O2, other gases such as Ar may also be included. Among these, the type of gas that is plasma-formed is preferably a gas containing fluorine atoms, or a gas containing either N2 or O2, more preferably a gas containing fluorine atoms and O2, even more preferably a mixed gas containing O2 and at least one of N2 and CF4, and even more preferably a mixed gas containing O2 and CF4.

[0173] When a mixed gas is used as the gas species for plasma formation, the mixing ratio (gas containing either N2 or O2 / other gas: unit is sccm) is preferably 1 / 0.01 to 1 / 100, more preferably 1 / 0.5 to 1 / 10, and even more preferably 1 / 1 to 1 / 5.

[0174] The duration of the dry desmear treatment using plasma is not particularly limited, but is preferably 30 seconds or more, more preferably 60 seconds or more, 90 seconds or more, or 120 seconds or more. The upper limit of the roughening treatment time by the dry desmear treatment is preferably 10 minutes or less, more preferably 8 minutes or less, from the viewpoint of easily achieving a hardened layer with low surface roughness after the roughening treatment.

[0175] Plasma-based dry desmearing can be performed using commercially available dry desmearing equipment. Among commercially available dry desmearing equipment, examples suitable for circuit board manufacturing include plasma dry etching equipment from Oxford Instruments, microwave plasma equipment from Nissin, atmospheric pressure plasma etching equipment from Sekisui Chemical Co., Ltd., and vacuum plasma etching equipment from Tepla.

[0176] The method for manufacturing a circuit board may include a step (V) of forming a conductive layer on an insulating layer. If the method for manufacturing a circuit board includes step (III) or (IV), the step of forming the conductive layer (V) is usually preferably performed after steps (III) and (IV).

[0177] The conductive material used in the conductive layer is not particularly limited. In a preferred embodiment, the conductive layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductive layer may be a single-metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). Among these, single-metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy are preferred from the viewpoint of versatility in conductive layer formation, cost, and ease of patterning, more preferred are single-metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, more preferred are single-metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy are preferred, and single-metal layers of copper are even more preferred.

[0178] The conductive layer may have a single-layer structure, or it may have a multi-layer structure including two or more single-metal layers or alloy layers made of different types of metals or alloys. When the conductive layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single-metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

[0179] The thickness of the conductor layer depends on the design of the circuit board, but is preferably 3 μm to 35 μm, and more preferably 5 μm to 30 μm.

[0180] In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer using conventionally known techniques such as the semi-additive method or the fully additive method. From the viewpoint of ease of manufacture, the semi-additive method is preferred. An example of forming the conductor layer by the semi-additive method is shown below.

[0181] First, an electroless plating layer (plating seed layer) is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed electroless plating layer, exposing a portion of the electroless plating layer corresponding to the desired wiring pattern. After forming an electroplating layer on the exposed electroless plating layer by electroplating, the mask pattern is removed. Subsequently, the unnecessary electroless plating layer can be removed by etching to form a conductor layer having the desired wiring pattern.

[0182] The plating seed layer may be formed by dry plating or by wet plating. Examples of dry plating include physical vapor deposition (PVD) methods such as sputtering, ion plating, and vacuum deposition, and chemical vapor deposition (CVD) methods such as thermal CVD and plasma CVD. Examples of wet plating include electroless plating.

[0183] In another embodiment, the conductive layer may be formed by sputtering. When forming the conductive layer by sputtering, typically, a conductive seed layer is first formed on the surface of the insulating layer by sputtering, and then a conductive sputtered layer is formed on the conductive seed layer by sputtering. Before forming the conductive seed layer by sputtering, the surface of the insulating layer may be cleaned by reverse sputtering. Various gases can be used for the reverse sputtering, but Ar, O2, and N2 are preferred. If the seed layer is Cu or a Cu alloy, Ar, O2, or a mixed gas of Ar and O2 is preferred. If the seed layer is Ti, Ar, N2, or a mixed gas of Ar and N2 is preferred. If the seed layer is Cr or a Cr alloy (such as nichrome), Ar, O2, or a mixed gas of Ar and O2 is preferred. Sputtering can be performed using various sputtering devices such as magnetron sputtering and mirrortron sputtering. Examples of metals used to form the conductive seed layer include Cr, Ni, Ti, and nichrome. Cr and Ti are particularly preferred. The thickness of the conductive seed layer is usually preferably 5 nm or more, more preferably 10 nm or more, preferably 1000 nm or less, and more preferably 500 nm or less. Examples of metals used to form the conductive sputtered layer include Cu, Pt, Au, and Pd. Cu is particularly preferred. The thickness of the conductive sputtered layer is usually preferably 50 nm or more, more preferably 100 nm or more, preferably 3000 nm or less, and more preferably 1000 nm or less.

[0184] After forming a conductive layer by sputtering, a copper plating layer may be further formed on the conductive layer by electrolytic copper plating. The thickness of the copper plating layer is usually preferably 5 μm or more, more preferably 8 μm or more, preferably 75 μm or less, and more preferably 35 μm or less. Known methods such as the subtractive method and the semi-additive method can be used for circuit formation.

[0185] As another example, the conductor layer may be formed using metal foil. When forming the conductor layer using metal foil, step (V) is preferably performed between steps (I) and (II). For example, after step (I), the support is removed and the metal foil is laminated onto the surface of the exposed resin composition layer. The lamination of the resin composition layer and the metal foil may be carried out by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Subsequently, using the metal foil on the insulating layer, a conductor layer having a desired wiring pattern can be formed by known techniques such as the subtractive method or the modified semi-additive method. The metal foil can be manufactured by known methods such as the electrolytic method or the rolling method. Examples of commercially available metal foils include HLP foil and JXUT-III foil from JX Metals, and 3EC-III foil and TP-III foil from Mitsui Mining & Smelting Co., Ltd.

[0186] When a conductive layer is formed on an insulating layer, the method for manufacturing the circuit board may include annealing after the formation of the conductive layer. Annealing can improve the adhesion between the insulating layer and the conductive layer. Annealing can be performed, for example, by heating at 150°C to 210°C for 20 to 180 minutes.

[0187] In the method for manufacturing a circuit board, each of the above-described steps may be performed only once or repeated two or more times. For example, steps (I) to (V) may be repeatedly performed to form a circuit board having a multilayer structure, such as a multilayer printed wiring board, which comprises multiple insulating layers and conductive layers.

[0188] The method for manufacturing a circuit board may include any additional steps in addition to the steps described above. For example, the method for manufacturing a circuit board may include a step of providing a semiconductor chip so as to be bonded to a conductor layer. Specifically, when manufacturing a circuit board for a semiconductor chip package that includes a semiconductor chip, the method for manufacturing the circuit board may include a step of providing the semiconductor chip. The semiconductor chip can employ appropriate conditions that allow the terminal electrodes of the semiconductor chip and the conductor layer formed on the insulating layer to be conductively connected. For example, conditions used in flip-chip mounting may be employed. The semiconductor chip may also be bonded via an insulating adhesive or by reflow soldering. Furthermore, if necessary, the provided semiconductor chip may be filled with mold underfill material. The method for manufacturing a circuit board may also include, for example, a step of forming a sealing layer, a step of forming a solder resist layer, and a step of dicing the manufactured circuit board into individual pieces.

[0189] Examples of circuit boards include printed circuit boards and semiconductor chip packages. Examples of semiconductor chip packages include FC-CSP, MIS-BGA packages, ETS-BGA packages, fan-out type WLP (Wafer Level Package), fan-in type WLP, fan-out type PLP (Panel Level Package), and fan-in type PLP. In these semiconductor chip packages, it is preferable to form a rewiring layer as an insulating layer using a cured product obtained by curing the resin composition layer described above. However, the circuit board is not limited to those exemplified herein.

[0190] [Semiconductor device] The aforementioned circuit board can be used in the manufacture of semiconductor devices. The semiconductor device comprises the aforementioned circuit board. Examples of semiconductor devices include various types of semiconductor devices used in electrical products (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, and televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft, etc.). [Examples]

[0191] The present invention will be described in detail below with reference to examples. The present invention is not limited to these examples. In the following, "parts" and "%" refer to "parts by mass" and "mass%" respectively, unless otherwise specified. Unless otherwise specified, the temperature and pressure conditions are room temperature (25°C) and atmospheric pressure (1 atm). Unless otherwise specified, the weight-average molecular weight was measured by gel permeation chromatography (GPC) as a polystyrene equivalent. The modulus of elasticity was measured by a tensile test in accordance with JIS K6251, and the details are as described above.

[0192] <Synthesis Example 1: Synthesis of Polymer A> In a reaction vessel, 69 g of bifunctional hydroxyl-terminated polybutadiene (G-3000, manufactured by Nippon Soda Co., Ltd., number average molecular weight = 3000, hydroxyl group equivalent = 1800 g / eq.), 40 g of PGMEA (propylene glycol monomethyl ether acetate, manufactured by Showa Denko Corporation), and 0.005 g of dibutyltin laurate were added and mixed until homogeneously dissolved. Once homogeneous, the temperature was raised to 60°C, and while stirring, 8 g of isophorone diisocyanate (IPDI, manufactured by Evonik Degussa Japan, isocyanate group equivalent = 113 g / eq.) was added, and the reaction was carried out for approximately 3 hours.

[0193] Next, 23 g of cresol novolac resin (DIC Corporation "KA-1160", hydroxyl group equivalent = 117 g / eq.) and 60 g of PGMEA were added to the reactant, and the mixture was stirred and heated under reflux at 150°C for approximately 10 hours. FT-IR analysis yielded 2250 cm⁻¹. -1The disappearance of the NCO peak was confirmed. The reaction was considered to have terminated upon confirmation of the disappearance of the NCO peak, and the reactants were cooled to room temperature. The reactants were then filtered through a 100-mesh filter cloth to obtain a polymer having a butadiene structure and phenolic hydroxyl groups (phenolic hydroxyl group-containing butadiene resin: 50% by mass of nonvolatile components). Polymer A had a weight-average molecular weight of 27,000, a glass transition temperature of -7°C, and an elastic modulus of 0.05 GPa.

[0194] <Synthesis Example 2: Synthesis of Polymer B> In a 1 L separable flask equipped with a stirring rod and an oil bath, 200 g of cyclohexanone was added while introducing nitrogen gas. Then, 149.4 g of dimeramine (PRIAMINE 1075, Croda Japan) as a diamine and 4.7 g of m-aminophenol as a monoamine compound were added while stirring. Subsequently, 67.3 g of 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride was added as a tetracarboxylic acid, and the mixture was stirred at room temperature for 30 minutes. The temperature was raised to 100°C and stirred for 3 hours, after which the oil bath was removed and the mixture returned to room temperature to obtain a varnish-like polyimide precursor. Subsequently, the mixture was heated at 170°C for 10 hours while removing the distilled water from the system using a Dean-Stark trap to imidize it and obtain polymer B (50% by mass of nonvolatile components) having a carbon skeleton derived from dimer acid. The obtained polymer B had a weight-average molecular weight of 10,000, a hydroxyl group equivalent of 3,900 g / eq., a glass transition temperature of -1°C, and an elastic modulus of 0.20 GPa.

[0195] <Synthesis Example 3: Synthesis of Polymer C> In a flask equipped with a stirrer, thermometer, and condenser, 770.1 g of propylene glycol methyl ether acetate (hereinafter also referred to as PGMAc), 67.5 g (0.30 mol) of isophorone diisocyanate (hereinafter also referred to as IPDI), 562.6 g (0.15 mol) of polybutadiene with OH groups at both ends (G-3000, manufactured by Nippon Soda Co., Ltd., hydroxyl value: 30.3 mg KOH / g), 0.28 g of zirconium dibutoxybis(ethyl acetate) (Orgatics ZC-580, manufactured by Matsumoto Fine Chemical Co., Ltd.), and 0.14 g of zinc complex (K-KAT XK-614, manufactured by Kusumoto Chemical Co., Ltd.) were added. The mixed solution was heated to 60°C and then maintained at this temperature for 4 hours.

[0196] 16.6 g (0.076 mol) of pyromellitic anhydride was added to the aforementioned mixed solution. The mixed solution was then heated to 140°C and the reaction was continued for 4 hours. After confirming that the increase in viscosity had subsided, the solution was cooled to 120°C. Subsequently, 20.0 g of 2-hydroxyethyl methacrylate (0.15 mol) and 0.37 g of methoquinone were added, and the reaction was carried out at 120°C for 2 hours. The characteristic absorption was measured by infrared spectroscopy, and the characteristic absorption of the isocyanate group was 2270 cm⁻¹. -1 After confirming that the absorption peak had completely disappeared, the non-volatile content was adjusted to 45% using PGMAc (propylene glycol monomethyl ether acetate). In this manner, polymer C having methacryloyl groups at the terminals was synthesized. The mixed solution containing polymer C had a non-volatile content of 45% by mass, a viscosity of 740 mPa·s at 25°C, a weight-average molecular weight of 13000, an elastic modulus of 0.02 GPa, and a glass transition temperature of 1°C.

[0197] <Synthesis Example 4: Synthesis of Maleimide A> A methyl ethyl ketone solution (62% by mass of non-volatile components) of a maleimide compound synthesized by the method described in Synthesis Example 1 of the Japan Institute of Invention and Innovation, Technical Report No. 2020-500211, was prepared. This maleimide compound had the structure represented by the following formula (where m is 1.47 (mainly 1, 2, or 3)), a weight-average molecular weight of 2000, and a Mw / Mn ratio of 1.81. [ka]

[0198] <Examples 1-19, Comparative Examples 1-4> (1) Preparation of resin composition Each component was weighed in the mass parts listed in the table below, and then 10 parts of methyl ethyl ketone and 20 parts of cyclohexanone were added and the mixture was uniformly dispersed using a high-speed rotary mixer to obtain a resin composition (resin varnish).

[0199] [Table 1] [Table 2] *The content of components (A) to (H) in the table represents the content when the non-volatile components contained in the resin composition layer are taken as 100% by mass.

[0200] The details of each component listed in the table above are as follows: (A) component • 2-(2-hydroxyphenyl)benzimidazole (manufactured by Asahi Kasei Corporation) (B) Component • ESN-4100V: Methoxy group-containing naphthol aralkyl resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent: 363 g / eq., methyl ethyl ketone solution with 75% non-volatile components) • ZX-1059: Bisphenol-type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent 165 g / eq.) • NC3000L: Biphenyl-type epoxy resin (manufactured by Nippon Chemical Corporation, epoxy equivalent approximately 271 g / eq.) • HP4032SS: Naphthalene-type epoxy resin (manufactured by DIC Corporation, epoxy equivalent approximately 144 g / eq.) • YX4000HK: Bixylenol-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent approximately 194 g / eq.) (C) Component • SO-C2: Spherical silica (average particle size 0.5 μm, manufactured by Admatex) surface-treated with an aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) • SO-C6: Spherical silica (average particle size 2.0 μm, manufactured by Admatex) surface-treated with an aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) (D) Component • HPC-8000-65T: Active ester compound (manufactured by DIC Corporation, active group equivalent approximately 223 g / eq., toluene solution with 65% by mass of non-volatile components) • LA-3018-50P: Triazine skeleton-containing phenolic curing agent (manufactured by DIC Corporation, hydroxyl group equivalent approximately 151 g / eq., 50% solids 1-methoxy-2-propanol solution) • V-03: Carbodiimide resin (manufactured by Nisshinbo Chemical Co., Ltd., toluene solution with 50% solids content) (E) Component • Polymer A: Polymer A synthesized in Synthesis Example 2 • Polymer B: Polymer B synthesized in Synthesis Example 3 • Polymer C: Polymer C synthesized in Synthesis Example 4 • YX7553BH30: Phenoxy resin (manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of methyl ethyl ketone and cyclohexanone with a solid content of 70%, elastic modulus of 3.2 GPa) (F) component • Maleimide A: Maleimide A synthesized in Synthesis Example 5 • SLK-6895-T90: Bismaleimide resin (manufactured by Shin-Etsu Chemical Co., Ltd., maleimide equivalent of approximately 345 g / eq., toluene solution with 90% solids content) • OPE-2St 1200: Vinylbenzyl-modified polyphenylene ether (manufactured by Mitsubishi Gas Chemical Co., Ltd., toluene solution with 65% non-volatile content) • ALP-d: Bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazine-3-yl)phenyl]methane (manufactured by Shikoku Chemicals Co., Ltd.) (G) Component • EXL2655: Organic filler (manufactured by Dow) • AC3401: Organic filler (manufactured by Aica Kogyo Co., Ltd.) (H) Component • 2P4MZ: 2-phenyl-4-methylimidazole (manufactured by Shikoku Chemicals Co., Ltd.) • DMAP: 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0201] <Preparation of thermosetting resin sheets> As a support, we prepared a polyethylene terephthalate film (Toray Industries, Ltd.'s "Lumirror R80," 38 μm thick, softening point 130°C) that had been treated with an alkyd resin-based release agent (Lintec Corporation's "AL-5").

[0202] On the support, the resin compositions obtained in Examples 1 to 19 and Comparative Examples 1 to 4 were uniformly applied using a die coater so that the thickness of the dried resin composition layer was 50 μm, and the resin composition layer was formed on the support by drying at 70°C to 100°C for 3 minutes. Next, a rough surface of a polypropylene film (Alfan MA-411, manufactured by Oji F-Tex Co., Ltd., 15 μm thick) was laminated as a protective film to the side of the resin composition layer that was not bonded to the support. This resulted in obtaining a thermosetting resin sheet having the support, resin composition layer, and protective film in that order.

[0203] <Test Example 1: Measurement of Dielectric Loss Tangent> The protective film was peeled off the thermosetting resin sheets prepared in the examples and comparative examples, and the resin composition layer was heat-cured by heating at 200°C for 90 minutes. After that, the support was peeled off. The resulting cured material was cut into pieces 2 mm wide and 80 mm long to be used as test specimens for evaluation.

[0204] For each test specimen, the dielectric loss tangent was measured using the cavity resonance perturbation method with an Agilent Technologies HP8362B at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. Measurements were performed on three test specimens, the average value was calculated, and the specimens were evaluated according to the following evaluation criteria. ○: Dielectric loss tangent is 0.0030 or less △: Dielectric loss tangent is greater than 0.0030 and less than or equal to 0.0050 ×: Dielectric loss tangent is greater than 0.0050

[0205] <Test Example 2: Measurement of Arithmetic Mean Roughness (Ra) of the Insulating Layer Surface> (1) Preparation of the inner layer substrate A glass cloth substrate epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, Panasonic "R1515A") with an inner layer circuit was subjected to a 1 μm roughening treatment of the copper surface by etching both sides with a micro-etching agent (MEC "CZ8101").

[0206] (2) Lamination of thermosetting resin sheets Using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., 2-stage build-up laminator "CVP700"), thermosetting resin sheets were laminated to both sides of the inner layer substrate so that the resin composition layer was in contact with the inner layer substrate. Lamination was performed by reducing the pressure to 13 hPa or less by depressurizing for 30 seconds, and then pressing at 120°C and a pressure of 0.74 MPa for 30 seconds. Subsequently, a hot press was performed at 100°C and a pressure of 0.5 MPa for 60 seconds.

[0207] (3) Thermocuring of the resin composition layer An inner layer substrate laminated with a thermosetting resin sheet was placed in a 130°C oven and heated for 30 minutes, then transferred to a 170°C oven and heated for another 30 minutes to heat-cur the resin composition layer and form an insulating layer. Subsequently, the support was peeled off to obtain a cured substrate having the insulating layer, inner layer substrate, and insulating layer in that order.

[0208] (4) Roughening treatment The cured substrate was subjected to a desmear treatment as a roughening treatment. The following wet desmear treatment was performed.

[0209] (Wet desmear treatment) The cured substrate was immersed in a swelling solution (Atotec Japan's "Swelling Dip Securigant P," an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 5 minutes, and then immersed in an oxidizing agent solution (Atotec Japan's "Concentrate Compact CP," an aqueous solution of approximately 6% potassium permanganate and approximately 4% sodium hydroxide) at 80°C for 20 minutes. Next, it was immersed in a neutralizing solution (Atotec Japan's "Reduction Solution Securigant P," an aqueous sulfuric acid solution) at 40°C for 5 minutes, and then dried at 80°C for 15 minutes.

[0210] (5) Measurement of the arithmetic mean roughness (Ra) of the insulating layer surface after roughening treatment The arithmetic mean roughness (Ra) of the insulating layer surface of the hardened substrate after roughening treatment was determined using a non-contact surface roughness meter (Bruker WYKO NT3300) in VSI mode with a 50x lens, measuring a range of 121 μm × 92 μm. The average of 10 points was calculated for each measurement, and the following evaluation criteria were used. ○: Arithmetic mean roughness is greater than 50 nm and less than or equal to 500 nm. ×: Arithmetic mean roughness is 50nm or less

[0211] <Test Example 3: Measurement of Elongation> The protective film was peeled off the thermosetting resin sheet, and the resin composition layer was heat-cured by heating at 200°C for 90 minutes. After that, the support was peeled off to obtain a cured product. The cured product was cut into a dumbbell shape conforming to JIS K6251 tensile strength type 5 to obtain a cured product sample for measuring the linear thermal expansion coefficient. This cured product sample was subjected to a tensile test using a universal testing machine (Shimadzu Autograph AGS-X-5kN) with a load cell of 50N and a test speed of 5 mm / min, and the elongation at the breaking point (%) at 23°C was measured and evaluated according to the following criteria. ○: Elongation at fracture is 1.5% or more △: Elongation at fracture 1.0% or more, less than 1.5% ×: Elongation at break less than 1.0%

[0212] <Test Example 4: Measurement of sputtered copper adhesion after HAST> (1) Preparation of the inner layer substrate A glass cloth substrate epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, Panasonic "R1515A") with an inner layer circuit was subjected to a 1 μm roughening treatment of the copper surface by etching both sides with a micro-etching agent (MEC "CZ8101").

[0213] (2) Lamination of thermosetting resin sheets Using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., 2-stage build-up laminator "CVP700"), thermosetting resin sheets were laminated to both sides of the inner layer substrate so that the resin composition layer was in contact with the inner layer substrate. Lamination was performed by reducing the pressure to 13 hPa or less by depressurizing for 30 seconds, and then pressing at 120°C and a pressure of 0.74 MPa for 30 seconds. Subsequently, a hot press was performed at 100°C and a pressure of 0.5 MPa for 60 seconds.

[0214] (3) Thermocuring of the resin composition layer An inner layer substrate laminated with a thermosetting resin sheet was placed in a 100°C oven and heated for 30 minutes, then transferred to a 170°C oven and heated for another 30 minutes to heat-cur the resin composition layer and form an insulating layer. Subsequently, the support was peeled off to obtain a cured substrate C1 having the insulating layer / inner layer substrate / insulating layer in that order.

[0215] (4) Dry desmear treatment The hardened substrate C1 was processed for 5 minutes using a vacuum plasma etching system (Tepla's "100-E PLASMA SYSTEM") under the conditions of O2 / CF4 (mixed gas ratio) = 25 / 75 and a vacuum of 100 Pa.

[0216] (5) Formation of the conductive layer A titanium layer (30 nm thick) and then a copper layer (300 nm thick) were formed on the hardened substrate C1 after dry desmearing using a sputtering apparatus (Canon Anelva "E-400S"). The resulting substrate was annealed by heating at 150°C for 30 minutes, and then copper sulfate electroplating was performed to form a conductive layer with a thickness of 25 μm. After the conductive layer was formed, it was annealed by heating at 190°C for 90 minutes to obtain evaluation substrate C2.

[0217] (6) HAST test Evaluation substrate C2 was subjected to an accelerated environmental test (HAST test) for 100 hours at 130°C and 85%RH using an advanced accelerated life testing apparatus (PM422, manufactured by Kusumoto Chemical Co., Ltd.), and evaluation substrate C3 was obtained.

[0218] (7) Measurement of adhesion strength (peel strength) with the conductor layer after HAST test A rectangular section measuring 10 mm wide and 100 mm long was cut into the conductive layer of evaluation substrate C3. One end of this rectangular section was peeled off and grasped with a gripper (Autocom type tester "AC-50C-SL" manufactured by TSE Corporation). A 35 mm length section of the rectangular area was peeled vertically, and the load (kgf / cm) during this peeling was measured as the peel strength. The peeling was performed at room temperature at a speed of 50 mm / min. Based on the measured values, the adhesion strength to the conductive layer was evaluated according to the following criteria. ○: Peel strength value is greater than 0.30 kgf / cm △: Peel strength value is greater than 0.20 kgf / cm and less than or equal to 0.30 kgf / cm. ×: Peel strength value is 0.20 kgf / cm or less

[0219] [Table 3] [Table 4]

Claims

1. A thermosetting resin sheet comprising a support and a resin composition layer provided on the support, The resin composition layer (A) Compound represented by formula (1), (B) Epoxy resin, and (C) Inorganic filler, A thermosetting resin sheet in which the content of component (C) is 40% by mass or more, when the nonvolatile components in the resin composition layer are taken as 100% by mass. 【Chemistry 1】 ・・・（１）

2. Furthermore, the thermosetting resin sheet according to claim 1, further comprising (E) a polymer resin.

3. The thermosetting resin sheet according to claim 2, wherein component (E) comprises a polymer resin having an elastic modulus of 1 GPa or less as measured in accordance with JIS K6251 (E-1).

4. The content of component (A) when the nonvolatile component in the resin composition layer is taken as 100% by mass is M. Ａ Assuming that the non-volatile components in the resin composition layer are 100% by mass, the content of component (E) is M Ｅ When that happens, M Ａ / M Ｅ The thermosetting resin sheet according to claim 2, wherein the ratio is 0.01 or more and 1 or less.

5. Furthermore, the thermosetting resin sheet according to claim 1, further comprising (F) a radical polymerizable resin.

6. The thermosetting resin sheet according to claim 5, wherein component (F) comprises any one of maleimide resin, (meth)acrylic resin, allyl resin, and vinyl resin.

7. The thermosetting resin sheet according to claim 5, wherein component (F) contains maleimide resin.

8. The content of component (A) when the nonvolatile component in the resin composition layer is taken as 100% by mass is M. Ａ The content of component (F) when the nonvolatile components in the resin composition layer are set to 100% by mass is M. Ｆ When that happens, M Ａ / M Ｆ The thermosetting resin sheet according to claim 5, wherein the ratio is 0.005 or more and 0.8 or less.

9. The thermosetting resin sheet according to claim 5, wherein the weight-average molecular weight of component (F) is 150 or more and 5,000 or less.

10. Furthermore, the thermosetting resin sheet according to claim 1, further comprising (G) an organic filler.

11. The thermosetting resin sheet according to claim 1, wherein the dielectric loss tangent of the cured product obtained by heat-curing the resin composition layer at 200°C for 90 minutes is 0.0050 or less.

12. The thermosetting resin sheet according to claim 1, wherein the elongation of the cured product obtained by heat-curing the resin composition layer at 200°C for 90 minutes is 1.5% or more, as measured in accordance with JIS K6251.

13. A thermosetting resin sheet according to claim 1, for use in semiconductor encapsulation.

14. A thermosetting resin sheet according to claim 1, for use as an interlayer insulating layer.

15. A circuit board comprising an insulating layer formed of a cured product of a resin composition layer of a thermosetting resin sheet according to any one of claims 1 to 14.

16. A semiconductor device comprising the circuit board described in claim 15.

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