Resin sheet

Abstract

To provide a resin sheet which maintains a hollow structure and stably provides sufficient sealing moldability even when stored at room temperature prior to sealing molding.SOLUTION: In a manufacture of a sealing structure having a hollow structure, a resin sheet for sealing molding includes a support and a resin composition layer provided on the support, and the resin composition layer contains (A) an epoxy resin, (B) a curing agent, (C) a thermally conductive inorganic filler, and (D) a phosphorus-based curing accelerator. A loss tangent tanδ (tanδ=loss modulus E" / storage modulus E') of the resin composition layer at 80°C is 0.50 or more and 0.90 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin sheet, a sealing structure, and a method for manufacturing the same. [Background technology]

[0002] In recent years, alongside semiconductor packages, the development of microelectronic components known as MEMS (Micro-Electro-Mechanical Systems), such as SAW (Surface Acoustic Wave) filters, CMOS (Complementary Metal Oxide Semiconductor) sensors, and acceleration sensors, has been progressing. Packages that encapsulate these electronic components generally have a hollow structure to ensure the propagation of surface acoustic waves, maintain optical systems, and ensure the mobility of the electronic component's movable parts. This hollow structure is often provided as a gap between the substrate and the electronic component (element). During encapsulation, the hollow structure may be maintained to ensure the operational reliability of the movable parts and the connection reliability of the element.

[0003] As a method for sealing while maintaining the hollow structure, a method of sealing using a sheet-like laminate material such as a resin sheet has been investigated (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6282626 Summary of the Invention [Problem to be solved by the invention]

[0005] When a resin sheet is used for encapsulation while maintaining a hollow structure, the resin composition layer contained in the resin sheet is required to exhibit sufficient encapsulation moldability at the temperature during encapsulation molding while suppressing the inflow of resin into the hollow structure. However, with regard to conventional resin sheets, when stored at room temperature prior to encapsulation molding, variations in encapsulation moldability occur, and it has sometimes been impossible to stably achieve sufficient encapsulation moldability while maintaining the hollow structure.

[0006] The present invention has been made in view of the above problems, and aims to provide a resin sheet that stably provides sufficient encapsulation moldability while maintaining a hollow structure even when stored at room temperature prior to encapsulation molding; an encapsulated structure including a cured product of a resin composition layer of the resin sheet; and a method for producing the same. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above-mentioned problems. As a result, the present inventors have found that the above-mentioned problems can be solved by using a resin sheet comprising a support and a resin composition layer provided on the support, wherein the resin composition layer contains (A) an epoxy resin, (B) a curing agent, (C) a thermally conductive inorganic filler, and (D) a phosphorus-based curing accelerator, and wherein the resin composition layer has a loss tangent tanδ (tanδ=loss modulus E" / storage modulus E') at 80°C of 0.50 or more and 0.90 or less, and have completed the present invention. That is, the present invention includes the following.

[0008] <1> In the manufacture of a sealing structure having a hollow structure, a resin sheet for sealing molding is provided, The resin sheet includes a support and a resin composition layer provided on the support, the resin composition layer contains (A) an epoxy resin, (B) a curing agent, (C) a thermally conductive inorganic filler, and (D) a phosphorus-based curing accelerator; A resin sheet, wherein the loss tangent tanδ (tanδ=loss modulus E″ / storage modulus E′) of the resin composition layer at 80° C. is 0.50 or more and 0.90 or less. <2> The tan δ of the resin composition layer at 80°C is 0h The resin sheet was left standing for 72 hours in an environment of a temperature of 23°C and a humidity of 40 to 45%, and the tan δ of the resin composition layer at 80°C was calculated as tan δ 72h When 1.00≦tanδ 72h / tanδ 0h ≦1.50 Satisfy the relationship of <1> The resin sheet according to claim 1. <3> The melt viscosity of the resin composition layer at 80°C is MV 0h The resin sheet was left standing for 72 hours in an environment with a temperature of 23°C and a humidity of 40 to 45%, and the melt viscosity of the resin composition layer at 80°C was measured as MV 72h When (poise) is used, 1.00≦MV 72h / MV 0h ≦1.50 Satisfy the relationship of <1> or <2> The resin sheet according to claim 1. <4> the thermal conductivity of the cured resin composition layer is 1.0 W / m K or more; <1> ~ <3> The resin sheet according to any one of the above. <5> The resin composition layer further contains (E) a thermoplastic resin. <1> ~ <4> 10. The resin sheet according to claim 1 . <6> The component (E) contains (E-1) a thermoplastic resin having a glass transition temperature of 25°C or lower. <5> The resin sheet according to claim 1. <7> For sealing an object to be sealed that is provided on a substrate via bumps. <1> ~ <6> The resin sheet according to any one of the above. <8> A sealing structure comprising a substrate, an object to be sealed provided on the substrate via bumps, and a cured material layer that seals the object to be sealed, The cured material layer is <1> ~ <7> The resin sheet according to any one of claims 1 to 10, further comprising a cured resin composition layer, The sealing structure has a hollow structure between the substrate and the sealing body. <9> The sealed object includes an electrode disposed on the hollow structure side. <8> The sealing structure according to claim 1. <10> A method for manufacturing a sealing structure including a substrate, an object to be sealed provided on the substrate via bumps, and a cured material layer that seals the object to be sealed, A structure including a substrate and an object to be sealed provided on the substrate via bumps, <1> ~ <7> a step of laminating the resin sheet according to any one of the above items so that the resin composition layer seals the object to be sealed; and a step of curing the resin composition layer to form a cured layer; A method for manufacturing a sealing structure, comprising: [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a resin sheet that maintains a hollow structure and stably provides sufficient encapsulation moldability even when stored at room temperature prior to encapsulation molding; an encapsulated structure including a cured product of a resin composition layer of the resin sheet; and a method for producing the same. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating step (I) of a method for producing a sealing structure according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating step (II) of the method for producing a sealing structure according to one embodiment of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view illustrating step (III) of the method for producing a sealing structure according to one embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating step (IV) of the method for producing a sealing structure according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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 within the scope of the claims and their equivalents.

[0012] [Resin sheet overview] The resin sheet of the present invention is a resin sheet used for encapsulation molding in the production of an encapsulated structure having a hollow structure. The resin sheet of the present invention includes a support and a resin composition layer provided on the support, the resin composition layer containing (A) an epoxy resin, (B) a curing agent, (C) a thermally conductive inorganic filler, and (D) a phosphorus-based curing accelerator. The resin sheet of the present invention is characterized in that the loss tangent tanδ (tanδ = loss modulus E" / storage modulus E') of the resin composition layer at 80°C is 0.50 or more and 0.90 or less.

[0013] As described above, when conventional resin sheets are used for encapsulation while maintaining a hollow structure, variations in encapsulation moldability may occur when the resin sheet is stored at room temperature prior to encapsulation molding, and sufficient encapsulation moldability may not be stably achieved while maintaining the hollow structure. The present inventors have discovered that, with respect to the resin composition layer in a resin sheet, when the tan δ value of the resin composition layer at 80°C satisfies a specific numerical range, sufficient encapsulation moldability can be stably achieved while maintaining the hollow structure, even when stored at room temperature prior to encapsulation molding. Furthermore, the present inventors have discovered that by adjusting the composition of the resin composition layer, the tan δ value of the resin composition layer at 80°C can be adjusted, and as a result, a resin sheet can be obtained that stably achieves sufficient encapsulation moldability while maintaining the hollow structure, even when stored at room temperature prior to encapsulation molding.

[0014] Each layer constituting the resin sheet will be described in detail below.

[0015] <Support> The resin sheet of the present invention includes a support, such as a film made of a plastic material, a metal foil, or a release paper, with a film made of a plastic material being preferred.

[0016] When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"); polycarbonate (hereinafter sometimes abbreviated as "PC"); acrylic polymers such as polymethyl methacrylate (hereinafter sometimes abbreviated as "PMMA"); cyclic polyolefins; triacetyl cellulose (hereinafter sometimes abbreviated as "TAC"); polyether sulfide (hereinafter sometimes abbreviated as "PES"); polyether ketone; polyimide; etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0017] When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil. Of these, copper foil is preferred. The copper foil may be a foil made of a single metal, copper, or a foil made of an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0018] The surface of the support that is to be bonded to the resin composition layer may be subjected to a matte treatment, a corona treatment, an antistatic treatment or the like.

[0019] The support may also be a support with a release layer, which has a release layer on the surface that bonds to the resin composition layer. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available release agents include alkyd resin-based release agents such as "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation. Commercially available support with a release layer includes PET films having a release layer primarily composed of an alkyd resin-based release agent, such as "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation; "Lumirror T60" manufactured by Toray Industries, Inc.; "Purex" manufactured by Teijin Limited; and "Uni-Peel" manufactured by Unitika Limited.

[0020] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably 10 μm to 60 μm. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is in the above range.

[0021] <Resin composition layer> The resin sheet of the present invention includes a resin composition layer provided on the support, which contains a combination of (A) an epoxy resin, (B) a curing agent, (C) a thermally conductive inorganic filler, and (D) a phosphorus-based curing accelerator so that tan δ at 80°C satisfies a specific range.

[0022] The resin composition layer may further contain optional components in combination with the components (A) to (D). Examples of optional components include (D') other curing accelerators, (E) thermoplastic resins, (F) other additives, and (G) organic solvents. Each component contained in the resin composition layer will be described in detail below.

[0023] In this specification, the term "non-volatile components" in relation to the resin composition layer refers to the components constituting the resin composition layer excluding the (G) organic solvent, which will be described later. Also, in this specification, the term "resin components" in relation to the resin composition layer refers to the components constituting the resin composition layer excluding the (C) thermally conductive inorganic filler, which will be described later.

[0024] <(A) Epoxy resin> The resin composition layer contains an epoxy resin as the component (A).

[0025] Examples of epoxy resins include bisphenol-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-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, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins. Bisphenol-type epoxy resins refer to epoxy resins having a bisphenol structure, such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins. Biphenyl-type epoxy resin refers to an epoxy resin having a biphenyl structure, where the biphenyl structure may have a substituent such as an alkyl group, an alkoxy group, or an aryl group. Therefore, bixylenol-type epoxy resins and biphenylaralkyl-type epoxy resins are also included in the biphenyl-type epoxy resin. The epoxy resins may be used alone or in combination of two or more.

[0026] The epoxy resin preferably has two or more epoxy groups in one molecule. When the non-volatile components of the epoxy resin are taken as 100% by mass, the proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

[0027] Epoxy resins include those that are liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resins") and those that are solid at a temperature of 20°C (hereinafter referred to as "solid epoxy resins").

[0028] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0029] Preferred liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins such as alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, and epoxy resins having a butadiene structure.

[0030] Specific examples of liquid epoxy resins include "HP-4032," "HP-4032-D," and "HP-4032-SS" (naphthalene type epoxy resins) manufactured by DIC Corporation; "828US," "jER828EL," "825," and "Epikote 828EL" (bisphenol A type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "630" and "630LSD" (glycidylamine type epoxy resins) manufactured by Mitsubishi Chemical Corporation. Examples include "ZX1059" manufactured by Nippon Steel Chemical & Material Co., Ltd. (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); "EX-721" manufactured by Nagase ChemteX Corporation (glycidyl ester type epoxy resin); "Celloxide 2021P" manufactured by Daicel Corporation (alicyclic epoxy resin with an ester skeleton); "PB-3600" manufactured by Daicel Corporation (epoxy resin with a butadiene structure); and "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.

[0031] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferred.

[0032] Specific examples of solid epoxy resins include "HP-4032H" (naphthalene type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "HP-7200HH", "HP-7200H", and "HP-7200" (dicyclopentadiene epoxy resins) manufactured by DIC Corporation. DIC Corporation's "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", and "HP6000" (naphthylene ether type epoxy resin); Nippon Kayaku Corporation's "EPPN-502H" (trisphenol type epoxy resin); Nippon Kayaku Corporation's "NC-7000L" (naphthol novolac type epoxy resin); Nippon Kayaku Corporation's "NC-3000H", "NC-3000", and "NC-3000" L, "NC-3100" (biphenyl-type epoxy resin); "ESN-475V" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN-485" (naphthol novolac-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX4000HK" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation. Examples of epoxy resins include "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YL7760" (bisphenol AF-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (solid bisphenol A-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "jER1031S" (tetraphenylethane-type epoxy resin) manufactured by Mitsubishi Chemical Corporation.

[0033] The resin composition layer may contain only a liquid epoxy resin as the epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. When a liquid epoxy resin and a solid epoxy resin are used in combination, the ratio by mass between them (liquid epoxy resin:solid epoxy resin) is preferably 1:0.01 to 1:50, more preferably 1:0.05 to 1:20, and even more preferably 1:0.1 to 1:10.

[0034] The epoxy equivalent of the epoxy resin is preferably 50 g / eq to 5,000 g / eq, more preferably 50 g / eq to 3,000 g / eq, even more preferably 80 g / eq to 2,000 g / eq, and even more preferably 110 g / eq to 1,000 g / eq. The epoxy equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0035] The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The Mw of the epoxy resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0036] From the viewpoint of significantly achieving the desired effects of the present invention, the content of component (A) in the resin composition layer is preferably 1.5% by mass or more, more preferably 2.5% by mass or more, even more preferably 3.0% by mass or more, 3.2% by mass or more, or 3.4% by mass or more, when the total amount of non-volatile components in components (A) to (D) is taken as 100% by mass, and is preferably 10.0% by mass or less, more preferably 8.0% by mass or less, even more preferably 7.5% by mass or less, or 7.3% by mass or less.

[0037] When the resin composition layer contains components other than the components (A) to (D), the content of the component (A) in the resin composition layer is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 1.0 mass% or more, more preferably 2.0 mass% or more, even more preferably 3.0 mass% or more or 3.3 mass% or more, when the non-volatile components in the resin composition layer are taken as 100 mass%, and is preferably 10.0 mass% or less, more preferably 8.0 mass% or less, even more preferably 7.5 mass% or less, 7.3 mass% or less, or 7.2 mass% or less.

[0038] When the resin composition layer contains components other than the components (A) to (D), the content of the component (A) in the resin composition layer is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 25% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, and is preferably 70% by mass or less, more preferably 65% by mass or less, even more preferably 60% by mass or less or 58% by mass or less, based on 100% by mass of the resin components in the resin composition layer.

[0039] <(B) Hardener> The resin composition layer contains a curing agent as component (B). (B) curing agents do not include those corresponding to component (A). The (B) curing agent may be a compound that reacts with component (A) to cure the resin composition layer, and examples thereof include phenol-based curing agents, naphthol-based curing agents, active ester-based curing agents, carbodiimide-based curing agents, benzoxazine-based curing agents, and cyanate ester-based curing agents. From the viewpoint of improving insulation reliability, the (B) curing agent preferably contains one or more of a phenol-based curing agent, a naphthol-based curing agent, and an active ester-based curing agent, more preferably one or more of a phenol-based curing agent and an active ester-based curing agent, and even more preferably a phenol-based curing agent. The curing agents may be used singly or in combination of two or more.

[0040] As the phenol-based curing agent and naphthol-based curing agent, a phenol-based curing agent having a novolac structure or a naphthol-based curing agent having a novolac structure is preferred from the viewpoint of heat resistance and water resistance. Furthermore, as the phenol-based curing agent, a nitrogen-containing phenol-based curing agent is preferred, and a triazine skeleton-containing phenol-based curing agent is more preferred.

[0041] Specific examples of phenol-based curing agents and naphthol-based curing agents include "MEH-7700," "MEH-7810," "MEH-7851," and "MEH-8000H" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-495V," and "SN-37" manufactured by Nippon Steel Chemical & Material Co., Ltd. 5" and "SN-395" manufactured by DIC Corporation; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165" manufactured by Gun-ei Chemical Co., Ltd.; and "GDP-6115L", "GDP-6115H", and "ELPC75" manufactured by Gun-ei Chemical Co., Ltd.

[0042] The active ester curing agent is not particularly limited, but compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are generally preferred. The active ester curing agent is preferably one 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. 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. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0043] Specifically, an active ester compound containing a dicyclopentadiene-type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of phenol novolac, or an active ester compound containing a benzoylated product of phenol novolac is preferred, and among these, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene-type diphenol structure are more preferred. The "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0044] Commercially available active ester curing agents include active ester compounds containing a dicyclopentadiene-type diphenol structure, such as "EXB-9451," "EXB-9460," "EXB-9460S," "HPC-8000-65T," "HPC-8000H-65TM," and "HPC-8000L-65TM" (manufactured by DIC Corporation); active ester compounds containing a naphthalene structure, such as "EXB-9416-70BK," "EXB-8100L-65T," "EXB-8150-65T," "EXB-8150L-65T," "HPC-8150-60T," "HPC-8150-62T," and "HP-B-8151-62T" (manufactured by DIC Corporation); and phenol novolac. Examples of active ester compounds containing acetylated phenol novolac include "DC808" (manufactured by Mitsubishi Chemical Corporation), active ester compounds containing benzoated phenol novolac include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), active ester curing agents that are acetylated phenol novolac include "DC808" (manufactured by Mitsubishi Chemical Corporation), active ester curing agents that are benzoated phenol novolac include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), and an active ester compound containing a styryl group includes "PC1300-02-65MA" (manufactured by Air Water Inc.).

[0045] The carbodiimide curing agent is a compound having one or more carbodiimide groups (-N=C=N-) in one molecule, and the carbodiimide curing agent is preferably a compound having two or more carbodiimide groups in one molecule.

[0046] Specific examples of commercially available carbodiimide curing agents include Carbodilite V-03 (carbodiimide group equivalent: 216, V-05 (carbodiimide group equivalent: 262), V-07 (carbodiimide group equivalent: 200), and V-09 (carbodiimide group equivalent: 200), all manufactured by Nisshinbo Chemical Inc.; and Stavaxol P (carbodiimide group equivalent: 302), all manufactured by Lanxess AG.

[0047] Specific examples of benzoxazine-based curing agents include "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Chemical Industry Co., Ltd.

[0048] 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-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)ether; multifunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (phenol novolac type multifunctional cyanate ester resins), "ULL-950S" (multifunctional cyanate ester resin), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine converted to a trimer), all of which are manufactured by Lonza.

[0049] The ratio of the amounts of component (A) to component (B) in the resin composition layer, expressed as the ratio of [total number of epoxy groups in component (A)] to [total number of active groups in component (B)], is preferably in the range of 1:0.01 to 1:10, more preferably 1:0.3 to 1:5, and even more preferably 1:0.4 to 1:4. Here, the "total number of epoxy groups in the epoxy resin" refers to the sum of all values obtained by dividing the mass of the nonvolatile components of component (A) present in the resin composition layer by the epoxy equivalent. Furthermore, the "total number of active groups in component (B)" refers to 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 active group equivalent. By maintaining the ratio of component (B) to component (A) within this range, the effects of the present invention can be significantly achieved.

[0050] From the viewpoint of significantly achieving the desired effects of the present invention, the content of component (B) in the resin composition layer is preferably 1.0 mass% or more, more preferably 1.5 mass% or more, and even more preferably 2.0 mass% or more, when the non-volatile components in components (A) to (D) are taken as 100 mass%, and is preferably 8.0 mass% or less, more preferably 6.0 mass% or less, and even more preferably 5.0 mass% or less, 4.7 mass% or less, or 4.5 mass% or less.

[0051] When the resin composition layer contains components other than the components (A) to (D), the content of the component (B) in the resin composition layer is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 1.0 mass% or more, more preferably 1.5 mass% or more, and even more preferably 2.0 mass% or more, and is preferably 7.0 mass% or less, more preferably 5.0 mass% or less, and even more preferably 4.5 mass% or less or 4.3 mass% or less, based on 100 mass% of the non-volatile components in the resin composition layer.

[0052] When the resin composition layer contains components other than the components (A) to (D), the content of the component (B) in the resin composition layer is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, 21% by mass or more, or 22% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on 100% by mass of the resin components in the resin composition layer.

[0053] <(C) Thermally conductive inorganic filler> The resin composition layer contains a thermally conductive inorganic filler as component (C). By including the thermally conductive inorganic filler (C) in the resin composition layer, a cured product layer with high thermal conductivity can be obtained. The thermally conductive inorganic filler can be included in the resin composition layer in the form of particles.

[0054] From the viewpoint of obtaining a cured product layer with high thermal conductivity, the thermal conductivity of the thermally conductive inorganic filler is preferably 20 W / m K or more, more preferably 30 W / m K or more, and even more preferably 50 W / m K or more or 100 W / m K or more. There is no particular upper limit, but it can be 1,000 W / m K or less.

[0055] The material of the thermally conductive inorganic filler is not particularly limited as long as its thermal conductivity is within the above range. Examples of the material of the thermally conductive inorganic filler include inorganic materials such as aluminum oxide (alumina), aluminum nitride, silicon carbide, and boron nitride. One type of inorganic material may be used alone, or two or more types may be used in combination. Among these, one or more inorganic materials selected from alumina and silica are preferred, and alumina is more preferred.

[0056] From the viewpoint of obtaining a cured product with excellent thermal conductivity and embeddability, the average particle size of the thermally conductive inorganic filler is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less, and preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more. The average particle size of the thermally conductive inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a particle size distribution of the thermally conductive inorganic filler is prepared on a volume basis using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of the thermally conductive inorganic filler and 10 g of methyl ethyl ketone into a vial and ultrasonically dispersing the mixture for 10 minutes. The volume-based particle size distribution of the thermally conductive inorganic filler is measured using a laser diffraction particle size distribution analyzer with blue and red wavelength light sources using a flow cell system, and the average particle size can be calculated as the median diameter from the obtained particle size distribution. Examples of laser diffraction / scattering particle size distribution measuring devices that can be used include "LA-500" and "LA-960" manufactured by Horiba Ltd. and "SALD2200" manufactured by Shimadzu Corporation.

[0057] The specific surface area of the thermally conductive inorganic filler is not particularly limited, but is preferably 0.1 m 2 / g or more, more preferably 0.5m 2 / g or more, more preferably 0.9m 2 / g or more, 1.1m 2 / g or more or 1.3m 2 The upper limit of the specific surface area is not particularly limited, but is preferably 10.0 m 2 / g or less, more preferably 5.0m 2 / g or less, more preferably 3.0m 2 / g or less, 2.0m 2 / g or less or 1.5m 2 / g or less. The specific surface area of the thermally conductive inorganic filler can be measured by the nitrogen BET method. Specifically, it can be measured using an automatic specific surface area measuring device, such as the "Macsorb HM-1210" manufactured by Mountech Co., Ltd.

[0058] The thermally conductive inorganic filler may be surface-treated with a silane coupling agent to enhance moisture resistance and dispersibility, such as aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilane compounds, organosilazane compounds, and titanate coupling agents. Commercially available surface treatment agents include, for example, Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM5783" (N-phenyl-3-aminooctyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd.'s "KBM103" (phenyltrimethoxysilane), and Shin-Etsu Chemical Co., Ltd.'s "KBM-4803" (long-chain epoxy-type silane coupling agent). The thermally conductive inorganic filler may be surface-treated with two or more surface treatment agents.

[0059] The degree of surface treatment of the thermally conductive inorganic filler is preferably within a predetermined range from the viewpoint of enhancing dispersibility. Specifically, 100% by mass of the thermally conductive inorganic filler is preferably surface-treated with 0.2% by mass to 5.0% by mass of a surface treatment agent, more preferably 0.2% by mass to 3.0% by mass, and even more preferably 0.3% by mass to 2.0% by mass.

[0060] The degree of surface treatment with a surface treatment agent can be evaluated by the amount of carbon per unit surface area of the thermally conductive inorganic filler. The amount of carbon per unit surface area of the thermally conductive inorganic filler is 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2 More preferably, 0.2 mg / m or more 2On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition layer and the melt viscosity in the form of a sheet, it is more preferable that the melt viscosity is 1.0 mg / m 2 Preferably less than 0.8 mg / m 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred:

[0061] The carbon content per unit surface area of the thermally conductive inorganic filler can be measured after the surface-treated thermally conductive inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the thermally conductive inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the carbon content per unit surface area of the thermally conductive inorganic filler can be measured using a carbon analyzer. An "EMIA-320V" manufactured by Horiba, Ltd., or the like can be used as the carbon analyzer.

[0062] From the viewpoint of significantly achieving the desired effects of the present invention, the content of component (C) in the resin composition layer is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more or 87% by mass or more, and is preferably 97% by mass or less, more preferably 96% by mass or less, even more preferably 95% by mass or less, when the non-volatile components in components (A) to (D) are taken as 100% by mass.

[0063] When the resin composition layer contains components other than the components (A) to (D), the content of the component (C) in the resin composition layer is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, 83% by mass or more, or 85% by mass or more, when the non-volatile components in the resin composition layer are taken as 100% by mass, and is preferably 97% by mass or less, more preferably 96% by mass or less, even more preferably 95% by mass or less, 94% by mass or less, or 93% by mass or less.

[0064] When the resin composition layer contains components other than the components (A) to (D), the content of the component (C) in the resin composition layer is preferably 50% by volume or more, more preferably 60% by volume or more, even more preferably 65% by volume or more or 66% by volume or more, and is preferably 95% by volume or less, more preferably 85% by volume or less, even more preferably 80% by volume or less or 79% by volume or less, based on 100% by volume of the non-volatile components in the resin composition layer, from the viewpoint of significantly achieving the desired effects of the present invention.

[0065] <(D) Phosphorus-based curing accelerator> The resin composition layer contains a phosphorus-based curing accelerator as component (D). This phosphorus-based curing accelerator as component (D) does not include those corresponding to the above-mentioned components (A) and (B). Component (D) functions as a catalyst in the reaction between the epoxy resin (A) and the curing agent (B), thereby accelerating the curing of the resin composition layer. The phosphorus-based curing accelerator may be used alone or in combination of two or more.

[0066] Examples of phosphorus-based curing accelerators include triphenylphosphine, tricyclohexylphosphine, tributylphosphine, methyldiphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, a salt of tetra-n-butylphosphonium and N-acetylglycine, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, etc. Component (D) may be a commercially available product, such as "TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd. or "AiL-01" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0067] From the viewpoint of significantly achieving the desired effects of the present invention, the content of component (D) in the resin composition layer is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.03% by mass or more, when the total non-volatile components in components (A) to (D) is taken as 100% by mass, and is preferably 1.00% by mass or less, more preferably 0.50% by mass or less, and even more preferably 0.30% by mass or less or 0.20% by mass or less.

[0068] When the resin composition layer contains components other than the components (A) to (D), the content of the component (D) in the resin composition layer is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.03% by mass or more, when the non-volatile components in the resin composition layer are taken as 100% by mass, and is preferably 1.00% by mass or less, more preferably 0.50% by mass or less, and even more preferably 0.30% by mass or less or 0.20% by mass or less.

[0069] When the resin composition layer contains components other than the components (A) to (D), the content of the component (D) in the resin composition layer is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 0.1 mass% or more, more preferably 0.2 mass% or more, and even more preferably 0.3 mass% or more, when the resin components in the resin composition layer are taken as 100 mass%, and is preferably 5.0 mass% or less, more preferably 3.0 mass% or less, and even more preferably 2.0 mass% or less or 1.8 mass% or less.

[0070] <(D') Other curing accelerators> In addition to the components described above, the resin composition layer may further contain (D') other curing accelerators as optional components. (D') other curing accelerators are curing accelerators other than those corresponding to the (D) phosphorus-based curing accelerators described above. (D') other curing accelerators may be used alone or in combination of two or more.

[0071] Examples of other curing accelerators include imidazole-based curing accelerators, amine-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators.

[0072] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct , 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and other imidazole compounds, as well as adducts of imidazole compounds with epoxy resins.

[0073] As the imidazole-based curing accelerator, commercially available products may be used, such as "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2P4MZ", "2PHZ", "2PHZ-PW", "2P4MHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" manufactured by Shikoku Chemicals Corporation; and "P200-H50" manufactured by Mitsubishi Chemical Corporation. These may be used alone or in combination of two or more.

[0074] Examples of the amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene.

[0075] As the amine-based curing accelerator, commercially available products may be used, for example, "DMAP" manufactured by Tokyo Chemical Industry Co., Ltd.

[0076] Examples of guanidine curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0077] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron complexes such as iron(III) acetylacetonate, organic nickel complexes such as nickel(II) acetylacetonate, and organic manganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0078] When the resin composition layer contains the (D') component, the content of the (D') component in the resin composition layer is, when the nonvolatile components in the resin composition layer are taken as 100% by mass, for example, 0.01% by mass or more, preferably 0.10% by mass or more, more preferably 0.30% by mass or more, and even more preferably 0.40% by mass or more. The upper limit of the content is not particularly limited, but is, for example, 10.0% by mass or less, preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 1.0% by mass or less.

[0079] When the resin composition layer contains the component (D'), the content of the component (D') in the resin composition layer is, when the resin component in the resin composition layer is taken as 100% by mass, for example, 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 1.5% by mass or more. The upper limit of the content is not particularly limited, but is, for example, 15.0% by mass or less, preferably 10.0% by mass or less, more preferably 5.0% by mass or less, and even more preferably 3.0% by mass or less.

[0080] <(E) Thermoplastic resin> The resin composition layer may further contain a thermoplastic resin (E) as an optional component in addition to the components described above. The thermoplastic resin (E) as component (E) does not include those corresponding to the above-described components (A) to (D). The thermoplastic resin may be used alone or in combination of two or more.

[0081] The thermoplastic resin preferably contains a resin having one or more structures selected from a polybutadiene structure, a poly(meth)acrylate structure, a polysiloxane structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, and a polycarbonate structure in its molecule, and more preferably contains a resin having one or more structures selected from a polybutadiene structure and a poly(meth)acrylate structure. The term "(meth)acrylate" encompasses methacrylate, acrylate, and combinations thereof. These structures may be contained in the main chain or in the side chain.

[0082] Component (E) preferably contains (E-1) a thermoplastic resin having a glass transition temperature of not more than 25° C. The glass transition temperature of component (E-1) is preferably not more than 20° C., more preferably not more than 15° C. The lower limit of the glass transition temperature is not particularly limited, but can be −50° C. or higher.

[0083] From the viewpoint of achieving the effects of the present invention more significantly, the component (E) preferably has a functional group capable of reacting with the epoxy resin (A). Note that the functional group capable of reacting with the epoxy resin (A) also includes a functional group that appears upon heating.

[0084] In a preferred embodiment, the functional group reactive with the (A) epoxy resin is one or more functional groups selected from the group consisting of a hydroxy group, a carboxy group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a urethane group. Among these, the functional group is preferably a hydroxy group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, or a urethane group, more preferably a hydroxy group, an acid anhydride group, a phenolic hydroxyl group, or an epoxy group, and particularly preferably a phenolic hydroxyl group. However, when the functional group contains an epoxy group, the number average molecular weight (Mn) is preferably 5,000 or more.

[0085] A preferred embodiment of component (E) is a resin containing a polybutadiene structure, and the polybutadiene structure may be contained in the main chain or in a side chain. The polybutadiene structure may be partially or completely hydrogenated. A resin containing a polybutadiene structure is called a polybutadiene resin.

[0086] Specific examples of polybutadiene resins include "Ricon 130MA8," "Ricon 130MA13," "Ricon 130MA20," "Ricon 131MA5," "Ricon 131MA10," "Ricon 131MA17," "Ricon 131MA20," and "Ricon 184MA6" (polybutadienes containing acid anhydride groups) manufactured by Cray Valley Corporation; "GQ-1000" (polybutadiene having hydroxyl and carboxyl groups introduced therein), "G-1000," "G-2000," and "G-3000" (polybutadienes having hydroxyl groups at both ends), "GI-1000," "GI-2000," and "GI-3000" (hydrogenated polybutadiene having hydroxyl groups at both ends) manufactured by Nippon Soda Co., Ltd.; and "FCA-061L" (an epoxy resin with a hydrogenated polybutadiene backbone) manufactured by Nagase ChemteX Corporation. Examples of the polyimide resin include hydroxyl-terminated polybutadiene, linear polyimides made from diisocyanate compounds and tetrabasic acid anhydrides (polyimides described in JP 2006-37083 A and WO 2008 / 153208 A), and phenolic hydroxyl group-containing butadienes. The polyimide resin preferably has a butadiene structure content of 60% to 95% by mass, more preferably 75% to 85% by mass. For details of the polyimide resin, please refer to the descriptions in JP 2006-37083 A and WO 2008 / 153208 A, the contents of which are incorporated herein by reference.

[0087] A preferred embodiment of component (E) is a resin containing a poly(meth)acrylate structure. The poly(meth)acrylate structure is a structure formed by polymerizing acrylic acid or an acrylic acid ester, and also includes a structure formed by polymerizing methacrylic acid or a methacrylic acid ester. The poly(meth)acrylate structure may be contained in the main chain or in a side chain.

[0088] Specific examples of poly(meth)acrylate resins include Nagase ChemteX's Teisan Resin "SG-70L," "SG-708-6," "WS-023," "SG-700AS," and "SG-280TEA" (carboxyl group-containing acrylic ester copolymer resin, acid value 5 to 34 mgKOH / g, weight average molecular weight 400,000 to 900,000, Tg -30°C to 5°C), "SG-80H," "SG-80H-3," and "SG-P3" (epoxy group-containing acrylic ester copolymer resin, epoxy equivalent 4761 to 14285 g / eq, weight average molecular weight 350,000). Examples include "SG-600TEA" and "SG-790" (hydroxy group-containing acrylic ester copolymer resin, hydroxyl value 20-40 mgKOH / g, weight average molecular weight 500,000-1,200,000, Tg -37°C to -32°C) manufactured by Negami Chemical Industrial Co., Ltd., as well as "ME-2000" and "W-116.3" (carboxy group-containing acrylic ester copolymer resin), "W-197C" (hydroxy group-containing acrylic ester copolymer resin), "KG-25" and "KG-3000" (epoxy group-containing acrylic ester copolymer resin).

[0089] Another embodiment of the component (E) is a resin containing a polysiloxane structure. A resin containing a polysiloxane structure is called a polysiloxane resin.

[0090] Examples of polysiloxane resins include "SMP-2006," "SMP-2003PGMEA," and "SMP-5005PGMEA" manufactured by Shin-Etsu Silicones Co., Ltd., and linear polyimides made from amine-terminated polysiloxanes and tetrabasic acid anhydrides (WO 2010 / 053185, JP 2002-12667 A, JP 2000-319386 A, etc.).

[0091] Another embodiment of the component (E) is a resin containing a polyalkylene structure or a polyalkyleneoxy structure. A resin containing a polyalkylene structure is called a polyalkylene resin, and a resin containing a polyalkyleneoxy structure is called a polyalkyleneoxy resin. The polyalkyleneoxy structure is preferably a polyalkyleneoxy structure having 2 to 15 carbon atoms, more preferably a polyalkyleneoxy structure having 3 to 10 carbon atoms, and even more preferably a polyalkyleneoxy structure having 5 to 6 carbon atoms.

[0092] Specific examples of polyalkylene resins and polyalkyleneoxy resins include "PTXG-1000" and "PTXG-1800" manufactured by Asahi Kasei Fibers Corporation.

[0093] Another embodiment of component (E) is a resin containing a polyisoprene structure. Resins containing a polyisoprene structure are called polyisoprene resins. Specific examples of polyisoprene resins include "KL-610" and "KL613" manufactured by Kuraray Co., Ltd.

[0094] Another embodiment of component (E) is a resin containing a polyisobutylene structure. Resins containing a polyisobutylene structure are called polyisobutylene resins. Specific examples of isobutylene resins include "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer), both manufactured by Kaneka Corporation.

[0095] Another embodiment of the component (E) is a resin containing a polycarbonate structure. A resin containing a polycarbonate structure is called a polycarbonate resin.

[0096] Specific examples of polycarbonate resins include "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd. Linear polyimides made from hydroxyl-terminated polycarbonates, diisocyanate compounds, and tetrabasic acid anhydrides can also be used. The carbonate structure content of the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. For details of the polyimide resin, please refer to the description in International Publication No. 2016 / 129541.

[0097] When the resin composition layer contains the component (E-1), the content of the component (E-1) in the resin composition layer is preferably 90% by mass or more, and more preferably 95% by mass or more, based on 100% by mass of the nonvolatile components of the component (E), from the viewpoint of significantly achieving the desired effects of the present invention. Of these, it is even more preferable that the component (E) contains only the component (E-1).

[0098] When the resin composition layer contains the (E) component, the content of the (E) component in the resin composition layer is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.4% by mass or more, 0.5% by mass or more, or 0.6% by mass or more, and is preferably 10.0% by mass or less, more preferably 7.0% by mass or less, even more preferably 5.0% by mass or less, 4.0% by mass or less, or 3.5% by mass or less, when the non-volatile components in the resin composition layer are taken as 100% by mass.

[0099] When the resin composition layer contains the (E) component, the content of the (E) component in the resin composition layer is preferably 2% by mass or more, more preferably 4% by mass or more, even more preferably 5% by mass or more or 6% by mass or more, and is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less, 39% by mass or less or 38% by mass or less, when the resin component in the resin composition layer is 100% by mass.

[0100] <(F) Other additives> In addition to the components described above, the resin composition layer may further contain (F) other additives as optional components. Examples of such additives include polymerization initiators; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; adhesion promoters such as triazole-based adhesion promoters, tetrazole-based adhesion promoters, and triazine-based adhesion promoters; and hindered phenol-based antioxidants. surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, and red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); 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 anhydride-based stabilizers; photopolymerization initiation aids such as tertiary amines; and photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones. (F) Other additives may be used singly or in combination of two or more.

[0101] <(G) Organic Solvent> The resin composition layer may contain (G) an organic solvent as a volatile component. Examples of the organic solvent include ketones such as methyl ethyl ketone (MEK) and cyclohexanone, aromatic hydrocarbons such as xylene and tetramethylbenzene, glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, and ethyl diglycol acetate, aliphatic hydrocarbons such as octane and decane, and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. The (G) organic solvent may be used alone or in combination of two or more.

[0102] From the viewpoint of thinning, the thickness of the resin composition layer is preferably 600 μm or less, more preferably 550 μm or less, and even more preferably 500 μm or less, 400 μm or less, 350 μm or less, 300 μm or less, or 250 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but may be, for example, 1 μm or more, 5 μm or more, or 10 μm or more.

[0103] <Other layers> In one embodiment, the resin sheet may further include other layers as necessary. Examples of such other layers include a protective film provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dust and the like to the surface of the resin composition layer and scratches can be suppressed.

[0104] [Manufacturing method of resin sheet] The resin sheet can be produced, for example, by preparing a resin varnish by dissolving the components contained in the resin composition layer in an organic solvent, applying the resin varnish to a support using a die coater or the like, and then drying the varnish to form a resin composition layer. As the organic solvent, the organic solvents described above can be used.

[0105] Drying may be carried out by known methods such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is carried out so that the content of organic solvent in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the solvent in the resin varnish, for example, when a resin varnish containing 30% by mass to 60% by mass of solvent is used, a resin composition layer can be formed by drying at 50°C to 150°C for 1 minute to 10 minutes.

[0106] The resin sheet can be stored in a rolled state. The resin sheet may not be used immediately after production. In such cases, it is preferable to store the resin sheet in a frozen and / or refrigerated state after production so as not to impair its properties. It is particularly preferable to store the resin sheet in a frozen state after production. The temperature conditions for storing the resin sheet in a frozen or refrigerated state are, for example, 5°C or lower, preferably 0°C or lower, and more preferably -20°C or lower. The lower limit of such a temperature is not particularly limited, and may be, for example, -40°C or higher. When the resin sheet is stored in a frozen or refrigerated state, it is thawed and cooled at room temperature (e.g., 23°C), and the resin composition layer contained in the resin sheet becomes usable when it reaches room temperature. Furthermore, when the resin sheet has a protective film, it can be used by peeling off the protective film.

[0107] [Characteristics and uses of resin sheets] The resin composition layer contained in the resin sheet contains a combination of components (A), (B), (C), and (D) (and, as necessary, components (D'), (E), (F), and (G)), which enables the resin composition layer to have a tan δ at 80°C that satisfies a specific range. Furthermore, by using the resin sheet of the present invention to seal a hollow structure, sufficient sealing moldability can be achieved stably while maintaining the hollow structure.

[0108] In the resin sheet of the present invention, the tan δ value of the resin composition layer at 80°C is 0.50 or more and 0.90 or less. When the tan δ value is within this range, even when the melt viscosity of the resin composition layer at 80°C is high, or when the resin sheet is stored at room temperature prior to encapsulation, sufficient encapsulation moldability can be achieved while maintaining the hollow structure. From the viewpoint of significantly achieving the desired effects of the present invention, the tan δ value is preferably 0.10 or more, more preferably 0.20 or more, even more preferably 0.30 or more, 0.40 or more, 0.50 or more, or 0.60 or more, and preferably 0.88 or less, more preferably 0.87 or less, and even more preferably 0.86 or less, 0.85 or less, or 0.84 or less. The tan δ value of the resin composition layer at 80°C can be measured by the method described in the section "Test Example 2: Measurement of Melt Viscosity and Tan δ" in the Examples section below.

[0109] The resin sheet of the present invention can maintain a hollow structure and provide sufficient encapsulation moldability even when stored at room temperature prior to encapsulation molding. For example, a resin sheet or a resin sheet left standing for 72 hours is laminated on an evaluation substrate having a semiconductor chip flip-chip bonded to a glass substrate so that the resin composition layer covers the semiconductor chip on the evaluation substrate. After lamination, the resin composition layer is thermally cured at 130°C for 30 minutes and then at 200°C for 30 minutes to obtain a cured product layer. The amount of resin penetration into the hollow space between the semiconductor chip and the glass substrate is measured by observing the evaluation substrate from the glass substrate side using a digital microscope. In this case, the amount of resin penetration is preferably 70 μm or less, more preferably 50 μm or less. The amount of resin penetration can be measured using the method described in the section "Test Example 4: Measurement of Resin Penetration Amount" in the Examples section below.

[0110] In the resin sheet of the present invention, the cured product obtained by thermally curing the resin composition layer at 120°C for 90 minutes can exhibit excellent thermal conductivity. Therefore, a cured product layer with excellent thermal conductivity can be obtained. The thermal conductivity of the cured product is preferably 1.0 W / m·K or more, more preferably 1.5 W / m·K or more, and even more preferably 2.0 W / m·K or more. There is no particular upper limit to the thermal conductivity, but it can be 10 W / m·K or less. The thermal conductivity can be measured by the method described in the section "Test Example 1: Measurement of Thermal Conductivity" in the Examples section below.

[0111] In the resin sheet of the present invention, the resin composition layer can exhibit excellent stability of melt viscosity. Therefore, in the resin composition layer contained in the resin sheet, the melt viscosity of the resin composition layer at 80°C is MV 0h The resin sheet was left standing for 72 hours in an environment with a temperature of 23°C and a humidity of 40 to 45%, and the melt viscosity of the resin composition layer at 80°C was measured as MV 72h (poise), the ratio of these (MV 72h / MV 0h The melt viscosity ratio (MV 72h / MV 0h) is preferably 1.48 or less, more preferably 1.47 or less, and even more preferably 1.46 or less or 1.45 or less, from the viewpoint of significantly achieving the desired effects of the present invention. The melt viscosity of the resin composition layer at 80°C can be measured by the method described in the section <Test Example 2: Measurement of melt viscosity and tan δ> of the Examples below. Furthermore, the melt viscosity of the resin composition layer at 80°C after leaving the resin sheet undisturbed in an environment of a temperature of 23°C and a humidity of 40 to 45% for 72 hours can be measured by the method described in the section <Test Example 3: Measurement of melt viscosity and tan δ after leaving undisturbed for 72 hours> of the Examples below.

[0112] In the resin sheet of the present invention, the resin composition layer can exhibit excellent stability of tan δ. Therefore, in the resin composition layer contained in the resin sheet, the tan δ of the resin composition layer at 80° C. is 0h The resin sheet was left standing for 72 hours in an environment of a temperature of 23°C and a humidity of 40 to 45%, and the tan δ of the resin composition layer at 80°C was determined as tan δ 72h When these ratios (tanδ 72h / tanδ 0h The ratio of tan δ (tan δ) can be 1.00 or more and 1.50 or less. 72h / tanδ 0h ) is preferably 1.45 or less, more preferably 1.35 or less, and even more preferably 1.30 or less, from the viewpoint of significantly achieving the desired effects of the present invention. The tan δ at 80°C of the resin composition layer when the resin sheet is left to stand for 72 hours in an environment of a temperature of 23°C and a humidity of 40 to 45% can be measured by the method described in the section <Test Example 3: Measurement of melt viscosity and tan δ after standing for 72 hours> in the Examples section below.

[0113] In the resin sheet of the present invention, the melt viscosity (MV 0h ) and tanδ(tanδ 0hWhen measuring the melt viscosity (MV), a resin sheet in a frozen or refrigerated state is left standing in an environment at a temperature of 23°C and a humidity of 40 to 45% to thaw and adjust the temperature, and the resin sheet may be subjected to measurement immediately after the temperature of the resin composition layer reaches 23°C (for example, if the point in time when the temperature reaches 23°C is defined as TO, the resin sheet may be subjected to measurement before 1 hour has elapsed, within 45 minutes, within 30 minutes, or within 15 minutes after TO). In addition, in the resin sheet of the present invention, a resin sheet in a frozen or refrigerated state may be used to measure the melt viscosity (MV) of the resin composition layer when the resin sheet is left standing in an environment at a temperature of 23°C and a humidity of 40 to 45% for 72 hours. 72h ) and tanδ(tanδ 72h When measuring the thermal expansion coefficient (T0), the resin sheet may be left to stand in an environment of a temperature of 23°C and a humidity of 40 to 45% for a further 72 hours from the time T0 when the temperature of the resin composition layer reaches 23°C, and then subjected to measurement.

[0114] The resin sheet of the present invention can be suitably used as a resin sheet for sealing an object to be sealed provided on a substrate via bumps. Furthermore, when a hollow structure is sealed using the resin sheet, the resin sheet of the present invention can stably provide sufficient sealing moldability while maintaining the hollow structure, and therefore can be more suitably used as a resin sheet for sealing an object to be sealed in a sealing structure having a hollow structure between a substrate and the object to be sealed.

[0115] As described above, the resin sheet of the present invention can be suitably used as a resin sheet for sealing a sealed object of a sealing structure having a hollow structure, but the sealing structure does not have to have a hollow structure. Therefore, the resin sheet of the present invention can also be suitably used as a resin sheet for sealing a semiconductor chip.

[0116] The resin sheet of the present invention can also have the properties of excellent thermal conductivity and excellent melt viscosity stability. Therefore, the resin sheet of the present invention can be suitably used as a resin sheet for forming an insulating layer of a semiconductor chip package (a resin sheet for forming an insulating layer of a semiconductor chip package) or a resin sheet for forming an insulating layer of a circuit board (including a printed wiring board) (a resin sheet for forming an insulating layer of a circuit board), and can even be suitably used as a resin sheet for forming an interlayer insulating layer on which a conductor layer is formed by plating (a circuit board on which a conductor layer is formed by plating, i.e., a resin sheet for forming an interlayer insulating layer of a circuit board on which a circuit is formed by a semi-additive process). The resin sheet of the present invention can also be suitably used as a resin sheet for forming wiring on a semiconductor chip (a resin sheet for forming semiconductor chip wiring).

[0117] [Sealing structure and manufacturing method thereof] The sealing structure of the present invention comprises a substrate, an object to be sealed provided on the substrate via bumps, and a cured material layer that seals the object to be sealed. The cured material layer comprises a cured product of the resin composition layer of the resin sheet of the present invention, and preferably comprises only the cured product of the resin composition layer. The sealing structure preferably has a hollow structure between the substrate and the object to be sealed. Therefore, in a preferred embodiment, the sealing structure comprises a substrate, an object to be sealed provided on the substrate via bumps, a hollow structure between the substrate and the object to be sealed, and a cured material layer that seals the object to be sealed. The sealing structure may comprise a plurality of objects to be sealed. When the sealing structure has a plurality of objects to be sealed, the plurality of objects to be sealed may be the same type or different types.

[0118] The sealing structure may be, for example, an electronic component device. The electronic component device includes an electronic component as the object to be sealed. Examples of the electronic component include a semiconductor chip, a semiconductor wafer, an integrated circuit, a semiconductor device, a filter such as a SAW filter, and a sensor. The semiconductor chip may be a semiconductor chip obtained by singulating the semiconductor wafer. The electronic component device may be a semiconductor device including a semiconductor chip or a semiconductor wafer as an electronic component, or a circuit board such as a printed wiring board. When the electronic component device has a hollow structure, the object to be sealed may be provided on a substrate via bumps so that the electronic component is located on the surface facing the hollow structure. Examples of such an object to be sealed include electronic components such as a SAW device such as a SAW filter and a sensor such as an acceleration sensor. When the object to be sealed is a SAW filter, the surface of the piezoelectric substrate on which a pair of interdigital transducers (IDTs) are attached serves as the movable part.

[0119] The sealing structure of the present invention can be manufactured using the resin sheet of the present invention. Hereinafter, the method for manufacturing the sealing structure will be described with reference to the drawings.

[0120] The sealing structure may be, for example: a step (I) of arranging a structure including a substrate and an object to be sealed provided on the substrate via bumps, and a resin sheet so that the surface of the structure facing the object to be sealed faces the surface of the resin sheet facing the resin composition layer; Step (II) of laminating a resin sheet on the structure so that the resin composition layer seals the object to be sealed; and Step (III) of curing the resin composition layer to form a cured layer; Furthermore, if necessary, the method may include a step (IV) of dividing the sealing structure into individual pieces after the step (III) is completed.

[0121] 1 is a schematic cross-sectional view illustrating step (I) of a method for manufacturing a sealed structure according to one embodiment of the present invention. In step (I), a structure 50 including a substrate 30 and an object to be sealed 20 provided on the substrate 30 via bumps 40, and a resin sheet 10 are arranged such that a surface 50A of the structure 50 facing the object to be sealed 20 faces a surface 10A of the resin sheet 10 facing the resin composition layer 10a.

[0122] In the structure 50, the objects to be sealed 20 are provided on the substrate 30 via bumps 40. The number of objects to be sealed 20 provided on the substrate 30 can be set appropriately depending on the shape and size of the objects to be sealed 20, the number of intended sealed structures to be produced, etc. For example, a plurality of objects to be sealed 20 may be provided on the substrate 30 via bumps 40. The number of bumps 40 between the substrate 30 and the objects to be sealed 30 can be set appropriately depending on the shape and size of the objects to be sealed 20, the number of intended sealed structures to be produced, etc.

[0123] When the structure 50 has a hollow structure 60, the sealed object 20 may be a SAW device. When the sealed object 20 is a SAW device, the sealed object 20 may have an electrode 70 on the surface 20A on the hollow structure side. In this case, the electrode 70 may be a movable part. The number of electrodes 70 that the sealed object 20 has may be set appropriately depending on the shape and size of the sealed object 20, the number of sealing structures to be produced, the shape and size of the electrode 70, etc.

[0124] 2 is a schematic cross-sectional view illustrating step (II) of the method for producing a sealed structure according to one embodiment of the present invention. In step (II), a resin sheet 10 is laminated so that a resin composition layer 10b seals a sealed object 20. Molding conditions (lamination conditions) vary depending on the composition of the resin composition, and appropriate conditions can be adopted to achieve good sealing.

[0125] The resin sheet 10 may be laminated by a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60°C to 160°C, the thermocompression pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1.47 MPa, and the thermocompression time is preferably in the range of 20 seconds to 600 seconds, more preferably 30 seconds to 300 seconds. The lamination is preferably carried out under reduced pressure conditions of 13 hPa or less.

[0126] 3 is a schematic cross-sectional view illustrating step (III) of the method for producing a sealed structure according to one embodiment of the present invention. In step (III), the resin composition layer 10b in which the sealed object 20 is sealed is cured to form a cured product layer 10c. This allows the sealed structure 100 to be obtained. For example, the curing conditions for the resin composition layer 10b vary depending on the composition of the resin composition, but the curing temperature can be in the range of 120°C to 240°C, and the curing time can be in the range of 5 minutes to 120 minutes. Before curing the resin composition layer 10b, the resin composition layer 10b may be preheated at a temperature lower than the curing temperature.

[0127] The support 10a contained in the resin sheet 10 may be peeled off before the resin sheet 10 is laminated, or after the resin sheet 10 is laminated, or after the resin composition layer 10b is cured.

[0128] 4 is a schematic cross-sectional view illustrating step (IV) of the method for manufacturing a sealed structure according to one embodiment of the present invention. The method for manufacturing a sealed structure of the present invention may include step (IV) of dividing the sealed structure into individual pieces, as necessary. Step (IV) allows a plurality of sealed structures 200 to be obtained from the sealed structure 100. Step (IV) may be performed according to various methods known to those skilled in the art.

[0129] In this embodiment, the sealing structure is obtained by laminating resin sheets, but the sealing structure may also be obtained by compression molding using a compression molding device, or by press molding using a press. For example, a structure including a substrate and an object to be sealed provided on the substrate via bumps, and a resin sheet are arranged so that the surface of the structure facing the object to be sealed and the surface of the resin sheet facing the resin composition layer are in contact, and then compression molding or press molding is performed, thereby allowing the resin composition layer to seal the object to be sealed. The support contained in the resin sheet may be peeled off before compression molding or press molding, or may be peeled off after compression molding or press molding. The temperature when sealing the object to be sealed by compression molding or press molding may be the same as the heat-pressure bonding temperature in the vacuum lamination method. [Example]

[0130] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, the temperature and pressure conditions were room temperature (23°C) and atmospheric pressure (1 atm), unless otherwise specified.

[0131] <Synthesis Example 1: Synthesis of Elastomer A> A reaction vessel was charged with 69 g of bifunctional hydroxy-terminated polybutadiene ("G-3000" manufactured by Nippon Soda Co., Ltd., number average molecular weight 3,000, hydroxy group equivalent weight 1,800 g / eq.), 40 g of an aromatic hydrocarbon mixed solvent ("IPZOL 150" manufactured by Idemitsu Petrochemical Co., Ltd.), and 0.005 g of dibutyltin laurate, which were mixed and dissolved uniformly. Once homogeneous, the mixture was heated to 60°C, and 8 g of isophorone diisocyanate ("IPDI" manufactured by Evonik Degussa Japan Co., Ltd., isocyanate group equivalent weight 113 g / eq.) was added with further stirring, and the reaction was carried out for approximately 3 hours.

[0132] Next, 23 g of cresol novolak resin (DIC Corporation "KA-1160", hydroxyl group equivalent 117 g / eq.) and 60 g of ethyl diglycol acetate (Daicel Corporation) were added to the reaction mixture, and the mixture was heated to 150°C with stirring and reacted for about 10 hours. -1 The disappearance of the NCO peak was confirmed. The disappearance of the NCO peak was considered to be the end of the reaction, and the reaction mixture was cooled to room temperature. The reaction mixture was then filtered through a 100-mesh filter cloth to obtain an elastomer A having a polybutadiene structure and phenolic hydroxyl groups (phenolic hydroxyl group-containing butadiene resin: non-volatile components 50% by mass). The number-average molecular weight of elastomer A was 5,900, and the glass transition temperature was -7°C.

[0133] <Examples 1 to 9 and Comparative Examples 1 to 4. Production of Resin Sheets> [Example 1] 2.0 parts of biphenyl-type epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent weight approximately 272 g / eq.) and 4.0 parts of bisphenol-type epoxy resin ("ZX1059" manufactured by Nippon Steel Chemical & Material Co., Ltd., a 1:1 mixture of bisphenol A type and bisphenol F type, epoxy equivalent weight 169 g / eq.) were heated and dissolved with stirring in a mixed solvent of 6 parts solvent naphtha and 2 parts cyclohexanone. This was cooled to room temperature to prepare a dissolved epoxy resin composition. To this epoxy resin solution composition, 13.0 parts of an acrylic ester polymer ("SG-P3" manufactured by Nagase ChemteX Corporation, an epoxy group-containing acrylic ester copolymer resin, a MEK solution containing 15% nonvolatile components, a weight average molecular weight of 350,000 to 850,000, a glass transition temperature of 11 to 12°C, and an epoxy equivalent of 4,761 to 14,285 g / eq.), phenol novolak resin ("TD-2090-60M" manufactured by DIC, a MEK solution containing 60% nonvolatile components, and a phenolic hydroxyl group equivalent of 1 0.05g / eq.) 6.0 parts, carbon black pigment (Mikoni Color Co., Ltd., "MHI Black #RK-799M", MEK solution with 20% by mass of non-volatile components) 0.5 parts, curing accelerator (Hokuko Chemical Industry Co., Ltd., "TBP-DA", tetrabutylphosphonium decanoate, MEK solution with 10% by mass of non-volatile components) 1.0 part, inorganic filler A (alumina surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical Co., Ltd., "KBM573"), average particle size 2.6 μm, specific surface area 1.4 m 2 120.0 parts of the above ingredients (1 / g) were mixed and dispersed uniformly in a high-speed rotating mixer to produce a resin varnish.

[0134] A polyethylene terephthalate film ("AL-5" manufactured by Lintec Corporation, thickness 38 μm) with a release layer was prepared as a support. The above-mentioned resin varnish was uniformly applied onto the release layer of this support so that the thickness of the resin composition layer after drying would be 200 μm. Thereafter, the resin varnish was dried at 80°C to 120°C (average 100°C) for 5 minutes to produce a resin sheet 1 including a support and a resin composition layer (thickness 200 μm).

[0135] [Example 2] In Example 1, 1) The amount of inorganic filler A was changed from 120.0 parts to 161.1 parts, 2) The amount of acrylic ester polymer ("SG-P3" manufactured by Nagase ChemteX Corporation) was changed from 13.0 parts to 39.0 parts. 3) The drying time of the resin varnish was changed from 5 minutes to 6 minutes. Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 2 was produced.

[0136] [Example 3] In Example 1, 1) The amount of inorganic filler A was changed from 120.0 parts to 108.3 parts. 2) The amount of acrylic ester polymer ("SG-P3" manufactured by Nagase ChemteX Corporation) was changed from 13.0 parts to 5.0 parts. 3) The drying time of the resin varnish was changed from 5 minutes to 4 minutes. Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 3 was produced.

[0137] [Example 4] In Example 1, the amount of the curing accelerator ("TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.) was changed from 1.0 part to 2.0 parts. Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 4 was produced.

[0138] [Example 5] In Example 1, the amount of the curing accelerator ("TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.) was changed from 1.0 part to 0.4 part. Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 5 was produced.

[0139] [Example 6] In Example 1, 1) The amount of inorganic filler A was changed from 120.0 parts to 74.0 parts. 2) The drying time of the resin varnish was changed from 5 minutes to 6 minutes. Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 6 was produced.

[0140] [Example 7] In Example 1, 13.0 parts of the acrylic acid ester polymer ("SG-P3" manufactured by Nagase ChemteX Corporation) was changed to 4.4 parts of the elastomer A obtained in Synthesis Example 1. Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 7 was produced.

[0141] [Example 8] In Example 1, 1.0 part of the curing accelerator ("TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.) was changed to 1.0 part of the curing accelerator ("AiL-01" manufactured by Ajinomoto Fine-Techno Co., Ltd., a salt of tetra-n-butylphosphonium and N-acetylglycine, MEK solution with 10% by mass of non-volatile components). Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 8 was produced.

[0142] [Example 9] In Example 1, 13.0 parts of an acrylic acid ester polymer ("SG-P3" manufactured by Nagase ChemteX Corporation) was changed to 9.9 parts of another acrylic acid ester polymer ("ME-2000" manufactured by Negami Chemical Industrial Co., Ltd., a carboxyl group-containing acrylic acid ester copolymer resin, weight average molecular weight 600,000, glass transition temperature -35°C). Aside from the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 9 was produced.

[0143] [Comparative Example 1] In Example 1, 1.0 part of the curing accelerator ("TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.) was changed to 1.0 part of a curing accelerator (1-benzyl-2-phenylimidazole (1B2PZ), MEK solution containing 10% by mass of non-volatile components). Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 10 was produced.

[0144] Comparative Example 2 In Example 1, 1.0 part of the curing accelerator ("TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.) was changed to 1.0 part of a curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution containing 2.5% by mass of non-volatile components). A resin varnish was obtained in the same manner as in Example 1, except for the above, and a resin sheet 11 was produced.

[0145] Comparative Example 3 In Example 1, 1.0 part of the curing accelerator ("TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.) was changed to 0.1 part of the curing accelerator ("2P4MHZ-PW" manufactured by Shikoku Chemical Industry Co., Ltd., 2-phenyl-4-methyl-5-hydroxymethylimidazole). Except for the above, a resin varnish was obtained in the same manner as in Example 1, and a resin sheet 12 was produced.

[0146] Comparative Example 4 In Example 1, 13.0 parts of an acrylic acid ester polymer ("SG-P3" manufactured by Nagase ChemteX Corporation) was changed to 6.5 parts of a phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, MEK:cyclohexanone = 1:1 solution with 30 mass% non-volatile components, weight average molecular weight 35,000, glass transition temperature 155 ° C.). A resin varnish was obtained in the same manner as in Example 1 except for the above, and a resin sheet 13 was produced.

[0147] The resin sheets produced in the Examples and Comparative Examples were stored in a frozen state (temperature -20°C) after production. In addition, when measuring the physical properties of the resin sheets, the frozen resin sheets were left to stand in an environment of a temperature of 23°C and a humidity of 40 to 45% to thaw and adjust the temperature, and the resin sheets were subjected to measurement of the physical properties within 30 minutes from the time T0 when the temperature of the resin composition layer reached 23°C.

[0148] <Test Example 1: Measurement of thermal conductivity of cured resin composition layer> (1) Preparation of cured sample The resin sheets produced in the examples and comparative examples were placed in an oven at 130°C and subjected to a pre-cure process for 30 minutes, then transferred to an oven at 200°C and subjected to a post-cure process for 30 minutes, thereby thermally curing the resin composition layer and obtaining cured product samples.

[0149] (2) Measurement of thermal diffusivity α For the cured sample, the thermal diffusivity α (m 2 / s) was measured by thermal wave analysis using the "ai-Phase Mobile 1u" manufactured by ai-Phase Co., Ltd. Measurements were taken three times for the same sample, and the average value was calculated.

[0150] (3) Measurement of specific heat capacity Cp The cured samples were measured using a differential scanning calorimeter (DSC7020 manufactured by SII Nano Technology Co., Ltd.) by heating from -40°C to 80°C at a rate of 10°C / min, and the specific heat capacity Cp (J / kg·K) of the cured samples at 25°C was calculated.

[0151] (4) Measurement of density ρ Density of the hardened sample ρ (kg / m 3 ) was measured using an analytical balance (Mettler-Toledo "XP105" (using a specific gravity measurement kit)).

[0152] (5) Calculation of thermal conductivity λ: The thermal diffusivity α(m 2 / s), specific heat capacity Cp (J / kg K), and density ρ (kg / m 3 ) was substituted into the following formula (M1) to calculate the thermal conductivity λ (W / m K) of the cured product. λ=α×Cp×ρ(M1)

[0153] <Test Example 2: Measurement of melt viscosity and tan δ> Only the resin composition layer was peeled off from the resin sheets obtained in the Examples and Comparative Examples and compressed in a mold to obtain pellets for measurement (diameter 18 mm, 2.0 to 2.1 g).

[0154] Using a dynamic viscoelasticity measuring device (UBM "Rheosol-G3000"), 2 g of pellets were heated from an initial temperature of 70°C to 180°C at a heating rate of 5°C / min using parallel plates with a diameter of 18 mm, and the dynamic viscoelastic modulus was measured under the following measurement conditions: temperature interval 2.5°C, frequency 1 Hz, strain 1 deg. After measuring the dynamic viscoelastic modulus, a graph was created with temperature on the horizontal axis and melt viscosity and tanδ on the vertical axis. The melt viscosity at 80°C (MV 0h ) and tanδ(tanδ0h ) was calculated.

[0155] <Test Example 3: Measurement of Melting Viscosity and tanδ after Standing for 72 Hours> In an environment with a temperature of 23°C and a humidity of 40 - 45%, the resin sheets obtained in the examples and comparative examples were allowed to stand for 72 hours from the time point T0 when the temperature of the resin composition layer reached 23°C. Only the resin composition layer was peeled off from the resin sheet after standing, and measurement pellets (diameter 18 mm, 2.0 - 2.1 g) were obtained by compressing with a mold. For 2 g of the measurement pellets, the dynamic viscoelastic modulus was measured under the same measurement conditions as in <Test Example 2: Measurement of Melting Viscosity and tanδ>. After measuring the dynamic viscoelastic modulus, a graph with temperature on the horizontal axis and melting viscosity and tanδ on the vertical axis was created, and the melting viscosity (MV 72h ) and tanδ (tanδ 72h ) were calculated.

[0156] <Evaluation of Stability of Melting Viscosity> Based on the values of MV 0h and MV 72h obtained in the above measurement, the stability of the melting viscosity was evaluated according to the following criteria. [Evaluation Criteria for Stability of Melting Viscosity] ○: 1.00 ≤ MV 72h / MV 0h < 1.30 is satisfied. △: 1.30 ≤ MV 72h / MV 0h ≤ 1.50 is satisfied. ×: MV 72h / MV 0h < 1.00, or MV 72h / MV 0h < 1.50.

[0157] <Evaluation of Stability of tanδ> Based on the values of tanδ 0h and tanδ 72h obtained in the above measurement, the stability of tanδ was evaluated according to the following criteria. [Evaluation Criteria for Stability of tanδ] ○: 1.00 ≤ tanδ 72h / tanδ 0h ≤ 1.50 is satisfied. ×: tanδ 72h / tanδ 0h <1.00, or tan δ 72h / tanδ 0h >1.50.

[0158] <Test Example 4: Measurement of resin penetration amount> (1) Manufacturing of evaluation boards An evaluation substrate was manufactured in which a semiconductor chip (960 μm long, 1350 μm wide, 200 μm thick) was flip-chip bonded onto a glass substrate (38 mm square, 1 mm thick). The semiconductor chips were connected to the glass substrate using gold bumps (60 μm diameter, 240 μm pitch) so that there was a 30 μm gap between the glass substrate and the semiconductor chips, with 4 chips arranged vertically and 3 chips horizontally, for a total of 12 chips.

[0159] (2) Lamination of resin sheets (manufacturing of substrate A1) Using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator "CVP700"), the resin sheets obtained in the Examples and Comparative Examples were laminated onto the evaluation substrate so that the resin composition layer covered the semiconductor chip of the evaluation substrate, thereby obtaining substrate A1. This lamination was performed by reducing the pressure for 30 seconds to adjust the air pressure to 13 hPa or less, and then pressing at a temperature of 80°C and a pressure of 0.10 to 0.74 MPa for 30 seconds.

[0160] (3) Lamination of resin sheet after leaving it for 72 hours (production of substrate A2) The resin sheets obtained in the examples and comparative examples were allowed to stand for 72 hours in an environment of a temperature of 23°C and a humidity of 40 to 45%. Substrate A2 was obtained by carrying out the same operations as in "(2) Lamination of resin sheets (production of substrate A1)", except that the resin sheets to be laminated were changed to those that had been left standing for 72 hours.

[0161] (4) Curing of the resin composition layer Substrate A1 was placed in an oven at 130°C and subjected to a pre-cure process for 30 minutes, then transferred to an oven at 200°C and subjected to a post-cure process for 30 minutes to thermally cure the resin composition layer, thereby obtaining evaluation substrate B1.

[0162] The resin composition layer of the substrate A2 was also thermally cured under the same thermal curing conditions as above to obtain a substrate B2 for evaluation.

[0163] (5) Measurement of resin penetration For evaluation substrates B1 and B2, a digital microscope (Keyence Corporation's "VHX-7000") was used to observe evaluation substrates B1 and B2 from the glass substrate side to measure the amount of resin infiltration into the hollow space between the semiconductor chip and the glass substrate. The maximum distance that the resin reached that infiltrated from the edge of the semiconductor chip into the hollow space was measured, and this was taken as the amount of resin infiltration. The measured amount of resin infiltration was evaluated according to the following criteria. In the following evaluation criteria, "amount of resin infiltration < 0 μm" means that the space between adjacent semiconductor chips was not filled with resin. [Evaluation criteria for resin penetration amount] ○: 0 μm≦resin penetration amount≦50 μm △:50μm<resin penetration amount≦70μm ×: 70 μm<resin penetration amount, or resin penetration amount<0 μm

[0164] <Result> The results of the examples and comparative examples are shown in Table 1 below.

[0165] [Table 1]

[0166] In Examples 1 to 9, it was confirmed that even when components (E) to (F) were not contained, the same results as in the above Examples were obtained, although to different degrees. [Explanation of symbols]

[0167] 10 Resin sheet 10a Resin composition layer 10b Support 10c Cured material layer 10A: Resin composition layer side of resin sheet 20 Encapsulated object 30 boards 40 Bump 50 structures 50A Surface of the structure facing the sealed object 60 Hollow structure 70 electrodes 100 Sealing structure 200 Multiple sealing structures

Claims

1. In the manufacture of a sealing structure having a hollow structure, a resin sheet for sealing molding is provided, The resin sheet includes a support and a resin composition layer provided on the support, the resin composition layer contains (A) an epoxy resin, (B) a curing agent, (C) a thermally conductive inorganic filler, and (D) a phosphorus-based curing accelerator; A resin sheet in which the loss tangent tanδ (tanδ=loss modulus E″ / storage modulus E′) of the resin composition layer at 80°C is 0.50 or more and 0.90 or less.

2. The tan δ of the resin composition layer at 80°C is ０ｈ The resin sheet was left standing for 72 hours in an environment of a temperature of 23°C and a humidity of 40 to 45%, and the tan δ of the resin composition layer at 80°C was calculated as tan δ ７２ｈ When 1.00≦tanδ ７２ｈ / tanδ ０ｈ ≦1.50 The resin sheet according to claim 1 , which satisfies the following relationship:

3. The melt viscosity of the resin composition layer at 80°C is MV ０ｈ The resin sheet was left standing for 72 hours in an environment of 23°C and 40 to 45% humidity, and the melt viscosity of the resin composition layer at 80°C was defined as MV ７２ｈ When (poise) is used, 1.00≦MV ７２ｈ / MV ０ｈ ≦1.50 The resin sheet according to claim 1 , which satisfies the following relationship:

4. The resin sheet according to claim 1, wherein the cured product of the resin composition layer has a thermal conductivity of 1.0 W / m·K or more.

5. The resin sheet according to claim 1 , wherein the resin composition layer further comprises (E) a thermoplastic resin.

6. The resin sheet according to claim 5, wherein the component (E) includes (E-1) a thermoplastic resin having a glass transition temperature of 25°C or lower.

7. 2. The resin sheet according to claim 1, which is used to seal an object to be sealed that is provided on a substrate via bumps.

8. A sealing structure comprising a substrate, a sealed object provided on the substrate via bumps, and a cured material layer that seals the sealed object, The cured product layer comprises a cured product of the resin composition layer of the resin sheet according to any one of claims 1 to 7, The sealing structure has a hollow structure between the substrate and the sealing body.

9. The sealed structure according to claim 8 , wherein the sealed body includes an electrode disposed on the hollow structure side.

10. A method for manufacturing a sealing structure including a substrate, an object to be sealed provided on the substrate via bumps, and a cured material layer that seals the object to be sealed, A step of laminating the resin sheet according to any one of claims 1 to 7 onto a structure including a substrate and an object to be sealed provided on the substrate via bumps, so that the resin composition layer seals the object to be sealed; a step of curing the resin composition layer to form a cured layer; A method for manufacturing a sealing structure, comprising:

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