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 producing the same. Background Art

[0002] In recent years, along with semiconductor packages, development of microelectronic components called MEMS such as SAW (Surface Acoustic Wave) filters, CMOS (Complementary Metal Oxide Semiconductor) sensors, and acceleration sensors has been progressing. Packages sealing these electronic components generally each have a hollow structure for propagating surface acoustic waves, maintaining an optical system, and ensuring the movability of movable members of the electronic component. This hollow structure is often provided as a gap between a substrate and the electronic component (element). During sealing, sealing may be performed while maintaining the hollow structure to ensure the operational reliability of the movable member and the connection reliability of the element.

[0003] As a method of sealing while maintaining a hollow structure, a sealing method using a sheet-like laminated material such as a resin sheet has been studied (for example, Patent Document 1). Prior Art Documents Patent Documents

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

[0005] When sealing a hollow structure using a resin sheet while maintaining the hollow structure, the resin composition layer included in the resin sheet is required to exhibit sufficient sealing moldability at the temperature during sealing molding and to be capable of suppressing the inflow of resin into the hollow structure. However, when conventional resin sheets are stored at room temperature prior to sealing molding, variations occur in sealing moldability, and sufficient sealing moldability cannot be stably provided while maintaining the hollow structure in some cases.

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

[0007] The present inventor conducted intensive studies to solve the above problems. As a result, the inventor found that the above problems can be solved by using a resin sheet including 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 the loss tangent tanδ (tanδ = loss elastic modulus E" / storage elastic modulus E') of the resin composition layer at 80°C is 0.50 or more and 0.90 or less, and completed the present invention. That is, the present invention includes the following.

[0008] <1> A resin sheet for sealing molding in production of a sealed structure having a hollow structure, wherein 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, and the loss tangent tanδ (tanδ = loss elastic modulus E" / storage elastic modulus E') of the resin composition layer at 80°C is 0.50 or more and 0.90 or less. <2> The tanδ of the resin composition layer at 80°C is tanδ 0h The tanδ of the resin composition layer at 80°C was obtained when the resin sheet was left standing for 72 hours in an environment with a temperature of 23°C and a humidity of 40-45%. 72h In that case, 1.00 ≤ tanδ 72h / tanδ 0h ≤1.50 Satisfying the relationship, <1> The resin sheet described above. <3> The melt viscosity of the resin composition layer at 80°C is MV 0h (poise) The melt viscosity of the resin composition layer at 80°C after the resin sheet was left standing for 72 hours in an environment of 23°C and 40-45% humidity was defined as MV. 72h When we use (poise), 1.00 ≤ MV 72h / MV 0h ≤1.50 Satisfying the relationship, <1> or <2> The resin sheet described above. <4> The thermal conductivity of the cured resin composition layer is 1.0 W / m·K or higher. <1> ~ <3> A resin sheet as described in any one of the items. <5> The resin composition layer further comprises (E) a thermoplastic resin. <1> ~ <4> A resin sheet as described in any one of the items. <6> (E) Component contains (E-1) a thermoplastic resin with a glass transition temperature of 25°C or lower. <5> The resin sheet described above. <7> For sealing a sealed object provided on a substrate via bumps, <1> ~ <6> A resin sheet as described in any one of the items. <8> A sealing structure comprising a substrate, a sealed body provided on the substrate via bumps, and a cured material layer that seals the sealed body, The hardened layer is <1> ~ <7> The resin sheet comprises a cured resin composition layer of any one of the items described in the item, A sealing structure having a hollow structure between the substrate and the sealing body. <9> The sealed body includes an electrode positioned on the hollow structure side. <8> The sealing structure described above. <10> A method for manufacturing a sealing structure comprising a substrate, a sealed body provided on the substrate via bumps, and a cured layer that seals the sealed body, A structure comprising a substrate and a sealed body provided on the substrate via bumps, <1> ~ <7> A step of laminating the resin sheet described in any one of the items such that the resin composition layer seals the object to be sealed, and A process of curing a resin composition layer to form a cured layer. A method for manufacturing a sealing structure, including [the specified element]. [Effects of the Invention]

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

[0010] [Figure 1] Figure 1 is a schematic cross-sectional view illustrating step (I) of a method for manufacturing a sealing structure according to one embodiment of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view illustrating step (II) of the manufacturing method of a sealing structure according to one embodiment of the present invention. [Figure 3] Figure 3 is a schematic cross-sectional view illustrating step (III) of the method for manufacturing a sealing structure according to one embodiment of the present invention. [Figure 4] Figure 4 is a schematic cross-sectional view illustrating step (IV) of the method for manufacturing a sealing structure according to one embodiment of the present invention. [Modes for carrying out 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 without departing from the scope of the claims and their equivalents.

[0012] [Overview of resin sheets] The resin sheet of the present invention is a resin sheet for sealing and molding in the manufacture of a sealing structure having a hollow structure. The resin sheet of the present invention comprises a support and a resin composition layer provided on the support, wherein the resin composition layer contains (A) epoxy resin, (B) curing agent, (C) thermally conductive inorganic filler, and (D) 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 sealing while maintaining a hollow structure using conventional resin sheets, variations in sealing moldability may occur when stored at room temperature prior to sealing molding, and it may not be possible to stably obtain sufficient sealing moldability while maintaining the hollow structure. The inventors have found that, with respect to the resin composition layer in the resin sheet, if the value of tanδ at 80°C of the resin composition layer satisfies a specific numerical range, sufficient sealing moldability can be stably obtained while maintaining the hollow structure, even when stored at room temperature prior to sealing molding. Furthermore, the inventors have found that by adjusting the composition of the resin composition layer, the value of tanδ at 80°C of the resin composition layer can be adjusted, and as a result, a resin sheet can be obtained that stably obtains sufficient sealing moldability while maintaining the hollow structure, even when stored at room temperature prior to sealing molding.

[0014] The following describes in detail each layer that makes up the resin sheet.

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

[0016] When using a film made of plastic material as a support, examples of plastic materials include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"); polycarbonate (hereinafter sometimes abbreviated as "PC"); acrylic polymers such as polymethyl methacrylate (hereinafter sometimes abbreviated as "PMMA"); cyclic polyolefins; triacetylcellulose (hereinafter sometimes abbreviated as "TAC"); polyether sulfide (hereinafter sometimes abbreviated as "PES"); polyether ketones; polyimides; and others. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0017] When using metal foil as a support, examples of metal foil include copper foil and aluminum foil. Among these, copper foil is preferred. As for copper foil, foil made of single-metal copper may be used, or foil made of an alloy of copper with another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

[0018] The support may be subjected to treatments such as matte finish, corona treatment, or antistatic treatment on the surface that bonds with the resin composition layer.

[0019] Furthermore, as the support, a support with a release layer may be used, which has a release layer on the surface that is bonded to the resin composition layer. Examples of release agents used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Examples of commercially available release agents include the alkyd resin-based release agents "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation. Examples of commercially available supports with a release layer include the PET films having a release layer mainly 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 Corporation; and "Unipeel" manufactured by Unitika Corporation.

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

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

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

[0023] In this specification, "non-volatile components" with respect to the resin composition layer refer to the components constituting the resin composition layer excluding the organic solvent (G) described later. Also, in this specification, "resin components" with respect to the resin composition layer refer to the components constituting the resin composition layer excluding the thermally conductive inorganic filler (C) described later.

[0024] <(A) Epoxy resin> The resin composition layer contains epoxy resin as 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, and examples include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins. Biphenyl-type epoxy resins refer to epoxy resins having a biphenyl structure, where the biphenyl structure may have substituents such as alkyl groups, alkoxy groups, or aryl groups. Therefore, bixylenol-type epoxy resins and biphenylaralkyl-type epoxy resins are also included in biphenyl-type epoxy resins. Epoxy resins may be used individually or in combination of two or more types.

[0026] The epoxy resin preferably has two or more epoxy groups in one molecule. When the non-volatile components of the epoxy resin are considered to be 100% by mass, the proportion of 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 liquid epoxy resins at 20°C (hereinafter referred to as "liquid epoxy resins") and solid epoxy resins at 20°C (hereinafter referred to as "solid epoxy resins").

[0028] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

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

[0030] Specific examples of liquid epoxy resins include DIC's "HP-4032," "HP-4032-D," and "HP-4032-SS" (naphthalene-type epoxy resin); Mitsubishi Chemical's "828US," "jER828EL," "825," and "Epicote 828EL" (bisphenol A-type epoxy resin); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F-type epoxy resin); Mitsubishi Chemical's "jER152" (phenol novolac-type epoxy resin); and Mitsubishi Chemical's "630" and "630LSD" (glycidylamine-type epoxy resin). Examples include: epoxy resins; "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Co., Ltd.; "Celoxide 2021P" (alicyclic epoxy resin with an ester skeleton) manufactured by Daicel Corporation; "PB-3600" (epoxy resin with a butadiene structure) manufactured by Daicel Corporation; 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 per molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups per molecule is more preferred.

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

[0033] The resin composition layer may contain only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. When a combination of a liquid epoxy resin and a solid epoxy resin is used, their mass ratio (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 the 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 by gel permeation chromatography (GPC).

[0036] From the viewpoint of significantly obtaining 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, and 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, when the nonvolatile components in components (A) to (D) are taken as 100% by mass.

[0037] If the resin composition layer contains components other than components (A) to (D), the content of component (A) in the resin composition layer is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, even more preferably 3.0% by mass or more or 3.3% by mass or more, and preferably 10.0% by mass or less, more preferably 8.0% by mass or less, even more preferably 7.5% by mass or less, 7.3% by mass or less or 7.2% by mass or less, when the nonvolatile components in the resin composition layer are considered to be 100% by mass.

[0038] If the resin composition layer contains components other than components (A) to (D), the content of component (A) in the resin composition layer is preferably 25% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, 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, when the total resin components in the resin composition layer are considered to be 100% by mass.

[0039] <(B) Hardener> The resin composition layer contains a curing agent as component (B). The curing agent (B) excludes those that correspond to component (A). As the curing agent (B), compounds that have the function of curing the resin composition layer by reacting with component (A) can be used, such as phenolic curing agents, naphthol-based curing agents, activated ester-based curing agents, carbodiimide-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, etc. Among these, from the viewpoint of improving insulation reliability, it is preferable that the curing agent (B) contains one or more of the phenolic curing agents, naphthol-based curing agents, and activated ester-based curing agents, more preferably one or more of the phenolic curing agents and activated ester-based curing agents, and even more preferably a phenolic curing agent. The curing agent may be used alone or in combination of two or more types.

[0040] From the viewpoint of heat resistance and water resistance, phenolic curing agents having a novolac structure or naphthol curing agents having a novolac structure are preferred as phenolic curing agents and naphthol curing agents having a novolac structure. Furthermore, nitrogen-containing phenolic curing agents are preferred as phenolic curing agents, and triazine skeleton-containing phenolic curing agents are more preferred.

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

[0042] While there are no particular restrictions on the active ester curing agent, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are generally preferred. The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. 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 / 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, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolac. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by the condensation of two phenol molecules with one dicyclopentadiene molecule.

[0043] Specifically, active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing an acetylated phenol novolac, and active ester compounds containing a benzoylated phenol novolac are preferred, with active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure being more preferred. "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), and 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), as well as phenol novolacs. Examples of active ester compounds containing acetylated compounds include "DC808" (manufactured by Mitsubishi Chemical Corporation), examples of active ester compounds containing benzoylated phenol novolacs include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), examples of active ester curing agents that are acetylated phenol novolacs include "DC808" (manufactured by Mitsubishi Chemical Corporation), examples of active ester curing agents that are benzoylated phenol novolacs include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), and examples of active ester compounds containing a styryl group include "PC1300-02-65MA" (manufactured by Air Water Corporation).

[0045] Carbodiimide-based curing agents are compounds having one or more carbodiimide groups (-N=C=N-) in one molecule, and it is preferable that carbodiimide-based curing agents are compounds having two or more carbodiimide groups in one molecule.

[0046] Specific examples of carbodiimide-based curing agents include commercially available carbodiimide-based curing agents such as Carbodilite V-03 (carbodiimide group equivalent: 216), V-05 (carbodiimide group equivalent: 262), V-07 (carbodiimide group equivalent: 200), V-09 (carbodiimide group equivalent: 200) from Nisshinbo Chemical Co., Ltd., and Stavaxol P (carbodiimide group equivalent: 302) from Lanxess Co., Ltd.

[0047] Specific examples of benzoxazine-based curing agents include "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Chemicals 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-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl) thioether, and bis(4-cyanatephenyl) ether; polyfunctional cyanate resins derived from phenol novolacs and cresol novolacs; and prepolymers in which these cyanate resins are partially triazined. Specific examples of cyanate ester-based curing agents include "PT30" and "PT60" (phenol novolac type polyfunctional cyanate ester resins) manufactured by Lonza Corporation, "ULL-950S" (polyfunctional cyanate ester resin), "BA230", and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazined and trimerized).

[0049] The ratio of components (A) to (B) in the resin composition layer 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, as expressed in the ratio of [total number of epoxy groups in component (A)] to [total number of active groups in component (B)]. Here, "total number of epoxy groups in the epoxy resin" is 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. Similarly, "total number of active groups in component (B)" is the sum of all values ​​obtained by dividing the mass of the nonvolatile components of component (B) present in the resin composition layer by the active group equivalent. By setting the ratio of component (B) to component (A) within this range, the effects of the present invention can be significantly obtained.

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

[0051] If the resin composition layer contains components other than components (A) to (D), the content of component (B) in the resin composition layer is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, even more preferably 2.0% by mass or more, preferably 7.0% by mass or less, more preferably 5.0% by mass or less, even more preferably 4.5% by mass or less or 4.3% by mass or less, when the nonvolatile components in the resin composition layer are taken as 100% by mass, from the viewpoint of significantly obtaining the desired effects of the present invention.

[0052] If the resin composition layer contains components other than components (A) to (D), the content of component (B) in the resin composition layer is 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 preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, when the total amount of resin components in the resin composition layer is considered to be 100% by mass.

[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 layer with high thermal conductivity can be obtained. The thermally conductive inorganic filler may be included in the resin composition layer in granular form.

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

[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 materials for 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] The average particle size of the thermally conductive inorganic filler is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more, from the viewpoint of obtaining a cured product with excellent thermal conductivity and embedding properties. The average particle size of the thermally conductive inorganic filler can be measured by the laser diffraction-scattering method based on Mie scattering theory. Specifically, the particle size distribution of the thermally conductive inorganic filler can be created on a volume basis using a laser diffraction-scattering particle size distribution analyzer, and the average particle size can be measured by taking the median diameter as the average particle size. A sample can be used in which 100 mg of thermally conductive inorganic filler and 10 g of methyl ethyl ketone are weighed into a vial and dispersed using ultrasound for 10 minutes. The sample can be measured using a laser diffraction-type particle size distribution analyzer with blue and red light source wavelengths, using a flow cell method to measure the volume-based particle size distribution of the thermally conductive inorganic filler, and the average particle size can be calculated as the median diameter from the obtained particle size distribution. For laser diffraction scattering particle size distribution analyzers, models such as the "LA-500" and "LA-960" from Horiba, Ltd., and the "SALD2200" from Shimadzu Corporation can be used.

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

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

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

[0060] The degree of surface treatment by 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 / m². 2 The above is preferred, and 0.1 mg / m² 2 The above is more preferable, 0.2 mg / m² 2The above is even more preferable. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition layer and the melt viscosity in sheet form, 1.0 mg / m² 2 The following is preferred: 0.8 mg / m² 2 The following is more preferable: 0.5 mg / m² 2 The following are even more preferable.

[0061] The amount of carbon per unit surface area of ​​a thermally conductive inorganic filler can be measured after surface treatment by washing the thermally conductive inorganic filler with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK 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 solids, the amount of carbon per unit surface area of ​​the thermally conductive inorganic filler can be measured using a carbon analyzer. A carbon analyzer such as the "EMIA-320V" manufactured by Horiba, Ltd. can be used.

[0062] From the viewpoint of significantly obtaining 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, preferably 97% by mass or less, more preferably 96% by mass or less, and even more preferably 95% by mass or less, when the nonvolatile components in components (A) to (D) are taken as 100% by mass.

[0063] If the resin composition layer contains components other than components (A) to (D), the content of component (C) in the resin composition layer is 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, and 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, when the nonvolatile components in the resin composition layer are taken as 100% by mass.

[0064] If the resin composition layer contains components other than components (A) to (D), the content of 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 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, when the nonvolatile components in the resin composition layer are taken as 100% by volume.

[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 components (A) and (B) described above. Component (D) functions as a catalyst in the reaction between the epoxy resin (A) and the curing agent (B) to accelerate the curing of the resin composition layer. The phosphorus-based curing accelerator may be used alone or in combination of two or more types.

[0066] Examples of phosphorus-based curing accelerators include triphenylphosphine, tricyclohexylphosphine, tributylphosphine, methyldiphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, salts of tetra-n-butylphosphonium and N-acetylglycine, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate. 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., Ltd.

[0067] From the viewpoint of significantly obtaining 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, even more preferably 0.03% by mass or more, preferably 1.00% by mass or less, more preferably 0.50% by mass or less, even more preferably 0.30% by mass or less, or 0.20% by mass or less, when the nonvolatile components in components (A) to (D) are taken as 100% by mass.

[0068] If the resin composition layer contains components other than components (A) to (D), 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, even more preferably 0.03% by mass or more, preferably 1.00% by mass or less, more preferably 0.50% by mass or less, even more preferably 0.30% by mass or less, or 0.20% by mass or less, when the nonvolatile components in the resin composition layer are taken as 100% by mass.

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

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

[0071] Other curing accelerators include, for example, imidazole-based curing accelerators, amine-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators.

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

[0073] Commercially available imidazole-based curing accelerators 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" from Shikoku Chemicals Corporation; and "P200-H50" from Mitsubishi Chemical Corporation. These may be used individually or in combination of two or more.

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

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

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

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

[0078] When the resin composition layer contains component (D'), the content of component (D') in the resin composition layer is, 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, when the nonvolatile components in the resin composition layer are taken as 100% by mass. The upper limit of the content is not particularly limited, but 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 component (D'), the content of component (D') in the resin composition layer is, 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, when the total resin components in the resin composition layer are considered to be 100% by mass. The upper limit of this content is not particularly limited, but for example, it is 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 also contain, in addition to the components described above, an optional component (E) thermoplastic resin. This (E) thermoplastic resin does not include components (A) to (D) described above. The thermoplastic resin may be used alone or in combination of two or more types.

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

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

[0083] From the viewpoint of significantly obtaining the effects of the present invention, component (E) preferably has a functional group that can react with epoxy resin (A). Note that the functional group that can react with epoxy resin (A) includes functional groups that appear upon heating.

[0084] In one preferred embodiment, (A) the functional group that can react with the epoxy resin is one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl 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 hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a urethane group, more preferably a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, and an epoxy group, and particularly preferably a phenolic hydroxyl group. However, when the functional group includes 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, which may be contained in the main chain or in the side chains. The polybutadiene structure may be partially or entirely hydrogenated. A resin containing a polybutadiene structure is called a polybutadiene resin.

[0086] Specific examples of polybutadiene resins include Clay Valley's "Ricon 130MA8," "Ricon 130MA13," "Ricon 130MA20," "Ricon 131MA5," "Ricon 131MA10," "Ricon 131MA17," "Ricon 131MA20," and "Ricon 184MA6" (polybutadiene containing acid anhydride groups); Nippon Soda's "GQ-1000" (polybutadiene with hydroxyl and carboxyl groups), "G-1000," "G-2000," and "G-3000" (polybutadiene with hydroxyl groups at both ends), "GI-1000," "GI-2000," and "GI-3000" (hydrogenated polybutadiene with hydroxyl groups at both ends); and Nagase ChemteX's "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin). One embodiment includes a linear polyimide (as described in Japanese Patent Publication No. 2006-37083 and International Publication No. 2008 / 153208) made from hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride, and a phenolic hydroxyl-containing butadiene. The butadiene structure content of the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. Details of the polyimide resin can be found in Japanese Patent Publication No. 2006-37083 and International Publication No. 2008 / 153208, and this content is 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 included in the main chain or in the 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", "SG-280TEA" (carboxyl group-containing acrylic ester copolymer resin, acid value 5-34 mgKOH / g, weight-average molecular weight 400,000-900,000, Tg -30℃-5℃), "SG-80H", "SG-80H-3", "SG-P3" (epoxy group-containing acrylic ester copolymer resin, epoxy equivalent 4761-14285 g / eq, weight-average molecular weight 350,000). Examples include "SG-600TEA" and "SG-790" (hydroxyl 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), and "ME-2000" and "W-116.3" (carboxyl group-containing acrylic ester copolymer resin), "W-197C" (hydroxyl group-containing acrylic ester copolymer resin), "KG-25" and "KG-3000" (epoxy group-containing acrylic ester copolymer resin) from Negami Kogyo Co., Ltd.

[0089] Another embodiment of 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 Silicone Co., Ltd., as well as linear polyimides made from amine-terminated polysiloxanes and tetrabasic acid anhydrides (International Publication No. 2010 / 053185, Japanese Patent Publication No. 2002-12667 and Japanese Patent Publication No. 2000-319386, etc.).

[0091] Other embodiments of component (E) include resins containing a polyalkylene structure or a polyalkylene oxy structure. Resins containing a polyalkylene structure are called polyalkylene resins, and resins containing a polyalkylene oxy structure are called polyalkylene oxy resins. The polyalkylene oxy structure is preferably a polyalkylene oxy structure having 2 to 15 carbon atoms, more preferably a polyalkylene oxy structure having 3 to 10 carbon atoms, and even more preferably a polyalkylene oxy structure having 5 to 6 carbon atoms.

[0092] Specific examples of polyalkylene resins and polyalkylene oxy resins include "PTXG-1000" and "PTXG-1800" manufactured by Asahi Kasei Fibers Co., Ltd.

[0093] Another embodiment of component (E) is a resin containing a polyisoprene structure. A resin containing a polyisoprene structure is called a polyisoprene resin. 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. A resin containing a polyisobutylene structure is called a polyisobutylene resin. Specific examples of isobutylene resins include Kaneka Corporation's "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer).

[0095] Another embodiment of 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) from Asahi Kasei Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) from Kuraray Co., Ltd. Linear polyimides made from hydroxyl-terminated polycarbonates, diisocyanate compounds, and tetrabasic acid anhydrides can also be used. The content of the carbonate structure in the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. Details of the polyimide resin can be found in International Publication No. 2016 / 129541.

[0097] When the resin composition layer contains component (E-1), the content of component (E-1) in the resin composition layer is preferably 90% by mass or more, and more preferably 95% by mass or more, when the non-volatile component of component (E) is set to 100% by mass, from the viewpoint of significantly obtaining the desired effects of the present invention. In particular, it is even more preferable that component (E) contains only component (E-1).

[0098] When the resin composition layer contains component (E), the content of component (E) 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 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 nonvolatile components in the resin composition layer are taken as 100% by mass.

[0099] If the resin composition layer contains component (E), the content of component (E) 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, 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 total amount of resin components in the resin composition layer is taken as 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 dioxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentonite and montmorillonite; defoamers such as silicone-based defoamers, acrylic-based defoamers, fluorine-based defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion enhancers such as urea silane; adhesion ferrants such as triazole-based adhesion ferrants, tetrazole-based adhesion ferrants, and triazine-based adhesion ferrants; and hindered phenol-based antioxidants. Examples include antioxidants such as stilbene derivatives; fluorescent whitening agents such as stilbene derivatives; 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, 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 dispersants, polyoxyalkylene dispersants, acetylene dispersants, silicone dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic acid anhydride-based stabilizers; photopolymerization initiators such as tertiary amines; and photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones. (F) Other additives may be used individually or in combination of two or more types.

[0101] <(G) Organic Solvents> The resin composition layer may contain (G) an organic solvent as a volatile component. Examples of organic solvents 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. (G) The organic solvent may be used alone or in combination of two or more types.

[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 needed. Such other layers include, for example, a protective film provided on the side of the resin composition layer that is not bonded to the support (i.e., the side opposite to the support). The thickness of the protective film is not particularly limited, but for example, it is 1 μm to 40 μm. By laminating the protective film, the adhesion of dust and other debris and scratches to the surface of the resin composition layer can be suppressed.

[0104] [Method for manufacturing resin sheets] A resin sheet can be manufactured, for example, by preparing a resin varnish by dissolving the components contained in the resin composition layer in an organic solvent, applying this resin varnish onto a support using a die coater or the like, and then drying it to form a resin composition layer. The organic solvents mentioned above can be used.

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

[0106] Resin sheets can be stored by being rolled up. Resin sheets may not be used immediately after manufacturing. In such cases, it is preferable to store the resin sheets in a frozen and / or refrigerated state after manufacturing so as not to impair their properties. In particular, it is more preferable to store the resin sheets in a frozen state after manufacturing. The temperature conditions for storing resin sheets 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. There is no particular limit to such a lower temperature, and it can be, for example, -40°C or higher. When resin sheets are stored in a frozen or refrigerated state, they can be used after being thawed and temperature-controlled at room temperature (for example, 23°C), and the resin composition layer contained in the resin sheet reaches room temperature. Also, if the resin sheet has a protective film, it can be used after the protective film is peeled off.

[0107] [Characteristics and applications of resin sheets] The resin composition layer contained in the resin sheet contains a combination of components (A), (B), (C), and (D) (and, if necessary, components (D'), (E), (F), and (G)), making it possible for the tanδ of the resin composition layer at 80°C to satisfy a specific numerical range. Furthermore, by sealing a hollow structure using the resin sheet of the present invention, it is possible to stably provide sufficient sealing moldability while maintaining the hollow structure.

[0108] In the resin sheet of the present invention, the tanδ value of the resin composition layer at 80°C is 0.50 or more and 0.90 or less. When the tanδ value is within this range, even when the melt viscosity of the resin composition layer at 80°C is high, and even when the resin sheet is stored at room temperature prior to sealing molding, sufficient sealing moldability can be obtained while maintaining the hollow structure. From the viewpoint of significantly obtaining the desired effects of the present invention, the tanδ value is preferably is 0 The tanδ 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 Tanδ" of the Examples described later.

[0109] The resin sheet of the present invention can stably provide sufficient encapsulation moldability while maintaining a hollow structure, even when stored at room temperature prior to encapsulation molding. For example, a resin sheet or a resin sheet after 72 hours of standing is laminated onto an evaluation substrate in which a semiconductor chip is flip-chip connected to a glass substrate, such that the resin composition layer covers the semiconductor chip on the evaluation substrate. After lamination, the resin composition layer is heat-cured at 130°C for 30 minutes, followed by 200°C for 30 minutes, to obtain a cured 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 by the method described in the "Test Example 4: Measurement of Resin Penetration Amount" section of the examples described later.

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

[0111] In the resin sheet of the present invention, the resin composition layer may exhibit excellent stability in 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 (poise) The melt viscosity of the resin composition layer at 80°C after the resin sheet was left standing for 72 hours in an environment of 23°C and 40-45% humidity was defined as MV. 72h When (poise) is used, the ratio of these (MV) 72h / MV 0h The ratio of the melt viscosity (MV) may be between 1.00 and 1.50. 72h / MV 0h From the viewpoint of significantly obtaining the desired effects of the present invention, the value of ) 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. The melt viscosity of the resin composition layer at 80°C can be measured by the method described in the <Test Example 2: Measurement of Melt Viscosity and tanδ> section of the Examples described later. Furthermore, the melt viscosity of the resin composition layer at 80°C after the resin sheet has been left standing for 72 hours in an environment of 23°C and 40-45% humidity can be measured by the method described in the <Test Example 3: Measurement of Melt Viscosity and tanδ after 72 Hours of Standing> section of the Examples described later.

[0112] In the resin sheet of the present invention, the resin composition layer may exhibit excellent stability of tanδ. Therefore, in the resin composition layer contained in the resin sheet, the tanδ of the resin composition layer at 80°C is tanδ 0hThe tanδ of the resin composition layer at 80°C was obtained when the resin sheet was left standing for 72 hours in an environment with a temperature of 23°C and a humidity of 40-45%. 72h When this is the case, the ratio of these (tanδ 72h / tanδ 0h The ratio of tanδ (tanδ) can be between 1.00 and 1.50. 72h / tanδ 0h From the viewpoint of significantly obtaining the desired effects of the present invention, the tanδ of the resin composition layer at 80°C after the resin sheet has been left standing for 72 hours in an environment of 23°C and 40-45% humidity can be measured by the method described in the section "<Test Example 3: Measurement of melt viscosity and tanδ after standing for 72 hours>" of the examples described later.

[0113] In the present invention, a resin sheet in a frozen or refrigerated state is used to determine the melt viscosity (MV) of the resin composition layer. 0h ) and tanδ(tanδ 0h When measuring the melt viscosity (MV) of the resin composition layer, the resin sheet, which is in a frozen or refrigerated state, should be thawed and temperature-controlled by leaving it undisturbed in an environment with a temperature of 23°C and a humidity of 40-45%. The resin sheet should be subjected to measurement immediately after the temperature of the resin composition layer reaches 23°C (for example, if the time when the temperature reaches 23°C is defined as T0, then before 1 hour, within 45 minutes, within 30 minutes, or within 15 minutes from T0). Furthermore, in the resin sheet of the present invention, the melt viscosity (MV) of the resin composition layer when the resin sheet, which is in a frozen or refrigerated state, is left undisturbed for 72 hours in an environment with a temperature of 23°C and a humidity of 40-45% can be measured. 72h ) and tanδ(tanδ 72h When measuring the temperature of the resin composition layer, from the point T0 when the temperature of the resin composition layer reaches 23°C, the resin sheet should be left to stand for another 72 hours in an environment of 23°C and 40-45% humidity before being subjected to measurement.

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

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

[0116] Furthermore, the resin sheet of the present invention may have excellent thermal conductivity and excellent stability of melt viscosity. 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 (resin sheet for forming an insulating layer of a semiconductor chip package), a resin sheet for forming an insulating layer of a circuit board (including printed wiring boards) (resin sheet for forming an insulating layer of a circuit board), and even more suitably used as a resin sheet for forming an interlayer insulating layer on which a conductive layer is formed by plating (a circuit board on which a conductive layer is formed by plating, i.e., a resin sheet for forming an interlayer insulating layer of a circuit board in which circuits are formed by a semi-additive process method). In addition, the resin sheet of the present invention can be suitably used as a resin sheet for forming wiring on a semiconductor chip (resin sheet for forming wiring on a semiconductor chip).

[0117] [Sealing structure and method for manufacturing the same] The sealing structure of the present invention comprises a substrate, a sealed body provided on the substrate via bumps, and a cured layer that seals the sealed body. The cured layer includes a cured product of the resin composition layer of the resin sheet of the present invention, and preferably includes only the cured product of the resin composition layer. The sealing structure is preferably a sealing structure having a hollow structure between the substrate and the sealed body. Therefore, in a preferred embodiment, the sealing structure comprises a substrate, a sealed body provided on the substrate via bumps, a hollow structure between the substrate and the sealed body, and a cured layer that seals the sealed body. The sealing structure may have a plurality of sealed bodies. When the sealing structure has a plurality of sealed bodies, the plurality of sealed bodies may be of the same type or of different types.

[0118] The encapsulated structure may be, for example, an electronic component device. The electronic component device includes an electronic component as the encapsulated body. Examples of electronic components include semiconductor chips, semiconductor wafers, integrated circuits, semiconductor devices, filters such as SAW filters, and sensors. As the semiconductor chip, a semiconductor chip obtained by framing the semiconductor wafer may be used. The electronic component device may also be a semiconductor device comprising a semiconductor chip or semiconductor wafer as an electronic component, or a circuit board such as a printed wiring board. If the electronic component device has a hollow structure, the encapsulated body may be provided on a substrate via bumps, for example, so that the electronic component is on the surface facing the hollow structure. Examples of such encapsulated bodies include SAW devices such as SAW filters, sensors such as acceleration sensors, and other electronic components. If the encapsulated body is a SAW filter, the movable part is the surface of the piezoelectric substrate on which a pair of comb-shaped electrodes, called IDTs (Inter Digital Transducers), are attached.

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

[0120] The sealing structure is, for example, A step (I) of arranging a structure comprising a substrate and a sealed body provided on the substrate via bumps, and a resin sheet, such that the side of the structure facing the sealed body and the side of the resin sheet facing the resin composition layer. (II) A step of laminating a resin sheet onto the structure such that the resin composition layer seals the object to be sealed, and (III) A step of curing the resin composition layer to form a cured layer. It can be manufactured by a method including the above. Furthermore, if necessary, the method may include a step (IV) to separate the encapsulated structure into individual pieces after the completion of step (III).

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

[0122] In the structure 50, the encapsulated body 20 is provided on the substrate 30 via bumps 40. The number of encapsulated bodies 20 provided on the substrate 30 can be appropriately set according to the shape and size of the encapsulated body 20, the number of encapsulated structures to be produced, etc. For example, multiple encapsulated bodies 20 may be provided on the substrate 30 via bumps 40. The number of bumps 40 between the substrate 30 and the encapsulated body 30 can also be appropriately set according to the shape and size of the encapsulated body 20, the number of encapsulated structures to be produced, etc.

[0123] If the structure 50 has a hollow structure 60, the sealed body 20 may be a SAW device. If the sealed body 20 is a SAW device, the sealed body 20 may have electrodes 70 on the hollow structure side surface 20A. In this case, the electrodes 70 may be movable parts. The number of electrodes 70 on the sealed body 20 can be appropriately set according to the shape, size, and production number of the target sealed structure of the sealed body 20; the shape and size of the electrodes 70; etc.

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

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

[0126] Figure 3 is a schematic cross-sectional view illustrating step (III) of a method for manufacturing a sealing structure according to one embodiment of the present invention. In step (III), a cured layer 10c is formed by curing the resin composition layer 10b in which the object to be sealed 20 is sealed. This allows the sealing 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 included in the resin sheet 10 may be peeled off before laminating the resin sheet 10, after laminating the resin sheet 10, or after curing the resin composition layer 10b.

[0128] Figure 4 is a schematic cross-sectional view illustrating step (IV) of a method for manufacturing a sealing structure according to one embodiment of the present invention. The method for manufacturing a sealing structure of the present invention may optionally include step (IV) of separating the sealing structure into individual pieces. By step (IV), a plurality of sealing structures 200 can be obtained from the sealing structure 100. Step (IV) may be carried out 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 apparatus, or by press molding using a press machine. For example, a structure comprising a substrate and a body to be sealed provided on the substrate via bumps, and a resin sheet are arranged such that the surface of the structure on the body to be sealed and the surface of the resin sheet on the resin composition layer side are in contact, and then subjected to compression molding or press molding, thereby the resin composition layer can seal the body to be sealed. The support contained in the resin sheet may be peeled off before or after compression molding or press molding. The temperature when sealing the body to be sealed by compression molding or press molding may be the same as the heat bonding temperature in the vacuum lamination method. [Examples]

[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 "%" refer to "parts by mass" and "mass%" respectively, unless otherwise specified. Unless otherwise specified, the temperature and pressure conditions were room temperature (23°C) and atmospheric pressure (1 atm).

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

[0132] Next, 23 g of cresol novolac 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 temperature was raised to 150°C while stirring, and the reaction was carried out for approximately 10 hours. FT-IR measurements were taken at 2250 cm⁻¹. -1 The disappearance of the NCO peak was confirmed. The reaction endpoint was considered to be confirmed by the disappearance of the NCO peak, and the reactants were cooled to room temperature. The reactants were then filtered through a 100-mesh filter cloth to obtain elastomer A (phenolic hydroxyl group-containing butadiene resin: 50% by mass of nonvolatile components) having a polybutadiene structure and phenolic hydroxyl groups. The number-average molecular weight of elastomer A was 5,900, and the glass transition temperature was -7°C.

[0133] <Examples 1-9 and Comparative Examples 1-4: Manufacturing of Resin Sheets> [Example 1] Two parts of biphenyl-type epoxy resin (NC3000L, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent approximately 272 g / eq.) and four parts of bisphenol-type epoxy resin (ZX1059, manufactured by Nippon Steel Chemical & Material Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent 169 g / eq.) were heated and dissolved in a mixed solvent of six parts solvent naphtha and two parts cyclohexanone while stirring. This mixture was then cooled to room temperature to prepare the epoxy resin solution. This epoxy resin dissolution composition contains 13.0 parts of acrylic ester polymer (SG-P3 manufactured by Nagase ChemteX, an epoxy group-containing acrylic ester copolymer resin, a MEK solution with 15% non-volatile components, weight-average molecular weight 350,000-850,000, glass transition temperature 11-12°C, epoxy equivalent 4761-14285 g / eq.), and phenol novolac resin (TD-2090-60M manufactured by DIC, a MEK solution with 60% by mass of non-volatile components, phenolic hydroxyl group equivalent 1 6.0 parts of 0.5g / eq.) carbon black pigment (Mikuni Shikkei Co., Ltd., "MHI Black #RK-799M", MEK solution with 20% by mass of non-volatile components) 0.5 parts, curing accelerator (Hokko 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 amine-based alkoxysilane compound (Shin-Etsu Chemical Co., Ltd., "KBM573"), average particle size 2.6μm, specific surface area 1.4m²) 2 120.0 parts ( / g) were mixed and uniformly dispersed in a high-speed rotary mixer to produce a resin varnish.

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

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

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

[0137] [Example 4] In Example 1, the amount of 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 and a resin sheet 4 was manufactured in the same manner as in Example 1.

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

[0139] [Example 6] In Example 1, 1) Change the amount of inorganic filler A 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 matters mentioned above, a resin varnish was obtained and a resin sheet 6 was manufactured in the same manner as in Example 1.

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

[0141] [Example 8] In Example 1, 1.0 part of the curing accelerator (TBP-DA, manufactured by Hokko Chemical Industry Co., Ltd.) was replaced with 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, in a MEK solution containing 10% by mass of non-volatile components). Except for the above, a resin varnish was obtained and a resin sheet 8 was manufactured in the same manner as in Example 1.

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

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

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

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

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

[0147] The resin sheets produced in the examples and comparative examples were stored in a frozen state (temperature -20°C) after production. Furthermore, for the measurement of each physical property of the resin sheets, the frozen resin sheets were thawed and temperature-controlled by being left undisturbed in an environment of 23°C and 40-45% humidity. Within 30 minutes from the point (T0) when the temperature of the resin composition layer reached 23°C, the resin sheets were subjected to the measurement of each physical property.

[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 subjected to a pre-curing process for 30 minutes after being placed in an oven at 130°C, and then transferred to an oven at 200°C for a post-curing process for 30 minutes to heat-cur the resin composition layer and obtain cured samples.

[0149] (2) Measurement of thermal diffusivity α Regarding the cured sample, the thermal diffusivity α(m) in the thickness direction of the cured sample is 2The temperature ( / s) was measured using the thermal wave analysis method with the "ai-Phase Mobile 1u" manufactured by ai-Phase Inc. Three measurements were performed on the same sample, and the average value was calculated.

[0150] (3) Measurement of specific heat capacity Cp For the cured sample, the specific heat capacity Cp (J / kg·K) of the cured sample at 25°C was calculated by heating it from -40°C to 80°C at a rate of 10°C / min using a differential scanning calorimeter (DSC7020, manufactured by SII Nanotechnology).

[0151] (4) Measurement of density ρ Density ρ (kg / m³) of the cured sample 3 The specific gravity 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) obtained in (2) to (4) above 2 ρ(kg / m³), specific heat capacity Cp(J / kg·K), and density ρ(kg / m³). 3 The thermal conductivity λ (W / m·K) of the cured material was calculated by substituting ) into the following formula (M1). λ = α × Cp × ρ (M1)

[0153] <Test Example 2: Measurement of Melt Viscosity and Tanδ> From the resin sheets obtained in the examples and comparative examples, only the resin composition layer was peeled off and compressed in a mold to obtain measuring pellets (18 mm in diameter, 2.0-2.1 g).

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

[0155] <Test Example 3: Measurement of Melt Viscosity and tanδ After 72 Hours of Standing> In an environment with a temperature of 23°C and a humidity of 40 to 45%, the resin sheets obtained in Examples and Comparative Examples were allowed to stand for 72 hours from time point T0 when the temperature of the resin composition layer reached 23°C. Only the resin composition layer was peeled from the resin sheet after standing, and compressed with a mold to obtain measurement pellets (diameter 18 mm, 2.0 to 2.1 g). 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 Melt Viscosity and tanδ>. After measuring the dynamic viscoelastic modulus, a graph with temperature on the horizontal axis and melt viscosity and tanδ on the vertical axis was prepared, and the melt viscosity at 80°C (MV 72h ) and tanδ (tanδ 72h ) was calculated.

[0156] <Evaluation of Melt Viscosity Stability> From the values of MV 0h and MV 72h obtained in the above measurement, the stability of melt viscosity was evaluated according to the following criteria. [Evaluation Criteria for Melt Viscosity Stability] ○: 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 tanδ Stability> From 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 tanδ Stability] ○: 1.00≦tanδ 72h / tanδ 0hThe relationship ≤ 1.50 is satisfied. ×: tanδ 72h / tanδ 0h <1.00, or tanδ 72h / tanδ 0h The result is >1.50.

[0158] <Test Example 4: Measurement of Resin Penetration Amount> (1) Manufacturing of evaluation boards An evaluation substrate was manufactured in which semiconductor chips (960 μm long, 1350 μm wide, 200 μm thick) were flip-chip connected on a glass substrate (38 mm square, 1 mm thick). Twelve semiconductor chips were connected to the glass substrate in a 4x3 arrangement, with a chip-to-chip distance of 400 μm and a gap of 30 μm between the glass substrate and the semiconductor chips, using gold bumps (60 μm diameter, 240 μm pitch).

[0159] (2) Lamination of resin sheets (manufacturing of substrate A1) Using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., 2-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 on the evaluation substrate, thereby obtaining substrate A1. This lamination was performed by reducing the pressure to 13 hPa or less by depressurizing for 30 seconds, and then applying pressure at a temperature of 80°C and a pressure of 0.10 to 0.74 MPa for 30 seconds.

[0160] (3) Lamination of resin sheets after standing for 72 hours (manufacturing of substrate A2) Under conditions of 23°C and 40-45% humidity, the resin sheets obtained in the examples and comparative examples were left to stand for 72 hours. Except for changing the resin sheet to be laminated to the resin sheet that had been left to stand for 72 hours, the same procedure as in "(2) Lamination of resin sheets (manufacturing of substrate A1)" was performed to obtain substrate A2.

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

[0162] Furthermore, the resin composition layer of substrate A2 was also heat-cured under the same heat-curing conditions as described above to obtain evaluation substrate B2.

[0163] (5) Measurement of resin penetration On evaluation substrates B1 and B2, the amount of resin penetration into the hollow space between the semiconductor chip and the glass substrate was measured by observing evaluation substrates B1 and B2 from the glass substrate side using a digital microscope (Keyence "VHX-7000"). The amount of resin penetration was defined as the maximum distance the resin reached from the edge of the semiconductor chip into the hollow space. The measured amount of resin penetration was evaluated according to the following criteria. In the following evaluation criteria, "amount of resin penetration < 0 μm" means that the space between adjacent semiconductor chips is not filled with resin. [Evaluation criteria for resin penetration] ○: 0μm ≤ resin penetration ≤ 50μm △: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] [Explanation of Symbols]

[0167] 10 Resin Sheets 10a Resin composition layer 10b Support 10c Cured material layer 10A The side of the resin composition layer of the resin sheet 20 Encapsulated object 30 circuit boards 40 Bump 50 structures 50A The side of the structure that is to be sealed 60 Hollow structure 70 electrodes 100 Sealing structure 200 Multiple Encapsulation Structures

Claims

1. In the manufacture of a sealing structure having a hollow structure, a resin sheet for sealing and molding, The resin sheet comprises a support and a resin composition layer provided on the support. The resin composition layer comprises (A) epoxy resin, (B) curing agent, (C) thermally conductive inorganic filler, and (D) 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 tanδ of the resin composition layer at 80°C is tanδ ０ｈ The tanδ of the resin composition layer at 80°C was obtained when the resin sheet was left standing for 72 hours in an environment with a temperature of 23°C and a humidity of 40-45%. ７２ｈ In that case, 1.00≦tanδ ７２ｈ / tanδ ０ｈ ≦1.50 A resin sheet according to claim 1 that satisfies the relationship.

3. The melt viscosity of the resin composition layer at 80°C is MV ０ｈ (Poise) is used, and the melt viscosity of the resin composition layer at 80°C after the resin sheet has been left standing for 72 hours in an environment of 23°C and 40-45% humidity is MV. ７２ｈ When (poise) is used, 1.00≦MV ７２ｈ / MV ０ｈ ≦1.50 A resin sheet according to claim 1 that satisfies the relationship.

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

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 component (E) comprises (E-1) a thermoplastic resin having a glass transition temperature of 25°C or less.

7. The resin sheet according to claim 1, for sealing an object to be sealed, which is provided on a substrate via bumps.

8. The resin sheet according to claim 1, wherein, when the nonvolatile components in the resin composition layer are considered to be 100% by mass, the content of component (C) is 80% by mass or more.

9. The resin sheet according to claim 1, wherein, when the nonvolatile components in the resin composition are considered to be 100% by volume, the content of component (C) is 65% by volume or more.

10. A sealing structure comprising a substrate, a sealed body provided on the substrate via bumps, and a cured material layer that seals the sealed body, The cured layer comprises a cured resin composition layer of the resin sheet described in any one of claims 1 to 9. A sealing structure having a hollow structure between the substrate and the object to be sealed.

11. The sealing structure according to claim 10, wherein the sealed body includes an electrode disposed on the hollow structure side.

12. A method for manufacturing a sealing structure comprising a substrate, a sealed body provided on the substrate via bumps, and a cured layer that seals the sealed body, A step of laminating a resin sheet according to any one of claims 1 to 9 onto a structure comprising a substrate and a sealed body provided on the substrate via bumps, such that the resin composition layer seals the sealed body, and A process of curing a resin composition layer to form a cured layer. A method for manufacturing a sealing structure, including [the specified element].

Images