Resin composition

Abstract

An object of the present invention is to provide a resin composition and the like that can produce a cured product having a low dielectric constant. A solution of the present invention is a resin composition containing bubbles.

Description

Technical Field

[0001] The present invention relates to a resin composition and further to a resin sheet, a printed wiring board, and a semiconductor device formed using the resin composition, as well as a method for producing the resin composition and the printed wiring board. Background Art

[0002] As a manufacturing technology for printed wiring boards, a manufacturing method based on a buildup method is known in which insulating layers and conductive layers are alternately stacked on an inner layer circuit board. The insulating layer is generally formed by curing a resin composition.

[0003] For example, Patent Document 1 describes a resin composition containing a liquid epoxy resin, a solid epoxy resin, an active ester curing agent, and an inorganic filler. Meanwhile, Patent Document 2 describes a technique using microbubbles.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-029494

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2016-056317. Summary of the Invention

[0008] Problems to be solved by the invention

[0009] Furthermore, in recent years, when manufacturing a multilayer printed wiring board, a lower dielectric constant is required for a cured product of a resin composition used to form an insulating layer.

[0010] The present invention aims to provide: a resin composition capable of producing a cured product having a low dielectric constant; a resin sheet obtained using the resin composition; a printed wiring board; a semiconductor device; a method for producing the resin composition; and a method for producing a printed wiring board.

[0011] Means for solving problems

[0012] The present inventors have conducted intensive studies to solve the aforementioned problems and, as a result, have found that the aforementioned problems can be solved by containing bubbles in a resin composition, thereby completing the present invention.

[0013] That is, the present invention includes the following contents;

[0014] [1] A resin composition containing bubbles;

[0015] [2] The resin composition according to [1], wherein the average particle size of the bubbles is 50 μm or less;

[0016] [3] The resin composition according to [1] or [2], wherein the bubbles are microbubbles;

[0017] [4] The resin composition according to any one of [1] to [3], comprising a liquid epoxy resin;

[0018] [5] The resin composition according to [4], wherein the content of the liquid epoxy resin is 1% by mass or more and 30% by mass or less, based on 100% by mass of the non-volatile component in the resin composition;

[0019] [6] The resin composition according to [4] or [5], wherein the viscosity of the liquid epoxy resin at 25°C is 300 mPa·s or more and 5000 mPa·s or less;

[0020] [7] The resin composition according to any one of [1] to [6], which contains an inorganic filler;

[0021] [8] The resin composition according to [7], wherein the content of the inorganic filler is 20% by mass or more when the non-volatile component in the resin composition is 100% by mass;

[0022] [9] The resin composition according to any one of [1] to [8], which is used to form an insulating layer;

[0023]

[10] The resin composition according to any one of [1] to [9], which is used to form an insulating layer, wherein the insulating layer is an insulating layer for forming a conductor layer;

[0024]

[11] A resin sheet comprising a support and a resin composition layer comprising the resin composition described in any one of [1] to

[10] and provided on the support;

[0025]

[12] A printed wiring board comprising an insulating layer formed from a cured product of the resin composition described in any one of [1] to

[10] .

[0026]

[13] A semiconductor device comprising the printed wiring board described in

[12] ;

[0027]

[14] A method for producing a resin composition, comprising: (a) dispersing bubbles in a resin component;

[0028] The viscosity of the resin component at 25° C. is greater than or equal to 300 mPa·s and less than or equal to 5000 mPa·s;

[0029]

[15] The method for producing a resin composition according to

[14] , wherein the resin component comprises a liquid epoxy resin;

[0030]

[16] The method for producing a resin composition according to

[14] or

[15] , wherein the bubble ratio (bubble ratio) of bubbles in the resin component is 30% by volume or more and 90% by volume or less;

[0031]

[17] A method for manufacturing a printed wiring board, the method comprising:

[0032] (I) forming a resin composition layer comprising the resin composition described in any one of [1] to

[10] on an inner layer substrate, and (II) thermally curing the resin composition layer to form an insulating layer.

[0033] Effects of the Invention

[0034] The present invention provides: a resin composition capable of producing a cured product having a low dielectric constant; a resin sheet obtained using the resin composition; a printed wiring board; a semiconductor device; a method for producing a resin composition; and a method for producing a printed wiring board. DETAILED DESCRIPTION

[0035] Hereinafter, the resin composition of the present invention, the resin sheet obtained using the resin composition, the printed wiring board, the semiconductor device, the method for producing the resin composition, and the method for producing the printed wiring board will be described in detail.

[0036] [Resin composition]

[0037] The resin composition of the present invention contains bubbles. By making the resin composition contain bubbles, a cured product with a low dielectric constant can be obtained. In addition, in the present invention, usually, a cured product with excellent insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient (CTE), and bubbles existing for a long time (process suitability (process correctness) is excellent) can be obtained. Usually, it is said that if there are bubbles (voids) in the resin composition, the electrical properties of the cured product of the resin composition are adversely affected. Therefore, it is believed that it is preferred not to contain bubbles in the resin composition. However, in the present invention, by making the resin composition contain bubbles, a cured product with a low dielectric constant can be obtained. In addition, by regulating the average particle size of the bubbles, a cured product with excellent insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient can also be obtained. As far as the inventors know, it can be said that in the past, no technical idea of ​​daring to contain bubbles in the resin composition as described above has been proposed.

[0038] As the average particle size of bubbles, from the viewpoint of obtaining a cured product having excellent dielectric constant, insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient, it is preferably less than 60 μm, more preferably less than 50 μm, further preferably less than 45 μm, less than 40 μm, less than 30 μm, less than 20 μm, less than 10 μm or less than 5 μm. In addition, for the lower limit, from the viewpoint of significantly obtaining the effect of the present invention, it is preferably more than 0.01 μm, more preferably more than 0.1 μm, more preferably more than 0.5 μm, more than 1 μm. The average particle size of bubbles can be measured according to the method described in the embodiments described later. In addition, bubbles with the average particle size of the aforementioned range are not easy to assemble, condense in the resin composition, and are difficult to discharge from the resin composition. Therefore, because the bubbles are stable, it is possible to easily manufacture a cured product having excellent dielectric constant, insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient. In addition, the smaller the average particle size of bubbles, the more significantly the effect of the present invention can be obtained.

[0039] The standard deviation of the average particle size of the bubbles is preferably 25 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less from the viewpoint of significantly achieving the effects of the present invention. The lower limit is not particularly limited, but is usually 0.1 μm or more.

[0040] As bubble, as long as it is the bubble that can obtain the low solidified material of dielectric constant, for example microbubble, nano bubble (nanobubble), ultrafine bubble (ultrafine bubble) etc. can be enumerated. In addition, when using these bubbles, insulation reliability, mechanical strength, glass transition temperature (Tg) and linear thermal expansion coefficient can be made good usually. In this manual, so-called microbubble refers to the fine bubble with a diameter of more than 1 μm and less than 60 μm. The smaller the average particle size of the microbubble, the more significantly the effect of the present invention can be obtained.

[0041] The gas component constituting the bubbles can be any gas component that produces a cured product with a low dielectric constant. Examples include air; rare gases such as helium, neon, and argon; oxygen; nitrogen; and carbon dioxide. Air is preferred from the perspective of significantly achieving the effects of the present invention. Furthermore, when the gas components constituting the bubbles are the aforementioned gas components, insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient are generally improved.

[0042] Regarding the content of bubbles in the resin composition, from the perspective of obtaining a cured product having excellent dielectric constant, insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient, when the non-volatile component in the resin composition is set to 100% by volume, it is preferably 1% by volume or more, more preferably 3% by volume or more, further preferably 5% by volume or more, 8% by volume or more, 10% by volume or more, 30% by volume or more, 50% by volume or more, preferably 95% by volume or less, more preferably 90% by volume or less, and particularly preferably 85% by volume or less. Assuming that the mass of the bubbles themselves is light to a negligible degree, the content of bubbles can be calculated from the specific gravity of the resin composition before and after the inclusion of bubbles.

[0043] The content of bubbles (bubble content) contained in the cured product of the resin composition is preferably 3% by volume or more, more preferably 5% by volume or more, and further preferably 10% by volume or more. The upper limit is not particularly limited and may be 50% by volume or less. The bubble content of the cured product of the resin composition can be measured by the method described in the examples described below.

[0044] For resin composition, it is preferred that its cured product has sufficient hardness and insulation. Therefore, as resin composition, it is preferred that, in addition to comprising bubbles, for example, it also comprises a curable resin. As curable resin, the existing known curable resin that can be used when forming the insulating layer of a printed wiring board can be used, wherein, epoxy resin, curing agent are preferred. Therefore, in one embodiment, the resin composition preferably includes (A) epoxy resin, (B) curing agent. In addition, the resin composition may further include (C) inorganic filler, (D) curing accelerator, (E) thermoplastic resin, (F) free radical polymerizable resin, (G) polymerization initiator, (H) flame retardant and (I) other additives. Below, each component that may be included in the resin composition is described in detail.

[0045] <(A) Epoxy resin>

[0046] The resin composition may contain an epoxy resin (A) as the component (A). Examples of the component (A) include bixylenol epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, bisphenol AF epoxy resins, dicyclopentadiene epoxy resins, trisphenol epoxy resins, naphthol novolac epoxy resins, phenol novolac epoxy resins, tert-butyl-catechol epoxy resins, naphthalene epoxy resins, naphthol epoxy resins, anthracene epoxy resins, glycidylamine epoxy resins, glycidyl ester epoxy resins, cresol novolac epoxy resins, and the like. 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, tetraphenylethane-type epoxy resins, etc. Component (A) may be used alone or in combination of two or more.

[0047] The resin composition preferably contains an epoxy resin having two or more epoxy groups per molecule as component (A). From the perspective of significantly achieving the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the non-volatile components of component (A) is preferably 20% by mass or more, more preferably 30% by mass or more, and particularly preferably 40% by mass or more.

[0048] Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition 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 as component (A). However, from the viewpoint of significantly achieving the desired effects of the present invention, a combination of a liquid epoxy resin and a solid epoxy resin is preferred.

[0049] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0050] As liquid epoxy resins, preferred are bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol AF epoxy resins, naphthalene epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, phenol novolac epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane epoxy resins, cyclohexanedimethanol epoxy resins, glycidyl amine epoxy resins, and epoxy resins having a butadiene structure, and naphthalene epoxy resins are more preferred.

[0051] Specific examples of liquid epoxy resins include: "HP4032", "HP4032D", and "HP4032SS" manufactured by DIC Corporation (naphthalene-type epoxy resins); "828US", "jER828EL", "825", and "EPIKOTE828EL" manufactured by Mitsubishi Chemical Corporation (bisphenol A-type epoxy resins); "jER807" and "1750" manufactured by Mitsubishi Chemical Corporation (bisphenol F-type epoxy resins); "jER152" manufactured by Mitsubishi Chemical Corporation (phenol novolac-type epoxy resin); "630" and "630LSD" manufactured by Mitsubishi Chemical Corporation (glycidylamine-type epoxy resins); "ZX1059" manufactured by NIPPON STEEL Chemical & Material Co., Ltd. (a mixture of bisphenol A-type epoxy resin and bisphenol F-type epoxy resin); Nagase Examples include ChemteX's "EX-721" (glycidyl ester epoxy resin); Daicel's "Celloxide 2021P" (alicyclic epoxy resin with an ester skeleton); Daicel's "PB-3600" (epoxy resin with a butadiene structure); and Nippon Steel Chemicals' "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane epoxy resins). These can be used alone or in combination.

[0052] The viscosity of the liquid epoxy resin at 25°C is preferably 300 mPa·s or higher, more preferably 500 mPa·s or higher, and even more preferably 1000 mPa·s or higher, from the perspective of ensuring stable presence of bubbles in the resin composition. It is preferably 5000 mPa·s or lower, more preferably 4000 mPa·s or lower, and even more preferably 3000 mPa·s or lower. The viscosity of the liquid epoxy resin can be measured using, for example, an E-type viscometer.

[0053] The solid epoxy resin is preferably a solid epoxy resin having three or more epoxy groups in one molecule, and more preferably an aromatic solid epoxy resin having three or more epoxy groups in one molecule.

[0054] As solid epoxy resins, preferred are biphenylol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, and tetraphenylethane-type epoxy resins, and more preferred are naphthol-type epoxy resins.

[0055] Specific examples of solid epoxy resins include: "HP4032H" manufactured by DIC Corporation (naphthalene-type epoxy resin); "HP-4700" and "HP-4710" manufactured by DIC Corporation (naphthalene-type tetrafunctional epoxy resin); "N-690" manufactured by DIC Corporation (cresol novolac-type epoxy resin); "N-695" manufactured by DIC Corporation (cresol novolac-type epoxy resin); "HP-7200", "HP-7200HH", "HP-7200" manufactured by DIC Corporation; 0H" (dicyclopentadiene type epoxy resin); "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin) manufactured by DIC Corporation; "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel Chemicals; "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel Chemicals; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical; "YX4000HK" (dimethylphenol type epoxy resin) manufactured by Mitsubishi Chemical Resin); "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "YL7760" (bisphenol AF-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (solid bisphenol A-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane-type epoxy resin) manufactured by Mitsubishi Chemical Corporation. These may be used alone or in combination of two or more.

[0056] When a liquid epoxy resin and a solid epoxy resin are used in combination as component (A), their amount ratio (liquid epoxy resin: solid epoxy resin) is preferably 1:1 to 1:20 by mass ratio, more preferably 1:1.5 to 1:15, and particularly preferably 1:2 to 1:10. By making the amount ratio of the liquid epoxy resin to the solid epoxy resin within the above range, the desired effect of the present invention can be significantly obtained. In addition, usually, when used in the form of a resin sheet, moderate adhesion can be achieved. In addition, usually, when used in the form of a resin sheet, sufficient flexibility can be obtained and handleability is improved. In addition, usually, a cured product with sufficient breaking strength can be obtained.

[0057] The epoxy equivalent of component (A) is preferably 50 g / eq. to 5000 g / eq., more preferably 50 g / eq. to 3000 g / eq., even more preferably 80 g / eq. to 2000 g / eq., and even more preferably 110 g / eq. to 1000 g / eq. By falling within this range, the crosslink density of the cured resin composition layer is sufficient, enabling the formation of an insulating layer with minimal surface roughness. The epoxy equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

[0058] From the viewpoint of significantly achieving the desired effects of the present invention, the weight average molecular weight (Mw) of component (A) is preferably 100 to 5000, more preferably 200 to 3000, and even more preferably 250 to 1500. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a value in terms of polystyrene.

[0059] From the viewpoint of obtaining the insulating layer showing good mechanical strength and insulation reliability, when the non-volatile component in resin combination is set to 100 mass %, the content of (A) component is preferably more than 1 mass %, more preferably more than 5 mass %, further preferably more than 10 mass %. For the upper limit of the content of epoxy resin, from the viewpoint of significantly obtaining the desired effect of the present invention, preferably below 25 mass %, more preferably below 20 mass %, particularly preferably below 15 mass %. It should be noted that, in the present invention, as long as not otherwise clearly stated, the content of each component in resin combination is the value when the non-volatile component in resin combination is set to 100 mass %.

[0060] From the viewpoint of significantly achieving the effects of the present invention, the content of the liquid epoxy resin, relative to 100% by mass of the non-volatile component in the resin composition, is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0061] (B) Curing agent

[0062] The resin composition may further contain a curing agent (B) as an optional component. Component (B) generally reacts with component (A) to cure the resin composition. Component (B) may be used alone or in combination of two or more in any ratio.

[0063] As the component (B), a compound that can react with the component (A) to cure the resin composition can be used, and examples thereof include active ester curing agents, phenol curing agents, benzoxazine curing agents, carbodiimide curing agents, acid anhydride curing agents, amine curing agents, and cyanate curing agents. Among these, from the viewpoint of significantly achieving the effects of the present invention, any of active ester curing agents, phenol curing agents, benzoxazine curing agents, and carbodiimide curing agents is preferred, and any of active ester curing agents, phenol curing agents, and carbodiimide curing agents is more preferred.

[0064] As active ester curing agent, curing agent with more than one active ester group in one molecule can be enumerated. Among them, as active ester curing agent, preferably phenolic ester, thiophenolic ester, N-hydroxylamine ester, ester of heterocyclic hydroxy compound etc. have the compound of ester group with more than two reactive activities in one molecule. This active ester curing agent is preferably obtained by the condensation reaction of carboxylic acid compound and / or thiocarboxylic acid compound and hydroxy compound and / or thiol compound. Especially considering from the viewpoint that heat resistance improves, preferably the active ester curing agent obtained by carboxylic acid compound and hydroxy compound, more preferably the active ester curing agent obtained by carboxylic acid compound and phenol (phenol) compound and / or naphthol compound.

[0065] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0066] Examples of the phenolic compound or naphthol compound 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, phloroglucinol, pyrogallol, dicyclopentadiene-type diphenolic compounds, and phenol novolac. Here, the term "dicyclopentadiene-type diphenolic compound" refers to a diphenolic compound obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

[0067] Preferred examples of active ester curing agents include active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing acetylated products of phenol novolac resins, and active ester compounds containing benzoylated products of phenol novolac resins. Among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are more preferred. The term "dicyclopentadiene-type diphenol structure" refers to a divalent structure composed of phenylene-dicyclopentylene-phenylene.

[0068] Examples of commercially available active ester curing agents include: "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", "HPC-8000H", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L", "EXB-8000L-65TM" (manufactured by DIC Corporation), which are active ester compounds containing a dicyclopentadiene-type diphenol structure; "HPC-8150-60T", "HPC-8150-62T", "EXB-8150-65T", "EXB-8100L-65T", "EXB-8100L-65TM" (manufactured by DIC Corporation), which are active ester compounds containing a naphthalene structure. B-8150L-65T", "EXB9416-70BK" (manufactured by DIC Corporation); "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated product of a linear phenolic resin; "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing a benzoylated product of a linear phenolic resin; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester curing agent for an acetylated product of a linear phenolic resin; "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester curing agents for a benzoylated product of a linear phenolic resin; and the like.

[0069] As phenolic curing agents, curing agents having one or more, preferably two or more, hydroxyl groups bonded to aromatic rings (benzene rings, naphthalene rings, etc.) in one molecule can be cited. Among them, compounds having hydroxyl groups bonded to benzene rings are preferred. In addition, from the viewpoint of heat resistance and water resistance, phenolic curing agents having a novolak structure are preferred. In addition, from the viewpoint of adhesion, nitrogen-containing phenolic curing agents are preferred, and phenolic curing agents containing a triazine skeleton are more preferred. In particular, from the viewpoint of highly satisfying heat resistance, water resistance and adhesion, novolak resin curing agents containing a triazine skeleton are preferred.

[0070] Specific examples of phenolic curing agents (phenolic curing agents) and naphthol curing agents include: "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Chemicals; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", and "SN-375" manufactured by Nippon Steel Chemicals Co., Ltd. ", "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" manufactured by DIC Corporation; "GDP-6115L", "GDP-6115H", "ELPC75" and so on manufactured by Qunrong Chemical Company.

[0071] Specific examples of the benzoxazine-based curing agent include “ODA-BOZ” manufactured by JFE Chemical Industries, Ltd., “HFB2006M” manufactured by Showa Highpolymer Co., Ltd., and “Pd” and “Fa” manufactured by Shikoku Chemicals Co., Ltd.

[0072] Specific examples of the carbodiimide-based curing agent include "V-03," "V-05," and "V-07" manufactured by Nisshinbo Chemical Co., Ltd.; and Stabaxol (registered trademark) P manufactured by Rhein Chemie.

[0073] Examples of the acid anhydride curing agent include curing agents having one or more acid anhydride groups in one molecule. Specific examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, and homobenzene. Polymer-type acid anhydrides such as tetracarboxylic anhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furyl)-naphtho[1,2-c]furan-1,3-dione, ethylene glycol bis(trimellitic anhydride), and styrene-maleic acid resin obtained by copolymerizing styrene and maleic acid can be used. Commercially available acid anhydride curing agents can be used, for example, "MH-700" manufactured by Shin Nippon Chemical Co., Ltd.

[0074] As the amine curing agent, there can be mentioned a curing agent having one or more amino groups in one molecule, for example, aliphatic amines, polyether amines, alicyclic amines, aromatic amines, etc. Among them, aromatic amines are preferred from the viewpoint of achieving the desired effect of the present invention. The amine curing agent is preferably a primary amine or a secondary amine, more preferably a primary amine. Specific examples of the amine curing agent include: 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, metaphenylenediamine, metaphenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino- 4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Commercially available amine curing agents can be used, and examples thereof include "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD AA", "KAYAHARD AB", and "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd., and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

[0075] Examples of cyanate curing agents include difunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenylcyanate), 4,4'-ethylenediphenyl 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-(methylethylene))benzene, bis(4-cyanatephenyl)sulfide, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac resins and cresol novolac resins; and prepolymers obtained by partially triazinizing these cyanate resins. Specific examples of cyanate curing agents include: "PT30" and "PT60" manufactured by Lonza Japan Co., Ltd. (both are phenol novolac-type multifunctional cyanate resins); "ULL-950S" (a multifunctional cyanate resin); "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazinized to form a trimer); and the like.

[0076] From the viewpoint of significantly achieving the effects of the present invention, the content of the (B) curing agent, relative to 100% by mass of the non-volatile component in the resin composition, is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0077] When the number of epoxy groups of component (A) is set to 1, the active radical number of the curing agent (B) is preferably more than 0.1, more preferably more than 0.3, further preferably more than 0.5, preferably less than 2, more preferably less than 1.8, further preferably less than 1.5. Here, the so-called "number of epoxy groups of component (A)" is the value obtained by adding up all the values ​​obtained by dividing the mass of the non-volatile components of component (A) present in the resin composition by the epoxy equivalent. In addition, the so-called "number of active radicals of the curing agent (B)" is the value obtained by adding up all the values ​​obtained by dividing the mass of the non-volatile components of the curing agent (B) present in the resin composition by the active group equivalent. By making the active radical number of the curing agent (B) when the number of epoxy groups of component (A) is set to 1 within the aforementioned range, the desired effect of the present invention can be significantly obtained.

[0078] <(C) Inorganic fillers>

[0079] For resin composition, as arbitrary component, (C) inorganic filling material can be further contained as (C) component.As the material of inorganic filling material, inorganic compound is used.As the example of the material of inorganic filling material, silicon dioxide, aluminum oxide, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate, calcium zirconate, zirconium phosphate and zirconium tungstic phosphotungstate etc. can be enumerated. Among these, silicon dioxide is particularly preferred.As silicon dioxide, for example, amorphous silicon dioxide, fused silica, crystalline silicon dioxide, synthetic silicon dioxide, hollow silica etc. can be enumerated. In addition, as silicon dioxide, spherical silicon dioxide is preferred. The component (C) may be used alone or in combination of two or more.

[0080] Commercially available products of component (C) include, for example, "UFP-30" manufactured by Denka; "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Corporation; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatechs; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama Co., Ltd.; "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs; and the like.

[0081] From the viewpoint of significantly achieving the desired effects of the present invention, the average particle size of component (C) is preferably 0.01 μm or more, more preferably 0.05 μm or more, particularly preferably 0.1 μm or more, preferably 5 μm or less, more preferably 2 μm or less, and further preferably 1 μm or less.

[0082] The average particle size of the (C) component can be measured using a laser diffraction-scattering method based on Mie scattering theory. Specifically, it can be measured in the following manner: using a laser diffraction scattering particle size distribution measuring device, the particle size distribution of the inorganic filler is made on a volume basis, and the median particle size is used as the average particle size. Regarding the determination sample, a sample obtained in the following manner can be used: 100 mg of inorganic filler and 10 g of methyl ethyl ketone are weighed into a vial and dispersed for 10 minutes using ultrasound. For the determination sample, a laser diffraction particle size distribution measuring device can be used, the wavelength of the light source is set to blue and red, and the particle size distribution of the volume basis of the (C) inorganic filler is measured in a flow cell manner, and the average particle size is calculated as the median particle size from the obtained particle size distribution. As a laser diffraction particle size distribution measuring device, for example, "LA-960" manufactured by Horiba, Ltd. can be cited.

[0083] From the viewpoint of significantly obtaining the desired effects of the present invention, the specific surface area of ​​the component (C) is preferably 1 m 2 / g or more, more preferably 2m 2 / g or more, particularly preferably 3m 2 There is no particular upper limit, but it is preferably 60 m 2 / g or less, 50m 2 / g or less or 40m 2 The specific surface area can be obtained by adsorbing nitrogen on the sample surface using a specific surface area measuring apparatus (Macsorb HM-1210 manufactured by Mountech) according to the BET method, and calculating the specific surface area by the BET multipoint method.

[0084] For component (C), from the viewpoint of improving moisture resistance and dispersibility, it is preferably treated with a surface treatment agent. As the surface treatment agent, for example, fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, etc. can be mentioned. In addition, the surface treatment agent can be used alone or in combination of two or more.

[0085] Examples of commercially available surface treatment agents include "KBM-403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-503" (3-methacryloyloxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBE-903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBE-903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Gakuin Kogyo Co., Ltd., "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-4803" (long-chain epoxy-type silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.

[0086] From the viewpoint of improving the dispersibility of the inorganic filler, it is preferred to control the degree of surface treatment based on the surface treatment agent within a specified range. Specifically, for 100 parts by mass of the inorganic filler, it is preferred that 0.2 to 5 parts by mass of the surface treatment agent be used for surface treatment, preferably 0.2 to 3 parts by mass, and preferably 0.3 to 2 parts by mass.

[0087] The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the perspective of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler is preferably 0.02 mg / m 2 More than 0.1 mg / m 2 More preferably, 0.2 mg / m 2 On the other hand, from the viewpoint of suppressing the increase in the melt viscosity of the resin varnish and the melt viscosity in the sheet form, it is preferably 1 mg / m 2 Below, more preferably 0.8 mg / m 2 Below, more preferably 0.5 mg / m 2 the following.

[0088] The amount of carbon per unit surface area of ​​the (C) component can be measured after washing the surface-treated inorganic filler with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent can be added to the inorganic filler surface-treated with a surface treatment agent, and ultrasonic washing is performed at 25°C for 5 minutes. The supernatant is removed, the solid component is dried, and then the amount of carbon per unit surface area of ​​the inorganic filler is measured using a carbon analyzer. As a carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd. can be used.

[0089] From the viewpoint of reducing the linear thermal expansion coefficient, when the non-volatile component in the resin composition is set to 100% by mass, the content of the component (C) is preferably 20% by mass or more, more preferably 30% by mass or more, further preferably 50% by mass or more and 70% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and further preferably 80% by mass or less.

[0090] <(D) Curing accelerator>

[0091] For the resin composition, as component (D), a curing accelerator (D) may be included. As the curing accelerator (D), for example, phosphorus curing accelerators, amine curing accelerators, imidazole curing accelerators, guanidine curing accelerators, and metal curing accelerators can be cited. Among them, phosphorus curing accelerators, amine curing accelerators, imidazole curing accelerators, and metal curing accelerators are preferred, and amine curing accelerators, imidazole curing accelerators, and metal curing accelerators are more preferred. One of the curing accelerators (D) can be used alone, or two or more can be used in combination.

[0092] Examples of the phosphorus-based curing accelerator include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate. Triphenylphosphine and tetrabutylphosphonium decanoate are preferred.

[0093] Examples of the amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. 4-Dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene are preferred.

[0094] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4- Imidazole compounds such as diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, and adducts of imidazole compounds with epoxy resins, preferably 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

[0095] As the imidazole-based curing accelerator, a commercially available item can be used, and examples thereof include "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0096] Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, and 1-(o-tolyl)biguanidine. Preferred examples include dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene.

[0097] As metal curing accelerators, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin can be mentioned. Specific examples of organometallic complexes include organocobalt complexes such as cobalt acetylacetonate (II) and cobalt acetylacetonate (III), organocopper complexes such as copper acetylacetonate (II), organozinc complexes such as zinc acetylacetonate (II), organoferric complexes such as iron acetylacetonate (III), organonickel complexes such as nickel acetylacetonate (II), and organomanganese complexes such as manganese acetylacetonate (II). As organometallic salts, for example, zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate can be mentioned.

[0098] From the viewpoint of significantly achieving the desired effects of the present invention, the content of component (D) is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, and is preferably 0.3% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less, based on 100% by mass of the non-volatile component in the resin composition.

[0099] <(E) Thermoplastic resin>

[0100] For the resin composition, as component (E), a (E) thermoplastic resin may be further included. Regarding the thermoplastic resin as component (E), for example, phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamide-imide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polycarbonate resin, polyetheretherketone resin, polyester resin, etc. can be mentioned. Among them, from the viewpoint of significantly obtaining the desired effect of the present invention, phenoxy resin is preferred. In addition, the (E) thermoplastic resin can be used alone or in combination of two or more.

[0101] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeletons, bisphenol F skeletons, bisphenol S skeletons, bisphenol acetophenone skeletons, novolac skeletons, biphenyl skeletons, fluorene skeletons, dicyclopentadiene skeletons, norbornene skeletons, naphthalene skeletons, anthracene skeletons, adamantane skeletons, terpene skeletons, and trimethylcyclohexane skeletons. The termini of the phenoxy resins may be any functional group such as a phenolic hydroxyl group or an epoxy group.

[0102] Specific examples of phenoxy resins include: "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (a phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (a phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel Chemicals; "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482" manufactured by Mitsubishi Chemical Corporation; and the like.

[0103] Examples of the polyvinyl acetal resin include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of the polyvinyl acetal resin include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP manufactured by Denki Kagaku Kogyo Co., Ltd.; and S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemical Co., Ltd.

[0104] Specific examples of polyimide resins include "RIKACOAT SN20" and "RIKACOAT PN20" manufactured by Shin Nippon Chemical Co., Ltd. Specific examples of polyimide resins include modified polyimides such as linear polyimides obtained by reacting bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (polyimides described in Japanese Patent Application Laid-Open No. 2006-37083 ), and polyimides containing a polysiloxane skeleton (polyimides described in Japanese Patent Application Laid-Open Nos. 2002-12667 and 2000-319386 ).

[0105] Specific examples of polyamide-imide resins include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polyamide-imides containing a polysiloxane skeleton) manufactured by Hitachi Chemical Co., Ltd.

[0106] Specific examples of the polyethersulfone resin include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. and the like.

[0107] Specific examples of the polysulfone resin include polysulfone "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0108] From the viewpoint of significantly achieving the desired effects of the present invention, the weight average molecular weight (Mw) of the thermoplastic resin (E) is preferably 8,000 or more, more preferably 10,000 or more, and particularly preferably 20,000 or more, and is preferably 70,000 or less, more preferably 60,000 or less, and particularly preferably 50,000 or less.

[0109] From the viewpoint of significantly achieving the desired effects of the present invention, the content of the thermoplastic resin (E) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, and is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of the non-volatile component in the resin composition.

[0110] <(F) Radically polymerizable resin>

[0111] The resin composition may contain a radically polymerizable resin (F) as the component (F). By including the radically polymerizable resin (F) in the resin composition, a cured product having excellent dielectric constant, insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient can be obtained.

[0112] As component (F), a resin having a free radical polymerizable unsaturated group can be used. The so-called free radical polymerizable group refers to a group having an olefinic double bond that shows curability by irradiation with active energy rays such as ultraviolet rays or heat. Examples of such groups include vinyl, vinylphenyl, acryloyl, methacryloyl, maleimide, fumaryl, and maleoyl, and preferably at least one selected from vinylphenyl, acryloyl, and methacryloyl. Here, acryloyl and methacryloyl are sometimes collectively referred to as "(meth)acryloyl". In addition, the so-called vinylphenyl is a group having the structure shown below;

[0113] [Chemical Formula 1]

[0114]

[0115] (* indicates a bond).

[0116] The component (F) preferably has two or more radically polymerizable unsaturated groups per molecule from the viewpoint of obtaining a cured product excellent in dielectric constant, insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient.

[0117] From the viewpoint of obtaining a cured product having excellent dielectric constant, insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient, (F) component preferably has a cyclic structure. As the cyclic structure, a preferred divalent cyclic group. As the divalent cyclic group, it can be any one of the cyclic groups comprising alicyclic structure and the cyclic groups comprising aromatic ring structure. In addition, a variety of divalent cyclic groups can be provided.

[0118] From the viewpoint of significantly obtaining the desired effect of the present invention, the divalent cyclic group is preferably a 3-membered ring or more, more preferably a 4-membered ring or more, further preferably a 5-membered ring or more, preferably a 20-membered ring or less, more preferably a 15-membered ring or less, further preferably a 10-membered ring or less. In addition, the divalent cyclic group may be a monocyclic structure or a polycyclic structure.

[0119] For the ring in the divalent cyclic group, in addition to carbon atoms, the ring skeleton may also be composed of heteroatoms. Examples of heteroatoms include oxygen atoms, sulfur atoms, nitrogen atoms, and the like, with oxygen atoms being preferred. The ring may have one heteroatom or two or more heteroatoms.

[0120] Specific examples of the divalent cyclic group include the following divalent groups (i) to (xiii);

[0121] [Chemical Formula 2]

[0122]

[0123] (In the divalent groups (xii) and (xiii), R 1 、R 2 、R 5 、R 6 、R 7 、R 11 , and R 12 Each independently represents a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, and R 3 、R 4 、R 8 、R 9 , and R 10 (each independently represents a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group).

[0124] Examples of the halogen atom include fluorine, chlorine, bromine, and iodine. Examples of the alkyl group having 6 or less carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl, preferably methyl. 1 、R 2 、R 5 、R 6 、R 7、R 11 and R 12 , preferably represents a methyl group. 3 、R 4 、R 8 、R 9 and R 10 Preferred is a hydrogen atom or a methyl group.

[0125] In addition, for the divalent cyclic group, a plurality of divalent cyclic groups may be combined. As a specific example of the case where the divalent cyclic groups are combined, a divalent cyclic group represented by the following formula (a) (divalent group (a)) can be cited;

[0126] [Chemical Formula 3]

[0127]

[0128] (In formula (a), R 21 、R 22 、R 25 、R 26 、R 27 、R 31 、R 32 、R 35 and R 36 Each independently represents a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, and R 23 、R 24 、R 28 、R 29 、R 30 、R 33 and R 34 Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. n and m represent integers of 0 to 300 (excluding the case where either n or m is 0).

[0129] R 21 、R 22 、R 35 and R 36 and R in the divalent group (xii) 1 Same. 23 、R 24 、R 33 and R 34 and R in the divalent group (xii) 3 Same. 25 、R 26 、R 27 、R 31 and R 32 and R in formula (xiii) 5 Same. 28 、R 29 and R30 and R in formula (xiii) 8 same.

[0130] n and m represent integers of 0 to 300. However, this does not include the case where one of n and m is 0. n and m are preferably integers of 1 to 100, more preferably integers of 1 to 50, and even more preferably integers of 1 to 10. n and m may be the same or different.

[0131] As the divalent cyclic group, the divalent group (x), the divalent group (xi), or the divalent group (a) is preferred, and the divalent group (x) or the divalent group (a) is more preferred.

[0132] The divalent cyclic group may have a substituent. Examples of such a substituent include a halogen atom, an alkyl group, an alkoxy group, an aryl group, an arylalkyl group, a silyl group, an acyl group, an acyloxy group, a carboxyl group, a sulfo group, a cyano group, a nitro group, a hydroxyl group, a mercapto group, and an oxo group (carbonyl group). An alkyl group is preferred.

[0133] The radical polymerizable unsaturated group can be directly bonded to the divalent cyclic group or bonded via a divalent linking group. Examples of the divalent linking group include alkylene, alkenylene, arylene, heteroarylene, -C(=O)O-, -O-, -NHC(=O)-, -NC(=O)N-, -NHC(=O)O-, -C(=O)-, -S-, -SO-, -NH-, etc., and groups formed by combining multiple of these groups are also possible. As the alkylene group, an alkylene group having 1 to 10 carbon atoms is preferred, an alkylene group having 1 to 6 carbon atoms is more preferred, an alkylene group having 1 to 5 carbon atoms is further preferred, or an alkylene group having 1 to 4 carbon atoms is further preferred. The alkylene group may be any of a straight chain, a branched chain, and a cyclic group. Examples of such alkylene groups include methylene, ethylene, propylene, butylene, pentylene, hexylene, and 1,1-dimethylethylene, with methylene, ethylene, and 1,1-dimethylethylene being preferred. Alkenylene groups are preferably alkenylene groups having 2 to 10 carbon atoms, more preferably alkenylene groups having 2 to 6 carbon atoms, and even more preferably alkenylene groups having 2 to 5 carbon atoms. Arylene and heteroarylene groups are preferably arylene or heteroarylene groups having 6 to 20 carbon atoms, more preferably arylene or heteroarylene groups having 6 to 10 carbon atoms. Alkylene groups are preferred as divalent linking groups, with methylene and 1,1-dimethylethylene being particularly preferred.

[0134] The component (F) is preferably represented by the following formula (1):

[0135] [Chemical Formula 4]

[0136]

[0137] (In formula (1), R 51 and R54 Each independently represents a radical polymerizable unsaturated group, R 52 and R 53 Each independently represents a divalent linking group. Ring B represents a divalent cyclic group).

[0138] R 51 and R 54 Each independently represents a radically polymerizable unsaturated group, preferably a vinylphenyl group or a (meth)acryloyl group.

[0139] R 52 and R 53 Each independently represents a divalent linking group. The divalent linking group is the same as the above-mentioned divalent linking group.

[0140] Ring B represents a divalent cyclic group. Ring B is the same as the divalent cyclic group described above.

[0141] Ring B may have a substituent. The substituent is the same as the substituent that the aforementioned divalent cyclic group may have.

[0142] Specific examples of the component (F) are shown below, but the present invention is not limited thereto.

[0143] [Chemical Formula 5]

[0144]

[0145] (n1 is the same as n in formula (a), and m1 is the same as m in formula (a)).

[0146] As the component (F), commercially available products can be used, for example, "OPE-2St" manufactured by Mitsubishi Gas Chemical Co., Ltd., "A-DOG" manufactured by Shin-Nakamura Chemical Co., Ltd., and "DCP-A" manufactured by Kyoeisha Chemical Co., Ltd. The component (B) may be used alone or in combination of two or more.

[0147] From the viewpoint of significantly obtaining the desired effects of the present invention, the number average molecular weight of component (F) is preferably 3000 or less, more preferably 2500 or less, and even more preferably 2000 or less and 1500 or less. The lower limit is preferably 100 or more, more preferably 300 or more, and even more preferably 500 or more and 1000 or more. The number average molecular weight is a polystyrene-equivalent number average molecular weight measured using gel permeation chromatography (GPC).

[0148] From the viewpoint of significantly obtaining the effect of the present invention, when the non-volatile component in the resin composition is set to 100 mass %, the content of the (F) component is preferably 0.1 mass % or more, more preferably 0.3 mass % or more, and further preferably 0.5 mass % or more. For the upper limit, it is preferably 30 mass % or less, more preferably 10 mass % or less, and further preferably 5 mass % or less.

[0149] <(G) Polymerization initiator>

[0150] The resin composition may contain a polymerization initiator (G) as the component (G). The component (G) generally has the function of promoting crosslinking of the free radical polymerizable unsaturated groups in the component (F). The components (G) may be used alone or in combination of two or more.

[0151] Examples of the polymerization initiator (G) include peroxides such as tert-butylcumyl peroxide, tert-butyl peroxyacetate, α,α′-di(tert-butylperoxy)diisopropylbenzene, tert-butyl peroxylaurate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyneodecanoate, and tert-butyl peroxybenzoate.

[0152] Examples of commercially available products of the polymerization initiator (G) include "PERBUTYL C", "PERBUTYL A", "PERBUTYL P", "PERBUTYL L", "PERBUTYL O", "PERBUTYL ND", "PERBUTYL Z", "PERCUMYLP", and "PERCUMYLD" manufactured by NOF Corporation.

[0153] From the viewpoint of significantly achieving the desired effects of the present invention, the content of the (G) polymerization initiator, relative to 100% by mass of the non-volatile component in the resin composition, 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, and is preferably 0.3% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less.

[0154] <(H) Flame retardant>

[0155] The resin composition may contain a flame retardant (H) as the component (H). Examples of the flame retardant (H) include phosphazene compounds, organophosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, organosilicon flame retardants, and metal hydroxides, with phosphazene compounds being preferred. The flame retardants may be used alone or in combination of two or more.

[0156] The phosphazene compound is not particularly limited as long as it is a cyclic compound containing nitrogen and phosphorus as constituent elements. The phosphazene compound is preferably a phosphazene compound having a phenolic hydroxyl group.

[0157] Specific examples of phosphazene compounds include "SPH-100", "SPS-100", "SPB-100", "SPE-100" manufactured by Otsuka Chemical Co., Ltd., "FP-100", "FP-110", "FP-300", "FP-400" manufactured by Fushimi Pharmaceutical Co., Ltd., and the like. Preferably, "SPH-100" manufactured by Otsuka Chemical Co., Ltd. is used.

[0158] As flame retardants other than phosphazene compounds, commercially available products can be used, for example, "HCA-HQ" manufactured by Sanko Co., Ltd. and "PX-200" manufactured by Daihachi Chemical Industry Co., Ltd. As flame retardants, those that are not easily hydrolyzed are preferred, for example, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide is preferred.

[0159] From the viewpoint of significantly obtaining the effect of the present invention, when the non-volatile component in the resin composition is set to 100 mass %, the content of the (H) flame retardant is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and further preferably 0.3 mass % or more. As for the upper limit, it is preferably 5 mass % or less, more preferably 3 mass % or less, and further preferably 1 mass % or less.

[0160] <(I) Other additives>

[0161] For resin combination, except above-mentioned composition, as arbitrary composition, other additives can be further included.As such additive, resin additives such as thickener, defoamer, leveling agent, adhesion imparting agent etc. can be enumerated.These additives can be used alone 1 kind, also can be used in combination more than 2 kinds.Those skilled in the art can suitably set respective content.

[0162] <Physical Properties and Applications of Resin Compositions>

[0163] The cured product obtained by thermally curing the resin composition at 180°C for 90 minutes exhibits the characteristic of a low dielectric constant. Therefore, the cured product forms an insulating layer with a low dielectric constant. The dielectric constant is preferably less than 3.0, more preferably 2.98 or less, and more preferably 2.95 or less. On the other hand, the lower limit of the dielectric constant is not particularly limited and may be 0.0001 or more. The dielectric constant can be measured according to the method described in the Examples described below.

[0164] The cured product obtained by heat curing the resin composition at 180°C for 90 minutes generally exhibits the characteristic of a low linear thermal expansion coefficient (CTE). Therefore, the aforementioned cured product forms an insulating layer with a low linear thermal expansion coefficient. As the linear thermal expansion coefficient, it is preferably less than 30 ppm, more preferably less than 29 ppm, and more preferably less than 28 ppm. On the other hand, the lower limit of the linear thermal expansion coefficient is not particularly limited and can be 1 ppm or more. The evaluation of the aforementioned linear thermal expansion coefficient can be measured according to the method described in the examples described below.

[0165] A cured product obtained by thermally curing a resin composition at 180°C for 90 minutes generally exhibits a high glass transition temperature. Therefore, the cured product forms an insulating layer having a high glass transition temperature. The glass transition temperature is preferably 140°C or higher, more preferably 150°C or higher, and even more preferably 160°C or higher. On the other hand, the upper limit of the glass transition temperature is not particularly limited and may be 300°C or lower. The glass transition temperature can be measured according to the method described in the Examples below.

[0166] The cured product obtained by heat curing the resin composition at 190°C for 90 minutes generally exhibits excellent insulation reliability. Therefore, the cured product forms an insulating layer with excellent insulation reliability. Specifically, the initial resistance value of the insulating layer was measured at 7 locations. Next, the resistance value after HAST after being left at 130°C and 85% Rh for 100 hours was measured at 7 locations. The measured resistance value was 10 6 The resistance values ​​of Ω or above were considered good, and the number of locations with good resistance values ​​both initially and after HAST was preferably 6 or more, more preferably 7. The above-mentioned insulation reliability evaluation can be measured by the method described in the Examples below.

[0167] The cured product obtained by heat curing the resin composition at 180°C for 90 minutes shows excellent mechanical strength. Therefore, the cured product forms an insulating layer with excellent mechanical strength. The mechanical strength can be evaluated by the elastic modulus and the elongation at break. As the elastic modulus, it is preferably 20 GPa or less, more preferably 15 GPa or less, and further preferably 10 GPa or less. The lower limit of the elastic modulus is not particularly limited and may be 0.1 GPa or more. As the elongation at break, it is preferably 0.5% or more, more preferably 0.8% or more, and further preferably 1% or more. The upper limit is not particularly limited and may be 10% or less. The aforementioned mechanical strength can be measured according to the method described in the examples described later.

[0168] Even when a resin composition is thermally cured, bubbles can still be present in the cured product. Specifically, a cured product was obtained by thermally curing the resin composition at 180°C for 90 minutes. When observing a cross-section of this cured product, bubbles were found, although this depends on the bubble content. The specific experimental method can be used for measurement according to the methods described in the Examples below.

[0169] Resin combination of the present invention can form an insulating layer with excellent dielectric constant. In addition, the common insulation reliability, mechanical strength, glass transition temperature (Tg) and linear thermal expansion coefficient of the aforementioned insulating layer are excellent. Therefore, resin combination of the present invention can be suitably used as the resin combination of insulating purposes. Specifically, it can be suitably used as: the resin combination for forming an insulating layer (insulating layer forming resin composition for forming a conductor layer), the insulating layer is the insulating layer for forming a conductor layer (including a rewiring layer), and the conductor layer is formed on the insulating layer.

[0170] Furthermore, in the multilayer printed wiring board described later, it can be suitably used as a resin composition for forming an insulating layer of a multilayer printed wiring board (resin composition for forming an insulating layer of a multilayer printed wiring board), a resin composition for forming an interlayer insulating layer of a printed wiring board (resin composition for forming an interlayer insulating layer of a printed wiring board), and a resin composition for forming an insulating layer of a flexible substrate (resin composition for forming an insulating layer of a flexible substrate).

[0171] Furthermore, for example, when a semiconductor chip package is manufactured through the following steps (1) to (6), the resin composition of the present invention can also be suitably used as a resin composition for a redistribution forming layer (resin composition for redistribution forming layer formation) as an insulating layer for forming a redistribution layer, and a resin composition for sealing a semiconductor chip (resin composition for semiconductor chip sealing). When manufacturing a semiconductor chip package, a redistribution layer can be further formed on the sealing layer.

[0172] (1) a step of laminating a temporary fixing film on a substrate,

[0173] (2) a process of temporarily fixing the semiconductor chip on a temporary fixing film,

[0174] (3) a step of forming a sealing layer on a semiconductor chip,

[0175] (4) a step of peeling the substrate and the temporary fixing film from the semiconductor chip,

[0176] (5) a step of forming a rewiring forming layer as an insulating layer on the surface of the semiconductor chip from which the substrate and the temporary fixing film have been peeled off, and

[0177] (6) A step of forming a rewiring layer as a conductive layer on the rewiring formation layer.

[0178] [Method for producing resin composition]

[0179] The method for producing the resin composition of the present invention can be produced, for example, by a method comprising the following step (a);

[0180] (a) A step of dispersing bubbles in a resin component having a viscosity of 300 mPa·s to 5000 mPa·s at 25°C.

[0181] The resin component used in step (a) represents a part or all of the components contained in the resin composition except (C) inorganic filler. As the resin component, preferably (A) epoxy resin, more preferably liquid epoxy resin. The viscosity of the resin component at 25°C is greater than or equal to 300 mPa·s and less than or equal to 5000 mPa·s, and the preferred range of viscosity is the same as that of the liquid epoxy resin. The resin component can be used alone or in combination of two or more. In addition, in order to adjust the viscosity, the resin component may contain an organic solvent. The organic solvent is the same as the organic solvent used when preparing the resin varnish.

[0182] Furthermore, from the viewpoint of effectively dispersing bubbles in the resin component, the resin component preferably contains a surfactant.

[0183] Examples of surfactants include cationic surfactants such as alkylamine salts, alkyltrimethylammonium salts, and alkyldimethylbenzylammonium salts; anionic surfactants such as fatty acid salts such as sodium oleate, alkyl sulfate ester salts, alkylbenzenesulfonates, alkylsulfosuccinates, naphthalenesulfonates, polyoxyethylene alkylsulfates, sodium alkanesulfonates (sodium petroleumsulfonates), and sodium alkyldiphenylethersulfonates; nonionic surfactants such as polyoxyalkylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene sorbitan tetraoleate, polyoxyethylene-polyoxypropylene copolymers, and alkyl ethers; and fluorine-based surfactants having a fluorine-containing carbon chain in the molecule. Among these, nonionic surfactants and fluorine-based surfactants are preferred from the viewpoint of significantly achieving the effects of the present invention.

[0184] As the surfactant, commercially available products can be used. Examples of commercially available products include "MEGAFACRS-72-K" manufactured by DIC Corporation, "LB-1520" manufactured by ADEKA Corporation, "T-81" manufactured by ADEKA Corporation, "NK-3" manufactured by ADEKA Corporation, "L-23" manufactured by ADEKA Corporation, "TR-701" manufactured by ADEKA Corporation, "PEG-1000" manufactured by ADEKA Corporation, "NONION K-204" manufactured by NOF Corporation, "L-2" manufactured by NOF Corporation, "NONION CP-08R" manufactured by NOF Corporation, "UNISTER E-275" manufactured by NOF Corporation, "MONOGLY D" manufactured by NOF Corporation, "UNIOX HC-8" manufactured by NOF Corporation, "UNIOX ST-30E" manufactured by NOF Corporation, "UNIGLY GO-102R" manufactured by NOF Corporation, and "NYMEEN" manufactured by NOF Corporation. L-201", "STAFOAM F" made by NOF Corporation, "NAIMIDO MF-203" made by NOF Corporation, "UNISAFE A-LM" made by NOF Corporation, "MALIALIMAKM1511-60" made by NOF Corporation, etc.

[0185] From the viewpoint of allowing bubbles to exist stably in the resin composition, the content of the surfactant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, further preferably 0.3% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 1% by mass or less, when the content of the resin component is set to 100% by mass.

[0186] As one embodiment of step (a), bubbles are generated in the liquid epoxy resin using a bubble generator such as a microbubble generator, and the bubbles are directly dispersed in the liquid epoxy resin.

[0187] From the viewpoint of allowing bubbles to stably exist in the resin composition, the frequency of the bubble generator is preferably 20 Hz or higher, more preferably 25 Hz or higher, and even more preferably 30 Hz or higher, and is preferably 70 Hz or lower, more preferably 60 Hz or lower, and even more preferably 50 Hz or lower.

[0188] The bubble generation pressure of the bubble generating device is 0.05 MPa or more, more preferably 0.1 MPa or more, further preferably 0.2 MPa or more, preferably 0.5 MPa or less, more preferably 0.4 MPa or less, further preferably 0.3 MPa or less, from the viewpoint of allowing bubbles to exist stably in the resin composition.

[0189] The suction pressure of the bubble generating device is preferably -0.5 MPa or more, more preferably -0.3 MPa or more, further preferably -0.1 MPa or more, preferably -0.001 MPa or less, more preferably -0.005 MPa or less, further preferably -0.01 MPa or less, from the viewpoint of allowing bubbles to exist stably in the resin composition.

[0190] The air intake volume of the bubble generating device is 1 mL / min or more, more preferably 5 mL / min or more, further preferably 10 mL / min or more, preferably 40 mL / min or less, more preferably 30 mL / min or less, further preferably 20 mL / min or less, from the viewpoint of allowing bubbles to exist stably in the resin composition.

[0191] The operating time of the microbubble generating device is preferably 3 minutes or more, more preferably 5 minutes or more, further preferably 10 minutes or more, preferably 120 minutes or less, more preferably 90 minutes or less, and further preferably 60 minutes or less per 5 kg of resin component in which the bubbles are dispersed, from the viewpoint of ensuring that the bubbles exist stably in the resin composition.

[0192] The bubble ratio of the bubbles in the resin component is preferably 10% by volume or more, more preferably 30% by volume or more, and even more preferably 50% by volume or more, from the viewpoint of significantly achieving the effects of the present invention. It is preferably 95% by volume or less, more preferably 90% by volume or less, and even more preferably 85% by volume or less. The bubble ratio refers to the proportion (volume %) of bubbles contained in the resin component in which bubbles are dispersed. It can be determined by measuring the weights of the resin component before and after the bubbles are dispersed in a container of a predetermined volume, using the following formula:

[0193] Bubble ratio (volume %)=(1−(mass of the resin component after the bubbles are dispersed / mass of the resin component before the bubbles are dispersed))×100.

[0194] The method for manufacturing a resin composition may include, as needed: (b) a process of mixing a resin component containing bubbles with a component to be included in a resin composition other than the resin component. In addition, the method for manufacturing a resin composition may include: (c) a process of mixing and dispersing the resin composition using a rotary mixer or the like. It should be noted that when making a resin composition or making a resin varnish described later, bubbles sometimes combine (associate) with each other through operations such as stirring, and the average particle size of the bubbles becomes larger. Especially in the case of bubbles with a larger average particle size, there is a tendency that bubbles become easily combined with each other through stirring, and the average particle size becomes larger.

[0195] The bubbles contained in the resin composition obtained by the production method of the present invention preferably exist stably for 1 hour or more, more preferably 2 hours or more, and even more preferably 3 hours or more after the resin composition is produced. The upper limit is not particularly limited and can be 30 days or less.

[0196] [Resin sheet]

[0197] The resin sheet of the present invention includes a support and a resin composition layer formed from the resin composition of the present invention and provided on the support.

[0198] From the perspective of reducing the thickness of printed wiring boards and providing a cured product having excellent insulating properties even when the cured product of the resin composition is a thin film, the thickness of the resin composition layer is preferably 200 μm or less, more preferably 180 μm or less, and even more preferably 150 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but can generally be 5 μm or more.

[0199] Examples of the support include films made of plastic materials, metal foils, and release papers, and films made of plastic materials and metal foils are preferred.

[0200] When a film formed of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes referred to as "PET") and polyethylene naphthalate (hereinafter sometimes referred to as "PEN"), polycarbonate (hereinafter sometimes referred to as "PC"), acrylic polymers such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0201] When a metal foil is used as a support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of copper alone or an alloy of copper and other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0202] The surface of the support that contacts the resin composition layer may be subjected to matte treatment, corona treatment, or antistatic treatment.

[0203] In addition, as the support, a support with a release layer having a release layer on the surface bonded to the resin composition layer can be used. As the release agent used in the release layer of the support with the release layer, for example, one or more release agents selected from alkyd resins, polyolefin resins, polyurethane resins, and silicone resins can be mentioned. The support with the release layer can use commercially available products, for example, PET films having a release layer with an alkyd resin-based release agent as the main component, i.e., "SK-1", "AL-5", "AL-7" manufactured by Lintec, "Lumirror T60" manufactured by Toray Industries, "Purex" manufactured by Teijin, "Unipeel" manufactured by UNITIKA, etc.

[0204] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably in the range of 10 μm to 60 μm. When a support with a release layer is used, the entire thickness of the support with a release layer is preferably within the above range.

[0205] In one embodiment, the resin sheet may further include other layers as needed. As the other layers, for example, a protective film selected according to the support and provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface on the opposite side of the support) can be cited. The thickness of the protective film is not particularly limited, for example, 1 μm to 40 μm. By laminating the protective film, dust and the like can be suppressed from adhering to the surface of the resin composition layer or from being damaged on the surface of the resin composition layer.

[0206] The resin sheet can be produced, for example, by preparing a resin varnish by dissolving a resin composition in an organic solvent, applying the resin varnish on a support using a die coater or the like, and drying the varnish to form a resin composition layer.

[0207] Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone. These organic solvents may be used alone or in combination of two or more.

[0208] Drying can be carried out by known methods such as heating and hot air blowing. Drying conditions are not particularly limited, but drying is performed so that the organic solvent content in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. While the boiling point of the organic solvent in the resin varnish varies, for example, when using a resin varnish containing 30% to 60% by mass of an organic solvent, drying at 50°C to 150°C for 3 to 10 minutes can form a resin composition layer.

[0209] The resin sheet can be stored in a roll. If the resin sheet has a protective film, the protective film can be peeled off before use.

[0210] [Printed wiring board and method of manufacturing the same]

[0211] The printed wiring board of the present invention includes an insulating layer formed from a cured product of the resin composition of the present invention.

[0212] The printed wiring board can be produced, for example, by a method including the following steps (I) and (II):

[0213] (I) forming a resin composition layer containing a resin composition on an inner substrate;

[0214] (II) A step of thermally curing the resin composition layer to form an insulating layer.

[0215] The resin composition layer in step (I) can be formed by directly coating the resin composition on the inner substrate, or by using the above-mentioned resin sheet, preferably by using a resin sheet. Therefore, a preferred embodiment of step (I) is a step of laminating the resin sheet on the inner substrate in such a manner that the resin composition layer of the resin sheet is bonded to the inner substrate.

[0216] The "inner substrate" used in step (I) is a component that becomes the substrate of the printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. In addition, the substrate may have a conductor layer on one or both sides, and the conductor layer may be patterned. Sometimes an inner substrate having a conductor layer (circuit) formed on one or both sides of the substrate is referred to as an "inner circuit substrate". In addition, when manufacturing a printed wiring board, an intermediate product to be further formed with an insulating layer and / or a conductor layer is also included in the so-called "inner substrate" in the present invention. When the printed wiring board is a component-built-in circuit board, an inner substrate with built-in components can be used.

[0217] The inner substrate and the resin sheet can be laminated, for example, by heat-pressing the resin sheet onto the inner substrate from the support side. As a member for heat-pressing the resin sheet onto the inner substrate (hereinafter also referred to as a "heat-pressing member"), for example, a heated metal plate (SUS end plate, etc.) or a metal roller (SUS roller) can be cited. It should be noted that it is preferred that the heat-pressing member is not pressed directly onto the resin sheet, but is pressed through an elastic material such as heat-resistant rubber so that the resin sheet fully follows the surface unevenness of the inner substrate.

[0218] Lamination of the inner layer substrate and the resin sheet can be performed using a vacuum lamination method. In vacuum lamination, the heat-pressing temperature is preferably 60°C to 160°C, more preferably 80°C to 140°C, the heat-pressing pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1.47 MPa, and the heat-pressing time is preferably 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably performed under reduced pressure conditions of 26.7 hPa or less.

[0219] Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressure laminator manufactured by Meiki Mfg. Co., Ltd., a vacuum applicator manufactured by Nikko Materials, and a batch vacuum pressure laminator.

[0220] After lamination, the laminated resin sheet can be smoothed by, for example, pressing the heated pressing member from the support side under normal pressure (atmospheric pressure). The pressing conditions for the smoothing treatment can be set to the same conditions as the heated pressing conditions for the above-mentioned lamination. The smoothing treatment can be performed using a commercially available laminator. It should be noted that the lamination and smoothing treatment can be performed continuously using the above-mentioned commercially available vacuum laminator.

[0221] The support may be removed between step (I) and step (II), or may be removed after step (II).

[0222] In step (II), the resin composition layer is thermally cured to form an insulating layer. The thermal curing conditions of the resin composition layer are not particularly limited, and conditions commonly used when forming an insulating layer of a printed wiring board can be used.

[0223] For example, the thermal curing conditions of the resin composition layer vary depending on the type of resin composition, but the curing temperature is preferably 120° C. to 240° C., more preferably 150° C. to 220° C., and even more preferably 170° C. to 210° C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0224] Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C or higher and lower than 120°C (preferably 60°C or higher and 115°C or lower, more preferably 70°C or higher and 110°C or lower) for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes).

[0225] Because the insulating layer is formed from the cured product of the resin composition of the present invention, the thickness of the insulating layer can be relatively thin. The thickness of the insulating layer is preferably 200 μm or less, more preferably 180 μm or less, and even more preferably 150 μm or less or 100 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but can generally be 1 μm or more, 5 μm or more, etc.

[0226] After step (II) is completed, the support is peeled off in step (III) from the viewpoint of obtaining an insulating layer excellent in dielectric constant, insulation reliability, mechanical strength, glass transition temperature (Tg), and linear thermal expansion coefficient.

[0227] When manufacturing a printed wiring board, the process of (III) opening a hole in the insulating layer, the process of (IV) roughening the insulating layer, and the process of (V) forming a conductor layer can be further implemented. These processes (III) to (V) can be implemented according to various methods known to those skilled in the art used in the manufacture of printed wiring boards. It should be noted that, when the support is removed after process (II), the removal of the support can be implemented between process (II) and process (III), between process (III) and process (IV), or between process (IV) and process (V). In addition, as needed, the formation of the insulating layer and the conductor layer of process (II) to process (V) can also be repeatedly implemented to form a multilayer wiring board.

[0228] Step (III) is a step of drilling holes in the insulating layer. This process can form holes such as through holes and through holes in the insulating layer. Step (III) can be carried out using, for example, a drill, laser, plasma, etc., depending on the composition of the resin composition used to form the insulating layer. The size and shape of the holes can be appropriately determined based on the design of the printed wiring board.

[0229] Step (IV) is a step of roughening the insulating layer. Usually, smear is also removed in this step (IV). There are no particular restrictions on the steps and conditions of the roughening treatment, and the known steps and conditions commonly used when forming the insulating layer of the printed wiring board can be adopted. For example, swelling treatment using a swelling solution, roughening treatment using an oxidizing agent, and neutralization treatment using a neutralizing solution can be sequentially implemented to roughen the insulating layer. There are no particular restrictions on the swelling solution used for the roughening treatment, and an alkaline solution, a surfactant solution, etc. can be cited. An alkaline solution is preferred, and a sodium hydroxide solution and a potassium hydroxide solution are more preferred as the alkaline solution. Examples of commercially available swelling solutions include "Swelling Dip Securiganth P (Swelling Dip Securigant P)", "Swelling Dip Securiganth SBU", and "Swelling Dip Securiganth P (Swelling Dip Securigant P)" manufactured by Atotech Japan Co., Ltd. The swelling treatment using the swelling solution is not particularly limited and can be performed, for example, by immersing the insulating layer in the swelling solution at 30°C to 90°C for 1 to 20 minutes. From the perspective of suppressing swelling of the resin in the insulating layer to an appropriate level, it is preferred to immerse the insulating layer in the swelling solution at 40°C to 80°C for 5 to 15 minutes. There are no particular restrictions on the oxidizing agent used for the roughening treatment, and examples include alkaline permanganate solutions formed by dissolving potassium permanganate and sodium permanganate in an aqueous solution of sodium hydroxide. The roughening treatment performed using an oxidizing agent such as an alkaline permanganate solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 minutes to 30 minutes. In addition, the concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. As commercially available oxidizing agents, examples include alkaline permanganate solutions such as “Concentrate Compact CP” and “Dosing Solution Securiganth P” manufactured by Atotech Japan Co., Ltd. In addition, as a neutralizing solution for the roughening treatment, an acidic aqueous solution is preferred, and as a commercially available product, examples include “Reduction Solution Securiganth P” manufactured by Atotech Japan Co., Ltd. Treatment with a neutralizing solution can be performed by immersing the surface roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 1 to 30 minutes. From the perspective of operability, a method in which the surface roughened with an oxidizing agent is immersed in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes is preferred.

[0230] In one embodiment, the arithmetic mean roughness (Ra) of the insulating layer surface after the roughening treatment is preferably 500 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. There is no particular restriction on the lower limit, but it is preferably 30 nm or more, more preferably 40 nm or more, and even more preferably 50 nm or more. The arithmetic mean roughness (Ra) of the insulating layer surface can be measured using a non-contact surface roughness meter.

[0231] Step (V) is a step of forming a conductor layer, in which a conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer comprises one or more metals selected from gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The conductor layer can be a single metal layer or an alloy layer. As the alloy layer, for example, a layer formed by an alloy of two or more metals selected from the above metals (for example, nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy) can be mentioned. Among them, from the viewpoints of versatility, cost, ease of patterning, etc. of the formation of the conductor layer, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel-chromium alloy, copper-nickel alloy or copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel-chromium alloy is more preferred, and a single metal layer of copper is further preferred.

[0232] The conductor layer may have a single-layer structure or a multilayer structure comprising two or more stacked single metal layers or alloy layers formed from different types of metals or alloys. When the conductor layer has a multilayer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

[0233] The thickness of the conductor layer depends on the desired design of the printed wiring board, but is usually 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0234] In one embodiment, the conductor layer can be formed by plating. For example, a conventionally known technique such as a semi-additive method or a fully additive method can be used to plate the surface of the insulating layer to form a conductor layer having a desired wiring pattern. From the perspective of ease of production, formation using a semi-additive method is preferred. An example of forming a conductor layer using a semi-additive method is shown below.

[0235] First, a plating seed layer is formed on the surface of the insulating layer using electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. A metal layer is formed on the exposed plating seed layer using electrolytic plating, and the mask pattern is then removed. The unnecessary plating seed layer is then removed using etching or other methods, forming a conductor layer having the desired wiring pattern.

[0236] The printed wiring board of the present invention includes an insulating layer formed from a cured product of the resin composition of the present invention, and therefore, contains bubbles in the insulating layer. The average particle size of the bubbles in the insulating layer is the same as the average particle size of the bubbles contained in the resin composition. The bubbles in the insulating layer can be confirmed, for example, by observing a cross section of the insulating layer.

[0237] [Semiconductor devices]

[0238] The semiconductor device of the present invention includes the printed wiring board of the present invention. The semiconductor device of the present invention can be produced using the printed wiring board of the present invention.

[0239] Examples of semiconductor devices include various semiconductor devices used in electrical products (eg, computers, mobile phones, digital cameras, and televisions) and vehicles (eg, motorcycles, automobiles, trains, ships, and airplanes).

[0240] The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) at a conductive location on a printed wiring board. The term "conductive location" refers to a location on the printed wiring board where electrical signals are transmitted, and this location can be either on the surface or embedded. Furthermore, the semiconductor chip is not particularly limited, as long as it is an electrical circuit element made of semiconductor material.

[0241] The method for mounting a semiconductor chip when manufacturing a semiconductor device is not particularly limited as long as the semiconductor chip can function effectively. Specifically, there can be cited a wire bonding mounting method, a flip chip mounting method, a mounting method based on a built-in non-bump-less build-up layer (BBUL), a mounting method based on anisotropic conductive film (ACF), a mounting method based on a non-conductive film (NCF), and the like. Here, "mounting method based on a built-in non-bump-less layer (BBUL)" refers to "a mounting method in which a semiconductor chip is directly embedded in a recess of a printed wiring board to connect the semiconductor chip to the wiring on the printed wiring board."

[0242] Example

[0243] The present invention is described in detail below by way of examples, but the present invention is not limited to these examples. It should be noted that, in the following descriptions, "parts" and "%" refer to "parts by mass" and "mass %" respectively, unless otherwise specified. It should be noted that, unless otherwise specified, all reactions were conducted at room temperature and atmospheric pressure.

[0244] <Production Example 1: Production of Microbubble-Containing Epoxy Resin 1>

[0245] 5 kg of a mixture of liquid bisphenol A epoxy resin and liquid bisphenol F epoxy resin ("ZX-1059" manufactured by Nippon Steel Chemicals Co., Ltd., epoxy equivalent weight approximately 165 g / eq., viscosity 2200 mPa·s at 25°C) was added to a glass container. A microbubble generator ("MBelifeLab MBLL11-102V-S" manufactured by Kansai Automation Co., Ltd.) was connected to the glass container. After performing a priming water injection (exhaling water) operation, the microbubble generator was operated for 30 minutes at a frequency of 43 Hz, a microbubble generation pressure of 0.25 MPa, an intake pressure (intake pressure) of -0.018 MPa, and an intake volume of 15 mL / min. This yielded microbubble-containing epoxy resin 1.

[0246] <Measurement of the Microbubble Ratio>

[0247] The bubble ratio was calculated using the following formula from the mass (g) of 20 mL of the immediately obtained microbubble-containing epoxy resin 1 and the mass (g) of 20 mL of a mixture of liquid bisphenol A epoxy resin and liquid bisphenol F epoxy resin ("ZX-1059" manufactured by Nippon Steel Chemicals Co., Ltd., epoxy equivalent weight approximately 165 g / eq.) measured in a graduated cylinder. The result was 45% by volume.

[0248] Bubble ratio (volume %)=(1-(mass of epoxy resin containing microbubbles / mass of epoxy resin))×100.

[0249] <Measurement of the average particle size, standard deviation, and number of microbubbles>

[0250] Next, a small amount of the newly obtained microbubble-containing epoxy resin 1 was placed between glass plates with a gap of approximately 120 μm created using commercially available tape. Microscopic observation was performed within a random 1.2 mm x 1.6 mm observation area to measure the number of microbubbles. The particle sizes of 50 random microbubbles within the observation area were then measured. The average particle size and standard deviation of the microbubbles were calculated from these measured values. The results showed an average particle size of 36.5 μm and a standard deviation of 13.4 μm.

[0251] <Evaluation of microbubble stability>

[0252] The epoxy resin 1 containing microbubbles was left to stand in a glass container. The average particle size and number of microbubbles were measured for the epoxy resin 1 containing microbubbles immediately after it was obtained and for the epoxy resin 1 containing microbubbles that had been left to stand in a glass container for 3 hours and 24 hours, using the same method as described above in <Measurement of the average particle size, standard deviation, and number of microbubbles>. The number of microbubbles (N1) in the epoxy resin 1 containing microbubbles immediately after it was obtained was measured. ini ) and average particle size (R1ini ), the number of microbubbles after 3 hours (N1 3h ) and average particle size (R1 3h ), and the number of microbubbles after 24 hours (N1 24h ) and average particle size (R1 24h ) were compared and evaluated according to the following criteria;

[0253] ◎:0.9<(N1 24h / N1 ini ) and 0.9<(R1 24h / R1 ini )≤1.1 microbubbles;

[0254] ○: Except ◎, and 0.9<(N1 3h / N1 ini ) and 0.9<(R1 3h / R1 ini )≤1.1 microbubbles;

[0255] △: Except ◎, ○, and 0.3<(N1 3h / N1 ini ) and 0.9<(R1 3h / R1 ini )≤1.1 microbubbles;

[0256] ×: Microbubbles that do not belong to ◎, ○, or △.

[0257] <Measurement of Viscosity of Liquid Epoxy Resin>

[0258] The viscosity of the liquid epoxy resin was measured using an E-type viscometer RE-80 (manufactured by Toki Sangyo Co., Ltd., rotor: 3°×R9.7) at 25° C. The rotation speed during measurement was appropriately adjusted according to the viscosity of the liquid epoxy resin to 10 to 90% of the measurable range at each rotation speed.

[0259] <Production Example 2: Production of Microbubble-Containing Epoxy Resin 2>

[0260] In Production Example 1, 5 g of a fluorine-based surfactant ("MEGAFAC RS-72-K" manufactured by DIC Corporation) was additionally used. Microbubble-containing epoxy resin 2 was obtained by following the same procedures as in Production Example 1, except for the above matters. The microbubble content of the obtained microbubble-containing epoxy resin 2 was measured in the same manner as for microbubble-containing epoxy resin 1 and was found to be 51% by volume. The average particle size of the microbubbles was 28.9 μm, and the standard deviation was 13.0 μm. Furthermore, the microbubble stability was evaluated in the same manner as for microbubble-containing epoxy resin 1.

[0261] <Production Example 3: Production of Epoxy Resin 3 Containing Microbubbles>

[0262] In Production Example 1, 20 g of an ether-type nonionic surfactant ("LB-1520" manufactured by ADEKA, polyoxyalkylene lauryl ether) pre-diluted with 3 times the amount of methyl ethyl ketone was additionally used. The same procedures as in Production Example 1 were followed with the exception of the above matters to obtain Microbubble-Containing Epoxy Resin 3. The microbubble content of the obtained Microbubble-Containing Epoxy Resin 3 was measured in the same manner as for Microbubble-Containing Epoxy Resin 1 and was found to be 50% by volume. The average particle size of the microbubbles was 1.8 μm, with a standard deviation of 1.0 μm. Furthermore, the stability of the microbubbles was evaluated in the same manner as for Microbubble-Containing Epoxy Resin 1.

[0263] <Production Example 4: Production of Microbubble-Containing Epoxy Resin 4>

[0264] In Production Example 1, 5 kg of a mixture of liquid bisphenol A epoxy resin and liquid bisphenol F epoxy resin ("ZX-1059" manufactured by Nippon Steel Chemicals, Ltd., epoxy equivalent weight approximately 165 g / eq., viscosity at 25°C 2200 mPa·s) was replaced with 5 kg of liquid 1,4-glycidylcyclohexane epoxy resin ("ZX1658GS" manufactured by Nippon Steel Chemicals, Ltd., epoxy equivalent weight approximately 135 g / eq., viscosity at 25°C 30 mPa·s).

[0265] The frequency of the microbubble generator was changed from 43 Hz to 60 Hz, and the microbubble generation pressure of the microbubble generator was changed from 0.25 MPa to 0.20 MPa;

[0266] Except for the above, the same procedures as in Production Example 1 were followed to obtain microbubble-containing epoxy resin 4. The microbubble content of the obtained microbubble-containing epoxy resin 4 was measured in the same manner as in microbubble-containing epoxy resin 1 and was found to be 28% by volume. The average particle size of the microbubbles was 21.7 μm, with a standard deviation of 11.9 μm. Furthermore, the stability of the microbubbles was evaluated in the same manner as in microbubble-containing epoxy resin 1, and the microbubbles disappeared after one hour.

[0267] <Production Example 5: Production of Microbubble-Containing Epoxy Resin 5>

[0268] In Manufacturing Example 1, the suction pressure of the microbubble generating device was changed from -0.018 MPa to -0.020 MPa, and the suction volume of the microbubble generating device was changed from 15 mL / min to 25 mL / min.

[0269] Except for the above, the same procedures as in Production Example 1 were followed to obtain microbubble-containing epoxy resin 5. The microbubble content of the obtained microbubble-containing epoxy resin 5 was measured in the same manner as in microbubble-containing epoxy resin 1 and was found to be 58% by volume. The average particle size of the microbubbles was 55.1 μm, and the standard deviation was 22.2 μm. Furthermore, the stability of the microbubbles was evaluated in the same manner as in microbubble-containing epoxy resin 1.

[0270] [Table 1]

[0271] (Table 1)

[0272] Manufacturing Example 1 2 3 4 5 Liquid epoxy resin ZX1059 ZX1059 ZX1059 ZX1658GS ZX1059 Viscosity of epoxy resin (mPa·s) 2200 2200 2200 30 2200 surfactants - RS-72-K LB-1520 - - Frequency (Hz) 43 43 43 60 43 Generated pressure (MPa) 0.25 0.25 0.25 0.2 0.25 Suction pressure (MPa) -0.018 -0.018 -0.018 -0.018 -0.020 Inspiratory volume (mL / min) 15 15 15 15 25 Average particle size (μm) 36.5 28.9 1.8 21.7 55.1 Standard deviation (μm) 13.4 13.0 1.0 11.9 22.2 Microbubble stability ○ ◎ ◎ × △ Bubble rate (volume %) 45 51 50 28 58

[0273] <Example 1>

[0274] While stirring, 5 parts of a biphenyl epoxy resin ("NC-3000-L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of approximately 269 g / eq.), 5 parts of a bisphenol AF epoxy resin ("YX7760" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of approximately 238 g / eq.), 3 parts of a phosphazene resin ("SPS-100" manufactured by Daitaku Chemical Co., Ltd.), and 10 parts of a phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of MEK and cyclohexanone having a solid content of 30% by mass) were heated and dissolved in 20 parts of MEK and 37.8 parts of solvent naphtha. After cooling to room temperature, 86 parts of an active ester curing agent (DIC Corporation "EXB9416-70BK", a methyl isobutyl ketone solution with an active group equivalent of about 330 g / eq. and a non-volatile content of 70% by mass), 10 parts of a phenolic curing agent (DIC Corporation "LA-3018-50P", a 2-methoxypropanol solution with an active group equivalent of about 151 g / eq. and a solid content of 50%), 10 parts of a carbodiimide curing agent (Nisshinbo Chemical Co., Ltd. "V-03", an active group equivalent of about 216 g / eq. and a toluene solution with a solid content of 50%), 5 parts of a (meth)acrylate (Shin-Nakamura Chemical Co., Ltd. "NK Ester A-DOG", a molecular weight of 326 and a (meth)acryloyl equivalent of 163 g / eq.), and 5 parts of a polymerization initiator (NOF Corporation "PERBUTYL C") 0.2 parts, a curing accelerator (4-dimethylaminopyridine (DMAP), a MEK solution having a solid content of 5% by mass) 8 parts, spherical silica (average particle size of 0.5 μm, specific surface area of ​​5.9 m) surface-treated with an aminosilane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-573") 2400 parts of 400 parts of 1,0 ...

[0275] <Example 2>

[0276] In Example 1, 50 parts of microbubble-containing epoxy resin 1 was replaced with 50 parts of microbubble-containing epoxy resin 2. Resin varnish 2 was prepared in the same manner as in Example 1 except for the above. The microbubble content in resin varnish 2 was 13.0% by volume, assuming the nonvolatile content in the resin composition was 100% by volume. The average particle size of the bubbles in the resin varnish was 30.1 μm.

[0277] <Example 3>

[0278] In Example 1, spherical silica (average particle size 0.5 μm, specific surface area 5.9 m) surface-treated with an aminosilane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., “KBM-573”) was used. 2 / g, the amount of "SO-C2" manufactured by Yaduma Co., Ltd. was changed from 400 parts to 380 parts, and 20 parts of spherical silica ("UFP-30" manufactured by DENKA Co., Ltd., average particle size 0.3 μm) surface-treated with an aminosilane-based coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.) was additionally used.

[0279] 50 parts of epoxy resin 1 containing microbubbles was replaced with 50 parts of epoxy resin 3 containing microbubbles;

[0280] Resin varnish 3 was prepared in the same manner as in Example 1 except for the above matters. The microbubble content in resin varnish 3 was 12.3% by volume, assuming the nonvolatile component in the resin composition was 100% by volume. The average particle size of the bubbles in the resin varnish was 1.9 μm.

[0281] <Example 4>

[0282] In Example 1, 50 parts of microbubble-containing epoxy resin 1 was replaced with 50 parts of microbubble-containing epoxy resin 5. Resin varnish 4 was prepared in the same manner as in Example 1 except for the above. The microbubble content in resin varnish 4 was 5.2% by volume, assuming the nonvolatile content in the resin composition was 100% by volume. The average particle size of the bubbles in the resin varnish was 51.5 μm.

[0283] Comparative Example 1

[0284] In Example 1, 50 parts of the microbubble-containing epoxy resin 1 was replaced with 10 parts of the microbubble-containing epoxy resin 4, and 40 parts of a mixture of liquid bisphenol A epoxy resin and liquid bisphenol F epoxy resin ("ZX-1059" manufactured by Nippon Steel Chemicals Co., Ltd., epoxy equivalent weight approximately 165 g / eq.) was used.

[0285] Except for the above matters, the same procedure as in Example 1 was carried out to prepare a resin varnish 5. When the nonvolatile component in the resin composition was taken as 100% by volume, the content of microbubbles in the resin varnish 5 was 0% by volume.

[0286] Comparative Example 2

[0287] While stirring, 30 parts of a mixture of liquid bisphenol A epoxy resin and liquid bisphenol F epoxy resin ("ZX-1059" manufactured by Nippon Steel Chemicals Co., Ltd., epoxy equivalent of approximately 165 g / eq.), 25 parts of a biphenyl epoxy resin ("NC-3000-L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of approximately 269 g / eq.), 5 parts of a bisphenol AF epoxy resin ("YX7760" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of approximately 238 g / eq.), 3 parts of a phosphazene resin ("SPS-100" manufactured by Otsuka Chemical Co., Ltd.), and 10 parts of a phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of MEK and cyclohexanone having a solid content of 30% by mass) were heated and dissolved in 20 parts of MEK and 40 parts of solvent naphtha. After cooling to room temperature, 86 parts of an active ester curing agent (DIC Corporation "EXB9416-70BK", a methyl isobutyl ketone solution with an active group equivalent of about 330 g / eq. and a non-volatile content of 70% by mass), 10 parts of a phenolic curing agent (DIC Corporation "LA-3018-50P", a 2-methoxypropanol solution with an active group equivalent of about 151 g / eq. and a solid content of 50%), 10 parts of a carbodiimide curing agent (Nisshinbo Chemical Co., Ltd. "V-03", an active group equivalent of about 216 g / eq. and a toluene solution with a solid content of 50%), 5 parts of a (meth)acrylate (Shin-Nakamura Chemical Co., Ltd. "NK Ester A-DOG", a molecular weight of 326 and a (meth)acryloyl equivalent of 163 g / eq.), and 5 parts of a polymerization initiator (NOF Corporation "PERBUTYL C") 0.2 parts, a curing accelerator (4-dimethylaminopyridine (DMAP), a MEK solution having a solid content of 5% by mass) 8 parts, spherical silica (average particle size of 0.5 μm, specific surface area of ​​5.9 m) surface-treated with an aminosilane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-573") 2 / g, 300 parts of "SO-C2" manufactured by Yaduma Co., Ltd., and 100 parts of polytetrafluoroethylene (PTFE) particles ("LUBRON L-2" manufactured by Daikin Industries, Ltd., average particle size 3 μm) were uniformly dispersed using a high-speed rotary mixer, and then filtered using a cartridge filter ("SHP100" manufactured by Rokitechno Co., Ltd.) and degassed under reduced pressure to obtain Resin Varnish 6. The content of microbubbles in Resin Varnish 6 was 0% by volume, based on 100% by volume of the nonvolatile component in the resin composition.

[0288] Comparative Example 3

[0289] In Comparative Example 2, 100 parts of polytetrafluoroethylene (PTFE) particles ("LUBRON L-2" manufactured by Daikin Industries, Ltd., average particle size 3 μm) were replaced with 60 parts of hollow glass particles ("Microbubble iM30K" manufactured by 3M Japan, average particle size 16 μm). Resin Varnish 7 was prepared in the same manner as in Comparative Example 2 except for the above. The microbubble content in Resin Varnish 7 was 0% by volume, assuming the nonvolatile content in the resin composition was 100% by volume.

[0290] <Measurement of dielectric constant, linear thermal expansion coefficient, glass transition temperature, and bubble content, and evaluation of process suitability>

[0291] (1) Preparation of Cured Material for Evaluation

[0292] A glass cloth-based epoxy resin double-sided copper-clad laminate ("R5715ES" manufactured by Panasonic Corporation, with a thickness of 0.7 mm and a square diameter of 255 mm) was overlapped on the release-untreated surface of a release-treated PET film ("501010" manufactured by Lintec Corporation, with a thickness of 50 μm and a square diameter of 240 mm) and fixed on all four sides with polyimide tape (10 mm wide) (hereinafter sometimes referred to as "fixed PET film").

[0293] Resin varnishes 1 to 7 obtained in Examples and Comparative Examples were applied to the release-treated surface of the "fixed PET film" using a die coater to a thickness of 40 μm after drying. The coating was then dried at 80°C to 120°C (average 100°C) for 6 minutes to produce resin sheets. The average particle size of the microbubbles in the resulting resin sheets was compared with that of the microbubble-containing epoxy resins 1 to 5, but no significant difference was observed.

[0294] The resin composition layer was then thermally cured in an oven at 180°C for 90 minutes. After thermal curing, the polyimide tape was peeled off, and the cured product was removed from the glass cloth-based, epoxy resin, double-sided copper-clad laminate. The PET film ("501010" manufactured by Lintec) was also peeled off to obtain a sheet of cured product. The resulting cured product is referred to as the "cured product for evaluation."

[0295] (2) Determination of dielectric constant

[0296] The evaluation samples were cut into pieces of 80 mm in length and 2 mm in width. The relative dielectric constant of these samples was measured using an Agilent Technologies HP8362B instrument using the cavity perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. Two test pieces were measured, and the average value was calculated. Evaluation was performed based on the following criteria:

[0297] ○: Dielectric constant less than 3.0

[0298] ×: The dielectric constant is 3.0 or more.

[0299] (3) Measurement and evaluation of linear thermal expansion coefficient and glass transition temperature

[0300] The cured product for evaluation was cut into test pieces with a width of approximately 5 mm and a length of approximately 15 mm. Thermomechanical analysis was performed using a thermomechanical analyzer (Rigaku Corporation, "Thermo Plus TMA8310") using the tensile load method. The test piece was loaded into the aforementioned apparatus and measured twice continuously under the measurement conditions of a load of 1 g and a heating rate of 5°C / minute. In the second measurement, the glass transition temperature and the average linear thermal expansion coefficient from 25°C to 150°C were calculated, and evaluation was performed based on the following criteria:

[0301] ○: Linear thermal expansion coefficient is less than 30ppm

[0302] ×: The linear thermal expansion coefficient is 30 ppm or more.

[0303] (4) Evaluation of process suitability

[0304] Using a FIB-SEM hybrid device (SII Nanotechnologies, Inc., "SMI3050SE"), cross-sections of the evaluation cured products were observed at a magnification of 14,000x. The resulting FIB-SEM images were used to examine the presence of microbubbles in Examples 1 to 4 and Comparative Example 1, and evaluated according to the following criteria. It should be noted that for each evaluation cured product, measurements were performed on 10 random fields of view.

[0305] ○: Microbubbles present

[0306] ×: Microbubbles disappear

[0307] In addition, since Comparative Examples 2 and 3 did not contain microbubbles, the evaluation of process suitability could not be performed.

[0308] (5) Determination of bubble content of cured product

[0309] Resin varnishes 1 to 5 were prepared in the same manner as resin varnishes 1 to 5 except that they did not contain microbubbles. These resin varnishes were applied to the release-treated surface of the fixed PET film using a die coater in such a manner that the thickness of the dried resin composition layer became 40 μm, and dried at 80° C. to 120° C. (average 100° C.) for 6 minutes to obtain a resin sheet. Next, the resin composition layer was thermally cured under the curing conditions of being placed in an oven at 180° C. and thermally cured for 90 minutes. After thermal curing, the polyimide tape was peeled off, and the cured product was removed from the glass cloth substrate epoxy resin double-sided copper-clad laminate. A PET film (“501010” manufactured by Lintec) was further added to obtain a sheet-like cured product. The specific gravity of the sheet-like cured product was measured using an analytical balance XP105 manufactured by METTLER TOLEDO (using a specific gravity measurement component). It is referred to as “ρref”. In addition, the specific gravity of the evaluation cured product was measured in the same manner as the specific gravity of the sheet-like cured product. This specific gravity is referred to as "ρs". The bubble content (volume %) was calculated using the following formula:

[0310] Bubble content of cured product (volume %) = (1-(ρs / ρref)) × 100

[0311] In addition, since Comparative Examples 2 and 3 did not contain microbubbles, the bubble content of the cured product could not be measured.

[0312] <Evaluation of insulation reliability>

[0313] Resin varnishes 1 to 7 obtained in Examples and Comparative Examples were uniformly applied to the release surface of a polyethylene terephthalate film ("AL5" manufactured by Lintec, 38 μm thick) with a release treatment as a support, and dried at 80-120°C (average 100°C) for 5 minutes to produce a resin sheet with a support. Next, the resin sheet with a support was laminated onto TAB tape with an L / S ratio of 20 μm / 20 μm using a batch vacuum laminator (VP160 manufactured by Nichigo-Morton Co., Ltd.). The resin composition layer was then cured by heating at 180°C for 90 minutes in a batch oven to produce an insulating layer. The electrical resistance of the cured insulating layer was measured at seven locations. Subsequently, the insulating layer was left for 100 hours at 130°C and 85% Rh using a HAST tester ("ETAC PM422" manufactured by Kusumoto Chemicals Co., Ltd.), and the electrical resistance was measured at seven locations. For insulation, the resistance value is 10 6 Ω and above are considered to be good insulation, and resistance values ​​less than 10 6 Ω is considered as poor insulation, and the insulation reliability is evaluated according to the following criteria:

[0314] ◎: 7 samples showed good insulation both initially and after HAST

[0315] ○: Six samples showed good insulation both initially and after HAST.

[0316] △: There are 5 samples with good insulation both initially and after HAST

[0317] ×: There are less than 5 samples with good insulation both initially and after HAST.

[0318] <Measurement of mechanical strength>

[0319] The cured product for evaluation was subjected to a tensile test using a TENSILON universal testing machine ("RTC-1250A" manufactured by Orientec) in accordance with Japanese Industrial Standards (JIS K7127) to measure the elastic modulus and elongation at break.

[0320] [Table 2]

[0321] (Table 2)

[0322]

Claims

1. A resin composition comprising bubbles, a liquid epoxy resin and an inorganic filler, The viscosity of the liquid epoxy resin at 25°C is 300 mPa·s or more and 5000 mPa·s or less. When the non-volatile component in the resin composition is 100% by mass, the content of the inorganic filler is 50% by mass or more, and the gas component constituting the bubbles is one or more gases selected from the group consisting of air, rare gas, oxygen, nitrogen, and carbon dioxide. The average particle size of the bubbles is 0.1 μm or more and 60 μm or less. The standard deviation of the bubble particle size is 0.1 μm or more and 25 μm or less. When the nonvolatile component in the resin composition is 100% by volume, the content of bubbles is 1% by volume or more and 85% by volume or less.

2. The resin composition according to claim 1, wherein The average particle size of the bubbles is 50 μm or less.

3. The resin composition according to claim 1, wherein The average particle size of the bubbles is 45 μm or less.

4. The resin composition according to claim 1, wherein The average particle size of the bubbles is 5 μm or less.

5. The resin composition according to claim 1, wherein The average particle size of the bubbles is 1 μm or more. The resin composition according to claim 1 , wherein When the nonvolatile component in the resin composition is 100% by volume, the content of bubbles is 1% by volume or more and 58% by volume or less.

7. The resin composition according to claim 1, wherein The bubbles are microbubbles.

8. The resin composition according to claim 1, wherein When the nonvolatile component in the resin composition is 100% by mass, the content of the liquid epoxy resin is 1% by mass or more and 30% by mass or less.

9. The resin composition according to claim 1, wherein When the nonvolatile component in the resin composition is 100% by mass, the content of the liquid epoxy resin is 5% by mass or more.

10. The resin composition according to claim 1, wherein When the nonvolatile component in the resin composition is 100% by mass, the content of the liquid epoxy resin is 10% by mass or less.

11. The resin composition according to claim 1, wherein The viscosity of the liquid epoxy resin at 25° C. is 1000 mPa·s or more.

12. The resin composition according to claim 1, wherein The viscosity of the liquid epoxy resin at 25° C. is 3000 mPa·s or less.

13. The resin composition according to claim 1, wherein When the non-volatile component in the resin composition is 100% by mass, the content of the inorganic filler is 70% by mass or more.

14. The resin composition according to claim 1, wherein When the nonvolatile component in the resin composition is 100% by mass, the content of the inorganic filler is 90% by mass or less.

15. The resin composition according to claim 1, wherein When the nonvolatile component in the resin composition is 100% by mass, the content of the inorganic filler is 80% by mass or less. The resin composition according to claim 1 , which is used for forming an insulating layer. 17 . The resin composition according to claim 1 , which is used for forming an insulating layer, wherein the insulating layer is an insulating layer for forming a conductor layer.

18. A resin sheet comprising: Support, and A resin composition layer provided on the support and comprising the resin composition according to any one of claims 1 to 17. 19 . A printed wiring board comprising an insulating layer formed from a cured product of the resin composition according to claim 1 . 20 . A semiconductor device comprising the printed wiring board according to claim 19 .

21. A liquid epoxy resin containing bubbles, wherein: The viscosity of the liquid epoxy resin at 25°C is 300 mPa·s or more and 5000 mPa·s or less. The gas component constituting the bubbles is one or more gases selected from the group consisting of air, rare gas, oxygen, nitrogen, and carbon dioxide. The average particle size of the bubbles is 0.1 μm or more and 60 μm or less. The standard deviation of the bubble particle size is 0.1 μm or more and 25 μm or less. When the nonvolatile component in the liquid epoxy resin is 100% by volume, the content of bubbles is 1% by volume or more and 85% by volume or less.

22. The liquid epoxy resin according to claim 21, wherein When the nonvolatile component in the liquid epoxy resin is 100% by volume, the content of bubbles is 1% by volume or more and 58% by volume or less.

23. A method for producing a resin composition comprising: bubbles, a liquid epoxy resin, and an inorganic filler. The method comprises the steps of (a) dispersing bubbles in a resin component having a viscosity at 25° C. of 300 mPa·s or more and 5000 mPa·s or less, When the non-volatile component in the resin composition is 100% by mass, the content of the inorganic filler is 50% by mass or more, and the gas component constituting the bubbles is one or more gases selected from the group consisting of air, rare gas, oxygen, nitrogen, and carbon dioxide. The average particle size of bubbles contained in the resin composition is 0.1 μm or more and 60 μm or less, The standard deviation of the particle size of bubbles contained in the resin composition is 0.1 μm or more and 25 μm or less, When the nonvolatile component in the resin composition is 100% by volume, the content of bubbles contained in the resin composition is 1% by volume or more and 85% by volume or less.

24. The method for producing a resin composition according to claim 23, wherein The viscosity of the resin component at 25° C. is 1000 mPa·s or more.

25. The method for producing a resin composition according to claim 23, wherein The viscosity of the resin component at 25° C. is 3000 mPa·s or less.

26. The method for producing a resin composition according to claim 23, wherein When the nonvolatile component in the resin composition is 100% by volume, the content of bubbles contained in the resin composition is 1% by volume or more and 58% by volume or less.

27. The method for producing a resin composition according to claim 23, wherein The resin component comprises liquid epoxy resin.

28. The method for producing a resin composition according to claim 23, wherein When the non-volatile component in the resin composition is 100% by mass, the content of the liquid epoxy resin in the resin composition is 1% by mass or more.

29. The method for producing a resin composition according to claim 23, wherein When the nonvolatile component in the resin composition is 100% by mass, the content of the liquid epoxy resin in the resin composition is 5% by mass or more.

30. The method for producing a resin composition according to claim 23, wherein When the nonvolatile component in the resin composition is 100% by mass, the content of the liquid epoxy resin in the resin composition is 30% by mass or less.

31. The method for producing a resin composition according to claim 23, wherein When the nonvolatile component in the resin composition is 100% by mass, the content of the liquid epoxy resin in the resin composition is 10% by mass or less.

32. The method for producing a resin composition according to claim 23, wherein The cell ratio of the cells in the resin component is 30% by volume or more and 90% by volume or less.

33. The method for producing a resin composition according to claim 23, wherein The cell ratio of cells in the resin component is 50% by volume or more.

34. The method for producing a resin composition according to claim 23, wherein The cell ratio of cells in the resin component is 85% by volume or less.

35. A method for producing a liquid epoxy resin, which is a method for producing a liquid epoxy resin containing bubbles. The method comprises the steps of (a) dispersing bubbles in a resin component having a viscosity at 25° C. of 300 mPa·s or more and 5000 mPa·s or less, The gas component constituting the bubbles is one or more gases selected from the group consisting of air, rare gas, oxygen, nitrogen, and carbon dioxide. The average particle size of bubbles contained in the liquid epoxy resin is 0.1 μm or more and 60 μm or less. The standard deviation of the particle size of bubbles contained in the liquid epoxy resin is 0.1 μm or more and 25 μm or less. When the nonvolatile component in the liquid epoxy resin is 100% by volume, the content of bubbles contained in the liquid epoxy resin is 1% by volume or more and 85% by volume or less.

36. The method for producing a liquid epoxy resin according to claim 35, wherein: When the nonvolatile component in the liquid epoxy resin is 100% by volume, the content of bubbles contained in the liquid epoxy resin is 1% by volume or more and 58% by volume or less.

37. A method for manufacturing a printed wiring board, the method comprising: (I) forming a resin composition layer comprising the resin composition according to any one of claims 1 to 17 on an inner layer substrate, and (II) A step of thermally curing the resin composition layer to form an insulating layer.

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