Resin composition

Abstract

To provide a resin composition which can obtain a cured product which can reduce tackiness even when an inorganic filler is blended in a small amount and has excellent flexibility and excellent insulation reliability.SOLUTION: The resin composition contains (A) an epoxy resin, (B) an inorganic filler and (C) a polyimide resin, in which the component (A) contains (A-1) a siloxane skeleton-containing epoxy resin, and a content of the component (B) is 40 mass% or less when a non-volatile component in the resin composition is 100 mass%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition containing a polyimide resin, and further to a cured product, a resin sheet, a multilayer flexible substrate, and a semiconductor device obtained by using the resin composition. [Background technology]

[0002] In recent years, there has been an increasing demand for thinner, lighter, and more densely packed semiconductor components. To meet this demand, the use of flexible boards as substrates for semiconductor components has been attracting attention. Flexible boards can be made thinner and lighter than rigid boards. Furthermore, flexible boards are flexible and deformable, so they can be folded for mounting.

[0003] Insulating materials for flexible substrates generally need to be blended with flexible resins such as polyimide resins, but blending polyimide resins can increase tackiness (adhesiveness) and make them difficult to handle. Blending with inorganic fillers can reduce tackiness (Patent Document 1), but as the blending rate of inorganic fillers increases, it becomes difficult to achieve flexibility. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-95047 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a resin composition and the like which can suppress tackiness to a low level despite the low content of inorganic filler, and which can give a cured product having excellent flexibility and excellent insulation reliability. [Means for solving the problem]

[0006] Means for Solving the Problems of the Invention The present inventors conducted intensive research in order to achieve the objects of the present invention, and as a result, discovered that by using a resin composition comprising (A) an epoxy resin, (B) an inorganic filler, and (C) a polyimide resin, where component (A) comprises (A-1) a siloxane skeleton-containing epoxy resin, it is possible to keep tackiness low even when the content of inorganic filler (B) is as low as 40 mass% or less, and to obtain a cured product having excellent flexibility and excellent insulation reliability, thereby completing the present invention.

[0007] That is, the present invention includes the following. [1] A resin composition comprising (A) an epoxy resin, (B) an inorganic filler, and (C) a polyimide resin, The component (A) contains (A-1) a siloxane skeleton-containing epoxy resin, A resin composition, the content of the component (B) being 40 mass% or less, when the total amount of non-volatile components in the resin composition is taken as 100 mass%. [2] The resin composition according to the above [1], wherein the component (A-1) is a cyclic siloxane skeleton-containing epoxy resin. [3] The component (A-1) is represented by the formula (A1):

[0008] [ka]

[0009] [In the formula, R 1 each independently represents an epoxyalkyl group; R 2 each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group; R 3 and R 4 each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R 3 and R 4are bonded to each other to form a cyclic siloxane skeleton; and s is an integer of 1 or more. [4] The resin composition according to any one of the above [1] to [3], wherein the molecular weight of the component (A-1) is 800 or less. [5] The resin composition according to any one of the above [1] to [4], wherein the epoxy equivalent of the component (A-1) is 150 g / eq. to 250 g / eq. [6] The resin composition according to any one of the above [1] to [5], wherein the content of the component (A-1) is 5% by mass or more, based on 100% by mass of the non-volatile components in the resin composition. [7] The resin composition according to any one of the above [1] to [6], wherein the content of the component (A-1) is 10 mass % or less, based on 100 mass % of the non-volatile components in the resin composition. [8] The resin composition according to any one of the above [1] to [7], wherein the average particle size of the component (B) is 1 μm or less. [9] The resin composition according to any one of the above [1] to [8], wherein the component (B) is silica.

[10] The resin composition according to any one of the above [1] to [9], wherein the weight average molecular weight of the component (C) is 1,000 or more and 100,000 or less.

[11] The resin composition according to any one of the above [1] to

[10] , wherein the content of the component (C) is 20 mass% or more, based on 100 mass% of the non-volatile components in the resin composition.

[12] The resin composition according to any one of the above [1] to

[11] , wherein the content of the component (C) is 30 mass % or less, based on 100 mass % of the non-volatile components in the resin composition.

[13] The resin composition according to any one of the above [1] to

[12] , further comprising (D) a curing agent.

[14] The resin composition according to the above

[13] , wherein the component (D) contains an active ester-based curing agent.

[15] The resin composition according to any one of the above [1] to

[14] , which is for forming an insulating layer of a multilayer flexible substrate.

[16] A cured product of the resin composition according to any one of [1] to

[15] above.

[17] A resin sheet comprising a support and a resin composition layer formed on the support from the resin composition according to any one of [1] to

[15] above.

[18] A multilayer flexible substrate comprising an insulating layer formed by curing the resin composition according to any one of the above [1] to

[15] .

[19] A semiconductor device comprising the multilayer flexible substrate described in

[18] above. Effect of the Invention

[0010] According to the resin composition of the present invention, tackiness can be suppressed to a low level despite the low content of inorganic filler, and a cured product having excellent flexibility and excellent insulation reliability can be obtained. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described in detail below with reference to preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and can be modified and implemented as desired without departing from the scope of the claims of the present invention and their equivalents.

[0012] <Resin composition> The resin composition of the present invention is a resin composition containing (A) an epoxy resin, (B) an inorganic filler, and (C) a polyimide resin, in which the (A) component contains (A-1) a siloxane skeleton-containing epoxy resin, and the (B) component is contained in an amount of 40 mass% or less. By using such a resin composition, it is possible to suppress tackiness to a low level despite the low content of inorganic filler, and to obtain a cured product having excellent flexibility and excellent insulation reliability.

[0013] The resin composition of the present invention may further contain optional components in addition to (A) epoxy resin, (B) inorganic filler, and (C) polyimide resin. Examples of the optional components include (D) curing agent, (E) curing accelerator, (F) other additives, and (G) organic solvent. Each component contained in the resin composition will be described in detail below.

[0014] <(A) Epoxy resin> The resin composition of the present invention contains an epoxy resin (A). The epoxy resin (A) means a curable resin having an epoxy group. The epoxy resin (A) also includes modified epoxy resins.

[0015] The content of the epoxy resin (A) in the resin composition is not particularly limited, but is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and particularly preferably 30% by mass or more, when the non-volatile components in the resin composition are 100% by mass. The upper limit of the content of the epoxy resin (A) in the resin composition is not particularly limited, but is preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, and particularly preferably 40% by mass or less, when the non-volatile components in the resin composition are 100% by mass.

[0016] <(A-1) Siloxane skeleton-containing epoxy resin> The (A) epoxy resin includes (A-1) a siloxane skeleton-containing epoxy resin. (A-1) A siloxane skeleton-containing epoxy resin refers to a compound having two or more epoxy groups and a siloxane (Si-O-Si) bond.

[0017] The (A-1) siloxane skeleton-containing epoxy resin may be either a cyclic siloxane skeleton-containing epoxy resin or a chain siloxane skeleton-containing epoxy resin, but is preferably a cyclic siloxane skeleton-containing epoxy resin.

[0018] The number of silicon atoms forming siloxane bonds in the siloxane skeleton-containing epoxy resin (A-1) is not particularly limited, but may be preferably 3 or more, and preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and even more preferably 5 or less in one molecule. The number is particularly preferably 4.

[0019] The number of epoxy groups in the siloxane skeleton-containing epoxy resin (A-1) is not particularly limited, but may be preferably 3 or more, and preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and even more preferably 5 or less in one molecule. The number is particularly preferably 4.

[0020] It is preferred that all substitutable sites of the silicon atoms in the siloxane skeleton-containing epoxy resin (A-1) are substituted with a hydrocarbon group such as an alkyl group, an alkenyl group, an aryl group, or the like, which may or may not have an epoxy group. The hydrocarbon group may have a substituent other than an epoxy group.

[0021] The siloxane skeleton-containing epoxy resin (A-1) is preferably represented by the formula (A1):

[0022] [ka]

[0023] [In the formula, R 1 each independently represents an epoxyalkyl group; R 2 each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group; R 3 and R 4 each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R 3 and R 4 are combined together to represent one -O- group and bonded to each other to form a cyclic siloxane skeleton; and s represents an integer of 1 or more.

[0024] The term "alkyl group" refers to a linear, branched, and / or cyclic monovalent aliphatic saturated hydrocarbon group. The "alkyl group" is preferably an alkyl group having 1 to 10 carbon atoms. Examples of the "alkyl group" include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a sec-pentyl group, a tert-pentyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a 2-cyclohexylmethyl group, a 2-cyclopentylethyl group, and a 2-cyclohexylethyl group.

[0025] The term "epoxy alkyl group" refers to a group in which two hydrogen atoms bonded to different carbon atoms of an alkyl group are replaced by one oxygen atom to form an oxacyclopropane (ethylene oxide) ring. The "epoxy alkyl group" is preferably an epoxy alkyl group having 2 to 10 carbon atoms. Examples of the "epoxy alkyl group" include linear epoxy alkyl groups such as 2,3-epoxypropyl group, 3,4-epoxybutyl group, 4,5-epoxypentyl group, and 5,6-epoxyhexyl group; branched epoxy alkyl groups such as 2,3-epoxy-2-methylpropyl group and 3,4-epoxy-3-methylbutyl group; cyclic epoxy alkyl groups such as 2,3-epoxycyclopentyl group, 3,4-epoxycyclopentyl group, 2,3-epoxycyclohexyl group, and 3,4-epoxycyclohexyl group; 2,3-epoxycyclopentylmethyl group, 3,4-epoxycyclopentylmethyl group, 2,3-epoxycyclohexylmethyl group, 3,4-epoxycyclohexylmethyl group, 2-(2,3-epoxycyclopent ...

[0113] Examples of such cyclic epoxyalkyl groups include linear alkyl groups having a cyclic epoxyalkyl group at the terminal, such as a 2-(3,4-epoxycyclopentyl)ethyl group, a 2-(2,3-epoxycyclohexyl)ethyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-(2,3-epoxycyclopentyl)propyl group, a 3-(3,4-epoxycyclopentyl)propyl group, a 3-(2,3-epoxycyclohexyl)propyl group, a 3-(3,4-epoxycyclohexyl)propyl group, a 4-(2,3-epoxycyclopentyl)butyl group, a 4-(3,4-epoxycyclopentyl)butyl group, a 4-(2,3-epoxycyclohexyl)butyl group, and a 4-(3,4-epoxycyclohexyl)butyl group.

[0026] The term "alkenyl group" refers to a linear, branched, and / or cyclic monovalent aliphatic unsaturated hydrocarbon group having at least one carbon-carbon double bond. The "alkenyl group" is preferably an alkenyl group having 2 to 10 carbon atoms. Examples of the "alkenyl group" include a vinyl group, a 1-propenyl group, a 2-propenyl group, a 2-methyl-1-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 3-methyl-2-butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, a 4-pentenyl group, a 4-methyl-3-pentenyl group, a 1-hexenyl group, a 3-hexenyl group, a 5-hexenyl group, and a 2-cyclohexenyl group.

[0027] The alkyl group in the "substituted or unsubstituted alkyl group" and the alkenyl group in the "substituted or unsubstituted alkenyl group" are not particularly limited, and examples thereof include a halogen atom, a cyano group, a nitro group, an alkyl-oxy group, an alkyl-carbonyl group, an alkyl-oxy-carbonyl group, an alkyl-carbonyl-oxy group, an alkenyl-oxy group, an alkenyl-carbonyl group, an alkenyl-oxy-carbonyl group, an alkenyl-carbonyl-oxy group, an aryl group, an aryl-oxy group, an aryl-carbonyl group, an aryl-oxy-carbonyl group, an aryl-carbonyl-oxy group, and the like, or a combination thereof. The number of the substituents is preferably 1 to 3, and more preferably 1.

[0028] The term "aryl group" refers to a monovalent aromatic hydrocarbon group. The "aryl group" is preferably an aryl group having 6 to 14 carbon atoms. Examples of the "aryl group" include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.

[0029] The substituent of the aryl group in the "substituted or unsubstituted aryl group" is not particularly limited, and examples thereof include a halogen atom, a cyano group, a nitro group, an alkyl group, an alkyl-oxy group, an alkyl-carbonyl group, an alkyl-oxy-carbonyl group, an alkyl-carbonyl-oxy group, an alkenyl group, an alkenyl-oxy group, an alkenyl-carbonyl group, an alkenyl-oxy-carbonyl group, an alkenyl-carbonyl-oxy group, an aryl group, an aryl-alkyl group, an aryl-alkenyl group, an aryl-oxy group, an aryl-carbonyl group, an aryl-oxy-carbonyl group, an aryl-carbonyl-oxy group, and the like, or a combination thereof. The number of the substituents is preferably 1 to 3, and more preferably 1.

[0030] The "halogen atom" includes, for example, a fluorine atom, a chlorine atom, a bromine atom, and the like.

[0031] In formula (A1), R 1 each independently represents an epoxyalkyl group, is preferably a linear alkyl group having a cyclic epoxyalkyl group at its terminal, is more preferably a methyl group having a cyclic epoxyalkyl group or an ethyl group having a cyclic epoxyalkyl group at its terminal, and is particularly preferably a 2-(3,4-epoxycyclohexyl)ethyl group.

[0032] In formula (A1), R 2 each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, preferably a substituted or unsubstituted alkyl group, more preferably an (unsubstituted) alkyl group, further preferably a methyl group, an ethyl group, a propyl group, or an isopropyl group, and particularly preferably a methyl group.

[0033] In formula (A1), R 3 and R 4 each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R 3and R 4 Together, they form a cyclic siloxane skeleton, with one -O- bond between them. 3 and R 4 Preferably, they are combined together to represent one -O- and bond to each other to form a cyclic siloxane skeleton.

[0034] In formula (A1), s represents an integer of 1 or more, and preferably an integer of 2 or more. s is preferably an integer of 9 or less, more preferably an integer of 7 or less, even more preferably an integer of 5 or less, and even more preferably an integer of 4 or less. Particularly preferably, s is 3.

[0035] Specific examples of the (A-1) siloxane skeleton-containing epoxy resin include linear siloxane skeleton-containing epoxy resins such as 1,3,5-tris(2-(3,4-epoxycyclohexyl)ethyl)-1,1,3,5,5-pentamethyltrisiloxane; 2,4,6,8-tetrakis(4-(3,4-epoxycyclopentyl)butyl)-2,4,6,8-tetramethylcyclotetrasiloxane, and 2,4,6,8-tetrakis(3-(3,4-epoxycyclopentyl)propyl)-2,4,6,8-tetramethylcyclotetrasiloxane. Examples of the epoxy resin include epoxy resins having a cyclic siloxane skeleton, such as 2,4,6,8-tetrakis(2-(3,4-epoxycyclohexyl)ethyl)-2,4,6,8-tetramethylcyclotetrasiloxane and 2,4,6,8,10-pentakis(2-(3,4-epoxycyclohexyl)ethyl)-2,4,6,8,10-pentamethylcyclopentasiloxane. Of these, 2,4,6,8-tetrakis(2-(3,4-epoxycyclohexyl)ethyl)-2,4,6,8-tetramethylcyclotetrasiloxane is particularly preferred.

[0036] (A-1) Examples of commercially available siloxane skeleton-containing epoxy resins include "KR-470" (main component: 2,4,6,8-tetrakis(2-(3,4-epoxycyclohexyl)ethyl)-2,4,6,8-tetramethylcyclotetrasiloxane) and "X-40-2667" (main component: 1,3,5-tris(2-(3,4-epoxycyclohexyl)ethyl)-1,1,3,5,5-pentamethyltrisiloxane), both manufactured by Shin-Etsu Chemical Co., Ltd.

[0037] The molecular weight of the siloxane skeleton-containing epoxy resin (A-1) is preferably 2,000 or less, more preferably 1,500 or less, even more preferably 1,000 or less, and particularly preferably 800 or less. The lower limit can be, for example, 200 or more, 400 or more, 600 or more, etc.

[0038] The epoxy equivalent of the siloxane skeleton-containing epoxy resin (A-1) is preferably 1,000 g / eq or less, more preferably 500 g / eq or less, even more preferably 300 g / eq or less, and particularly preferably 250 g / eq or less. The lower limit is preferably 50 g / eq or more, more preferably 100 g / eq or more, even more preferably 130 g / eq or more, and particularly preferably 150 g / eq or more.

[0039] The viscosity (25° C.) of the siloxane skeleton-containing epoxy resin (A-1) is preferably 100 mPa·s to 10,000 mPa·s, and more preferably 1,000 mPa·s to 5,000 mPa·s.

[0040] The content of the (A-1) siloxane skeleton-containing epoxy resin in the resin composition is not particularly limited, but is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, and particularly preferably 5% by mass or more, when the non-volatile components in the resin composition are 100% by mass. The upper limit of the content of the (A-1) siloxane skeleton-containing epoxy resin in the resin composition is not particularly limited, but is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 10% by mass or less, when the non-volatile components in the resin composition are 100% by mass.

[0041] <Any epoxy resin other than component (A-1)> The (A) epoxy resin may further contain any other epoxy resin in addition to the (A-1) siloxane skeleton-containing epoxy resin.

[0042] Examples of the optional epoxy resin other than the component (A-1) include bixylenol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, tetraphenylethane type epoxy resins, isocyanurate type epoxy resins, and glycidylcyclohexane type epoxy resins. Any epoxy resin may be used alone or in combination of two or more kinds.

[0043] The resin composition preferably contains an epoxy resin having two or more epoxy groups in one molecule as an optional epoxy resin other than the component (A-1). The proportion of the epoxy resin having two or more epoxy groups in one molecule relative to 100% by mass of the non-volatile components of the optional epoxy resin other than the component (A-1) is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0044] Epoxy resins include epoxy resins that are liquid at a temperature of 20° C. (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20° C. (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition of the present invention may contain only a liquid epoxy resin or only a solid epoxy resin as an optional epoxy resin other than the component (A-1), but it is preferable that the resin composition contains a combination of a liquid epoxy resin and a solid epoxy resin.

[0045] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0046] As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexane dimethanol type epoxy resin, and epoxy resin having a butadiene structure are preferred.

[0047] Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins) manufactured by DIC Corporation; "828US", "828EL", "jER828EL", "825", and "Epicoat 828EL" (bisphenol A type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", and "604" (glycidylamine type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycirol type epoxy resin) manufactured by ADEKA Corporation; and "EP-3950L" manufactured by ADEKA Corporation. Examples of such epoxy resins include "EP-3980S" (glycidylamine type epoxy resin); "EP-4088S" (dicyclopentadiene type epoxy resin) manufactured by ADEKA; "ZX1059" (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Chemical; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase Chemtex; "Celloxide 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel; "PB-3600" manufactured by Daicel, "JP-100" and "JP-200" (epoxy resin having a butadiene structure) manufactured by Nippon Steel & Sumitomo Metal Chemical; and "ZX1658" and "ZX1658GS" (cyclohexane type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Chemical. These may be used alone or in combination of two or more types.

[0048] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable.

[0049] As the solid epoxy resin, bixylenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, and tetraphenylethane type epoxy resin are preferred.

[0050] Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", and "HP-7200H" (dicyclopentadiene type epoxy resin) manufactured by DIC Corporation; and "EXA-731" manufactured by DIC Corporation. 1", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd. "ESN475V" (naphthalene type epoxy resin) from Nippon Steel Chemical & Material Co., Ltd.; "ESN485" (naphthol type epoxy resin) from Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene type epoxy resin) from Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", "YL7890" (bixylenol type epoxy resin) from Mitsubishi Chemical Co., Ltd.; "YL6121" (biphenyl type epoxy resin) from Mitsubishi Chemical Co., Ltd.; "YX8800" (anthracene type epoxy resin) from Mitsubishi Chemical Co., Ltd. epoxy resin); "YX7700" (xylene structure-containing novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation, etc. These may be used alone or in combination of two or more types.

[0051] When a liquid epoxy resin and a solid epoxy resin are used in combination as the optional epoxy resin other than the component (A-1), the mass ratio thereof (liquid epoxy resin:solid epoxy resin) is preferably in the range of 100:1 to 1:100, more preferably in the range of 10:1 to 1:40, and even more preferably in the range of 1:1 to 1:20.

[0052] The epoxy equivalent of any epoxy resin other than the component (A-1) is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 2,000 g / eq., even more preferably 70 g / eq. to 1,000 g / eq., and even more preferably 80 g / eq. to 500 g / eq. The epoxy equivalent is the mass of the resin per equivalent of epoxy group. This epoxy equivalent can be measured according to JIS K7236.

[0053] The weight average molecular weight (Mw) of any epoxy resin other than the component (A-1) is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0054] When the resin composition contains any epoxy resin other than the (A-1) component, the content of the epoxy resin other than the (A-1) component in the resin composition is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, when the non-volatile components in the resin composition are 100% by mass. The upper limit of the content of the epoxy resin other than the (A-1) component in the resin composition is not particularly limited, but is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less, when the non-volatile components in the resin composition are 100% by mass.

[0055] When the resin composition contains any epoxy resin other than the (A-1) component, the content of the (A-1) siloxane skeleton-containing epoxy resin in the (A) epoxy resin is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, when the total amount of the (A) epoxy resin is taken as 100% by mass. The upper limit of the content of the (A-1) siloxane skeleton-containing epoxy resin in the (A) epoxy resin is not particularly limited, but is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and particularly preferably 25% by mass or less, when the total amount of the (A) epoxy resin is taken as 100% by mass.

[0056] <(B) Inorganic filler> The resin composition of the present invention contains an inorganic filler (B). The inorganic filler (B) is contained in the resin composition in the form of particles.

[0057] (B) An inorganic compound is used as the material of the inorganic filler. (B) Examples of the material of the inorganic filler include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. In addition, spherical silica is preferable as the silica. The (B) inorganic filler may be used alone or in combination of two or more kinds in any ratio.

[0058] (B) Commercially available inorganic fillers include, for example, "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatechs Co., Ltd.; "Silfill NSS-3N", "Silfill NSS-4N", and "Silfill NSS-5N" manufactured by Tokuyama Corporation; "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs Co., Ltd.; and "UFP-30", "DAW-03", and "FB-105FD" manufactured by Denka Co., Ltd.

[0059] The average particle size of the (B) inorganic filler is not particularly limited, but is preferably 40 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, even more preferably 3 μm or less, and particularly preferably 1 μm or less. The lower limit of the average particle size of the (B) inorganic filler is not particularly limited, but is preferably 0.005 μm or more, more preferably 0.01 μm or more, even more preferably 0.05 μm or more, even more preferably 0.1 μm or more, even more preferably 0.2 μm or more, and particularly preferably 0.3 μm or more. The average particle size of the (B) inorganic filler can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is prepared on a volume basis using a laser diffraction / scattering type particle size distribution measuring device, and the median diameter is taken as the average particle size. The measurement sample can be prepared by weighing 100 mg of the inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing it by ultrasonic waves for 10 minutes. The measurement sample was measured using a laser diffraction type particle size distribution measuring device with blue and red light source wavelengths, and the particle size distribution of the inorganic filler on a volume basis was measured using a flow cell method, and the average particle size was calculated as the median diameter from the particle size distribution obtained. An example of a laser diffraction type particle size distribution measuring device is the "LA-960" manufactured by Horiba, Ltd.

[0060] The specific surface area of ​​the (B) inorganic filler is not particularly limited, but is preferably 0.1 m 2 / g or more, more preferably 0.5m 2 / g or more, more preferably 1m2 / g or more, particularly preferably 5m 2 The upper limit of the specific surface area of ​​the inorganic filler (B) is not particularly limited, but is preferably 50 m 2 / g or less, more preferably 30m 2 / g or less, more preferably 20m 2 / g or less, particularly preferably 15m 2 The specific surface area of ​​the inorganic filler is obtained by adsorbing nitrogen gas onto the surface of the sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountec Co., Ltd.) according to the BET method, and calculating the specific surface area using the BET multipoint method.

[0061] The inorganic filler (B) is preferably surface-treated with an appropriate surface treatment agent, which can enhance the moisture resistance and dispersibility of the inorganic filler (B). Examples of the surface treatment agent include vinyl-based silane coupling agents such as vinyltrimethoxysilane and vinyltriethoxysilane; epoxy-based silane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane; styryl-based silane coupling agents such as p-styryltrimethoxysilane; methacryl-based silane coupling agents such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; acrylic-based silane coupling agents such as 3-acryloxypropyltrimethoxysilane; N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, and N-2-(aminoethyl)-3-aminopropyltriethoxysilane; Amino-based silane coupling agents such as trimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-8-aminooctyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane; isocyanurate-based silane coupling agents such as tris-(trimethoxysilylpropyl)isocyanurate; ureido-based silane coupling agents such as 3-ureidopropyltrialkoxysilane; mercapto-based silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; isocyanate-based silane coupling agents such as 3-isocyanatepropyltriethoxysilane; acid anhydride-based silane coupling agents such as 3-trimethoxysilylpropylsuccinic anhydride; and other silane coupling agents;Examples of the non-silane coupling alkoxysilane compounds include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, and trifluoropropyltrimethoxysilane. Among these, amino-based silane coupling agents are preferred. The surface treatment agent may be used alone or in combination of two or more in any ratio.;

[0062] Commercially available surface treatment agents include, for example, "KBM-1003" and "KBE-1003" (vinyl-based silane coupling agents) manufactured by Shin-Etsu Chemical Co., Ltd.; "KBM-303", "KBM-402", "KBM-403", "KBE-402", and "KBE-403" (epoxy-based silane coupling agents); "KBM-1403" (styryl-based silane coupling agents); "KBM-502", "KBM-503", "KBE-502", and "KBE-503" (methacrylic-based silane coupling agents); "KBM-5103" (acrylic-based silane coupling agents); "KBM-602", "KBM-603", "KBM-903", "KBE-903", "KBE-9103P", "KBM-573", and "KBM-575" (amino-based silane coupling agents); Examples include "KBM-9659" (isocyanurate-based silane coupling agent); "KBE-585" (ureido-based silane coupling agent); "KBM-802", "KBM-803" (mercapto-based silane coupling agent); "KBE-9007N" (isocyanate-based silane coupling agent); "X-12-967C" (acid anhydride-based silane coupling agent); "KBM-13", "KBM-22", "KBM-103", "KBE-13", "KBE-22", "KBE-103", "KBM-3033", "KBE-3033", "KBM-3063", "KBE-3063", "KBE-3083", "KBM-3103C", "KBM-3066", and "KBM-7103" (non-silane coupling alkoxysilane compound).

[0063] From the viewpoint of improving the dispersibility of the inorganic filler, the degree of surface treatment with the surface treatment agent is preferably within a predetermined range. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably 0.2% to 3% by mass, and even more preferably 0.3% to 2% by mass.

[0064] The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler is set to 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2 More preferably, 0.2 mg / m or more 2 On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition or the melt viscosity in the form of a sheet, it is more preferable that the melt viscosity is 1.0 mg / m 2 Less than 0.8 mg / m is preferred. 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred:

[0065] (B) The amount of carbon per unit surface area of ​​the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, the "EMIA-320V" manufactured by Horiba, Ltd., or the like can be used.

[0066] The content of the (B) inorganic filler in the resin composition is 40% by mass or less, preferably 38% by mass or less, more preferably 36% by mass or less, even more preferably 34% by mass or less, and particularly preferably 32% by mass or less, when the non-volatile components in the resin composition are 100% by mass. The lower limit of the content of the (B) inorganic filler in the resin composition is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and particularly preferably 30% by mass or more, when the non-volatile components in the resin composition are 100% by mass.

[0067] <(C) Polyimide resin> The resin composition of the present invention contains a polyimide resin (C). The polyimide resin (C) is a resin having an imide bond in the repeating unit. The polyimide resin (C) may generally contain (1) a resin obtained by an imidization reaction between a diamine compound and a tetracarboxylic acid anhydride, or (2) a resin obtained by an imidization reaction between a diisocyanate compound and a tetracarboxylic acid anhydride. The polyimide resin (C) also includes modified polyimide resins such as siloxane-modified polyimide resins.

[0068] The polyimide resin (C) is not particularly limited, but may be, for example, a polyimide resin represented by the formula (C1):

[0069] [ka]

[0070] [In the formula, X 1 represents a tetravalent group obtained by removing two -CO-O-CO- from a tetracarboxylic dianhydride, and may be, for example, an organic group having two or more (e.g., 2 to 3,000, 2 to 1,000, 2 to 100, or 2 to 50) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms. X 2 represents a divalent group obtained by removing two -NH2 from a diamine compound, or a divalent group obtained by removing two -NCO from a diisocyanate compound, and may be, for example, an organic group consisting of two or more (e.g., 2 to 3,000, 2 to 1,000, 2 to 100, 2 to 50) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms. n represents an integer of 2 or more.]. X in formula (C1) 1 and X 2 The organic group is not particularly limited as long as it is within the range of a chemically stable structure, and may be a structure appropriately selected by a person skilled in the art, for example, a structure of a known polyimide resin. When the (C) polyimide resin contains a structure represented by formula (C1), it preferably contains 60 mass % or more of the structure represented by formula (C1), more preferably contains 80 mass % or more, further preferably contains 90 mass % or more, and particularly preferably contains 95 mass % or more.

[0071] The diamine compound for preparing the (C) polyimide resin is not particularly limited, but examples thereof include aliphatic diamine compounds and aromatic diamine compounds.

[0072] Examples of the aliphatic diamine compound include linear aliphatic diamine compounds such as 1,2-ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-hexamethylenediamine, 1,5-diaminopentane, and 1,10-diaminodecane; branched aliphatic diamine compounds such as 1,2-diamino-2-methylpropane, 2,3-diamino-2,3-butane, and 2-methyl-1,5-diaminopentane; alicyclic diamine compounds such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, and 4,4'-methylenebis(cyclohexylamine); and dimer acid diamines (hereinafter also referred to as "dimer diamines").

[0073] The dimer acid type diamine means a diamine compound obtained by substituting two terminal carboxyl groups (-COOH) of a dimer acid with an aminomethyl group (-CH2-NH2) or an amino group (-NH2). Dimer acid is a known compound obtained by dimerizing an unsaturated fatty acid (preferably one having 11 to 22 carbon atoms, particularly preferably one having 18 carbon atoms), and its industrial production process is almost standardized in the industry. Dimer acid is easily obtained, mainly consisting of a dimer acid having 36 carbon atoms obtained by dimerizing an unsaturated fatty acid having 18 carbon atoms, such as oleic acid and linoleic acid, which are particularly inexpensive and easily available. In addition, dimer acid may contain any amount of monomer acid, trimer acid, other polymerized fatty acid, etc., depending on the production method, degree of purification, etc. In addition, although double bonds remain after the polymerization reaction of unsaturated fatty acid, in this specification, hydrogenated products in which the degree of unsaturation is reduced by further hydrogenation reaction are also included in dimer acid. Dimer acid diamines are commercially available, such as "PRIAMINE 1073", "PRIAMINE 1074", and "PRIAMINE 1075" manufactured by Croda Japan, and "VERSAMINE 551" and "VERSAMINE 552" manufactured by Cognis Japan.

[0074] Examples of the aromatic diamine compounds include phenylenediamine compounds such as 1,4-phenylenediamine, 1,2-phenylenediamine, 1,3-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,5-diaminobiphenyl, and 2,4,5,6-tetrafluoro-1,3-phenylenediamine; naphthalenediamine compounds such as 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,6-diaminonaphthalene, and 2,3-diaminonaphthalene; and 4,4'-diamino-2,2' -Ditrifluoromethyl-1,1'-biphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4-aminophenyl 4-aminobenzoate, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-aminophenyl)propane , 4,4'-(hexafluoroisopropylidene)dianiline, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, α,α-bis[4-(4-aminophenoxy)phenyl]-1,3-diisopropylbenzene, α,α-bis[4-(4-aminophenoxy)phenyl]-1,4-diisopropylbenzene, 4,4'-(9-fluorenylidene)dianiline, 2,2-bis(3-methyl-4-aminopheny dianiline compounds such as 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane, and 5-amino-1,1'-biphenyl-2-yl 4-aminobenzoate.

[0075] The diamine compound may be a commercially available product or may be synthesized by a known method. The diamine compound may be used alone or in combination of two or more kinds.

[0076] The diisocyanate compound for preparing the (C) polyimide resin is not particularly limited, but examples thereof include aliphatic diisocyanate compounds, aromatic diisocyanate compounds, and polyurethanes having isocyanate groups at both ends.

[0077] Examples of the aliphatic diisocyanate compound include linear aliphatic diisocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, and dodecamethylene diisocyanate; branched aliphatic diisocyanate compounds such as 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and 2,2-dimethylpentamethylene diisocyanate; isophorone diisocyanate (IPDI), 1,4-cyclohexyl Alicyclic diisocyanate compounds such as diisocyanate (CHDI), 4-methyl-1,3-cyclohexylene diisocyanate, 2-methyl-1,3-cyclohexylene diisocyanate, 2-methyl-1,4-cyclohexylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and 3a,4,5,6,7,7a-hexahydro-4,7-methanoindan-1,8-ylene diisocyanate; and dimer acid diisocyanates.

[0078] The dimer acid diisocyanate refers to a diisocyanate compound obtained by substituting an amino group (-NH2) of the above-described dimer acid diamine with an isocyanato group (-NCO).

[0079] Examples of aromatic diisocyanate compounds include phenylene diisocyanate compounds such as 1,4-phenylene diisocyanate, 1,3-phenylene diisocyanate, tolylene-2,6-diisocyanate, tolylene-2,4-diisocyanate, and tolylene-3,5-diisocyanate; naphthalene diisocyanate compounds such as 1,3-naphthalene diisocyanate, 1,6-naphthalene diisocyanate, 1,7-naphthalene diisocyanate, 1,8-naphthalene diisocyanate, 2,6-naphthalene diisocyanate, and 2,7-naphthalene diisocyanate; and bisisocyanatobenzene compounds such as 4,4'-diphenylmethane diisocyanate and 4,4'-diphenylether diisocyanate.

[0080] The polyurethane having isocyanato groups at both ends can be obtained by a urethane reaction between an aliphatic diisocyanate compound and / or an aromatic diisocyanate compound as described above and a polymer having hydroxy groups at both ends. The polymer having hydroxy groups at both ends can be, for example, a polyolefin having hydroxy groups at both ends, such as polybutadiene having hydroxy groups at both ends, hydrogenated polybutadiene having hydroxy groups at both ends, polyisoprene having hydroxy groups at both ends, or hydrogenated polyisoprene having hydroxy groups at both ends; a polyether having hydroxy groups at both ends, such as polyethylene glycol having hydroxy groups at both ends, polypropylene glycol having hydroxy groups at both ends, or polytetramethylene glycol having hydroxy groups at both ends, or the like.

[0081] The number average molecular weight of the polymer having hydroxy groups at both ends is not particularly limited, but is preferably 500 or more, more preferably 1,000 or more, and even more preferably 2,000 or more. The upper limit of the number average molecular weight of the polymer having hydroxy groups at both ends is not particularly limited, but is preferably 10,000 or less, more preferably 8,000 or less. The number average molecular weight here is a value measured by gel permeation chromatography (GPC) method (polystyrene equivalent).

[0082] The polyurethane having isocyanato groups at both ends is, for example, represented by the formula (C2):

[0083] [ka]

[0084] [In the formula, X 2a Each of X independently represents a divalent group obtained by removing two -NCO groups from an aliphatic diisocyanate compound or an aromatic diisocyanate compound, and may be, for example, an organic group having 2 to 50 skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms. 2b each independently represents a divalent group obtained by removing two -OH from a polymer having hydroxy groups at both ends, and may be, for example, an organic group having two or more (e.g., 2 to 1,000, 2 to 500) skeletal atoms selected from carbon atoms and oxygen atoms. m represents an integer of 1 to 10. The polyurethane has isocyanato groups at both ends and is represented by the following formula.

[0085] The diisocyanate compound may be a commercially available product, or may be synthesized by a known method or a method similar thereto. The diisocyanate compound may be used alone or in combination of two or more kinds.

[0086] The tetracarboxylic acid anhydride for preparing the (C) polyimide resin is not particularly limited, but examples thereof include aliphatic tetracarboxylic acid dianhydrides and aromatic tetracarboxylic acid dianhydrides.

[0087] Specific examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-cyclobutane tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyl tetracarboxylic dianhydride, carbonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, and sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride.

[0088] Examples of aromatic tetracarboxylic dianhydrides include benzenetetracarboxylic dianhydrides such as pyromellitic dianhydride and 1,2,3,4-benzenetetracarboxylic dianhydride; naphthalenetetracarboxylic dianhydrides such as 1,4,5,8-naphthalenetetracarboxylic dianhydride and 2,3,6,7-naphthalenetetracarboxylic dianhydride; anthracenetetracarboxylic dianhydrides such as 2,3,6,7-anthracenetetracarboxylic dianhydride; 3,3',4,4'-benzophenonetetracarboxylic dianhydride and 3,3' ,4,4'-Diphenylethertetracarboxylic acid dianhydride, 3,3',4,4'-Diphenylsulfonetetracarboxylic acid dianhydride, 3,3',4,4'-Biphenyltetracarboxylic acid dianhydride, 2,2',3,3'-Biphenyltetracarboxylic acid dianhydride, 2,3,3',4'-Biphenyltetracarboxylic acid dianhydride, 2,3,3',4'-Benzophenonetetracarboxylic acid dianhydride, 2,3,3',4'-Diphenylethertetracarboxylic acid dianhydride, 2,3,3',4'-Diphenylsulfonetetracarbo 2,2'-bis(3,4-dicarboxyphenoxyphenyl)sulfone dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethynylidene-4,4'-diphthalic dianhydride, 2,2-propylidene-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 1,3-bis(3,4-di 1,4-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, and diphthalic dianhydrides such as 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic dianhydride.

[0089] The tetracarboxylic dianhydride may be a commercially available product, or may be synthesized by a known method or a method similar thereto. The tetracarboxylic dianhydride may be used alone or in combination of two or more kinds.

[0090] The content of structures derived from aromatic tetracarboxylic dianhydrides relative to all structures derived from tetracarboxylic dianhydrides constituting the polyimide resin (C) is preferably 10 mol % or more, more preferably 30 mol % or more, even more preferably 50 mol % or more, still more preferably 70 mol % or more, still more preferably 90 mol % or more, and particularly preferably 100 mol %.

[0091] The weight average molecular weight of the polyimide resin (C) is not particularly limited, but is preferably at least 1,000, more preferably at least 3,000, even more preferably at least 5,000, and particularly preferably at least 7,000. The upper limit of the weight average molecular weight of the polyimide resin (C) is not particularly limited, but is preferably not more than 100,000, more preferably not more than 80,000, particularly preferably not more than 60,000, and particularly preferably not more than 50,000.

[0092] The number average molecular weight of the polyimide resin (C) is not particularly limited, but is preferably at least 1,000, more preferably at least 3,000, even more preferably at least 5,000, and particularly preferably at least 7,000. The upper limit of the number average molecular weight of the polyimide resin (C) is not particularly limited, but is preferably not more than 100,000, more preferably not more than 80,000, particularly preferably not more than 60,000, and particularly preferably not more than 50,000.

[0093] The content of the polyimide resin (C) in the resin composition is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, when the non-volatile components in the resin composition are 100% by mass. The upper limit of the content of the polyimide resin (C) in the resin composition is not particularly limited, but is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, and particularly preferably 30% by mass or less, when the non-volatile components in the resin composition are 100% by mass.

[0094] <(D) Hardener> The resin composition of the present invention may further comprise a curing agent (D). The curing agent (D) has the function of curing the epoxy resin (A).

[0095] The (D) curing agent is not particularly limited, but examples thereof include phenol-based curing agents, naphthol-based curing agents, acid anhydride-based curing agents, active ester-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, and carbodiimide-based curing agents. The curing agents may be used alone or in combination of two or more. The (D) curing agent preferably contains a curing agent selected from phenol-based curing agents, naphthol-based curing agents, and active ester-based curing agents, and particularly preferably contains an active ester-based curing agent.

[0096] As the phenol-based curing agent and naphthol-based curing agent, from the viewpoint of heat resistance and water resistance, a phenol-based curing agent having a novolac structure or a naphthol-based curing agent having a novolac structure is preferred. Also, from the viewpoint of adhesion to the adherend, a nitrogen-containing phenol-based curing agent or a nitrogen-containing naphthol-based curing agent is preferred, and a triazine skeleton-containing phenol-based curing agent or a triazine skeleton-containing naphthol-based curing agent is more preferred. Among them, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a triazine skeleton-containing phenol novolac resin is preferred. Specific examples of phenol-based curing agents and naphthol-based curing agents include, for example, "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Kasei Co., Ltd., "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd., "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-375", and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd., and "LA-7052", "LA-7054", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", and "TD-2090-60M" manufactured by DIC Corporation.

[0097] Examples of the acid anhydride curing agent include a curing agent having one or more acid anhydride groups in one molecule, and a curing agent having two or more acid anhydride groups in one molecule is preferable. Specific examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, and the like. Examples of acid anhydrides include polymeric acid anhydrides such as anhydrides, 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-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and styrene-maleic acid resins, which are copolymers of styrene and maleic acid. Commercially available acid anhydride hardeners include "HNA-100" and "MH-700" manufactured by New Japan Chemical Co., Ltd.

[0098] The active ester curing agent is not particularly limited, but generally, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are preferably used. The active ester curing agent is preferably one obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester curing agent obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferred. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolac, etc. Here, the term "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

[0099] Specifically, active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing an acetylated product of phenol novolac, and active ester compounds containing a benzoylated product of phenol novolac are preferred, and among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are more preferred. The "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentalene-phenylene.

[0100] Commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", "HPC-8000H", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L", "EXB-8000L-65M", and "EXB-8000L-65TM" (manufactured by DIC Corporation) as active ester compounds containing a dicyclopentadiene-type diphenol structure; and "EXB -9416-70BK", "EXB-8150-65T", "EXB-8100L-65T", "EXB-8150L-65T" (manufactured by DIC Corporation); as an active ester type curing agent which is an acetylated product of phenol novolac, "DC808" (manufactured by Mitsubishi Chemical Corporation); as active ester type curing agents which are benzoylated products of phenol novolac, "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), "YLH1048" (manufactured by Mitsubishi Chemical Corporation); and the like.

[0101] Specific examples of benzoxazine-based curing agents include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation; "HFB2006M" manufactured by Showa Polymer Co., Ltd.; and "Pd" and "Fa" manufactured by Shikoku Chemical Industry Co., Ltd.

[0102] Examples of the cyanate ester curing agent include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate ester-based curing agents include "PT30" and "PT60" (both of which are phenol novolac-type multifunctional cyanate ester resins), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been converted to triazine to form a trimer), all of which are manufactured by Lonza Japan.

[0103] Specific examples of carbodiimide-based curing agents include "V-03" and "V-07" manufactured by Nisshinbo Chemical Inc.

[0104] When the resin composition contains a (D) curing agent, the ratio of the amount of the (A) epoxy resin to the (D) curing agent is preferably 1:0.2 to 1:2, more preferably 1:0.3 to 1:1.5, and even more preferably 1:0.4 to 1:1.4, in terms of the ratio of [the number of epoxy groups in the (A) epoxy resin]:[the number of reactive groups in the (D) curing agent]. Here, the reactive groups of the (D) curing agent are, for example, aromatic hydroxyl groups in the case of phenol-based curing agents and naphthol-based curing agents, and active ester groups in the case of active ester-based curing agents, and vary depending on the type of curing agent.

[0105] The reactive group equivalent of the (D) curing agent is preferably 50 g / eq. to 3,000 g / eq., more preferably 100 g / eq. to 1,000 g / eq., further preferably 100 g / eq. to 500 g / eq., and particularly preferably 100 g / eq. to 300 g / eq. The reactive group equivalent is the mass of the curing agent per equivalent of reactive group.

[0106] When the (D) curing agent contains an active ester curing agent, its content is not particularly limited, but is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and particularly preferably 40% by mass or more, when the total amount of the (D) curing agent is taken as 100% by mass.

[0107] When the resin composition contains a (D) curing agent, the content of the (D) curing agent in the resin composition is not particularly limited, but is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, and particularly preferably 5% by mass or more, when the non-volatile components in the resin composition are 100% by mass. The upper limit of the content of the (D) curing agent in the resin composition is not particularly limited, but is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 8% by mass or less, when the non-volatile components in the resin composition are 100% by mass.

[0108] <(E) Curing accelerator> The resin composition of the present invention may contain, as an optional component, (E) a curing accelerator which has the function of accelerating the curing of (A) the epoxy resin.

[0109] (E) The curing accelerator is not particularly limited, but examples thereof include phosphorus-based curing accelerators, urea-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators. Among them, phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, and metal-based curing accelerators are preferred, and imidazole-based curing accelerators are particularly preferred. The curing accelerator may be used alone or in combination of two or more types.

[0110] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrabutyl phosphonium acetate, tetrabutyl phosphonium decanoate, tetrabutyl phosphonium laurate, bis(tetrabutyl phosphonium)pyromellitate, tetrabutyl phosphonium hydrogen hexahydrophthalate, tetrabutyl phosphonium cresol novolac trimer salt, and di-tert-butylmethyl phosphonium tetraphenylborate; methyl triphenyl phosphonium bromide, ethyl triphenyl phosphonium bromide, propyl triphenyl phosphonium bromide, butyl triphenyl phosphonium bromide, benzyl triphenyl phosphonium chloride, tetraphenyl phosphonium bromide, p-tolyl triphenyl phosphonium tetra-p-tolyl borate, and tetraphenyl phosphonium tetraphenyl borate. aromatic phosphonium salts such as tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone adducts such as triphenylphosphine-p-benzoquinone adduct; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine Examples of aromatic phosphines include tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether.

[0111] Examples of the urea-based curing accelerator include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. aromatic dimethylureas such as butylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea].

[0112] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine (DMAP), benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, with 4-dimethylaminopyridine being preferred.

[0113] Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct imidazole compounds such as 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds and epoxy resins.

[0114] As the imidazole-based curing accelerator, a commercially available product may be used, for example, "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0115] Examples of the guanidine 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-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0116] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, and organomanganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0117] When the resin composition contains the (E) curing accelerator, the content of the (E) curing accelerator in the resin composition is not particularly limited, but is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.05% by mass or more, and particularly preferably 0.1% by mass or more, when the non-volatile components in the resin composition are 100% by mass. The upper limit of the content of the (E) curing accelerator in the resin composition is not particularly limited, but is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less, when the non-volatile components in the resin composition are 100% by mass.

[0118] <(F) Other additives> The resin composition of the present invention may further contain any additive as a non-volatile component. Examples of such additives include organic fillers such as rubber particles, polyamide fine particles, and silicone particles; thermoplastic resins such as phenoxy resins, polyvinyl acetal resins, polyolefin resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, and polyester resins; organic metal compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; and leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents. ; thickeners such as bentone and montmorillonite; defoamers such as silicone-based defoamers, acrylic-based defoamers, fluorine-based defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; adhesion imparters such as triazole-based adhesion imparters, tetrazole-based adhesion imparters, and triazine-based adhesion imparters; antioxidants such as hindered phenol-based antioxidants and hindered amine-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, and red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide). The additives may be used alone or in combination of two or more in any ratio. (F) The content of other additives can be appropriately set by those skilled in the art.

[0119] <(G) Organic solvent> The resin composition of the present invention may further contain an arbitrary organic solvent as a volatile component in addition to the non-volatile components described above. As the (G) organic solvent, a known one may be appropriately used, and the type is not particularly limited. As the (G) organic solvent, for example, ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, etc.; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, etc.; alcohol-based solvents such as methanol, ethanol, propanol, butanol, ethylene glycol, etc.; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, methyl methoxypropionate, etc. Examples of the organic solvent include ether ester solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. The organic solvent (G) may be used alone or in combination of two or more in any ratio.

[0120] <Method of producing resin composition> The resin composition of the present invention can be produced, for example, by adding (A) epoxy resin, (B) inorganic filler, (C) polyimide resin (preliminarily imidized), if necessary (D) curing agent, if necessary (E) curing accelerator, if necessary (F) other additives, if necessary (G) organic solvent, in any order and / or all at once and mixing them in any reaction vessel. In addition, the temperature can be appropriately set during the process of adding and mixing each component, and heating and / or cooling may be performed temporarily or throughout. In addition, stirring or shaking may be performed during the process of adding and mixing each component. In addition, during or after adding and mixing, the resin composition may be stirred using a stirring device such as a mixer to disperse uniformly.

[0121] <Characteristics of resin composition> The resin composition of the present invention comprises (A) an epoxy resin, (B) an inorganic filler, and (C) a polyimide resin. Since component (A) comprises (A-1) an epoxy resin containing a siloxane skeleton, even when the content of inorganic filler (B) is as low as 40 mass% or less, tackiness can be kept low, and a cured product having excellent flexibility and excellent insulation reliability can be obtained.

[0122] The cured product of the resin composition of the present invention has excellent flexibility. For example, as in Test Example 1 described below, when a layered cured product of the resin composition having a thickness of 40 μm, a width of 15 mm and a length of 110 mm is subjected to an MIT folding endurance test in accordance with JIS C-5016 under conditions of a load of 2.5 N, a folding angle of 90 degrees, a folding speed of 175 times / min and a folding radius of 1.0 mm, the number of folding times can be preferably 3,000 or more, more preferably 5,000 or more, even more preferably 7,000 or more, and particularly preferably 8,000 or more.

[0123] The cured product of the resin composition of the present invention has excellent insulation reliability. For example, the insulation resistance value of the insulating layer of the evaluation substrate measured by the method of Test Example 3 described below is preferably 1.00×10 7 Ω or more, preferably 1.00×10 8 Ω or more, more preferably 1.00×109 Ω or more, particularly preferably 1.00×10 10 It can be Ω or more.

[0124] Since the resin composition of the present invention can suppress tackiness to a low level, for example, as in Test Example 2 described below, a glass probe with a diameter of 5 mm and a load of 1 kgf / cm was used. 2 The tack force measured under conditions of a contact speed of 0.5 mm / sec, a tensile speed of 0.5 mm / sec, a holding time of 10 seconds, and a temperature of 80°C is preferably 1.8 N or less, more preferably 1.6 N or less, even more preferably 1.4 N or less, and particularly preferably 1.2 N or less.

[0125] <Applications of resin composition> The resin composition of the present invention can be used in a wide range of applications, such as insulating materials for printed wiring boards and multilayer flexible substrates, solder resists, underfill materials, die bonding materials, semiconductor encapsulants, hole filling resins, component embedding resins, etc. Printed wiring boards, multilayer flexible substrates, etc. can be produced using sheet-like laminate materials such as resin sheets and prepregs, for example.

[0126] <Resin sheet> The resin sheet of the present invention includes a support and a resin composition layer formed from the resin composition of the present invention provided on the support.

[0127] The thickness of the resin composition layer is preferably 200 μm or less, more preferably 150 μm or less, further preferably 100 μm or less, and particularly preferably 70 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 1 μm or more, 1.5 μm or more, 2 μm or more, etc.

[0128] Examples of the support include films made of plastic materials, metal foils, and release papers, with films made of plastic materials and metal foils being preferred.

[0129] When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0130] When a metal foil is used as the support, examples of the metal foil include copper foil, aluminum foil, etc., and copper foil is preferred. As the copper foil, a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

[0131] The surface of the support to be bonded to the resin composition layer may be subjected to a matte treatment, a corona treatment, or an antistatic treatment.

[0132] In addition, as the support, a support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used. The release agent used in the release layer of the support with a release layer may be, for example, one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. The support with a release layer may be a commercially available product, for example, "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Unipeel" manufactured by Unitika Limited, which are PET films having a release layer mainly composed of an alkyd resin-based release agent.

[0133] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When a support with a release layer is used, it is preferable that the total thickness of the support with a release layer is in the above range.

[0134] In one embodiment, the resin sheet may further include other layers as necessary. Examples of such other layers include a protective film equivalent to the support provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite to the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dirt and the like to the surface of the resin composition layer and scratches can be suppressed.

[0135] The resin sheet can be produced by applying the resin composition as is, or a resin varnish prepared by dissolving the resin composition in an organic solvent, onto a support using a die coater or the like, and then drying to form a resin composition layer.

[0136] Examples of organic solvents that can be used when applying the resin composition onto a support include the same organic solvents as those described above as components of the resin composition. The organic solvents may be used alone or in combination of two or more.

[0137] Drying may be performed by a known method such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is performed so that the content of the organic solvent in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although it varies depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when a resin composition or resin varnish containing 30% by mass to 60% by mass of the organic solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 minutes to 10 minutes.

[0138] The resin sheet can be stored in a rolled state. When the resin sheet has a protective film, it can be used by peeling off the protective film.

[0139] <Laminated sheet> The laminate sheet is a sheet produced by laminating and curing a plurality of resin composition layers. The laminate sheet includes a plurality of insulating layers as cured products of the resin composition layers. Usually, the number of resin composition layers laminated to produce the laminate sheet corresponds to the number of insulating layers contained in the laminate sheet. The specific number of insulating layers per laminate sheet is usually 2 or more, preferably 3 or more, particularly preferably 5 or more, and preferably 20 or less, more preferably 15 or less, particularly preferably 10 or less.

[0140] The laminated sheet may be a sheet that is folded so that one surface of the laminated sheet faces the other surface when used. The minimum bending radius of the laminated sheet is not particularly limited, but is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more, and is preferably 5 mm or less, more preferably 4 mm or less, and particularly preferably 3 mm or less.

[0141] Each insulating layer included in the laminated sheet may have a hole formed therein, which can function as a via hole or a through hole in the multi-layer flexible substrate.

[0142] The laminate sheet may further include an optional element in addition to the insulating layer. For example, the laminate sheet may include a conductor layer as an optional element. The conductor layer is usually partially formed on the surface of the insulating layer or between the insulating layers. This conductor layer usually functions as wiring in the multilayer flexible substrate.

[0143] The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The conductor material may be a single metal or an alloy. Examples of the alloy include alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy). Among them, from the viewpoints of versatility of conductor layer formation, cost, ease of patterning, etc., single metals such as chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper; and alloys such as nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy; are preferred. Among them, single metals such as chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper; and nickel-chromium alloy; are more preferred, and single metal copper is even more preferred.

[0144] The conductor layer may be a single-layer structure or a multi-layer structure including two or more single metal layers or alloy layers made of different kinds of metals or alloys. When the conductor layer is a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc or titanium, or an alloy layer of a nickel-chromium alloy.

[0145] The conductor layer may be patterned to function as wiring.

[0146] The thickness of the conductor layer depends on the design of the multilayer flexible board, but is preferably 3 μm to 35 μm, more preferably 5 μm to 30 μm, further preferably 10 μm to 20 μm, and particularly preferably 15 μm to 20 μm.

[0147] The thickness of the laminate sheet is preferably 100 μm or more, more preferably 150 μm or more, particularly preferably 200 μm or more, and is preferably 2,000 μm or less, more preferably 1,000 μm or less, particularly preferably 500 μm or less.

[0148] <Method of manufacturing laminated sheet> The laminated sheet can be manufactured by a manufacturing method including the steps of (a) preparing a resin sheet, and (b) laminating and curing a plurality of resin composition layers using the resin sheet. The order of laminating and curing the resin composition layers is arbitrary as long as a desired laminated sheet is obtained. Depending on the components contained in the resin composition, for example, after laminating all of the plurality of resin composition layers, the laminated plurality of resin composition layers may be cured all at once. In addition, for example, each time a certain resin composition layer is laminated on another resin composition layer, the laminated resin composition layer may be cured.

[0149] A preferred embodiment of step (b) will be described below. In the embodiment described below, for the purpose of distinction, the resin composition layers are appropriately numbered and shown as "first resin composition layer" and "second resin composition layer", and the insulating layers obtained by curing these resin composition layers are also numbered and shown as "first insulating layer" and "second insulating layer" in the same manner as the resin composition layers.

[0150] In a preferred embodiment, step (b) comprises: (II) curing the first resin composition layer to form a first insulating layer; (VI) laminating a second resin composition layer on the first insulating layer; (VII) curing the second resin composition layer to form a second insulating layer; Step (b) may further include, as necessary: (I) laminating a first resin composition layer onto a sheet supporting substrate; (III) drilling holes in the first insulating layer; (IV) subjecting the first insulating layer to a roughening treatment; (V) forming a conductor layer on the first insulating layer Each step will be described below.

[0151] Step (I) is a step of laminating a first resin composition layer onto a sheet supporting substrate prior to step (II). The sheet supporting substrate is a peelable member, and for example, a plate-, sheet- or film-shaped member is used.

[0152] The lamination of the sheet support substrate and the first resin composition layer may be performed by a vacuum lamination method. In the vacuum lamination method, the heat-pressure bonding temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heat-pressure bonding pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably in the range of 0.29MPa to 1.47MPa, and the heat-pressure bonding time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination is preferably performed under reduced pressure conditions of 26.7hPa or less.

[0153] The lamination can be performed by a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch type vacuum pressure laminator.

[0154] When a resin sheet is used, the lamination of the sheet support substrate and the first resin composition layer can be performed, for example, by pressing the resin sheet from the support side and thermocompressing the first resin composition layer of the resin sheet to the sheet support substrate. Examples of the member for thermocompressing the resin sheet to the sheet support substrate (hereinafter, also referred to as "thermocompression member") include a heated metal plate (SUS mirror plate, etc.) or a metal roll (SUS roll), etc. It is preferable to press the thermocompression member through an elastic material such as heat-resistant rubber so that the first resin composition layer sufficiently follows the surface irregularities of the sheet support substrate, rather than directly pressing the resin sheet with the thermocompression member.

[0155] After lamination, the first resin composition layer may be smoothed by pressing, for example, with a heat-pressure bonding member under normal pressure (atmospheric pressure). For example, when a resin sheet is used, the first resin composition layer of the resin sheet can be smoothed by pressing the resin sheet from the support side with a heat-pressure bonding member. The pressing conditions for the smoothing treatment can be the same as the heat-pressure bonding conditions for the lamination. The smoothing treatment can be performed with a commercially available laminator. The lamination and the smoothing treatment may be performed continuously using the commercially available vacuum laminator.

[0156] Step (II) is a step of curing the first resin composition layer to form a first insulating layer. The curing conditions for the first resin composition layer are not particularly limited, and any conditions adopted when forming an insulating layer of a printed wiring board can be applied. The first resin composition layer can be cured, for example, by thermal curing.

[0157] Generally, specific heat curing conditions vary depending on the type of resin composition. For example, the curing temperature is preferably 120° C. to 240° C., more preferably 150° C. to 220° C., and even more preferably 170° C. to 210° C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 110 minutes, and even more preferably 20 minutes to 100 minutes.

[0158] Before the first resin composition layer is thermally cured, the first resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the first resin composition layer, the first resin composition layer may be preheated 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) at a temperature of 50°C or more and less than 120°C (preferably 60°C or more and 115°C or less, and more preferably 70°C or more and 110°C or less).

[0159] Step (III) is a step of drilling holes in the first insulating layer. This step (III) allows holes such as via holes and through holes to be formed in the first insulating layer. The holes may be drilled using, for example, a drill, a laser, plasma, etc., depending on the composition of the resin composition. The dimensions and shape of the holes may be appropriately set depending on the design of the multilayer flexible substrate.

[0160] Step (IV) is a step of performing a roughening treatment on the first insulating layer. Usually, in this step (IV), smears are also removed. Therefore, the roughening treatment is sometimes called a desmear treatment. An example of the roughening treatment is a method in which a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid are performed in this order.

[0161] The swelling liquid is not particularly limited, and examples thereof include alkaline aqueous solutions such as an aqueous sodium hydroxide solution and an aqueous potassium hydroxide solution. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. The swelling treatment using the swelling liquid can be carried out, for example, by immersing the cured body in the swelling liquid at 30 to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in the swelling liquid at 40 to 80°C for 5 to 15 minutes.

[0162] The oxidizing agent is not particularly limited, but examples thereof include an alkaline permanganate solution in which a permanganate is dissolved in an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution. The concentration of the permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact P", "Concentrate Compact CP", and "Dosing Solution Securigans P" manufactured by Atotech Japan. The roughening treatment using an oxidizing agent can be performed by immersing the cured body in an oxidizing agent solution heated to 60°C to 80°C for 10 minutes to 30 minutes.

[0163] An acidic aqueous solution is used as the neutralizing liquid. An example of a commercially available product is "Reduction Solution Securigant P" manufactured by Atotech Japan. The treatment with the neutralizing liquid can be carried out by immersing the hardened body in the neutralizing liquid at 30°C to 80°C for 5 to 30 minutes. From the viewpoint of workability, etc., it is preferable to immerse the hardened body in the neutralizing liquid at 40°C to 70°C for 5 to 20 minutes.

[0164] The arithmetic mean roughness (Ra) of the surface of the first insulating layer after the roughening treatment is preferably 400 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. The lower limit is not particularly limited, but may be 30 nm or more, 40 nm or more, or 50 nm or more.

[0165] Step (V) is a step of forming a conductor layer on the first insulating layer as necessary. The conductor layer can be formed by, for example, plating, sputtering, vapor deposition, etc., among which plating is preferred. A suitable example is a method of plating the surface of the first insulating layer by an appropriate method such as a semi-additive method or a full-additive method to form a conductor layer having a desired wiring pattern. Among these, the semi-additive method is preferred from the viewpoint of ease of production.

[0166] An example of forming a conductor layer by a semi-additive method is shown below. First, a plating seed layer is formed on the surface of a first insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a part of the plating seed layer corresponding to a desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layer is removed by a process such as etching to form a conductor layer having a desired wiring pattern.

[0167] A first insulating layer is obtained in step (II), and step (III), step (IV), and step (V) are performed as necessary, followed by step (VI). Step (VI) is a step of laminating a second resin composition layer on the first insulating layer. The lamination of the first insulating layer and the second resin composition layer can be performed in the same manner as the lamination of the sheet support substrate and the first resin composition layer in step (I).

[0168] However, when the first resin composition layer is formed using a resin sheet, the support of the resin sheet is removed prior to step (VI). The removal of the support may be performed between step (I) and step (II), between step (II) and step (III), between step (III) and step (IV), or between step (IV) and step (V).

[0169] After step (VI), step (VII) is performed. Step (VII) is a step of curing the second resin composition layer to form a second insulating layer. The second resin composition layer can be cured by the same method as the curing of the first resin composition layer in step (II). This makes it possible to obtain a laminate sheet including a plurality of insulating layers, namely, a first insulating layer and a second insulating layer.

[0170] In addition, in the method according to the embodiment, the steps of (VIII) drilling holes in the second insulating layer, (IX) roughening the second insulating layer, and (X) forming a conductor layer on the second insulating layer may be performed as necessary. The drilling of the second insulating layer in step (VIII) can be performed in the same manner as the drilling of the first insulating layer in step (III). The roughening of the second insulating layer in step (IX) can be performed in the same manner as the roughening of the first insulating layer in step (IV). Furthermore, the formation of the conductor layer on the second insulating layer in step (X) can be performed in the same manner as the formation of the conductor layer on the first insulating layer in step (V).

[0171] In the above embodiment, the laminate sheet is produced by laminating and curing two resin composition layers, a first resin composition layer and a second resin composition layer, but a laminate sheet may be produced by laminating and curing three or more resin composition layers. For example, in the method according to the above embodiment, the lamination and curing of the resin composition layers in steps (VI) to (VII), and, if necessary, the drilling of the insulating layer, the roughening treatment of the insulating layer, and the formation of a conductor layer on the insulating layer in steps (VIII) to (X) may be repeatedly carried out to produce a laminate sheet. This provides a laminate sheet including three or more insulating layers.

[0172] Furthermore, the method according to the embodiment may include any step other than the steps described above. For example, when step (I) is performed, a step of removing the sheet support substrate may be performed.

[0173] <Multi-layer flexible circuit board> The multilayer flexible substrate includes a laminate sheet. The multilayer flexible substrate may include only the laminate sheet, or may include an optional member in combination with the laminate sheet. Examples of the optional member include electronic components and coverlay films.

[0174] The multilayer flexible substrate can be manufactured by a manufacturing method including the above-mentioned method for manufacturing a laminate sheet. Thus, the multilayer flexible substrate can be manufactured by a manufacturing method including the steps of (a) preparing a resin sheet, and (b) laminating and curing a plurality of resin composition layers using the resin sheet.

[0175] The method for manufacturing a multilayer flexible substrate may further include any step in combination with the above steps. For example, the method for manufacturing a multilayer flexible substrate including an electronic component may include a step of bonding the electronic component to a laminate sheet. The bonding conditions between the laminate sheet and the electronic component may be any condition that allows a conductive connection between the terminal electrodes of the electronic component and the conductor layer as wiring provided on the laminate sheet. Also, for example, the method for manufacturing a multilayer flexible substrate including a coverlay film may include a step of laminating the laminate sheet and the coverlay film.

[0176] The multilayer flexible substrate can be used by usually folding the laminated sheets contained in the multilayer flexible substrate so that one side of the laminated sheets faces each other. For example, the multilayer flexible substrate is stored in a housing of a semiconductor device in a folded and reduced size state. Also, for example, the multilayer flexible substrate is provided on a movable part of a semiconductor device having a foldable movable part.

[0177] <Semiconductor device> The semiconductor device includes the multilayer flexible substrate. The semiconductor device includes, for example, a multilayer flexible substrate and a semiconductor chip mounted on the multilayer flexible substrate. In many semiconductor devices, the multilayer flexible substrate can be stored in the housing of the semiconductor device by folding the multilayer flexible substrate so that one side of the laminated sheets included in the multilayer flexible substrate faces each other.

[0178] Examples of the semiconductor device include various semiconductor devices used in electrical appliances (such as computers, mobile phones, digital cameras, and televisions) and vehicles (such as motorcycles, automobiles, trains, ships, and aircraft).

[0179] The semiconductor device can be manufactured by a manufacturing method including, for example, a step of preparing a multilayer flexible substrate, a step of folding the multilayer flexible substrate so that one side of the laminated sheet faces each other, and a step of storing the folded multilayer flexible substrate in a housing. EXAMPLES

[0180] The present invention will be specifically described below with reference to examples. The present invention is not limited to these examples. In the following, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, the operations described below were carried out in an environment of normal temperature and pressure (25°C, 1 atm) unless otherwise specified.

[0181] <Synthesis Example 1: Synthesis of Polyimide Resin 1> In a reaction vessel, 50 g of G-3000 (bifunctional hydroxyl group-terminated polybutadiene, number average molecular weight = 5,047 (GPC method), hydroxyl group equivalent = 1,798 g / eq., solid content 100 mass%: manufactured by Nippon Soda Co., Ltd.), 23.5 g of Ipzole 150 (aromatic hydrocarbon-based mixed solvent: manufactured by Idemitsu Petrochemical Co., Ltd.), and 0.005 g of dibutyltin laurate were mixed and dissolved uniformly. When the mixture became uniform, the temperature was raised to 50°C, and 4.8 g of toluene-2,4-diisocyanate (isocyanate group equivalent = 87.08 g / eq.) was added while further stirring, and the reaction was carried out for about 3 hours. Next, the reaction mixture was cooled to room temperature, and 8.96 g of benzophenonetetracarboxylic dianhydride (acid anhydride equivalent = 161.1 g / eq.), 0.07 g of triethylenediamine, and 40.4 g of ethyl diglycol acetate (manufactured by Daicel Corporation) were added thereto, and the mixture was heated to 130°C with stirring and reacted for about 4 hours. -1 The disappearance of the NCO peak was confirmed. The disappearance of the NCO peak was regarded as the end point of the reaction, and the reaction mixture was cooled to room temperature and filtered through a 100 mesh filter cloth to obtain polyimide resin 1 having an imide skeleton, a urethane skeleton, and a butadiene skeleton. Viscosity: 7.5Pa s (25℃, E-type viscometer) Acid value: 16.9mgKOH / g Solid content: 50% by mass Number average molecular weight: 13,723 Glass transition temperature: -10℃ Polybutadiene structural portion content: 50 / (50+4.8+8.96)×100=78.4% by mass

[0182] <Synthesis Example 2: Synthesis of Polyimide Resin 2> In a 500 ml separable flask equipped with a nitrogen inlet tube and a stirrer, 9.13 g (30 mmol) of 5-amino-1,1'-biphenyl-2-yl 4-aminobenzoate, 15.61 g (30 mmol) of 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic dianhydride, 94.64 g of N-methyl-2-pyrrolidone, 0.47 g (6 mmol) of pyridine, and 10 g of toluene were added, and the mixture was subjected to an imidization reaction under a nitrogen atmosphere at 180°C for 4 hours while removing toluene from the system during the reaction, to obtain a polyimide solution (non-volatile content 20% by mass) containing polyimide resin 2. No precipitation of the synthesized polyimide resin 2 was observed in the polyimide solution. The weight average molecular weight of polyimide resin 2 was 45,000.

[0183] <Synthesis Example 3: Synthesis of polyimide resin 3> A reaction vessel equipped with a stirrer, a water divider, a thermometer, and a nitrogen gas inlet tube was charged with 65.0 g of aromatic tetracarboxylic dianhydride (SABIC Japan "BisDA-1000", 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic dianhydride), 266.5 g of cyclohexanone, and 44.4 g of methylcyclohexane, and the solution was heated to 60 ° C. Next, 43.7 g of dimer diamine (Croda Japan "PRIAMINE 1075") and 5.4 g of 1,3-bis(aminomethyl)cyclohexane were dropped, and then the imidization reaction was carried out at 140 ° C. for 1 hour. As a result, a polyimide solution (non-volatile content 30% by mass) containing polyimide resin 3 was obtained. The weight average molecular weight of polyimide resin 3 was 25,000.

[0184] <Synthesis Example 4: Synthesis of Polyimide Resin 4> A 500 mL separable flask equipped with a water content receiver connected to a reflux condenser, a nitrogen inlet tube, and a stirrer was prepared. 20.3 g of 4,4'-oxydiphthalic anhydride (ODPA), 200 g of γ-butyrolactone, 20 g of toluene, and 29.6 g of 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane were added to this flask, and the mixture was stirred at 45°C for 2 hours under a nitrogen stream to carry out a reaction. Next, the reaction solution was heated and, while maintaining the temperature at about 160°C, condensed water was azeotropically removed together with toluene under a nitrogen stream. It was confirmed that a predetermined amount of water had accumulated in the water content receiver and that no water was flowing out. After confirmation, the reaction solution was further heated and stirred at 200°C for 1 hour. The mixture was then cooled to obtain a polyimide solution (non-volatile content: 20% by mass) containing polyimide resin 4 having a 1,1,3-trimethylindane skeleton. The obtained polyimide resin 4 had a repeating unit represented by the following formula (X1) and a repeating unit represented by the following formula (X2). The weight average molecular weight of the polyimide resin 4 was 12,000.

[0185] [ka]

[0186] [ka]

[0187] <Example 1: Preparation of resin composition 1> 5 parts of a bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 185 g / eq.), 5 parts of a naphthalene type epoxy resin ("ESN475V" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent: approximately 332 g / eq.), 10 parts of a bisphenol AF type epoxy resin ("YL7760" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 238 g / eq.), 2 parts of a cyclohexane type epoxy resin ("ZX1658GS" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 135 g / eq.), and 40 parts of the polyimide resin 1 obtained in Synthesis Example 1 (non-volatile component: 50% by mass) were dissolved in 10 parts of cyclohexanone by heating with stirring. After cooling to room temperature, 4 parts of a triazine skeleton-containing cresol novolac-based hardener (DIC Corporation's "LA3018-50P", hydroxyl group equivalent of approximately 151 g / eq., 2-methoxypropanol solution with 50% nonvolatile content), 6 parts of an active ester-based hardener (DIC Corporation's "EXB-8000L-65M", active group equivalent of approximately 220 g / eq., MEK solution with 65% nonvolatile content by mass), and spherical silica (Admatechs Corporation's "SC2500SQ", average particle size 0.5 μm, specific surface area 11.2 m) were added. 2 Resin composition 1 was prepared by mixing 25 parts of silica (surface-treated with 1 part of N-phenyl-3-aminopropyltrimethoxysilane (KBM573, manufactured by Shin-Etsu Chemical Co., Ltd.) per 100 parts of silica, 6 parts of a siloxane skeleton-containing epoxy resin (KR470, manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent: approximately 200 g / eq.), and 0.2 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP)), and dispersing the mixture uniformly using a high-speed rotating mixer. The mixture was then filtered using a cartridge filter (SHP020, manufactured by ROKITECHNO Co., Ltd.),

[0188] <Example 2: Preparation of resin composition 2> Resin composition 2 was prepared by carrying out the same operations as in Example 1, except that 100 parts of polyimide resin 2 (20% by mass of non-volatile component) obtained in Synthesis Example 2 was used instead of 40 parts of polyimide resin 1 (50% by mass of non-volatile component) obtained in Synthesis Example 1.

[0189] <Example 3: Preparation of resin composition 3> Resin composition 3 was prepared by carrying out the same operation as in Example 1, except that 66.7 parts of polyimide resin 3 (30% by mass of non-volatile component) obtained in Synthesis Example 3 was used instead of 40 parts of polyimide resin 1 (50% by mass of non-volatile component) obtained in Synthesis Example 1.

[0190] <Example 4: Preparation of resin composition 4> Resin composition 4 was prepared by carrying out the same operation as in Example 1, except that 100 parts of polyimide resin 4 (20% by mass of non-volatile component) obtained in Synthesis Example 4 was used instead of 40 parts of polyimide resin 1 (50% by mass of non-volatile component) obtained in Synthesis Example 1.

[0191] <Comparative Example 1: Preparation of Resin Composition 5> Resin composition 5 was prepared in the same manner as in Example 1, except that 6 parts of a siloxane skeleton-containing epoxy resin (manufactured by Shin-Etsu Chemical Co., Ltd., "KR470", epoxy equivalent: approximately 200 g / eq.) was not used.

[0192] <Comparative Example 2: Preparation of Resin Composition 6> Resin composition 6 was prepared by carrying out the same operation as in Example 1, except that 66 parts of a phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, solid content 30% by mass) was used instead of 40 parts of the polyimide resin 1 (non-volatile component 50% by mass) obtained in Synthesis Example 1.

[0193] <Test Example 1: Evaluation of flexibility (MIT folding endurance)> The resin composition of each Example and Comparative Example was uniformly applied using a die coater onto the release-treated surface of a PET film (thickness 38 μm) that had been treated with an alkyd-based release agent, so that the resin composition layer would have a thickness of 40 μm after drying, and then dried at 80 to 120°C (average 100°C) for 6 minutes to obtain resin sheet 1.

[0194] The obtained resin sheet 1 was laminated onto a polyimide film (Upilex S, manufactured by Ube Industries, Ltd.) using a batch-type vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) to obtain a resin sheet with a protective film. For lamination, the pressure was reduced for 30 seconds to make the air pressure 13 hPa or less, and then the laminate was pressed at 120°C for 30 seconds under a pressure of 0.74 MPa. Thereafter, the PET film was peeled off, and the resin composition was cured under curing conditions of 190°C and 90 minutes, and the polyimide film was peeled off to obtain a cured sample.

[0195] The obtained cured sample was cut into a test piece of width 15 mm and length 110 mm, and the number of times the cured body could be folded before breaking was measured using an MIT test device (MIT folding fatigue tester "MIT-DA" manufactured by Toyo Seiki Seisakusho Co., Ltd.) under the measurement conditions of load 2.5N, bending angle 90 degrees, bending radius 1.0 mm, and bending speed 175 times / min in accordance with JIS C-5016. The measurement was performed on five samples, and the average value of the top three points was calculated. A folding endurance of less than 8,000 times was evaluated as "x", and a folding endurance of 8,000 times or more was evaluated as "○".

[0196] <Test Example 2: Evaluation of tackiness (adhesiveness)> The protective film was peeled off from the resin sheet with the protective film obtained in Test Example 1, and the resin composition layer was subjected to a tack test using a probe tack tester (manufactured by Tester Sangyo Co., Ltd., "TE-6002") with a glass probe of 5 mm in diameter and a load of 1 kgf / cm. 2 The tack strength was measured at a contact speed of 0.5 mm / sec, a pulling speed of 0.5 mm / sec, a holding time of 10 seconds, and a temperature of 80° C. A tack strength exceeding 1.6 N was evaluated as “×”, and a tack strength of 1.6 N or less was evaluated as “◯”.

[0197] <Test Example 3: Evaluation of insulation reliability> (1) Surface preparation for inner layer circuit boards As an inner layer circuit board, a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 3 μm, substrate thickness 0.15 mm, Mitsubishi Gas Chemical Company's "HL832NSF LCA", 255 × 340 mm size) having circuit conductors (copper) formed on both sides with a wiring pattern of L / S = 10 μm / 10 μm was prepared. Both sides of the inner layer circuit board were treated with an organic coating on the copper surface using MEC's ​​"FlatBOND-FT".

[0198] (2) Lamination of resin sheet The protective film was peeled off from the resin sheet with protective film obtained in Test Example 1, and the resin composition layer was laminated on both sides of the inner layer circuit board using a batch type vacuum pressure laminator (Nikko Materials Co., Ltd., 2-stage build-up laminator, CVP700) so that the resin composition layer was in contact with the inner layer circuit board. The lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, and pressing at 130°C and a pressure of 0.74 MPa for 45 seconds. Next, a heat press was performed at 120°C and a pressure of 0.5 MPa for 75 seconds.

[0199] (3) Thermal curing of the resin composition layer The inner layer circuit board laminated with the resin sheet was placed in a 100° C. oven for 30 minutes, then transferred to a 180° C. oven for 30 minutes, where it was thermally cured to form an insulating layer, and the release PET was peeled off.

[0200] (4) Roughening treatment The inner layer circuit board on which the insulating layer was formed was subjected to a desmear treatment as a roughening treatment. The desmear treatment was a wet desmear treatment as described below. Wet desmear process: The substrate was immersed in a swelling solution (Atotech Japan's "Swelling Dip Securigant P", an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 5 minutes, then in an oxidizing solution (Atotech Japan's "Concentrate Compact CP", an aqueous solution of potassium permanganate at approximately 6% and sodium hydroxide at approximately 4%) at 80°C for 10 minutes, and finally in a neutralizing solution (Atotech Japan's "Reduction Solution Securigant P", an aqueous solution of sulfuric acid) at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. This was designated "roughened substrate A."

[0201] (5) Conductive layer formation (5-1) Electroless plating In order to form a conductive layer on the roughened surface of the above-mentioned roughened substrate A, a plating process (a copper plating process using a chemical solution manufactured by Atotech Japan) including the following steps 1 to 6 was carried out to form a conductive layer.

[0202] 1. Alkaline cleaning (cleaning the surface of the insulating layer and adjusting the charge) The surface of the roughened substrate A was cleaned at 60° C. for 5 minutes using Cleaning Cleaner Securiganth 902 (trade name). 2. Soft etching (cleaning inside the via hole) The surface of the roughened substrate A was treated with an aqueous solution of sodium peroxodisulfate acidified with sulfuric acid at 30° C. for 1 minute. 3. Pre-dip (adjusting the charge on the surface of the insulating layer for Pd deposition) The surface of the roughened substrate A was treated with Pre. Dip Neoganth B (trade name) at room temperature for 1 minute. 4. Adding an activator (adding Pd to the surface of the insulating layer) The surface of the roughened substrate A was treated with Activator Neoganth 834 (trade name) at 35° C. for 5 minutes. 5. Reduction (reducing Pd added to the insulating layer) The surface of the roughened substrate A was treated with a mixed solution of Reducer Neoganth WA (trade name) and Reducer Accelerator 810 mod. (trade name) at 30° C. for 5 minutes. 6. Electroless copper plating (Cu is deposited on the surface of the insulating layer (Pd surface)) The surface of the roughened substrate A was treated with a mixture of Basic Solution Printganth MSK-DK (trade name), Copper solution Printganth MSK (trade name), Stabilizer Printganth MSK-DK (trade name), and Reducer Cu (trade name) at 35°C for 20 minutes to form an electroless copper plating layer. The thickness of the electroless copper plating layer formed was 0.8 μm.

[0203] (5-2) Electrolytic plating Next, an electrolytic copper plating process was performed using a chemical solution manufactured by Atotech Japan under conditions that filled the via holes with copper. After that, a conductor layer having a land and conductor pattern with a thickness of 10 μm was formed on the surface of the insulating layer using a land pattern with a diameter of 1 mm that was connected to the lower conductor and a circular conductor pattern with a diameter of 10 mm that was not connected to the lower conductor as a resist pattern for patterning by etching. Next, an annealing treatment was performed at 200° C. for 90 minutes. This substrate was designated as "Evaluation Substrate A."

[0204] (6) Evaluation of insulation reliability of insulating layer The 10 mm diameter circular conductor side of evaluation board A was used as the positive electrode, and the lattice circuit conductor (copper) side of the inner layer circuit board connected to the 1 mm diameter land was used as the negative electrode. Using a highly accelerated life test device (ETAC's "PM422"), the insulation resistance value after 100 hours under conditions of 110°C, 85% relative humidity, and 20 V DC voltage application was measured with an electrochemical migration tester (J-RAS's "ECM-100"). This measurement was performed six times, and the resistance value of all six test pieces was 1.00 x 10 8 Ω or more is marked as "○", and even one is 1.00×10 8When the resistance was less than Ω, it was marked as "X," and the evaluation results and insulation resistance values ​​are shown in the table below. The insulation resistance values ​​shown in Table 1 below are the minimum insulation resistance values ​​of the six test pieces.

[0205] The amounts of non-volatile components used in the resin compositions of the Examples and Comparative Examples, the measurement results of the Test Examples, the evaluation results, etc. are shown in Table 1 below.

[0206] [Table 1]

[0207] It has been found that by using a resin composition comprising (A) an epoxy resin, (B) an inorganic filler, and (C) a polyimide resin, in which component (A) contains (A-1) a siloxane skeleton-containing epoxy resin, it is possible to keep tackiness low even when the content of inorganic filler (B) is as low as 40 mass% or less, and to obtain a cured product that has excellent flexibility and excellent insulation reliability.

Claims

1. A resin sheet comprising a support and a resin composition layer formed of a resin composition provided on the support, The resin composition contains (A) an epoxy resin, (B) an inorganic filler, and (C) a polyimide resin, The component (A) contains (A-1) a siloxane skeleton-containing epoxy resin, The component (A-1) is a cyclic siloxane skeleton-containing epoxy resin, The content of the component (A) is 10% by mass or more, based on 100% by mass of the non-volatile components in the resin composition; When the total amount of the component (A) is taken as 100% by mass, the content of the component (A-1) is 20% by mass or more, The content of the (B) component is 20% by mass or more and 40% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass, the component (C) is (1) a resin obtained by a reaction including imidization between a diamine compound and a tetracarboxylic acid anhydride, or (2) a resin obtained by a reaction including imidization between a diisocyanate compound and a tetracarboxylic acid anhydride, The content of the (C) component is 10% by mass or more, based on 100% by mass of the non-volatile components in the resin composition; The resin composition is uniformly applied onto a release-treated surface of a PET film that has been treated with an alkyd-based release agent so that the thickness of the resin composition layer after drying is 40 μm, and the resin composition is dried at 80 to 120° C. (average 100° C.) for 6 minutes to form a sheet. In this case, the tack strength of the resin composition layer measured under the conditions of a glass probe diameter of 5 mm, a load of 1 kgf / cm 2 , a contact speed of 0.5 mm / sec, a pulling speed of 0.5 mm / sec, a holding time of 10 seconds, and a temperature of 80° C. is 1.8 N or less. Resin sheet.

2. The resin sheet according to claim 1 , wherein the tetracarboxylic acid anhydride comprises a tetracarboxylic acid anhydride selected from an aliphatic tetracarboxylic acid dianhydride and a diphthalic acid dianhydride.

3. the diamine compound includes a diamine compound selected from an aliphatic diamine compound and a dianiline compound; The resin sheet according to claim 1 , wherein the diisocyanate compound comprises a diisocyanate compound selected from an aliphatic diisocyanate compound, a bisisocyanatobenzene compound, and a polyurethane having isocyanato groups at both ends.

4. the tetracarboxylic acid anhydride is selected from aliphatic tetracarboxylic acid dianhydrides and diphthalic acid dianhydride containing an oxygen atom as a skeleton atom; the diamine compound includes a diamine compound selected from an aliphatic diamine compound and a dianiline compound; The resin sheet according to claim 1 , wherein the diisocyanate compound comprises a diisocyanate compound selected from an aliphatic diisocyanate compound, a bisisocyanatobenzene compound, and a polyurethane having isocyanato groups at both ends.

5. The diamine compound comprises an aliphatic diamine compound, The diisocyanate compound includes a diisocyanate compound selected from an aliphatic diisocyanate compound and a polyurethane having isocyanato groups at both ends obtained by a urethanization reaction of an aliphatic diisocyanate compound with a polymer having hydroxy groups at both ends, The resin sheet according to claim 3.

6. The component (A-1) is represented by the formula (A1): 【Chemistry 1】 [In the formula, R １ each independently represents an epoxyalkyl group; R ２ each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group; R ３ and R ４ each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R ３ and R ４ are bonded to each other to form a cyclic siloxane skeleton; and s is an integer of 1 or more.

7. The resin sheet according to any one of claims 1 to 6, wherein the molecular weight of the component (A-1) is 800 or less.

8. The resin sheet according to any one of claims 1 to 7, wherein the epoxy equivalent of the component (A-1) is 150 g / eq. to 250 g / eq.

9. The resin sheet according to any one of claims 1 to 8, wherein the content of the component (A-1) is 5% by mass or more, based on 100% by mass of non-volatile components in the resin composition.

10. The resin sheet according to any one of claims 1 to 9, wherein the content of the component (A-1) is 10% by mass or less, when the content of the non-volatile components in the resin composition is 100% by mass.

11. The resin sheet according to any one of claims 1 to 10, wherein the average particle size of the (B) component is 0.005 µm or more and 1 µm or less.

12. The resin sheet according to any one of claims 1 to 11, wherein the component (B) is silica.

13. The resin sheet according to any one of claims 1 to 12, wherein the weight average molecular weight of the component (C) is 1,000 or more and 100,000 or less.

14. The resin sheet according to any one of claims 1 to 13, wherein the content of the component (C) is 20% by mass or more, based on 100% by mass of non-volatile components in the resin composition.

15. The resin sheet according to any one of claims 1 to 14, wherein the content of the component (C) is 30% by mass or less, when the content of the non-volatile components in the resin composition is 100% by mass.

16. The resin sheet according to any one of claims 1 to 15, further comprising (D) a curing agent.

17. The resin sheet according to claim 16, wherein the component (D) comprises a curing agent selected from a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, and a carbodiimide-based curing agent.

18. The resin sheet according to claim 16 , wherein the component (D) comprises an active ester-based curing agent.

19. The resin sheet according to any one of claims 1 to 18, which is for forming an insulating layer of a multilayer flexible board.

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