Underfill composition, coating film, cured film, multilayer wiring board, and method for manufacturing multilayer wiring board

Abstract

The present invention provides an underfill composition that has excellent temporal stability and favorable adhesion to metal and a coating film, a cured film, a multilayer wiring board, and a production method for the multilayer wiring board that use the underfill composition. This underfill composition contains a polymer and a maleimide compound that has a maleimide group. The polymer has a cyano group. The cyano group content of the polymer is 0.1–6 mmol / g.

Description

[Technical Field]

[0001] The present invention relates to an underfill composition, a coating film, a cured film, a multilayer wiring board, and a method for producing a multilayer wiring board. [Background technology]

[0002] Metal-filled microstructures (devices), which are formed by filling micropores in an insulating substrate with metal, are one of the fields that have attracted attention in recent years in nanotechnology, and are expected to be used, for example, as anisotropic conductive bonding materials. This anisotropic conductive bonding member can be inserted between an electronic component such as a semiconductor element and a circuit board and electrically connected to the electronic component by simply applying pressure. Therefore, it is widely used as an electrical connecting member for electronic components such as semiconductor elements, and as an inspection connector for functional testing. In particular, electronic components such as semiconductor elements are becoming significantly smaller, and conventional methods such as wire bonding, which directly connects wiring boards, flip-chip bonding, and thermocompression bonding cannot fully guarantee connection stability. Therefore, anisotropic conductive bonding materials are attracting attention as electronic connection materials.

[0003] As a method for manufacturing a multilayer wiring board using such an anisotropic conductive bonding material, for example, Patent Document 1 describes a manufacturing method including a temporary bonding process in which an anisotropic conductive bonding material and a wiring board are bonded together using a non-conductive thermosetting resin ([Claim 1]). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-037509 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have studied the thermosetting resin described in Patent Document 1 and found that it has good adhesion to metal wiring and metal pillars (hereinafter abbreviated as "metal adhesion"), but that it may have poor stability over time and may not be able to ensure a long usable life.

[0006] Therefore, an object of the present invention is to provide an underfill composition that has excellent stability over time and good metal adhesion, as well as a coated film, a cured film, a multilayer wiring board, and a method for manufacturing a multilayer wiring board that use the underfill composition. [Means for solving the problem]

[0007] As a result of intensive research to achieve the above object, the present inventors have found that use of a composition containing a polymer having a specific amount of cyano groups and a maleimide compound results in excellent stability over time and good metal adhesion, and have completed the present invention. That is, the present inventors have found that the above problems can be solved by the following configuration.

[0008] [1] An underfill composition containing a polymer and a maleimide compound having a maleimide group, the polymer has a cyano group, An underfill composition having a cyano group content per 1 g of polymer of 0.1 to 6 mmol / g. [2] The underfill composition according to [1], wherein the total content of the polymer and the maleimide compound is 10 to 80 mass % based on the total mass of the underfill composition. [3] Further, the composition contains a solvent, The underfill composition according to [1] or [2], wherein the solvent-soluble components account for 95 mass % or more of the total mass of the non-volatile components. [4] The underfill composition according to any one of [1] to [3], wherein the polymer is a thermosetting resin having a curable group other than an epoxy group. [5] The underfill composition according to any one of [1] to [4], wherein the polymer has a repeating unit, and the repeating unit has a side chain containing a cyano group. [6] The underfill composition according to any one of [1] to [5], wherein the polymer has a repeating unit represented by formula (1) described below. [7] The underfill composition according to any one of [1] to [6], wherein the weight average molecular weight of the polymer is 100,000 to 1,200,000. [8] The underfill composition according to any one of [1] to [7], wherein the content of the maleimide compound is 5 to 70 mass % based on the total mass of the underfill composition. [9] The underfill composition according to any one of [1] to [8], wherein the maleimide compound is a compound having two or more maleimide groups in one molecule.

[10] The underfill composition according to any one of [1] to [9], wherein the maleimide compound is a bismaleimide compound.

[11] The underfill composition according to any one of [1] to

[10] , further comprising an allylphenol compound.

[12] The underfill composition according to

[11] , wherein the content of the allylphenol compound is 3 to 60 mass % based on the total mass of the underfill composition.

[13] The underfill composition according to any one of [1] to

[12] , further comprising at least one monomer selected from the group consisting of acrylic monomers and methacrylic monomers.

[0009]

[14] A coating film formed using the underfill composition according to any one of [1] to

[13] .

[15] A cured film formed by curing the coating film according to

[14] .

[16] A multilayer wiring board having, in this order, a semiconductor element having a plurality of electrodes, an anisotropic conductive bonding member, and a circuit board having a plurality of electrodes, The cured film according to

[15] is disposed between a semiconductor element and an anisotropic conductive bonding member, and between a circuit board and an anisotropic conductive bonding member; the anisotropic conductive bonding member has an insulating base material made of an inorganic material, and a plurality of conductive paths made of a conductive material that penetrate the insulating base material in a thickness direction and are insulated from each other, and the plurality of conductive paths have protruding portions that protrude from a surface of the insulating base material; A multilayer wiring board in which the height of the electrodes on the circuit board is 10 μm or less.

[17] The multilayer wiring board according to

[16] , wherein the conductive member of the anisotropic conductive bonding member, the plurality of electrodes of the semiconductor element, and the plurality of electrodes of the circuit board all contain copper.

[0010]

[18] A method for manufacturing a multilayer wiring board, which includes, in order, a semiconductor element having a plurality of electrodes, an anisotropic conductive bonding member, and a circuit board having a plurality of electrodes, the method comprising: a temporary bonding process in which an anisotropic conductive bonding member, a semiconductor element, and a circuit board are bonded together using the underfill composition according to any one of [1] to

[13] ; a bonding process in which the conductive paths of the anisotropic conductive bonding member are electrically bonded to a plurality of electrodes of the semiconductor element and a plurality of electrodes of the circuit board by heating at a temperature lower than the curing temperature of the underfill composition; a curing process of curing the underfill composition by heating at a temperature equal to or higher than the curing temperature of the underfill composition, The temperature condition in the temporary bonding process is 20 to 140°C, A method for manufacturing a multilayer wiring board, wherein the temperature conditions in the main bonding process are higher than the temperature in the temporary bonding process.

[19] The method for producing a multilayer wiring board according to

[18] , wherein in the temporary bonding process, a coating film formed using an underfill composition is provided on the surface of the anisotropic conductive bonding member on the semiconductor element side and the circuit board side.

[20] The method for manufacturing a multilayer wiring board according to

[18] , wherein in the temporary bonding process, a coating film formed using an underfill composition is provided on the surface of the semiconductor element and the circuit board on the anisotropic conductive bonding member side.

[21] The method for manufacturing a multilayer wiring board according to any one of

[18] to

[20] , wherein in the bonding process, heating is carried out after or while applying pressure. [Effects of the Invention]

[0011] As will be described below, the present invention can provide an underfill composition that has excellent stability over time and good metal adhesion, as well as a coated film, a cured film, a multilayer wiring board, and a method for manufacturing a multilayer wiring board that use the underfill composition. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating the method for manufacturing a multilayer wiring board of the present invention, showing a state where an anisotropic conductive bonding member, a semiconductor element, and a circuit board are temporarily bonded. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating the method for manufacturing a multilayer wiring board of the present invention, showing the conductive paths of the anisotropic conductive bonding member and the electrodes of the semiconductor element and the circuit board when they are finally bonded together. [Figure 3] FIG. 3 is a schematic cross-sectional view illustrating the method for producing a multilayer wiring board of the present invention, showing the state in which the underfill composition has been cured after the main bonding. [Figure 4] FIG. 4 is a diagram showing the classification of evaluation criteria for metal adhesion. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below. The following description of the components may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In addition, in this specification, each component may be a single substance corresponding to the component, or two or more substances may be used in combination. Here, when two or more substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified. Furthermore, in this specification, "(meth)acrylate" is a notation representing "acrylate" or "methacrylate", "(meth)acrylic" is a notation representing "acrylic" or "methacrylic", and "(meth)acryloyl" is a notation representing "acryloyl" or "methacryloyl".

[0014] [Underfill composition] The underfill composition of the present invention (hereinafter also referred to as "the composition of the present invention") is a composition containing a polymer and a maleimide compound having a maleimide group. The polymer has a cyano group, and the content of the cyano group per 1 g of the polymer is 0.1 to 6 mmol / g.

[0015] In the present invention, as described above, when a composition containing a polymer containing a specific amount of cyano groups and a maleimide compound is used, the composition has excellent stability over time and good metal adhesion. Although the mechanism is not clear in detail, it is presumed to be as follows. That is, it is believed that the metal adhesion was improved because π adsorption occurred on the metal (especially copper) surface due to the coordination of π electrons of the cyano groups contained in a specific amount in the polymer. Furthermore, the maleimide compound has high thermal stability, and even if the composition of the present invention is left in an applied state during the manufacturing process of a multilayer wiring board, its function as a thermal polymerization initiator is not inhibited, which is thought to be why the stability over time is good.

[0016] Furthermore, as will be shown in the examples below, the present invention has the unexpected effect of improving bonding suitability when the composition of the present invention is used in the production of a multilayer wiring board. Although the mechanism is not clear in detail, it is presumed to be as follows. That is, it is considered that the viscosity of the polymer contained in the composition of the present invention is likely to decrease as the interaction of the cyano groups weakens during heating in the temporary bonding process or the main bonding process described below, thereby increasing fluidity and making it difficult for the composition of the present invention to remain between the conductive paths of the anisotropic conductive bonding member and the multiple electrodes of the semiconductor element and the multiple electrodes of the circuit board. The polymer and maleimide compound contained in the composition of the present invention will be described in detail below.

[0017] [Polymer] The polymer contained in the composition of the present invention has a cyano group, and the content of the cyano group per 1 g of the polymer is 0.1 to 6 mmol / g. Here, the content of cyano groups is 13 Measurement can be performed using a method such as C-NMR (Nuclear Magnetic Resonance). In the present invention, the content of cyano groups is preferably 1 to 5 mmol / g.

[0018] In the present invention, the polymer is preferably a thermosetting resin having a curable group other than an epoxy group, because this improves the stability over time and the adhesion to metals. Specific examples of thermosetting resins having a curing group other than an epoxy group include polyacrylonitrile (including copolymers with acrylic acid esters or methacrylic acid esters; the same applies hereinafter), AS (acrylonitrile styrene copolymer) resin, ABS (acrylonitrile butadiene styrene copolymer) resin, acrylic resin, phenol resin, amino resin (urea resin, melamine resin, etc.), furan resin, unsaturated polyester resin, thermosetting urethane resin, silicone resin, thermosetting polyimide resin, diallyl phthalate resin, and vinyl ester resin. Of these, polyacrylonitrile is preferred.

[0019] In the present invention, for the reason that adhesion to metals (especially copper) is improved, it is preferable that the polymer has a repeating unit having a side chain containing a cyano group. Specifically, it is more preferable that the polymer has a repeating unit represented by the following formula (1): [ka]

[0020] In the above formula (1), R 1 represents a hydrogen atom or a substituent, and L 1 represents a single bond or a divalent linking group.

[0021] Next, R in the above formula (1) 1 The hydrogen atom or substituent represented by will be explained. In the above formula (1), R 1 The substituent represented by one embodiment of the formula (1) is preferably a halogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a linear halogenated alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a cyano group, or an amino group. In the present invention, R in the above formula (1) 1 is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0022] Next, L in the above formula (1) 1 The single bond or divalent linking group represented by will be explained. In the above formula (1), L 1The divalent linking group represented by one embodiment of the formula (1) is preferably a divalent linking group formed by combining at least two or more groups selected from the group consisting of an optionally substituted linear alkylene group having 1 to 18 carbon atoms, an optionally substituted branched or cyclic alkylene group having 3 to 18 carbon atoms, an optionally substituted arylene group having 6 to 12 carbon atoms, an ether group (-O-), a carbonyl group (-C(=O)-), and an optionally substituted imino group (-NH-). In the present invention, L in the above formula (1) 1 is preferably a single bond.

[0023] The polymer may be a homopolymer of a monomer component containing a cyano group (e.g., acrylonitrile, etc.) (hereinafter also referred to as "cyano group-containing monomer"), but is preferably a copolymer obtained by copolymerizing a cyano group-containing monomer with a (meth)acrylate component. Specific examples of the (meth)acrylate component include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, and lauryl (meth)acrylate. The (meth)acrylate component is preferably introduced in a copolymerization ratio of 70 to 99 mol %, more preferably 80 to 98 mol %, and even more preferably 90 to 98 mol %, relative to the cyano group-containing monomer.

[0024] The polymer may also be a copolymer obtained by copolymerizing, in addition to the above-mentioned cyano group-containing monomer and (meth)acrylate component, other monomer component copolymerizable with the above-mentioned (meth)acrylate component. As the other monomer component, for example, a carboxyl group-containing monomer (such as (meth)acrylic acid) can be used.

[0025] In the present invention, the polymer can be obtained by polymerizing the above-mentioned monomer components. The polymerization method is not particularly limited, and examples thereof include solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. The types of polymerization reaction include, for example, radical polymerization, cationic polymerization, anionic polymerization, living radical polymerization, living cationic polymerization, living anionic polymerization, and coordination polymerization.

[0026] In the present invention, from the viewpoints of solubility in a solvent and ease of handling the liquid in a coating operation, the weight average molecular weight (Mw) of the polymer is preferably 100,000 to 1,200,000, and more preferably 500,000 to 1,000,000. Here, the weight average molecular weight in the present invention is a value measured by gel permeation chromatography (GPC). Solvent (eluent): tetrahydrofuran (THF) Device name: Shimadzu Prominence LC-20AD and Shodex RI-104 Column: TOSOH TSKgel SuperHM-M (6.0mmφ×150mm) used in one connection Column temperature: 40℃ Sample concentration: 1mg / mL ·Flow rate: 0.6mL / min. Calibration curve: A calibration curve using five samples of TOSOH TSK standard polystyrene Mw = 2,630 to 710,000 (Mw / Mn = 1.01 to 1.05)

[0027] In the present invention, the content of the polymer is preferably 10 to 60 mass %, more preferably 10 to 45 mass %, and even more preferably 15 to 40 mass %, relative to the total mass of the composition of the present invention, because this makes it easier to eliminate voids in the composition, enables low-pressure mounting in the semiconductor mounting process, and improves connectivity. The polymer may be one type of polymer alone or two or more types of polymers in combination. When two or more types of polymers are used in combination, the total content of the polymers in the composition is preferably within the above-mentioned range.

[0028] [Maleimide Compound] The maleimide compound contained in the composition of the present invention is not particularly limited as long as it is a compound having a maleimide group, and is preferably a low molecular weight compound having a maleimide group and a molecular weight of 1,000 or less. The maleimide compound is preferably, for example, a compound having two or more maleimide groups in one molecule, and more preferably a bismaleimide compound having two maleimide groups in one molecule. Specific examples of the maleimide compound include 4-methyl-1,3-phenylene bismaleimide, 4,4-bismaleimide diphenylmethane, m-phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, and 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide. Among these, aromatic bismaleimides are preferred, and in particular, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, which has good solvent solubility and flowability, is preferred when considering workability in the temporary bonding process.

[0029] In the present invention, the content of the maleimide compound is preferably 5 to 70 mass %, more preferably 20 to 60 mass %, and even more preferably 20 to 55 mass %, relative to the total mass of the composition of the present invention, for reasons such as facilitating the elimination of voids in the composition, enabling low-pressure mounting in the semiconductor mounting process, and improving connectivity. The maleimide compound may be a single maleimide compound or a combination of two or more maleimide compounds. When two or more maleimide compounds are used in combination, the total content of the maleimide compounds in the composition is preferably within the above-mentioned range.

[0030] Furthermore, in the present invention, from the viewpoint of achieving both ensuring curability and workability (low viscosity), the total content of the above-mentioned polymer and maleimide compound is preferably 10 to 80 mass %, and more preferably 15 to 70 mass %, of the total mass of the underfill composition.

[0031] [Allylphenol compounds] The composition of the present invention preferably contains an allylphenol compound having an ethylenically unsaturated double bond and a phenolic hydroxyl group, because this allows for sufficient curability. Examples of the ethylenically unsaturated double bond include a (meth)acryloyl group, a (meth)acrylamide group, a styryl group, a vinyl group (for example, a vinyl ester, a vinyl ether, etc.), and an allyl group (for example, an allyl ether, an allyl ester, etc.). The phenolic hydroxyl group refers to a hydroxyl group substituting a hydrogen atom on an aromatic ring, and is preferably a hydroxyl group substituting a hydrogen atom on a benzene ring.

[0032] The allylphenol compound includes, for example, allylated bisphenol. Specific examples of allylated bisphenols include 2,2'-diallylbisphenol A, 4,4'-(dimethylmethylene)bis[2-(2-propenyl)phenol], 4,4'-methylenebis[2-(2-propenyl)phenol], and 4,4'-(dimethylmethylene)bis[2-(2-propenyl)-6-methylphenol], and among these, 2,2'-diallylbisphenol A is preferred.

[0033] In the present invention, the content of the allylphenol compound is preferably 3 to 60 mass %, more preferably 6 to 55 mass %, and even more preferably 6 to 50 mass %, relative to the total mass of the composition of the present invention, because this makes it easier to eliminate voids in the composition and improves connectivity. The allylphenol compound may contain one kind of allylphenol compound alone, or may contain two or more kinds of allylphenol compounds in combination. When two or more kinds of allylphenol compounds are used in combination, it is preferable that the total content of the allylphenol compounds in the composition is within the above-mentioned range.

[0034] 〔monomer〕 From the viewpoint of ensuring both curability and workability (low viscosity), the composition of the present invention preferably contains at least one monomer selected from the group consisting of acrylic monomers and methacrylic monomers. The above-mentioned monomer may be either a monofunctional (meth)acrylate having one (meth)acryloyl group or a polyfunctional (meth)acrylate having two or more (meth)acryloyl groups.

[0035] Examples of the monomer include isocyanuric acid EO-modified diacrylate, isocyanuric acid EO-modified triacrylate, dipentaerythritol tetraacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, tricyclodecane dimethanol diacrylate, ethoxylated bisphenol A diacrylate, and fluorene-based acrylates (for example, product names: OGSOL EA0200, EA0300, manufactured by Osaka Gas Chemicals Co., Ltd.). Among these monomers, fluorene-based acrylates are preferred in view of heat resistance and the like, as they have high heat resistance.

[0036] In the present invention, the content of the above-mentioned monomer is preferably 15% by mass or less based on the total mass of the polymer, the maleimide compound, the allylphenol compound, and the above-mentioned monomer. The above-mentioned monomers may be contained alone or in combination of two or more monomers. When two or more monomers are used in combination, the total content of the monomers in the composition is preferably within the above-mentioned range.

[0037] 〔solvent〕 The composition of the present invention preferably contains a solvent for the reason that workability is improved. Examples of the solvent include ketones (e.g., acetone, methyl ethyl ketone, 2-butanone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and acetylacetone), ethers (e.g., dioxane, tetrahydrofuran, tetrahydropyran, dioxolane, tetrahydrofurfuryl alcohol, cyclopentyl methyl ether, and dibutyl ether), aliphatic hydrocarbons (e.g., hexane), alicyclic hydrocarbons (e.g., cyclohexane), aromatic hydrocarbons (e.g., benzene, toluene, xylene, tetralin, and trimethylbenzene), halogenated carbons (e.g., dichloromethane, trichloromethane (chloroform), dichloroethane, dichlorobenzene, 1,1,2,2-tetrachloroethane, and chlorotoluene), esters (e.g., methyl acetate, ethyl acetate, butyl acetate, diethyl carbonate, ethyl acetoacetate, n-pentyl acetate, ethyl benzoate, benzyl benzoate, butyl carbitol acetate, and diethylene glycol monoethyl ester). Examples of suitable solvents include organic solvents such as ethanol, isopropanol, butanol, cyclohexanol, furfuryl alcohol, 2-ethylhexanol, octanol, benzyl alcohol, ethanolamine, ethylene glycol, propylene glycol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, phenols (e.g., phenol, cresol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, 1,2-dimethoxyethane, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc.), and heterocyclic compounds (e.g., pyridine, 2,6-lutidine, etc.); and water. These solvents may be used alone or in combination of two or more.

[0038] In the composition of the present invention, the content of components soluble in the solvent is preferably 95% by mass or more based on the total mass of non-volatile components, for the reason that workability is improved. Here, the non-volatile components refer to components that constitute the composition other than the solvent.

[0039] [Other ingredients] The composition used for the underfill material may contain, in addition to the above-mentioned components, various additives such as an antioxidant, a migration inhibitor, an inorganic filler, a dispersant, a buffer, and a viscosity adjuster, depending on the purpose.

[0040] [Coating film] The coating film of the present invention is a coating film formed using the above-described composition of the present invention. Here, the coated film means an uncured film (resin layer) obtained by coating the composition of the present invention described above and then drying to remove the solvent.

[0041] The thickness of the coating film of the present invention is not particularly limited, but is preferably 50 to 3000 nm, more preferably 250 to 2000 nm, from the viewpoint of conforming to the surface shapes of the semiconductor element and circuit board to be connected in the method for manufacturing a multilayer wiring board of the present invention described below.

[0042] The method for forming the coating film of the present invention is not particularly limited. When the coating film is provided on the surface of the semiconductor element side and the surface of the circuit board side of an anisotropically conductive bonding member described later, the above-mentioned composition of the present invention is applied to the surface of the insulating substrate of the anisotropically conductive bonding member and the protruding parts of the conductive paths, dried, and optionally fired. The method for applying the composition of the present invention is not particularly limited, and any conventionally known coating method can be used, such as gravure coating, reverse coating, die coating, blade coating, roll coating, air knife coating, screen coating, bar coating, or curtain coating. Furthermore, the drying method after application is not particularly limited, and examples thereof include a heating treatment in the atmosphere at a temperature of 0 to 100°C for several seconds to several tens of minutes, or a heating treatment under reduced pressure at a temperature of 0 to 80°C for several minutes to several hours. The firing method after drying is not particularly limited as it differs depending on the materials used, but examples include a treatment in which the material is heated at a temperature of 160 to 300° C. for 2 minutes to 6 hours.

[0043] [Cured film] The cured film of the present invention is a cured film formed by curing the above-described coating film of the present invention. Here, the method for forming the cured film is not particularly limited, but examples include a method in which the composition is heated at a temperature equal to or higher than the curing temperature of the composition of the present invention. The heating temperature in the method for forming the cured film is preferably 200°C or higher and 400°C or lower, and more preferably 200°C or higher and 300°C or lower. The heating time in the method for forming the cured film is preferably 1 to 60 minutes from the viewpoint of allowing the curing to proceed sufficiently.

[0044] [Multilayer wiring board] The multilayer wiring board of the present invention is a multilayer wiring board having, in this order, a semiconductor element having a plurality of electrodes, an anisotropic conductive bonding member, and a circuit board having a plurality of electrodes. In addition, in the multilayer wiring board of the present invention, the above-mentioned cured film of the present invention is arranged between the semiconductor element and the anisotropic conductive bonding member, and between the circuit board and the anisotropic conductive bonding member. The anisotropic conductive bonding member has an insulating base material made of an inorganic material and a plurality of conductive paths made of a conductive material that penetrate the insulating base material in the thickness direction and are insulated from each other, and the plurality of conductive paths have protruding portions that protrude from the surface of the insulating base material. The height of the plurality of electrodes on the circuit board is 10 μm or less.

[0045] [Anisotropic conductive bonding material] As described above, the anisotropic conductive bonding member of the multilayer wiring board of the present invention comprises an insulating base material made of an inorganic material, and a plurality of conductive paths made of a conductive material that penetrate the insulating base material in the thickness direction and are insulated from each other. Each conductive path has a protruding portion that protrudes from the surface of the insulating substrate.

[0046] In the present invention, the anisotropically conductive bonding member and its manufacturing method can be that described in Patent Document 1 (JP 2018-037509 A), the contents of which are incorporated herein by reference. Furthermore, methods other than that described in JP 2018-037509 A can also be used for manufacturing an anisotropic conductive bonding member, such as the method described in JP 2008-270157 A, the method described in WO 2017 / 057150 A, the method described in WO 2018 / 155273 A, and the method described in JP 2019-153415 A. The contents of these publications are incorporated herein by reference.

[0047] [Semiconductor element] The semiconductor element included in the multilayer wiring board of the present invention is a semiconductor element having a plurality of electrodes, as described above. In the present invention, the semiconductor element may be a conventionally known semiconductor element, and specific examples thereof include logic LSIs (Large Scale Integration) (for example, ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), ASSPs (Application Specific Standard Products), etc.), microprocessors (for example, CPUs (Central Processing Units), GPUs (Graphics Processing Units), etc.), memories (for example, DRAMs (Dynamic Random Access Memory), HMCs (Hybrid Memory Cubes), MRAMs (Magnetic RAMs), PCMs (Phase-Change Memorys), ReRAMs (Resistive RAMs), FeRAMs (Ferroelectric RAMs), flash memories (NAND (Not AND) flash), etc.), LEDs (Light Emitting Diodes) (for example, microflash for mobile terminals, in-vehicle devices, projector light sources, LCD backlights, general lighting, etc.), power devices, and analog ICs (Integrated Circuits). Circuit), (e.g., DC (Direct Current)-DC (Direct Current) converters, insulated gate bipolar transistors (IGBT), etc.), MEMS (Micro Electro Mechanical Systems), (e.g., acceleration sensors, pressure sensors, vibrators, gyro sensors, etc.), wireless (e.g., GPS (Global Positioning System), FM (Frequency Modulation), NFC (Near field communication), RFEM (RF Expansion Module), MMIC (Monolithic Microwave Integrated Circuit), WLAN (Wireless Local Area Network), etc.), discrete elements, BSI (Back Side Array)Examples include semiconductor devices such as semiconductor integrated circuits (ICs), contact image sensors (CISs), camera modules, complementary metal oxide semiconductors (CMOSs), passive devices, surface acoustic wave (SAW) filters, radio frequency (RF) filters, RFIPDs (Radio Frequency Integrated Passive Devices), and broadband (BB). A semiconductor element is, for example, a self-contained device that performs a specific function such as a circuit or a sensor. The semiconductor element may also have an interposer function. It is also possible to stack multiple devices, such as a logic chip having a logic circuit and a memory chip, on a device with an interposer function. In this case, bonding is possible even if the electrode sizes of each device are different.

[0048] [Circuit board] The circuit board of the multilayer wiring board of the present invention has a substrate and a plurality of electrodes each having a height of 10 μm or less, and may further have other members as required. Here, the electrode height refers to the average value of electrode heights measured at 10 points when the cross section of the circuit board is observed at 10,000 times magnification using a field emission scanning electron microscope. The circuit board may also be a semiconductor element having an integrated circuit mounted on a substrate (for example, a silicon substrate). Examples of the semiconductor element include those described above.

[0049] <Substrate> The substrate is not particularly limited and can be appropriately selected depending on the purpose. Examples include a plastic substrate and a glass substrate. The shape, size and structure of the substrate are not particularly limited and can be appropriately selected depending on the purpose.

[0050] <Electrode> Examples of materials for the electrodes include gold, silver, copper, and aluminum. The shape of the electrode is not particularly limited as long as it has a height of 10 μm or less, and may be a wiring shape, and can be appropriately selected depending on the purpose. The height of the electrodes is preferably 0.05 μm or more, and more preferably 0.1 to 5 μm.

[0051] [Cured film] The cured film of the multilayer wiring board of the present invention is the cured film of the present invention described above. Here, the thickness of the cured film in the multilayer wiring board of the present invention is not particularly limited, but is preferably 50 to 3000 nm, and more preferably 250 to 2000 nm.

[0052] In the present invention, for the reason that the effects of the present invention become apparent, it is preferable that the conductive member of the above-mentioned anisotropic conductive bonding member, the plurality of electrodes of the semiconductor element, and the plurality of electrodes of the circuit board all contain copper.

[0053] [Manufacturing method for multilayer wiring boards] The method for manufacturing a multilayer wiring board of the present invention (hereinafter referred to as "the manufacturing method of the present invention") is a method for manufacturing a multilayer wiring board having, in this order, a semiconductor element having a plurality of electrodes, an anisotropic conductive bonding member, and a circuit board having a plurality of electrodes. The manufacturing method of the present invention includes, in this order: a temporary bonding process in which the anisotropic conductive bonding member is bonded to the semiconductor element and the circuit board using the composition of the present invention; a main bonding process in which the anisotropic conductive bonding member is heated at a temperature lower than the curing temperature of the composition of the present invention to electrically bond the conductive paths of the anisotropic conductive bonding member to the plurality of electrodes of the semiconductor element and the plurality of electrodes of the circuit board; and a curing process in which the composition of the present invention is cured by heating at a temperature equal to or higher than the curing temperature of the composition of the present invention. The temperature condition in the temporary bonding process is 20 to 140°C. The temperature condition in the main bonding process is higher than the temperature in the temporary bonding process. The anisotropically conductive bonding member, semiconductor element, and circuit board used in the manufacturing method of the present invention are the same as those explained in the multilayer wiring board of the present invention. The temporary bonding process, the main bonding process, and the curing process of the manufacturing method of the present invention will be described in detail below.

[0054] [Temporary bonding process] The temporary bonding process of the manufacturing method of the present invention is a process of bonding the above-mentioned anisotropic conductive bonding member, the above-mentioned semiconductor element, and the circuit board using the above-mentioned composition of the present invention under a temperature condition of 20 to 140°C. In the present invention, when the composition of the present invention is applied, a coating film formed using the composition of the present invention may be provided on the surface of the anisotropically conductive bonding member on the semiconductor element side and the circuit board side, or on the surface of the semiconductor element and the circuit board on the anisotropically conductive bonding member side.

[0055] In the present invention, in order to prevent misalignment due to softening of the resin by heating, it is preferable to carry out heating at 20 to 140° C. after or while applying pressure.

[0056] The temperature conditions in the temporary bonding process are not particularly limited as long as they are 20 to 140°C, and are preferably 25 to 100°C. Furthermore, the pressure conditions when applying pressure in the temporary bonding process are not particularly limited, but are preferably 10 MPa or less, and more preferably 6 MPa or less.

[0057] In the present invention, the temporary bonding process is preferably performed using a CoW (Chip On Wafer) process. The semiconductor wafer and semiconductor chip wafer are inspected to identify good and bad chips in advance (known good die: KGD), and only good chips on the semiconductor chip wafer are bonded to good parts of the semiconductor wafer, thereby reducing loss. If the temporary bonding strength is weak during temporary bonding, misalignment will occur during the processes leading up to the actual bonding (such as the transport process), so the temperature and pressure conditions in the temporary bonding process described above are important.

[0058] [Main bonding process] The bonding process of the manufacturing method of the present invention is a process of electrically bonding the conductive paths of the anisotropic conductive bonding member to the plurality of electrodes of the semiconductor element and the plurality of electrodes of the circuit board by heating at a temperature lower than the curing temperature of the composition of the present invention described above and higher than the temperature of the temporary bonding process.

[0059] In the present invention, in order to prevent misalignment due to softening of the resin by heating, the heating at a temperature lower than the curing temperature of the composition of the present invention is preferably carried out after or while pressurizing.

[0060] The temperature conditions in the main bonding process are not particularly limited as long as the temperature is higher than the temperature in the temporary bonding process, but is preferably higher than 100°C and not higher than 300°C, and more preferably 120 to 250°C. Furthermore, the pressure conditions when applying pressure in this bonding process are not particularly limited, but are preferably 150 MPa or less, and more preferably 0.1 to 100 MPa. The time for this bonding process is not particularly limited, but is preferably 1 second to 60 minutes, and more preferably 5 seconds to 40 minutes. By carrying out this bonding process under the above-mentioned conditions, the composition of the present invention used in the temporary bonding process described above is more likely to flow between the electrodes of the semiconductor element and the circuit board, and is less likely to remain in the bonded portion. This bonding process may be carried out for each chip of the semiconductor element, but is preferably carried out for the entire wafer in bulk in order to reduce the takt time.

[0061] [Curing process] The curing process of the production method of the present invention is a process in which the above-mentioned composition of the present invention is cured by heating at a temperature equal to or higher than the curing temperature of the above-mentioned composition of the present invention. In the present invention, the temperature conditions in the curing process are not particularly limited as long as they are equal to or higher than the curing temperature of the composition of the present invention described above, but are preferably 200°C or higher and 400°C or lower, and more preferably 200°C or higher and 300°C or lower. Furthermore, in order to prevent misalignment due to softening of the resin caused by heating, it is preferable that the heating in the curing process be carried out after or while pressure is being applied. The time for the curing process is not particularly limited, but is preferably 1 to 60 minutes from the viewpoint of sufficiently progressing the curing of the composition of the present invention described above. The curing process may be carried out for each semiconductor chip, as in the main bonding process, but is preferably carried out for the entire wafer in bulk in order to reduce the takt time. Furthermore, the pressure conditions when pressure is applied in the curing process are not particularly limited, but are preferably 150 MPa or less, and more preferably 0.1 to 100 MPa.

[0062] Next, the above-mentioned temporary bonding process, main bonding process, and hardening process will be described with reference to FIGS. As shown in FIG. 1, an anisotropic conductive bonding member 1 (reference numeral 2: insulating substrate, reference numeral 3: conductive path), a semiconductor element 11, and a circuit board 13 are temporarily bonded using an underfill composition 4 provided on the surface of the anisotropic conductive bonding member 1. Next, as shown in FIG. 2, the anisotropic conductive bonding member 1 is heated at a temperature lower than the curing temperature of the underfill composition 4, thereby electrically bonding (main bonding) the conductive paths 3 of the anisotropic conductive bonding member 1 to the multiple electrodes 12 of the semiconductor element 11 and the multiple electrodes 14 of the circuit board 13. Next, as shown in FIG. 3, the underfill composition 4 is heated at a temperature equal to or higher than the curing temperature thereof to cure the underfill composition 4, thereby making it possible to produce the multilayer wiring board 30. [Example]

[0063] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0064] [Fabrication of anisotropic conductive joint materials] <Preparation of aluminum substrate> A molten metal was prepared using an aluminum alloy containing 0.06 mass% Si, 0.30 mass% Fe, 0.005 mass% Cu, 0.001 mass% Mn, 0.001 mass% Mg, 0.001 mass% Zn, 0.001 mass% Ti, and the remainder being Al and unavoidable impurities. After molten metal treatment and filtration, an ingot measuring 500 mm thick and 1200 mm wide was produced using a DC (Direct Chill) casting method. Next, the surface was scraped off to an average thickness of 10 mm using a facing mill, and then the material was soaked at 550°C for approximately 5 hours. When the temperature dropped to 400°C, it was rolled into a 2.7 mm thick plate using a hot rolling mill. Further, the sheet was heat-treated at 500° C. using a continuous annealing machine, and then cold-rolled to a thickness of 1.0 mm to obtain an aluminum substrate of JIS (Japanese Industrial Standards) 1050 material. This aluminum substrate was cut to a width of 1030 mm and then subjected to the following treatments.

[0065] <Electrolytic polishing treatment> The above aluminum substrate was subjected to electrolytic polishing treatment using an electrolytic polishing solution having the following composition under conditions of a voltage of 25 V, a solution temperature of 65° C., and a solution flow rate of 3.0 m / min. The cathode was a carbon electrode, and the power supply was GP0110-30R (manufactured by Takasago Manufacturing Co., Ltd.) The flow rate of the electrolyte was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE Corporation).

[0066] (Electrolytic polishing liquid composition) 85% by weight phosphoric acid (reagent manufactured by Wako Pure Chemical Industries, Ltd.) 660 mL ·Pure water 160mL ·Sulfuric acid 150mL 30mL of ethylene glycol

[0067] <Anodizing process> Next, the aluminum substrate after the electrolytic polishing treatment was subjected to anodizing treatment by a self-ordering method according to the procedure described in JP-A-2007-204802. The aluminum substrate after electrolytic polishing was subjected to a pre-anodizing treatment for 5 hours using an electrolytic solution of 0.50 mol / L oxalic acid under conditions of a voltage of 40 V, a solution temperature of 16°C, and a solution flow rate of 3.0 m / min. Thereafter, the aluminum substrate after the pre-anodizing treatment was subjected to a film removal treatment by immersing it in a mixed aqueous solution of 0.2 mol / L chromic anhydride and 0.6 mol / L phosphoric acid (liquid temperature: 50° C.) for 12 hours. Thereafter, the plate was subjected to re-anodization treatment for 3 hours and 45 minutes in an electrolyte solution of 0.50 mol / L oxalic acid under conditions of a voltage of 40 V, a liquid temperature of 16°C, and a liquid flow rate of 3.0 m / min, to obtain an anodized film with a thickness of 30 μm. In both pre-anodizing and re-anodizing treatments, a stainless steel cathode was used, and a GP0110-30R power supply (manufactured by Takasago Manufacturing Co., Ltd.) was used. The cooling device was a NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.), and the stirring and heating device was a Pair Stirrer PS-100 (manufactured by EYELA Tokyo Rikakikai Co., Ltd.). The electrolyte flow rate was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE Corporation).

[0068] <Barrier layer removal process> Next, after the anodizing treatment step, an etching treatment was performed by immersing the substrate in an alkaline aqueous solution of sodium hydroxide (50 g / l) with zinc oxide dissolved to a concentration of 2000 ppm at 30°C for 150 seconds, thereby removing the barrier layer at the bottom of the micropores of the anodized film and simultaneously depositing zinc on the surface of the exposed aluminum substrate. The average thickness of the anodic oxide film after the barrier layer removal step was 30 μm.

[0069] <Metal filling process> Next, electrolytic plating was carried out using the aluminum substrate as the cathode and platinum as the anode. Specifically, a metal-filled microstructure in which nickel was filled into the micropores was fabricated by constant-current electrolysis using a copper plating solution with the composition shown below. Here, constant-current electrolysis was performed using a plating device manufactured by Yamamoto Plating Tester Co., Ltd. and a power supply (HZ-3000) manufactured by Hokuto Denko Corporation. After confirming the deposition potential by performing cyclic voltammetry in the plating solution, the process was carried out under the conditions shown below. (Copper plating solution composition and conditions) ·Copper sulfate 100g / L ·Sulfuric acid 50g / L Hydrochloric acid 15g / L ·Temperature 25℃ ·Current density 10A / dm 2

[0070] The surface of the anodized film after filling the micropores with metal was observed using FE-SEM, and the presence or absence of metal sealing in 1,000 micropores was observed. The sealing rate (number of sealed micropores / 1,000) was calculated to be 98%. In addition, after filling the micropores with metal, the anodized film was cut in the thickness direction using FIB, and the cross section was photographed using FE-SEM (magnification 50,000x) to check the inside of the micropores.It was found that the inside of the sealed micropores was completely filled with metal.

[0071] <Surface metal protrusion process> After the metal filling process, the structure was immersed in a sodium hydroxide aqueous solution (concentration: 5% by mass, liquid temperature: 20°C). The immersion time was adjusted so that the height of the protruding parts was 400 nm, and the surface of the aluminum anodized film was selectively dissolved to produce a structure with protruding copper, the filling metal.

[0072] <Resin layer formation process> A thermal peelable resin substrate with an adhesive layer (Rivalpha 3195MS, manufactured by Nitto Denko Corporation) was attached to the surface on the side where the aluminum substrate was not provided.

[0073] <Substrate removal process> The aluminum substrate was then dissolved and removed by immersion in a mixed solution of copper chloride and hydrochloric acid, producing a metal-filled microstructure with an average thickness of 30 μm. The diameter of the conductive paths in the fabricated metal-filled microstructure was 60 nm, the pitch between the conductive paths was 100 nm, and the density of the conductive paths was 57.7 million / mm 2 It was.

[0074] <Back metal protrusion process> After the substrate removal process, the structure was immersed in a sodium hydroxide aqueous solution (concentration: 5% by mass, liquid temperature: 20°C). The immersion time was adjusted so that the height of the protruding parts was 400 nm, and the surface of the aluminum anodized film was selectively dissolved, producing an anisotropic conductive bonding member with protruding copper, the filling metal.

[0075] [Example 1] [Underfill Composition] Underfill composition 1 was prepared according to the following formulation. The cyano group content of the synthesized ethyl acrylate-acrylonitrile copolymer is shown in Table 1 below. ---------------------------------------------------------------------------------- Underfill composition 1 ---------------------------------------------------------------------------------- Methyl ethyl ketone 50 parts by mass Ethyl acrylate-acrylonitrile copolymer (Mw: 160,000, copolymerization molar ratio 95:5) 16 parts by mass Maleimide compounds (Product name: BMI5100, manufactured by Daiwa Chemical Industry Co., Ltd.) 22 parts by mass Bisallylphenol (Product name: DABPA, manufactured by Daiwa Chemical Industry Co., Ltd.) 12 parts by mass ----------------------------------------------------------------------------------

[0076] After peeling off the peelable resin substrate with adhesive layer (REVALPHA 3195MS, manufactured by Nitto Denko Corporation) provided on the surface of the anisotropic conductive bonding member prepared above, the prepared underfill composition 1 was applied to the front surface (exposed surface) and back surface using a spin coater to a thickness of 400 nm. A TEG chip (daisy chain pattern) and an interposer manufactured by Waltz Corporation were prepared, and these were placed above and below the chip bonder, and the alignment was adjusted in advance. After adjusting the alignment, the anisotropic conductive material was placed on the Cu post side of the interposer placed underneath, and then temporarily bonded by thermocompression bonding at a temperature of 100°C, 1 minute, and 6 MPa using a room-temperature bonding device (WP-100, manufactured by PMT). Next, the temporarily bonded samples were subjected to thermocompression bonding using a room temperature bonding device (WP-100, manufactured by Bond Tech Co., Ltd.) under conditions of a temperature of 180° C., 5 minutes, and 50 MPa, for permanent bonding. Next, the underfill composition was cured by thermocompression bonding under conditions of a temperature of 220° C., a pressure of 50 MPa for 25 minutes, and a multilayer wiring board was produced.

[0077] [Example 2] A multilayer wiring board was fabricated in the same manner as in Example 1, except that a composition in which the copolymerization molar ratio of the ethyl acrylate-acrylonitrile copolymer was changed to 85:15 was used.

[0078] [Example 3] A multilayer wiring board was fabricated in the same manner as in Example 1, except that a composition in which the copolymerization molar ratio of the ethyl acrylate-acrylonitrile copolymer was changed to 75:25 was used.

[0079] [Example 4] A multilayer wiring board was fabricated in the same manner as in Example 1, except that a composition in which the copolymerization molar ratio of the ethyl acrylate-acrylonitrile copolymer was changed to 99:1 was used.

[0080] [Example 5] A multilayer wiring board was produced in the same manner as in Example 1, except that underfill composition 1 was changed to underfill composition 2 below. ---------------------------------------------------------------------------------- Underfill composition 2 ---------------------------------------------------------------------------------- Methyl ethyl ketone 50 parts by mass Ethyl acrylate-acrylonitrile copolymer (Mw: 160,000, copolymerization molar ratio 95:5) 16 parts by mass Maleimide compounds (Product name: BMI5100, manufactured by Daiwa Chemical Industry Co., Ltd.) 22 parts by mass Bisallylphenol (Product name: DABPA, manufactured by Daiwa Chemical Industry Co., Ltd.) 8 parts by mass Fluorene-based acrylate (product name: Oxol EA0200, EA0300, manufactured by Osaka Gas Chemicals Co., Ltd.) 4 parts by mass ----------------------------------------------------------------------------------

[0081] [Example 6] A multilayer wiring board was produced in the same manner as in Example 1, except that underfill composition 1 was changed to underfill composition 3 below. ---------------------------------------------------------------------------------- Underfill composition 3 ---------------------------------------------------------------------------------- Methyl ethyl ketone 50 parts by mass Ethyl acrylate-acrylonitrile copolymer (Mw: 160,000, copolymerization molar ratio 95:5) 16 parts by mass Maleimide compounds (Product name: BMI5100, manufactured by Daiwa Chemical Industry Co., Ltd.) 20 parts by mass Bisallylphenol (Product name: DABPA, manufactured by Daiwa Chemical Industry Co., Ltd.) 8 parts by mass Silica particles (Product name: Aerosil R202, Nippon Aerosil Co., Ltd.) 6 parts by mass ----------------------------------------------------------------------------------

[0082] [Example 7] A multilayer wiring board was fabricated in the same manner as in Example 1, except that the polymer in the underfill composition was changed to an ethyl acrylate-acrylonitrile copolymer (Mw: 1,400,000, copolymerization ratio 95:5).

[0083] [Example 8] A multilayer wiring board was produced in the same manner as in Example 1, except that underfill composition 1 was changed to underfill composition 4 below. ---------------------------------------------------------------------------------- Underfill composition 4 ---------------------------------------------------------------------------------- Methyl ethyl ketone 50 parts by mass Ethyl acrylate-acrylonitrile copolymer (Mw: 160,000, copolymerization molar ratio 95:5) 14 parts by mass Epoxy resin (product name: BST001A, Curing temperature: 150°C, manufactured by Namics) 2 parts by weight Maleimide compound (product name: BMI5100, (manufactured by Daiwa Chemical Industry Co., Ltd.) 22 parts by mass Bisallylphenol (Product name: DABPA, manufactured by Daiwa Chemical Industry Co., Ltd.) 12 parts by mass ----------------------------------------------------------------------------------

[0084] [Comparative Example 1] A multilayer wiring board was fabricated in the same manner as in Example 1, except that a composition in which the copolymerization ratio of acrylonitrile in the ethyl acrylate-acrylonitrile copolymer was changed to 0 was used.

[0085] Comparative Example 2 A multilayer wiring board was produced in the same manner as in Example 1, except that a composition was used in which the polymer in the underfill composition was changed to an epoxy resin (product name: BST001A, curing temperature: 150° C., manufactured by Namics Corporation).

[0086] Comparative Example 3 A multilayer wiring board was produced in the same manner as in Example 1, except that the underfill composition was not used.

[0087] [evaluation] 〔viscosity〕 The underfill compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were subjected to dynamic viscoelasticity measurements (apparatus: rheometer DHR-2 manufactured by TA Instruments). Specifically, using a 25 mm diameter parallel plate and an ETC (environmental test chamber) lower plate (gap: 0.5 mm), the melt viscosity was measured at a temperature (set value) of approximately 30 to 100°C, a heating rate of 5°C / min, a frequency of 1 Hz, and a strain of 0.5%, and the viscosity at 100°C was measured. This measurement was performed four times, and the average value was calculated. The results are shown in Table 1 below.

[0088] [Stability over time] After leaving the composition in an environment of 25°C and relative humidity of 50% for 72 hours, the viscosity at 25°C was measured by the method described above. If the rate of change in viscosity was less than 5%, it was rated A, if the rate of change was 5% or more but less than 20%, it was rated B, and if the rate of change was 20% or more, it was rated C. The results are shown in Table 1 below.

[0089] [Joining suitability] The electrical connection was evaluated by measuring the resistance between the chip wiring. The measurement results of the resistance are shown in Table 1 below.

[0090] [Metal Adhesion] The underfill compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were applied to a copper plate to a thickness of 1 μm, and then heated at 220° C. for 30 minutes to prepare samples. The adhesive strength of the prepared samples was evaluated using the cross-cut method specified in JIS K5600-5-6 on a 5-point scale according to the classification shown in Figure 4 below. The cut interval was 1 mm. The results are shown in Table 1 below.

[0091] [Reliability] The fabricated multilayer wiring board was subjected to a temperature cycle test under the conditions of (-50°C / +200°C) and evaluated according to the following criteria. The results are shown in Table 1 below. A: The resistance value is measured every 10 cycles, and the rate of change in resistance value (resistance value at 50 cycles) is less than 10%. B: The resistance value is measured every 10 cycles, and the rate of change in resistance value (resistance value at 50 cycles) is 10% or more but less than 50%. C: The resistance value is measured every 10 cycles, and the rate of change in resistance value (resistance value at 50 cycles) is 50% or more.

[0092] [Table 1]

[0093] The results shown in Table 1 above indicate that when a polymer not containing a cyano group was used, metal adhesion was poor (Comparative Examples 1 and 2). In particular, Comparative Example 2, which used an epoxy resin, was found to have poor stability over time. Furthermore, it was found that when no underfill composition was used, the reliability of the multilayer wiring board was poor (Comparative Example 3).

[0094] In contrast, it was found that when a polymer containing a predetermined amount of cyano groups was used, the underfill composition had excellent stability over time and good metal adhesion (Examples 1 to 8). In particular, a comparison between Example 1 and Example 5 revealed that when an acrylic monomer was blended into the underfill composition, the viscosity was lowered and workability improved. Furthermore, a comparison between Example 1 and Example 6 revealed that Example 1, in which the solvent-soluble components contained in the underfill composition were 95 mass % or more relative to the total mass of the non-volatile components, had higher metal adhesion and improved bondability. Furthermore, a comparison between Example 1 and Example 7 revealed that Example 1, in which the weight average molecular weight of the polymer was 100,000 to 1,200,000, had a lower viscosity and better workability. Furthermore, a comparison between Example 1 and Example 8 revealed that Example 1, in which the polymer is a thermosetting resin having a curable group other than an epoxy group, has better stability over time and metal adhesion. [Explanation of symbols]

[0095] 1 Anisotropic conductive bonding material 2. Insulating substrate 3 Conduction Path 4. Underfill composition 4a Underfill composition after curing 6. Thickness of insulating substrate 11 Semiconductor elements 12 electrodes 13 Circuit Board 14 electrodes 30 Multilayer wiring board

Claims

1. An underfill composition comprising a polymer, a maleimide compound having a maleimide group, an allylphenol compound, and a ketone solvent, the polymer has a cyano group, the content of the cyano group contained per 1 g of the polymer is 0.1 to 6 mmol / g, the content of the polymer is 10 to 60% by mass relative to the total mass of the underfill composition; the content of the maleimide compound is 5 to 70% by mass relative to the total mass of the underfill composition, The underfill composition has a content of the allylphenol compound of 3 to 60% by mass relative to the total mass of the underfill composition.

2. 2. The underfill composition according to claim 1, wherein the total content of the polymer and the maleimide compound is 15 to 80% by mass with respect to the total mass of the underfill composition.

3. 3. The underfill composition according to claim 1, wherein the components soluble in the ketone solvent account for 95% by mass or more of the total mass of the non-volatile components.

4. 4. The underfill composition according to claim 1, wherein the polymer is a thermosetting resin having a curable group other than an epoxy group.

5. The underfill composition according to any one of claims 1 to 4, wherein the polymer has a repeating unit, and the repeating unit has a side chain containing a cyano group.

6. 6. The underfill composition according to claim 1, wherein the polymer has a repeating unit represented by the following formula (1): 【Chemistry 1】 Here, in the formula (1), R １ represents a hydrogen atom or a substituent, L １ represents a single bond or a divalent linking group.

7. 7. The underfill composition according to claim 1, wherein the polymer has a weight average molecular weight of 100,000 to 1,200,000.

8. The underfill composition according to any one of claims 1 to 7, wherein the ketone solvent includes at least methyl ethyl ketone.

9. 9. The underfill composition according to claim 1, wherein the maleimide compound is a compound having two or more maleimide groups in one molecule.

10. The underfill composition according to any one of claims 1 to 9, wherein the maleimide compound is a bismaleimide compound.

11. The underfill composition according to any one of claims 1 to 10, further comprising at least one monomer selected from the group consisting of acrylic monomers and methacrylic monomers.

12. A method for manufacturing a multilayer wiring board, which includes, in order, a semiconductor element having a plurality of electrodes, an anisotropic conductive bonding member, and a circuit board having a plurality of electrodes, the method comprising: a temporary bonding process in which the anisotropic conductive bonding member, the semiconductor element, and the circuit board are bonded together using the underfill composition according to any one of claims 1 to 11; a bonding process in which the conductive paths of the anisotropic conductive bonding member are electrically bonded to the plurality of electrodes of the semiconductor element and the plurality of electrodes of the circuit board by heating the anisotropic conductive bonding member at a temperature lower than the curing temperature of the underfill composition; a curing process of curing the underfill composition by heating at a temperature equal to or higher than the curing temperature of the underfill composition, The temperature condition in the temporary bonding process is 20 to 140°C, A method for manufacturing a multilayer wiring board, wherein the temperature condition in the main bonding process is higher than the temperature in the temporary bonding process.

13. 13. The method for manufacturing a multilayer wiring board according to claim 12, wherein in the temporary bonding process, a coating film formed using the underfill composition is provided on a surface of the anisotropic conductive bonding member on the semiconductor element side and on the circuit board side.

14. 13. The method for manufacturing a multilayer wiring board according to claim 12, wherein in the temporary bonding process, a coating film formed using the underfill composition is provided on surfaces of the semiconductor element and the circuit board on the anisotropic conductive bonding member side.

15. The method for manufacturing a multilayer wiring board according to any one of claims 12 to 14, wherein in the main bonding process, the heating is carried out after or while pressure is applied.

Images