Thermosetting composition, composition for fixing semiconductor element, and composition for forming thermally and electrically conductive film

Abstract

To provide a thermosetting composition that exhibits superior thixotropic properties and forms a cured product having both thermal and electrical conductivity, as well as a composition for fixing a semiconductor element comprising the thermosetting composition, and a composition for forming a thermally and electrically conductive film comprising the thermosetting composition.SOLUTION: There are provided a thermosetting composition comprising the following components (A) and (B), a composition for fixing a semiconductor element comprising the thermosetting composition, and a composition for forming a thermally and electrically conductive film comprising the thermosetting composition. Component (A): a silane compound polymer having a repeating unit [repeating unit (1)] represented by formula (a-1) [R1 represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms or a hydrocarbon group having 1 to 12 carbon atoms with a substituent]. Component (B): a carbon-based filler.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermosetting composition having excellent thixotropy, a composition for fixing a semiconductor element, and a composition for forming a thermally and electrically conductive film. [Background technology]

[0002] BACKGROUND ART Curable compositions have been improved in various ways depending on the intended use, and have been widely used industrially as raw materials for optical parts and molded articles, adhesives, coating agents, and the like. Furthermore, in recent years, curable compositions containing polysilsesquioxane compounds have been attracting attention because they form cured products that are excellent in heat resistance, transparency, and the like.

[0003] For example, Patent Documents 1 to 3 describe curable compositions containing polysilsesquioxane compounds and the use of the curable compositions as sealing materials.

[0004] In recent years, various fillers have been added to curable compositions to impart additional functions to the curable compositions. For example, Patent Document 4 describes a concrete protection material that contains silica particles and has good thixotropy. Furthermore, Patent Document 5 describes a thermally conductive material containing alumina powder and zinc oxide powder. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-359933 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-263869 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-328231 [Patent Document 4] Patent Publication No. 2021-98949 [Patent Document 5] Japanese Patent Application Laid-Open No. 2011-84621 Summary of the Invention [Problem to be solved by the invention]

[0006] When fixing various elements using a curable composition, it is necessary to apply a predetermined amount of the curable composition accurately to a predetermined position, and therefore, such a curable composition is usually required to have excellent thixotropy. Furthermore, it is thought that the occurrence of element failure can be reduced if the fixing member for the element has thermal conductivity and electrical conductivity.

[0007] As described above, Patent Document 4 describes that a curable composition containing silica particles has good thixotropy, and Patent Document 5 describes that a thermally conductive material can be obtained by using alumina powder and zinc oxide powder. Furthermore, the inventors have found that adding these additives to a curable composition containing a silane compound polymer results in a cured product that is excellent in thixotropy and thermal conductivity, but the cured product has poor electrical conductivity.

[0008] The present invention has been made under these circumstances, and aims to provide a thermosetting composition having excellent thixotropy and capable of forming a cured product having thermal conductivity and electrical conductivity, a composition for fixing a semiconductor element, and a composition for forming a thermally and electrically conductive film, each of which is made of this thermosetting composition. [Means for solving the problem]

[0009] In order to solve the above problems, the present inventors have conducted extensive research into thermosetting compositions containing silane compound polymers. As a result, they found that a thermosetting composition containing a silane compound polymer having a repeating unit derived from a trifunctional silane compound and a carbon-based filler gives a cured product that has excellent thixotropy and further has thermal and electrical conductivity, and they have completed the present invention.

[0010] Thus, according to the present invention, there are provided the following thermosetting compositions [1] to

[12] , a semiconductor element fixing composition

[13] , and a thermally and electrically conductive film-forming composition

[14] .

[0011] [1] A thermosetting composition containing the following components (A) and (B): Component (A): Formula (a-1) below

[0012] [ka]

[0013] [R 1 represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms, or a substituted hydrocarbon group having 1 to 12 carbon atoms. A silane compound polymer having a repeating unit represented by the following formula (1): (B) Component: Carbon-based filler [2] The thermosetting composition according to [1], wherein the amount of repeating unit (1) in component (A) is 90 to 100 mol % of the total amount of repeating units in component (A). [3] The thermosetting composition according to [1] or [2], wherein the mass average molecular weight (Mw) of the component (A) is 1,000 to 10,000. [4] The thermosetting composition according to any one of [1] to [3], wherein the component (A) has thermosetting properties. [5] The thermosetting composition according to any one of [1] to [4], wherein the content of component (A) is 5 to 75 mass % of the total amount of components constituting the thermosetting composition (excluding the solvent). [6] The thermosetting composition according to any one of [1] to [5], wherein the component (B) is at least one selected from the group consisting of graphene, graphite, carbon nanotubes, fullerene, and carbon black. [7] Particle size of component (B) (D 50 The thermosetting composition according to any one of [1] to [6], wherein the thickness of the porous layer is 1 to 30 μm. [8] The thermosetting composition according to any one of [1] to [7], wherein the content of the component (B) is 5 to 200 parts by mass per 100 parts by mass of the component (A). [9] The thermosetting composition according to any one of [1] to [8], further comprising the following component (C): Component (C): Silane coupling agent

[10] The thermosetting composition according to [9], wherein the content of the component (C) is 5 to 50 parts by mass per 100 parts by mass of the component (A).

[11] Thixotropy index (2s -1 / 200s -1 ) is 1.5 or more.

[12] The thermosetting composition according to any one of [1] to

[11] , wherein the cured product obtained by curing the thermosetting composition at 120°C for 4 hours has a thermal conductivity of 1.0 W / (m·K) or more at 23°C.

[13] A semiconductor element fixing composition comprising the thermosetting composition according to any one of [1] to

[12] above.

[14] A composition for forming a thermally and electrically conductive film, comprising the thermosetting composition according to any one of [1] to

[12] above. [Effects of the Invention]

[0014] According to the present invention, there are provided a thermosetting composition having excellent thixotropy and capable of forming a cured product having thermal conductivity and electrical conductivity, a composition for fixing a semiconductor element, and a composition for forming a thermally and electrically conductive film, each of which is made of this thermosetting composition. DETAILED DESCRIPTION OF THE INVENTION

[0015] In this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower and upper limits described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60."

[0016] [Component (A): Silane Compound Polymer] The thermosetting composition of the present invention contains the following component (A): Component (A): a silane compound polymer having a repeating unit represented by the following formula (a-1) [repeating unit (1)]

[0017] [ka]

[0018] [R 1 represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms, or a substituted hydrocarbon group having 1 to 12 carbon atoms.

[0019] Since the thermosetting composition of the present invention contains a silane compound polymer as component (A) (hereinafter, may be referred to as "silane compound polymer (A)"), the cured product thereof has high adhesive strength.

[0020] In formula (a-1), R 1 represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms or a substituted hydrocarbon group having 1 to 12 carbon atoms. 1 The number of carbon atoms is preferably 1 to 10, and more preferably 1 to 5. Examples of the unsubstituted hydrocarbon group having 1 to 12 carbon atoms include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, and n-decyl groups; alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, isopropenyl, 1-butenyl, 2-butenyl, and 3-butenyl groups; ethynyl, 1-propenyl, and 2-propenyl groups; alkynyl groups having 2 to 12 carbon atoms such as cyclopropyl, 2-propynyl, 1-butynyl, 2-butynyl, and 3-butynyl; cycloalkyl groups having 3 to 12 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl; aryl groups having 6 to 12 carbon atoms such as phenyl, 1-naphthyl, 2-naphthyl, tolyl, and xylyl; and combinations thereof such as benzyl and cyclohexylmethyl.

[0021] Examples of the substituted hydrocarbon group having 1 to 12 carbon atoms include the above-mentioned unsubstituted hydrocarbon group having 1 to 12 carbon atoms in which one or more hydrogen atoms have been substituted with a substituent. Examples of the substituent include an amino group, an epoxy group, an acryloyloxy group, a methacryloyloxy group, a fluorine atom, a chlorine atom, and a bromine atom.

[0022] Among these, R 1 As the alkyl group, an alkyl group having 1 to 12 carbon atoms or a fluoroalkyl group having 1 to 12 carbon atoms is preferred.

[0023] The amount of the repeating unit (1) in the silane compound polymer (A) is preferably 90 to 100 mol %, more preferably 95 to 100 mol %, based on the total amount of repeating units in the silane compound polymer (A).

[0024] When the silane compound polymer (A) has a repeating unit other than the repeating unit (1) [repeating unit (2)], examples of the repeating unit (2) include repeating units derived from monofunctional silane compounds such as trimethylmethoxysilane, repeating units derived from difunctional silane compounds such as dimethyldimethoxysilane, repeating units derived from trifunctional silane compounds (excluding the repeating unit (1)), and repeating units derived from tetrafunctional silane compounds such as tetramethoxysilane.

[0025] The mass average molecular weight (Mw) of the silane compound polymer (A) is preferably 1,000 to 10,000, more preferably 1,200 to 9,000, and even more preferably 1,500 to 8,000. The molecular weight distribution (Mw / Mn) of the silane compound polymer (A) is not particularly limited, but is usually 1.0 to 10.0, preferably 1.1 to 6.0. A silane compound polymer having a mass average molecular weight and a molecular weight distribution (Mw / Mn) within the above ranges is suitably used as a curable component in a thermosetting composition. The mass average molecular weight (Mw) and number average molecular weight (Mn) can be determined, for example, as values ​​converted into standard polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0026] The silane compound polymer (A) is preferably thermosetting, and the thermosetting silane compound polymer (A) is suitably used as a curable component of a thermosetting composition. In the present invention, the term "thermosetting" in the silane compound polymer or composition refers to the property of being cured by heating alone, without the presence of a curing catalyst.

[0027] The structure of the silane compound polymer (A) may be any of a ladder structure, a double-decker structure, a cage structure, a partially cleaved cage structure, a cyclic structure, and a random structure. Furthermore, when the silane compound polymer (A) is a copolymer, it may be any of a random copolymer, a block copolymer, a graft copolymer, an alternating copolymer, etc., but from the viewpoint of ease of production, etc., a random copolymer is preferred.

[0028] The content of the silane compound polymer (A) is preferably 5 to 75 mass %, more preferably 10 to 65 mass %, and even more preferably 20 to 50 mass %, of the total amount of components (excluding the solvent) constituting the thermosetting composition.

[0029] The method for producing the silane compound polymer (A) is not particularly limited. For example, the silane compound polymer (A) used in the present invention can be produced by carrying out a step (step PO) of hydrolyzing and polycondensing a trifunctional alkoxysilane compound corresponding to a desired repeating unit in the presence of water and a catalyst, and a step (step PU) of purifying the silane compound polymer obtained in step PO.

[0030] Step PO is a step of hydrolyzing and polycondensing a trifunctional alkoxysilane compound corresponding to a desired repeating unit in the presence of water and a catalyst.

[0031] In the step PO, for example, a compound represented by the following formula (a-2) is used as the trifunctional alkoxysilane compound.

[0032] [ka]

[0033] In formula (a-2), R 1 has the same meaning as above. OR represents an alkoxy group. OR may be the same or different.

[0034] The alkoxy group represented by OR preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms. Examples of the alkoxy group represented by OR include a methoxy group, an ethoxy group, and a propoxy group.

[0035] Specific examples of the trifunctional alkoxysilane compound represented by formula (a-2) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, pentafluoroethyltrimethoxysilane, pentafluoroethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, and 3,3,3-trifluoropropyltriethoxysilane. These trifunctional alkoxysilane compounds can be used alone or in combination of two or more.

[0036] In step PO, in addition to the above trifunctional alkoxysilane compounds, monofunctional alkoxysilane compounds such as trimethylmethoxysilane, bifunctional alkoxysilane compounds such as dimethyldimethoxysilane, trifunctional alkoxysilane compounds other than the compound represented by formula (a-2), and tetrafunctional alkoxysilane compounds such as tetramethoxysilane may be used as monomers.

[0037] In the method for producing the silane compound polymer (A), the amount of the compound represented by formula (a-2) is preferably 90 to 100 mol %, more preferably 95 to 100 mol %, based on the total amount of monomers.

[0038] In the step PO, it is preferable to add water to the reaction system in an amount that can sufficiently hydrolyze the hydrolyzable group (for example, "OR" in formula (a-2)) contained in the monomer. The amount of water added is preferably such that the molar ratio M of water to alkoxy groups calculated by the following formula (F1) is 0.95 or more, more preferably 0.97 to 5.0, even more preferably 0.99 to 3.0, and particularly preferably 1.0 to 1.5.

[0039]

number

[0040] In formula (F1), M H2O is the amount of water (molar quantity) added to the reaction system, and M OR is the total number of alkoxy groups in the monomer (total number of moles). For example, when 3.0 mol of water is added to 1.0 mol of a trifunctional alkoxysilane compound, the value of the molar ratio M is 3.0 / 3.0 (=1.0).

[0041] When the molar ratio M is 0.95 or more, the hydrolysis reaction of the monomers can be sufficiently progressed, and a silane compound polymer having excellent thermosetting properties can be easily obtained.

[0042] The catalyst used in step (PO) includes an acid catalyst and a base catalyst. In step (PO), either an acid catalyst or a base catalyst may be used alone, or both an acid catalyst and a base catalyst may be used. Examples of the acid catalyst include inorganic acids such as phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, and nitric acid; and organic acids such as formic acid, citric acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Among these, at least one selected from phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, formic acid, citric acid, acetic acid, and methanesulfonic acid is preferred.

[0043] Examples of the base catalyst include aqueous ammonia; organic bases such as trimethylamine, triethylamine, lithium diisopropylamide, lithium bis(trimethylsilyl)amide, pyridine, 1,8-diazabicyclo[5.4.0]-7-undecene, aniline, picoline, 1,4-diazabicyclo[2.2.2]octane, and imidazole; organic hydroxides such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; metal alkoxides such as sodium methoxide, sodium ethoxide, sodium t-butoxide, and potassium t-butoxide; metal hydrides such as sodium hydride and calcium hydride; metal hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; metal carbonates such as sodium carbonate, potassium carbonate, and magnesium carbonate; and metal hydrogencarbonates such as sodium hydrogencarbonate and potassium hydrogencarbonate.

[0044] The amount of the catalyst used is usually 0.05 to 10 mol %, preferably 0.1 to 5 mol %, based on the total amount of the monomers. By adjusting the amount of catalyst used, the polycondensation reaction can be allowed to proceed appropriately, and a silane compound polymer having the desired molecular weight can be obtained.

[0045] Step PO can be performed, for example, by placing a trifunctional alkoxysilane compound, water, and a catalyst in a reaction vessel and stirring the resulting mixture. In addition to these components, an organic solvent may also be present in the reaction vessel. Examples of organic solvents include aromatic hydrocarbons such as benzene, toluene, and xylene; esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and methyl propionate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, s-butyl alcohol, and t-butyl alcohol. These solvents can be used alone or in combination of two or more. When an organic solvent is used in step PO, the amount of the organic solvent used is preferably 0.05 to 3 times, more preferably 0.1 to 1.5 times, by volume, the amount of the trifunctional alkoxysilane compound.

[0046] The reaction conditions for step PO are not particularly limited. The reaction temperature in step PO is usually 0 to 95°C, preferably 5 to 80°C. The reaction time in step PO is usually 30 minutes to 50 hours, preferably 1 to 24 hours.

[0047] The process PO may be carried out under constant conditions from start to finish (i.e., it may have one step), or it may have multiple steps with different reaction conditions.

[0048] The step PU is a step of purifying the obtained silane compound polymer. By carrying out the step PU, a high-purity silane compound polymer can be obtained, which is more suitable as a curable component of a thermosetting composition used for fixing semiconductor elements.

[0049] The process PU includes a purification process using a solvent extraction method. An example of a purification process using the solvent extraction method includes the following steps: (Step PU-I) A step of adding a water-immiscible organic solvent or water to the reaction mixture obtained in step PO as needed, stirring the mixture, and then allowing it to stand to separate into an organic phase and an aqueous phase. (Step PU-II) A step of separating and collecting the organic phase produced in Step PU-I, and washing the organic phase with water as needed. (Step PU-III) A step of concentrating and drying the organic phase separated in Step PU-II

[0050] In step PU-I, a solvent such as a water-immiscible organic solvent or water is added to the reaction mixture obtained in step PO as needed so that the reaction mixture separates into an organic phase and an aqueous phase. The amount of solvent added and the type of organic solvent are not particularly limited, as long as the reaction mixture obtained in step PO separates into an organic phase and an aqueous phase.

[0051] The silane compound polymer is usually contained in the organic phase. Therefore, in step PU-II, the organic phase produced in step PU-I is separated and collected. Thereafter, the organic phase may be washed with water according to a conventional method.

[0052] Step PU-III can be carried out by a conventional method such as concentration treatment with an evaporator and vacuum drying treatment.

[0053] [Component (B): Carbon-based filler] The thermosetting composition of the present invention contains the following component (B): (B) Component: Carbon-based filler

[0054] The thermosetting composition of the present invention has excellent thixotropy due to the inclusion of a carbon-based filler. Furthermore, the thermosetting composition of the present invention contains a carbon-based filler, and therefore, after curing, the composition becomes a cured product having excellent thermal conductivity and electrical conductivity.

[0055] Examples of the carbon-based filler include graphene, graphite, carbon nanotubes, fullerene, and carbon black.

[0056] Graphene is SP 2 It is a sheet-like substance whose basic structure is a six-membered ring made up of carbon atoms. In the present invention, graphene does not only mean a sheet-like substance having one layer, but also includes a laminate having 2 to 10 layers. Furthermore, graphene may partially contain a five-membered ring or a seven-membered ring, or may be graphene oxide or graphene containing a functional group.

[0057] Graphite is a multilayer of graphene. In the present invention, graphite refers to a laminate of 11 or more layers.

[0058] Carbon nanotubes are SP 2 Carbon nanotubes are tubular structures that contain a six-membered ring composed of carbon atoms as a basic structure. Carbon nanotubes may be single-walled or multi-walled carbon nanotubes.

[0059] Fullerenes are closed-shell hollow structures whose main constituent atoms are carbon atoms. Examples of fullerenes include fullerene C60, fullerene C70, fullerene C76, fullerene C78, ​​fullerene C82, fullerene C84, fullerene C90, fullerene C94, and fullerene C96. In the present invention, the fullerene may be a fullerene derivative such as a hydrogenated fullerene, an oxidized fullerene, a hydroxide fullerene, or a halogenated fullerene.

[0060] Carbon black is a finely divided carbon particle. Examples of carbon black include furnace black, acetylene black, channel black, and thermal black.

[0061] These carbonaceous fillers can be used alone or in combination of two or more.

[0062] Carbon filler particle diameter (D 50 ) is preferably 1 to 30 μm, more preferably 5 to 25 μm. Particle diameter (D 50 A thermosetting composition containing a carbonaceous filler having a particle size of 1 to 30 μm is superior in thixotropy. In the present invention, the particle diameter (D 50 ) refers to the volume-based cumulative 50% particle size obtained by laser diffraction / scattering method.

[0063] The content of the carbonaceous filler is preferably 5 to 200 parts by mass, more preferably 10 to 180 parts by mass, and even more preferably 15 to 150 parts by mass, per 100 parts by mass of the component (A).

[0064] [Component (C): Silane Coupling Agent] The thermosetting composition of the present invention may contain a silane coupling agent. A cured product of a thermosetting composition containing a silane coupling agent tends to have superior adhesive strength at room temperature and at high temperatures. Therefore, a thermosetting composition containing a silane coupling agent is preferably used as a fixing agent for components with a small adhesion area, such as semiconductor elements, whereas a thermosetting composition without a silane coupling agent is preferably used as a material for forming films with a relatively large adhesion area, such as thermally and electrically conductive films.

[0065] The silane coupling agent refers to a silane compound having a silicon atom, a functional group, and a hydrolyzable group bonded to the silicon atom. The functional group refers to a group that has reactivity with other compounds (mainly organic substances), and examples thereof include a vinyl group, an allyl group, an epoxy group, an amino group, a substituted amino group, an acrylic group, a methacrylic group, a mercapto group, an isocyanate group, a group having an isocyanurate structure, a group having a urea structure, and a group having an acid anhydride structure. The component (C) can be used alone or in combination of two or more.

[0066] When the thermosetting composition of the present invention contains a silane coupling agent, the content thereof is preferably from 5 to 50 parts by mass, and more preferably from 15 to 40 parts by mass, per 100 parts by mass of the component (A). Cured products of thermosetting compositions containing 5 parts by mass or more of the silane coupling agent per 100 parts by mass of the component (A) tend to have superior adhesive strength at room temperature and at high temperatures. A thermosetting composition containing 50 parts by mass or less of the silane coupling agent per 100 parts by mass of the component (A) tends to be less susceptible to cracks caused by by-products such as alcohol during the curing reaction.

[0067] As the silane coupling agent, a silane coupling agent having a nitrogen atom in the molecule and a silane coupling agent having an acid anhydride structure in the molecule are preferred.

[0068] Examples of silane coupling agents having a nitrogen atom in the molecule include trialkoxysilane compounds represented by the following formula (c-1), dialkoxyalkylsilane compounds or dialkoxyarylsilane compounds represented by the following formula (c-2), and the like.

[0069] [ka]

[0070] In the above formula, R a represents an alkoxy group having 1 to 6 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, or a t-butoxy group. a They may be the same or different. R b represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a t-butyl group; or an aryl group having or having no substituent, such as a phenyl group, a 4-methylphenyl group, a 1-naphthyl group, or a 4-chlorophenyl group.

[0071] R c represents an organic group having a nitrogen atom and having 1 to 10 carbon atoms. c may further be bonded to another group containing a silicon atom. R cSpecific examples of the organic group having 1 to 10 carbon atoms include an N-(2-aminoethyl)-3-aminopropyl group, a 3-aminopropyl group, an N-(1,3-dimethyl-butylidene)-3-aminopropyl group, a 3-ureidopropyl group, and an N-phenyl-3-aminopropyl group.

[0072] Among the compounds represented by the above formula (c-1) or formula (c-2), R c In the case where the silane coupling agent is an organic group bonded to another silicon atom-containing group, examples of the compound include an isocyanurate-based silane coupling agent bonded to another silicon atom via an isocyanurate skeleton, and a urea-based silane coupling agent bonded to another silicon atom via a urea skeleton.

[0073] Among these, as silane coupling agents having a nitrogen atom in the molecule, isocyanurate-based silane coupling agents and urea-based silane coupling agents are preferred because they tend to give cured products with superior adhesive strength, and furthermore, those having four or more alkoxy groups bonded to silicon atoms in the molecule are preferred. "Having four or more alkoxy groups bonded to a silicon atom" means that the total number of alkoxy groups bonded to the same silicon atom and alkoxy groups bonded to different silicon atoms is four or more.

[0074] An example of an isocyanurate-based silane coupling agent having four or more alkoxy groups bonded to a silicon atom is a compound represented by the following formula (c-3): An example of an urea-based silane coupling agent having four or more alkoxy groups bonded to a silicon atom is a compound represented by the following formula (c-4):

[0075] [ka]

[0076] In the formula, R a has the same meaning as above. t1 to t5 each independently represent an integer of 1 to 10, preferably an integer of 1 to 6, and particularly preferably 3.

[0077] Among these, as the silane coupling agent having a nitrogen atom in the molecule, it is preferable to use 1,3,5-N-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-N-tris(3-triethoxysilylpropyl)isocyanurate (hereinafter referred to as "isocyanurate compound"), N,N'-bis(3-trimethoxysilylpropyl)urea, N,N'-bis(3-triethoxysilylpropyl)urea (hereinafter referred to as "urea compound"), and combinations of the above-mentioned isocyanurate compounds and urea compounds.

[0078] When the thermosetting composition of the present invention contains a silane coupling agent having a nitrogen atom in the molecule, the content thereof is not particularly limited, but the amount is preferably less than 50 parts by mass, more preferably 40 parts by mass or less, and even more preferably 35 parts by mass or less, per 100 parts by mass of the component (A). There is no particular lower limit for the content of the silane coupling agent having a nitrogen atom in the molecule, but it is preferably at least 0.1 part by mass, more preferably at least 0.3 part by mass, and even more preferably at least 1 part by mass per 100 parts by mass of component (A). Therefore, the content of the silane coupling agent having a nitrogen atom in the molecule is preferably 0.1 parts by mass or more and less than 50 parts by mass per 100 parts by mass of the component (A).

[0079] Silane coupling agents having an acid anhydride structure in the molecule are organosilicon compounds that have both a group having an acid anhydride structure and a hydrolyzable group in one molecule.Specific examples include compounds represented by the following formula (c-5).

[0080] [ka]

[0081] In the formula, Q represents a group having an acid anhydride structure, and R d represents an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted phenyl group, and Re represents an alkoxy group having 1 to 6 carbon atoms or a halogen atom, i and k represent integers of 1 to 3, j represents an integer of 0 to 2, and i+j+k=4. When j is 2, R d When k is 2 or 3, multiple R e When i is 2 or 3, multiple Qs may be the same or different. Q is expressed by the following formula:

[0082] [ka]

[0083] (wherein h represents an integer of 0 to 10, and * represents a bond), and the group represented by (Q1) is particularly preferred.

[0084] Examples of silane coupling agents having an acid anhydride structure in the molecule include tri(C1-C6)alkoxysilyl(C2-C8)alkyl succinic anhydrides, such as 2-(trimethoxysilyl)ethyl succinic anhydride, 2-(triethoxysilyl)ethyl succinic anhydride, 3-(trimethoxysilyl)propyl succinic anhydride, and 3-(triethoxysilyl)propyl succinic anhydride; Di(C1-C6)alkoxymethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(dimethoxymethylsilyl)ethyl succinic anhydride; (C1-C6)alkoxydimethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(methoxydimethylsilyl)ethyl succinic anhydride;

[0085] Trihalogenosilyl (C2-C8) alkyl succinic anhydrides such as 2-(trichlorosilyl)ethyl succinic anhydride and 2-(tribromosilyl)ethyl succinic anhydride; Dihalogenomethylsilyl (C2-C8) alkyl succinic anhydrides such as 2-(dichloromethylsilyl)ethyl succinic anhydride; halogenodimethylsilyl (having 2 to 8 carbon atoms) alkyl succinic anhydrides such as 2-(chlorodimethylsilyl)ethyl succinic anhydride; and the like.

[0086] Among these, as the silane coupling agent having an acid anhydride structure in the molecule, tri(C1 to C6)alkoxysilyl(C2 to C8)alkyl succinic anhydride is preferred, and 3-(trimethoxysilyl)propyl succinic anhydride or 3-(triethoxysilyl)propyl succinic anhydride is particularly preferred.

[0087] When the thermosetting composition of the present invention contains a silane coupling agent having an acid anhydride structure in the molecule, the content thereof is not particularly limited, but the amount is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the component (A). There is no particular lower limit for the content of the silane coupling agent having an acid anhydride structure in the molecule, but it is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of component (A). Therefore, the content of the silane coupling agent having an acid anhydride structure in the molecule is preferably 0.1 to 30 parts by mass per 100 parts by mass of the component (A).

[0088] 〔solvent〕 The thermosetting composition of the present invention may contain a solvent. The solvent used is preferably one with a high boiling point, since the concentration of the thermosetting composition is less likely to change during application. Examples of the solvent include polyether solvents such as dipropylene glycol dimethyl ether (boiling point 171°C), diethylene glycol dimethyl ether (boiling point 162°C), and diethylene glycol ethyl methyl ether (boiling point 176°C); γ-butyrolactone (boiling point 204°C), ethyl lactate (boiling point 154°C), 3-methoxybutyl acetate (boiling point 171°C), diethylene glycol monoethyl ether acetate (boiling point 217°C), and diethylene glycol monobutyl Examples of suitable solvents include ester-based solvents such as butyl ether acetate (boiling point 247°C); alcohol-based solvents such as tripropylene glycol monobutyl ether (boiling point 276°C); ketone-based solvents such as cyclohexanone (boiling point 156°C); amide-based solvents such as N,N-dimethylformamide (boiling point 153°C), N,N-dimethylacetamide (boiling point 165°C), and N-methylpyrrolidone (boiling point 202°C); and sulfoxide-based solvents such as dimethyl sulfoxide (boiling point 189°C). When the thermosetting composition of the present invention contains a solvent, its content is not particularly limited, but is preferably an amount that results in a concentration of components other than the solvent (active ingredients) of 10 to 95 mass %, more preferably an amount that results in a concentration of 20 to 90 mass %.

[0089] [Other ingredients] The thermosetting composition of the present invention may contain components other than those described above, provided that the object of the present invention is not impaired. Examples of components other than those mentioned above include fine particles other than component (B), and additives such as antioxidants, ultraviolet absorbers, and light stabilizers. The content of these additives can be determined appropriately depending on the purpose.

[0090] [Thermosetting composition] The thermosetting composition of the present invention can be prepared, for example, by mixing the above-mentioned components (A) and (B), and, if desired, other components, in predetermined ratios and degassing the mixture. The mixing method and degassing method are not particularly limited, and known methods can be used.

[0091] The thermosetting composition of the present invention contains a carbonaceous filler and therefore has excellent thixotropy. The thixotropy index (2s -1 / 200s -1 ) is preferably 1.5 or more, more preferably 2.0 or more. There is no particular upper limit, but it is usually 20 or less.

[0092] In the present invention, the thixotropy index is the value measured by a rheometer using a cone plate with a cone radius of 50 mm and a cone angle of 0.5° at a temperature of 25°C and a shear rate of 2 s -1 The viscosity at the temperature of 25°C and the shear rate of 200 s -1 The viscosity was measured at each shear rate of 2 s -1 The viscosity at a shear rate of 200 s -1 This refers to the value obtained by dividing the viscosity by the viscosity at the time of

[0093] A thermosetting composition with a thixotropic index of 1.5 or greater has excellent thixotropy. Thixotropy is the property of a material to lose viscosity and easily deform when force is applied, and then to increase viscosity again when left at rest. A thermosetting composition having excellent thixotropy has excellent workability during application. In other words, when a thermosetting composition is discharged to a predetermined position using a discharge pipe, if a thermosetting composition with excellent thixotropy is discharged from the discharge pipe and then the discharge pipe is pulled up, the amount of stringiness is small or the stringiness breaks immediately. Therefore, by using a thermosetting composition with this property, it is possible to prevent the surrounding area from being contaminated by resin scattering or the spreading of droplets.

[0094] When the thermosetting composition of the present invention is heated, the thermosetting composition cures and becomes a cured product. The heating temperature when the thermosetting composition of the present invention is heat-cured is usually 100 to 200° C. The heating time is usually 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

[0095] Since the thermosetting composition of the present invention contains a carbonaceous filler, the cured product thereof has excellent thermal conductivity. The thermal conductivity of the cured product of the thermosetting composition of the present invention is preferably 1.0 W / (m·K) or more, and more preferably 1.5 to 100 W / (m·K). The thermal conductivity of the cured product of the thermosetting composition of the present invention can be measured, for example, by using the cured product obtained by curing the thermosetting composition at 120°C for 4 hours as a measurement sample.

[0096] Since the thermosetting composition of the present invention contains a carbonaceous filler, the cured product thereof has excellent electrical conductivity. The surface resistivity of the cured product of the thermosetting composition of the present invention is preferably 1.0×10 10 Ω / □ or less, more preferably 1.0 to 1.0×10 8 It is Ω / □. The surface resistivity of the cured product of the thermosetting composition of the present invention can be measured, for example, by using a cured product obtained by curing the thermosetting composition at 120°C for 4 hours as a measurement sample.

[0097] The thermosetting composition of the present invention has an adhesive strength of 1.0 N / 1 mm at 23° C. when measured by the method described in the Examples. 2 It is preferable that the resistance is 2.0N / 1mm or more. 2 More preferably, it is equal to or greater than this. In this specification, "1 mm 2 " means "1mm square," that is, 1mm x 1mm (a square with each side measuring 1mm).

[0098] Because of these properties, the thermosetting composition of the present invention is suitably used as a composition for fixing semiconductor elements and a composition for forming thermally and electrically conductive films.

[0099] [Composition for fixing semiconductor elements] Examples of the semiconductor element fixing composition include an adhesive for fixing a semiconductor element and a sealant for fixing a semiconductor element. Examples of semiconductor elements include light-emitting elements such as light-emitting diodes (LEDs) and laser diodes (LDs); light-receiving elements such as photodiodes, solar cells, and CMOS image sensors; composite optical elements; integrated circuits; and large-scale integrated circuits.

[0100] When the thermosetting composition of the present invention is used as an adhesive for fixing a semiconductor element, a predetermined amount of the thermosetting composition of the present invention is usually applied to one or both bonding surfaces of the materials to be bonded (such as a semiconductor element and a substrate), pressed together, and then heated and cured. This process allows the materials to be firmly bonded together.

[0101] Materials constituting the substrate include glasses such as soda lime glass and heat-resistant hard glass; ceramics; sapphire; metals such as iron, copper, aluminum, gold, silver, platinum, chromium, titanium and alloys of these metals, and stainless steel (SUS302, SUS304, SUS304L, SUS309, etc.); and synthetic resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, acrylic resin, norbornene-based resin, cycloolefin resin, and glass epoxy resin.

[0102] When the thermosetting composition of the present invention is used as a sealant for fixing a semiconductor element, the thermosetting composition of the present invention is usually molded into a desired shape to obtain a molded product containing a semiconductor element, which is then heat-cured to obtain a semiconductor element-encapsulated product. The method for molding the thermosetting composition of the present invention into a desired shape is not particularly limited, and known molding methods such as ordinary transfer molding and casting can be used.

[0103] [Thermal and Electrical Conductive Film-Forming Composition] When the thermosetting composition of the present invention is used as a composition for forming a thermally and electrically conductive film, the thermosetting composition of the present invention is typically applied, and the resulting coating is then heat-cured. This process results in a film having thermal and electrical conductivity on a predetermined surface. This thermally and electrically conductive film can prevent the accumulation of heat and electricity, and by properly positioning this film, the occurrence of device failure can be reduced. [Example]

[0104] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0105] [Average molecular weight measurement] The mass average molecular weight (Mw) of the silane compound polymer was measured using the following device under the following conditions. Device name: Tosoh Corporation HLC-8220GPC Column: "TSK guard column SuperH-H", "TSK gel SuperHM-H", "TSK gel SuperHM-H", and "TSK gel SuperH2000" connected in sequence Solvent: tetrahydrofuran Standard material: polystyrene Injection volume: 20μl Measurement temperature: 40℃ Flow rate: 0.6ml / min Detector: differential refractometer

[0106] [Production Example 1] (Synthesis of silane compound polymer) A 300 ml eggplant-shaped flask was charged with 77.7 mmol (17.0 g) of 3,3,3-trifluoropropyltrimethoxysilane and 181.3 mmol (32.33 g) of methyltriethoxysilane, and then, with stirring, an aqueous hydrochloric acid solution [0.0675 g of 35 mass % hydrochloric acid (0.25 mol % relative to the total amount of silane compounds) added to 14.0 ml of distilled water] was added, and the entire contents were stirred at 30°C for 2 hours, then heated to 70°C and stirred for 20 hours. While continuing to stir the contents, a mixed solution of 0.0394 g of 28% by mass ammonia water (NH3 content: 0.65 mmol) and 46.1 g of propyl acetate was added thereto to adjust the pH of the reaction solution to 6.9, and the mixture was stirred at 70°C for 40 minutes. After allowing the reaction mixture to cool to room temperature, 50 g of propyl acetate and 100 g of water were added and the mixture was separated to obtain an organic phase containing the reaction product. Magnesium sulfate was added to this organic phase and the mixture was dried. After filtering off the magnesium sulfate, the organic phase was concentrated using an evaporator, and the resulting concentrate was then vacuum dried to obtain a silane compound polymer. The mass-average molecular weight (Mw) of the silane compound polymer was 5,500, and the molecular weight distribution was 3.40.

[0107] Example 1 (Preparation of Thermosetting Composition) A mixed solvent of diethylene glycol monobutyl ether acetate (BDGAC):tripropylene glycol monobutyl ether (TPnB) = 40:60 (mass ratio) was added to 100 parts by mass of the silane compound polymer obtained in Production Example 1 so that the solid content (active ingredient) of the thermosetting composition was 60 mass%, and the mixture was stirred. To this mixture, 50 parts by mass of graphene (ADEKA CORPORATION: CNS-1A1), 20 parts by mass of 1,3,5-N-tris[3-(trimethoxysilyl)propyl]isocyanurate, and 4 parts by mass of 3-(trimethoxysilyl)propylsuccinic anhydride were added and stirred to obtain a thermosetting composition.

[0108] [Examples 2 to 5, Comparative Examples 1 to 3] Thermosetting compositions were obtained in the same manner as in Example 1, except that the components and solid content of the thermosetting compositions were changed to those shown in Table 1. The details of each component in Table 1 are as follows: Silane compound polymer: Silane compound polymer obtained in Production Example 1 Filler 1: Graphene (ADEKA Corporation: CNS-1A1, particle size (D 50 )12μm) Filler 2: Silica (Nippon Aerosil Co., Ltd.: RX300, particle size (D 50 )0.007μm) Filler 3: Zinc oxide (manufactured by Sakai Chemical Industry Co., Ltd.: LPZINC11, particle diameter (D 50 )11μm) Filler 4: Alumina (Sumitomo Chemical Co., Ltd.: AA-2, particle size (D 50 )2μm) SC1: 1,3,5-N-tris[3-(trimethoxysilyl)propyl]isocyanurate SC2: 3-(trimethoxysilyl)propylsuccinic anhydride

[0109] The following measurements were carried out on the thermosetting compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 3. The results are shown in Table 1.

[0110] [Evaluation of thixotropy] A rheometer (Anton Paar: MCR301) was used, with a cone plate having a radius of 50 mm and a cone angle of 0.5°, at a temperature of 25°C and a shear rate of 2 s -1 The viscosity at the temperature of 25°C and the shear rate of 200 s -1 The viscosity at each time was measured. The thixotropy index (shear rate 2 s -1 Viscosity / shear rate at 200s -1 The viscosity at this time was calculated.

[0111] [Thermal conductivity measurement] The thermosetting composition was poured into a Teflon® frame measuring 10 mm long x 10 mm wide x 0.2 mm high, and then subjected to a heat curing treatment at 120°C for 4 hours to obtain a test piece with a smooth surface. The thermal diffusivity of this test piece was then measured by the temperature wave method using a thermal diffusivity / thermal conductivity measuring device (ai-phase mobile, manufactured by ai-phase Corporation).

[0112] [Surface resistivity measurement] The thermosetting composition was poured into a Teflon (registered trademark) frame measuring 10 mm in length, 10 mm in width, and 0.2 mm in height, and subjected to a heat curing treatment at 120°C for 4 hours to obtain a test piece with a smooth surface. The surface resistivity (Ω / □) of the surface of the obtained test piece was measured using a resistivity meter (Hiresta UX MCP-HT800, manufactured by Nitto Seiko Analytech Co., Ltd.) in accordance with JIS K6911-1995.

[0113] [Adhesion strength measurement (shear strength)] 1mm square (area 1mm 2 The thermosetting composition was applied to the mirror surface of a silicon chip (1.5 mm thick) to a thickness of approximately 2 μm, and the coated surface was placed on an adherend (silver-plated copper plate) and pressed. This was then subjected to a heat-curing treatment at 170°C for 2 hours to obtain an adherend with a test piece attached. This adherend with the test piece attached was left on the measurement stage of a bond tester (Daisi: Series 4000) for 30 seconds, and stress was applied to the adhesive surface in the horizontal direction (shear direction) at a speed of 200 μm / s from a position 100 μm above the adherend, and the adhesive strength (N / 1 mm) between the test piece and the adherend at 25°C was measured. 2 ) was measured.

[0114] [Table 1]

[0115] The following can be seen from the Examples and Comparative Examples. The thermosetting compositions of Examples 1 to 5 have a high thixotropy index, and the cured products thereof have good thermal conductivity. On the other hand, the thermosetting composition of Comparative Example 1 contains silica instead of graphene as a filler, and although it has a high thixotropy index, the thermal conductivity of the cured product is poor. The thermosetting composition of Comparative Example 2 contains zinc oxide instead of graphene as a filler, and the cured product thereof has excellent thermal conductivity but a low thixotropy index. High thermal conductivity is achieved by combining silica and zinc oxide, as in the cured product of the thermosetting composition of Comparative Example 3. However, the cured product of the thermosetting composition of Example 4, which uses graphene, has even higher thermal conductivity. Furthermore, compared to the cured product of the thermosetting composition of Comparative Example 3, the cured product of the thermosetting composition of Example 4 has lower surface resistivity and better electrical conductivity.

Claims

1. A thermosetting composition comprising the following components (A) and (B): Component (A): Formula (a-1) below 【Chemical 1】 [R １ represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms, or a substituted hydrocarbon group having 1 to 12 carbon atoms. A silane compound polymer having a repeating unit [repeating unit (1)] represented by the following formula: Component (B): Carbon-based filler

2. 2. The thermosetting composition according to claim 1, wherein the amount of repeating unit (1) in component (A) is 90 to 100 mol % of the total amount of repeating units in component (A).

3. 2. The thermosetting composition according to claim 1, wherein the weight average molecular weight (Mw) of component (A) is 1,000 to 10,000.

4. The thermosetting composition according to claim 1, wherein component (A) has thermosetting properties.

5. 2. The thermosetting composition according to claim 1, wherein the content of component (A) is 5 to 75 mass% of the total amount of components constituting the thermosetting composition (excluding the solvent).

6. 2. The thermosetting composition according to claim 1, wherein component (B) is at least one selected from the group consisting of graphene, graphite, carbon nanotubes, fullerenes, and carbon black.

7. Particle diameter (D ５０ 2. The thermosetting composition according to claim 1, wherein the thickness of the first and second particles is 1 to 30 μm.

8. 2. The thermosetting composition according to claim 1, wherein the content of the component (B) is 5 to 200 parts by mass per 100 parts by mass of the component (A).

9. The thermosetting composition according to claim 1, further comprising the following component (C): Component (C): Silane coupling agent

10. 10. The thermosetting composition according to claim 9, wherein the content of the component (C) is 5 to 50 parts by mass per 100 parts by mass of the component (A).

11. Thixotropy index (2s －１ / 200s －１ 2. The thermosetting composition of claim 1, wherein the ρ is 1.5 or greater.

12. 2. The thermosetting composition according to claim 1, wherein the cured product obtained by curing the thermosetting composition at 120°C for 4 hours has a thermal conductivity at 23°C of 1.0 W / (m·K) or more.

13. A semiconductor element fixing composition comprising the thermosetting composition according to claim 1.

14. A composition for forming a thermally and electrically conductive film, comprising the thermosetting composition according to claim 1.

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