Latent curing agent, curable composition, and method for producing latent curing agent

Abstract

Provided is a core-shell type latent curing agent comprising at least a thermoplastic resin and a curing component. The latent curing agent is any one of a curing agent for a sealing resin, a curing agent for an underfill agent, or a curing agent for a mold underfill agent, with a gap between materials being 10 μm or less, and the latent curing agent has an average particle diameter in a range of 0.05-3.00 μm and a maximum particle diameter of 10 μm or less.

Description

Latent curing agent, curable composition, and method for producing a latent curing agent

[0001] This disclosure relates to a latent curing agent, a curable composition, and a method for producing a latent curing agent. More specifically, it relates to a latent curing agent that exhibits excellent impregnation properties into materials with a gap of 10 μm or less, and has excellent storage stability and electrical properties.

[0002] Electronic devices are required to be highly functional, miniaturized, and thin. For example, semiconductor chips, which are a type of electronic device, are required to be miniaturized, integrated, and have high-density circuits. The gaps between semiconductor chips and the wiring widths between materials surrounding these semiconductor chips are very narrow, and sealing resins containing curing agents, underfills, or molded underfills are used for these purposes. Furthermore, there is an increasing demand for materials suitable for narrow gaps between materials (10 μm or less).

[0003] In recent years, latent curing agents have been used as curing agents as described above, and for example, those disclosed in Patent Document 1 and Patent Document 2 have been disclosed, but there was still room for improvement in all of these curing agents.

[0004] Japanese Patent Publication No. 2006-291053, International Publication No. 2007 / 037378

[0005] A "latent curing agent" is a curing agent that contains at least a curing component, does not exhibit a curing reaction accelerating effect until a reaction trigger is obtained, and exhibits a curing reaction accelerating effect when certain conditions are met. Generally, encapsulating resins, underfills, or mold underfills containing latent curing agents are stored for long periods from the manufacturing stage to the use stage. For this reason, latent curing agents, encapsulating resins, underfills, or mold underfills containing latent curing agents require excellent storage stability. Furthermore, at the use stage, higher levels of functionality are required, such as suppression of uneven curing and the exhibiting of excellent electrical properties.

[0006] The latent curing agent described in Patent Document 1 is manufactured by a build-up method, resulting in small and uniform particle size. Furthermore, it is stated that this latent curing agent does not dissolve below 35°C and has good storage stability. However, because this latent curing agent is manufactured by impregnating the core component with an impregnating agent containing the curing component after particleization, the curing component is exposed on the surface, making it highly reactive and resulting in poor storage stability. In addition, when this latent curing agent is included in encapsulating resin, underfill, or mold underfill, the liquid stability of these materials is poor, and the components may change during use, leading to problems in obtaining desired electrical properties and other performance characteristics.

[0007] Although the latent curing agent described in Patent Document 2 minimizes the exposure of the curing component to the surface, it is manufactured by a crushing method, resulting in larger particle sizes and making it difficult to produce particles with stable particle sizes. For example, particles with a particle size larger than 10 μm are always present. Furthermore, the particle size of these particles does not easily fall within a certain standard range. For these reasons, when encapsulating resins, underfills, or mold underfills containing the latent curing agent described in Patent Document 2 are used with semiconductor materials, uneven curing occurs during curing, resulting in the inability to obtain desired electrical properties and other performance characteristics. Therefore, it is unsuitable for application to semiconductor materials, especially those with chip gaps of 10 μm or less.

[0008] This disclosure has been made in view of the above-mentioned problems and circumstances, and the problem to be solved is to provide a latent curing agent, a curable composition, and a method for producing a latent curing agent that have excellent impregnation properties into materials with a gap between materials of 10 μm or less, and excellent storage stability and electrical properties.

[0009] The Discloser investigated the causes of the above-mentioned problems in order to solve them. As a result, it was found that the above-mentioned problems can be solved by using a core-shell type latent curing agent that contains at least a thermoplastic resin and a curing component, has an average particle size in the range of 0.05 to 3.00 μm, and a maximum particle size of 10 μm or less, and thus made this disclosure. In other words, the above-mentioned problems related to this disclosure are solved by the following means.

[0010] 1. A core-shell type latent curing agent comprising at least a thermoplastic resin and a curing component, wherein the latent curing agent is one of the curing agents for sealing resins, underfill agents, or mold underfill agents, with a material gap of 10 μm or less, and the average particle size of the latent curing agent is in the range of 0.05 to 3.00 μm, and the maximum particle size is 10 μm or less.

[0011] 2. The latent curing agent according to paragraph 1, wherein when the portion from the outermost surface of the latent curing agent toward the center up to 10% of the average particle size is considered as the surface layer, the content ratio of the curing component in the surface layer is 10% or less of the total curing component of the latent curing agent.

[0012] 3. A curable composition containing the latent curing agent described in paragraph 1 or 2, and also containing an inorganic filler and an epoxy resin.

[0013] 4. A method for producing a latent curing agent described in paragraph 1 or 2, wherein the core particles of the latent curing agent are produced by emulsion polymerization of a miniemulsion.

[0014] The means described above in this disclosure make it possible to provide a latent curing agent, a curable composition, and a method for producing a latent curing agent that exhibit excellent impregnation properties into materials with a gap of 10 μm or less, as well as excellent storage stability and electrical properties. The mechanism of action or mechanism of the effects of this disclosure is not clearly defined, but it is inferred as follows.

[0015] The latent curing agent of this disclosure is a core-shell type latent curing agent comprising at least a thermoplastic resin and a curing component, wherein the latent curing agent is one of the curing agents for sealing resins, underfill agents, or mold underfill agents, with a material gap of 10 μm or less, and the average particle size of the latent curing agent is in the range of 0.05 to 3.00 μm, and the maximum particle size is 10 μm or less.

[0016] The latent curing agent of this disclosure has a maximum particle size of 10 μm or less, making it suitable for injection between semiconductor materials as a curing agent for encapsulating resins, underfill agents, or mold underfill agents with a material gap of 10 μm or less. Furthermore, since the average particle size is in the range of 0.05 to 3.00 μm, it does not cause uneven curing during use, and it is easy to obtain desired electrical properties and other performance characteristics.

[0017] Furthermore, the latent curing agent of this disclosure is of the core-shell type, and since the curing component is coated by the shell, it has excellent storage stability.

[0018] Furthermore, since the latent curing agent of this disclosure contains a thermoplastic resin, it is possible to effectively select the thermoplastic resin according to the desired application.

[0019] An example of a conceptual diagram of a latent curing agent. A schematic diagram showing the distribution of curing components in a latent curing agent. An example of a conceptual diagram of a one-component resin composition disclosed herein. An example of a conceptual diagram of a curable composition disclosed herein. A schematic diagram of a semiconductor material used for injection evaluation. A schematic diagram of a comb-shaped electrode used when fabricating a encapsulant for electrical property evaluation.

[0020] The latent curing agent of this disclosure is a core-shell type latent curing agent comprising at least a thermoplastic resin and a curing component, wherein the latent curing agent is one of the curing agents for sealing resins, underfill agents, or mold underfill agents, with a material gap of 10 μm or less, and the average particle size of the latent curing agent is in the range of 0.05 to 3.00 μm, and the maximum particle size is 10 μm or less. This feature is a technical feature common to or corresponding to each of the embodiments (appearances) described below.

[0021] In the embodiments of this disclosure, the portion of the latent curing agent from the outermost surface to the center, up to 10% of the average particle size, is defined as the surface layer. In this case, it is preferable from the viewpoint of improving storage stability and suppressing uneven curing that the content ratio of the curing component in the surface layer is 10% or less of the total curing component of the latent curing agent.

[0022] The curable composition of this disclosure contains the latent curing agent of this disclosure and also contains an inorganic filler and an epoxy resin.

[0023] The method for producing the latent curing agent of this disclosure is a method for producing the latent curing agent of this disclosure, wherein the core particles of the latent curing agent are produced by emulsion polymerization of a miniemulsion.

[0024] The following provides a detailed explanation of this disclosure, its components, and the forms and methods for implementing this disclosure. In this application, "~" is used to mean that the numerical values ​​before and after it are included as the lower and upper limits.

[0025] While the advantages and features provided by one or more embodiments of this disclosure will be better understood from the following detailed description and accompanying drawings, these drawings are for illustrative purposes only and are not intended to define the limitations of this disclosure.

[0026] [Latent Curing Agent] The latent curing agent of the present disclosure is a core-shell type latent curing agent comprising at least a thermoplastic resin and a curing component, wherein the latent curing agent is one of the curing agents for sealing resins, underfill agents, or mold underfill agents, with a material gap of 10 μm or less, and the average particle size of the latent curing agent is in the range of 0.05 to 3.00 μm, and the maximum particle size is 10 μm or less.

[0027] Figure 1 is an example of a conceptual diagram of a latent curing agent. The latent curing agent H is composed of core particles C and a shell S that covers the core particles C. The main component of the core particles C is curing component A.

[0028] 1. Curing Component While commonly known curing components can be used, it is preferable that the curing component be an amine adduct or an amine compound. "Amine adduct" refers to a compound having an amine structure produced by the reaction of at least one compound from epoxy resins, carboxylic acid compounds, sulfonic acid compounds, urea compounds, and isocyanate compounds with an amine compound. "Adduct" refers to a compound produced by the direct addition of two or more different molecules, resulting in a single reaction product.

[0029] (Epoxy resin) An epoxy resin is a resinous compound having an epoxy group that easily reacts at the ends of its molecules, and is a thermosetting compound formed by the polymerization of the compound and a curing agent. The cured product of an epoxy resin has excellent performance in terms of mechanical properties, electrical properties, thermal properties, chemical resistance, and adhesion.

[0030] Examples of epoxy resins include polyvalent epoxy compounds, monoepoxy compounds, and the like. Mixtures thereof are also included. From the viewpoint of enhancing the storage stability of the curable composition, it is preferable that the epoxy resin is a polyvalent epoxy compound.

[0031] Examples of polyvalent epoxy compounds include the following compounds (1) to (11), and these epoxy resins may be used alone or in combination of a plurality. (1) Bisphenol type epoxy resin obtained by glycidylating bisphenols (2) Epoxy resin obtained by glycidylating other divalent phenols (3) Epoxy resin obtained by glycidylating trisphenols (4) Epoxy resin obtained by glycidylating tetrakisphenols (5) Novolak type epoxy resin obtained by glycidylating novolaks (6) Aliphatic ether type epoxy resin obtained by glycidylating polyhydric alcohols (7) Ether ester type epoxy resin obtained by glycidylating hydroxycarboxylic acids (8) Ester type epoxy resin obtained by glycidylating polycarboxylic acids (9) Glycidylates of amine compounds (10) Glycidyl type epoxy resins such as amine type epoxy resins (11) Alicyclic epoxides

[0032] As the polyvalent epoxy compound, a glycidyl type epoxy resin is preferable, and this makes the productivity of the amine adduct extremely high. From the viewpoints of improving adhesion and heat resistance, it is preferable that the polyvalent epoxy compound is a glycidyl type epoxy resin obtained by glycidylating polyvalent phenols.

[0033] More preferably, the polyvalent epoxy compound is a bisphenol type epoxy resin. Even more preferably, it is an epoxy resin obtained by glycidylating bisphenol F. Even more preferably, it is an epoxy resin obtained by glycidylating bisphenol A.

[0034] (1) Bisphenol type epoxy resins obtained by glycidylating bisphenols Examples of bisphenol type epoxy resins obtained by glycidylating bisphenols include bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol AD, tetramethyl bisphenol S, tetrabromo bisphenol A, tetrachloro bisphenol A, tetrafluoro bisphenol A, etc.

[0035] (2) Epoxy resins obtained by glycidylating other divalent phenols Examples of epoxy resins obtained by glycidylating other divalent phenols include biphenol, dihydroxynaphthalene, 9,9-bis(4-hydroxyphenyl)fluorene, etc.

[0036] (3) Epoxy resins obtained by glycidylating trisphenols Examples of epoxy resins obtained by glycidylating trisphenols include 1,1,1-tris(4-hydroxyphenyl)methane, 4,4-(1-(4-(1-(4-hydroxyphenyl)-1-methylethyl)phenyl)ethylidene)bisphenol, etc.

[0037] (4) Epoxy resins obtained by glycidylating tetrakisphenols Examples of epoxy resins obtained by glycidylating tetrakisphenols include 1,1,2,2,-tetrakis(4-hydroxyphenyl)ethane, etc.

[0038] (5) Novolac type epoxy resins obtained by glycidylating novolacs Examples of novolac type epoxy resins obtained by glycidylating novolacs include phenol novolac, cresol novolac, bisphenol A novolac, brominated phenol novolac, brominated bisphenol A novolac, etc.

[0039] (6) Aliphatic ether type epoxy resin obtained by glycidylation of polyhydric alcohols Examples of aliphatic ether type epoxy resin obtained by glycidylation of polyhydric alcohols include epoxy resins obtained by glycidylation of polyhydric phenols, glycerin, polyethylene glycol, etc.

[0040] (7) Ether ester type epoxy resin obtained by glycidylation of hydroxycarboxylic acid Examples of ether ester type epoxy resin obtained by glycidylation of hydroxycarboxylic acid include p-oxybenzoic acid and β-oxynaphthoic acid.

[0041] (8) Ester-type epoxy resins obtained by glycidylation of polycarboxylic acids Examples of ester-type epoxy resins obtained by glycidylation of polycarboxylic acids include phthalic acid and terephthalic acid.

[0042] (9) Glycidylides of amine compounds Examples of glycidylides of amine compounds include 4,4-diaminodiphenylmethane and m-aminophenol.

[0043] (10) Glycidyl epoxy resins such as amine-type epoxy resins Examples of glycidyl epoxy resins such as amine-type epoxy resins include triglycidyl isocyanurate.

[0044] (11) Alicyclic Epoxides Examples of alicyclic epoxides include 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate.

[0045] Examples of monoepoxy compounds include butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, para-tert-butylphenyl glycidyl ether, ethylene oxide, propylene oxide, paraxylyl glycidyl ether, glycidyl acetate, glycidyl butyrate, glycidyl hexoate, and glycidyl benzoate.

[0046] (Carboxylic acid compounds) Examples of carboxylic acid compounds include succinic acid, adipic acid, sebacic acid, phthalic acid, and dimer acid.

[0047] (Sulfonic acid compounds) Examples of sulfonic acid compounds include ethanesulfonic acid and p-toluenesulfonic acid.

[0048] (Urea compounds) Examples of urea compounds include urea, methylurea, dimethylurea, ethylurea, and t-butylurea.

[0049] (Isocyanate Compounds) Examples of isocyanate compounds include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aliphatic triisocyanates, and polyisocyanates.

[0050] Examples of aliphatic diisocyanates include ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate.

[0051] Examples of alicyclic diisocyanates include isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, norbornane diisocyanate, 1,4-isocyanatocyclohexane, 1,3-bis(isocyanatomethyl)-cyclohexane, and 1,3-bis(2-isocyanatopropyl-2yl)-cyclohexane.

[0052] Examples of aromatic diisocyanates include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate, and 1,5-naphthalene diisocyanate.

[0053] Examples of aliphatic triisocyanates include 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-triisocyanate methylhexane, 2,6-diisocyanatohexanoate-2-isocyanatoethyl, and 2,6-diisocyanatohexanoate-1-methyl-2-isocyanate ethyl.

[0054] Examples of polyisocyanates include polymethylene polyphenyl polyisocyanate and polyisocyanates derived from the above-mentioned diisocyanate compounds.

[0055] Examples of polyisocyanates derived from the above-mentioned diisocyanates include isocyanurate-type polyisocyanates, biuret-type polyisocyanates, urethane-type polyisocyanates, allohanate-type polyisocyanates, and carbodiimide-type polyisocyanates.

[0056] (Amine Compounds) An "amine compound" refers to a compound having one or more primary to tertiary amino groups. Examples of amine compounds include aliphatic amines, alicyclic amines, aromatic amines, hydrazides, guanidine derivatives, and imidazoles.

[0057] As the amine compound, imidazole is preferred. In particular, if the aforementioned amine adduct is formed by the reaction of epoxy resin and imidazole, the curability of the latent curing agent H is enhanced, and the storage stability is improved.

[0058] Amine compounds include compounds that do not have a tertiary amino group and compounds that have a tertiary amino group. Specifically, the following (1) and (2) are included: (1) Compounds having at least one primary amino group and / or a secondary amino group but no tertiary amino group (2) Compounds having at least one tertiary amino group and at least one active hydrogen group

[0059] Examples of compounds that do not have a tertiary amino group include primary amines and secondary amines.

[0060] Examples of primary amines that do not have a tertiary amino group include methylamine, ethylamine, propylamine, butylamine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, ethanolamine, propanolamine, cyclohexylamine, isophoronediamine, aniline, toluidine, diaminodiphenylmethane, and diaminodiphenylsulfone.

[0061] Examples of secondary amines that do not have a tertiary amino group include dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, dimethanolamine, diethanolamine, dipropanolamine, dicyclohexylamine, piperidine, piperidone, diphenylamine, phenylmethylamine, and phenylethylamine.

[0062] Examples of active hydrogen groups in compounds having a tertiary amino group include primary amino groups, secondary amino groups, hydroxyl groups, thiol groups, carboxylic acids, and hydrazide groups.

[0063] Examples of compounds having active hydrogen groups include imidazoles, imidazolines, amino alcohols, aminophenols, tertiary aminoamines, amino mercaptans, aminocarboxylic acids, and aminohydrazides.

[0064] As the amine compound, imidazole is preferred, and among amine adducts, the amine adduct produced by the reaction of epoxy resin with imidazole is particularly preferred. This enhances the curability of the latent curing agent and ensures storage stability.

[0065] Examples of imidazoles include imidazole, 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, 4-methylimidazole, 2-ethyl-4-methylimidazole, 2-ethylimidazole, 2-butylimidazole, 1-vinylimidazole, 2-methyl-1-vinylimidazole, 1-allyumidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 4-formylimidazole, and 2-butyl-4-formylimidazole. 4- hydroxymethylimidazole, 2-butyl-4-chloro-5-formylimidazole, 2-hydroxymethylimidazole, 1-(2-hydroxyethyl)-imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, 2-hydroxymethyl-1-benzylimidazole, 4-hydroxymethyl-2-methylimidazole, 4-formyl-1-methylimidazole, 5-formyl-1-methylimidazole, 4-formyl-5-methylimidazole, 4-formyl-1-tritylimidazole, 4- Carboxymethylimidazole, 4-carboxyethylimidazole, 4-carboxylate imidazole, 2-aminoimidazole sulfate, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-formylimidazole, 1-benzyl-5-hydroxymethylimidazole, 1-benzyl-5-hydroxymethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethylimidazole, 4-methylimidazole, 1- Examples include anoethyl-2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-aminoethyl-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, and 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole.

[0066] Examples of amino alcohols include 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, methyldiethanolamine, triethanolamine, and N-β-hydroxyethylmorpholine.

[0067] Examples of aminophenols include 2-(dimethylaminomethyl)phenol and 2,4,6-tris(dimethylaminomethyl)phenol.

[0068] Examples of tertiary aminoamines include dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, dipropylaminoethylamine, dibutylaminoethylamine, N-methylpiperazine, N-aminoethylpiperazine, and diethylaminoethylpiperazine.

[0069] Examples of aminomercaptans include 2-dimethylaminoethanethiol, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptopyridine, and 4-mercaptopyridine.

[0070] Examples of aminocarboxylic acids include N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, nicotinic acid, isonicotinic acid, and picolinic acid.

[0071] Examples of aminohydrazides include N,N-dimethylglycine hydrazide, nicotinic acid hydrazide, and isonicotinic acid hydrazide.

[0072] As for amine compounds, compounds having at least one tertiary amino group and at least one active hydrogen group are preferred because they offer an excellent balance between storage stability and curability. Imidazoles are even more preferred among the compounds having active hydrogen groups, and 2-methylimidazole or 2-ethyl-4-methylimidazole are even more preferred.

[0073] (Other) If the main component of core particle C in a latent curing agent is not an amine adduct, then the main component is an amine compound.

[0074] As the main component, the same amine compound as described above can be used. When the main component is an amine compound, a particularly preferred compound is imidazole.

[0075] Imidazole is a low-molecular-weight amine compound, a type of heterocyclic aromatic compound amine containing nitrogen atoms at the 1st and 3rd positions on a five-membered ring.

[0076] Examples of imidazoles are given as compounds having a tertiary amino group in the aforementioned amine compounds. Among these, 2-methylimidazole, 2-phenylimidazole, and 1,2-dimethylimidazole are preferred from the viewpoint of improving the storage stability and reactivity of the main component of the core particles. 2-methylimidazole and 1,2-dimethylimidazole are more preferred from the viewpoint of having less steric hindrance to the active site.

[0077] 2. Figure 2 shows the distribution of the curing component in the latent curing agent. The portion from the outermost surface of the latent curing agent H toward the center O is the surface layer LS, up to 10% of the average particle size. １０ In this case, the surface layer LS １０ From the viewpoint of improving storage stability and suppressing uneven curing, it is preferable that the content ratio of curing component A in the latent curing agent H is 10% or less of the total curing component A contained in the latent curing agent H.

[0078] The content ratio of curing components in latent curing agents can be calculated, for example, by time-of-flight secondary ion mass spectrometry (TOF-SIMS). For example, the "nanoTOF3+" manufactured by ULVAC PHI can be used as the measuring instrument. Specific measurement methods and conditions will be described in the examples below.

[0079] 3. The latent curing agent for thermoplastic resins contains a thermoplastic resin. The type of thermosetting resin can be appropriately selected and used depending on the application of the latent curing agent.

[0080] As thermoplastic resins, various known thermoplastic resins such as polyethylene, polypropylene, polystyrene, acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin, methacrylic resin, polyvinyl chloride, polyamide, polyurethane, polyacetal, polybutylene terephthalate, polymethylpentene, polycarbonate, polyphenylene ether, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, polyetherimide, polyarylate, polysulfone, polyethersulfone, polyamideimide, polyester, polyacrylic acid ester, acrylic / styrene resin, polyvinyl ester, polyvinyl ether, polymonoolefin, polydiolefin, and polyhalogenated olefin can be used.

[0081] 4. When preparing latent curing agents with other components, other components such as radical polymerizable crosslinking agents, chain transfer agents, radical polymerization initiators, and surfactants may be used as needed.

[0082] Furthermore, additives to control the coefficient of thermal expansion may be added to the latent curing agent, and it is preferable that the agent does not contain highly hygroscopic substances or ionic impurities as a measure against ion migration.

[0083] (Radical Polymerizable Crosslinking Agents) Examples of radical polymerizable crosslinking agents include compounds having two or more unsaturated bonds, such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

[0084] The amount of radical polymerizable crosslinking agent in the monomer mixture used to form the shell of the latent curing agent is preferably in the range of 0.1 to 10% by mass.

[0085] (Chain transfer agent) A commonly used chain transfer agent may be used for the purpose of adjusting the molecular weight of the resin. The chain transfer agent is not particularly limited and examples include mercaptans such as octyl mercaptan, dodecyl mercaptan, and tert-dodecyl mercaptan, and styrene dimers.

[0086] (Radical polymerization initiator) Any water-soluble radical polymerization initiator can be used as the radical polymerization initiator to obtain the resin.

[0087] Examples of radical polymerization initiators include persulfates, azo compounds, and peroxide compounds. Examples of persulfates include potassium persulfate and ammonium persulfate. Examples of azo compounds include 4,4'-azobis-4-cyanovaleric acid, salts of 4,4'-azobis-4-cyanovaleric acid, and 2,2'-azobis(2-amidinopropane) salts.

[0088] Radical polymerization initiators can be combined with reducing agents as needed to form redox initiators. Using redox initiators increases polymerization activity, lowers the polymerization temperature, and further shortens the polymerization time.

[0089] The polymerization temperature is not particularly limited as long as it is above the minimum radical generation temperature of the radical polymerization initiator. For example, the polymerization temperature is in the range of 50 to 90°C. However, by using a polymerization initiator that starts polymerization at room temperature, such as a combination of hydrogen peroxide and a reducing agent such as ascorbic acid, polymerization can also be carried out at temperatures above room temperature.

[0090] (Surfactants) Surfactants are used when polymerizing radical polymerizable monomers. The surfactant is not particularly limited, but ionic surfactants such as sulfonates, sulfate esters, and fatty acid salts are suitable for polymerizing radical polymerizable monomers.

[0091] Examples of sulfonates include sodium dodecylbenzenesulfonate and sodium arylalkyl polyethersulfonate. Examples of sulfate esters include sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, and sodium octyl sulfate. Examples of fatty acid salts include sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, and calcium oleate.

[0092] Nonionic surfactants such as polyethylene oxide, polypropylene oxide, combinations of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, esters of higher fatty acids and polyethylene glycol, esters of higher fatty acids and polypropylene oxide, and sorbitan esters may also be used.

[0093] Surfactants are used as emulsifiers in the emulsion polymerization process, but they may also be used in other processes or for purposes other than emulsification.

[0094] 5. Particle Size The particle size of the latent curing agent of this disclosure is in the range of 0.05 to 3.00 μm. The maximum particle size is 10 μm or less. Although the latent curing agent of this disclosure is an aggregate of powder particles, "particle size of the latent curing agent" in this specification refers to the average particle size of the powder particles, and is defined as the median diameter based on volume.

[0095] The particle size of the latent curing agent in this disclosure can be appropriately changed depending on the thickness of the shell covering the core particles, and this particle size can be controlled when the core particles are produced by emulsion polymerization of the miniemulsion.

[0096] Particle size can be measured using, for example, the "LA-950V2" (laser diffraction / scattering particle size distribution analyzer) manufactured by Horiba, Ltd. The particle size of the latent curing agent in this disclosure is defined as the particle size before the freeze-drying process in the manufacturing of the latent curing agent described below.

[0097] [Method for Manufacturing Latent Curing Agent] In the method for manufacturing the latent curing agent described herein, the core particles of the latent curing agent are produced by emulsion polymerization of a miniemulsion. The following describes each step in the production of the latent curing agent. Note that "miniemulsion" refers to emulsion particles (oil droplets).

[0098] The latent curing agent of this disclosure is mainly produced by the following steps: • A step of producing core particles • A step of forming a shell • A step of freeze-drying

[0099] (Process for producing core particles) In the emulsion polymerization method for producing core particles according to this disclosure, a monomer solution is prepared by dissolving a predetermined monomer in an aqueous medium obtained by dissolving a surfactant at a concentration below the critical micelle concentration, and then dispersing the monomer solution in oil droplets using mechanical energy to prepare a dispersion. Next, a water-soluble polymerization initiator is added to the obtained dispersion and radical polymerization is carried out. Hereinafter referred to as the "miniemulsion method" in this specification. In addition, instead of adding a water-soluble polymerization initiator, or in addition to adding the water-soluble polymerization initiator, an oil-soluble polymerization initiator may be added to the monomer solution.

[0100] The disperser used to prepare a dispersion by dispersing oil droplets using mechanical energy is not particularly limited. Examples include the CLEARMIX agitator manufactured by M-Technique Co., Ltd., which is equipped with a high-speed rotating rotor, ultrasonic dispersers, mechanical homogenizers, Manton-Gorins, and pressure homogenizers.

[0101] (Shell formation process) In the shell formation process, resin is added to core particles produced by emulsion polymerization to polymerize around the core particles and coat them with a shell.

[0102] In this process, a dispersion of shell resin particles is prepared according to a conventional method such as emulsion polymerization, and a radical polymerizable monomer is added to the dispersion of shell resin particles and polymerized to form a multilayer (composite) structure. The emulsion polymerization method is as described above.

[0103] [When the resin particles for the shell are not composite resin particles] The procedure for preparing the dispersion of resin particles for the shell when the resin particles for the shell are not composite resin particles is, for example, carried out in the following order: (1) A surfactant-containing aqueous medium obtained by dissolving a surfactant in ion-exchanged water and a polymerization initiator-containing solution obtained by dissolving a radical polymerization initiator in ion-exchanged water are mixed and heated to prepare a mixture [1] containing the surfactant and the radical polymerization initiator.

[0104] An "aqueous medium" refers to a medium consisting of 50 to 100% by mass of water and 0 to 50% by mass of a water-soluble organic solvent. When an aqueous medium is used as an emulsifier, an aqueous solution of a surfactant is used as the aqueous medium.

[0105] In addition to surfactants used as emulsifiers, other water-soluble organic solvents that can be used include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, tetrahydrofuran, etc. Alcohol-based organic solvents that do not dissolve the resulting resin can also be used.

[0106] (2) Prepare a monomer mixture [1] containing a radical polymerizable monomer. Preferably, the monomer mixture [1] contains at least one of the radical polymerizable monomers having an acidic group and a radical polymerizable monomer having a basic group in a proportion of 0.1 to 20% by mass.

[0107] After heating, when the mixture [1] containing the surfactant and radical polymerization initiator reaches a predetermined temperature, a monomer mixture [1] containing a radical polymerizable monomer is added, and the system is heated while stirring, usually under a nitrogen atmosphere, to prepare a dispersion [1] of resin particles for shells.

[0108] The "specified temperature" mentioned above refers to the "polymerization temperature." The polymerization temperature and polymerization time can be set appropriately within the range in which the polymerization reaction occurs.

[0109] [Dispersion treatment of core particles] The disperser used for the dispersion treatment of core particles is not particularly limited, but preferred examples include the "CLEARMIX" stirring device manufactured by M-Technique Co., Ltd., which is equipped with a high-speed rotating rotor, ultrasonic dispersers, mechanical homogenizers, pressurized dispersers such as Manton Gorin and pressure homogenizers, and medium-type dispersers such as Getzmann mills and diamond fine mills.

[0110] (Freeze-drying process) The latex [HML] produced by the above process is subjected to freeze-drying to produce a latent curing agent. For freeze-drying, for example, a freeze-dryer "RLE-100L" manufactured by Kyowa Vacuum Technology Co., Ltd. can be used.

[0111] The latent curing agent of this disclosure is manufactured through the above process.

[0112] [One-component resin composition] Figure 3 is an example of a conceptual diagram of a one-component resin composition of the present disclosure. The one-component resin composition PH of the present disclosure contains a latent curing agent H and a resin composition P. The resin composition P contains at least a resin. Furthermore, a thermosetting agent may be included in the resin composition P to the extent that it does not impair the function of the one-component resin composition PH.

[0113] The resin contained in the above resin composition P is also called a "binding resin" and is used as a medium or matrix (base) for dispersing and holding the latent curing agent H, and has the function of adhering to, for example, a fixing member.

[0114] In the one-component resin composition of this disclosure, the weight ratio of the latent curing agent to the resin composition is preferably 100:0.1 to 100:1000. The one-component resin composition of this disclosure is preferably liquid at room temperature or paste-like with a viscosity of 50 mPa·s to 10 million mPa·s at 25°C. Lower viscosity is preferable because it improves workability, reduces the amount that adheres to the container, and reduces waste.

[0115] A method for producing the one-component resin composition of the present disclosure includes dispersing the latent curing agent of the present disclosure in the resin composition using a three-roller system or the like.

[0116] In recent years, particularly in the field of electronic equipment, one-component resin compositions have been used as connecting materials to meet the demands of increased circuit density and improved connection reliability, to enable the use of materials with low heat resistance for lighter mobile devices, and to significantly improve productivity. These one-component resin compositions require excellent curing properties while maintaining storage stability.

[0117] The latent curing agent of this disclosure can accelerate the curing reaction at a lower temperature compared to conventional latent curing agents. Furthermore, when used in combination with a resin composition as a one-component resin composition, the viscosity increase rate of the resin composition during the curing reaction is dramatically increased, making it suitable for satisfying the above requirements.

[0118] (Resin Composition) There are no particular restrictions on the resin contained in the one-component resin composition, and conventionally known resins can be used. Examples include epoxy resins, polyesters, polyurethanes, acrylic resins, polyethers, melamine resins, and modified epoxy resins such as urethane-modified epoxy resins, rubber-modified epoxy resins, and alkyd-modified epoxy resins.

[0119] Epoxy resin can be used in combination with conventionally known resins. Furthermore, different resins can be selected from among the conventionally known resins and used in combination.

[0120] It is preferable that the resin in the resin composition is an epoxy resin from the viewpoint of improving adhesion due to the curing reaction acceleration effect and durability against organic solvents. It is also preferable from the viewpoint of obtaining a cured product with a low coefficient of thermal expansion (CTE).

[0121] Preferably, the epoxy resin used is a different type of epoxy resin than the one used for the shell of the latent curing agent.

[0122] [Curable Composition] A curable composition is obtained by further diluting a one-component resin composition with a diluent resin composition, for example, and by adding thermosetting agents and additives as needed. The curable composition of this disclosure is a further improvement of the one-component resin composition for specific applications. It also contains the latent curing agent of this disclosure, as well as an inorganic filler and an epoxy resin.

[0123] (Dilution resin composition: epoxy resin) The curable composition of this disclosure contains at least an epoxy resin as a dilution resin composition. If a resin other than epoxy resin is used as the dilution resin composition, the same resin composition P as that contained in the one-component resin composition described above can be used.

[0124] Figure 4 is an example of a conceptual diagram of the curable composition of this disclosure. The curable composition HPH contains a resin composition Pd diluted with a diluent resin composition (not shown), and a latent curing agent H. It may also contain an inorganic filler IF or other additives as needed.

[0125] (Inorganic Filler) Because the curable composition of this disclosure contains an inorganic filler, it is expected to reduce the coefficient of thermal expansion. In addition, the toughness of the cured product formed by the curable composition is improved.

[0126] Examples of inorganic fillers include alumina particles, silica particles, strontium titanate particles, zirconia particles, zinc oxide particles, chromium oxide particles, cerium oxide particles, antimony oxide particles, tungsten oxide particles, tin oxide particles, tellurium oxide particles, manganese oxide particles, and boron oxide particles.

[0127] It is preferable that the inorganic filler is hydrophobized using a silane coupling agent, a titanium coupling agent, or the like.

[0128] While there are no particular limitations on the degree of hydrophobic treatment, a methanol wettability in the range of 40 to 95 is preferred. "Methanol wettability" represents the degree of hydrophobicity and is an index used to evaluate wettability to methanol. Methanol wettability, or the degree of hydrophobicity, is calculated as follows.

[0129] Add 0.2 g of the inorganic filler to be measured to 50 ml of distilled water in a 200 ml beaker. Slowly add methanol dropwise through a burette with its tip immersed in the liquid, stirring gently, until the entire inorganic filler is wet. If the amount of methanol required to completely wet these inorganic particles is a (ml), the degree of hydrophobicity is calculated using the following formula: Degree of hydrophobicity = [a / (a ​​+ 50)] × 100

[0130] (Thermosetting agents) There are two types of thermosetting agents: those that exhibit a curing reaction even at relatively low temperatures, and those that do not exhibit a curing reaction unless high temperatures are required. However, the thermosetting agent that does not exhibit a curing reaction unless high temperatures are required is preferred for inclusion in a one-component resin composition.

[0131] Examples of thermosetting agents that exhibit a curing reaction even at relatively low temperatures include aliphatic polyamines, polyaminoamides, and polymer captans.

[0132] Examples of thermosetting agents that do not exhibit a curing reaction unless the temperature is high include aromatic polyamines, acid anhydrides, phenol novolac resins, and dicyandiamides. By using these, it is possible to obtain cured products with high heat resistance, low thermal expansion coefficient, high glass transition temperature, and excellent film strength and insulation properties.

[0133] Among the thermosetting agents mentioned above, acid anhydrides are more preferred due to their high solubility in epoxy resins and reactive diluents. High solubility in resin compositions is desirable from the viewpoint of ejection stability and pot life. Solid materials such as dicyandiamide may precipitate even after being dissolved, making it difficult to obtain inkjet suitability, such as ejection stability, when, for example, a one-component resin composition is ejected using an inkjet printer. In addition, solid materials may require heating to dissolve, which may degrade the ink's pot life.

[0134] Examples of acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, dodecyl succinic anhydride, chlorendic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, methylcyclohexenetetracarboxylic anhydride, trimellitic anhydride, and polyazelaic anhydride.

[0135] As a thermosetting agent other than acid anhydrides, modified polyamine compounds such as amine-epoxy adducts may be used, or other thermosetting agents may be used.

[0136] Adduct forms such as epoxy compound-added polyamines (reaction products of epoxy compounds and polyamines), Michael-added polyamines (reaction products of α,β unsaturated ketones and polyamines), Mannich-added polyamines (condensates of polyamines, formalin, and phenol), thiourea-added polyamines (reaction products of thiourea and polyamines), and ketone-blocking polyamines (reaction products of ketone compounds and polyamines [ketimines]) may also be used.

[0137] The thermosetting agent content is preferably in the range of 1 to 60% by mass, more preferably in the range of 5 to 60% by mass, and even more preferably in the range of 5 to 50% by mass, based on 100% by mass of the one-component resin composition.

[0138] Specifically, for example, when the thermosetting compound is an epoxy resin, the optimal ratio varies depending on the compound used, but it is generally preferable to use a molar ratio of 0.8 to 1.2 equivalents of thermosetting agent relative to the epoxy equivalent (molecular weight divided by the number of glycidyl groups).

[0139] (Additives) Examples of additives that can be included in the curable composition of this disclosure include diluents, pigments, conductive fine particles, organic particles, lubricants, organic solvents, crystalline alcohols, and water. Other examples of additives include coupling agents, fillers, and reinforcing agents.

[0140] A "diluent" is a colorless, low-viscosity liquid added to a substance to reduce its viscosity and make it easier to handle. By including a diluent in a one-component resin composition, the viscosity of the one-component resin composition can be reduced.

[0141] The purpose of adding a reactive diluent is to reduce the viscosity of the one-component resin composition, and among these, using a monomer with a high glass transition temperature is more preferable because it can raise the glass transition temperature of the cured product.

[0142] Diluents include reactive and non-reactive diluents. Examples of reactive diluents include butyl glycidyl ether, N,N'-glycidyl-o-toluidine, phenyl glycidyl ether, styrene oxide, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. Examples of non-reactive diluents include dioctyl phthalate, dibutyl phthalate, dioctyl adivate, and petroleum-based solvents.

[0143] Examples of pigments include kaolin, aluminum oxide trihydrate, aluminum hydroxide, chalk powder, gypsum, calcium carbonate, antimony trioxide, pentone, silica, aerosol, lithopone, barite, and titanium dioxide.

[0144] Examples of conductive nanoparticles include carbon black, graphite, carbon nanotubes, fullerenes, iron oxide, gold, silver, aluminum powder, iron powder, nickel, copper, zinc, chromium, solder, nano-sized metal crystals, and intermetallic compounds. Each of these can be effectively used depending on its application.

[0145] The organic particles can be any particles whose main component is an organic material. Examples of such organic particles include homopolymers such as styrene and methyl methacrylate, as well as polystyrene, polymethyl methacrylate, and styrene-methyl methacrylate copolymers. Examples of organic fine particles include spherical fine particles with a number mean primary particle size of about 10 to 2000 nm.

[0146] Examples of lubricants include metal salts of higher fatty acids. Examples of metal salts of higher fatty acids include metal stearate, metal oleate, metal palmitate, metal linoleate, and metal ricinoleate.

[0147] Examples of metal stearate salts include zinc stearate, aluminum stearate, copper stearate, magnesium stearate, and calcium stearate. Examples of metal oleate salts include zinc oleate, manganese oleate, iron oleate, copper oleate, and magnesium oleate. Examples of metal palmitate salts include zinc palmitate, copper palmitate, magnesium palmitate, and calcium palmitate. Examples of metal linoleate salts include zinc linoleate and calcium linoleate. Examples of metal ricinoleate salts include zinc ricinoleate and calcium ricinoleate.

[0148] Examples of organic solvents include hydrocarbons, ketones, esters, and alcohols.

[0149] Examples of hydrocarbons include benzene, toluene, xylene, cyclohexane, mineral spirits, and naphtha. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters include ethyl acetate, n-butyl acetate, and propylene glycol monomethyl ether acetate. Examples of alcohols include methanol, isopropanol, n-butanol, butyl cellosolve, and butyl carbitol.

[0150] The above-mentioned organic solvents may be used in combination. When forming core particles, it is preferable that organic solvents that are active against amine adducts or amine compounds be removed by distillation or the like.

[0151] By including an organic solvent that is inert to amine adducts or amine compounds within a specific range, the one-component resin composition can be made highly stable in storage, have excellent fluidity, and exhibit excellent dispersibility when compounding with a curing agent, without impairing the curability of the one-component resin composition.

[0152] However, the content of the organic solvent is preferably kept to 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, based on 100% by mass of the one-component resin composition.

[0153] Examples of crystalline alcohols include 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, pentaerythritol, sorbitol, sucrose, and trimethylolpropane.

[0154] The water used is not particularly limited and may be deionized water, distilled water, or pure water. However, the water content is preferably kept to 1% by mass or less per 100% by mass of the one-component resin composition, more preferably 0.5% by mass or less, and even more preferably 0.2% by mass or less.

[0155] The additive content is preferably less than 30% by weight. Furthermore, it is preferable that the additive content be in the range of 0.05 to 5.0 parts by mass relative to the total mass of the one-component resin composition, from the viewpoint of improving fluidity and stabilizing the physical properties after the cured product is formed by ensuring uniformity of the components contained in the one-component resin composition.

[0156] (Applications) The curing agent composition of this disclosure can be used in paste form, film form, and for a wide range of applications, and is useful, for example, as a sealing material. In addition to adhesives and / or bonding pastes and bonding films, it is also useful as a conductive material, anisotropic conductive material, conductive particles, insulating material, coating material, paint composition, prepreg, thermal conductive material, sealing material for fuel cells, etc.

[0157] As a sealing material, it is useful as a solid sealing material, liquid sealing material, film sealing material, etc., and as a liquid sealing material, it is useful as an underfill material, potting material, dam material, etc.

[0158] As a method for manufacturing sealing materials, for example, Japanese Patent Publication No. 5-43661 and Japanese Patent Publication No. 2002-226675 describe them as molding materials for sealing and impregnating electrical and electronic components.

[0159] More specifically, a bisphenol A type epoxy resin, a curing agent such as methylhexahydrophthalic anhydride as a curing agent, and spherical fused silica filler powder are added and uniformly mixed, and the curing agent composition obtained in this disclosure is added and uniformly mixed to obtain a sealing material.

[0160] The curable composition is suitable for use as a semiconductor encapsulating material in the above-mentioned encapsulating material applications.

[0161] The present disclosure will be described in detail below with reference to examples, but this disclosure is not limited to these examples. In the examples, the units "parts" or "%" are used, and unless otherwise specified, they refer to "parts by mass" or "mass%".

[0162] [A] Preparation of latent curing agent [A-1] Latent curing agent [1] <Preparation of core particles> In a flask equipped with a stirring device, the curing component [1] below was added to the monomer mixture [1c] below, heated to 80°C, and dissolved. ・Curing component [1] 1,2-dimethylimidazole 300 g ・Monomer mixture [1c] Styrene (St) 349 g n-butyl acrylate (BA) 128 g Methyl methacrylate (MMA) 34 g Dodecyl mercaptan (NDM) 5.1 g

[0163] This allowed us to prepare a monomer solution containing a hardening component [1-1c].

[0164] Meanwhile, a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet tube was filled with the following aqueous medium [w1], and the internal temperature was raised to 80°C. • Aqueous medium [w1]: A surfactant solution prepared by dissolving 1.5 g of sodium lauryl sulfate (SDS), an anionic surfactant, in 1823 g of deionized water.

[0165] (Mixing and dispersion treatment with aqueous medium) A monomer solution containing a curing component at 80°C [1-1c] was added to an aqueous medium [w1] at 80°C, and the mixture was mixed and dispersed for 30 minutes using "Cleamix". "Cleamix" is a mechanical disperser with a circulation path manufactured by M-Technique Co., Ltd. This prepared an emulsion particle (oil droplet) dispersion [α1] having a uniform dispersion particle size.

[0166] (Polymerization process) Polymerization was carried out by adding the following initiator solution [ck1] and 683g of deionized water to the emulsion particle (oil droplet) dispersion [α1] and heating and stirring the system at 80°C for 3 hours. • Initiator solution [ck1] A solution prepared by dissolving 17g of potassium persulfate (KPS), a polymerization initiator, in 219g of deionized water.

[0167] This allowed for the preparation of latex (C-1). Note that "latex" refers to a dispersion of high molecular weight resin particles.

[0168] <Shell Formation> A monomer solution for the shell [S-1] was prepared by adding the following initiator solution [sk1] to latex (C-1) composed of resin particles (core particles), and then dropping a monomer mixture [1s] containing the following compounds in the following amounts over 1 hour at a temperature of 80°C. • Initiator solution [sk1]: A solution prepared by dissolving 6.4 g of potassium persulfate (KPS), a polymerization initiator, in 81 g of deionized water. • Monomer mixture [1s]: Styrene (St) 130 g, n-butyl acrylate (BA) 47 g, methyl methacrylate (MMA) 13 g, dodecyl mercaptan (NDM) 1.9 g

[0169] After the dropwise addition of the monomer mixture [1s] was complete, polymerization (shell formation) was carried out by heating and stirring the monomer solution for the shell [S-1] for 2 hours, and then it was cooled to 30°C. This prepared the latex (CS-1).

[0170] The average particle size (median diameter by volume) of the resin particles (core-shell type particles) constituting the latex (CS-1) was 300 nm. The maximum particle size was 700 nm.

[0171] In Table III, the average particle size and maximum particle size of the latent curing agent [1] refer to the average particle size and maximum particle size of the resin particles (core-shell type particles) that constitute the latex (CS-1) described above.

[0172] Furthermore, the average particle size and maximum particle size were measured using the "LA-950V2" (laser diffraction / scattering particle size distribution analyzer) manufactured by Horiba, Ltd.

[0173] The average and maximum particle sizes were measured using the same method for other latent curing agents described below.

[0174] <Freeze-drying> The latex (CS-1) was transferred to a container to a depth of 1.5 cm and placed in a freeze-drying machine "RLE-100L" manufactured by Kyowa Vacuum Technology Co., Ltd. Freeze-drying was carried out for one day to produce a latent curing agent [1] in the form of powder particles.

[0175] [A-2] Latent curing agents [2], [3], [8], and [9] Latent curing agents [2], [3], [8], and [9] were prepared in the same manner as latent curing agent [1], except that the mixing and dispersion treatment time with the aqueous medium in the preparation of core particles was changed to 5 minutes, 60 minutes, 1 minute, and 3 minutes using "Cleamix".

[0176] Table I shows the average particle size (volume-based median diameter) and maximum particle size of the resin particles (core-shell type particles) constituting the latex (CS-2), (CS-3), (CS-8), and (CS-9) during the preparation of latent curing agents [2], [3], [8], and [9].

[0177] [A-3] Latent curing agent [4] <Preparation of core particles> In a flask equipped with a stirring device, the curing component [4] below was added to the monomer mixture [4c] below, heated to 80°C, and dissolved. • Curing component [4] 1,2-dimethylimidazole 300g • Monomer mixture [4c] Styrene (St) 245g n-butyl acrylate (BA) 90g methyl methacrylate (MMA) 24g dodecyl mercaptan (NDM) 3.6g

[0178] This allowed us to prepare a monomer solution containing a hardening component [4-4c].

[0179] Meanwhile, a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet tube was filled with the following aqueous medium [w4], and the internal temperature was raised to 80°C. • Aqueous medium [w4]: A surfactant solution prepared by dissolving 1.0 g of sodium lauryl sulfate (SDS), an anionic surfactant, in 1280 g of deionized water.

[0180] (Mixing and dispersion treatment with aqueous medium) A monomer solution containing a curing component at 80°C [4-4c] was added to an aqueous medium [w4] at 80°C, and the mixture was mixed and dispersed for 30 minutes using "Cleamix". This prepared an emulsion particle (oil droplet) dispersion [α4] having a uniform dispersion particle size.

[0181] (Polymerization process) Polymerization was carried out by adding the following initiator solution [ck4] and 480g of deionized water to the emulsion particle (oil droplet) dispersion [α4] and heating and stirring the system at 80°C for 3 hours. • Initiator solution [ck4]: A solution prepared by dissolving 12g of potassium persulfate (KPS), a polymerization initiator, in 154g of deionized water.

[0182] This allowed us to prepare latex (C-4).

[0183] <Shell Formation> A monomer solution for the shell [S-4] was prepared by adding the following initiator solution [sk4] to latex (C-4) composed of resin particles (core particles), and then dropping a monomer mixture [4s] containing the following compounds in the following quantities over 1 hour at a temperature of 80°C. • Initiator Solution [sk4] A solution was used in which 12 g of potassium persulfate (KPS), a polymerization initiator, was dissolved in 146 g of deionized water. • Monomer Mixture [4s] Styrene (St) 234 g n-butyl acrylate (BA) 85 g methyl methacrylate (MMA) 23 g dodecyl mercaptan (NDM) 3.4 g

[0184] After the dropwise addition of the monomer mixture [4s] was complete, polymerization (shell formation) was carried out by heating and stirring the monomer solution for the shell [S-4] for 2 hours, and then it was cooled to 30°C. This prepared the latex (CS-4).

[0185] The average particle size (volume-based median diameter) of the resin particles (core-shell type particles) constituting the latex (CS-4) was 300 nm. The maximum particle size was 700 nm. The average and maximum particle sizes of the latent curing agent [4] in Table III are the same as the average and maximum particle sizes of the resin particles (core-shell type particles) constituting the latex (CS-4) described above.

[0186] <Freeze-drying> The latex (CS-4) was transferred to a container to a depth of 1.5 cm and placed in a freeze-drying machine "RLE-100L" manufactured by Kyowa Vacuum Technology Co., Ltd. Freeze-drying was carried out for one day to produce a latent curing agent [4] in the form of powder particles.

[0187] [A-4] Latent curing agent [5] <Preparation of core particles> In a flask equipped with a stirring device, the curing component [5] below was added to the monomer mixture [5c] below, heated to 80°C, and dissolved. • Curing component [5] 1,2-dimethylimidazole 300g • Monomer mixture [5c] Styrene (St) 410g n-butyl acrylate (BA) 150g methyl methacrylate (MMA) 40g dodecyl mercaptan (NDM) 6.0g

[0188] This allowed us to prepare a monomer solution containing a hardening component [5-5c].

[0189] Meanwhile, a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet tube was filled with the following aqueous medium [w5], and the internal temperature was raised to 80°C. • Aqueous medium [w5]: A surfactant solution prepared by dissolving 1.7 g of sodium lauryl sulfate (SDS), an anionic surfactant, in 2143 g of deionized water.

[0190] (Mixing and dispersion treatment with aqueous medium) A monomer solution containing a curing component at 80°C [5-5c] was added to an aqueous medium [w5] at 80°C, and the mixture was mixed and dispersed for 30 minutes using "Cleamix". This prepared an emulsion particle (oil droplet) dispersion [α5] having a uniform dispersion particle size.

[0191] (Polymerization process) Polymerization was carried out by adding the following initiator solution [ck5] and 803g of deionized water to the emulsion particle (oil droplet) dispersion [α5] and heating and stirring the system at 80°C for 3 hours. • Initiator solution [ck5] A solution prepared by dissolving 20g of potassium persulfate (KPS), a polymerization initiator, in 257g of deionized water.

[0192] This allowed us to prepare latex (C-5).

[0193] <Shell Formation> A monomer solution for the shell [S-5] was prepared by adding the following initiator solution [sk5] to latex (C-5) composed of resin particles (core particles), and then dropping a monomer mixture [5s] containing the following compounds in the following amounts over 1 hour at a temperature of 80°C. • Initiator solution [sk5]: A solution prepared by dissolving 3.4 g of potassium persulfate (KPS), a polymerization initiator, in 43 g of deionized water. • Monomer mixture [5s]: Styrene (St) 68 g, n-butyl acrylate (BA) 25 g, methyl methacrylate (MMA) 6.6 g, dodecyl mercaptan (NDM) 1.0 g

[0194] After the dropwise addition of the monomer mixture [5s] was complete, polymerization (shell formation) was carried out by heating and stirring the monomer solution for the shell [S-5] for 2 hours, and then it was cooled to 30°C. This prepared the latex (CS-5).

[0195] The average particle size (volume-based median diameter) of the resin particles (core-shell type particles) constituting the latex (CS-5) was 300 nm. The maximum particle size was 700 nm.

[0196] In addition, the average particle size and maximum particle size of the latent curing agent [5] in Table III shall be the average particle size and maximum particle size of the resin particles (core-shell type particles) constituting the latex (CS-5) described above.

[0197] <Freeze-drying> The latex (CS-5) was transferred to a container to a depth of 1.5 cm and placed in a freeze-drying machine "RLE-100L" manufactured by Kyowa Vacuum Technology Co., Ltd. Freeze-drying was carried out for one day to produce a latent curing agent [5] in the form of powder particles.

[0198] [A-5] Latent curing agent [6] <Preparation of core particles> In a flask equipped with a stirring device, the curing component [6] below was added to the monomer mixture [6c] below, heated to 80°C, and dissolved. • Curing component [6] 1,2-dimethylimidazole 300 g • Monomer mixture [6c] Styrene (St) 410 g n-butyl acrylate (BA) 67 g Methyl methacrylate (MMA) 34 g Dodecyl mercaptan (NDM) 5.1 g

[0199] This allowed us to prepare a monomer solution containing a hardening component [6-6c].

[0200] Meanwhile, a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet tube was filled with the following aqueous medium [w6], and the internal temperature was raised to 80°C. • Aqueous medium [w6]: A surfactant solution prepared by dissolving 1.0 g of sodium lauryl sulfate (SDS), an anionic surfactant, in 1823 g of deionized water.

[0201] (Mixing and dispersion treatment with aqueous medium) A monomer solution containing a curing component at 80°C [6-6c] was added to an aqueous medium [w6] at 80°C, and the mixture was mixed and dispersed for 30 minutes using "Cleamix". This prepared an emulsion particle (oil droplet) dispersion [α6] having a uniform dispersion particle size.

[0202] (Polymerization process) Polymerization was carried out by adding the following initiator solution [ck6] and 683g of deionized water to the emulsion particle (oil droplet) dispersion [α6] and heating and stirring the system at 80°C for 3 hours. • Initiator solution [ck6]: A solution prepared by dissolving 17g of potassium persulfate (KPS), a polymerization initiator, in 219g of deionized water.

[0203] This allowed us to prepare latex (C-6).

[0204] <Shell Formation> Latex (C-6), composed of resin particles (core particles), was mixed with the following initiator solution [sk6]. Under a temperature of 80°C, a monomer mixture [6s] containing the following compounds in the following quantities was added dropwise over 1 hour to prepare the monomer solution [S-6] for the shell. • Initiator solution [sk6]: A solution prepared by dissolving 6.0 g of potassium persulfate (KPS), a polymerization initiator, in 81 g of deionized water. • Monomer mixture [6s]: Styrene (St) 152 g, n-butyl acrylate (BA) 25 g, methyl methacrylate (MMA) 13 g, dodecyl mercaptan (NDM) 1.9 g

[0205] After the dropwise addition of the monomer mixture [6s] was complete, polymerization (shell formation) was carried out by heating and stirring the monomer solution for the shell [S-6] for 2 hours, and then it was cooled to 30°C. This prepared the latex (CS-6).

[0206] The average particle size (volume-based median diameter) of the resin particles (core-shell type particles) constituting the latex (CS-6) was 300 nm. The maximum particle size was 700 nm.

[0207] In addition, the average particle size and maximum particle size of the latent curing agent [6] in Table III shall be the average particle size and maximum particle size of the resin particles (core-shell type particles) constituting the latex (CS-6) described above.

[0208] <Freeze-drying> The latex (CS-6) was transferred to a container to a depth of 1.5 cm and placed in a freeze-drying machine "RLE-100L" manufactured by Kyowa Vacuum Technology Co., Ltd. Freeze-drying was carried out for one day to produce a latent curing agent [6] in the form of powder particles.

[0209] [A-6] Latent curing agent [7] <Preparation of core particles> In a flask equipped with a stirring device, the curing component [7] below was added to the monomer mixture [7c] below, heated to 80°C, and dissolved. • Curing component [7] 1,2-dimethylimidazole 300 g • Monomer mixture [7c] Styrene (St) 273 g n-butyl acrylate (BA) 203 g Methyl methacrylate (MMA) 34 g Dodecyl mercaptan (NDM) 5.1 g

[0210] This allowed us to prepare a monomer solution containing a hardening component [7-7c].

[0211] Meanwhile, a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet tube was filled with the following aqueous medium [w7], and the internal temperature was raised to 80°C. • Aqueous medium [w7]: A surfactant solution prepared by dissolving 1.0 g of sodium lauryl sulfate (SDS), an anionic surfactant, in 1823 g of deionized water.

[0212] (Mixing and dispersion treatment with aqueous medium) A monomer solution containing a curing component at 80°C [7-7c] was added to an aqueous medium [w7] at 80°C, and the mixture was mixed and dispersed for 30 minutes using "Cleamix". This prepared an emulsion particle (oil droplet) dispersion [α7] having a uniform dispersion particle size.

[0213] (Polymerization process) Polymerization was carried out by adding the following initiator solution [ck7] and 683g of deionized water to the emulsion particle (oil droplet) dispersion [α7] and heating and stirring the system at 80°C for 3 hours. • Initiator solution [ck7]: A solution prepared by dissolving 17g of potassium persulfate (KPS), a polymerization initiator, in 219g of deionized water.

[0214] This allowed us to prepare latex (C-7).

[0215] <Shell Formation> A monomer solution for the shell [S-7] was prepared by adding the following initiator solution [sk7] to latex (C-7) composed of resin particles (core particles), and then dropping a monomer mixture [7s] containing the following compounds in the following quantities over 1 hour at a temperature of 80°C. • Initiator solution [sk7]: A solution prepared by dissolving 6.0 g of potassium persulfate (KPS), a polymerization initiator, in 81 g of deionized water. • Monomer mixture [7s]: Styrene (St) 102 g, n-butyl acrylate (BA) 76 g, methyl methacrylate (MMA) 13 g, dodecyl mercaptan (NDM) 1.9 g

[0216] After the dropwise addition of the monomer mixture [7s] was complete, polymerization (shell formation) was carried out by heating and stirring the monomer solution for the shell [S-7] for 2 hours, and then it was cooled to 30°C. This prepared the latex (CS-7).

[0217] The average particle size (median diameter by volume) of the resin particles (core-shell type particles) constituting the latex (CS-7) was 300 nm. The maximum particle size was 700 nm.

[0218] In addition, the average particle size and maximum particle size of the latent curing agent [7] in Table III shall be the average particle size and maximum particle size of the resin particles (core-shell type particles) constituting the latex (CS-7) described above.

[0219] <Freeze-drying> The latex (CS-7) was transferred to a container to a depth of 1.5 cm and placed in a freeze-drying machine "RLE-100L" manufactured by Kyowa Vacuum Technology Co., Ltd. Freeze-drying was carried out for one day to produce a latent curing agent [7] in the form of powder particles.

[0220] [Summary of Core Particle and Shell Formulations for Latent Curing Agents [1] to [9]] Table I summarizes the core particle (latex) formulations for latent curing agents [1] to [9]. Table II summarizes the shell formulations.

[0221]

[0222]

[0223] [A-7] Latent curing agent

[10] The curing component

[10] and the material below were reacted in the following amounts in a 1 / 1 mixed solvent of n-butanol and toluene (50% resin content) at 80°C in a flask equipped with a stirring device. Then, under reduced pressure, the solvent was distilled off with the 1,2-dimethylimidazole until the content was less than 10 ppm. The epoxy resin [e1] below is a bisphenol A type epoxy resin with an epoxy equivalent of 185 g / equivalent and a total chlorine content of 1400 ppm. The 50% resin content refers to the total resin content of the epoxy resin and 1,2-dimethylimidazole in the solvent. Curing component

[10] 1,2-dimethylimidazole (in terms of active hydrogen) 1.0 equivalent Material epoxy resin [e1] 1.5 equivalent

[0224] This yielded a solid amine adduct

[10] at 25°C.

[0225] 100 parts by mass of amine adduct

[10] was melted and 2-ethyl-4-methylimidazole was uniformly mixed in. After cooling to room temperature, the mixture was pulverized to prepare a latent curing agent

[10] in solid form at 25°C. The average particle size (median diameter by volume) of the latent curing agent

[10] was 5000 nm. The maximum particle size was 15000 nm.

[0226] [A-8] Latent curing agent

[11] A raw material solution was prepared by dissolving 11 parts by mass of isocyanate in 60 parts by mass of ethyl acetate. The isocyanate used here was "D-109" manufactured by Mitsui Takeda Chemical Co., Ltd., which is an adduct in which methylenediphenyl-4,4-diisocyanate (3 moles) is added to trimethylolpropane (1 mole).

[0227] The following materials were added to a dispersion solvent in the following quantities. The above raw material liquid was added to this solvent and heated to 80°C while stirring with a homogenizer to produce resin particles [is]. The surfactant "Newlex R-T" is a product of Nippon Oil & Fats Co., Ltd. • Materials: Distilled water 800 parts by mass, Surfactant "Newlex R-T" 0.05 parts by mass, Dispersant (polyvinyl alcohol) 4 parts by mass

[0228] The curing component

[11] was used as 1,2-dimethylimidazole, which was dissolved in ethanol to prepare a curing agent solution [iz] containing 30% by mass of the curing component

[11] .

[0229] Resin particles [is] were added to the curing agent solution [iz] so that the content was 2% by mass, and the mixture was stirred at 40°C for 6 hours, followed by stirring overnight at room temperature.

[0230] Resin particles [is] impregnated with the curing component

[11] were washed with a small amount of polar solvent, filtered, and then air-dried to prepare the latent curing agent

[11] . The average particle size (volume-based median diameter) of the latent curing agent

[11] was 2290 nm. The maximum particle size was 5000 nm.

[0231] [Calculation of Curing Component Content Ratio] For the prepared latent curing agents, the curing component content ratio in the surface layer was calculated using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The calculation results for the curing component content ratio for each latent curing agent are shown in Table III. The method for calculating the curing component content ratio will be explained in detail below.

[0232] Using "nanoTOF3+" manufactured by ULVAC PHI, we will detect and measure ions derived from the curing components contained in the latent curing agent.

[0233] For example, since the curing component of the latent curing agent [1] is 1,2-dimethylimidazole, the detection and measurement of ions (m / z = 97.1) derived from the 1,2-dimethylimidazole are performed. The measurement conditions were as follows: Measurement range: 1 μm square area; Measurement time: 5 minutes; Primary ion: Na ＋ (30kV)

[0234] Areas where ions derived from the curing component are detected appear with higher brightness in the image displayed by "nanoTOF3+" compared to areas where ions are not detected in the latent curing agent.

[0235] From the image above, calculate the area multiplied by the brightness value of the region where ions originating from the curing component of the latent curing agent are detected. This value is called the A value.

[0236] Furthermore, the area multiplied by the brightness value of the region where ions originating from the curing component are detected in the surface layer of the latent curing agent is calculated. This value is called the B value.

[0237] "The surface portion of the latent curing agent" refers to the portion of the latent curing agent from the outermost surface toward the center, up to 10% of the average particle size.

[0238] The following formula is used to calculate the content ratio of the curing component in the surface layer of the latent curing agent: Content ratio of curing component [%] = (B value / A value) × 100

[0239] Table III shows the curing component content ratio in the surface layer for each latent curing agent. Table III also includes information on the latex No., average particle size, maximum particle size, presence or absence of core-shell structure, and presence or absence of thermoplastic resin.

[0240]

[0241] [B] Preparation of one-component resin compositions [Pa1] to [Pa11] [B-1] One-component resin composition [Pa1] One-component resin composition [Pa1] was prepared by mixing latent curing agent [1] and bisphenol A type epoxy resin (BPA) in the following amounts. Latent curing agent [1] 50 parts Bisphenol A type epoxy resin (BPA type EP) 100 parts

[0242] [B-2] One-component resin compositions [Pa2] to [Pa9] One-component resin compositions [Pa2] to [Pa9] were prepared in the same manner as one-component resin composition [Pa1], except that the latent curing agent [1] was changed as shown in Table IV.

[0243] [B-3] One-component resin composition [Pa10] 200 parts by mass of epoxy resin [e1] were mixed with the following materials in the amounts specified below, and the reaction was continued for 3 hours while stirring at 40°C. The epoxy resin [e1] is a bisphenol A type epoxy resin with an epoxy equivalent of 185 g / equivalent and a total chlorine content of 1400 ppm. • Latent curing agent

[10] 100 parts by mass Water 1.5 parts by mass Tolylene diisocyanate 7 parts by mass

[0244] Subsequently, a shell-forming reaction was carried out at 50°C for 8 hours to prepare a one-component resin composition [Pa10].

[0245] [B-4] One-component resin composition [Pa11] A one-component resin composition [Pa11] was prepared by mixing epoxy resin [e1] and latent curing agent

[11] in a weight ratio of 100:50. The epoxy resin [e1] is a bisphenol A type epoxy resin with an epoxy equivalent of 185 g / equivalent and a total chlorine content of 1400 ppm.

[0246] [Storage Stability Evaluation] One-component resin compositions [Pa1] to [Pa11] were stored at 50°C for one week to prepare one-component resin compositions [PA1] to [PA11].

[0247] The viscosity ratio for each one-component resin composition was calculated using the following formula, and storage stability was evaluated according to the following evaluation criteria. The results are shown in Table IV. Viscosity was measured at 25°C using a BM-type viscometer. Formula: Viscosity ratio [times] = Viscosity after 1 week of storage / Viscosity before 1 week of storage

[0248] <Evaluation Criteria> A: The calculated viscosity ratio is less than 1.5 times. B: The calculated viscosity ratio is 1.5 times or more and less than 2 times. C: The calculated viscosity ratio is 2 times or more and less than 3 times. D: The calculated viscosity ratio is 3 times or more, or gelled during storage.

[0249] [Evaluation of storage stability during heating] One-component resin compositions [Pa1] to [Pa11] were held at a constant temperature of 30°C and 85% humidity for 6 hours to prepare one-component resin compositions [Pb1] to [Pb11].

[0250] Subsequently, the one-component resin compositions [Pb1] to [Pb11] were stored at 50°C and 50% humidity for one week to produce the one-component resin compositions [PB1] to [PB11].

[0251] The viscosity ratio for each one-component resin composition was calculated using the following formula, and the storage stability during heating was evaluated according to the following evaluation criteria. The results are shown in Table IV. Viscosity was measured at 25°C using a BM-type viscometer. Formula: Viscosity ratio [times] = Viscosity after 1 week of storage / Viscosity before 1 week of storage after 6 hours of holding

[0252] <Evaluation Criteria> A: The calculated viscosity ratio is less than 2 times. B: The calculated viscosity ratio is 2 times or more and less than 5 times. C: The calculated viscosity ratio is 5 times or more and less than 10 times. D: The calculated viscosity ratio is 10 times or more, or gelled during storage.

[0253]

[0254] [C] Preparation of curable composition [C-1] Curable composition [1] The following materials were prepared by adding the following amounts and stirring at room temperature of 25°C to prepare curable composition [1]. The silica filler "SE1050SMO" below is a silica filler manufactured by Admatex Co., Ltd., with an average particle size of 0.3 μm and a maximum particle size of 1 μm. ・Materials One-component resin composition [Pa1] 18 parts by mass Methyltetrahydroxy anhydride (acid anhydride equivalent 164 g / eq) 18 parts by mass Silica filler "SE1050SMO" 78 parts by mass 3-Glycidoxypropyltrimethoxysilane (silane coupling agent) 3 parts by mass Carbon black 1 part by mass

[0255] [C-2] Curable compositions [2] to

[11] Curable compositions [2] to

[11] were prepared in the same manner as curable composition [1], except that the one-component resin composition [Pa1] described above was modified as shown in Table V.

[0256]

[0257] [D] Injectability evaluation [D-1] Fabrication of encapsulant [D-1-1] Encapsule [1] (Placement of silicon wafer) Figure 5 is a schematic diagram of the semiconductor material used for injectionability evaluation. In Figure 5, "20" represents the silicon wafer, "21" represents the silicon chip, and "22" represents the spacer. "h" is the gap between the silicon chip 21 and the silicon wafer 20.

[0258] First, the following silicon wafer, silicon chip, and spacer were prepared. The thickness of the spacer was adjusted as needed to match the gap between the silicon chip 21 and the silicon wafer 20, as described later. • Silicon wafer: 300 mm diameter, 760 μm thickness • Spacer: 1-2 mm diameter • Silicon chip: 18 mm length, 18 mm width, 300 μm thickness

[0259] Next, a silicon chip 21 was placed on the silicon wafer 20 via nine disc-shaped spacers 22. At this time, the spacers 22 were arranged at equal intervals along the diagonal of the silicon chip 21.

[0260] Following the above procedure, four silicon chips were placed at equal intervals near the outer edge of the silicon wafer.

[0261] (Gap adjustment) At this time, the gap h between the silicon chip and the silicon wafer was set to 20 μm. The fact that the gap h was 20 μm was confirmed by SEM imaging.

[0262] The silicon wafer 20, along with the silicon chip 21 and spacer 22, was placed inside a compression molding apparatus equipped with a mold. The compression apparatus used was the "YPM1180" manufactured by TOWA Corporation.

[0263] (Filling and Compression Molding of Curable Composition) The curable composition [1] was filled into the mold described above, compression molding was performed under the following conditions, and then it was heated at this temperature for 400 seconds to cure. • Temperature: 120°C • Pressure: 250kN

[0264] This formed a cured layer of a curable composition [1] with a thickness of 500 μm that covered the entire silicon wafer (the silicon chip and spacer were enclosed within it).

[0265] By cutting the silicon wafer, which has been removed from the compression molding apparatus and is coated with a cured layer of the curable composition [1], at a position slightly away from the outer edge of the silicon chip, the sealant [1] is obtained. ２０μｍ A seal was fabricated. In addition, the gap h was set to 20 μm for gap adjustment, and the seal [1] that was compression molded was made into seal [1]. ２０μｍ Let's assume that.

[0266] Except that the gap h between the silicon chip and the silicon wafer in the gap adjustment was set to 10 μm and 5 μm, the sealant [1] ２０μｍ was prepared in the same manner as the sealant [1] １０μｍ and the sealant [1] ５μｍ was fabricated. In the gap adjustment, the sealant [1] obtained by setting the gap h to 10 μm and performing compression molding was designated as the sealant [1] １０μｍ and the sealant [1] obtained by setting the gap h to 5 μm and performing compression molding was designated as the sealant [1] ５μｍ for use.

[0267] [D-1-2] Sealants [2] to [5], [8] to

[11] Except that the curable composition [1] was changed to the curable compositions [2] to [5], in the same manner as the sealants [1] of 20 μm, 10 μm, and 5 μm, the sealants [2] of 20 μm, 10 μm, and 5 μm to [5] of 20 μm, 10 μm, and 5 μm were prepared.

[0268] Except that the curable composition [1] was changed to the curable compositions [8] to

[11] , in the same manner as the sealants [1] of 20 μm, 10 μm, and 5 μm, the sealants [8] of 20 μm, 10 μm, and 5 μm to

[11] of 20 μm, 10 μm, and 5 μm were prepared.

[0269] [D-1-3] Sealant [6] Except that the temperature condition was changed from 120 °C to 140 °C in the process of filling the curable composition and compression molding, in the same manner as the sealants [1] of 20 μm, 10 μm, and 5 μm, the sealants [6] of 20 μm, 10 μm, and 5 μm were prepared.

[0270] [D-1-4] Sealant [7] Except that the temperature condition was changed from 120 °C to 100 °C in the process of filling the curable composition and compression molding, in the same manner as the sealants [1] of 20 μm, 10 μm, and 5 μm, the sealants [7] of 20 μm, 10 μm, and 5 μm were prepared.

[0271] [D-2] Preparation of test specimens for injection properties [D-2-1] Test specimens for injection properties [1] The silicon chip, the cured layer made of curable composition [1], and the spacer were removed from the sealant [1] 20 μm, 10 μm, and 5 μm by planar polishing until the thickness of the cured layer measured from the silicon wafer was approximately 10 μm. This prepared test specimens [1] 20 μm, 10 μm, and 5 μm for injection properties.

[0272] [D-2-2] Test specimens for injection properties [2] to

[11] were prepared in the same way as test specimens for injection properties [1] (20 μm, 10 μm, 5 μm) to

[11] (20 μm, 10 μm, 5 μm), except that the curable composition [1] and sealant [1] (20 μm, 10 μm, 5 μm) were changed as shown in Table VI.

[0273] [D-3] Evaluation The polished side of the obtained test specimens for evaluating injectability was observed visually or under a microscope (magnification: 100x), and the presence or absence of injectability was evaluated according to the following evaluation criteria.

[0274] <Evaluation Criteria> (Injectable) If no voids are found in the test specimen for evaluating injectability, or if the maximum width of voids found in the test specimen for evaluating injectability is less than 20 μm. (Injectable) If the maximum width of voids found in the test specimen for evaluating injectability is 20 μm or more.

[0275]

[0276] [D-4] Confirmation of curing temperature by glass transition temperature (Tg) When latent curing agents [1], [6], and [7] were subjected to differential scanning calorimeter (DSC), baseline shifts of approximately 115°C, 125°C, and 95°C were observed, respectively. It is considered that each of these temperatures corresponds to the glass transition temperature (Tg).

[0277] Furthermore, the results above confirm that by increasing the glass transition temperature (Tg) of the core-shell resin in the latent curing agent [6], it is possible to raise the curing temperature corresponding to the appropriate gel time.

[0278] Furthermore, the results above confirm that by lowering the glass transition temperature (Tg) of the core-shell resin in the latent curing agent [7], the curing temperature corresponding to the appropriate gel time can be lowered.

[0279] [E] Electrical characteristics evaluation [E-1] Fabrication of sealing material for electrical characteristics evaluation [E-1-1] Sealing material for electrical characteristics evaluation [1] Figure 6 is a schematic diagram of the comb-shaped electrode used when fabricating the sealing material for electrical characteristics evaluation. In Figure 6, "E" is the comb-shaped electrode, "B ＰＩ " is a polyimide film substrate with a thickness of 38 μm, "W ＣＵ This is a copper wiring with a thickness of 8 μm.

[0280] The comb-shaped electrode E is made of a polyimide film substrate B. ＰＩ and patterned copper wiring W ＣＵ It consists of (wire width 15 μm, wire spacing X = 20 μm). Note that copper wiring W ＣＵ It is coated with a tin plating that is 0.2 ± 0.05 μm thick.

[0281] A curable composition [1] is applied to the comb-shaped electrode E to a thickness of 150 μm, and the curable composition [1] is cured by heating it in a dryer at 120°C for 1 hour, thereby creating an electrical characteristic evaluation encapsulant [1]. ２０μｍ I made it.

[0282] Encapsulation for electrical characteristic evaluation [1] ２０μｍ In the fabrication of the copper wiring W ＣＵ Except for setting the wiring distance X to 10 μm and 5 μm, the electrical characteristic evaluation encapsulant [1] ２０μｍ Similarly, an electrical characteristic evaluation seal [1] １０μｍ , Encapsulation for electrical characteristic evaluation [1] ５μｍ I made it.

[0283] [E-1-2] Encapsulations for electrical property evaluation [2] to [5], [8] to

[11] Encapsulations for electrical property evaluation [2] 20 μm, 10 μm, 5 μm to [5] 20 μm, 10 μm, 5 μm were prepared in the same manner as in the preparation of Encapsulations for electrical property evaluation [1] 20 μm, 10 μm, 5 μm, except that the curable composition [1] was changed as shown in Table VII.

[0284] In the preparation of electrical property evaluation sealants [1] 20 μm, 10 μm, and 5 μm, the electrical property evaluation sealants [8] 20 μm, 10 μm, and 5 μm to

[11] 20 μm, 10 μm, and 5 μm were prepared in the same manner, except that the curable composition [1] was changed as shown in Table VII.

[0285] [E-1-3] Sealings for electrical property evaluation [6] In the preparation of sealings for electrical property evaluation [1] 20 μm, 10 μm, and 5 μm, the sealings for electrical property evaluation [6] 20 μm, 10 μm, and 5 μm were prepared in the same manner, except that the temperature at which the curable composition was heated and cured using a dryer was changed from 120°C to 140°C.

[0286] [E-1-4] Sealing for electrical property evaluation [7] Except for changing the temperature from 120°C to 100°C, the 20 μm, 10 μm, and 5 μm sealing materials for electrical property evaluation [1] were prepared in the same manner as for test specimen [1]. Except for changing the temperature at which the curable composition is heated and cured using a dryer from 120°C to 100°C, the 20 μm, 10 μm, and 5 μm sealing materials for electrical property evaluation [7] were prepared in the same manner as for test specimen [1].

[0287] [E-2] Evaluation Each electrical characteristic evaluation encapsulation prepared was mounted on a HAST device (model number: PC-422R8) manufactured by Hirayama Seisakusho Co., Ltd., and the electrical resistance was continuously monitored under conditions of 85% relative humidity and 130°C with a bias voltage of 3V applied. The time [hr] from the start of the test until a short circuit occurred (electrical resistance value became 10kΩ or less) was measured and evaluated according to the evaluation criteria below. The results are shown in Table VII.

[0288] <Evaluation Criteria> A: No short circuit occurs even after more than 180 hours. B: No short circuit occurs within the range of 100 to 180 hours. C: A short circuit occurs in less than 100 hours.

[0289]

[0290] [F] Storage Stability Evaluation The viscosity of curable compositions [1] to

[11] was measured, and the viscosity of curable compositions [1] to

[11] after storage at 50°C for 24 hours was also measured. From these viscosity measurements, the viscosity ratio after 24 hours for each curable composition was calculated using the following formula: Formula) Viscosity ratio [times] = Viscosity after 24 hours of storage / Viscosity before 24 hours of storage

[0291] Based on the calculated viscosity ratio, each curable composition was evaluated according to the following evaluation criteria.

[0292] <Evaluation Criteria> A: The calculated viscosity ratio is less than 2 times. B: The calculated viscosity ratio is 2 times or more and less than 5 times. C: The calculated viscosity ratio is 5 times or more and less than 10 times. D: The calculated viscosity ratio is 10 times or more, or the curable composition has gelled.

[0293]

[0294] [G] Overall assessment As is clear from the above, the example is superior to the comparative example in terms of injectability, electrical properties, and storage stability.

[0295] While embodiments of this disclosure have been described and illustrated in detail above, the disclosed embodiments are illustrative and illustrative only, and are not limiting. The scope of this disclosure should be construed in accordance with the terms of the appended claims.

[0296] The present invention can be used for latent curing agents, curable compositions, and methods for producing latent curing agents, which exhibit excellent injectability into materials with a gap between materials of 10 μm or less, and have excellent storage stability and electrical properties.

[0297] H Latent curing agent S Shell covering the core particles O Center of the latent curing agent LS １０ Surface layer PH One-component resin composition P Resin composition HPH Curable composition Pd Resin composition IF Inorganic filler 20 Silicon wafer 21 Silicon chip 22 Spacer h Gap between silicon chip and silicon wafer E Comb-shaped electrode B ＰＩ Polyimide film substrate WＣＵ Copper wiring X Distance between wirings

Claims

1. A core-shell type latent curing agent comprising at least a thermoplastic resin and a curing component, wherein the latent curing agent is one of the curing agents for sealing resins, underfill agents, or mold underfill agents, with a material gap of 10 μm or less, and the average particle size of the latent curing agent is in the range of 0.05 to 3.00 μm, and the maximum particle size is 10 μm or less.

2. The latent curing agent according to claim 1, wherein, when the portion of the latent curing agent from the outermost surface toward the center up to 10% of the average particle size is defined as the surface portion, the content ratio of the curing component in the surface portion is 10% or less of the total curing component of the latent curing agent.

3. A curable composition containing the latent curing agent described in claim 1 or claim 2, and also containing an inorganic filler and an epoxy resin.

4. A method for producing a latent curing agent according to claim 1 or claim 2, wherein the core particles of the latent curing agent are produced by emulsion polymerization of a miniemulsion.

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