Solvent-free curable composition, cured product and method for producing the same

Abstract

The present application provides a solvent-free curable composition, a cured product and a method for producing the cured product, which can obtain a cured product having excellent adhesiveness and moisture resistance even after cold and heat cycles, and excellent bending strength when the cured product is produced. The solvent-free curable composition is a melt molding curable composition exhibiting thermal curability, comprising a polyamide resin (A) having a dimer structure derived from at least either one of dimer acid and dimer diamine, an epoxy resin (B), and at least one of a silica filler (C) and a thermally conductive filler (D), wherein the total input rate of the dimer acid and the dimer diamine is set to 50% to 100% of 100% by mass of the total monomer used in the polymerization of the polyamide resin (A), and the epoxy resin (B) satisfies at least one of a softening point of 50°C to 120°C and a melting point of 70°C to 120°C.

Description

Technical Field

[0001] This invention relates to a solvent-free curable composition containing at least one of a polyamide resin, an epoxy resin, a silica filler, and a thermally conductive filler. Additionally, it relates to a cured product obtained by hot melting the curable composition and then curing it, and a method for manufacturing the same. Background Technology

[0002] Integrated circuits (ICs), as key components of electronic devices such as microprocessors, transistors, and memory, are integrated into various electronic devices including computers, smartphones, and flat panel displays. The packages containing ICs or the mounting substrates on which ICs are mounted use insulating resins such as sealants, adhesives, underfills, and potting materials.

[0003] In Japanese Patent Application Publication No. 2017-057313 (Patent Document 1), a resin composition comprising a polymer resin, an inorganic filler, an epoxy resin, and a curing accelerator is disclosed as a mold bottom filler for wafer level chip size package (WL-CSP). The polymer resin has an average molecular weight within a specific range and has one or more structures selected from polybutadiene, polyisoprene, polycarbonate, (meth)acrylate, and polysiloxane.

[0004] In addition, International Publication No. 2016 / 136741 (Patent Document 2) discloses a sealing membrane containing one or more elastomers selected from the group consisting of butadiene rubbers and silicone rubbers, epoxy resins, hardeners and inorganic fillers, and containing a specific amount of the elastomer component.

[0005] Furthermore, Japanese Patent Application Publication No. 2019-119886 (Patent Document 3) discloses a free-radical polymerizable polyamide as a reactant of a polyamide with hydroxyl groups on its side chains and a free-radical polymerizable epoxy group. The polyamide with hydroxyl groups on its side chains has a dimer structure comprising a dimer acid or a dimer diamine, and phenolic hydroxyl units. Additionally, a resin composition containing the aforementioned free-radical polymerizable polyamide, a photopolymerization initiator, an epoxy resin, a phenolic resin, a silica filler, a solvent, etc., is disclosed.

[0006] In addition, International Publication No. 2016 / 001949 (Patent Document 4) discloses a thermosetting resin composition comprising: a polyamide (A) having a dimer structure, which is formed by polymerizing a polybasic acid monomer and a polyamine monomer, and having phenolic hydroxyl groups on its side chain; and a compound (B) having more than three functions, which can react with the phenolic hydroxyl groups. Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] In semiconductor packaging manufacturing, multiple heating steps are involved in forming the rewiring layer. For example, fan-out wafer level packages (FO-WLPs) are attracting attention as chip-size packages that can increase pin count. However, in the manufacturing process of the representative face-down type FO-WLP, there is a step where the semiconductor chip is sealed on one side using a molding resin composition, and then repeatedly heated during the subsequent rewiring layer formation step. Therefore, there is a need for a resin composition with high resistance to damp heat that can suppress foaming and cracking during heating.

[0009] Electronic components and devices are widely used in automobiles, industrial machinery, ships, aircraft, and other applications, creating a market demand for resin compositions that offer high reliability and excellent thermal cycling performance even under harsh conditions. Improvements in thermal cycling performance are particularly urgent in sealing materials for power IC packages, which are expected to become more widespread. Furthermore, driven by the trend towards thinner and smaller electronic components, IC packages and other electronic components also require thinner designs, necessitating resin compositions that can produce hardened forms with high flexural strength.

[0010] The present invention was made in view of the aforementioned background, and aims to provide a curing composition, a curing material, and a method thereof that yields a curing material with excellent adhesion and resistance to damp heat, as well as excellent flexural strength, even after thermal cycling tests.

[0011] [Technical means to solve the problem]

[0012] Through repeated and diligent research, the inventors discovered that the problem of this invention can be solved in the following form, thereby completing this invention.

[0013] [1]: A solvent-free curable composition, which is a melt-forming curable composition exhibiting thermosetting properties.

[0014] The product comprises at least one of a polyamide resin (A) having a dimer structure derived from at least one of a dimer acid and a dimer diamine, an epoxy resin (B), a silica filler (C), and a thermally conductive filler (D).

[0015] In the polymerization of polyamide resin (A), the total input rate of the dimer acid and dimer diamine is set to 50% to 100% by mass of all monomers used.

[0016] The epoxy resin (B) satisfies at least one of the following: softening point of 50°C to 120°C and melting point of 70°C to 120°C.

[0017] [2]: The curable composition according to [1], wherein the glass transition temperature of the polyamide resin (A) is 0°C to 90°C.

[0018] [3]: The curable composition according to [1] or [2], wherein the mass ratio of polyamide resin (A) to epoxy resin (B) is 5:95 to 50:50.

[0019] [4]: The curable composition according to any one of [1] to [3], wherein the polyamide resin (A) has a weight average molecular weight of 15,000 to 100,000.

[0020] [5]: The curing composition according to any one of [1] to [4] further comprises one or more compounds (E) selected from compounds containing an anhydride group, isocyanate compounds, aziridine compounds, amine compounds, phenolic compounds and metal chelates.

[0021] [6]: The curing composition according to any one of [1] to [5] further comprises a liquid epoxy compound (F).

[0022] [7]: The curable composition according to any one of [1] to [6], wherein at least one of the silica filler (C) and the thermally conductive filler (D) comprises two or more.

[0023] [8]: The curing composition according to any one of [1] to [7] is in the form of flakes, powder, granules or tablets.

[0024] [9]: A hardened material is formed by heating and hardening a hardening composition according to any one of [1] to [8].

[0025]

[10] : The hardened material according to [9], wherein the glass transition temperature is 100°C to 200°C.

[0026]

[11] : A method for manufacturing a curable, comprising the steps of forming a solvent-free curable composition by hot melting and then thermosetting the solvent-free curable composition, the solvent-free curable composition exhibiting thermosetting properties, comprising a polyamide resin (A) having a dimer structure derived from at least one of a dimer acid and a dimer diamine, an epoxy resin (B), and at least one of a silica filler (C) and a thermally conductive filler (D).

[0027] In 100% by mass of all monomers constituting polyamide resin (A), the total content of the dimer acid and dimer diamine is 50% to 100% by mass.

[0028] The epoxy resin (B) satisfies at least one of the following: softening point of 50°C to 120°C and melting point of 70°C to 120°C.

[0029] [The effects of the invention]

[0030] According to the present invention, the following excellent effects are achieved: a curing composition, a curing material, and a method thereof can be provided to obtain a curing material with excellent adhesion and resistance to damp heat even after thermal cycling tests and excellent flexural strength. Detailed Implementation

[0031] The present invention will now be described in detail. Furthermore, other embodiments that conform to the spirit of the present invention are also naturally included within the scope of the present invention. Additionally, in this specification, the symbol “~” is used to indicate a specific numerical range, encompassing the values ​​described before and after the symbol as the lower and upper limits. Furthermore, in this specification, “film” or “sheet” is not distinguished based on thickness. In other words, “sheet” in this specification also includes thin film-like sheets, and “film” in this specification also includes sheet-like films of a certain thickness. Furthermore, unless otherwise specified, each component appearing in this specification may be used independently or in combination with two or more components.

[0032] In this specification, "Mw" and "Mn" refer to the weight-average molecular weight and number-average molecular weight of polystyrene, respectively, determined by gel permeation chromatography (GPC). These can be determined using the method described in the [Example] section.

[0033] The curable composition of this embodiment is a solvent-free composition for melt molding exhibiting thermosetting properties, comprising a polyamide resin (A) (hereinafter also simply referred to as "polyamide resin (A)"), an epoxy resin (B) (hereinafter also simply referred to as "epoxy resin (B)"), and at least one of a silica filler (C) and a thermally conductive filler (D). The polyamide resin (A) has a dimer structure derived from at least one of a dimer acid and a dimer diamine, and the epoxy resin (B) satisfies at least one of a softening point of 50°C to 120°C and a melting point of 70°C to 120°C. Regarding the polyamide resin (A), the total input rate of the dimer acid and dimer diamine is set to 50% to 100% by mass of all monomers used in the polymerization of the polyamide resin (A). The input ratio of monomers used in the polymerization of the polyamide resin (A) substantially becomes the proportion of the constituent components derived from the monomers of the polyamide resin (A).

[0034] In this specification, "solvent-free" means that the solvent in 100% by mass of the curing composition is 2% by mass or less. Although some solvent used in the synthesis of the formulation components of the curing composition or in the preparation of the composition may remain, it is preferable to remove it as much as possible, and more preferably, to make it substantially solvent-free (excluding solvents other than those unavoidably included). "Melting" refers to forming a molded body of other shapes by flowing such a solvent-free curing composition in a molten state. Furthermore, the formulation components of these solvent-free curing compositions can partially crosslink (semi-curing) during the curing stage of the composition. The solvent is a low-molecular-weight compound that is liquid at room temperature and pressure and can be removed by heating or reducing pressure. It is also used for the purpose of dissolving and dispersing the components constituting the curing composition. Examples of solvents include low-molecular-weight organic compounds such as toluene, ethyl acetate, and ethyl methyl ketone.

[0035] The solvent content is defined as the mass difference of the curing composition before and after vacuum drying at room temperature, which is considered as the mass of the solvent contained. It is the percentage of the mass of the solvent contained relative to the mass of the curing composition before vacuum drying.

[0036] Furthermore, the term "other shaped molded bodies" refers to forms that only involve changes in size or minor deformations in the surface roughness of the coated joints, maintaining the original shape macroscopically, and are not included in the melt forming process of this invention. For example, in the case where the hardening composition is a sheet, forms that are thinned only by hot pressing, or forms where the sheet is coated with wiring with a thickness less than the sheet's thickness, are not included.

[0037] According to this curable composition having at least one of polyamide resin (A), epoxy resin (B), silica filler (C), and thermally conductive filler (D), the following effects can be obtained in the cured product obtained by melt molding and curing: the polyamide resin (A) contains a specific amount of a dimer structure derived from at least one of dimer acid and dimer diamine. That is, when the cured product is used as a sealing resin, such as for IC packages, its resistance to damp heat can be improved. In addition, it exhibits excellent adhesion to semiconductor chips, metals, etc. Furthermore, a cured product with excellent adhesion and resistance to damp heat, even after thermal cycling tests, and with superior flexural strength can be provided. As a result, a cured product with excellent foaming and crack resistance can be provided. A detailed description will follow.

[0038] [[Curing composition]]

[0039] [Polyamide resin (A)]

[0040] Polyamide resin is a polymer containing repeating structural units comprising amide groups, wherein a resin having a dimer structure derived from at least one of a dimer acid and a dimer diamine is designated as polyamide resin (A). Polyamide resin (A) is a polymer of a polybasic acid compound, a polyamine compound, and other monomers as desired, or a modified form of said polymer. Here, a modified form refers to a derivative obtained by converting a portion of the molecular structure of said polymer (e.g., conversion of functional groups, substitution with other compounds, or addition with other compounds). Introducing a dimer structure into a polyamide resin requires only the use of a monomer having a dimer structure; preferably, a dimer acid as a polybasic acid compound and / or a dimer diamine as a polyamine compound are used.

[0041] The total input rate of dimer acid and dimer diamine in 100% by mass of all monomers used in the polymerization of polyamide resin (A) is set to 50% to 100% by mass. The input ratio of monomers used in the polymerization of polyamide resin (A) is substantially consistent with the proportion of constituent components derived from the monomers of polyamide resin (A). That is, the proportion of constituent units of the dimer structure derived from dimer acid and dimer diamine in polyamide resin (A) is substantially 50% to 100% by mass. Therefore, by setting the input rate to 50% to 100% by mass, the effect of the dimer structure can be fully utilized. The total content of dimer acid and dimer diamine is preferably 60% to 95% by mass, more preferably 70% to 90% by mass.

[0042] Furthermore, regarding the content of the dimer structure, in the case of a polymer, it can be determined based on the content (mass%) of the monomers having the dimer structure out of 100% by mass of all raw material monomers used in the synthesis of polyamide resin (A). Alternatively, in the case of a modified body, a virtual monomer with the modified structure is assumed. For the unmodified monomer, it can be determined using raw material monomers and based on the content (mass%) of the monomers having the dimer structure out of 100% by mass of all monomers. The content of the virtual monomer with the modified structure can be determined by considering the reaction rate with the polymer. For example, when the side groups derived from monomer a are modified after obtaining the polymer, the monomer content (mass) X, calculated according to "the amount (moles) of monomer a × the modification rate of the side groups / 100 × the molecular weight of the virtual monomer with the modified side group structure", and the monomer content (mass) Y, calculated according to "the amount (moles) of monomer a × (1 - the modification rate of the side groups / 100) × the molecular weight of monomer a", can be determined for other monomers in the same way as the method for determining the polymer.

[0043] The dimer structure has a hydrocarbon chain or ring structure and is less polar than the formulated epoxy resin, thus it can suppress moisture absorption from the outside of the system.

[0044] By forming a solid state through a melting step, polyamide resin (A) and epoxy resin (B) readily undergo phase separation at the micrometer level, forming a microphase-separated structure. The dimer structure of polyamide resin (A) becomes the flexible component, while the hydrogen bonds originating from the amide bonds of polyamide resin (A) and the sites readily compatible with epoxy resin (B) become the binding components. It is believed that by combining this polyamide resin (A) with epoxy resin (B), which is the rigid component, and then undergoing a hot melting step, a microphase-separated structure is formed. It is believed that by using a resin component that readily forms a microphase-separated structure through melt molding as the resin component of the curing composition, the thermal cycling and flexural strength of the cured product of this curing composition can be improved. Furthermore, the cured product contains strong hydrogen bonds originating from the amide bonds of polyamide resin (A). Through these, flexural strength can be improved, effectively suppressing the decrease in adhesion and hygroscopicity after repeated high-temperature and low-temperature cycling, and suppressing the formation of foam and cracks in the cured product.

[0045] The polyamide resin (A) preferably has functional groups that can be crosslinked with the epoxy groups of the epoxy resin (B) by heat. Examples of functional groups include carboxyl, amino, and hydroxyl groups. These functional groups can be monolithic functional groups derived from the polyamide resin (A), or they can be introduced as modifiers after obtaining the polymer. In addition to being located at the end of the polymer, functional groups can also be present in side groups and / or side chains. As a preferred example, a form with a carboxyl or amino functional group at the end of the polymer can be shown. In addition, a form with at least one of the functional groups such as carboxyl, amino, and hydroxyl groups in the side groups or side chains can be shown.

[0046] Furthermore, if a photopolymerizable group is present as a functional group, the curing composition containing polyamide resin may become over-crosslinked and have reduced adhesion, or a thermal free radical reaction may occur during the hot melt molding of the curing composition, resulting in reduced formability. Therefore, it is preferable not to have a photopolymerizable group.

[0047] When the polyamide resin (A) has hydroxyl groups, phenolic hydroxyl groups are preferred. By having phenolic hydroxyl groups, a crosslinking structure with the epoxy resin (B) can be constructed, resulting in a cured product with excellent durability. Phenolic hydroxyl groups can be readily introduced by using polyacid compounds having phenolic hydroxyl groups and / or polyamine compounds having phenolic hydroxyl groups. The aromatic ring of the phenolic hydroxyl group is preferably contained in the main locking skeleton of the polyamide resin (A). Furthermore, from the viewpoint of durability, it is preferable to use a polyacid compound having phenolic hydroxyl groups as the monomer of the polyamide resin (A).

[0048] The polyamide resin (A) may be a polyamide imide having an imide group or a polyamide ester having an ester group, without departing from the spirit of the present invention.

[0049] <Polybasic acid compounds>

[0050] Polybasic acid compounds are carboxylic acids, either dibasic or higher. A portion of polybasic acid compounds may be acid anhydrides. Examples of polybasic acid compounds include dimer acids and other polybasic acid compounds besides dimer acids.

[0051] When a dimer acid is used in a polybasic acid compound, the content of the dimer acid in 100% by mass of the polybasic acid compound is preferably 60% by mass or more and 100% by mass or less, more preferably 80% by mass or more. When the content of the dimer acid in 100% by mass of the polybasic acid compound is 60% by mass or more, the resistance to damp heat is improved, the stress relaxation effect brought about by the dimer structure is fully manifested, and better adhesion can be exhibited.

[0052] (dimeric acid)

[0053] Dimer acids are polyacid compounds with a dimer structure, and are dimers of fatty acids (hereinafter referred to as fatty acid dimers).

[0054] The fatty acid dimer is preferably a compound with 20 to 60 carbon atoms, more preferably a compound with 24 to 56 carbon atoms, further preferably a compound with 28 to 48 carbon atoms, and particularly preferably a compound with 36 to 44 carbon atoms. The fatty acid dimer is preferably a dicarboxylic acid compound having a branched structure that allows the fatty acid to undergo a Diels-Alder reaction. The branched structure is preferably a compound containing an aliphatic chain or an aliphatic chain and a ring structure, more preferably an aliphatic chain and a ring structure. The ring structure is preferably one or more aromatic rings or alicyclic structures, more preferably alicyclic structures. Alicyclic structures may have a single double bond within the ring or may not have a double bond.

[0055] Polybasic acid compounds with a dimer structure can be exemplified by the structures shown in chemical formulas (1) to (4) below. However, polybasic acid compounds with a dimer structure are not limited to the structures shown below.

[0056] [Chemistry 1]

[0057] Chemical formula (1)

[0058]

[0059] [Chemistry 2]

[0060] Chemical formula (2)

[0061]

[0062] [Chemistry 3]

[0063] Chemical formula (3)

[0064]

[0065] [Chemistry 4]

[0066] Chemical formula (4)

[0067]

[0068] The fatty acid is preferably an unsaturated fatty acid with 10 to 30 carbon atoms, more preferably an unsaturated fatty acid with 10 to 24 carbon atoms. The unsaturated fatty acid has one or more carbon-carbon double or triple bonds. Examples of the fatty acid include natural fatty acids such as soybean oil fatty acid, pine oil fatty acid, and rapeseed oil fatty acid, as well as refined fatty acids such as oleic acid, linoleic acid, alpha-linolenic acid, and sinapic acid.

[0069] In the synthesis of the fatty acid dimer, in addition to the fatty acid dimer, a fatty acid trimer or, depending on the situation, a tetramer is generated. Therefore, the polyacid compound containing the dimer backbone is a mixture that includes not only the fatty acid dimer as the main component, but also fatty acid trimers and, depending on the situation, fatty acids as raw materials. The fatty acid dimer is preferably 70% by mass or more in 100% by mass of the dimer acid, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0070] Dimer acids sometimes retain residual unsaturated bonds due to the use of unsaturated fatty acids as raw materials. In such cases, hydrogenation (also known as a hydrogenation reaction) can suppress the number of unsaturated bonds. This improves the reaction stability during the synthesis of polyamide resin (A), and consequently enhances the high-temperature resistance of the cured product containing the polyamide resin (A). Dimer acids can be used alone or in combination with two or more types.

[0071] Commercially available dimer acids include, for example, those manufactured by Croda Japan: "Pripol 1004", "Pripol 1006", "Pripol 1009", "Pripol 1013", "Pripol 1015", "Pripol 1017", "Pripol 1022", "Pripol 1025", and "Pripol 1040"; and those manufactured by BASF Japan. The company manufactures "Empol 1008", "Empol 1012", "Empol 1016", "Empol 1026", "Empol 1028", "Empol 1043", "Empol 1061", and "Empol 1062". Among these, "Pripol 1009" with 36 carbon atoms easily yields a polyamide resin with superior thermal cycling performance (A) while maintaining good adhesion to metals. Furthermore, "Pripol 1004" with 44 carbon atoms easily yields a polyamide resin with good flexibility (A).

[0072] (Other polyacid compounds)

[0073] Other polybasic acid compounds are polybasic acid compounds other than dimer acids, and are compounds with more than one function. Polybasic acid compounds can be used alone or in combination of two or more.

[0074] Examples of dicarboxylic acid compounds include: aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, benzophenone-4,4′-dicarboxylic acid, and 4,4′-biphenyl dicarboxylic acid; aliphatic dicarboxylic acids such as oxalic acid, malonic acid, methylmalonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, malic acid, tartaric acid, thiomalic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, dodecanoic acid, hexadecanoic acid, and oxodiacetic acid; and alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid. Among these, isophthalic acid and 1,4-cyclohexanedicarboxylic acid are preferred as dicarboxylic acid compounds.

[0075] Examples of trifunctional or higher polybasic acid compounds include trimellitic acid, hydrogenated trimellitic acid, pyromellitic acid, hydrogenated pyromellitic acid, pyromellitic acid, and 1,4,5,8-naphthalenetetracarboxylic acid. When using trifunctional or higher polybasic acid compounds, branched structures can be introduced into the polyamide resin (A), thereby improving the cohesiveness of the cured material and enhancing its thermal cycling performance or dimensional stability.

[0076] Preferred examples of other polybasic acid compounds include polybasic acid compounds having phenolic hydroxyl groups. Polybasic acid compounds having phenolic hydroxyl groups are compounds that, like phenol, have hydroxyl groups directly bonded to the aromatic ring (also called phenolic hydroxyl groups) and have two or more acidic functional groups. Examples of acidic functional groups include carboxyl groups.

[0077] By using polyacid compounds with phenolic hydroxyl groups, the crosslinking structure of polyamide resin (A) and epoxy resin (B) can be easily adjusted during the curing process. As a result, a strong crosslinking is formed, thus effectively improving the durability of the cured product.

[0078] Examples of polyacid compounds with phenolic hydroxyl groups include: monohydroxy isophthalic acids such as 2-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, and 5-hydroxyisophthalic acid; dihydroxyisophthalic acids such as 2,5-dihydroxyisophthalic acid, 2,4-dihydroxyisophthalic acid, and 4,6-dihydroxyisophthalic acid; monohydroxy terephthalic acids such as 2-hydroxyterephthalic acid; dihydroxy terephthalic acids such as 2,3-dihydroxyterephthalic acid and 2,6-dihydroxyterephthalic acid; hydroxy phthalic acids such as 3-hydroxyphthalic acid and 4-hydroxyphthalic acid; and dihydroxy phthalic acids such as 3,4-dihydroxyphthalic acid, 3,5-dihydroxyphthalic acid, 4,5-dihydroxyphthalic acid, and 3,6-dihydroxyphthalic acid.

[0079] Among these, 5-hydroxyisophthalic acid is preferred as a polybasic acid compound having phenolic hydroxyl groups in terms of copolymerization properties and ease of acquisition. Furthermore, regarding polybasic acid compounds having phenolic hydroxyl groups, the carboxyl group of the compounds exemplified above can form an anhydride group, and the carboxyl group can also form an ester.

[0080] <Polyamine compounds>

[0081] Polyamine compounds are compounds having two or more amino groups. Preferred examples of polyamine compounds include dimer diamines and other polyamine compounds.

[0082] When a dimerized diamine is used in the polyamine compound, the content of the dimerized diamine in 100% by mass of the polyamine compound is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more. By setting the content of the dimerized diamine in 100% by mass of the polyamine compound to 50% by mass or more, the stress relaxation property brought about by the dimer structure can be fully manifested, and better thermal cycling performance can be achieved.

[0083] (Dimeric diamine)

[0084] Dimeric diamines are compounds containing two amino groups having a dimer structure, and can be compounds obtained by converting the carboxyl group of the dimer acid to an amino group. Examples of conversion methods include amidation of a carboxylic acid followed by amination via Hofmann rearrangement, and then distillation and purification.

[0085] Dimeric diamines are preferably compounds with 20 to 60 carbon atoms, more preferably compounds with 24 to 56 carbon atoms, and even more preferably compounds with 28 to 48 carbon atoms. From the viewpoint of easy availability, compounds with 36 to 44 carbon atoms are even more preferred.

[0086] Commercially available dimer diamines include, for example, "Priamine 1071", "Priamine 1073", "Priamine 1074", and "Priamine 1075" manufactured by Croda Japan, or "Versamine 551" manufactured by BASF Japan. Dimer diamines can be used alone or in combination of two or more.

[0087] (Other polyamine compounds)

[0088] Other polyamine compounds are polyamine compounds other than dimerized diamines, such as diamine compounds and polyamine compounds with more than three functions.

[0089] Examples of diamine compounds include: 1,4-diaminobenzene, 1,3-diaminobenzene, 1,2-diaminobenzene, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,3-diaminonaphthalene, 2,6-diaminotoluene, 2,4-diaminotoluene, 3,4-diaminotoluene, 4,4′-diaminodiphenylmethane, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 4,4′-diamino-1,2-diphenylethane, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diamino-1,2-diphenylethane, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diamino Aromatic diamines such as benzophenone, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, and 3,3′-diaminodiphenyl sulfone; aliphatic diamines such as ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,9-nonanediamine, 1,12-dodecylmethylenediamine, and m-xylenediamine; and alicyclic diamines such as isophoronediamine, norbornenediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4′-diaminodicyclohexylmethane, and piperazine.

[0090] Additionally, polyamine compounds having phenolic hydroxyl groups can be cited as examples. Polyamide resin (A) using a polyamine compound having phenolic hydroxyl groups is preferred in terms of durability. When using a polyamine compound having phenolic hydroxyl groups, phenolic hydroxyl groups can be introduced into the polyamide resin (A), which is therefore preferable. By introducing phenolic hydroxyl groups, three-dimensional crosslinking with the formulated epoxy resin (B) can be achieved, resulting in a more robust cured product.

[0091] Polyamine compounds with phenolic hydroxyl groups have multiple amino groups and phenolic hydroxyl groups. Examples of polyamine compounds with phenolic hydroxyl groups include those represented by the following general formula (1).

[0092] [Chemistry 5]

[0093]

[0094] In the formula, R 1 This indicates a direct bond or a group containing carbon, hydrogen, oxygen, nitrogen, sulfur, or halogen. Examples of such groups include divalent hydrocarbon groups with 1 to 30 carbon atoms, divalent hydrocarbon groups with 1 to 30 carbon atoms whose hydrogen atoms are partially or completely substituted with halogen atoms, -(C=O)-, -SO2-, -O-, -S-, -NH-(C=O)-, -(C=O)-O-, groups represented by the following general formula (2), and groups represented by the following general formula (3).

[0095] [Chemistry 6]

[0096]

[0097] [Chemistry 7]

[0098]

[0099] In the formula, r and s independently represent integers from 1 to 20, and R 2 It represents a hydrogen atom or a methyl group.

[0100] Examples of polyamines represented by general formula (1) include 2,2-bis(3-amino-4-hydroxyphenyl)propane, 9,9-bis(3-amino-4-hydroxyphenyl)fluorene, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, and 4,4′-diamino-3,3′-2-hydroxybisphenyl.

[0101] Amines having three or more amino groups but not phenolic hydroxyl groups include, for example, 1,2,4-triaminobenzene and 3,4,4′-triaminodiphenyl ether.

[0102] Among these, isophorone diamine or norbornene diamine are preferred as other polyamine compounds in terms of improving resistance to damp heat, further improving adhesion and thermal cycling performance.

[0103] <Manufacturing Method of Polyamide Resin (A)>

[0104] Polyamide resin (A) can be synthesized, for example, by melt polymerization, interfacial polymerization, solution polymerization, bulk polymerization, and solid-state polymerization, as well as combinations thereof. Among these, solution polymerization is preferred.

[0105] Polyamide resin (A) can be polymerized using the aforementioned polyacid compound, polyamine compound, and other monomers as desired, with or without a catalyst. For example, a predetermined amount of dimer acid, other acid monomers, dimer diamine, other amine monomers, and deionized water are added to a nitrogen-filled flask, and stirred at 20°C to 100°C to uniformly dissolve or disperse them. Then, while removing the deionized water and the water generated through the reaction, the temperature is slowly raised to 230°C, and after reaching 230°C, the pressure is reduced to approximately 15 mmHg, and this state is maintained for approximately 1 hour, thereby obtaining polyamide resin (A). The heating temperature after depressurization is, for example, 150°C to 300°C, and the heating time can be set to approximately 1 hour to 24 hours. To promote the synthesis reaction, a dehydration or de-alcoholization reaction is preferred. To avoid coloring and decomposition reactions caused by high temperatures, the reaction is preferably carried out under reduced pressure at 180°C to 270°C.

[0106] In addition to polyamines, monoamines can also be used as other monomers. Monoamines act as reaction stoppers, thus making it easier to adjust the molecular weight of polyamide resin (A). Furthermore, a portion of the main chain terminal of polyamide resin (A) is not a reactive functional group, thus improving its stability over time. Examples of monoamines include aniline, benzylamine, 4-aminophenol, and 2-ethylhexylamine.

[0107] <Physical Properties of Polyamide Resin (A)>

[0108] The glass transition temperature (Tg) of the polyamide resin (A) is preferably 0°C to 90°C, more preferably 10°C to 70°C, and even more preferably 20°C to 60°C. Tg is the temperature at which the value (tanδ) obtained by dividing the viscosity term of the polyamide resin (A) by the elastic term using a dynamic viscoelasticity measuring device exhibits its maximum value.

[0109] By setting the Tg of the polyamide resin (A) to above 0°C, adhesion between sheets can be effectively suppressed when the curable composition is formed into, for example, a sheet, resulting in good processability. Furthermore, by setting the Tg of the polyamide resin (A) to below 90°C, compatibility with the epoxy resin (B), silica filler (C), and thermally conductive filler (D) is further improved during the step of forming the melt of the curable composition, making it easier to obtain a uniform phase-separated structure.

[0110] The weight average molecular weight (Mw) of the polyamide resin (A) is preferably 15,000 to 100,000, more preferably 17,000 to 78,000. A Mw of 15,000 or higher improves resistance to damp heat and further optimizes thermal cycling performance. A Mw of 100,000 or lower improves wettability to the substrate and further optimizes adhesion.

[0111] The acid value of the polyamide resin (A) is preferably 2 mg KOH / g to 30 mg KOH / g, more preferably 3 mg KOH / g to 25 mg KOH / g, and even more preferably 4 mg KOH / g to 20 mg KOH / g. By setting the acid value to 2 mg KOH / g to 30 mg KOH / g, a suitable crosslinking density can be obtained when preparing the cured material, further improving the adhesion to semiconductor chips and the thermal cycling performance.

[0112] [Epoxy Resin (B)]

[0113] Epoxy resin is a thermosetting resin that can be cured by heat through the presence of epoxy groups. Among them, epoxy resin (B) is a resin that satisfies at least one of a softening point of 50°C to 120°C and a melting point of 70°C to 120°C. Epoxy resin (B) undergoes thermal crosslinking through a curing treatment. Furthermore, the softening point in this invention is the temperature at which the epoxy resin softens, and is a value obtained by measuring the softening point test (ring and ball method) (testing conditions: according to Japanese Industrial Standards (JIS)-2817).

[0114] The melting point of epoxy resin is determined within the capillary-based melting range. The sample is filled into a capillary tube, heated at a constant rate, and the shape change is visually observed to determine the melting range.

[0115] Regarding epoxy resin (B), if epoxy resin (B) itself possesses reactive functional groups such as hydroxyl groups, a cross-linked structure can be formed using epoxy resin (B) alone. In addition to or instead of individual cross-linking, a form of thermal cross-linking between polyamide resin (A) and epoxy resin (B) is also preferred. A three-dimensional cross-linked structure based on thermal cross-linking of polyamide resin (A) and epoxy resin (B) exhibits excellent adhesion, thereby achieving superior thermal cycling performance. Furthermore, a form in which a cross-linked structure is formed between the compound (E) described later and epoxy resin (B) is also preferred. These thermal cross-linking methods can be one type or a combination of two or more.

[0116] The preferred mass ratio of polyamide resin (A) to epoxy resin (B) is (A):(B) = 5:95 to 50:50, more preferably 10:90 to 30:70. By setting this ratio, resistance to damp heat is improved, and adhesion and thermal cycling performance are well balanced. Relative to 100% by mass of the non-volatile components of the curing composition, polyamide resin (A) preferably contains 0.3% by mass or more, more preferably 0.6% by mass or more, and even more preferably 0.7% by mass or more.

[0117] In 100% by mass of the curing composition, the content of epoxy resin (B) is preferably 5% to 30% by mass, more preferably 7% to 20% by mass. By being within the range described above, the resistance to damp heat can be improved, and the adhesion and thermal cycling performance can be well balanced.

[0118] The epoxy resin (B) is preferably in the form of repeating units comprising aromatic rings. Furthermore, it is preferable that at least a portion of the aromatic rings in the repeating units contains an organic group containing an epoxy group as a substituent. The epoxy equivalent of the epoxy resin (B) is preferably 100 g / eq. to 300 g / eq., and from the viewpoints of improving rigidity, effectively promoting microphase separation of resin components during melt molding, suppressing foaming during curing, and further improving crack resistance and resistance to damp heat, it is preferably 200 g / eq. or more. More preferably 220 g / eq. to 320 g / eq., and even more preferably 250 g / eq. to 300 g / eq.

[0119] From the viewpoint of improving compatibility with polyamide resin (A) during compounding, epoxy resin (B) is preferably a monocyclic aromatic hydrocarbon having one ring, such as a benzene ring, compared to polycyclic aromatic hydrocarbons such as naphthalene. Furthermore, polyaromatic epoxy resins having multiple monocyclic aromatic hydrocarbons are also preferred. Moreover, from the viewpoint of effectively forming a phase-separated structure between polyamide resin (A) and epoxy resin (B) during melt molding, epoxy resin (B) containing repeating unit structures is preferred.

[0120] Epoxy resins (B) include, for example, bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin; phenolic varnish type epoxy resins such as o-cresol phenolic varnish type epoxy resin; biphenyl type epoxy resin, naphthalene type epoxy resin, naphthalene-containing phenolic varnish type epoxy resin, dicyclopentadiene type epoxy resin, phenol aralkyl type epoxy resin, triphenol methane type epoxy resin, phenol modified xylene resin type epoxy resin, and chemical formulas (5) to (10) described below.

[0121] From the viewpoint of improving resistance to damp heat and further optimizing thermal cycling performance, the preferred epoxy resins are biphenyl-type epoxy resins, o-cresol phenolic varnish-type epoxy resins, triphenol methane-type epoxy resins, dicyclopentadiene-type epoxy resins, naphthalene-containing phenolic varnish-type epoxy resins, phenol aralkyl-type epoxy resins, and phenol-modified xylene resin-type epoxy resins.

[0122] As a preferred example, epoxy resins with the following chemical formulas (5) to (10) can be exemplified. In the formula, n is an integer, preferably 1 to 10.

[0123] [Chemistry 8]

[0124]

[0125] [Chemistry 9]

[0126]

[0127] [Chemistry 10]

[0128]

[0129] [Chemistry 11]

[0130]

[0131] [Chemistry 12]

[0132]

[0133] [Chemistry 13]

[0134]

[0135] Two or more epoxy resins (B) can be used in combination. By using two or more in combination, the adhesion or thermal cycling performance can be easily adjusted. For example, it is preferable to include a phenol arylene type epoxy resin and a phenol-modified xylene type epoxy resin, or a phenol arylene type epoxy resin and a triphenol methane type epoxy resin. Among these, when the phenol arylene type epoxy resin and the phenol-modified xylene type epoxy resin, or the phenol arylene type epoxy resin and the triphenol methane type epoxy resin are used in a mass ratio of 2:8 to 8:2, they have suitable compatibility with polyamide resin (A), and the adhesion or thermal cycling performance is improved, which is therefore preferred. In addition, the total content of polyamide resin (A) and epoxy resin (B) is preferably set to 9% by mass or more relative to 100% by mass of the non-volatile components of the curing composition.

[0136] [Silica filler (C) and thermally conductive filler (D)]

[0137] The curable composition of this embodiment includes at least one of silica filler (C) and thermally conductive filler (D). By combining at least one of silica filler (C) and thermally conductive filler (D) with the polyamide resin (A) and epoxy resin (B), mechanical strength and moisture absorption can be improved. In addition, the thermal cycling performance of the cured product is improved by using at least one of silica filler (C) and thermally conductive filler (D).

[0138] Examples of silica fillers (C) include molten and crushed silica, molten spherical silica, crystalline silica, and secondary agglomerated silica. In terms of excellent flowability, molten spherical silica is preferred among silica fillers (C).

[0139] Among the thermally conductive fillers (D), a higher thermal conductivity at 20°C is preferred, with a filler having a thermal conductivity of 15 (W / m·K) or higher. Furthermore, a higher volume resistivity is preferred, with a filler having a volume resistivity of 10⁶ (Ω·cm) or higher. Preferred examples of thermally conductive fillers (D) include alumina, aluminum nitride, silicon nitride, boron nitride, and silicon carbide. Among these, alumina or boron nitride are preferred in terms of ease of acquisition. The type of boron nitride is not particularly limited. Examples include hexagonal boron nitride (h-BN), cubic boron nitride (c-BN), and wurtzite-type boron nitride. Of these, hexagonal boron nitride (h-BN) is preferred from the viewpoint of thermal conductivity. The shape of the boron nitride is not limited, but it is preferably flaky, and can be primary particles or secondary particles formed by the aggregation of primary particles. Examples of thermally conductive fillers (D) include molten fragments, molten spheroids, crystals, and secondary aggregates. In terms of excellent fluidity, molten spheres are preferred.

[0140] The average particle size of the silica filler (C) and the thermally conductive filler (D) is preferably in the range of 1 μm to 50 μm, more preferably 5 μm to 30 μm, and even more preferably 10 μm to 22 μm. Setting the average particle size to 1 μm or more further improves the flexibility and suppleness of the hardened material. Setting the average particle size to 50 μm or less provides the advantage of easy high-filling. Furthermore, the average particle size is the average particle size D. 50 For example, a sample arbitrarily extracted from the parent group can be used to determine the particle size distribution using a laser diffraction scattering particle size distribution measuring device.

[0141] Silica filler (C) and thermally conductive filler (D) can also be treated independently using silane coupling agents (pretreatment). By treating with silane coupling agents, the affinity with other materials is improved, and the dispersibility of silica filler (C) and / or thermally conductive filler (D) is further improved.

[0142] Silane coupling agents are compounds having hydrolyzable and reactive functional groups. Examples of hydrolyzable groups include alkoxy groups with 1 to 6 carbon atoms, such as methoxy and ethoxy; acetoxy; and 2-methoxyethoxy. Among these, methoxy groups are preferred in terms of ease of removal of volatile components such as alcohols generated by hydrolysis.

[0143] The reactive functional groups may include vinyl, epoxy, styrene, methacrylic acid, acrylic acid, amino, urea, mercapto, thioether, isocyanate, etc., with epoxy being preferred.

[0144] Examples of silane coupling agents include: vinyltrimethoxysilane, vinyltriethoxysilane, and other vinyl-containing silane coupling agents; 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and other epoxy-containing silane coupling agents; p-styrene-containing silane coupling agents such as p-styrenetrimethoxysilane; 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane, and other methacrylic acid-containing silane coupling agents; and 3-acryloyloxypropyltrimethoxysilane, and other acrylic acid-containing silane coupling agents. Silane coupling agents; N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-amino Amino-containing silane coupling agents such as methyl ethyl-3-aminopropyltrimethoxysilane; urea-containing silane coupling agents such as 3-ureopropyltriethoxysilane; mercapto-containing silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; thioether-containing silane coupling agents such as bis(triethoxysilylpropyl)tetrasulfide; isocyanate-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane.

[0145] From the viewpoint of exhibiting excellent adhesion and thermal cycling performance, phenylaminosilane treatment and / or vinylsilane treatment are preferred.

[0146] Methods for treating silica filler (C) with a silane coupling agent include, for example, a wet method of mixing silica filler (C) and silane coupling agent in a solvent, and a dry method of treating silica filler (C) and silane coupling agent in the gas phase. The amount of silane coupling agent treated is preferably about 0.1 to 1 part by weight of silane coupling agent relative to 100 parts by weight of untreated silica filler (C).

[0147] The method and amount of thermally conductive filler (D) treated with silane coupling agent are the same as those for the silica filler (C).

[0148] Relative to 100 parts by mass of the non-volatile components of the curing composition, the total amount of silica filler (C) and thermally conductive filler (D) is preferably 40 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 70 parts by mass or more. When it contains 40 parts by mass or more, the thermal cycling performance of the cured product is further improved. Furthermore, the upper limit of the content of silica filler (C) and thermally conductive filler (D) is preferably 95 parts by mass. This curing composition is available in a form containing only one of silica filler (C) and thermally conductive filler (D), and in a form containing both.

[0149] The silica filler (C) and the thermally conductive filler (D) can be a single type, or two or more can be used together. From the viewpoint of improving adhesion, it is preferable to include two or more types.

[0150] As a form containing two or more types of silica filler (C), it includes any two or more forms selected from self-melting and crushing silica, molten spherical silica, crystalline silica, and secondary agglomerated silica. Additionally, examples can be given of forms using two or more types with different average particle sizes and two or more types of silica fillers with different surface treatments.

[0151] As a form that incorporates two or more thermally conductive fillers (D), there are two or more forms that are combined from the following: self-melting fragments, molten spheroids, crystals, and secondary aggregates. In addition, examples can be given of two or more forms that use different average particle sizes and two or more forms that use different surface treatments.

[0152] By combining silica filler (C) with thermally conductive filler (D), thermal conductivity can be better utilized in addition to adhesion, resulting in better thermal cycling performance.

[0153] From the viewpoint of improving filler properties, it is preferable to combine two or more types of molten spherical silica with different average particle sizes. The average particle size range is preferably including both 0.2 μm to 10 μm and 10 μm to 100 μm, and the content ratio (mass ratio) of each silica filler (C) is preferably 5:95 to 95:5, and more preferably 10:90 to 90:10. Using a content ratio in the range of 5:95 to 95:5 easily improves filler properties.

[0154] The same applies to the thermally conductive filler (D). From the viewpoint of improving filling performance, it is preferable to combine two or more types with different average particle sizes. The range of average particle sizes is preferably including both 0.2 μm to 10 μm and 10 μm to 100 μm, and the content ratio (mass ratio) of each thermally conductive filler (D) is the same as that of the silica filler (C).

[0155] [Compound (E)]

[0156] The curing composition may also contain one or more compounds (E) selected from compounds containing anhydride groups, isocyanate compounds, aziridine compounds, amine compounds, phenolic compounds, and metal chelates as any component. Compound (E) may be a high molecular weight compound or a low molecular weight compound.

[0157] Compounds containing an anhydride group are compounds with an anhydride group; isocyanate compounds are compounds containing an isocyanate group; aziridine compounds are compounds with an aziridine group; amine compounds are compounds with an amino group; and phenolic compounds are compounds with a structure in which a hydroxyl group and an aromatic group (aromatic ring) are directly bonded. Chelate compounds are complexes formed by the coordination of a polydentate ligand (chelate ligand) with a metal ion.

[0158] Compound (E) acts as a catalyst for compounds with functional groups that are more readily reactive with epoxy groups, or for epoxy groups themselves, thus promoting crosslinking. As a result, adhesion or thermal cycling performance can be improved more effectively.

[0159] Relative to 100 parts by mass of the total epoxy resin, compound (E) preferably comprises 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, and even more preferably 3 to 20 parts by mass. Here, the total epoxy resin refers to the sum of epoxy resin (B) and epoxy resins not equivalent to epoxy resin (B). The total epoxy resin includes the liquid epoxy compound (F), which will be described later.

[0160] Examples of compounds containing anhydride groups include: 1,2,4,5-benzenetetracarboxylic acid dianhydride, 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, and 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c Examples of acid dianhydrides include furan-1,3-dione, ethylene glycol bis(triphenylamine) anhydride, 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride, 1,4-bis(3,4-dicarboxyphenol) phthalic anhydride, p-phenylene bis(triphenylamine) 4,4′-oxydiphthalic anhydride, 1,1′-biphenyl-2,3,3′,4′-tetracarboxylic acid 2,3:3′,4′-dianhydride, and dicyclohexyl-3,4,3′,4′-tetracarboxylic dianhydride. Additionally, copolymers such as styrene-maleic anhydride copolymer and ethylene-maleic anhydride copolymer, and modified polypropylene with acid anhydride can also be listed.

[0161] Examples of commercially available products include Rikacid (registered trademark, manufactured by Shin Nippon Rikka Co., Ltd.), Xibond (registered trademark, manufactured by POLYSCOPE POLYMERS Co., Ltd.), SMA (registered trademark) resin (manufactured by Claybury USA Co., Ltd.), and TAFMER (registered trademark, manufactured by Mitsui Chemicals Co., Ltd.).

[0162] There are no particular limitations on isocyanate compounds; examples include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates. Furthermore, multiple compounds containing isocyanate groups can be used in combination.

[0163] Examples of aromatic polyisocyanates include: 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4′-diisocyanobiphenyl, 3,3′-dimethyl-4,4′-diisocyanobiphenyl, 3,3′-dimethyl-4,4′-diisocyanodiphenylmethane, 1,5-naphthalene diisocyanate, 4,4′,4″-triphenylmethane triisocyanate, m-isocyanophenylsulfonyl isocyanate, p-isocyanophenylsulfonyl isocyanate, etc.

[0164] Examples of aliphatic polyisocyanates include: ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecanethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanomethylhexanoate, bis(2-isocyanoethyl) transbutenedioate, bis(2-isocyanoethyl) carbonate, 2-isocyanoethyl-2,6-diisocyanohexanoate, etc.

[0165] Examples of alicyclic polyisocyanates include: isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (H12-MDI), cyclohexene diisocyanate, methylcyclohexene diisocyanate (hydrogenated TDI), bis(2-isocyanoethyl)-4-cyclohexene-1,2-dicarboxylic acid ester, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate.

[0166] Additionally, examples include: trimethylolpropane adducts of diisocyanates, biuret forms that react with water, and trimers containing isocyanurate rings.

[0167] As the block-shaped isocyanate compound, any block-shaped isocyanate-containing compound protected by ε-caprolactam or methyl ethyl ketone (MEK) oxime is acceptable and is not particularly limited. Specifically, compounds formed by blocking the isocyanate groups of the isocyanate-containing compound with ε-caprolactam, MEK oxime, cyclohexanone oxime, pyrazole, phenol, etc., can be cited as examples. In particular, when a hexamethylene diisocyanate trimer having an isocyanurate ring and blocked by MEK oxime or pyrazole is used in this embodiment, the storage stability is excellent, and the adhesion strength to bonding materials such as polyimide or copper or the heat resistance of solder are excellent, so it is very preferred.

[0168] Examples of aziridine compounds include: N,N′-diphenylmethane-4,4′-bis(1-aziridine carbonyl), N,N′-toluene-2,4-bis(1-aziridine carbonyl), bis(isophthaloyl-1-(2-methylaziridine), tri-1-aziridine phosphine oxide, N,N′-hexamethylene-1,6-bis(1-aziridine carbonyl), trimethylolpropane-tri-β-aziridine propionate, tetramethylolmethane-tri-β-aziridine propionate, tri-2,4,6-(1-aziridine)-1,3,5-triazine, and trimethylolpropane-tri[3-(1-aziridine)propionate]. Trimethylolpropane tris[3-(1-aziridinyl)butyrate], Trimethylolpropane tris[3-(1-(2-methyl)aziridinyl)propionate], Trimethylolpropane tris[3-(1-aziridinyl)-2-methylpropionate], 2,2′-dihydroxymethylbutanol tris[3-(1-aziridinyl)propionate], Pentaerythritol tetra[3-(1-aziridinyl)propionate], Diphenylmethane-4,4-bis-N,N′-vinylurea, 1,6-hexamethylenebis-N,N′-vinylurea, 2,4,6-(triethyleneimino)-triazine, Bis[1-(2-ethyl)aziridinyl]benzene-1,3-carboxylic acid amide.

[0169] In particular, 2,2′-dihydroxymethylbutanol tris[3-(1-aziridinyl)propionate] can improve heat resistance while maintaining the flexibility of the hardened material, and is therefore preferred.

[0170] Examples of amine compounds include polyamines with a dimer structure, as exemplified in the monomer of polyamide resin (A), and other polyamines without a dimer structure.

[0171] There are no particular limitations on the types of phenolic compounds, but phenolic resins having two or more phenolic hydroxyl groups per molecule are preferred. Examples of such phenolic resins include: bisphenol A type phenolic resin, bisphenol F type phenolic resin, phenol aryl alkyl type phenolic resin, dicyclopentadiene type phenolic resin, triphenylmethane type phenolic resin, phenolic varnish type phenolic resin, dicyclopentadiene type phenolic resin, xylene-methyl type phenolic resin, and biphenyl type phenolic resin.

[0172] Specific examples of metal chelates include aluminum chelates, titanium chelates, and zirconium chelates. The central metal can be various metals such as iron, cobalt, and indium.

[0173] [Liquid epoxy compound (F)]

[0174] This curing composition may further contain a liquid epoxy compound (F) (hereinafter also referred to as liquid epoxy compound (F)) as an optional component, which is liquid at room temperature (25°C).

[0175] Examples of liquid epoxy compounds (F) include: bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, phenolic varnish type epoxy resin, dicyclopentadiene type epoxy resin, polyfunctional phenolic epoxy resin, naphthalene type epoxy resin, phenol aralkyl modified epoxy resin, alicyclic and alcoholic glycidyl ether epoxy resin, alicyclic and alcoholic glycidyl amine epoxy resin, and alicyclic and alcoholic glycidyl ester epoxy resin.

[0176] By using a liquid epoxy compound (F), the processability of this curing composition can be improved. Furthermore, adhesion can be improved more effectively.

[0177] In terms of easily improving the flowability of this curing composition, bisphenol F type epoxy resin or phenolic varnish type epoxy resin is preferred. Specific examples include jER806 (bisphenol F type epoxy resin, manufactured by Mitsubishi Chemical Corporation) and jER152 (phenolic varnish type epoxy resin, manufactured by Mitsubishi Chemical Corporation).

[0178] The crosslinking density can be easily adjusted using liquid epoxy compound (F). Furthermore, it acts as a binder for silica filler (C) and thermally conductive filler (D) when the curable composition is molded into sheets or granules, making molding easier.

[0179] When using liquid epoxy compound (F), the content ratio (mass ratio) of epoxy resin (B) to liquid epoxy compound (F) is preferably epoxy resin (B): liquid epoxy compound (F) = 50:50 to 95:5, and more preferably 60:40 to 90:10. In 100% by mass of the curing composition, the content of liquid epoxy compound (F) is preferably 1% to 10% by mass, more preferably 1% to 5% by mass. Setting it to 1% by mass or more improves its effect as a binder in the curing composition, and setting it to 10 parts by mass or less improves the resistance of the cured product to damp heat or thermal cycling.

[0180] [Mold Release Agent (G)]

[0181] This curing composition can then be further used with a release agent (G). Especially when molding is performed using a mold, it is preferable to add a release agent (G). By using a release agent (G), the thermoforming device's ability to peel off from the mold is improved. Examples of release agents (G) include: natural waxes, synthetic waxes such as lignite esters, higher fatty acids or their metal salts, paraffin wax, and oxidized polyethylene. Examples of natural waxes include carnauba wax and candelilla wax. Examples of synthetic waxes include paraffin wax, microcrystalline wax, Fischer-Tropsch wax, and polyethylene wax. When using a release agent (G), only one type can be used, or two or more types can be used in combination.

[0182] When using a release agent (G), its content is, for example, 0.1% to 0.5% by mass, preferably 0.2% to 0.3% by mass, out of 100% by mass of the total solids in the curing composition.

[0183] [Other fillers (H)]

[0184] The curing composition may also contain fillers (H) other than silica filler (C) and thermally conductive filler (D). Examples of other fillers (H) include flame-retardant fillers, electromagnetic shielding fillers, etc. Examples of other fillers (H) include quartz glass, talc, aluminum hydroxide, magnesium hydroxide, ferrite, etc. The preferred average particle size D of the other filler (H) is... 50 The surface treatment method is the same as that of the silica filler (C).

[0185] From the viewpoint of exhibiting other properties such as electromagnetic shielding, the content ratio (mass ratio) of silica filler (C) and thermally conductive filler (D) to other fillers is preferably 50:50 to 90:10. Specifically, the total content of silica filler (C) and thermally conductive filler (D) to other fillers relative to 100% by mass of the curing composition is preferably not more than 95% by mass.

[0186] [Any other ingredients]

[0187] The curing composition may further include additives without departing from the spirit of the invention. For example, a polyamide resin that is not equivalent to polyamide resin (A), or an epoxy resin that is not equivalent to epoxy resin (B) and liquid epoxy compound (F) may also be used. As a preferred example, an epoxy resin with a softening point of less than 50°C may be exemplified.

[0188] Alternatively, thermoplastic resins (elastomers) can be used. Other examples include: dyes, pigments (e.g., carbon black), flame retardants, antioxidants, polymerization inhibitors, defoamers, leveling agents, ion trapping agents, humectants, viscosity modifiers, preservatives, antibacterial agents, antistatic agents, antiblocking agents, ultraviolet absorbers, infrared absorbers, and electromagnetic shielding agents.

[0189] [Method for manufacturing the hardening composition]

[0190] Curable compositions are obtained by mixing the various formulation components. For example, after mixing the formulation components, melt-mixing is performed in a substantially solvent-free state, thereby obtaining a solvent-free curable composition. In this case, desired shapes such as flakes, granules, pellets, powders, and tablets can be produced. Alternatively, the composition can be amorphous solid formed by melt-mixing the formulated composition.

[0191] A sheet-like curable composition can be obtained, for example, by formulating the components of a substantially solvent-free curable composition, melt-blending it using a roller or kneader, forming the blend into sheets, and then cooling it. Melt-blending can be performed using existing mixing machines such as mixing rollers, pressure kneaders, and extruders. As for mixing conditions, the temperature is preferably above the softening point of each component, for example, 30°C to 150°C; considering the thermosetting properties of epoxy resin, it is preferably 40°C to 140°C, and even more preferably 60°C to 120°C. The time is, for example, 1 minute to 30 minutes, preferably 5 minutes to 15 minutes.

[0192] The mixing process is preferably carried out under reduced pressure, which degasses the mixture and prevents gas from entering it. The preferred pressure under reduced pressure is 0.1 kg / cm². 2 The following is more preferably 0.05 kg / cm 2 The lower limit of the pressure under decompression is not specifically limited, for example, it is 1×10.-4 kg / cm 2 above.

[0193] When plastically processing the compound to form a hardened composite sheet, the compound after melt mixing is preferably plastically processed at a high temperature without cooling. There are no particular limitations on the plastic processing method; examples include flatbed pressing, T-die extrusion, spiral die extrusion, roll forming, roll mixing, blow molding, co-extrusion, and calendering. Examples of forming machines include T-die spiral forming machines, die casting forming machines, and calendering machines. The plastic processing temperature is preferably above the softening point of each component; considering the thermosetting and formability of the epoxy resin, it is, for example, 40°C to 150°C, preferably 50°C to 140°C, and even more preferably 70°C to 130°C. Furthermore, a protective film may be laminated onto the surface of the sheet-like hardened composite. Additionally, the sheet-like hardened composite can be made into a single sheet or a roll that can be wound.

[0194] The thickness of the sheet can be adjusted appropriately according to the application, preferably 50 μm or more, and more preferably 70 μm or more. By setting it to 50 μm or more, for example in applications where it is used to seal IC chips or their surrounding wiring layers and insulating layers, it is easy to completely cover the object to be covered, and an excellent hardened material can be produced.

[0195] Alternatively, the obtained flake-shaped hardened composition can be pulverized to produce powder or granules. Furthermore, the powder or granules can be compressed into tablets.

[0196] Powdered, granular, or tablet-form hardening compositions can be directly manufactured from the mixture by melt mixing via rollers or kneaders without passing through sheets. The method can be carried out using, for example, kneaders, roller mills, super mixers, Henschel mixers, Shugi mixers, vertical granulators, high-speed mixers, farmmatrix mills, ball mills, steel mills, sand mills, vibratory mills, ultrafine grinding mills, Banbury mixers, batch mixers, twin-screw extruders, single-screw extruders, and rotor-type twin-screw mixers.

[0197] Specifically, the following methods can be listed: A method in which a molten, hardened composition is supplied to the inside of a rotating body comprising a cylindrical outer periphery with multiple small holes and a disc-shaped bottom surface, and the hardened composition is forced through the small holes by the centrifugal force obtained by rotating the rotating body; a method in which the raw material components of the hardened composition are premixed in a mixer, then heated and mixed in a mixer such as a roller, kneader, or extruder, followed by cooling and pulverizing steps to produce a pulverized material, and coarse and fine particles are removed using a sieve; a method in which the raw material components of the hardened composition are premixed in a mixer, then heated and mixed in an extruder with a die having multiple small holes at the front end of the screw, and the molten resin extruded in a rope-like manner from the small holes in the die is cut by a cutter that slides and rotates approximately parallel to the die surface.

[0198] When produced in granular form, the particle size is preferably 70 μm to 500 μm. By setting the particle size to 70 μm to 500 μm, it is easy to adjust the thickness of the hardened composition while suppressing contamination caused by powder. The particle size is determined by extracting or quantifying particles using image binarization based on microscopic observation.

[0199] Alternatively, the various formulation components can be mixed with a solvent to produce a varnish, or a hardening composition obtained by mixing the various raw material components can be dissolved or dispersed in an organic solvent to produce a varnish. The varnish is then applied and dried to obtain a sheet-like hardened composition. Examples of coating methods include coating methods using a coating machine such as a corner wheel coater or a die coater, and printing methods such as stencil printing or gravure printing.

[0200] Similarly, the sheet-like hardening composition produced by the varnish can be further pulverized into granules or powder. Furthermore, it can be shaped from granules or powder into desired forms such as tablets (granules). Alternatively, the varnish can be spray-dried to form granules or powder.

[0201] The shape of the hardening composition can be appropriately selected according to the application. For example, from the viewpoint of mold filling, granules or powder are preferred, and from the viewpoint of production, flakes are preferred.

[0202] Hardened materials and their manufacturing methods

[0203] A cured product can be obtained by hot-melting and molding the solvent-free, thermosetting curable composition of this embodiment and then subjecting it to a curing treatment. Hot-melt molding and curing treatment can be performed simultaneously, or curing treatment can be performed after hot-melt molding. Furthermore, the cured product described herein refers to a state where it has hardened to the point that it does not substantially undergo a curing reaction even with further heating. A portion of the curable composition may undergo a curing reaction during melt mixing when it is manufactured, but a state where it can harden with further heating is not included in the cured product described herein. When using the curable composition, for example, in sealing IC chips, stress relaxation occurs due to the dimer structure contained in the polyamide resin (A) during the process of softening and fluidizing the molded body by applying heat. However, the stress is dispersed longitudinally along the surface direction of the sealed body, resulting in the ability to suppress adhesion reduction, inhibit foaming, and suppress cracking. Pressure can also be applied during melt molding.

[0204] Compared to methods that involve directly coating a solvent-containing resin composition onto, for example, the wiring layer or insulating layer around an IC chip, drying it, and then curing it to obtain a hardened product, the method of hot-melting a solvent-free curable composition to form a hardened product and then heat-treating it effectively suppresses the tendency of polyamide resin (A) in the composition to exist at air interfaces. As a result, stress relaxation is fully utilized, foaming is suppressed, and a hardened product with excellent crack resistance and flexural strength is obtained. Furthermore, the solvent-free curable composition according to this embodiment promotes the uniform dispersion of polyamide resin (A) in the composition, thereby reducing the amount of moisture absorbed into the composition and improving the heat resistance of the solder after humidification of the hardened product.

[0205] The preferred thermosetting temperature is 150°C to 230°C, and the preferred heating time is 30 minutes to 180 minutes. Through heat, the epoxy resin (B), satisfying at least one of a softening point of 50°C to 120°C and a melting point of 70°C to 120°C, forms a three-dimensional cross-link to become a cured product. In addition to heat, pressure can also be applied during thermomelting. Applying heat and pressure facilitates softening and flowability. Furthermore, it promotes stress relaxation caused by the dimer structure contained in the polyamide resin (A).

[0206] When the polyamide resin (A) has reactive functional groups, it is incorporated into the three-dimensional crosslinking of the epoxy resin (B). Similarly, when liquid epoxy compounds (F) are included, these are also incorporated into the crosslinking.

[0207] The glass transition temperature (Tg) of the hardened material is preferably 100°C to 200°C, more preferably 120°C to 180°C. By setting it to this range, the thermal cycling performance is improved.

[0208] When the curable composition of this embodiment is in sheet form, for example, the sheet is placed on a semiconductor chip, melted and formed by hot pressing, and then cured, thereby obtaining an IC package in which the cured material, which functions as a sealing resin, is coated on the semiconductor chip. Alternatively, when the curable composition of this embodiment is in tablet form, for example, the tablet can be melted and injected into a mold on which a semiconductor chip is disposed, and after a forming step and a curing step, an IC package in which the cured material of the curable composition serves as a sealing resin is obtained.

[0209] Furthermore, besides the method using a solvent-free curing composition as in this invention, there are methods that obtain a cured product by directly applying a solvent-containing varnish-like curing composition to a semiconductor chip or electronic component and then curing it. In terms of manufacturing via direct application, the processability is excellent. However, if a solvent is included during the thermosetting of the molded body, porosity can sometimes occur, reducing reliability. Additionally, delamination can sometimes occur between the substrate and the cured product due to porosity. Furthermore, orientation components tend to be concentrated at air interfaces, reducing the uniformity of the composition.

[0210] On the other hand, according to this embodiment, compared to the method of directly applying a solvent-containing varnish to, for example, the wiring layer or insulating layer of an IC chip or its surroundings, drying it, and obtaining a cured product through a curing process, it can effectively prevent the polyamide resin (A) from being present at the air interface, etc. Furthermore, the curable composition according to this embodiment, obtained by hot-melting and molding the curable composition and then performing a curing process, exhibits excellent adhesion and resistance to damp heat even after thermal cycling. This is believed to be because hot melting promotes a microphase separation structure in which a polyamide resin (A) phase with a soft dimer structure is contained within a hard epoxy resin (B) phase; through this microphase separation structure, a stress relaxation effect can be obtained. Furthermore, it is believed that because the microphase separation structure obtained in this manner is stabilized by thermal crosslinking, structural stability can be achieved even under harsh thermal conditions. From the viewpoint of further promoting the microphase separation structure, when manufacturing a solvent-free curable composition, compared to manufacturing it from a solvent-containing varnish, a method of mixing the components without using a solvent, melt-blending them, and molding them as needed is preferred. It is also excellent in terms of minimizing the use of solvent.

[0211] [Example]

[0212] The present invention will be described in more detail below, but the following embodiments do not limit the scope of the claims. Furthermore, in the embodiments, "parts" means "parts by mass," and "%" means "% by mass." The mixing amounts in the table are parts by mass.

[0213] <Determination of Acid Value>

[0214] Accurately weigh approximately 1 g of the sample into a stoppered Erlenmeyer flask and dissolve it in 100 mL of cyclohexanone solvent. Add phenolphthalein indicator and maintain for 30 seconds. Then, titrate with 0.1 N alcoholic potassium hydroxide solution until the solution turns pale pink. The acid value can be calculated using the following formula (unit: mg KOH / g).

[0215] Acid value (mgKOH / g) = (5.611 × a × F) / S

[0216] in,

[0217] S: Sample volume (g)

[0218] a: Volume (mL) of 0.1N alcoholic potassium hydroxide solution consumed.

[0219] F: Potassium hydroxide solution of 0.1N alcoholic form

[0220] <Determination of Amine Value>

[0221] Precisely weigh approximately 1 g of the sample into a stoppered Erlenmeyer flask and dissolve it in 100 mL of cyclohexanone solvent. Add 2-3 drops of indicator and maintain for 30 seconds. The indicator is prepared separately by mixing a solution of 0.20 g of methyl orange dissolved in 50 mL of distilled water and a solution of 0.28 g of xylene cyanol FF dissolved in 50 mL of methanol. Then, titrate with 0.1 N alcoholic hydrochloric acid solution until the solution turns blue-gray. The amine value can be determined by the following formula (unit: mg KOH / g).

[0222] Amine value (mgKOH / g) = (5.611 × a × F) / S

[0223] in,

[0224] S: Sample volume (g)

[0225] a: Volume (mL) of 0.1N alcoholic hydrochloric acid solution consumed.

[0226] F: Potency of 0.1N alcoholic hydrochloric acid solution

[0227] <Method for determining weight-average molecular weight (Mw)>

[0228] The determination of molecular weight (Mw) was performed using a gel permeation chromatography (GPC-101) instrument manufactured by Showa Denko Corporation. GPC is a liquid chromatograph used to separate and quantify substances dissolved in a solvent (THF (Tetrahydrofuran)) based on differences in their molecular size. In this invention, two KF-805L columns (manufactured by Showa Denko Corporation: GPC columns, 8mm ID × 300mm size) were connected in series. The determination was performed at a sample concentration of 1% by mass, a flow rate of 1.0 mL / min, a pressure of 3.8 MPa, and a column temperature of 40°C. The weight-average molecular weight (Mw) was determined by conversion using polystyrene. Data analysis was performed using the manufacturer's built-in software to calculate the calibration curve, molecular weight, and peak area. The weight-average molecular weight was calculated using a retention time range of 17.9 minutes to 30.0 minutes.

[0229] <Method for determining the glass transition temperature of polyamide resin (A)>

[0230] Polyamide resin was dissolved in cyclohexanone to make the non-volatile component 35%, thus preparing a polyamide resin varnish. The varnish was applied to a heat-resistant release film using a 10 μm blade and dried at 130°C for 10 min to obtain a 25 μm thick polyamide resin film, which was used as a sample for glass transition temperature determination. The glass transition temperature was determined by measuring Tanδ using a dynamic viscoelasticity measuring device within a temperature range of -50°C to 200°C.

[0231] Dynamic viscoelasticity measuring device: DVA-200 (manufactured by IT Measurement & Control Company)

[0232] Heating rate: 10℃ / min

[0233] Measurement frequency: 10Hz

[0234] Length between chucks: 15mm

[0235] Width: 5mm

[0236] Synthesis of Polyamide Resins

[0237] [Polyamide resin (A-1)]

[0238] In a four-necked flask including a stirrer, a reflux cooling tube with a Dean-Stark apparatus, a nitrogen inlet tube, and a thermometer, 1075481.0 g (0.901 mol) of primamine (a 36-carbon dimer), 187.5 g (0.938 mol) of 3,4′-diaminodiphenyl ether (another diamine), 139.1 g (0.952 mol) of adipic acid (a polyacid), and 192.4 g (0.952 mol) of sebacic acid (a polyacid) were added and stirred. After heating ceased, the reaction was slowly induced. While removing water generated during the reaction, the internal temperature was raised to 230°C and maintained at this temperature for 4 hours. Then, the reaction was stopped by maintaining the same temperature under reduced pressure of approximately 2 kPa for 2 hours. A polyamide resin (A-1) with a weight average molecular weight of 30,000, an acid value of 11.4 mgKOH / g, an amine value of 0.2 mgKOH / g, and a Tg of 21℃ was obtained. Furthermore, the total content of the dimer diamine and dimer acid constituting the polyamide resin (A) was 48.1% by mass.

[0239] [Polyamide resin (A-2~A-13)]

[0240] Polyamide resin was synthesized using the same method as polyamide resin (A-1), according to the composition and mass parts specified in Table 1. Its characteristic values ​​are shown in Table 1.

[0241] [Polyamide resin (A-14)]

[0242] In a four-necked flask including a stirrer, a reflux cooling tube with a Dean-Stark apparatus, a nitrogen inlet tube, and a thermometer, 1075672.6 g (1.26 mol) of primamine (a 36-carbon dimer), 59.1 g (0.295 mol) of 3,4′-diaminodiphenyl ether (another diamine), 194.5 g (1.33 mol) of adipic acid (a polyacid), and 59.1 g (0.292 mol) of sebacic acid (a polyacid) were added and stirred. After heating ceased, the reaction was slowly induced. While removing water generated during the reaction, the internal temperature was raised to 230°C and maintained at this temperature for 4 hours. Then, the reaction was carried out at the same temperature under reduced pressure of approximately 2 kPa for 2 hours. Then, the internal temperature was lowered to 180℃, 14.7g (0.137mol) of benzylamine was added, and the temperature was slowly increased to 240℃ to stop the reaction. A polyamide resin (A-14) with a weight average molecular weight of 30,000, an acid value of 0.5mgKOH / g, an amine value of 0.6mgKOH / g, and a Tg of 26℃ was obtained.

[0243] The abbreviations of Table 1 are shown below.

[0244] DA: A 36-carbon dimer diamine with a 6-carbon ring structure (dimer ratio: ≥95%, amine value: 210 mg KOH / g, "Priamine 1075", manufactured by Croda Japan).

[0245] Dacid: A 36-carbon dimer acid with a 6-carbon ring structure (dimer ratio: over 95%, acid value: 197 mg KOH / g, "Pripol 1009", manufactured by Croda Japan).

[0246] DAPE: 3,4′-Diaminodiphenyl ether

[0247] AdA: Adipic acid

[0248] SeA: Sebacic acid

[0249] 5-HIP: 5-hydroxyisophthalic acid

[0250] [Table 1]

[0251]

[0252] [Example 1]

[0253] According to the mixing ratio in Table 2, mix the components and then mix them in a mixer at 100℃ under reduced pressure (0.01 kg / cm³). 2 The mixture was melt-blended for 10 minutes to prepare a compound. Then, the obtained compound was pressed into a sheet-like hardening composition with a thickness of 300 μm using a plate pressing method.

[0254] [Examples 2-35], [Comparative Examples 1-3]

[0255] Using the same method as in Example 1, as shown in Tables 2 to 4, sheet-like hardening compositions were prepared using the same method as in Example 1.

[0256] [Comparative Example 4]

[0257] 270 parts of cyclohexanone were placed in a flask including a stirrer, a reflux cooling pipe, a nitrogen inlet pipe, and a thermometer. 30 parts of the polyamide resin (A-3) obtained in Synthesis Example 3 were added, and the mixture was heated to 140°C while stirring until a homogeneous solution was obtained, yielding a polyamide resin (A-3) solution (varnish). 799 parts of silica filler (C-1) were added to the polyamide resin (A-3) solution, and the silica filler (C-1) was dispersed using a stirring blade. 120 parts of phenolic aralkyl epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) NC-3000 (as epoxy resin (B)), 50 parts of triphenylmethane phenolic resin (manufactured by Meiwa Kasei Co., Ltd.) MEH-7500 (as compound (E)), and 1 part of a curing catalyst (2P4MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) were added to the dispersion, and the mixture was stirred. The dissolution was visually confirmed, and the mixture was stirred for 30 minutes. The dispersion was filtered through a nylon #200 mesh (75 μm opening) to prepare a varnish-like polyamide resin composition. The varnish-like polyamide resin composition was coated onto a support (38 μm thick release-treated polyethylene terephthalate) using a 6 mil doctor blade to prepare a 50 μm thick sheet of curable composition. Drying conditions included heating at 80°C for 2 minutes followed by heating at 120°C for 5 minutes. The release film of the 50 μm sheet of curable composition was peeled off, and the sheets were overlapped using a laminator to prepare a 100 μm sheet of curable composition. This process was repeated to prepare a 300 μm sheet of curable composition. The solvent content of the sheet of curable composition was 1.5% by mass.

[0258] [Comparative Example 5]

[0259] Except that the silica filler (C-1) was replaced with a thermally conductive filler (D-1), the sheet-like curable composition of Comparative Example 5 was manufactured using the same method as Comparative Example 4. Furthermore, the solvent content of the sheet-like curable composition was 1.4% by mass.

[0260] Details of the materials used in the embodiments and comparative examples are shown below.

[0261] • Epoxy resin (B) that meets at least one of the following conditions: softening point of 50℃~120℃ and melting point of 70℃~120℃.

[0262] B-1: Softening point 54℃, triphenol methane type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., EPPN-501H, EPW (epoxy equivalent) = 167.

[0263] B-2: Softening point 58℃, phenolic alkyl type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., NC-3000, EPW=275.

[0264] B-3: Softening point 65℃, phenol-modified xylene resin type epoxy resin, manufactured by Mitsubishi Chemical Corporation, YX7700, EPW=270.

[0265] B-4: Softening point 73℃, dicyclopentadiene type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., XD-1000, EPW=253.

[0266] B-5: Melting point 105℃, biphenyl type epoxy resin, manufactured by Mitsubishi Chemical Corporation, YX4000HK, EPW=185.

[0267] B-6: Softening point 90℃, tetraphenol ethane type epoxy resin, manufactured by Mitsubishi Chemical Corporation, jER1031S, EPW=200.

[0268] B-7: Softening point 80℃, naphthalene-type epoxy resin, manufactured by DIC, HP-6000, EPW=250.

[0269] B-8: Softening point 88℃, naphthalene-containing phenolic varnish-type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., NC-7000L, EPW=231.

[0270] • Silica filler (C)

[0271] C-1: Spherical silica (manufactured by Admatechs, SO-E5, average particle size 1.5μm, specific surface area 4m²) 2 / g)

[0272] C-2: Molten spherical silica (manufactured by Denka, FB-105FC, average particle size d50: 12μm)

[0273] C-3: Molten spherical silica (manufactured by Admatechs, SO-25R, average particle size d50: 0.5μm)

[0274] C-4: Molten spherical silica (manufactured by Denka, FB-950FC, average particle size d50: 22μm)

[0275] Thermally conductive filler (D)

[0276] D-1: Molten spherical alumina (manufactured by Denka Corporation, DAW-01, average particle size d50: 1.9 μm)

[0277] D-2: Molten spherical alumina (manufactured by Denka, DAW-10, average particle size d50: 12 μm)

[0278] D-3: Boron nitride (manufactured by Denka Corporation, MGP, average particle size d50: 10 μm)

[0279] Compound (E)

[0280] E-1: Triphenylmethane-type phenolic resin, manufactured by Meiwa Chemical Co., Ltd., MEH-7500, OH equivalent = 97 g / eq.

[0281] E-2: Xylene-based phenolic resin, manufactured by Meiwa Chemical Co., Ltd., MEHC-7800-SS, OH equivalent = 173 g / eq.

[0282] • Liquid epoxy compound (F) that is liquid at 25°C

[0283] F-1: Liquid at 25℃, bisphenol F type epoxy resin, JER806, manufactured by Mitsubishi Chemical Corporation, EPW=160

[0284] Other additives: hardening catalyst (imidazole)

[0285] J-1: Imidazole compound (2P4MZ, manufactured by Shikoku Chemical Industry Co., Ltd.)

[0286] <Method for determining softening point>

[0287] The softening point was determined according to JIS K-2207 using the ring and ball method. Specifically, the sample was filled into a specified ring, horizontally supported in a water or glycerol bath, and a specified ball was placed in the center of the sample. The bath temperature was increased at a rate of 5°C / min, and the temperature at which the sample encasing the ball contacted the bottom plate of the ring was defined as the softening point.

[0288] [Table 2]

[0289]

[0290]

[0291]

[0292] The cured products of the curable compositions of each embodiment and comparative example are shown in Table 5, with evaluation results of Tg, resistance to damp heat before and after thermal cycling tests, and adhesion. The test methods and evaluation criteria are as described below.

[0293] <Method for determining the glass transition temperature (Tg) of hardened materials>

[0294] A 300 μm sheet-like curable composition, prepared using the same method as in Example 1, was heat-cured on a heat-resistant release film at 180°C for 60 minutes to prepare a sample for glass transition temperature determination. The glass transition temperature was determined by measuring Tanδ using a dynamic viscoelasticity measuring device within a temperature range of -50°C to 200°C.

[0295] Dynamic viscoelasticity measuring device: DVA-200 (manufactured by IT Measurement & Control Company)

[0296] Heating rate: 10℃ / min

[0297] Measurement frequency: 10Hz

[0298] Length between chucks: 15mm

[0299] Width: 5mm

[0300] <Evaluation of resistance to damp heat>

[0301] A 300μm sheet of curable composition was temporarily bonded using a laminator, with a 50μm polyimide film (Kapton 200EN) clamping it. The temperature was set to 90°C and the cylinder pressure to 0.3MPa. After hot lamination, hot pressing (150°C × 1MPa × 2min) was performed, followed by post-baking (170°C × 2h) to obtain a cured product. The cured product was cut into strips 10mm wide and 120mm long to obtain samples for damp heat resistance testing. The samples were subjected to moisture absorption at 40°C and 80% RH for 24 hours, then heated in a molten solder bath (260°C) for 10 seconds. The appearance of the samples was visually evaluated. The evaluation criteria are as described below.

[0302] 5: Excellent (no foaming and / or cracking was found in the samples used in the damp heat resistance test).

[0303] 4: Superior (1 to 3 instances of foaming and / or cracking in samples used for damp heat resistance testing)

[0304] 3: Excellent (4 to 5 instances of foaming and / or cracking in the sample used for damp heat resistance test)

[0305] 2: Practical (6 to 10 instances of foaming and / or cracking in the sample used in the damp heat resistance test)

[0306] 1: Unusable (peeling was found between the polyimide films of the samples used in the damp heat resistance test).

[0307] <Resistance to damp heat after thermal cycling>

[0308] Prepare the samples for the damp heat resistance test, conduct the following temperature cycling test, and then perform the damp heat resistance test. The evaluation criteria are the same as described above.

[0309] Thermal cycling test chamber: TSE-11 (manufactured by ESPEC)

[0310] Test temperatures: -40℃ and 150℃

[0311] Exposure time: 30 minutes at all temperatures.

[0312] Test cycles: 500 cycles

[0313] <Continuing the Force>

[0314] A 50mm × 50mm sheet of curable composition was cut from the prepared sheet. Nine 5mm × 5mm × 300μm silicon chips with an Au-plated layer were then arranged on the sheet in three rows vertically and three rows horizontally, with equal spacing. The sheet of curable composition was positioned to contact the silicon surface of the silicon chip. To ensure a tight bond between the sheet of curable composition and the silicon chip, 38μm pieces of polyethylene terephthalate (PET) that had undergone silicone demolding were placed face-to-face and heat-laminated using a heat lamination test apparatus (temperature 80°C, cylinder pressure 0.3MPa). After heat lamination, slits were cut around the silicon chip using a dicing tool to create an adhesion test sample with the sheet of curable composition temporarily attached to one side of the silicon chip.

[0315] As the substrate, a gold-plated copper frame substrate is prepared, on which a silicon chip with a sheet-like curable composition is temporarily attached. The substrate is then hot-pressed (150°C × 1 MPa × 2 min) and then baked (170°C × 2 h) to prepare a sample for adhesion testing.

[0316] The bonding of the silicon chip to a copper frame substrate was evaluated using a bond tester (manufactured by Nordson Advanced Technology, product name: Dage 4000-PXY). The test conditions were a test speed of 100 μm / s and a test height of 100 μm. The arithmetic mean of the adhesion force measured at three points is shown in Table 2. A higher value indicates better adhesion of the cured material to both the silicon chip and the substrate. The evaluation criteria are as follows.

[0317] 5: Excellent (adhesion strength is above 10 N / mm).

[0318] 4: Superior (adhesion force is above 7N / mm and less than 10N / mm).

[0319] 3: Excellent (adhesive strength is 5N / mm or more and less than 7N / mm).

[0320] 2: Practicable (adhesive strength is 3N / mm or more and less than 5N / mm).

[0321] 1: Impracticable (adhesive strength is less than 3N / mm).

[0322] <Adhesive strength after thermal cycling>

[0323] Prepare the sample for said adhesive strength test, conduct the following temperature cycling test, and then implement said adhesive strength test. The evaluation criteria are the same as described above.

[0324] Thermal cycling tester: TSE-11 (manufactured by ESPEC)

[0325] Test temperature: -40°C and 150°C

[0326] Exposure time: 30 minutes at each temperature

[0327] Test cycles: 500 cycles

[0328] [Table 5]

[0329] Table 5

[0330]

[0331] As shown in Table 5, it was confirmed that the cured product obtained from the curable composition of the present example is excellent in humidity heat resistance and adhesiveness before and after thermal cycling.

[0332] The evaluation results of scanning electron microscope (Scanning Electron Microscope, SEM) observation, flexural strength, and the results of humidity heat resistance and adhesiveness before and after thermal cycling are shown in Table 6. The evaluation criteria for SEM observation and the measurement method for flexural strength are as described below.

[0333] <SEM Observation>

[0334] The sheet-shaped curable compositions obtained in Example 2, Example 33, Comparative Example 4, and Comparative Example 5 were thermally cured on a heat-resistant release film under the conditions of 180°C for 60 minutes. A cross-section in the thickness direction of the obtained cured composition is formed using a cross section polisher, and used as a sample for SEM observation. Then, the cross-section is observed at a magnification of 1500 times using a scanning electron microscope (SEM S-4300, manufactured by Hitachi, Ltd.). The evaluation criteria are as described below.

[0335] ○: Microphase separation is observed.

[0336] ×: No microphase separation was observed.

[0337] <Bending Strength>

[0338] The obtained resin composition was fed into an injection molding machine (manufactured by Toshiba Machine Co., Ltd.) and molded into a strip test piece at a temperature of 190°C. The strip test piece conformed to the specifications of type B2 (80mm long × 10mm wide × 4mm thick) as described in JISK 7139. The bending strength of the prepared strip test piece was determined using a fully automatic bending testing machine, Bend Graph II (manufactured by Toyo Seiki Co., Ltd.), according to JISK 7171. The bending strength was calculated based on the bending stress σ obtained using a three-point bending test. With the bending load F (unit: N), the distance between the support points L (unit: mm), the test piece width b (unit: mm), and the test piece thickness h (unit: mm), the bending stress σ was (3 × F × L) / (2 × b × h × h). The bending stress σmax at which the bending load F exhibited its maximum value was taken as the bending strength (unit: N / mm). 2 =MPa). The higher the bending strength, the greater the rigidity, and the more difficult it is to deform when a load is applied to the formed object.

[0339] [Table 6]

[0340] Table 6

[0341]

[0342] As shown in Example 2, microphase separation was observed in the cured product manufactured from the solvent-free curing composition of this example. Furthermore, as shown in Example 2 and Comparative Example 4, it was confirmed that the cured product of this example exhibited superior flexural strength compared to the cured product manufactured from the varnish-like curing composition. Additionally, it was confirmed that superior results were obtained in terms of resistance to damp heat and adhesion before and after thermal cycling.

[0343] [[Industry availability]]

[0344] The curable composition according to this embodiment exhibits excellent adhesion and resistance to damp heat even after thermal cycling, making it preferably suitable as an insulating resin material, such as a sealant, adhesive, underfill, or potting compound for semiconductor chips. Furthermore, it possesses excellent flexural strength, making it particularly preferred for insulating resin materials used in thin film applications. Additionally, it exhibits excellent adhesion to metals, making it preferred for applications such as copper-clad laminates, bonding sheets for wiring board formation, and surface coatings for flexible substrates.

Claims

1. A solvent-free curable composition, which is a melt-forming curable composition exhibiting thermosetting properties. The product comprises at least one of a polyamide resin (A) having a dimer structure derived from at least one of a dimer acid and a dimer diamine, an epoxy resin (B), a silica filler (C), and a thermally conductive filler (D). In the polymerization of polyamide resin (A), the total input rate of the dimer acid and dimer diamine is set to 50% to 100% by mass of all monomers used. Epoxy resin (B) satisfies at least one of the following: a softening point of 50°C to 120°C and a melting point of 70°C to 120°C. The polyamide resin (A) comprises more than 0.3% by mass of the non-volatile components of the curing composition, relative to 100% by mass. In 100% by mass of the curing composition, the epoxy resin (B) contains 5% to 30% by mass. Relative to 100 parts by weight of the non-volatile component of the curing composition, the total amount of the silica filler (C) and the thermally conductive filler (D) is 40 parts by weight or more and 95 parts by weight or less. The mass ratio of the polyamide resin (A) to the epoxy resin (B) is 10:90 to 30:

70.

2. The solvent-free curable composition according to claim 1, wherein the glass transition temperature of the polyamide resin (A) is 0°C to 90°C.

3. The solvent-free curable composition according to claim 1 or 2, wherein the polyamide resin (A) has a weight average molecular weight of 15,000 to 100,000.

4. The solvent-free curable composition according to claim 1 or 2, further comprising one or more compounds (E) selected from compounds containing anhydride groups, isocyanate compounds, aziridine compounds, amine compounds, phenolic compounds and metal chelates.

5. The solvent-free curable composition according to claim 1 or 2, further comprising a liquid epoxy compound (F).

6. The solvent-free curable composition according to claim 1 or 2, in the form of flakes, powder, granules or tablets.

7. A hardened material is formed by hot melting and hardening a solvent-free hardening composition as described in any one of claims 1 to 6.

8. The hardened material according to claim 7, wherein the glass transition temperature is 100°C to 200°C.

9. A method for manufacturing a curable, comprising the steps of forming a solvent-free curable composition by hot melting and then thermosetting the solvent-free curable composition, said solvent-free curable composition exhibiting thermosetting properties, comprising a polyamide resin (A) having a dimer structure derived from at least one of a dimer acid and a dimer diamine, an epoxy resin (B), and at least one of a silica filler (C) and a thermally conductive filler (D). In 100% by mass of all monomers constituting polyamide resin (A), the total content of the dimer acid and dimer diamine is 50% to 100% by mass. Epoxy resin (B) satisfies at least one of the following: a softening point of 50°C to 120°C and a melting point of 70°C to 120°C. The polyamide resin (A) comprises more than 0.3% by mass of the non-volatile components of the curing composition, relative to 100% by mass. In 100% by mass of the curing composition, the epoxy resin (B) contains 5% to 30% by mass. Relative to 100 parts by weight of the non-volatile component of the curing composition, the total amount of the silica filler (C) and the thermally conductive filler (D) is 40 parts by weight or more and 95 parts by weight or less. The mass ratio of the polyamide resin (A) to the epoxy resin (B) is 10:90 to 30:70.

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