Resin composition, resin sheet, multilayer body, and semiconductor element

Abstract

The present invention provides a resin composition, a resin sheet, a multilayer body, and a semiconductor element. The resin composition according to the present disclosure comprises a polyfunctional cyanate compound (A), a polyfunctional epoxy compound (B), and a thermally-conductive filler (C). The polyfunctional cyanate compound (A) contains a compound represented by formula (IS1) and / or a prepolymer of the compound represented by formula (IS1).

Description

Resin composition, resin sheet, multilayer body, and semiconductor element

[0001] The present invention relates to a resin composition, a resin sheet, a multilayer body, and a semiconductor element.

[0002] In recent years, the heat generation density inside electronic devices has been increasing year by year due to the increasing speed and integration of circuits in electrical or electronic devices and the increasing mounting density of electronic components on printed wiring boards. Therefore, there is a demand for components with high thermal conductivity and electrical insulation properties that can efficiently dissipate heat generated by electronic components, etc. Patent Document 1 discloses a thermally conductive sheet comprising a resin composition layer made of a thermosetting resin composition containing an epoxy resin (A), a curing agent (B), and a thermally conductive filler (C), where the epoxy resin (A) contains an epoxy resin (A1) having a triaryltriazine skeleton, and the curing agent (B) contains a cyanate ester resin (B1). Furthermore, Patent Document 2 discloses a resin sheet made of a thermosetting resin composition comprising an epoxy resin (A), a curing agent (B), and thermally conductive particles (C), wherein the epoxy resin (A) contains a mesogenic skeleton and has a softening point of 60°C or lower, and wherein a cured product of the thermosetting resin composition has a thermal conductivity λ200 at 200°C of 12.0 W / (m·K) or higher.

[0003] JP 2024-51867 A International Publication No. 2021 / 172387

[0004] As described above, resin compositions with excellent thermal conductivity and resin sheets using the same have been investigated. However, there are cases where high peel strength is required, such as when the resin is applied to the surface of a metal substrate. The present invention aims to solve this problem and provides a resin composition capable of providing a resin sheet with excellent thermal conductivity and high peel strength against a metal substrate, as well as a resin sheet, a multilayer body, and a semiconductor element.

[0005] In light of the above-mentioned problems, the present inventors have conducted research and found that the above-mentioned problems can be solved by preparing a resin composition using a predetermined cyanate compound, an epoxy compound, and a thermally conductive filler. Specifically, the above-mentioned problems have been solved by the following means. [1] A resin composition comprising a polyfunctional cyanate compound (A), a polyfunctional epoxy compound (B), and a thermally conductive filler (C), wherein the polyfunctional cyanate compound (A) comprises a compound represented by formula (IS1) and / or a prepolymer of the compound represented by formula (IS1). Formula (IS1) [2] The resin composition according to [1], further comprising a curing catalyst (D), wherein the curing catalyst (D) comprises a metal catalyst. [3] The resin composition according to [1] or [2], further comprising a curing catalyst (D), wherein the curing catalyst (D) comprises a metal catalyst containing at least one selected from the group consisting of zinc, copper, aluminum, tin, iron, manganese, and cobalt. [4] The resin composition according to any one of [1] to [3], wherein the polyfunctional epoxy compound (B) comprises a compound represented by formula (EP): Formula (EP) (In formula (EP), each Ar is independently a phenylene group or a naphthylene group, and X is an alkylene group, an ether group, a sulfonyl group, a phenylene group, a naphthylene group, or a divalent group consisting of a combination of two or more of the above groups (with the proviso that the group adjacent to the ether group is not an ether group).) [5] The resin composition according to any one of [1] to [4], wherein the polyfunctional epoxy compound (B) comprises at least one selected from the group consisting of a bisphenol-type epoxy resin, a biphenyl-type epoxy resin, a naphthalene-type epoxy resin, and a phenoxy resin containing an epoxy group. [6] The resin composition according to any one of [1] to [5], wherein the polyfunctional epoxy compound (B) comprises at least one selected from the group consisting of compounds represented by formulas (EP1) to (EP4). Formula (EP1) (In formula (EP1), R ２ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP2), R３ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP3), R ４ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.) Formula (EP4) (In formula (EP4), A represents a single bond, an ether group, a methylene group, or a divalent group formed by combining two or more of these groups; R ５ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.) [7] The resin composition according to any one of [1] to [6], wherein the thermally conductive filler (C) comprises a boron nitride aggregate. [8] The resin composition according to [1], further comprising a curing catalyst (D), wherein the curing catalyst (D) comprises a metal catalyst containing at least one selected from the group consisting of zinc, copper, aluminum, tin, iron, manganese, and cobalt, wherein the polyfunctional epoxy compound (B) comprises at least one selected from the group consisting of compounds represented by formulas (EP1) to (EP4), and wherein the thermally conductive filler (C) comprises a boron nitride aggregate. Formula (EP1) (In formula (EP1), R ２ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP2), R ３ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP3), R ４ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.) Formula (EP4) (In formula (EP4), A represents a single bond, an ether group, a methylene group, or a divalent group formed by combining two or more of these groups; R ５ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.) [9] A resin sheet formed from the resin composition according to any one of [1] to [8].

[10] A multilayer body having a metal substrate and the resin sheet according to [9] provided on the metal substrate.

[11] A multilayer body having a metal substrate, the resin sheet according to [9] provided on the metal substrate, and a heat spreader provided on the resin sheet.

[12] A semiconductor element having the multilayer body according to

[10] or

[11] .

[0006] According to the present invention, it is possible to provide a resin composition capable of providing a resin sheet having excellent thermal conductivity and high peel strength against a metal substrate, as well as a resin sheet, a multilayer body, and a semiconductor element.

[0007] Hereinafter, a detailed description of an embodiment of the present invention (hereinafter simply referred to as "the present embodiment") will be given. Note that the following present embodiment is an example for explaining the present invention, and the present invention is not limited to this embodiment. In this specification, the term "to" is used to mean that the numerical values ​​before and after it are included as the upper and lower limits. "A to B" means that the range is A or greater and B or less. Furthermore, any combination of the upper and lower limit values ​​of numerical values ​​in this specification is included as an example of this embodiment. In this specification, various physical property values ​​and characteristic values ​​are those at 23°C unless otherwise specified. In this specification, when a group (atomic group) is described without specifying whether it is substituted or unsubstituted, it encompasses both a group (atomic group) that has no substituent and a group (atomic group) that has a substituent. For example, the term "alkyl group" encompasses not only an alkyl group that has no substituent (unsubstituted alkyl group) but also an alkyl group that has a substituent (substituted alkyl group). In this specification, when a group is described without specifying whether it is substituted or unsubstituted, it is preferred that it be unsubstituted. Examples of the substituent herein are preferably a halogen atom, a cyano group, a nitro group, a hydroxy group, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a heterocyclic group, a heterocyclicoxy group, an alkenyl group, an alkylsulfanyl group, an arylsulfanyl group, an acyl group, or an amino group, more preferably a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkenyl group, or an acyl group, even more preferably an alkyl group, an aryl group, an aryloxy group, or an alkenyl group, and still more preferably an alkyl group. The formula weight of these substituents is preferably 15 or more, and preferably 200 or less. The formula weight is, for example, the formula weight of a methyl group (-CH ３ ) is 15. These substituents may further have a substituent, but it is preferable that they have no substituent.

[0008] In this specification, unless otherwise specified, the weight average molecular weight and number average molecular weight are polystyrene-equivalent values ​​measured by GPC (gel permeation chromatography). In this specification, the term "sheet" refers to a generally flat molded body that is thin relative to its length and width, and also includes films. Furthermore, the term "sheet" in this specification may be single-layer or multi-layer. If the measurement methods, etc. described in the standards shown in this specification vary from year to year, they shall be based on the standards as of January 1, 2024, unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification are discontinued as of January 1, 2024, they shall be based on the standards at the time of discontinuation.

[0009] The resin solid content in this embodiment means components other than the thermally conductive filler (C) contained in the resin composition and the solvent blended as necessary, and is intended to include the polyfunctional cyanate compound (A), the polyfunctional epoxy compound (B), the curing catalyst (D), etc.

[0010] <Resin Composition> The resin composition of this embodiment contains a polyfunctional cyanate compound (A), a polyfunctional epoxy compound (B), and a thermally conductive filler (C), and is characterized in that the polyfunctional cyanate compound (A) contains a compound represented by formula (IS1) and / or a prepolymer of the compound represented by formula (IS1).

[0011] These characteristics result in a resin composition capable of providing a resin sheet with excellent thermal conductivity and high peel strength against metal substrates. In this embodiment, the cyanate groups in the compound represented by formula (IS1) and / or the prepolymer of the compound represented by formula (IS1) (hereinafter, sometimes referred to as "the compound represented by formula (IS1) or the like") react with each other under heat to form a triazine ring, and the triazine ring reacts with the polyfunctional epoxy compound (B) to form a sufficiently cured film, which is presumed to impart good thermal conductivity to the resulting resin sheet. Meanwhile, it is presumed that by thoroughly mixing the polyfunctional epoxy compound (B) with the thermally conductive filler (C), a thermally conductive path is formed within the resin sheet. Furthermore, the compound represented by formula (IS1) or the like is liquid at room temperature and can be cured with high adhesion when in contact with metal (e.g., metal foil, metal substrate, etc.).

[0012] Hereinafter, the embodiments of the present invention will be described in detail. However, the explanation of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to these contents.

[0013] <Polyfunctional cyanate compound (A)> The resin composition of this embodiment contains a polyfunctional cyanate compound (A). The polyfunctional cyanate compound (A) is usually a polyfunctional cyanate resin. The polyfunctional cyanate compound (A) is usually a thermosetting resin. The polyfunctional cyanate compound (A) preferably contains a compound represented by formula (IS1) and / or a prepolymer of the compound represented by formula (IS1), and further contains a compound represented by formula (IS1). Formula (IS1)

[0014] Examples of the prepolymer of the compound represented by formula (IS1) include dimers to pentamers of the compound represented by formula (IS1), with dimers to tetramers being preferred, dimers and / or trimers being more preferred, and dimers being even more preferred. In this embodiment, out of a total of 100 parts by mass of the compound represented by formula (IS1) and / or the prepolymer of the compound represented by formula (IS1), the compound represented by formula (IS1) preferably accounts for 90 parts by mass or more, more preferably 95 parts by mass or more, and even more preferably 99 parts by mass or more, and is 100 parts by mass or less.

[0015] The total content of the compound represented by formula (IS1) and / or the prepolymer of the compound represented by formula (IS1) contained in the resin composition of this embodiment is preferably 30 parts by mass or more, more preferably 45 parts by mass or more, even more preferably 60 parts by mass or more, even more preferably 75 parts by mass or more, even more preferably 85 parts by mass or more, even more preferably 90 parts by mass or more, particularly preferably 95 parts by mass or more, and preferably 100 parts by mass or less, relative to 100 parts by mass of the polyfunctional cyanate compound (A) contained in the resin composition. By setting the content to the above lower limit or more, the adhesion of the resulting resin sheet to metals (e.g., metal foil, metal substrate, etc.) tends to be further improved. The resin composition of this embodiment may contain only one type of compound represented by formula (IS1), etc., or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

[0016] The resin composition of the present embodiment may or may not contain one or more polyfunctional cyanate compounds (A) other than the compound represented by formula (IS1). The polyfunctional cyanate compound (A) other than the compound represented by formula (IS1) is not particularly limited as long as it is a bifunctional or higher functional cyanate compound other than the compound represented by formula (IS1). However, difunctional to octafunctional cyanate compounds are preferred, difunctional to octafunctional cyanate compounds are more preferred, difunctional to hexafunctional cyanate compounds are even more preferred, and difunctional to tetrafunctional cyanate compounds are even more preferred.

[0017] As the polyfunctional cyanate compound (A) other than the compound represented by formula (IS1), a cyanate compound containing an aromatic ring is preferred, and examples thereof include a bisphenol-type cyanate compound, a biphenyl-type cyanate compound, and a novolak phenol-type cyanate compound. More specifically, examples of the polyfunctional cyanate compound (A) other than the compound represented by formula (IS1) include dicyanate benzene, tricyanate benzene, dicyanate naphthalene, dicyanate biphenyl, 2,2-bis(4-cyanate phenyl)propane, bis(4-cyanate phenyl)methane, bis(3,5-dimethyl-4-cyanate phenyl)methane, 2,2-bis(3,5-dimethyl-4-cyanate phenyl)propane, 2,2-bis(4-cyanate phenyl)ethane, 2,2-bis(4-cyanate phenyl)hexafluoropropane, bis(4-cyanate phenyl)sulfone, bis(4-cyanate phenyl)thioether, and phenol novolac cyanate. Among these, 2,2-bis(4-cyanate phenyl)propane and / or phenol novolac cyanate are preferred. Commercially available polyfunctional cyanate compounds (A) other than the compounds represented by formula (IS1) include cyanate LeCy, PT-15, PT-30, PT-60, etc. manufactured by Lonza; L-10, XU366, XU371, XU378, etc. manufactured by Huntsman; and TA, TA-100, TA-1500, P-201, NCN-M, etc. manufactured by Mitsubishi Gas Chemical Company, Inc.

[0018] The total amount of the polyfunctional cyanate compound (A) in the resin composition of this embodiment is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 35 parts by mass or more, even more preferably 40 parts by mass or more, even more preferably 45 parts by mass or more, and is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 74 parts by mass or less, even more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 59 parts by mass or less, and particularly preferably 55 parts by mass or less, based on 100 parts by mass of the resin solid content contained in the resin composition. By setting the total amount of the polyfunctional cyanate compound (A) to be equal to or greater than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, the thermal conductivity of the resulting resin sheet tends to be further improved. The resin composition of this embodiment may contain only one type of polyfunctional cyanate compound (A), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above-mentioned range.

[0019] The resin composition of this embodiment may contain one or more monofunctional cyanate compounds, or may not contain any monofunctional cyanate compounds. The content of the monofunctional cyanate compound in the resin composition of this embodiment is preferably 0 to 10 parts by mass, more preferably 0 to 5 parts by mass, and even more preferably 0 to 3 parts by mass, or may be 0 to 1 part by mass, relative to 100 parts by mass of the polyfunctional cyanate compound (A) contained in the resin composition.

[0020] <Multifunctional Epoxy Compound (B)> The resin composition of this embodiment contains a multifunctional epoxy compound (B). The multifunctional epoxy compound (B) is typically a multifunctional epoxy resin. Furthermore, the multifunctional epoxy compound (B) is typically a thermosetting resin. The multifunctional epoxy compound is not particularly limited as long as it is a bifunctional or higher epoxy compound; however, difunctional to decafunctional epoxy compounds are preferred, difunctional to octafunctional epoxy compounds are more preferred, difunctional to hexafunctional epoxy compounds are even more preferred, and difunctional to tetrafunctional epoxy compounds are even more preferred. The multifunctional epoxy compound (B) preferably contains an aromatic ring, and the aromatic ring is preferably linked by an alkylene chain and / or an ether chain. The aromatic ring is preferably a benzene ring and / or a naphthalene ring. Furthermore, the multifunctional epoxy compound (B) preferably contains a compound represented by formula (EP).

[0021] Expression (EP) (In formula (EP), each Ar is independently a phenylene group or a naphthylene group, and each X is an alkylene group, an ether group, a sulfonyl group, a phenylene group, a naphthylene group, or a divalent group formed by a combination of two or more of the above groups (with the proviso that the group adjacent to the ether group is not an ether group).) In formula (EP), the alkylene group, phenylene group, or naphthylene group may have a substituent. Examples of the substituent include an alkyl group and a hydroxyl group, with a methyl group and a hydroxyl group being preferred. The alkylene group preferably has 1 to 3 carbon atoms. The molecular weight of the compound represented by formula (EP) is preferably 250 to 1,500.

[0022] More specifically, the polyfunctional epoxy compound (B) preferably contains at least one selected from the group consisting of bisphenol-type epoxy resins, biphenyl-type epoxy resins, naphthalene-type epoxy resins, and phenoxy resins containing an epoxy group, and more preferably contains at least one selected from the group consisting of compounds represented by formulas (EP1) to (EP4). (In formula (EP1), R ２are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.

[0023] In formula (EP1), R ２ are each independently preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. In formula (EP1), n ​​is preferably 10 or less, more preferably 8 or less, even more preferably 5 or less, and even more preferably 3 or less. In formula (EP1), n ​​is an average value when two or more compounds represented by formula (EP1) are contained.

[0024] Formula (EP2) (In formula (EP2), R ３ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.

[0025] In formula (EP2), R ３ are each independently preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyl group, and more preferably a hydrogen atom or a methyl group. In formula (EP2), n is preferably 10 or less, more preferably 8 or less, even more preferably 5 or less, and still more preferably 3 or less. In formula (EP2), n is an average value when two or more compounds represented by formula (EP2) are contained.

[0026] Expression (EP3) (In formula (EP3), R ４ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.

[0027] In formula (EP3), R ４are each independently preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyl group, and more preferably a hydrogen atom or a methyl group. In formula (EP3), n is preferably 10 or less, more preferably 8 or less, even more preferably 5 or less, and still more preferably 3 or less. In formula (EP3), n is an average value when two or more compounds represented by formula (EP3) are contained.

[0028] Expression (EP4) (In formula (EP4), A represents a single bond, an ether group, a methylene group, or a divalent group formed by combining two or more of these groups; R ５ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.

[0029] In formula (EP4), A is preferably a single bond or an ether group, and R ５ are each preferably independently a hydrogen atom or an alkyl group. The alkyl group may have a substituent, and an example thereof is a phenylmethyl group. In formula (EP4), n is preferably 10 or less, more preferably 8 or less, even more preferably 5 or less, and still more preferably 3 or less. In formula (EP4), n is an average value when two or more compounds represented by formula (EP4) are included.

[0030] The total amount of the polyfunctional epoxy compound (B) in the resin composition of this embodiment is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 26 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, even more preferably 41 parts by mass or more, particularly more preferably 45 parts by mass or more, and is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, even more preferably 65 parts by mass or less, even more preferably 60 parts by mass or less, and even more preferably 55 parts by mass or less. By making the total amount of the polyfunctional epoxy compound (B) equal to or greater than the lower limit, the adhesion of the resulting resin sheet to metals (e.g., metal foil, metal substrate, etc.) tends to be further improved. Furthermore, by making the total amount of the polyfunctional epoxy compound (B) equal to or less than the upper limit, the thermal conductivity of the resulting resin sheet tends to be further improved. The resin composition of the present embodiment may contain only one type of polyfunctional epoxy compound (B), or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0031] The resin composition of this embodiment may contain one or more monofunctional epoxy compounds, or may not contain any monofunctional epoxy compounds. The content of the monofunctional epoxy compound in the resin composition of this embodiment is preferably 0 to 10 parts by mass, more preferably 0 to 5 parts by mass, and even more preferably 0 to 3 parts by mass, or may be 0 to 1 part by mass, relative to 100 parts by mass of the polyfunctional epoxy compound (B) contained in the resin composition.

[0032] The mass ratio of the polyfunctional cyanate compound (A) (preferably a compound represented by formula (IS1) or the like, more preferably a compound represented by formula (IS1)) to the polyfunctional epoxy compound (B) in the resin composition of the present embodiment is, when the total of the polyfunctional cyanate compound (A) and the polyfunctional epoxy compound (B) is taken as 100 parts by mass, the proportion of the polyfunctional epoxy compound (B) is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, still more preferably 35 parts by mass or more, even more preferably 40 parts by mass or more, still more preferably 45 parts by mass or more, and preferably 90 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 70 parts by mass or less, still more preferably 65 parts by mass or less, even more preferably 60 parts by mass or less, and still more preferably 55 parts by mass or less.

[0033] <Thermal Conductive Filler (C)> The resin composition of this embodiment contains a thermally conductive filler (C). The thermally conductive filler (C) can be any thermally conductive filler commonly used in the technical field of the present invention, with ceramic particles being a typical example. Among ceramic particles, ceramic particles with high insulating properties and thermal conductivity are preferred. The thermally conductive filler (C) used in this embodiment is not particularly limited in type, but examples include nitrides, alumina, fibrous alumina, zinc oxide, magnesium oxide, beryllium oxide, titanium oxide, diamond, fullerene, aluminum hydroxide, and magnesium hydroxide, with nitrides being preferred. Examples of nitrides include aluminum nitride, silicon nitride, and boron nitride, with boron nitride being preferred. The shape of the thermally conductive filler (C) can be fibrous, plate-like, or particle aggregates, with particle aggregates being preferred. The thermally conductive filler (C) used in this embodiment preferably contains boron nitride aggregates, in particular.

[0034] The boron nitride aggregates are aggregates of boron nitride particles, and are preferably aggregates of primary particles of boron nitride.

[0035] For the boron nitride aggregate, the descriptions in paragraphs 0026 to 0029 of JP-A-2024-6085, the descriptions in paragraphs 0017 to 0069 of JP-A-2024-003261, and the descriptions in paragraphs 0025 to 0027 of JP-A-2023-173096 can be referred to, the contents of which are incorporated herein by reference.

[0036] The volume average particle diameter of the boron nitride aggregate is preferably 10 μm or more, more preferably 15 μm or more, even more preferably 17 μm or more, even more preferably 20 μm or more, even more preferably 25 μm or more, and preferably 70 μm or less. If the volume average particle diameter of the boron nitride aggregate is equal to or greater than the above-mentioned lower limit, it is possible to reduce the contact resistance between the boron nitride particles, thereby improving the thermal conductivity of the resulting resin sheet. On the other hand, if the volume average particle diameter of the boron nitride aggregate is equal to or less than the above-mentioned upper limit, it is possible to appropriately fill the resulting resin sheet with the boron nitride aggregate, thereby improving the thermal conductivity of the resin sheet. Here, the average particle diameter means the median diameter (D50).

[0037] The boron nitride aggregate (preferably an aggregate of primary particles of boron nitride) is preferably mixed with a dispersant and stirred in advance. Furthermore, the boron nitride aggregate (preferably an aggregate of primary particles of boron nitride) is preferably heated after stirring, with the heating temperature preferably being 80°C or higher and 140°C or lower. Such a preliminary stirring treatment makes it possible to uniformly attach the dispersant to the boron nitride. Furthermore, heating tends to hydrolyze and dehydration-condense the silane coupling agent that serves as the dispersant, further improving its effect of adhering to the boron nitride.

[0038] The type of dispersant is not particularly limited, but specific examples include silane coupling agents, titanate coupling agents, aluminate coupling agents, polycarboxylic acid dispersants, acrylic dispersants, and urethane dispersants, with aluminate coupling agents being preferred. The amount of dispersant is preferably 0.0 to 10 parts by mass per 100 parts by mass of the boron nitride aggregates finally obtained. Only one type of dispersant may be used, or two or more types may be used.

[0039] The boron nitride aggregate in this embodiment may contain a binder from the viewpoint of improving the robustness of the boron nitride aggregate. The binder originally acts to firmly bind boron nitride particles together and stabilize the shape of the boron nitride aggregate.

[0040] As such a binder, a metal oxide is preferred, and specifically, aluminum oxide, magnesium oxide, yttrium oxide, calcium oxide, silicon oxide, boron oxide, cerium oxide, zirconium oxide, titanium oxide, etc. are preferably used. Among these, aluminum oxide and yttrium oxide are preferred from the viewpoints of thermal conductivity and heat resistance as oxides, and the bonding strength that bonds primary particles of hexagonal boron nitride together. The binder may be a liquid binder such as alumina sol, or may be one that is converted into a metal oxide by firing, such as an organometallic compound. These binders may be used alone or in combination of two or more.

[0041] The boron nitride aggregates treated with a dispersant may be further treated by, for example, surface oxidation by heat treatment in the presence of oxygen, steam treatment, surface modification with an organometallic compound or polymer using a carrier or reactive gas at room temperature or under heat, or a sol-gel method using boehmite or silica. These treatments may be used alone or in combination of two or more.

[0042] The content of the thermally conductive filler (C) in the resin composition of this embodiment is preferably 10% by volume or more, more preferably 15% by volume or more, even more preferably 20% by volume or more, even more preferably 25% by volume or more, even more preferably 30% by volume or more, and preferably 60% by volume or less, more preferably 55% by volume or less, even more preferably 50% by volume or less, even more preferably 45% by volume or less, even more preferably 40% by volume or less. By making the content of the thermally conductive filler (C) above the lower limit, the thermal conductivity of the resin composition is improved, the loss modulus (DMA, viscosity) is lowered, and tan δ (loss tangent, vibration absorption) tends to be lowered. In addition, the adhesion of the resin sheet to metals (e.g., metal foil, metal substrate, etc.) tends to be improved. On the other hand, by setting the content of the thermally conductive filler (C) to the above upper limit or less, the occurrence of voids when made into a resin sheet tends to be effectively suppressed and the voltage resistance tends to be further improved. The resin composition of this embodiment may contain only one type of thermally conductive filler (C) or may contain two or more types. When two or more types are contained, it is preferable that the total amount is in the above range.

[0043] <Curing Catalyst (D)> The resin composition of this embodiment preferably contains a curing catalyst (D). The inclusion of the curing catalyst (D) tends to more effectively promote curing of the polyfunctional cyanate compound (A) and the polyfunctional epoxy compound (B). The type of curing catalyst (D) is not particularly limited, but it preferably contains at least one selected from the group consisting of metal catalysts, organic peroxides, tertiary amines, phenols, and high-temperature decomposition-type radical generators, and more preferably contains a metal catalyst. The use of a metal catalyst tends to further improve the thermal conductivity of the resulting resin sheet. In this embodiment, two reactions proceed: a reaction in which the polyfunctional cyanate compounds (A) react with each other to form triazine rings, and a reaction in which the triazine rings react with the polyfunctional epoxy compound (B). It is presumed that the use of a metal catalyst as a curing catalyst allows the reaction with the polyfunctional epoxy compound (B) to proceed after the reaction in which the triazine rings are formed to proceed sufficiently, resulting in further curing and achieving good thermal conductivity.

[0044] The metal catalyst is preferably a metal catalyst containing at least one selected from the group consisting of zinc, copper, aluminum, tin, iron, manganese, and cobalt, more preferably a metal catalyst containing at least one selected from the group consisting of zinc, copper, aluminum, iron, and cobalt, and more preferably a metal catalyst containing zinc and / or iron. Specific examples of the metal catalyst include organic metal salts such as lead naphthenate, lead stearate, zinc naphthenate, zinc octoate, manganese octoate, copper octoate, aluminum acetylacetonate, tin oleate, dibutyltin maleate, iron acetylacetonate, manganese naphthenate, and cobalt naphthenate; compounds obtained by dissolving these organic metal salts in hydroxyl group-containing compounds such as phenol and bisphenol; organic metal complexes such as cyclopentadienyl iron dicarbonyl dimer; inorganic metal salts such as tin chloride, zinc chloride, and aluminum chloride; and organic tin compounds such as dioctyltin oxide, other alkyltins, and alkyltin oxides, with organic metal salts being preferred.

[0045] In this embodiment, the curing accelerators described in paragraph 0256 of WO 2024 / 090409 can also be used, the contents of which are incorporated herein by reference.

[0046] When the resin composition of this embodiment contains a curing catalyst (D), the content thereof is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and even more preferably 0.01 parts by mass or more, relative to 100 parts by mass of the resin solid content contained in the resin composition. It is also preferable that the content is 1.0 parts by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.1 parts by mass or less. By setting the content to be equal to or greater than the lower limit, the thermal conductivity of the resulting resin sheet tends to be further improved. Furthermore, by setting the content to be equal to or less than the upper limit, the thermal conductivity of the resulting resin sheet tends to be further improved. The resin composition of this embodiment may contain only one type of curing catalyst (D), or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

[0047] The resin composition of the present embodiment may be configured to be substantially free of curing catalysts other than the metal catalyst. "Substantially free" means that the content of the metal catalyst in the resin composition of the present embodiment is less than 10 parts by mass, preferably less than 5 parts by mass, more preferably less than 1 part by mass, and may even be less than 0.1 parts by mass, relative to 100 parts by mass of the metal catalyst.

[0048] <Solvent> The resin composition of this embodiment may contain a solvent, and preferably contains an organic solvent. When a solvent is contained, the resin composition of this embodiment is in a form (solution or varnish) in which at least a portion, preferably all, of the various resin solid components described above are dissolved or compatible in the solvent. The solvent is not particularly limited as long as it is a polar organic solvent or a non-polar organic solvent that can dissolve or compatible at least a portion, preferably all, of the various resin solid components described above. Examples of polar organic solvents include ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), cellosolves (e.g., propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, etc.), esters (e.g., methyl lactate, ethyl lactate, methyl acetate, butyl acetate, isoamyl acetate, methyl methoxypropionate, methyl hydroxyisobutyrate, etc.), and amides (e.g., dimethoxyacetamide, dimethylformamide, etc.). Examples of non-polar organic solvents include aromatic hydrocarbons (e.g., toluene, xylene, etc.). The solvents may be used alone or in combination of two or more. When two or more solvents are used, the total amount falls within the above range.

[0049] <Other Components> In addition to the above, the resin composition of this embodiment can contain resins other than the polyfunctional cyanate compound (A) and the polyfunctional epoxy compound (B) (thermosetting resins and / or thermoplastic resins), various polymeric compounds such as binders and elastomers, and various additives. These are not particularly limited as long as they are commonly used. Examples of the various additives include flame retardants, ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, flow control agents, lubricants, antifoaming agents, dispersants, leveling agents, gloss agents, and polymerization inhibitors. These can be used alone or in combination of two or more, as desired.

[0050] Examples of resins other than the polyfunctional cyanate compound (A) and the polyfunctional epoxy compound (B) include thermosetting resins other than the polyfunctional cyanate compound (A) and the polyfunctional epoxy compound (B), such as compounds having a terminal carbon-carbon unsaturated double bond, maleimide compounds, nadimide compounds, phenolic compounds, oxetane resins, benzoxazine compounds, arylcyclobutene compounds, perfluorovinyl ether resins, polyimide compounds, compounds having a vinylene group, phenolic resins, urea resins, melamine resins, unsaturated polyester resins, and silicone resins. Examples of thermosetting resins include the descriptions in paragraphs 0012 to 0085 of International Publication No. 2023 / 026829 and paragraphs 0017 to 0034 of Japanese Patent Application Laid-Open No. 2016-10964, the contents of which are incorporated herein by reference. Examples of thermoplastic resins include polyolefins, vinyl chloride resins, methyl methacrylate resins, nylons, and fluororesins. In addition, synthetic rubber, liquid gel, and other resins can also be used.

[0051] Of 100 parts by mass of resin solid content contained in the resin composition of the present embodiment, the total amount of the polyfunctional cyanate compound (A) and the polyfunctional epoxy compound (B) is preferably 85 parts by mass or more, more preferably 90 parts by mass or more, even more preferably 95 parts by mass or more, still more preferably 97 parts by mass or more, and may be 99 parts by mass or more, and of 100 parts by mass of resin solid content, components other than the curing catalyst (D) may be occupied by the polyfunctional cyanate compound (A) and the polyfunctional epoxy compound (B).

[0052] <Resin sheet and multilayer body> The resin sheet of this embodiment is formed from the resin composition of this embodiment. For the manufacturing method of the resin sheet of this embodiment, the description in paragraphs 0045 to 0048 of JP 2024-6085 A and the description in paragraphs 0034 to 0050 of JP 2023-173096 A can be referred to, and the contents thereof are incorporated herein by reference.

[0053] The resin sheet of this embodiment preferably has a thermal conductivity of 10 W / m K or more, more preferably 15 W / m K or more, and even more preferably 17 W / m K or more, measured at 25° C. along the thickness direction of the resin sheet. There is no particular upper limit to the thermal conductivity, but a value of 25 W / m K or less is practical.

[0054] The resin sheet of this embodiment has heat dissipation and insulation properties, and is therefore preferably used as a highly thermally conductive insulating sheet incorporated for the purpose of heat dissipation and insulation of semiconductor elements. One example of the use of the resin sheet of this embodiment is a highly thermally conductive resin sheet provided on (preferably on) a metal substrate.

[0055] That is, an example of the multilayer body of this embodiment is a multilayer body having a metal substrate and a resin sheet of this embodiment provided on (preferably on) the metal substrate. Furthermore, the multilayer body of this embodiment is preferably a multilayer body having a metal substrate, a resin sheet of this embodiment provided on (preferably on) the metal substrate, and a heat spreader provided on (preferably on) the resin sheet. An example of the metal substrate is a copper substrate. A heat spreader is a highly thermally conductive metallic structural member used in semiconductor devices to efficiently dissipate heat from IC chips. Therefore, the semiconductor device of this embodiment has the multilayer body of this embodiment.

[0056] Other uses of the resin sheet of this embodiment include prepregs and build-up materials for semiconductor elements. For details, see paragraphs 0114 to 0125 of International Publication No. 2023 / 026829 and paragraphs 0051 to 0064 of Japanese Patent Laid-Open Publication No. 2016-010964, the contents of which are incorporated herein by reference.

[0057] The resin composition of this embodiment is also used as a cured product. Specifically, the resin composition of this embodiment can be suitably used as a resin composition for electronic materials such as an insulating layer for a printed wiring board or a material for a semiconductor package. The resin composition of this embodiment can be suitably used as a material for prepregs, metal foil-clad laminates using prepregs, and printed wiring boards. The printed wiring board referred to here is not particularly limited and includes, for example, rigid substrates, flexible substrates, semiconductor package substrates (substrates for mounting semiconductor elements), and organic interposers. For details of these, please refer to the descriptions in paragraphs 0152 to 0167 of WO 2024 / 024664, as well as the descriptions in JP 2022-99579 A and JP 2022-089837 A, the contents of which are incorporated herein by reference.

[0058] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0059] 1. Raw Materials <Polyfunctional Cyanate Compound (A)> P-201: Manufacturer: Mitsubishi Gas Chemical Company, Inc., Product Number: CYTESTER (registered trademark) P-201 PT-30: Manufacturer: arxada Corporation, Product Number: Primaset (registered trademark) PT-30 TA-100: Manufacturer: Mitsubishi Gas Chemical Company, Inc., Product Number: CYTESTER (registered trademark) TA-100

[0060] <Multifunctional epoxy compound (B)> NC-3000-L: Manufacturer: Nippon Kayaku Co., Ltd., Product No.: NC-3000-L CER-3000-L: Manufacturer: Nippon Kayaku Co., Ltd., Product No.: CER-3000-L NC-7000-L: Manufacturer: Nippon Kayaku Co., Ltd., Product No.: NC-7000-L HP-6000: Manufacturer: DIC Corporation, Product Number: HP-6000 jER828: Manufacturer: Mitsubishi Chemical Corporation, Product Number: jER828 EPOX MK710: Manufacturer: Printec Co., Ltd., Product Number: EPOX MK710 jER806: Manufacturer: Mitsubishi Chemical Corporation, Product Number: jER806 YX8100BH30: Manufacturer: Mitsubishi Chemical Corporation, Product Number: YX8100BH30

[0061] <Thermal conductive filler (C)> A boron nitride aggregate produced according to the following production method was used as the thermal conductive filler (C): Tap density: 0.4 g / cm ３ Isopropanol was added to 100 parts by mass of a boron nitride aggregate having an average particle size of 60 μm (PTX60, manufactured by Momentive Performance, average particle size (D50) 60 μm), and then 1 part by mass of alkylacetoacetate aluminum diisopropylate (manufacturer: Ajinomoto Fine-Techno Co., Ltd., product number: PLENACT™ AL-M) was added dropwise, followed by stirring for 3 hours at 70° C. This dispersion was filtered, dried in the air for 12 hours, and then dried at 130° C. for 2 hours to obtain a surface-treated boron nitride aggregate.

[0062] <Curing catalyst (D)> Zinc octylate: Manufacturer: Nippon Chemical Industry Co., Ltd., Product No.: Nikka Octix (registered trademark) Zinc octylate: Manufacturer: Sigma-Aldrich Corporation, Product No.: 337323 Aluminum acetylacetonate: Manufacturer: Tokyo Chemical Industry Co., Ltd., Product No.: A0241 Cyclopentadienyl iron dicarbonyl dimer: Manufacturer: Tokyo Chemical Industry Co., Ltd., Product No.: C1592 Cobalt naphthenate: Manufacturer: Tokyo Chemical Industry Co., Ltd., Product No.: C3480

[0063] 2. Examples 1 to 16, Comparative Examples 1 and 2 <Preparation of Semi-Cured Resin Sheets> A mixture of the polyfunctional cyanate compound (A), polyfunctional epoxy compound (B), thermally conductive filler (C), and curing catalyst (D) shown in Tables 1 to 3 was diluted with a solvent (21.4 parts by mass of cyclohexanone / 21.4 parts by mass of methyl ethyl ketone) to prepare a varnish. The varnish obtained by the above method was applied to the surface of a PET film (38 μm thick) whose surface had been treated for release using an applicator (gap 350 μm). The varnish was then dried at room temperature for 12 hours or more and at 130°C for 10 minutes to prepare a semi-cured resin sheet with a PET film on one side. Two semi-cured resin sheets with a PET film on one side were then stacked with the resin surfaces facing each other and bonded together using a vacuum heat press (110°C, 5 minutes, press pressure 1.5 MPa). The PET films on both sides were then peeled off to prepare a semi-cured resin sheet.

[0064] <Preparation of test piece for measuring thermal conductivity> The semi-cured resin sheet obtained by the above method was filled into a press mold having a thickness of 1 mm, and a resin sheet was prepared by vacuum heat pressing (180°C, 60 minutes, pressing pressure 1.5 MPa). The obtained resin sheet was cut into a size of 10 mm x 10 mm to prepare a test piece for measuring thermal conductivity.

[0065] <Preparation of test piece for measuring copper foil adhesion> Electrolytic copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., 3EC-M3-VLP, thickness 35 μm) was placed on the top and bottom surfaces of the semi-cured resin sheet obtained by the method described above, with the matte side of the copper foil facing the resin sheet surface, and a double-sided copper foil-covered cured resin product was prepared using a vacuum hot press (180°C, 60 minutes, press pressure 1.5 MPa).

[0066] <Thermal Conductivity in the Thickness Direction> The thermal conductivity in the thickness direction of the thermal conductivity measurement specimen obtained above was evaluated by the following method. Thermal Diffusion Coefficient in the Thickness Direction: Measured at 25°C in the atmosphere using a xenon flash thermal diffusivity measurement device (NETZSCH, LFA447, NanoFlash). Specific Heat: Measured using a DSC (Hitachi High-Tech Science Corporation, DSC7020) in accordance with JIS K7123 (Method for Measuring the Specific Heat Capacity of Plastics). Density: Measured by the underwater displacement method using a density meter (Ohaus Co., Ltd., Density Measurement Kit). Thermal Conductivity: The thermal conductivity of the cured product was calculated from the calculated thermal diffusion coefficient, specific heat, and density using the following formula: λ = α Cp ρ [λ: thermal conductivity (W / m K), α: thermal diffusion coefficient (m ２ / s), Cp: specific heat (J / g・K), ρ: density (kg / m ３ )

[0067] <Copper foil adhesion> Using the cured resin product with copper foil on both sides (10 mm x 100 mm) obtained above, the copper foil peel strength (copper foil adhesion, kN / m) was measured using an autograph (AG-X plus, manufactured by Shimadzu Corporation) in accordance with JIS C6481. The evaluation was as follows: A: 0.2 kN / m or more B: Less than 0.2 kN / m, 0.1 kN / m or more C: Less than 0.1 kN / m

[0068]

[0069]

[0070]

[0071] In Tables 1 to 3 above, the content of the curing catalyst (D) is shown as the amount relative to 100 parts by mass of the total of the polyfunctional cyanate compound (A) and the polyfunctional epoxy compound.

[0072] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.

Claims

1. A resin composition comprising a polyfunctional cyanate compound (A), a polyfunctional epoxy compound (B), and a thermally conductive filler (C), wherein the polyfunctional cyanate compound (A) comprises a compound represented by formula (IS1) and / or a prepolymer of the compound represented by formula (IS1). Formula (IS1) 2. The resin composition according to claim 1, further comprising a curing catalyst (D), wherein the curing catalyst (D) comprises a metal catalyst.

3. The resin composition according to claim 1, further comprising a curing catalyst (D), wherein the curing catalyst (D) comprises a metal catalyst containing at least one selected from the group consisting of zinc, copper, aluminum, tin, iron, manganese, and cobalt.

4. The resin composition according to any one of claims 1 to 3, wherein the polyfunctional epoxy compound (B) comprises a compound represented by formula (EP): Formula (EP) In formula (EP), each Ar is independently a phenylene group or a naphthylene group, and each X is an alkylene group, an ether group, a sulfonyl group, a phenylene group, a naphthylene group, or a divalent group formed by combining two or more of the above groups (provided that the group adjacent to the ether group is not an ether group).

5. The resin composition according to any one of claims 1 to 3, wherein the polyfunctional epoxy compound (B) comprises at least one selected from the group consisting of bisphenol-type epoxy resins, biphenyl-type epoxy resins, naphthalene-type epoxy resins, and phenoxy resins containing an epoxy group.

6. The resin composition according to any one of claims 1 to 3, wherein the polyfunctional epoxy compound (B) comprises at least one selected from the group consisting of compounds represented by formulas (EP1) to (EP4): Formula (EP1) (In formula (EP1), R ２ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP2), R ３ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP3), R ４ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP4), A represents a single bond, an ether group, a methylene group, or a divalent group formed by combining two or more of these groups; R ５ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.

7. The resin composition according to any one of claims 1 to 3, wherein the thermally conductive filler (C) comprises a boron nitride aggregate.

8. The resin composition according to claim 1, further comprising a curing catalyst (D), wherein the curing catalyst (D) comprises a metal catalyst containing at least one selected from the group consisting of zinc, copper, aluminum, tin, iron, manganese, and cobalt, the polyfunctional epoxy compound (B) comprises at least one selected from the group consisting of compounds represented by formulas (EP1) to (EP4), and the thermally conductive filler (C) comprises a boron nitride aggregate. Formula (EP1) (In formula (EP1), R ２ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP2), R ３ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP3), R ４ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more. (In formula (EP4), A represents a single bond, an ether group, a methylene group, or a divalent group formed by combining two or more of these groups; R ５ are each independently a hydrogen atom, an alkyl group, an allyl group, a hydroxyl group, an alkoxy group, or a glycidyloxy group, and n is a number of 2 or more.

9. A resin sheet formed from the resin composition according to claim 1, 2, 3 or 8.

10. A multilayer body having a metal substrate and the resin sheet according to claim 9 provided on the metal substrate.

11. A multilayer body having a metal substrate, the resin sheet according to claim 9 provided on the metal substrate, and a heat spreader provided on the resin sheet.

12. A semiconductor device comprising the multilayer body according to claim 10.

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