Thermosetting resin compositions, resin sheets, thermally conductive members, metal-based substrates, and electronic devices

Abstract

To provide a thermosetting resin composition and a resin sheet which can achieve a thermally conductive member with improved balance between thermal conductivity and heat resistance, and a thermally conductive member, a metal base substrate, and an electronic apparatus with improved balance between thermal conductivity and heat resistance.SOLUTION: A thermosetting resin composition includes an epoxy resin (A), a cyanate ester resin (B), and a thermally conductive filler (C), wherein the epoxy resin (A) includes a resveratrol epoxy resin (A1) having a resveratrol skeleton in each molecule.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a thermosetting resin composition, a resin sheet, a heat conductive member, a metal base substrate, and an electronic device.

Background Art

[0002] With the improvement of the processing capacity of electronic components, the amount of heat generated from electronic components tends to increase. Therefore, heat dissipation measures for effectively dissipating heat from electronic components to the outside are important. As such heat dissipation measures, heat conductive members made of heat dissipation materials such as metals, ceramics, or resin compositions are applied.

[0003] Among these heat conductive members, a heat conductive epoxy resin molded body formed of an epoxy resin composition has good electrical insulation, mechanical properties, heat resistance, chemical resistance, adhesiveness, etc., and is widely used mainly in the electric and electronic fields as cast products, laminates, sealing materials, heat conductive sheets, adhesives, etc.

[0004] Examples of technologies related to such heat conductive epoxy resin molded bodies include those described in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2015-193504) and Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2004-331811).

[0005] Patent Document 1 describes that a resin composition containing a resin component and a heat conductive filler dispersed in the resin component, wherein the heat conductive filler contains boron nitride particles having (1) a loose bulk density of 0.52 g / mL or more and (2) an average circularity of 0.65 or more can obtain a material with excellent heat dissipation.

[0006] Patent Document 2 describes that a heat conductive epoxy resin molded body mainly composed of an epoxy resin having an azomethine group, characterized in that the heat conductivity is 0.5 to 30 W / (m·K), can exhibit excellent heat conductivity.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 2015-193504 [Patent Document 2] Japanese Patent Publication No. 2004-331811 [Overview of the project] [Problems that the invention aims to solve]

[0008] As the processing capabilities of electronic components continue to improve, there is a growing demand for a further balance between thermal conductivity and heat resistance in thermally conductive materials.

[0009] The present invention has been made in view of the above circumstances, and provides a thermosetting resin composition and resin sheet that can realize a thermally conductive member with an improved balance of thermal conductivity and heat resistance, as well as a thermally conductive member, a metal base substrate, and an electronic device with an improved balance of thermal conductivity and heat resistance. [Means for solving the problem]

[0010] The inventors diligently conducted research to achieve the above objectives. As a result, they discovered that by using a thermosetting resin composition containing a resveratrol-type epoxy resin, a cyanate ester resin, and a thermally conductive filler, the balance between thermal conductivity and heat resistance of the resulting thermally conductive member can be improved, thus completing the present invention.

[0011] According to the present invention, the following thermosetting resin composition, resin sheet, thermally conductive member, metal base substrate, and electronic device are provided.

[0012] [1] It comprises epoxy resin (A), cyanate ester resin (B), and thermally conductive filler (C), The epoxy resin (A) is a thermosetting resin composition comprising a resveratrol-type epoxy resin (A1) having a resveratrol skeleton in its molecule. [2] The thermosetting resin composition according to [1], further comprising a phenoxy resin (D). [3] The thermosetting resin composition according to [1] or [2], wherein the thermally conductive filler (C) comprises at least one selected from the group consisting of silica, alumina, aluminum nitride, silicon carbide, boron nitride, silicon nitride, magnesium oxide, aluminum hydroxide, and barium sulfate. [4] A thermosetting resin composition according to any one of [1] to [3], wherein the thermally conductive filler (C) contains boron nitride. [5] A thermosetting resin composition according to any one of [1] to [4], further comprising a curing accelerator (E). [6] The thermosetting resin composition according to [5], wherein the curing accelerator (E) comprises at least one selected from the group consisting of nitrogen atom-containing compounds, phenol compounds, phenol resins, and benzoxazine resins. [7] A resin sheet comprising a resin composition layer made of the thermosetting resin composition described in any of the above [1] to [6]. [8] The resin sheet according to [7], wherein the resin composition layer is in a B-stage state. [9] A thermally conductive member comprising a resin cured layer made of a cured product of any of the thermosetting resin compositions described in [1] to [6] above.

[10] The thermal conductive member described in [9] above, which is a thermal conductive sheet.

[11] The thermal conductive member according to [9] or

[10] , wherein the glass transition temperature of the resin cured layer, as measured by dynamic viscoelasticity measurement under the conditions of a heating rate of 5°C / min and a frequency of 10 Hz, is 210°C or higher.

[12] A thermal conductive member according to any one of [9] to

[11] above, wherein the thermal conductivity in the thickness direction of the resin cured layer is 15 W / (m·K) or more, as measured under atmospheric conditions at 25°C by the flash method in accordance with JIS R 1611:2010.

[13] A metal substrate, an insulating layer provided on the metal substrate, and a metal layer provided on the insulating layer, and includes: The insulating layer includes a resin composition layer made of the thermosetting resin composition according to any one of [1] to [6], and a metal base substrate including one selected from the group consisting of the heat conductive members according to any one of [9] to

[12] .

[14] The metal base substrate according to

[13] , electronic components provided on the metal base substrate, and an electronic device comprising the same.

[15] The electronic device according to

[14] , which is a power module. [Advantages of the Invention]

[0013] According to the present invention, it is possible to provide a thermosetting resin composition and a resin sheet capable of realizing a heat conductive member with an improved balance between heat conductivity and heat resistance, and a heat conductive member, a metal base substrate, and an electronic device with an improved balance between heat conductivity and heat resistance. [Brief Description of the Drawings]

[0014] [Figure 1] It is a schematic cross-sectional view showing an example of the configuration of the metal base substrate according to the present embodiment. [Figure 2] It is a schematic cross-sectional view showing an example of the configuration of the electronic device according to the present embodiment. [Modes for Carrying Out the Invention]

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Further, the drawings are schematic views and do not match the actual dimensional ratios. In addition, "~" indicating a numerical range represents "above" to "below" unless otherwise specified.

[0016] [Thermosetting Resin Composition] The thermosetting resin composition according to this embodiment comprises an epoxy resin (A), a cyanate ester resin (B), and a thermally conductive filler (C), wherein the epoxy resin (A) includes a resveratrol-type epoxy resin (A1) having a resveratrol skeleton in its molecule.

[0017] According to the thermosetting resin composition of this embodiment, it is possible to improve the balance between thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member. Furthermore, according to the thermosetting resin composition of the present invention, it is possible to realize a metal-based substrate and an electronic device with an improved balance between thermal conductivity and heat resistance. The reasons for these effects are presumed to be as follows: Resveratrol-type epoxy resin (A1) has a resveratrol skeleton within its molecule. This resveratrol skeleton is polyfunctional, rigid, linear, and electron-conjugated, and also has a symmetric structure. Therefore, during curing, the resveratrol skeleton can improve the crosslinking density and crystallinity, and as a result, it is thought that the balance between the thermal conductivity and heat resistance of the resulting resin sheet and thermal conductive member can be improved.

[0018] The following describes each component constituting the thermosetting resin composition according to this embodiment.

[0019] <Epoxy resin (A)> The thermosetting resin composition according to this embodiment includes an epoxy resin (A).

[0020] (Resveratrol-type epoxy resin (A1)) The epoxy resin (A) contains a resveratrol-type epoxy resin (A1). Resveratrol-type epoxy resin (A1) is an epoxy resin having a resveratrol skeleton in its molecule, and is, for example, an epoxy resin derived from a resveratrol compound and an epoxy compound such as epichlorohydrin. Here, the resveratrol skeleton is, for example, the structure shown in formula (1) below.

[0021] [ka] (In formula (1) above, R1 and R2 each independently represent a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a linear or branched alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, even more preferably a hydrogen atom; a is each independently an integer between 0 and 3, preferably 0 or 1, more preferably 0; b is each independently an integer between 0 and 4, preferably 0 or 1, more preferably 0; and * represents a bond.)

[0022] The monomer of the resveratrol-type epoxy resin (A1) is shown, for example, in (2) below. The polymer (oligomer) of the resveratrol-type epoxy resin (A1) is shown, for example, in (3) below.

[0023] [ka] (In formula (2) above, R1 and R2 each independently represent a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a linear or branched alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, even more preferably a hydrogen atom; a is each independently an integer between 0 and 3, preferably 0 or 1, more preferably 0; and b is each independently an integer between 0 and 4, preferably 0 or 1, more preferably 0.)

[0024] [ka] (In formula (3) above, R1 and R2 each independently represent a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a linear or branched alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, even more preferably a hydrogen atom; a each independently represent an integer between 0 and 3, preferably 0 or 1, more preferably 0; b each independently represent an integer between 0 and 4, preferably 0 or 1, even more preferably 0; n is preferably an integer between 1 and 50, more preferably 2 to 30, even more preferably 3 to 15, and even more preferably 4 to 10.)

[0025] The epoxy equivalent of the resveratrol-type epoxy resin (A1) is preferably 130 g / eq or more, more preferably 150 g / eq or more, even more preferably 180 g / eq or more, even more preferably 200 g / eq or more, and preferably 500 g / eq or less, more preferably 400 g / eq or less, even more preferably 350 g / eq or less, and even more preferably 300 g / eq or less, from the viewpoint of further improving the balance between the thermal conductivity and heat resistance of the resulting resin sheet and thermal conductive member.

[0026] The method for measuring epoxy equivalent in this specification is described below. Dissolve the epoxy resin in 20 mL of a suitable solvent such as chloroform or cyclohexanone. Add 20 mL of acetic acid and 10 mL of tetraethylammonium bromide acetic acid solution (a solution prepared by adding 400 mL of acetic acid to 100 g of tetraethylammonium bromide and dissolving it) to the resulting solution, and titrate using a potentiometric automatic titrator (Metrohm 916 Ti-Touch) with a perchloric acid solution adjusted to 0.1 N. Perform a blank test and calculate the epoxy equivalent using the following formula. Epoxy equivalent (g / eq) = (1000 × W) / {(SB) × N} W: Sample mass B: Amount of 0.1N perchloric acid solution used in the blank test (mL) S: Volume (mL) of 0.1N perchloric acid solution used for titration of the sample. N: Normality of perchloric acid solution (0.1N)

[0027] The weight-average molecular weight (Mw) of the resveratrol-type epoxy resin (A1) is preferably 350 or more, more preferably 500 or more, even more preferably 1,000 or more, even more preferably 1,500 or more, even more preferably 1,800 or more, even more preferably 2,000 or more, even more preferably 2,300 or more, even more preferably 2,500 or more, even more preferably 2,800 or more, and preferably 10,000 or less, more preferably 7,000 or less, and even more preferably 4,000 or less. The weight-average molecular weight of the resveratrol-type epoxy resin (A1) was measured by gel permeation chromatography (GPC), and the value shown is the value converted using a standard polystyrene calibration curve.

[0028] In this specification, the weight-average molecular weight (Mw) of resveratrol-type epoxy resin (A1) can be measured by obtaining a molecular weight distribution curve using GPC (Gel Permeation Chromatography). The weight-average molecular weight (Mw) of resveratrol-type epoxy resin (A1) is calculated using the polystyrene equivalent value obtained from the calibration curve of standard polystyrene (PS) obtained by GPC measurement. The measurement conditions for GPC are as follows, for example: Tosoh Corporation's gel permeation chromatography apparatus HLC-8320GPC Columns: TSK-GEL GMH, G2000H, SuperHM-M manufactured by Tosoh Corporation. Detector: UV detector for liquid chromatograms Measurement temperature: 40℃ Solvent: THF Sample concentration: 2.0 mg / ml

[0029] (Other epoxy resins (A2)) The epoxy resin (A) may include epoxy resins other than resveratrol-type epoxy resin (A1), such as (A2), from the viewpoint of further improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation, and adhesion to other components of the resulting resin sheet or thermal conductive member.

[0030] The epoxy resin (A2) is not particularly limited, but examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol M type epoxy resin (4,4'-(1,3-phenylenediisopridiene)bisphenol type epoxy resin), bisphenol P type epoxy resin (4,4'-(1,4-phenylenediisopridiene)bisphenol type epoxy resin), bisphenol Z type epoxy resin (4,4'-cyclohexydienebisphenol type epoxy resin), etc. Bisphenol-type epoxy resins; Novolac-type epoxy resins such as phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, tetraphenol group ethane-type novolac-type epoxy resins, and novolac-type epoxy resins having a condensed ring aromatic hydrocarbon structure; Epoxy resins having a biphenyl skeleton; Arylalkylene-type epoxy resins such as xylylene-type epoxy resins and epoxy resins having a biphenyl aralkyl skeleton; Naphthylene ether-type epoxy resins; Naphthol-type epoxy resins; Naphthalenediol-type epoxy resins; 1,6-dihydroxy The epoxy resin contains at least one selected from the group consisting of naphthalene-type epoxy resins, 2,7-dihydroxynaphthalene-type epoxy resins, 1,5-dihydroxynaphthalene-type epoxy resins, 1,4-dihydroxynaphthalene-type epoxy resins, 2,6-dihydroxynaphthalene-type epoxy resins, bifunctional to tetrafunctional epoxy-type naphthalene resins; binaphthyl-type epoxy resins; epoxy resins having a naphthalene aralkyl skeleton; anthracene-type epoxy resins; epoxy resins having a dicyclopentadiene skeleton; norbornene-type epoxy resins; epoxy resins having an adamantane skeleton; fluorene-type epoxy resins; and epoxy resins having a phenol aralkyl skeleton, and preferably contains at least one selected from the group consisting of bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, epoxy resins having a dicyclopentadiene skeleton, epoxy resins having a biphenyl skeleton, epoxy resins having an adamantane skeleton, epoxy resins having a phenol aralkyl skeleton, epoxy resins having a biphenyl aralkyl skeleton, and epoxy resins having a naphthalene aralkyl skeleton.

[0031] The epoxy resin (A2) preferably includes an epoxy resin that is liquid or semi-solid at 23°C, from the viewpoint of further improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation, and adhesion to other components of the resulting resin sheet or thermal conductive member. In this embodiment, the epoxy resin (A) preferably comprises a combination of a resveratrol-type epoxy resin (A1) and an epoxy resin (A2) that is liquid or semi-solid at 23°C, from the viewpoint of further improving the moldability of the resulting thermosetting resin composition.

[0032] From the viewpoint of further improving the balance between thermal conductivity and heat resistance of the resulting resin sheet and thermal conductive member, the epoxy resin (A) preferably contains 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 80% by mass or more, and preferably 100% by mass or less of resveratrol-type epoxy resin (A1).

[0033] The content of epoxy resin (A) in the thermosetting resin composition according to this embodiment is, when the total amount of components excluding the thermal conductive filler (C) in the thermosetting resin composition according to this embodiment, i.e., the total amount of epoxy resin (A), cyanate ester resin (B), phenoxy resin (D), and curing accelerator (E) (hereinafter referred to as "total amount of resin components" in this specification) is 100 parts by mass, preferably 10 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more, from the viewpoint of further improving the balance of thermal conductivity and heat resistance of the obtained resin sheet and thermal conductive member, preferably 80 parts by mass or less, more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, even more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less, from the viewpoint of further improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation, adhesion to other members, etc. of the obtained resin sheet and thermal conductive member.

[0034] <Cyanate ester resin (B)> The thermosetting resin composition according to this embodiment includes a cyanate ester resin (B) from the viewpoint of improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation properties, and adhesion to other components of the resulting resin sheet or thermal conductive member. In this specification, the cyanate ester resin (B) does not contain isocyanate compounds. The cyanate ester resin (B) includes, for example, at least one selected from the group consisting of novolac-type cyanate ester resins; bisphenol-type cyanate ester resins such as bisphenol A-type cyanate ester resins, bisphenol E-type cyanate ester resins, and tetramethylbisphenol F-type cyanate ester resins; naphthol aralkyl-type cyanate ester resins obtained by the reaction of naphthol aralkyl-type phenol resins with cyanide halides; dicyclopentadiene-type cyanate ester resins; and biphenylene skeleton-containing phenol aralkyl-type cyanate ester resins. From the viewpoint of further improving the balance between thermal conductivity and heat resistance of the resulting resin sheet or thermal conductive member, it preferably includes at least one selected from the group consisting of novolac-type cyanate ester resins and naphthol aralkyl-type cyanate ester resins, and more preferably includes novolac-type cyanate ester resins.

[0035] Examples of novolac-type cyanate ester resins include those represented by the following formula (I).

[0036] [ka]

[0037] The average repeating unit n of the novolac-type cyanate ester resin represented by formula (I) above is any integer. The average repeating unit n is not particularly limited, but from the viewpoint of further improving the heat resistance of the novolac-type cyanate ester resin and further suppressing the desorption and volatilization of low-molecules during heating, it is preferably 1 or more, more preferably 2 or more, and from the viewpoint of suppressing an increase in melt viscosity and further improving moldability, it is preferably 10 or less, more preferably 7 or less.

[0038] Examples of naphthol aralkyl type cyanate ester resins include those represented by the following formula (II). The naphthol aralkyl type cyanate ester resin represented by the following formula (II) is obtained, for example, by condensing a naphthol aralkyl type phenol resin, which is obtained by the reaction of naphthols such as α-naphthol or β-naphthol with p-xylylene glycol, α,α'-dimethoxy-p-xylene, 1,4-di(2-hydroxy-2-propyl)benzene, etc., with a cyanide halogen. The repeating unit n in the following formula (II) is preferably an integer of 10 or less, from the viewpoint of obtaining a more uniform resin sheet and preventing a decrease in yield.

[0039] [ka]

[0040] In formula (II) above, R independently represents either a hydrogen atom or a methyl group, and n represents an integer between 1 and 10.

[0041] The cyanate ester resin (B) content in the thermosetting resin composition according to this embodiment is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more, from the viewpoint of further improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation, and adhesion to other members of the resulting resin sheet or thermal conductive member, when the total amount of resin components in the thermosetting resin composition according to this embodiment is 100 parts by mass. From the viewpoint of further improving the balance between thermal conductivity and heat resistance of the resulting resin sheet or thermal conductive member, the content is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less.

[0042] <Thermal conductive filler (C)> The thermosetting resin composition according to this embodiment includes a thermally conductive filler (C) from the viewpoint of improving the thermal conductivity of the resulting resin sheet or thermally conductive member. The thermally conductive filler (C) includes, for example, at least one selected from the group consisting of silica, alumina, aluminum nitride, silicon carbide, boron nitride, silicon nitride, magnesium oxide, aluminum hydroxide, and barium sulfate, and from the viewpoint of further improving thermal conductivity, it preferably includes at least one selected from the group consisting of boron nitride, aluminum nitride, and alumina, and more preferably includes boron nitride.

[0043] The boron nitride preferably comprises flaky boron nitride, more preferably comprises at least one selected from the group consisting of monodisperse particles of flaky boron nitride and aggregated particles of flaky boron nitride, and even more preferably comprises aggregated particles of flaky boron nitride. The flaky boron nitride may be granulated. The aggregated particles of flaky boron nitride may be sintered or unsintered.

[0044] The average particle size of the thermally conductive filler (C) is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 30 μm or more, and even more preferably 50 μm or more, from the viewpoint of further improving the thermal conductivity of the resulting resin sheet or thermally conductive member. From the viewpoint of improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation, and adhesion to other members of the resulting resin sheet or thermally conductive member, it is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 200 μm or less. Here, the average particle size of the thermally conductive filler (C) is the median diameter (D) when the particle size distribution is measured on a volume basis using a laser diffraction particle size distribution analyzer. 50 )

[0045] The thermally conductive filler (C) preferably contains 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and preferably 100% by mass or less of the boron nitride.

[0046] The content of the thermal conductive filler (C) in the thermosetting resin composition according to this embodiment is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, even more preferably 150 parts by mass or more, even more preferably 200 parts by mass or more, even more preferably 250 parts by mass or more, and even more preferably 280 parts by mass or more, from the viewpoint of further improving thermal conductivity, and from the viewpoint of improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation, adhesion to other members, etc. of the resulting resin sheet or thermal conductive member, preferably 500 parts by mass or less, more preferably 450 parts by mass or less, even more preferably 400 parts by mass or less, even more preferably 350 parts by mass or less, and even more preferably 330 parts by mass or less.

[0047] <Phenoxy resin (D)> The thermosetting resin composition according to this embodiment preferably further contains phenoxy resin (D) from the viewpoint of further improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation properties, and adhesion to other components of the resulting resin sheet or thermal conductive member.

[0048] Phenoxy resin (D) includes, for example, at least one selected from the group consisting of phenoxy resins having a bisphenol skeleton, phenoxy resins having a naphthalene skeleton, phenoxy resins having an anthracene skeleton, phenoxy resins having a biphenyl skeleton, phenoxy resins having a bisphenolacetophenone skeleton, and phenoxy resins having a structure with multiple of these skeletons; more preferably includes a phenoxy resin having a bisphenol skeleton; even more preferably includes at least one selected from phenoxy resins having a bisphenol A skeleton, phenoxy resins having a bisphenol F skeleton, and phenoxy resins having both a bisphenol A skeleton and a bisphenol F skeleton; and even more preferably includes a phenoxy resin having a bisphenol A skeleton.

[0049] The weight-average molecular weight (Mw) of the phenoxy resin (D) is not particularly limited, but is preferably 1,000 or more, more preferably 2,000 or more, even more preferably 5,000 or more, even more preferably 10,000 or more, even more preferably 20,000 or more, and preferably 80,000 or less. The weight-average molecular weight of the phenoxy resin (D) is measured by gel permeation chromatography (GPC) and the value is shown converted using a standard polystyrene calibration curve.

[0050] In this embodiment, the weight-average molecular weight (Mw) of the phenoxy resin (D) can be measured by obtaining a molecular weight distribution curve using GPC (Gel Permeation Chromatography). The weight-average molecular weight (Mw) of the phenoxy resin is calculated using the polystyrene equivalent value obtained from the calibration curve of standard polystyrene (PS) obtained by GPC measurement. The measurement conditions for GPC are as follows, for example: Tosoh Corporation's gel permeation chromatography apparatus HLC-8320GPC Columns: TSK-GEL GMH, G2000H, SuperHM-M manufactured by Tosoh Corporation. Detector: UV detector for liquid chromatograms Measurement temperature: 40℃ Solvent: THF Sample concentration: 2.0 mg / ml

[0051] The content of phenoxy resin (D) in the thermosetting resin composition according to this embodiment is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, and even more preferably 20 parts by mass or more, from the viewpoint of further improving the moldability, appearance, flexibility, pliability, bending resistance, stress relaxation, and adhesion to other members of the resulting resin sheet or thermal conductive member, and preferably 60 parts by mass or less, more preferably 50 parts by mass or less, even more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, from the viewpoint of further improving the balance between thermal conductivity and heat resistance of the resulting resin sheet or thermal conductive member.

[0052] <Curing accelerator (E)> The thermosetting resin composition according to this embodiment preferably further includes a curing accelerator (E) from the viewpoint of further improving thermosetting properties, reactivity, and heat resistance. The curing accelerator (E) is not particularly limited, but may include, for example, at least one selected from the group consisting of nitrogen atom-containing compounds, organophosphorus compounds, phenolic compounds, organic acids, organometallic salts, and phenolic resins. The type and amount of curing accelerator (E) are not particularly limited, but an appropriate one can be selected from the viewpoint of reaction rate, reaction temperature, storage properties, etc.

[0053] From the viewpoint of further improving heat resistance, the curing accelerator (E) preferably includes at least one selected from the group consisting of nitrogen atom-containing compounds such as imidazoles and tertiary amines; phenol compounds; phenol resins; and benzoxazine resins.

[0054] From the viewpoint of further improving heat resistance, the imidazoles preferably include at least one selected from the group consisting of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2,4-diethylimidazole, 2-phenyl-4-methyl-5-hydroxyimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate. From the viewpoint of further improving heat resistance, the tertiary amines preferably include at least one selected from the group consisting of triethylamine, tributylamine, 1,4-diazabicyclo[2.2.2]octane, and 1,8-diazabicyclo(5,4,0)undecene-7. From the viewpoint of further improving heat resistance, the phenol compound preferably includes at least one selected from the group consisting of phenol, bisphenol A, bisphenol F, nonylphenol, allylphenol, and 2,2-bis(3-methyl-4-hydroxyphenyl)propane. From the viewpoint of further improving heat resistance, the phenolic resin preferably includes at least one selected from the group consisting of novolac-type phenolic resins such as phenol novolac resin, cresol novolac resin, naphthol novolac resin, aminotriazine novolac resin, novolac resin, and trisphenylmethane-type phenol novolac resin; modified phenolic resins such as terpene-modified phenolic resin and dicyclopentadiene-modified phenolic resin; aralkyl-type resins such as phenol aralkyl resin having a phenylene skeleton and / or biphenylene skeleton, naphthol aralkyl resin having a phenylene skeleton and / or biphenylene skeleton; and resol-type phenolic resin. From the viewpoint of further improving heat resistance, benzoxazine resins are preferably o-cresolaniline type benzoxazine resin, m-cresolaniline type benzoxazine resin, p-cresolaniline type benzoxazine resin, phenol-aniline type benzoxazine resin, phenol-methylamine type benzoxazine resin, phenol-cyclohexylamine type benzoxazine resin, phenol-m-toluidine type benzoxazine resin, phenol-3,5-dimethylaniline type benzoxazine resin, bisphenol A-aniline type benzoxazine resin, bisphenol A-amine type benzoxazine resin, and bisphenol F-amine type benzoxazine resin. It comprises at least one selected from the group consisting of diline-type benzoxazine resin, bisphenol S-aniline-type benzoxazine resin, dihydroxydiphenylsulfone-aniline-type benzoxazine resin, dihydroxydiphenylether-aniline-type benzoxazine resin, benzophenone-type benzoxazine resin, biphenyl-type benzoxazine resin, bisphenol AF-aniline-type benzoxazine resin, bisphenol A-methylaniline-type benzoxazine resin, phenol-diaminodiphenylmethane-type benzoxazine resin, triphenylmethane-type benzoxazine resin, and phenolphthalein-type benzoxazine resin.

[0055] The content of the curing accelerator (E) in the thermosetting resin composition according to this embodiment is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.10 parts by mass or more, even more preferably 0.20 parts by mass or more, even more preferably 0.50 parts by mass or more, even more preferably 1.0 part by mass or more, and preferably 10.0 parts by mass or less, more preferably 8.0 parts by mass or less, even more preferably 5.0 parts by mass or less, and even more preferably 3.0 parts by mass or less, when the total amount of resin components in the thermosetting resin composition according to this embodiment is 100 parts by mass, from the viewpoint of further improving thermosetting properties, reactivity and heat resistance.

[0056] <Other ingredients> The thermosetting resin composition according to this embodiment may contain components other than those described above. Examples of other components include coupling agents, antioxidants, leveling agents, dispersion stabilizers, and surfactants.

[0057] The total content of epoxy resin (A), cyanate ester resin (B), thermal conductive filler (C), phenoxy resin (D), and curing accelerator (E) in the thermosetting resin composition according to the present invention is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and preferably 100% by mass or less, when the total content of the thermosetting resin composition is considered to be 100% by mass.

[0058] [Method for producing thermosetting resin compositions] For example, the following method can be used to produce the thermosetting resin composition according to this embodiment. First, a resin varnish (a varnish-like thermosetting resin composition) is prepared by mixing each of the above components, excluding the thermally conductive filler (C), in a solvent. This mixing can be performed using various mixers such as ultrasonic dispersion, high-pressure impact dispersion, high-speed rotational dispersion, bead mill, high-speed shear dispersion, and rotational dispersion. The above solvent is not particularly limited, but includes, for example, at least one selected from the group consisting of acetone, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, toluene, ethyl acetate, cyclohexane, heptane, cyclohexanone, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, ethylene glycol, cellosorb-based solvents, carbitol-based solvents, anisole, and N-methylpyrrolidone.

[0059] Next, a thermosetting resin composition in the B-stage state can be obtained by adding a thermally conductive filler (C) to the obtained resin varnish and kneading it using a three-roll press or the like. Adding the thermally conductive filler (C) during kneading makes it possible to disperse the thermally conductive filler (C) more uniformly in the thermosetting resin composition, but the method is not limited to this method. The thermosetting resin composition may be added during kneading, or it may be added when mixing the resin varnish. After kneading, it may be cooled and solidified, and the kneaded material may be processed into granules, tablets, or sheets.

[0060] [Resin sheet] The resin sheet according to this embodiment includes a resin composition layer made of the thermosetting resin composition according to this embodiment described above. The resin composition layer is preferably in the B stage state. A specific form of the resin sheet according to this embodiment includes, for example, a base material and a resin composition layer provided on the base material, which is made of the thermosetting resin composition according to this embodiment.

[0061] The resin sheet according to this embodiment can be obtained, for example, by applying a varnish-like thermosetting resin composition to a substrate and then performing a solvent removal treatment on the resulting coating film. Preferably, the solvent content in the resin sheet is 10% by mass or less relative to the entire thermosetting resin composition. For example, the solvent removal treatment can be performed under conditions of 80°C to 200°C for 1 to 30 minutes.

[0062] The planar shape of the resin sheet according to this embodiment is not particularly limited and can be appropriately selected according to the shape of the heat sink or heat generating element, but it can be rectangular, for example. The thickness of the resin composition layer of the resin sheet according to this embodiment is, for example, 50 μm to 500 μm, from the viewpoint of further improving the balance of mechanical strength, heat resistance, insulation, and heat dissipation.

[0063] The above-mentioned substrate includes, for example, at least one selected from the group consisting of resin film and metal foil. The resin film is not particularly limited, but includes, for example, at least one selected from the group consisting of polyolefin films such as polyethylene film and polypropylene film; polyester films such as polyethylene terephthalate film and polybutylene terephthalate film; polycarbonate film; fluororesin film; and polyimide resin film. The metal foil is not particularly limited, but includes, for example, at least one selected from the group consisting of copper foil, copper alloy foil, aluminum foil, aluminum alloy foil, iron foil, iron alloy foil, silver foil, silver alloy foil, gold foil, gold alloy foil, zinc foil, zinc alloy foil, nickel foil, nickel alloy foil, tin foil, and tin alloy foil. The thickness of the above-mentioned substrate is, for example, 10 μm or more and 500 μm or less.

[0064] The resin sheet according to this embodiment can be used for various substrate applications, and from the viewpoint of balancing thermal conductivity and heat resistance, it can be suitably used as a material for power module substrates used in power modules.

[0065] [Thermal conductive material] The thermally conductive member according to this embodiment includes a resin curing layer made from a cured product of a thermosetting resin composition. The resin curing layer is preferably in the C stage state. The thermally conductive member according to this embodiment can be obtained, for example, by curing the resin sheet according to this embodiment described above and peeling off the base material as necessary. Furthermore, the thermally conductive member according to this embodiment is preferably a thermally conductive sheet from the viewpoint of improving handling.

[0066] The thermally conductive member according to this embodiment is used, for example, as a thermal conductive material interposed between a heat-generating element and a heat-sinking element. Examples of heat-generating elements include semiconductor elements, LED elements, substrates on which semiconductor elements or LED elements are mounted, Central Processing Units (CPUs), power semiconductors, lithium-ion batteries, and fuel cells. Examples of heat dissipation devices include heat sinks, heat spreaders, and cooling fins.

[0067] Furthermore, the thermally conductive member according to this embodiment can be provided, for example, at a bonding interface in an electronic device where high thermal conductivity is required, thereby promoting heat conduction from the heat-generating element to the heat-sinking element. This suppresses failures caused by characteristic fluctuations in semiconductor chips and the like, and improves the stability of the electronic device.

[0068] The planar shape of the thermal conductive member according to this embodiment is not particularly limited and can be appropriately selected according to the shape of the heat sink, heat generating element, etc., but it can be rectangular, for example. The thickness of the resin cured material layer in the thermal conductive member according to this embodiment is preferably 10 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, and even more preferably 100 μm or more, from the viewpoint of further improving mechanical strength, heat resistance and insulation, and preferably 400 μm or less, more preferably 350 μm or less, and even more preferably 250 μm or less, from the viewpoint of further improving heat dissipation.

[0069] In the thermally conductive member according to this embodiment, the glass transition temperature of the resin cured layer, measured by dynamic viscoelasticity measurement under the conditions of a heating rate of 5°C / min and a frequency of 10 Hz, is preferably 210°C or higher, more preferably 215°C or higher, and even more preferably 220°C or higher, from the viewpoint of further improving heat resistance and insulation properties. The upper limit of the glass transition temperature is not particularly limited, but for example it may be 350°C or lower, 330°C or lower, or 300°C or lower. The glass transition temperature can be controlled by appropriately adjusting the types and proportions of each component that make up the thermally conductive member.

[0070] In the thermally conductive member according to this embodiment, the thermal conductivity in the thickness direction of the resin cured layer, measured under atmospheric conditions at 25°C using the flash method in accordance with JIS R 1611:2010, is preferably 15 W / (m·K) or higher, more preferably 16 W / (m·K) or higher, and even more preferably 17 W / (m·K) or higher, from the viewpoint of further improving the heat dissipation performance of the resulting metal base substrate and electronic device. Specifically, the thermal conductivity can be calculated using the following formula based on the thermal diffusivity (α) measured by the flash method (half-time method), the specific heat (Cp) measured by the DSC method, and the density (ρ) measured in accordance with JIS-K-6911. The measurement temperature is 25°C. Thermal conductivity [W / (m·K)]=α[m 2 / s] × Cp[J / (kg·K)] × ρ[kg / m 3 ]

[0071] The thermally conductive member according to this embodiment can be used for various substrate applications, and from the viewpoint of balancing thermal conductivity and heat resistance, it can be suitably used as a material for power module substrates used in power modules.

[0072] [Metal-based substrate] Figure 1 is a schematic cross-sectional view showing an example of the configuration of the metal base substrate 100 according to this embodiment. The metal base substrate 100 according to this embodiment comprises a metal substrate 101, an insulating layer 102 provided on the metal substrate 101, and a metal layer 103 provided on the insulating layer 102, wherein the insulating layer 102 includes a resin composition layer made of the thermosetting resin composition according to this embodiment described above, and one selected from the group consisting of the thermally conductive member according to this embodiment described above.

[0073] The insulating layer 102 may be composed of a resin composition layer in a B-stage state before circuit processing of the metal layer 103, and may be a cured resin layer obtained by curing the insulating layer after circuit processing.

[0074] The thickness of the insulating layer 102 is preferably 10 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, and even more preferably 100 μm or more, from the viewpoint of further improving mechanical strength, heat resistance and insulating properties, and preferably 400 μm or less, more preferably 350 μm or less, and even more preferably 250 μm or less, from the viewpoint of further improving the heat dissipation of the entire metal base substrate 100.

[0075] The metal layer 103 is provided on the insulating layer 102 and is subjected to circuit processing. The metal constituting this metal layer 103 includes at least one selected from the group consisting of, for example, copper, copper alloys, aluminum, aluminum alloys, nickel, iron, and tin. From the viewpoint of further improving circuit processability, the metal layer 103 preferably includes at least one selected from the group consisting of a copper layer and an aluminum layer, and more preferably includes a copper layer. The metal layer 103 may be a metal foil available in sheet form or a metal foil available in roll form.

[0076] The thickness of the metal layer 103 is preferably 0.01 mm or more, more preferably 0.05 mm or more, even more preferably 0.10 mm or more, and even more preferably 0.25 mm or more, from the viewpoint of further suppressing heat generation of the circuit pattern even in applications requiring high current. From the viewpoint of further improving circuit processability and making the entire substrate thinner, it is preferably 10.0 mm or less, more preferably 5.0 mm or less, even more preferably 3.0 mm or less, even more preferably 2.0 mm or less, and even more preferably 1.0 mm or less.

[0077] The metal substrate 101 has the role of dissipating heat accumulated in the metal base substrate 100. The metal substrate 101 is not particularly limited as long as it is a heat-dissipating metal substrate, but preferably it includes at least one selected from the group consisting of copper substrates, copper alloy substrates, aluminum substrates and aluminum alloy substrates, and more preferably it includes at least one selected from the group consisting of copper substrates and aluminum substrates, and even more preferably it includes a copper substrate.

[0078] The thickness of the metal substrate 101 is not particularly limited, but from the viewpoint of improving processability in processes such as outer shape processing and cutting, and making the entire substrate thinner, it is preferably 20.0 mm or less, more preferably 10.0 mm or less, and even more preferably 5.0 mm or less. From the viewpoint of further improving heat dissipation, it is preferably 0.01 mm or more, more preferably 0.1 mm or more, even more preferably 0.5 mm or more, even more preferably 1.0 mm or more, and even more preferably 2.0 mm or more.

[0079] The metal base substrate 100 may have a metal layer 103 that has been processed with a circuit by etching or the like. In this metal base substrate 100, a solder resist (not shown) may be formed on the outermost layer, and connection electrode portions may be exposed so that electronic components can be mounted by exposure and development.

[0080] The metal base substrate 100 according to this embodiment can be used for various substrate applications, and from the viewpoint of balancing thermal conductivity and heat resistance, it can be suitably used as a power module substrate for power modules.

[0081] [Electronic equipment] The metal base substrate 100 according to this embodiment can be used in various applications where heat dissipation and insulation are required, and can be used, for example, in electronic devices such as semiconductor devices. Figure 2 is a schematic cross-sectional view showing an example of the configuration of the electronic device 200 according to this embodiment. The electronic device 200 according to this embodiment comprises the metal base substrate 100 according to this embodiment described above, and an electronic component 201 provided on the metal base substrate 100. The metal base substrate 100 can function as a heat spreader against the heat generated by the electronic components 201 (various heat-generating elements) during operation.

[0082] The electronic device 200 shown in Figure 2 has electronic components 201 such as semiconductor elements mounted on a metal layer 103 of a metal base substrate 100 via an adhesive layer 202 such as a die attach material. The electronic components 201 are connected to connection electrodes formed on the metal base substrate 100 via bonding wires 203 and are mounted on the metal base substrate 100. The electronic components 201 are then encapsulated together on the metal base substrate 100 by a sealing resin layer 205. A heat sink 207 is provided on the metal substrate 101 side of the metal base substrate 100 via a thermal conductive layer 209 (thermal interface material (TIM)). The heat sink 207 is made of a material with excellent thermal conductivity, such as aluminum, iron, or copper.

[0083] As the electronic component 201, a power semiconductor element can be used. This makes it possible to configure the electronic device 200 according to this embodiment as a power module. In a power module, other electronic components besides power semiconductor elements may be mounted on the metal base substrate 100. Power semiconductor devices, such as those using wide-bandgap materials like SiC, GaN, Ga2O3, or diamond, are designed for use with high voltage and high current. As a result, they generate more heat than ordinary silicon chips (semiconductor devices) and operate in even higher temperature environments. Power semiconductor devices are required to operate for extended periods in high-temperature environments, such as 200°C or 250°C or higher. Examples of power semiconductor devices include rectifier diodes, power transistors, power MOSFETs, insulated-gate bipolar transistors (IGBTs), thyristors, gate-turn-off thyristors (GTOs), and triacs.

[0084] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted as long as they do not impair the effects of the present invention.

[0085] It should be noted that the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that can achieve the objectives of the present invention are included in the present invention. [Examples]

[0086] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited in any way to the descriptions in these examples and comparative examples.

[0087] [Preparation of varnish-like thermosetting resin compositions] Thermosetting resin compositions were prepared for the examples and comparative examples as follows. A varnish-like thermosetting resin composition was obtained by uniformly dissolving and dispersing the resin component and filler component in a solvent, according to the composition of the thermosetting resin composition shown in Table 1. The details of each component in Table 1 are as follows. Note that the unit of measurement for each component in Table 1 is parts by mass.

[0088] (Epoxy resin (A)) • Epoxy resin 1: Resveratrol-type epoxy resin having a resveratrol skeleton in its molecule (weight-average molecular weight: 3319, epoxy equivalent: 257 g / eq, manufactured according to manufacturing example 1 below) • Epoxy resin 2: Bisphenol F type epoxy resin (DIC Corporation, EPICLON 830, liquid at 23°C) • Epoxy resin 3: Dicyclopentadiene type epoxy resin (DIC Corporation, EPICLON HP-7200, solid at 23°C)

[0089] Production Example 1: 41.1 parts by mass of epichlorohydrin, 20.3 parts by mass of resveratrol, 0.3 parts by mass of tetrabutylammonium chloride, and 8.9 parts by mass of dimethyl sulfoxide were weighed into a reaction vessel and dissolved and stirred at 45-50°C, then reacted at 45-50°C for 2 hours. Next, 14.7 parts by mass of 50% by mass aqueous sodium hydroxide solution were slowly added dropwise, and the temperature was raised to 50°C and stirred for 2 hours to react. Next, 14.7 parts by mass of 50% by mass aqueous sodium hydroxide solution were slowly added dropwise, and the temperature was raised to 80-90°C and stirred for 6 hours to react. After concentrating the resulting reaction solution, a resveratrol-type epoxy resin was obtained by reprecipitation using 7 times the volume of pure water relative to the reaction mixture.

[0090] (Cyanate ester resin (B)) • Cyanate ester resin 1: Novolac-type cyanate ester resin (manufactured by Lonza Japan, PT-30)

[0091] (Thermal conductive filler (C)) • Thermally conductive filler 1: Aggregated particles of flaky boron nitride (manufactured by Mizushima Iron Alloy Co., Ltd., boron nitride powder HP-40)

[0092] (Phenoxy resin (D)) • Phenoxy resin 1: Phenoxy resin having a bisphenol A skeleton (manufactured by Nippon Steel Chemical & Material Co., Ltd., YP-55)

[0093] (Curing accelerator (E)) • Curing accelerator 1: Novolac-type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd., product name: PR-55617) • Curing accelerator 2: 2-methylimidazole (2MZ, manufactured by Shikoku Chemicals Co., Ltd.) • Curing accelerator 3: Benzoxazine resin (manufactured by Shikoku Chemicals Co., Ltd., Pd type)

[0094] [Measurement of physical properties of epoxy resin (A)] (Epoxy equivalent) The epoxy resin was dissolved in 20 mL of cyclohexanone. To the resulting solution, 20 mL of acetic acid and 10 mL of tetraethylammonium bromide acetic acid solution (a solution prepared by adding 400 mL of acetic acid to 100 g of tetraethylammonium bromide and dissolving it) were added, and the solution was titrated using a potentiometric automatic titrator (Metrohm 916 Ti-Touch) with a perchloric acid solution adjusted to 0.1 N. A blank test was performed, and the epoxy equivalent was calculated using the following formula. Epoxy equivalent (g / eq) = (1000 × W) / {(SB) × N} W: Sample mass B: Amount of 0.1N perchloric acid solution used in the blank test (mL) S: Volume (mL) of 0.1N perchloric acid solution used for titration of the sample. N: Normality of perchloric acid solution (0.1N)

[0095] (Weight average molecular weight (Mw)) The weight-average molecular weight (Mw) of epoxy resin (A) was calculated using the polystyrene equivalent value obtained from the calibration curve of standard polystyrene (PS) obtained by GPC measurement. The measurement conditions for GPC are as follows: Tosoh Corporation's gel permeation chromatography apparatus HLC-8320GPC Columns: TSK-GEL GMH, G2000H, SuperHM-M manufactured by Tosoh Corporation. Detector: UV detector for liquid chromatograms Measurement temperature: 40℃ Solvent: THF Sample concentration: 2.0 mg / ml

[0096] [Evaluation of resin sheets and thermally conductive materials] The obtained resin sheets and thermally conductive components were evaluated based on the following evaluation criteria. The evaluation results are shown in Table 1.

[0097] (Thermal conductivity) • Fabrication of thermally conductive components Using the obtained varnish-like thermosetting resin composition, a resin sheet in the B-stage state was prepared, sandwiched between 0.018 mm copper foil, and compression molding was performed at 10 MPa, 180°C, and 90 min to obtain a resin molded body (thermal conductive member). A 10 mm square sample for thermal diffusivity measurement was cut from the obtained resin molded body and used for thermal diffusivity measurement.

[0098] • Density (specific gravity) of a resin molded product Density (specific gravity) measurements were performed in accordance with JIS K 6911 (General Test Methods for Thermosetting Plastics). Test specimens were cut from the above-mentioned resin molded body, measuring 2 cm x 2 cm. The unit of density (specific gravity) (ρ) is kg / m³. 3 Let's assume that.

[0099] • Specific heat of resin molded body The specific heat (Cp) of the obtained resin molded articles was measured by the DSC method.

[0100] • Measurement of the thermal conductivity of a resin molded body From the obtained resin molded body, a 10 mm square was cut out to serve as a test specimen for thickness direction measurement. Next, the thermal diffusivity (α) in the thickness direction of the plate-shaped test specimen was measured using the transient method with a ULVAC Xe flash analyzer TD-1RTV. The measurement was performed under atmospheric conditions at 25°C. For the resin molded article, the thermal conductivity was calculated from the obtained measured values ​​of thermal diffusivity (α), specific heat (Cp), and density (ρ) based on the following formula. The results are shown in Table 1. Thermal conductivity [W / (m·K)]=α[m 2 / s] × Cp[J / (kg·K)] × ρ[kg / m 3 ] In Table 1, the thermal conductivity of the resin molded article is referred to as "thermal conductivity".

[0101] (Glass transition temperature (Tg)) The glass transition temperature (Tg) of a resin molded body was measured by dynamic viscoelasticity measurement (DMA) using a dynamic viscoelasticity analyzer (Hitachi High-Tech Corporation, product name: DMA-7100) under conditions of a heating rate of 5°C / min and a frequency of 10 Hz.

[0102] (Flexibility of resin sheets) The flexibility of the obtained B-stage resin sheet was evaluated according to the following criteria. When winding the sheets using a 9cm diameter core, sheets showing cracks or chips were judged as "NG," while those showing no visible abnormalities were judged as "OK."

[0103] [Table 1] [Explanation of symbols]

[0104] 100 Metal base substrate 101 Metal substrate 102 Insulating layer 103 Metal layer 200 Electronic equipment 201 Electronic Components 202 Adhesive layer 203 Bonding Wire 205 Sealing resin layer 207 Heatsink 209 Thermal conductive layer

Claims

1. It comprises epoxy resin (A), cyanate ester resin (B), and thermally conductive filler (C), The epoxy resin (A) comprises a resveratrol-type epoxy resin (A1) having a resveratrol skeleton in its molecule. A thermosetting resin composition in which, when the total epoxy resin (A) is considered to be 100% by mass, the content of the resveratrol-type epoxy resin (A1) is 30% by mass or more and 100% by mass or less.

2. The thermosetting resin composition according to claim 1, further comprising phenoxy resin (D).

3. The thermosetting resin composition according to claim 1 or 2, wherein the thermally conductive filler (C) comprises at least one selected from the group consisting of silica, alumina, aluminum nitride, silicon carbide, boron nitride, silicon nitride, magnesium oxide, aluminum hydroxide, and barium sulfate.

4. The thermosetting resin composition according to claim 1 or 2, wherein the thermally conductive filler (C) contains boron nitride.

5. The thermosetting resin composition according to claim 1 or 2, further comprising a curing accelerator (E).

6. The thermosetting resin composition according to claim 5, wherein the curing accelerator (E) comprises at least one selected from the group consisting of nitrogen atom-containing compounds, phenol compounds, phenolic resins, and benzoxazine resins.

7. A resin sheet comprising a resin composition layer made of the thermosetting resin composition according to claim 1 or 2.

8. The resin sheet according to claim 7, wherein the resin composition layer is in a B-stage state.

9. A thermally conductive member comprising a resin cured layer made of a cured product of the thermosetting resin composition according to claim 1 or 2.

10. The thermal conductive member according to claim 9, which is a thermal conductive sheet.

11. The thermal conductive member according to claim 9, wherein the glass transition temperature of the resin cured layer, as measured by dynamic viscoelasticity measurement under the conditions of a heating rate of 5°C / min and a frequency of 10 Hz, is 210°C or higher.

12. The thermal conductive member according to claim 9, wherein the thermal conductivity in the thickness direction of the resin cured layer, as measured under atmospheric conditions at 25°C by the flash method in accordance with JIS R 1611:2010, is 15 W / (m·K) or more.

13. A metal substrate and An insulating layer provided on the metal substrate, A metal layer provided on the insulating layer, comprising A metal-based substrate wherein the insulating layer includes one selected from the group consisting of a resin composition layer made of the thermosetting resin composition described in claim 1 or 2, and a thermally conductive member described in claim 9.

14. A metal base substrate according to claim 13, An electronic component provided on the aforementioned metal base substrate, An electronic device equipped with the following features.

15. The electronic device according to claim 14, which is a power module.

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