JP2023180727A - Resveratrol epoxy resin, thermosetting resin composition, resin sheet, thermally conductive member, metal base substrate, and electronic apparatus - Google Patents

Abstract

To provide a resveratrol epoxy resin, 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 resveratrol epoxy resin has an epoxy equivalent of 130 g/eq or more and 400 g/eq or less and includes a resveratrol skeleton in each molecule.SELECTED DRAWING: Figure 1

Description

The present invention relates to a resveratrol type epoxy resin, a thermosetting resin composition, a resin sheet, a thermally conductive member, a metal base substrate, and an electronic device.

As the processing capacity of electronic components improves, the amount of heat generated from electronic components tends to increase. Therefore, heat dissipation measures that effectively dissipate heat from electronic components to the outside have become important. As such heat dissipation measures, thermally conductive members made of heat dissipating materials such as metals, ceramics, or resin compositions are used.

Among these thermally conductive members, thermally conductive epoxy resin molded bodies formed from epoxy resin compositions have good electrical insulation, mechanical properties, heat resistance, chemical resistance, adhesive properties, etc. It is widely used mainly in the electrical and electronic fields as cast products, laminates, encapsulants, thermally conductive sheets, adhesives, etc.

Examples of techniques related to such a thermally conductive epoxy resin molded body include those described in Patent Document 1 (Japanese Patent Laid-Open No. 2015-193504) and Patent Document 2 (Japanese Patent Laid-Open No. 2004-331811).

Patent Document 1 includes a resin component and a thermally conductive filler dispersed in the resin component, and the thermally conductive filler (1) has a loose bulk density of 0.52 g/mL or more. , (2) states that a resin composition containing boron nitride particles having an average circularity of 0.65 or more provides a material with excellent heat dissipation properties.

Patent Document 2 describes a thermally conductive epoxy resin molded body mainly composed of an epoxy resin having an azomethine group, which is characterized by a thermal conductivity of 0.5 to 30 W/(m·K). It is described that a thermally conductive epoxy resin molded article can exhibit excellent thermal conductivity.

Japanese Patent Application Publication No. 2015-193504 Japanese Patent Application Publication No. 2004-331811

With the further improvement in the processing capacity of electronic components, thermally conductive members are required to further improve the balance between thermal conductivity and heat resistance.

The present invention has been made in view of the above circumstances, and provides a resveratrol-type epoxy resin, a thermosetting resin composition, and a resin sheet, which can realize a thermally conductive member with an improved balance of thermal conductivity and heat resistance, and The present invention provides a thermally conductive member, a metal base substrate, and an electronic device with improved balance between thermal conductivity and heat resistance.

The present inventors have made extensive studies to achieve the above object. As a result, by using a resveratrol-type epoxy resin with an epoxy equivalent within a specific range and a resveratrol skeleton in the molecule, the balance between thermal conductivity and heat resistance of the resulting thermally conductive member is improved. After discovering what could be done, the present invention was completed.

According to the present invention, the following resveratrol-type epoxy resin, thermosetting resin composition, resin sheet, thermally conductive member, metal base substrate, and electronic device are provided.

[1]
A resveratrol type epoxy resin having an epoxy equivalent of 130 g/eq or more and 400 g/eq or less and having a resveratrol skeleton in the molecule.
[2]
The resveratrol-type epoxy resin according to [1] above, which has a weight average molecular weight of 350 or more and 5,000 or less.
[3]
The resveratrol-type epoxy resin according to [1] or [2] above, which is used for a thermally conductive member.
[4]
The resveratrol-type epoxy resin according to any one of [1] to [3] above, which has a glass transition temperature of 170° C. or higher as measured by Method 1 below.
(Method 1)
A composition consisting of 100 parts by mass of the resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180°C for 90 minutes to form a 3 mm× A cured product of 3 mm x 3 mm was prepared, and the temperature read from the intersection of the tangents at 60° C. and 200° C. when measured by thermomechanical analysis (TMA) at a heating rate of 5° C./min was determined as Glass transition temperature.
[5]
The resveratrol-type epoxy resin according to any one of [1] to [4] above, which has a thermal diffusivity of 0.190 mm ² /s or more as measured by Method 2 below.
(Method 2)
A composition consisting of 100 parts by mass of the resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180°C for 90 minutes to form a 10 mm× A cured product of 10 mm x 1 mm was prepared, and then the thermal diffusivity of the obtained cured product was measured at 25° C. in an air atmosphere by the Xe flash method, and the obtained value was calculated based on the resveratrol. Let it be the thermal diffusivity of the mold epoxy resin.
[6]
The resveratrol type epoxy resin contains a monomer, a dimer or more, and the content of the monomer is 10% by mass or more, according to any one of [1] to [5] above. Resveratrol type epoxy resin.
[7]
The resveratrol-type epoxy resin according to any one of [1] to [6] above, which has a linear expansion coefficient of 45 ppm/°C or less as measured by method 3 below.
(Method 3)
A composition consisting of 100 parts by mass of the resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180°C for 90 minutes to form a 3 mm× A 3 mm x 3 mm cured product was produced, and then the coefficient of linear expansion in the thickness direction in the range of 50°C to 70°C of the obtained cured product was measured by thermomechanical analysis. It is the linear expansion coefficient of Troll type epoxy resin.
[8]
The resveratrol-type epoxy resin according to any one of [1] to [7] above, which has a 5% weight loss temperature (Td5) of 300° C. or higher as measured by method 4 below.
(Method 4)
A composition consisting of 100 parts by mass of the resveratrol type epoxy resin and 0.1 part by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180° C. for 90 minutes. A cured product powder was prepared by pulverizing the product in a mortar, and then, using a simultaneous differential thermogravimetric measurement device, the obtained cured product was pulverized under a dry nitrogen stream at a heating rate of 10°C/min. By raising the temperature from 30°C to 600°C, the temperature at which the cured product loses 5% weight (Td5) was measured, and the obtained value was calculated as the 5% weight loss temperature (Td5) of the resveratrol-type epoxy resin. ).
[9]
The epoxy resin (A) contains an epoxy resin (A) and a thermally conductive filler (C), and the epoxy resin (A) contains the resveratrol-type epoxy resin (A1) according to any one of [1] to [8] above. A thermosetting resin composition containing.
[10]
[9] The thermally conductive filler (C) contains 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. The thermosetting resin composition described in ].
[11]
The thermosetting resin composition according to [9] or [10], wherein the thermally conductive filler (C) contains boron nitride.
[12]
A resin sheet comprising a resin composition layer made of the thermosetting resin composition according to any one of [9] to [11] above.
[13]
The resin sheet according to [12] above, wherein the resin composition layer is in a B-stage state.
[14]
A thermally conductive member comprising a cured resin layer made of a cured product of the thermosetting resin composition according to any one of [9] to [11] above.
[15]
The thermally conductive member according to [14] above, which is a thermally conductive sheet.
[16]
[14] or [15] above, wherein the cured resin layer has a glass transition temperature of 210°C or higher, as measured by dynamic viscoelasticity measurement at a heating rate of 5°C/min and a frequency of 10Hz. Thermal conductive member.
[17]
The thermal conductivity of the cured resin layer in the thickness direction is 15 W/(m K) or more, as measured by a flash method in accordance with JIS R 1611:2010 in an air atmosphere at 25°C. The thermally conductive member according to any one of [14] to [16].
[18]
a metal substrate;
an insulating layer provided on the metal substrate;
a metal layer provided on the insulating layer,
The insulating layer is a resin composition layer made of the thermosetting resin composition according to any one of [9] to [11], and the thermal conductivity layer according to any one of [14] to [17] above. A metal base substrate comprising one selected from the group consisting of members.
[19]
The metal base substrate according to [18] above,
an electronic component provided on the metal base substrate;
An electronic device comprising:
[20]
The electronic device according to [19] above, which is a power module.

According to the present invention, a resveratrol-type epoxy resin, a thermosetting resin composition, and a resin sheet that can realize a thermally conductive member with an improved balance of thermal conductivity and heat resistance, and A thermally conductive member, a metal base substrate, and an electronic device with improved balance can be provided.

FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a metal base substrate according to the present embodiment. 1 is a schematic cross-sectional view showing an example of the configuration of an electronic device according to an embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that in all the drawings, similar components are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate. Furthermore, the figure is a schematic diagram and does not correspond to the actual dimensional ratio. In addition, "~" indicating a numerical range represents "more than" to "less than" unless otherwise specified.

[Resveratrol type epoxy resin (A1)]
The resveratrol type epoxy resin (A1) of the present invention has an epoxy equivalent of 130 g/eq or more and 400 g/eq or less, and has a resveratrol skeleton in the molecule.
Resveratrol type epoxy resin (A1) is an epoxy resin having a resveratrol skeleton in the molecule, for example, an epoxy resin derived from a resveratrol compound and an epoxy compound such as epichlorohydrin. . Here, the resveratrol skeleton is, for example, a structure represented by the following formula (1).

（前記式（１）において、Ｒ_１及びＲ_２は、それぞれ独立して、水素原子、炭素数１以上４以下のアルコキシ基、又は炭素数１以上６以下の直鎖もしくは分枝鎖のアルキル基を示し、好ましくは水素原子又は炭素数１以上４以下のアルキル基を示し、より好ましくは水素原子又はメチル基、更に好ましくは水素原子を示し、ａは、それぞれ独立して、０以上３以下の整数、好ましくは０又は１、より好ましくは０であり、ｂは、それぞれ独立して、０以上４以下の整数、好ましくは０又は１、より好ましくは０であり、＊は結合手を示す。）

(In the above formula (1), R ₁ and R ₂ are each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a straight 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, and a is each independently a 0 to 3 alkyl group. b is an integer, preferably 0 or 1, more preferably 0, b is each independently an integer of 0 or more and 4 or less, preferably 0 or 1, more preferably 0, and * represents a bond. )

According to the resveratrol-type epoxy resin (A1) according to the present embodiment, the balance of thermal conductivity and heat resistance of the resulting thermosetting resin composition, resin sheet, and thermally conductive member can be improved. Furthermore, according to the resveratrol-type epoxy resin (A1), thermosetting resin composition, and resin sheet of the present invention, a metal base substrate and an electronic device with improved balance of thermal conductivity and heat resistance can be realized. be able to.
The reason why such an effect is obtained is presumed to be as follows.
The resveratrol type epoxy resin (A1) has a resveratrol skeleton in the molecule. This resveratrol skeleton has polyfunctionality, rigidity, linearity, and electronic conjugation, and has a symmetrical structure, so the resveratrol skeleton can improve crosslink density and crystallinity during curing, and as a result, It is thought that the balance between thermal conductivity and heat resistance of the resulting thermosetting resin composition, resin sheet, and thermally conductive member can be improved.

The monomer of the resveratrol type epoxy resin (A1) is, for example, shown in (2) below. The multimer (oligomer) of the resveratrol type epoxy resin (A1) is shown, for example, in (3) below.

（前記式（２）において、Ｒ_１及びＲ_２は、それぞれ独立して、水素原子、炭素数１以上４以下のアルコキシ基、又は炭素数１以上６以下の直鎖もしくは分枝鎖のアルキル基を示し、好ましくは水素原子又は炭素数１以上４以下のアルキル基を示し、より好ましくは水素原子又はメチル基、更に好ましくは水素原子を示し、ａは、それぞれ独立して、０以上３以下の整数、好ましくは０又は１、より好ましくは０であり、ｂは、それぞれ独立して、０以上４以下の整数、好ましくは０又は１、より好ましくは０である。）

(In the above formula (2), R ₁ and R ₂ are each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a straight 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, and a is each independently a 0 to 3 alkyl group. (b is an integer, preferably 0 or 1, more preferably 0, and b is each independently an integer of 0 to 4, preferably 0 or 1, more preferably 0)

（前記式（３）において、Ｒ_１及びＲ_２は、それぞれ独立して、水素原子、炭素数１以上４以下のアルコキシ基、又は炭素数１以上６以下の直鎖もしくは分枝鎖のアルキル基を示し、好ましくは水素原子又は炭素数１以上４以下のアルキル基を示し、より好ましくは水素原子又はメチル基、更に好ましくは水素原子を示し、ａは、それぞれ独立して、０以上３以下の整数、好ましくは０又は１、より好ましくは０であり、ｂは、それぞれ独立して、０以上４以下の整数、好ましくは０又は１、より好ましくは０であり、ｎは、好ましくは１以上５０以下の整数であり、より好ましく２以上３０以下の整数、更に好ましくは３以上１５以下の整数、更に好ましくは４以上１０以下の整数である。）

(In the above formula (3), R ₁ and R ₂ are each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a straight 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, and a is each independently a 0 to 3 alkyl group. an integer, preferably 0 or 1, more preferably 0, b is each independently an integer of 0 or more and 4 or less, preferably 0 or 1, more preferably 0, and n is preferably 1 or more (It is an integer of 50 or less, more preferably an integer of 2 or more and 30 or less, still more preferably an integer of 3 or more and 15 or less, and even more preferably an integer of 4 or more and 10 or less.)

The epoxy equivalent of the resveratrol type epoxy resin (A1) is 130 g/eq or more, preferably 150 g/eq or more, from the viewpoint of improving the balance of thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member. More preferably 180 g/eq or more, still more preferably 200 g/eq or more, and 400 g/eq or less, preferably 350 g/eq or less, more preferably 330 g/eq or less, still more preferably 300 g/eq or less.

The method for measuring epoxy equivalent in this specification will be described below.
Dissolve the epoxy resin in 20 mL of a suitable solvent such as chloroform or cyclohexanone. To the obtained solution, add 20 mL of acetic acid and 10 mL of acetic acid solution of tetraethylammonium bromide (a solution obtained by adding and dissolving 400 mL of acetic acid to 100 g of tetraethylammonium bromide), and use a perchloric acid solution adjusted to 0.1N. Titrate using an automatic potentiometric titrator (Metrohm 916 Ti-Touch). A blank test is performed, and the epoxy equivalent is calculated from the following formula.
Epoxy equivalent (g/eq) = (1000 x W) / {(SB) x N}
W: Sample mass B: Amount of 0.1N perchloric acid solution used for blank test (mL)
S: Volume of 0.1N perchloric acid solution used for sample titration (mL)
N: Normality of perchloric acid solution (0.1N)

The weight average molecular weight (Mw) of the resveratrol type epoxy resin (A1) is preferably 350 or more, more preferably is 500 or more, 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 Above, more preferably 2,800 or more, and preferably 10,000 or less, more preferably 7,000 or less, still more preferably 4,000 or less.
The weight average molecular weight of the resveratrol type epoxy resin (A1) is measured by gel permeation chromatography (GPC), and the value is calculated using a standard polystyrene calibration curve.

In this specification, the weight average molecular weight (Mw) of the 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 the resveratrol type epoxy resin (A1) is calculated using a polystyrene equivalent value determined from a standard polystyrene (PS) calibration curve obtained by GPC measurement.
GPC measurement conditions are, for example, as follows.
Gel permeation chromatography device HLC-8320GPC manufactured by Tosoh Corporation
Column: TSK-GEL GMH, G2000H, SuperHM-M manufactured by Tosoh Corporation
Detector: UV detector for liquid chromatogram Measurement temperature: 40℃
Solvent: THF
Sample concentration: 2.0mg/ml

The glass transition temperature of the resveratrol type epoxy resin (A1), measured by method 1 below, is preferably 170 from the viewpoint of improving the balance of thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member. The temperature is at least 180°C, more preferably at least 185°C, even more preferably at least 190°C, even more preferably at least 195°C, and even more preferably at least 200°C. The upper limit of the glass transition temperature is not particularly limited, but is, for example, 300°C or lower, may be 250°C or lower, or may be 220°C or lower.
(Method 1)
A composition consisting of 100 parts by mass of resveratrol type epoxy resin (A1) and 0.1 parts by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180 ° C. for 90 minutes. A cured product of 3 mm x 3 mm x 3 mm was prepared, and thermomechanical analysis (TMA) was measured at a heating rate of 5° C./min. The temperature that can be read from the intersection of the tangents at 60° C. and 200° C. The glass transition temperature is (A1).

The thermal diffusivity of the resveratrol type epoxy resin (A1) measured by method 2 below is preferably 0 from the viewpoint of improving the balance of thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member. .190 mm ² /s or more, preferably 0.200 mm ² /s or more, preferably 0.210 mm ² /s or more. The upper limit value of the thermal diffusivity is not particularly limited, but may be, for example, 0.500 mm ² /s or less, 0.300 mm ² /s or less, or 0.250 mm ² /s or less.
(Method 2)
A composition consisting of 100 parts by mass of resveratrol type epoxy resin (A1) and 0.1 parts by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180 ° C. for 90 minutes. A cured product of 10 mm x 10 mm x 1 mm was prepared, and then the thermal diffusivity of the obtained cured product was measured by the Xe flash method under atmospheric conditions at 25°C, and the obtained value was measured using Resvera. Let it be the thermal diffusivity of Troll type epoxy resin (A1).

The resveratrol type epoxy resin (A1) preferably contains a monomer and a component of a dimer or more (also referred to as a multimer).
The content of the monomer in the resveratrol type epoxy resin (A1) is preferably 10% by mass or more from the viewpoint of improving the balance of thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member. , more preferably 15% by mass or more, still more preferably 20% by mass or more, even more preferably 25% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass. The content is preferably 50% by mass or less.

The linear expansion coefficient of the resveratrol type epoxy resin (A1), measured by method 3 below, is preferably 45 ppm from the viewpoint of improving the balance of thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member. /°C or less, more preferably 42 ppm/°C or less, still more preferably 40 ppm/°C or less. The lower limit of the linear expansion coefficient is not particularly limited, but is, for example, 5 ppm/°C or more, may be 10 ppm/°C or more, or may be 15 ppm/°C or more.
(Method 3)
A composition consisting of 100 parts by mass of resveratrol type epoxy resin (A1) and 0.1 parts by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180 ° C. for 90 minutes. A cured product of 3 mm x 3 mm x 3 mm was prepared, and then the coefficient of linear expansion in the thickness direction in the range of 50°C to 70°C of the obtained cured product was measured by thermomechanical analysis, and the obtained value was reported. This is the linear expansion coefficient of veratrol type epoxy resin (A1).

The 5% weight loss temperature (Td5) of the resveratrol type epoxy resin (A1) measured by method 4 below is a point of view for improving the balance of thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member. The temperature is preferably 300°C or higher, more preferably 305°C or higher, even more preferably 310°C or higher, even more preferably 315°C or higher, and even more preferably 320°C or higher. The upper limit of the weight loss temperature (Td5) is not particularly limited, but is, for example, 500°C or lower, may be 400°C or lower, or may be 350°C or lower.
(Method 4)
Prepared by preparing a composition consisting of 100 parts by mass of resveratrol type epoxy resin (A1) and 0.1 part by mass of 2-methylimidazole as a measurement sample, and heating the measurement sample at 180 ° C. for 90 minutes. The obtained cured product was ground in a mortar to prepare a cured product powder, and then the obtained cured product was pulverized in a dry nitrogen stream at a heating rate of 10°C/min using a simultaneous differential thermogravimetric measurement device. Depending on the conditions, the temperature at which the cured product decreases by 5% in weight (Td5) is measured by raising the temperature from 30°C to 600°C, and the obtained value is calculated as the 5% weight of the resveratrol-type epoxy resin (A1). It is assumed that the temperature decreases (Td5).

[Thermosetting resin composition]
The thermosetting resin composition according to the present embodiment includes an epoxy resin (A) and a thermally conductive filler (C), and the epoxy resin (A) is the resveratrol type epoxy resin (A1) described above. including.

Each component constituting the thermosetting resin composition according to this embodiment will be explained below.

<Epoxy resin (A)>
The thermosetting resin composition according to this embodiment contains an epoxy resin (A).
The epoxy resin (A) contains the above-mentioned resveratrol type epoxy resin (A1).

(Other epoxy resins (A2))
Epoxy resin (A) is used from the viewpoint of further improving the moldability, appearance, softness, flexibility, bending resistance, stress relaxation property, adhesion with other parts, etc. of the resulting resin sheet and thermally conductive member. , an epoxy resin (A2) other than the resveratrol type epoxy resin (A1).

Epoxy resin (A2) is not particularly limited, but examples include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E epoxy resin, bisphenol S epoxy resin, bisphenol M epoxy resin (4,4'-(1 , 3-phenylene diisopridiene) bisphenol type epoxy resin), bisphenol P type epoxy resin (4,4'-(1,4-phenylene diisopridiene) bisphenol type epoxy resin), bisphenol Z type epoxy resin (4,4'-(1,4-phenylene diisopridiene) bisphenol type epoxy resin) , 4'-cyclohexydiene bisphenol type epoxy resin); phenol novolak type epoxy resin, cresol novolak type epoxy resin, tetraphenol group ethane type novolak type epoxy resin, having a condensed ring aromatic hydrocarbon structure Novolac type epoxy resins such as novolac type epoxy resins; epoxy resins having a biphenyl skeleton; aryl alkylene type epoxy resins such as xylylene type epoxy resins and epoxy resins having a biphenylaralkyl skeleton; naphthylene ether type epoxy resins; naphthol type epoxy resins; Naphthalene diol type epoxy resin; 1,6-dihydroxynaphthalene type epoxy resin, 2,7-dihydroxynaphthalene type epoxy resin, 1,5-dihydroxynaphthalene type epoxy resin, 1,4-dihydroxynaphthalene type epoxy resin, 2,6- Dihydroxynaphthalene type epoxy resin, difunctional to tetrafunctional epoxy type naphthalene resin; binaphthyl type epoxy resin; naphthalene type epoxy resin such as epoxy resin having a naphthalene aralkyl skeleton; anthracene type epoxy resin; epoxy resin having a dicyclopentadiene skeleton; norbornene type epoxy resin; epoxy resin having an adamantane skeleton; fluorene type epoxy resin; epoxy resin having a phenol aralkyl skeleton, including at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and dicyclopentadiene. selected from the group consisting of an epoxy resin having a skeleton, an epoxy resin having a biphenyl skeleton, an epoxy resin having an adamantane skeleton, an epoxy resin having a phenol aralkyl skeleton, an epoxy resin having a biphenylaralkyl skeleton, and an epoxy resin having a naphthalene aralkyl skeleton. It is preferable to include at least one type of.

Epoxy resin (A2) is used from the viewpoint of further improving the moldability, appearance, softness, flexibility, bending resistance, stress relaxation property, adhesion with other parts, etc. of the resulting resin sheet and thermally conductive member. , preferably a liquid or semi-solid epoxy resin at 23°C.
In this embodiment, the epoxy resin (A) is a resveratrol-type epoxy resin (A1) and an epoxy resin that is liquid or semi-solid at 23°C, from the viewpoint of further improving the moldability of the resulting thermosetting resin composition. It is preferable to include it in combination with resin (A2).

The epoxy resin (A) preferably contains 30% by mass or more of the resveratrol-type epoxy resin (A1), from the viewpoint of further improving the balance of thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member. The content is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, even more preferably 80% by mass or more, and preferably 100% by mass or less.

The content of the epoxy resin (A) in the thermosetting resin composition according to the present embodiment is the total amount of the components excluding the thermally conductive filler (C) of the thermosetting resin composition according to the present embodiment, that is, the epoxy resin The total amount of 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. From the viewpoint of further improving the balance of thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member, preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and even more preferably 20 parts by mass. Above, more preferably 25 parts by mass or more, still more preferably 30 parts by mass or more, and the moldability, appearance, softness, flexibility, bending resistance, stress relaxation properties of the resulting resin sheet or thermally conductive member, From the viewpoint of further improving adhesion with other members, preferably 80 parts by mass or less, more preferably 60 parts by mass or less, still more preferably 50 parts by mass or less, still more preferably 45 parts by mass or less, still more preferably 40 parts by mass. below.

<Cyanate ester resin (B)>
The thermosetting resin composition according to the present embodiment is characterized by moldability, appearance, softness, flexibility, bending resistance, stress relaxation properties, adhesion with other members, etc. of the resulting resin sheet and thermally conductive member. The composition further contains cyanate ester resin (B) from the viewpoint of further improving the properties.
Here, in this specification, the cyanate ester resin (B) does not include an isocyanate compound.
The cyanate ester resin (B) is, for example, novolak type cyanate ester resin; bisphenol type cyanate ester resin such as bisphenol A type cyanate ester resin, bisphenol E type cyanate ester resin, tetramethylbisphenol F type cyanate ester resin; naphthol aralkyl type phenol The product contains at least one selected from the group consisting of naphthol aralkyl cyanate ester resin obtained by reaction of a resin and cyanogen halide; dicyclopentadiene cyanate ester resin; and phenol aralkyl cyanate ester resin containing a biphenylene skeleton. From the viewpoint of further improving the balance of thermal conductivity and heat resistance of the resin sheet or thermally conductive member, it preferably contains at least one selected from the group consisting of novolak-type cyanate ester resins and naphthol aralkyl-type cyanate ester resins, and more Preferably, a novolac type cyanate ester resin is included.

Examples of the novolak-type cyanate ester resin include those represented by the following formula (I).

The average repeating unit n of the novolak cyanate ester resin represented by the formula (I) is an arbitrary integer. The average repeating unit n is not particularly limited, but is preferably 1 or more, more The number is preferably 2 or more, and is preferably 10 or less, more preferably 7 or less, from the viewpoint of being able to suppress an increase in melt viscosity and further improving moldability.

Examples of naphthol aralkyl cyanate ester resins include those represented by the following formula (II).
The naphthol aralkyl cyanate ester resin represented by the following formula (II) includes, for example, naphthols such as α-naphthol or β-naphthol, p-xylylene glycol, α,α'-dimethoxy-p-xylene, 1,4 It is obtained by condensing a naphthol aralkyl type phenol resin obtained by reaction with -di(2-hydroxy-2-propyl)benzene or the like and cyanogen halide.
The repeating unit n of 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.

In the formula (II), R each independently represents a hydrogen atom or a methyl group, and n represents an integer of 1 or more and 10 or less.

The content of the cyanate ester resin (B) in the thermosetting resin composition according to the present embodiment is determined based on the total amount of resin components of the thermosetting resin composition according to the present embodiment being 100 parts by mass. From the viewpoint of further improving the moldability, appearance, softness, flexibility, bending resistance, stress relaxation properties, adhesion with other members, etc. of the resin sheet and thermally conductive member, preferably 10 parts by mass or more, More preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, still more preferably 25 parts by mass or more, even more preferably 30 parts by mass or more, and the thermal conductivity and heat resistance of the resulting resin sheet and thermally conductive member are improved. From the viewpoint of further improving the balance, the amount is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less, still more preferably 50 parts by mass or less.

<Thermal conductive filler (C)>
The thermosetting resin composition according to the present embodiment contains a thermally conductive filler (C) from the viewpoint of improving the thermal conductivity of the resulting resin sheet and thermally conductive member.
The thermally conductive filler (C) contains, 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 conductivity, the material preferably contains at least one selected from the group consisting of boron nitride, aluminum nitride, and alumina, and more preferably contains boron nitride.

The boron nitride preferably contains scaly boron nitride, more preferably at least one selected from the group consisting of monodispersed particles of scaly boron nitride and aggregated particles of scaly boron nitride, and even more preferably scaly boron nitride. Contains agglomerated particles of boron nitride.
The flaky boron nitride may be granulated. The aggregated particles of scale-like boron nitride may be sintered particles or non-sintered particles.

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, from the viewpoint of further improving the thermal conductivity of the resulting resin sheet or thermally conductive member. More preferably, it is 50 μm or more, from the viewpoint of improving the moldability, appearance, softness, flexibility, bending resistance, stress relaxation property, adhesion with other members, etc. of the resulting resin sheet or thermally conductive member. , preferably 500 μm or less, more preferably 300 μm or less, even more preferably 200 μm or less.
Here, the average particle diameter of the thermally conductive filler (C) is the median diameter (D ₅₀ ) when the particle size distribution of particles is measured on a volume basis using a laser diffraction particle size distribution measuring device.

The thermally conductive filler (C) preferably contains boron nitride in an amount of 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 100% by mass or less.

The content of the thermally conductive filler (C) in the thermosetting resin composition according to this embodiment is, when the total amount of resin components of the thermosetting resin composition according to this embodiment is 100 parts by mass. From the viewpoint of further improving thermal conductivity, preferably 50 parts by mass or more, more preferably 100 parts by mass or more, still more preferably 150 parts by mass or more, still more preferably 200 parts by mass or more, still more preferably 250 parts by mass or more, and It is preferably 280 parts by mass or more, from the viewpoint of improving the moldability, appearance, softness, flexibility, bending resistance, stress relaxation property, adhesion with other members, etc. of the resulting resin sheet and thermally conductive member. , preferably 500 parts by mass or less, more preferably 450 parts by mass or less, still more preferably 400 parts by mass or less, still more preferably 350 parts by mass or less, still more preferably 330 parts by mass or less.

<Phenoxy resin (D)>
The thermosetting resin composition according to the present embodiment is characterized by moldability, appearance, softness, flexibility, bending resistance, stress relaxation properties, adhesion with other members, etc. of the resulting resin sheet and thermally conductive member. From the viewpoint of further improving the properties, it preferably further contains a phenoxy resin (D).

The phenoxy resin (D) is, for example, a phenoxy resin having a bisphenol skeleton, a phenoxy resin having a naphthalene skeleton, a phenoxy resin having an anthracene skeleton, a phenoxy resin having a biphenyl skeleton, a phenoxy resin having a bisphenolacetophenone skeleton, or a phenoxy resin having a plurality of these skeletons. Contains at least one selected from the group consisting of phenoxy resins with a seeded structure, more preferably phenoxy resins having a bisphenol skeleton, and even more preferably phenoxy resins having a bisphenol A skeleton, phenoxy resins having a bisphenol F skeleton, and It contains at least one selected from phenoxy resins having both a bisphenol A skeleton and a bisphenol F skeleton, and more preferably a phenoxy resin having a bisphenol A skeleton.

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, More preferably, it is 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 is a value converted using a standard polystyrene calibration curve.

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 a polystyrene equivalent value determined from a standard polystyrene (PS) calibration curve obtained by GPC measurement.
GPC measurement conditions are, for example, as follows.
Gel permeation chromatography device HLC-8320GPC manufactured by Tosoh Corporation
Column: TSK-GEL GMH, G2000H, SuperHM-M manufactured by Tosoh Corporation
Detector: UV detector for liquid chromatogram Measurement temperature: 40℃
Solvent: THF
Sample concentration: 2.0mg/ml

The content of the phenoxy resin (D) in the thermosetting resin composition according to the present embodiment is obtained when the total amount of the resin components of the thermosetting resin composition according to the present embodiment is 100 parts by mass. From the viewpoint of further improving the moldability, appearance, softness, flexibility, bending resistance, stress relaxation properties, adhesion with other parts, etc. of the resin sheet or thermally conductive member, preferably 1 part by mass or more, or more. Preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, and the resulting resin sheet or thermally conductive member From the viewpoint of further improving the balance between thermal conductivity and heat resistance, the amount is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less.

<Curing accelerator (E)>
The thermosetting resin composition according to the present embodiment preferably further contains 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 includes, for example, at least one selected from the group consisting of nitrogen atom-containing compounds, organic phosphorus compounds, phenolic compounds, organic acids, organic metal salts, and phenolic resins.
Although the type and amount of the curing accelerator (E) are not particularly limited, an appropriate one can be selected from the viewpoints of reaction rate, reaction temperature, storage stability, and the like.

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

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

The content of the curing accelerator (E) in the thermosetting resin composition according to the present embodiment is determined based on the total amount of resin components of the thermosetting resin composition according to the present embodiment being 100 parts by mass. From the viewpoint of further improving curability, reactivity and heat resistance, preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, still more preferably 0.10 parts by mass or more, and even more preferably 0.20 parts by mass. Parts by mass or more, more preferably 0.50 parts by mass or more, still more preferably 1.0 parts 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 It is 5.0 parts by mass or less, more preferably 3.0 parts by mass or less.

<Other ingredients>
The thermosetting resin composition according to the present embodiment can contain components other than those described above. Examples of other components include coupling agents, antioxidants, leveling agents, dispersion stabilizers, and surfactants.

Total content of epoxy resin (A), cyanate ester resin (B), thermally conductive filler (C), phenoxy resin (D), and curing accelerator (E) in the thermosetting resin composition according to the present invention is preferably from the viewpoint of further improving the balance of thermal conductivity and heat resistance of the resulting thermally conductive member, metal base substrate, and electronic device when the entire thermosetting resin composition is 100% by mass. The content is 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, and preferably 100% by mass or less.

[Method for producing thermosetting resin composition]
Examples of methods for manufacturing the thermosetting resin composition according to the present embodiment include the following methods.
First, a resin varnish (a varnish-like thermosetting resin composition) is prepared by mixing the above-mentioned components other than the thermally conductive filler (C) in a solvent. For this mixing, various mixers such as an ultrasonic dispersion method, a high-pressure collision dispersion method, a high-speed rotation dispersion method, a bead mill method, a high-speed shear dispersion method, and a rotation-revolution dispersion method can be used.
The above solvents are not particularly limited, but examples include acetone, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, toluene, ethyl acetate, cyclohexane, heptane, cyclohexanone, tetrahydrofuran, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, ethylene glycol, cellosolve type , carbitol, anisole, and N-methylpyrrolidone.

Next, a thermally conductive filler (C) is added to the obtained resin varnish and kneaded using a triple roll or the like to obtain a thermosetting resin composition in a B-stage state. By adding the thermally conductive filler (C) during kneading, it is possible to more uniformly disperse the thermally conductive filler (C) in the thermosetting resin composition, but the method is not limited to this. The thermosetting resin composition may be added at the time of kneading, or may be added at the time of mixing the resin varnish. After kneading, the mixture may be cooled and solidified, and the kneaded product may be processed into granules, tablets, or sheets.

[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 a B-stage state.
A specific form of the resin sheet according to the present embodiment includes, for example, a base material and a resin composition layer made of the thermosetting resin composition according to the present embodiment provided on the base material. It is.

The resin sheet according to the present embodiment can be obtained, for example, by subjecting a coating film obtained by applying a varnish-like thermosetting resin composition onto a base material to a solvent removal treatment. It is preferable that the solvent content in the resin sheet is 10% by mass or less based on the entire thermosetting resin composition. For example, the solvent removal treatment can be performed at 80° C. to 200° C. for 1 minute to 30 minutes.

The planar shape of the resin sheet according to this embodiment is not particularly limited, and can be appropriately selected depending on the shape of the heat sink, heat generating body, etc., and may be rectangular, for example.
The thickness of the resin composition layer of the resin sheet according to the present embodiment is, for example, 50 μm or more and 500 μm or less, from the viewpoint of further improving the balance of mechanical strength, heat resistance, insulation, and heat dissipation.

The base material includes, for example, at least one selected from the group consisting of a resin film and a metal foil.
The resin film is not particularly limited, but includes, for example, a polyolefin film such as a polyethylene film or a polypropylene film; a polyester film such as a polyethylene terephthalate film or a polybutylene terephthalate film; a polycarbonate film; a fluororesin film; and a polyimide resin film. Contains at least one selected type.
Metal foils are not particularly limited, but include, for example, copper foil, copper-based alloy foil, aluminum foil, aluminum-based alloy foil, iron foil, iron-based alloy foil, silver foil, silver-based alloy foil, gold foil, gold-based alloy foil, and zinc. The foil includes at least one selected from the group consisting of foil, zinc-based alloy foil, nickel foil, nickel-based alloy foil, tin foil, and tin-based alloy foil.
The thickness of the base material is, for example, 10 μm or more and 500 μm or less.

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

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

The thermally conductive member according to this embodiment is used, for example, as a thermally conductive material interposed between a heating element and a heat radiating element.
Examples of the heating element include semiconductor elements, LED elements, substrates on which semiconductor elements and LED elements are mounted, central processing units (CPUs), power semiconductors, lithium ion batteries, fuel cells, and the like.
Examples of the heat dissipation body include a heat sink, a heat spreader, a heat dissipation (cooling) fin, and the like.

Further, the thermally conductive member according to the present embodiment is provided, for example, at a bonding interface where high thermal conductivity is required in an electronic device, and can promote heat conduction from a heat generating element to a heat radiating element. This suppresses failures caused by characteristic variations in semiconductor chips and the like, and improves the stability of electronic devices.

The planar shape of the thermally conductive member according to this embodiment is not particularly limited, and can be appropriately selected depending on the shape of the heat sink, heat generating body, etc., and may be rectangular, for example.
The thickness of the cured resin layer in the thermally conductive member according to this embodiment is preferably 10 μm or more, more preferably 30 μm or more, and still more preferably 50 μm or more, from the viewpoint of further improving mechanical strength, heat resistance, and insulation properties. , more preferably 100 μm or more, and from the viewpoint of further improving heat dissipation, preferably 400 μm or less, more preferably 350 μm or less, still more preferably 250 μm or less.

In the thermally conductive member according to the present embodiment, the glass transition temperature of the cured resin layer, which is measured by dynamic viscoelasticity measurement at a heating rate of 5° C./min and a frequency of 10 Hz, is determined by the heat resistance and insulation properties. From the viewpoint of further improving the temperature, the temperature is preferably 210°C or higher, more preferably 215°C or higher, and still more preferably 220°C or higher. The upper limit of the glass transition temperature is not particularly limited, but is, for example, 350°C or lower, may be 330°C or lower, or may be 300°C or lower.
The glass transition temperature can be controlled by appropriately adjusting the type and blending ratio of each component constituting the thermally conductive member.

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

The thermally conductive member according to this embodiment can be used for various substrate applications, and from the viewpoint of the balance between thermal conductivity and heat resistance, it can be suitably used as a material for a power module substrate used in a power module. Can be done.

[Metal base board]
FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a metal base substrate 100 according to this embodiment.
The metal base substrate 100 according to the present embodiment includes 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, and the insulating layer 102 includes: It includes a resin composition layer made of the thermosetting resin composition according to the embodiment described above, and one selected from the group consisting of the thermally conductive member according to the embodiment described above.

The insulating layer 102 may be composed of a resin composition layer in a B stage state before the circuit processing of the metal layer 103, and after the circuit processing, it may be a cured resin layer obtained by curing the same. It's okay.

The thickness of the insulating layer 102 is preferably 10 μm or more, more preferably 30 μm or more, still more preferably 50 μm or more, still more preferably 100 μm or more, from the viewpoint of further improving mechanical strength, heat resistance, and insulation. From the viewpoint of further improving the heat dissipation properties of the entire substrate 100, the thickness is preferably 400 μm or less, more preferably 350 μm or less, and still more preferably 250 μm or less.

The metal layer 103 is provided on the insulating layer 102 and is subjected to circuit processing. The metal constituting the metal layer 103 includes, for example, at least one selected from the group consisting of copper, copper alloy, aluminum, aluminum alloy, nickel, iron, tin, and the like.
From the viewpoint of further improving circuit workability, 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 made of metal foil that is available in plate form or may be made of metal foil that is available in roll form.

The thickness of the metal layer 103 is preferably 0.01 mm or more, more preferably 0.05 mm or more, and even more preferably 0.10 mm or more, from the viewpoint of further suppressing heat generation of the circuit pattern even in applications that require high current. , more preferably 0.25 mm or more, and from the viewpoint of further improving circuit workability and making the entire board thinner, preferably 10.0 mm or less, more preferably 5.0 mm or less, still more preferably 3. It is 0 mm or less, more preferably 2.0 mm or less, even more preferably 1.0 mm or less.

The metal substrate 101 has a 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 includes at least one selected from the group consisting of a copper substrate, a copper alloy substrate, an aluminum substrate, and an aluminum alloy substrate to further improve heat dissipation. From the viewpoint of achieving this, it more preferably includes at least one selected from the group consisting of a copper substrate and an aluminum substrate, and still more preferably a copper substrate.

The thickness of the metal substrate 101 is not particularly limited, but is preferably 20.0 mm or less, more preferably 10.0 mm or less, from the viewpoint of improving workability in external processing, cutting, etc., and making the entire substrate thinner. More preferably, it is 5.0 mm or less, and 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, still more preferably 1.0 mm or more, More preferably, it is 2.0 mm or more.

The metal base substrate 100 can have a metal layer 103 processed into a circuit by etching or the like into a pattern. 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.

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

[Electronic device]
The metal base substrate 100 according to this embodiment can be used in various applications requiring heat dissipation and insulation properties, and can be used, for example, in electronic devices such as semiconductor devices.
FIG. 2 is a schematic cross-sectional view showing an example of the configuration of the electronic device 200 according to the present embodiment.
The electronic device 200 according to the present embodiment includes the metal base substrate 100 according to the present embodiment described above and the electronic component 201 provided on the metal base substrate 100.
The metal base substrate 100 can function as a heat spreader for heat from the electronic components 201 (various heat generating elements) that generate heat due to operation.

In an electronic device 200 shown in FIG. 2, an electronic component 201 such as a semiconductor element is 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 component 201 is connected to a connection electrode portion formed on the metal base substrate 100 via a bonding wire 203, and is mounted on the metal base substrate 100. The electronic components 201 are collectively sealed on the metal base substrate 100 with 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 thermally conductive layer 209 (thermal interface material (TIM)). The heat sink 207 is made of a material with excellent thermal conductivity, and examples thereof include metals such as aluminum, iron, and copper.

As the electronic component 201, a power semiconductor element can be used. Thereby, it is possible to use the electronic device 200 according to this embodiment as a power module. In the power module, other electronic components may be mounted on the metal base substrate 100 in addition to the power semiconductor element.
Power semiconductor devices use wide bandgap materials such as SiC, GaN, Ga ₂ O ₃ or diamond, and are designed to be used at high voltages and large currents, so they are usually Because it generates more heat than a silicon chip (semiconductor element), it must operate in a higher temperature environment. Power semiconductor devices are required to be used for long periods of time in high-temperature operating environments of, for example, 200° C. or higher or 250° C. or higher. Examples of power semiconductor elements include rectifier diodes, power transistors, power MOSFETs, insulated gate bipolar transistors (IGBT), thyristors, gate turn-off thyristors (GTO), triacs, and the like.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted within a range that does not impair the effects of the present invention.

Note that the present invention is not limited to the above-described embodiments, and the present invention includes modifications, improvements, etc. within a range that can achieve the purpose of the present invention.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to the description of these Examples and Comparative Examples.

[Production of resveratrol type epoxy resin (A1)]
For Examples and Comparative Examples, resveratrol type epoxy resins (A1) were produced as follows.

(Example 1)
Weighed 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 into a reaction container, and dissolved them at 45 to 50°C. - Stirred and then reacted at 45-50°C for 2 hours. Next, 14.7 parts by mass of a 50% by mass aqueous sodium hydroxide solution was slowly added dropwise, the temperature was raised to 50°C, and the mixture was stirred for 2 hours to react. Next, 14.7 parts by mass of a 50% by mass aqueous sodium hydroxide solution was slowly added dropwise, and the mixture was heated to 80-90°C and stirred for 6 hours to react. After concentrating the obtained reaction solution, a resveratrol type epoxy resin was obtained by a reprecipitation method using pure water in an amount seven times the amount of the reaction mixture.

(Examples 2 to 6 and Comparative Example 1)
Ratio between the number of moles of epichlorohydrin and the number of moles of the hydroxyl group of resveratrol (written as "Ep-Cl/OH" in the table), the number of moles of tetrabutylammonium chloride and the number of moles of the hydroxyl group of resveratrol (denoted as "TBAC/OH" in the table), and the ratio of the number of moles of sodium hydroxide in a 40% by mass aqueous sodium hydroxide solution to the number of moles of hydroxyl groups of resveratrol (denoted as "NAOH/OH" in the table). Resveratrol-type epoxy resins were obtained in the same manner as in Example 1, except that the amount of each component used was changed so that each of the resveratrol-type epoxy resins had the values shown in Table 1.

(Comparative example 2)
Weigh out 70.7 parts by mass of epichlorohydrin, 17.4 parts by mass of resveratrol, 1.1 parts by mass of tetrabutylammonium chloride, and 8.7 parts by mass of dimethyl sulfoxide into a reaction container, dissolve and stir at 40°C. I let it happen. After slowly dropping 4.2 parts by mass of a 25 wt % aqueous sodium hydroxide solution, the temperature was raised to 60° C. and the mixture was stirred for 3 hours to react. After concentrating the obtained reaction solution, a resveratrol type epoxy resin was obtained by a reprecipitation method using a 1N aqueous sodium hydroxide solution and pure water in an amount 6 times the amount of the reaction mixture.

[Evaluation of resveratrol type epoxy resin (A1)]
The obtained resveratrol type epoxy resin (A1) was evaluated based on the following evaluation items. The evaluation results are shown in Table 2.

(epoxy equivalent)
The epoxy resin was dissolved in 20 mL of cyclohexanone. To the obtained solution, add 20 mL of acetic acid and 10 mL of acetic acid solution of tetraethylammonium bromide (a solution obtained by adding and dissolving 400 mL of acetic acid to 100 g of tetraethylammonium bromide), and use a perchloric acid solution adjusted to 0.1N. Titration was carried out using an automatic potentiometric titrator (916 Ti-Touch manufactured by Metrohm). A blank test was conducted, and the epoxy equivalent was calculated from the following formula.
Epoxy equivalent (g/eq) = (1000 x W) / {(SB) x N}
W: Sample mass B: Amount of 0.1N perchloric acid solution used for blank test (mL)
S: Volume of 0.1N perchloric acid solution used for sample titration (mL)
N: Normality of perchloric acid solution (0.1N)

(Weight average molecular weight (Mw), monomer content in resveratrol type epoxy resin)
The weight average molecular weight (Mw) of the epoxy resin (A) was calculated using a polystyrene equivalent value obtained from a standard polystyrene (PS) calibration curve obtained by GPC measurement. In addition, the peak at elution time of 19.4 to 21.4 minutes at this time is taken as the monomer peak, and the value obtained by dividing the integral value of the peak by the total integral value is multiplied by 100. It was taken as the monomer content.
The measurement conditions for GPC are as follows.
Gel permeation chromatography device HLC-8320GPC manufactured by Tosoh Corporation
Column: TSK-GEL GMH, G2000H, SuperHM-M manufactured by Tosoh Corporation
Detector: UV detector for liquid chromatogram Measurement temperature: 40℃
Solvent: THF
Sample concentration: 2.0mg/ml

(Glass transition temperature (Tg))
100 parts by mass of resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole (2MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) were melt-mixed on a hot plate at 120°C for 1 minute, and then cooled to room temperature. A measurement sample was obtained.
Using the obtained measurement sample, a cured product of 3 mm x 3 mm x 3 mm was produced by heating and curing at 180° C. for 90 minutes using a mold that had been heated to 180° C. in advance. The results were obtained using a TMA (Thermal Mechanical Analyzer) test device (TMA/SS6100 manufactured by Seiko Instruments) under the conditions of a temperature increase rate of 5 °C/min, a load of 50 N, a tensile mode, and a measurement temperature range of 30 to 300 °C. Thermomechanical analysis (TMA) was performed on the cured product. The temperature read from the intersection of the tangents at 60° C. and 200° C. was defined as the glass transition temperature of the resveratrol-type epoxy resin.

(thermal diffusivity)
100 parts by mass of resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole (2MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) were melt-mixed on a hot plate at 120°C for 1 minute, and then cooled to room temperature. A measurement sample was obtained.
Using the obtained measurement sample, a cured product of 10 mm x 10 mm x 1 mm was produced by heating and curing at 180° C. for 90 minutes using a mold that had been heated to 180° C. in advance.
Next, the thermal diffusivity of the plate-shaped cured product in the thickness direction was measured by an unsteady method using a Xe flash analyzer TD-1RTV manufactured by ULVAC. The measurements were carried out under atmospheric conditions at 25°C.

(linear expansion coefficient)
100 parts by mass of resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole (2MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) were melt-mixed on a hot plate at 120°C for 1 minute, and then cooled to room temperature. A measurement sample was obtained.
Using the obtained measurement sample, a cured product of 3 mm x 3 mm x 3 mm was produced by heating and curing at 180° C. for 90 minutes using a mold that had been heated to 180° C. in advance. The linear expansion coefficient of the obtained cured product was measured. Using a TMA (Thermal Mechanical Analyzer) test device (TMA/SS6100 manufactured by Seiko Instruments), the temperature increase rate was 5°C/min, the load was 0.05N, the tensile mode was measured, and the measurement temperature range was 30 to 320°C. Two cycles of thermomechanical analysis (TMA) were measured. From the obtained results, the average value of the coefficient of linear expansion (CTE) in the thickness direction in the range of 50° C. to 70° C. was calculated. In addition, for each linear expansion coefficient (ppm/° C.), the value of the second cycle was adopted.

(5% weight loss temperature (Td5))
100 parts by mass of resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole (2MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) were melt-mixed on a hot plate at 120°C for 1 minute, and then cooled to room temperature. A measurement sample was obtained.
A cured product was produced by heat-treating the obtained measurement sample at 180° C. for 90 minutes. The produced cured product was ground in a mortar to prepare a cured product powder. Next, the sample was heated from 30°C to 600°C at a heating rate of 10°C/min under a stream of dry nitrogen using a simultaneous differential thermogravimetric measurement device (manufactured by Seiko Instruments, model TG/DTA6200). By raising the temperature, the temperature (Td5) at which the cured product lost 5% weight was measured, and the obtained value was defined as the 5% weight loss temperature (Td5) of the resveratrol type epoxy resin.

[Preparation of varnish-like thermosetting resin composition]
For Examples and Comparative Examples, thermosetting resin compositions were prepared as follows.
According to the composition of the thermosetting resin composition shown in Table 3, a varnish-like thermosetting resin composition was obtained in which the resin component and the filler component were uniformly dissolved and dispersed in a solvent.
Details of each component in Table 3 are as follows. In addition, the unit of the amount of each component in Table 3 is parts by mass.

(Epoxy resin (A))
- Epoxy resin 1: resveratrol type epoxy resin having a resveratrol skeleton in the molecule (weight average molecular weight: 3319, epoxy equivalent: 257 g/eq, manufactured according to Example 2)
・Epoxy resin 2: Bisphenol F type epoxy resin (manufactured by DIC, EPICLON 830, liquid at 23°C)
・Epoxy resin 3: Dicyclopentadiene type epoxy resin (manufactured by DIC, EPICLON HP-7200, solid at 23°C)

(Cyanate ester resin (B))
・Cyanate ester resin 1: Novolac type cyanate ester resin (manufactured by Lonza Japan, PT-30)

(Thermal conductive filler (C))
・Thermal conductive filler 1: Agglomerated particles of scale-like boron nitride (manufactured by Mizushima Alloy Co., Ltd., boron nitride powder HP-40)

(Phenoxy resin (D))
・Phenoxy resin 1: Phenoxy resin having a bisphenol A skeleton (manufactured by Nippon Steel Chemical & Materials, YP-55)

(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 Kasei Kogyo Co., Ltd.)
・Curing accelerator 3: Benzoxazine resin (manufactured by Shikoku Kasei Kogyo Co., Ltd., P-d type)

[Evaluation of resin sheet and thermally conductive member]
The obtained resin sheet and thermally conductive member were evaluated based on the following evaluation items. The evaluation results are shown in Table 3.

(Thermal conductivity)
・Preparation of thermally conductive member Using the obtained varnish-like thermosetting resin composition, a resin sheet in a B-stage state was prepared, sandwiched and set with 0.018 mm copper foil, and compression molded at 10 MPa at 180° C. C. for 90 minutes to obtain a resin molded body (thermally conductive member). A 10 mm square sample for thermal diffusivity measurement was cut out from the obtained resin molding and used for thermal diffusivity measurement.

・Density (specific gravity) of resin molded body
Density (specific gravity) measurement was performed in accordance with JIS K 6911 (General Test Methods for Thermosetting Plastics). The test piece used was a piece cut out from the above resin molding into a size of 2 cm long x 2 cm wide. The unit of density (specific gravity) (ρ) is kg/m ³ .

- Specific heat of resin molded article The specific heat (Cp) of the obtained resin molded article was measured by the DSC method.

-Measurement of thermal conductivity of resin molded body A test piece cut out to a size of 10 mm square from the obtained resin molded body was used for measurement in the thickness direction. Next, the thermal diffusion coefficient (α) in the thickness direction of the plate-shaped test piece was measured by an unsteady method using a Xe flash analyzer TD-1RTV manufactured by ULVAC. The measurements were carried out under atmospheric conditions at 25°C.
The thermal conductivity of the resin molded body was calculated from the obtained measured values of the thermal diffusion coefficient (α), specific heat (Cp), and density (ρ) based on the following formula. The results are shown in Table 3.
Thermal conductivity [W/(m・K)]=α[m ² /s]×Cp[J/(kg・K)]×ρ[kg/m ³ ]
In Table 3, the thermal conductivity of the resin molded body was defined as "thermal conductivity".

(Glass transition temperature (Tg))
The glass transition temperature (Tg) of the resin molded body was determined by DMA (dynamic viscoelasticity measurement) using a dynamic viscoelasticity device (manufactured by Hitachi High-Tech Corporation, product name: DMA-7100) at a heating rate of 5°C/min. , measured at a frequency of 10 Hz.

(Flexibility of resin sheet)
The flexibility of the obtained B-stage resin sheet was evaluated based on the following criteria.
When the sheet was wound using a winding core with a diameter of 9 cm, a sheet with cracks or chips on the sheet was judged as "NG", and a sheet with no appearance abnormality was judged as "OK".

100 Metal base substrate 101 Metal substrate 102 Insulating layer 103 Metal layer 200 Electronic device 201 Electronic component 202 Adhesive layer 203 Bonding wire 205 Sealing resin layer 207 Heat sink 209 Thermal conductive layer

Claims (20)

A resveratrol type epoxy resin having an epoxy equivalent of 130 g/eq or more and 400 g/eq or less and having a resveratrol skeleton in the molecule. The resveratrol-type epoxy resin according to claim 1, having a weight average molecular weight of 350 or more and 5,000 or less. The resveratrol type epoxy resin according to claim 1 or 2, which is used for a thermally conductive member. The resveratrol-type epoxy resin according to claim 1 or 2, which has a glass transition temperature of 170° C. or higher as measured by method 1 below.
(Method 1)
A composition consisting of 100 parts by mass of the resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180°C for 90 minutes to form a 3 mm× A cured product of 3 mm x 3 mm was prepared, and the temperature read from the intersection of the tangents at 60° C. and 200° C. when measured by thermomechanical analysis (TMA) at a heating rate of 5° C./min was determined as Glass transition temperature. The resveratrol type epoxy resin according to claim 1 or 2, which has a thermal diffusivity of 0.190 mm ² /s or more as measured by method 2 below.
(Method 2)
A composition consisting of 100 parts by mass of the resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180°C for 90 minutes to form a 10 mm× A cured product of 10 mm x 1 mm was prepared, and then the thermal diffusivity of the obtained cured product was measured at 25° C. in an air atmosphere by the Xe flash method, and the obtained value was calculated based on the resveratrol. Let it be the thermal diffusivity of the mold epoxy resin. The resveratrol-type epoxy resin according to claim 1 or 2, wherein the resveratrol-type epoxy resin contains a component of a monomer and a dimer or more, and the content of the monomer is 10% by mass or more. . The resveratrol-type epoxy resin according to claim 1 or 2, which has a linear expansion coefficient of 45 ppm/°C or less as measured by method 3 below.
(Method 3)
A composition consisting of 100 parts by mass of the resveratrol-type epoxy resin and 0.1 part by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180°C for 90 minutes to form a 3 mm× A 3 mm x 3 mm cured product was produced, and then the coefficient of linear expansion in the thickness direction in the range of 50°C to 70°C of the obtained cured product was measured by thermomechanical analysis. It is the linear expansion coefficient of Troll type epoxy resin. The resveratrol-type epoxy resin according to claim 1 or 2, which has a 5% weight loss temperature (Td5) of 300°C or higher as measured by method 4 below.
(Method 4)
A composition consisting of 100 parts by mass of the resveratrol type epoxy resin and 0.1 part by mass of 2-methylimidazole was prepared as a measurement sample, and the measurement sample was heat-treated at 180° C. for 90 minutes. A cured product powder was prepared by pulverizing the product in a mortar, and then, using a simultaneous differential thermogravimetric measurement device, the obtained cured product was pulverized under a dry nitrogen stream at a heating rate of 10°C/min. By raising the temperature from 30°C to 600°C, the temperature at which the cured product loses 5% weight (Td5) was measured, and the obtained value was calculated as the 5% weight loss temperature (Td5) of the resveratrol-type epoxy resin. ). Thermosetting resin composition comprising an epoxy resin (A) and a thermally conductive filler (C), wherein the epoxy resin (A) comprises the resveratrol-type epoxy resin (A1) according to claim 1 or 2. thing. Claim 9, wherein the thermally conductive filler (C) contains 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. The thermosetting resin composition described in . The thermosetting resin composition according to claim 9, wherein the thermally conductive filler (C) contains boron nitride. A resin sheet comprising a resin composition layer made of the thermosetting resin composition according to claim 9. The resin sheet according to claim 12, wherein the resin composition layer is in a B-stage state. A thermally conductive member comprising a cured resin layer made of a cured product of the thermosetting resin composition according to claim 9. The thermally conductive member according to claim 14, which is a thermally conductive sheet. The thermally conductive member according to claim 14, wherein the cured resin layer has a glass transition temperature of 210°C or higher, as measured by dynamic viscoelasticity measurement at a heating rate of 5°C/min and a frequency of 10Hz. The cured resin layer has a thermal conductivity in the thickness direction of 15 W/(m K) or more, as measured by a flash method in accordance with JIS R 1611:2010 in an air atmosphere at 25°C. The thermally conductive member according to item 14. a metal substrate;
an insulating layer provided on the metal substrate;
a metal layer provided on the insulating layer,
A metal base substrate, wherein the insulating layer includes one selected from the group consisting of a resin composition layer made of the thermosetting resin composition according to claim 9, and a thermally conductive member according to claim 14. A metal base substrate according to claim 18,
an electronic component provided on the metal base substrate;
An electronic device comprising: The electronic device according to claim 19, which is a power module.

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