JP2022088777A - Thermally conductive resin composition, thermally conductive sheet, and metal-based substrate - Google Patents

Abstract

To provide a thermally conductive resin composition capable of forming a thermally conductive sheet having improved reliability of moisture absorbing solder resistance, due to an action such as an adhesion aid effect and a structural material by adhesion between a thermally-curable resin and clay ore and adhesion between BN and clay ore.SOLUTION: A thermally conductive resin composition contains a thermally curable resin, boron nitride particles, and clay ore.SELECTED DRAWING: Figure 1

Description

The present invention relates to a thermally conductive resin composition, a thermally conductive sheet, and a metal-based substrate.

Insulating materials that make up electrical and electronic equipment are required to have heat dissipation. Various developments have been made on the heat dissipation of insulating materials. As this kind of technique, for example, there is one disclosed in Patent Document 1.

JP-A-2015-193504

However, the thermosetting resin and boron nitride (BN) resin-cured composite material, which is often used in heat-dissipating insulating resin sheets and heat-dissipating insulating resin substrates, has a functional group other than the end face in the flat plate crystal structure of BN. Therefore, there was a problem in the adhesion between the resin and the BN.
Specifically, when the cured resin is put into a solder bath in a moisture-absorbing state, the resin layer swells at a certain temperature and time, and there is a problem in terms of reliability such as moisture-absorbing solder resistance.

The present invention has been made in view of the above problems, and due to the adhesiveness of the heat-curable resin-clay mineral and the adhesiveness of BN-clay mineral, it has an adhesive agent effect and acts like a structural material, and thus has moisture absorption solder resistance. It is an object of the present invention to provide a heat conductive resin composition capable of forming a heat conductive sheet having improved reliability.

As a result of diligent studies to solve the above problems, the present inventor added a clay mineral to the composite material of the thermosetting resin and boron nitride, and the resin and the clay mineral adhere to each other to adhere the entire composite material. The present invention has been completed by finding that it is possible to improve the properties.

According to the present invention, there is provided a thermally conductive resin composition containing a thermosetting resin, boron nitride particles, and a clay mineral.

According to the present invention, there is provided a heat conductive sheet which is a semi-cured product of the above heat conductive resin composition.

Further, according to the present invention, a metal substrate and
Insulation layer and
With a metal layer,
In this order,
A metal base substrate is provided in which the insulating layer is a cured product of the heat conductive sheet.

According to the present invention, a thermally conductive resin capable of forming a thermally conductive sheet having improved adhesion of the entire composite material of a thermosetting resin, boron nitride particles, and clay minerals and improved reliability such as moisture absorption solder resistance. The composition is provided. A heat conductive sheet made of such a heat conductive resin composition can suppress swelling even if it is put into a solder bath in a hygroscopic state.

It is a figure which shows an example of the mixture of the layered mineral and the rod-like mineral in the clay mineral applicable to this embodiment. It is a schematic sectional drawing which shows an example of the structure of the metal base substrate which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the present specification, the notation "XY" in the description of the numerical range indicates X or more and Y or less unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass or more and 5% by mass or less".

<Thermal conductive resin composition>
In the present embodiment, the thermally conductive resin composition is a composition containing a thermosetting resin, boron nitride particles, and a clay mineral. When the heat conductive resin composition contains a clay mineral, it has the effect of improving the adhesion of the entire composite material of the heat-curable resin, boron nitride particles, and clay mineral.
Conventionally, the addition of clay mineral, which is a non-thermally conductive filler, to the thermally conductive filler has not been conceived because it may reduce the thermal conductivity of the thermally conductive resin composition.
As a result of diligent studies, the present inventor has found that a composition having high thermal conductivity can be obtained even with a resin composition containing clay minerals with a non-thermally conductive filler, and completed the present invention.
Although the details of such a mechanism are not clear, the clay mineral acts as a structural material due to the fact that the clay mineral acts as an adhesion aid for the resin-BN and the clay mineral acts as a structural material during the heating expansion of the moisture-absorbing component, resulting in heating expansion. It is considered that it can withstand.

[Thermosetting resin]
The thermosetting resin is not particularly limited as long as it is a resin that can be cured by heating, but is not particularly limited, but is an epoxy resin, a cyanate resin, a polyimide resin, a benzoxazine resin, an unsaturated polyester resin, a phenol resin, a phenoxy resin, a melamine resin, a silicone resin, and a screw. Maleimide resin and acrylic resin are preferable. One of these may be used alone, or two or more thereof may be used in combination.
Among these, epoxy resin and phenol resin are preferable as the thermosetting resin from the viewpoint of having high insulating property.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, and bisphenol M type epoxy resin (4,4'-(1,3-phenylenediiso). Pridiene) 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'-cyclohexy) Bisphenol type epoxy resin such as dienbisphenol type epoxy resin); phenol novolac type epoxy resin, cresol novolac type epoxy resin, trisphenol group methane type novolak type epoxy resin, tetraphenol group ethane type novolak type epoxy resin, condensed ring aromatic carbonization Novolak type epoxy resin such as novolak type epoxy resin having a hydrogen structure; biphenyl type epoxy resin; arylalkylene type epoxy resin such as xylylene type epoxy resin and biphenyl aralkyl type epoxy resin; naphthylene ether type epoxy resin, naphthol type epoxy resin, Naphthalene type epoxy resin such as naphthalenediol type epoxy resin, bifunctional to tetrafunctional naphthalene type epoxy resin, binaphthyl type epoxy resin, naphthalene aralkyl type epoxy resin; anthracene type epoxy resin; phenoxy type epoxy resin; dicyclopentadiene type epoxy resin; Norbornen type epoxy resin; Adamantane type epoxy resin; Fluorene type epoxy resin and the like can be mentioned. One of these may be used alone, or two or more thereof may be used in combination.

Among the epoxy resins, bisphenol type epoxy resin, novolak type epoxy resin, biphenyl type epoxy resin, arylalkylene type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, from the viewpoint of further improving heat resistance and insulation reliability, It is preferably one or more selected from the group consisting of dicyclopentadiene type epoxy resins.

Examples of the phenol resin include novolak-type phenol resins such as phenol novolac resin, cresol novolak resin, and bisphenol A novolak resin, and resol-type phenol resins. One of these may be used alone, or two or more thereof may be used in combination.
Among the phenolic resins, phenol novolac resin is preferable.

Further, the heat conductive resin composition may contain a phenoxy resin. By using the phenoxy resin, it is possible to reduce the elastic modulus of the heat conductive sheet which is a semi-cured product having a heat conductive resin composition. As a result, the bending resistance of the heat conductive sheet can be improved. Further, when the phenoxy resin is contained in the heat conductive resin composition, the stress relaxation force of the heat conductive sheet can be improved. Further, when the phenoxy resin is contained in the heat conductive resin composition, the fluidity can be reduced by increasing the clay, so that voids and the like can be generated. In addition, the adhesion between the heat conductive sheet and the heat radiating member can be improved. Due to these synergistic effects, the insulation stability of the metal base substrate provided with the heat conductive sheet according to the present embodiment can be further enhanced.

Specific examples of the phenoxy resin include phenoxy resins having a bisphenol skeleton such as bisphenol A type phenoxy resin, phenoxy resins having a naphthalene skeleton, phenoxy resins having an anthracene skeleton, and phenoxy resins having a biphenyl skeleton. Further, a phenoxy resin having a structure having a plurality of these skeletons can also be used.
The content of the phenoxy resin can be, for example, 1% by mass or more and 10% by mass or less with respect to the total solid content of the resin composition.

The content of the thermosetting resin is preferably 5% by mass or more, more preferably 10% by mass or more, based on 100% by mass of the non-volatile content of the heat conductive resin composition. Further, 35% by mass or less is preferable, and 30% by mass or less is more preferable.
When the content of the heat-curable resin is not more than the above upper limit, the handleability of the heat-conducting resin composition is improved, it becomes easy to form the heat-conducting sheet, and the strength of the heat-conducting sheet is increased. improves. Further, when the content of the thermosetting resin is at least the above lower limit value, the elastic modulus is further improved and the thermal conductivity is further improved.

[Boron Nitride Particles]
Boron nitride (BN) particles are thermally conductive fillers that impart thermal conductivity and electrical insulation. In the thermally conductive resin composition according to the present embodiment, by using the boron nitride particles according to the present embodiment together with the clay mineral described in detail later, the heat-curable resin, the boron nitride particles, and the clay mineral composite material adhere to the entire composite material. It is a heat conductive resin composition capable of forming a heat conductive sheet having improved properties.

The boron nitride particles preferably include secondary aggregated particles formed by aggregating the primary particles of scaly boron nitride. By doing so, the balance between the heat dissipation characteristic and the insulation characteristic is excellent.
The secondary aggregated particles formed by sintering and aggregating the primary particles of scaly boron nitride can be produced, for example, by the method disclosed in International Publication No. 2018/056205.

The content of the boron nitride particles is preferably 85% by mass or less, more preferably 80% by mass or less, based on 100% by mass of the non-volatile component of the heat conductive resin composition. On the other hand, from the viewpoint of thermal conductivity, the content is preferably 50% by mass or more, more preferably 65% by mass or more, based on 100% by mass of the non-volatile content of the thermally conductive resin composition.

[Clay minerals]
By containing the clay mineral, the heat conductive resin composition according to the present embodiment can form a heat conductive sheet having improved adhesion of the entire composite material of the heat curable resin, boron nitride particles, and clay mineral. It can be a conductive resin composition. Although the detailed mechanism is not clear, it is presumed that clay minerals act like structural materials and can withstand the heat expansion of moisture absorption.
The clay mineral is not particularly limited, but is preferably a surface-modified clay mineral having a large amount of functional groups such as OH groups, and particularly preferably an organically modified clay mineral containing an OH group. Such a clay mineral can be used as a heat conductive resin composition capable of forming a heat conductive sheet having further improved adhesion of the entire composite material of the heat curable resin, boron nitride particles, and clay mineral. .. Examples of surface-modified clay minerals include bentonite. Examples of bentonite include organite, Wenger, Esben (registered trademark of Hojun Co., Ltd.), GARAMITE, CLYTONE, LAPONITE, and POTIBENT series (registered trademark of Big Chemie Japan). In the present embodiment, GARAMITE (manufactured by Big Chemy Japan, registered trademark), which is a kind of modified bentonite and is a mixture of a disk-shaped silicate and a rod-shaped saponite, is particularly preferable.

Here, an example of the clay mineral according to the present embodiment will be described with reference to FIG. The clay mineral 1 is a mixture of the layered mineral 2 and the rod-shaped mineral 3. The surfaces of the layered mineral 2 and the rod-shaped mineral 3 are preferably surface-modified, and in the example shown in FIG. 1, the organic modifying group 4 is modified to the surfaces of the layered mineral 2 and the rod-shaped mineral 3.
As described above, the clay mineral according to the present embodiment is preferably a mixture of layered minerals and rod-shaped minerals. With such a thermally conductive resin composition using clay minerals, when the sheet is semi-cured, it becomes easy to form a card house structure described later.

In the clay mineral, as shown in FIG. 1, a negatively charged layered mineral and a positively charged rod-shaped mineral attract each other to form a three-dimensional association structure of the layered mineral and the rod-shaped mineral. This structure is called a card house structure. The card house structure can be observed with, for example, a scanning electron microscope (SEM).

It is preferable that the clay mineral forms a curd house structure in the heat conductive sheet, which is a semi-cured product of the heat conductive resin composition according to the present embodiment. The clay mineral, boron nitride, and the thermosetting resin are integrated to further improve the adhesion. It is presumed that the adhesion between the thermosetting resin and the clay mineral is higher than the adhesion between the clay mineral and boron nitride. This mechanism is not clear, but the following mechanism is presumed. It is presumed that the clay mineral forming the curdhouse structure in the heat conductive sheet enables boron nitride having no functional group other than the end face to interact with the clay mineral having the curdhouse structure.

The content of the clay mineral contained in the thermally conductive resin composition according to the present embodiment is preferably 0.05% by mass or more, more preferably 0% by mass, based on 100% by mass of the non-volatile content of the thermally conductive resin composition. It is 1% by mass or more, most preferably 0.2% by mass or more. The content of the clay mineral is preferably 10% by mass or less, more preferably 7% by mass or less, and more preferably 5% by mass or less.
When the content of the clay mineral is within the above range, the heat conductive resin composition can form a heat conductive sheet having improved adhesion of the entire composite material of the heat curable resin, boron nitride particles, and clay mineral. Can be done.

[Coupling agent]
The thermally conductive resin composition according to this embodiment may contain a coupling agent. The coupling agent can improve the wettability of the interface between the thermosetting resin and boron nitride.

The coupling agent is not particularly limited, but a silane coupling agent is preferable. As the silane coupling agent, for example, various silane coupling agents such as epoxysilane coupling agent, cationic silane coupling agent, aminosilane coupling agent, alkylsilane, ureidosilane, vinylsilane, and methacrylicsilane are preferable. The coupling agent may be used alone or in combination of two or more.

The content of the coupling agent is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, based on 100% by mass of the non-volatile component of the heat conductive resin composition. Further, 5% by mass or less is preferable, and 3% by mass or less is more preferable.

[Other ingredients]
The heat conductive resin composition may contain, for example, an antioxidant, a leveling material, or the like as other components as long as the object of the present embodiment is not impaired.

Next, a method for producing the thermally conductive resin composition will be described.
As the heat conductive resin composition, for example, each of the above-mentioned components is added to a solvent to obtain a varnish-like resin composition for a sheet. In the present embodiment, for example, a thermosetting resin, boron nitride particles, clay minerals, etc. are added to a solvent to prepare a resin varnish, and then the resin varnish is stirred by using a high-speed stirring device or the like to heat the resin varnish. A conductive resin composition can be obtained. Thereby, the boron nitride particles can be more uniformly dispersed in the resin composition.
The solvent is not particularly limited, but is limited to acetone, methyl isobutyl ketone, toluene, ethyl acetate, cyclohexane, heptane, cyclohexane, cyclohexanone, tetrahydrofuran, dimethylacetamide, dimethyl sulfoxide, ethylene glycol, cellsolve, carbitol, anisole, and N. -Methylpyrrolidone and the like can be mentioned.
At this time, the temperature at the time of kneading the varnish is preferably 40 ° C. or lower. As a result, the dispersibility of boron nitride in the thermally conductive resin composition is improved, and the dispersed state can be maintained more stably. As a result, the curing characteristics of the thermally conductive sheet, which is a semi-cured product of the thermally conductive resin composition, can be easily maintained, and the storage stability can be improved.

[Thermal Conductive Sheet]
The heat conductive resin composition according to the present embodiment can be a heat conductive sheet which is a semi-cured product. That is, it is preferable to use a heat conductive sheet which is a semi-cured product of the heat conductive resin composition. Such a sheet can be a heat conductive sheet having improved adhesion between the thermosetting resin and the composite material of the boron nitride particles. The semi-cured product means a B-stage state.

The heat conductive sheet can be manufactured, for example, as follows.
The heat conductive resin composition obtained by the above method is molded into a sheet. In the present embodiment, for example, a varnish-like heat conductive resin composition is applied onto a base material, and then the heat conductive resin composition is heated and dried. By this drying treatment, the resin film made of the heat conductive resin composition is B-staged, and a heat conductive sheet formed on the substrate can be obtained.
Examples of the base material include a metal foil and a polymer film constituting a peelable carrier material and the like. The polymer film is not particularly limited, but is, for example, heat resistant to polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, release papers such as polycarbonate and silicone sheets, fluororesins and polyimide resins. Examples thereof include a thermoplastic resin sheet having the above. The metal foil is not particularly limited, and is, for example, copper and / or copper-based alloy, aluminum and / or aluminum-based alloy, iron and / or iron-based alloy, silver and / or silver-based alloy, gold and gold-based alloy. , Zinc and zinc-based alloys, nickel and nickel-based alloys, tin and tin-based alloys and the like. The drying time of the heat conductive resin composition can be, for example, 80 ° C. or higher and 200 ° C. or lower, and 1 minute or longer and 1 hour or shorter. The film thickness can typically be 50 μm or more and 500 μm or less.

Further, it is preferable to remove air bubbles in the heat conductive sheet by compressing the resin film with a substrate with a press after the drying treatment.
In the present embodiment, the thermal conductivity and the insulating property of the heat conductive sheet can be improved by including the step of removing air bubbles from the heat conductive sheet with a base material by pressurizing and heating. It is presumed that this is because the density of the resin component in the heat conductive sheet increases by removing the bubbles.
Here, the compression pressure can be, for example, 1 MPa or more and 20 MPa or less.

The thermally conductive sheet according to this embodiment has high thermal conductivity and insulating properties. Therefore, it can be used as a material for a printed circuit board for mounting electronic components such as LEDs and power modules.
The thermal conductivity of the heat conductive sheet can be measured as follows.

<Thermal conductivity test>
The heat conductive resin composition is heat-treated at 100 ° C. for 30 minutes to prepare a B-stage heat conductive sheet having a film thickness of 400 μm. Next, the heat conductive sheet is heat-treated at 200 ° C. for 90 minutes to obtain a cured product of the heat conductive sheet. Then, the thermal conductivity in the thickness direction of the cured product of the heat conductive sheet is measured by using a laser flash method.

At this time, the thermal conductivity of the heat conductive sheet measured by the test method is preferably 6.0 W / (Km) or more and 20.0 W / (Km) or less, more preferably 8.0 W. / (K ・ m) or more and 19.5 W / (K ・ m) or less, more preferably 10.0 W / (K ・ m) or more and 19.0 W / (K ・ m) or less. Since such a heat conductive sheet has high thermal conductivity, it can be suitably used for a heat dissipation sheet such as a metal base substrate.

The heat conductive sheet has high adhesion between the thermosetting resin and the boron nitride particles. Therefore, when the cured resin is put into the solder bath in a hygroscopic state, the swelling of the resin layer is suppressed while maintaining high thermal conductivity.

The resin substrate of the present embodiment includes an insulating layer made of a cured product of the thermosetting resin composition. This resin substrate can be used as a material for a printed circuit board for mounting electronic components such as LEDs and power modules.

That is, in the present embodiment, a metal substrate, an insulating layer, and a metal layer are provided in this order, and a metal base substrate which is a cured product of the heat conductive sheet can be obtained.

(Metal base substrate)
The metal base substrate 100 of this embodiment will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing an example of the configuration of the metal base substrate 100.

As shown in FIG. 2, the metal base substrate 100 can include 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. .. The insulating layer 102 can be composed of one selected from the group consisting of a resin layer made of the above-mentioned thermosetting resin composition, a cured product of the thermosetting resin composition, and a laminated board. Each of these resin layers and laminated plates may be composed of a thermosetting resin composition in a B stage state before the circuit processing of the metal layer 103, and after the circuit processing, it is cured. It may be a cured product.

The metal layer 103 is provided on the insulating layer 102 and is circuit-processed. Examples of the metal constituting the metal layer 103 include one or more selected from copper, copper alloys, aluminum, aluminum alloys, nickel, iron, tin and the like.
The thickness of the metal substrate 103 can be appropriately set as long as the object of the present embodiment is not impaired.

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, and examples thereof include one or more selected from a copper substrate, a copper alloy substrate, an aluminum substrate, and an aluminum alloy substrate.
The thickness of the metal substrate 101 can be appropriately set as long as the object of the present embodiment is not impaired.

In the present embodiment, the metal base substrate 100 can be used for various substrate applications, but since it is excellent in thermal conductivity and heat resistance, it can be used as a printed circuit board using an LED or a power module. ..

The metal base substrate 100 can have a metal layer 103 circuit-processed by etching a pattern or the like. In the metal base substrate 100, a solder resist (not shown) may be formed on the outermost layer, and the connection electrode portion may be exposed so that electronic components can be mounted by exposure / development.

The present invention is not limited to the above embodiment, and the present invention also includes modifications, improvements, and the like to the extent that the object of the present embodiment can be achieved.

Although the embodiments of the present invention have been described above with reference to the drawings, these are examples of the present invention, and various configurations other than the above can be adopted.

Hereinafter, embodiments of the present invention will be described in detail based on Examples and Comparative Examples, but the present invention is not limited thereto.

(Examples 1 to 3, Comparative Example 1)
A thermally conductive resin composition was prepared by the following procedure. According to the formulation shown in Table 1, a thermosetting resin, clay mineral, etc., a curing agent, etc. were added to cyclohexanone, and the mixture was stirred to obtain a solution of the thermosetting resin composition.
Then, the boron nitride particles were mixed with this solution to obtain a varnish-like thermosetting resin composition in which the boron nitride particles were uniformly dispersed.
Next, a varnish-like resin composition is applied onto a PET film and heat-treated at 100 ° C. for 30 minutes to obtain a B-stage (semi-cured) heat conductive sheet having a film thickness of 400 μm (0.4 mm). Was produced. This was peeled off from the PET film and heat-treated at 200 ° C. for 90 minutes to obtain a cured heat conductive sheet.

(Thermosetting resin)
-Epoxy resin: HP-4710 (manufactured by DIC)
-Phenol resin: PR-15470 (manufactured by Sumitomo Bakelite)
・ Phenoxy resin: YP-55 (manufactured by Nittetsu Chemical & Materials Co., Ltd.)
-Cyanate resin: PT-30 (manufactured by Lonza)

(Boron nitride particles)
-Heat conductive filler: Coagulated boron nitride (manufactured by Mizushima Ferroalloy Co., Ltd., HP-40)

(Clay mineral)
・ Surface-modified clay mineral: GARAMITE7305 (manufactured by Big Chemie Japan)

(Silane coupling agent)
-Silane coupling agent: A-187 (manufactured by Momentive Performance Materials)

(Evaluation method)
-Thermal conductivity test The heat-conducting resin compositions of Examples 1 to 3 and Comparative Example 1 were heat-treated at 100 ° C. for 30 minutes to prepare a B-stage-shaped heat-conducting sheet having a film thickness of 400 μm. Next, the heat conductive sheet was heat-treated at 200 ° C. for 90 minutes to obtain a cured heat conductive sheet. Then, the thermal conductivity in the thickness direction of the cured product of the heat conductive sheet was measured by using a laser flash method. The results are shown in Table 2.

・ Adhesion evaluation (number of swelling)
A heat conductive sheet was prepared using the heat conductive resin compositions of Examples 1 to 3 and Comparative Example 1 having a length × width × thickness = 5 cm × 5 cm × about 400 μm. This was absorbed at 30 ° C. and 90% humidity for 48 hours, and then immersed in a solder bath at 275 ° C. for 1 minute. The number of swellings after immersion was counted twice. The results are shown in Table 2. In Table 2, 〇 represents 0 swellings, and × represents the case where there is one or more swellings.

In Example 1, the number of swellings could be suppressed to 0 in both the first and second times while maintaining a high thermal conductivity of 10.3 W / (m · K). Further, in Example 2, the thermal conductivity was 10.8 W / (m · K), which was higher than that in Example 1, and the number of swellings could be suppressed to 0. Further, in Example 3, the thermal conductivity was 11.2 W / (m · K), which was even higher, and the number of swellings could be suppressed to zero. From the above, in Examples 1 to 3, it is possible to improve the adhesion of the entire composite material of the thermosetting resin, boron nitride particles, and clay mineral, and suppress swelling even when immersed in a solder bath in a moisture-absorbing state. I was able to.

On the other hand, in Comparative Example 1, the thermal conductivity was as high as 12.0 W / (Km), but the number of swellings was one or more in both the first and second swellings. Therefore, the adhesion between the thermosetting resin and the boron nitride particles was low.

As described above, according to the resin composition according to the present invention, the heat conductive sheet can improve the adhesion of the entire composite material of the thermosetting resin, boron nitride particles, and clay mineral by containing the clay mineral. I was able to get.

1 ... Clay mineral 2 ... Layered mineral 3 ... Rod-shaped mineral 4 ... Organic modifying group 100 ... Metal base substrate 101 ... Metal substrate 102 ... Insulation layer 103 ... Metal layer

Claims (13)

A thermally conductive resin composition comprising a thermosetting resin, boron nitride particles, and a clay mineral. The heat conductive resin composition according to claim 1.
A thermally conductive resin composition in which the clay mineral is a surface-modified clay mineral. The heat conductive resin composition according to claim 1 or 2.
A thermally conductive resin composition in which the clay mineral is an organically modified clay mineral. The thermally conductive resin composition according to any one of claims 1 to 3.
A thermally conductive resin composition in which the clay mineral is GARAMITE (registered trademark). The thermally conductive resin composition according to any one of claims 1 to 4.
The thermosetting resin is selected from among epoxy resin, cyanate resin, polyimide resin, benzoxazine resin, unsaturated polyester resin, phenol resin, phenoxy resin, melamine resin, silicone resin, bismaleimide resin, and acrylic resin. A thermally conductive resin composition comprising a species or two or more. The thermally conductive resin composition according to any one of claims 1 to 5.
A thermally conductive resin composition further comprising a silane coupling agent. The thermally conductive resin composition according to any one of claims 1 to 6.
A thermally conductive resin composition in which the clay mineral is a mixture of a rod-shaped mineral and a layered mineral. The thermally conductive resin composition according to any one of claims 1 to 7.
A heat conductive resin composition having a clay mineral content of 0.05% by mass or more and 5.0% by mass or less with respect to 100% by mass of the non-volatile content of the heat conductive resin composition. A heat conductive sheet which is a semi-cured product of the heat conductive resin composition according to any one of claims 1 to 8. The heat conductive sheet according to claim 9.
A thermal conductivity sheet having a thermal conductivity of 6.0 W / (Km) or more and 20.0 W / (Km) or less, as measured by the following thermal conductivity test.
<Thermal conductivity test>
The heat conductive resin composition is heat-treated at 100 ° C. for 30 minutes to prepare a B-stage heat conductive sheet having a film thickness of 400 μm. Next, the heat conductive sheet is heat-treated at 200 ° C. for 90 minutes to obtain a cured product of the heat conductive sheet. Next, the thermal conductivity in the thickness direction of the cured heat conductive sheet is measured by using a laser flash method. The heat conductive sheet according to claim 9 or 10, wherein the clay mineral forms a card house structure. The heat conductive sheet according to any one of claims 9 to 11, which is used to form the insulating layer of a metal base substrate in which a metal substrate, an insulating layer, and a metal layer are laminated in this order. With a metal substrate
Insulation layer and
With a metal layer,
In this order,
A metal-based substrate in which the insulating layer is a cured product of the heat conductive sheet according to any one of claims 9 to 12.

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