Thermosetting resin composition, resin sheet, heat sink, method for manufacturing resin sheet, and method for manufacturing heat sink

Abstract

This thermosetting resin composition includes: an epoxy resin; a curing agent for curing the epoxy resin; an ethylene acrylic copolymer having a glass transition temperature of -30°C or lower and having a carboxy group in a side chain; a first spherical filler having thermal conductivity of 20 W / m·K or more and an average particle diameter (D50) of 30-60 μm; and a second spherical filler having thermal conductivity of 20 W / m·K or more and an average particle diameter (D50) of 1-10 μm. The weight ratio of the total of the first spherical filler and the second spherical filler is 84%-90% by weight based on 100% by weight of the total solid content. The ratio between the first spherical filler and the second spherical filler is 55:45 to 85:15. The content of the ethylene acrylic copolymer is 700-1,000 parts by weight based on 100 parts by weight of the epoxy resin.

Description

Technical Field

[0001] The present invention relates to a thermosetting resin composition, a resin sheet, a heat sink, a method for manufacturing a resin sheet, and a method for manufacturing a heat sink.

Background Art

[0002] When driving a device on which a large number of electronic components such as IC chips and transistors are mounted, a lot of heat is generated from the electronic components. If the generated heat cannot be efficiently dissipated, the functions of the electronic components deteriorate due to the influence of heat, and the device malfunctions. To prevent this malfunction, the substrate on which the electronic components are installed is provided with a metal plate having high thermal conductivity via a resin sheet having insulating properties and thermal conductivity on the surface opposite to the surface on which the electronic components are installed. With this metal plate, the heat generated from the electronic components can be efficiently dissipated through the resin sheet.

[0003] For example, Patent Document 1 discloses a metal base substrate composed of a metal plate, an insulating adhesive layer laminated thereon, and a copper foil laminated further on the insulating adhesive layer. Further, Patent Document 1 discloses an adhesive composition that can be used as the insulating adhesive layer, including an epoxy resin, a curing agent, a high molecular weight resin compatible with the epoxy resin and having a weight average molecular weight of 30,000 or more, a high molecular weight resin having a glass transition temperature of 0°C or lower and having reactive functional groups and a weight average molecular weight of 100,000 or more, a curing accelerator, and an inorganic filler having a small particle size.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Such a metal-based substrate may have poor heat cycle characteristics. Specifically, when a heat cycle test is performed on a metal-based substrate with electronic components installed on a circuit formed by etching a copper foil, due to temperature changes, the metal plate constituting the metal-based substrate repeatedly expands and contracts. Due to this repeated expansion and contraction, stress is generated inside the insulating adhesive layer laminated on the metal plate. However, since this insulating adhesive layer cannot relieve this stress, the circuit moves in accordance with the expansion and contraction of the metal plate. When the circuit moves, stress concentrates on the solder connecting the electronic components and the circuit, and cracks are likely to occur in the solder. Therefore, the heat cycle characteristics of the above-mentioned metal-based substrate may be poor. Furthermore, since the particle size of the inorganic filler contained in the insulating adhesive layer is small, resin is likely to be interposed between the fillers, and the thermal conductivity of the insulating adhesive layer is low.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a heat sink having excellent heat cycle characteristics, a resin sheet having excellent thermal conductivity, a resin layer of the heat sink, a thermosetting resin composition constituting the resin sheet, a method for manufacturing the resin sheet, and a method for manufacturing the heat sink.

Means for Solving the Problems

[0007] The present invention is as follows. [1] The thermosetting resin composition according to the present invention is an epoxy resin, a curing agent for curing the epoxy resin, an ethylene acrylic copolymer having a glass transition temperature of -30°C or lower and having a carboxy group in the side chain, a first spherical filler having a thermal conductivity of 20 W / m·K or more and an average particle diameter (D50) of 30 μm or more and 60 μm or less, a second spherical filler having a thermal conductivity of 20 W / m·K or more and an average particle diameter (D50) of 1 μm or more and 10 μm or less, and the total weight ratio of the first spherical filler and the second spherical filler is 84% by weight or more and 90% by weight or less with respect to 100% by weight of the total solid content, The ratio of the first spherical filler to the second spherical filler is 55:45 to 85:15, The content of the ethylene acrylic copolymer is 700 parts by weight or more and 1000 parts by weight or less with respect to 100 parts by weight of the epoxy resin.

[0008] Also, [2] the first spherical filler may be composed of at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, and silicon nitride.

[0009] Also, [3] the second spherical filler may be composed of at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, and silicon nitride.

[0010] Also, [4] the thermosetting resin composition contains an ion scavenger that captures ions, The content of the ion scavenger may be 40 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the epoxy resin.

[0011] Also, [5] the thermosetting resin composition has a thermal conductivity of 2 W / m·K or more after curing, a storage elastic modulus at -30°C after curing of 7000 MPa or less, a storage elastic modulus at 25°C after curing of 10 MPa or more and 100 MPa or less, and a storage elastic modulus at 125°C after curing of 1 MPa or more and 100 MPa or less, and may be so.

[0012] Also, [6] the resin sheet according to the present invention is composed of the thermosetting resin composition according to any one of [1] to [5].

[0013] Also, [7] the cured state of the resin sheet may be a semi-cured state.

[0014] Also, [8] the heat sink according to the present invention a metal plate, A resin layer composed of the thermosetting resin composition according to any one of [1] to [5], and the resin layer is formed on at least one surface of the metal plate.

[0015] Also, [9] the cured state of the resin layer may be a semi-cured state.

[0016] Also,

[10] the method for manufacturing a resin sheet according to the present invention is a preparation step of preparing the thermosetting resin composition according to any one of [1] to [5], a forming step of forming a resin layer composed of the thermosetting resin composition into a film, and a heating step of heating the film on which the resin layer is formed.

[0017] Also,

[11] the method for manufacturing a heat sink according to the present invention is a lamination step of laminating the resin layer of the resin sheet obtained by the method for manufacturing a resin sheet according to

[10] on a metal plate, and a heating and pressing step of heating and pressing the metal plate on which the resin layer is laminated.

[0018] Also,

[12] the method for manufacturing a heat sink according to the present invention is a preparation step of preparing the thermosetting resin composition according to any one of [1] to [5], a forming step of forming a resin layer composed of the thermosetting resin composition on a metal plate, and a heating step of heating the metal plate on which the resin layer is formed. [Advantages of the Invention]

[0019] According to the present invention, it is possible to provide a heat sink having excellent heat cycle characteristics, a resin sheet having excellent thermal conductivity, a thermosetting resin composition constituting the resin layer of the heat sink and the resin sheet, a method for manufacturing a resin sheet, and a method for manufacturing a heat sink. [Brief Description of the Drawings]

[0020]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0021] Hereinafter, a thermosetting resin composition, a resin sheet, a heat sink, a method for manufacturing the resin sheet, and a method for manufacturing the heat sink, which are embodiments for carrying out the present invention (hereinafter referred to as embodiments), will be described in detail. The following embodiments are examples for explaining the present invention and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of its gist. The parts by weight used in the embodiments mean the weight of only the resin excluding volatile components such as organic solvents contained in the resin, that is, the weight of the non-volatile components. The semi-cured state (B-stage) means a state in which the curing reaction of the thermosetting resin composition has proceeded halfway.

[0022] [Thermosetting Resin Composition] The thermosetting resin composition of the embodiment includes an epoxy resin, a curing agent, an ethylene acrylic copolymer having a carboxy group in the side chain, a first spherical filler, and a second spherical filler. Further, the thermosetting resin composition of the embodiment is suitably used as the resin composition constituting the resin sheet and the resin composition of the resin layer constituting the heat sink.

[0023] Hereinafter, the components contained in the thermosetting resin composition of the embodiment will be described.

[0024] (Epoxy Resin) The epoxy resin only needs to be able to react with the curing agent to cure the thermosetting resin composition. For example, it has two or more epoxy groups in one molecule and has an epoxy equivalent of 100 g / eq or more and 400 g / eq or less.

[0025] Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, novolak type epoxy resin, amine type epoxy resin, biphenyl type epoxy resin, alicyclic epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, naphthalene ring-containing epoxy resin, dicyclopentadiene type epoxy resin, and the like. Among the above epoxy resins, from the viewpoint of enhancing the dielectric breakdown voltage characteristics, for example, novolak type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, and bisphenol A type epoxy resin are preferable.

[0026] The epoxy resin may be used alone or in combination of two or more kinds of epoxy resins. Further, the epoxy resin may be dissolved in an organic solvent in advance in order to facilitate mixing with other materials contained in the thermosetting resin composition.

[0027] (Curing agent) The curing agent may be any agent that can cure the epoxy resin. Examples thereof include diaminodiphenylmethane (DDM), diaminodiphenylsulfone (DDS), diaminodiphenylether (DDE), hexamethylenediamine, dicyandiamide, phenol novolak type phenol resin, phenol novolak type cyanate ester resin, and the like. From the viewpoint of easy control of the curing reaction, dicyandiamide and diaminodiphenylsulfone are preferable as the curing agent. Further, the curing agent may be used alone or in combination of two or more kinds of curing agents.

[0028] The content of the curing agent may be any amount as long as the thermosetting resin composition can be cured. For example, with respect to 100 parts by weight of the epoxy resin, 1 part by weight or more and 40 parts by weight or less are preferable, and 5 parts by weight or more and 40 parts by weight or less are more preferable. Thereby, the dielectric breakdown voltage characteristics and heat resistance after curing of the thermosetting resin composition can be improved. Further, the heat cycle characteristics of the resin sheet and heat sink plate composed of this resin composition can be improved.

[0029] The equivalent amount of the curing agent only needs to be able to cure the thermosetting resin composition. Preferably, it is 0.1 equivalent or more and 0.8 equivalent or less, more preferably 0.1 equivalent or more and 0.6 equivalent or less, and still more preferably 0.2 equivalent or more and 0.4 equivalent or less with respect to 1 equivalent of the epoxy group contained in the epoxy resin. Thereby, the dielectric breakdown voltage characteristics and heat resistance after curing of the thermosetting resin composition can be improved. Further, the heat cycle characteristics of the heat sink using this resin composition can be improved.

[0030] (Ethylene acrylic copolymer having a carboxy group in the side chain) Examples of the ethylene acrylic copolymer having a carboxy group in the side chain include (meth)acrylic acid ester copolymers having an ethylene structure in the main chain and a carboxy group in the side chain. The glass transition temperature of the ethylene acrylic copolymer having a carboxy group in the side chain is -30 °C or lower, preferably -35 °C or lower, and more preferably -40 °C or lower from the viewpoint of relaxing the stress generated during the heat cycle. Here, the (meth)acrylic acid ester copolymer means an acrylic acid ester copolymer or a methacrylic acid ester copolymer. The glass transition temperature can be measured by a differential scanning calorimetry (DSC) method.

[0031] The (meth)acrylic acid ester copolymer having a carboxy group in the side chain is composed of, for example, two or more kinds of monomers. Examples of the monomers constituting this copolymer include (meth)acrylic acid ester monomers, carboxy group-containing monomers, anhydrides of carboxy group-containing monomers, and the like. Here, the (meth)acrylic acid ester monomer means an acrylic acid ester monomer or a methacrylic acid ester monomer.

[0032] The ethylene acrylic copolymer having a carboxy group in the side chain can introduce an ethylene structure into the main chain of the copolymer by polymerizing with the above-mentioned monomers. Examples of the introduction method include an introduction method by a Ziegler-Natta catalyst polymerization method, a metallocene catalyst polymerization method, a Versipol catalyst polymerization method, and a free radical polymerization method.

[0033] Examples of the (meth)acrylic acid ester monomer include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate; N,N-dimethylaminoalkyl (meth)acrylates such as N,N-dimethylaminomethyl (meth)acrylate; and epoxy group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate. Note that methyl (meth)acrylate means methyl acrylate or methyl methacrylate. Also, (meth)acrylic acid means acrylic acid or methacrylic acid. The same applies hereinafter.

[0034] Examples of the carboxy group-containing monomer include (meth)acrylic acid, fumaric acid, and maleic acid.

[0035] Examples of the anhydride of the carboxy group-containing monomer include anhydrides of (meth)acrylic acid, maleic acid, and the like.

[0036] From the viewpoint of preventing stress from occurring in the resin layer of the heat sink, the weight average molecular weight of the ethylene acrylic copolymer having a carboxy group in the side chain is, for example, 100,000 or more and 400,000 or less, and preferably 150,000 or more and 300,000 or less. Here, the weight average molecular weight can be measured by gel permeation chromatography (GPC) using standard polystyrene having an average molecular weight of about 500 or more and about 1,000,000 or less.

[0037] From the viewpoints of preventing stress from occurring in the resin layer of the heat sink and heat conductivity, the content of the ethylene acrylic copolymer having a carboxy group in the side chain is 700 parts by weight or more and 1000 parts by weight or less, and preferably 700 parts by weight or more and 900 parts by weight or less with respect to 100 parts by weight of the epoxy resin.

[0038] From the viewpoint of preventing stress from occurring in the resin layer of the heat sink, the carboxy group content is preferably, for example, 3 mgKOH / g or more and 30 mgKOH / g or less, more preferably 10 mgKOH / g or more and 30 mgKOH / g or less. The carboxy group content can be measured by a titration method using a 0.1N aqueous potassium hydroxide solution.

[0039] Examples of commercially available ethylene-acrylic copolymers having a carboxy group in the side chain include VMX4017 manufactured by DuPont.

[0040] (First spherical filler) The average particle diameter (D50) of the first spherical filler is 30 μm or more and 60 μm or less. When the average particle diameter (D50) is 30 μm or more and 60 μm or less, the first spherical filler is less likely to protrude from the surface of the resin layer. Thereby, the smoothness of the surface of the resin layer is improved. Further, with the above particle size, a network is easily formed between the first spherical fillers, and the thermal conductivity of the resin layer is improved.

[0041] From the viewpoint of improving the thermal conductivity of the resin layer of the heat sink, the thermal conductivity of the first spherical filler is 20 W / m·K or more. The first spherical filler may be a filler having excellent insulation and thermal conductivity, and is composed of at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, and silicon nitride, and alumina is more preferable. Here, the average particle diameter (D50) refers to the particle diameter when, in the volume-based particle size distribution, counting from the particles with a small particle diameter and the integration reaches 50% of the total volume. The particle diameter can be measured by the dynamic light scattering method.

[0042] (Second spherical filler) The average particle diameter (D50) of the second spherical filler is 1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less. The second spherical filler having such an average particle diameter (D50) is filled so as to fill the gaps between one first spherical filler and another first spherical filler. This contributes to the improvement of the thermal conductivity of the resin layer described later. From the viewpoint of improving the thermal conductivity of the resin layer composed of the thermosetting resin composition, the thermal conductivity of the second spherical filler is 20 W / m·K or more. The second spherical filler may be a filler having excellent insulating properties and thermal conductivity, and is composed of at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, and silicon nitride, and alumina is more preferable.

[0043] From the viewpoints of improving the thermal conductivity, heat cycle characteristics, and dielectric breakdown voltage characteristics, the total weight ratio of the first spherical filler and the second spherical filler described above is 84% by weight or more and 90% by weight or less, preferably 85% by weight or more and 90% by weight or less, and more preferably 85% by weight or more and 89% by weight or less with respect to 100% by weight of the total solid content contained in the thermosetting resin composition. Also, from the viewpoint of preventing stress from being generated in the resin layer of the heat sink, the ratio of the first spherical filler to the second spherical filler is 55:45 to 85:15, preferably 55:45 to 65:35.

[0044] The resin layer composed of the thermosetting resin composition containing the above-described materials and having the above-described composition ratio and the like has the following effects. The resin layer formed from the thermosetting resin composition in which the above-described materials are uniformly mixed is configured by filling the second spherical filler so as to fill the gaps between one first spherical filler and another first spherical filler. By filling the spherical fillers without gaps, a network of spherical fillers is densely formed in the resin layer. As a result, the resin layer composed of the thermosetting resin composition of the present embodiment has excellent thermal conductivity.

[0045] Furthermore, since the thermosetting resin composition of the present embodiment contains an ethylene acrylic copolymer having a glass transition temperature of -30°C or lower and the above-described spherical filler, the generation of stress can be reduced. That is, a heat sink having a resin layer composed of such a thermosetting resin composition can reduce the generation of stress in the resin layer even when a temperature change occurs, and thus has excellent heat cycle characteristics.

[0046] Note that the first spherical filler and the second spherical filler do not necessarily have to be perfect spheres, and any filler having a shape with few surface irregularities to the extent that the stress generated inside the resin layer can be released may be used. In addition, the spherical filler includes, for example, a filler composed of a polyhedron having 12 or more faces. Also, the materials of the first spherical filler and the second spherical filler may be the same or different.

[0047] (Other components) The thermosetting resin composition of the embodiment may contain an ion scavenger that captures ions generated in the thermosetting resin composition. By including this ion scavenger, the ions present in the resin composition are reduced, and the dielectric breakdown voltage characteristics are improved. The content of the ion scavenger contained in the thermosetting resin composition is 40 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the epoxy resin.

[0048] The thermosetting resin composition of the embodiment may further contain other additives. Examples of other additives include imidazole-based curing accelerators such as 2-methylimidazole, 2-undecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, and N-benzyl-2-methylimidazole; Lewis acid complex-based curing accelerators such as boron trifluoride monoethylamine and boron trifluoride diethylamine; curing accelerators such as polyamine and melamine resin, dispersants, softeners, heat aging inhibitors, and silane coupling agents.

[0049] As described above, the thermosetting resin composition of the embodiment is obtained by mixing the above-described materials.

[0050] The thermal conductivity of the thermosetting resin composition after curing is 2 W / m·K or more, and it has excellent thermal conductivity. Further, this thermosetting resin composition has a storage elastic modulus at -30°C after curing of 7000 MPa or less, a storage elastic modulus at 25°C after curing of 10 MPa or more and 100 MPa or less, and a storage elastic modulus at 125°C after curing of 1 MPa or more and 100 MPa or less. A heat sink comprising a resin layer and a metal plate composed of such a thermosetting resin composition has excellent heat cycle characteristics in a heat cycle test in which it is alternately and repeatedly exposed to two temperature atmospheres, a low temperature atmosphere of -20°C to -40°C and a high temperature atmosphere of 100°C to 175°C.

[0051] Note that the conditions for curing the thermosetting resin composition are, for example, 160°C or more and 200°C or less for 1 hour or more. The thermal conductivity of the thermosetting resin composition can be measured by the laser flash method using an LFA (Laser Flash Analyzer) device. The storage elastic modulus of the thermosetting resin composition can be measured by the dynamic viscoelasticity measurement method.

[0052] Next, the resin sheet of the embodiment will be described. [Resin Sheet] As shown in FIG. 1, the resin sheet 10 of the embodiment is composed of the thermosetting resin composition of the embodiment and has a sheet-like shape. The cured state of the resin sheet 10 is a semi-cured state.

[0053] The thickness of the resin sheet 10 only needs to have adhesiveness and excellent thermal conductivity and heat cycle characteristics when the resin sheet 10 is used as the resin layer of the heat sink, and is, for example, 80 μm or more and 500 μm or less.

[0054] The resin sheet 10 is manufactured, for example, according to the following procedure. A predetermined amount of an epoxy resin, a curing agent, an ethylene acrylic copolymer, a first spherical filler, and a second spherical filler are added to a container and mixed to prepare a thermosetting resin composition. The thermosetting resin composition is applied to a separator film using, for example, a coating device and heated. After cooling, a separator film formed with a resin layer composed of the thermosetting resin composition, that is, the resin sheet 10 is obtained. When using the obtained resin sheet 10, the separator film is peeled off. The curing state of the resin sheet 10 is a semi-cured state. The curing conditions are, for example, 100°C or higher and 250°C or lower, 5 seconds or longer and 30 minutes or shorter, and can be adjusted according to the thickness of the resin sheet 10.

[0055] The thickness of the separator film used when manufacturing the resin sheet 10 only needs to be easy to handle, and is, for example, 25 μm or more and 100 μm or less. The thickness of the separator film is determined according to the thickness of the resin layer. Examples of the material of the separator film include polyethylene, polypropylene, polyimide, polyamide, polyethylene naphthalate, and polyethylene terephthalate. From the viewpoint of facilitating peeling of the separator film from the resin sheet 10, a release treatment may be applied to the surface of the separator film. Examples of the treatment agent for the release treatment include silicone-based treatment agents and fluorine-based treatment agents.

[0056] Note that the resin sheet 10 may have another configuration. As the resin sheet 10 having another configuration, a double-sided resin sheet having resin layers formed on both sides of the film can be mentioned from the viewpoint of enhancing rigidity and electrical insulation reliability. Examples of the material of this film include polyimide, polyamide, and polyethylene naphthalate from the viewpoints of enhancing heat resistance and enhancing the rigidity of the resin sheet. The resin sheet of the embodiment has been described above.

[0057] Next, the heat sink of the embodiment will be described. [Heat sink] As shown in FIG. 2, the heat sink 20 of the embodiment includes a metal plate 21 and a resin layer 23 composed of the thermosetting resin composition of the embodiment. The resin layer 23 is formed on at least one surface of the metal plate 21. The curing state of the resin layer 23 is a semi-cured state. As shown in FIG. 3, the electronic component 40 is installed on the substrate 30 via a circuit 31 formed on the substrate 30. The substrate 30 is provided on the surface opposite to the surface of the resin layer 23 where the metal plate 21 is formed.

[0058] The thickness of the resin layer 23 only needs to be able to maintain insulation between the substrate 30 and the metal plate 21, and is, for example, 80 μm or more and 500 μm or less, preferably 100 μm or more and 200 μm or less.

[0059] The metal plate 21 only needs to be able to efficiently dissipate the heat generated from the electronic component 40 installed on the substrate 30, and is preferably composed of a metal having a high thermal conductivity. Examples of metals having a high thermal conductivity include copper, aluminum, stainless steel, etc. Among these, copper and aluminum, which are excellent in workability and have a high thermal conductivity, are preferable.

[0060] The thickness of the metal plate 21 only needs to be easy to process, and is, for example, 9 μm or more and 10 mm or less, preferably 500 μm or more and 2 mm or less. Note that the metal plate 21 includes metal foil.

[0061] As shown in FIG. 3, a plurality of fins 22 may be provided on the surface of the metal plate 21 opposite to the surface where the resin layer 23 is formed. The metal plate 21 provided with the plurality of fins 22 is also called a heat sink.

[0062] The thickness of the metal plate 21 provided with a plurality of fins 22 is, for example, 0.3 mm or more and 50 mm or less. The fins 22 are composed of, for example, plates or bars. The height of the fins 22 is, for example, 1 mm or more and 100 mm or less. The thickness of the plate-shaped fins is, for example, 0.2 mm or more and 9 mm or less, and it is preferably thinner than the thickness of the metal plate 21. Also, the plate-shaped fins are preferably smaller than the metal plate 21. The bar-shaped fins have a cross-sectional shape in a direction orthogonal to the longitudinal direction of the fins, for example, a square or a circle.

[0063] The entire surface of the fins 22 may be covered with the thermosetting resin composition of the embodiment, or only a part of the surface of the fins 22 may be covered with the thermosetting resin composition of the embodiment.

[0064] The heat sink 20 is manufactured, for example, by the following procedure. Prepare a metal plate 21 and a resin sheet 10 as the resin layer 23. Peel off the separator film from the resin surface of the resin sheet 10 before laminating the resin sheet 10 on the metal plate 21. Next, laminate the resin sheet 10 on the metal plate 21 so that the resin sheet 10 and the metal plate 21 are in contact. Then, heat and press the metal plate 21 laminated with the resin sheet 10, for example, under the conditions of 0.3 MPa or more and 10 MPa or less, 100 °C or more and 250 °C or less, and 5 seconds or more and 30 minutes or less. After cooling, the heat sink 20 is obtained. The heating and pressing conditions can be adjusted according to the thickness of the resin layer 23.

[0065] As another method of manufacturing the heat sink 20, for example, the following method can be mentioned. Add a predetermined amount of an epoxy resin, a curing agent, an ethylene acrylic copolymer, a first spherical filler, and a second spherical filler to a container and mix them to prepare a thermosetting resin composition. Also, prepare a metal plate 21. Next, apply the thermosetting resin composition to the metal plate 21 using, for example, a coating device and heat it. After cooling, the metal plate 21 with the resin layer 23 formed, that is, the heat sink 20 is obtained. The heating conditions are, for example, 100 °C or more and 250 °C or less, and 5 seconds or more and 30 minutes or less. The heating conditions can be adjusted according to the thickness of the resin layer 23. Above, the heat sink of the embodiment has been described.

[0066] In addition, an organic solvent may be used when preparing the thermosetting resin composition of the embodiment. Examples of the organic solvent include alcohols such as methanol and ethanol; glycols such as ethylene glycol and propylene glycol; glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; glycol dialkyl ethers such as ethylene glycol dimethyl ether and ethylene glycol diethyl ether; alkyl esters such as methyl acetate, ethyl acetate, propyl acetate, and methyl acetoacetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane, cyclohexane, and octane; amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; cyclic ethers such as tetrahydrofuran and dioxane, and the like.

[0067] In addition, examples of the apparatus used for forming the resin layers 23 of the resin sheet 10 and the heat sink 20 of the embodiment include a coating apparatus. Examples of the coating apparatus include known coaters, such as a die coater and a comma coater.

Examples

[0068] The present invention will be described in more detail with reference to the following examples. The present invention is not limited to the following examples in any way.

[0069] The following components were used as the components included in the thermosetting resin compositions in the examples and comparative examples. (Epoxy resin) (1) jER (registered trademark) 828: Bisphenol A type epoxy resin, epoxy equivalent 190 g / eq, manufactured by Mitsubishi Chemical Corporation.

[0070] (Hardener) Seika Cure-S: 4,4'-DDS (4,4'-diaminodiphenyl sulfone), amine value 62 g / eq, manufactured by Wakayama Seika Kogyo Co., Ltd.

[0071] (Acrylic copolymer) (1) VMX4017: Ethylene acrylic copolymer having a carboxy group in the side chain, glass transition temperature -41 °C, manufactured by DuPont (2) GLS: Ethylene acrylic copolymer having a carboxy group in the side chain, glass transition temperature -24 °C, manufactured by DuPont (3) 1HY-3006Y: Acrylic copolymer having a carboxy group in the side chain (ethylene is not included in the main chain), weight average molecular weight of about 280,000, glass transition temperature -53 °C, manufactured by Dainippon Fine Chemical Co., Ltd. (4) 1HY-2002M: Acrylic copolymer having a carboxy group in the side chain (ethylene is not included in the main chain), weight average molecular weight of about 280,000, glass transition temperature -3 °C, manufactured by Dainippon Fine Chemical Co., Ltd.

[0072] (Ion scavenger) KW-2200: Magnesium oxide-aluminum oxide solid solution, manufactured by Kyowa Chemical Industry Co., Ltd.

[0073] (Filler) (1) DAM-45: Spherical alumina, average particle size (D50) 45 μm, thermal conductivity 36 W / m·K, manufactured by Denka Co., Ltd. (2) DAM-20: Spherical alumina, average particle size (D50) 20 μm, thermal conductivity 36 W / m·K, manufactured by Denka Co., Ltd. (3) DAM-10: Spherical alumina, average particle size (D50) 10 μm, thermal conductivity 36 W / m·K, manufactured by Denka Co., Ltd. (4) DAM-03: Spherical alumina, average particle size (D50) 3 μm, thermal conductivity 36 W / m·K, manufactured by Denka Co., Ltd. (5) AA18: Non-spherical alumina, average particle size (D50) 20 μm, thermal conductivity 36 W / m·K, manufactured by Sumitomo Chemical Co., Ltd. (6) AS-50: Non-spherical alumina, average particle size (D50) 10 μm, thermal conductivity 36 W / m·K, manufactured by Showa Denko KK (7) LS-210: Non-spherical alumina, average particle size (D50) 2 μm, thermal conductivity 36 W / m·K, manufactured by Nippon Light Metal Co., Ltd. (8) AO-502: Spherical alumina, average particle diameter (D50) 0.25 μm, thermal conductivity 36 W / m·K, manufactured by Admatechs Co., Ltd., (9) FAN-f50-A1: Spherical aluminum nitride, average particle diameter (D50) 50 μm, thermal conductivity 170 W / m·K, manufactured by Furukawa Electric Co., Ltd., (10) FAN-f05: Polyhedral shape, aluminum nitride, average particle diameter (D50) 5.0 μm, thermal conductivity 170 W / m·K, manufactured by Furukawa Electric Co., Ltd., (11) FB-40R: Spherical silica, average particle diameter (D50) 40 μm, thermal conductivity 1 W / m·K, manufactured by Denka Co., Ltd., (12) FB-5SDC: Spherical silica, average particle diameter (D50) 3.0 μm, thermal conductivity 1 W / m·K, manufactured by Denka Co., Ltd.

[0074] (Example 1) First, a thermosetting resin composition was prepared. Also, a resin sheet 10 composed of the thermosetting resin composition was produced. Next, using the resin sheet 10, the storage elastic modulus after curing of the thermosetting resin composition was measured. Also, the thermal conductivity of the resin sheet 10 was measured. Furthermore, a heat cycle test was conducted on the heat sink 20 using the resin sheet 10.

[0075] (Preparation of Thermosetting Resin Composition) Into a container, 100 parts by weight of jER (registered trademark) 828, 10 parts by weight of Seikacure-S, 800 parts by weight of VMX4017, 4006 parts by weight of DAM-45, 2670 parts by weight of DAM-03, and 500 parts by weight of methyl ethyl ketone as an organic solvent were added. Then, these were stirred at room temperature to obtain a thermosetting resin composition.

[0076] (Measurement of Storage Elastic Modulus) In order to measure the storage elastic modulus of the obtained thermosetting resin composition, a sample for measurement was prepared. First, the thermosetting resin composition was applied to the release-treated surface of a release PET (polyethylene terephthalate) film with a thickness of 50 μm (PET5011 manufactured by Lintec Corporation) so that the thickness after pressing would be 100 μm, and it was covered with another release PET film. Then, under the conditions of 180 °C, 3 MPa, and 60 minutes, the laminate laminated in the order of the release PET film, the thermosetting resin composition, and the release PET film was heated and pressurized. After cooling, a cured resin sheet 10 having a thickness of 100 μm was obtained. The obtained cured resin sheet 10 was cut into a rectangle with a length of 30 mm and a width of 4 mm to obtain a sample for measuring the storage elastic modulus.

[0077] The storage elastic modulus was measured by the dynamic viscoelastic measurement method using RSA-G2 (manufactured by TA Instruments). The measurement conditions were a temperature range of -50 °C to 200 °C, a heating rate of 10 °C / min, a frequency of 1 Hz, a chuck distance of 20 mm, and a tensile mode. The storage elastic modulus of the cured thermosetting resin composition of Example 1 was 325 MPa at -30 °C, 15 MPa at 25 °C, and 8 MPa at 125 °C.

[0078] (Preparation of Resin Sheet 10) The thermosetting resin composition was applied to the release-treated surface of a release PET film with a thickness of 50 μm (PET5011 manufactured by Lintec Corporation) so that the thickness after heating would be 100 μm. Then, it was heated at 120 °C for 10 minutes, cooled, and a resin sheet 10 with a release PET film attached to one side was obtained. The curing state of the resin sheet 10 was a semi-cured state (B-stage).

[0079] <Thermal Conductivity> The thermal diffusivity (α), specific heat (Cp), and density (ρ) of the sample for measuring the thermal conductivity were measured, and the thermal conductivity was calculated from the following formula. Thermal conductivity [W / (m·K)] = α [mm 2 / s] × Cp [J / g·K] × ρ [g / cm 3 α [mm 2 / s]: Thermal diffusivity, Cp [J / g·K]: Specific heat, ρ [g / cm 3 : Density. The evaluation criteria were as follows. Good: 2 W / (m·K) or more, Poor: Less than 2 W / (m·K). Note that the sample for measuring thermal conductivity with a Good evaluation result has excellent thermal conductivity.

[0080] (Preparation of Sample for Measuring Thermal Conductivity) Two resin sheets 10 with a release PET film attached to one side were prepared, laminated so that their resin surfaces were in contact with each other, and a laminate was obtained. The laminate was heated and pressed under the conditions of 185°C, 5 MPa, and 180 minutes. Then, the release PET film was peeled off from the laminate to obtain a sample for measuring thermal conductivity.

[0081] (Measurement of Thermal Diffusivity (α)) The laser flash method was adopted to measure the temperature change on the other side when the sample for measuring thermal conductivity was irradiated with pulsed light on one side. Also, the obtained measurement data was analyzed by the half-time method to obtain the thermal diffusivity (α). As the measuring instrument, LFA447 manufactured by NETZSCH was used, and the measurement was carried out under the condition of 25°C.

[0082] (Measurement of Specific Heat (Cp)) In accordance with JIS K7123, the specific heat Cp (J / g·K) of the sample for measuring thermal conductivity was determined by the differential scanning calorimetry (DSC method). As the measuring instrument, Q200 manufactured by TA Instruments was used, and the measurement was carried out under the conditions of a heating rate of 10°C / min and a temperature range of -30°C or more and 50°C or less.

[0083] (Measurement of Density (ρ)) The immersion method was adopted for the measurement of density (ρ). As the measuring instruments, AUX220 and SMK-401 manufactured by Shimadzu Corporation were used. The numerical values of the thermal diffusivity (α), specific heat (Cp), and density (ρ) obtained above were substituted into the formula for thermal conductivity to calculate the thermal conductivity. The thermal conductivity of the resin sheet 10 of Example 1 was 2.9 W / (m·K), and the evaluation was Good. It was found that the resin sheet 10 of Example 1 was excellent in thermal conductivity.

[0084] <Heat Cycle Test> Next, a heat cycle test was conducted on the resin sheet 10 of Example 1. Samples for heat cycle test measurement were prepared as follows.

[0085] (Preparation of Samples for Heat Cycle Test Measurement) Rolled copper foil (BHY manufactured by JX Nippon Mining & Metals Co., Ltd.) with a thickness of 35 μm assuming the substrate 30 and the circuit 31 was prepared. The rolled copper foil and the resin sheet 10 were laminated so that the rough surface of the rolled copper foil was in contact with the resin surface of the resin sheet 10. Next, an aluminum foil (soft single-sided aluminum foil manufactured by Toyo Aluminum) with a thickness of 50 μm corresponding to the metal plate 21 was laminated with the resin sheet 10 so that the rough surface of the aluminum foil was in contact with the resin surface opposite to the resin surface on which the rolled copper foil was laminated, and a laminate was obtained. The obtained laminate had a structure in which the rolled copper foil, the resin sheet 10, and the aluminum foil were laminated in this order. Next, this laminate was heated and pressed under the conditions of 180°C, 5 MPa, and 60 minutes. After cooling, the laminate was cut into a rectangle of 10 mm × 50 mm. The resin sheet 10 was used after peeling off the release PET film.

[0086] Next, in order to form a resin layer that protects the surface of the laminate, the laminate was placed in a container, resin was added so that the entire surface of the laminate was covered with the resin, and the resin was hardened by heating at 100 °C for 24 hours. After cooling, the laminate covered with the resin was taken out of the container, and the laminate covered with the resin was polished until the end face (cross-section) of the laminate was exposed. It was confirmed that the end face (cross-section) of the polished laminate had a structure in which a rolled copper foil, a resin sheet, and an aluminum foil were laminated in that order. This was used as a sample for heat cycle test measurement. The resin used was a two-component epoxy adhesive (Denatite manufactured by Nagase ChemteX Corporation). Specifically, the resin obtained by mixing the main agent (XNR5021) and the curing agent (XNH5021) was put into the container containing the laminate.

[0087] The sample for heat cycle test measurement was put into a thermal shock tester (TSA-72EL-A manufactured by Espec Corporation). After being put in, the temperature inside the tester was cooled to -40 °C, held at that temperature for 30 minutes, then heated up to 150 °C, and held at that temperature for 30 minutes. This was defined as one cycle, and 3000 cycles were performed. (Evaluation) After 3000 cycles, the end face (cross-section) of the polished laminate was observed with an optical microscope (VHX-8000 manufactured by Keyence Corporation) and evaluated according to the following criteria. Good: When the end face (cross-section) of the laminate was checked, no cracks were found in the copper foil layer. Poor: When the end face (cross-section) of the laminate was checked, cracks were found in the copper foil layer. There were no cracks in the sample for heat cycle test measurement of Example 1 after the heat cycle test, and the evaluation was Good.

[0088] As described above, it was found that the resin sheet 10 of Example 1 had excellent thermal conductivity. Also, the heat sink using the resin sheet 10 of Example 1 had excellent thermal conductivity. Furthermore, it was found that the heat sink of Example 1 had excellent heat cycle characteristics.

[0089] (Example 2) to (Example 15) and (Comparative Example 1) to (Comparative Example 15) As shown in Table 1 and Table 2, a thermosetting resin composition was prepared in the same manner as in Example 1 except that the types and contents of the respective components contained in the thermosetting resin composition were changed, and a resin sheet 10 was produced. Regarding the fillers contained in the thermosetting resin compositions from Comparative Example 1 to Comparative Example 7 shown in Table 2, since the ratio of the first spherical filler to the second spherical filler could not be calculated, the column of "First spherical filler: Second spherical filler" was set to "-". The storage elastic modulus of the thermosetting resin composition after curing prepared in each example and each comparative example was measured by the same method as the method measured in Example 1. The measurement of the thermal conductivity and the heat cycle test of the resin sheets produced in each example and each comparative example were carried out by the same test methods as those carried out in Example 1. In addition, the unit of the content in the table is "parts by weight" unless otherwise specified.

[0090]

Table 1

[0091]

Table 2

[0092] As shown in Table 1, it was found that the resin sheets 10 from Example 2 to Example 15 had excellent thermal conductivity. In addition, the heat sinks using the resin sheets 10 from Example 2 to Example 15 had excellent thermal conductivity. Furthermore, it was found that the heat sinks from Example 2 to Example 15 had excellent heat cycle characteristics.

[0093] Furthermore, regarding the resin sheets 10 from Example 1 to Example 15, the peel strength, the dielectric breakdown voltage, and the dielectric breakdown voltage after the long-term damp heat test were measured, and the adhesiveness and the dielectric breakdown voltage characteristics were evaluated. Hereinafter, Example 1 will be described as an example.

[0094] <Dielectric breakdown voltage> (Sample for measuring dielectric breakdown voltage) The sample for measuring the breakdown voltage of Example 1 was fabricated as follows. First, a rolled copper foil (BHY manufactured by JX Nippon Mining & Metals Co., Ltd.) with a thickness of 35 μm assuming the resin sheet 10, the substrate 30, and the circuit 31 fabricated in Example 1, and an aluminum plate (A1100 manufactured by Showa Denko KK) with a thickness of 1 mm corresponding to the metal plate 21 were prepared respectively. Next, the rolled copper foil and the resin sheet 10 were laminated so that the rough surface of the rolled copper foil was in contact with the resin surface of the resin sheet 10. Next, the aluminum plate and the resin sheet 10 were laminated so that one side of the aluminum plate was in contact with the resin surface opposite to the surface where the rolled copper foil was laminated, and a laminate was obtained. The obtained laminate had a structure laminated in the order of the rolled copper foil, the resin sheet 10, and the aluminum plate. Next, this laminate was heated and pressed under the conditions of 185 °C, 5 MPa, and 180 minutes. Further, this laminate was heated in an oven at 160 °C for another 5 hours and then cooled. For the obtained laminate, the rolled copper foil was etched to have a circular shape with a diameter of 20 mm. Then, it was washed with water and dried to obtain a sample for measuring the breakdown voltage. Note that the resin sheet 10 was used after peeling off the release PET film.

[0095] (Measurement and Evaluation of Breakdown Voltage) As a breakdown voltage tester, B-5120AT-2 manufactured by Nippon Technoart Co., Ltd. was used. With the sample for measuring the breakdown voltage immersed in oil at 25 °C, a voltage was applied between the rolled copper foil etched into a circular shape and the aluminum plate. The voltage was increased at a pace of 1 kV / 0.5 sec, and the voltage at which breakdown occurred was measured. This test was conducted 5 times, and the average value was calculated and evaluated according to the following criteria. Note that this breakdown voltage is also referred to as the breakdown voltage before the long-term damp heat test. Good: The voltage is 2 kV or more. Poor: The voltage is less than 2 kV. The breakdown voltage of Example 1 was 3.5 kV, and the evaluation was Good. It was found that the resin sheet 10 of Example 1 had excellent insulation properties.

[0096] <Peel Strength> (Sample for Measuring Peel Strength) A laminate obtained in the process of manufacturing a sample for measuring the breakdown voltage was separately prepared. The laminate was etched with rolled copper foil to a width of 10 mm × a length of 100 mm. After etching, the laminate was washed with water and dried to obtain a sample for measuring the peel strength of Example 1.

[0097] (Measurement and Evaluation of Peel Strength) As a measuring instrument, Autograph AGS-500 manufactured by Shimadzu Corporation was used. The rolled copper foil was peeled off in the 90° direction (a direction perpendicular to the main surface of the sample), and the peel strength at the interface between the rolled copper foil and the resin sheet 10 was measured. The test speed was 50 mm / min. The test was conducted twice, and the average value was calculated. The evaluation criteria were as follows. Good: The peel strength is 2 N / cm or more, Poor: The peel strength is less than 2 N / cm. The peel strength of Example 1 was 10 N / cm, and the evaluation was Good.

[0098] (Breakdown Voltage after Long-Term Damp Heat Test) The insulation property of the resin sheet 10 after the long-term damp heat test was evaluated by measuring the breakdown voltage of the resin sheet 10. (Sample for Measuring Breakdown Voltage after Long-Term Damp Heat Test) The sample used in this evaluation was prepared by the same method as the method for preparing the sample for measuring the breakdown voltage described above. (Measurement and Evaluation of Breakdown Voltage after Long-Term Damp Heat Test) The sample for measuring the breakdown voltage after the long-term damp heat test was stored in an atmosphere of 85°C × 85% RH × 1000 hours, and then the moisture adhering to the surface of this sample was wiped off and measured under the same measurement conditions as the breakdown voltage described above. The evaluation criteria were as follows. Good: The voltage is 1 kV or more, Poor: The voltage is less than 1 kV. The breakdown voltage of Example 1 after the long-term damp heat test was 0.5 kV, and the evaluation was Poor.

[0099] As described above, although the resin sheet 10 composed of the thermosetting resin composition of Example 1 had a low breakdown voltage after the long-term damp heat test, it had a high breakdown voltage before the long-term damp heat test and was found to have excellent adhesiveness to metal. Also, for the resin sheets 10 composed of the thermosetting resin compositions from Example 2 to Example 15, the breakdown voltage, peel strength, and breakdown voltage after the long-term damp heat test were measured in the same manner as in Example 1, and the breakdown voltage characteristics and adhesiveness were evaluated. The results are shown in Table 3.

[0100]

Table 3

[0101] From Table 3, for example, the breakdown voltage before the long-term damp heat test, the breakdown voltage after the long-term damp heat test, and the peel strength of the resin sheet 10 of Example 2 composed of the thermosetting resin composition containing an ion scavenger were high. From this, it was found that the resin sheet 10 of Example 2 had excellent breakdown voltage characteristics and adhesiveness.

[0102] Also, it was found that the resin sheets 10 of Examples 3 to 6, Examples 8 to 11, Example 13, and Example 14 were also excellent in breakdown voltage characteristics and adhesiveness.

[0103] From the above results, it was found that the resin sheets 10 from Example 1 to Example 15 had excellent thermal conductivity and adhesiveness. Also, the heat sinks using the resin sheets 10 from Example 1 to Example 15 had excellent thermal conductivity. Also, it was found that the heat sinks 20 from Example 1 to Example 15 had excellent heat cycle characteristics. Furthermore, it was found that the resin sheets 10 of Examples 2 to 6, Examples 8 to 11, Example 13, and Example 14 had excellent breakdown voltage characteristics.

[0104] The present invention can be implemented in various embodiments and variations without departing from the broad spirit and scope of the present invention. Further, the above-described embodiments are for explaining the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is indicated by the claims rather than the embodiments. And various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are considered to be within the scope of this invention.

[0105] This application is based on Japanese Patent Application No. 2023-066101, filed on April 14, 2023. The specification and claims of Japanese Patent Application No. 2023-066101 are incorporated herein by reference.

[0106] (Appendix) (Appendix 1) An epoxy resin, A curing agent for curing the epoxy resin, An ethylene acrylic copolymer having a glass transition temperature of -30°C or lower and a carboxy group in the side chain, A first spherical filler having a thermal conductivity of 20 W / m·K or more and an average particle diameter (D50) of 30 μm or more and 60 μm or less, A second spherical filler having a thermal conductivity of 20 W / m·K or more and an average particle diameter (D50) of 1 μm or more and 10 μm or less, and The total weight ratio of the first spherical filler and the second spherical filler is 84% by weight or more and 90% by weight or less based on 100% by weight of the total solid content, The ratio of the first spherical filler to the second spherical filler is 55:45 to 85:15, A thermosetting resin composition in which the content of the ethylene acrylic copolymer is 700 parts by weight or more and 1000 parts by weight or less with respect to 100 parts by weight of the epoxy resin.

[0107] (Appendix 2) The thermosetting resin composition according to Supplementary Note 1, wherein the first spherical filler is composed of at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, and silicon nitride.

[0108] (Supplementary Note 3) The thermosetting resin composition according to Supplementary Note 1 or Supplementary Note 2, wherein the second spherical filler is composed of at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, and silicon nitride.

[0109] (Supplementary Note 4) comprising an ion scavenger that captures ions, The thermosetting resin composition according to any one of Supplementary Notes 1 to 3, wherein the content of the ion scavenger is 40 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the epoxy resin.

[0110] (Supplementary Note 5) The thermosetting resin composition according to any one of Supplementary Notes 1 to 4, wherein the thermal conductivity after curing is 2 W / m·K or more, the storage modulus at -30°C after curing is 7000 MPa or less, the storage modulus at 25°C after curing is 10 MPa or more and 100 MPa or less, and the storage modulus at 125°C after curing is 1 MPa or more and 100 MPa or less.

[0111] (Supplementary Note 6) A resin sheet composed of the thermosetting resin composition according to any one of Supplementary Notes 1 to 5.

[0112] (Supplementary Note 7) The resin sheet according to Supplementary Note 6, wherein the cured state is a semi-cured state.

[0113] (Supplementary Note 8) a metal plate, comprising a resin layer composed of the thermosetting resin composition according to any one of Supplementary Notes 1 to 5, The heat sink, wherein the resin layer is formed on at least one surface of the metal plate.

[0114] (Supplementary Note 9) The heat dissipation plate according to Supplementary Note 8, wherein the cured state of the resin layer is a semi-cured state.

[0115] (Supplementary Note 10) A preparation step of preparing a thermosetting resin composition according to any one of Supplementary Notes 1 to 5, A forming step of forming a resin layer composed of the thermosetting resin composition into a film, A heating step of heating the film on which the resin layer is formed, and a method for manufacturing a resin sheet including the heating step.

[0116] (Supplementary Note 11) A laminating step of laminating a resin layer of a resin sheet obtained by the method for manufacturing a resin sheet according to Supplementary Note 10 on a metal plate, A heating and pressing step of heating and pressing the metal plate on which the resin layer is laminated, and a method for manufacturing a heat dissipation plate including the heating and pressing step.

[0117] (Supplementary Note 12) A preparation step of preparing a thermosetting resin composition according to any one of Supplementary Notes 1 to 5, A forming step of forming a resin layer composed of the thermosetting resin composition on a metal plate, A heating step of heating the metal plate on which the resin layer is formed, and a method for manufacturing a heat dissipation plate including the heating step.

Explanation of Reference Numerals

[0118] 10 Resin sheet, 20 Heat dissipation plate, 21 Metal plate, 22 Fin, 23 Resin layer, 30 Substrate, 31 Circuit, 40 Electronic component.

Claims

1. An epoxy resin, a curing agent for curing the epoxy resin, an ethylene acrylic copolymer having a glass transition temperature of -30°C or lower and having a carboxy group in the side chain, a first spherical filler having a thermal conductivity of 20 W / m·K or more and an average particle diameter (D50) of 30 μm or more and 60 μm or less, a second spherical filler having a thermal conductivity of 20 W / m·K or more and an average particle diameter (D50) of 1 μm or more and 10 μm or less, and the total weight ratio of the first spherical filler and the second spherical filler is 84% by weight or more and 90% by weight or less based on 100% by weight of the total solid content, the ratio of the first spherical filler to the second spherical filler is 55:45 to 85:15, a thermosetting resin composition in which the content of the ethylene acrylic copolymer is 700 parts by weight or more and 1000 parts by weight or less based on 100 parts by weight of the epoxy resin.

2. The thermosetting resin composition according to claim 1, wherein the first spherical filler is composed of at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, and silicon nitride.

3. The thermosetting resin composition according to claim 1, wherein the second spherical filler is composed of at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, magnesium oxide, zinc oxide, and silicon nitride.

4. comprising an ion scavenger for scavenging ions, the thermosetting resin composition according to claim 1, wherein the content of the ion scavenger is 40 parts by weight or more and 60 parts by weight or less based on 100 parts by weight of the epoxy resin.

5. The thermosetting resin composition according to claim 1, having a thermal conductivity after curing of 2 W / m·K or more, a storage elastic modulus at -30°C after curing of 7000 MPa or less, a storage elastic modulus at 25°C after curing of 10 MPa or more and 100 MPa or less, and a storage elastic modulus at 125°C after curing of 1 MPa or more and 100 MPa or less.

6. A resin sheet composed of the thermosetting resin composition according to any one of claims 1 to 5.

7. The resin sheet according to claim 6, wherein the cured state is a semi-cured state.

8. a metal plate, a resin layer composed of the thermosetting resin composition according to any one of claims 1 to 5, and a heat sink in which the resin layer is formed on at least one surface of the metal plate.

9. The heat dissipation plate according to claim 8, wherein the cured state of the resin layer is a semi-cured state.

10. A preparation step of preparing a thermosetting resin composition according to any one of claims 1 to 5; A forming step of forming a resin layer composed of the thermosetting resin composition into a film; A manufacturing method of a resin sheet, comprising a heating step of heating the film on which the resin layer is formed.

11. A lamination step of laminating a resin layer of a resin sheet obtained by the manufacturing method of the resin sheet according to claim 10 on a metal plate; A manufacturing method of a heat dissipation plate, comprising a heating and pressing step of heating and pressing the metal plate on which the resin layer is laminated.

12. A preparation step of preparing a thermosetting resin composition according to any one of claims 1 to 5; A forming step of forming a resin layer composed of the thermosetting resin composition on a metal plate; A manufacturing method of a heat dissipation plate, comprising a heating step of heating the metal plate on which the resin layer is formed.

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