Thermally conductive resin composition and semiconductor device

Abstract

To provide a thermally conductive resin composition that contains silicon carbide particles as a filler and exhibits superior insulating properties.SOLUTION: A thermally conductive resin composition comprises a thermosetting resin and a filler, wherein the filler includes silicon carbide particles containing silicon carbide, and the silicon carbide particles have, on at least part of their surface, a region containing an insulating material whose volume resistivity is higher than that of silicon carbide.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a thermally conductive resin composition and a semiconductor device.

Background Art

[0002] As miniaturization and high functionality of electronic devices progress, substrates in semiconductor devices are required to have sufficient heat dissipation performance to dissipate heat generated by semiconductor elements.

[0003] Patent Document 1 describes a circuit board using a paste-like resin composition, which contains a thermally conductive filler containing silicon carbide in the paste-like resin composition.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, resins for encapsulating semiconductor elements are required to have both thermal conductivity and insulation. As an example of a method for increasing the thermal conductivity of a resin, silicon carbide may be used as a filler. However, when silicon carbide is used as a filler, the insulation may decrease.

[0006] An example of the problem to be solved by the present invention is to provide a thermally conductive resin composition containing silicon carbide particles as a filler and having excellent insulation.

Means for Solving the Problems

[0007] According to the present invention, the following thermally conductive resin composition and semiconductor device are provided. [1] A thermosetting resin and a filler, The filler contains silicon carbide particles containing silicon carbide, The silicon carbide particles have a region containing an insulating material having a higher volume resistivity than silicon carbide on at least a part of the surface, a thermally conductive resin composition. [2] The content of the silicon carbide particles is 30% by volume or less with respect to 100% by volume of the filler, The thermally conductive resin composition according to [1]. [3] The insulating material contains silicon dioxide, The thermally conductive resin composition according to [1] or [2]. [4] Further containing a silane coupling agent, The thermally conductive resin composition according to [3]. [5] At least some of the silicon carbide particles are covered with a film containing the insulating material over the entire surface, The thermally conductive resin composition according to any one of [1] to [4]. [6] The sphericity of the silicon carbide particles at a particle size class of 45 μm or more is 0.8 or more, The thermally conductive resin composition according to any one of [1] to [5]. [7] The 50% volume cumulative particle size D50 of the silicon carbide particles is 40 μm or more and 60 μm or less, The thermally conductive resin composition according to any one of [1] to [6]. [8] Used for sealing a circuit element, The thermally conductive resin composition according to any one of [1] to [7]. [9] In a semiconductor device including a circuit layer for mounting a semiconductor element and a substrate for holding the circuit layer, used for adhering the circuit layer and the base substrate, The thermally conductive resin composition according to any one of [1] to [8].

[10] A semiconductor device including a circuit layer for mounting a semiconductor element and a substrate for holding the circuit layer, wherein the circuit layer and the base substrate are adhered by the thermally conductive resin composition according to any one of [1] to [8].

Effect of the Invention

[0008] According to the present invention, a thermally conductive resin composition containing silicon carbide particles as a filler and having excellent insulation can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description will be omitted as appropriate. Further, the figures are schematic views and do not match the actual dimensional ratios.

[0011] [Semiconductor Device 100] FIG. 1 shows a cross-sectional view of an example of the semiconductor device 100 according to the present embodiment. The semiconductor device 100 includes a substrate 10, a heat dissipation layer 20, a circuit layer 30, a sealing layer 40, and a semiconductor element 50. As shown in FIG. 1, the heat dissipation layer 20 is disposed on one surface of the substrate 10. And on one surface of the heat dissipation layer 20 opposite to the base substrate 10, a circuit layer 30 for mounting the semiconductor element 50 is disposed. And the heat dissipation layer 20, the circuit layer 30, and the semiconductor element 50 are sealed by the sealing material layer 40.

[0012] [Substrate 10] The substrate 10 holds the heat dissipation layer 20. Although omitted in FIG. 1, heat dissipation members such as heat dissipation fins and radiators may be attached to the surface of the substrate 10 opposite to the heat dissipation layer 20. Thereby, the heat dissipation property of the substrate 10 is improved. Note that the heat dissipation member may be integrated with the substrate 10.

[0013] As the material constituting the substrate 10, for example, one or a combination of two or more selected from copper, copper alloy, aluminum, and aluminum alloy can be used. Among these, from the viewpoint of strength, it is preferable to include at least one of copper and aluminum.

[0014] <Heat dissipation layer 20> The heat dissipation layer 20 adheres to the circuit layer 30 and the substrate 10 and transfers the heat of the circuit layer 30 to the substrate 10. From the viewpoint of efficiently transferring heat, the heat dissipation layer 20 preferably has a thermal conductivity of 3 W / (m·K) or more, more preferably 7 W / (m·K) or more, and even more preferably 12 W / (m·K) or more.

[0015] As the material constituting the heat dissipation layer 20, for example, it is a thermosetting resin. As the thermosetting resin, one or a combination of two or more selected from epoxy resin, phenol resin, urea resin, melamine resin, polyester (unsaturated polyester) resin, polyimide resin, silicone resin, and polyurethane resin can be used. Further, the heat dissipation layer 20 is formed using, for example, the thermally conductive resin composition according to the present embodiment described later.

[0016] It is preferable to mix a filler composed of particles having electrical insulation and high thermal conductivity in the heat dissipation layer 20. As the constituent material of the particles of such a filler, for example, one or a combination of two or more selected from metal oxides such as alumina and nitrides such as boron nitride can be used.

[0017] <Circuit layer 30> The circuit layer 30 is composed of a conductive metal material, and for example, semiconductor elements are mounted thereon. As the metal material constituting the circuit layer 30, for example, one or a combination of two or more selected from copper, copper alloy, aluminum, and aluminum alloy can be used. Note that at least a part of the circuit layer 30 may be covered with a resist material such as an anti-rust agent.

[0018] <Sealing layer 40> The sealing layer 40 seals the heat dissipation layer 20, the circuit layer 30, and the semiconductor element 50. Thereby, deterioration such as corrosion of the circuit layer 30 and the semiconductor element 50 is suppressed. The sealing layer 40 is formed using, for example, the thermally conductive resin composition according to the present embodiment described later.

[0019] [Manufacturing method of semiconductor device 100] As an example, the manufacturing method of the semiconductor device 100 according to the present embodiment includes a first step of disposing a heat dissipation material on the substrate 10, a second step of disposing the circuit layer 30 on one surface of the substrate 10 opposite to the heat dissipation material, a third step of heating to cure the heat dissipation material to form the heat dissipation layer 20 and fix the circuit layer 30, a fourth step of mounting the semiconductor element 50 on the surface of the circuit layer 30 opposite to the heat dissipation layer 20, and a fifth step of forming a sealing layer 40 that seals the heat dissipation layer 20, the circuit layer 30, and the semiconductor element 50 by processing the thermally conductive resin composition according to the present embodiment by a transfer molding method or a compression molding method.

[0020] [Thermally conductive resin composition] Next, the configuration of the thermally conductive resin composition according to the present embodiment will be described in detail. The thermally conductive resin composition includes a thermosetting resin and a filler. The filler includes silicon carbide particles, and the silicon carbide particles have a region containing an insulating material having a higher volume resistivity than silicon carbide on at least a part of the surface. Further, as described above, the thermally conductive resin composition is used, for example, as the sealing layer 40.

[0021] <Thermosetting resin> As the thermosetting resin, one or a combination of two or more selected from epoxy resins, phenolic resins, urea resins, resins having a triazine ring such as melamine resins, unsaturated polyester resins, maleimide resins such as bismaleimide compounds, polyurethane resins, diallyl phthalate resins, silicone resins, benzoxazine resins, polyimide resins, polyamideimide resins, benzocyclobutene resins, novolak type cyanate resins, bisphenol A type cyanate resins, bisphenol E type phenolic resins, cyanate ester resins such as tetramethyl bisphenol F type cyanate resins, etc. can be used.

[0022] Specifically, as the epoxy resin, bisphenol A type epoxy resins, hydrogenated bisphenol A type epoxy resins, bisphenol F type epoxy resins, tetramethyl bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol E type epoxy resins, bisphenol M type epoxy resins, bisphenol P type epoxy resins, bisphenol Z type epoxy resins and other bisphenol type epoxy resins; novolak type epoxy resins such as phenol novolak type epoxy resins, cresol novolak type epoxy resins; biphenyl type epoxy resins, biphenyl aralkyl type epoxy resins, aryl alkylene type epoxy resins, naphthalene type epoxy resins, anthracene type epoxy resins, phenoxy type epoxy resins, dicyclopentadiene type epoxy resins, norbornene type epoxy resins, adamantane type epoxy resins, fluorene type epoxy resins, triphenylmethane type epoxy resins, 4-tert-butylphenyl glycidyl ether, m,p-cresyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether and other epoxy monomers, etc. One or a combination of two or more selected from these can be used.

[0023] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the content of the thermosetting resin is preferably 3 parts by mass or more, more preferably 5 parts by mass or more. Further, the upper limit of the content of the thermosetting resin is preferably 15 parts by mass or less, more preferably 10 parts by mass or less. By setting the content of the thermosetting resin within the above range, the curability and the like of the thermally conductive resin composition are improved.

[0024] <Filler> The thermally conductive resin composition according to the present embodiment contains a filler. Further, the filler contains silicon carbide particles which are particles containing silicon carbide, and the silicon carbide particles have a region containing an insulating material having a higher volume resistivity than silicon carbide on at least a part of their surfaces. The insulating material contains, for example, silicon dioxide. Further, the region containing the insulating material in the silicon carbide particles described above is at least one of a region where particulate insulating material is attached and a region where a layer made of the insulating material is formed. It is preferable that at least a part of the silicon carbide particles has the entire surface covered with a film containing an insulating material. Here, as a method for confirming that the whole or at least a part of the surface of the silicon carbide particles is covered with a film containing an insulating material, for example, a direct observation method using a scanning electron microscope or a transmission electron microscope, an indirect observation method based on an increase or decrease in thermal conductivity or insulation, etc. can be mentioned. As an example, in the case of silicon carbide particles having an average particle diameter of 5 - 30 μm, when covered with silicon dioxide, the thermal conductivity measured by the flash method may decrease from about 230 W / m·K to about 160 W / m·K.

[0025] The insulating material preferably has a volume resistivity of 1×10 15 (Ω·cm) or more, more preferably 1×10 16 (Ω·cm) or more, and even more preferably 1×10 17 (Ω·cm) or more.

[0026] Further, the insulating material preferably has a new Mohs hardness of 12 or less, more preferably 10 or less, still more preferably 9 or less, and even more preferably 7 or less, not in a state of being present on the surface of, for example, silicon carbide particles, but in a lump state having a certain size. By the new Mohs hardness of the insulating material being equal to or less than the above upper limit value, damage to equipment in the production of the thermally conductive resin composition can be suppressed. For example, damage to the barrel during melt-kneading by a twin-screw extruder can be suppressed.

[0027] Further, the filler may contain particles other than silicon carbide particles, for example, at least one of particles containing alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, silicon carbide, aluminum hydroxide, magnesium hydroxide, titanium white, talc, clay, mica, and glass fiber. From the viewpoint of thermal conductivity, the filler preferably contains alumina particles.

[0028] When the total volume of the filler is 100% by volume, the lower limit of the content of silicon carbide particles is preferably 5% by volume or more, more preferably 10% by volume or more, and still more preferably 20% by volume or more. Further, the upper limit of the content of the silicon carbide particles is preferably 50% by volume or less, more preferably 40% by volume or less, still more preferably 30% by volume or less, and even more preferably 25% by volume or less. By setting the content of the silicon carbide particles within the above range, both the curability and thermal conductivity of the thermally conductive resin composition can be achieved.

[0029] Further, from the viewpoint of thermal conductivity, in the volume-based cumulative frequency distribution curve measured using a laser diffraction particle size distribution measuring device, the particle diameter D50 of the silicon carbide particles at a cumulative frequency of 50% is preferably 40 μm or more, more preferably 42 μm or more, and still more preferably 45 μm or more. Also, the particle diameter D50 of the silicon carbide particles is preferably 60 μm or less, more preferably 55 μm or less, and still more preferably 50 μm or less.

[0030] Also, from the viewpoint of thermal conductivity, for the entire filler, in the cumulative frequency distribution curve based on volume measured using a laser diffraction particle size distribution analyzer, the particle diameter D50 at a cumulative frequency of 50% is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. Also, for the entire filler, the particle diameter D50 is preferably 55 μm or less, more preferably 45 μm or less, and even more preferably 20 μm or less.

[0031] Also, from the viewpoint of fluidity, for silicon carbide particles, the roundness at a particle diameter class of 45 μm or more measured using a flow-type particle image analyzer is preferably 0.8 or more, more preferably 0.85 or more, and even more preferably 0.9 or more. Further, the roundness at a particle diameter class of 30 μm or more and 45 μm or less is preferably 0.8 or more, more preferably 0.9 or more, and even more preferably 0.95 or more. Further, the roundness at a particle diameter class of 20 μm or more and 30 μm or less is preferably 0.8 or more, more preferably 0.9 or more, and even more preferably 0.95 or more.

[0032] Also, from the viewpoint of fluidity, for the entire filler, the roundness at a particle diameter class of 45 μm or more measured using a flow-type particle image analyzer is preferably 0.8 or more, more preferably 0.85 or more, and even more preferably 0.9 μm or more.

[0033] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the filler content is preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 70 parts by mass or more. Also, the upper limit of the filler content is preferably 98 parts by mass or less, more preferably 95 parts by mass or less, and even more preferably 92 parts by mass or less. By setting the filler content within the above range, the thermal conductivity of the thermally conductive resin composition is improved.

[0034] [Hardening agent] The thermally conductive resin composition according to this embodiment may further contain a hardening agent. As the hardening agent, for example, a phenol resin hardening agent can be used. Specifically, as the phenol resin hardening agent, novolak type phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A type novolak resin, and triazine skeleton-containing phenol novolak resin; bisphenol compounds such as bisphenol A and bisphenol F (dihydroxydiphenylmethane); unmodified resol phenol resin; resol type phenol resins such as oil-modified resol phenol resin modified with tung oil, linseed oil, walnut oil, etc.; aralkyl type phenol resins such as phenol aralkyl resin and biphenyl aralkyl type phenol resin; one or a combination of two or more selected from triphenylmethane type phenol resins and the like can be used.

[0035] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the content of the hardening agent is preferably 0.5 part by mass or more, more preferably 0.7 part by mass or more, and even more preferably 1.0 part by mass or more. Also, the upper limit of the content of the hardening agent is preferably 5.0 parts by mass or less, more preferably 3.0 parts by mass or less. By setting the content of the hardening agent within the above range, the curability and the like of the thermally conductive resin composition are improved.

[0036] [Hardening accelerator] The thermally conductive resin composition according to this embodiment may further contain a curing accelerator for promoting the reaction between the reactive groups of the thermosetting resin and the reactive groups of the curing agent. As the curing accelerator, an imidazole-based curing accelerator; a phosphorus atom-containing compound such as an organic phosphine, a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, an adduct of a phosphonium compound and a silane compound; an amidine such as dicyandiamide, 1,8-diazabicyclo[5.4.0]undecene-7, benzyldimethylamine, or a tertiary amine; one or a combination of two or more selected from nitrogen atom-containing compounds such as a quaternary ammonium salt of the above amidine or the above tertiary amine can be used.

[0037] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the content of the curing accelerator is preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more. Also, the upper limit of the content of the curing accelerator is preferably 1.0 part by mass or less, more preferably 0.5 part by mass or less. By setting the content of the curing accelerator within the above range, the curability and the like of the thermally conductive resin composition are improved.

[0038] [Coupling agent] The thermally conductive resin composition according to this embodiment may further contain a coupling agent. Thereby, the fluidity of the thermally conductive resin composition can be increased. As the coupling agent, for example, a silane-based coupling agent, a titanium-based coupling agent, a zirconia-based coupling agent, an aluminum-based coupling agent, etc. can be used. In particular, the silane-based coupling agent is effective when the silicon carbide particles are covered with silicon dioxide.

[0039] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the content of the coupling agent is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more. Also, the upper limit of the content of the coupling agent is preferably 1.0 parts by mass or less, more preferably 0.5 parts by mass or less. By setting the content of the coupling agent within the above range, the curability and the like of the thermally conductive resin composition are improved.

[0040] [Release agent] The thermally conductive resin composition according to this embodiment may further contain a release agent. As the release agent, for example, one or a combination of two or more selected from natural waxes, synthetic waxes such as montanic acid esters, higher fatty acids or their metal salts, paraffin, polyethylene oxide, etc. can be used.

[0041] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the content of the release agent is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more. Also, the upper limit of the content of the release agent is preferably 1.0 parts by mass or less, more preferably 0.5 parts by mass or less.

[0042] [Low stress agent] The thermally conductive resin composition according to this embodiment may contain a low stress agent. As the low stress agent, for example, one or a combination of two or more selected from silicone compounds such as silicone oil and silicone rubber; polybutadiene compounds; acrylonitrile-butadiene copolymer compounds such as acrylonitrile-carboxyl group-terminated butadiene copolymer compounds can be used.

[0043] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the content of the low stress agent is preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more. Also, the upper limit of the content of the low stress agent is preferably 1.0 part by mass or less, more preferably 0.5 part by mass or less. When the content of the low stress agent is below the above upper limit, the curing shrinkage rate of the thermally conductive resin composition becomes small and the adhesiveness is improved.

[0044] [Ion scavenger] The thermally conductive resin composition may contain an ion scavenger for suppressing the adverse effects of ionic impurities such as halogen ions and sodium ions. As the ion scavenger, one or a combination of two or more selected from hydrotalcite, zeolite (aluminosilicate ore), bismuth hydroxide, bismuth hydroxide nitrate, etc. can be used.

[0045] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the content of the ion scavenger is preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more. Also, the upper limit of the content of the ion scavenger is preferably 1.0 part by mass or less, more preferably 0.5 part by mass or less. When the content of the ion scavenger is below the above upper limit, the curing shrinkage rate of the thermally conductive resin composition becomes small and the adhesiveness is improved.

[0046] [Colorant] The thermally conductive resin composition according to this embodiment may contain a colorant. As the colorant, for example, carbon black can be used.

[0047] When the total amount of the thermally conductive resin composition is 100 parts by mass, the lower limit of the content of the colorant is preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more. Also, the upper limit of the content of the colorant is preferably 1.0 part by mass or less, more preferably 0.5 part by mass or less. When the content of the colorant is below the above upper limit, the curing shrinkage rate of the thermally conductive resin composition becomes small and the adhesiveness is improved.

[0048] [Spiral flow] Next, the physical properties of the thermally conductive resin composition according to this embodiment will be described. First, the thermally conductive resin composition preferably has a flow length measured by a spiral flow test at a temperature of 175°C of 150 cm or more, more preferably 160 cm or more, and even more preferably 180 cm or more.

[0049] Also, the above spiral flow test can be performed, for example, by using a low-pressure transfer molding machine ("KTS-15" manufactured by Kotaki Seiki Co., Ltd.) and injecting the thermally conductive resin composition into a mold for spiral flow measurement according to EMMI-1-66 under the conditions of a mold temperature of 175°C, an injection pressure of 6.9 MPa, and a curing time of 120 seconds, and measuring the flow length.

[0050] [Gel time] The thermally conductive resin composition according to this embodiment preferably has a gel time of 30 seconds or more, more preferably 40 seconds or more, and even more preferably 50 seconds or more. Also, from the viewpoint of the handleability of the thermally conductive resin composition, the gel time is preferably 100 seconds or less, more preferably 90 seconds or less, and even more preferably 80 seconds or less.

[0051] Note that the gel time is the time from when the thermally conductive resin composition melts due to heat until it cures when placed on a hot plate controlled at 175°C and kneaded with a spatula at a stroke of about once per second.

[0052] [Thermal conductivity] The thermally conductive resin composition according to this embodiment preferably has a thermal conductivity measured by the laser flash method of 2.0 W / mK or more, more preferably 3.0 W / mK or more, and even more preferably 3.5 W / mK or more.

[0053] [Volume resistivity] The volume resistivity of the thermally conductive resin composition according to this embodiment, measured in accordance with JIS K 6911, is preferably 1.0×10 14 Ω·cm or more, more preferably 1.1×10 14 Ω·cm or more, and even more preferably 1.2×10 14 Ω·cm or more.

[0054] [Method for Forming Region Containing Insulating Material on Silicon Carbide Particles] As a method for forming a region containing an insulating material on silicon carbide particles, a vapor deposition method in which a raw material gas containing components of the insulating material is supplied and a film is deposited on the surface of the silicon carbide particles by a chemical reaction in the gas phase, or a liquid phase growth method in which the insulating material dissolved in a solvent is deposited on the surface of the silicon carbide particles to deposit a film on the surface can be used.

[0055] [Method for Producing Thermally Conductive Resin Composition] In this embodiment, the thermally conductive resin composition can be obtained, for example, by mixing the above-described respective components by known means, further melt-kneading with a kneader such as a roll, a kneader, or an extruder, and pulverizing after cooling. Further, if necessary, after pulverization in the above method, it may be compression-molded into a tablet shape to obtain a particulate thermally conductive resin composition. [Examples]

[0056] The present invention will be described in detail based on examples and comparative examples. Note that the present invention is not limited to the examples.

[0057] Table 1 shows the parts by mass of each component with respect to 100 parts by mass of the thermally conductive resin composition in the examples and comparative examples. Filler 3 is silicon carbide particles at least partially coated on the surface with silicon dioxide. In the examples, a part of Filler 2 (alumina particles) is replaced with Filler 3 as compared with the comparative examples.

[0058] [Production of Thermally Conductive Resin Composition] First, each component described in Table 1 was prepared and mixed at the described ratios, and then melt-kneaded using a twin-screw extruder or the like, cooled, and pulverized to obtain the thermally conductive resin compositions of the examples and comparative examples. · Thermosetting resin: Biphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX-4000K) · Curing agent: Tris-phenylmethane mixed type phenol resin (manufactured by Air Water Inc., HE910-20) · Curing accelerator 1: Phosphorus-based catalyst, bis(naphthalene-2,3-dioxy)phenylsilicate adduct of tetraphenylphosphonium · Curing accelerator 2: Phosphorus-based catalyst, tetraphenylphosphonium 4,4'-sulfonyldiphenolate · Coupling agent 1: Phenylaminopropyltrimethoxysilane · Coupling agent 2: Mercaptosilane (manufactured by Dow Corning Toray Co., Ltd.) · Release agent 1: Diethanolamine dimontanate ester (manufactured by Ito Seiyu Co., Ltd.) · Low stress agent 1: Dimethylsiloxane-alkyl carboxylic acid-4,4'-(1-methylethylidene)bisphenol glycidyl ether copolymer (manufactured by Sumitomo Bakelite Co., Ltd.) · Low stress agent 2: Carboxyl group-terminated butadiene-acrylonitrile copolymer (manufactured by Ube Industries, Ltd.) · Ion scavenger: Hydrotalcite (manufactured by Kyowa Chemical Industry Co., Ltd.) · Colorant: Carbon black · Filler 1: Silica filler (manufactured by Denka Co., Ltd.) · Filler 2: Alumina particles, average particle diameter D50: 13.2 μm (manufactured by Denka Co., Ltd.) · Filler 3: Silicon carbide particles at least partially coated on the surface with silicon dioxide, average particle diameter D50: 41.6 μm, sphericity at particle size class 45 μm or more: 0.87 (manufactured by Rare Metal Materials Research Institute Co., Ltd.) · Filler 4: Silica filler (Admatechs Co., Ltd.) · Filler 5: Fused spherical silica (manufactured by Tokuyama Corporation)

[0059]

Table 1

[0060] [Evaluation] The following measurements were carried out on the thermally conductive resin compositions of the examples and comparative examples. The measurement results are shown in Table 1.

[0061] [Spiral Flow] Using a low-pressure transfer molding machine (manufactured by Kotaki Seiki Co., Ltd., "KTS-15"), the thermally conductive resin compositions of the examples and comparative examples were injected into a mold for spiral flow measurement according to EMMI-1-66 under the conditions of 175 °C, a measurement time of 5 minutes, an injection pressure of 6.9 MPa, and a holding pressure time of 120 seconds, and the flow length was measured and taken as the spiral flow.

[0062] [Gel Time] The thermosetting resin compositions of the examples and comparative examples were placed on a hot plate controlled at 175 °C and kneaded with a spatula at a stroke of about 1 time / second. The time from when the thermosetting resin composition was melted by heat until it hardened was measured and taken as the gel time.

[0063] [Thermal Conductivity] The thermally conductive resin compositions of the examples and comparative examples were tableted to obtain tablets. The obtained tablets were injection molded using a transfer molding machine under the conditions of a mold temperature of 175 °C, an injection pressure of 8.3 MPa, and a curing time of 2 minutes to obtain molded products of 10 mm × 10 mm × 1.0 mm. These molded products were post-cured under the conditions of 175 °C for 4 hours to obtain test pieces. Next, using a Xe flash analyzer TD-1RTV manufactured by ULVAC, the thermal diffusivity (α) in the length direction of the plate-shaped test piece was measured by the laser flash method. The measurement was carried out under the conditions of an air atmosphere and 25 °C. Based on the following formula, the thermal conductivity was calculated from the measured values of the obtained thermal diffusivity (α), specific heat (Cp), and specific gravity (SP). (Formula): Thermal conductivity [W / m·K] = α [m 2 / s] × Cp [J / kg·K] × Sp [g / cm 3

[0064] ​<Volume Resistivity> The thermally conductive resin compositions of the examples and comparative examples were compression-molded to obtain tablets. The obtained tablets were injection-molded using a transfer molding machine under the conditions of a mold temperature of 175°C, an injection pressure of 8.3 MPa, and a curing time of 2 minutes to obtain disk-shaped molded articles having a diameter of 100 mm and a thickness of 3 mm. These disk-shaped molded articles were post-cured under the conditions of 175°C for 4 hours to obtain test pieces. On the obtained test pieces, a main electrode having a diameter of 300 mm, a guard electrode having a diameter of 32 mm, and a counter electrode having a diameter of 45 mm were formed using carbon paste. Then, using a super insulation meter (manufactured by Kawaguchi Electric Works Co., Ltd., R-503), the volume resistivity was measured by a method conforming to JIS K 6911. The measurement was performed at room temperature under the condition of an applied voltage of 500 V.

[0065] When comparing the spiral flow of a comparative example that does not use silicon carbide particles as a filler with that of an example that uses silicon carbide particles as a part (17.3% by volume) of the filler, the comparative example was 235 cm, while the example was 185 cm, and there was no significant difference. Also, the gel times were both 53 seconds. When comparing the volume resistivity, the comparative example was 1.5×10 14 Ω·cm, while the comparative example was 1.2×10 14 Ω·cm, and there was no significant difference in the volume resistivity either. On the other hand, when comparing the thermal conductivity, the comparative example was 2.6 W / mK, while the example was 3.5 W / mK, and the example was superior.

[0066] As described above, according to the present example, a thermally conductive resin composition containing silicon carbide particles as a filler could be provided. Also, each measurement result of the present example was comparable to that of a comparative example not containing silicon carbide particles. Furthermore, with respect to the thermal conductivity, the present example was superior to the comparative example.

Description of Reference Numerals

[0067] 100 Semiconductor device 10 Substrate 20 Heat dissipation layer 30 Circuit layer 40 Encapsulation layer 50 semiconductor elements

Claims

1. A thermosetting resin and a filler, wherein the filler includes silicon carbide particles containing silicon carbide, and the silicon carbide particles have a region containing an insulating material with a higher volume resistivity than silicon carbide on at least a part of the surface, a thermally conductive resin composition.

2. The content of the silicon carbide particles is 30% by volume or less based on 100% by volume of the filler, The thermally conductive resin composition according to Claim 1.

3. The insulating material includes silicon dioxide, The thermally conductive resin composition according to Claim 1 or 2.

4. Further including a silane coupling agent, The thermally conductive resin composition according to Claim 3.

5. At least a part of the silicon carbide particles is covered by a film containing the insulating material over the entire surface, The thermally conductive resin composition according to Claim 1 or 2.

6. The sphericity of the silicon carbide particles at a particle size class of 45 μm or more is 0.8 or more, The thermally conductive resin composition according to Claim 1 or 2.

7. The 50% volume cumulative particle size D50 of the silicon carbide particles is 40 μm or more and 60 μm or less, The thermally conductive resin composition according to Claim 1 or 2.

8. Used for encapsulating a circuit element, The thermally conductive resin composition according to Claim 1 or 2.

9. In a semiconductor device including a circuit layer for mounting a semiconductor element and a substrate for holding the circuit layer, used for adhering the circuit layer and the substrate, The thermally conductive resin composition according to Claim 1 or 2.

10. A semiconductor device including a circuit layer for mounting a semiconductor element and a substrate for holding the circuit layer, wherein the circuit layer and the substrate are adhered by the thermally conductive resin composition according to Claim 1 or 2.

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