Thermally conductive resin composition and method for producing the same, as well as electronic equipment and semiconductor equipment.

Abstract

The objective is to provide a thermally conductive resin composition having excellent fluidity and high thermal conductivity. [Solution] A thermally conductive resin composition comprising a resin (A), a liquid metal (B), and an inorganic filler (C), wherein the inorganic filler (C) comprises metal particles (C-1) and ceramic particles (C-2), and has a viscosity of 210 Pa·s or less at 25°C.

Description

Technical Field

[0001] The present invention relates to a thermally conductive resin composition, a method for producing the same, an electronic device, and a semiconductor device.

Background Art

[0002] In recent years, along with higher performance, smaller size, and lighter weight of electronic devices, semiconductor packages have been made higher density, LSIs have been made higher integration and higher speed, and the amount of heat generated per unit area in electronic components has been increasing. Therefore, for materials used in electronic devices, it is important to improve thermal conductivity to effectively dissipate heat from electronic components to the outside.

[0003] For example, Patent Document 1 discloses a semiconductor package including a resin layer and a thermally conductive adhesive layer containing a heat dissipating filler that is contained in the resin layer and includes a liquid metal. Patent Document 1 also describes that the thermally conductive adhesive layer further contains a solid filler with high thermal conductivity such as a metal or a ceramic.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0005] To handle a composite material of resin (resin layer) and liquid metal (thermal conductive adhesive layer) in paste form, as described in Patent Document 1, fluidity is necessary. However, the composite material of resin and liquid metal has a separation structure of sea (resin) and strips (liquid metal). Furthermore, as mentioned above, Patent Document 1 states that highly thermally conductive solid fillers such as metals and ceramics can be used, but the metal is unevenly distributed on the liquid metal side, and the ceramic is unevenly distributed on the resin side. Therefore, depending on the dispersion state of the filler, fluidity may be poor, and furthermore, high thermal conductivity due to the filler cannot be obtained in the areas where the filler is absent. As a result, even if the amount of filler is increased, there is a problem in that the high thermal conductivity of the resin composition cannot be sufficiently obtained.

[0006] Therefore, the present invention was made in response to these circumstances and aims to provide a thermally conductive resin composition having excellent fluidity and high thermal conductivity, and a method for producing the same. Furthermore, the present invention aims to provide electronic equipment and semiconductor equipment using the thermally conductive resin composition. [Means for solving the problem]

[0007] As a result of diligent research to solve the above problems, the inventors have found that the above problems can be solved by the following means.

[0008] A thermally conductive resin composition according to one aspect of the present invention comprises a resin (A), a liquid metal (B), and an inorganic filler (C), wherein the inorganic filler (C) comprises at least metal particles (C-1) and ceramic particles (C-2), and is characterized in that its viscosity at 25°C is 210 Pa·s or less. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a thermally conductive resin composition having excellent fluidity and high thermal conductivity, and a method for producing the same. Furthermore, according to the present invention, it is possible to provide electronic devices and semiconductor devices using the thermally conductive resin composition. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a model diagram showing an example of a phase separation structure between resin (A) and liquid metal (B). [Figure 2] Figure 2 is a model diagram showing an example of the dispersion structure of metal particles (C-1) in resin (A) and liquid metal (B). [Figure 3] Figure 3 is a model diagram showing an example of the dispersion structure of metal particles (C-1) and ceramic particles (C-2) in resin (A) and liquid metal (B). [Figure 4] Figure 4 is a schematic cross-sectional view showing an electronic device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described below, but the present invention is not limited thereto.

[0012] [Thermally conductive resin composition] The thermally conductive resin composition according to this embodiment comprises a resin (A), a liquid metal (B), and an inorganic filler (C). The inorganic filler (C) comprises metal particles (C-1) and ceramic particles (C-2). Furthermore, the thermally conductive resin composition has a viscosity of 210 Pa·s or less at 25°C. With this configuration, a thermally conductive resin composition having excellent fluidity and high thermal conductivity can be provided. In this specification, the viscosity of the thermally conductive resin composition is measured using an E-type rotational viscometer under the following measurement conditions: temperature 25°C, rotation speed 0.3 rpm, and measurement time 200 seconds.

[0013] Here, the statement that the thermally conductive resin composition is fluid means that the thermally conductive resin composition is in a liquid or paste-like state.

[0014] (Resin (A)) In this embodiment, any type of resin may be used as the resin component (A), but specifically, for example, epoxy resin, silicone resin, and acrylic resin can be used. From the viewpoint of adhesion strength to the substrate such as semiconductor elements and lids, and heat resistance in heating environments exceeding 100°C, it is preferable that resin (A) contains epoxy resin. Note that only one type of resin component may be used, or two or more types may be used in combination.

[0015] The resin components contained in resin (A) are preferably fluid at room temperature, specifically at 25°C. If so, the viscosity of the thermally conductive resin composition at 25°C can be reduced to 210 Pa·s or less. Here, "resin (A) is fluid" means that resin (A) is in a liquid or paste state, and if it contains multiple types of resin components, it means that the entire resin (A), which is a mixture of multiple types of components, is fluid.

[0016] The epoxy resin is not particularly limited, but examples include glycidyl ether type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, and olefin oxidation type (alicyclic) epoxy resin. More specifically, examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyfunctional epoxy resin, flexible epoxy resin, polymer type epoxy resin, and biphenyl type epoxy resin. These may be used individually or in combination of two or more types.

[0017] From the viewpoint of being able to lower the viscosity of the thermally conductive resin composition after mixing with the inorganic filler (C), the epoxy resin preferably has a viscosity of, for example, 50 mPa·s or less at 25°C. In this specification, the viscosity of the epoxy resin is measured using an E-type rotational viscometer under the following measurement conditions: temperature 25°C, rotation speed 0.3 rpm, and measurement time 200 seconds.

[0018] The silicone resin is not particularly limited, and examples thereof include silicone gels, silicone rubbers, and silicone oils. These may be used alone or in combination of two or more.

[0019] The acrylic resin is not particularly limited, and examples thereof include methyl (meth)acrylate-type (meth)acrylic resins and glycidyl (meth)acrylate-type (meth)acrylic resins. These may be used alone or in combination of two or more.

[0020] From the viewpoint of long-term reliability and the viewpoint of continuously retaining the paste between a semiconductor element and an adherend such as a lid, the resin (A) may further contain a curing accelerator. As the curing accelerator, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole and the like can be used. Commercially available products may be used as the curing accelerator, and for example, Curezol (registered trademark) 2E4MZ-CN (manufactured by Shikoku Chemicals Corporation), 2E4MZ (manufactured by Shikoku Chemicals Corporation), 2P4MZ (manufactured by Shikoku Chemicals Corporation) and the like may be used. These may be used alone or in combination of two or more.

[0021] When the resin (A) contains a curing accelerator, the content of the curing accelerator is preferably 0.1% by volume or more and 1.0% by volume or less with respect to 100% by volume of the total amount of resin components (for example, epoxy resin, silicone resin, acrylic resin, etc.) contained in the resin (A).

[0022] In this specification, "volume ratio" and "% by volume" mean values at 25°C and 1 atmosphere.

[0023] The content of resin (A) is preferably 1% to 40% by volume, more preferably 1% to 30% by volume, and even more preferably 3% to 20% by volume, based on the total amount (100% by volume) of the thermal conductive resin composition. By having a resin (A) content of 1% to 40% by volume based on the total amount of the thermal conductive resin composition, the content ratio of the thermal conductive components, inorganic filler (C) and liquid metal (B), can be sufficiently high, and a high thermal conductivity can be obtained for the thermal conductive resin composition.

[0024] (Liquid metal (B)) The liquid metal (B) in this embodiment is not particularly limited as long as it is liquid in the process of manufacturing the thermal interface material (TIM) described later and in the actual usage environment (room temperature). Specifically, examples of liquid metal (B) include pure gallium or gallium / indium alloys, gallium / indium / tin alloys, gallium / indium / tin / zinc alloys, etc. One of these components may be used alone, or two or more may be used in combination.

[0025] The ratio of each metallic element constituting the above gallium alloy is not particularly limited, as long as it remains in a liquid state in the TIM manufacturing process and the temperature range in which it is actually used in this embodiment. For example, as the gallium / indium alloy, an alloy with a mass ratio of Ga:In=75.5:24.5 may be used, an alloy with a mass ratio of Ga:In=78.6:21.4 may be used, or an alloy with a mass ratio of Ga:In=95:5 may be used. As the gallium / indium / tin alloy, an alloy with a mass ratio of Ga:In:Sn=66.5:20.5:13.0 may be used, or an alloy with a mass ratio of Ga:In:Sn=62.5:21.5:16.0 may be used. As the gallium / indium / tin / zinc alloy, an alloy with a mass ratio of Ga:In:Sn:Zn=61.0:25.0:13.0:1.0 may be used.

[0026] The liquid metal (B) content is preferably 5% to 60% by volume, more preferably 10% to 50% by volume, and even more preferably 15% to 40% by volume, based on the total amount (100% by volume) of the thermal conductive resin composition. By having a liquid metal (B) content of 5% to 60% by volume, the proportion of liquid metal (B), which is a liquid component, in the thermal conductive resin composition can be sufficiently high, and high fluidity can be obtained as a thermal conductive resin composition.

[0027] In this embodiment, the ratio of resin (A) to liquid metal (B) is preferably, for example, 9:91 to 50:50 by volume. If the amount of resin (A) is small, it becomes difficult to form a separation structure of sea (resin) and stripe (liquid metal). If the amount of liquid metal (B) is small, the thermal conductivity due to the liquid metal weakens, and the thermal conductivity of the thermally conductive resin composition deteriorates.

[0028] (Inorganic filler (C)) In this embodiment, the inorganic filler (C) includes metal particles (C-1) and ceramic particles (C-2).

[0029] Examples of metal particles (C-1) include silver, copper, aluminum, nickel, tin, and stainless steel. These components may be used individually or in combination of two or more. The shape of the metal particles (C-1) is not particularly limited, but examples include spherical, ellipsoidal, spheroidal, pearly, polyhedral, plate-like, rod-like, needle-like, and flaky shapes. Spheroidal shapes include elongated spheres like rugby balls and oblate spheres like Go stones.

[0030] The average particle diameter of the metal particles (C-1) is preferably 0.1 μm or more and 50 μm or less, and more preferably 0.5 μm or more and 20 μm or less. An average particle diameter of 0.1 μm or more allows for low viscosity when mixed with liquid components (resin, liquid metal). An average particle diameter of 50 μm or less allows for the creation of a thermally conductive resin composition that is easy to mount in the gap between a semiconductor element and an adherend such as a lid (the typical gap for a semiconductor package is 100 μm or less). In this specification, "average particle diameter" refers to the particle size (D50: median diameter) at the 50% frequency from the smallest particle size on the volume-based cumulative particle size distribution curve. The volume-based cumulative particle size distribution curve can be determined using a laser diffraction particle size distribution analyzer that uses the laser diffraction-scattering method as its measurement principle.

[0031] The thermal conductivity of the metal particles (C-1) is preferably 100 W / mK or higher, and more preferably 200 W / mK or higher.

[0032] The content of metal particles (C-1) is preferably 10% to 60% by volume, more preferably 20% to 50% by volume, and even more preferably 25% to 40% by volume, based on the total amount (100% by volume) of the thermally conductive resin composition. By having a metal particle (C-1) content of 10% to 60% by volume, the ratio of metal particles (C-1), which are the thermal conductive component, can be sufficiently high, and a high thermal conductivity can be obtained for the thermally conductive resin composition.

[0033] Examples of ceramic particles (C-2) include aluminum oxide, zinc oxide, aluminum nitride, and silicon carbide. Preferably, the ceramic particles (C-2) have high thermal conductivity equivalent to or better than that of the liquid metal (B) and are commonly used as heat dissipation fillers. These components may be used individually or in combination of two or more. The shape of the ceramic particles (C-2) is not particularly limited and includes, for example, spherical, ellipsoidal, spheroidal, pearly, polyhedral, plate-like, rod-like, needle-like, and flaky shapes. Spheroidal shapes include oblong spheres and flattened spheres like Go stones.

[0034] The average particle diameter of the ceramic particles (C-2) is preferably 0.1 μm or more and 50 μm or less, and more preferably 0.5 μm or more and 20 μm or less. An average particle diameter of 0.1 μm or more for the ceramic particles (C-2) allows for low viscosity when mixed with liquid components (resin, liquid metal). An average particle diameter of 50 μm or less allows for the creation of a thermally conductive resin composition that is easy to mount in the gap between the semiconductor element and the substrate (the typical gap for a semiconductor package is 100 μm or less).

[0035] The thermal conductivity of the ceramic particles (C-2) is preferably 10 W / mK or higher, and more preferably 20 W / mK or higher.

[0036] The content of ceramic particles (C-2) is preferably 1% to 60% by volume, more preferably 1% to 50% by volume, and even more preferably 5% to 40% by volume, based on the total amount (100% by volume) of the thermal conductive resin composition. By having a ceramic particle (C-2) content of 1% to 60% by volume, the ratio of ceramic particles (C-2), which are the thermal conductive component, can be sufficiently high, and a high thermal conductivity can be obtained for the thermal conductive resin composition.

[0037] The ratio of metal particles (C-1) to ceramic particles (C-2) is preferably 40:60 to 90:10 by volume. Within this range, the thermal conductivity of the thermally conductive resin composition can be increased by utilizing the thermal conductivity of the metal particles (C-1), which has higher thermal conductivity than the ceramic particles (C-2). The ratio of metal particles (C-1) to ceramic particles (C-2) is more preferably 50:50 to 80:20 by volume.

[0038] In the thermally conductive resin composition of this embodiment, the resin (A) and the liquid metal (B) have a separation structure of sea (resin) and strips (liquid metal). The metal particles (C-1) are predominantly located in the liquid metal (B) rather than in the resin (A). On the other hand, the ceramic particles (C-2) are predominantly located in the resin (A) rather than in the liquid metal (B). As a result, inorganic fillers (C) are present in both the resin (A) and the liquid metal (B), and the thermally conductive resin composition has excellent fluidity and high thermal conductivity. It is preferable that 50% or more of the metal particles (C-1) contained in the thermally conductive resin composition are predominantly located in the liquid metal (B), and it is more preferable that 80% or more of the metal particles are predominantly located in the liquid metal (B). Furthermore, it is preferable that 50% or more of the ceramic particles (C-2) contained in the thermally conductive resin composition are predominantly located in the resin (A), and it is more preferable that 80% or more of the ceramic particles are predominantly located in the resin (A).

[0039] The inorganic filler (C) may include inorganic fillers other than metal particles (C-1) and ceramic particles (C-2), such as graphite and diamond.

[0040] The content of the inorganic filler (C) is preferably 30% to 80% by volume relative to the total amount (100% by volume) of the thermal conductive resin composition, and if so, a thermal conductive resin composition having high thermal conductivity can be obtained. The content of the inorganic filler (C) is more preferably 40% to 70% by volume relative to the total amount (100% by volume) of the thermal conductive resin composition.

[0041] (Other ingredients) The thermally conductive resin composition may further contain components other than those described above (other components) as necessary, to the extent that it does not impair the fluidity and thermal conductivity effects according to this embodiment. Examples of other components include dispersants, coupling agents, pigments, flame retardants, colorants, and adhesion promoters.

[0042] In this embodiment, the thermally conductive resin composition has a viscosity of 210 Pa·s or less at 25°C, and if so, the thermally conductive resin composition can have high thermal conductivity and excellent fluidity. It is more preferable that the viscosity of the thermally conductive resin composition at 25°C be 170 Pa·s or less. On the other hand, from the viewpoint of preventing dripping when the thermally conductive resin composition is molded into a film (press molding / extrusion molding / calendering / dispenser coating), it is preferable that the viscosity of the thermally conductive resin composition at 25°C be 10 Pa·s or more, and more preferably 100 Pa·s or more.

[0043] In this embodiment, the thermally conductive resin composition preferably has a thermal conductivity of 4.5 W / mK or higher. This allows for more reliable acquisition of high thermal conductivity. More preferably, the thermal conductivity of the thermally conductive resin composition is 6 W / mK or higher. In this specification, "thermal conductivity" can be measured by the method described in the examples later.

[0044] (Manufacturing method) The method for producing the aforementioned thermally conductive resin composition is not particularly limited, but the following production method makes it possible to more reliably obtain a thermally conductive resin composition having excellent fluidity and high thermal conductivity.

[0045] The method for producing the thermally conductive resin composition in this embodiment includes mixing a resin (A) and a liquid metal (B), adding metal particles (C-1) to the mixture of resin (A) and liquid metal (B) and mixing, and adding ceramic particles (C-2) to the mixture of resin (A), liquid metal (B), and metal particles (C-1) and mixing.

[0046] First, when resin (A) and liquid metal (B) are mixed, they separate because resin (A) and liquid metal (B) have low compatibility. Specifically, as shown in Figure 1, resin (A)1 and liquid metal (B)2 have a separation structure of sea (resin) and strips (liquid metal). That is, Figure 1 shows a structure in which multiple liquid metal (B)2 particles are scattered within resin (A)1. At this time, a solvent may be mixed in as needed. Examples of such solvents include toluene and methyl ethyl ketone (MEK).

[0047] Subsequently, by adding metal particles (C-1) to the mixture of resin (A) and liquid metal (B) and mixing, the metal particles (C-1) 3 become unevenly distributed within the liquid metal (B) 2, as shown in Figure 2.

[0048] Furthermore, by adding ceramic particles (C-2) to a mixture of resin (A), liquid metal (B), and metal particles (C-1) and mixing, the ceramic particles (C-2) 4 are filled into resin (A) 1, as shown in Figure 3.

[0049] Furthermore, the mixture of resin (A), liquid metal (B), metal particles (C-1), and ceramic particles (C-2) may be further mixed with inorganic fillers other than metal particles (C-1) and ceramic particles (C-2), as well as the other components mentioned above.

[0050] When mixing the components, for example, a ball mill, bead mill, planetary mixer, or roll mill can be used to disperse them until the desired dispersion state is achieved. Heating may also be performed during this process if necessary.

[0051] According to the manufacturing method described above, inorganic fillers (C) are more reliably present in the resin (A) and the liquid metal (B), respectively. Specifically, metal particles (C-1) are more predominantly present in the liquid metal (B) than in the resin (A), and ceramic particles (C-2) are more predominantly present in the resin (A) than in the liquid metal (B). Therefore, according to the manufacturing method described above, a thermally conductive resin composition with excellent fluidity and high thermal conductivity can be more reliably obtained.

[0052] (Application) The thermally conductive resin composition in this embodiment is suitably used as a thermally conductive material. Specifically, the thermally conductive resin composition can be used as a thermal interface material (TIM) that can be interposed between a heat-generating element, such as an electronic component like a semiconductor chip, and a heat-dissipating element, such as a heat sink. Such a thermally conductive material can be interposed as a thermal conductive layer 14 between an electronic component 12 and an outer shell member 13 in an electronic device 10 described later. Furthermore, such a thermally conductive material can also be interposed as a thermal conductive layer 16 between an outer shell member 13 and a heat sink 15. Moreover, the thermally conductive material is particularly suitably applied to semiconductor devices among the electronic devices 10.

[0053] In this embodiment, the thermally conductive material may be produced, for example, by curing the thermally conductive resin composition by heating it under conditions corresponding to its composition. In other words, a thermally conductive material containing a cured product of the thermally conductive resin composition can be obtained.

[0054] Furthermore, when producing a thermal conductive material from the thermal conductive resin composition, the thermal conductive resin composition may be filled into the location where the thermal conductive material is to be placed, and then the filled thermal conductive resin composition may be cured by heating it under conditions appropriate to its composition to produce the thermal conductive material. In addition, the thermal conductive resin composition may be formed into a film by appropriate methods such as press molding, extrusion molding, or calendering, or formed into a film using a dispenser, and then the film-shaped thermal conductive resin composition may be cured by heating it under conditions appropriate to its composition to produce a film-shaped thermal conductive material. It should be noted that the method for producing a thermal conductive material from a thermal conductive resin composition is not limited to the above methods. In other words, various production methods can be adopted according to the application of the thermal conductive material.

[0055] [Electronic equipment, semiconductor devices] As described above, the thermally conductive material made from the thermally conductive resin composition can be used to create a thermally conductive layer 14 for transferring heat generated from the electronic device 10 to the outside of the electronic device 10, as shown in Figure 4. Specifically, the electronic device 10 comprises an electronic component 12, an outer shell member 13 covering the electronic component 12, and a thermally conductive layer 14 interposed between the electronic component 12 and the outer shell member 13. This thermally conductive layer 14 is made from a thermally conductive material made from the thermally conductive resin composition. In other words, the thermally conductive layer 14 includes the thermally conductive resin composition or a cured product of the thermally conductive resin composition. Therefore, the thermal conductivity of the thermally conductive layer 14 is particularly enhanced, and heat generated from the electronic device 10 can be smoothly transferred to the outer shell member 13 through the thermally conductive layer 14. This makes it possible to suppress heat accumulation inside the electronic device 10. Furthermore, the thermally conductive material may be used to create a thermally conductive layer 16 interposed between the outer shell member 13 and the heat sink 15. This thermally conductive layer 16 is made from a thermally conductive material made from the thermally conductive resin composition, and the thermally conductive layer 16 contains the thermally conductive resin composition or a cured product of the thermally conductive resin composition.

[0056] Furthermore, as described above, the thermally conductive material made from the thermally conductive resin composition is particularly suitable for use in semiconductor devices among electronic devices 10. Specifically, the semiconductor device, which is the electronic device 10, comprises a semiconductor element, which is an electronic component 12; a lid, which is an outer shell member 13, that covers the semiconductor element; and a thermally conductive layer 14 interposed between the semiconductor element and the lid. This thermally conductive layer 14 is made of a thermally conductive material made from the thermally conductive resin composition, and includes the thermally conductive resin composition or a cured product of the thermally conductive resin composition.

[0057] The configuration of the electronic device 10 will be described below.

[0058] The electronic device 10 comprises a substrate 11, an electronic component 12, an outer shell member 13 covering the electronic component 12, a thermal conductive layer 14 interposed between the electronic component 12 and the outer shell member 13 containing the thermal conductive resin composition or a cured product of the thermal conductive resin composition, a heat sink 15, and a thermal conductive layer 16 interposed between the outer shell member 13 and the heat sink 15 containing the thermal conductive resin composition or a cured product of the thermal conductive resin composition.

[0059] The substrate 11 can be, for example, a printed circuit board, a motherboard, a package board, or an interposer board. The material of the substrate 11 can be, for example, glass epoxy, polyimide, polyester, or ceramic.

[0060] The electronic component 12 includes, for example, active elements such as transistors and diodes; passive elements such as resistors, capacitors, inductors, reactors, memristors and transformers; and at least one selected from the group consisting of CPUs, MPUs, driver ICs and memory. Furthermore, the electronic component 12 may be a semiconductor element, and the semiconductor element includes, for example, at least one selected from the group consisting of transistors, diodes, thyristors and modules. In addition, multiple electronic components 12 may be mounted on the substrate 11. In this case, the thicknesses of the electronic components 12 may differ from one another.

[0061] As described above, the outer shell member 13 is mounted on the substrate 11 so as to cover the electronic component 12. The outer shell member 13 is, for example, a housing for the electronic device 10, such as a lid, and is a material with high thermal conductivity. The electronic device 10 may also include a heat spreader and a heat sink 15. In this embodiment, it is preferable that the heat spreader and heat sink 15 are arranged on the outer shell member 13 of the electronic device 10, but this is not particularly limited. For example, the heat spreader and heat sink 15 may be arranged on the side of the substrate 11 opposite to the side on which the outer shell member 13 is mounted. In this case, the heat spreader may be interposed between the substrate 11 and the heat sink 15. Furthermore, a thermal conductive layer 16 may be interposed between the heat spreader and the heat sink 15, and this thermal conductive layer 16 may be a thermal conductive material made from the thermal conductive resin composition.

[0062] The thermal conductive layer 14 of the electronic device 10 can be manufactured, for example, by the following method. First, the thermal conductive resin composition is filled into the gap between the electronic component 12 and the outer shell member 13 located outside it. At this time, it may be cured by heating. In this way, a thermal conductive layer 14 containing the thermal conductive resin composition or a cured product of the thermal conductive resin composition can be manufactured in the gap between the electronic component 12 and the outer shell member 13 located outside it. In this embodiment, the thermal conductive resin composition is preferably in paste form at room temperature, specifically 25°C, in which case the thermal conductive resin composition can be easily applied with a dispenser device. This makes it easy to fill the gap between the electronic component 12 and the outer shell member 13 located outside it with the thermal conductive resin composition. The thermal conductive layer 16 can also be manufactured in the same way as the thermal conductive layer 14, for example, by filling the gap between the outer shell member 13 and the heat sink 15 located outside it with the thermal conductive resin composition and curing it by heating as needed.

[0063] Alternatively, a thermally conductive resin composition may be formed into a film, and then the film-shaped thermally conductive resin composition may be cured by heating it under conditions corresponding to its composition to obtain a film-shaped thermally conductive material. A thermal conductive layer 14 may be created by interposing this film-shaped thermally conductive material between the electronic component 12 and the outer shell member 13. Furthermore, a thermal conductive layer 16 may be created by interposing the film-shaped thermally conductive material between the outer shell member 13 and the heat sink 15.

[0064] This specification discloses various aspects of technology as described above, but the main technologies are summarized below.

[0065] The thermally conductive resin composition in the first aspect of the present invention comprises a resin (A), a liquid metal (B), and an inorganic filler (C), wherein the inorganic filler (C) comprises metal particles (C-1) and ceramic particles (C-2), and has a viscosity of 210 Pa·s or less at 25°C.

[0066] In the second aspect of the present invention, the thermally conductive resin composition is such that, in the thermally conductive resin composition of the first aspect, the ratio of resin (A) to liquid metal (B) is 9:91 to 50:50 by volume.

[0067] In a third aspect of the present invention, the thermally conductive resin composition is such that, in the first or second thermally conductive resin composition, the ratio of metal particles (C-1) to ceramic particles (C-2) is 40:60 to 90:10 by volume.

[0068] The thermally conductive resin composition in the fourth aspect of the present invention is a thermally conductive resin composition in any one of the first to third aspects, wherein the resin (A) comprises at least one selected from the group consisting of epoxy resin, silicone resin, and acrylic resin.

[0069] The fifth aspect of the present invention is a thermally conductive resin composition in any one of the first to fourth aspects, wherein the liquid metal (B) comprises at least one selected from the group consisting of elemental gallium, gallium / indium alloy, gallium / indium / tin alloy, and gallium / indium / tin / zinc alloy.

[0070] The thermally conductive resin composition in the sixth aspect of the present invention is a thermally conductive resin composition in any one of the first to fifth aspects, wherein the metal particles (C-1) include at least one selected from the group consisting of silver, copper, and aluminum.

[0071] The thermally conductive resin composition in the seventh aspect of the present invention is a thermally conductive resin composition in any one of the first to sixth aspects, wherein the ceramic particles (C-2) include at least one selected from the group consisting of aluminum oxide, zinc oxide, aluminum nitride, and silicon carbide.

[0072] A method for producing a thermally conductive resin composition according to the eighth aspect of the present invention is a method for producing a thermally conductive resin composition according to any one of the first to seventh claims, comprising mixing a resin (A) and a liquid metal (B), adding metal particles (C-1) to the mixture of resin (A) and liquid metal (B) and mixing, and adding ceramic particles (C-2) to the mixture of resin (A), liquid metal (B), and metal particles (C-1) and mixing.

[0073] An electronic device according to the ninth aspect of the present invention comprises an electronic component, an outer shell member covering the electronic component, and a thermal conductive layer interposed between the electronic component and the outer shell member, wherein the thermal conductive layer includes a thermal conductive resin composition according to any one of the first to seventh claims or a cured product of the thermal conductive resin composition.

[0074] A semiconductor device according to a tenth aspect of the present invention comprises a semiconductor element, a lid covering the semiconductor element, and a thermal conductive layer interposed between the semiconductor element and the lid, wherein the thermal conductive layer includes a thermal conductive resin composition according to any one of the first to seventh claims or a cured product of the thermal conductive resin composition.

[0075] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited thereto. [Examples]

[0076] First, the components used in preparing the thermally conductive resin composition in this embodiment will be described. (Resin (A)) • Glycidylamine-type epoxy resin ("EP-3950S", manufactured by ADEKA Corporation), and 2-ethyl-4-methylimidazole ("2E4MZ", manufactured by Shikoku Chemicals Co., Ltd.) Furthermore, 2-ethyl-4-methylimidazole is a curing accelerator, and it is present in a concentration of 0.1% by volume per 100% by volume of glycidylamine-type epoxy resin. (Liquid metal (B)) • 78.6Ga / 21.4In ("300E", manufactured by Indium Inc.) (Inorganic filler (C)) ·Metal particles (C-1): Ag (“Ag-HWQ”, manufactured by Fukuda Metal Co., Ltd.) • Ceramic particles (C-2): ZnO (fine zinc oxide, manufactured by Sakai Chemical Industry Co., Ltd.)

[0077] <Examples 1-3, Comparative Examples 1-6> Each component was mixed according to the proportions (volume %) listed in Table 1, using the following procedure (1) to (3), with a rotation / revolution mixer "Awatori Rentaro ARV-310" manufactured by Thinky Co., Ltd., at 1000 rpm for 1 minute (a total of 3 times). (1) Mix resin (A) and liquid metal (B) (2) Add metal particles (C-1) to the mixture obtained in (1) and mix. (3) Add ceramic particles (C-2) to the mixture obtained in (2) and mix. By mixing and dispersing each component according to the above procedure, a paste-like thermally conductive resin composition was obtained.

[0078] <Comparative Example 7> As Comparative Example 7, a thermal conductive resin composition was prepared in the same manner as in the preparation of the thermal conductive resin compositions of Examples 1 to 3 and Comparative Examples 1 to 6 described above, except that ceramic particles (C-2) were added to the mixture obtained in (1) above and mixed, and then metal particles (C-1) were added to the resulting mixture (a mixture of resin (A), liquid metal (B), and ceramic particles (C-2)) and mixed. The obtained thermal conductive resin composition did not have paste-like properties.

[0079] [Measurement method] The thermal conductivity and viscosity of the thermally conductive resin compositions of Examples 1-3 and Comparative Examples 1-7, prepared as described above, were measured as follows. The results are shown in Table 1.

[0080] (Thermal conductivity) The measurement sample (the prepared thermally conductive resin composition) was placed on the probe of a Mentorgraphic DynTIM Tester compliant with ASTM D5470. Specifically, the uncured thermally conductive resin composition sample was sandwiched between two aluminum plates, and pressure was applied with the DynTIM Tester to reduce the sample thickness to 100 μm. The pressure was then reduced to 0 at the specified thickness, and the thermal resistance (K / W) was measured. The thermal conductivity (W / m·K) was calculated from the thermal resistance measurements at several points (three or more points) of thickness. In addition, thermal grease ("G-779", manufactured by Shin-Etsu Chemical Co., Ltd.) was used between the aluminum plates and the DynTIM Tester probe to reduce interfacial thermal resistance. The temperature gradient at this time was 60°C for the heating section and 25°C for the cooling section. A thermal conductivity of 4.5 W / m·K was considered acceptable.

[0081] (viscosity) The viscosity of the aforementioned thermally conductive resin composition was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., model number RC-215) under the following conditions: measurement temperature 25°C, rotation speed 0.3 rpm, and measurement time 200 seconds.

[0082] [Table 1]

[0083] Furthermore, since the thermally conductive resin composition of Comparative Example 7 did not have paste-like properties, it was not possible to measure its thermal conductivity.

[0084] (Consideration) The thermally conductive resin compositions of Examples 1 to 3 contained resin (A), liquid metal (B), and inorganic filler (C), with the inorganic filler (C) containing metal particles (C-1) and ceramic particles (C-2). The viscosity of the thermally conductive resin composition was 210 Pa·s or less, and it was found to have excellent fluidity and high thermal conductivity. The thermally conductive resin compositions of Comparative Examples 1, 3, and 5 did not contain ceramic particles (C-2), and the viscosity of the thermally conductive resin composition exceeded 210 Pa·s, resulting in low thermal conductivity. Furthermore, the thermally conductive resin compositions of Comparative Examples 2, 4, and 6 did not contain metal particles (C-1), and the viscosity of the thermally conductive resin composition exceeded 210 Pa·s, resulting in low thermal conductivity. In addition, in the preparation process of the thermally conductive resin composition of Comparative Example 7, ceramic particles (C-2) were mixed with the mixture of resin (A) and liquid metal (B) before metal particles (C-1). The thermally conductive resin composition prepared in this manner did not have paste-like properties. [Explanation of Symbols]

[0085] 1. Resin (A) 2 Liquid metal (B) 3 Metal particles (C-1) 4. Ceramic particles (C-2) 10 Electronic equipment 11 circuit boards 12 Electronic Components 13 Outer shell member 14, 16 Thermal conductive layer 15 Heatsink

Claims

1. The material comprises resin (A), liquid metal (B), and inorganic filler (C), The inorganic filler (C) contains metal particles (C-1) and ceramic particles (C-2). A thermally conductive resin composition having a viscosity of 210 Pa·s or less at 25°C.

2. The thermally conductive resin composition according to claim 1, wherein the ratio of resin (A) to liquid metal (B) is 9:91 to 50:50 by volume.

3. The thermally conductive resin composition according to claim 1, wherein the ratio of metal particles (C-1) to ceramic particles (C-2) is 40:60 to 90:10 by volume.

4. The thermally conductive resin composition according to claim 1, wherein resin (A) comprises at least one selected from the group consisting of epoxy resin, silicone resin, and acrylic resin.

5. The thermally conductive resin composition according to claim 1, wherein the liquid metal (B) comprises at least one selected from the group consisting of elemental gallium, gallium / indium alloy, gallium / indium / tin alloy, and gallium / indium / tin / zinc alloy.

6. The thermally conductive resin composition according to claim 1, wherein the metal particles (C-1) include at least one selected from the group consisting of silver, copper, and aluminum.

7. The thermally conductive resin composition according to claim 1, wherein the ceramic particles (C-2) include at least one selected from the group consisting of aluminum oxide, zinc oxide, aluminum nitride, and silicon carbide.

8. A method for producing a thermally conductive resin composition according to any one of claims 1 to 7, Mixing resin (A) and liquid metal (B), The process involves adding metal particles (C-1) to a mixture of resin (A) and liquid metal (B) and mixing them, A method for producing a thermally conductive resin composition, comprising adding and mixing ceramic particles (C-2) to a mixture of resin (A), liquid metal (B), and metal particles (C-1).

9. The device comprises an electronic component, an outer shell member covering the electronic component, and a heat conductive layer interposed between the electronic component and the outer shell member. An electronic device wherein the heat conductive layer comprises a heat conductive resin composition according to any one of claims 1 to 7 or a cured product of the heat conductive resin composition.

10. The device comprises a semiconductor element, a lid covering the semiconductor element, and a thermal conductive layer interposed between the semiconductor element and the lid. A semiconductor device wherein the thermal conductive layer comprises a thermal conductive resin composition according to any one of claims 1 to 7 or a cured product of the thermal conductive resin composition.

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