Conductive and insulating composite heat dissipation pad and manufacturing method therefor

Abstract

Disclosed are a conductive and insulating composite heat dissipation pad and a manufacturing method therefor, the conductive and insulating composite heat dissipation pad having excellent thermal conductivity in both the vertical direction and the horizontal direction and thus maximizing heat dissipation. The conductive and insulating composite heat dissipation pad according to the present invention comprises: an insulating heat dissipation layer which includes a polymer resin and insulating heat dissipation particles dispersed in the polymer resin and dissipates heat in the vertical direction; and a conductive heat dissipation layer which is on the insulating heat dissipation layer, includes a metal mesh and a metal paste filled in the metal mesh, and dissipates heat in the horizontal direction.

Description

Insulating conductive composite heat dissipation pad and its manufacturing method

[0001] The present invention relates to an insulating conductive composite heat dissipation pad and a method for manufacturing the same, and more particularly, to an insulating conductive composite heat dissipation pad having excellent vertical and horizontal thermal conductivity and thus maximizing heat dissipation, and a method for manufacturing the same.

[0002] Battery packs, a vital component of electric vehicles, utilize numerous insulating heat-dissipating pads to dissipate heat generated by the battery and circuitry. However, most insulating heat-dissipating pads exhibit poor heat transfer performance. Specifically, they fail to rapidly transfer heat in the horizontal direction, impairing the performance of battery modules and packs.

[0003] Thermal pads used in battery packs or semiconductor packages are manufactured by dispersing thermal fillers into polymer resins such as silicone or urethane resins. When insulating properties are required, ceramic thermal fillers, such as metal nitrides or oxides, are commonly used. When insulation is not required, graphite or metal particles are commonly used as thermal fillers.

[0004] Typically, silicone or urethane-based thermal pads have a vertical thermal conductivity of 3 to 5 W / mK, and because they have an isotropic thermal filler dispersion structure, they have a similar thermal conductivity in the horizontal direction, so the thermal conductivity in the horizontal direction is not high.

[0005] In order to obtain high thermal conductivity, the filler content can be increased, but as the filler content increases, mechanical properties such as adhesive strength deteriorate, and if a lot of conductive particles are used as fillers, the insulating performance is lost, making it impossible to function as an insulating heat dissipation pad. In order to dissipate heat in a large structure such as a battery pack, thermal conductivity in the vertical direction and high heat dissipation performance in the horizontal direction are required at the same time. Therefore, there is a request to develop an insulating heat dissipation pad that exhibits excellent thermal conductivity in both the vertical and horizontal directions while maintaining mechanical properties and insulating performance.

[0006] The present invention is intended to solve the above-described problems, and the purpose of the present invention is to provide an insulating conductive composite heat dissipation pad having excellent vertical and horizontal thermal conductivity and thus maximized heat dissipation, and a method for manufacturing the same.

[0007] In order to achieve the above-described purpose, an insulating conductive composite heat dissipation pad according to one aspect of the present invention comprises: an insulating heat dissipation layer that releases heat in a vertical direction, including a polymer resin and insulating heat dissipation particles dispersed in the polymer resin; and a conductive heat dissipation layer that releases heat in a horizontal direction, including a metal mesh and a metal paste filling the metal mesh on the insulating heat dissipation layer.

[0008] The insulating heat-dissipating particles may be at least one of aluminum oxide, silicon carbide, diamond, beryllium oxide, boron nitride, boron phosphide, aluminum nitride, beryllium sulfide, boron azenide, silicon nitride, gallium nitride, aluminum phosphide, gallium phosphide, magnesium oxide, and zinc oxide.

[0009] The insulating heat-radiating particles may have two or more average particle sizes.

[0010] The insulating heat-dissipating particles may include a metal layer on their surface.

[0011] The metal layer may be a liquid metal layer.

[0012] The insulating heat-radiating particles can be necked together by the liquid metal layer.

[0013] The insulating heat dissipation particles of the insulating heat dissipation layer and the conductive heat dissipation layer metal can be necked together by the liquid metal layer at the interface of the insulating heat dissipation layer and the conductive heat dissipation layer.

[0014] The metal may be selected from copper, aluminum, nickel, gold, silver, palladium, chromium and their alloys.

[0015] The conductive heat dissipation layer may include two or more layers of metal mesh.

[0016] According to another aspect of the present invention, a method for manufacturing an insulating conductive composite heat dissipation pad is provided, comprising: a step of filling a metal mesh with a metal paste to obtain a conductive heat dissipation layer that dissipates heat in a horizontal direction; and a step of dispersing insulating heat dissipation particles in a polymer resin and applying the particles on the conductive heat dissipation layer to obtain an insulating heat dissipation layer that dissipates heat in a vertical direction.

[0017] According to another aspect of the present invention, an insulating conductive composite heat dissipation pad is provided, which comprises two or more layers of an insulating conductive composite heat dissipation pad, including an insulating heat dissipation layer that dissipates heat in a vertical direction, including a polymer resin and insulating heat dissipation particles dispersed in the polymer resin; and a conductive heat dissipation layer that dissipates heat in a horizontal direction, including a metal mesh and a metal paste filling the metal mesh on the insulating heat dissipation layer.

[0018] According to another aspect of the present invention, a heat dissipation method for dissipating heat from a heat dissipation target in vertical and horizontal directions is provided, the method comprising: preparing an insulating conductive composite heat dissipation pad, the insulating heat dissipation layer including a polymer resin and insulating heat dissipation particles dispersed in the polymer resin, which dissipates heat in a vertical direction; and a conductive heat dissipation layer including a metal mesh and a metal paste filling the metal mesh on the insulating heat dissipation layer, which dissipates heat in a horizontal direction; and a step of bringing the insulating heat dissipation layer of the insulating conductive composite heat dissipation pad into contact with the heat dissipation target.

[0019] The insulating conductive composite heat dissipation pad according to the present invention comprises an insulating heat dissipation layer and a conductive heat dissipation layer, wherein the insulating heat dissipation layer has a vertical heat dissipation effect, and the conductive heat dissipation layer has a horizontal heat dissipation effect, thereby enabling heat generated in an object requiring large-area heat dissipation, such as a vehicle battery pack, to be transferred vertically and then quickly released horizontally, thereby achieving an optimal heat dissipation effect.

[0020] In addition, according to the present invention, by adding a liquid metal layer to the insulating heat dissipation particles used in the insulating heat dissipation layer of the insulating-conductive composite heat dissipation pad, a heat conduction pass is effectively formed between the insulating heat dissipation particles, thereby increasing the vertical thermal conductivity, and an insulating-conductive composite heat dissipation pad having excellent reliability and mechanical properties can be obtained due to improved interfacial adhesion at the interface between the insulating heat dissipation layer and the conductive heat dissipation layer by the liquid metal.

[0021] FIG. 1 is a cross-sectional view of an insulating conductive composite heat dissipation pad according to an embodiment of the present invention, and FIG. 2 is a drawing illustrating heat transfer in an insulating conductive composite heat dissipation pad.

[0022] FIG. 3 is a cross-sectional view of insulating heat-radiating particles in an insulating conductive composite heat-radiating pad according to another embodiment of the present invention, FIG. 4 is a drawing showing a necking structure between insulating heat-radiating particles, and FIG. 5 is a drawing showing a necking structure between insulating heat-radiating particles and a conductive heat-radiating layer of an insulating heat-radiating layer.

[0023] Figure 6 is a cross-sectional view of an insulating conductive composite heat dissipation pad according to another embodiment of the present invention.

[0024] FIG. 7 is a drawing illustrating heat transfer in an insulating conductive composite heat dissipation pad according to another embodiment of the present invention.

[0025] FIG. 8 is a graph showing the results of volume resistance analysis according to the amount of heat dissipation particles of examples and comparative examples of insulating conductive composite heat dissipation pads according to the present invention, FIG. 9 is a graph showing the results of vertical thermal conductivity analysis according to the amount of heat dissipation particles, and FIG. 10 is a graph showing the results of horizontal thermal conductivity analysis according to the amount of heat dissipation particles.

[0026] Fig. 11 is a graph showing the results of vertical thermal conductivity analysis of examples and comparative examples of insulating conductive composite heat dissipation pads according to the present invention, and Fig. 12 is a graph showing the results of horizontal thermal conductivity analysis.

[0027] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided so that those skilled in the art may more completely explain the present invention. Although components may be depicted as having a specific pattern or having a predetermined thickness in the attached drawings, this is for convenience of description or distinction, and therefore, even if they have a specific pattern and a predetermined thickness, the present invention is not limited to the features of the depicted components.

[0028] FIG. 1 is a cross-sectional view of an insulating-conductive composite heat dissipation pad according to an embodiment of the present invention, and FIG. 2 is a drawing illustrating heat transfer in an insulating-conductive composite heat dissipation pad. An insulating-conductive composite heat dissipation pad (100) according to the present embodiment includes an insulating heat dissipation layer (110) that releases heat in a vertical direction, including a polymer resin (111) and insulating heat dissipation particles (112) dispersed in the polymer resin (111); and a conductive heat dissipation layer (120) that releases heat in a horizontal direction, including a metal mesh (121) and a metal paste (122) filling the metal mesh (121) on the insulating heat dissipation layer (110).

[0029] The insulating-conductive composite heat dissipation pad (100) according to the present invention is a composite heat dissipation pad including a heat dissipation layer having insulating properties and a heat dissipation layer having conductive properties. The insulating-conductive composite heat dissipation pad (100) according to the present invention has heat dissipation structures of the insulating layer and the conductive layer designed differently, thereby improving the thermal conductivity in the thickness direction, i.e., the vertical direction, of the insulating-conductive composite heat dissipation pad (100), and at the same time, has high heat diffusion performance in the surface direction, i.e., the horizontal direction.

[0030] The insulating heat dissipation layer (110) can be obtained by dispersing insulating heat dissipation particles (112) in a polymer resin (111). The polymer resin (111) that can be used in the insulating heat dissipation layer (110) is a resin that exhibits heat dissipation properties. Since the insulating heat dissipation layer (110) is in contact with the conductive heat dissipation layer (120) and is used as a single insulating-conductive composite heat dissipation pad (100), it is preferable that the resin exhibit adhesive properties in consideration of adhesiveness with the conductive heat dissipation layer (120).

[0031] An adhesive can be injected between the insulating heat dissipation layer (110) and the conductive heat dissipation layer (120) to bond them together, but since the heat dissipation characteristics in the vertical direction may deteriorate, it is preferable to use a heat dissipation resin that exhibits adhesiveness to the insulating heat dissipation layer (110) without forming a separate adhesive layer. The polymer resin (111) may be a silicone resin or a urethane resin.

[0032] The insulating heat-radiating particles (112) are particles that can transmit heat in a vertical direction while securing the insulating properties of the insulating heat-radiating layer (110). Examples of the insulating heat-radiating particles that can be used in the present invention include aluminum oxide, silicon carbide, diamond, beryllium oxide, boron nitride, boron phosphide, aluminum nitride, beryllium sulfide, boron azenide, silicon nitride, gallium nitride, aluminum phosphide, gallium phosphide, magnesium oxide, or zinc oxide.

[0033] The insulating heat-radiating particles (112) may include one type of heat-radiating particles and may have one average particle size. Alternatively, the insulating heat-radiating particles (112) may include one type of heat-radiating particles, but may have two or more average particle sizes. Alternatively, the insulating heat-radiating particles (112) may include two or more types of heat-radiating particles, but may have one average particle size. Alternatively, the insulating heat-radiating particles (112) may include two or more types of heat-radiating particles, but may have two or more average particle sizes. For example, the insulating heat-radiating layer (110) may have three types of average particle sizes of the insulating heat-radiating particles (112) (Fig. 1).

[0034] The insulating heat dissipation layer (110) includes insulating heat dissipation particles (112) dispersed in a polymer resin (111) to release heat in a vertical direction, and the heat transferred in the vertical direction is transferred to the conductive heat dissipation layer (120) and released as heat transferred in a horizontal direction.

[0035] The conductive heat dissipation layer (120) includes metal to increase the thermal conductivity in the horizontal direction, and the conductive heat dissipation layer (120) includes a metal mesh (121) and a metal paste (122) filling the metal mesh (121). The metal mesh (121) quickly transfers the transferred heat in the horizontal direction, thereby effectively dissipating the heat to the outside.

[0036] The metal included in the metal mesh (121) and the metal paste (122) may be selected from among copper, aluminum, nickel, gold, silver, palladium, chromium, and alloys thereof, which have excellent thermal conductivity. For example, the metal mesh (121) may be a copper mesh, and the metal paste (122) may be a copper paste. The metal mesh (121) may be surface-treated with a silane coupling agent.

[0037] According to another aspect of the present invention, a heat dissipation method for dissipating heat from a heat dissipation target in vertical and horizontal directions is provided, the method comprising: preparing an insulating conductive composite heat dissipation pad, the insulating heat dissipation layer including a polymer resin and insulating heat dissipation particles dispersed in the polymer resin, which dissipates heat in a vertical direction; and a conductive heat dissipation layer including a metal mesh and a metal paste filling the metal mesh on the insulating heat dissipation layer, which dissipates heat in a horizontal direction; and a step of bringing the insulating heat dissipation layer of the insulating conductive composite heat dissipation pad into contact with the heat dissipation target.

[0038] Referring to FIG. 2, heat is transferred from a heat dissipation target (not shown) located below an insulating conductive composite heat dissipation pad (100) based on the drawing to the insulating conductive composite heat dissipation pad (100) as indicated by an arrow. The insulating conductive composite heat dissipation pad (100) on the upper portion of the heat dissipation target (not shown) is positioned in a form in which an insulating heat dissipation layer (110) and a conductive heat dissipation layer (120) are laminated, so that heat first reaches the insulating heat dissipation layer (110) that is in contact with the heat dissipation target (not shown). The arrived heat is transferred vertically by the insulating heat dissipation layer (110), and the heat transferred to the upper portion of the insulating heat dissipation layer (110) is quickly transferred horizontally by the conductive heat dissipation layer (120) and discharged to the outside.

[0039] In the case where the area of ​​the heat dissipation target (not shown) is large, if only the horizontal thermal conductivity of the heat dissipation pad is high, the heat released on the upper part of the heat dissipation target (not shown), i.e., the upper part of the heat dissipation pad, accumulates, and the heat of the heat dissipation target (not shown) is not effectively discharged. Therefore, by using an insulating heat dissipation layer (110), such as the insulating conductive composite heat dissipation pad (100) according to the present invention, the heat of the heat dissipation target (not shown) is discharged vertically, and the heat transferred to the conductive heat dissipation layer (120) on the upper part of the insulating heat dissipation layer (110) is transferred horizontally, so that the heat is discharged to the outside from both side ends of the heat dissipation pad, so that even in the case of a large-area heat dissipation target (not shown), the heat can be effectively discharged.

[0040] FIG. 3 is a cross-sectional view of insulating heat-radiating particles in an insulating-conductive composite heat-radiating pad according to another embodiment of the present invention, FIG. 4 is a drawing illustrating a necking structure between insulating heat-radiating particles, and FIG. 5 is a drawing illustrating a necking structure between insulating heat-radiating particles and a conductive heat-radiating layer of an insulating heat-radiating layer. The following description will be made with reference to FIGS. 1 to 5.

[0041] According to the present embodiment, the insulating heat-radiating particles (112) in the insulating heat-radiating layer (110) of the insulating conductive composite heat-radiating pad (100) may include a metal layer (113) on the surface. When the insulating heat-radiating particles (112) include the metal layer (113), a heat transfer path is formed by the metal layer (113), thereby increasing the heat-radiating effect.

[0042] The metal layer (113) may include a metal selected from among copper, aluminum, nickel, gold, silver, palladium, chromium, and alloys thereof, which have excellent thermal conductivity. The metal layer may be a liquid metal layer. The liquid metal is a metal in a liquid state at room temperature, and the layer formation is easier than forming a layer of a metal in a solid state at room temperature on the surface of the insulating heat-radiating particle (112), resulting in excellent processability.

[0043] In addition, when the surface metal layer (113) of the insulating heat-radiating particle (112) is a liquid metal layer, as shown in FIG. 4, a necking structure as indicated by an arrow is formed between the insulating heat-radiating particle (112) and the insulating heat-radiating particle (112), thereby forming a heat transfer network and improving the thermal conductivity of the insulating heat-radiating layer (110).

[0044] When a metal layer (113) is formed on the surface of an insulating heat-radiating particle (112), a heat conduction path between the heat-radiating particles is created when the surfaces of the heat-radiating particles are in contact. In the case of an insulating heat-radiating particle (112) as shown in FIG. 3, it is a spherical particle with a metal layer (113) formed on the surface, and the contact area where these insulating heat-radiating particles (112) are in contact with each other is small. In order to increase the contact area between the heat-radiating particles to form a heat conduction path, the input amount of the heat-radiating particles must be increased. On the other hand, when the metal layer (113) is a liquid metal layer, a necking structure is formed between the heat-radiating particles as shown in FIG. 4, so that the formation of a heat-conduction path is excellent, thereby improving thermal conductivity, and thus there is no need to increase the input amount of the heat-radiating particles.

[0045] In addition, the liquid metal layer (113) on the surface of the insulating heat-dissipating particle (112) can be necked with the metal of the conductive heat-dissipating layer (120) when the insulating heat-dissipating layer (110) comes into contact with the conductive heat-dissipating layer (120). Therefore, due to the formation of a necking structure by the liquid metal layer (113) on the surface of the insulating heat-dissipating particle (112) at the interface of the insulating heat-dissipating layer (110) and the conductive heat-dissipating layer (120), a heat-conducting path is directly formed, so that heat transfer occurs efficiently, and since the interface adhesion is improved, interface detachment or separation of the insulating-conductive composite heat-dissipating pad (100) can be minimized.

[0046] Fig. 6 is a cross-sectional view of an insulating conductive composite heat dissipation pad according to another embodiment of the present invention. The insulating conductive composite heat dissipation pad (100) according to this embodiment includes two layers of metal mesh (121) in a conductive heat dissipation layer (120). The above description will be omitted below.

[0047] In the present embodiment, the insulating conductive composite heat dissipation pad (100) includes a conductive heat dissipation layer (120) comprising two layers of metal mesh (121). The metal mesh (121) improves the horizontal thermal conductivity, and thus the horizontal thermal conductivity of the insulating conductive composite heat dissipation pad (100) is improved.

[0048] Therefore, in cases where the area of ​​the heat dissipation target (not shown) that requires heat dissipation is large or where the heat released on the surface of the heat dissipation target (not shown) in contact with the insulating conductive composite heat dissipation pad (100) must not have an adverse effect, it is preferable to include two or more layers of metal mesh (121) so that the heat transferred vertically by the insulating heat dissipation layer (110) can be transferred as much as possible in the horizontal direction as well as the vertical direction by the conductive heat dissipation layer (120).

[0049] FIG. 7 is a diagram illustrating heat transfer in an insulating-conductive composite heat dissipation pad according to another embodiment of the present invention. The insulating-conductive composite heat dissipation pad (100) according to this embodiment includes two or more layers: an insulating heat dissipation layer that releases heat in a vertical direction, including a polymer resin and insulating heat dissipation particles dispersed in the polymer resin; and a conductive heat dissipation layer that releases heat in a horizontal direction, including a metal mesh and a metal paste filling the metal mesh on the insulating heat dissipation layer.

[0050] Referring to FIG. 7, the insulating-conductive composite heat dissipation pad (100) of the present embodiment includes three pairs of insulating heat dissipation layers and conductive heat dissipation layers. The insulating-conductive composite heat dissipation pad (100) includes a first insulating heat dissipation layer (110-1) that receives heat from a heat dissipation target (not shown), a first conductive heat dissipation layer (120-1) that receives heat from the first insulating heat dissipation layer (110-1), a second insulating heat dissipation layer (110-2) and a second conductive heat dissipation layer (120-2) to which heat remaining after heat is released horizontally from the first conductive heat dissipation layer (120-1) is transferred, and a third insulating heat dissipation layer (110-3) and a third conductive heat dissipation layer (120-3) to which heat remaining after heat is released horizontally from the second conductive heat dissipation layer (120-2) is transferred.

[0051] The insulating conductive composite heat dissipation pad (100) can determine the number of pairs of insulating heat dissipation layers and conductive heat dissipation layers by considering the heat generation amount and heat generation area of ​​the heat dissipation target (not shown). Alternatively, the insulating conductive composite heat dissipation pad (100) can determine the thickness of the insulating heat dissipation layer and the conductive heat dissipation layer by considering the heat generation amount and heat generation area of ​​the heat dissipation target (not shown).

[0052] According to another aspect of the present invention, a method for manufacturing an insulating conductive composite heat dissipation pad is provided, comprising: a step of filling a metal mesh with a metal paste to obtain a conductive heat dissipation layer that dissipates heat in a horizontal direction; and a step of dispersing insulating heat dissipation particles in a polymer resin and applying the particles on the conductive heat dissipation layer to obtain an insulating heat dissipation layer that dissipates heat in a vertical direction.

[0053]

[0054] Hereinafter, the present invention will be described in more detail through examples.

[0055] <Example>

[0056] [Manufacturing of Insulating and Conductive Composite Heat Dissipation Pads]

[0057] The materials used in the heat dissipation pads of the examples and comparative examples are as follows.

[0058] Aluminum nitride (AlN) powder (80 ㎛, 55 ㎛, 30 ㎛ powder, Thrutek Applied Materials)

[0059] Silver-coated copper particles (average particle size ~2 ㎛, Hyunseong Technology Co., Ltd.)

[0060] Silver nanopowder (30 nm, 150 nm, Ditto Technology)

[0061] Ethylene glycol (Sigma-Aldrich)

[0062] Oleylamine (TCI)

[0063] Liquid metal (eGaIn: eutectic GaIn liquid metal alloy, Sigma-Aldrich)

[0064] Copper mesh (#100 or #200, 99.9% copper)

[0065] (3-Mercaptopropyl)trimethoxysilane (85%) (Thermo scientific)

[0066] Dispersant (BYK-LP X 21879, BYK Additives & Instruments)

[0067] Silicone resin and curing agent (SYLGARD 184, Dow Corning Corporation)

[0068]

[0069] [Manufacturing of Liquid Metal (LM)-Ceramic Particle (AlN) Composite Filler]

[0070] AlN powders of 80 ㎛ and 55 ㎛ in size are ball milled at 220 rpm for 25 minutes, and AlN 30 ㎛ is obtained by ball milling at 220 rpm for 20 minutes. 12 g of the obtained AlN and 3.35 g of e-GaIn are ball milled to obtain an AlN-LM coated composite filler in which liquid metal is coated on the surface of the AlN heat-radiating particles.

[0071]

[0072] [Metal paste-copper paste manufacturing]

[0073] Mix 2.2 g of Ag 30 nm powder, 5 g of Ag 150 nm powder, 5.5 g of ethylene glycol, and 0.5 g of oleylamine. Mix in a paste mixer capable of both rotation and revolution at rotation 90 RPM, revolution 80 RPM, for 50 seconds, and then rotation 80 RPM, revolution 20 RPM, for 120 seconds.

[0074] Add 40 g of silver-coated copper powder and mix again for 2 minutes and 30 seconds. Repeat the 3-Roll-mill process 3 times to prepare a paste, and mix again for 2 minutes and 30 seconds to obtain a copper paste for a conductive heat-dissipating layer based on silver-coated copper particles.

[0075]

[0076] [Challenging Heat Dissipation Layer Manufacturing]

[0077] Copper paste is spread on a #100 copper mesh with a thickness of 0.1 mm, and sintered by vacuum pressing at 170°C for 30 minutes under 1 atm. The same process is repeated once more on the copper mesh layer on which the copper paste has been sintered, thereby obtaining a conductive heat-dissipating layer with two copper meshes overlapping each other.

[0078] The fabricated copper mesh layer is placed in a solution of 240 ml of ethanol (99.5%), 10 ml of distilled water, and 0.8 ml of (3-mercaptopropyl)trimethoxysilane (85%) and stirred at 40°C to undergo silane coupling.

[0079]

[0080] [Manufacturing of Insulating and Conductive Composite Heat Dissipation Pads]

[0081] Mix 3 g of AlN(80㎛)-LM coated particles, 2.75 g of AlN(55㎛)-LM coated particles, 2.5 g of AlN(30㎛)-LM coated particles, 2.4 g of silicone resin, 0.24 g of curing agent, and 0.158 g of dispersant. Mix for 3 minutes at high intensity in an acoustic mixer, then mix for 30 seconds at 2000 RPM and 30 seconds at 2200 RPM in a paste mixer capable of revolution and rotation.

[0082] A liquid metal-heat-dissipating particle composite paste is applied on a copper mesh layer in which copper paste is sintered, and hot pressing is performed at 130°C for 2 hours to obtain an insulating conductive composite heat-dissipating pad (Example 1, LM-Cu Composite pad).

[0083] An insulating conductive composite thermal pad manufactured in the same manner as in Example 1 except that AlN was not coated with liquid metal (Example 2, AlN-Cu Composite pad), a thermal pad manufactured only with a liquid metal-thermal particle composite paste without including a copper mesh layer (Comparative Example 1, LM Composite pad), and a thermal pad manufactured only with a thermal particle paste without including a copper mesh layer and without coating with liquid metal (Comparative Example 2, AlN Composite pad) were manufactured, and their thermal conductivities were evaluated.

[0084]

[0085] [evaluation]

[0086] [Volume resistance and thermal conductivity measurement]

[0087] The volume resistivity and thermal conductivity of Example 1, Example 2, Comparative Example 1, and Comparative Example 2 were measured. Example 1 (LM-Cu Composite pad) is an insulating-conductive composite heat dissipation pad according to the present invention, which is a heat dissipation pad including an insulating heat dissipation layer including heat dissipation particles having liquid metal coated on the surface of AlN particles and a conductive heat dissipation layer in which a copper mesh is filled with copper paste. Example 2 (AlN-Cu Composite pad) is an insulating-conductive composite heat dissipation pad according to the present invention, which is a heat dissipation pad including an insulating heat dissipation layer including AlN heat dissipation particles and a conductive heat dissipation layer in which a copper mesh is filled with copper paste. Comparative Example 1 (LM Composite pad) is a heat dissipation pad including only an insulating heat dissipation layer including heat dissipation particles having liquid metal coated on the surface of AlN particles, and Comparative Example 2 (AlN Composite pad) is a heat dissipation pad including only an insulating heat dissipation layer including AlN heat dissipation particles. Thermal conductivity was measured in the vertical and horizontal directions using the laser flash method.

[0088] Fig. 8 is a graph showing the results of volume resistance analysis according to the amount of heat dissipation particles of the heat dissipation pads of Example 1 and Comparative Example 1, Fig. 9 is a graph showing the results of vertical thermal conductivity analysis according to the amount of heat dissipation particles, and Fig. 10 is a graph showing the results of horizontal thermal conductivity analysis according to the amount of heat dissipation particles.

[0089] It can be confirmed that the thermal pad of Example 1 has a lower volume resistivity than the thermal pad of Comparative Example 1 that does not include a copper mesh-copper paste layer, and that both vertical and horizontal thermal conductivities are very high. In particular, when the particle ratio of the AlN thermal particle is 70 vol%, a thermal conductivity exceeding 20 W / mK in the vertical direction and 100 W / mK in the horizontal direction can be secured simultaneously.

[0090] Fig. 11 is a graph showing the results of vertical thermal conductivity analysis of the heat dissipation pads of Examples 1, 2, Comparative Examples 1, and 2, and Fig. 12 is a graph showing the results of horizontal thermal conductivity analysis. When the volume ratio of the heat dissipation particles is 50%, both the vertical thermal conductivity and the horizontal thermal conductivity of the examples showed superior characteristics compared to the comparative examples, confirming the superiority of the insulating-conductive composite heat dissipation pad including a conductive heat dissipation layer together with an insulating heat dissipation layer.

[0091] In addition, it can be confirmed in FIGS. 11 and 12 that the vertical thermal conductivity and horizontal thermal conductivity of the heat dissipation pad of Example 1 are much better than those of Example 2. This is presumed to be because a liquid metal thermal conduction path is formed at the interface of the insulating heat dissipation layer and the conductive heat dissipation layer by the liquid metal layer formed on the surface of the heat dissipation particle, which has a beneficial effect on the thermal conductivity, or because the interfacial adhesion is improved due to the liquid metal. It is presumed that the heat dissipation pad of Example 2, which used heat dissipation particles without a metal layer such as the liquid metal layer formed thereon, exhibited lower thermal conductivity than the heat dissipation pad of Example 1 because the heat transferred in the vertical direction of the insulating heat dissipation layer was not efficiently transferred at the interface with the conductive heat dissipation layer.

[0092] Above, embodiments of the present invention have been described, but those of ordinary skill in the art will be able to modify and change the present invention in various ways by adding, changing, deleting or adding components, etc., within the scope that does not depart from the spirit of the present invention described in the claims, and this will also be considered to be included within the scope of the rights of the present invention.

Claims

1. An insulating heat-radiating layer that releases heat in a vertical direction, including a polymer resin and insulating heat-radiating particles dispersed in the polymer resin; and An insulating-conductive composite heat-dissipating pad comprising a conductive heat-dissipating layer that dissipates heat in a horizontal direction, including a metal mesh and a metal paste filling the metal mesh on an insulating heat-dissipating layer; 2. In claim 1, An insulating conductive composite heat-dissipating pad characterized in that the insulating heat-dissipating particles are at least one of aluminum oxide, silicon carbide, diamond, beryllium oxide, boron nitride, boron phosphide, aluminum nitride, beryllium sulfide, boron amide, silicon nitride, gallium nitride, aluminum phosphide, gallium phosphide, magnesium oxide, and zinc oxide.

3. In claim 1, An insulating conductive composite heat-radiating pad characterized by having insulating heat-radiating particles having two or more different average particle sizes.

4. In claim 1, An insulating conductive composite heat-radiating pad characterized in that the insulating heat-radiating particles include a metal layer on the surface.

5. In claim 4, An insulating conductive composite heat-dissipating pad characterized in that the metal layer is a liquid metal layer.

6. In claim 5, An insulating conductive composite heat-radiating pad characterized in that the insulating heat-radiating particles are necked together by a liquid metal layer.

7. In claim 5, An insulating-conductive composite heat-dissipating pad, characterized in that the insulating heat-dissipating particles of the insulating heat-dissipating layer and the conductive heat-dissipating layer metal are necked together by a liquid metal layer at the interface of the insulating heat-dissipating layer and the conductive heat-dissipating layer.

8. In claim 1, An insulating conductive composite heat-dissipating pad characterized in that the metal is selected from copper, aluminum, nickel, gold, silver, palladium, chromium and alloys thereof.

9. In claim 1, An insulating conductive composite heat-dissipating pad characterized in that the conductive heat-dissipating layer includes two or more layers of metal mesh.

10. A step of filling a metal mesh with metal paste to obtain a conductive heat dissipation layer that releases heat in a horizontal direction; and A method for manufacturing an insulating-conductive composite heat-dissipating pad, comprising the steps of dispersing insulating heat-dissipating particles in a polymer resin and applying the particles on a conductive heat-dissipating layer to obtain an insulating heat-dissipating layer that releases heat in a vertical direction.

11. An insulating conductive composite heat-radiating pad comprising two or more layers of insulating conductive composite heat-radiating pads according to claim 1.

12. A step of preparing an insulating conductive composite heat-dissipating pad according to claim 1; A heat dissipation method for dissipating heat from a heat dissipation target in vertical and horizontal directions, comprising the step of bringing an insulating heat dissipation layer of an insulating conductive composite heat dissipation pad into contact with a heat dissipation target.

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