Heat dissipating structure and battery using the same

Abstract

To provide a heat dissipation structure which can be easily fixed and has improved gripping properties, and a battery using the heat dissipation structure.SOLUTION: A heat dissipation structure 1 for dissipating heat from a heat source includes two or more long heat dissipation members 10, a fixing member 20 for fixing the two or more heat dissipation members 10 so as to maintain a state of an assembly 16 in which the two or more heat dissipation members 10 are arranged in a direction different from a longitudinal direction of the heat dissipation members 10, and a covering member 30 for covering an outer side of the fixing member 20. The heat dissipation member 10 includes a hollow or solid cushion member and a thermally conductive sheet covering an outer circumferential surface of the cushion member, the fixing member 20 exposes an intermediate portion 15 sandwiched between both end portions in a length direction of the respective heat dissipation members 10 and fixes the intermediate portion 15, and the covering member 30 exposes the intermediate portion 15 and covers both end portions in the length direction of the two or more heat dissipation members 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a heat dissipation structure and a battery using the same. [Background technology]

[0002] Control systems for automobiles, aircraft, ships, and home and commercial electronic devices are becoming more precise and complex, and as a result, the integration density of small electronic components on circuit boards is steadily increasing. As a result, there is a strong demand for solutions to the problems of electronic component failure and shortened lifespan caused by heat generation around the circuit board.

[0003] Conventionally, rapid heat dissipation from circuit boards has been achieved by constructing the circuit board itself out of a material with excellent heat dissipation properties, attaching a heat sink, or driving a cooling fan, either singly or in combination. Among these methods, constructing the circuit board itself out of a material with excellent heat dissipation properties, such as diamond, aluminum nitride (AlN), or cubic boron nitride (cBN), significantly increases the cost of the circuit board. Furthermore, the placement of a cooling fan poses problems, such as the risk of failure of the rotating device, the need for maintenance to prevent failure, and the difficulty of securing installation space. In contrast, heat dissipation fins are simple components that can increase surface area and enhance heat dissipation by forming numerous columnar or flat protrusions made of a highly thermally conductive metal (e.g., aluminum). Therefore, they are widely used as heat dissipation components (see Patent Document 1).

[0004] Currently, there is a growing global movement to gradually replace conventional gasoline-powered or diesel-powered vehicles with electric vehicles (EVs) in order to reduce the burden on the global environment. Electric vehicles are becoming increasingly popular, particularly in European countries such as France, the Netherlands, and Germany, as well as China. The widespread adoption of EVs requires the development of high-performance batteries and the installation of numerous charging stations. Technological development to improve the charging and discharging capabilities of lithium-based automotive batteries is particularly important. It is well known that automotive batteries are unable to fully function at temperatures above 60°C. For this reason, improving heat dissipation is becoming increasingly important for batteries, just as it was for the circuit boards discussed above.

[0005] To achieve rapid heat dissipation from a battery, it is necessary to form the heat transfer path with a highly thermally conductive material and to reduce the thermal resistance between the battery cell and the highly thermally conductive material. For example, a heat dissipation structure can be formed by using a graphite sheet as the heat transfer path and laminating a rubber-like elastic material on the sheet to form a cylindrical shape. Since battery cells can take various shapes (including uneven or non-smooth surfaces such as steps), placing such a heat dissipation structure between a battery cell and a cooling member, or between battery cells, makes it easy for the heat dissipation structure to adapt to various shapes of the battery cell and to form a heat transfer path. In addition, the heat dissipation structure easily returns to a shape close to its original shape when the battery cell is removed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-090937 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-294407 Summary of the Invention [Problem to be solved by the invention]

[0007] However, it is desirable to make it easier to fix multiple heat dissipation members when integrating them into a heat dissipation structure. In such cases, it is also desirable to improve the gripping ability when placing the heat dissipation member between a battery cell and a cooling member. This applies not only to battery cells, but also to other heat sources such as DC / DC converters, circuit boards, electronic components, and electronic devices themselves. Meeting these demands will also contribute to the achievement of the applicant's sustainable development goal of "ensuring access to affordable, reliable, sustainable, and modern energy for all."

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a heat dissipation structure that allows multiple heat dissipation members to be fixed more easily and has improved grippability, and a battery equipped with the same. [Means for solving the problem]

[0009] (1) In order to achieve the above object, a heat dissipation structure according to one embodiment comprises: A heat dissipation structure for dissipating heat from a heat source, Two or more elongated heat dissipation members; a fixing member that fixes the two or more heat dissipation members so as to maintain a state in which the two or more heat dissipation members are arranged in a direction different from the longitudinal direction of the heat dissipation members; a covering member that covers the outside of the fixing member; Equipped with the heat dissipation member includes a hollow or solid cushion member and a heat conduction sheet covering an outer peripheral surface of the cushion member; the fixing member exposes a middle portion sandwiched between both end portions of each of the heat dissipation members in the length direction, while encompassing and fixing each end portion of the two or more heat dissipation members in the length direction; The covering member covers each end portion of the two or more heat dissipation members in the length direction while leaving the intermediate portion exposed. (2) In another embodiment of the heat dissipation structure, the covering member may preferably form a piece that protrudes from the assembly of two or more of the heat dissipation members in at least one direction in which the heat dissipation members are arranged. (3) In the heat dissipation structure according to another embodiment, the fixing member may preferably be an adhesive tape having an adhesive surface on one or both sides. (4) In the heat dissipation structure according to another embodiment, the covering member may preferably be a single-sided adhesive tape having an adhesive surface on the fixing member side. (5) In another embodiment of the heat dissipation structure, preferably, the assembly of two or more of the heat dissipation members further includes an insulating film on at least one surface in a thickness direction thereof, The covering member may be located outside the insulating film. (6) In the heat dissipation structure according to another embodiment, the insulating film may preferably protrude in at least one direction of the arrangement of the heat dissipation members in the assembly. (7) In the heat dissipation structure according to another embodiment, the insulating film may be preferably provided on both sides in the thickness direction. (8) In order to achieve the above object, a battery according to one embodiment comprises: Any of the heat dissipation structures described above; a battery cell as a heat source; a housing as a cooling member, The heat dissipation structure is disposed between the battery cell and the housing. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a heat dissipation structure that can be fixed more easily and has improved gripping properties, and a battery that uses the heat dissipation structure. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows a plan view of a heat dissipation structure according to a first embodiment and a cross-sectional view taken along line AA of the plan view. [Figure 2] 2 shows a cross-sectional view taken along line BB in the plan view of FIG. 1 and an enlarged view of a part C thereof. [Figure 3] FIG. 3 shows a plan view of a heat dissipation structure according to the second embodiment and a cross-sectional view taken along line DD of the plan view. [Figure 4] FIG. 4 shows a cross-sectional view (4A) taken along line EE of the plan view in FIG. 3, and a cross-sectional view (4B) of the same view according to a modification thereof. [Figure 5] FIG. 5 shows a diagram for explaining a part of a method for manufacturing the heat dissipation structure of FIG. [Figure 6] FIG. 6 shows a longitudinal cross-sectional view of a battery according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below do not limit the invention according to the claims, and not all of the elements and combinations thereof described in the embodiments are necessarily essential to the solution of the present invention.

[0013] 1. Heat dissipation structure (First embodiment) FIG. 1 shows a plan view of a heat dissipation structure according to a first embodiment and a cross-sectional view of the plan view taken along line AA. FIG. 2 shows a cross-sectional view of the plan view taken along line BB in FIG. 1 and an enlarged view of a portion C thereof. In this embodiment, the heat source is disposed at the top of the paper surface of FIG. 2. This also applies to subsequent embodiments. Furthermore, the heat dissipation structure 1 in FIG. 1 includes 14 heat dissipation members 10, but the number of heat dissipation members 10 is not particularly limited. This also applies to subsequent embodiments. In the cross-sectional view of line BB in FIG. 2, the left side piece 40 is omitted in plan view.

[0014] (1) Schematic configuration The heat dissipation structure 1 according to the first embodiment is a heat dissipation structure 1 for dissipating heat from a heat source, and includes two or more elongated heat dissipation members 10, a fixing member 20 that fixes the two or more heat dissipation members 10 so as to maintain a state in which the two or more heat dissipation members 10 are arranged in a direction different from the longitudinal direction of the heat dissipation members 10, and a covering member 30 that covers the outside of the fixing member 20. The heat dissipation member 10 includes a hollow or solid cushion member 12 and a thermally conductive sheet 11 that covers the outer peripheral surface of the cushion member 12.

[0015] (2) Thermal Conduction Sheet The thermally conductive sheet 11 may be made of any material, but is preferably a sheet containing carbon, and more preferably a sheet composed of 90% by mass or more of carbon. For example, the thermally conductive sheet 11 may be a graphite film formed by baking a resin. However, the thermally conductive sheet 11 may also be a sheet containing carbon and a resin. In this case, the resin may be a synthetic fiber, and in this case, aramid fiber is preferably used as the resin. In this application, "carbon" is broadly interpreted to include any structure made of carbon (element symbol: C), such as graphite, carbon black with lower crystallinity than graphite, diamond, and diamond-like carbon with a structure similar to diamond. In this embodiment, the thermally conductive sheet 11 may be a thin sheet made by hardening a material in which graphite fibers or carbon particles are blended and dispersed in a resin. The thermally conductive sheet 11 may be a mesh-woven carbon fiber, or may be a spun or knitted blend. It should be noted that various fillers such as graphite fibers, carbon particles, and carbon fibers are all included in the concept of carbon filler.

[0016] When the thermally conductive sheet 11 is a sheet containing carbon and resin, the resin may account for more than 50% by mass or less of the total mass of the thermally conductive sheet 11. In other words, the thermally conductive sheet 11 may be made primarily of resin, as long as it does not significantly impede thermal conduction. A suitable example of the resin is a thermoplastic resin. A thermoplastic resin preferably has a high melting point so that it does not melt when conducting heat from a heat source. Suitable examples of the thermoplastic resin include polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyamide-imide (PAI), and aromatic polyamide (aramid fiber). Before molding the thermally conductive sheet 11, the resin is dispersed in the gaps between the carbon fillers, for example, in the form of particles or fibers. In addition to the carbon filler and resin, the thermally conductive sheet 11 may also contain dispersed fillers such as Al2O3, AlN, or diamond to further enhance thermal conductivity. Instead of resin, an elastomer, which is more flexible than resin, may be used. The thermally conductive sheet 11 may also be a sheet containing metal and / or ceramic instead of or in addition to the carbon described above. The metal may be aluminum, copper, or an alloy containing at least one of these, each of which has a relatively high thermal conductivity. The ceramic may be Al2O3, AlN, cBN, hBN, or other ceramics with a relatively high thermal conductivity.

[0017] The thermally conductive sheet 11 may or may not have excellent electrical conductivity. The thermal conductivity of the thermally conductive sheet 11 is preferably 10 W / mK or higher. In this embodiment, the thermally conductive sheet 11 is preferably a graphite film, made of a material with excellent thermal and electrical conductivity. The thermally conductive sheet 11 is preferably a sheet with excellent flexibility (or bendability). There are no restrictions on its thickness, but a thickness of 0.02 to 3 mm is preferred, and a thickness of 0.03 to 0.5 mm is more preferred. However, the thermal conductivity of the thermally conductive sheet 11 decreases in the thickness direction as the thickness increases, but the amount of heat transmitted increases with increasing thickness. Therefore, it is preferable to determine the thickness by comprehensively considering the strength, flexibility, and thermal conductivity of the sheet. The thermally conductive sheet 11 is preferably a cylindrical body covering the outer surface of the cushion member 12. However, the thermally conductive sheet 11 may also be a thin strip wound in a spiral shape around the outer surface of the cushion member 12.

[0018] (3) Cushion material Important functions of the cushion member 12 are its deformability and resilience. Resilience is due to its elastic deformability. Deformability is a necessary characteristic for it to conform to the shape of the heat source. In particular, in the case of battery cells such as lithium-ion batteries, which are packaged in easily deformable packages containing semi-solid or liquid-like contents, the design dimensions are often irregular or lack dimensional precision. For this reason, it is important for the cushion member 12 to maintain its deformability and resilience to maintain its conformability.

[0019] The cushion member 12 is preferably a cylindrical member having a hollow portion 13 extending along the longitudinal direction of the heat dissipation member 10 (the depth direction of the paper in FIG. 2 ). The cushion member 12 ensures good contact between the heat conductive sheet 11 and the heat source even when the heat source in contact with the heat conductive sheet 11 is not flat. Furthermore, the hollow portion 13 facilitates deformation of the cushion member 12, contributes to weight reduction of the heat dissipation structure 1, and also functions to improve contact between the heat conductive sheet 11 and the heat source. The cushion member 12 also functions as a protective member to prevent damage to the heat conductive sheet 11 due to a load applied thereto. In this embodiment, the cushion member 12 is a member with lower thermal conductivity than the heat conductive sheet 11. Note that in this embodiment, the hollow portion 13 is formed to have a circular cross section; however, the cross-sectional shape of the hollow portion 13 is not limited to a circle and may be, for example, a polygon, an ellipse, a semicircle, or a substantially polygonal shape with rounded vertices. Furthermore, the hollow portion 13 may be composed of a plurality of hollow portions, such as two semicircular hollow portions formed by dividing a circular cross section into two parts, vertically or horizontally. The cushion member 12 may be rolled into a U-shape so that the sheet is not completely closed, or may be rolled more than once. The cushion member 12 may also be solid and not have a hollow portion 13.

[0020] The cushion member 12 preferably includes a thermosetting elastomer such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, nitrile rubber (NBR), or styrene butadiene rubber (SBR); a thermoplastic elastomer such as a urethane-based, ester-based, styrene-based, olefin-based, butadiene-based, or fluorine-based elastomer, or a composite thereof. The cushion member 12 is preferably made of a material with high heat resistance so that it can maintain its shape without melting or decomposing due to the heat transmitted through the thermally conductive sheet 11. In this embodiment, the cushion member 12 is more preferably made of a urethane-based elastomer impregnated with silicone or silicone rubber. To enhance its thermal conductivity, the cushion member 12 may be made of rubber with a filler, such as Al2O3, AlN, cBN, hBN, or diamond particles, dispersed therein. The cushion member 12 may contain or not contain air bubbles. Furthermore, the term "cushion member" refers to a flexible member that is elastically deformable so as to fit closely to the surface of the heat source, and in this sense can be interpreted as a "rubber-like elastic body." Furthermore, as a variation of the cushion member 12, it can be constructed using metal instead of the rubber-like elastic body. For example, the cushion member 12 can be constructed using spring steel. Furthermore, a coil spring can also be disposed as the cushion member 12. Alternatively, a spirally wound metal can be used as spring steel and disposed on the annular back surface of the thermally conductive sheet 11 as the cushion member. Furthermore, the cushion member 12 can also be constructed using a sponge or solid (non-porous structure like a sponge) made of resin, rubber, etc.

[0021] (4) Fixing member The fixing member 20 is a member for fixing a plurality of aligned heat dissipation members 10, and while exposing an intermediate region 15 sandwiched between both longitudinal ends of each heat dissipation member 10, it encompasses and fixes each longitudinal end of two or more heat dissipation members 10. By exposing the intermediate region 15, it is possible to fix the heat dissipation members 10 to each other without impairing the heat dissipation performance of the heat dissipation structure 1. The length of the intermediate region 15 exposed from the heat dissipation member 10 is not particularly limited, and is, for example, preferably 50 to 90%, and more preferably 80 to 95%, when the total length of the heat dissipation member 10 is taken as 100%.

[0022] Hereinafter, the plurality of heat dissipating members 10 fixed by the fixing member 20 in the above manner will also be referred to as an "assembly." In this embodiment, the fixing member 20 is a single-sided adhesive tape having an adhesive layer 25 on one surface of a substrate 27, and is disposed at both ends of the heat dissipating member 10 in the longitudinal direction (the vertical direction in FIG. 1). The fixing member 20 preferably fixes the plurality of heat dissipating members 10 by bringing the adhesive layer 25 into surface contact with the heat dissipating members 10 (see the enlarged view of part C in FIG. 2). In this case, the surface of the adhesive layer 25 of the fixing member 20 may be in surface contact with the heat dissipating members 10, and the surface of the substrate 27 may be joined to the adhesive layer 35 of the covering member 30. Furthermore, as shown in FIG. 2, the fixing manner using the fixing member 20 may be such that two pieces of adhesive tape are used to fix both sides of the heat dissipating members 10 in the thickness direction, one side at a time, or one piece of adhesive tape may be wrapped around the heat dissipating members 10 in a circular shape to cover both sides of the heat dissipating members 10 in the thickness direction. Even when the heat dissipating members 10 are fixed one side at a time in the thickness direction, three or more adhesive tapes may be used.

[0023] The fixing member 20 may be a double-sided adhesive tape having adhesive layers 25 on both sides of a base material 27. When the fixing member 20 is a double-sided adhesive tape, the adhesive layer 25 on one side may be fixed to the heat dissipation member 10 in surface contact with the heat dissipation member 10, and the adhesive layer 25 on the other side may be bonded to the covering member 30 described below. When the fixing member 20 is a double-sided adhesive tape, the adhesive layer 25 on the other side may be bonded to the insulating film 50 described below. Note that the fixing members 20 at both ends may be made of different materials or may have different shapes, as long as at least the adhesive layer 25 can be fixed to the heat dissipation member 10 in surface contact with the heat dissipation member 10.

[0024] The adhesive tape used as the fixing member 20 is preferably a tape that can withstand a temperature rise due to heat dissipation from a heat source. More specifically, the adhesive tape is a tape that can withstand a high temperature of about 100°C, and is preferably made of a thermally conductive adhesive tape made of silicone rubber or acrylic resin. By using an adhesive tape as the fixing member 20, multiple heat dissipation members 10 can be fixed more easily.

[0025] The adhesive tape may also contain dispersed carbon filler, Al2O3, AlN, or diamond as a filler to further enhance thermal conductivity. The adhesive tape may also contain metal and / or ceramics instead of or in addition to the resin described above. Metals with relatively high thermal conductivity, such as aluminum, copper, or alloys containing at least one of these, can be selected. Ceramics with relatively high thermal conductivity, such as Al2O3, AlN, cBN, and hBN, can be selected. The adhesive tape may or may not have excellent electrical conductivity. The adhesive tape preferably has a thermal conductivity of 1 W / mK or higher. The adhesive tape is preferably a tape with excellent flexibility (or flexibility). There are no restrictions on the width and thickness of the adhesive tape; the width is preferably 3 to 10 mm, more preferably 4 to 8 mm, and even more preferably 5 to 7 mm. The thickness is preferably 20 to 200 μm, and more preferably 50 to 160 μm. However, the thermal conductivity of the adhesive tape decreases in the thickness direction as its thickness increases, but the amount of heat transmitted increases as the thickness increases, so it is preferable to determine the thickness by taking into consideration the strength, flexibility, and thermal conductivity of the sheet as a whole.

[0026] The distance L1 between the heat dissipating members 10 narrows when the heat dissipating members 10 are compressed by pressure from the heat source. If the heat dissipating members 10 are barely compressed, the adhesion between the thermally conductive sheet 11 and the heat source, etc., may be reduced. To reduce this risk, the thickness of the heat dissipating members 10 when compressed in the vertical direction, i.e., in the direction from the heat source toward the cooling portion equipped with the cooling member, is at least 80% of the tube diameter (= equivalent circular diameter: D) of the heat dissipating members 10. Here, the "equivalent circular diameter" refers to the diameter of a perfect circle with the same area as the cross-section of the heat dissipating member 10 when cut perpendicular to its longitudinal direction. If the heat dissipating member 10 is a cylinder with a perfect circular cross section, its diameter is the same as the equivalent circular diameter. When the heat dissipation members 10 are compressed as described above, they can be considered to deform so that the surfaces in contact with the heat source and the cooling area via the insulating film 50 become flat, and the distance L1 between the heat dissipation members 10 becomes a substantially arc-shaped cross section (see the enlarged view of part C in Figure 2). If the distance L1 is sufficiently large, the heat dissipation members 10 do not come into contact with adjacent heat dissipation members 10. Conversely, if the gap L1 is too small, even if the heat dissipation members 10 are compressed in the vertical direction, they may come into contact with adjacent heat dissipation members 10 and be unable to be further compressed. If the distance L1 is set to 11.4% or more of the equivalent circle diameter D of the heat dissipation members 10, contact between the heat dissipation members 10 and hinder the deformation when the heat dissipation members 10 are compressed and deformed to a thickness that is 80% of the equivalent circle diameter D can be prevented. Therefore, it is preferable that the heat dissipation structure 1 has multiple heat dissipation members 10 arranged so that the distance L1 between the heat dissipation members 10 is 11.4% or more of the equivalent circle diameter D of the heat dissipation members 10.

[0027] The heat dissipation structure 1 holds the heat dissipation members 10 by the adhesive layer 25 of the fixing member 20 being in surface contact with the heat dissipation members 10 while the heat dissipation members 10 are arranged in a direction different from their longitudinal direction. This ensures good contact between the thermally conductive sheet 11 and the lower ends of the heat sources even if the lower ends are not flat. To achieve high heat transfer efficiency, it is desirable to uniformly dissipate heat from each of the multiple heat sources so that the temperature of each heat source is uniform. To achieve this, it is preferable to arrange the multiple heat dissipation members 10 so that the number of heat dissipation members 10 in contact with each heat source is uniform. Note that the multiple heat dissipation members 10 do not necessarily need to be arranged so that the distance L1 between the heat dissipation members 10 is equal. Preferably, the heat dissipation structure 1 arranges the heat dissipation members 10 at different distances so that the heat dissipation members 10 are densely packed at the positions of the heat sources with higher temperatures. That is, it is preferable that the heat dissipation structure 1 has a small distance L1 between the heat dissipation members 10 in contact with the high-temperature heat source so that the number of heat dissipation members 10 in contact with the high-temperature heat source is greater than the number of heat dissipation members 10 in contact with the other heat sources. In this way, the heat dissipation structure 1 can be easily and reliably positioned relative to the heat sources in accordance with the shape of the heat sources, etc., so that the heat dissipation performance of each of the multiple heat sources is uniform.

[0028] (5) Covering material The covering member 30 covers both longitudinal ends of two or more heat dissipation members 10 while exposing the intermediate portions 15. The covering member 30 also covers the outside of the fixing members 20 that fix both end portions of the heat dissipation members 10. Preferably, the covering member 30 simultaneously covers both the heat dissipation members 10 and the fixing members 20 in the thickness direction of the assembly 16 of multiple heat dissipation members 10, as shown in the cross-sectional view of line AA in FIG. 1 . The covering member 30 may cover the fixing members 20 in any manner, preferably beyond the fixing members 20. However, the covering member 30 may cover all or part of the fixing members 20 without exceeding the fixing members 20. The covering member 30 increases the connection strength of the assembly 16 of heat dissipation members 10 and contributes to preventing damage to the product. It also facilitates assembly when fixing the heat dissipation structure 1 inside the housing 110.

[0029] The covering member 30 according to this embodiment preferably forms a piece 40 that protrudes from the assembly 16 of two or more heat dissipation members 10 in at least one direction in which the heat dissipation members 10 are arranged. In this application, the term "piece" refers to a portion that protrudes further outward from both ends of the assembly 16 of heat dissipation members 10 in the width direction. The piece may include not only the covering member 30 but also other members other than the heat dissipation members 10, such as the fixing member 20 and the insulating film 50 described below, and does not necessarily have to include the covering member 30. Forming the piece 40 can improve the gripping ability when the heat dissipation structure 1 is installed inside the housing 110 of the battery 100.

[0030] Although the piece 40 is formed to protrude significantly to the right side in plan view in Fig. 1, this is not limited thereto, and for example, the piece 40 may be formed to protrude by the same length on both sides in plan view of the heat dissipation structure 1, or may be formed to protrude by different lengths on both sides. The length of the piece 40 is not particularly limited, and is preferably 10 to 30 mm, for example. Furthermore, in Fig. 2, the piece 40 is provided with the fixing members 20 inside the covering member 30, and is formed to cover the fixing members 20 joined to each other, but this is not limited thereto, and the piece 40 may be formed to be composed of only the covering members 30, and to join the covering members 30 to each other, for example.

[0031] The covering member 30 is preferably a single-sided adhesive tape having an adhesive surface on the fixing member 20 side. That is, the adhesive layer 35 is adhered to the adhesive layer 25 of the fixing member 20 or the substrate 27. The material of the adhesive tape used for the covering member 30 may be the same as or different from that used for the fixing member 20. Because the covering member 30 is a single-sided adhesive tape, the non-adhesive side of the substrate 37 is exposed on the surface. This can further improve the grip of the heat dissipation structure 1.

[0032] The width of the covering member 30 is not particularly limited, but is preferably a value calculated by the following formula (I) for the convenience of comprehensively covering each end of two or more heat dissipation members 10 in the longitudinal direction. The thickness of the covering member 30 is also not particularly limited, and may be the same as or different from the thickness of the fixing member 20. The units of the width, equivalent circle diameter, and x in formula (I) are mm. Width of covering member (mm) = (Width of fixing member × 2) + (Circular equivalent diameter of heat dissipation member D) + x (I) (x is between 1 and 2 inclusive.)

[0033] (Second embodiment) Fig. 3 shows a plan view of a heat dissipation structure according to a second embodiment and a cross-sectional view of the plan view taken along line DD. Fig. 4 shows a cross-sectional view (4A) of the plan view in Fig. 3 taken along line EE and a cross-sectional view (4B) of the same view according to a modified example. Note that in the cross-sectional view taken along line DD in Fig. 3, a portion of the part behind the cross section is omitted. Parts common to the previous embodiment are designated by the same reference numerals, and redundant explanations will be omitted.

[0034] The heat dissipation structure may further include an insulating film 50 on at least one surface in the thickness direction of the assembly 16 of two or more heat dissipation members 10, and a covering member 30 may be disposed on the outside of the insulating film 50. The heat dissipation structure 1a according to this embodiment includes insulating films 50 on both surfaces in the thickness direction of the assembly 16. By providing insulating films 50 on both surfaces in the thickness direction, it is possible to prevent graphite pieces from falling due to contact and friction with surrounding components, and to prevent contamination caused by this. The heat dissipation structure 1a includes two insulating films 50, one on each surface in the thickness direction of the assembly 16, but this is not limited thereto. For example, one longitudinal insulating film 50 may be disposed so as to sandwich both surfaces of the assembly 16 in the thickness direction.

[0035] The covering member 30 according to this embodiment is located outside the insulating film 50. In the heat dissipation structure 1a, the covering member 30 covers at least the portion of the insulating film 50 that covers the fixing member 20. The heat dissipation structure 1a according to this embodiment may also be provided with a piece 40a. In FIGS. 3 and 4A, some portions of the piece 40a are not covered by the covering member 30, but this is not limited thereto, and the entire surface of the piece 40a may be covered by the covering member 30.

[0036] Furthermore, the heat dissipation structure 1b according to a modified example of this embodiment differs from the heat dissipation structure 1a in that an insulating film 50 is provided on one surface (corresponding to the surface that contacts a battery cell 200, which will be described later, and hereinafter also referred to as the contact surface) in the thickness direction of the assembly 16 of two or more heat dissipation members 10. The heat dissipation structure 1b may also be provided with a piece 40b. In FIG. 4B , some portions of the piece 40b are not covered with the covering member 30, but this is not limited thereto, and the entire surface of the piece 40b may be covered with the covering member 30. In FIG. 4B , both ends of the insulating film 50 in the heat dissipation structure 1b are fixed in a manner that they are sandwiched between the fixing member 20 and the covering member 30 on the surface opposite the contact surface. However, this is not limited thereto, and for example, both ends of the insulating film 50 may be fixed between the fixing member 20 and the covering member 30 on the contact surface.

[0037] (6) Insulating film In this embodiment, the insulating film 50 is a member that extends along the longitudinal direction (the vertical direction in FIG. 3) of the heat dissipation member 10. The insulating film 50 is located outside the heat dissipation member 10 and the fixing member 20, and is located inside the covering member 30.

[0038] When the insulating film 50 is provided on both sides, the insulating films 50 may be joined together with adhesive tape at the ends in the direction perpendicular to the longitudinal direction of the heat dissipation member 10. The adhesive tape is the same as that of the covering member 30 in FIG. 4, but it may be the single-sided adhesive tape used for the fixing member 20 or a different tape.

[0039] The insulating film 50 is a sheet-like member with higher insulating properties than the fixing member 20, preferably a heat-resistant sheet-like member. The insulating film 50 may be made of any material, but is preferably made of polyester, polypropylene, polyethylene, polyethylene terephthalate, polycarbonate, polyamide, polyimide, phenolic resin, glass fiber-impregnated epoxy resin, or acrylic insulating films. Plastic insulating films such as polyethylene terephthalate, polycarbonate, polyether ether ketone, and polyimide, which have excellent dimensional stability, insulating properties, and heat resistance, are more preferred. The thickness of the insulating film 50 is preferably 3 to 50 μm, and more preferably 3 to 10 μm. However, the thickness of the insulating film 50 is preferably determined taking into consideration the strength, flexibility, insulating properties, and other factors of the film. The insulating film 50 is preferably a film with an electrical resistivity of 1.0 × 10 Ω·m or greater.

[0040] The insulating film 50 preferably protrudes in at least one direction in the direction in which the heat dissipation members 10 are arranged in the assembly 16, and more preferably protrudes in both directions in the direction in which the heat dissipation members 10 are arranged in the assembly 16. This protrusion improves the gripping ability when fixing the heat dissipation structure 1a to the housing 110. The protruding insulating film 50 may form a piece 40a together with the covering member 30. Providing the piece 40a further improves the gripping ability of the heat dissipation structure 1a.

[0041] 2. Manufacturing method of heat dissipation structure Next, an example of a suitable method for manufacturing the heat dissipation structure 1 according to the first embodiment will be described.

[0042] FIG. 5 shows a diagram for explaining a part of a method for manufacturing the heat dissipation structure of FIG.

[0043] First, an example of a suitable manufacturing method for the heat dissipation member 10 constituting the heat dissipation structure 1 will be described. First, a cushion member 12 having a hollow portion 13 is molded. Next, a strip-shaped thermally conductive sheet 11 is spirally wound around the outer surface of the cushion member 12. At this time, the thermally conductive sheet 11 is wrapped around the outer surface of the cushion member 12 while the cushion member 12 is still in an uncured state, and then the cushion member 12 is heated to completely cure. Next, any portions of the strip-shaped thermally conductive sheet 11 that protrude beyond both ends of the cushion member 12 are cut off. By manufacturing the heat dissipation member 10 in this manner, the uncured cushion member 12 is cured while filling microscopic gaps in the thermally conductive sheet 11, allowing the cushion member 12 and the thermally conductive sheet 11 to be firmly fixed together without the use of adhesives or the like. The heat dissipation member 10 thus completed has a shape that protrudes beyond the outer surface of the cushion member 12 by the thickness of the thermally conductive sheet 11. However, the thermally conductive sheet 11 and the cushion member 12 may be flush with each other. If the outer surface of the cushion member 12 does not have adhesiveness, the thermally conductive sheet 11 may be fixed to the cushion member 12 using an adhesive or the like.

[0044] The heat dissipation structure 1 is manufactured as follows. First, a plurality of heat dissipation members 10 manufactured by the above-described manufacturing method are arranged on fixing members 20 arranged at intervals along the longitudinal direction of the fixing members 20 (the left-right direction in FIG. 1 ) in a direction different from the longitudinal direction of the heat dissipation members 10 (in FIG. 1 , a direction perpendicular to the longitudinal direction of the heat dissipation members 10). At this time, the fixing members 20 are arranged along both ends of the heat dissipation members 10 in the longitudinal direction (the up-down direction in FIG. 1 ). Furthermore, the fixing members 20 are preferably arranged so that the adhesive layer 25 is in surface contact with the plurality of heat dissipation members 10. Then, another fixing member 20 is attached from above to the surface of the heat dissipation member 10 opposite the surface fixed to the fixing member 20 in the thickness direction. As a result, the plurality of heat dissipation members 10 are fixed so that both ends are sandwiched between the fixing members 20 located on both sides in the thickness direction. In this way, an assembly 16 of a plurality of heat dissipation members 10 is completed. Thereafter, both ends of the assembly 16 are covered with covering members 30, along with the fixing members 20. The covering members 30 are preferably arranged so that the adhesive layers 35 are in surface contact with the adhesive layers 25 or base materials 27 of the fixing members 20 located on both thickness-wise sides of the assembly 16, and with the end faces of the heat dissipation members 10 sandwiched between the fixing members 20. At this time, the length of the covering members 30 is preferably longer in the longitudinal direction (left-right direction in FIG. 1 ) than the width of each end of the assembly 16 in the width direction (left-right direction in FIG. 1 ). This allows the pieces 40 to be formed by joining the covering members 30 protruding in at least one width direction from each end of the assembly 16. Note that, as an alternative manufacturing method, the heat dissipation members 10 may be aligned, and then a fixing member 20 may be attached to the opposite side.

[0045] In the heat dissipation structure 1a according to the second embodiment, insulating films 50 are provided on both sides of the assembly 16 in the thickness direction before being covered with the covering member 30. The insulating films 50 may be fixed by the adhesive layer 25 of the fixing member 20, or may be placed on the substrate 27 without being fixed. After this placement, the covering member 30 is applied as appropriate. The heat dissipation structure 1b is similar to the heat dissipation structure 1a, except that insulating films 50 are provided on one side of the assembly 16 in the thickness direction before being covered with the covering member 30.

[0046] 3. Battery Next, the battery according to this embodiment will be described.

[0047] FIG. 6 shows a longitudinal cross-sectional view of a battery according to one embodiment. Here, the term "longitudinal cross-sectional view" refers to a view taken vertically from the upper opening of the battery housing to the bottom. In FIG. 6, the heat dissipation structure 1 is depicted in a cross-sectional view taken along line BB in FIG. 2. Note that in FIG. 6, one piece 40 of the heat dissipation structure 1 is omitted.

[0048] In this embodiment, the battery 100 is, for example, a battery for an electric vehicle, and includes a number of battery cells 200. The battery 100 is preferably a lithium-ion battery. The battery 100 includes a housing 110 with a bottom that is open on one side. The housing 110 is preferably made of aluminum or an aluminum-based alloy. The battery cells 200 are disposed inside the housing 110. Electrodes (not shown) protrude from the upper sides of the battery cells 200. The multiple battery cells 200 are preferably tightly attached to each other within the housing 110 by applying compressive force from both sides using screws or the like (not shown). The bottom 120 of the housing 110 is provided with one or more water-cooling pipes 130 for flowing cooling water, which is an example of a cooling member 150. The battery cells 200 are disposed within the housing 110 such that the heat dissipation structure 1 is sandwiched between the battery cells 200 and the bottom 120.

[0049] The battery 100 includes one or more battery cells 200 as heat sources within a housing 110 configured to allow a cooling member 150 to flow. The heat dissipation structure 1 is interposed between the battery cells 200 and the cooling member 150. The heat dissipation structure 1 brings the heat dissipation member 10 into surface contact with the battery cells 200. In a battery 100 configured in this manner, heat is transferred from the battery cells 200 to the housing 110 through the heat dissipation structure 1, and is effectively removed by water cooling. Note that the cooling member 150 may be interpreted as a "cooling medium" or "coolant." The cooling member 150 is not limited to coolant water, but may also include organic solvents such as liquid nitrogen and ethanol. The cooling member 150 is not limited to a liquid, and may be a gas or solid under the conditions in which it is used for cooling.

[0050] When the battery cell 200 is set in the housing 110 (see FIG. 6 ), the heat dissipation structure 1 is compressed in the thickness direction of the heat dissipation structure 1 between the battery cell 200 and the bottom 120 including the water-cooling pipe 130. As a result, heat from the battery cell 200 is easily transferred to the thermally conductive sheet 11, the bottom 120, the water-cooling pipe 130, and the cooling member 150. Note that the battery 100 may include the above-mentioned heat dissipation structure 1a instead of the heat dissipation structure 1. Furthermore, because the heat dissipation structure 1a includes the insulating film 50, it is possible to prevent electrical short circuits with peripheral components even if the heat conductive sheet 11 is conductive.

[0051] 4. Other embodiments As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to these and can be practiced in various modifications.

[0052] The insulating film 50 is not restricted in its shape, and may have any shape that allows it to be placed between the heat source and the heat dissipation members 10 with at least a plurality of heat dissipation members 10 arranged along a direction perpendicular to the longitudinal direction thereof, such as a polygon, ellipse, circle, or approximately polygon with rounded vertices when viewed in a plane.

[0053] The double-sided adhesive tape or single-sided adhesive tape constituting the fixing member 20 and the covering member 30 is not restricted in shape, and as long as it is capable of fixing at least a plurality of heat dissipation members 10 arranged in a direction perpendicular to their longitudinal direction by bringing the adhesive layers 25, 35 into surface contact with the heat dissipation members 10 and the substrate 27, respectively, it may have a shape such as a polygon, ellipse, circle, or approximately polygon with rounded vertices when viewed in a plane.

[0054] In the heat dissipation structure 1a, the insulating films 50, 50 on both sides may be bag-shaped.

[0055] The heat dissipation member 10 does not need to have a hollow portion 13 formed in the cushion member 12. In that case, the heat dissipation member 10 has a configuration in which the cushion member 12 is filled in the hollow portion of the thermally conductive sheet 11. As long as the hollow portion is formed by the wound structure of at least the thermally conductive sheet 11, out of the thermally conductive sheet 11 and the cushion member 12, the hollow portion does not need to be formed in the cushion member 12.

[0056] The heat source includes not only the battery cell 200 but also any object that generates heat, such as a circuit board or the main body of an electronic device. For example, the heat source may be an electronic component such as a DC / DC converter, a capacitor, or an IC chip. Similarly, the cooling medium 150 may be not only water for cooling, but also an organic solvent, liquid nitrogen, or a cooling gas. Furthermore, the heat dissipation structure 1, 1a may be disposed in a structure other than the battery 100, such as an electronic device, a home appliance, or a power generation device.

[0057] The components of each of the above-described embodiments can be freely combined except for cases where they cannot be combined with each other. For example, the heat dissipation structure 1a may be provided in the battery 100. [Explanation of symbols]

[0058] 1, 1a, 1b... heat dissipation structure, 10, 10a, 10b, 10c, 10d... heat dissipation member, 11... thermally conductive sheet, 12... cushion member, 13... hollow portion, 15... intermediate portion, 16... assembly, 20... fixing member, 30... covering member, 40, 40a, 40b... side portion, 50... insulating film, 100... battery, 110... housing, 120... bottom portion, 130... water-cooling pipe, 140... interior, 150... cooling member, 200... battery cell (an example of a heat source).

Claims

1. A heat dissipation structure for dissipating heat from a heat source, Two or more elongated heat dissipation members; a fixing member that fixes the two or more heat dissipation members so as to maintain a state in which the two or more heat dissipation members are arranged in a direction different from the longitudinal direction of the heat dissipation members; a covering member that covers the outside of the fixing member; Equipped with the heat dissipation member includes a hollow or solid cushion member and a heat conduction sheet covering an outer peripheral surface of the cushion member; the fixing member exposes a middle portion sandwiched between both end portions of each of the heat dissipation members in the length direction, while enclosing and fixing each end portion of the two or more heat dissipation members in the length direction; The heat dissipation structure is characterized in that the covering member covers each end portion of the two or more heat dissipation members in the length direction while leaving the intermediate portion exposed.

2. 2. The heat dissipation structure according to claim 1, wherein the covering member forms a piece that protrudes from the assembly of two or more heat dissipation members in at least one direction of the arrangement of the heat dissipation members.

3. 2. The heat dissipation structure according to claim 1, wherein the fixing member is an adhesive tape having an adhesive surface on one or both sides.

4. 2. The heat dissipation structure according to claim 1, wherein the covering member is a single-sided adhesive tape having an adhesive surface on the fixing member side.

5. an insulating film is further provided on at least one surface in a thickness direction of the assembly of two or more of the heat dissipation members; The heat dissipation structure according to claim 1 , wherein the covering member is located outside the insulating film.

6. 6. The heat dissipation structure according to claim 5, wherein the insulating film protrudes in at least one direction of the arrangement of the heat dissipation members in the assembly.

7. The heat dissipation structure according to claim 5 , wherein the insulating film is provided on both sides in the thickness direction.

8. The heat dissipation structure according to any one of claims 1 to 7; a battery cell as a heat source; a housing as a cooling member, The battery, wherein the heat dissipation structure is disposed between the battery cell and the housing.

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