Heat-dissipating structure

Abstract

This heat-dissipating structure comprises a conductive member and a cold energy member, and has an adhesive layer and an insulating layer between the conductive member and the cold energy member.

Description

heat dissipation structure

[0001] The present disclosure relates to a heat dissipation structure.

[0002] Vehicles equipped with motors, such as hybrid vehicles and electric vehicles, are equipped with a drive means for driving the motor. The drive means is composed of a power module having a plurality of power semiconductors such as insulated gate bipolar transistors (IGBTs), electronic components such as capacitors, and bus bars that electrically connect these electronic components. When the motor is driven, a large current may flow through the bus bars that connect these electronic components, such as the power semiconductors and capacitors. When a large current flows through the bus bars, the drive means generates heat due to switching loss, resistance loss, and the like, and therefore, it is necessary to efficiently cool the drive means. As a cooling means for cooling the drive means, a heat sink made of a metal such as aluminum (Al) or copper (Cu) is used because of its high thermal conductivity (see, for example, Patent Document 1).

[0003] Furthermore, Patent Document 2 describes bonding a heat sink and a heating element via an insulating adhesive layer.

[0004] JP 2010-182831 A JP 2009-135524 A

[0005] When installing a heat sink in a vehicle or the like, it is required that the heat sink be thin. Here, from the viewpoint of heat dissipation, cooling components such as heat sinks are often made of metal, and insulation is required between the conductive component and the cooling component. Therefore, from the viewpoint of ensuring insulation, it has been difficult to narrow the distance from the conductive component to the cooling component and thereby make the heat sink thin. Furthermore, narrowing the distance from the conductive component to the cooling component tends to improve heat dissipation.

[0006] Therefore, an object of the present disclosure is to provide a heat dissipation structure that can reduce the distance from the conductive member to the cooling member.

[0007] The present disclosure includes the following aspects. <1> A heat dissipation structure comprising a conductive member and a cooling / heating member, and an adhesive layer and an insulating layer between the conductive member and the cooling / heating member. <2> The heat dissipation structure according to <1>, wherein the area of ​​the insulating layer is larger than the area of ​​the adhesive surface of the conductive member or the adhesive surface of the cooling / heating member. <3> The heat dissipation structure according to <1> or <2>, wherein an adhesive layer, an insulating layer, and an adhesive layer are arranged in this order from the conductive member side. <4> The heat dissipation structure according to any one of <1> to <3>, wherein at least one of the conductive member and the cooling / heating member is in contact with an insulating layer, and the insulating layer covers corners of at least one of the conductive member and the cooling / heating member. <5> The heat dissipation structure according to <4>, wherein an insulating layer and an adhesive layer are arranged in this order from the conductive member side. <6> The heat dissipation structure according to <4>, wherein an adhesive layer and an insulating layer are arranged in this order from the conductive member side. <7> The heat dissipation structure according to any one of <1> to <6>, wherein the distance between the conductive member and the heat-reducing member is 500 μm or less. <8> The heat dissipation structure according to any one of <1> to <7>, wherein the conductive member includes at least one member selected from the group consisting of a bus bar and a terminal for fastening the bus bar.

[0008] According to an embodiment of the present disclosure, it is possible to provide a heat dissipation structure that can reduce the distance from a conductive member to a cooling member.

[0009] FIG. 1 is a schematic perspective view showing a portion of a housing for arranging a heat generating element such as a semiconductor element, and shows an example of a case where a heat dissipation structure as an example of the heat dissipation structure of the present disclosure is incorporated into the housing. FIG. 2 is a schematic cross-sectional view showing an example of the cross-sectional structure of the heat dissipation structure of the present disclosure. FIG. 3 is a schematic cross-sectional view showing another example of the cross-sectional structure of the heat dissipation structure of the present disclosure. FIG. 4 is a schematic cross-sectional view showing another example of the cross-sectional structure of the heat dissipation structure of the present disclosure. FIG. 5 is a schematic cross-sectional view showing another example of the cross-sectional structure of the heat dissipation structure of the present disclosure. FIG. 6 is a schematic cross-sectional view showing another example of the cross-sectional structure of the heat dissipation structure of the present disclosure. FIG. 7 is a schematic cross-sectional view showing another example of the cross-sectional structure of the heat dissipation structure of the present disclosure. FIG. 8 is a schematic cross-sectional view showing another example of the cross-sectional structure of the heat dissipation structure of the present disclosure. FIG. 9 is a schematic cross-sectional view showing another example of the cross-sectional structure of the heat dissipation structure of the present disclosure. Fig. 14 is a schematic cross-sectional view showing another example of the cross-sectional structure around the bolt 21. Fig. 15 is a view explaining a manufacturing example of a heat dissipation terminal block having the cross-sectional structure of Fig. 9. Fig. 16 is a view explaining a manufacturing example of a heat dissipation terminal block having the cross-sectional structure of Fig. 11. Fig. 17 is a view explaining a manufacturing example of a heat dissipation terminal block having the cross-sectional structure of Fig. 12. Fig. 18 is a view explaining a manufacturing example of a heat dissipation terminal block having the cross-sectional structure of Fig. 14. Fig. 19 is a schematic cross-sectional view showing an example of a heat dissipation terminal block having a shoulder bolt.

[0010] Modes for carrying out the present invention are described in detail below. However, the present invention is not limited to the following embodiments. In the following embodiments, components (including elementary steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present invention. In this disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the Examples. In this disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in a composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In this disclosure, each component may contain multiple types of particles. When multiple types of particles corresponding to each component are present in a composition, the particle size of each component refers to the value for the mixture of the multiple types of particles present in the composition unless otherwise specified. In this disclosure, the vertical direction refers to the vertical direction in the figure, but it can also be used upside down. It can also be used as the left-right direction instead of the vertical direction. In this disclosure, the surface on which the conductive member is fastened will be described as the upper surface, and the opposite surface will be described as the lower surface.

[0011] The heat dissipation structure of the present disclosure includes a conductive member and a cooling member, and an adhesive layer and an insulating layer are provided between the conductive member and the cooling member. The reason why the distance from the conductive member to the cooling member can be reduced in the heat dissipation structure of the present disclosure is presumed to be as follows.

[0012] In the heat dissipation structure of the present disclosure, the insulating adhesive layer provided between the conductive member and the heat dissipation member is functionally separated into an insulating layer and an adhesive layer. This allows for the provision of an insulating layer specialized for insulation performance and the disposition of an adhesive layer specialized for adhesiveness, thereby making it possible to reduce the thickness of each layer. As a result, the distance from the conductive layer to the heat dissipation layer can be narrowed, thereby improving heat dissipation.

[0013] Furthermore, by separating the functions into the insulating layer and the adhesive layer, the area of ​​the insulating layer can be made larger than the area of ​​the adhesive surface of the conductive member or the area of ​​the adhesive surface of the cooling / heating member, thereby further improving the insulation properties. Accordingly, it is also possible to make the area of ​​the adhesive surface of the conductive member larger than the area of ​​the adhesive surface of the cooling / heating member, thereby further improving the heat dissipation properties.

[0014] Specific examples of the heat dissipation structure of the present disclosure will be described below with reference to the drawings, but the above-described embodiments are not limited to these. Also, the sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to these.

[0015] FIG. 1 is a schematic perspective view showing a portion of a housing for arranging a heat-generating body (member to be cooled) such as a semiconductor element, and illustrates an example in which a heat dissipation structure 200, as an example of a heat dissipation structure of the present disclosure, is incorporated into the housing 300. FIG. 1 also illustrates an exploded view of the heat dissipation structure 200. In the housing of FIG. 1, a cooling member 52, such as a heat spreader, is arranged below the O bus bar 12 that connects to the semiconductor element, and an adhesive layer 42, an insulating layer 60, and an adhesive layer 44 are arranged in this order between the O bus bar 12 and the cooling member 52. Note that, although the cooling member 52 is arranged below the O bus bar 12 in the housing of FIG. 1, a conductive member other than the O bus bar may be used. The shape of the housing and the arrangement of each member are not limited.

[0016] Fig. 2 is a schematic cross-sectional view showing an example of the cross-sectional structure of the heat dissipation structure of the present disclosure, which corresponds to the cross-sectional view taken along line A-A' in Fig. 1. In the heat dissipation structure of Fig. 2, a conductive member 10, an adhesive layer 42, an insulating layer 60, an adhesive layer 44, and a cooling member 52 are arranged in this order.

[0017] Examples of the conductive member 10 include bus bars such as a 0 bus bar, an N bus bar, and a P bus bar, and terminals for fastening conductive members such as bus bars. Examples of the material of the conductive member 10 include metals such as Al and Cu.

[0018] The adhesive layer 42 and the adhesive layer 44 may be made of the same material or different materials, and may have the same thickness or different thicknesses.

[0019] The adhesive layers 42, 44 are not particularly limited in terms of material as long as they have adhesive properties. Examples of materials for the adhesive layers 42, 44 include thermoplastic resins, thermosetting resins, and the like. Examples of thermoplastic resins include phenoxy resins and ethylene vinyl acetate resins. Examples of thermosetting resins include epoxy resins, silicone resins, and acrylic resins.

[0020] From the viewpoint of excellent work efficiency in manufacturing, it is preferable that the adhesive layers 42, 44 are made of an adhesive sheet. Examples of the material for the adhesive sheet include phenoxy-based and ethylene vinyl acetate-based resins.

[0021] From the viewpoint of ensuring adhesiveness, the thickness of each of the adhesive layers 42, 44 is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. Furthermore, from the viewpoint of improving thermal conductivity from the conductive member 10 to the cooling member 52, the thickness of each of the adhesive layers 42, 44 is preferably 100 μm or less, and more preferably 90 μm or less. The thickness of the adhesive layers 42, 44 can be measured with a micrometer and is the arithmetic average value of measurements at two locations.

[0022] The adhesive layers 42, 44 may be insulating adhesive layers having insulating properties, or may be conductive. Since the insulating layers are separately provided to separate the functions, the adhesive layers 42, 44 do not need to have insulating properties.

[0023] The insulating layer 60 may be configured to contain a resin. Examples of the resin contained in the insulating layer 60 include polyimide, polypropylene, polyphenylene sulfide (PPS), etc., and polyimide is preferred from the viewpoints of high heat resistance, high insulation properties, solvent resistance, etc.

[0024] The insulating layer 60 may be made of ceramics. Examples of the ceramic contained in the insulating layer 60 include conventionally known ceramics, such as aluminum oxide, titanium oxide, and aluminum nitride.

[0025] From the viewpoint of ensuring insulation, the thickness of the insulating layer 60 is preferably 0.5 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, and particularly preferably 50 μm or more. From the viewpoint of improving thermal conductivity from the conductive member 10 to the cooling member 52, the thickness of the insulating layer 60 is preferably 300 μm or less, more preferably 250 μm or less, and may be 50 μm or less, or may be 40 μm or less. The thickness of the insulating layer 60 can be measured with a micrometer and is the arithmetic average of measurements at two locations.

[0026] The insulation resistance value of the insulating layer 60 is set to 0.5×10 １６ It is preferable that the resistance is 1.0×10 Ωcm or more. １６ More preferably, it is 1.5×10 Ωcm or more. １６ It is more preferable that the insulation resistance value of the insulating layer 60 is Ωcm or more. The higher the insulation resistance value of the insulating layer 60, the more preferable. The insulation resistance value of the insulating layer 60 can be measured using an insulation resistance meter (for example, an insulation resistance measuring device manufactured by Kikusui Electronics Co., Ltd.).

[0027] Examples of the cooling member 52 include a heat sink and a heat spreader. The shape of the cooling member 52 is not particularly limited. The higher the thermal conductivity of the cooling member 52, the better, and it is preferably 50 W / mK or higher, more preferably 90 W / mK or higher, still more preferably 100 W / mK or higher, and may be 150 W / mK or higher, or may be 200 W / mK or higher. Examples of materials for the cooling member 52 include metals such as Al, Cu, and Fe, and ceramics mainly made of aluminum oxide.

[0028] The distance between the conductive member 10 and the heating / cooling member 52 is preferably 500 μm or less, more preferably 450 μm or less, and even more preferably 400 μm or less. From the viewpoint of thinning, the shorter the distance between the conductive member 10 and the heating / cooling member 52, the better, but from the viewpoint of ensuring insulation between the conductive member 10 and the heating / cooling member 52, the distance may be 5 nm or more, 10 nm or more, or 50 nm or more.

[0029] The distance between the conductive member 10 and the heating member 52 corresponds to the total thickness of the three layers, for example, an adhesive layer, an insulating layer, and an adhesive layer, if three layers are provided between the conductive member 10 and the heating member 52.

[0030] 2 has three layers, an adhesive layer, an insulating layer, and another adhesive layer, provided between the conductive member 10 and the cooling member 52. In the heat dissipation structure of Fig. 2, the length of the conductive member 10 in the A-A' direction (referred to as the width direction) is the same as the length of the cooling member 52, and the lengths of the adhesive layers 42, 44 and the insulating layer 60 are also aligned with the lengths of the conductive member 10 and the cooling member 52. The area of ​​the insulating layer 60 is the same as the area of ​​the adhesive surface of the conductive member 10.

[0031] The heat dissipation structure of Fig. 3 is the heat dissipation structure of Fig. 2 , except that the length of the insulating layer 60 in the width direction is changed. In the heat dissipation structure of Fig. 3 , the length of the adhesive layer 42 on the conductive member 10 side is the same as the length of the conductive member 10, and the length of the adhesive layer 44 on the cooling member 52 side is the same as the length of the cooling member 52. The length of the insulating layer 60 in the width direction is longer than the lengths of the adhesive layers 42, 44. The area of ​​the insulating layer 60 is larger than the areas of the adhesive surfaces of the conductive member 10 and the cooling member 52. This further ensures insulation.

[0032] In the heat dissipation structure of Fig. 4, the length of the conductive member 10 is longer than the length of the cooling member 52 in the width direction. In the heat dissipation structure of Fig. 4, the length of the adhesive layer 42 on the conductive member 10 side is the same as the length of the conductive member 10, and the length of the adhesive layer 44 on the cooling member 52 side is the same as the length of the cooling member 52. Of the adhesive layers 42, 44, the adhesive layer 42 has the longer length in the width direction, and the insulating layer 60 has the same length. The area of ​​the insulating layer 60 is larger than the area of ​​the adhesive surface of the cooling member 52. This further ensures insulation.

[0033] In the heat dissipation structure of FIG. 5 , the length of the cooling member 52 is longer in the width direction than the length of the conductive member 10. In the heat dissipation structure of FIG. 5 , the length of the adhesive layer 42 on the conductive member 10 side is the same as the length of the conductive member 10, and the length of the adhesive layer 44 on the cooling member 52 side is the same as the length of the cooling member 52. The length of the insulating layer 60 is aligned with that of the adhesive layer 44, which has the longer length in the width direction, of the adhesive layers 42, 44. The area of ​​the insulating layer 60 is larger than the area of ​​the adhesive surface of the conductive member 10. This further ensures insulation. In the heat dissipation structure of FIG. 5 , the length of the cooling member 52 is longer in the width direction than the length of the conductive member 10. The area of ​​the adhesive surface of the cooling member 52 is larger than the area of ​​the adhesive surface of the conductive member 10. This further improves cooling efficiency.

[0034] The heat dissipation structure of Fig. 6 does not have an adhesive layer 42 on the conductive member 10 side, and the conductive member 10 is in contact with an insulating layer 60. Two layers, the insulating layer 60 and the adhesive layer 44, are provided between the conductive member 10 and the cooling member 52. This allows the distance from the conductive member 10 to the cooling member 52 to be further narrowed compared to the heat dissipation structures of Figs. 2 to 5. Furthermore, in the heat dissipation structure of Fig. 6, the insulating layer 60 covers the corners of the conductive member 10. By having the insulating layer 60 cover the corners of the conductive member 10, the creepage distance is increased, and insulation properties can be further ensured.

[0035] The insulating layer 60, which is provided in contact with the conductive member 10 and covers the corners of the conductive member 10, can be formed by various methods, such as electroless plating, sputtering, aerosol deposition (AD), atomic layer deposition (ALD), thermal spraying, and chemical densification. It is preferable to select an appropriate method from these methods depending on the material used, the desired film thickness, and the like. For example, the film thickness can be 3 μm to 20 μm by electrolytic plating, 10 nm to 500 nm by sputtering and AD, and 10 nm to 1000 nm by ALD.

[0036] The insulating layer 60 in FIG. 6 may be made of ceramics or the like.

[0037] 6, the length of the cooling member 52 and the length of the conductive member 10 are the same in the width direction, but the length of the cooling member 52 may be longer or shorter than the length of the conductive member 10. When the length of the cooling member 52 is longer than the length of the conductive member 10, the cooling efficiency can be further improved.

[0038] The heat dissipation structure of Fig. 7 does not have an adhesive layer 44 on the cooling member 52 side, and the cooling member 52 is in contact with an insulating layer 60. Two layers, the adhesive layer 42 and the insulating layer 60, are provided between the conductive member 10 and the cooling member 52. This allows the distance from the conductive member 10 to the cooling member 52 to be further narrowed compared to the heat dissipation structures of Figs. 2 to 5. Furthermore, in the heat dissipation structure of Fig. 7, the insulating layer 60 covers the corners of the cooling member 52. By having the insulating layer 60 cover the corners of the cooling member 52, the creepage distance is increased, and insulation properties can be further ensured.

[0039] The method for forming the insulating layer 60 in FIG. 7 is the same as the method for forming the insulating layer 60 in FIG.

[0040] In the heat dissipation structure of Figure 7, the length of the conductive member 10 is longer than the length of the cooling member 52 in the width direction, but the length of the conductive member 10 and the length of the cooling member 52 may be the same, or the length of the cooling member 52 may be longer than the length of the conductive member 10.If the length of the cooling member 52 is longer than the length of the conductive member 10, the cooling efficiency can be further improved.

[0041] <Addendum> The present disclosure includes the following aspects. <1> A heat dissipation terminal block having terminals for fastening conductive members and a resin portion filling the periphery of the terminals, wherein the resin portion has a molding shrinkage rate of 1.0% or less. <2> The heat dissipation terminal block according to <1>, wherein the resin portion has a thermal conductivity of 0.1 W / mK or more. <3> The heat dissipation terminal block according to <1> or <2>, wherein, when the heat dissipation terminal block has two or more terminals, the surface of the resin portion between the terminals has at least one of a protrusion extending outward and a recess recessed in the thickness direction. <4> The heat dissipation terminal block according to any one of <1> to <3>, further having an insulating adhesive layer. <5> The heat dissipation terminal block according to any one of <1> to <4>, further having a heat dissipation plate. <6> The heat dissipation terminal block according to any one of <1> to <5>, further having an insulating layer.

[0042] The heat dissipation terminal block described above has terminals for fastening conductive members and a resin portion filling the periphery of the terminals, with the resin portion having a molding shrinkage rate of 1.0% or less. The reason for the excellent heat dissipation properties of the heat dissipation terminal block described above is believed to be as follows: In JP 2016-126925 A, the resin portion integrates the heat sink and other components, but even in this case, deformation of the resin portion can result in reduced heat dissipation. Investigation into the cause of this problem has revealed that deformation, such as warping, of the resin portion is caused by the volume change rate due to hardening during molding of the resin portion. Deformation of the resin portion during molding can create voids between the heat dissipation terminal block and the heat sink, etc., which impede heat conduction and reduce heat dissipation. Therefore, by setting the molding shrinkage rate of the resin portion filling the periphery of the terminals to 1.0% or less, deformation, such as warping, of the resin portion is suppressed, and the contact area between the heat sink, etc., located on the underside, and the resin portion is prevented from decreasing. This allows the heat generated from the conductive member to be effectively transferred to the heat sink, and it is therefore presumed that the heat dissipation terminal block described above has excellent heat dissipation properties.

[0043] Furthermore, because the heat dissipation terminal block described above has excellent flatness on the underside, even if a heat sink or the like is attached to the underside of the heat dissipation terminal block after manufacturing the heat dissipation terminal block, the heat dissipation performance is unlikely to be impaired. Therefore, the heat dissipation terminal block described above can be applied to various heat sinks, and the range of applications is extremely wide. Furthermore, the heat dissipation terminal block described above can be manufactured with the heat sink as a separate component. Therefore, the mold for forming the resin portion of the heat dissipation terminal block described above is less complex than that of Patent Document 1, which reduces manufacturing costs and simplifies manufacturing.

[0044] 8 shows a schematic perspective view of a heat dissipation terminal block 100 as an example of the heat dissipation terminal block. The heat dissipation terminal block 100 has terminals 20 for fastening conductive members 10 such as bus bars. The terminals 20 are preferably made of metal from the viewpoint of thermal conductivity.

[0045] The terminals 20 may be bolts 21 or nuts 22 as long as they can fasten the conductive member 10. In FIG. 8 , the heat dissipation terminal block 100 is provided with both bolts 21 and nuts 22, but only one of these may be provided. Also, in FIG. 8 , the heat dissipation terminal block 100 is provided with a plurality of bolts 21 and nuts 22, but a single bolt 21 or a single nut 22 may be provided. Furthermore, from the viewpoint of reinforcing the strength of the heat dissipation terminal block 100 and suppressing deformation, the heat dissipation terminal block 100 may have a reinforcing member such as a collar (not shown in FIG. 8 ). The presence of a reinforcing member further ensures the flatness of the lower surface of the heat dissipation terminal block.

[0046] The conductive members 10 may have through holes through which the bolts 21 pass. A plurality of conductive members 10 are stacked and placed on the bolts 21, and then nuts (not shown) are screwed onto the conductive members 10 to electrically connect them. If the heat dissipation terminal block 100 has nuts 22, bolts (not shown) are screwed onto the nuts 22 to fasten the conductive members 10.

[0047] A resin portion 30 is provided around the terminal 20. The molding shrinkage of the resin portion 30 is 1.0% or less, preferably 0.7% or less, more preferably 0.5% or less, even more preferably 0.3% or less, particularly preferably 0.2% or less, extremely preferably 0.1% or less, and extremely preferably 0%. The molding shrinkage is measured using the following formula: α=(L0-L) / L0 In the formula, α is the molding shrinkage, L0 is the mold dimension (mm), and L is the molded product dimension (mm).

[0048] The resin contained in the resin portion 30 may be a cured thermosetting resin or a thermoplastic resin. From the viewpoint of heat resistance, a cured thermosetting resin is preferable. When the resin portion 30 is a cured thermosetting resin, it has excellent dimensional stability in addition to heat resistance. Examples of thermosetting resins include unsaturated polyester resin, vinyl ester styrene resin, and phenolic resin. Examples of thermoplastic resins include polyethylene resin, polypropylene resin, and polyphenylene sulfide resin (PPS).

[0049] The resin part 30 may contain a filler, a reinforcing material, a curing agent, a release agent, and other additives. From the viewpoint of increasing the thermal conductivity of the resin part 30, the filler preferably contains thermally conductive particles. Examples of the thermally conductive particles include alumina particles and beryllium oxide particles. Examples of fillers other than thermally conductive particles include calcium carbonate particles, carbon black, and carbon fiber. Examples of reinforcing materials include glass fiber and aramid fiber. The curing agent can be selected appropriately depending on the resin used.

[0050] The proportions of resin, filler, reinforcing material, etc. in the resin portion 30 can be adjusted as appropriate. For example, from the viewpoint of keeping the molding shrinkage rate of the resin portion low, the resin content in the resin portion 30 may be 80% by mass or less, 70% by mass or less, or 60% by mass or less. Furthermore, from the viewpoint of insulation properties, the resin content in the resin portion 30 may be 10% by mass or more, 30% by mass or more, or 50% by mass or more.

[0051] The filler content in the resin portion 30 may be 20% by mass or more, 30% by mass or more, or 40% by mass or more. The filler content in the resin portion 30 may be 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[0052] The content of the reinforcing material in the resin part 30 may be 10% by mass or more, 20% by mass or more, or 30% by mass or more. The content of the reinforcing material in the resin part 30 may be 60% by mass or less, 50% by mass or less, or 40% by mass or less.

[0053] Other additives include a curing accelerator, a coupling agent, a flame retardant, a mold release agent, a colorant, and the like.

[0054] Bulk molding compound (BMC) can be used as the resin composition for molding the resin portion 30. BMC is a bulk clay-like thermosetting resin composition in which various additives are added to unsaturated polyester resin.

[0055] The thermal conductivity of the resin part 30 is preferably 0.1 W / mK or more, more preferably 0.3 W / mK or more, even more preferably 0.5 W / mK or more, particularly preferably 1.0 W / mK or more, and extremely preferably 2.0 W / mK or more. The higher the thermal conductivity of the resin part 30, the better.

[0056] The thermal conductivity was measured as follows. The cured resin portion 30 was cut into 10 mm x 10 mm pieces to obtain a sample. The sample was then blackened with graphite spray, and the thermal diffusivity was measured using a xenon flash method (trade name: LFA447 nanoflash, manufactured by NETZSCH). The thermal conductivity in the thickness direction of the resin portion 30 was calculated from the product of this value, the density measured by the Archimedes method, and the specific heat measured by a DSC (differential scanning calorimeter; trade name: DSC Pyris1, manufactured by Perkin-Elmer).

[0057] When two or more terminals 20 are provided, it is preferable to provide a protrusion 32 extending outward on the surface of the resin portion 30 between the terminals 20. Instead of or in addition to the protrusion 32, a recess (not shown) recessed in the thickness direction may be provided. The protrusion 32 and the recess may be made of the same material as the resin portion 30. Providing the protrusion 32 or the recess on the surface of the resin portion 30 between the terminals 20 increases the creeping distance of the resin portion 30, thereby reducing so-called creeping discharge along the surface of the resin portion 30. Therefore, providing the protrusion 32 or the recess allows the terminals 20 to be spaced closer together, thereby enabling the heat dissipation terminal block 100 to be miniaturized. The height of the protrusion 32 and the depth of the recess can be appropriately designed depending on the material of the resin portion 30, the distance between the terminals 20, etc. In the case of a resin portion 30 prone to creeping discharge, the height of the protrusion 32 is increased and the depth of the recess is deepened. 8, one protrusion 32 is provided between the terminals 20, but a plurality of protrusions may be provided. When a recess is used instead, a plurality of recesses may also be provided.

[0058] 9 to 14 are schematic cross-sectional views of the periphery of the bolt 21. When the heat dissipation terminal block 100 has a nut 22, the bolt 21 in FIGS.

[0059] As shown in Figure 9, a resin portion 30 may be filled around the side and bottom surfaces of the bolt 21. From the viewpoint of ensuring insulation, the thickness A of the resin portion 30 on the bottom side of the bolt 21 is preferably 0.2 mm or more, and more preferably 0.5 mm or more. Furthermore, from the viewpoint of improving thermal conductivity from the bolt 21 to a heat sink or the like, the thickness A is preferably 1.5 mm or less, and more preferably 1.0 mm or less. Note that the thickness A may be less than 0.2 mm or more than 1.5 mm. The thickness A of the resin portion 30 can be measured using a tool microscope and is the arithmetic average value of two locations.

[0060] 10, the resin portion 30 may be filled only around the side surfaces of the bolt 21, without filling the bottom surface of the bolt 21. In the embodiment shown in FIG. 10, the resin portion 30 is not filled on the bottom surface side of the bolt 21, and therefore the embodiment shown in FIG. 9 has better thermal conductivity than the embodiment shown in FIG.

[0061] 10, from the viewpoint of suppressing electrical conduction from the bolt 21 to other components such as a heat sink, it is preferable to further provide an insulating adhesive layer 40 on the bottom surface of the bolt 21, as shown in FIG. 11. The adhesiveness of the insulating adhesive layer 40 allows it to adhere to other components such as a heat sink. From the viewpoint of arranging the insulating adhesive layer 40 on the bottom side of the bolt 21, it is preferable that the bottom surface of the bolt 21 and the lower surface of the resin part 30 are flush with each other without any steps.

[0062] The insulating adhesive layer 40 may be configured to contain a thermoplastic resin. When the insulating adhesive layer 40 contains a thermoplastic resin, it can be adhered to another member such as a heat sink by heating. Examples of the thermoplastic resin contained in the insulating adhesive layer 40 include polyamideimide, polyimide, fluororesin, and polypropylene, and polyamideimide is preferred from the viewpoints of high heat resistance, high insulation properties, solvent resistance, and the like.

[0063] The thickness of the insulating adhesive layer 40 is preferably 10 μm or more, and more preferably 40 μm or more, from the viewpoint of ensuring insulation. Furthermore, the thickness of the insulating adhesive layer 40 is preferably 100 μm or less, and more preferably 60 μm or less, from the viewpoint of improving thermal conductivity from the bolt 21 to a heat sink or the like. The thickness of the insulating adhesive layer 40 can be measured with a micrometer and is the arithmetic average value of measurements at two locations.

[0064] The dielectric breakdown voltage of the insulating adhesive layer 40 is preferably 250 V / μm or more, more preferably 300 V / μm or more, and even more preferably 400 V / μm or more. The dielectric breakdown voltage is measured using a dielectric breakdown tester (e.g., YST-243-100RHO manufactured by Yamayo Test Instruments) at a voltage rise rate of 500 V / s at room temperature (25°C) in Fluorinert (FC-40 manufactured by Sumitomo 3M), and the voltage at which dielectric breakdown occurs (dielectric breakdown voltage) is determined. 20 measurement points are used. The dielectric breakdown voltage is determined by dividing the dielectric breakdown voltage by the thickness of the measurement sample.

[0065] The heat dissipation terminal block 100 may further include a heat dissipation plate 50. In Fig. 12, the heat dissipation plate 50 is provided on the outer surface of the insulating adhesive layer 40. When the insulating adhesive layer 40 contains a thermoplastic resin, it can be bonded to the heat dissipation plate 50 by heating.

[0066] Examples of the heat sink 50 include a metal plate and a ceramic plate, and specifically an aluminum plate. The higher the thermal conductivity of the heat sink, the better, and it is preferably 100 W / mK or higher, more preferably 150 W / mK or higher, and even more preferably 200 W / mK or higher.

[0067] From the viewpoint of ensuring heat dissipation, the thickness of the heat sink 50 is preferably 1 mm or more, more preferably 2 mm or more, and even more preferably 3 mm or more. The thickness of the heat sink 50 can be measured with a micrometer and is the arithmetic average value of measurements at two locations.

[0068] Furthermore, from the viewpoint of further ensuring insulation, the heat dissipation terminal block 100 may further include an insulating layer 60. In FIG. 13 , the insulating layer 60 is provided on the outer surface of the insulating adhesive layer 40. The insulating layer 60 may be made of a material that is more insulating than the resin portion 30. Therefore, the total thickness B of the insulating adhesive layer 40 and the insulating layer 60 arranged on the bottom side of the bolt 21 in the embodiment of FIG. 6 can be designed to be thinner than the thickness A of the resin portion 30 on the bottom side of the bolt 21 in the embodiment of FIG. 9 . The insulating layer 60 of the heat dissipation terminal block 100 can be the insulating layer 60 described in the heat dissipation structure of this disclosure.

[0069] 13, the positions of the insulating adhesive layer 40 and the insulating layer 60 may be reversed. If the insulating adhesive layer 40 is disposed on the outer surface, the insulating adhesive layer 40 can be used to adhere to a heat sink or the like.

[0070] 13 may be used as the adhesive layer. The adhesive layer of the heat dissipation terminal block 100 may refer to the insulating layer 60 described in the heat dissipation structure of the present disclosure.

[0071] Although not shown, the insulating adhesive layer 40 in Fig. 13 may be used as an adhesive layer, and an adhesive layer may also be disposed on the outside of the insulating layer 60. In this case, the bolt 21 is the conductive member 10, and the adhesive layer 42, insulating layer 60, and adhesive layer 44 are provided in this order from the conductive member 10 side, with the cooling / heating member 52 disposed on the outside of the adhesive layer 44. Therefore, in this case, the heat dissipation structure of the present disclosure shown in Figs. 2 to 5 may be applied.

[0072] Furthermore, the positions of the adhesive layer and insulating layer 60 may be reversed, in which case the insulating layer 60 and adhesive layer are disposed in this order from the side surface of the bolt 21, with the adhesive layer forming the outer surface. In this case, the bolt 21 is the conductive member 10, and the insulating layer 60 and adhesive layer 44 are disposed in this order from the conductive member 10 side, with the cooling member 52 disposed outside the adhesive layer 44. Therefore, in this case, the heat dissipation structure of the present disclosure shown in Figures 6 and 7 may be applied.

[0073] 11 to 13 (including the case where the insulating adhesive layer is replaced with an adhesive layer) show the configuration of FIG. 3 in which the resin portion 30 is not filled on the bottom side of the bolt 21, and further show the insulating adhesive layer 40, the heat sink 50, or the insulating layer 60. However, the configuration of FIG. 9 in which the resin portion 30 is filled on the bottom side of the bolt 21 may also show the insulating adhesive layer 40, the heat sink 50, or the insulating layer 60. When the insulating adhesive layer 40 is provided in the configuration of FIG. 9, the thickness A can be thinner than the above range, and can be, for example, 2.0 mm or less, 1.5 mm or less, or 1.0 mm or less.

[0074] 14, an insulating adhesive layer 40 may be disposed on the side and bottom surfaces of the bolt 21, and the periphery of the side surfaces may be filled with a resin portion 30. The insulating adhesive layer 40 may be integral from the bottom surface to the side surfaces. Since the insulating adhesive layer 40 on the bottom surface side is disposed as part of the outer surface, this portion of the insulating adhesive layer 40 can be used to bond to a heat sink or the like.

[0075] <Method for manufacturing heat dissipation terminal block> The heat dissipation terminal block may be manufactured by insert molding, in which resin is filled around the terminals. Specific examples of a method for manufacturing a heat dissipation terminal block by insert molding are shown below, but the method for manufacturing the heat dissipation terminal block is not limited to these examples.

[0076] In the heat dissipation terminal block of the form shown in FIG. 9 , as shown in FIG. 15(A), the bolt 21 and, if necessary, a collar 70 as a reinforcing member are placed in a molding die. The bolt 21 is placed so as not to come into contact with the lower die of the mold, so that the resin portion 30 is also formed on the bottom side of the bolt 21. The mold is then closed, filled with a resin composition, and heated to form the resin portion 30 as shown in FIG. 15(B). The resin composition may be heated during filling. The resin composition may contain, in addition to a thermosetting resin, fillers, reinforcing materials, curing agents, mold release agents, and other additives. The resin composition may also contain a thermoplastic resin as a resin component.

[0077] In the heat dissipation terminal block shown in FIG. 11 , the bolt 21 and, if necessary, the collar 70 are placed in a molding die as shown in FIG. 16(A). The bolt 21 is placed in contact with the lower die of the mold so that the resin portion 30 is not formed on the bottom surface of the bolt 21. When the collar 70 is placed, it is preferable to position the lower die so that the distance in the thickness direction from the bottom of the collar 70 to the bottom surface of the bolt 21 is equal to the thickness of the insulating adhesive layer 40 to be bonded later. The mold is then closed, filled with a resin composition, and heated to form the resin portion 30 as shown in FIG. 16(B). Thereafter, the insulating adhesive layer 40 is formed on the bottom surface of the bolt 21. The method for forming the insulating adhesive layer 40 is not particularly limited. For example, the insulating adhesive layer 40 may be formed by spraying, dispensing, spin coating, brush coating, or the like using a coating liquid containing a thermoplastic resin, or by attaching a sheet or film containing a thermoplastic resin.

[0078] For the heat dissipation terminal block shown in FIG. 12 , the bolt 21 and, if necessary, the collar 70 are placed in a molding die as shown in FIG. 17(A). When placing the collar 70 in FIG. 17(A), it is preferable to position the lower die so that the thicknesswise distance from the bottom of the reinforcing member to the bottom surface of the bolt 21 is equal to the total thickness of the insulating adhesive layer 40 and the heat dissipation plate 50 to be bonded later. The mold is then closed, filled with a resin composition, and heated to form the resin part 30 as shown in FIG. 17(B). The insulating adhesive layer 40 is then formed on the bottom side of the bolt 21. The method for forming the insulating adhesive layer 40 is the same as the method described with reference to FIG. 17(B). The heat dissipation plate 50 is then bonded to the outer surface of the insulating adhesive layer 40. If the insulating adhesive layer 40 contains a thermoplastic resin, the insulating adhesive layer 40 can be heated to bond it to the heat dissipation plate 50.

[0079] The heat dissipation terminal block of the configuration shown in FIG. 13 is placed in a mold with an insulating adhesive layer 40 provided on an insulating layer 60, and a bolt 21 placed on the insulating adhesive layer 40, as shown in FIG. 18(A). If a collar 70 is provided, both the insulating layer 60 and the collar 70 are placed in contact with the lower mold. If the surface of the lower mold on which the insulating layer 60 and the collar 70 are placed is flat, the insulating layer 60 and the collar 70 will be placed flat without any steps. The mold is then closed, filled with a resin composition, and heated to form the resin part 30, as shown in FIG. 18(B). By placing the insulating layer 60 outside the insulating adhesive layer 40, the insulating adhesive layer 40 can be prevented from melting and adhering to the mold due to heating. Therefore, the bolt 21 with the insulating adhesive layer 40 can be placed in the mold and insert-molded, as shown in FIG. 18.

[0080] The insert molding method of Fig. 18 can also be applied to the heat dissipation terminal block of the form shown in Fig. 12. In this case, the heat dissipation plate 50, insulating adhesive layer 40, and bolt 21 are arranged in this order and placed in a mold, and then insert molding is performed. Because the heat dissipation plate 50 is arranged on the outer surface of the insulating adhesive layer 40, the insulating adhesive layer 40 is prevented from adhering to the mold due to heating.

[0081] When providing a convex portion 32 or a concave portion extending outward on the surface of the resin portion 30 between the bolts 21, an upper mold having a concave portion or a convex portion that is the inverse of the shape of the convex portion 32 or the concave portion may be used. This method makes it possible to easily manufacture a heat dissipation terminal block that suppresses creeping discharge.

[0082] 16 to 18, the resin composition described in Fig. 15 can be used. In Fig. 15 to 18, the bolt 21 can be replaced with a nut 22. In Fig. 15 to 18, a reinforcing member such as a collar 70 may or may not be provided, and other members other than the reinforcing member may also be provided.

[0083] 15 to 18 have been described using a collar 70 as a reinforcing member, but as shown in Fig. 19, a shoulder bolt 80 may be used instead of the collar 70. In the case of a shoulder bolt 80, the amount of screw penetration is fixed, so compared to when a collar 70 is used, the operation of ensuring the flatness of the lower surface can be omitted.

[0084] The heat dissipation terminal block can be arranged on various heat sinks and can be attached to motor cases mounted on vehicles such as electric vehicles and hybrid vehicles.

[0085] REFERENCE SIGNS LIST 10 Conductive member 12 O bus bar 20 Terminal 21 Bolt 22 Nut 30 Resin portion 32 Convex portion 40 Insulating adhesive layer 42, 44 Adhesive layer 50 Heat sink 52 Cooling member 60 Insulating layer 70 Collar 80 Shoulder bolt 100 Heat dissipation terminal block 200 Heat dissipation structure 300 Housing

Claims

1. A heat dissipation structure comprising a conductive member and a heat-receiving member, with an adhesive layer and an insulating layer between the conductive member and the heat-receiving member.

2. The heat dissipation structure according to claim 1, wherein the area of ​​the insulating layer is larger than the area of ​​the adhesive surface of the conductive member or the adhesive surface of the cooling / heating member.

3. The heat dissipation structure according to claim 1 or 2, wherein an adhesive layer, an insulating layer, and an adhesive layer are arranged in this order from the conductive member side.

4. A heat dissipation structure according to claim 1 or 2, wherein at least one of the conductive member and the cooling / heating member is in contact with an insulating layer, and the insulating layer covers corners of at least one of the conductive member and the cooling / heating member.

5. The heat dissipation structure according to claim 4, further comprising an insulating layer and an adhesive layer disposed in this order from the conductive member side.

6. The heat dissipation structure according to claim 4, further comprising an adhesive layer and an insulating layer disposed in this order from the conductive member side.

7. A heat dissipation structure according to claim 1 or 2, wherein the distance between the conductive member and the heat dissipation member is 500 μm or less.

8. The heat dissipation structure according to claim 1 or 2, wherein the conductive member includes at least one member selected from the group consisting of a bus bar and a terminal for fastening the bus bar.

Images