Cooling system

Abstract

This provides cooling technology that improves the ability to cool heat-generating elements. [Solution] The cooling system 100 includes a condenser 3, an expansion valve 4, a cooling section 10 cooled by a heat transfer medium 8, and a compressor 2. The cooling section 10 includes a pipe 30 through which the heat transfer medium 8 flows and a sealing resin 20 that seals the pipe 30. The thermal conductivity of the sealing resin 20 is 0.7 W / m·K or higher.

Description

Technical Field

[0001] The present invention relates to a cooling system.

Background Art

[0002] The market for electric vehicles is expanding. In electric vehicles, electrical components such as inverters used to drive motors generate a large amount of heat, and heat dissipation measures are important. For example, a vehicle heat pump device that includes a heat pump and performs heat exchange between a refrigerant and a coolant is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As the output of the motor increases, the heat generation of heat sources such as electrical components increases. In the conventional technology, it is also assumed that sufficient cooling cannot be achieved, and an improvement in the ability to cool the heat source has been demanded.

[0005] The present invention has been made in view of such a situation, and an object thereof is to provide a cooling technology that improves the ability to cool a heat source.

Means for Solving the Problems

[0006] According to the present invention, the following technology is realized. 1. A condenser, an expansion valve, a cooling unit cooled by a heat medium, a compressor, and having the cooling unit has a pipe through which the heat medium flows and a sealing resin that seals the pipe, A cooling system in which the thermal conductivity of the sealing resin is 0.7 W / m·K or higher. 2. The cooling system according to 1, wherein the distance from the upper end of the pipe to the upper surface of the sealing resin is 0.5 mm or more and 5 mm or less. 3. The sealing resin is a thermosetting resin, The aforementioned thermosetting resin is Epoxy resin and Hardener and Inorganic fillers and A cooling system as described in 1. or 2., including the cooling system described in 1. or 2. 4. The cooling system according to 3, wherein the content of the inorganic filler is 50% by mass or more and 90% by mass or less relative to the sealing resin. 5. The cooling system according to 3. or 4., wherein the epoxy resin comprises at least one selected from the group consisting of biphenyl-type epoxy resin, bisphenol-type epoxy resin, stilbene-type epoxy resin, novolac-type epoxy resin, polyfunctional epoxy resin, phenol aralkyl-type epoxy resin, and naphthol-type epoxy resin. 6. The cooling system according to any one of 3 to 5, wherein the inorganic filler includes one selected from the group consisting of silica, alumina, aluminum hydroxide, silicon nitride, and aluminum nitride. 7. The cooling system according to any one of 1 to 6, wherein the surface roughness Ra of the outer surface of the pipe, as measured in accordance with JIS B0601, is 10 μm or more and 100 μm or less. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a cooling technology that improves the ability to cool a heat-generating element. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a cooling system according to an embodiment. [Figure 2] This is a plan view of the cooling unit according to the embodiment. [Figure 3] This is a cross-sectional view taken along line A2-A2 in Figure 2, according to an embodiment of the present invention. [Figure 4] It is a plan view of a cooling part having a complex pipe design according to an embodiment. [Figure 5] It is a diagram for explaining a comparison structure according to an embodiment.

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawings are for illustrative purposes only. The shapes, dimensional ratios, etc. of each member in the drawings do not necessarily correspond to actual articles.

[0010] <Summary of the Invention>

[0011] A cooling system having a heat pump is used for cooling an electrical component mounting device (electrical component) mounted on an electric vehicle or the like (electrical component). In the present embodiment, the pipes of the refrigerant circulation are integrated with a resin mold, and the space from the electrical component serving as a heat source (heating element) to the refrigerant pipe is filled with a high thermal conductivity resin. Thereby, the cooling performance of the electrical component mounting device is improved. Note that the cooling system 100 described below is mounted on, for example, an electric vehicle, but may be used for other applications. Specific description will be given below.

[0012] <Electrical Component Mounting Device 1> The electrical component mounting device 1 according to the present embodiment will be described. FIG. 1 is a diagram schematically showing the electrical component mounting device 1 according to an embodiment of the present invention. FIG. 1(a) is a cross-sectional view (cross-sectional view taken along line A1 - A1 of FIG. 1(b)), and FIG. 1(b) is a plan view. FIG. 2 is a plan view of the cooling part 10. FIG. 3 is a cross-sectional view taken along line A2 - A_{2} of FIG. 2.

[0013] The electrical equipment device 1 has an electrical component 9 and a cooling system 100. The electrical component 9 is attached to the cooling system 100 and cooled. The electrical component 9 includes, for example, units such as an in-vehicle inverter, an in-vehicle on-board charger, and an in-vehicle DC-DC converter, and components of these units such as a power module, a capacitor, a bus bar, a power semiconductor, a reactor, a capacitor, and a transformer. The electrical component 9 attached to the cooling system 100 may be entirely attached, or only some parts of the electrical component 9 may be attached. Also, a plurality of electrical components 9 may be mounted on one cooling system 100.

[0014] <Cooling system 100> The cooling system 100 of the present embodiment is a system that performs cooling by a so-called heat pump cycle. The cooling system 100 has a condenser 3, an expansion valve 4, a cooling unit 10 cooled by a heat medium 8, and a compressor 2. The cooling unit 10 has a pipe 30 through which the heat medium 8 flows and a sealing resin 20 that seals the pipe 30. The thermal conductivity of the sealing resin 20 is 0.7 W / m·K or more.

[0015] In the cooling system 100, the heat medium 8 circulates through the condenser 3, the expansion valve 4, the pipe 30 inside the sealing resin 20, and the compressor 2. By this operation, the electrical component 9 attached to the sealing resin 20 of the cooling unit 10 is cooled.

[0016] As the compressor 2, the condenser 3, and the expansion valve 4, which are components of the cooling system 100, devices used in a known heat pump cooling system can be used.

[0017] The components of the cooling cycle and their operations are briefly described below. The compressor 2 is connected to the discharge part 33 of the pipe 30, compresses the heat medium 8 discharged from the discharge part 33, changes it to a high-temperature and high-pressure gas state, and sends it to the condenser _. The condenser 3 cools the heat medium 8, which has become a high-temperature and high-pressure gas compressed and sent by the compressor 2, and condenses at least a part of it into a liquid. The expansion valve 4 expands the heat transfer medium 8 by reducing the pressure, causing it to turn from a liquid into a mist and lowering the temperature of the heat transfer medium 8. The heat transfer medium 8 that has passed through the expansion valve 4 is sent to the pipe 30 of the cooling unit 10. Pipe 30 functions as an evaporator, and the heat transfer medium 8 supplied from the expansion valve 4 absorbs heat from the electrical components 9 via the sealing resin 20 as it passes through pipe 30, gaining heat of vaporization and evaporating. The heat-absorbing heat transfer medium 8 is then sent to the compressor 2. Examples of heat transfer fluids 8 (working fluids) include fluorocarbons, ammonia, carbon dioxide, and lithium bromide. This series of circulations of the heat transfer medium 8 allows the cooling system 100 to effectively cool the electrical components 9.

[0018] <Cooling section 10> The cooling unit 10 includes a pipe 30 and a sealing resin 20. The pipe 30 is sealed in the sealing resin 20, efficiently transferring heat between the electrical components 9 and the pipe 30.

[0019] <Pipe 30> The pipe 30 is sealed inside the sealing resin 20 in a zigzag pattern, for example, so that it can fully perform its cooling performance in the vicinity of the heat-generating electrical component 9. The shape and size of the pipe 30 and the amount of heat transfer medium 8 are appropriately set according to the location where the electrical component 9 is mounted and the required cooling performance.

[0020] For example, the pipe 30 can be a metal pipe, ceramic pipe, glass pipe, or resin pipe. For example, metal pipes can be made of metals such as copper, aluminum, iron, and titanium, or their alloys. Any combination of metal pipes, ceramic pipes, glass pipes, or resin pipes may be used. When using a resin pipe, it is preferable to use a resin with high thermal conductivity, such as the sealing resin 20 described later.

[0021] The surface roughness Ra of the outer surface of pipe 30, measured in accordance with JIS B0601, is between 10 μm and 100 μm. The lower limit of the surface roughness Ra is preferably 20 μm or more, and more preferably 40 μm or more. The upper limit of the surface roughness Ra is preferably 90 μm or less, and more preferably 80 μm or less. By setting the lower limit of the surface roughness Ra to the above range, good adhesion between the pipe 30 and the sealing resin 20 can be maintained, and the occurrence of gaps at the interface between the sealing resin 20 and the pipe 30 can be suppressed. By setting the upper limit of the surface roughness Ra to the above range, good productivity can be achieved.

[0022] <Sealing resin 20> The sealing resin 20 seals the pipe 30. This allows the heat from the electrical components 9 to be efficiently transferred to the pipe 30. In addition, because the pipe 30 is sealed by the sealing resin 20, it is possible to prevent the pipe 30 from being damaged and the heat transfer medium 8 from leaking out.

[0023] The thermal conductivity of the sealing resin 20 (at room temperature of 25°C) is, for example, 0.7 W / m·K or higher. The lower limit of the thermal conductivity is preferably 1.0 W / m·K or higher, and more preferably 1.5 W / m·K or higher. There is no particular upper limit, but a practical value would be 50 W / m·K or lower, and 25 W / m·K or lower. Resin materials with a thermal conductivity of 50 W / m·K are available. The thermal conductivity can be adjusted to a desired range by adjusting the type and content of the inorganic filler (e.g., filler) in the resin material. By setting the thermal conductivity to the above range, the thermal conductivity from the electrical components 9 to the pipe 30 is improved, and high cooling performance can be achieved for the cooling unit 10.

[0024] In the cooling section 10, the distance d1 (see Figure 3) from the upper end 35 of the pipe 30 to the upper surface 25 of the sealing resin 20 is 0.5 mm or more and 5 mm or less. The lower limit of the distance d1 is preferably 0.7 mm or more, and more preferably 1 mm or more. If the distance d1 is shorter than the above lower limit, the sealing of the sealing resin 20 may be insufficient, and the pipe 30 may be exposed. The upper limit of the distance d1 is preferably 4 mm or less, and more preferably 3 mm or less. If the distance d1 is greater than the above upper limit, the distance between the electrical component 9 and the pipe 30 becomes too long, and the performance of heat conduction from the electrical component 9 to the pipe 30, i.e., the cooling performance, deteriorates. Furthermore, the distance d2 from the lower end 36 of the pipe 30 to the lower surface 26 of the sealing resin 20 can be the same as distance d1. If no electrical components 9 are mounted on the lower surface 26 of the sealing resin 20, cooling performance is not required in that area, so there is no particular upper limit to distance d2.

[0025] As the sealing resin composition of the sealing resin 20, a thermosetting resin composition containing a thermosetting resin and a thermoplastic resin composition containing a thermoplastic resin can be used.

[0026] The thermosetting resin composition preferably includes, for example, a thermosetting resin, a filler, and a curing agent.

[0027] [Thermosetting resin] Examples of thermosetting resins include epoxy resins, cyanate resins, polyimide resins, benzoxazine resins, unsaturated polyester resins, phenolic resins, melamine resins, silicone resins, bismaleimide resins, phenoxy resins, and acrylic resins. One of these thermosetting resins may be used alone, or two or more may be used in combination. In particular, from the viewpoint of having high insulating properties, the thermosetting resin is preferably epoxy resin, phenolic resin, or phenoxy resin, with epoxy resin being more preferred.

[0028] As the epoxy resin, any monomer, oligomer, or polymer having two or more epoxy groups in one molecule can be used, and its molecular weight and molecular structure are not particularly limited. Examples of epoxy resins include crystalline epoxy resins such as biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, tetramethylbisphenol F-type epoxy resins, stilbene-type epoxy resins, and hydroquinone-type epoxy resins; novolac-type epoxy resins such as cresol novolac-type epoxy resins, phenol novolac-type epoxy resins, and naphthol novolac-type epoxy resins; aralkyl-type epoxy resins such as phenylene skeleton-containing phenol aralkyl-type epoxy resins, biphenylene skeleton-containing phenol aralkyl-type epoxy resins, phenylene skeleton-containing naphthol aralkyl-type epoxy resins, and alkoxynaphthalene skeleton-containing phenol aralkyl-type epoxy resins; trifunctional epoxy resins such as triphenolmethane-type epoxy resins and alkyl-modified triphenolmethane-type epoxy resins; modified phenol-type epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resins and terpene-modified phenol-type epoxy resins; and heterocyclic epoxy resins such as triazine nucleus-containing epoxy resins. These may be used individually or in combination of two or more types. Among these, from the viewpoint of improving the balance of thermal conductivity, reliability, and moldability of the cooling section 10, it is more preferable to use an epoxy resin that includes at least one selected from the group consisting of bisphenol-type epoxy resin, novolac-type epoxy resin, biphenyl-type epoxy resin, stilbene-type epoxy resin, polyfunctional epoxy resin, phenol aralkyl-type epoxy resin, and naphthol-type epoxy resin.

[0029] The content of the thermosetting resin is not particularly limited, but is preferably 1% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 30% by mass or less, and even more preferably 5% by mass or more and 20% by mass or less, relative to the entire sealing resin composition. By setting the content of thermosetting resin above the lower limit, the fluidity and moldability of the sealing resin composition can be more effectively improved. Furthermore, by setting the content of thermosetting resin (A) below the upper limit, the reliability of the cooling unit 10 can be more effectively improved. More specifically, the curability of the sealing resin composition can be improved and the coefficient of thermal expansion of the resin can be reduced, thereby improving reliability.

[0030] [Inorganic filler] Examples of inorganic fillers include silica, alumina, aluminum hydroxide, kaolin, talc, clay, mica, rock wool, wollastonite, glass powder, glass flakes, glass beads, glass fiber, silicon carbide, silicon nitride, aluminum nitride, carbon black, graphite, titanium dioxide, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, cellulose, aramid, or wood. These may be used individually or in combination of two or more. From the viewpoint of improving thermal conductivity, it is preferable that the inorganic filler includes one selected from the group consisting of silica, alumina, aluminum hydroxide, silicon nitride, and aluminum nitride.

[0031] Examples of the above-mentioned silica include crystalline silica (crushed crystalline silica), fused silica (crushed amorphous silica, spherical amorphous silica), and liquid sealing silica (spherical amorphous sealing silica for liquid sealing). Among these, fused spherical silica is preferred from the viewpoint of improving fluidity and filling properties.

[0032] The average particle size of the inorganic filler is not particularly limited, but is typically 1 to 100 μm, preferably 1 to 50 μm, and more preferably 1 to 20 μm. A suitable average particle size improves the ability to fill the area around the semiconductor element within the mold cavity. The volume-based particle size distribution of inorganic fillers can be measured using a commercially available laser particle size analyzer (for example, the SALD-7000 manufactured by Shimadzu Corporation).

[0033] The content of the inorganic filler is not particularly limited, but is preferably 50% by mass or more and 90% by mass or less of the total encapsulating resin composition. The lower limit is more preferably 60% by mass or more, and even more preferably 65% ​​by mass or more. The upper limit is more preferably 85% by mass or less, and even more preferably 80% by mass or less. By setting the inorganic filler content above the lower limit, the curability of the encapsulating resin composition can be improved, and the coefficient of thermal expansion of the resin can be reduced, thereby improving reliability. Furthermore, by setting the inorganic filler content below the upper limit, the fluidity of the encapsulating resin composition can be improved, and moldability can be more effectively enhanced.

[0034] [Hardening agent] The sealing resin composition may contain a curing agent. The curing agent is not particularly limited as long as it reacts with the thermosetting resin to cure, but examples include linear aliphatic diamines having 2 to 20 carbon atoms such as ethylenediamine, trimethylenediamine, tetramethylenediamine, and hexamethylenediamine, as well as amines such as metaphenylenediamine, paraphenylenediamine, paraxylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodicyclohexane, bis(4-aminophenyl)phenylmethane, 1,5-diaminonaphthalene, metaxylenediamine, paraxylenediamine, 1,1-bis(4-aminophenyl)cyclohexane, and dicyanodiamide; resol-type phenolic resins such as aniline-modified resol resins and dimethyl ether resol resins; phenol novolac resins, cresol no Examples include novolac-type phenolic resins such as volac resins, tert-butylphenol novolac resins, and nonylphenol novolac resins; phenolic aralkyl resins such as phenylene skeleton-containing phenolic aralkyl resins and biphenylene skeleton-containing phenolic aralkyl resins; phenolic resins having condensed polycyclic structures such as naphthalene skeletons and anthracene skeletons; polyoxystyrenes such as polyparaoxystyrene; acid anhydrides including alicyclic acid anhydrides such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA), and aromatic acid anhydrides such as trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), and benzophenonetetracarboxylic acid (BTDA); polymercaptan compounds such as polysulfides, thioesters, and thioethers; isocyanate compounds such as isocyanate prepolymers and blocked isocyanates; and organic acids such as carboxylic acid-containing polyester resins. These may be used individually or in combination of two or more types.Among these, it is preferable to use phenol novolac type resins (PN), triphenolmethane type phenol resins (MF), biphenyl skeleton-containing polyfunctional phenol resins (polyvalent MAR), or binaphthalene type phenol resins (naphthalene resins) that exhibit high Tg, in order to maintain reliability even when semiconductor chips reach high temperatures.

[0035] The content of the curing agent in the encapsulating resin composition is not particularly limited, but is preferably 1% by mass or more and 12% by mass or less, and more preferably 3% by mass or more and 10% by mass or less, relative to the entire encapsulating resin composition. By setting the curing agent content above the lower limit, the encapsulating resin composition becomes easier to cure properly. On the other hand, by setting the curing agent content below the upper limit, appropriate fluidity is maintained, and curing becomes easier.

[0036] [Coupling agent] The sealing resin composition may include, for example, a coupling agent. As the coupling agent, known coupling agents such as various silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane, as well as titanium compounds, aluminum chelates, and aluminum / zirconium compounds can be used. More specifically, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropylmethyldimethoxysilane, γ-[bis(β-hydroxyethyl)]aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl) Silane coupling agents such as -γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-(β-aminoethyl)aminopropyldimethoxymethylsilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3-isocyanatetopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and hydrolysates of 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine;Examples of titanate coupling agents include isopropyl triisostearoyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl) phosphite titanate, bis(dioctyl pyrophosphate) oxyacetate titanate, bis(dioctyl pyrophosphate) ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacrylate isostearoyl titanate, isopropyl toridodecylbenzenesulfonyl titanate, isopropyl isostearoyl diacrylic titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, and tetraisopropyl bis(dioctyl phosphite) titanate. These may be used individually or in combination of two or more types.

[0037] The content of the coupling agent in the encapsulating resin composition is not particularly limited, but is preferably 0.05% by mass or more and 3% by mass or less, and more preferably 0.1% by mass or more and 2% by mass or less, relative to the entire encapsulating resin composition. By setting the content of the coupling agent to be above the lower limit, the dispersibility of the inorganic filler in the encapsulating resin composition can be improved. Furthermore, by setting the content of the coupling agent to be below the upper limit, the fluidity of the encapsulating resin composition can be improved, thereby improving moldability.

[0038] Furthermore, in addition to the above components, the sealing resin composition of this embodiment may also contain various additives such as: colorants such as carbon black; release agents such as natural waxes, synthetic waxes, higher fatty acids or their metal salts, paraffin, and polyethylene oxide; ion scavenging agents such as hydrotalcite; stress-reducing agents such as silicone oil and silicone rubber; flame retardants such as aluminum hydroxide; and antioxidants.

[0039] [Thermoplastic resin] When the sealing resin composition of the sealing resin 20 is a thermoplastic resin composition, the thermoplastic resin included is not particularly limited, but examples include one or more selected from polyamide resins such as nylon 6 and nylon 66, polyolefin resins such as polyester and polypropylene, polyphenylene sulfide resin, polyacetal resin, polyetheretherimide resin, polybutylene terephthalate resin, polyetherimide resin, polyamideimide resin, polyethersulfone resin, and engineering plastics. In particular, engineering plastics are preferred. Examples of engineering plastics include one or more selected from the group consisting of polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), syndiotactic polystyrene (SPS), or polyamide (PA).

[0040] Even if the sealing resin composition of the sealing resin 20 includes a thermoplastic resin, according to the sealing resin 20 of this embodiment, sealing can be achieved at low temperatures, thus maintaining a good appearance and reliability of the cooling unit 10.

[0041] <Effects of Cooling System 100> The effects of the cooling system 100 with the above configuration can be summarized as follows: The cooling system 100 of this embodiment provides the following effects. (1) Heat conduction can be carried out throughout the entire pipe 30. (2) The shape and arrangement of the pipes 30 enable uniform cooling. (3) Compared to the case where the electrical component 9, which is the object to be cooled (heat-generating element), and the pipe 30 are joined by welding, the number of man-hours is reduced. (4) Compared to joining the electrical components 9 and the pipe 30 using die-cast aluminum alloy or the like, this method is less expensive and lighter. (5) Complex shapes and arrangements of the pipes 30, as shown in Figure 4, are possible, and even relatively complex shapes can be achieved in a single sealing process.

[0042] The differences in features between the six comparative structures (a) to (e) and this embodiment will be explained. Comparative structures (a) to (c) describe a comparison of the mounting structure of the refrigerant pipe (corresponding to pipe 30), and will be explained with reference to the comparative structure in Figure 5. Comparative structures (d) to (e) are comparative structures of the water-cooled structure. Comparative structure (a): The cooling section 110 shown in Figure 5(a) has a structure in which a pipe 130 is welded to a metal case 120. The joint is made by a weld structure using a welding point 125 or a welding line 126. In this structure, the welding point 125 and the welding line 126 have high thermal conductivity. Also, uniform cooling can be achieved with the design of the pipe 130. On the other hand, the parts that contribute to heat conduction are the welding point 125 and the welding line 126, and heat conduction does not occur in the other parts, so the entire pipe cannot be used effectively. Comparative structure (b): The cooling unit 210 shown in Figure 5(b) has a structure in which a refrigerant space 230 (sealed box) is formed in a metal case 220. As shown in the figure, this structure has the advantage of a large heat transfer area, but it cannot cool only the area near the input or cool a specific area intensively. In addition, it is necessary to ensure the pressure resistance of the refrigerant space 23, which tends to increase the weight. Furthermore, welding of the refrigerant space 230 (sealed box) is required, making the work time-consuming. Comparative structure (c): The cooling section 310 shown in Figure 5(c) has a structure in which the outer circumference of the pipe 330 is embedded in a casting 320 such as an aluminum die-cast. In this structure, heat can be conducted across the entire surface of the pipe 330, uniform cooling can be achieved with the design of the pipe 330, and complex pipe designs are also possible. On the other hand, castings are more expensive and heavier. Comparative structure (d): This is the case where cooling water is circulated in the cooling unit 10 shown in Figure 2. For example, the temperature of cooling water for automobiles is generally around 65°C. On the other hand, when a heat pump is applied as in the present invention, the temperature of the heat transfer medium 8 can be reduced to 15°C or lower. This is because a larger temperature difference ΔT can be taken with the heat-generating electrical component 9, thereby enabling more aggressive cooling. Comparative structure (e): This is a case where a molded channel is created in which the sealing resin itself forms the channel wall without using pipes. In this case, only essentially straight channels are possible with a single resin molding, and complex channels require a separate lid component for the planar structure. Also, because the sealing resin itself forms the channel wall, if cracks occur in the sealing resin, the risk of heat transfer fluid leakage increases.

[0043] <Features of Cooling System 100> The features of the cooling system 100 of this embodiment can be summarized as follows: 1. Condenser 3 and, Expansion valve 4 and A cooling unit 10 that is cooled by a heat transfer medium 8, Compressor 2 and It has, The cooling unit 10 includes a pipe 30 through which the heat transfer medium 8 flows and a sealing resin 20 that seals the pipe 30. A cooling system 100 in which the sealing resin 20 has a thermal conductivity of 0.7 W / m·K or more. 2. The cooling system 100 according to 1, wherein the distance from the upper end 35 of the pipe 30 to the upper surface 21 of the sealing resin 20 is 0.5 mm or more and 5 mm or less. 3. The sealing resin 20 is a thermosetting resin, The aforementioned thermosetting resin is Epoxy resin and Hardener and Inorganic fillers and The cooling system 100 described in 1. or 2., including the cooling system described in 1. or 2. 4. The cooling system 100 according to 3, wherein the content of the inorganic filler is 50% by mass or more and 90% by mass or less relative to the sealing resin. 5. The cooling system 100 according to 3., wherein the epoxy resin comprises at least one selected from the group consisting of bisphenol-type epoxy resin, novolac-type epoxy resin, biphenyl-type epoxy resin, stilbene-type epoxy resin, polyfunctional epoxy resin, phenol aralkyl-type epoxy resin, and naphthol-type epoxy resin. 6. The cooling system 100 according to 3., wherein the inorganic filler includes one selected from the group consisting of silica, alumina, aluminum hydroxide, silicon nitride, and aluminum nitride. 7. The cooling system 100 according to 1. or 2., wherein the surface roughness Ra of the outer surface of the pipe 30, measured in accordance with JIS B0601, is 10 μm or more and 100 μm or less.

[0044] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted. Furthermore, the present invention is not limited to the embodiments described above, and modifications, improvements, etc., within the scope that can achieve the objectives of the present invention are included in the present invention. [Explanation of Symbols]

[0045] 1. Electrical equipment 2 Compressor 3. Condenser 4. Expansion valve 8 Heat medium 9. Electrical components 10 Cooling section 20 Sealing resin 30 pipes 31 Pipe body 32 Introduction 33 Discharge section 100 Cooling System

Claims

1. Condenser and, Expansion valve and, A cooling unit that is cooled by a heat transfer medium, Compressor and, It has, The cooling unit includes a pipe through which the heat transfer medium flows and a sealing resin that seals the pipe. A cooling system in which the thermal conductivity of the sealing resin is 0.7 W / m·K or higher.

2. The cooling system according to claim 1, wherein the distance from the upper end of the pipe to the upper surface of the sealing resin is 0.5 mm or more and 5 mm or less.

3. The sealing resin is a thermosetting resin, The aforementioned thermosetting resin is Epoxy resin and Hardener and Inorganic fillers and A cooling system according to claim 1 or 2, comprising:

4. The cooling system according to claim 3, wherein the content of the inorganic filler is 50% by mass or more and 90% by mass or less relative to the sealing resin.

5. The cooling system according to claim 3, wherein the epoxy resin comprises at least one selected from the group consisting of biphenyl-type epoxy resin, bisphenol-type epoxy resin, stilbene-type epoxy resin, novolac-type epoxy resin, polyfunctional epoxy resin, phenol aralkyl-type epoxy resin, and naphthol-type epoxy resin.

6. The cooling system according to claim 3, wherein the inorganic filler includes one selected from the group consisting of silica, alumina, aluminum hydroxide, silicon nitride, and aluminum nitride.

7. The cooling system according to claim 1 or 2, wherein the surface roughness Ra of the outer surface of the pipe, as measured in accordance with JIS B0601, is 10 μm or more and 100 μm or less.

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