Electric power conversion apparatus

Abstract

This electric power conversion apparatus is provided with an electric power unit (20). The electric power unit (20) includes: a substrate (21) having a first surface (21A) and a second surface (21B); a first heat dissipation member (22) having a third surface (22A) that is thermally connected to the first surface (21A); and a first heat transport member (23) that includes a first portion (23A) disposed inside the first heat dissipation member (22) and a second portion (23B) connected to the first portion (23A) and disposed outside the first heat dissipation member (22), and that is provided so as to transport heat from the first portion (23A) to the second portion (23B). The first surface (21A) of the substrate (21) has a first electronic component mounted thereon. The first portion (23A) of the first heat transport member (23) is thermally connected to the first electronic component via the first heat dissipation member (22).

Description

Power Conversion Device

[0001] The present disclosure relates to a power conversion device.

[0002] In recent years, with the increasing demand for miniaturization and higher output of power conversion devices, the heat density of electronic components (circuit components) mounted in the power conversion devices has been increasing. In order to prevent the temperature of the electronic components from exceeding an allowable temperature due to heat generation, there is a strong demand for improving the heat dissipation performance of the power conversion device. In other words, in order to realize miniaturization and higher output of the power conversion device, it is necessary to improve the heat dissipation performance of the power conversion device.

[0003] Generally, a power conversion device includes a heat dissipation member (cooler) for dissipating heat generated in the electronic components to the outside in order to suppress a rise in temperature of the electronic components.

[0004] The power conversion device described in Patent No. 6158051 (Patent Document 1) comprises a heat dissipation base having a base portion with one side facing a flow path of a cooling refrigerant and a standing portion formed on the other side of the base portion opposite the one side, and a power supply circuit mounted on the standing portion of the heat dissipation base.

[0005] Patent No. 6158051

[0006] However, in the power conversion device described in Patent Document 1, electronic components that generate a large amount of heat need to be mounted near the region of the standing section that is connected to the base section, because with the heat dissipation base described in Patent Document 1, the further away from the base section the electronic components are mounted on the standing section, the lower the heat dissipation performance for the electronic components.

[0007] Therefore, in the power conversion device described in Patent Document 1, in order to achieve high output, it is necessary to provide a long connection region of the upright portion connected to the base portion in order to mount a large number of electronic components that generate a large amount of heat near the base portion, making it difficult to achieve a compact power conversion device. Also, even when mounting a relatively large electronic component that generates a large amount of heat (e.g., a relatively large package including a large number of electronic components) near the base portion, it is necessary to provide a long connection region so that the longitudinal direction of the electronic component is aligned with the connection region.

[0008] A primary object of the present disclosure is to provide a power conversion device that can achieve both miniaturization and high output.

[0009] A power conversion device according to the present disclosure includes at least one power unit. The at least one power unit includes a substrate having a first surface and a second surface opposite the first surface, a first heat dissipation member having a third surface thermally connected to the first surface or the second surface, and at least one first heat transfer member including a first portion disposed inside the first heat dissipation member and a second portion connected to the first portion and disposed outside the first heat dissipation member, the first portion being configured to transfer heat from the first portion to the second portion. At least one first electronic component is mounted on at least one of the first surface and the second surface of the substrate. The first portion of the at least one first heat transfer member is thermally connected to the at least one first electronic component via the first heat dissipation member.

[0010] According to the present disclosure, it is possible to provide a power conversion device that can achieve both miniaturization and high output.

[0011] 6 is a circuit diagram illustrating an example of a power supply circuit in a power conversion device according to an embodiment of the present disclosure. FIG. 1 is a perspective view illustrating an example of a power unit and a cooler included in a power conversion device according to a first embodiment of the present disclosure. FIG. 12 is a plan view illustrating an example of a wiring pattern formed on a substrate of the power conversion device shown in FIG. 2 and constituting a part of the power supply circuit shown in FIG. 1. FIG. 13 is an exploded perspective view of a power unit of the power conversion device shown in FIG. 2. FIG. 14 is a front view of a power unit of the power conversion device shown in FIG. 2. FIG. 15 is a perspective view of a transformer included in the power unit of the power conversion device shown in FIG. 2. FIG. 16 is a cross-sectional view taken along line VII-VII in FIG. 6. FIG. 17 is a perspective view illustrating an example of a power unit included in a power conversion device according to a second embodiment. FIG. 18 is an exploded perspective view of a power unit of the power conversion device shown in FIG. 8. FIG. 19 is a cross-sectional view of a power unit of the power conversion device shown in FIG. 8. FIG. 19 is a circuit diagram illustrating an example of a plurality of power supply circuits in a power conversion device according to a third embodiment. FIG. 20 is a perspective view illustrating an example of a power unit and a cooler included in a power conversion device according to the third embodiment. FIG. 21 is an exploded perspective view of the power unit shown in FIG. 2. FIG. 22 is a side view for explaining the structure of the power unit shown in FIG. 12 and the connection structure between the power unit and the cooler. FIG. 23 is a cross-sectional view of the power unit shown in FIG. 12. 21. A perspective view illustrating an example of a plurality of power units, a cooler, and a housing included in a power conversion apparatus according to a third embodiment, the perspective view showing a state in which a side panel of the housing is open. 16. A perspective view of the housing shown in FIG. 16 viewed from a direction different from that of FIG. 16. 17. An exploded perspective view illustrating an example of a power unit included in a power conversion apparatus according to a fourth embodiment. 18. A cross-sectional view of the power unit shown in FIG. 18. 19. A cross-sectional view of a first modified example of a power unit included in a power conversion apparatus according to the fourth embodiment. 20. An exploded perspective view of a power unit included in a power conversion apparatus according to a sixth embodiment. 21. A cross-sectional view taken along line XXIV-XXIV in FIG. 23. 22. A perspective view illustrating a modified example of a cooler included in a power conversion apparatus according to the fifth embodiment. 23. An oblique view showing an example of a power unit included in a power conversion apparatus according to a sixth embodiment.Fig. 10 is an exploded perspective view for explaining a first modified example of a power unit included in a power conversion device according to embodiment 6. Fig. 11 is an exploded perspective view for explaining a second modified example of a power unit included in a power conversion device according to embodiment 6. Fig. 12 is a perspective view for explaining an example of a plurality of power units, a cooler, and a housing included in a power conversion device according to embodiment 6, showing a state in which a side plate of the housing is open.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following, the same or corresponding parts will be denoted by the same reference numerals, and redundant description will not be repeated.

[0013] <Configuration of Power Conversion Device and Power Supply Circuit> A power conversion device according to an embodiment of the present disclosure includes a power supply circuit. The power supply circuit is, for example, a DC-DC converter. Fig. 1 shows an example of a circuit diagram of a DC-DC converter.

[0014] The power conversion device according to the embodiment of the present disclosure is not particularly limited in its application, but may be used in, for example, an electric vehicle. The DC-DC converter converts the input voltage of a lithium-ion battery, for example, from about 100 V to about 300 V, to a voltage of about 12 V to about 15 V, and outputs the converted voltage to charge a lead-acid battery.

[0015] 1, the DC-DC converter as a power supply circuit 1 includes an input terminal 2, an input capacitor 3, an inverter circuit section 4, a transformer section 5, a rectifier circuit section 6, a smoothing circuit section 7, a control circuit section 8, and an output terminal 9. The inverter circuit section 4 and a part of the transformer section 5 constitute a primary side circuit, and the remaining part of the transformer section 5, the rectifier circuit section 6, and the smoothing circuit section 7 constitute a secondary circuit having an operating voltage different from that of the primary side circuit.

[0016] The inverter circuit unit 4 is composed of four switching elements 10a, 10b, 10c, and 10d. The switching operations of the four switching elements 10a, 10b, 10c, and 10d are controlled by the control circuit unit 8. Each of the switching elements 10a, 10b, 10c, and 10d is a power semiconductor element such as a metal oxide semiconductor field effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). The semiconductor material constituting each of the switching elements 10a, 10b, 10c, and 10d is not particularly limited, but may include, for example, silicon carbide (SiC).

[0017] The transformer unit 5 is composed of two transformers 11a and 11b, each having a primary winding 111 and a secondary winding 112. The rectifier circuit unit 6 is composed of four rectifier elements 12a, 12b, 12c, and 12d. Each of the rectifier elements 12a, 12b, 12c, and 12d is a power semiconductor element such as a diode, a MOS transistor, or a thyristor. The smoothing circuit unit 7 is composed of a smoothing reactor 13 and a smoothing capacitor 14.

[0018] In the DC-DC converter serving as the power supply circuit 1, the DC voltage input from the input terminal 2 is converted into an AC voltage by controlling the switching operation of each of the four switching elements 10a, 10b, 10c, and 10d in the inverter circuit unit 4 using a control circuit unit 8. In the transformer unit 5, the AC voltage converted in the inverter circuit unit 4 is converted into a desired voltage by transformers 11a and 11b. The converted voltage is determined by the turns ratio between the primary winding unit 111 and the secondary winding unit 112 in the transformers 11a and 11b. The transformers 11a and 11b electrically insulate the input terminal 2 from the output terminal 9.

[0019] In the rectifier circuit 6, the AC voltage supplied from the transformer 5 is converted back to DC voltage by four rectifier elements 12a, 12b, 12c, and 12d. In the smoothing circuit 7, the DC voltage converted by the rectifier circuit 6 is smoothed by a smoothing reactor 13 and a smoothing capacitor 14. This stabilizes the output voltage output from the output terminal 9. One potential of the smoothing capacitor 14 is used as the reference potential of the power conversion device.

[0020] 1, the power supply circuit 1 includes semiconductor elements, such as switching elements 10a, 10b, 10c, and 10d, rectifying elements 12a to 12d, transformers 11a and 11b, and smoothing reactor 13, which generate a relatively large amount of heat. Therefore, a power conversion device according to an embodiment of the present disclosure that includes power supply circuit 1 includes a heat dissipation unit that dissipates heat generated by at least one electronic component (first electronic component) among switching elements 10a, 10b, 10c, and 10d, rectifying elements 12a to 12d, transformers 11a and 11b, and smoothing reactor 13, and keeps the temperature of the first electronic component below its allowable temperature. The allowable temperature of each of the above-mentioned electronic components is, for example, 100°C or higher and 120°C or lower.

[0021] In the following first to fourth embodiments, the heat dissipation section of the power conversion device according to the embodiments of the present disclosure will be specifically described.

[0022] 2 to 5, a power conversion device according to a first embodiment includes a power unit 20 and a cooler 30. The power unit 20 includes a substrate 21, a first heat dissipation member 22, a plurality of first heat transfer members 23, a thermally conductive member 24, and a positioning member 25.

[0023] The substrate 21 is a wiring substrate that constitutes at least a part of the power supply circuit 1. The substrate 21 has a first surface 21A and a second surface 21B located on the opposite side of the first surface 21A. For ease of explanation, hereinafter, a direction along the first surface 21A will be referred to as a first direction DR1. A direction along the first surface 21A and perpendicular to the first direction will be referred to as a second direction DR2. A direction perpendicular to the first surface 21A will be referred to as a third direction DR3.

[0024] The transformers 11a and 11b are mounted on the first surface 21A. The switching elements 10a, 10b, 10c, and 10d, the rectifying elements 12a to 12d, and the smoothing reactor 13 are mounted on the second surface 21B. For example, an input capacitor 3 and a smoothing capacitor 14 are also mounted on the second surface 21B. The capacitance of the input capacitor 3 and the smoothing capacitor 14 is preferably several tens of microfarads or more from the viewpoint of smoothing the input voltage or the output voltage. The input capacitor 3 and the smoothing capacitor 14 are, for example, electrolytic capacitors.

[0025] The substrate 21 further has a wiring pattern that electrically connects the electronic components in the power supply circuit 1. The wiring pattern is formed, for example, on each of the first surface 21A and the second surface 21B. The substrate 21 is, for example, a glass composite substrate, a glass epoxy substrate, or a halogen-free substrate. The material that constitutes the wiring pattern may be any conductive material, such as copper.

[0026] 3, the substrate 21 has a first wiring pattern 15 that electrically connects the inverter circuit unit 4 and the primary windings 111 of the transformers 11a and 11b of the transformer unit 5, and a second wiring pattern 16 that electrically connects the rectifier circuit unit 6 and the secondary windings 112 of the transformers 11a and 11b. Each of the first wiring pattern 15 and the second wiring pattern 16 has, for example, a portion formed on the first surface 21A of the substrate 21, a portion formed on the second surface 21B, and a portion formed in a through hole that penetrates between the first surface 21A and the second surface 21B and electrically connects the two portions. The switching elements 10a, 10b, 10c, and 10d included in the inverter circuit unit 4 are arranged on one side of the transformers 11a and 11b, and the rectifying elements 12a, 12b, 12c, and 12d included in the rectifying circuit unit 6 are arranged on the opposite side of the transformers 11a and 11b from the switching elements 10a, 10b, 10c, and 10d. The switching elements 10a, 10b, 10c, and 10d are arranged side by side in the first direction DR1. The rectifying elements 12a, 12b, 12c, and 12d are arranged side by side in the first direction DR1. The first wiring pattern 15 has, for example, a portion arranged between the switching elements 10a and 10b in the first direction DR1 and a portion arranged between the switching elements 10c and 10d in the first direction DR1. The second wiring pattern 16 has, for example, a portion arranged between the rectifying elements 12a and 12b in the first direction DR1, and a portion arranged between the rectifying elements 12c and 12d in the first direction DR1.

[0027] Preferably, each of the first wiring pattern 15 and the second wiring pattern 16 is designed to be wide so as to have low electrical resistance and not generate excessive Joule heat when conductive. Preferably, each of the first wiring pattern 15 and the second wiring pattern 16 is designed to be short in length and have a loop-shaped planar shape so as to reduce parasitic inductance. Furthermore, each of the first wiring pattern 15 and the second wiring pattern 16 is designed so that the distance between them (insulation distance) satisfies various safety standards.

[0028] The substrate 21 is positioned relative to the first heat dissipation member 22 by a plurality of positioning members 25 .

[0029] The first heat dissipation member 22 has a third surface 22A thermally connected to the first surface 21A and a fourth surface 22B located on the opposite side of the third surface. The third surface 22A is, for example, parallel to the first surface 21A. The third surface 22A is thermally connected to the first surface 21A via, for example, a thermally conductive member 24. The third surface 22A may be in contact with the first surface 21A. The material constituting the first heat dissipation member 22 may be any material with high thermal conductivity, including, for example, aluminum (Al). The thermal conductivity of the first heat dissipation member 22 is 1.0 W / (m·K) or more, preferably 10.0 W / (m·K) or more, and more preferably 100.0 W / (m·K) or more. The first heat dissipation member 22 is, for example, an extruded material.

[0030] 2 to 4, a groove 221 is formed in the third surface 22A of the first heat dissipation member 22. The groove 221 has a pair of side surfaces 221A and a bottom surface 221B. The pair of side surfaces 221A are connected to the third surface 22A. Each of the pair of side surfaces 221A is, for example, perpendicular to the third surface 22A. The bottom surface 221B is, for example, parallel to the third surface 22A.

[0031] 2 to 4, a plurality of grooves 221 may be formed at intervals in the second direction DR2 on the third surface 22A of the first heat dissipation member 22. The depths of the plurality of grooves 221 may be equal to or different from one another. The grooves 221 are formed to extend, for example, from one end face to the other end face of the first heat dissipation member 22 in the first direction DR1.

[0032] At least a portion of the transformers 11a and 11b is housed inside the groove 221. For example, the entire transformers 11a and 11b and a portion of the thermally conductive member 24 are housed inside the groove 221. A pair of side surfaces 221A and a bottom surface 221B of the groove 221 are thermally connected to the transformers 11a and 11b via the thermally conductive member 24. The pair of side surfaces 221A are thermally connected to, for example, the outer peripheral surfaces of the cores of the transformers 11a and 11b. As shown in FIG. 4 , the bottom surface 221B is thermally connected to, for example, the spacers 113 of the transformers 11a and 11b.

[0033] The multiple first heat transfer members are separate from the first heat dissipation member 22. The thermal conductivity of each of the multiple first heat transfer members 23 is higher than that of the first heat dissipation member 22. The thermal conductivity of each of the multiple first heat transfer members 23 is 10.0 W / (m·K) or higher, preferably 100.0 W / (m·K) or higher, and more preferably 1000.0 W / (m·K) or higher. Each of the multiple first heat transfer members 23 includes a first portion 23A disposed inside the first heat dissipation member 22 and a second portion 23B connected to the first portion 23A and disposed outside the first heat dissipation member 22. Each of the multiple first heat transfer members 23 is configured to transport heat from the first portion 23A to the second portion 23B. At least a portion of the first portion 23A of each of the multiple first heat transfer members 23 extends parallel to the third surface 22A. At least a portion of the first portions 23A of each of the multiple first heat transfer members 23 are spaced apart from one another in the second direction DR2. At least a portion of the first portions 23A of each of the multiple first heat transfer members 23 extend parallel to one another along, for example, the first direction DR1. At least a portion of the second portions 23B of each of the multiple first heat transfer members 23 extend parallel to one another along, for example, the third direction DR3. Each of the multiple first heat transfer members 23 has, for example, a bent portion between the first portion 23A and the second portion 23B.

[0034] Each of the plurality of first heat transfer members 23 is, for example, a heat pipe. In the heat pipe, the refrigerant vaporizes in the first portion 23A by absorbing heat from the first heat dissipation member 22, and liquefies in the second portion 23B by dissipating heat to the outside of the first heat dissipation member 22. As a result, the refrigerant circulates within the heat pipe due to capillary action. The second portion 23B of each of the plurality of first heat transfer members 23 is thermally connected to the cooler 30.

[0035] The cross-sectional shape of each of the first heat transfer members 23 perpendicular to the extension direction is, for example, a circular shape. Note that the cross-sectional shape of each of the first heat transfer members 23 perpendicular to the extension direction may be any shape, such as an ellipse or a rectangle.

[0036] Furthermore, each of the plurality of first heat transfer members 23 may have any configuration that can transfer heat from the first heat dissipation member 22 to the outside of the first heat dissipation member 22. Each of the plurality of first heat transfer members 23 may be provided to form a flow path through which cooling water flows, or may include a graphite sheet made of graphite having a layered crystal structure.

[0037] The multiple first heat transfer members 23 include a first first heat transfer member 231 (hereinafter also simply referred to as the first heat transfer member 231), a second first heat transfer member 232 (hereinafter also simply referred to as the first heat transfer member 232), and a third first heat transfer member 233 (hereinafter also simply referred to as the first heat transfer member 233).

[0038] The first portion 231A of the first heat transfer member 231 extends along the side surface 221A of the groove portion 221. At least a portion of the first portion 231A of the first heat transfer member 231 is arranged to overlap the side surface 221A and the transformers 11a and 11b in a direction perpendicular to the side surface 221A (e.g., the second direction DR2). At least a portion of the first portion 231A of the first heat transfer member 231 is arranged to overlap the third surface 22A, the substrate 21, and the switching elements 10a, 10b, 10c, and 10d in the third direction DR3. Furthermore, at least a portion of the first portion 231A of the first heat transfer member 231 is arranged to overlap the portion of the first wiring pattern 15 located between the switching elements 10a and 10b in the third direction DR3 and the portion located between the switching elements 10c and 10d in the first direction DR1.

[0039] Preferably, the center of the first portion 231A of the first heat transfer member 231 is arranged so as to overlap with the side surface 221A and the transformers 11a and 11b in a direction perpendicular to the side surface 221A, and is arranged so as to overlap with each of the third surface 22A, the substrate 21, and the switching elements 10a, 10b, 10c, and 10d in the third direction DR3. More preferably, the entire first portion 231A of the first heat transfer member 231 is arranged so as to overlap with the side surface 221A and the transformers 11a and 11b in a direction perpendicular to the side surface 221A, and is arranged so as to overlap with each of the third surface 22A, the substrate 21, and the switching elements 10a, 10b, 10c, and 10d in the third direction DR3.

[0040] The first portion 232A of the first heat transfer member 232 extends along the side surface 221A of the groove portion 221. At least a portion of the first portion 232A of the first heat transfer member 232 is arranged to overlap the side surface 221A and the transformers 11a and 11b in a direction perpendicular to the side surface 221A (e.g., the second direction DR2). At least a portion of the first portion 232A of the first heat transfer member 232 is arranged to overlap each of the rectifying elements 12a, 12b, 12c, and 12d in the third direction DR3. Furthermore, at least a portion of the first portion 232A of the first heat transfer member 232 is arranged to overlap, in the third direction DR3, with a portion of the second wiring pattern 16 that is disposed between the rectifying elements 12a and 12b in the first direction DR1 and a portion that is disposed between the rectifying elements 12c and 12d in the first direction DR1. The first heat transfer member 231 and the first heat transfer member 232 are arranged to sandwich the groove portion 221 and the transformers 11a and 11b in the third direction DR3.

[0041] Preferably, the center of the first portion 232A of the first heat transfer member 232 is arranged so as to overlap with the side surface 221A and the transformers 11a and 11b in the direction perpendicular to the side surface 221A, and is arranged so as to overlap with each of the third surface 22A, the substrate 21, and the rectifying elements 12a, 12b, 12c, and 12d in the third direction DR3. More preferably, the entire first portion 232A of the first heat transfer member 232 is arranged so as to overlap with the side surface 221A and the transformers 11a and 11b in the direction perpendicular to the side surface 221A, and is arranged so as to overlap with each of the third surface 22A, the substrate 21, and the rectifying elements 12a, 12b, 12c, and 12d in the third direction DR3.

[0042] The first portion 233A of the first heat transfer member 233 extends along the bottom surface 221B of the groove portion 221. At least a part of the first portion 232A of the first heat transfer member 232 is disposed so as to overlap with each of the bottom surface 221B, the transformer 11a, and the transformer 11b in a direction perpendicular to the bottom surface 221B (e.g., the third direction DR3).

[0043] Preferably, the center of the first portion 233A of the first heat transfer member 233 is arranged to overlap with each of the bottom surface 221B, the transformer 11a, and the transformer 11b in a direction perpendicular to the bottom surface 221B. More preferably, the entire first portion 233A of the first heat transfer member 233 is arranged to overlap with each of the bottom surface 221B, the transformer 11a, and the transformer 11b in a direction perpendicular to the bottom surface 221B.

[0044] The first portion 231A of the first heat transfer member 231, the first portion 232A of the first heat transfer member 232, and the first portion 233A of the first heat transfer member 233 are thermally connected to the transformers 11a and 11b via the first heat dissipation member 22 and the thermally conductive member 24. The first portion 231A of the first heat transfer member 231, the first portion 232A of the first heat transfer member 232, and the first portion 233A of the first heat transfer member 233 are thermally connected to the transformers 11a and 11b without the substrate 21 being interposed therebetween.

[0045] The first portion 232A of the first heat transfer member 232 is thermally connected to each of the switching elements 10a, 10b, 10c, and 10d via the first heat dissipation member 22, the substrate 21, and the thermally conductive member 24. The first portion 233A of the first heat transfer member 233 is thermally connected to each of the rectifying elements 12a to 12d via the first heat dissipation member 22 and the thermally conductive member 24.

[0046] The thermally conductive member 24 has high thermal conductivity and electrical insulation. The thermal conductivity of the thermally conductive member 24 is preferably 0.1 W / (m·K) or more, more preferably 1.0 W / (m·K) or more, and even more preferably 10.0 W / (m·K) or more. The thermally conductive member 24 includes, for example, at least one selected from the group consisting of thermally conductive grease, a thermally conductive sheet, a thermally conductive adhesive, and a thermally conductive gap filler. The gap filler may be, for example, a one-component non-mixing type gap filler or a two-component mixing type gap filler.

[0047] The plurality of positioning members 25 position the substrate 21 and the first heat dissipation member 22, which are stacked with the thermally conductive member 24 sandwiched between them. The plurality of positioning members 25 includes, for example, a spacer portion spanning between the substrate 21 and the first heat dissipation member 22 and a fixing member such as a screw that fixes the substrate 21 and the first heat dissipation member 22 to the spacer portion. The plurality of positioning members 25 maintains the dimension (thickness) of the thermally conductive member 24 in the third direction DR3 constant regardless of its position in the first direction DR1 and the second direction DR2. As a result, the thermally conductive member 24 does not form regions with locally poor insulation performance (voltage resistance) and heat dissipation performance, thereby suppressing a decrease in the reliability of the power conversion device. For example, if the thickness of the thermally conductive member 24 is uneven, a thick region where the thermally conductive member 24 is locally thicker will have poorer heat dissipation performance than a thin region where the thermally conductive member 24 is thinner than the thick region, and hot spots are more likely to form. Therefore, cracks may occur in the soldered portions of the substrate 21 located on the thick regions of the thermally conductive member 24. In the power conversion device according to the present embodiment, the thickness of the thermally conductive member 24 is uniform, so that the above-mentioned cracks are less likely to form.

[0048] The plurality of positioning members 25 include, for example, a first positioning member 25 extending between the third surface 22A of the first heat dissipation member 22 and the substrate 21, and a second positioning member 25 extending between the bottom surface of the groove portion 221 of the first heat dissipation member 22 and the substrate 21. The material constituting each of the plurality of positioning members 25 is not particularly limited, and may include at least either a metal or a resin.

[0049] The cooler 30 is provided to cool the second portion 23B of each of the multiple first heat transfer members 23. The cooler 30 may have any structure capable of cooling the second portion 23B of each of the multiple first heat transfer members 23. The cooler 30 includes, for example, at least one cooling body 31 thermally connected to the second portions 231B, 232B, and 233B (see FIG. 5 ) of each of the multiple first heat transfer members 231, 232, and 233, and at least one fan 32 that blows air to the at least one cooling body 31. The cooling body 31 is forcedly air-cooled by the fan 32. The air blowing direction of the fan 32 is, for example, along the second direction DR2. The cooling body 31 may have an air tunnel and fins exposed within the air tunnel.

[0050] The cooler 30 is arranged side by side with the substrate 21 and the first heat dissipation member 22 in the first direction DR1. One of the transformers 11a, 11b is farther from the cooler 30 than the other. The transformer 11b is farther from the cooler 30 than the transformer 11a. The switching elements 10a, 10b, 10c, and 10d are arranged side by side from the cooler 30 side in the first direction DR1. The rectifying elements 12a, 12b, 12c, and 12d are arranged side by side from the cooler 30 side in the first direction DR1.

[0051] The configuration of the transformers 11a and 11b is not particularly limited. As shown in Figures 6 and 7, the transformers 11a and 11b have a core (EI core) structured by combining, for example, an E-type core 114 and an I-type core 115. Note that the transformers 11a and 11b may also have a structure in which two U-type cores are combined, a structure in which two E-type cores are combined, or a structure in which a T-type core and a U-type core are combined.

[0052] In the transformers 11a and 11b, the secondary winding portion 112 is wound around the primary winding portion 111, for example, so as to surround the primary winding portion 111. In this case, the transformers 11a and 11b may further include a U-shaped spacer 113 inserted between the primary winding portion 111 and the secondary winding portion 112. The spacer 113 is exposed, for example, on the side of the transformers 11a and 11b opposite to the terminal electrically connected to the substrate 21. In the power conversion device according to the first embodiment, the exposed surface of the spacer 113 may be thermally connected to the bottom surface 221B of the groove portion 221 via the thermally conductive member 24.

[0053] The core of each of the transformers 11a and 11b is, for example, a ferrite core such as a manganese zinc (Mn--Zn) ferrite core or a nickel zinc (Ni--Zn) ferrite core, an amorphous core, or an iron dust core.

[0054] The power unit 20 may further include a first heat transfer element having a first portion thermally connected to the input capacitor 3, and a first heat transfer element having a first portion thermally connected to the smoothing capacitor 14.

[0055] <Effects of the Power Conversion Device> The power conversion device according to the first embodiment includes a first heat transfer member 231 whose first portion 231A is thermally connected to each of the transformers 11a and 11b (first electronic components) via the first heat dissipation member 22. Therefore, heat generated in each of the transformers 11a and 11b is rapidly transferred to the second portion 231B of the first heat transfer member 231 via the first heat dissipation member 22 and the first portion 231A of the first heat transfer member 231, and can be released from the second portion 231B to the outside of the power conversion device by the cooler 30 or the like. Therefore, in the power conversion device, it is not necessary to arrange multiple electronic components that generate a large amount of heat, such as the transformers 11a and 11b, in the second direction DR2 along the edge of the substrate 21 that is closer to the cooler 30. Furthermore, even when a single electronic component that generates a large amount of heat (e.g., a relatively large package including multiple electronic components) is mounted on the substrate 21, it is not necessary to arrange the electronic component so that its longitudinal direction is aligned with the edge of the substrate 21 that is closer to the cooler 30. Therefore, the power conversion device according to the first embodiment can achieve both miniaturization and high output compared to the conventional power conversion device described above.

[0056] Specifically, in the power conversion device according to the first embodiment, the transformers 11a and 11b are arranged side by side in the first direction DR1. At least a portion of the first portion 231A of the first heat transfer member 231 extends along the first direction DR1 and is arranged so as to overlap with the first heat dissipation member 22 and each of the transformers 11a and 11b in the third direction DR3 orthogonal to the first surface. In the power conversion device having the above configuration, the heat dissipation performance for each of the transformers 11a and 11b is improved compared to a power conversion device not having the above configuration.

[0057] Furthermore, in the conventional power conversion device described above, the placement of electronic components that generate a large amount of heat is restricted, which increases the wiring path of the circuit including the electronic components, increasing parasitic inductance and potentially generating high switching surges. As a result, the conventional power conversion device described above requires high-voltage semiconductor elements and noise countermeasures, making it difficult to reduce the device size and manufacturing costs. In contrast, in the power conversion device according to embodiment 1, the placement of electronic components that generate a large amount of heat is not restricted by their distance from the cooler 30. Therefore, the transformers 11a and 11b, the switching elements 10a, 10b, 10c, and 10d, and the rectifying elements 12a, 12b, 12c, and 12d can be positioned as shown in FIG. 3 . This allows the power conversion device according to embodiment 1 to suppress increases in parasitic inductance and noise generation, while also enabling miniaturization and reduced manufacturing costs.

[0058] In the power conversion device according to the first embodiment, the power unit 20 and the cooler 30 are arranged side by side in the first direction DR1, so that the dimension of the power conversion device in the third direction DR3 can be reduced (reduced in height). In addition, in the cooler 30, the cooling body 31 and the fan 32 are arranged side by side in the second direction DR2, so that the dimension of the cooler 30 in the third direction DR3 can be reduced compared to when the cooling body 31 and the fan 32 are arranged side by side in the third direction DR3, and as a result, the dimension of the power conversion device in the third direction DR3 can be reduced.

[0059] Furthermore, in the power conversion device according to the first embodiment, a groove 221 is formed in the third surface 22A of the first heat dissipation member 22, and a pair of side surfaces 221A of the groove 221 are thermally connected to the side surfaces of the transformers 11a and 11b. At least a portion of the first portion 231A of the first heat transfer member 231 extends along the side surface 221A and is disposed so as to overlap with each of the transformers 11a and 11b and the side surface 221A in a direction perpendicular to the side surface 221A. Therefore, heat generated in the transformers 11a and 11b can be quickly conducted to the first portion 231A of the first heat transfer member 231 via the side surface and the side surface 221A of the groove 221 of the first heat dissipation member 22.

[0060] Furthermore, in the power conversion device according to the first embodiment, at least a portion of the first portion 231A of the first heat transfer member 231 is disposed so as to overlap with each of the switching elements 10a, 10b, 10c, and 10d (second electronic components) in the third direction DR3, and is thermally connected to each of the switching elements 10a, 10b, 10c, and 10d via the first heat dissipation member 22 and the substrate 21. In a power conversion device having the above configuration, the heat dissipation performance for each of the transformers 11a, 11b and the switching elements 10a, 10b, 10c, and 10d is improved compared to a power conversion device not having the above configuration. Furthermore, a power conversion device having the above configuration can be made smaller than a power conversion device in which the first heat transfer member, which is arranged so that at least a portion of the first part overlaps with each of the switching elements 10a, 10b, 10c, and 10d in the third direction DR3, is provided as a separate entity from the first heat transfer member, which is arranged so that at least a portion of the first part overlaps with each of the transformers 11a and 11b.

[0061] Similarly, in the power conversion device according to the first embodiment, at least a portion of the first portion 232A of the first heat transfer member 232 overlaps with each of the transformers 11a and 11b and the side surface 221A in a direction perpendicular to the side surface 221A, and is arranged to overlap with each of the rectifying elements 12a, 12b, 12c, and 12d in the third direction DR3. The first portion 232A of the first heat transfer member 232 is thermally connected to each of the transformers 11a and 11b via the first heat dissipation member 22, and is thermally connected to each of the rectifying elements 12a, 12b, 12c, and 12d via the first heat dissipation member 22 and the substrate 21. In a power conversion device having the above configuration, the heat dissipation performance for each of the transformers 11a and 11b and the rectifying elements 12a, 12b, 12c, and 12d is improved compared to a power conversion device not having the above configuration. Furthermore, a power conversion device having the above configuration can be made smaller than a power conversion device in which the first heat transfer member, which is arranged so that at least a portion of the first part overlaps with each of the rectifying elements 12a, 12b, 12c, and 12d in the third direction DR3, is provided as a separate entity from the first heat transfer member, which is arranged so that at least a portion of the first part overlaps with each of the transformers 11a and 11b.

[0062] Furthermore, in the power conversion device according to the first embodiment, the bottom surface 221B of the groove portion 221 is thermally connected to the transformers 11a and 11b. At least a part of the first portion 233A of the first heat transfer member 233 extends along the bottom surface 221B and is disposed so as to overlap with each of the transformers 11a and 11b and the bottom surface 221B in a direction perpendicular to the bottom surface 221B. In the power conversion device having the above configuration, the heat dissipation performance for each of the transformers 11a and 11b is improved compared to a power conversion device not having the first heat transfer member 233.

[0063] Furthermore, in the power conversion device according to the first embodiment, at least a portion of the first portion 231A of the first heat transfer member 231 is arranged to overlap, in the third direction DR3, a portion of the first wiring pattern 15 that electrically connects the first heat transfer member 231 to the primary windings 111 of the transformers 11a and 11b. Similarly, at least a portion of the first portion 232A of the first heat transfer member 232 is arranged to overlap, in the third direction DR3, a portion of the second wiring pattern 16 that electrically connects the rectifier circuit unit 6 to the secondary windings 112 of the transformers 11a and 11b. Therefore, Joule heat generated in the first wiring pattern 15 and the second wiring pattern 16 can also be rapidly conducted to the first portions 231A and 232A of the first heat transfer members 231 and 232 via the first heat dissipation member 22. That is, in the power conversion device according to the first embodiment, the heat dissipation performance for the first wiring pattern 15 and the second wiring pattern 16 is also improved to the same level as the heat dissipation performance for the transformers 11a, 11b, etc.

[0064] 2 to 5 include a plurality of first heat transfer members thermally connected to each of the switching elements 10a, 10b, 10c, and 10d, the rectifying elements 12a to 12d, and the transformers 11a and 11b, but are not limited thereto. The power conversion device according to the embodiment of the present disclosure may include at least one first heat transfer member thermally connected to at least one electronic component that generates a relatively large amount of heat. From a different perspective, in the power conversion device according to the embodiment of the present disclosure, the first electronic component thermally connected to the first portion of the at least one first heat transfer member may be at least one of the transformers 11a and 11b, the switching elements 10a, 10b, 10c, and 10d, the rectifying elements 12a to 12d, and the smoothing reactor 13.

[0065] In the power conversion device according to the first embodiment, the arrangement of the electronic components and the arrangement of the at least one first heat transfer member 23 are not particularly limited, as long as at least one first heat transfer member is thermally connected to at least one electronic component that generates a relatively large amount of heat. At least one first heat transfer member 23 may be thermally connected to various types of electronic components. Furthermore, multiple electronic components of the same type may each be thermally connected to a different first heat transfer member. For example, one first heat transfer member 23 may be thermally connected to the transformer 11a and the switching element 10a, and another first heat transfer member 23 may be thermally connected to the transformer 11b and the switching element 10b.

[0066] At least one first heat transfer member may be thermally connected to an electronic component that generates a relatively small amount of heat. For example, the first heat transfer member 231 may be thermally connected to the input capacitor 3 in addition to the switching elements 10a, 10b, 10c, and 10d, the transformers 11a and 11b, and the first wiring pattern 15. Preferably, the electronic component that generates a relatively large amount of heat is thermally connected to a region of the first portion of the first heat transfer member that is closer to the second portion than the electronic component that generates a relatively small amount of heat.

[0067] 2 to 5, the first portion 231A of the first heat transfer member 231 extends linearly along the first direction DR1, but is not limited to this. The first portion 231A may have, for example, a bent shape, such as a U-shape, an L-shape, or a serpentine shape.

[0068] 2 to 5, the transformer unit 5 of the power supply circuit 1 includes two transformers 11a and 11b, but the number of transformers included in the transformer unit 5 is not limited to two. The number of transformers included in the transformer unit 5 may be one. When one transformer has a longitudinal direction and a lateral direction as viewed from the third direction DR3, the longitudinal direction of the one transformer is arranged along the first direction DR1, and the lateral direction of the one transformer is arranged along the second direction DR2. Such a power conversion device can also achieve both compactness and high output compared to the conventional power conversion device described above.

[0069] The groove 221 may be formed in at least a portion of the first heat dissipation member 22 between one end surface and the other end surface in the first direction DR1, as long as the groove 221 can accommodate at least a portion of each of the transformers 11 a and 11 b.

[0070] 8 to 10, unless otherwise specified, the power conversion device according to the second embodiment has the same configuration and effects as those of the first embodiment. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

[0071] As shown in Figures 8 to 10, in the power unit 20 of the power conversion device of embodiment 2, at least a portion of the transformers 11a and 11b are arranged on the second surface 21B together with the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d.

[0072] Each of the transformers 11a and 11b has a portion arranged on the first surface 21A, a portion arranged on the second surface 21B, and a portion inserted into a through hole that passes through between the first surface 21A and the second surface 21B.

[0073] Each of the transformers 11a and 11b has a structure combining, for example, an E-shaped core and an I-shaped core. In this case, for example, a portion of the E-shaped core is disposed on the first surface 21A, and the I-shaped core is disposed on the second surface 21B. The legs of the E-shaped core are inserted into through-holes formed in the substrate 21 so as to penetrate between the first surface 21A and the second surface 21B. As shown in FIG. 9 , the transformer 11b has a portion 11b1 disposed on the first surface 21A and a portion 11b2 disposed on the second surface 21B. The primary winding 111 and the secondary winding 112 of each of the transformers 11a and 11b are formed as wiring patterns on, for example, the second surface 21B of the substrate 21.

[0074] 9 and 10 , a groove 221 for accommodating the portion of each of the transformers 11a and 11b disposed on the first surface 21A is formed on the third surface 22A of the first heat dissipation member 22. The groove 221 is formed, for example, only in a partial region between one end surface and the other end surface of the first heat dissipation member 22 in the first direction DR1. Note that the groove 221 may be formed to extend from one end surface to the other end surface of the first heat dissipation member 22 in the first direction DR1.

[0075] The portion of each of the transformers 11a and 11b disposed on the first surface 21A is thermally connected to the inner circumferential surface of the groove portion 221 via the thermal conductive member 26. The thermal conductive member 26 is configured as a member separate from the thermal conductive member 24. The thermal conductive member 26 may also be configured as the same member integrally with the thermal conductive member 24.

[0076] The thermally conductive member 26 has high thermal conductivity and electrical insulation. The thermal conductivity of the thermally conductive member 26 is preferably 0.1 W / (m·K) or more, more preferably 1.0 W / (m·K) or more, and even more preferably 10.0 W / (m·K) or more. The thermally conductive member 26 includes, for example, at least one selected from the group consisting of thermally conductive grease, a thermally conductive sheet, a thermally conductive adhesive, and a thermally conductive gap filler. The gap filler may be, for example, a one-component non-mixing type gap filler or a two-component mixing type gap filler. When the thermally conductive member 26 is composed of a thermally conductive gap filler, after filling the groove 221 with the thermally conductive gap filler, the portion of each of the transformers 11a and 11b mounted on the substrate 21 that is disposed on the first surface 21A is accommodated in the groove 221. Thereafter, the thermally conductive gap filler hardens, whereby the transformers 11a and 11b are adhered to the first heat dissipation member 22 by the thermally conductive member 26, and the transformers 11a and 11b are thermally connected to the first heat dissipation member 22 via the thermally conductive member 26.

[0077] The power unit 20 includes a plurality of first heat transfer members 23. The plurality of first heat transfer members 23 include a fourth first heat transfer member 234 (hereinafter also simply referred to as the first heat transfer member 234), a fifth first heat transfer member 235 (hereinafter also simply referred to as the first heat transfer member 235), a sixth first heat transfer member 236 (hereinafter also simply referred to as the first heat transfer member 236), and a sixth first heat transfer member 237 (hereinafter also simply referred to as the first heat transfer member 237).

[0078] The first portion 234A of the first heat transfer member 234 extends along the side surface of the groove portion 221. At least a portion of the first portion 234A of the first heat transfer member 234 is arranged to overlap the side surface and the transformers 11a and 11b in a direction perpendicular to the side surface (e.g., the second direction DR2). At least a portion of the first portion 234A of the first heat transfer member 234 is arranged to overlap the third surface 22A, the substrate 21, and the primary winding portion 111 in the third direction DR3.

[0079] Preferably, the center of the first portion 234A of the first heat transfer member 234 is arranged so as to overlap with the side surface and the transformers 11a and 11b in a direction perpendicular to the side surface, and is arranged so as to overlap with each of the third surface 22A, the substrate 21, and the primary winding 111 in the third direction DR3. More preferably, the entire first portion 234A of the first heat transfer member 234 is arranged so as to overlap with the side surface and the transformers 11a and 11b in a direction perpendicular to the side surface, and is arranged so as to overlap with each of the third surface 22A, the substrate 21, and the primary winding 111 in the third direction DR3.

[0080] At least a part of the first portion 235A of the first heat transfer member 235 is disposed so as to overlap with each of the third surface 22A, the substrate 21, and the switching elements 10a, 10b, 10c, and 10d in the third direction DR3.

[0081] Preferably, the first portion 235A of the first heat transfer member 235 is disposed so that the center thereof overlaps with each of the third surface 22A, the substrate 21, and the switching elements 10a, 10b, 10c, and 10d in the third direction DR3. More preferably, the first portion 235A of the first heat transfer member 235 is disposed so that the entirety thereof overlaps with each of the third surface 22A, the substrate 21, and the switching elements 10a, 10b, 10c, and 10d in the third direction DR3.

[0082] The first heat transfer members 236 and 237 are symmetrical to the first heat transfer members 234 and 235 with respect to the groove 221, for example.

[0083] The first portion 236A of the first heat transfer member 236 extends along the side surface of the groove portion 221. At least a portion of the first portion 236A of the first heat transfer member 236 is arranged to overlap the side surface and the transformers 11a and 11b in a direction perpendicular to the side surface (e.g., the second direction DR2). At least a portion of the first portion 236A of the first heat transfer member 236 is arranged to overlap the third surface 22A, the substrate 21, and the secondary winding portion 112 in the third direction DR3.

[0084] Preferably, the center of the first portion 236A of the first heat transfer member 236 is arranged so as to overlap with the side surface and the transformers 11a and 11b in a direction perpendicular to the side surface, and is arranged so as to overlap with each of the third surface 22A, the substrate 21, and the secondary winding portion 112 in the third direction DR3. More preferably, the entire first portion 236A of the first heat transfer member 236 is arranged so as to overlap with the side surface and the transformers 11a and 11b in a direction perpendicular to the side surface, and is arranged so as to overlap with each of the third surface 22A, the substrate 21, and the secondary winding portion 112 in the third direction DR3.

[0085] At least a part of the first portion 237A of the first heat transfer member 237 is disposed so as to overlap with each of the third surface 22A, the substrate 21, and the rectifying elements 12a, 12b, 12c, and 12d in the third direction DR3.

[0086] Preferably, the center of the first portion 237A of the first heat transfer member 237 is arranged to overlap with each of the third surface 22A, the substrate 21, and the rectifying elements 12a, 12b, 12c, and 12d in the third direction DR3. More preferably, the entire first portion 237A of the first heat transfer member 237 is arranged to overlap with each of the third surface 22A, the substrate 21, and the rectifying elements 12a, 12b, 12c, and 12d in the third direction DR3.

[0087] The power conversion device according to the second embodiment also achieves the same effects as the power conversion device according to the first embodiment.

[0088] In the power conversion device according to embodiment 2, the heat generated in the primary winding portion 111 and the secondary winding portion 112 of the transformers 11a and 11b is quickly transferred to the first portions 234A and 236A of the first heat transfer members 234 and 236 via the first heat dissipation member 22, thereby improving the heat dissipation performance of the transformers 11a and 11b.

[0089] Furthermore, in the power conversion device according to the second embodiment, each of the switching elements 10a, 10b, 10c, and 10d is thermally connected to the first heat transfer member 235 via the first heat dissipation member 22, and is also thermally connected to the first heat transfer member 234 via the primary winding portion 111 and the first heat dissipation member 22. Similarly, each of the rectifying elements 12a, 12b, 12c, and 12d is thermally connected to the first heat transfer member 237 via the first heat dissipation member 22, and is also thermally connected to the first heat transfer member 236 via the secondary winding portion 112 and the first heat dissipation member 22. Therefore, in the power conversion device according to the second embodiment, the heat dissipation performance of the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d is also improved.

[0090] <Modification> The entire transformers 11a and 11b may be disposed on the first surface 21A. The third surface 22A of the first heat dissipation member 22 does not have to have a groove.

[0091] The wiring pattern of the substrate 21 may be formed only on the second surface 21B. The substrate 21 may be a metal base substrate formed by stacking a metal base body, an insulating layer, and a wiring layer in this order. In this case, the first surface 21A is the surface of the metal base body, and the second surface 21B is the surface of the wiring layer. The thermal conductivity of the metal base body is preferably 1.0 W / (m·K) or more, more preferably 10.0 W / (m·K) or more, and more preferably 100.0 W / (m·K) or more. The metal material constituting the metal base body is, for example, copper (Cu), iron (Fe), aluminum (Al), or an alloy thereof.

[0092] The primary winding 111 and the secondary winding 112 of each of the transformers 11a and 11b may be laminated bus bars mounted on the substrate 21. The primary winding 111 and the secondary winding 112 may be formed by laminating a laminate of an insulating film sheet and a metal conductor. The insulating film sheet may include at least one selected from the group consisting of a film made of polyethylene terephthalate (PET), a film made of polyimide (PI), and a sheet made of aramid (fully aromatic polyamide) fibers. The insulating film sheet may be adhered to the metal conductor by an adhesive layer or a pressure-sensitive adhesive layer.

[0093] The power unit 20 may include a first heat transfer member 233 similarly to the power unit 20 .

[0094] The power conversion device according to the second embodiment can be modified in the same manner as the above-described modified example of the power conversion device according to the first embodiment.

[0095] Embodiment 3 Unless otherwise specified, the power conversion device according to embodiment 3 has the same configuration and effects as those of the above-described embodiment 1 or embodiment 2. Therefore, the same components as those of embodiment 1 or embodiment 2 are denoted by the same reference numerals, and description thereof will not be repeated.

[0096] 11 , the power conversion device according to the third embodiment includes a plurality of power units 20. Each of the plurality of power units 20 has a configuration equivalent to that of the power unit 20 according to the second embodiment, for example. Each of the plurality of power units 20 includes a power supply circuit 1. The smoothing circuit section 7 of each of the plurality of power supply circuits 1 has a ground terminal 17. The first heat dissipation member 22 is electrically connected to the ground terminal 17. As a result, the potential of one of the smoothing capacitors 14 of each of the plurality of power units 20 and the potential of the first heat dissipation member 22 are set to the same potential as the earth.

[0097] 12 to 15, the multiple power units 20 are stacked and arranged in the third direction DR3. The multiple power units 20 include a first power unit 20A and a second power unit 20B. The second surface 21B of the substrate 21 of the first power unit 20A faces the fourth surface 22B of the first heat dissipation member 22 of the second power unit 20B. The fourth surface 22B of the first heat dissipation member 22 of the second power unit 20B is thermally connected to the transformers 11a and 11b of the first power unit 20A. The fourth surface 22B of the first heat dissipation member 22 of the second power unit 20B is thermally connected to the top surfaces of the transformers 11a and 11b of the first power unit 20A via, for example, a thermally conductive member 27.

[0098] The thermally conductive member 27 has high thermal conductivity and electrical insulation. The thermal conductivity of the thermally conductive member 27 is preferably 0.1 W / (m·K) or more, more preferably 1.0 W / (m·K) or more, and even more preferably 10.0 W / (m·K) or more. The thermally conductive member 27 includes, for example, at least one selected from the group consisting of thermally conductive grease, a thermally conductive sheet, a thermally conductive adhesive, and a thermally conductive gap filler. The gap filler may be, for example, a one-component non-mixing type gap filler or a two-component mixing type gap filler.

[0099] The fourth surface 22B of the first heat dissipation member 22 of the second power unit 20B is disposed at a distance from, for example, the top surfaces of the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d of the first power unit 20A. Note that the fourth surface 22B of the first heat dissipation member 22 of the second power unit 20B may be thermally connected to the top surfaces of the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d of the first power unit 20A via a thermally conductive member.

[0100] 12 to 15, the power conversion device according to the third embodiment further includes a heat dissipation unit 40. The power units 20 and the heat dissipation units 40 are stacked and arranged at intervals in the third direction DR3. The heat dissipation unit 40 is arranged on the opposite side of the second power unit 20B from the first power unit 20A.

[0101] The heat dissipation unit 40 includes a second heat dissipation member 41 and a plurality of second heat transfer members 42. The second heat dissipation member 41 has, for example, a configuration similar to that of the first heat dissipation member 22. The second heat transfer member 42 has, for example, a configuration similar to that of the first heat transfer member 41. The second heat dissipation member 41 is thermally connected to the second power unit 20B. The second heat dissipation member 41 has a fifth surface 41A that faces the second surface 21B of the substrate 21 of the second power unit 20B. The fifth surface 41A of the second heat dissipation member 41 is thermally connected to the transformers 11a and 11b of the second power unit 20B. The fifth surface 41A is, for example, perpendicular to the third direction DR3.

[0102] The plurality of second heat transport members 42 are separate members from the second heat dissipation member 41. The thermal conductivity of each of the plurality of second heat transport members 42 is higher than the thermal conductivity of the second heat dissipation member 41. Each of the plurality of second heat transport members 42 includes a third portion 42A disposed inside the second heat dissipation member 41 and a fourth portion 42B connected to the third portion 42A and disposed outside the second heat dissipation member 41. Each of the plurality of second heat transport members 42 is provided to transport heat from the third portion 42A to the fourth portion 42B.

[0103] At least a portion of the third portion 42A of each of the plurality of second heat transfer members 42 extends parallel to the fifth surface 41A. At least a portion of the third portion 42A of each of the plurality of second heat transfer members 42 is arranged at intervals from one another in the second direction DR2. At least a portion of the third portion 42A of each of the plurality of second heat transfer members 42 extends parallel to one another, for example, along the first direction DR1. Each of the plurality of second heat transfer members 42 has, for example, the same configuration as each of the plurality of first heat transfer members 23. Each of the plurality of second heat transfer members 42 is, for example, a heat pipe.

[0104] The second portions 23B of the first heat transfer members 23 of the power units 20 and the fourth portions 42B of the second heat transfer members 42 of the heat dissipation unit 40 are thermally connected to, for example, one cooling body 31. In other words, one cooler 30 is provided to cool the power units 20 and the heat dissipation units 40.

[0105] 16 , the cooler 30 includes, for example, one cooling body 31 and multiple fans 32. The multiple fans 32 are arranged side by side in the third direction DR3, for example. As described above, it is sufficient for the cooler 30 to include at least one fan 32.

[0106] 16 and 17 , the power conversion device according to the third embodiment further includes a housing 50 that houses therein the plurality of power units 20 and the cooling body 31 of the cooler 30. The fan 32 of the cooler 30 is disposed, for example, outside the housing 50. The plurality of power units 20 and the cooler 30 are disposed inside the housing 50 such that, for example, the first direction DR1 is aligned along the up-down direction. The plurality of power units 20 are disposed side by side at intervals from each other in the third direction DR3. The plurality of power units 20 are disposed, for example, below the cooler 30.

[0107] The housing 50 includes a plurality of plates that separate the interior and exterior of the housing 50. The plurality of plates include a front plate 51, a rear plate 52, side plates 53, a top plate 54, and a bottom plate 55. The front plate 51 and the rear plate 52 are spaced apart from each other in the second direction DR2. The pair of side plates 53 are spaced apart from each other in the third direction DR3. The top plate 54 and the bottom plate 55 are spaced apart from each other in the first direction DR1.

[0108] The fan 32 is fixed above the front plate 51. An opening (not shown) is formed above the front plate 51, through which air sent from the fan 32 to the cooling body 31 flows from the outside of the housing 50 into the inside. An opening 57 (see FIG. 17 ) is formed above the rear plate 52, through which air flowing around the cooling body 31 flows from the inside of the housing 50 to the outside. Furthermore, a pair of intake and exhaust ports 56 are formed in each of the front plate 51 and the rear plate 52 to communicate between the inside and outside of the housing 50. A portion of each of the multiple power units 20 is disposed between the pair of intake and exhaust ports 56 in the second direction DR2. The pair of intake and exhaust ports 56 are disposed so as to sandwich a portion of each of the multiple power units 20 in the second direction DR2. An air flow path can be formed between the pair of intake and exhaust ports 56 between two power units 20 adjacent to each other in the third direction DR3. In the front plate 51, the intake and exhaust ports 56 are formed below the openings.

[0109] There are no particular limitations on the number and shape of the intake and exhaust ports 56. A fan may be provided to create an air flow passing through the pair of intake and exhaust ports 56.

[0110] The power conversion device according to the third embodiment also achieves the same effects as the power conversion device according to the first embodiment.

[0111] Furthermore, in the power conversion device according to the third embodiment, the transformers 11a and 11b of the first power unit 20A are thermally connected not only to the first heat dissipation member 22 and the first heat transfer member 23 of the first power unit 20A, but also to the first heat dissipation member 22 and the first heat transfer member 23 of the second power unit 20B. Furthermore, the transformers 11a and 11b of the second power unit 20B are thermally connected not only to the first heat dissipation member 22 and the first heat transfer member 23 of the second power unit 20B, but also to the second heat dissipation member 41 and the second heat transfer member 42 of the heat dissipation unit 40. Therefore, in the power conversion device according to the third embodiment, the cooling performance for the transformers 11a and 11b included in the multiple power units 20 is high.

[0112] Furthermore, in the power conversion device according to the third embodiment, the potential of the first heat dissipation member 22 of each of the plurality of power units 20 is set to the same potential as the ground, so that the radiation noise from each power supply circuit 1 can be blocked by each first heat dissipation member 22. As a result, in the power conversion device according to the third embodiment, the influence of the radiation noise on each of the plurality of power supply circuits 1 is suppressed, and malfunctions are less likely to occur.

[0113] Furthermore, within the housing 50 of the power conversion device according to the third embodiment, air tunnels are formed between the first power unit 20A and the second power unit 20B and between the second power unit 20B and the heat dissipation unit 40. The electronic components mounted on the second surfaces 21B of the first power unit 20A and the second power unit 20B face the respective air tunnels. Convection within each air tunnel can be promoted by the chimney effect. Therefore, air flowing into the housing 50 through one of the air intake and exhaust ports 56 passes through the respective air tunnels, exchanges heat with the respective electronic components, and is then discharged to the outside of the housing 50 through the other air intake and exhaust port 56. As a result, the respective electronic components can be air-cooled. Such air cooling is particularly effective for dissipating heat from electronic components that are not thermally connected to the first heat transfer member 23 and the second heat transfer member 42.

[0114] <Modification> In the power conversion device according to the third embodiment, electronic components other than the transformers 11a and 11b may be thermally connected to the first heat dissipation member 22 of another power unit 20 or the second heat dissipation member 41 of the heat dissipation unit 40 that is different from the power unit 20 in which the electronic components are mounted. For example, at least any one of the transformers 11a and 11b, the switching elements 10a, 10b, 10c, and 10d, and the rectifying elements 12a, 12b, 12c, and 12d may be thermally connected to the first heat dissipation member 22 of the other power unit 20 or the second heat dissipation member 41 of the heat dissipation unit 40.

[0115] The power conversion device according to the third embodiment can be modified in the same manner as the modifications of the first and second embodiments. The heat dissipation unit 40 may be provided in the power conversion device according to the first or second embodiment.

[0116] Embodiment 4 Unless otherwise specified, the power conversion device according to embodiment 4 has the same configuration and effects as those of the above-described embodiment 3. Therefore, the same components as those of the above-described embodiment 3 are denoted by the same reference numerals, and description thereof will not be repeated.

[0117] As shown in Figure 18, in the power conversion device of embodiment 4, the first heat dissipation member 22 of the second power unit 20B has a first protrusion 22C and a second protrusion 22D that protrude from the fourth surface 22B toward the second surface 21B of the first power unit 20A.

[0118] The first protrusion 22C and the second protrusion 22D are each arranged in the second direction DR2 so as to overlap with a portion of the transformers 11a and 11b of the first power unit 20A that is arranged on the second surface 21B. The first protrusion 22C and the second protrusion 22D are arranged in the second direction DR2 so as to sandwich the portion of the transformers 11a and 11b of the first power unit 20A that is arranged on the second surface 21B.

[0119] The top surfaces of the first protrusion 22C and the second protrusion 22D are thermally connected to the second surface 21B of the substrate 21 of the first power unit 20A. The top surface of the first protrusion 22C is thermally connected to the primary winding 111 (third electronic component) mounted on the second surface 21B of the substrate 21 of the first power unit 20A, for example, via a thermally conductive member 28. The top surface of the second protrusion 22D is thermally connected to the secondary winding 112 (third electronic component) mounted on the second surface 21B of the substrate 21 of the first power unit 20A, for example, via a thermally conductive member 28.

[0120] The thermally conductive member 28 has high thermal conductivity and electrical insulation. The thermal conductivity of the thermally conductive member 28 is preferably 0.1 W / (m·K) or more, more preferably 1.0 W / (m·K) or more, and even more preferably 10.0 W / (m·K) or more. The thermally conductive member 28 includes, for example, at least one selected from the group consisting of thermally conductive grease, a thermally conductive sheet, a thermally conductive adhesive, and a thermally conductive gap filler. The gap filler may be, for example, a one-component non-mixing type gap filler or a two-component mixing type gap filler. The thermally conductive member 28 may have a configuration equivalent to any one of the thermally conductive members 24, 26, and 27.

[0121] A first portion 231A of the first heat transfer member 231 is disposed inside the first protrusion 22C. For example, the entire first portion 231A is sandwiched between both side surfaces of the first protrusion 22C. At least a portion of the first portion 231A of the first heat transfer member 231 is disposed so as to overlap, in the second direction DR2, with a portion of the transformers 11a and 11b of the first power unit 20A that is disposed on the second surface 21B. At least a portion of the first portion 231A of the first heat transfer member 231 is disposed so as to overlap, in the third direction DR3, with the primary winding 111 of the first power unit 20A.

[0122] A first portion 232A of the first heat transfer member 232 is disposed inside the second protrusion 22D. For example, the entire first portion 232A is sandwiched between both side surfaces of the second protrusion 22D. At least a portion of the first portion 231A of the first heat transfer member 232 is disposed so as to overlap, in the second direction DR2, with a portion of the transformers 11a and 11b of the first power unit 20A that is disposed on the second surface 21B. At least a portion of the first portion 231A of the first heat transfer member 232 is disposed so as to overlap, in the third direction DR3, with the secondary winding portion 112 of the first power unit 20A.

[0123] 18 , the second heat dissipation member 41 of the heat dissipation unit 40 has a third protrusion 41C and a fourth protrusion 41D that protrude from the fifth surface 41A toward the second surface 21B of the second power unit 20B. The third protrusion 41C and the fourth protrusion 41D have the same configuration as, for example, the first protrusion 22C and the second protrusion 22D.

[0124] The top surfaces of the third protrusion 41C and the fourth protrusion 41D are thermally connected to the second surface 21B of the substrate 21 of the second power unit 20B. The top surface of the third protrusion 41C is thermally connected to the primary winding 111 as a wiring pattern mounted on the second surface 21B of the substrate 21 of the second power unit 20B, for example, via a thermally conductive member 28. The top surface of the fourth protrusion 41D is thermally connected to the secondary winding 112 as a wiring pattern mounted on the second surface 21B of the substrate 21 of the second power unit 20B, for example, via a thermally conductive member 28.

[0125] The plurality of second heat transfer members 42 include a first group of second heat transfer members 421 (hereinafter simply referred to as second heat transfer members 421) and a second group of second heat transfer members 422 (hereinafter simply referred to as second heat transfer members 421). The third portion 421A of each of the first group of second heat transfer members 421 is disposed inside the third protrusion 41C or the fourth protrusion 41D. For example, the entire third portion 42A is sandwiched between both side surfaces of the third protrusion 41C or the fourth protrusion 41D. The third portion 422A of the second heat transfer member 422 is disposed so as to overlap a surface region of the fifth surface 41A located between the third protrusion 41C and the fourth protrusion 41D in a direction perpendicular to the fifth surface 41A (e.g., the third direction DR3).

[0126] For example, at least a portion of the third portion 421A of the second heat transfer member 421 and the third portion 422A of the second heat transfer member 422 are arranged to overlap with the transformers 11a and 11b of the second power unit 20B in the second direction DR2. At least a portion of the third portion 421A of the second heat transfer member 421 and the third portion 422A of the second heat transfer member 422 are arranged to overlap with the primary winding portion 111 or the secondary winding portion 112 of the second power unit 20B in the third direction DR3.

[0127] At least a portion of the third protrusion 41C is arranged to overlap with the first protrusion 22C in the third direction DR3, for example. At least a portion of the fourth protrusion 41D is arranged to overlap with the second protrusion 22D in the third direction DR3, for example.

[0128] The power conversion device according to the fourth embodiment also achieves the same effects as the power conversion device according to the third embodiment.

[0129] Furthermore, in the power conversion device according to the fourth embodiment, heat from the primary winding portion 111 and the secondary winding portion 112 of each power unit 20 can be rapidly conducted not only to the first heat dissipation member 22 and the first heat transfer member 23 of the power unit 20 in which they are mounted, but also to the first heat dissipation member 22 and the first heat transfer member 23 of another power unit 20 adjacent to them in the third direction DR3, or to the second heat dissipation member 41 and the second heat transfer member 42 of the heat dissipation unit 40. As a result, in the power conversion device according to the fourth embodiment, heat generation from the transformers 11a and 11b to the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d, and heat generation from the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d to the transformers 11a and 11b can be suppressed.

[0130] In the power converter according to the fourth embodiment, the first heat dissipation member 22 may include at least one of the first protrusion 22C and the second protrusion 22D. The second heat dissipation member 41 may include at least one of the third protrusion 41C and the fourth protrusion 41D.

[0131] 20 , only a portion of the first portion 23A of the first heat transfer member 23 of the second power unit 20B may be disposed inside the first protrusion 22C and the second protrusion 22D. The first portion 23A of the first heat transfer member 23 of the second power unit 20B may have a portion disposed so as to overlap with each of the transformers 11a and 11b of the second power unit 20B in the second direction DR2, and a portion disposed so as to overlap with each of the transformers 11a and 11b of the first power unit 20A in the second direction DR2. The first portion 23A of the first heat transfer member 23 of the second power unit 20B is thermally connected not only to the transformers 11a and 11b of the second power unit 20B but also to the transformers 11a and 11b of the first power unit 20A. The power unit 20 shown in FIG. 20 is suitable, for example, when the allowable temperatures of the primary winding section 111 and the secondary winding section 112 are high and the heat dissipation performance required for these is lower than the heat dissipation performance achieved by the configurations shown in FIGS. 18 and 19.

[0132] 21 and 22 , the first protrusion 22C and the second protrusion 22D of the second power unit 20B may be thermally connected to each of the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d of the first power unit 20A, instead of the primary winding portion 111 and the secondary winding portion 112 of the first power unit 20A. The first protrusion 22C and the second protrusion 22D of the second power unit 20B may be thermally connected to each of the top surfaces of the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d of the first power unit 20A, for example, via a thermally conductive member 28.

[0133] Similarly, the third protrusion 41C and the fourth protrusion 41D of the heat dissipation unit 40 may be thermally connected to each of the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d (third electronic components) of the second power unit 20B, instead of the primary winding portion 111 and the secondary winding portion 112 of the second power unit 20B. The third protrusion 41C and the fourth protrusion 41D of the heat dissipation unit 40 may be thermally connected to each of the top surfaces of the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d of the second power unit 20B via the thermally conductive member 28.

[0134] In this way, heat from the switching elements 10a, 10b, 10c, and 10d and rectifying elements 12a, 12b, 12c, and 12d of each power unit 20 can be quickly conducted not only to the first heat dissipation member 22 and the first heat transfer member 23 of the power unit 20 in which they are mounted, but also to the first heat dissipation member 22 and the first heat transfer member 23 of another power unit 20 adjacent to it in the third direction DR3, or the second heat dissipation member 41 and the second heat transfer member 42 of the heat dissipation unit 40. As a result, heat transfer from the switching elements 10a, 10b, 10c, and 10d and the rectifying elements 12a, 12b, 12c, and 12d to the transformers 11a and 11b can be suppressed.

[0135] The power conversion device according to the fourth embodiment can be modified in the same manner as the modifications of the first, second, and third embodiments described above.

[0136] <Modifications common to Embodiments 1 to 4> In each of Embodiments 1 to 4, cooler 30 has an air-cooled structure in which cooling body 31 is cooled by air sent from fan 32, but the cooling structure of cooler 30 is not limited to this. In each of Embodiments 1 to 4, cooler 30 may have a water-cooled structure in which cooling is performed by liquid (e.g., water) sent from a pump or the like.

[0137] In each of the first to fourth embodiments, the electronic components that form at least a part of the power supply circuit 1 are mounted on the second surface 21B of the substrate 21, but the mounting location of the electronic components is not limited to the substrate 21. In each of the first to fourth embodiments, some of the electronic components may be mounted on a second substrate connected to the substrate 21. For example, the input capacitor 3 and the output capacitor 14 may be mounted on the second substrate.

[0138] In each of the first to fourth embodiments, the two modifications may be implemented simultaneously, or only one of the modifications may be implemented. Details of the two modifications will be described later in the fifth and sixth embodiments.

[0139] Embodiment 5 Unless otherwise specified, the power conversion device according to embodiment 5 has the same configuration and effects as those of the above-described embodiments 3 and 4. Therefore, the same components as those of the above-described embodiments 3 and 4 are denoted by the same reference numerals, and the description thereof will not be repeated.

[0140] 23 , the power conversion device according to the fifth embodiment includes a cooler 30 having a water-cooled structure. The cooler 30 includes at least one cooling plate 33 (cooling body) and at least one pipe 34.

[0141] The cooling plate 33 is thermally connected to the second portions 23B of the multiple first heat transfer members 23 of each of the multiple power units 20. The cooling plate 33 is arranged, for example, alongside each of the multiple power units 20 in the first direction DR1. The cooling plate 33 has through holes or fastening holes formed therein for accommodating at least a portion of the second portions 23B. The through holes or fastening holes of the cooling plate 33 extend, for example, along the first direction DR1.

[0142] Each second portion 23B has a portion that is disposed inside, for example, a through hole or a fastening hole in the cooling plate 33. Each second portion 23B extends, for example, in the first direction DR1. In each second portion 23B, one end that is connected to the first portion 23A and the other end that is located opposite to the first portion 23A are, for example, closed.

[0143] The cooling plate 33 may be made of any material having high thermal conductivity, such as aluminum (Al). The thermal conductivity of the cooling plate 33 is 0.1 W / (m·K) or more, preferably 1.0 W / (m·K) or more, and more preferably 10.0 W / (m·K) or more.

[0144] The conduit 34 is thermally connected to the cooling plate 33. The conduit 34 is thermally connected to the second portions 23B of each of the plurality of first heat transfer members 23 via the cooling plate 33. The conduit 34 is disposed inside the cooling plate 33. A flow path is provided inside the conduit 34 for circulating a heat medium. The heat medium is, for example, water. The conduit 34 is formed, for example, by piping. The conduit 34 has an inlet 34A through which the heat medium flows in and an outlet 34B through which the heat medium flows out. The inlet 34A and the outlet 34B are disposed side by side on one surface of the cooling plate 33, for example.

[0145] The inlet 34A and the outlet 34B are disposed, for example, outside the power conversion apparatus according to the fifth embodiment, and are connected to a heat medium circulating device (not shown) that supplies a heat medium to the inlet 34A and recovers the heat medium from the outlet 34B. In this case, the pipe 34 forms part of a circuit through which the heat medium circulates. The heat medium circulating device is, for example, a chiller capable of cooling the heat medium. The heat medium circulating device is, for example, a chiller capable of cooling the heat medium. The inlet 34A and the outlet 34B are connected to the heat medium circulating device via, for example, flexible hoses.

[0146] The conduit 34 is thermally connected to the cooling plate 33 via, for example, a thermally conductive member (not shown). The thermally conductive member may have a configuration similar to any one of the thermally conductive members 24, 26, 27, and 28 described above.

[0147] Preferably, the first portion 23A and the second portion 23B are linearly connected in each of the plurality of first heat transfer members 23. Preferably, each of the plurality of first heat transfer members 23 does not have a bent portion between the first portion 23A and the second portion 23B.

[0148] 24 , when viewed from the extension direction of each second portion 23B, the conduit 34 has, for example, a corrugated shape inside the cooling plate 33. The corrugated shape refers to a wave-like shape in which multiple bent portions are connected in series. The conduit 34 has, for example, multiple bent portions 34C and multiple straight pipe portions 34D inside the cooling plate 33. Each of the multiple bent portions 34C connects the multiple straight pipe portions 34D. Each of the multiple bent portions 34C has, for example, an L-shape. Each of the multiple bent portions 34C and the multiple straight pipe portions 34D is arranged around the second portion 23B inside the cooling body 33.

[0149] The plurality of straight pipe portions 34D include a first straight pipe portion 34D1 and a second straight pipe portion 34D2. The first straight pipe portion 34D1 and the second straight pipe portion 34D2 are connected in series to each other via at least one bent portion 34C and are adjacent to each other in the third direction DR3. Of the plurality of first heat transfer members 23, the plurality of second portions 23B arranged side by side in the second direction DR2 are arranged between the first straight pipe portion 34D1 and the second straight pipe portion 34D2.

[0150] The straight pipe sections 34D further include, for example, a third straight pipe section 34D3 connecting the first straight pipe section 34D1 and the second straight pipe section 34D2. The first straight pipe section 34D1 and the second straight pipe section 34D2 are connected in series with each other via, for example, two bent sections 34C and the third straight pipe section 34D3 connecting the two bent sections 34C.

[0151] The cooling plate 33 is also thermally connected to, for example, the fourth portions 42B of the second heat transfer members 42 of the heat dissipation unit 40. A through hole or a blind hole for accommodating at least a part of the fourth portion 42B is further formed in the cooling plate 33. The conduit 34 is also thermally connected to the fourth portions 42B of the second heat transfer members 42 via the cooling plate 33.

[0152] The effects of the power conversion device according to the fifth embodiment will be described by comparing it with a power conversion device according to a comparative example. The power conversion device according to the comparative example does not include a plurality of first heat transfer members 23, and the cooler includes a plurality of pipes thermally connected to each of the substrates of a plurality of power units, a distributor such as a manifold for distributing the heat medium to each of the plurality of pipes, and a flow control valve for adjusting the flow rate of the heat medium in each of the plurality of pipes. In this comparative example, the cooler has a complex structure and a large number of parts, which increases the size of the power conversion device and the manufacturing cost of the power conversion device.

[0153] In contrast, in the power conversion device according to the fifth embodiment, the pipe 34 through which the heat medium flows is thermally connected to the plurality of first heat transfer members 23 via the cooling plate 33, and therefore there is no need to provide a plurality of pipes and distributors for flowing the heat medium to each of the plurality of power units 20. Therefore, in the power conversion device according to the fifth embodiment, the structure of the cooler 30 is simplified compared to the comparative example, and the number of parts constituting the cooler 30 can also be reduced. As a result, the power conversion device according to the fifth embodiment can be made smaller than the comparative example, and manufacturing costs can be reduced.

[0154] Furthermore, if each of the plurality of first heat transfer members 23 is a heat pipe, the capillary structure on the inner wall of the heat pipe collapses at the bent portion, reducing the heat transfer capacity. In contrast, in the power conversion device according to the fifth embodiment, each of the plurality of first heat transfer members 23 can have a structure without bent portions, thereby making it possible to fully utilize the heat transfer capacity of the heat pipe.

[0155] The power conversion device according to the fifth embodiment may include at least one power unit, and the cooling plate 33 may be thermally connected to the second portions 23B of the first heat transfer members 23 of at least one power unit 20.

[0156] The pipe 34 may be configured as part of a circuit through which the heat medium circulates. In this case, the cooler 30 may further include a cooling unit capable of cooling the heat medium recovered from inside the pipe 34. The pipe 34 may be configured by a hollow portion provided inside the cooling plate 33 and a pipe arranged outside the cooling plate 33.

[0157] When viewed from the extending direction of each second portion 23B, the pipe 34 may not have any bent portion 34C, or may have only one bent portion 34C.

[0158] As shown in FIG. 25 , in the power conversion device according to the fifth embodiment, the cooler 30 may have a plurality of cooling plates 33, 36 and a plurality of pipes 34, 37 arranged to sandwich a plurality of power units 20 therebetween.

[0159] The plurality of cooling plates 33, 36 include a first cooling plate 33 and a second cooling plate 36. The first cooling plate 33 and the second cooling plate 36 are arranged to sandwich the plurality of power units 20 in the first direction DR1.

[0160] Each of the multiple first heat transfer members 23 has a first portion 23A and a pair of second portions 23B connected to one end or the other end in the first direction DR1 of the first portion 23A. One of the pair of second portions 23B is thermally connected to the first cooling plate 33. The other of the pair of second portions 23B is thermally connected to the second cooling plate 36.

[0161] The multiple pipes 34, 37 include a first pipe 34 and a second pipe 37. The first pipe 34 is thermally connected to one of the pair of second portions 23B of each of the multiple first heat transfer members 23 via a first cooling plate 33. The second pipe 37 is thermally connected to the other of the pair of second portions 23B of each of the multiple first heat transfer members 23 via a second cooling plate 36. Preferably, in each of the multiple first heat transfer members 23, the first portion 23A and the pair of second portions 23B are linearly connected.

[0162] The first pipeline 34 and the second pipeline 37 are, for example, independent of each other. Note that the first pipeline 34 and the second pipeline 37 may be connected in parallel to each other or in series to each other.

[0163] 25, the heat transferred to each of the plurality of first heat transfer members 23 can be discharged from each of the pair of second portions 231B to the heat medium flowing through the first pipe 34 or the second pipe 37. Therefore, the heat dissipation performance of the power conversion device shown in FIG. 25 is higher than that of the power conversion device shown in FIG.

[0164] Sixth Embodiment Unless otherwise specified, the power conversion device according to the sixth embodiment has the same configuration and effects as those of the third and fourth embodiments. Therefore, the same components as those of the third and fourth embodiments are denoted by the same reference numerals, and the description thereof will not be repeated.

[0165] As shown in Figure 26, the power conversion device of embodiment 6 further includes a second substrate 61, an input capacitor 3 and an output capacitor 14 as examples of a fourth electronic component, and a connecting member 62 that connects the second substrate 61 and the substrate 21.

[0166] The second substrate 61 is, for example, a wiring substrate that, together with the substrate 21, constitutes part of the power supply circuit 1. The second substrate 61 is disposed at a distance from the substrate 21 in the first direction DR1. The second substrate 61 is disposed so as not to overlap the first surface 21A and the second surface 21B of the substrate 21 when viewed from the third direction DR3. The second substrate 61 is disposed on the side of the power unit 20 opposite to the side where the second portion 23B protrudes from the first heat dissipation member 22.

[0167] The second substrate 61 has a sixth surface 61A and a seventh surface 61B located opposite the sixth surface 61A. The input capacitor 3 and the output capacitor 14 are mounted on the sixth surface 61A. The input capacitor 3 and the output capacitor 14 are preferably arranged side by side in the second direction DR2. The seventh surface 61B faces the substrate 21. Each of the sixth surface 61A and the seventh surface 61B is, for example, perpendicular to the first direction DR1. The seventh surface 61B faces the substrate 21 in the first direction DR1, for example. The dimension of the second substrate 61 in the third direction DR3 is preferably smaller than the dimension of the second substrate 61 in the second direction DR2.

[0168] The input capacitor 3 and the output capacitor 14 are, for example, film capacitors. A film capacitor has a polymer film as a dielectric and does not contain an electrolyte.

[0169] The connection member 62 electrically connects the wiring formed on each of the substrate 21 and the second substrate 61. The connection member 62 acts, for example, as a fixing member that fixes the second substrate 61 to the substrate 21. The connection member 62 is, for example, a bus bar.

[0170] In the power conversion device of embodiment 6, the input capacitor 3 and the output capacitor 14 are mounted on the second substrate 61 rather than on the substrate 21, and therefore the substrate 21 can be made smaller in the third direction DR3 compared to a power conversion device in which the input capacitor 3 and the output capacitor 14 are mounted on the first surface 21A or the second surface 21B of the substrate 21.

[0171] In particular, the dimension (height) in the third direction DR3 of a typical film capacitor is the largest among the electronic components included in a power converter. Therefore, when mounting a film capacitor on a substrate 21, it is necessary to increase the distance in the third direction DR3 between the substrate 21 and the substrate 21 of another power unit 20, or the distance in the third direction DR3 between the substrate 21 and the second heat dissipation member 41 of the heat dissipation unit 40. Therefore, a power converter in which a film capacitor is mounted on a substrate 21 is large in size in the third direction DR3.

[0172] In contrast, in the power conversion device according to embodiment 6, the film capacitor is mounted on the second substrate 61 instead of the substrate 21, so that the entire power conversion device can be made smaller in size in the third direction DR3.

[0173] Furthermore, in the power conversion device according to the sixth embodiment, film capacitors can be used for the input capacitor 3 and the output capacitor 14, eliminating the problems that would be expected if electrolytic capacitors were used for the input capacitor 3 and the output capacitor 14. Specifically, the electrolytic capacitor is provided with a sealing rubber to prevent evaporation and leakage of the electrolyte, and the anode and cathode lead terminals pass through openings in the sealing rubber. Generally, sealing rubber is made of an organic material. Therefore, the deterioration of the sealing rubber proceeds according to the Arrhenius law, and it is known that, for example, a 10°C increase in operating temperature halves the sealing rubber's lifespan. When the sealing rubber deteriorates and the electrolyte evaporates, the capacitance of the electrolytic capacitor decreases. Therefore, if the input capacitor 3 and the output capacitor 14 are made of electrolytic capacitors, the capacitance of the input capacitor 3 and the output capacitor 14 decreases, impairing their ability to smooth the voltage required of the input capacitor 3 and the output capacitor 14. As a result, the output voltage of the power supply circuit 1 may not be controlled to the target value. In contrast, in the power conversion device according to the sixth embodiment, film capacitors can be used for the input capacitor 3 and the output capacitor 14, so there is no degradation in the performance of the input capacitor 3 and the output capacitor 14 due to evaporation and leakage of the electrolyte. The reliability of the power conversion device according to the sixth embodiment is higher than that of a power conversion device that uses electrolytic capacitors for the input capacitor 3 and the output capacitor 14.

[0174] <Modification> In the power conversion device according to the sixth embodiment, the second substrate 61 may be a laminate bus bar. The input capacitor 3 and the output capacitor 14 may be fastened to the laminate bus bar by, for example, screws. The input capacitor 3 and the output capacitor 14 are electrically connected to wiring formed on the substrate 21 via the laminate bus bar.

[0175] The fourth electronic component mounted on the second substrate 61 is not limited to a film capacitor. The fourth electronic component may be any electronic component whose dimension in the third direction DR3 is larger than that of the first electronic component.

[0176] 27 , the power conversion device according to the sixth embodiment may include a plurality of power units 20 and a plurality of second substrates 61. Electronic components of the power supply circuit 1 included in each of the plurality of power units 20 are mounted on the plurality of second substrates 61. For example, the input capacitor 3 and the output capacitor 14 of each power supply circuit 1 are mounted on the plurality of second substrates 61. The dimension of each second substrate 61 in the third direction DR3 is preferably smaller than the dimension of each second substrate 61 in the second direction DR2.

[0177] 28 , the power conversion device according to the sixth embodiment may include a cooler 30 similar to that of the power conversion device according to the fifth embodiment. The cooling plate 33 of the cooler 30 is disposed on the opposite side of each of the plurality of power units 20 in the first direction DR1 from the plurality of second boards 61 and the input capacitors 3 and output capacitors 14 mounted on each second board 61.

[0178] 29 , the power conversion apparatus according to the sixth embodiment may further include a housing 50. The housing 50 may have a configuration similar to that of the housing 50 of the power conversion apparatus according to the third embodiment. The inlet 34A and the outlet 34B of the conduit 34 of the cooler 30 each protrude to the outside of the housing 50 from a through-hole formed in the front plate 51, for example. The inlet 34A and the outlet 34B are each connected to one end of a hose 70. For example, the second substrate 61 is disposed below the multiple power units 20, and the input capacitor 3 and the output capacitor 14 are disposed below the second substrate 61.

[0179] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0180] 1 power supply circuit, 2 input terminal, 3 input capacitor, 4 inverter circuit section, 5 transformer section, 6 rectifier circuit section, 7 smoothing circuit section, 8 control circuit section, 9 output terminal, 10a, 10b, 10c, 10d switching elements, 11a, 11b transformer, 11b1, 11b2 section, 12a, 12b, 12c, 12d rectifier elements, 13 smoothing reactor, 14 smoothing capacitor, 15 first wiring pattern, 16 second wiring pattern, 17 ground terminal, 20 power unit, 20A first power unit, 20B second power unit, 21 substrate, 21A first surface, 21B second surface, 22 first heat dissipation member, 22A third surface, 22B fourth surface, 22C first protrusion, 22D Second protrusion, 23, 231, 232, 233, 234, 235, 236, 237 First heat transfer member, 23A, 231A, 232A, 233A, 234A, 235A, 236A, 237A First portion, 23B, 231B Second portion, 24, 26, 27, 28 Thermally conductive member, 25 Positioning member, 30 Cooler, 31 Cooling body, 32 Fan, 33, 36 Cooling plate, 34, 37 Pipe, 34A Inlet, 34B Outlet, 34C Bent portion, 34D Straight pipe portion, 34D1 First straight pipe portion, 34D2 Second straight pipe portion, 34D3 Third straight pipe portion, 40 Heat dissipation unit, 41 Second heat dissipation member, 41A Fifth surface, 41C Third protrusion, 41D Fourth protrusion, 42, 421, 422 Second heat transfer member, 42A, 421A, 422A Third part, 2B Fourth part, 56 Intake and exhaust port, 50 Housing, 51 Front plate, 52 Rear plate, 53 Side plate, 54 Top plate, 55 Bottom plate, 57 Opening, 61 Second board, 61A Sixth surface, 61B Seventh surface, 62 Connecting member, 70 Hose, 111 Primary winding portion, 112 Secondary winding portion, 113 Spacer, 114, 115 Core, 221 Groove portion, 221A Side surface, 221B Bottom surface.

Claims

1. at least one power unit; The at least one power unit a substrate having a first surface and a second surface opposite the first surface; a first heat dissipation member having a third surface thermally connected to the first surface or the second surface; at least one first heat transport member including a first portion disposed inside the first heat dissipation member and a second portion connected to the first portion and disposed outside the first heat dissipation member, the first portion transporting heat from the first portion to the second portion; at least one first electronic component is mounted on at least one of the first surface and the second surface of the substrate; the at least one first heat transport member is a member separate from the first heat dissipation member, the first portion of the at least one first heat transfer member is thermally connected to the at least one first electronic component via the first heat dissipation member; the at least one power unit is a plurality of power units; the plurality of power units include a first power unit and a second power unit stacked on the first power unit in a direction perpendicular to the first surface, a fourth surface of the first heat dissipation member of the second power unit that is thermally connected to the at least one first electronic component of the first power unit;

2. In the first power unit, the at least one first electronic component is a plurality of first electronic components arranged side by side in a first direction along the first surface, 2. The power conversion device according to claim 1, wherein at least a portion of the first portion of the at least one first heat transfer member extends along the first direction and is arranged so as to overlap the first heat dissipation member and each of the plurality of first electronic components in a direction perpendicular to the first surface.

3. In the first power unit, the at least one first electronic component has a portion disposed on the first surface; a groove is formed in the third surface, the third surface of the first heat dissipation member is thermally connected to the first surface, a side surface of the groove is thermally connected to the at least one first electronic component; 2. The power conversion device according to claim 1, wherein at least a portion of the first portion of the at least one first heat transfer member extends along the side surface and is arranged so as to overlap with the side surface of the at least one first electronic component and the groove portion in a direction perpendicular to the side surface.

4. In the first power unit, a second electronic component is mounted on the second surface of the substrate; 4. The power conversion device according to claim 3, wherein at least a portion of the first portion of the at least one first heat transfer member is arranged so as to overlap the second electronic component in a direction perpendicular to the first surface, and is thermally connected to the second electronic component via the first heat dissipation member and the substrate.

5. In the first power unit, the at least one first electronic component has a portion disposed on the first surface; a groove is formed in the third surface, the third surface of the first heat dissipation member is thermally connected to the first surface, a bottom surface of the groove portion is thermally connected to each of the at least one first electronic component; 2. The power conversion device according to claim 1, wherein at least a portion of the first portion of the at least one first heat transfer member extends along the bottom surface and is arranged so as to overlap with the at least one first electronic component and the bottom surface of the groove portion in a direction perpendicular to the bottom surface.

6. Further comprising a heat dissipation unit, The heat dissipation unit is a second heat dissipation member thermally connected to the second power unit; A power conversion device as described in any one of claims 1 to 5, comprising: a third portion arranged inside the second heat dissipation member; a fourth portion connected to the third portion and arranged outside the second heat dissipation member; and at least one second heat transport member arranged to transport heat from the third portion to the fourth portion.

7. the at least one first electronic component and a third electronic component are mounted on the second surface of the first power unit; the fourth surface of the first heat dissipation member of the second power unit faces the second surface of the first power unit and is thermally connected to the at least one first electronic component of the first power unit, and the first heat dissipation member of the second power unit has a first protrusion protruding from the fourth surface toward the second surface; a top surface of the first protrusion is thermally connected to the second surface of the first power unit or the third electronic component; The power conversion device according to any one of claims 1 to 5, wherein in the second power unit, at least a part of the first portion of the at least one first heat transfer member is disposed inside the first protrusion.

8. the first heat dissipation member of the second power unit further includes a second protrusion protruding from the fourth surface toward the second surface, the first protrusion and the second protrusion are arranged to sandwich the at least one first electronic component in a third direction along the fourth surface, 8. The power conversion device according to claim 7, wherein a surface region of the fourth surface located between the first protrusion and the second protrusion is thermally connected to each of the at least one first electronic component.

9. Further comprising a heat dissipation unit, The heat dissipation unit is a second heat dissipation member thermally connected to the at least one power unit; a third portion disposed inside the second heat dissipation member; and a fourth portion connected to the third portion and disposed outside the second heat dissipation member, and a plurality of second heat transport members provided to transport heat from the third portion to the fourth portion. the second heat dissipation member has a fifth surface facing the second surface of the second power unit and thermally connected to the at least one first electronic component of the second power unit, and a third protrusion protruding from the fifth surface toward the second surface, The plurality of second heat transfer members include a first second heat transfer member, at least a part of the third portion of which is disposed inside the third protrusion; 9. The power conversion device according to claim 8, further comprising: a second second heat transfer member arranged so that at least a portion of the third portion overlaps with the at least one first electronic component in a direction perpendicular to the fifth surface.

10. A power supply circuit including a transformer is mounted on the substrate, the power supply circuit includes a primary circuit and a secondary circuit having an operating voltage different from that of the primary circuit and including a ground terminal; The power conversion device according to any one of claims 1 to 5, wherein the first heat dissipation member is electrically connected to the ground terminal.

11. 6. The power conversion device according to claim 1, further comprising a cooler that cools the second portion of the at least one first heat transfer member.

12. The power conversion device according to claim 11 , wherein the cooler is arranged side by side with the first heat dissipation member in a first direction along the first surface.

13. the at least one power unit is a plurality of power units stacked and arranged in a direction perpendicular to the first surface, the first portion of the at least one first heat transfer member of each of the plurality of power units extends along the first surface; the second portion of the at least one first heat transfer member of each of the plurality of power units extends along a direction intersecting the first surface; The power conversion device according to claim 11 , wherein the cooler cools the second portion of the at least one first heat transfer member of each of the plurality of power units.

14. Further comprising a heat dissipation unit, The heat dissipation unit is a second heat dissipation member thermally connected to the at least one power unit; a third portion disposed inside the second heat dissipation member, and a fourth portion connected to the third portion and disposed outside the second heat dissipation member, and at least one second heat transport member provided to transport heat from the third portion to the fourth portion; The power conversion apparatus according to claim 11 , wherein the cooler further cools the fourth portion of the at least one second heat transfer member.

15. 12. The power conversion device according to claim 11, wherein the cooler includes at least one cooling body thermally connected to the second portion of the at least one first heat transfer member, and at least one fan that blows air onto the at least one cooling body.

16. 12. The power conversion device according to claim 11, wherein the cooler includes at least one cooling body thermally connected to the second portion of the at least one first heat transfer member, and at least one pipe thermally connected to the at least one cooling body.

17. the second portion of the at least one first heat transfer member is disposed inside the at least one cooling body; The power converter of claim 16 , wherein the at least one conduit has a bend disposed around the second portion within the at least one cooling body.

18. the at least one first heat transfer member is a plurality of first heat transfer members, the at least one pipe line has a first pipe section and a second pipe section connected in series to each other via the bent section; 18. The power conversion device according to claim 17, wherein, inside the at least one cooling body, the second portion of each of the plurality of first heat transfer members is disposed between the first pipe portion and the second pipe portion.

19. The at least one power unit a second substrate having a sixth surface; and at least one fourth electronic component mounted on the sixth surface, The second substrate and the at least one fourth electronic component are arranged so as not to overlap with the first surface and the second surface of the substrate when viewed from a direction perpendicular to the first surface. The power conversion device according to any one of claims 1 to 5.

20. A power supply comprising at least one power unit, The at least one power unit a substrate having a first surface and a second surface opposite the first surface; a first heat dissipation member having a third surface thermally connected to the first surface or the second surface; at least one first heat transport member including a first portion disposed inside the first heat dissipation member and a second portion connected to the first portion and disposed outside the first heat dissipation member, the first portion transporting heat from the first portion to the second portion; at least one first electronic component is mounted on at least one of the first surface and the second surface of the substrate; the at least one first heat transport member is a member separate from the first heat dissipation member, the first portion of the at least one first heat transport member is thermally connected to the at least one first electronic component via the first heat dissipation member; The at least one power unit a second substrate having a sixth surface; and at least one fourth electronic component mounted on the sixth surface, A power conversion device, wherein the second substrate and the at least one fourth electronic component are arranged so as not to overlap with the first surface and the second surface of the substrate when viewed from a direction perpendicular to the first surface.