Power conversion device

Abstract

A power conversion device (1) comprises: a plurality of circuit components (21, 22, 23); a metal base substrate (30); a first heat transport member (40); and a cooler (50). The metal base substrate (30) includes: a main surface (33) on which the plurality of circuit components (21, 22, 23) are mounted; and an end surface (32) connected to the main surface (33). The first heat transport member (40) includes a main surface (43), and an end surface (42) facing the cooler (50). The end surface (32) and the end surface (42) are thermally connected to the cooler (50). The main surface (43) is thermally connected to the metal base substrate (30).

Description

Power Conversion Device

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

[0002] Japanese Patent No. 4983959 (Patent Document 1) discloses a switching power supply including electronic components, a storage case for storing the electronic components, a base portion formed integrally with the storage case and for placing the electronic components thereon, and a refrigerant flow path that passes through the base portion and through which a refrigerant flows to cool the electronic components.

[0003] Patent No. 4983959

[0004] An object of the present disclosure is to provide a power conversion device that can cool a plurality of circuit components without increasing the size of the cooler, even if the number of circuit components increases.

[0005] A power conversion device according to a first aspect of the present disclosure includes a plurality of circuit components, a metal base substrate including a metal plate, a heat transfer member, and a cooler. The metal base substrate includes a first main surface on which the plurality of circuit components are mounted and a first end surface connected to the first main surface. The thermal conductivity of the heat transfer member is equal to or greater than the thermal conductivity of the metal plate. The heat transfer member includes a second main surface and a second end surface connected to the second main surface and facing the cooler. The first end surface and the second end surface are thermally connected to the cooler. The second main surface is thermally connected to the metal base substrate.

[0006] A power conversion device according to a second aspect of the present disclosure includes a plurality of circuit components, a metal base substrate including a metal plate, a heat transfer member, and a cooler. The metal base substrate includes a first main surface on which the plurality of circuit components are mounted, a second main surface opposite the first main surface, and a first end surface connected to the first and second main surfaces. The metal plate includes the second main surface. The first end surface faces the cooler and is thermally connected to the cooler. The thermal conductivity of the heat transfer member is equal to or greater than the thermal conductivity of the metal plate. The heat transfer member faces the second main surface and is thermally connected to the second main surface. In a plan view of the first main surface, the heat transfer member includes a protrusion protruding from the first end surface. The cooler is provided with a hole or a recess. The protrusion of the heat transfer member is inserted into the hole or recess and is thermally connected to the cooler.

[0007] The cooler is thermally connected to the first end surface of the metal base substrate and the heat transfer member. Heat generated in the plurality of circuit components is transferred to the cooler by both the metal base substrate and the heat transfer member and collected in the cooler. According to the power conversion device of the present disclosure, even if the number of circuit components increases and the size of the metal base substrate increases, the plurality of circuit components can be cooled without increasing the size of the cooler.

[0008] 1 is a circuit diagram of a power conversion device according to a first embodiment. 2 is a schematic plan view of a power conversion device according to a first embodiment. 3 is a schematic cross-sectional view of a power conversion device according to a first embodiment, taken along the cross-sectional line III-III shown in FIG. 2. 4 is a schematic partially enlarged cross-sectional view of a region IV shown in FIG. 3 of a power conversion device according to a first embodiment. 5 is a schematic cross-sectional view of a power conversion device according to a second embodiment. 6 is a schematic cross-sectional view of a power conversion device according to a third embodiment. 7 is a schematic plan view of a power conversion device according to a fourth embodiment. 8 is a schematic cross-sectional view of a power conversion device according to a fourth embodiment, taken along the cross-sectional line VIII-VIII shown in FIG. 7. 9 is a schematic cross-sectional view of a power conversion device according to a fourth embodiment, taken along the cross-sectional line IX-IX shown in FIG. 7. 10 is a schematic plan view of a power conversion device according to a fifth embodiment. 11 is a schematic cross-sectional view of a power conversion device according to a fifth embodiment, taken along the cross-sectional line XI-XI shown in FIG. 10. 12 is a schematic plan view of a power conversion device according to a sixth embodiment. 13 is a schematic cross-sectional view of a power conversion device according to a sixth embodiment, taken along the cross-sectional line XIII-XIII shown in FIG. 12. 14 is a schematic cross-sectional view of a power conversion device according to a sixth embodiment, taken along the cross-sectional line XIV-XIV shown in FIG. 12. 12 is a schematic cross-sectional view of a power conversion device according to a sixth embodiment, taken along the cross-sectional line XV-XV shown in FIG. 12 . FIG. 13 is a schematic plan view of a power conversion device according to a seventh embodiment. FIG. 14 is a schematic cross-sectional view of a power conversion device according to a seventh embodiment, taken along the cross-sectional line XVII-XVII shown in FIG. 16 . FIG. 15 is a schematic cross-sectional view of a power conversion device according to a seventh embodiment, taken along the cross-sectional line XVIII-XVIII shown in FIG. 16 . FIG. 16 is a schematic cross-sectional view of a power conversion device according to a seventh embodiment, taken along the cross-sectional line XIX-XIX shown in FIG. 16 . FIG. 17 is a schematic plan view of a power conversion device according to an eighth embodiment. FIG. 20 is a schematic cross-sectional view of a power conversion device according to an eighth embodiment, taken along the cross-sectional line XXI-XXI shown in FIG. 20 . FIG. 21 is a schematic cross-sectional view of a power conversion device according to an eighth embodiment, taken along the cross-sectional line XXII-XXII shown in FIG. 20 . FIG. 21 is a schematic cross-sectional view of a power conversion device according to an eighth embodiment, taken along the cross-sectional line XXIII-XXIII shown in FIG. 20 . FIG. 22 is a schematic cross-sectional view of a power conversion device according to a ninth embodiment. FIG. 10 is a schematic cross-sectional view of a power conversion device according to a tenth embodiment. FIG. 17 is a schematic cross-sectional view of a power conversion device according to another modification of the tenth embodiment. FIG. 18 is a schematic cross-sectional view of a power conversion device according to an eleventh embodiment.37 is a schematic cross-sectional view of a power conversion device according to a modification of embodiment 11. FIG. 38 is a schematic cross-sectional view of a power conversion device according to embodiment 12. FIG. 39 is a schematic cross-sectional view of a power conversion device according to a modification of embodiment 12. FIG. 40 is a schematic plan view of a power conversion device according to embodiment 13. FIG. 41 is a schematic cross-sectional view of a power conversion device according to embodiment 13, taken along section line XXXII-XXXII shown in FIG. 31. FIG. 42 is a schematic arrow view of a power conversion device according to embodiment 13, viewed from the direction of arrow XXXIII shown in FIG. 31. FIG. 43 is a schematic plan view of a power conversion device according to a first modification of embodiment 13. FIG. 44 is a schematic cross-sectional view of a power conversion device according to a first modification of embodiment 13, taken along section line XXXV-XXXV shown in FIG. 34. FIG. 45 is a schematic arrow view of a power conversion device according to a first modification of embodiment 13, viewed from the direction of arrow XXXVI shown in FIG. 34. FIG. 46 is a schematic plan view of a power conversion device according to a second modification of embodiment 13. FIG. 47 is a schematic cross-sectional view of a power conversion device according to a second modification of embodiment 13, taken along section line XXXVIII-XXXVIII shown in FIG. 37 is a schematic arrow view of a power conversion device according to a second modified example of embodiment 13, taken in the direction of arrow XXXIX shown in FIG. 37 . FIG. 40 is a schematic plan view of a power conversion device according to a third modified example of embodiment 13. FIG. 41 is a schematic cross-sectional view of a power conversion device according to a third modified example of embodiment 13, taken along the section line XLI-XLI shown in FIG. 40 . FIG. 42 is a schematic arrow view of a power conversion device according to a third modified example of embodiment 13, taken along the section line XLIV-XLIV shown in FIG. 43 . FIG. 43 is a schematic arrow view of a power conversion device according to a fourth modified example of embodiment 13. FIG. 44 is a schematic cross-sectional view of a power conversion device according to a fourth modified example of embodiment 13, taken along the section line XLIV-XLIV shown in FIG. 43 . FIG. 44 is a schematic arrow view of a power conversion device according to a fourth modified example of embodiment 13, taken along the section line XLV-XLIV shown in FIG. 43 . FIG. 45 is a schematic plan view of a power conversion device according to a fifth modified example of embodiment 13. FIG. 46 is a schematic cross-sectional view of a power conversion device according to a fifth modified example of embodiment 13, taken along the section line XLVII-XLVII shown in FIG. 46 . FIG. 47 is a schematic arrow view of a power conversion device according to a fifth modification of the thirteenth embodiment, viewed from the direction of arrow XLVIII shown in FIG. 46 .

[0009] Hereinafter, embodiments of the present disclosure will be described. Note that the same reference numerals are used to designate the same components, and the description thereof will not be repeated.

[0010] First Embodiment. An example of a circuit configuration of a power conversion device 1 according to a first embodiment will be described with reference to FIG. 1 . The power conversion device 1 includes an inverter circuit 2, a transformer circuit 3, a rectifier circuit 4, a smoothing circuit 5, an input terminal 6, an output terminal 7, an input capacitor 8, and a control circuit 10. The power conversion device 1 is, for example, a DC-DC converter mounted on an electric vehicle. An input DC voltage of 100 V to approximately 300 V, for example, from a lithium-ion battery, is input to the input terminal 6. The power conversion device 1 converts the input DC voltage into an output DC voltage of, for example, 12 V to 15 V. The output DC voltage is output from the output terminal 7. The output DC voltage is used, for example, to charge a lead-acid battery.

[0011] The input capacitor 8 is connected to the input terminal 6 and the inverter circuit 2. The input capacitor 8 reduces the ripple voltage.

[0012] The inverter circuit 2 converts the input DC voltage input from the input terminal 6 into a first AC voltage. The inverter circuit 2 includes switching elements 9a, 9b, 9c, and 9d. The switching elements 9a, 9b, 9c, and 9d are power semiconductor elements such as metal oxide semiconductor field effect transistors (MOSFETs) or insulated gate bipolar transistors (IGBTs). The switching elements 9a, 9b, 9c, and 9d are formed of a semiconductor material such as silicon (Si), silicon carbide (SiC), or gallium nitride (GaN).

[0013] The control circuit 10 controls the switching elements 9 a , 9 b , 9 c , and 9 d included in the inverter circuit 2 .

[0014] The transformer circuit 3 converts the first AC voltage output from the inverter circuit 2 into a second AC voltage. The transformer circuit 3 includes a transformer 11. The transformer 11 includes a primary winding 11a and a secondary winding 11b. The primary winding 11a is connected to the inverter circuit 2. The secondary winding 11b is connected to the rectifier circuit 4. The secondary winding 11b is magnetically coupled to the primary winding 11a. The ratio between the first AC voltage and the second AC voltage depends on the turns ratio between the primary winding 11a and the secondary winding 11b. The transformer 11 electrically insulates the input terminal 6 from the output terminal 7.

[0015] The rectifier circuit 4 converts the second AC voltage output from the transformer circuit 3 into an output DC voltage. The rectifier circuit 4 includes rectifier elements 12 a and 12 b. The rectifier elements 12 a and 12 b are power semiconductor elements such as diodes, MOS transistors, or thyristors. The rectifier elements 12 a and 12 b are made of a semiconductor material such as Si, SiC, or GaN.

[0016] The smoothing circuit 5 is connected to the rectifier circuit 4 and the output terminal 7. The smoothing circuit 5 includes a smoothing reactor 13 and a smoothing capacitor 14. In the smoothing circuit 5, the output DC voltage converted by the rectifier circuit 4 is smoothed by the smoothing reactor 13 and the smoothing capacitor 14. Therefore, the output DC voltage output from the output terminal 7 is stabilized.

[0017] In the power conversion device 1, the switching elements 9a, 9b, 9c, and 9d, the rectifying elements 12a and 12b, the transformer 11, and the smoothing reactor 13 are electronic components that generate a large amount of heat. The heat from these electronic components easily causes the transformer 11 and the smoothing reactor 13 to malfunction. Therefore, the power conversion device 1 needs to be cooled.

[0018] The configuration of the power conversion device 1 of this embodiment will be described with reference to Figures 2 to 4. The power conversion device 1 includes a metal base substrate 30, a plurality of circuit components 21, 22, and 23, a cooler 50, and a first heat transfer member 40.

[0019] The metal base substrate 30 includes an end face 31, an end face 32 opposite to the end face 31, a main face 33, and a main face 34 opposite to the main face 33. The end faces 31 and 32 are, for example, both end faces in the longitudinal direction (e.g., z direction) of the metal base substrate 30. The longitudinal direction (e.g., z direction) of the metal base substrate 30 is not particularly limited, but may be the direction of gravity. The end face 31 is the distal end face of the metal base substrate 30 with respect to the cooler 50. The end face 32 is the proximal end face of the metal base substrate 30 with respect to the cooler 50. The end face 32 faces the cooler 50.

[0020] The main surfaces 33 and 34 each extend in the longitudinal direction (e.g., z direction) of the metal base substrate 30 and in the lateral direction (e.g., x direction) of the metal base substrate 30 perpendicular to the longitudinal direction (e.g., z direction) of the metal base substrate 30. The main surfaces 33 and 34 are connected to the end surfaces 31 and 32, respectively. The main surfaces 33 and 34 are both end surfaces of the metal base substrate 30 in the thickness direction (e.g., y direction).

[0021] Referring to FIG. 4, the metal base substrate 30 includes a metal plate 36, an insulating layer 37, and a circuit pattern 38.

[0022] The metal plate 36 is formed of a metal material such as copper, iron, aluminum, a copper alloy, or an aluminum alloy. The metal plate 36 has a thermal conductivity of, for example, 1.0 W / (m·K) or more. The metal plate 36 may have a thermal conductivity of 10.0 W / (m·K) or more, or may have a thermal conductivity of 100.0 W / (m·K) or more. The metal plate 36 supports the multiple circuit components 21, 22, and 23 and conducts heat generated by the multiple circuit components 21, 22, and 23 to the cooler 50. The metal plate 36 is, for example, a rigid substrate.

[0023] The insulating layer 37 has electrical insulation properties and is provided on the metal plate 36. The insulating layer 37 electrically insulates the circuit pattern 38 from the metal plate 36. The insulating layer 37 is formed of an insulating resin such as an epoxy resin, a glass fiber reinforced epoxy resin, or a polyimide resin. In order to improve the thermal conductivity of the insulating layer 37, the insulating layer 37 may be formed of an insulating resin to which a thermally conductive filler such as a silica filler, an alumina filler, or an aluminum nitride filler has been added.

[0024] Heat generated in the multiple circuit components 21, 22, and 23 is transferred through the insulating layer 37 to the metal plate 36 and the first heat transfer member 40. Therefore, it is preferable that the thickness of the insulating layer 37 be as thin as possible as long as this does not adversely affect the electrical insulation ability of the insulating layer 37. The thickness of the insulating layer 37 is, for example, 1 μm or more and 2000 μm or less. The thickness of the insulating layer 37 may also be 1 μm or more and 200 μm or less.

[0025] The circuit pattern 38 is provided on the insulating layer 37. The circuit pattern 38 is formed of a conductive material such as a metal such as copper, nickel, gold, aluminum, silver, or tin, or an alloy containing these metals. The thickness of the circuit pattern 38 is, for example, 1 μm or more and 2000 μm or less.

[0026] 2 to 4, the main surface 33 of the metal base substrate 30 is mainly formed by an insulating layer 37 and a circuit pattern 38. The main surface 34 of the metal base substrate 30 is formed by a metal plate 36.

[0027] Each of the multiple circuit components 21, 22, and 23 includes at least one of the input capacitor 8, switching elements 9a, 9b, 9c, and 9d, transformer 11, rectifying elements 12a and 12b, smoothing reactor 13, and smoothing capacitor 14 shown in FIG. 1 . The multiple circuit components 21, 22, and 23 may further include other electronic components such as resistors. Each of the multiple circuit components 21, 22, and 23 may include wiring components (not shown) such as leads. The heat generated in the multiple circuit components 21, 22, and 23 includes heat generated in the wiring components.

[0028] A plurality of circuit components 21, 22, and 23 are mounted on a main surface 33 of a metal base substrate 30. The circuit components 21, 22, and 23 are electrically connected to a circuit pattern 38. Specifically, the circuit components 21, 22, and 23 may be fixed to the circuit pattern 38 using a conductive bonding member 39 such as solder. The circuit components 21, 22, and 23 may be fixed to the circuit pattern 38 by welding or crimping wiring components (not shown) of the circuit components 21, 22, and 23 to the circuit pattern 38.

[0029] In a plan view of the main surface 33, the circuit components 21, 22, and 23 are arranged, for example, in a direction away from the cooler 50 (for example, the −z direction). The circuit components 21, 22, and 23 are arranged, for example, in a direction perpendicular to the end surface 32 of the metal base substrate 30 facing the cooler 50 (for example, the z direction). The circuit components 21, 22, and 23 are arranged, for example, in a direction perpendicular to the end surface 42 of the first heat transfer member 40 facing the cooler 50 (for example, the z direction). Of the multiple circuit components 21, 22, and 23, the circuit component 21 is arranged farthest from the cooler 50. Of the multiple circuit components 21, 22, and 23, the circuit component 23 is arranged closest to the cooler 50. The circuit component 22 is arranged between the circuit components 21 and 23.

[0030] 2 and 3 , the cooler 50 cools the power conversion device 1 by dissipating heat generated in the multiple circuit components 21, 22, and 23 to the outside of the power conversion device 1. The cooler 50 includes a heat sink 51. The heat sink 51 is formed of a metal such as copper, iron, aluminum, an iron alloy, or an aluminum alloy. The heat sink 51 has a thermal conductivity of, for example, 1.0 W / (m·K) or more. The heat sink 51 may have a thermal conductivity of 10.0 W / (m·K) or more, or may have a thermal conductivity of 100.0 W / (m·K) or more. The heat sink 51 dissipates heat generated in the multiple circuit components 21, 22, and 23 into the air surrounding the heat sink 51.

[0031] A refrigerant flow path may be formed in the cooler 50. The cooler 50 may further include a cooling pipe 52 that penetrates the heat sink 51 as the refrigerant flow path. A refrigerant such as air or water flows through the cooling pipe 52. Heat generated in the multiple circuit components 21, 22, and 23 is carried to the outside of the power conversion device 1 by the refrigerant. For example, the cooling pipe 52 is connected to a refrigerant circulation device (not shown) via a hose (not shown). The hose is, for example, a bendable resin hose. When the refrigerant is water, the refrigerant circulation device is, for example, a cooling water circulation device. The refrigerant circulation device supplies refrigerant at a constant temperature to the cooling pipe 52 at a constant flow rate.

[0032] The cooler 50 is thermally connected to the end surface 32 of the metal base substrate 30. In this specification, the term "member A is thermally connected to member B" means that member A is in direct contact with member B or is connected to member B via a thermally conductive member having a thermal conductivity of 0.5 W / (m·K) or more. Examples of such a thermally conductive member include thermally conductive grease, a thermally conductive sheet, and a thermally conductive adhesive. The cooler 50 is fixed to the end surface 32 of the metal base substrate 30 by crimping, pressure welding, soldering, brazing, adhesion, welding, or the like.

[0033] The first heat transport member 40 transports or diffuses the heat generated in the plurality of circuit components 21 , 22 , and 23 to the cooler 50 .

[0034] The first heat transfer member 40 includes an end surface 41, an end surface 42 opposite the end surface 41, a main surface 43, and a main surface 44 opposite the main surface 43. The end surfaces 41, 42 are, for example, both end surfaces in the longitudinal direction (e.g., z direction) of the first heat transfer member 40. The longitudinal direction (e.g., z direction) of the first heat transfer member 40 is not particularly limited, but may be the direction of gravity. The end surface 41 is the distal end surface of the first heat transfer member 40 relative to the cooler 50. The end surface 42 is the proximal end surface of the first heat transfer member 40 relative to the cooler 50. The end surface 42 faces the cooler 50. The main surfaces 43, 44 are connected to the end surfaces 41, 42, respectively. The main surfaces 43, 44 are both end surfaces in the thickness direction (e.g., y direction) of the first heat transfer member 40.

[0035] The main surface 43 of the first heat transfer member 40 is thermally connected to the main surface 34 of the metal base substrate 30. The main surface 43 of the first heat transfer member 40 is fixed to the main surface 34 of the metal base substrate 30 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The end surface 42 of the first heat transfer member 40 is thermally connected to the cooler 50. The end surface 42 of the first heat transfer member 40 is fixed to the cooler 50 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0036] In a plan view of the main surface 33, the first heat transfer member 40 extends from the end surface 32 of the metal base substrate 30 to the end surface 31 of the metal base substrate 30. The end surface 41 of the first heat transfer member 40 may be flush with the end surface 31 of the metal base substrate 30. The end surface 42 of the first heat transfer member 40 may be flush with the end surface 32 of the metal base substrate 30. In a plan view of the main surface 33, the first heat transfer member 40 overlaps the multiple circuit components 21, 22, and 23. In a plan view of the main surface 33, the first heat transfer member 40 may overlap the entire metal base substrate 30.

[0037] The cross-sectional area of ​​the first heat transfer member 40 may be larger than the cross-sectional area of ​​the metal base substrate 30. The cross-sectional area of ​​the first heat transfer member 40 may be larger than the cross-sectional area of ​​the metal plate 36. The cross-sectional area of ​​the first heat transfer member 40 is the cross-sectional area of ​​the first heat transfer member 40 in a cross section perpendicular to the direction (e.g., z direction) in which heat generated in the multiple circuit components 21, 22, and 23 is mainly transferred. The cross-sectional area of ​​the metal base substrate 30 is the cross-sectional area of ​​the metal base substrate 30 in a cross section perpendicular to the direction (e.g., z direction) in which heat generated in the multiple circuit components 21, 22, and 23 is mainly transferred. The cross-sectional area of ​​the metal plate 36 is the cross-sectional area of ​​the metal plate 36 in a cross section perpendicular to the direction (e.g., z direction) in which heat generated in the multiple circuit components 21, 22, and 23 is mainly transferred.

[0038] The thermal conductivity of the first heat transfer member 40 is equal to or higher than that of the metal plate 36. The first heat transfer member 40 is, for example, a heat pipe, a vapor chamber, or a graphite sheet, or a metal plate integrated with any of these. The first heat transfer member 40 is formed of, for example, a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy, or carbon. The first heat transfer member 40 has, for example, a thermal conductivity of 1.0 W / (m·K) or more. The first heat transfer member 40 may have a thermal conductivity of 10.0 W / (m·K) or more, or may have a thermal conductivity of 100.0 W / (m·K) or more.

[0039] A capillary structure is formed on the inner wall of the heat pipe to enhance its heat transport capacity. Therefore, bending the heat pipe destroys the capillary structure, reducing the heat transport capacity of the heat pipe. However, in this embodiment, when the first heat transport member 40 is a heat pipe, the heat pipe can be used without bending the heat pipe. This prevents a reduction in the heat transport capacity of the heat pipe. Furthermore, when the first heat transport member 40 is a heat pipe and the longitudinal direction of the first heat transport member 40 is the direction of gravity, the performance of the heat pipe is improved, allowing the cooler 50 to be made smaller.

[0040] The operation of the power conversion device 1 of this embodiment will be described. Heat generated in the plurality of circuit components 21, 22, and 23 is transferred to the cooler 50 by both the metal base substrate 30 and the first heat transfer member 40. This reduces the thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, and 23 to the cooler 50. The plurality of circuit components 21, 22, and 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0041] In a comparative example in which the cooler 50 is thermally connected to the main surface 34 of the metal base substrate 30, as the number of the plurality of circuit components 21, 22, and 23 increases and the size of the metal base substrate 30 increases, the size of the cooler 50 also increases. In contrast, in the present embodiment, the cooler 50 is thermally connected to the end surface 32 of the metal base substrate 30 and the end surface 42 of the first heat transfer member 40, rather than to the main surface 34 of the metal base substrate 30. Therefore, the heat generated by the plurality of circuit components 21, 22, and 23 is collected in the cooler 50 by the metal base substrate 30 and the first heat transfer member 40. Even if the number of the plurality of circuit components 21, 22, and 23 increases and the size of the metal base substrate 30 increases, there is no need to increase the size of the cooler 50.

[0042] The power conversion device 1 includes a first heat transfer member 40 in addition to the metal base substrate 30. This reduces the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50. The power conversion device 1 can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1 is facilitated.

[0043] In a plan view of the main surface 33, the circuit components 21, 22, and 23 are arranged in a direction (e.g., z direction) perpendicular to the end surface 32 of the metal base substrate 30 facing the cooler 50. Therefore, in a plan view of the main surface 33, the size of the metal base substrate 30 is reduced in a direction (e.g., x direction) along the end surface 32 of the metal base substrate 30. In a plan view of the main surface 33, the size of the cooler 50 is reduced in a direction (e.g., x direction) along the end surface 32 of the metal base substrate 30.

[0044] The effects of the power conversion device 1 of this embodiment will be described. The power conversion device 1 includes a metal base substrate 30 including a plurality of circuit components 21, 22, and 23, a metal plate 36, a first heat transfer member 40, and a cooler 50. The metal base substrate 30 includes a first main surface (main surface 33) on which the plurality of circuit components 21, 22, and 23 are mounted, and a first end surface (end surface 32) connected to the first main surface. The thermal conductivity of the first heat transfer member 40 is equal to or greater than that of the metal plate 36. The first heat transfer member 40 includes a second main surface (main surface 43) and a second end surface (end surface 42) connected to the second main surface and facing the cooler 50. The first end surface and the second end surface are thermally connected to the cooler 50. The second main surface is thermally connected to the metal base substrate 30.

[0045] Therefore, heat generated in the plurality of circuit components 21, 22, 23 is transferred to the cooler 50 by both the metal base substrate 30 and the first heat transfer member 40. The cooler 50 is thermally connected to the first end face (end face 32) of the metal base substrate 30 and the second end face (end face 42) of the first heat transfer member 40. The heat generated in the plurality of circuit components 21, 22, 23 is collected in the cooler 50 by the metal base substrate 30 and the first heat transfer member 40. Even if the number of the plurality of circuit components 21, 22, 23 increases and the size of the metal base substrate 30 increases, the plurality of circuit components 21, 22, 23 can be cooled without increasing the size of the cooler 50.

[0046] In the power conversion device 1, the metal base substrate 30 includes a third end face (end face 31) opposite to the first end face (end face 32). In a plan view of the first main surface (main surface 33), the first heat transfer member 40 extends from the first end face to the third end face.

[0047] Therefore, heat generated in a circuit component (e.g., circuit component 21) located far from the cooler 50 can be transferred to the cooler 50 with lower thermal resistance. This improves the degree of freedom in arranging the multiple circuit components 21, 22, and 23. This facilitates the thermal design of the power conversion device 1. The cooler 50 can be made smaller.

[0048] Second Embodiment A power conversion device 1b according to a second embodiment will be described with reference to Fig. 5. The power conversion device 1b of this embodiment has a similar configuration to the power conversion device 1 of the first embodiment, but differs mainly in the following respects.

[0049] The first heat transfer member 40 is warped relative to the metal base substrate 30. An air layer 55 exists between the metal base substrate 30 and the first heat transfer member 40. The distance between the metal base substrate 30 and the first heat transfer member 40 decreases with increasing distance from the cooler 50 (i.e., from the end face 42 to the end face 41). The distance between the end face 32 and the end face 42 is greater than the distance between the end face 31 and the end face 41. The distance between the end face 32 and the end face 42 is, for example, 10 μm or less. The distance between the end face 31 and the end face 41 is, for example, 0 μm.

[0050] As shown in FIG. 2 , in a plan view of the main surface 33, in the arrangement direction (e.g., z direction) of the multiple circuit components 21, 22, and 23, the length of the heat transfer path from the circuit components to the cooler 50 increases with increasing distance from the cooler 50. In contrast, the thickness of the air layer 55 decreases with increasing distance from the cooler 50. A portion of the heat generated by the circuit components 21, 22, and 23 that are located farther from the cooler 50 is transferred to the cooler 50 through the first heat transfer member 40 and the thinner air layer 55. The thermal conductivity of the air layer 55 is greater than the thermal conductivity of the metal base substrate 30 and the thermal conductivity of the first heat transfer member 40. Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component located farther from the cooler 50 (e.g., circuit component 21) to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component located closer to the cooler 50 (e.g., circuit component 23) to the cooler 50 decreases.

[0051] The power conversion device 1b of this embodiment has the following advantages in addition to the advantages of the power conversion device 1 of the first embodiment.

[0052] In the power converter 1 b, the distance between the metal base substrate 30 and the first heat transfer member 40 decreases with increasing distance from the cooler 50 .

[0053] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. The power conversion device 1b can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1b is facilitated.

[0054] Third Embodiment A power conversion device 1c according to a third embodiment will be described with reference to Fig. 6. The power conversion device 1c of this embodiment has a similar configuration to the power conversion device 1 of the first embodiment, but differs mainly in the following respects.

[0055] In the power conversion device 1c, the contact area between the metal base substrate 30 and the first heat transfer member 40 increases with increasing distance from the cooler 50 (i.e., from the end face 42 to the end face 41). For example, the surface roughness of the main surface 34 of the first heat transfer member 40 decreases with increasing distance from the cooler 50.

[0056] 2 , in a plan view of the main surface 33, in the arrangement direction (e.g., z direction) of the plurality of circuit components 21, 22, 23, the length of the heat transfer path from the circuit components to the cooler 50 increases with increasing distance from the cooler 50. In contrast, as the contact area between the metal base substrate 30 and the first heat transfer member 40 increases, the thermal resistance between the metal base substrate 30 and the first heat transfer member 40 decreases. Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 decreases.

[0057] The power conversion device 1c of this embodiment has the following advantages in addition to the advantages of the power conversion device 1 of the first embodiment.

[0058] In the power converter 1 c, the contact area between the metal base substrate 30 and the first heat transfer member 40 increases with increasing distance from the cooler 50 .

[0059] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. The power conversion device 1c can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1c is facilitated.

[0060] Fourth Embodiment A power conversion device 1d according to a fourth embodiment will be described with reference to Figures 7 to 9. The power conversion device 1d of this embodiment has a configuration similar to that of the power conversion device 1 of the first embodiment, but differs mainly in the following respects.

[0061] In the power conversion device 1d, the first heat transfer member 40 includes a plurality of heat transfer portions 45, 46. The heat transfer portions 45, 46 are each thermally connected to the main surface 34 of the metal base substrate 30. The heat transfer portions 45, 46 are each fixed to the main surface 34 of the metal base substrate 30 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The main surface 43 of the first heat transfer member 40 is composed of the main surface of the heat transfer portion 45 facing the main surface 34 of the metal base substrate 30 and the main surface of the heat transfer portion 46 facing the main surface 34 of the metal base substrate 30. The heat transfer portions 45, 46 are each thermally connected to the cooler 50. The heat transfer portions 45, 46 are each fixed to the cooler 50 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0062] In a plan view of the main surface 33, the heat transporting portions 45, 46 each extend from the end surface 32 of the metal base substrate 30 to the end surface 31 of the metal base substrate 30. The distal end surface of the heat transporting portion 45 relative to the cooler 50 and the distal end surface of the heat transporting portion 46 relative to the cooler 50 may be flush with the end surface 31 of the metal base substrate 30. The proximal end surface of the heat transporting portion 45 relative to the cooler 50 and the proximal end surface of the heat transporting portion 46 relative to the cooler 50 may be flush with the end surface 32 of the metal base substrate 30. The end surface 41 of the first heat transport member 40 is defined by the distal end surface of the heat transporting portion 45 relative to the cooler 50 and the distal end surface of the heat transporting portion 46 relative to the cooler 50. The end surface 42 of the first heat transport member 40 is defined by the proximal end surface of the heat transporting portion 45 relative to the cooler 50 and the proximal end surface of the heat transporting portion 46 relative to the cooler 50.

[0063] In the power conversion device 1d, in a plan view of the main surface 33, the first heat transfer member 40 does not overlap the plurality of circuit components 21, 22, and 23. Specifically, in a plan view of the main surface 33, the heat transport portions 45 and 46 do not overlap the plurality of circuit components 21, 22, and 23. In a plan view of the main surface 33, the plurality of circuit components 21, 22, and 23 are disposed between the heat transport portion 45 and the heat transport portion 46. In a plan view of the main surface 33, the heat transport portion 45 and the heat transport portion 46 may be disposed symmetrically with respect to the plurality of circuit components 21, 22, and 23. In a plan view of the main surface 33, the distance between the plurality of circuit components 21, 22, and 23 and the heat transport portion 45 may be equal to the distance between the plurality of circuit components 21, 22, and 23 and the heat transport portion 46.

[0064] The power conversion device 1d further includes a metal support member 60. The metal support member 60 includes an end face 61, an end face 62 opposite to the end face 61, and a main surface 63. The end faces 61, 62 are, for example, both end faces of the metal support member 60 in the longitudinal direction (e.g., the z direction). The longitudinal direction (e.g., the z direction) of the metal support member 60 is not particularly limited, but may be the direction of gravity. The end face 61 is a distal end face of the metal support member 60 relative to the cooler 50. The end face 62 is a proximal end face of the metal support member 60 relative to the cooler 50. The end face 62 faces the cooler 50. The main surface 63 is connected to the end faces 61, 62. The main surface 63 is an end face of the metal support member 60 in the thickness direction (e.g., the y direction). The main surface 63 faces the main surface 44 of the first heat transfer member 40.

[0065] The metal support member 60 supports the first heat transport member 40. Specifically, grooves 65, 66 are provided in the main surface 63. The heat transport portion 45 is housed in the groove 65. The heat transport portion 46 is housed in the groove 66. The main surface 63 of the metal support member 60 may be flush with the main surface of the heat transport portion 45 facing the main surface 34 of the metal base substrate 30 and the main surface of the heat transport portion 46 facing the main surface 34 of the metal base substrate 30.

[0066] The first heat transfer member 40 is thermally connected to the metal support member 60. The first heat transfer member 40 is fixed to the metal support member 60 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The heat transfer portions 45, 46 are thermally connected to the metal support member 60. The heat transfer portions 45, 46 are fixed to the metal support member 60 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0067] A main surface 63 of the metal support member 60 is thermally connected to the main surface 34 of the metal base substrate 30. The main surface 63 of the metal support member 60 is fixed to the main surface 34 of the metal base substrate 30 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. An end surface 62 of the metal support member 60 is thermally connected to the cooler 50. The end surface 62 of the metal support member 60 is fixed to the cooler 50 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0068] In a plan view of the main surface 33, the metal support member 60 overlaps the multiple circuit components 21, 22, and 23. In a plan view of the main surface 33, the metal support member 60 may overlap the entire metal base substrate 30 and the entire first heat transfer member 40. In a plan view of the main surface 33, the metal support member 60 extends from the end face 32 of the metal base substrate 30 to the end face 31 of the metal base substrate 30. In a plan view of the main surface 33, the metal support member 60 extends from the end face 42 of the first heat transfer member 40 to the end face 41 of the first heat transfer member 40.

[0069] The cross-sectional area of ​​the metal support member 60 may be larger than that of the metal base substrate 30. The cross-sectional area of ​​the metal support member 60 may be larger than that of the metal plate 36. The cross-sectional area of ​​the metal support member 60 may be larger than that of the first heat transfer member 40. The cross-sectional area of ​​the metal support member 60 is the cross-sectional area of ​​the metal support member 60 in a cross section perpendicular to the direction in which heat generated in the multiple circuit components 21, 22, and 23 is mainly transferred (e.g., the z direction).

[0070] The thermal conductivity of the metal support member 60 is equal to or higher than that of the metal plate 36. The thermal conductivity of the metal support member 60 is equal to or lower than that of the first heat transfer member 40. The metal support member 60 is formed of a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy. The metal support member 60 has a thermal conductivity of, for example, 1.0 W / (m·K) or more. The metal support member 60 may have a thermal conductivity of 10.0 W / (m·K) or more, or may have a thermal conductivity of 100.0 W / (m·K) or more. The metal support member 60 transfers heat generated in the multiple circuit components 21, 22, and 23 to the cooler 50. The metal support member 60 is, for example, a rigid plate.

[0071] The power conversion device 1d of this embodiment has the following advantages in addition to the advantages of the power conversion device 1 of the first embodiment.

[0072] The power conversion device 1d further includes a metal support member 60 that supports the first heat transfer member 40. The metal base substrate 30 includes a third main surface (main surface 34) opposite the first main surface (main surface 33). The third main surface is connected to the first end surface (end surface 32). The metal support member 60 includes a fourth main surface (main surface 63) thermally connected to the third main surface, and a fourth end surface (end surface 62) connected to the fourth main surface. The fourth end surface is thermally connected to the cooler 50.

[0073] Therefore, heat generated in the plurality of circuit components 21, 22, and 23 is transferred to the cooler 50 not only by the metal base substrate 30 and the first heat transfer member 40 but also by the metal support member 60. The thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, and 23 to the cooler 50 is reduced. The cooler 50 is thermally connected to the first end face (end face 32) of the metal base substrate 30, the second end face (end face 42) of the first heat transfer member 40, and the fourth end face (end face 62) of the metal support member 60. The heat generated in the plurality of circuit components 21, 22, and 23 is collected in the cooler 50 by the metal base substrate 30, the first heat transfer member 40, and the metal support member 60. Even if the number of the plurality of circuit components 21, 22, and 23 increases and the size of the metal base substrate 30 increases, the plurality of circuit components 21, 22, and 23 can be cooled without increasing the size of the cooler 50.

[0074] In the power conversion device 1d, in addition to the second end face (end face 42) of the first heat transfer member 40, the fourth end face (end face 62) of the metal support member 60 that supports the first heat transfer member 40 is also thermally connected to the cooler 50. This makes it easy to fix the first heat transfer member 40 to the cooler 50. Furthermore, if the metal support member 60 is a rigid plate, the mechanical strength of the power conversion device 1d is improved.

[0075] Fifth Embodiment A power conversion device 1e according to a fifth embodiment will be described with reference to Figures 10 and 11. The power conversion device 1e of this embodiment has a similar configuration to the power conversion device 1d of the fourth embodiment, but differs mainly in the following respects.

[0076] The power conversion device 1e further includes circuit components 24, 25, and 26. In a plan view of the main surface 33, the circuit components 24, 25, and 26 are arranged, for example, in a direction away from the cooler 50 (-z direction). In a plan view of the main surface 33, the circuit components 24, 25, and 26 are arranged, for example, in the longitudinal direction of the metal base substrate 30 (z direction). In a plan view of the main surface 33, the circuit components 24, 25, and 26 are arranged, for example, in a direction perpendicular to the end surface 32 of the metal base substrate 30 (z direction). In a plan view of the main surface 33, the circuit components 24, 25, and 26 are arranged, for example, in a direction perpendicular to the end surface 42 of the first heat transfer member 40 (z direction).

[0077] Of the circuit components 24, 25, and 26, the circuit component 24 is arranged farthest from the cooler 50. Of the circuit components 24, 25, and 26, the circuit component 26 is arranged closest to the cooler 50. The circuit component 25 is arranged between the circuit components 24 and 26. The circuit components 24, 25, and 26 are arranged offset from the circuit components 21, 22, and 23 in the short-side direction (e.g., the x-direction) of the metal base substrate 30.

[0078] Each of the circuit components 24, 25, and 26 includes at least one of the input capacitor 8, switching elements 9a, 9b, 9c, and 9d, transformer 11, rectifying elements 12a and 12b, smoothing reactor 13, and smoothing capacitor 14 shown in FIG. 1 . The circuit components 24, 25, and 26 may further include other electronic components such as resistors. Each of the circuit components 24, 25, and 26 may include wiring components (not shown) such as leads. The heat generated in the multiple circuit components 24, 25, and 26 includes heat generated in the wiring components.

[0079] In a plan view of the main surface 33, the first heat transport member 40 overlaps the plurality of circuit components 21, 22, 23, 24, 25, and 26. Specifically, in a plan view of the main surface 33, the heat transport portion 45 overlaps the circuit components 21, 22, and 23. In a plan view of the main surface 33, the heat transport portion 46 overlaps the circuit components 24, 25, and 26.

[0080] The power conversion device 1e of this embodiment has the following advantages in addition to the advantages of the power conversion device 1d of the fourth embodiment.

[0081] In the power conversion device 1 e, the plurality of circuit components 21 , 22 , 23 , 24 , 25 , and 26 overlap the first heat transfer member 40 in a plan view of the first main surface (main surface 33 ).

[0082] Therefore, the heat transfer path from the plurality of circuit components 21, 22, 23, 24, 25, and 26 to the cooler 50 is shortened, and the thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, 23, 24, 25, and 26 to the cooler 50 is reduced. Even if the number of the plurality of circuit components 21, 22, 23, 24, 25, and 26 increases and the size of the metal base substrate 30 increases, the plurality of circuit components 21, 22, 23, 24, 25, and 26 can be cooled without increasing the size of the cooler 50.

[0083] Sixth Embodiment A power conversion device 1f according to a sixth embodiment will be described with reference to Figures 12 to 15. The power conversion device 1f of this embodiment has a configuration similar to that of the power conversion device 1d of the fourth embodiment, but differs mainly in the following respects.

[0084] The first heat transfer member 40 includes a heat transfer portion 47 in addition to the heat transfer portions 45 and 46. The heat transfer portion 47 is also thermally connected to the main surface 34 of the metal base substrate 30. The heat transfer portion 47 is fixed to the main surface 34 of the metal base substrate 30 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The main surface 43 of the first heat transfer member 40 is composed of the main surface of the heat transfer portion 45 facing the main surface 34 of the metal base substrate 30, the main surface of the heat transfer portion 46 facing the main surface 34 of the metal base substrate 30, and the main surface of the heat transfer portion 47 facing the main surface 34 of the metal base substrate 30. The heat transfer portion 47 is also thermally connected to the cooler 50. The heat transfer portion 47 is fixed to the cooler 50 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0085] In a plan view of the main surface 33, the heat transporting portion 47 also extends from the end surface 32 of the metal base substrate 30 to the end surface 31 of the metal base substrate 30. A distal end surface of the heat transporting portion 47 relative to the cooler 50 may be flush with the end surface 31 of the metal base substrate 30. A proximal end surface of the heat transporting portion 47 relative to the cooler 50 may be flush with the end surface 32 of the metal base substrate 30. The end surface 41 of the first heat transport member 40 is made up of the distal end surface of the heat transporting portion 45 relative to the cooler 50, the distal end surface of the heat transporting portion 46 relative to the cooler 50, and the distal end surface of the heat transporting portion 47 relative to the cooler 50. The end surface 42 of the first heat transport member 40 is made up of the proximal end surface of the heat transporting portion 45 relative to the cooler 50, the proximal end surface of the heat transporting portion 46 relative to the cooler 50, and the proximal end surface of the heat transporting portion 47 relative to the cooler 50.

[0086] In a plan view of the main surface 33, a portion of the first heat transport member 40 overlaps the plurality of circuit components 21, 22, and 23. For example, in a plan view of the main surface 33, the heat transport portion 47 overlaps the plurality of circuit components 21, 22, and 23.

[0087] The metal support member 60 also supports the heat transporting portion 47. Specifically, a groove 67 is provided in the main surface 63. The heat transporting portion 47 is housed in the groove 67. The main surface 63 of the metal support member 60 may be flush with the main surface of the heat transporting portion 47 that faces the main surface 34 of the metal base substrate 30. The heat transporting portion 47 is also thermally connected to the metal support member 60. The heat transporting portion 47 is fixed to the metal support member 60 by caulking, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0088] In a plan view of the main surface 33, the heat transporting portion 45 includes a side surface 45s facing the plurality of circuit components 21, 22, and 23. In a plan view of the main surface 33, the heat transporting portion 46 includes a side surface 46s facing the plurality of circuit components 21, 22, and 23. In a plan view of the main surface 33, the heat transporting portion 45 and the heat transporting portion 46 may be disposed symmetrically with respect to the heat transporting portion 47. In a plan view of the main surface 33, the heat transporting portion 45 and the heat transporting portion 46 may be disposed symmetrically with respect to the plurality of circuit components 21, 22, and 23.

[0089] In a plan view of the main surface 33, the distance between the heat transport portion 45 and the plurality of circuit components 21, 22, and 23 decreases with increasing distance from the cooler 50. Specifically, in a plan view of the main surface 33, the side surface 45s of the heat transport portion 45 approaches the plurality of circuit components 21, 22, and 23 with increasing distance from the cooler 50. In a plan view of the main surface 33, the side surface 45s of the heat transport portion 45 is inclined with respect to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., the z direction). In a plan view of the main surface 33, in a direction (e.g., the x direction) perpendicular to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., the z direction), the distance between the circuit component 22 and the heat transport portion 45 is smaller than the distance between the circuit component 23 and the heat transport portion 45. In a planar view of the main surface 33, in a direction (e.g., the x direction) perpendicular to the direction in which the multiple circuit components 21, 22, and 23 are arranged (e.g., the z direction), the distance between the circuit component 21 and the heat transport portion 45 is smaller than the distance between the circuit component 22 and the heat transport portion 45.

[0090] In a plan view of the main surface 33, the distance between the heat transport portion 46 and the plurality of circuit components 21, 22, and 23 decreases with increasing distance from the cooler 50. Specifically, in a plan view of the main surface 33, the side surface 46s of the heat transport portion 46 approaches the plurality of circuit components 21, 22, and 23 with increasing distance from the cooler 50. In a plan view of the main surface 33, the side surface 46s of the heat transport portion 46 is inclined with respect to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., the z direction). In a plan view of the main surface 33, in a direction (e.g., the x direction) perpendicular to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., the z direction), the distance between the circuit component 22 and the heat transport portion 46 is smaller than the distance between the circuit component 23 and the heat transport portion 46. In a planar view of the main surface 33, in a direction (e.g., the x direction) perpendicular to the direction in which the multiple circuit components 21, 22, and 23 are arranged (e.g., the z direction), the distance between the circuit component 21 and the heat transport portion 46 is smaller than the distance between the circuit component 22 and the heat transport portion 46.

[0091] In a plan view of the main surface 33, in the arrangement direction (e.g., z direction) of the plurality of circuit components 21, 22, 23, the length of the heat transfer path from the circuit components to the cooler 50 increases with increasing distance from the cooler 50. In contrast, in a direction (e.g., x direction) perpendicular to the arrangement direction (e.g., z direction) of the plurality of circuit components 21, 22, 23 in a plan view of the main surface 33, the distance between the circuit component and at least one of the plurality of heat transport portions 45, 46, 47 (e.g., heat transport portion 45, 46) decreases with increasing distance from the cooler 50. Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 decreases.

[0092] In a modification of this embodiment, the heat transport portions 45 and 46 may overlap at least one of the circuit components 21 , 22 , and 23 in a plan view of the main surface 33 .

[0093] The power conversion device 1f of this embodiment has the following advantages in addition to the advantages of the power conversion device 1d of the fourth embodiment.

[0094] In the power conversion device 1f, the first heat transfer member 40 includes a plurality of heat transfer portions 45, 46, and 47. Each of the plurality of heat transfer portions 45, 46, and 47 is thermally connected to the metal base substrate 30 and the cooler 50. The distance between the plurality of circuit components 21, 22, and 23 and at least one of the plurality of heat transfer portions 45, 46, and 47 (e.g., the heat transfer portion 45 or 46) decreases with increasing distance from the cooler 50.

[0095] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. The power conversion device 1f can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1f is facilitated.

[0096] The power conversion device 1f includes more heat transport portions 45, 46, and 47. This reduces the thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, and 23 to the cooler 50. The plurality of circuit components 21, 22, and 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0097] In the power conversion device 1f, in a planar view of the first main surface (main surface 33), as the distance from the cooler 50 increases, the side surface (e.g., side surface 45s, 46s) of at least one of the multiple heat transport portions 45, 46, 47 (e.g., heat transport portion 45, 46) facing the multiple circuit components 21, 22, 23 approaches the multiple circuit components 21, 22, 23.

[0098] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. The power conversion device 1f can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1f is facilitated.

[0099] In the power conversion device 1f, in a plan view of the first principal surface (principal surface 33), the plurality of circuit components 21, 22, 23 are arranged in a direction (e.g., the −z direction) away from the cooler 50. In a plan view of the first principal surface, at least one of the plurality of heat transport portions 45, 46, 47 (e.g., the heat transport portion 45, 46) is inclined with respect to the direction in which the plurality of circuit components 21, 22, 23 are arranged.

[0100] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1f is facilitated.

[0101] Seventh Embodiment A power conversion device 1g according to a seventh embodiment will be described with reference to Fig. 16 to Fig. 19. The power conversion device 1g of this embodiment has a similar configuration to the power conversion device 1f of the sixth embodiment, but differs mainly in the following respects.

[0102] In a plan view of the main surface 33, the width of the heat transport portion 45 increases with increasing distance from the cooler 50. A side surface 45s of the heat transport portion 45 is inclined with respect to the direction in which the multiple circuit components 21, 22, and 23 are arranged (e.g., the z direction). Therefore, in a plan view of the main surface 33, the distance between the multiple circuit components 21, 22, and 23 and the heat transport portion 45 decreases with increasing distance from the cooler 50. In a plan view of the main surface 33, the side surface 45s of the heat transport portion 45 approaches the multiple circuit components 21, 22, and 23 with increasing distance from the cooler 50.

[0103] In a plan view of the main surface 33, the width of the heat transporting portion 46 increases with increasing distance from the cooler 50. A side surface 46s of the heat transporting portion 46 is inclined with respect to the direction in which the multiple circuit components 21, 22, and 23 are arranged (e.g., the z direction). Therefore, in a plan view of the main surface 33, the distance between the multiple circuit components 21, 22, and 23 and the heat transporting portion 46 decreases with increasing distance from the cooler 50. In a plan view of the main surface 33, the side surface 46s of the heat transporting portion 46 approaches the multiple circuit components 21, 22, and 23 with increasing distance from the cooler 50.

[0104] In a plan view of the main surface 33, in the arrangement direction (e.g., z direction) of the plurality of circuit components 21, 22, 23, the length of the heat transfer path from the circuit components to the cooler 50 increases with increasing distance from the cooler 50. In contrast, in a direction (e.g., x direction) perpendicular to the arrangement direction (e.g., z direction) of the plurality of circuit components 21, 22, 23 in a plan view of the main surface 33, the distance between the circuit component and at least one of the plurality of heat transport portions 45, 46, 47 (e.g., heat transport portion 45, 46) decreases with increasing distance from the cooler 50. Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 decreases.

[0105] The power conversion device 1g of this embodiment has the following effects similar to those of the power conversion device 1f of the sixth embodiment.

[0106] In the power conversion device 1 g , in a plan view of the first main surface (main surface 33 ), the width of at least one of the heat transporting portions 45 , 46 , 47 (for example, the heat transporting portions 45 and 46 ) increases with increasing distance from the cooler 50 .

[0107] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. The power conversion device 1g can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1g is facilitated.

[0108] In the power conversion device 1g, in a plan view of the first principal surface (principal surface 33), the plurality of circuit components 21, 22, 23 are arranged in a direction (-z direction) away from the cooler 50. In a plan view of the first principal surface, a side surface (e.g., side surface 45s, 46s) of at least one of the plurality of heat transport portions 45, 46, 47 (e.g., heat transport portion 45, 46) is inclined with respect to the direction in which the plurality of circuit components 21, 22, 23 are arranged.

[0109] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. The power conversion device 1g can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1g is facilitated.

[0110] Eighth Embodiment A power conversion device 1h according to an eighth embodiment will be described with reference to Fig. 20 to Fig. 23. The power conversion device 1h of this embodiment has a similar configuration to the power conversion device 1g of the seventh embodiment, but differs mainly in the following respects.

[0111] In a plan view of the main surface 33, the side surface 45s of the heat transporting portion 45 has a stepped shape. Therefore, in a plan view of the main surface 33, the width of the heat transporting portion 45 increases with increasing distance from the cooler 50. In a plan view of the main surface 33, the distance between the heat transporting portion 45 and the multiple circuit components 21, 22, and 23 decreases with increasing distance from the cooler 50. In a plan view of the main surface 33, the side surface 45s of the heat transporting portion 45 approaches the multiple circuit components 21, 22, and 23 with increasing distance from the cooler 50.

[0112] Specifically, the heat transport portion 45 includes heat transport elements 45a, 45b, and 45c. In a plan view of the main surface 33, the heat transport element 45a faces the circuit component 21 but does not face the circuit components 22 and 23. In a plan view of the main surface 33, the heat transport element 45b faces the circuit components 21 and 22 but does not face the circuit component 23. In a plan view of the main surface 33, the heat transport element 45c faces the circuit components 21, 22, and 23.

[0113] In a plan view of the main surface 33, the heat transport element 45c is longer than the heat transport elements 45a and 45b. In a plan view of the main surface 33, the heat transport element 45b is longer than the heat transport element 45a. A distal end face of the heat transport element 45a relative to the cooler 50 may be flush with the end face 31 of the metal base substrate 30. A distal end face of the heat transport element 45b relative to the cooler 50 may be flush with the end face 31 of the metal base substrate 30. A distal end face of the heat transport element 45c relative to the cooler 50 may be flush with the end face 31 of the metal base substrate 30. A proximal end face of the heat transport element 45a relative to the cooler 50 is away from the end face 32 of the metal base substrate 30. A proximal end face of the heat transport element 45b relative to the cooler 50 is away from the end face 32 of the metal base substrate 30. The proximal end face of the heat transport element 45 c relative to the cooler 50 may be flush with the end face 32 of the metal base substrate 30 .

[0114] In a plan view of the main surface 33, in a direction (e.g., x direction) perpendicular to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., z direction), the heat transport element 45a is arranged closest to the plurality of circuit components 21, 22, and 23 among the heat transport elements 45a, 45b, and 45c. In a plan view of the main surface 33, in a direction (e.g., x direction) perpendicular to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., z direction), the heat transport element 45c is arranged farthest from the plurality of circuit components 21, 22, and 23 among the heat transport elements 45a, 45b, and 45c. In a plan view of the main surface 33, in a direction (e.g., x direction) perpendicular to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., z direction), the heat transport element 45b is arranged between the heat transport elements 45a and 45c. The heat transport element 45b is thermally connected to the heat transport element 45a and the heat transport element 45c. The heat transport elements 45a, 45b, and 45c may be integrated into a single component.

[0115] In a plan view of the main surface 33, the side surface 46s of the heat transporting portion 46 has a stepped shape. Therefore, in a plan view of the main surface 33, the width of the heat transporting portion 46 increases with increasing distance from the cooler 50. In a plan view of the main surface 33, the distance between the heat transporting portion 46 and the multiple circuit components 21, 22, and 23 decreases with increasing distance from the cooler 50. In a plan view of the main surface 33, the side surface 46s of the heat transporting portion 46 approaches the multiple circuit components 21, 22, and 23 with increasing distance from the cooler 50.

[0116] Specifically, the heat transport portion 46 includes heat transport elements 46a, 46b, and 46c. In a plan view of the main surface 33, the heat transport element 46a faces the circuit component 21, but does not face the circuit components 22 and 23. In a plan view of the main surface 33, the heat transport element 46b faces the circuit components 21 and 22, but does not face the circuit component 23. In a plan view of the main surface 33, the heat transport element 46c faces the circuit components 21, 22, and 23.

[0117] In a plan view of the main surface 33, the heat transport element 46c is longer than the heat transport elements 46a and 46b. In a plan view of the main surface 33, the heat transport element 46b is longer than the heat transport element 46a. A distal end face of the heat transport element 46a relative to the cooler 50 may be flush with the end face 31 of the metal base substrate 30. A distal end face of the heat transport element 46b relative to the cooler 50 may be flush with the end face 31 of the metal base substrate 30. A distal end face of the heat transport element 46c relative to the cooler 50 may be flush with the end face 31 of the metal base substrate 30. A proximal end face of the heat transport element 46a relative to the cooler 50 is away from the end face 32 of the metal base substrate 30. A proximal end face of the heat transport element 46b relative to the cooler 50 is away from the end face 32 of the metal base substrate 30. The proximal end face of the heat transport element 46 c relative to the cooler 50 may be flush with the end face 32 of the metal base substrate 30 .

[0118] In a plan view of the main surface 33, in a direction (e.g., x direction) perpendicular to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., z direction), the heat transport element 46a is arranged closest to the plurality of circuit components 21, 22, and 23 among the heat transport elements 46a, 46b, and 46c. In a plan view of the main surface 33, in a direction (e.g., x direction) perpendicular to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., z direction), the heat transport element 46c is arranged farthest from the plurality of circuit components 21, 22, and 23 among the heat transport elements 46a, 46b, and 46c. In a plan view of the main surface 33, in a direction (e.g., x direction) perpendicular to the direction in which the plurality of circuit components 21, 22, and 23 are arranged (e.g., z direction), the heat transport element 46b is arranged between the heat transport elements 46a and 46c. The heat transport element 46b is thermally connected to the heat transport element 46a and the heat transport element 46c. The heat transport elements 46a, 46b, and 46c may be integrated into a single component.

[0119] In a plan view of the main surface 33, in the arrangement direction (e.g., z direction) of the plurality of circuit components 21, 22, 23, the length of the heat transfer path from the circuit components to the cooler 50 increases with increasing distance from the cooler 50. In contrast, the side surfaces 45s, 46s of the heat transport portions 45, 46 have a stepped shape. In a plan view of the main surface 33, in a direction (e.g., x direction) perpendicular to the arrangement direction (e.g., z direction) of the plurality of circuit components 21, 22, 23, the distance between the circuit component and at least one of the plurality of heat transport portions 45, 46 (e.g., heat transport portion 45, 46) decreases with increasing distance from the cooler 50. Therefore, the difference in thermal resistance between the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 decreases.

[0120] The power conversion device 1h of this embodiment has the following effects similar to those of the power conversion device 1g of the seventh embodiment.

[0121] In the power conversion device 1h, in a plan view of the first main surface (main surface 33), the side surface (e.g., side surface 45s, 46s) of at least one of the multiple heat transport portions 45, 46 (e.g., heat transport portions 45, 46) has a stepped shape.

[0122] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. The power conversion device 1h can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1h is facilitated.

[0123] Ninth Embodiment A power conversion device 1i according to a ninth embodiment will be described with reference to Fig. 24. The power conversion device 1i of this embodiment has a configuration similar to that of the power conversion device 1d of the fourth embodiment, but differs mainly in the following respects.

[0124] The distance between the metal base substrate 30 and the first heat transfer member 40 decreases with increasing distance from the cooler 50. Therefore, the distance between the first heat transfer member 40 and the plurality of circuit components 21, 22, 23 decreases with increasing distance from the cooler 50.

[0125] Specifically, the distance between the metal base substrate 30 and the first heat transfer member 40 in the thickness direction (e.g., y direction) of the metal base substrate 30 decreases with increasing distance from the cooler 50. The distance between the circuit component 22 and the first heat transfer member 40 is shorter than the distance between the circuit component 23 and the first heat transfer member 40. The distance between the circuit component 21 and the first heat transfer member 40 is shorter than the distance between the circuit component 22 and the first heat transfer member 40.

[0126] In a plan view of the main surface 33, in the arrangement direction (e.g., z direction) of the plurality of circuit components 21, 22, 23, the length of the heat transfer path from the circuit components to the cooler 50 increases with increasing distance from the cooler 50. In contrast, in the thickness direction (e.g., y direction) of the metal base substrate 30, the distance between the circuit components and the first heat transfer member 40 decreases with increasing distance from the cooler 50. Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 decreases.

[0127] The power conversion device 1i of this embodiment has the following effects in addition to the effects of the power conversion device 1d of the fourth embodiment.

[0128] In the power converter 1 i , the distance between the metal base substrate 30 and the first heat transfer member 40 decreases with increasing distance from the cooler 50 .

[0129] Therefore, the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50 is reduced. The power conversion device 1i can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. The degree of freedom in the placement of the multiple circuit components 21, 22, and 23 is improved. The thermal design of the power conversion device 1i is facilitated.

[0130] Tenth Embodiment A power conversion device 1j according to a tenth embodiment will be described with reference to Fig. 25. The power conversion device 1j of this embodiment has a configuration similar to that of the power conversion device 1d of the fourth embodiment, but differs mainly in the following respects.

[0131] The power conversion device 1j further includes a metal member 70. The metal member 70 includes an end face 71, an end face 72 opposite to the end face 71, and a main surface 73. The end face 71 is a distal end face of the metal member 70 with respect to the cooler 50. The end face 71 faces the end face 32 of the metal base substrate 30. The end face 72 is a proximal end face of the metal member 70 with respect to the cooler 50. The end face 72 faces the cooler 50. The end faces 71 and 72 are each larger than the end face 32 of the metal base substrate 30. The end faces 71 and 72 may each be larger than the end face 42 of the first heat transfer member 40. The main surface 73 is connected to the end faces 71 and 72. The main surface 73 is an end face of the metal member 70 in the thickness direction (e.g., the y direction). The main surface 73 faces the main surface 43 of the first heat transfer member 40 and the main surface 63 of the metal support member 60 .

[0132] The metal base substrate 30 is thermally connected to the cooler 50 via a metal member 70. The metal member 70 is thermally connected to the metal base substrate 30, the first heat transfer member 40, the metal support member 60, and the cooler 50. Specifically, an end face 71 of the metal member 70 is thermally connected to an end face 32 of the metal base substrate 30. An end face 72 of the metal member 70 is thermally connected to the cooler 50. A main surface 73 of the metal member 70 is thermally connected to the main surface 43 of the first heat transfer member 40 and the main surface 63 of the metal support member 60.

[0133] The metal member 70 is fixed to the metal base substrate 30, the first heat transfer member 40, the metal support member 60, and the cooler 50. For example, an end face 71 of the metal member 70 is fixed to an end face 32 of the metal base substrate 30 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. An end face 72 of the metal member 70 is fixed to the cooler 50 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. A main surface 73 of the metal member 70 is fixed to the main surface 43 of the first heat transfer member 40 and the main surface 63 of the metal support member 60 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0134] The thermal conductivity of the metal member 70 is equal to or higher than the thermal conductivity of the metal plate 36. The metal member 70 is formed of a metal such as copper, iron, aluminum, an iron alloy, or an aluminum alloy. The metal member 70 may be formed of the same material as the metal support member 60. The metal member 70 has a thermal conductivity of, for example, 1.0 W / (m·K) or more. The metal member 70 may have a thermal conductivity of 10.0 W / (m·K) or more, or may have a thermal conductivity of 100.0 W / (m·K) or more. The metal member 70 conducts heat generated in the multiple circuit components 21, 22, and 23 to the cooler 50.

[0135] The metal member 70 may be a rigid member such as a metal block. The cross-sectional area of ​​the metal member 70 may be larger than the cross-sectional area of ​​the metal base substrate 30. The cross-sectional area of ​​the metal member 70 is the cross-sectional area of ​​the metal member 70 in a cross section perpendicular to the direction (e.g., the z direction) in which heat generated in the multiple circuit components 21, 22, and 23 is mainly transferred. The metal member 70 may be integrated with the metal support member 60, or the metal member 70 and the metal support member 60 may be a single member.

[0136] In a modification of this embodiment, the main surface 73 of the metal member 70 may be connected to at least one of the main surface 43 of the first heat transfer member 40 and the main surface 63 of the metal support member 60 .

[0137] 26 , in a power conversion device 1k according to another modification of the present embodiment, a metal member 70 is disposed between the metal base substrate 30 and the cooler 50, and also between the metal support member 60 and the cooler 50. An end face 62 of the metal support member 60 may be flush with the end face 32 of the metal base substrate 30. A main surface 73 of the metal member 70 may be flush with the main surface of the metal support member 60 opposite to the main surface 63. The metal support member 60 is thermally connected to the cooler 50 via the metal member 70. Specifically, an end face 71 of the metal member 70 faces the end face 32 of the metal base substrate 30 and the end face 62 of the metal support member 60, and is thermally connected to the end face 32 of the metal base substrate 30 and the end face 62 of the metal support member 60. The metal member 70 is fixed to the metal base substrate 30 and the metal support member 60 by caulking, pressure welding, soldering, brazing, bonding, welding, or the like.

[0138] A hole 74 is provided in the metal member 70. The hole 74 may be a through hole extending from the end face 71 to the end face 72, or may be a blind hole formed in the end face 71 but not reaching the end face 72. The first heat transfer member 40 includes a protruding portion 76 that protrudes from the end face 32 of the metal base substrate 30 in a plan view of the main surface 33. The protruding portion 76 includes the end face 42. The protruding portion 76 is inserted into the hole 74 and is thermally connected to the metal member 70. The protruding portion 76 is fixed to the metal member 70 by fitting, crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0139] The metal member 70 may be a single metal part, or may be formed by combining a plurality of metal parts.

[0140] The power conversion devices 1j and 1k of the present embodiment have the following advantages in addition to the advantages of the power conversion device 1d of the fourth embodiment.

[0141] The power conversion devices 1j and 1k further include a metal member 70 thermally connected to the cooler 50. The first end surface (end surface 32) is thermally connected to the metal member 70.

[0142] This reduces the thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, and 23 to the cooler 50. The plurality of circuit components 21, 22, and 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0143] In the power converters 1j and 1k, the end face 72 of the metal member 70 facing the cooler 50 is larger than the first end face (end face 32).

[0144] This reduces the thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, and 23 to the cooler 50. The plurality of circuit components 21, 22, and 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0145] Eleventh Embodiment A power conversion device 1m according to an eleventh embodiment will be described with reference to Fig. 27. The power conversion device 1m of this embodiment has a configuration similar to that of the power conversion device 1j of the tenth embodiment, but differs mainly in the following respects.

[0146] The first heat transfer member 40 includes a heat transfer portion 48 and a heat transfer portion 49. The heat transfer portion 48 includes main surfaces 43 and 44 of the first heat transfer member 40. The heat transfer portion 48 includes an end face 41 and an end face 48a of the first heat transfer member 40. The end face 41 of the first heat transfer member 40 is a distal end face of the heat transfer portion 48 with respect to the cooler 50. The end face 48a is a proximal end face of the heat transfer portion 48 with respect to the cooler 50. The end face 48a faces the cooler 50. The heat transfer portion 48 includes an end face 42 of the first heat transfer member 40. The end face 48a is a part of the end face 42 of the first heat transfer member 40. The end face 48a of the heat transfer portion 48 may be flush with the end face 62 of the metal support member 60 and the end face 72 of the metal member 70.

[0147] The heat transporting portion 48 is thermally connected to the metal base substrate 30, the metal member 70, the cooler 50, and the metal support member 60. The heat transporting portion 48 is fixed to the metal base substrate 30, the metal member 70, the cooler 50, and the metal support member 60 by caulking, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0148] The heat transport portion 49 is connected to the heat transport portion 48. The heat transport portion 49 protrudes from the main surface 43 of the first heat transport member 40 in the thickness direction (e.g., the y direction) of the metal base substrate 30. The heat transport portion 49 includes an end surface 49a. The end surface 49a is the proximal end surface of the heat transport portion 49 with respect to the cooler 50. The end surface 49a faces the cooler 50. The heat transport portion 49 includes the end surface 42 of the first heat transport member 40. The end surface 49a is a part of the end surface 42 of the first heat transport member 40. The end surface 49a of the heat transport portion 49 may be flush with the end surface 62 of the metal support member 60 and the end surface 72 of the metal member 70. The end surface 42 of the first heat transport member 40 is composed of the end surface 48a and the end surface 49a.

[0149] The heat transporting portion 49 is thermally connected to the metal member 70 and the cooler 50. The heat transporting portion 49 is fixed to the metal member 70 and the cooler 50 by caulking, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0150] A power conversion device 1n according to a modified example of the present embodiment will be described with reference to Fig. 28. In the power conversion device 1n, the first heat transfer member 40 is thermally connected to the cooler 50 via a metal member 70 and a metal support member 60. A portion of the metal member 70 and a portion of the metal support member 60 are located between the end surface 42 of the first heat transfer member 40 and the cooler 50. The end surface 42 of the first heat transfer member 40 is separated from the cooler 50 by the metal member 70 and the metal support member 60.

[0151] The heat transporting portion 48 is thermally connected to the metal base substrate 30, the metal member 70, and the metal support member 60. The heat transporting portion 48 is fixed to the metal base substrate 30, the metal member 70, and the metal support member 60 by caulking, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The heat transporting portion 48 is thermally connected to the cooler 50 via the metal support member 60. The metal support member 60 is located between an end face 48a of the heat transporting portion 48 and the cooler 50.

[0152] The heat transporting portion 49 is thermally connected to a metal member 70. The heat transporting portion 49 is fixed to the metal member 70 by caulking, fitting, soldering, brazing, adhesive bonding, welding, or the like. The metal member 70 is fixed to the cooler 50. The heat transporting portion 49 is thermally connected to the cooler 50 via the metal member 70. The metal member 70 is located between an end face 49 a of the heat transporting portion 49 and the cooler 50.

[0153] The power conversion devices 1m and 1n of this embodiment have the following advantages in addition to the advantages of the power conversion device 1j of the tenth embodiment.

[0154] In the power converters 1m and 1n, the first heat transport member 40 includes a first heat transport portion (heat transport portion 48) including a second main surface (main surface 43) and a second heat transport portion (heat transport portion 49) protruding from the second main surface. The second heat transport portion includes a second end surface (end surface 42) and is thermally connected to the cooler 50.

[0155] Therefore, a larger area of ​​the first heat transport member 40 faces the cooler 50. The thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, 23 to the cooler 50 is reduced. The plurality of circuit components 21, 22, 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0156] The power conversion devices 1m and 1n further include a metal member 70 thermally connected to the cooler 50. The first end surface (end surface 32) and the second heat transport portion (heat transport portion 49) are thermally connected to the metal member 70.

[0157] This reduces the thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, and 23 to the cooler 50. The plurality of circuit components 21, 22, and 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0158] Twelfth Embodiment A power conversion device 1p according to a twelfth embodiment will be described with reference to Fig. 29. The power conversion device 1p of this embodiment has a configuration similar to that of the power conversion device 1 of the first embodiment, but differs mainly in the following respects.

[0159] The power conversion device 1p further includes a second heat transfer member 80 and a fixing member 85. Similar to the first heat transfer member 40, the second heat transfer member 80 transfers or diffuses the heat generated in the plurality of circuit components 21, 22, and 23 to the cooler 50.

[0160] Specifically, the second heat transfer member 80 includes an end face 81, an end face 82 opposite to the end face 81, and a main surface 83. The end faces 81, 82 are, for example, both end faces in the longitudinal direction (e.g., z direction) of the second heat transfer member 80. The longitudinal direction (e.g., z direction) of the second heat transfer member 80 is not particularly limited, but may be the direction of gravity. The end face 81 is the distal end face of the second heat transfer member 80 with respect to the cooler 50. The end face 82 is the proximal end face of the second heat transfer member 80 with respect to the cooler 50. The end face 82 faces the cooler 50.

[0161] An end surface 82 of the second heat transfer member 80 is thermally connected to the cooler 50. The end surface 82 of the second heat transfer member 80 is fixed to the cooler 50 by caulking, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0162] The main surface 83 is connected to the end surfaces 81 and 82. The main surface 83 is an end surface in the thickness direction of the second heat transfer member 80. The main surface 83 faces the plurality of circuit components 21, 22, and 23 and the main surface 33 of the metal base substrate 30. The main surface 83 of the second heat transfer member 80 is thermally connected to the plurality of circuit components 21, 22, and 23. The main surface 83 of the second heat transfer member 80 is fixed to the plurality of circuit components 21, 22, and 23 by pressure welding, soldering, brazing, adhesion, welding, or the like.

[0163] The thermal conductivity of the second heat transfer member 80 is equal to or higher than that of the metal plate 36. The second heat transfer member 80 is, for example, a heat pipe, a vapor chamber, or a graphite sheet, or a metal plate integrated with any of these. The second heat transfer member 80 is formed of, for example, a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy, or carbon. The second heat transfer member 80 may be formed of the same material as the first heat transfer member 40. The second heat transfer member 80 has, for example, a thermal conductivity of 1.0 W / (m·K) or more. The second heat transfer member 80 may have a thermal conductivity of 10.0 W / (m·K) or more, or may have a thermal conductivity of 100.0 W / (m·K) or more.

[0164] The second heat transfer member 80 is fixed to the metal base substrate 30 using a fixing member 85. The fixing member 85 is, for example, a screw or an adhesive. The second heat transfer member 80 presses the plurality of circuit components 21, 22, 23 toward the metal base substrate 30. This improves the vibration resistance of the power conversion device 1p. Deterioration of the plurality of circuit components 21, 22, 23 can be prevented.

[0165] A power conversion device 1q according to a modification of the present embodiment will be described with reference to Fig. 30. The power conversion device 1q further includes a metal member 70, similar to the power conversion device 1j of the tenth embodiment.

[0166] The end face 71 of the metal member 70 faces the end face 82 of the second heat transfer member 80. The end face 71 of the metal member 70 may be larger than the end face 82 of the second heat transfer member 80. The end face 72 of the metal member 70 faces the cooler 50. The end face 72 of the metal member 70 may be larger than the end face 82 of the second heat transfer member 80. The main surface 73 of the metal member 70 faces the main surface 43 of the first heat transfer member 40.

[0167] The metal member 70 is thermally connected to the second heat transfer member 80, the metal base substrate 30, the first heat transfer member 40, and the cooler 50. The second heat transfer member 80 is thermally connected to the cooler 50 via the metal member 70. An end face 82 of the second heat transfer member 80 is thermally connected to an end face 71 of the metal member 70. The end face 72 of the metal member 70 is thermally connected to the cooler 50.

[0168] The metal member 70 is fixed to the second heat transfer member 80, the metal base substrate 30, the first heat transfer member 40, and the cooler 50. For example, an end face 71 of the metal member 70 is fixed to an end face 82 of the second heat transfer member 80 and an end face 32 of the metal base substrate 30 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. An end face 72 of the metal member 70 is fixed to the cooler 50 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. A main surface 73 of the metal member 70 is fixed to the main surface 43 of the first heat transfer member 40 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0169] The power conversion devices 1p and 1q of this embodiment have the following advantages in addition to the advantages of the power conversion device 1 of the first embodiment.

[0170] The power converters 1p and 1q further include a second heat transfer member 80 including a fifth main surface (main surface 83) and a fifth end surface (end surface 82) connected to the fifth main surface. The fifth main surface is thermally connected to the plurality of circuit components 21, 22, and 23. The fifth end surface is thermally connected to the cooler 50.

[0171] The heat generated in the plurality of circuit components 21, 22, 23 is transferred to the cooler 50 not only by the metal base substrate 30 and the first heat transfer member 40 but also by the second heat transfer member 80. Therefore, the thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, 23 to the cooler 50 is reduced. The plurality of circuit components 21, 22, 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0172] The power conversion device 1q further includes a metal member 70 thermally connected to the cooler 50. The first end face (end face 32) and the fifth end face (end face 82) are thermally connected to the metal member 70.

[0173] This reduces the thermal resistance of the heat transfer path from the plurality of circuit components 21, 22, and 23 to the cooler 50. The plurality of circuit components 21, 22, and 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0174] Thirteenth Embodiment A power conversion device 1r according to a thirteenth embodiment will be described with reference to Fig. 31 to Fig. 33. The power conversion device 1r of this embodiment has a configuration similar to that of the power conversion device 1 of the first embodiment, but differs mainly in the following respects.

[0175] The cooler 50 has a hole 53. The hole 53 may be a through hole formed in the surface of the cooler 50 facing the end face 32, or a blind hole formed in the surface of the cooler 50 facing the end face 32. The cross-sectional shape of the hole 53 (the shape of the hole 53 on the end face 32) is, for example, circular, elliptical, or rectangular. The first heat transfer member 40 includes a protruding portion 76 that protrudes from the end face 32 of the metal base substrate 30 in a plan view of the main surface 33. The protruding portion 76 includes the end face 42. When the hole 53 is a through hole, the end face 42 may protrude from the cooler 50. The protruding portion 76 is inserted into the hole 53 and is thermally connected to the cooler 50. The protruding portion 76 is fixed to the cooler 50 by fitting, crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0176] A central axis 52c of the coolant flow path (e.g., cooling pipe 52) intersects with the insertion direction (z direction) of the protrusion 76 into the hole 53. The central axis 52c may be perpendicular to the insertion direction (z direction) of the protrusion 76 into the hole 53. As shown in Fig. 33 , in a plan view from the insertion direction (z direction) of the protrusion 76 into the hole 53, the coolant flow path is shifted from the protrusion 76 in the thickness direction (e.g., y direction) of the metal base substrate 30.

[0177] 31 , in a plan view of the main surface 33, at least a portion of the refrigerant flow path (e.g., the cooling pipe 52) may overlap the protrusion 76 of the first heat transfer member 40. In a plan view of the main surface 33, the first heat transfer member 40 may extend to the side opposite the end face 41 with respect to the central axis 52c of the refrigerant flow path. In the insertion direction (z direction) of the protrusion 76 into the hole 53, the portion of the refrigerant flow path (e.g., the cooling pipe 52) that is provided in the heat sink 51 may be disposed between the end face 42 and the end face 32.

[0178] 34 to 36 , in a power conversion device 1s according to a first modification of the present embodiment, the first heat transfer member 40 may be divided into a plurality of heat transfer portions 45, 46, and a plurality of holes 53 into which the plurality of heat transfer portions 45, 46 are inserted may be provided in the cooler 50. The power conversion device 1s has a configuration similar to that of the power conversion device 1d according to the fourth embodiment, but differs mainly in the following respects.

[0179] A plurality of holes 53 are provided in the cooler 50. The plurality of holes 53 may be through holes formed in the surface of the cooler 50 facing the end face 32, blind holes formed in the surface of the cooler 50 facing the end face 32, or a combination of through holes and blind holes. The cross-sectional shapes of the plurality of holes 53 may be different from one another.

[0180] The first heat transfer member 40 includes a protruding portion 76 that protrudes from the end surface 32 of the metal base substrate 30 in a plan view of the main surface 33. The protruding portion 76 includes the end surface 42. Specifically, the heat transfer portion 45 includes a protruding portion 45p that protrudes from the end surface 32 of the metal base substrate 30 in a plan view of the main surface 33. The heat transfer portion 46 includes a protruding portion 46p that protrudes from the end surface 32 of the metal base substrate 30 in a plan view of the main surface 33. The protruding portion 76 includes a protruding portion 45p and a protruding portion 46p. The protruding portions 45p and 46p include the end surface 42. The protruding portions 45p and 46p are inserted into a plurality of holes 53 and are thermally connected to the cooler 50. The protruding portions 45p and 46p are fixed to the cooler 50 by fitting, crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0181] 34 , in a plan view of the main surface 33, at least a portion of the refrigerant flow path (cooling pipe 52) may overlap with the protruding portion 45p and the protruding portion 46p. In a plan view of the main surface 33, the protruding portion 45p and the protruding portion 46p may extend to the side opposite the end surface 41 with respect to the central axis 52c of the refrigerant flow path (e.g., cooling pipe 52) of the cooler. In the insertion direction (z direction) of the multiple protruding portions 45p, 46p into the multiple holes 53, the portion of the refrigerant flow path (e.g., cooling pipe 52) provided in the heat sink 51 may be disposed between the end surface 42 and the end surface 32.

[0182] 37 to 39 , a power conversion device 1t according to a second modification of the present embodiment is configured similarly to the power conversion device 1r of the present embodiment, except that a recess 54 is provided in the cooler 50 instead of the hole 53 (see FIGS. 31 to 33 ). The recess 54 is formed in the surface of the cooler 50 facing the end face 32. The recess 54 may or may not penetrate the cooler 50. The protrusion 76 is inserted into the recess 54 and thermally connected to the cooler 50. The protrusion 76 is fixed to the cooler 50 by fitting, crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. A central axis 52c of a refrigerant flow path (e.g., a cooling pipe 52) intersects with the insertion direction (z direction) of the protrusion 76 into the recess 54. The central axis 52c may be perpendicular to the insertion direction (z direction) of the protrusion 76 into the recess 54. As shown in Figure 36, when viewed from a plan view in the insertion direction (z direction) of the protrusion 76 into the recess 54, the coolant flow path is shifted from the protrusion 76 in the thickness direction (e.g., y direction) of the metal base substrate 30.

[0183] 40 to 42 , a power conversion device 1u according to a third modified example of the present embodiment is configured similarly to the power conversion device 1s according to the first modified example of the present embodiment. However, instead of the plurality of holes 53 (see FIGS. 34 to 36 ), a plurality of recesses 54 are provided in the cooler 50. The plurality of recesses 54 are formed on a surface of the cooler 50 facing the end face 32. The plurality of recesses 54 may or may not penetrate the cooler 50. Some of the plurality of recesses 54 may penetrate the cooler 50, and the remaining portions of the plurality of recesses 54 may not penetrate the cooler 50. The protruding portions 45p and 46p are inserted into the plurality of recesses 54 and are thermally connected to the cooler 50. The protruding portions 45p and 46p are fixed to the cooler 50 by fitting, crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like.

[0184] 43 to 45 , a power conversion device 1v according to a fourth modification of the present embodiment has the same configuration as the power conversion device 1t according to the second modification of the present embodiment, but further includes a fixing plate 87. The fixing plate 87 is fixed to the heat sink 51 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The fixing plate 87 may be fixed to the protruding portion 76 of the first heat transfer member 40 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The protruding portion 76 is sandwiched between the heat sink 51 and the fixing plate 87. The fixing plate 87 prevents the protruding portion 76 from coming out of the recess 54. The fixing plate 87 is formed of, for example, metal or resin. By forming the fixing plate 87 from metal, the thermal resistance of the heat transfer path from the multiple circuit components 21, 22, and 23 to the cooler 50 is further reduced.

[0185] 46 to 48 , a power conversion device 1w according to a fifth modification of the present embodiment has the same configuration as the power conversion device 1u according to the third modification of the present embodiment, but further includes a fixing plate 87. The fixing plate 87 is fixed to the heat sink 51 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The fixing plate 87 may be fixed to the protruding portions 45p and 46p of the heat transport portions 45 and 46 by crimping, pressure welding, soldering, brazing, adhesive bonding, welding, or the like. The protruding portions 45p and 46p are sandwiched between the heat sink 51 and the fixing plate 87. The fixing plate 87 prevents the protruding portions 45p and 46p from coming out of the recesses 54. The fixing plate 87 is formed of, for example, metal or resin. By forming the fixing plate 87 from metal, the thermal resistance of the heat transfer path from the multiple circuit components 21, 22, and 23 to the cooler 50 is further reduced.

[0186] In a sixth modification of the present embodiment, the plurality of protruding portions 45 p and 46 p of the heat transporting portions 45 and 46 may be inserted into at least one hole 53 and at least one recess 54 .

[0187] The power conversion devices 1r, 1s, 1t, 1u, 1v, and 1w of this embodiment have the following effects similar to those of the power conversion device 1 of the first embodiment.

[0188] The power converters 1r, 1s, 1t, 1u, 1v, and 1w of this embodiment each include a plurality of circuit components 21, 22, and 23, a metal base substrate 30 including a metal plate 36, a heat transfer member (first heat transfer member 40), and a cooler 50. The metal base substrate 30 includes a first main surface (main surface 33) on which the plurality of circuit components 21, 22, and 23 are mounted, a second main surface (main surface 34) opposite the first main surface, and a first end surface (end surface 32) connected to the first and second main surfaces. The metal plate 36 includes the second main surface. The first end surface faces the cooler 50 and is thermally connected to the cooler 50. The thermal conductivity of the heat transfer member is equal to or greater than the thermal conductivity of the metal plate 36. The heat transfer member faces the second main surface and is thermally connected to the second main surface. In a plan view of the first principal surface, the heat transfer member includes a protrusion 76 protruding from the first end face. The cooler 50 is provided with a hole 53 or a recess 54. The protrusion 76 of the heat transfer member is inserted into the hole 53 or the recess 54 and is thermally connected to the cooler 50.

[0189] The cooler 50 is thermally connected to the first end face (end face 32) of the metal base substrate 30 and the protrusion 76 of the heat transfer member. Therefore, heat generated in the plurality of circuit components 21, 22, 23 is transferred to the cooler 50 by both the metal base substrate 30 and the heat transfer member (first heat transfer member 40) and is collected in the cooler 50. Even if the number of the plurality of circuit components 21, 22, 23 increases and the size of the metal base substrate 30 increases, the plurality of circuit components 21, 22, 23 can be cooled without increasing the size of the cooler 50.

[0190] The power converters 1r, 1s, 1t, 1u, 1v, and 1w each include a heat transfer member (first heat transfer member 40) in addition to a metal base substrate 30. This reduces the difference between the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23 to the cooler 50 and the thermal resistance of the heat transfer path from a circuit component (e.g., circuit component 23) located closer to the cooler 50 to the cooler 50. The power converters 1r, 1s, 1t, 1u, 1v, and 1w can more uniformly cool the multiple circuit components 21, 22, and 23. A circuit component with a larger heat generation amount can be used as the circuit component (e.g., circuit component 21) located farther from the cooler 50 among the multiple circuit components 21, 22, and 23. This improves the degree of freedom in arranging the circuit components 21, 22, and 23. The thermal design of the power conversion devices 1r, 1s, 1t, 1u, 1v, and 1w becomes easier.

[0191] The protrusions 76 of the heat transfer member (first heat transfer member 40) are inserted into the holes 53 or the recesses 54. This improves the vibration resistance of the power converters 1r, 1s, 1t, 1u, 1v, and 1w.

[0192] In the power converters 1r, 1s, 1t, 1u, 1v, and 1w of this embodiment, a cooler 50 is formed with a flow path for a refrigerant (cooling pipe 52).

[0193] The heat generated in the plurality of circuit components 21, 22, 23 is carried by the coolant to the outside of the power conversion device 1. The plurality of circuit components 21, 22, 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller in size.

[0194] In the power conversion devices 1r, 1s, 1t, 1u, 1v, and 1w of this embodiment, when viewed in a plan view of the first main surface (main surface 33), at least a portion of the refrigerant flow path (cooling pipe 52) overlaps with the protrusion 76 of the heat transfer member (first heat transfer member 40).

[0195] Therefore, the distance between the coolant flow path (cooling pipe 52) and the heat transfer member (first heat transfer member 40) is reduced. Heat generated in the plurality of circuit components 21, 22, 23 can be transferred to the coolant flow path with lower thermal resistance. The plurality of circuit components 21, 22, 23 are efficiently cooled by the cooler 50. The cooler 50 can be made smaller.

[0196] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A power conversion device comprising: a plurality of circuit components; a metal base substrate including a metal plate; a first heat transfer member; and a cooler, wherein the metal base substrate includes a first main surface on which the plurality of circuit components are mounted and a first end face connected to the first main surface, wherein the thermal conductivity of the first heat transfer member is equal to or greater than the thermal conductivity of the metal plate, wherein the first heat transfer member includes a second main surface and a second end face connected to the second main surface and facing the cooler, wherein the first end face and the second end face are thermally connected to the cooler, and wherein the second main surface is thermally connected to the metal base substrate. (Appendix 2) The power conversion device according to Appendix 1, wherein the metal base substrate includes a third end face opposite to the first end face, and wherein the first heat transfer member extends from the first end face to the third end face in a plan view of the first main surface. (Supplementary Note 3) The power conversion device according to Supplementary Note 1, wherein a distance between the metal base substrate and the first heat transfer member decreases with increasing distance from the cooler. (Supplementary Note 4) The power conversion device according to Supplementary Note 1, wherein a contact area between the metal base substrate and the first heat transfer member increases with increasing distance from the cooler. (Supplementary Note 5) The power conversion device according to Supplementary Note 1, further comprising a metal support member supporting the first heat transfer member, wherein the metal base substrate includes a third main surface opposite to the first main surface, the third main surface being connected to the first end surface, and the metal support member includes a fourth main surface thermally connected to the third main surface and a fourth end surface connected to the fourth main surface, and the fourth end surface being thermally connected to the cooler. (Supplementary Note 6) The power conversion device according to Supplementary Note 5, wherein the plurality of circuit components overlap the first heat transfer member in a plan view of the first main surface. (Supplementary Note 7) The power conversion device described in Supplementary Note 5, wherein the first heat transfer member includes a plurality of heat transfer portions, each of the plurality of heat transfer portions is thermally connected to the metal base substrate and the cooler, and the distance between the plurality of circuit components and at least one of the plurality of heat transfer portions decreases with increasing distance from the cooler.(Supplementary Note 8) The power conversion device according to Supplementary Note 7, wherein, in a plan view of the first main surface, the at least one side surface of the plurality of heat transport portions facing the plurality of circuit components approaches the plurality of circuit components with increasing distance from the cooler. (Supplementary Note 9) The power conversion device according to Supplementary Note 8, wherein, in the plan view of the first main surface, the plurality of circuit components are arranged in a direction away from the cooler, and, in the plan view of the first main surface, the at least one of the plurality of heat transport portions is inclined with respect to the direction in which the plurality of circuit components are arranged. (Supplementary Note 10) The power conversion device according to Supplementary Note 8, wherein, in the plan view of the first main surface, a width of the at least one of the plurality of heat transport portions increases with increasing distance from the cooler. (Supplementary Note 11) The power conversion device according to Supplementary Note 10, wherein, in the plan view of the first main surface, the plurality of circuit components are arranged in a direction away from the cooler, and wherein, in the plan view of the first main surface, the at least one side surface of the plurality of heat transport portions is inclined with respect to the direction in which the plurality of circuit components are arranged. (Supplementary Note 12) The power conversion device according to Supplementary Note 10, wherein, in the plan view of the first main surface, the at least one side surface of the plurality of heat transport portions has a stepped shape. (Supplementary Note 13) The power conversion device according to Supplementary Note 7, wherein a distance between the metal base substrate and the first heat transport member decreases with increasing distance from the cooler. (Supplementary Note 14) The power conversion device according to Supplementary Note 1, further comprising a metal member thermally connected to the cooler, and wherein the first end surface is thermally connected to the metal member. (Supplementary Note 15) The power conversion device according to Supplementary Note 14, wherein an end surface of the metal member facing the cooler is larger than the first end surface. (Supplementary Note 16) The power conversion device according to Supplementary Note 1, wherein the first heat transport member includes a first heat transport portion including the second main surface and a second heat transport portion protruding from the second main surface, and the second heat transport portion includes the second end surface and is thermally connected to the cooler. (Supplementary Note 17) The power conversion device according to Supplementary Note 16, further comprising a metal member thermally connected to the cooler, and the first end surface and the second heat transport portion are thermally connected to the metal member.(Supplementary Note 18) The power conversion device according to Supplementary Note 1, further comprising a second heat transfer member including a fifth main surface and a fifth end surface connected to the fifth main surface, wherein the fifth main surface is thermally connected to the plurality of circuit components, and the fifth end surface is thermally connected to the cooler. (Supplementary Note 19) The power conversion device according to Supplementary Note 18, further comprising a metal member thermally connected to the cooler, wherein the first end surface and the fifth end surface are thermally connected to the metal member. (Supplementary Note 20) A power conversion device comprising: a plurality of circuit components; a metal base substrate including a metal plate; a heat transfer member; and a cooler; wherein the metal base substrate includes a first main surface on which the plurality of circuit components are mounted, a second main surface opposite the first main surface, and a first end surface connected to the first main surface and the second main surface, the metal plate includes the second main surface, the first end surface faces the cooler and is thermally connected to the cooler, a thermal conductivity of the heat transfer member is equal to or greater than a thermal conductivity of the metal plate, the heat transfer member faces the second main surface and is thermally connected to the second main surface, in a plan view of the first main surface, the heat transfer member includes a protrusion protruding from the first end surface, and the cooler is provided with a hole or a recess, and the protrusion of the heat transfer member is inserted into the hole or the recess and is thermally connected to the cooler. (Supplementary Note 21) The power conversion device according to Supplementary Note 20, wherein a flow path for a refrigerant is formed in the cooler. (Supplementary Note 22) The power conversion device according to Supplementary Note 21, wherein, in the plan view of the first main surface, at least a part of the flow path overlaps the protrusion of the heat transfer member.

[0197] The presently disclosed embodiments 1 to 13 and their modifications should be considered to be illustrative in all respects and not restrictive. Unless there is a contradiction, at least two of the presently disclosed embodiments 1 to 13 and their modifications may be combined. 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.

[0198] 1, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1m, 1n, 1p, 1q, 1r, 1s, 1t, 1u, 1v, 1w Power conversion device, 2 Inverter circuit, 3 Transformer circuit, 4 Rectifier circuit, 5 Smoothing circuit, 6 Input terminal, 7 Output terminal, 8 Input capacitor, 9a, 9b, 9c, 9d Switching element, 10 Control circuit, 11 Transformer, 11a Primary winding, 11b Secondary winding, 12a, 12b Rectifier element, 13 Smoothing reactor, 14 Smoothing capacitor, 21, 22, 23, 24, 25, 26 Circuit component, 30 Metal base substrate, 31, 32 End surface, 33, 34 Main surface, 36 Metal plate, 37 Insulating layer, 38 Circuit pattern, 39 Conductive bonding member, 40 First heat transfer member 41, 42 End faces 43, 44 Main faces 45, 46, 47 Heat transfer portions 45a, 45b, 45c, 46a, 46b, 46c Heat transfer elements 45p, 46p Protruding portions 45s, 46s Side faces 48, 49 Heat transfer portions 48a, 49a End faces 50 Cooler 51 Heat sink 52 Cooling pipe 52c Central axis 53 Hole 54 Recessed portion 55 Air layer 60 Metal support member 61, 62 End faces 63 Main faces 65, 66, 67 Grooves 70 Metal members 71, 72 End faces 73 Main faces 74 Holes 76 Protruding portions 80 Second heat transfer member 81, 82 End faces 83 Main faces 85 Fixing members 87 Fixed plate.

Claims

1. A plurality of circuit components; a metal base substrate including a metal plate; a first heat transfer member; a cooler; the metal base substrate includes a first main surface on which the plurality of circuit components are mounted and a first end surface connected to the first main surface, the thermal conductivity of the first heat transfer member is equal to or greater than the thermal conductivity of the metal plate; the first end surface is thermally connected to the cooler; The first heat transfer member is thermally connected to the cooler and the metal base substrate.

2. The first heat transfer member includes a second main surface and a second end surface connected to the second main surface and facing the cooler; The power conversion device according to claim 1 , wherein the second end surface is thermally connected to the cooler.

3. the metal base substrate includes a third end surface opposite the first end surface, The power conversion device according to claim 1 , wherein, in a plan view of the first main surface, the first heat transfer member extends from the first end surface to the third end surface.

4. The power conversion device according to claim 1 , wherein the distance between the metal base substrate and the first heat transfer member decreases with increasing distance from the cooler.

5. The power conversion device according to claim 1 , wherein a contact area between the metal base substrate and the first heat transfer member increases with increasing distance from the cooler.

6. a metal support member for supporting the first heat transfer member; the metal base substrate includes a third main surface opposite to the first main surface, the third main surface being connected to the first end surface; the metal support member includes a fourth main surface thermally connected to the third main surface and a fourth end surface connected to the fourth main surface, The power conversion device according to claim 1 , wherein the fourth end surface is thermally connected to the cooler.

7. The power conversion device according to claim 6 , wherein the plurality of circuit components overlap the first heat transfer member in a plan view of the first main surface.

8. the first heat transfer member includes a plurality of heat transfer portions; each of the plurality of heat transport portions is thermally connected to the metal base substrate and the cooler; The power conversion device according to claim 6 , wherein a distance between the plurality of circuit components and at least one of the plurality of heat transporting portions decreases with increasing distance from the cooler.

9. 9. The power conversion device according to claim 8, wherein, in a plan view of the first main surface, the at least one side surface of the heat transport portions facing the circuit components approaches the circuit components as the distance from the cooler increases.

10. In the plan view of the first main surface, the plurality of circuit components are arranged in a direction away from the cooler, The power conversion device according to claim 9 , wherein, in the plan view of the first main surface, the at least one of the plurality of heat transport portions is inclined with respect to the direction in which the plurality of circuit components are arranged.

11. The power conversion device according to claim 9 , wherein, in the plan view of the first main surface, a width of the at least one of the plurality of heat transport portions increases with increasing distance from the cooler.

12. In the plan view of the first main surface, the plurality of circuit components are arranged in a direction away from the cooler, The power conversion device according to claim 11 , wherein, in the plan view of the first main surface, the at least one side surface of the plurality of heat transport portions is inclined with respect to the direction in which the plurality of circuit components are arranged.

13. The power conversion device according to claim 11 , wherein the at least one side surface of the plurality of heat transport portions has a stepped shape in the plan view of the first main surface.

14. The power conversion device according to claim 8 , wherein the distance between the metal base substrate and the first heat transfer member decreases with increasing distance from the cooler.

15. a metal member thermally connected to the cooler; The power conversion device according to claim 1 , wherein the first end surface is thermally connected to the metal member.

16. The power conversion device according to claim 15 , wherein an end surface of the metal member facing the cooler is larger than the first end surface.

17. the first heat transport member includes a first heat transport portion including the second main surface and a second heat transport portion protruding from the second main surface; The power conversion device according to claim 2 , wherein the second heat transporting portion includes the second end surface and is thermally connected to the cooler.

18. a metal member thermally connected to the cooler; The power conversion device according to claim 17 , wherein the first end surface and the second heat transporting portion are thermally connected to the metal member.

19. a second heat transfer member including a fifth main surface and a fifth end surface connected to the fifth main surface; the fifth main surface is thermally connected to the plurality of circuit components; The power conversion device according to claim 1 , wherein the fifth end surface is thermally connected to the cooler.

20. a metal member thermally connected to the cooler; The power conversion device according to claim 19 , wherein the first end surface and the fifth end surface are thermally connected to the metal member.

21. A power conversion device described in any one of claims 1 to 20, wherein a refrigerant flow path is formed in the cooler.

22. A plurality of circuit components; a metal base substrate including a metal plate; a heat transfer member; a cooler; the metal base substrate includes a first main surface on which the plurality of circuit components are mounted, a second main surface opposite to the first main surface, and a first end surface connected to the first main surface and the second main surface, the first end surface faces the cooler and is thermally connected to the cooler; the thermal conductivity of the heat transfer member is equal to or greater than the thermal conductivity of the metal plate; the heat transfer member faces the second main surface and is thermally connected to the second main surface; In a plan view of the first principal surface, the heat transfer member includes a protrusion protruding from the first end surface, The cooler is provided with a hole or a recess, The power conversion device, wherein the protrusion of the heat transfer member is inserted into the hole or the recess and is thermally connected to the cooler.

23. The power conversion device according to claim 22 , wherein a flow path for a coolant is formed in the cooler.

24. The power conversion device according to claim 23 , wherein at least a portion of the flow path overlaps with the protruding portion of the heat transfer member in the plan view of the first main surface.

25. A power conversion device described in any one of claims 22 to 24, wherein the metal plate includes the second main surface.