Power Conversion Device

Abstract

To provide a power conversion device in which heat dissipation performance can be improved, and an input terminal and an output terminal can be easily connected to a wire to the outside.SOLUTION: A power conversion device 100 includes an electronic component, a first printed board 31, a first cooling body 51, a second printed board 32, a second cooling body 52, a third printed board 33, and a fourth printed board 34. A sixth main surface S6 of the third printed board 33 is thermally connected to the second cooling body 52. The fourth printed board 34 is thermally connected to a first main surface S1 of the first printed board 31 and the sixth main surface S6 of the third printed board 33. An input terminal 9a and an output terminal 10a are configured to be connected to a wire from the outside.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Generally, a power conversion device includes electronic components such as switching elements, rectifying elements, and magnetic components. These electronic components generate heat during operation of the power conversion device. The heat generated by these electronic components is transferred to a cooling body through a heat dissipation path and dissipated from the cooling body. In this way, the temperatures of these electronic components are kept below the allowable temperature of each electronic component.

[0003] In recent years, with the increasing demand for smaller and higher-output power conversion devices, the amount of heat generated by electronic components mounted in the power conversion devices has increased, creating a strong demand for improving the heat dissipation performance of power conversion devices.

[0004] As an example of a power conversion device, Japanese Patent No. 4231626 (Patent Document 1) describes an automobile motor drive device. In the automobile motor drive device described in this publication, among the electronic components housed in a housing, a power conversion element, which is a high-heat-generating component, is located on the bottom surface of the housing. The bottom surface of the housing on which the power conversion element is located is integrated with a cooling body. In addition, a printed circuit board on which a control element is mounted is fixed to a plate-shaped board mounting portion formed inside the housing. Heat generated by the control element is transferred to the housing via the plate-shaped board mounting portion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4231626 Summary of the Invention [Problem to be solved by the invention]

[0006] In the automotive motor drive device described in the above publication, heat generated in the control element is transferred to the housing (cooler) via the plate-shaped board mounting portion, resulting in a long heat dissipation path. As a result, heat dissipation performance is reduced. This can cause the temperature of the control element to rise and exceed its heat resistance temperature, potentially resulting in failure of the automotive motor drive device. In addition, Joule heat from the input and output wiring is transferred into the automotive motor drive device, further reducing heat dissipation performance.

[0007] Furthermore, since the power conversion element and the control element are housed in a closed space formed by the housing (cooling body), it is difficult to connect the input terminals and output terminals to external wiring.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a power conversion device that can improve heat dissipation and makes it easy to connect input terminals and output terminals to external wiring. [Means for solving the problem]

[0009] The power conversion device of the present disclosure includes an electronic component, a first substrate, a first cooling body, a second substrate, a second cooling body, a third substrate, and a fourth substrate. The electronic components include a first component, a second component, a third component, and a fourth component. The first substrate has a first main surface on which a first component of the electronic component is mounted and a second main surface opposite the first main surface. The first cooling body is thermally connected to the second main surface of the first substrate. The second substrate has a third main surface on which a second component of the electronic component is mounted and a fourth main surface opposite the third main surface. The second cooling body is thermally connected to the fourth main surface of the second substrate. The third substrate has a fifth main surface on which a third component of the electronic component is mounted and a sixth main surface opposite the fifth main surface. The fourth substrate has a seventh main surface on which a fourth component of the electronic component is mounted and an eighth main surface opposite the seventh main surface. The second cooling body extends in a direction from the second main surface of the first substrate toward the first main surface, and is thermally connected to the first cooling body. The sixth main surface of the third substrate is thermally connected to the second cooling body. The fourth substrate extends in a direction from the second main surface of the first substrate toward the first main surface, and is thermally connected to the first main surface of the first substrate and the sixth main surface of the third substrate. The third component isCurrent is input Input terminal and Current is output The input terminal and the output terminal are configured to be connected to external wiring. The first, second, and third components are high-heat-generating components. The fourth board is connected to a board connection member mounted on the third board. The board connection member penetrates the fifth and sixth main surfaces of the third board. An output terminal is mounted directly above the top surface of the second cooling body. [Effects of the Invention]

[0010] According to the power conversion device of the present disclosure, it is possible to improve heat dissipation properties and to facilitate connection of the input terminals and output terminals to external wiring. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a circuit diagram of a power conversion device according to a first embodiment. [Figure 2] 1 is a perspective view schematically illustrating a configuration of a power conversion device according to a first embodiment. [Figure 3] FIG. 3 is a perspective view of FIG. 2 with the fourth substrate removed. [Figure 4] 1 is a cross-sectional view schematically showing the configuration of a power conversion device according to a first embodiment. [Figure 5] FIG. 4 is a cross-sectional view schematically showing the configuration of a modified example of the power conversion device according to the first embodiment. [Figure 6] FIG. 10 is a perspective view schematically showing the configuration of a power conversion device according to a second embodiment. [Figure 7] FIG. 10 is a cross-sectional view schematically showing the configuration of a power conversion device according to a second embodiment. [Figure 8] FIG. 10 is a perspective view schematically showing the configuration of a power conversion device according to a third embodiment. [Figure 9] FIG. 11 is a perspective view schematically showing the configuration of a modified example of the power conversion device according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be described with reference to the drawings. In the following, the same or corresponding parts will be denoted by the same reference numerals, and overlapping descriptions will not be repeated.

[0013] Embodiment 1 First, a circuit diagram of the power conversion device according to the first embodiment will be described with reference to FIG.

[0014] FIG. 1 is an example of a circuit diagram of a power conversion device according to a first embodiment. The power conversion device shown in the circuit diagram of FIG. 1 is a DC-DC converter mounted on, for example, an electric vehicle, converts a lithium-ion battery input voltage of 100 V to 300 V DC into a DC voltage of 12 to 15 V, outputs the converted voltage, and charges a lead-acid battery. The power conversion device shown in the circuit diagram of FIG. 1 includes an input capacitor 1, an inverter circuit unit 11 consisting of four switching elements 2a, 2b, 2c, and 2d, a transformer unit 12 consisting of transformers 3a and 3b, a rectifier circuit unit 13 consisting of four rectifier elements 5a, 5b, 5c, and 5d, a smoothing circuit unit 14 consisting of a reactor 4 and a smoothing capacitor 8, input terminals 9a and 9b, output terminals 10a and 10b, a control circuit unit 15, and a pulse transformer circuit 16. Note that any number of electronic components indicated by circuit symbols in FIG. 1 may be configured in series or parallel.

[0015] Next, the operation of the power conversion device shown in the circuit diagram of FIG. 1 will be described. The power conversion device shown in the circuit diagram of FIG. 1 converts DC voltage input from input terminals 9a and 9b into AC voltage by controlling the switching of inverter circuit unit 11 using control circuit unit 15. Transformer unit 12 converts the AC voltage converted by inverter circuit unit 11 into an arbitrary voltage using the turns ratio of transformers 3a and 3b. Transformers 3a and 3b also provide electrical insulation between input terminals 9a and 9b and output terminals 10a and 10b. Rectifier circuit unit 13 converts the AC voltage supplied from transformers 3a and 3b back into DC voltage. Smoothing circuit unit 14 smoothes the DC voltage converted by rectifier circuit unit 13 to stabilize the voltage output from output terminals 10a and 10b.

[0016] Next, we will explain each component in the circuit diagram in Figure 1. Each of the switching elements 2a, 2b, 2c, and 2d is a power semiconductor element such as a transistor, a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), etc. Each of the rectifying elements 5a, 5b, 5c, and 5d is a power semiconductor element such as a diode, a MOSFET, a thyristor, etc.

[0017] The control circuit section 15 includes a control element 101 that generates and outputs a control signal for controlling the inverter circuit section 11, and an electronic component 110 for the control element such as a capacitor or a resistor.

[0018] The pulse transformer circuit 16 includes pulse transformers 22a and 22b. The pulse transformer circuit 16 electrically insulates the control signal output from the control circuit unit 15 and controls the switching elements 2a, 2b, 2c, and 2d of the inverter circuit unit 11.

[0019] In the power conversion device configured as described above and shown in the circuit diagram of Fig. 1, the four switching elements 2a, 2b, 2c, and 2d, the transformers 3a and 3b, the four rectifying elements 5a, 5b, 5c, and 5d, the reactor 4, and the control circuit unit 15 are high-heat-generating components. The heat generated by these high-heat-generating components must be dissipated to keep their temperatures below their allowable temperatures. The allowable temperatures of each component are, for example, between 100°C and 120°C.

[0020] Furthermore, the main circuit pattern that electrically connects these high-heat-generating components and the wiring that connects the input and output terminals generate heat due to Joule heat when current flows. The Joule heat from the wiring then transfers to the high-heat-generating components, potentially causing their temperatures to exceed their allowable temperatures. Therefore, it is necessary to dissipate the Joule heat from the wiring.

[0021] Next, the components and structure of the power converter 100 will be described with reference to FIGS. Fig. 2 is a perspective view of the power conversion device 100 according to the first embodiment. Fig. 3 is a perspective view of the power conversion device 100 according to the first embodiment, with a fourth printed circuit board removed for ease of explanation. Fig. 4 is a cross-sectional view of the power conversion device 100 according to the first embodiment. For ease of explanation, Fig. 4 does not include hatching.

[0022] 2 and 3, power conversion device 100 according to the first embodiment includes external cooler 21, first printed circuit board (first board) 31, first heat dissipation member 41, first cooling body 51, first fixing member 61, second printed circuit board (second board) 32, second heat dissipation member 42, second cooling body 52, second fixing member 62, third printed circuit board (third board) 33, third heat dissipation member 43, third fixing member 63, fourth printed circuit board (fourth board) 34, electronic components (such as switching elements, capacitors, and transformers on each board), input terminals 9a and 9b, output terminals 10a and 10b, connecting member 86, joint 87, input wiring member 88, output wiring member 89, and a control circuit (not shown). The electronic components include a first component, a second component, a third component, and a fourth component.

[0023] A main circuit pattern (not shown) is formed on the surface or inside each of the first printed circuit board 31, the second printed circuit board 32, the third printed circuit board 33, and the fourth printed circuit board 34. A control circuit pattern (not shown) is also formed in the control circuit section.

[0024] The first printed circuit board (first board) 31 has a front surface (first main surface) S1 on which electronic components (first components) are mounted, and a back surface (second main surface) S2 facing the first cooling body 51. The second main surface S2 faces the first main surface S1. The first heat dissipation member 41 is disposed between the second main surface S2 of the first printed circuit board 31 and the first cooling body 51. The first cooling body 51 is thermally connected to the second main surface S2 of the first printed circuit board 31. The first cooling body 51 is thermally connected to the second main surface S2 of the first printed circuit board 31 via the first heat dissipation member 41. The first cooling body 51 is thermally coupled to the external cooling body 21. The external cooling body 21 is thermally connected to the first cooling body 51. The first fixing member 61 is configured to fix the first printed circuit board 31 to the first cooling body 51. Switching elements 2a, 2b, 2c, and 2d are mounted on a first main surface S1 of the first printed circuit board 31. A connector 104 for fixing the fourth printed circuit board 34 is mounted on the first main surface S1 of the first printed circuit board 31.

[0025] The second printed circuit board (second board) 32 has a front surface (third main surface) S3 on which electronic components (second components) are mounted, and a back surface (fourth main surface) S4 facing the second cooling body 52. ​​The fourth main surface S4 faces the third main surface S3. The second heat dissipation member 42 is disposed between the fourth main surface of the second printed circuit board 32 and the second cooling body 52. ​​The second cooling body 52 is thermally connected to the fourth main surface S4 of the second printed circuit board 32. The second cooling body 52 is thermally connected to the fourth main surface S4 of the second printed circuit board 32 via the second heat dissipation member 42. The second cooling body 52 extends in a direction from the second main surface S2 toward the first main surface S1 of the first printed circuit board 31. The second cooling body 52 is thermally connected to the first cooling body 51. The second fixing member 62 is configured to fix the second printed circuit board 32 to the second cooling body 52. Rectifying elements 5a, 5b, 5c, and 5d are mounted on the second printed circuit board 32. The second printed circuit board 32 also has transformers 3a and 3b, a reactor 4, a smoothing capacitor 8, a connecting member 86, and a joint 87 mounted thereon.

[0026] The third printed circuit board (third board) 33 has a front surface (fifth main surface) S5 on which electronic components (third components) are mounted and a back surface (sixth main surface) S6 facing the second cooling body 52. ​​The sixth main surface S6 faces the fifth main surface S5. The sixth main surface S6 of the third printed circuit board 33 is disposed to face the first main surface S1 of the first printed circuit board 31. The electronic components (third components) include input terminals 9a, 9b and output terminals 10a, 10b. The input terminals 9a, 9b and the output terminals 10a, 10b are configured to be connected to external wiring (input wiring member 88 and output wiring member 89). The third heat dissipation member 43 is disposed between the sixth main surface S6 of the third printed circuit board 33 and the top surface 52a of the second cooling body 52. ​​The sixth main surface S6 of the third printed circuit board 33 is thermally connected to the second cooling body 52. The sixth main surface S6 of the third printed circuit board 33 is thermally connected to the top surface 52a of the second cooling body 52 via the third heat dissipation member 43. The third fixing member 63 is configured to fix the third printed circuit board 33 to the top surface 52a of the second cooling body 52.

[0027] Third printed circuit board 33 and top surface 52a of second cooling body 52 may be thermally connected without third heat dissipation member 43. At least a portion of the main circuit pattern, control circuit pattern, and output terminals 10a, 10b of third printed circuit board 33 are disposed directly above top surface 52a of second cooling body 52.

[0028] 2, output terminals 10a and 10b are mounted directly above top surface 52a of second cooling body 52. ​​Because the current value on the output side is greater than the current value on the input side, the temperature rise due to Joule heat in the main circuit pattern and wiring members is greater on the output side than on the input side. For this reason, output terminals 10a and 10b are mounted in a position closer to second cooling body 52. ​​Conversely, in cases where the current value on the input side is greater than the current value on the output side, such as in a boost circuit, it is preferable that input terminals 9a and 9b be mounted directly above top surface 52a of second cooling body 52.

[0029] In FIG. 2, the third printed circuit board 33 is fixed to the top surface 52a of the second cooling body 52 only by the third fixing member 63, but in order to fix the third printed circuit board 33 more sturdily, it may be fixed to the top surface 51a of the first cooling body using screws, bolts, supports, etc.

[0030] 2 and 4, the fifth main surface S5 of the third printed circuit board 33 is provided with input terminals 9a and 9b, output terminals 10a and 10b, a board connection member 105, an output board connection member 106, and a control circuit driving connection terminal 103. The input terminals 9a and 9b are electrically connected to an input wiring member 88. The output terminals 10a and 10b are electrically connected to an output wiring member 89. The input wiring member 88 and the output wiring member 89 are connected to a battery and other devices. The board connection member 105 penetrates the fifth main surface S5 and the sixth main surface S6 of the third printed circuit board 33. The board connection member 105 is connected to the fourth printed circuit board 34.

[0031] A control element 101, electronic components for the control element 110, and pulse transformers 22a and 22b are mounted on a sixth main surface S6 of the third printed circuit board. Although the control circuit unit 15 and the pulse transformer circuit 16 are mounted on the sixth main surface S6 in FIG. 4, they may be mounted on the fifth main surface S5. Mounting them on the sixth main surface S6 would make them susceptible to noise from external devices, so it is preferable that they be mounted on the fifth main surface S5.

[0032] The fourth printed circuit board (fourth board) 34 has a seventh main surface S7 on which electronic components (fourth components) are mounted and an eighth main surface S8 opposite the seventh main surface S7. The fourth printed circuit board 34 extends in a direction from the second main surface S2 toward the first main surface S1 of the first printed circuit board 31. The fourth printed circuit board 34 is electrically and thermally connected to the first main surface S1 of the first printed circuit board 31 and the sixth main surface S6 of the third printed circuit board 33. The eighth main surface S8 of the fourth printed circuit board 34 is disposed so as to face the third main surface S3 of the second printed circuit board 32. The fourth printed circuit board 34 is connected to a board connecting member 105 mounted on the third printed circuit board 33. The fourth printed circuit board 34 is connected to a connector 104 mounted on the first printed circuit board 31. The fourth printed circuit board 34 has an input capacitor 1 mounted thereon.

[0033] Next, the components mounted on the power conversion device 100 will be described in detail with reference to FIGS.

[0034] The external cooler 21 has a thermal conductivity of 1.0 W / (m·K) or more, preferably 10.0 W / (m·K) or more, and more preferably 100.0 W / (m·K) or more. The external cooler 21 is formed from a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy, or from a resin with high thermal conductivity. The external cooler 21 may be provided with piping for passing cooling water therethrough. The external cooler 21 may also be provided with heat dissipation fins or the like to promote heat dissipation into the surrounding atmosphere.

[0035] The main circuit patterns of the first printed circuit board 31, the second printed circuit board 32, the third printed circuit board 33, and the fourth printed circuit board 34 each have a thickness of 1 μm or more and 2000 μm or less. The main circuit patterns are made of a conductive material, such as copper, nickel, gold, aluminum, silver, tin, or an alloy thereof.

[0036] The first printed circuit board 31, the second printed circuit board 32, the third printed circuit board 33, and the fourth printed circuit board 34 may each be made of a material such as glass fiber reinforced epoxy resin, phenolic resin, polyphenylene sulfide (PPS), or polyether ether ketone (PEEK). In other words, the first printed circuit board 31, the second printed circuit board 32, the third printed circuit board 33, and the fourth printed circuit board 34 may each be made of a material generally considered to have low thermal conductivity. In other words, the first printed circuit board 31, the second printed circuit board 32, the third printed circuit board 33, and the fourth printed circuit board 34 may each be a general-purpose printed circuit board. Furthermore, the first printed circuit board 31, the second printed circuit board 32, the third printed circuit board 33, and the fourth printed circuit board 34 may each be made of ceramics such as aluminum oxide, aluminum nitride, or silicon carbide.

[0037] Each of the first heat dissipation member 41, the second heat dissipation member 42, and the third heat dissipation member 43 has electrical insulation properties. Each of the first heat dissipation member 41, the second heat dissipation member 42, and the third heat dissipation member 43 may have elasticity. Each of the first heat dissipation member 41, the second heat dissipation member 42, and the third heat dissipation member 43 may have a Young's modulus of 1 MPa or more and 100 MPa or less. Each of the first heat dissipation member 41, the second heat dissipation member 42, and the third heat dissipation member 43 has a thermal conductivity of 0.1 W / (m·K) or more, preferably 1.0 W / (m·K) or more. Each of the first heat dissipation member 41, the second heat dissipation member 42, and the third heat dissipation member 43 may be made of, for example, a rubber material such as silicone or urethane, a resin material such as acrylonitrile butadiene styrene (ABS), polybutylene terephthalate (PBT), polyphenylene sulfonate (PPS), or phenol, a polymer material such as polyimide, a ceramic material such as alumina or aluminum nitride, a phase change material whose main ingredient is silicon, etc. Also, each of the first heat dissipation member 41, the second heat dissipation member 42, and the third heat dissipation member 43 may be made of a material in which particles of aluminum oxide, aluminum nitride, boron nitride, or the like are mixed into silicone resin.

[0038] Each of the first cooling body 51 and the second cooling body 52 has a thermal conductivity of 1.0 W / (m·K) or more, preferably 10.0 W / (m·K) or more, and more preferably 100.0 W / (m·K) or more. Each of the first cooling body 51 and the second cooling body 52 is formed from a metal material such as copper, iron, aluminum, an iron alloy, or an aluminum alloy, or from a resin with high thermal conductivity. In this embodiment, each of the first cooling body 51 and the second cooling body 52 is made of a plate-shaped aluminum alloy. Furthermore, the first cooling body 51 and the second cooling body 52 may be electrically connected to other members so that their respective potentials are the same as the ground potential. Furthermore, the second cooling body 52 is connected and fixed to the first cooling body 51 directly or via another member.

[0039] The first cooling body 51 may be in surface contact with the external cooling body 21. When the first cooling body 51 and the external cooling body 21 are in surface contact with each other, a thermally conductive member such as thermally conductive grease, a thermally conductive sheet, or a thermally conductive adhesive may be disposed on the contact surface between the first cooling body 51 and the external cooling body 21.

[0040] The board connection member 105 connects the input current and control signal between the boards. Although only one board connection member 105 is shown in FIGS. 2 and 3, there may be multiple board connection members 105. The input current and control signal may also be separated. The board connection member 105 may be, for example, a terminal block, a board-to-board connector, a mounting socket, a finger, a clip, or other structural component. The board connection member 105 may also be a bus bar that is soldered to the main circuit pattern of the third printed circuit board 33.

[0041] Next, the flow of electricity in the power converter 100 will be described with reference to FIGS. A current flowing from the outside through the input wiring member 88 is input to the input terminals 9a and 9b and is supplied to the board connecting member 105 via the main circuit pattern of the third printed circuit board 33. The current supplied to the board connecting member 105 is supplied to the input capacitor 1 via the main circuit pattern of the fourth printed circuit board 34. The current supplied to the input capacitor 1 is supplied from the connector 104 to the switching elements 2a, 2b, 2c, and 2d via the main circuit pattern of the first printed circuit board 31. The current supplied to the switching elements 2a, 2b, 2c, and 2d is converted from DC to AC voltage by the switching elements 2a, 2b, 2c, and 2d.

[0042] The AC voltage converted by the switching elements 2a, 2b, 2c, and 2d is supplied in the following order: joint 87, connection member 86, the main circuit pattern of second printed circuit board 32, and transformers 3a and 3b. The voltage supplied to transformers 3a and 3b is converted to an arbitrary voltage depending on the winding ratio. The voltage output from transformers 3a and 3b is then supplied to rectifier elements 5a, 5b, 5c, and 5d, where it is converted back to DC voltage. The voltage converted by rectifier elements 5a, 5b, 5c, and 5d is then supplied to reactor 4 and smoothing capacitor 8, in that order. Reactor 4 and smoothing capacitor 8 stabilize the output voltage. The voltage (current) output from smoothing capacitor 8 is output to the outside via output board connecting member 106, third printed circuit board 33, output terminals 10a and 10b, and output wiring member 89.

[0043] Next, the heat dissipation structure of the power converter 100 will be described with reference to FIGS. Heat generated in the main circuit pattern of the first printed circuit board 31, the electronic components mounted on the first printed circuit board 31, the connecting member 86 and the connector 104 is transmitted and dissipated in the order of the first heat dissipation member 41, the first cooling body 51 and the external cooling body 21.

[0044] Heat generated in the main circuit pattern of the second printed circuit board 32, the electronic components mounted on the second printed circuit board 32, the connecting member 86 and the connector 104 is transferred and dissipated in the order of the second heat dissipation member 42, the second cooling body 52, the first cooling body 51 and the external cooling body 21.

[0045] Heat generated in the main circuit pattern of the third printed circuit board 33, the electronic components mounted on the third printed circuit board 33, the input terminals 9a and 9b, and the output terminals 10a and 10b is conducted and dissipated in the following order: third heat dissipation member 43, second cooling body 52, first cooling body 51, and external cooling body 21. Heat generated in the main circuit pattern of the third printed circuit board 33, the electronic components mounted on the third printed circuit board 33, the input terminals 9a and 9b, and the output terminals 10a and 10b is conducted and dissipated in the following order: board connection member 105, fourth printed circuit board 34, first printed circuit board 31, first heat dissipation member 41, first cooling body 51, and external cooling body 21.

[0046] Heat generated in the main circuit pattern of the fourth printed circuit board 34, the electronic components mounted on the fourth printed circuit board 34, and the board connecting member 105 is transmitted and dissipated in the following order: first printed circuit board 31, first heat dissipation member 41, first cooling body 51, and external cooling body 21.

[0047] Next, the effects of the power conversion device 100 according to the first embodiment will be described. According to the power conversion device 100 of the first embodiment, the sixth main surface S6 of the third printed circuit board 33 is thermally connected to the second cooling body 52. ​​Therefore, Joule heat of the input current and output current generated in the third printed circuit board 33 can be transferred to the second cooling body 52 and dissipated. Specifically, heat generated by Joule heat in the main circuit pattern, output terminals 10a and 10b, and output wiring member 89 of the third printed circuit board 33 can be transferred to the second cooling body 52 and dissipated. Heat generated in the control elements of the third printed circuit board 33 can also be transferred to the second cooling body 52 and dissipated. Furthermore, the fourth printed circuit board 34 is thermally connected to the first main surface S1 of the first printed circuit board 31 and the sixth main surface S6 of the third printed circuit board 33. Therefore, heat generated in the third printed circuit board 33 can be transferred to the fourth printed circuit board 34, the first printed circuit board 31, and the first cooling body 51 and dissipated. Therefore, the heat dissipation performance of the third printed circuit board 33 can be improved. This makes it possible to suppress a temperature rise in the power conversion device 100. As a result, the power conversion device 100 can operate at high output. Furthermore, the input terminals and output terminals of the third component mounted on the fifth main surface of the third substrate are configured to be connected to external wiring. This makes it easy to connect the input terminals and output terminals to external wiring.

[0048] Furthermore, by mounting electronic components on second printed circuit board 32, it is possible to shorten the heat dissipation path along which heat generated by the electronic components mounted on second printed circuit board 32 is transferred to second cooling body 52. ​​This improves heat dissipation.

[0049] In addition, second cooling body 52 is thermally connected to first cooling body 51. Therefore, heat generated in third printed circuit board 33 can be transferred to first cooling body 51 via second cooling body 52 and dissipated. Furthermore, heat generated in second printed circuit board 32 can be transferred to first cooling body 51 via second cooling body 52 and dissipated.

[0050] Furthermore, at least a portion of the main circuit pattern and output terminals 10a, 10b of third printed circuit board 33 are disposed directly above top surface 52a of second cooling body 52. ​​Therefore, heat generated by Joule heat in the output-side main circuit pattern, output terminals 10a, 10b, and output wiring member 89 can be effectively cooled by second cooling body 52. ​​This makes it possible to suppress a temperature rise in power conversion device 100.

[0051] Next, a modified example of the power conversion device 100 according to the first embodiment will be described with reference to Fig. 5. For ease of explanation, Fig. 5 does not include hatching.

[0052] In a modification of the power conversion device 100 according to the first embodiment, a plurality of via holes VH penetrating the fifth main surface S5 and the sixth main surface S6 are provided in the third printed circuit board 33. The via holes VH are arranged at intervals from one another. The via holes VH may be arranged at any position on the third printed circuit board 33. At least one of the plurality of via holes VH is arranged directly below the output terminals 10a and 10b.

[0053] Next, the effects of the modified example of the power conversion device 100 according to the first embodiment will be described. According to the modification of the power conversion device 100 according to the first embodiment, the third printed circuit board 33 is provided with via holes VH penetrating between the fifth main surface S5 and the sixth main surface S6. This reduces the thermal resistance of the third printed circuit board 33 in the direction from the fifth main surface S5 to the sixth main surface S6. Furthermore, at least one of the via holes VH is disposed directly below the output terminals 10a and 10b. This allows heat generated at the output terminals 10a and 10b to be dissipated through the via holes VH. This further improves the heat dissipation performance of the main circuit pattern of the third printed circuit board 33 and the output terminals 10a and 10b compared to the power conversion device 100 according to the first embodiment.

[0054] Embodiment 2 Unless otherwise specified, embodiment 2 has the same configuration, operation, and effect as above-described embodiment 1. Therefore, the same configuration as above-described embodiment 1 is given the same reference numeral, and description thereof will not be repeated.

[0055] The structure of the power conversion device 100 according to the second embodiment will be described with reference to FIGS.

[0056] The power conversion device 100 according to the second embodiment further includes a fifth printed circuit board (fifth board) 35, a fourth heat dissipation member 44, a fifth heat dissipation member 45, a third cooling body 53, and a main circuit board connecting member 107. The electronic components include a fifth component. The fifth printed circuit board 35 may also include electronic components (fifth components) such as switching elements 2a, 2b, 2c, and 2d, transformers 3a and 3b, rectifying elements 5a, 5b, 5c, and 5d, and a reactor 4, which are mounted on the first printed circuit board 31 and the second printed circuit board 32.

[0057] The fifth printed circuit board (fifth board) 35 has a front surface (ninth main surface) S9 on which electronic components (fifth components) are mounted, and a back surface (tenth main surface) S10 facing the third cooling body 53. The tenth main surface S10 faces the ninth main surface S9. The ninth main surface S9 of the fifth printed circuit board 35 is disposed to face the seventh main surface S7 of the fourth printed circuit board 34. The fourth heat dissipation member 44 is disposed between the tenth main surface S10 of the fifth printed circuit board 35 and the third cooling body 53. The third cooling body 53 is thermally connected to the tenth main surface S10 of the fifth printed circuit board 35. The third cooling body 53 extends in a direction from the second main surface S2 toward the first main surface S1 of the first printed circuit board 31. The third cooling body 53 is thermally connected to the first cooling body 51.

[0058] The fifth heat dissipation member 45 is disposed between the sixth main surface S6 of the third printed circuit board 33 and the top surface 53a of the third cooling body 53. The sixth main surface S6 of the third printed circuit board 33 is thermally connected to the third cooling body 53. The sixth main surface S6 of the third printed circuit board 33 is thermally connected to the top surface 53a of the third cooling body 53 via the fifth heat dissipation member 45.

[0059] The fifth printed circuit board 35 may be electrically connected to the second printed circuit board 32 by the main circuit board connecting member 107, the output board connecting member 106, and the third printed circuit board 33.

[0060] Next, a heat dissipation structure of the power conversion device 100 according to the second embodiment will be described. Heat generated in the main circuit pattern of fifth printed circuit board 35, the electronic components mounted on fifth printed circuit board 35, input wiring member 88, and input terminals 9a and 9b is conducted and dissipated in the order of fourth heat dissipation member 44, third cooling body 53, first cooling body 51, and external cooling body 21. Heat generated in the main circuit pattern of third printed circuit board 33, the electronic components mounted on third printed circuit board 33, input terminals 9a and 9b, and output terminals 10a and 10b is conducted and dissipated in the order of fifth heat dissipation member 45, third cooling body 53, first cooling body 51, and external cooling body 21.

[0061] Next, the effects of the power conversion device 100 according to the second embodiment will be described. According to the power conversion device 100 of the second embodiment, the sixth main surface S6 of the third printed circuit board 33 is thermally connected to the third cooling body 53. Therefore, the Joule heat of the input current and the output current generated in the third printed circuit board 33 can be transferred to the third cooling body 53 and dissipated. Specifically, the heat generated in the wiring of the output wiring member 89, the input terminals 9a and 9b, and the main circuit pattern of the third printed circuit board 33 can be transferred to the third cooling body 53 and dissipated. In addition, the heat generated in the control elements of the third printed circuit board 33 can also be transferred to the third cooling body 53 and dissipated. Therefore, the heat dissipation performance of the third printed circuit board 33 can be further improved.

[0062] Furthermore, by mounting electronic components on third printed circuit board 33, it is possible to shorten the heat dissipation path along which heat generated by the electronic components mounted on third printed circuit board 33 is transmitted to third cooling body 53. Therefore, it is possible to improve heat dissipation performance.

[0063] In addition, third cooling body 53 is thermally connected to first cooling body 51. Therefore, heat generated in third printed circuit board 33 can be transferred to first cooling body 51 via third cooling body 53 and dissipated. Furthermore, heat generated in third printed circuit board 33 can be transferred to first cooling body 51 via third cooling body 53 and dissipated.

[0064] Furthermore, the electronic components mounted on the first printed circuit board 31 and the second printed circuit board 32 in the first embodiment can be dispersed to the fifth printed circuit board 35. Therefore, heat generated by the electronic components can be dispersed to the fifth printed circuit board 35.

[0065] Furthermore, by reducing the number of electronic components mounted on first printed circuit board 31, the mounting area of ​​first cooling body 51 and first printed circuit board 31 can be reduced.

[0066] Embodiment 3 Unless otherwise specified, the third embodiment has the same configuration, operation, and effect as the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will not be repeated.

[0067] The structure of the power conversion device 100 according to the third embodiment will be described with reference to Fig. 7. For ease of explanation, Fig. 7 does not include hatching.

[0068] The power conversion device 100 according to the third embodiment further includes a sixth heat dissipation member 46 and a fourth cooling body 54. The fourth cooling body 54 extends in a direction from the second main surface S2 toward the first main surface S1 of the first printed circuit board 31. The fourth cooling body 54 is electrically connected to the first cooling body 51, the second cooling body 52, and the third cooling body 53. The fourth cooling body 54 is configured to fix the first cooling body 51, the second cooling body 52, and the third cooling body 53. The sixth heat dissipation member 46 is disposed between the sixth main surface S6 of the third printed circuit board 33 and a top surface 54a of the fourth cooling body 54. The sixth main surface S6 of the third printed circuit board 33 is thermally connected to the fourth cooling body 54. The sixth main surface S6 of the third printed circuit board 33 is thermally connected to the top surface 54a of the fourth cooling body 54 via the sixth heat dissipation member 46.

[0069] The main circuit pattern of the third printed circuit board 33 for electrically connecting the fifth printed circuit board 35 and the second printed circuit board 32 is disposed directly above the top surface 54 a of the fourth cooling body 54 .

[0070] Furthermore, similar to first cooling body 51, second cooling body 52, and third cooling body 53, a printed circuit board, electronic components, and heat dissipation members may be mounted on the inner main surface of fourth cooling body .

[0071] Next, a heat dissipation structure of the power conversion device 100 according to the third embodiment will be described. Heat generated in the main circuit pattern of the third printed circuit board 33 to electrically connect the fifth printed circuit board 35 and the second printed circuit board 32 is transferred and dissipated in the order of the sixth heat dissipation member 46, the fourth cooling body 54, and the external cooling body 21.

[0072] Next, the effects of the power conversion device 100 according to the third embodiment will be described. The fifth printed circuit board 35 is electrically connected to the second printed circuit board 32 via the main circuit board connecting member 107, the output board connecting member 106, and the main circuit pattern of the third printed circuit board 33. In this case, it is difficult to dissipate the heat generated by Joule heat in the third printed circuit board 33.

[0073] According to power conversion device 100 according to the third embodiment, sixth main surface S6 of third printed circuit board 33 is thermally connected to fourth cooling body 54. Therefore, Joule heat of the input current and output current generated in third printed circuit board 33 can be transferred to fourth cooling body 54 and dissipated.

[0074] Furthermore, by fixing first cooling body 51, second cooling body 52 and third cooling body 53 with fourth cooling body 54, power conversion device 100 can improve its vibration resistance.

[0075] Next, a modification of the power conversion device 100 according to the third embodiment will be described with reference to FIG.

[0076] The modification of power conversion device 100 according to the third embodiment further includes a fifth cooling body 55. Fifth cooling body 55 extends in a direction from second main surface S2 toward first main surface S1 of first printed circuit board 31. Fifth cooling body 55 is electrically connected to first cooling body 51, second cooling body 52, and third cooling body 53. Fifth cooling body 55 is arranged to face fourth cooling body 54. Fifth cooling body 55 is configured to fix first cooling body 51, second cooling body 52, and third cooling body 53. First cooling body 51, second cooling body 52, third cooling body 53, fourth cooling body 54, and fifth cooling body 55 are arranged so that the cooling bodies as a whole form power conversion device 100 into a box shape.

[0077] Next, the effects of the modified example of the power conversion device 100 according to the third embodiment will be described. According to the modification of power conversion device 100 according to the third embodiment, fifth cooling body 55 is arranged to face fourth cooling body 54. This allows power conversion device 100 to have improved resistance to noise from external devices.

[0078] Furthermore, the above embodiments can be combined as appropriate. The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0079] 9a input terminal, 10a output terminal, 31 to 35 first to fifth printed circuit boards, 51 to 55 first to fifth cooling bodies, 88 input wiring member, 89 output wiring member, 100 power conversion device, S1 to S10 first to tenth main surfaces, VH via hole.

Claims

1. an electronic component including a first component, a second component, a third component, and a fourth component; a first substrate having a first main surface on which the first component of the electronic component is mounted and a second main surface opposite to the first main surface; a first cooling body thermally connected to the second main surface of the first substrate; a second substrate having a third main surface on which the second component of the electronic component is mounted and a fourth main surface opposite to the third main surface; a second cooling body thermally connected to the fourth main surface of the second substrate; a third substrate having a fifth main surface on which the third component of the electronic component is mounted and a sixth main surface opposite to the fifth main surface; a fourth substrate having a seventh main surface on which the fourth component of the electronic component is mounted and an eighth main surface opposite to the seventh main surface, the second cooling body extends in a direction from the second main surface toward the first main surface of the first substrate and is thermally connected to the first cooling body; the sixth main surface of the third substrate is thermally connected to the second cooling body; the fourth substrate extends in a direction from the second main surface toward the first main surface of the first substrate, and is electrically and thermally connected to the first main surface of the first substrate and the sixth main surface of the third substrate; the third component includes an input terminal to which a current is input and an output terminal to which a current is output, the input terminal and the output terminal are configured to be connected to external wiring, the first component, the second component, and the third component are high-heat generating components, the fourth substrate is connected to a substrate connecting member mounted on the third substrate, the substrate connecting member penetrates the fifth main surface and the sixth main surface of the third substrate, The power conversion device, wherein the output terminal is mounted directly above the top surface of the second cooling body.

2. a plurality of via holes penetrating the fifth main surface and the sixth main surface are provided in the third substrate; The power conversion device according to claim 1 , wherein at least one of the plurality of via holes is disposed directly below the output terminal.

3. the electronic components include a fifth component, a fifth substrate having a ninth main surface on which the fifth component of the electronic component is mounted and a tenth main surface opposite to the ninth main surface; a third cooling body thermally connected to the tenth main surface of the fifth substrate, the third cooling body extends in a direction from the second main surface toward the first main surface of the first substrate and is thermally connected to the first cooling body; The power conversion device according to claim 1 , wherein the sixth main surface of the third substrate is thermally connected to the third cooling body.

4. a fourth cooling body extending in a direction from the second main surface toward the first main surface of the first substrate, the fourth cooling body is thermally connected to the first cooling body, the second cooling body, and the third cooling body; The power conversion device according to claim 3 , wherein the sixth main surface of the third substrate is thermally connected to the fourth cooling body.

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