Power conversion device

Abstract

To provide a power conversion device capable of suppressing vibration of a circuit board while suppressing an increase in size of the power conversion device.SOLUTION: The power conversion device 100 includes a circuit board 10 and a power module 20. The power module 20 includes semiconductor elements and a plurality of signal terminals 26a and 26b. The circuit substrate 10 is fixed to the power module 20 at a plurality of positions, has one surface facing the power module 20, and is electrically connected to the signal terminals 26a and 26b. Further, the power conversion device 100 includes the dummy terminal 30 fixed to the power module 20 in the facing region of the one surface and mechanically connected to the circuit board 10 without being electrically connected to the circuit board 10. The size of the contact portions of the dummy terminals 30 with the circuit substrate 10 is equal to the size of the contact portions of the signal terminals 26a and 26b with the circuit substrate 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a motor drive device including a power semiconductor module and a printed circuit board on which the power semiconductor module is mounted. The power semiconductor module has two rows of terminals. The power semiconductor module has dummy terminals at both ends of at least one of the terminal rows. The dummy terminals are configured to be thicker than the other terminals in the terminal row. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-206184 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the dummy terminals are thicker than the other terminals, which causes a problem of increased size. From the above perspective and other perspectives not mentioned, further improvements are required in power conversion devices.

[0005] One disclosed object is to provide a power conversion device that can suppress vibration of a circuit board while suppressing an increase in the size of the power conversion device. [Means for solving the problem]

[0006] The power conversion device disclosed herein comprises: a power module (20) including semiconductor elements (22a, 22b) including switching elements and a plurality of signal terminals (26a, 26b) connected to the semiconductor elements; a circuit board (10) fixed to the power module at a plurality of locations, having one surface (S1) facing the power module and an opposite surface (S2) to the one surface, and having signal terminals electrically connected thereto; dummy terminals (30, 31a, 32a, 32b) fixed to the power module in a facing region on one surface and mechanically connected to the circuit board without being electrically connected to the circuit board; The size of the contact portion of the dummy terminal with the circuit board is smaller than or equal to the size of the contact portion of the signal terminal with the circuit board.

[0007] In the power converter disclosed herein, the size of the contact portion of the dummy terminal is smaller than or equal to the size of the contact portion of the signal terminal, so that the power converter can suppress vibration of the circuit board while preventing an increase in size, thereby suppressing the application of stress caused by vibration of the circuit board to the signal terminal.

[0008] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims and in this section are intended to exemplify correspondences with the following embodiments and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become more apparent by reference to the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing a schematic configuration of a power conversion device according to an embodiment. [Figure 2] FIG. 2 is an enlarged plan view of a portion II in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is an enlarged plan view of a portion IV in FIG. [Figure 5] FIG. 1 is a plan view showing a schematic configuration of a power module according to an embodiment. [Figure 6] FIG. 6 is an enlarged perspective view of a portion VI in FIG. 5. [Figure 7] FIG. 2 is a perspective view showing a schematic configuration of a dummy terminal in the embodiment. [Figure 8] FIG. 2 is a perspective view of a power module according to an embodiment, in which a circuit board is disposed. [Figure 9] 10 is a plan view showing a schematic configuration of a wiring board in Modification 1. FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. [Figure 11] FIG. 10 is a cross-sectional view showing a dummy terminal in Modification 1. [Figure 12] FIG. 10 is a plan view showing a schematic configuration of a wiring board in Modification 2. [Figure 13] FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. [Figure 14] FIG. 10 is a cross-sectional view showing a dummy terminal in Modification 2. [Figure 15] FIG. 11 is a plan view showing a schematic configuration of a wiring board in Modification 3. [Figure 16] FIG. 10 is a plan view showing a schematic configuration of a power conversion device according to a fourth modification. [Figure 17] FIG. 13 is a plan view showing a schematic configuration of a power conversion device according to a fifth modification. [Figure 18] FIG. 13 is a plan view showing a schematic configuration of a power conversion device according to a sixth modification. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment may be assigned the same reference numerals, and duplicated explanations may be omitted. In each embodiment, when only a part of the configuration is described, other parts of the configuration can be applied by referring to the other embodiment described earlier. In the following, three mutually orthogonal directions are referred to as the X direction, the Y direction, and the Z direction.

[0011] (Embodiment) <Power conversion device> A power converter 100 of this embodiment will be described with reference to Figures 1 to 8. As shown in Figures 1, 8, etc., the power converter 100 includes a circuit board 10, a power module 20, a dummy terminal 30, a cooler 40, etc.

[0012] The power conversion device 100 has a power module 20 mounted on a cooler 40. Furthermore, the power conversion device 100 has a circuit board 10 mounted on the power module 20. That is, the power conversion device 100 is stacked in the Z direction in the order of the cooler 40, the power module 20, and the circuit board 10. The power conversion device 100 can be applied to inverter circuits, converter circuits, and the like. In this embodiment, as an example, a power conversion device 100 connectable to a three-phase motor is adopted. As shown in FIG. 1, the power conversion device 100 includes a U-phase region 10u, a V-phase region 10v, and a W-phase region 10w.

[0013] The power conversion device 100 is configured to be mountable on, for example, a mobile object. Examples of the mobile object include vehicles such as electric cars, hybrid cars, and fuel cell cars, flying objects such as electric vertical take-off and landing aircraft and drones, ships, construction machinery, agricultural machinery, etc. However, the power conversion device 100 may also be mounted on devices other than mobile objects.

[0014] <Power module> The power module 20 will be described with reference to Figures 5, 6, 8, etc. In this embodiment, as an example, a power module 20 constituting a three-phase inverter is employed.

[0015] The power module 20 includes a module housing 21, semiconductor elements 22a and 22b, a P terminal 23, an N terminal 24, an O terminal 25, a first signal terminal 26a, a second signal terminal 26b, and a sealing body 27. Fig. 5 shows the power module 20 in a state where the circuit board 10 is not mounted.

[0016] The module housing 21 is formed using an electrically insulating material such as resin. The housing 22 may be, for example, a resin molded body. The module housing 21 is provided with accommodation portions in which the semiconductor elements 22a and 22b are disposed. The module housing 21 is provided with an accommodation portion for the U-phase, an accommodation portion for the V-phase, and an accommodation portion for the W-phase. That is, the module housing 21 is provided with an accommodation portion included in the U-phase region 10u, an accommodation portion included in the V-phase region 10v, and an accommodation portion included in the W-phase region 10w. In FIG. 5, the portion where the sealing body 27 is provided corresponds to the accommodation portion.

[0017] The accommodating portion penetrates, for example, the module housing 21 in the Z direction. One opening of the accommodating portion of the module housing 21 is closed by attaching the cooler 40. It can also be said that the module housing 21 and the cooler 40 form an accommodating space in the power module 20 that accommodates the semiconductor elements 22a and 22b. The module housing 21 can also be said to be a frame-shaped member that surrounds the accommodating portion.

[0018] At least semiconductor elements 22a and 22b are disposed in each housing. For example, semiconductor element 22a is an upper arm element, and semiconductor element 22b is a lower arm element. The upper arm element may be a plurality of semiconductor elements 22a connected in parallel. Similarly, the lower arm element may be a plurality of semiconductor elements 22a connected in parallel. Note that each housing may also be provided with a resistor element, a capacitor element, or the like.

[0019] In this embodiment, as an example, the semiconductor elements 22a and 22b are used, each of which includes an n-channel MOSFET as a vertical element on a semiconductor substrate made of SiC, i.e., the semiconductor elements 22a and 22b include a MOSFET as a switching element.

[0020] The MOSFET has a drain electrode and a source electrode as main electrodes. The MOSFET has a drain electrode on one side and a source electrode on the opposite side. When the MOSFET is turned on, a current (main current) flows between the main electrodes of the semiconductor elements 22a and 22b. The semiconductor elements 22a and 22b may include a diode. The semiconductor elements 22a and 22b may include an IGBT as a switching element. The semiconductor elements 22a and 22b may also include a temperature-sensitive diode or the like.

[0021] The semiconductor elements 22a, 22b may be disposed on a substrate having conductors formed on both sides of an insulating base material. The substrate contains the housing portion when viewed in a plan view from the Z direction. One of the conductors is patterned to form wiring. The wiring includes a P wiring connected to the P terminal 23, an N wiring connected to the N terminal 24, and an O wiring connected to the O terminal 25, which will be described later. The other conductor is fixed to the cooler 40 via a bonding material. The substrate here can also be referred to as a high-current substrate or a base substrate. The P terminal 23, the N terminal 24, and the O terminal 25 can also be referred to as main terminals. The wiring provided on the substrate can also be referred to as high-current wiring.

[0022] The semiconductor elements 22a and 22b are disposed opposite the cooler 40 via the substrate. The cooler 40 is disposed on the side opposite the drain electrodes of the MOSFETs. The semiconductor elements 22a and 22b generate heat when the MOSFETs operate. Furthermore, the main terminals 23 to 25 become hot due to heat conduction from the semiconductor elements 22a and 22b. The cooler 40 is provided to cool the semiconductor elements 22a and 22b and the main terminals 23 to 25. It can be said that the power module 20 has a single-sided cooling structure.

[0023] The cooler 40 is fixed to the mounting target of the power conversion device 100 with bolts or the like. For this reason, the cooler 40 is provided with fixing holes 41 into which the bolts are inserted.

[0024] The module housing 21 is provided with a P terminal 23, an N terminal 24, an O terminal 25, and signal terminals 26a and 26b. The terminals 23 to 25, 26a, and 26b are, for example, integrally molded as insert parts with the module housing 21. The terminals 23 to 25, 26a, and 26b are provided in the U-phase region 10u, the V-phase region 10v, and the W-phase region 10w, respectively.

[0025] The P terminal 23 is part of the high-potential side wiring of the three-phase inverter. The P terminal 23 is electrically connected to the drain electrode of the semiconductor element 22a, which is the upper arm element. The N terminal 24 is part of the low-potential side wiring of the three-phase inverter. The N terminal 24 is electrically connected to the source electrode of the semiconductor element 22b, which is the lower arm element. The O terminal 25 is part of the output wiring connected to the terminals of the three-phase motor. The O terminal 25 is connected to the source electrode of the semiconductor element 22a and the drain electrode of the semiconductor element 22b.

[0026] The signal terminals 26a, 26b are electrically connected to the semiconductor elements 22a, 22b. The signal terminals 26a, 26b include a gate terminal, a Kelvin source terminal, an anode terminal, a cathode terminal, etc. The signal terminals 26a, 26b may be connected to the semiconductor elements 22a, 22b via wires, etc. The signal terminals 26a, 26b are press-fit terminals.

[0027] The signal terminals 26a, 26b include a first signal terminal 26a arranged along the Y direction and a second signal terminal 26b arranged along the X direction. That is, in the power module 20, a plurality of first signal terminals 26a are arranged in the Y direction, and a plurality of second signal terminals 26b are arranged in the X direction.

[0028] The arranged multiple first signal terminals 26a correspond to a terminal row, which can also be called a Y-direction terminal row. Similarly, the arranged multiple second signal terminals 26b correspond to a terminal row, which can also be called an X-direction terminal row. The Y-direction terminal row can also be called a first terminal row. The X-direction terminal row can also be called a second terminal row. The first terminal rows for each phase are arranged on different imaginary straight lines along the Y direction. The second terminal rows for each phase are arranged on the same imaginary straight line along the X direction.

[0029] One end of each of the terminals 23 to 25, 26a, 26b is disposed in the accommodation space, and the other end is provided so as to protrude into the external space of the module housing 21. The external space is the space surrounding the module housing 21 and the accommodation space.

[0030] One end of each of the terminals 23 to 25, 26a, 26b is electrically connected to the semiconductor elements 22a, 22b. The other end of each of the terminals 23 to 25, 26a, 26b is connected to an external device disposed around the power conversion device 100. The external device is a battery, a three-phase motor, or a circuit board 10. The P terminal 23 and the N terminal 24 are electrically connected to the battery. The O terminal 25 is electrically connected to the three-phase motor. The signal terminals 26a, 26b are electrically connected to the circuit board 10.

[0031] 5, each of the main terminals 23 to 25 protrudes from the module housing 21 into external space in the Y direction. The P terminal 23 and the N terminal 24 protrude in the same direction from the module housing 21. The O terminal 25 protrudes from the module housing 21 in the opposite direction from the P terminal 23 and the N terminal 24.

[0032] 5 and 6, the signal terminals 26a, 26a protrude into the external space in the Z direction relative to the module housing 21. Note that only the second signal terminal 26b is shown in Fig. 6. However, the first signal terminal 26a protrudes in the same manner as the second signal terminal 26b.

[0033] The power module 20 includes a plurality of clips connected to the respective source electrodes. Each clip is provided on the side of the power module 20 facing the circuit board 10. That is, the clips are arranged facing one surface S1 of the circuit board 10. For example, the plurality of clips include a clip that connects the source electrode of the upper arm element to the O terminal 25, and a clip that connects the source electrode of the lower arm element to the N terminal 24. The clip is a metal plate material whose main component is a metal with good conductivity, such as copper. The clip may also be referred to as a bridging member, a relay member, a metal bridge, or the like. For more information on clips, see JP 2024-66844 A, etc.

[0034] Sealing bodies 27 are provided in the accommodation space. That is, three sealing bodies 27 are provided in the power module 20. The sealing bodies 27 integrally seal one end side of the semiconductor elements 22a, 22b and each of the terminals 23 to 25, 26a, 26b. That is, the semiconductor elements 22a, 22b, etc. are covered by the sealing body 27 in a state where the sealing body 27 is in contact with them. In this embodiment, a gel is used as an example of the sealing body 27. However, a potting resin may also be used as the sealing body 27.

[0035] As shown in Fig. 5, the module housing 21 is provided with a plurality of fixing holes 28 into which bolts 50 are inserted. The fixing holes 28 are provided with female threads that correspond to the male threads of the bolts 50. As shown in Fig. 6, the fixing holes 28 are provided in protrusions that are provided on the module housing 21. These protrusions can also be referred to as fastening bosses.

[0036] As shown in Fig. 5, the module housing 21 has positioning protrusions 29 in at least two locations. The positioning protrusions 29 protrude further than the surrounding area of ​​the positioning protrusions 29. The positioning protrusions 29 protrude into the external space in the Z direction relative to the module housing 21. As shown in Fig. 8, the positioning protrusions 29 protrude in the same direction as the signal terminals 26a and 26b.

[0037] The positioning protrusions 29 are protrusions for positioning the circuit board 10 relative to the power module 20. More specifically, the power module 20 has the circuit board 10 mounted thereon such that the surface S1 faces the multiple sealing bodies 27. When the circuit board 10 is mounted, the signal terminals 26a, 26b and dummy terminals 30, which will be described later, are inserted into the through holes 14, 15 of the circuit board 10. Therefore, the positioning protrusions 29 are provided so that the signal terminals 26a, 26b and the dummy terminals 30 can be inserted into the through holes 14, 15.

[0038] Therefore, when mounting the circuit board 10 on the power module 20, the positioning protrusions 29 need to reach the circuit board 10 before the signal terminals 26a, 26b and the dummy terminals 30. Therefore, the tip of the positioning protrusions 29 is provided so as to be higher than the tip of the signal terminals 26a, 26b and the dummy terminals 30. For example, the length of the tip of the positioning protrusions 29 in the Z direction is longer than the length of the signal terminals 26a, 26b and the dummy terminals 30. The tip is an end in the Z direction.

[0039] <Circuit board> The circuit board 10 will be described with reference to Figures 1 to 4, 8, etc. The circuit board 10 is mounted on the power module 20 as described above. That is, the circuit board 10 is placed on the module housing 21 and fixed to the module housing 21 by fixing members such as bolts 50. The state in which the circuit board 10 is mounted on the power module 20 is also referred to as a mounted state.

[0040] The fixing member may be a press-fit fixing member provided in the module housing 21. The circuit board 10 is fixed by press-fitting the press-fit fixing member of the module housing 21 into fixing hole portions 16, which will be described later.

[0041] 1, circuit board 10 includes portions corresponding to U-phase region 10u, V-phase region 10v, and W-phase region 10w. In other words, circuit board 10 is formed such that the portions included in regions 10u, 10v, and 10w are integrated into one body. The portion of circuit board 10 included in U-phase region 10u is also referred to as the U-phase portion. Similarly, the portion of circuit board 10 included in V-phase region 10v is also referred to as the V-phase portion, and the portion of circuit board 10 included in W-phase region 10w is also referred to as the W-phase portion.

[0042] The circuit board 10 includes a wiring board 11 and a circuit element 12 mounted on the wiring board 11. The wiring board 11 has conductive wiring provided on an insulating base material whose main component is an electrically insulating material such as resin. The wiring on the wiring board 11 can also be referred to as signal wiring. As shown in FIG. 3, the wiring board 11 has one surface S1 and an opposite surface S2 of the surface S1.

[0043] As shown in Figures 4 and 8, wiring board 11 is provided with through holes 14, 15, 16, and 17 at multiple locations, extending from one surface S1 to the opposite surface S2. Through hole 14 is a hole into which signal terminals 26a and 26b are inserted and is also referred to as signal hole portion 14. Through hole 15 is a hole into which dummy terminal 30 is inserted and is also referred to as dummy hole portion 15. Through hole 16 is a hole into which bolt 50 for fixing circuit board 10 to power module 20 is inserted and is also referred to as fixing hole portion 16. Positioning hole portion 17 is a hole into which positioning protrusion 29 is inserted and is also referred to as positioning hole portion 17.

[0044] The wiring board 11 is provided with at least the same number of signal holes 14 as the signal terminals 26a, 26b. The wiring board 11 is also provided with the same number of dummy holes 15 as the dummy terminals 30. At least one dummy hole 15 is provided in the wiring board 11. Note that in Figures 1 and 2, etc., the through holes 14, 15 are omitted to avoid complicating the drawings.

[0045] 4, in the mounted state, a portion of the first signal terminal 26a is inserted into the signal hole 14. The first signal terminal 26a is inserted into the signal hole 14 and connected to a portion of the wiring provided in the signal hole 14. In other words, the first signal terminal 26a is electrically connected to the circuit board 10. The same is true for the signal terminal 26b. The position on the circuit board 10 where the signal terminals 26a and 26b are connected is also referred to as the signal terminal position.

[0046] 4, in the mounted state, a portion of the dummy terminal 30 is inserted into the dummy hole 15. The dummy terminal 30 is inserted into the dummy hole 15 and connected to the circuit board 10. The dummy hole 15 corresponds to a through-hole in which a portion of the dummy terminal 30 is disposed. The position on the circuit board 10 where the dummy terminal 30 is connected is also referred to as the dummy terminal position. The dummy terminal 30 will be described later.

[0047] Bolts 50 are inserted into the fixing holes 16. In FIG. 1 , the fixing holes 16 are hidden by the bolts 50. In this embodiment, a wiring board 11 is used in which fixing holes 16 are provided in eight locations. Furthermore, the wiring board 11 is provided with fixing holes 16 so as to surround a portion of each of the U-phase portion, the V-phase portion, and the W-phase portion. For example, a portion of the U-phase portion is surrounded by four fixing holes 16. The positions on the wiring board 11 where the bolts 50 are provided correspond to fixing positions. The wiring board 11 is provided with the same number of positioning holes 17 as the positioning protrusions 29.

[0048] The wiring includes lands 13 and patterned wiring patterns. As shown in Figures 1, 2, and 4, the lands 13 are provided corresponding to the respective signal holes 14. The lands 13 are provided around the respective signal holes 14.

[0049] The wiring is also provided in the signal hole 14. In other words, part of the wiring is also provided on the annular wall surface of the insulating substrate that forms the signal hole 14. The land 13 and the signal hole 14 can be collectively referred to as a through hole.

[0050] No wiring is provided in the dummy hole 15 and the fixing hole 16. However, a reinforcing conductor may be provided on the annular wall surface of the insulating base material that forms the dummy hole 15. The reinforcing conductor is provided, for example, on the entire annular wall surface of the insulating base material that forms the dummy hole 15. The reinforcing conductor is electrically insulated from the wiring.

[0051] As will be explained later, stress is applied to the annular wall surface that forms the dummy hole 15 from the connection portion 33 of the dummy terminal 30. Therefore, the insulating base material may be deformed by the stress. Furthermore, if the insulating base material is deformed, the connection reliability between the insulating base material and the dummy terminal 30 will decrease. By providing the wiring board 11 with a reinforcing conductor, deformation of the insulating base material can be suppressed. Therefore, the wiring board 11 can suppress a decrease in connection reliability.

[0052] 1 shows only one circuit element 12. However, multiple circuit elements 12 may be mounted on wiring board 11. Circuit element 12 is electrically connected to the wiring of wiring board 11. In circuit board 10, a circuit is formed by circuit elements 12 and the wiring of wiring board 11. For example, the U-phase portion, V-phase portion, and W-phase portion have the same circuit configuration.

[0053] In this embodiment, a control device that controls the gate electrode of a MOSFET is used as an example of the circuit element 12. The circuit element 12 is a microcomputer equipped with semiconductor elements.

[0054] Furthermore, in addition to the control device, a capacitor element and a resistor element may be mounted on the wiring board 11 as the circuit element 12. The control device is larger than the capacitor element and the resistor element. In other words, the control device is heavier than the capacitor element and the resistor element. The control device is also referred to as a large component. On the other hand, the capacitor element and the resistor element are also referred to as a small component.

[0055] Large components are more likely to adversely affect the vibration resistance of the circuit board 10 than small components. Large components are often placed near the center of the circuit board 10. Meanwhile, the circuit board 10 is prone to vibrate with an antinode near the center of the area surrounded by the fixing positions. Therefore, the circuit board 10 is more likely to vibrate when large components are mounted. For example, the circuit board 10 shown in FIG. 1 is prone to vibration antinodes near the center of the opposing area of ​​each sealing body 27. Furthermore, the circuit board 10 is prone to vibration antinodes near the center of the V-phase portion. The circuit board 10 vibrates while deforming.

[0056] <Dummy terminal> The dummy terminal 30 will be described with reference to Figures 1, 4, 5, 7, etc. As shown in Figure 7, the dummy terminal 30 includes a base 31, a shaft portion 32, a connecting portion 33, and an end portion 34. The base 31 has conductors 31y and 31z formed on both sides of an insulating substrate 31x. The base 31 is a so-called DBC substrate. DBC is an abbreviation for Direct Bonded Copper.

[0057] The shaft portion 32 is a portion that protrudes from the conductor 31y. The connection portion 33 is provided at the end of the shaft portion 32. The connection portion 33 is a portion that is disposed in the dummy hole 15. The connection portion 33 is disposed in the dummy hole 15 and elastically deforms, and is connected to the circuit board 10 by the reaction force of the elastic deformation. Therefore, the connection portion 33 applies stress to the annular wall surface of the insulating substrate that forms the dummy hole 15. The connection portion 33 corresponds to a portion of the dummy terminal 30 that is disposed in the dummy hole 15.

[0058] The end 34 is provided on the opposite side of the connecting portion 33 from the shaft portion 32. The end 34 has a beveled tip so that it can be easily inserted into the dummy hole 15.

[0059] The shank 32, connecting portion 33, and end portion 34 are made primarily of metal. The shank 32, connecting portion 33, and end portion 34 are configured as a single unit. The shank 32, connecting portion 33, and end portion 34 have the same configuration as a press-fit terminal. The shank 32, connecting portion 33, and end portion 34 can be collectively referred to as a terminal portion. Therefore, the dummy terminal 30 can be said to include a base 31 and a terminal portion. The terminal portion may have the same configuration as the signal terminals 26a and 26b.

[0060] The dummy terminal 30 is fixed to the power module 20 in an opposing region of the one surface S1. As described above, the power module 20 is provided with a clip at a position opposing the one surface S1. Therefore, the dummy terminal 30 can be mounted on the clip of the power module 20, for example. In this case, the dummy terminal 30 is fixed to the power module 20 by connecting the conductor 31z to the clip. It can also be said that the dummy terminal 30 is fixed to the power module 20 in the accommodation space. The terminal portion of the dummy terminal 30 is electrically insulated from the clip by the insulating base material 31x.

[0061] The conductor 31z can be connected to the clip by welding or a joining member. As shown in FIG.

[0062] In this way, the dummy terminal 30 can be provided even in an area where a fastening boss cannot be provided. In other words, the dummy terminal 30 can be provided even in an area where it cannot be fixed with a bolt or a press-fit fixing member. Therefore, it can be said that the dummy terminal 30 has a high degree of freedom in installation.

[0063] However, the configuration of the dummy terminal 30 is not limited to the above. For example, the dummy terminal 30 may be provided on the module housing 21. Furthermore, the dummy terminal 30 may be connected to the circuit board 10 by a joining member such as solder.

[0064] Furthermore, the dummy terminals 30 may have the same configuration as the signal terminals 26a, 26b. This eliminates the need for the power conversion device 100 to use a dummy terminal 30 of a type different from the signal terminals 26a, 26b. Therefore, the power conversion device 100 can reduce design costs, component costs, and manufacturing costs compared to when the above-described dummy terminals 30 are used.

[0065] As shown in FIG. 4, the dummy terminal 30 is connected to the circuit board 10 by arranging the connection portion 33 in the dummy hole 15. In the mounted state, the dummy terminal 30 is mechanically connected to the circuit board 10 but not electrically connected thereto. In other words, the dummy terminal 30 does not have the function of transmitting signals like the first signal terminal 26a. The dummy terminal 30 is provided to suppress vibration of the circuit board 10. It can also be said that the dummy terminal 30 is provided to suppress the application of stress caused by vibration of the circuit board 10 to the signal terminals 26a, 26b.

[0066] 4, the symbol L1 denotes the size of the contact portion of the signal terminal 26a with the circuit board 10. On the other hand, the symbol L2 denotes the size of the contact portion of the dummy terminal 30 with the circuit board 10.

[0067] The size L1 is also referred to as the signal terminal size. The size L2 is also referred to as the dummy terminal size. The sizes L1 and L2 can also be said to be the size of the outline of the cross section of the contact area. The cross section is a surface along the XY plane. In the following description, the cross sections of the signal terminals 26a, 26b and the dummy terminal 30 are also surfaces along the XY plane.

[0068] The dummy terminal size L2 is equal to the signal terminal size L1. Alternatively, the dummy terminal size L2 may be smaller than the signal terminal size L1. The size of the contact portion of the signal terminal 26b with the circuit board 10 is equal to the signal terminal size L1.

[0069] 1 and 5, the dummy connection area FA1 to which the dummy terminals 30 on the circuit board 10 are connected will be described. The dummy terminals 30 protrude in the Z direction relative to the power module 20. Therefore, the dummy connection area FA1 can also be said to be an area where the dummy terminals 30 on the power module 20 are mounted. In FIG. 1, some of the dummy connection areas FA1 are hatched with dots. Note that the dummy connection areas in modified examples described later are also hatched with dots.

[0070] The dummy connection area FA1 is an area in the XY plane. The XY plane is a plane defined by the X axis extending in the X direction and the Y axis extending in the Y direction. Note that only the end 34 of the dummy terminal 30 is shown in FIG.

[0071] As described above, the power module 20 is provided with a plurality of Y-direction terminal rows and a plurality of X-direction terminal rows. The signal terminal side Y11 is an imaginary straight line that runs along the Y-direction terminal row. The signal terminal side X11 is an imaginary straight line that runs along the X-direction terminal row. Here, the terminal sides Y11 and X11 that pass through the edge of the land 13 are used.

[0072] The dummy connection area FA1 is the area between two adjacent Y-direction terminal rows in a plan view from the Z direction. In other words, the dummy connection area FA1 is the area between two adjacent signal terminal sides Y11. In this embodiment, the dummy connection area FA1 is set in the U-phase portion and the V-phase portion. The dummy connection area FA1 can also be said to be the projection area of ​​the signal terminal side X11 in the Y direction.

[0073] The dummy terminals 30 are provided in the dummy connection area FA1. That is, the dummy terminals 30 are connected to the dummy connection area FA1 on the circuit board 10. It can also be said that the dummy terminals 30 are arranged between two Y-direction terminal rows. The dummy terminals 30 in the W-phase portion are connected to the circuit board 10 in a dummy connection area FA3, which will be described later. In this embodiment, the dummy terminals 30 in the W-phase portion do not necessarily have to be provided.

[0074] As described above, the circuit board 10 is likely to vibrate with an antinode near the center of the area surrounded by the fixing positions. Therefore, it is preferable that the dummy terminal 30 be connected to the center of the area surrounded by the multiple fixing positions on the circuit board 10. It is also preferable that the dummy terminal 30 be connected to a predetermined antinode of vibration on the circuit board 10. The antinode of vibration can be set in advance by simulation, experiment, or the like. Therefore, since the dummy terminal 30 is connected to the antinode of vibration on the circuit board 10, it is easy to suppress vibration of the circuit board 10.

[0075] Furthermore, as described above, the circuit board 10 becomes even more susceptible to vibration when large components are mounted on it. That is, the circuit board 10 is prone to large vibration at the locations where large components are mounted. Therefore, it is preferable that the distance between the dummy terminal locations and the circuit element 12 be shorter than the distance between the signal terminal locations and the circuit element 12. The distance between the signal terminal locations and the circuit element 12 is the shortest distance between the circuit element 12 and the terminal closest to the circuit element 12 among the multiple signal terminals 26a, 26b. Therefore, since the dummy terminals 30 are connected to locations on the circuit board 10 that are prone to large vibration, it is easy to suppress vibration of the circuit board 10.

[0076] In this embodiment, as an example, one dummy terminal 30 is connected to each of the U-phase portion, V-phase portion, and W-phase portion of the circuit board 10. However, the present disclosure is not limited to this. The power conversion device 100 may have multiple dummy terminals 30 connected to each phase portion of the circuit board 10.

[0077] Furthermore, the power conversion device 100 may have a different number of dummy terminals 30 connected to each phase portion of the circuit board 10. For example, it is conceivable that the V-phase portion of the circuit board 10 will have a larger amplitude than the U-phase portion and W-phase portion. Therefore, the V-phase portion is connected with a larger number of dummy terminals 30 than the U-phase portion and W-phase portion. This makes it easier for the power conversion device 100 to suppress vibrations of the circuit board 10.

[0078] <Effects> As described above, in the power converter 100, the size of the contact portion of the dummy terminal 30 is smaller than or equal to the size of the contact portion of the signal terminals 26a, 26b. Therefore, the power converter 100 can suppress vibration of the circuit board 10 while suppressing an increase in the size of the power converter 100. Therefore, the power converter 100 can suppress the application of stress caused by vibration of the circuit board 10 to the signal terminals 26a, 26b. Furthermore, the power converter 100 can suppress breakage of the signal terminals 26a, 26b due to stress caused by vibration of the circuit board 10. Note that the stress applied to the signal terminals 26a, 26b is a stress pulled from the circuit board 10 due to the vibration of the circuit board 10.

[0079] In the power converter 100, the dummy terminals 30 are connected to the dummy connection area FA1. This allows the power converter 100 to increase the resonant frequency. Furthermore, the power converter 100 can arrange the dummy terminals 30 between the vibration antinodes and the signal terminals 26a and 26b. Therefore, the power converter 100 can absorb vibrations of the circuit board 10 with the dummy terminals 30. Furthermore, the power converter 100 can arrange the dummy terminals 30 near the vibration antinodes. Therefore, the power converter 100 can move the vibration antinodes closer to areas where the signal terminals 26a and 26b are not present. Furthermore, the power converter 100 can arrange the dummy terminals 30 on sides of a rectangle surrounding each phase portion where the signal terminals 26a and 26b are not present. Therefore, the power converter 100 can effectively increase the resonant frequency.

[0080] The preferred embodiments of the present disclosure have been described above. However, the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the present disclosure. Modifications 1 to 6 will be described below as other aspects of the present disclosure. The above embodiments and modifications 1 to 6 can be implemented independently, or can be implemented in appropriate combinations. The present disclosure is not limited to the combinations shown in the embodiments, and can be implemented in various combinations.

[0081] <Variation 1> 9 to 11, a power conversion device 100 according to Modification 1 will be described. Modification 1 differs from dummy terminal 30 in the configuration of dummy terminal 31a. Note that Modification 1 employs, as an example, an example in which dummy terminal 31a is provided on module housing 21. Modification 1 will be described using first signal terminal 26a of signal terminals 26a, 26b. Modification 1 is similar to second signal terminal 26b.

[0082] The dummy terminals 31a are provided to be more easily deformed than the first signal terminals 26a. The dummy terminals 31a are more easily deformed at least in the XY plane than the first signal terminals 26a. As shown in Fig. 9, the dummy terminals 31a are disposed opposite the first signal terminals 26a across the vibration loop V1.

[0083] 10, the first signal terminal 26a protrudes from the protrusion 21a of the module housing 21. Therefore, the projection margin Z2 of the dummy terminal 31a is longer than the projection margin Z1 of the first signal terminal 26a. The projection margins Z1 and Z2 are the projection lengths from the module housing 21. In this way, by making the projection margin Z2 of the dummy terminal 31a longer than the projection margin Z1, the dummy terminal 31a is more easily deformed than the first signal terminal 26a.

[0084] 11, the dummy terminals 31a are more easily deformed than the first signal terminals 26a due to the provision of the bent portions 311. The first signal terminals 26a are not provided with bent portions.

[0085] Furthermore, the dummy terminals 31a may be made more easily deformable than the first signal terminals 26a depending on their cross-sectional shape and arrangement direction. In other words, by making the cross-sectional shape of the dummy terminals 31a less rigid, the dummy terminals 31a can be made more easily deformable than the first signal terminals 26a. The first signal terminals 26a and the dummy terminals 31a have rectangular cross sections. In this case, by changing the arrangement direction of the first signal terminals 26a and the dummy terminals 31a, the dummy terminals 31a can be made more easily deformable than the first signal terminals 26a. Furthermore, by making the dummy terminals 31a from a material with a smaller Young's modulus than the first signal terminals 26a, the dummy terminals 31a can be made more easily deformable than the first signal terminals 26a.

[0086] The first signal terminal 26a and the dummy terminal 31a are deformed by stress caused by vibration of the circuit board 10. The first signal terminal 26a and the dummy terminal 31a deform from the portion in contact with the circuit board 10 as the origin. The power conversion device 100 of the first modification can concentrate the deformation on the dummy terminal 31a. Therefore, the power conversion device 100 of the first modification can easily prevent the first signal terminal 26a from being broken by stress caused by vibration of the circuit board 10.

[0087] <Variation 2> 12 to 14, a power conversion device 100 according to Modification 2 will be described. Modification 2 differs from dummy terminal 30 in the configuration of dummy terminal 32a. Note that Modification 2 employs, as an example, an example in which dummy terminal 32a is provided on module housing 21. Modification 2 will be described using first signal terminal 26a of signal terminals 26a, 26b. Modification 2 is similar to second signal terminal 26b.

[0088] The dummy terminals 32a are provided to be less susceptible to deformation than the first signal terminals 26a. The dummy terminals 32a are less susceptible to deformation at least in the XY plane than the first signal terminals 26a. As shown in Fig. 12, the dummy terminals 32a are disposed adjacent to and opposite the first signal terminals 26a.

[0089] 13, the dummy terminals 32a protrude from the protrusions 21a of the module housing 21. Therefore, the projection margin Z2 of the dummy terminals 32a is shorter than the projection margin Z1 of the first signal terminals 26a. By making the projection margin Z2 of the dummy terminals 32a shorter than the projection margin Z1, the dummy terminals 32a are less likely to deform than the first signal terminals 26a.

[0090] 14, the dummy terminal 32b has two terminal portions 32b2 provided on a base 32b1. That is, the dummy terminal 32b has a shape in which the bases of the two terminal portions 32b2 are joined together. Note that the dummy terminal 32b may have three or more terminal portions 32b2 provided on one base 32b1. This makes the dummy terminal 32b less susceptible to deformation than the first signal terminal 26a.

[0091] Furthermore, the dummy terminals 32a may be made less prone to deformation than the first signal terminals 26a depending on their cross-sectional shape and arrangement direction. In other words, by giving the dummy terminals 32a a cross-sectional shape that increases their rigidity, the dummy terminals 32a can be made less prone to deformation than the first signal terminals 26a. The first signal terminals 26a and the dummy terminals 32a have rectangular cross sections. In this case, by changing the arrangement of the first signal terminals 26a and the dummy terminals 31a, the dummy terminals 31a can be made less prone to deformation than the first signal terminals 26a. Furthermore, by making the dummy terminals 32a from a material with a higher Young's modulus than the first signal terminals 26a, the dummy terminals 32a become less prone to deformation than the first signal terminals 26a.

[0092] The first signal terminal 26a and the dummy terminals 32a, 32b are deformed by stress caused by vibration of the circuit board 10. The first signal terminal 26a and the dummy terminals 32a, 32b are deformed starting from the portions in contact with the circuit board 10. The power conversion device 100 of the second modification can reduce deformation of the first signal terminal 26a by using the dummy terminals 32a, 32b. Therefore, the power conversion device 100 of the second modification can easily prevent breakage of the first signal terminal 26a due to stress caused by vibration of the circuit board 10.

[0093] <Variation 3> As shown in FIG. 15, Modification 3 is an example in which Modifications 1 and 2 are combined. That is, the power conversion device 100 of Modification 3 includes a dummy terminal 32a in addition to the dummy terminal 31a. In FIG. 15, the first signal terminal 26a and the dummy terminals 31a and 32a are hatched differently to make them easier to understand. Furthermore, Modification 3 will be described using the first signal terminal 26a of the signal terminals 26a and 26b. Modification 3 is similarly applicable to the second signal terminal 26b.

[0094] The power conversion device 100 of the third modification can achieve the effects of the first and second modifications. The power conversion device 100 of the third modification can use the dummy terminal 32b instead of the dummy terminal 32a.

[0095] <Variation 4> A power conversion device 100 according to Modification 4 will be described with reference to Fig. 16. Modification 4 differs from the above embodiment in the dummy connection area FA2. Here, the dummy connection area FA2 in the U-phase area 10u is used as an example. The dummy connection area FA2 is similar in the V-phase area 10v and the W-phase area 10w.

[0096] As shown in Fig. 16, the power module 20 includes a Y-direction terminal row arranged along one direction and an X-direction terminal row arranged along another direction intersecting the one direction. That is, the Y-direction terminal row and the X-direction terminal row are arranged along directions that intersect at right angles. Note that when the Y-direction terminal row corresponds to the first terminal row, the X-direction terminal row corresponds to the second terminal row. Also, when the X-direction terminal row corresponds to the first terminal row, the Y-direction terminal row corresponds to the second terminal row.

[0097] The dummy connection area FA2 is an area where the facing area of ​​the Y-direction terminal row and the facing area of ​​the X-direction terminal row overlap in a plan view from the Z direction. Therefore, the dummy terminal 30 is connected to the dummy connection area FA2. It can also be said that the dummy terminal 30 is arranged in the area where the facing area of ​​the Y-direction terminal row and the facing area of ​​the X-direction terminal row overlap.

[0098] Each facing area will be described in detail. Signal terminal end Y21 is an imaginary straight line extending one end of the Y-direction terminal row in the X direction. Signal terminal end Y22 is an imaginary straight line extending the other end of the Y-direction terminal row in the X direction. The facing area of ​​the Y-direction terminal row is the area between signal terminal end Y21 and signal terminal end Y22.

[0099] Signal terminal end X21 is an imaginary line extending one end of the X-direction terminal row in the Y direction. Signal terminal end X22 is an imaginary line extending the other end of the X-direction terminal row in the Y direction. The opposing region of the X-direction terminal row is the region between signal terminal end X21 and signal terminal end X22.

[0100] Here, an imaginary straight line is used that passes through the edge of the land 13. However, the imaginary straight line may be an imaginary straight line that passes through the signal terminals 26a and 26b that are arranged at the extreme ends of each terminal row.

[0101] 16 shows the dummy connection area FA2 only in the U-phase portion. That is, FIG. 16 shows an example in which the dummy terminal 30 is connected only in the U-phase portion. However, the dummy connection area FA2 may be provided in the V-phase portion or the W-phase portion. Therefore, the power conversion device 100 may have the dummy terminal 30 connected to the V-phase portion or the W-phase portion.

[0102] In the power converter 100, the dummy terminals 30 are connected to the dummy connection area FA2. This allows the power converter 100 to increase the resonant frequency. Furthermore, the power converter 100 can arrange the dummy terminals 30 between the vibration antinodes and the signal terminals 26a and 26b. This allows the power converter 100 to absorb vibrations of the circuit board 10 with the dummy terminals 30. Furthermore, the power converter 100 can arrange the dummy terminals 30 near the vibration antinodes. This allows the power converter 100 to bring the vibration antinodes closer to areas where the signal terminals 26a and 26b are not present.

[0103] <Variation 5> The power converter 100 of the fifth modified example will be described with reference to Fig. 17. The fifth modified example differs from the above embodiment in the dummy connection area FA3.

[0104] 17, the signal terminal side Y31 is a virtual straight line that runs along the Y-direction terminal row in the W-phase region 10w. The signal terminal side X31 is a virtual straight line that runs along the X-direction terminal row in the W-phase region 10w. Here, the terminal sides Y31 and X31 that pass along the edge of the land 13 are used.

[0105] In plan view from the Z direction, the dummy connection area FA3 is an area between the signal terminal side Y31 and the end of the circuit board 10. In this case, the end of the circuit board 10 is an end that faces the signal terminal side Y31 in the X direction.

[0106] In addition, in a plan view from the Z direction, the dummy connection area FA3 can also be said to be an area between the signal terminal side X31 and the end of the circuit board 10. In this case, the end of the circuit board 10 is an end that faces the signal terminal side X31 in the Y direction.

[0107] The dummy terminals 30 are connected to the dummy connection area FA3. It can also be said that the dummy terminals 30 are arranged between the Y-direction terminal row and the end of the circuit board 10. It can also be said that the dummy terminals 30 are arranged between the X-direction terminal row and the end of the circuit board 10.

[0108] The power converter 100 can achieve the same effects as the above embodiment by connecting the dummy terminals 30 to the dummy connection area FA3.

[0109] <Variation 6> The power converter 100 of the sixth modification will be described with reference to Fig. 18. The sixth modification differs from the above embodiment in the dummy connection area FA4.

[0110] 18, the signal terminal extension line Y41 is an imaginary straight line along the Y-direction terminal row and its extension. That is, the signal terminal extension line Y41 includes an imaginary straight line connecting the multiple first signal terminals 26a and an extension line of the imaginary straight line extending in the Y direction.

[0111] On the other hand, the signal terminal extension line X41 is a virtual line along the X-direction terminal row and its extension. That is, the signal terminal extension line X41 includes a virtual line connecting the multiple second signal terminals 26b and an extension of the virtual line in the X direction.

[0112] The dummy connection area FA4 is at least one of an area on an extension of the signal terminal extension line Y41 and an area on an extension of the signal terminal extension line X41. That is, the dummy connection area FA4 is an area outside the Y-direction terminal row on the signal terminal extension line Y41, or an area outside the X-direction terminal row on the signal terminal extension line X41. The dummy connection area FA4 is also an area adjacent to the Y-direction terminal row on the Y-direction side, or an area adjacent to the X-direction terminal row on the X-direction side.

[0113] The dummy connection area FA4 can be said to be an area including the above-mentioned extension line. In this case, the dummy connection area FA4 has a width approximately equal to the diameter of the dummy hole 15 in a direction perpendicular to the corresponding extension line.

[0114] The dummy terminals 30 are connected to the dummy connection area FA4. It can also be said that the dummy terminals 30 are disposed on at least one of the extensions of the imaginary straight lines connecting the plurality of first signal terminals 26a and the extensions of the imaginary straight lines connecting the plurality of second signal terminals 26b. Here, as an example, an example is adopted in which the dummy terminals 30 are provided on the imaginary lines connecting the plurality of second signal terminals 26b.

[0115] 18 shows the dummy connection area FA4 only in the U-phase portion. That is, FIG. 18 shows an example in which the dummy terminal 30 is connected only in the U-phase portion. However, the dummy connection area FA4 may be provided in the V-phase portion and the W-phase portion. Therefore, the power conversion device 100 may have the dummy terminal 30 connected to the V-phase portion and the W-phase portion.

[0116] In the power converter 100, the dummy terminals 30 are connected to the dummy connection area FA4. Therefore, in the power converter 100, the dummy terminals 30 can be arranged so as to be aligned linearly with the signal terminals 26a, 26b. Therefore, in the power converter 100 of Modification 4, the dummy terminals 30 can be easily arranged near the signal terminals 26a, 26b. Therefore, in the power converter 100 of Modification 4, the fixing force of the circuit board 10 on the side where the signal terminals 26a, 26b are present can be improved, and the signal terminals 26a, 26b can be effectively reinforced.

[0117] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more, or less than one element are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0118] 10...circuit board, 11...wiring board, 12...circuit element, 13...land, 14...signal hole, 15...dummy hole, 16...fixing hole, 17...positioning hole, 20...power module, 21...module housing, 22a, 22b...semiconductor element, 23...P terminal, 24...N terminal, 25...O terminal, 26a...first signal terminal, 26b...second signal terminal, 27...sealing body, 28...fixing hole, 29...positioning protrusion, 30, 31, 32, 32a...dummy terminal, 31...base, 32...shaft, 33...connection portion, 34...end, 40...cooler, 41...fixing hole, 50...bolt, 100...power conversion device

Claims

1. a power module (20) including semiconductor elements (22a, 22b) including switching elements and a plurality of signal terminals (26a, 26b) connected to the semiconductor elements; a circuit board (10) fixed to the power module at a plurality of locations, having one surface (S1) facing the power module and an opposite surface (S2) to the one surface, and having the signal terminals electrically connected thereto; dummy terminals (30, 31 a, 32 a, 32 b) fixed to the power module in the opposing region of the one surface and mechanically connected to the circuit board without being electrically connected to the circuit board, A power conversion device, wherein the size of the contact portion of the dummy terminal with the circuit board is smaller than or equal to the size of the contact portion of the signal terminal with the circuit board.

2. The circuit board is provided with a through hole (15) that extends from the one surface to the opposite surface, The power conversion device according to claim 1 , wherein the dummy terminal is connected to the circuit board by being partially disposed in the through hole.

3. The power conversion device according to claim 1 , wherein the dummy terminals are provided so as to be more easily deformed than the signal terminals.

4. The power converter according to claim 1 or 2, wherein the dummy terminals are provided so as to be less susceptible to deformation than the signal terminals.

5. the power module is provided with a plurality of terminal rows each including a plurality of the signal terminals, The plurality of terminal rows are arranged in one direction, The power conversion device according to claim 1 or 2, wherein the dummy terminal is disposed between two of the terminal rows.

6. the power module is provided with a plurality of terminal rows each including a plurality of the signal terminals, the plurality of terminal rows include a first terminal row arranged along one direction and a second terminal row arranged along another direction intersecting the one direction, a region between an imaginary straight line formed by extending one end of the first terminal row in the other direction and an imaginary straight line formed by extending the other end of the first terminal row in the other direction is defined as a facing region of the first terminal row; a region between an imaginary line formed by extending one end of the second terminal row in the one direction and an imaginary line formed by extending the other end of the second terminal row in the one direction is defined as a facing region of the second terminal row; The power conversion device according to claim 1 or 2, wherein the dummy terminals are arranged in an area where an opposing area of ​​the first terminal row and an opposing area of ​​the second terminal row overlap each other.

7. The power module has a terminal row including a plurality of the signal terminals arranged therein, The power conversion device according to claim 1 or 2, wherein the dummy terminal is disposed between the terminal row and an end of the circuit board.

8. The power conversion device according to claim 1 or 2, wherein the dummy terminal is arranged on an extension of an imaginary line connecting the plurality of signal terminals.

9. 3. The power conversion device according to claim 1, wherein the dummy terminal is connected to the center of an area surrounded by a plurality of fixing positions fixed to the power module on the circuit board.

10. The circuit board includes a wiring board (11) and a circuit element (12) mounted on the wiring board, a position on the circuit board where the dummy terminal is connected is defined as a dummy terminal position, and a position on the circuit board where the signal terminal is connected is defined as a signal terminal position; 3. The power conversion device according to claim 1, wherein a distance between the dummy terminal position and the circuit element is shorter than a distance between the signal terminal position and the circuit element.

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