Electrical device

Abstract

This electrical device comprises a semiconductor module, a bus bar (71P), an insulating member (161), and heat dissipation members (181, 182). The bus bar is electrically connected to the semiconductor module. A cooling member cools the bus bar. The insulating member is provided between the cooling member and the bus bar. The heat dissipation members are more flexible than the insulating member and dissipate the heat of the bus bar to the cooling member. The heat dissipation members include a first heat dissipation member that is in close contact with the bus bar and the insulating member, and a second heat dissipation member that is in close contact with the insulating member and the cooling member.

Description

Electrical device ,

[0008] , ,

[0007] Cross-reference to related applications

[0001] This application is based on Japanese Patent Application No. 2025-007102 filed in Japan on January 17, 2025, the content of the base application is incorporated herein by reference in its entirety.

[0002] The disclosure described in this specification relates to an electrical device.

[0003] The conductive member fastening structure described in Patent Document 1 electrically connects a plurality of conductive members via a terminal block. The terminal block includes a base formed of a conductive resin and a conductive base nut integrally formed with the base. The end face of the base nut is exposed from the base.

[0004] A fastening hole is formed in one end face of the base nut. By fastening a fastening member to the fastening hole, a plurality of conductive members are electrically and mechanically connected. An electrically insulating sheet is provided on the other end face of the base nut. A thermal compound is provided on the back surface of the insulating sheet. The base nut is provided on a metal heat sink via the insulating sheet and the thermal compound.

[0005] Japanese Patent Application Laid-Open No. 2008-98007

[0006] The heat generated in the conductive member is dissipated to the heat sink through the base nut, the insulating sheet, and the thermal compound. In a configuration where the base nut is in direct contact with the conductive member and the insulating sheet, the adhesion between the base nut and the conductive member and the insulating sheet tends to deteriorate. Even if the thermal compound is provided so as to adhere to the insulating sheet and the heat sink, it has been difficult to efficiently dissipate the heat of the conductive member to the heat sink.

[0007] An object of the present disclosure is to provide an electrical device that efficiently dissipates the heat of a conductive member to a heat sink.

[0008] An electrical device according to one aspect of the present disclosure comprises a semiconductor module, a busbar electrically connected to the semiconductor module, a cooling member for cooling the busbar, an insulating member provided between the cooling member and the busbar, and a heat dissipation member which is more flexible than the insulating member and dissipates heat from the busbar to the cooling member, wherein the heat dissipation member comprises a first heat dissipation member in close contact with the busbar and the insulating member, and a second heat dissipation member in close contact with the insulating member and the cooling member.

[0009] According to this, the busbar and the first heat dissipation member are in close contact, and the first heat dissipation member and the insulating member are in close contact, so the heat from the busbar is easily transferred to the insulating member via the first heat dissipation member. The insulating member and the second heat dissipation member are in close contact, and the second heat dissipation member and the cooling member are in close contact, so the heat from the insulating member is easily transferred to the cooling member via the second heat dissipation member. Therefore, the heat from the busbar can be efficiently dissipated to the cooling member.

[0010] The reference numbers in parentheses above merely indicate the correspondence with the configurations described in the embodiments below, and do not in any way limit the technical scope.

[0011] This figure shows the circuit configuration and drive system in a power conversion device as an electrical device according to the first embodiment. This is a plan view showing the power conversion device. This is a cross-sectional view along the line III-III in Figure 2. This is an enlarged view of the fastening portion between the capacitor busbar and the main terminal. This is an enlarged view of the fastening portion between the internal busbar and the main terminal. This is an enlarged view of the fastening portion between the capacitor busbar and the first busbar. This is a perspective view of the insulating member of the first cooling structure. This is a cross-sectional view along the line VIII-VIII in Figure 4. This is a cross-sectional view along the line IX-IX in Figure 4. This is a cross-sectional view along the line X-X in Figure 4. This is a cross-sectional view along the line XI-XI in Figure 4. This is a cross-sectional view along the line XII-XII in Figure 6. This is a cross-sectional view along the line XIII-XIII in Figure 6. This is a perspective view of the insulating member of the second cooling structure. This is a perspective view of the fastening portion between the capacitor busbar and the main terminal in the second embodiment. This is a perspective view of the insulating member of the first cooling structure in the second embodiment. This is a cross-sectional view illustrating the arrangement process. This is a cross-sectional view along the line XVIII-XVIII in Figure 15. This is a cross-sectional view along the line XIX-XIX in Figure 15.

[0012] Several embodiments will be described below with reference to the drawings. In each embodiment, the same reference numerals are used for corresponding components, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the configuration of other embodiments described earlier can be applied to the other parts of that configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations from multiple embodiments can be partially combined even if not explicitly stated, as long as there are no particular problems with the combination.

[0013] The electrical device of this embodiment is, for example, a power conversion device applied to a mobile body that uses a rotating electric machine as a drive source. Examples of mobile bodies include electric vehicles such as electric electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs), electric aircraft such as drones and electric vertical take-off and landing aircraft (eVTOLs), ships, construction machinery, and agricultural machinery. Examples of application to vehicles will be described below. Note that the electrical device of this embodiment is not limited to a power conversion device. The electrical device may also be applied to, for example, a battery device, a charging device, or a junction box.

[0014] (First Embodiment) First, the general configuration of the vehicle's drive system will be described based on Figure 1.

[0015] <Vehicle Drive System> As shown in Figure 1, the vehicle drive system 1 includes a DC power supply 2, a motor generator 3, and a power converter 4.

[0016] The DC power supply 2 is a DC voltage source composed of a rechargeable secondary battery. The motor generator 3 is a three-phase AC rotating electric machine. The motor generator 3 functions as the vehicle's driving source, i.e., an electric motor. The motor generator 3 also functions as a generator during regeneration. The power converter 4 performs power conversion between the DC power supply 2 and the motor generator 3.

[0017] <Circuit Configuration of Power Converter> Figure 1 shows the circuit configuration of the power converter 4. The power converter 4 of this embodiment includes an inverter 5 and a smoothing capacitor 6 as a power conversion circuit. The power converter 4 may further include a drive circuit 7. The smoothing capacitor 6 will be described first.

[0018] The smoothing capacitor 6 primarily smooths the DC voltage supplied from the DC power supply 2. The smoothing capacitor 6 is connected to the high-potential power line P line 8 and the low-potential power line N line 9. The P line 8 is connected to the positive terminal of the DC power supply 2, and the N line 9 is connected to the negative terminal of the DC power supply 2. The positive terminal of the smoothing capacitor 6 is connected to the P line 8 between the DC power supply 2 and the inverter 5. The negative terminal of the smoothing capacitor 6 is connected to the N line 9 between the DC power supply 2 and the inverter 5. The smoothing capacitor 6 is connected in parallel with the DC power supply 2. The smoothing capacitor 6 is provided by a capacitor 70. Details of the capacitor 70 will be described later.

[0019] The inverter 5 is a DC-AC conversion circuit. The inverter 5 converts a DC voltage to a three-phase AC voltage according to switching control by a control circuit (not shown) and outputs it to the motor generator 3. This drives the motor generator 3 to generate a predetermined torque. During regenerative braking of the vehicle, the inverter 5 converts the three-phase AC voltage generated by the motor generator 3 in response to the rotational force from the wheels to a DC voltage according to switching control by the control circuit and outputs it to the P line 8. In this way, the inverter 5 performs bidirectional power conversion between the DC power supply 2 and the motor generator 3.

[0020] The inverter 5 is configured with three phase upper and lower arm circuits 10. The upper and lower arm circuits 10 are sometimes referred to as legs. The upper and lower arm circuits 10 each have an upper arm 10H and a lower arm 10L. The upper arm 10H and the lower arm 10L are connected in series between the P line 8 and the N line 9, with the upper arm 10H on the P line 8 side.

[0021] The connection point between the upper arm 10H and the lower arm 10L, i.e., the midpoint of the upper and lower arm circuits 10, is connected to the corresponding phase winding 3a in the motor generator 3 via the output line 11. Of the upper and lower arm circuits 10, the U-phase upper and lower arm circuit 10U is connected to the U-phase winding 3a via the output line 11. The V-phase upper and lower arm circuit 10V is connected to the V-phase winding 3a via the output line 11. The W-phase upper and lower arm circuit 10W is connected to the W-phase winding 3a via the output line 11.

[0022] The upper and lower arm circuit 10 (10U, 10V, 10W) ​​has a series circuit 12. The series circuit 12 in the upper and lower arm circuit 10 may be one or more. If there are multiple series circuits 12, they are connected in parallel to each other to form one phase of the upper and lower arm circuit 10. The series circuit 12 is configured by connecting the switching element on the upper arm 10H side and the switching element on the lower arm 10L side in series between the P line 8 and the N line 9. The upper and lower arm circuit 10 is provided by a semiconductor module 30. The inverter 5 is composed of three semiconductor modules 30. Details of the semiconductor modules 30 will be explained later.

[0023] The number of high-side switching elements and low-side switching elements constituting the series circuit 12 is not particularly limited. There may be one or more. The series circuit 12 in this embodiment has two switching elements on the high-side and two switching elements on the low-side. The two high-side switching elements are connected in parallel, and the two low-side switching elements are connected in parallel to constitute one series circuit 12. In other words, each of the six arms 10H and 10L of the three-phase upper and lower arm circuits 10 is composed of two switching elements connected in parallel to each other.

[0024] In this embodiment, n-channel type MOSFETs 13 are used as each switching element. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. The two high-side MOSFETs 13 connected in parallel are turned on and off at the same timing by a common gate drive signal (drive voltage). The two low-side MOSFETs 13 connected in parallel are turned on and off at the same timing by a common gate drive signal (drive voltage).

[0025] Each of the MOSFETs 13 has a freewheeling diode 14 (hereinafter referred to as FWD14) connected in antiparallel. In the case of MOSFET 13, FWD14 may be a parasitic diode (body diode) or an external diode. On the upper arm 10H, the drain of MOSFET 13 is connected to the P line 8. On the lower arm 10L, the source of MOSFET 13 is connected to the N line 9. The drains of MOSFET 13 on the upper arm 10H and the drains of MOSFET 13 on the lower arm 10L are interconnected. The anode of FWD14 is connected to the source of the corresponding MOSFET 13, and its cathode is connected to the drain.

[0026] Note that the switching element is not limited to MOSFET 13. For example, an IGBT may be used. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. In the case of an IGBT, the FWD 14 is also connected in antiparallel.

[0027] The drive circuit 7 drives the switching elements that constitute the power conversion circuit, such as the inverter 5. Based on the drive command from the control circuit, the drive circuit 7 supplies a drive voltage to the gate of the corresponding MOSFET 13. By applying the drive voltage, the drive circuit drives the corresponding MOSFET 13, i.e., turns it on or off. The drive circuit is sometimes referred to as a driver. The drive circuit 7 is provided by the circuit board 80.

[0028] The power converter 4 may further include a control circuit for switching elements as a power conversion circuit. The control circuit generates a drive command for operating the MOSFET 13 and outputs it to the drive circuit 7. The control circuit generates the drive command based on, for example, a torque request input from a higher-level ECU (not shown) and signals detected by various sensors. ECU is an abbreviation for Electronic Control Unit. The control circuit may be provided within the higher-level ECU. The drive circuit 7 may be mounted on an extension circuit board 80.

[0029] <Structure of the Power Converter> Figure 2 is a plan view showing the power converter 4 of this embodiment. In Figure 2, the circuit board 80 is omitted so that the arrangement of the semiconductor module 30 can be seen. Figure 3 is a cross-sectional view taken along the line III-III in Figure 2. In Figure 3, for convenience, only the semiconductor element and the encapsulant are shown as the main body 31 of the semiconductor module 30. Also, the portion of the external connection terminal 32 of the semiconductor module 30 that is sealed by the encapsulant is omitted.

[0030] In the following, the direction in which the three semiconductor modules 30 are aligned is referred to as the X direction. The Z direction is perpendicular to the X direction and is the stacking direction of the base 21 and the semiconductor modules 30. The Y direction is perpendicular to both the X and Z directions. The X, Y, and Z directions are in a positional relationship that is orthogonal to each other. A plan view from the Z direction is sometimes simply referred to as a plan view. The direction perpendicular to the Z direction is sometimes referred to as the planar direction. When describing the relative positions of two components, the position of the component closer to the base 21 in the Z direction is sometimes referred to as the lower position, and the position of the component further from the base 21 is sometimes referred to as the upper position. The Z direction is the direction in which the front surfaces 163, 263 and back surfaces 164, 264 of the bases 162, 262, described later, are aligned, so it is sometimes referred to as the alignment direction. The planar direction is sometimes referred to as the orthogonal direction. The Y direction is sometimes referred to as one of the orthogonal directions.

[0031] In addition to the configuration described above, the power converter 4 includes a housing 20, first busbars 40P and 40N, second busbars 50P and 50N, a cooling structure 60, and a terminal block 90. ​​The power converter 4 of this embodiment includes a housing 20, three semiconductor modules 30, first busbars 40P and 40N, second busbars 50P and 50N, a cooling structure 60, a capacitor 70, a circuit board 80, and a terminal block 90. ​​The power converter 4 is sometimes simply referred to as an electrical device.

[0032] <Enclosure> The enclosure 20 has a base 21 having a plate thickness in the Z direction and a wall portion 23 erected from the base 21. The base 21 is electrically connected to the body ground of a chassis or the like. The base 21 provides ground potential. The base 21 has a front surface 21A and a back surface 21B aligned in the Z direction. The front surface 21A and the back surface 21B are sometimes collectively referred to as the main surfaces 21A and 21B. The front surface 21A is the surface facing the circuit board 80 and is also the mounting surface on which the semiconductor module 30, capacitor 70, terminal block 90, and first cooling structure 160 are mounted.

[0033] The back surface 21B is the mounting surface on which the first busbars 40P and 40N, the second busbars 50P and 50N, and the second cooling structure 260 are mounted. The base 21 is a support member that supports the semiconductor module 30, the first busbars 40P and 40N, the second busbars 50P and 50N, the cooling structure 60, the capacitor 70, and the terminal block 90. ​​The base 21 is formed using a metal material such as aluminum.

[0034] The base 21 has a cooler 22. The cooler 22 is constructed using the base 21. The cooler 22 may have a flow path for the refrigerant to flow through, or it may be a heat dissipation member with heat dissipation fins. As an example, the cooler 22 of this embodiment has a flow path 22A formed inside the base 21. The refrigerant flows through the flow path 22A. As the refrigerant, for example, a phase-changing refrigerant such as water or ammonia, or a non-phase-changing refrigerant such as ethylene glycol can be used.

[0035] In this embodiment, the cooler 22 is positioned to overlap the semiconductor module 30 in the Z direction. The cooler 22 cools the semiconductor module 30 from the lower back surface 31B. The cooler 22 extends in the planar direction. In addition to the semiconductor module 30, the cooler 22 overlaps the first cooling structure 160 in the Z direction. Note that the cooler 22 does not necessarily have to overlap the first cooling structure 160 and the second cooling structure 260 in the Z direction.

[0036] The base 21 is provided as part of the housing 20 that houses the components of the power converter 4. The base 21, together with the wall portion 23, defines the housing space. The base 21 is provided as a partition wall of the housing 20. The wall portion 23 has a first wall 23A and a third wall 23C spaced apart in the X direction, and a second wall 23B and a fourth wall 23D spaced apart in the Y direction. The first wall 23A, the second wall 23B, the third wall 23C, and the fourth wall 23D are connected in this order clockwise. The wall portion 23 extends in an annular shape along the edge of the base 21.

[0037] The wall portion 23 has a front wall portion 231 erected from the surface 21A and a back wall portion 232 erected from the back surface 21B. The base 21 and the front wall portion 231 partition the first housing space 26. The base 21 and the back wall portion 232 partition the second housing space 27. The semiconductor module 30, capacitor 70, circuit board 80, terminal block 90, and first cooling structure 160 are housed in the first housing space 26. The first busbars 40P, 40N, second busbars 50P, 50N, and second cooling structure 260 are housed in the second housing space 27. The housing 20 may also have a cover that closes the two openings. The base 21, wall portion 23, and cover may partition the first housing space 26 and the second housing space 27.

[0038] The three semiconductor modules 30 are arranged in the order of U-phase semiconductor module 30U, V-phase semiconductor module 30V, and W-phase semiconductor module 30W, from the first wall 23A to the third wall 23C. A capacitor 70 and a terminal block 90 are arranged so as to sandwich the three semiconductor modules 30. With respect to the Y direction, the capacitor 70 is located on the second wall 23B side of the semiconductor modules 30. With respect to the Y direction, the terminal block 90 is located on the fourth wall 23D side of the semiconductor modules 30.

[0039] The power converter 4 has a plurality of fastening members 110. In the first housing space 26, the main terminals 32P and 32N, which are conductive parts of the semiconductor module 30, and one end of the capacitor busbars 71P and 71N, which are conductive members of the capacitor 70, are electrically and mechanically connected via the fastening members 110. The main terminal 32O of the semiconductor module 30 and the internal busbar 91, which is a conductive member of the terminal block 90, are electrically and mechanically connected via the fastening members 110.

[0040] Figure 4 is an enlarged view of the first fastening portion, which is the fastening portion between the P-side capacitor busbar 71P, which is a conductive member of the capacitor 70, and the main terminal 32P of the semiconductor module 30. Figure 5 is an enlarged view of the second fastening portion, which is the fastening portion between the internal busbar 91 of the terminal block 90 and the main terminal 32P. The first cooling structure 160 is provided at a position that overlaps with the first fastening portion in the Z direction. The first cooling structure 160 is provided at a position that overlaps with the second fastening portion in the Z direction.

[0041] Figure 6 is an enlarged view of the third fastening portion, which is the fastening portion between the capacitor busbars 71P and 71N, which are conductive members of the capacitor 70, and the first busbars 40P and 40N. In the second housing space 27, the other ends of the capacitor busbars 71P and 71N and the first busbars 40P and 40N are electrically and mechanically connected via the fastening member 110. The second cooling structure 260 is provided at a position that does not overlap with the third fastening portion in the Z direction. The second cooling structure 260 is provided at a position that overlaps with the first busbars 40P and 40N in the Z direction.

[0042] The second bus bars 50P and 50N are welded and joined to the main surfaces of the first bus bars 40P and 40N. The first bus bars 40P and 40N and the second bus bars 50P and 50N are electrically connected. The joining part between the first bus bars 40P and 40N and the second bus bars 50P and 50N overlaps with the second cooling structure 260 in the Z direction. The second bus bars 50P and 50N extend toward the terminal block 90 so as to be away from the joining part with the first bus bars 40P and 40N. The tip ends of the second bus bars 50P and 50N are connected to the base 21 via bolts 120.

[0043] <Semiconductor Module> The semiconductor module 30 of the present embodiment provides one series circuit 12, that is, an upper and lower arm circuit 10 for one phase. The three semiconductor modules 30 include a semiconductor module 30U that constitutes the upper and lower arm circuit 10U, a semiconductor module 30V that constitutes the upper and lower arm circuit 10V, and a semiconductor module 30W that constitutes the upper and lower arm circuit 10W.

[0044] The three semiconductor modules 30 have a common structure with each other. Each semiconductor module 30 includes a main body portion 31 and external connection terminals 32 protruding from the main body portion 31. The main body portion 31 includes a semiconductor element 33, a sealing body 34, and the like.

[0045] As an example, the semiconductor element 33 of the present embodiment is formed by forming the above-described n-channel type MOSFET 13 and FWD 14 on a semiconductor substrate made of SiC. The MOSFET 13 has a vertical structure such that the main current flows in the thickness direction of the semiconductor element 33 (semiconductor substrate). The semiconductor element 33 has main electrodes on both surfaces in its own thickness direction. Specifically, each of the semiconductor elements 33 has a drain electrode on one surface and a source electrode on the back surface.

[0046] The main current flows between the drain electrode and the source electrode. The semiconductor element 33 of the present embodiment includes two semiconductor elements 33H that provide the switching element on the high side of the series circuit 12 and two semiconductor elements 33L that provide the switching element on the low side of the series circuit 12. The semiconductor elements 33H and 33L are arranged side by side in the Y direction. The two semiconductor elements 33H are arranged side by side in the X direction. Similarly, the two semiconductor elements 33L are arranged side by side in the X direction.

[0047] The sealing body 34 seals a part of each of the semiconductor element 33 and the external connection terminal 32. The other part of each of the external connection terminals 32 protrudes outside the sealing body 34. The sealing body 34 is made of a resin such as an epoxy resin, for example. The sealing body 34 has a substantially rectangular planar shape, for example. The sealing body 34 forms the outer contour of the main body portion 31. The main body portion 31 has a front surface 31A facing the circuit board 80, a back surface 31B facing the base 21 on the back side of the front surface 31A, and side surfaces 31C connecting the front surface 31A and the back surface 31B. Among the side surfaces 31C, the one located on the capacitor 70 side may be referred to as one side surface 311C, and the one located on the terminal block 90 side may be referred to as the other side surface 312C.

[0048] The plurality of external connection terminals 32 includes main terminals 32P, 32N, 32O electrically connected to the main electrodes of the semiconductor element 33 and signal terminals. The main terminal 32P is electrically connected to the drain electrode of the semiconductor element 33H. The main terminal 32N is electrically connected to the source electrode of the semiconductor element 33L. The main terminal 32P may be referred to as a P terminal, a high-potential power supply terminal, a positive electrode terminal, etc. The main terminal 32N may be referred to as an N terminal, a low-potential power supply terminal, a negative electrode terminal, etc.

[0049] The main terminals 32P and 32N are electrically connected to the capacitor element via the capacitor busbars 71P and 71N. The main terminals 32P and 32N protrude outside from one side surface 311C of the main body portion 31. The protruding portions of the main terminals 32P and 32N are arranged side by side in the X direction. The signal terminals (not shown) also protrude outside from one side surface 311C and are arranged side by side in the X direction. The signal terminals are bent at the root and extend in the Z direction and are connected to the circuit board 80 via solder or the like.

[0050] The main terminal 32O is electrically connected to the connection point between the source electrode of semiconductor element 33H and the drain electrode of semiconductor element 33L, that is, to the connection point (midpoint) of the series circuit 12. The main terminal 32O protrudes to the outside from the other side 312C of the main body 31. The main terminal 32O is sometimes referred to as the O terminal, output terminal, AC terminal, etc. The main terminal 32O is connected to the corresponding winding 3a of the motor generator 3 via the internal busbar 91.

[0051] <First Busbar> The first busbars 40P and 40N are conductive members that form part of the current path between the capacitor 70 and the DC power supply 2. The first busbars 40P and 40N include a P-side first busbar 40P that connects the positive terminal of the capacitor 70 to the positive terminal of the DC power supply 2, and an N-side first busbar 40N that connects the negative terminal of the capacitor 70 to the negative terminal of the DC power supply 2.

[0052] The first busbars 40P and 40N have a flattened shape with plate thickness in the Z direction. The first busbars 40P and 40N have a main surface that extends in the planar direction. The P-side first busbar 40P and the N-side first busbar 40N are spaced apart in the Y direction. The other ends of the first busbars 40P and 40N are electrically connected to the DC power supply 2 via connectors or the like (not shown).

[0053] <Second Busbars> The second busbars 50P and 50N are conductive members that provide an electrical path between the first busbars 40P and 40N and the body ground. The second busbars 50P and 50N consist of a P-side second busbar 50P connected to the P-side first busbar 40P and an N-side second busbar 50N connected to the N-side first busbar 40N.

[0054] The first busbars 40P and 40N have a flattened shape with plate thickness in the Z direction. One end of the P-side second busbar 50P is welded to the main surface of the P-side first busbar 40P. One end of the N-side second busbar 50N is welded to the main surface of the N-side first busbar 40N. The P-side second busbar 50P and the N-side second busbar 50N are spaced apart in the X direction. The second busbars 50P and 50N extend toward the terminal block 90 in the Y direction. The other ends of the second busbars 50P and 50N are electrically and mechanically connected to the base 21 via bolts 120.

[0055] <First Cooling Structure> The busbars 71P, 71N, 91 and terminals 32P, 32N, 32O described above generate heat when power is applied. The power converter 4 has a cooling structure 60 that efficiently dissipates this heat. The cooling structure 60 has a first cooling structure 160 and a second cooling structure 260. First, the first cooling structure 160 will be described.

[0056] The first cooling structure 160 is provided on the base 21 side so as to overlap in a plan view with the main terminals 32P, 32N, 32O, one end of the busbars 71P, 71N, 91, and the fastening member 110. One first cooling structure 160 is provided for each fastening portion. One semiconductor module 30 has three fastening portions. Three first cooling structures 160 are provided for each semiconductor module 30. In other words, the power converter 4 is provided with nine first cooling structures 160. However, the number of first cooling structures 160 provided in the power converter 4 is not limited to nine. There may be any number of first cooling structures 160.

[0057] The first cooling structure 160 includes an insulating member 161, a first heat dissipation member 181, and a second heat dissipation member 182. Figure 7 is a perspective view of the insulating member 161. The insulating member 161 includes a base 162, front flanges 166, 167, back flanges 168, 169, and storage sections 171, 172. The front flanges 166, 167, back flanges 168, 169, and storage sections 171, 172 are connected to the base 162. The front flanges 166, 167 and back flanges 168, 169 extend from the base 162 in the Z direction. The storage sections 171, 172 are connected to the edge 165 of the base 162. The second heat dissipation member 182 is housed in the storage sections 171, 172, which will be explained later.

[0058] Figures 8, 9, 10, and 11 are cross-sectional views of the first cooling structure 160. The base 162 has a flattened plate shape in the Z direction. The base 162 is rectangular in plan view. The base 162 has a surface 163 on the side of the busbars 71P, 71N, and 91, and a back surface 164 on the opposite side that faces the base 21. Furthermore, the base 162 has four edges 165. The four edges 165 have a first edge 165A and a third edge 165C spaced apart in the X direction, and a second edge 165B and a fourth edge 165D spaced apart in the Y direction. The first edge 165A faces the first wall 23A in the X direction. The second edge 165B faces the second wall 23B in the Y direction. The third edge 165C faces the third wall 23C in the X direction. The fourth edge portion 165D faces the fourth wall 23D in the Y direction.

[0059] The front flanges 166 and 167 protrude from the surface 163 in the Z direction and extend along a part of the edge 165. The front flanges 166 and 167 have a first front flange 166 and a second front flange 167 that are spaced apart in the Y direction. In plan view, the first front flange 166 and the second front flange 167 have a roughly U-shape relative to each other. The first front flange 166 and the second front flange 167 are arranged to face each other. The first front flange 166 and the second front flange 167 have first extensions 166A and 167A, second extensions 166B and 167B, and third extensions 166C and 167C.

[0060] The first extension 166A of the first front flange 166 extends in the X direction along the second edge 165B. The second extension 166B of the first front flange 166 extends in the Y direction along the first edge 165A. The third extension 166C of the first front flange 166 extends in the Y direction along the third edge 165C. The first extension 167A of the second front flange 167 extends in the X direction along the fourth edge 165D. The second extension 167B of the second front flange 167 extends in the Y direction along the first edge 165A. The third extension 167C of the second front flange 167 extends in the Y direction along the third edge 165C.

[0061] A gap is provided between the tip of the second extension 166B of the first front flange 166 and the tip of the second extension 167B of the second front flange 167. The second extensions 166B and 167B face each other in the Y direction. A gap is provided between the tip of the third extension 166C of the first front flange 166 and the tip of the third extension 167C of the third front flange 167. The third extensions 166C and 167C face each other in the Y direction.

[0062] The rear flanges 168 and 169 protrude from the back surface 164 in the Z direction and extend along a part of the edge 165. The rear flanges 168 and 169 are integrally connected to the front flanges 166 and 167. The rear flanges 168 and 169 have the same shape as the front flanges 166 and 167. The rear flanges 168 and 169 have a first rear flange 168 and a second rear flange 169 that are spaced apart in the Y direction. The first front flange 166 is integrally connected to the first rear flange 168. The second front flange 167 is integrally connected to the second rear flange 169.

[0063] The first rear flange 168 and the second rear flange 169 have a roughly U-shape relative to each other in a plan view. The first rear flange 168 and the second rear flange 169 are positioned facing each other. The first rear flange 168 and the second rear flange 169 have first extensions 168A, 169A, second extensions 168B, 169B, and third extensions 168C, 169C. The shapes of the extensions of the rear flanges 168 and 169 are the same as the shapes of the extensions of the front flanges 166 and 167, so their description is omitted.

[0064] The storage sections 171 and 172 are integrally connected to the base 162. The storage sections 171 and 172 include a first storage section 171 connected to the first edge 165A and a second storage section 172 connected to the third edge 165C. The storage section 171 is connected to the first edge 165A in the Y direction between the second extension 166B and the second extension 167B. The second storage section 172 is connected to the third edge 165C in the Y direction between the third extension 166C and the third extension 167C. The storage sections 171 and 172 have an arm section 174 and an enclosure section 175.

[0065] The arm portion 174 extends in a planar direction away from the edge. The arm portion 174 extends diagonally in the Z direction so that its tip approaches the base 21. In a plan view, the tip of the arm portion 174 is positioned outward from the first adjustment portion 210, which will be described later. The first adjustment portion 210 is provided on the base 21 and is for defining the position of at least the insulating member 161. The base 21 and the first adjustment portion 210 together are sometimes referred to as the cooling member. Details of the first adjustment portion 210 will be explained later.

[0066] An enclosing portion 175 is provided on the edge of the arm portion 174, extending in the Z direction toward the base 21 and extending along the edge so as to surround the arm portion 174. The length of the enclosing portion 175 in the Z direction is not constant, and is defined so that the tip is flush with the surface. The enclosing portion 175 of the first storage portion 171 is connected to the second extensions 168B and 169B. In the enclosing portion 175 of the first storage portion 171, the part connected to the tip of the arm portion 174 may be called the first tip portion 176, and the part connecting the first tip portion 176 to the second extensions 168B and 169B may be called the connecting portion. The first tip portion 176 is connected to the second extensions 168B and 169B via the connecting portion.

[0067] The enclosure portion 175 of the second storage portion 172 is connected to the third extension portions 168C and 169C. In the enclosure portion 175 of the second storage portion 172, the part connected to the tip of the arm portion 174 may be called the second tip portion 177, and the part connecting the second tip portion 177 to the third extension portions 168C and 169C may be called the connecting portion. The second tip portion 177 is connected to the third extension portions 168C and 169C via the connecting portion.

[0068] The first heat dissipation member 181 and the second heat dissipation member 182 are made of a material with higher thermal conductivity than the insulating member 161. The first heat dissipation member 181 and the second heat dissipation member 182 are insulating. The first heat dissipation member 181 and the second heat dissipation member 182 are softer than the insulating member 161. The first heat dissipation member 181 and the second heat dissipation member 182 are flexible enough to deform when an external force is applied. In this embodiment, the first heat dissipation member 181 and the second heat dissipation member 182 are gap fillers. The gap filler has high viscosity and fluidity before hardening. This makes it possible to tightly adhere the first heat dissipation member 181 and the second heat dissipation member 182 to the surrounding parts without any gaps. The gap filler has fluidity before hardening and does not have fluidity after hardening, but it is more flexible than the insulating member 161.

[0069] Furthermore, thermal conductive grease or thermal conductive gel may be used for the first heat dissipation member 181 and the second heat dissipation member 182. The first heat dissipation member 181 and the second heat dissipation member 182 may be made of the same material or different materials. For the sake of simplicity in the following explanation, the rear flanges 168, 169 and the housing parts 171, 172 may be collectively referred to as the rear extension part 180. The first heat dissipation member 181 is located in the space surrounded by the base 162 and the front flanges 166, 167 in the first cooling structure 160. The second heat dissipation member 182 is located in the space surrounded by the base 162 and the rear extension part 180 in the first cooling structure 160.

[0070] <Capacitor> The capacitor 70 comprises a case, a capacitor element housed in the case, and P-side capacitor busbars 71P and N-side capacitor busbars 71N connected to the capacitor element. In Figures 2 and 3, the capacitor 70 is shown in a simplified form. The P-side capacitor busbar 71P and N-side capacitor busbars 71N are sometimes simply referred to as capacitor busbars 71P and 71N.

[0071] As an example, the capacitor element in this embodiment is a film capacitor element. The capacitor element is formed by winding a film around an axis in the Z direction, for example. The capacitor element has electrodes (not shown) on both ends in the Z direction. The P-side capacitor busbar 71P is connected to the positive electrode. The N-side capacitor busbar 71N is connected to the negative electrode.

[0072] The capacitor busbars 71P and 71N are plate-shaped conductive members. The capacitor busbars 71P and 71N are connected to their corresponding electrodes by soldering, resistance welding, laser welding, or the like. The capacitor busbars 71P and 71N have one end and the other end. One end is drawn out toward the semiconductor module 30 in the Y direction. The main terminals 32P and 32N are drawn out toward the capacitor 70 in the Y direction. One end of the capacitor busbars 71P and 71N and the corresponding main terminals 32P and 32N overlap in the Z direction. One end of the capacitor busbars 71P and 71N and the corresponding main terminals 32P and 32N are electrically and mechanically connected via the fastening member 110.

[0073] The other ends of the capacitor busbars 71P and 71N are led out into the second housing space 27 in the Z direction. The base 21 is provided with holes (not shown). The other ends of the capacitor busbars 71P and 71N are led out from the first housing space 26 to the second housing space 27 through the holes. The other ends of the capacitor busbars 71P and 71N and the corresponding first busbars 40P and 40N overlap in the Z direction. The other ends of the capacitor busbars 71P and 71N and the corresponding first busbars 40P and 40N are electrically and mechanically fastened via fastening members 110.

[0074] The first busbars 40P and 40N have their main surfaces facing the back surface 21B in the Z direction. The first busbars 40P and 40N extend in the X direction along the back surface 21B. As described above, connectors (not shown) are connected to the ends of the first busbars 40P and 40N. Power is supplied to the power converter 4 by connecting the DC power supply 2 to the connectors. In addition to the other ends of the capacitor busbars 71P and 71N, the second busbars 50P and 50N are also connected to the first busbars 40P and 40N. The second busbars 50P and 50N are joined to the corresponding first busbars 40P and 40N by resistance welding, laser welding, or the like. The second busbars 50P and 50N extend in the Y direction toward the terminal block 90 from the point of connection with the first busbars 40P and 40N.

[0075] The ends of the second busbars 50P and 50N are fixed to the base 21, which provides ground potential, via bolts 120. This allows noise currents propagating through the first busbars 40P and 40N to be discharged to ground via the second busbars 50P and 50N. Furthermore, Y capacitors (not shown) may be connected to the second busbars 50P and 50N. The Y capacitors may be connected to the second busbars 50P and 50N between the junction point with the first busbars 40P and 40N and the junction point with the base 21.

[0076] <Terminal Block> The terminal block 90 is provided in the current path between the semiconductor module 30 and the motor generator 3. The terminal block 90 has an internal busbar 91, a current sensor 92, and a main body 93. The internal busbar 91 is a conductive member that forms part of the output line 11. The current sensor 92 measures the amount of current passing through the internal busbar 91. The main body 93 is a resin member that encloses part of the internal busbar 91 and the current sensor 92.

[0077] The internal busbar 91 is a plate-shaped conductive member. One end of the internal busbar 91 is drawn out toward the semiconductor module 30 in the Y direction. As shown in Figure 5, one end of the internal busbar 91 and the corresponding main terminal 32O overlap in the Z direction. One end of the internal busbar 91 and the corresponding main terminal 32O are electrically and mechanically connected via a fastening member 110. Although not shown in the drawing, the other end of the internal busbar 91 is drawn out toward the fourth wall 23D in the Y direction. The other end of the internal busbar 91 is electrically connected to the motor generator 3 via wiring, etc. (not shown).

[0078] The fastening member 110 is composed of a bolt 111 and a nut 116. The bolt 111 and nut 116 are made of metal. Through holes 32A are formed in the main terminals 32P, 32N, and 32O, and through holes 71A are formed in the capacitor busbars 71P and 71N. The bolt 111 is inserted into the through holes 32A and 71A. By tightening the inserted bolt 111 in the Z direction with the nut 116, the capacitor busbars 71P and 71N and the corresponding main terminals 32P and 32N are fastened to each other. The capacitor 70 and semiconductor module 30 are fixed to the base 21. The same applies to the internal busbar 91 and the main terminal 32O, although this will not be explained in detail.

[0079] In this embodiment, the busbars 71P, 71N, and 91 are positioned closer to the base 21 than the main terminals 32P, 32N, and 32O. The bolt 111 is inserted from the side of the busbars 71P, 71N, and 91. That is, the head 113 of the bolt 111 is in close contact with the busbars 71P, 71N, and 91, and the nut 116 is in close contact with the main terminals 32P, 32N, and 32O.

[0080] The bolt 111 has a shaft portion 112 and a head portion 113. The shaft portion 112 extends in the Z direction and is inserted into the through holes 71A and 32A, and has screw threads that engage with the nut 116. The bottom surface 113A of the head is located below the bottom surface 71B of the busbar.

[0081] <First Adjustment Section> As shown in Figure 3, the housing 20 has a first adjustment section 210 at the position where the first cooling structure 160 is installed. The first adjustment section 210 is provided on the surface 21A of the base 21. The first adjustment section 210 has a stepped structure that overlaps in two stages in the Z direction. The first adjustment section 210 adjusts the position of the first cooling structure 160 and the amount of the second heat dissipation member 182. As shown in Figures 8 to 11, the first adjustment section 210 has a first protrusion 211 that protrudes from the surface 21A in the Z direction, and a second protrusion 213 that protrudes from the first protrusion 211 in the Z direction. In plan view, the second protrusion 213 is enclosed within the first protrusion 211. The second protrusion 213 overlaps with the base 162 of the first cooling structure 160 in the Z direction.

[0082] The first projection 211 has a tip surface 211A and a side surface 212 connecting the tip surface 211A and the base 21. The side surface 212 has a first side surface 212A facing the first wall 23A, a second side surface 212B facing the second wall 23B, a third side surface 212C facing the third wall 23C, and a fourth side surface 212D facing the fourth wall 23D. The second projection 213 has a tip surface 213A and a side surface 214 connecting the tip surface 213A and the tip surface 211A of the first projection 211. The side surface 214 has a first side surface 214A facing the first wall 23A, a second side surface 214B facing the second wall 23B, a third side surface 214C facing the third wall 23C, and a fourth side surface 214D facing the fourth wall 23D.

[0083] As shown in Figure 8, the length between the second side surface 212B and the fourth side surface 212D of the first protrusion 211 is longer than the length between the second side surface 214B and the fourth side surface 214D of the second protrusion 213. As shown in Figures 9 to 11, the length between the first side surface 212A and the third side surface 212C of the first protrusion 211 is longer than the length between the first side surface 214A and the third side surface 214C of the second protrusion 213.

[0084] The first cooling structure 160 is positioned on the first adjustment section 210 such that its back surface 164 overlaps with the front surface 213A. The components are stacked in the Z-direction from bottom to top in the following order: base 21, first protrusion 211, second protrusion 213, first cooling structure 160, busbars 71P, 71N, 91, terminals 32P, 32N, 32O. The length of the first protrusion 211 in the Z-direction is shorter than the length of the back extension 180 in the Z-direction. A portion of the back extension 180 overlaps with the second protrusion 213 in the planar direction.

[0085] Regarding the overlap in the planar direction between the rear flanges 168 and 169 and the second projection 213, in the X direction, as shown in Figures 10 and 11, the second extensions 168B and 169B are in contact with the first side surface 214A. The third extensions 168C and 169C are in contact with the third side surface 214C. In the storage sections 171 and 172, as shown in Figure 9, the tip 176 and the first side surface 214A are spaced apart in the X direction. The tip 177 and the third side surface 214C are spaced apart in the X direction.

[0086] In the Y direction, as shown in Figure 8, the first extension 168A is in contact with the second side surface 214B, and the first extension 169A is in contact with the fourth side surface 214D. This restricts the movement of the insulating member 161 in the planar direction. In other words, the second projection 213 defines the planar position of the insulating member 161.

[0087] Furthermore, with respect to the Z direction, a portion of the tip of the back extension portion 180 is in contact with the tip surface 211A of the first projection portion 211. This restricts the movement of the insulating member 161 in the Z direction. The position of the insulating member 161 in the Z direction is defined by the first projection portion 211. The first adjustment portion 210 has a first projection portion 211 that defines the position of the insulating member 161 in the Z direction and a second projection portion 213 that defines the position of the insulating member 161 in the planar direction. In this way, the first adjustment portion 210 plays a positioning role in adjusting the position of the insulating member 161.

[0088] In this embodiment, the housing 20 has nine first adjustment sections 210 corresponding to the positions where the first cooling structure 160 is provided. The first adjustment sections 210 are cooled by a refrigerant. The temperature of the first adjustment sections 210 is lower than that of the main terminals 32P, 32N, 32O and their corresponding busbars 71P, 71N, 91. The first adjustment sections 210 are also provided so as to overlap with a portion of the flow path 22A in a plan view. Furthermore, the flow path 22A is provided so as to overlap with a portion of the first cooling structure 160 in a plan view so as to effectively cool the first cooling structure 160.

[0089] <Cooling Configuration> As shown in Figures 10 and 11, the lower parts of the rear flanges 168 and 169 overlap with the second projection 213 in the planar direction. The upper parts of the rear flanges 168 and 169 do not overlap with the second projection 213 in the planar direction. As shown in Figures 8 to 11, the second heat dissipation member 182 is provided in the space enclosed by the base 162, the rear extension 180, and the first adjustment part 210.

[0090] On the insulating member 161 side, the second heat dissipation member 182 is in close contact with the base 162, the storage sections 171 and 172, and a portion of the rear flanges 168 and 169. On the first adjustment section 210 side, the second heat dissipation member 182 is in close contact with the tip surface 213A, a portion of the side surface 214, and a portion of the tip surface 211A. The second heat dissipation member 182 dissipates heat from the busbars 71P, 71N, and 91 to the base 21.

[0091] Furthermore, a portion of the storage sections 171 and 172 is not in contact with the tip surface 211A in the Z direction. The tip portions 176 and 177 and the first protruding portion 211 are spaced apart in the X direction. In this area, a portion of the second heat dissipation member 182 housed in the storage sections 171 and 172 is exposed to the outside air. It can also be said that a portion of the second heat dissipation member 182 housed in the storage sections 171 and 172 is exposed to the outside. The second heat dissipation member 182 is discharged from this area. For this reason, the first adjustment section 210 can be said to have an adjustment function for the second heat dissipation member 182 in addition to positioning the insulating member 161.

[0092] The front flanges 166 and 167 extend in the Z direction from the surface 163. Busbars 71P, 71N, and 91 are provided away from the tips of the front flanges 166 and 167. The busbars 71P, 71N, and 91 extend along the Y direction, where the capacitor 70, semiconductor module 30, and terminal block 90 are aligned. The busbars 71P, 71N, and 91 are provided away from the tips of the first extensions 166A and 167A of the corresponding first adjustment section 210. The first heat dissipation member 181 is provided in the space enclosed by the base 162, the front flanges 166 and 167, and the busbars 71P, 71N, and 91.

[0093] The first heat dissipation member 181 is in close contact with the base 162, the front flanges 166 and 167, and the busbars 71P, 71N, and 91. The first heat dissipation member 181 dissipates heat from the busbars 71P, 71N, and 91 to the base 21. As shown in Figure 7, a gap is provided between the second extension 166B and the second extension 167B from which excess first heat dissipation member 181 can be discharged. A gap is also provided between the third extension 166C and the third extension 167C from which excess first heat dissipation member 181 can be released. The first heat dissipation member 181 can be discharged through this gap.

[0094] As described above, terminals 32P, 32N, 32O and busbars 71P, 71N, 91 are fastened together via a fastening member 110. The head 113 of the fastening member 110 protrudes downward from the bottom surface 71B of the busbars 71P, 71N, forming a step at the boundary with the busbars 71P, 71N. The first heat dissipation member 181 deforms to conform to the shape of the step and adheres tightly to it. The head 113 presses the first heat dissipation member 181 against the base 162. If the first heat dissipation member 181 is excessive, the busbars 71P, 71N, 91 also press the first heat dissipation member 181 against the base 162.

[0095] <Second Cooling Structure> Figure 6 is a plan view of the second cooling structure 260 as seen from the back surface 21B side. Figures 12 and 13 are cross-sectional views of the second cooling structure 260. Figure 14 is a perspective view of the insulating member 261 of the second cooling structure 260. The second cooling structure 260 is provided on the back surface 21B such that it overlaps with the first busbars 40P, 40N and the second busbars 50P, 50N in a plan view.

[0096] The second cooling structure 260 includes an insulating member 261, a first heat dissipation member 181, and a second heat dissipation member 182. The insulating member 261 includes a base 262, a busbar-side flange 266, a busbar-side rib 267, a base-side flange 268, and a base-side rib 269. The base 262 has a surface 263 facing the busbars 40P, 40N, 50P, and 50N, and a back surface 264 facing the back surface 21B. The busbar-side flange 266 is sometimes referred to as the front flange. The base-side flange 268 is sometimes referred to as the back flange.

[0097] In an alternative configuration, the insulating member 261 may not have a busbar-side flange 266, a busbar-side rib 267, a base-side flange 268, and a base-side rib 269. In yet another alternative configuration, the second cooling structure 260 may be provided with storage sections 171 and 172. The base-side flange 268 may extend diagonally so as to widen toward the base 21.

[0098] In this embodiment, the busbar-side flange 266, busbar-side rib 267, base-side flange 268, and base-side rib 269 are connected to the base 262. The busbar-side flange 266 and busbar-side rib 267 extend in the Z direction from the surface 263. The base-side flange 268 and base-side rib 269 extend in the Z direction from the back surface 264. The busbar-side flange 266 and base-side flange 268 are connected in the Z direction. The busbar-side rib 267 and base-side rib 269 are connected in the Z direction.

[0099] The base 262 has plate thickness in the Z direction. The base 162 is rectangular in plan view. A busbar-side flange 266 extends annularly from the surface 263 along the edge of the base 262. A base-side flange 268 extends annularly from the back surface 264 along the edge of the base 262. A busbar-side rib 267 is provided to divide the base 262 in the Y direction. Both ends of the busbar-side rib 267 are connected to the busbar-side flange 266. A base-side rib 269 is provided to divide the base 262 in the Y direction. Both ends of the base-side rib 269 are connected to the base-side flange 268.

[0100] The insulating member 261 also has a positioning portion 271 that defines its own position relative to the base 21. The positioning portion 271 is provided on the busbar-side flange 266, the base-side flange 268, or across both. The positioning portion 271 has an extension portion 272 that extends in the planar direction from the flanges 266 and 268, and a hole 273 provided in the extension portion 272. In addition to the base 21, wall portion 23, and adjustment portions 210 and 220, the housing 20 has a positioning pin 226 that defines the planar position of the insulating member 261. The positioning pin 226 extends in the Z direction from the back surface 21B. The positioning pin 226 is inserted into the hole 273. This defines the position of the insulating member 261. The positioning pin 226 is made of the same material as the base 21. The positioning pin 226 is made of a metallic material. In addition to defining the position of the insulating member 261, the positioning pin 226 also has the function of effectively dissipating heat from the busbars 40P, 40N, 50P, and 50N to the base 21.

[0101] <Second Adjustment Section> The housing 20 has a second adjustment section 220 at the location where the second cooling structure 260 is provided. The second adjustment section 220 is provided on the back surface 21B. The base 21, the first adjustment section 210, and the second adjustment section 220 described above are sometimes collectively referred to as a cooling member. The cooling member is sometimes referred to as a heat sink.

[0102] The second adjustment section 220 has a stepped structure that overlaps in two stages in the Z direction. The second adjustment section 220 adjusts the position of the insulating member 261 and the amount of the second heat dissipation member 182. The second adjustment section 220 has a first protrusion 221 that protrudes in the Z direction from the back surface 21B and a second protrusion 223 that protrudes in the Z direction from the first protrusion 221. In a plan view, the second protrusion 223 is enclosed within the first protrusion 211. The second protrusion 223 overlaps with the base 262 of the second cooling structure 260 in the Z direction.

[0103] The first projection 221 has a tip surface 221A and a side surface 222 that connects the tip surface 221A to the base 21. The side surface 222 has a first side surface 222A facing the first wall 23A, a second side surface 222B facing the second wall 23B, a third side surface 222C facing the third wall 23C, and a fourth side surface 222D facing the fourth wall 23D.

[0104] The second projection 223 has a tip surface 223A, a side surface 224 connecting the tip surface 223A and the tip surface 221A of the first projection 221, and a groove 225 that recesses from the tip surface 223A toward the base 21. The side surface 224 has a first side surface 224A facing the first wall 23A, a second side surface 224B facing the second wall 23B, a third side surface 224C facing the third wall 23C, and a fourth side surface 224D facing the fourth wall 23D.

[0105] As shown in Figures 12 and 13, the length between the second side surface 222B and the fourth side surface 222D of the first protrusion 221 is longer than the length between the second side surface 224B and the fourth side surface 224D of the second protrusion 223. The length between the first side surface 222A and the third side surface 222C of the first protrusion 221 is equal to the length between the first side surface 224A and the third side surface 224C of the second protrusion 223.

[0106] The second cooling structure 260 is positioned on the first adjustment section 210 such that its back surface 264 overlaps the front surface 223A. The components are stacked in the Z-direction from bottom to top in the order of base 21, first projection 221, second projection 223, second cooling structure 260, first busbars 40P and 40N. The length of the first projection 221 in the Z-direction is shorter than the length of the base-side flange 268 in the Z-direction. A portion of the base-side flange 268 overlaps with the second projection 223 in the planar direction, with a gap in between.

[0107] As shown in Figure 6, the insulating member 261 has a positioning portion 271 that defines its position relative to the base 21. The positioning portion 271 has an extension portion 272 that extends in the planar direction from the flanges 266 and 268, and a hole 273 provided in the extension portion 272. The housing 20 is provided with a positioning pin 226 that defines the planar position of the insulating member 261. The planar position of the insulating member 261 is defined by inserting the positioning pin 226 into the hole 273.

[0108] Furthermore, in the Z direction, the base side flange 268 on the base 21 side is in contact with the tip surface 221A of the first projection 221. This restricts the movement of the insulating member 261 in the Z direction. The position of the insulating member 261 in the Z direction is defined by the first projection 221. The second adjustment part 220 has the first projection 221 that defines the position of the insulating member 261 in the Z direction and the second projection 223 that defines the position of the insulating member 261 in the planar direction. In this way, the second adjustment part 220 plays a positioning role in adjusting the position of the insulating member 261. A base side rib 269 is inserted into the groove 225. The base side rib 269 is provided so close that it contacts the inner surface of the groove 225. The position in the planar and Z directions is also defined by the base side rib 269.

[0109] <Cooling configuration> The base flange 268 on the base 21 side overlaps with the second projection 223 in the planar direction. The base flange 268 on the base 262 side does not overlap with the second projection 223 in the planar direction. On the base 262 side, the second heat dissipation member 182 is provided in the space enclosed by the base 262, the base flange 268, the base rib 269, and the second adjustment part 220.

[0110] On the insulating member 261 side, the second heat dissipation member 182 is in close contact with the base 262, the base side flange 268, and the base side rib 269. On the second adjustment section 220 side, the second heat dissipation member 182 is in close contact with the tip surface 223A. The second heat dissipation member 182 dissipates the heat from the first busbar 40P, 40N to the base 21. The second heat dissipation member 182 fills both the space on the second wall 23B side and the space on the fourth wall 23D side, which are separated by the base side rib 269.

[0111] First busbars 40P and 40N are provided on the tip side of the busbar-side flange 266. The first busbars 40P and 40N are provided away from the corresponding tip of the busbar-side flange 266. The first busbars 40P and 40N are provided away from the tip of the wall on the first wall 23A side and the wall on the third wall 23C side of the busbar-side flange 266.

[0112] A first heat dissipation member 181 is provided in the space enclosed by the base 262, the busbar-side flange 266, the busbar-side rib 267, and the first busbars 40P and 40N. The first heat dissipation member 181 is in close contact with the base 262, the busbar-side flange 266, the busbar-side rib 267, and the first busbars 40P and 40N. The first heat dissipation member 181 dissipates heat from the first busbars 40P and 40N to the base 21. The first heat dissipation member 181 fills both the space on the second wall 23B side and the space on the fourth wall 23D side, which are separated by the busbar-side rib 267. The P-side first busbar 40P is provided so as to be in contact with the first heat dissipation member 181 provided in the space on the second wall 23B side. The N-side first busbar 40N is provided so as to be in contact with the first heat dissipation member 181 provided in the space on the fourth wall 23D side.

[0113] <Y Capacitor Function> The adjustment units 210 and 220 are integrally provided on the base 21, and the base 21 is connected to the chassis or the like to the body ground to provide the ground potential. The base 21 is thermally connected to the busbar fastening portion in an electrically insulated state by insulating members 161 and 261. A capacitor is made by sandwiching an insulator between metal plates in parallel, and in this embodiment, the Y capacitor function is performed on the busbars 71P, 71N, 91, 40P, 40N, insulating members 161 and 261, heat dissipation members 181 and 182, and the base 21. In the drawing, the Y capacitor function shown by the dashed line in Figure 1 is performed. It can be said that the P-side Y capacitor Y1 is substantially connected between the P line 8 and the ground, and the N-side Y capacitor Y2 is connected between the N line 9 and the ground.

[0114] As an example, one electrode of the P-side Y capacitor Y1 is provided by the P-side capacitor busbar 71P and the main terminal 32P, and the other electrode is provided by the base 21. The insulating layer placed between these two electrodes is provided by the insulating member 161. One electrode of the N-side Y capacitor Y2 is provided by the N-side capacitor busbar 71N and the main terminal 32N, and the other electrode is provided by the base 21. The insulating layer placed between these two electrodes is provided by the insulating member 161 in the same manner as for the P-side Y capacitor Y1.

[0115] As another example, one electrode of the P-side Y capacitor Y1 is provided by the P-side first busbar 40P, and the other electrode is provided by the base 21. The insulating layer placed between these two electrodes is provided by the insulating member 261. One electrode of the N-side Y capacitor Y2 is provided by the N-side first busbar 40N, and the other electrode is provided by the base 21. The insulating layer placed between these two electrodes is provided by the insulating member 261, similar to the N-side Y capacitor Y2. These Y capacitors are filter capacitors that remove noise, and are also called noise absorption capacitors.

[0116] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, while various combinations and forms are shown in this disclosure, other combinations and forms that include one, more, or fewer of those elements also fall within the scope and concept of this disclosure.

[0117] <Effects and Effects> The power converter 4 of this embodiment includes a housing 20, a semiconductor module 30, first busbars 40P and 40N, capacitor busbars 71P and 71N, an internal busbar 91, a first cooling structure 160, and a second cooling structure 260. The first busbars 40P and 40N, capacitor busbars 71P and 71N, and the internal busbar 91 are busbars electrically connected to the semiconductor module 30. The housing 20 includes a base 21, a first adjustment section 210, and a second adjustment section 220, which are cooling members. The base 21 cools the busbars 40P, 40N, 71P, 71N, and 91.

[0118] The cooling structures 160 and 260 include insulating members 161 and 261, a first heat dissipation member 181, and a second heat dissipation member 182. The insulating members 161 and 261 are provided between the busbars 40P, 40N, 71P, 71N, and 91 and the base 21. The heat dissipation members 181 and 182 are more flexible than the insulating members 161 and 261.

[0119] The first heat dissipation member 181 of the first cooling structure 160 is in close contact with the busbars 71P, 71N, and 91 and the insulating member 161. The thermal resistance between the busbars 71P, 71N, and 91 and the first heat dissipation member 181, and between the first heat dissipation member 181 and the insulating member 161, is easily reduced. The second heat dissipation member 182 of the first cooling structure 160 is in close contact with the insulating member 161 and the base 21. The thermal resistance between the insulating member 161 and the second heat dissipation member 182, and between the second heat dissipation member 182 and the base 21, is easily reduced. The heat dissipation members 181 and 182 effectively dissipate the heat from the busbars 71P, 71N, and 91 to the base 21. Consequently, the heat from the busbars 71P, 71N, and 91 is effectively dissipated to the base 21.

[0120] The first heat dissipation member 181 of the second cooling structure 260 is in close contact with the first busbars 40P and 40N and the insulating member 261. The thermal resistance between the first busbars 40P and 40N and the first heat dissipation member 181, and between the first heat dissipation member 181 and the insulating member 261 is easily reduced. The second heat dissipation member 182 of the second cooling structure 260 is in close contact with the insulating member 261 and the base 21. The thermal resistance between the insulating member 261 and the second heat dissipation member 182, and between the second heat dissipation member 182 and the base 21 is easily reduced. The heat dissipation members 181 and 182 effectively dissipate the heat from the first busbars 40P and 40N to the base 21. The heat from the first busbars 40P and 40N can be efficiently dissipated to the base 21.

[0121] Unlike this embodiment, in a configuration where only an insulating member 161 is provided between the busbars 71P, 71N, 91 and the base 21, the contact between the busbars 71P, 71N, 91 and the base 21 is poor, and heat is not efficiently dissipated from the busbars 71P, 71N, 91 to the base 21. Also unlike this embodiment, in a configuration where only heat dissipation members 181, 182 are provided between the busbars 71P, 71N, 91 and the base 21, insulation between the busbars 71P, 71N, 91 and the base 21 cannot be guaranteed. In this embodiment, since both the insulating member 161 and the heat dissipation members 181, 182 are provided between the busbars 71P, 71N, 91 and the base 21, it is possible to efficiently dissipate heat from the busbars 71P, 71N, 91 to the base 21 while ensuring insulation between the busbars 71P, 71N, 91 and the base 21.

[0122] The insulating member 161 has a base 162, front flanges 166 and 167, and back flanges 168 and 169. The base 162 has a front surface 163 on the busbar 71P, 71N, and 91 side, and a back surface 164 facing the base 21. The front flanges 166 and 167 extend in the Z direction from the front surface 163 and along the edge 165. The back flanges 168 and 169 extend in the Z direction from the back surface 164 and along the edge 165. The tips of the back flanges 168 and 169 are in contact with the base 21.

[0123] According to this, the first heat dissipation member 181 is provided in the space between the front flanges 166, 167, the base 162, and the busbars 71P, 71N, 91. The front flanges 166, 167 can prevent the first heat dissipation member 181 from leaking out from between the busbars 71P, 71N, 91 and the base 162. The minimum thickness of the first heat dissipation member 181 can be ensured. It is possible to avoid the thickness of the first heat dissipation member 181 becoming thinner than the specified value.

[0124] Furthermore, a second heat dissipation member 182 is provided in the space between the rear flanges 168 and 169 and the base 162 and the base 21. The rear flanges 168 and 169 can prevent the second heat dissipation member 182 from leaking out from between the base 162 and the base 21. The minimum thickness of the second heat dissipation member 182 can be ensured. It is possible to avoid the thickness of the second heat dissipation member 182 being thinner than the specified value.

[0125] As a result, the first heat dissipation member 181 can maintain a state of close contact with the base 162 and busbars 71P, 71N, and 91, and the second heat dissipation member 182 can maintain a state of close contact with the base 21 and base 162. Even if differences in deformation occur between the base 162 and busbars 71P, 71N, and 91, and between the base 162 and the base 21 due to differences in the coefficient of linear expansion, the thickness of the heat dissipation members 181 and 182 is maintained, which alleviates thermal stress at the interface and makes it difficult for the heat dissipation members 181 and 182 to peel off.

[0126] The insulating member 261 has a base 262, a busbar-side flange 266, and a base-side flange 268. The base 262 has a surface 263 on the busbar 40P, 40N side and a back surface 264 on the base 21 side. The busbar-side flange 266 extends from the surface 263 along the edge of the base 262. The base-side flange 268 extends from the back surface 264 along the edge of the base 262. The tip of the busbar-side flange 266 is set away from the busbars 40P, 40N. The tip of the base-side flange 268 is in contact with the base 21.

[0127] According to this, the first heat dissipation member 181 is provided in the space between the busbar-side flange 266, the base 262, and the busbars 40P and 40N. The busbar-side flange 266 can prevent the first heat dissipation member 181 from leaking out from between the busbars 40P and 40N and the base 262. The minimum thickness of the first heat dissipation member 181 can be ensured. It is possible to avoid the thickness of the first heat dissipation member 181 becoming thinner than the specified value.

[0128] A second heat dissipation member 182 is provided in the space between the base flange 268, the base 262, and the base 21. The base flange 268 can prevent the second heat dissipation member 182 from leaking out from between the base 262 and the base 21. The minimum thickness of the second heat dissipation member 182 can be ensured. It is possible to avoid the thickness of the second heat dissipation member 182 being thinner than the specified value.

[0129] As a result, the first heat dissipation member 181 can maintain a state of close contact with the base 262 and busbars 40P and 40N, and the second heat dissipation member 182 can maintain a state of close contact with the base 21 and base 262. Even if differences in deformation occur between the base 262 and busbars 40P and 40N, and between the base 262 and base 21 due to differences in the coefficient of linear expansion, the thickness of the heat dissipation members 181 and 182 is maintained, which alleviates thermal stress at the interface and makes it difficult for the heat dissipation members 181 and 182 to peel off.

[0130] The housing 20 has a base 21 having a plate thickness in the Z direction, a first projection 211 protruding from the surface 21A of the base 21, and a second projection 213 protruding from the first projection 211. The first projection 211 and the second projection 213 together are referred to as the first adjustment portion 210. In a plan view, the second projection 213 is enclosed within the first projection 211. An insulating member 161 is provided on the first adjustment portion 210 such that the base 162 overlaps with the second projection 213. The rear flanges 168 and 169 are in contact with the first projection 211. The base 21 side of the rear flanges 168 and 169 is in contact with the side surface 214 of the second projection 213. The second heat dissipation member 182 is provided in the space enclosed by the remainder of the rear flange 168, the first adjustment portion 210, and the base 162. According to this, while defining the position of the insulating member 161 in the X, Y, and Z directions, it is possible to secure space to accommodate a second heat dissipation member 182 in an amount sufficient for heat dissipation.

[0131] The housing 20 also has a first protrusion 221 that protrudes from the back surface 21B of the base 21, and a second protrusion 223 that protrudes from the first protrusion 221. In a plan view, the second protrusion 223 is enclosed within the first protrusion 221. An insulating member 261 is provided on the second adjustment section 220 such that the base 262 overlaps with the second protrusion 223. A part of the base-side flange 268 is provided so close that it contacts the first protrusion 221. A part of the base-side flange 268 is provided so close that it contacts the side surface 224 of the second protrusion 223. A second heat dissipation member 182 is provided in the space enclosed by the rest of the base-side flange 268, the second adjustment section 220, and the base 262. This allows for the position of the insulating member 261 to be defined in the X, Y, and Z directions, while securing space to accommodate a sufficient amount of the second heat dissipation member 182 for heat dissipation.

[0132] A first heat dissipation member 181 is provided in the space between the front flanges 166 and 167, the base 162, and the busbars 71P, 71N, and 91. The front flanges 166 and 167 consist of a first front flange 166 and a second front flange 167, which are spaced apart and facing each other in the Y direction. A gap is provided between the second extension 166B of the first front flange 166 and the second extension 167B of the second front flange 167 from which the first heat dissipation member 181 can leak. A gap is also provided between the third extension 166C of the first front flange 166 and the third extension 167C of the third front flange 167 from which the first heat dissipation member 181 can leak. In this embodiment, the first heat dissipation member 181 is a gap filler that is fluid before curing.

[0133] According to this, if an excess of the first heat dissipation member 181 is provided during the manufacturing process, the excess first heat dissipation member 181 can be discharged through this gap. When an excess of the first heat dissipation member 181 is provided, for example, the first heat dissipation member 181 may bulge out in a mountain-like shape. If the busbars 71N, 71P, and 91 are placed in this state, the first heat dissipation member 181 may not be in sufficient contact with the bottom surfaces of the busbars 71N, 71P, and 91. Therefore, by providing a gap through which the first heat dissipation member 181 can leak out, as in this embodiment, the surface of the first heat dissipation member 181 can be made closer to flat. Consequently, the contact between the bottom surfaces of the busbars 71N, 71P, and 91 and the first heat dissipation member 181 can be improved. Note that this effect is not limited to the manufacturing process. It is also effective when the first heat dissipation member 181 is a fluid material.

[0134] The insulating member 161 has a base 162, front flanges 166 and 167, and back flanges 168 and 169, as well as storage sections 171 and 172. Storage section 171 is connected to the first edge 165A between the second extension 166B and the second extension 167B. The second storage section 172 is connected to the third edge 165C between the third extension 166C and the third extension 167C. Storage sections 171 and 172 have an arm 174 and an enclosure 175. The arm 174 extends in a planar direction away from the edge. The enclosure 175 extends along the edge of the arm 174 so as to surround the arm 174. The arm 174 and the enclosure 175 constitute storage sections 171 and 172 capable of housing the second heat dissipation member 182.

[0135] Parts of the storage sections 171 and 172 are not in contact with the first protruding portion 211. In the non-contact portion, a part of the second heat dissipation member 182 housed in the storage sections 171 and 172 is exposed to the outside. The second heat dissipation member 182 is discharged from the non-contact portion. In addition to positioning the insulating member 161, the first adjustment unit 210 has an adjustment function for the second heat dissipation member 182.

[0136] The arm portion 174 extends diagonally in the Z direction so that its tip approaches the base 21. This allows for adjustment of the amount and direction of the discharged second heat dissipation member 182. The second heat dissipation member 182 can be actively discharged in the X direction, which is perpendicular to the Y direction, which is the extension direction of the busbars 71P, 71N, and 91. The leaked second heat dissipation member 182 can be actively transferred to the base 21. As the leaked second heat dissipation member 182 is transferred to the base 21, the contact area between the second heat dissipation member 182 and the base 21 increases. The heat dissipation performance can be improved by utilizing the leaked second heat dissipation member 182.

[0137] The first cooling structure 160 has fastening members 110 that fasten the busbars 71P, 71N, 91 and the main terminals 32P, 32N, 32O. The fastening members 110 fasten the busbars 71P, 71N, 91 and the main terminals 32P, 32N, 32O at a position that overlaps with the base 162 in the Z direction. The fastening members 110 are composed of bolts 111 and nuts 116. The bolts 111 are inserted into the through holes 32A, 71A. By tightening the inserted bolts 111 with nuts 116 in the Z direction, the busbars 71P, 71N and the main terminals 32P, 32N are fastened to each other. The head 113 of the fastening member 110 protrudes downward from the bottom surface of the busbars 71P, 71N, 91. The head 113 presses the first heat dissipation member 181 against the base 162. If the first heat dissipation member 181 is excessive, the first heat dissipation member 181 is also pressed against the base 162 by the busbars 71P, 71N, and 91.

[0138] Furthermore, if the second heat dissipation member 182 is excessively placed, the base 162 will be pushed toward the busbars 71P, 71N, and 91 by the second heat dissipation member 182. The base 162 is also pushed toward the base 21 by the first heat dissipation member 181. If the second heat dissipation member 182 is excessively placed, the base 162 will be pushed toward both the first heat dissipation member 181 and the second heat dissipation member 182. This may cause damage to the base 162.

[0139] In this embodiment, if an excessive number of second heat dissipation members 182 are provided, the second heat dissipation members 182 can be discharged from the housing sections 171 and 172. This suppresses the force with which the second heat dissipation members 182 push against the base 162. Consequently, the upward and downward pushing of the base 162 is suppressed. Damage to the base 162 can be suppressed. This also improves the cooling performance of the base 21 for the busbars 71P, 71N, and 91.

[0140] (Second Embodiment) The second embodiment will be described focusing on the differences from the first embodiment. Configurations, operations, and effects that are not specifically described are the same as in the first embodiment. As shown in Figure 15, the first cooling structure 360 ​​of the second embodiment is provided on the base 21 so as to overlap the fastening portion between the main terminal 32P and the P-side capacitor busbar 71P, and the fastening portion between the main terminal 32N and the N-side capacitor busbar 71N.

[0141] As shown in Figures 18 and 19, the first cooling structure 360 ​​includes an insulating member 361, first heat dissipation members 181P and 181N, and a second heat dissipation member 182. As shown in Figure 16, the insulating member 361 includes a base 362, a front flange 367, and a back flange 368. The base 362 includes a P-side base 362P, an N-side base 362N, and a connecting portion 362A. The front flange 367 protrudes in the Z direction away from the surface 363. The front flange 367 includes a P-side base flange 367P and an N-side base flange 367N. Further details will be explained later.

[0142] The rear flange 368 protrudes in the Z direction away from the back surface 364 and extends along the edge 365 of the base 362. The rear flange 368 extends in an annular shape along the edge 365. The rear flange 368 and the base 362 form a box-shaped structure that opens towards the first adjustment section 210. The first adjustment section 210 has a shape corresponding to the insulating member 361. The second heat dissipation member 182 is provided in the space enclosed by the base 362, the rear flange 368, and the first adjustment section 210. A part of the P-side base flange 367P and a part of the N-side base flange 367N are connected to the rear flange 368 in the Z direction.

[0143] As shown in Figures 15 and 18, the fastening portion between the main terminal 32P and the P-side capacitor busbar 71P is provided on the first cooling structure 360 ​​so that it overlaps with the P-side base 362P in the Z direction. As shown in Figures 15 and 19, the fastening portion between the main terminal 32N and the N-side capacitor busbar 71N is provided on the first cooling structure 360 ​​so that it overlaps with the N-side base 362N in the Z direction.

[0144] The P-side base 362P and the N-side base 362N have a flattened shape with a thin thickness in the Z direction. The P-side base 362P and the N-side base 362N have a front surface 363 and a back surface 364. As shown in Figure 16, the P-side base 362P and the N-side base 362N are arranged adjacent to each other in the X direction. The positions of the P-side base 362P and the N-side base 362N are different in the Z direction. The connecting portion 362A is provided between the P-side base 362P and the N-side base 362N in the X direction. The P-side base 362P and the N-side base 362N are connected via the connecting portion 362A.

[0145] The P-side base 362P and the N-side base 362N have edges 365P and 365N. The edges 365P and 365N are sometimes referred to as base edges. The P-side base 362P has a first edge 365PA, a second edge 365PB, a third edge 365PC, and a fourth edge 365PD as edges 365P. The N-side base 362N has a first edge 365NA, a second edge 365NB, a third edge 365NC, and a fourth edge 365ND as edges 365N.

[0146] The first edges 365PA and 365NA face the first wall 23A in the X direction. The second edges 365PB and 365NB face the second wall 23B in the Y direction. The third edges 365PC and 365NC face the third wall 23C in the X direction. The fourth edges 365PD and 365ND face the fourth wall 23D in the Y direction.

[0147] A P-side base flange 367P is provided on edge 365P. An N-side base flange 367N is provided on edge 365N. The P-side base flange 367P protrudes in the Z direction from edge 365P so as to be away from the surface 363. The N-side base flange 367N protrudes in the Z direction from edge 365N so as to be away from the back surface 364.

[0148] As shown in Figure 16, the P-side base flange 367P has a first extension 367PA, a second extension 367PB, and a third extension 367PC. The first extension 367PA extends in the X direction along the fourth edge 365PD. The second extension 367PB extends in the Y direction along the first edge 365PA. The third extension 367PC extends in the Y direction along the third edge 365PC. The P-side base flange 367P is not installed at the second edge 365PB, which is one end of the P-side base 362P in the Y direction. The first edge 365PA, the third edge 365PC, and the fourth edge 365PD are sometimes referred to as installation areas where the P-side base flange 367P is installed. The second edge portion 365PB is sometimes referred to as the non-installation portion where the P-side base flange 367P is not installed.

[0149] In the second embodiment, the second extension 367PB and the third extension 367PC extend from the fourth edge 365PD to just before the second edge 365PB. The second extension 367PB and the third extension 367PC may extend from the fourth edge 365PD to the second edge 365PB. The lengths of the second extension 367PB and the third extension 367PC may be the same or different. Parts of the second extension 367PB and parts of the third extension 367PC may be curved inward in the planar direction. The P-side base flange 367P has a substantially U-shape in plan view.

[0150] As shown in Figure 18, the fastening portion between the main terminal 32P and the P-side capacitor busbar 71P is provided on the insulating member 361 via the first heat dissipation member 181P. The P-side capacitor busbar 71P is provided on the insulating member 361 so as to be in close contact with the first heat dissipation member 181P. The P-side capacitor busbar 71P extends along the Y direction. The P-side capacitor busbar 71P has a longitudinal side in the Y direction and a short side in the X direction. The P-side capacitor busbar 71P extends in the Y direction so as to overlap the second edge portion 365PB.

[0151] Figure 17 shows the placement step of positioning the fastening portion of the main terminal 32P and the P-side capacitor busbar 71P on the first cooling structure 360. In the placement step, the first heat dissipation member 181P, before hardening, is placed on the surface 363. The main terminal 32P, the P-side capacitor busbar 71P, and the fastening member 110 are brought closer to the first heat dissipation member 181P so as to press the first heat dissipation member 181P against the surface 363. As the first heat dissipation member 181P approaches the surface 363, as shown in Figure 18, the first heat dissipation member 181P spreads out along the surface 363 and the P-side capacitor busbar 71P.

[0152] The first heat dissipation member 181P is provided in the space enclosed by the P-side base 362P and the P-side base flange 367P, and a portion of it overflows from the second edge 365PB. The portion of the first heat dissipation member 181P that overflows from the second edge 365PB is sometimes referred to as the overflow portion 183P. The overflow portion 183P is provided outside the second edge 365PB in the planar direction. The tip 181PA of the first heat dissipation member 181P is provided outside the second edge 365PB in the planar direction. The tip 181PA can be rephrased as the tip of the overflow portion 183P. The tip 181PA is sometimes referred to as the heat dissipation end.

[0153] The overflow portion 183P extends along the P-side capacitor busbar 71P. The overflow portion 183P adheres closely to the P-side capacitor busbar 71P without interruption all the way to the tip 181PA. This increases the contact area between the first heat dissipation member 181P and the P-side capacitor busbar 71P. This improves the heat dissipation performance and seismic resistance of the P-side capacitor busbar 71P.

[0154] By making the overflow portion 183P not simply spill out as excess, but instead closely attached to the P-side capacitor busbar 71P, the first heat dissipation member 181P can be used efficiently without waste. With this configuration, both the portion secured in the space surrounded by the P-side base 362P and the P-side base flange 367P, and the overflow portion 183P can be used for heat dissipation in the first heat dissipation member 181P. Compared to the case where the overflow portion 183P is not used for heat dissipation and only the secured portion is increased, the amount of the first heat dissipation member 181P used can be reduced, and the weight can be reduced. The same applies to the overflow portion 183N described later.

[0155] The P-side capacitor busbar 71P and the base 21 are arranged in overlapping positions via an insulating member 361 and a first heat dissipation member 181P. This configuration is similar to that of a so-called capacitor, where two conductors are sandwiched between insulating members. As a result, parasitic capacitance is formed between the P-side capacitor busbar 71P and the base 21.

[0156] As described above, the base 21 has a ground potential. The parasitic capacitance generated between the P-side capacitor busbar 71P and the base 21 acts similarly to a Y-capacitor, effectively guiding noise current to the ground path. As a result, unwanted high-frequency noise and electromagnetic waves are effectively absorbed, improving the overall EMC performance of the circuit. This effect also applies to the first embodiment.

[0157] As shown in Figure 16, the N-side base flange 367N has a first extension 367NA, a second extension 367NB, and a third extension 367NC. The extension configurations of the first extension 367NA, the second extension 367NB, and the third extension 367NC are the same as those of the first extension 367PA, the second extension 367PB, and the third extension 367PC.

[0158] The N-side base flange 367N is installed on the first edge 365NA, the third edge 365NC, and the fourth edge 365ND. The N-side base flange 367N is not installed on the second edge 365NB. The first edge 365NA, the third edge 365NC, and the fourth edge 365ND may be referred to as the installation area. The second edge 365NB may be referred to as the non-installation area.

[0159] As shown in Figure 19, the fastening portion between the main terminal 32N and the N-side capacitor busbar 71N is provided on the insulating member 361 via the first heat dissipation member 181N. The first heat dissipation member 181N is provided in the space surrounded by the N-side base 362N and the N-side base flange 367N, and a portion of it overflows from the second edge portion 365NB. A portion of the first heat dissipation member 181N is provided outside the second edge portion 365NB in ​​the planar direction. The portion of the first heat dissipation member 181N that overflows from the second edge portion 365NB is sometimes referred to as the overflow portion 183N.

[0160] The tip 181NA of the first heat dissipation member 181N is located outside the second edge portion 365NB in ​​the planar direction. The tip 181NA can be rephrased as the tip of the overflow portion 183N. The tip 181NA is sometimes referred to as the heat dissipation end.

[0161] The basic extension configuration of the N-side capacitor busbar 71N is the same as that of the P-side capacitor busbar 71P. The N-side capacitor busbar 71N extends in the Y direction so as to overlap the second edge portion 365NB. As shown in Figure 19, the N-side capacitor busbar 71N extends toward the base 21 at the portion that overlaps with the overflow portion 183N. The N-side capacitor busbar 71N bends toward the base 21 on the overflow portion 183N side. The starting point of the bend may be inward or outward in the planar direction from the second edge portion 365NB.

[0162] Generally, the overflow portion 183N tends to fall towards the base 21 due to gravity. However, in the second embodiment, the overflow portion 183N can make close contact with the N-side capacitor busbar 71N before falling onto the base 21. This effectively increases the contact area with the N-side capacitor busbar 71N.

[0163] (Other Embodiments) Up to this point, an embodiment has been described in which the base flanges 367P and 367N are not installed on the second edges 365PB and 365NB. However, the locations where they are not installed are not limited to the second edges 365PB and 365NB. The base flanges 367P and 367N may not be installed on any of the first edges 365PA and 365NA to the fourth edges 365PD and 365ND, excluding the second edges 365PB and 365NB. The base flanges 367P and 367N may not be installed on all of the first edges 365PA and 365NA to the fourth edges 365PD and 365ND.

[0164] The first heat dissipation members 181P and 181N that overflow from the edges 365P and 365N where the base flanges 367P and 367N are not installed should be in close contact with the capacitor busbars 71P and 71N without interruption all the way to the tips 181PA and 181NA. This will produce the same effect.

[0165] (Disclosure of Technical Ideas) This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs may be written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs may be written in a multiple dependent form, where they refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas. (Technical Concept 1) An electrical device comprising: a semiconductor module (30); busbars (40P, 40N, 71P, 71N, 91) electrically connected to the semiconductor module; cooling members (21, 210, 220) for cooling the busbars; insulating members (161, 261) provided between the cooling members and the busbars; and heat dissipation members (181, 182) having greater flexibility than the insulating members and dissipating heat from the busbars to the cooling members, wherein the heat dissipation members comprise a first heat dissipation member (181) in close contact with the busbars and the insulating members, and a second heat dissipation member (182) in close contact with the insulating members and the cooling members. (Technical Concept 2) The insulating member has a surface (163, 263) facing the busbar and a back surface (164, 264) facing the cooling member, and a base (162, 262) having a plate thickness in the direction (Z) where the surface and the back surface are aligned, a front flange (166, 167, 266) extending from the surface toward the busbar, and a back flange (168, 169, 268) extending from the back surface toward the cooling member with its tip in contact with the cooling member, the front flange and the back flange extending along the edge of the base, the first heat dissipation member being in close contact with the busbar and the base, and the second heat dissipation member being in close contact with the base and the cooling member, as described in Technical Concept 1.(Technical Concept 3) The electrical device according to Technical Concept 1, wherein the insulating member has a surface (363) facing the busbar and a back surface (364) facing the cooling member, and has a base (362P, 362N) having a plate thickness in the direction of alignment (Z) where the surface and the back surface are aligned, and the heat dissipation end (181PA, 181NA), which is the end of the first heat dissipation member in the orthogonal direction (X, Y) perpendicular to the alignment direction, is provided outward in the orthogonal direction from the base edge (365P, 365N), which is the edge of the base in the orthogonal direction, and the first heat dissipation member is in close contact with the busbar up to the heat dissipation end. (Technical Concept 4) The electrical device according to Technical Concept 3, wherein the insulating member has a front flange (367P, 367N) extending along a part of the base edge on its surface, the base edge has an installation portion (365PA, 365NA, 365PC, 365NC, 365PD, 365ND) on which the front flange is installed, and a non-installation portion (365PB, 365NB) on which the front flange is not installed, the busbar has an longitudinal length in one direction (Y) perpendicular to the direction, the non-installation portion is provided on the edge of the base in that direction, and the heat dissipation end in that direction is provided outward in the perpendicular direction from the non-installation portion. (Technical Idea 5) The electrical device according to Technical Idea 4, wherein the heat dissipation member has overflow portions (183P, 183N) provided outward in the direction perpendicular to the non-installed portion, and the portion of the busbar that overlaps with the overflow portions extends toward the cooling member. (Technical Idea 6) The electrical device according to Technical Idea 2, wherein the heat dissipation member is a fluid material before or after curing.(Technical Idea 7) The cooling member comprises a base (21) having a plate thickness in the direction of alignment, and an adjustment section (210, 220) including first protrusions (211, 221) protruding from the base in the direction of alignment, and second protrusions (213, 223) protruding from the first protrusions in the direction of alignment and being contained within the first protrusions with respect to orthogonal directions (X, Y) perpendicular to the direction of alignment, wherein the insulating member is provided on the adjustment section such that the base overlaps the second protrusions in the direction of alignment, a part of the back flange contacts the first protrusions in the direction of alignment and contacts the second protrusions in the orthogonal direction, and the second heat dissipation member is provided between the rest of the back flange, the adjustment section and the base, as described in Technical Idea 2 or 6. (Technical Idea 8) The electrical device according to Technical Idea 7, wherein the first heat dissipation member is provided between the front flange, the busbar and the base, the front flange has a first front flange (166) and a second front flange (167) that are arranged opposite each other in the orthogonal direction, and a gap is provided between the first front flange and the second front flange from which the first heat dissipation member can leak out. (Technical Idea 9) The electrical device according to Technical Idea 8, wherein the insulating member includes an arm portion (174) that extends from the edge to the edge and away from the edge between the first front flange and the second front flange in the orthogonal direction, and an enclosing portion (175) that extends to surround the arm portion, and further has a housing portion (171, 172) for housing the second heat dissipation member, and a part of the second heat dissipation member housed in the housing portion is exposed to the outside. (Technical Idea 10) The electrical device according to Technical Idea 9, wherein the arm portion extends diagonally toward the base. (Technical Idea 11) An electrical device according to Technical Idea 10, wherein the busbar is in close contact with the first heat dissipation member, and the busbar presses the first heat dissipation member against the base. (Technical Idea 12) An electrical device according to any one of Technical Ideas 1 to 11, wherein the cooling member provides a ground potential, and the busbar is thermally connected to the cooling member in an electrically insulated state.(Technical Idea 13) The electrical device according to any one of Technical Ideas 8 to 11, wherein the insulating member further has a positioning portion (271) that protrudes from the front flange or the back flange and has a hole (273) that penetrates in the direction of alignment, and the base has a positioning pin (226) that protrudes toward the positioning portion, and the positioning pin is passed through the hole.

Claims

1. An electrical device comprising: a semiconductor module (30); busbars (40P, 40N, 71P, 71N, 91) electrically connected to the semiconductor module; cooling members (21, 210, 220) for cooling the busbars; insulating members (161, 261) provided between the cooling members and the busbars; and heat dissipation members (181, 182) having greater flexibility than the insulating members and dissipating heat from the busbars to the cooling members, wherein the heat dissipation members comprise a first heat dissipation member (181) in close contact with the busbars and the insulating members, and a second heat dissipation member (182) in close contact with the insulating members and the cooling members.

2. The electrical device according to claim 1, wherein the insulating member has a surface (163, 263) facing the busbar and a back surface (164, 264) facing the cooling member, and a base (162, 262) having a plate thickness in the direction (Z) where the surface and the back surface are aligned, a front flange (166, 167, 266) extending from the surface toward the busbar, and a back flange (168, 169, 268) extending from the back surface toward the cooling member with its tip in contact with the cooling member, the front flange and the back flange extending along the edge of the base, the first heat dissipation member being in close contact with the busbar and the base, and the second heat dissipation member being in close contact with the base and the cooling member.

3. The electrical device according to claim 1, wherein the insulating member has a surface (363) facing the busbar and a back surface (364) facing the cooling member, and has a base (362P, 362N) having a plate thickness in the direction of alignment (Z) where the surface and the back surface are aligned, and the heat dissipation end (181PA, 181NA), which is the end of the first heat dissipation member in the orthogonal direction (X, Y) perpendicular to the alignment direction, is provided outward in the orthogonal direction than the base edge (365P, 365N), which is the edge of the base in the orthogonal direction, and the first heat dissipation member is in close contact with the busbar up to the heat dissipation end.

4. The electrical device according to claim 3, wherein the insulating member has a front flange (367P, 367N) extending along a part of the base edge on its surface, the base edge has an installation portion (365PA, 365NA, 365PC, 365NC, 365PD, 365ND) on which the front flange is installed, and a non-installation portion (365PB, 365NB) on which the front flange is not installed, the busbar has an longitudinal length in one orthogonal direction (Y), the non-installation portion is provided on the edge of the base in that one direction, and the heat dissipation end in that one direction is provided outward in the orthogonal direction from the non-installation portion.

5. The electrical device according to claim 4, wherein the heat dissipation member has overflow portions (183P, 183N) provided outward in the direction perpendicular to the non-installed portion, and the portion of the busbar that overlaps with the overflow portion extends toward the cooling member.

6. The electrical device according to claim 2, wherein the heat dissipation member is a member that is fluid before or after curing.

7. The cooling member comprises a base (21) having a plate thickness in the direction of alignment, and an adjustment section (210, 220) including first protrusions (211, 221) protruding from the base in the direction of alignment, and second protrusions (213, 223) protruding from the first protrusions in the direction of alignment and enclosed within the first protrusions with respect to orthogonal directions (X, Y) perpendicular to the direction of alignment, wherein the insulating member is provided on the adjustment section such that the base overlaps the second protrusions in the direction of alignment, a part of the back flange contacts the first protrusions in the direction of alignment and contacts the second protrusions in the orthogonal directions, and the second heat dissipation member is provided between the rest of the back flange, the adjustment section and the base, as described in claim 6.

8. The electrical device according to claim 7, wherein the first heat dissipation member is provided between the front flange, the busbar, and the base, the front flange has a first front flange (166) and a second front flange (167) that are arranged opposite each other in the orthogonal direction, and a gap is provided between the first front flange and the second front flange from which the first heat dissipation member can leak out.

9. The electrical device according to claim 8, wherein the insulating member includes an arm portion (174) extending from the edge between the first front flange and the second front flange with respect to the orthogonal direction, and an enclosing portion (175) extending to surround the arm portion, and further comprises a housing portion (171, 172) for housing the second heat dissipation member, wherein a part of the second heat dissipation member housed in the housing portion is exposed to the outside.

10. The electrical device according to claim 9, wherein the arm portion extends diagonally toward the base.

11. The electrical device according to claim 10, wherein the busbar is in close contact with the first heat dissipation member, and the busbar presses the first heat dissipation member against the base.

12. The electrical device according to any one of claims 1 to 11, wherein the cooling member provides a ground potential, and the busbar is thermally connected to the cooling member in an electrically insulated state.

13. The electrical device according to any one of claims 8 to 11, wherein the insulating member further has a positioning portion (271) that protrudes from the front flange or the back flange and has a hole (273) that penetrates in the direction of alignment, and the base has a positioning pin (226) that protrudes toward the positioning portion, and the positioning pin is passed through the hole.

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