Capacitor module

Abstract

To provide a capacitor module capable of improving heat dissipation while ensuring insulation.SOLUTION: The capacitor module 23 includes a metal case 30, capacitor elements 40, bus bars 50, a frame body 60, and a sealing body 70. The frame body 60 has a holding part interposed between the metal case 30 and the capacitor element 40 so as to hold the capacitor element 40 to which the bus bar 50 is connected. The sealing body 70 includes a material having higher thermal conductivity than the frame body 60, and seals the capacitor element 40, a part of the bus bar 50, and at least a part of the frame body 60. The holding part has a hole 64 for heat radiation. The capacitor element 40 and the bus bar 50 are thermally connected to the metal case 30 through the sealing body 70 disposed in the hole 64.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The disclosure herein relates to a capacitor module. [Background technology]

[0002] Patent Document 1 discloses a capacitor. The contents of the prior art documents are incorporated by reference as explanations of the technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-41578 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, a capacitor element and a sealing body are disposed in a resin case. This results in a problem of poor heat dissipation compared to configurations using a metal case. When a metal case is used, ensuring insulation between the capacitor element and / or bus bar and the case becomes an issue. In terms of the above and other aspects not mentioned, further improvements are required in capacitor modules.

[0005] One object of the present disclosure is to provide a capacitor module that can improve heat dissipation while ensuring insulation. [Means for solving the problem]

[0006] A capacitor module according to one embodiment of the present disclosure includes: a metal case (30) having a bottom wall (31) and a side wall (32) continuous with the bottom wall; a capacitor element (40) housed in a metal case; a bus bar (50) electrically connected to the capacitor element; a frame (60) including an electrically insulating material, the frame (60) having a holding portion (61) interposed between the metal case and the capacitor element so as to hold the capacitor element with the bus bar connected thereto; a seal (70) that is configured to include a material having higher thermal conductivity than the frame and seals the capacitor element, a portion of the bus bar, and at least a portion of the frame; Equipped with The holding portion has holes (64) for heat dissipation, The capacitor element and the bus bar are thermally connected to the metal case through a seal disposed in the hole.

[0007] According to the disclosed capacitor module, the holding portion of the frame is interposed between the capacitor element and the metal case with the bus bar connected, thereby ensuring insulation between the capacitor element and / or the bus bar and the metal case. Furthermore, holes are provided in the holding portion, and the capacitor element and the bus bar are thermally connected to the metal case through a seal placed in the hole. Because the seal has better thermal conductivity than the frame, heat dissipation can be improved even while the holding portion is interposed between the capacitor element and the metal case. As a result, a capacitor module can be provided that can improve heat dissipation while ensuring insulation.

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

[0009] [Figure 1] FIG. 2 illustrates a power conversion circuit and a drive system. [Figure 2] 1 is a plan view showing a power conversion device including a capacitor module according to a first embodiment. [Figure 3] FIG. 2 is a plan view showing the capacitor module. [Figure 4] FIG. 10 is a plan view showing a configuration in which the bus bars and the sealing body are omitted. [Figure 5] FIG. [Figure 6] FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, several embodiments will be described with reference to the drawings. Note that in each embodiment, corresponding components are designated by the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment previously described may be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

[0011] (First embodiment) The capacitor module of this embodiment is applied to, for example, a mobile body that uses a rotating electric machine as a drive source. Examples of the mobile body include electric vehicles such as battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs), electric flying bodies such as drones and electric vertical take-off and landing aircraft (eVTOLs), ships, construction machinery, and agricultural machinery. BEV is an abbreviation for Battery Electric Vehicle. HEV is an abbreviation for Hybrid Electric Vehicle. eVTOL is an abbreviation for electronic Vertical Take-Off and Landing aircraft. An example of application to a vehicle will be described below.

[0012] <Vehicle drive system> 1 shows an example of a vehicle drive system. The drive system 1 includes a DC power supply 2, a motor generator 3, and a power conversion circuit 4.

[0013] The DC power supply 2 is a DC voltage source composed of a rechargeable secondary battery. The secondary battery may be, for example, a lithium-ion battery or a nickel-metal hydride battery. The motor generator 3 is a three-phase AC rotating electric machine. The motor generator 3 functions as a drive source for the vehicle, that is, an electric motor. The motor generator 3 functions as a generator during regeneration. The power conversion circuit 4 converts power between the DC power supply 2 and the motor generator 3.

[0014] <Power conversion circuit> 1 shows an example of a power conversion circuit 4. The power conversion circuit 4 shown in FIG.

[0015] The smoothing capacitor 5 mainly smoothes the DC voltage supplied from the DC power supply 2. The smoothing capacitor 5 is connected to a P line 7, which is a power supply line on the high potential side, and an N line 8, which is a power supply line on the low potential side. The P line 7 is connected to the positive electrode of the DC power supply 2, and the N line 8 is connected to the negative electrode of the DC power supply 2. The positive electrode of the smoothing capacitor 5 is connected to the P line 7 between the DC power supply 2 and the inverter 6. The negative electrode of the smoothing capacitor 5 is connected to the N line 8 between the DC power supply 2 and the inverter 6. The smoothing capacitor 5 is connected in parallel to the DC power supply 2.

[0016] The inverter 6 is a DC-AC conversion circuit. In accordance with switching control by the control circuit, the inverter 6 converts a DC voltage into a three-phase AC voltage 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 6 converts the three-phase AC voltage generated by the motor generator 3 in response to rotational force from the wheels into a DC voltage in accordance with switching control by the control circuit and outputs it to the P line 7. In this way, the inverter 6 performs bidirectional power conversion between the DC power supply 2 and the motor generator 3.

[0017] The inverter 6 is configured to include upper and lower arm circuits 9 for three phases. The upper and lower arm circuits 9 are sometimes referred to as legs. Each upper and lower arm circuit 9 has an upper arm 9H and a lower arm 9L. The upper arm 9H and the lower arm 9L are connected in series between the P line 7 and the N line 8, with the upper arm 9H on the P line 7 side. Hereinafter, the upper arm 9H and the lower arm 9L may be simply referred to as arms 9H and 9L.

[0018] The connection point between the upper arm 9H and the lower arm 9L, i.e., the midpoint of the upper and lower arm circuits 9, is connected to the corresponding phase winding 3a of the motor generator 3 via an output line 10. Of the upper and lower arm circuits 9, the U-phase upper and lower arm circuit 9U is connected to the U-phase winding 3a via the output line 10. The V-phase upper and lower arm circuit 9V is connected to the V-phase winding 3a via the output line 10. The W-phase upper and lower arm circuit 9W is connected to the W-phase winding 3a via the output line 10.

[0019] The number of switching elements constituting each arm 9H, 9L is not particularly limited. It may be one or more. In the illustrated upper arm 9H, three switching elements are connected in parallel. In the lower arm 9L, three switching elements are connected in parallel. In other words, each of the six arms 9H, 9L of the three-phase upper and lower arm circuit 9 is composed of three switching elements connected in parallel to each other.

[0020] The illustrated switching element is an n-channel MOSFET 11. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. The three MOSFETs 11 on the high side connected in parallel are turned on and off at the same timing by a common gate drive signal (drive voltage). The three MOSFETs 11 on the low side connected in parallel are turned on and off at the same timing by a common gate drive signal (drive voltage).

[0021] A freewheeling diode 12 is connected in anti-parallel to each MOSFET 11. The diode 12 may be a parasitic diode (body diode) or an external diode. In the upper arm 9H, the drain of the MOSFET 11 is connected to the P line 7. In the lower arm 9L, the source of the MOSFET 11 is connected to the N line 8. The source of the MOSFET 11 in the upper arm 9H and the drain of the MOSFET 11 in the lower arm 9L are connected to each other. The anode of the diode 12 is connected to the source of the corresponding MOSFET 11, and the cathode is connected to the drain.

[0022] The switching element is not limited to the MOSFET 11. For example, an IGBT may be used. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. In the case of an IGBT, a freewheeling diode is also connected in anti-parallel.

[0023] The power conversion circuit 4 may include a converter. The converter is a DC-DC conversion circuit configured to be able to convert a DC voltage into a DC voltage of a different value, for example. The converter is provided between the DC power supply 2 and the smoothing capacitor 5. The converter is configured to include, for example, a reactor and the above-mentioned upper and lower arm circuits 9. This configuration allows for voltage step-up and step-down. The power conversion circuit 4 may also include a filter capacitor. The filter capacitor is provided between the DC power supply 2 and the converter.

[0024] The power conversion circuit 4 may include a snubber circuit. The snubber circuit is connected in parallel to the upper and lower arm circuits 9. The snubber circuit reduces the inductance of the upper and lower arm circuits 9. The snubber circuit absorbs a transient high voltage, known as a switching surge, that occurs when switching elements (MOSFETs 11) that constitute the upper and lower arm circuits 9. This enables the inverter 6 to perform high-speed switching.

[0025] The power conversion circuit 4 may include a drive circuit for a switching element constituting the inverter 6 or the like. The drive circuit supplies a drive voltage to the gate of the MOSFET 11 of the corresponding arm based on a drive command from the control circuit. The drive circuit drives the corresponding MOSFET 11, i.e., turns it on and off, by applying the drive voltage. The drive circuit is sometimes referred to as a driver.

[0026] The power conversion circuit 4 may include a control circuit for the switching element. The control circuit generates a drive command for operating the MOSFET 11 and outputs it to the drive circuit. 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.

[0027] The power conversion circuit 4 may include sensors. The sensors may include, for example, a current sensor 13, a rotation angle sensor, and a voltage sensor. The current sensor 13 detects the phase current flowing through the winding 3a of each phase. The rotation angle sensor detects the rotation angle of the rotor of the motor generator 3. The voltage sensor detects the voltage across the smoothing capacitor 5. The control circuit described above outputs a drive command, for example, a PWM signal, based on the signals detected by the sensors. The control circuit may include, for example, a processor and a memory. PWM is an abbreviation for Pulse Width Modulation.

[0028] <Power conversion device> 2 shows an example of a power conversion device including a capacitor module. The power conversion device 20 provides the above-described power conversion circuit 4. The power conversion device 20 includes a cooler 21, a semiconductor module 22, a capacitor module 23, and a current sensor 24. The illustrated power conversion device 20 includes a plurality of semiconductor modules 22. First, the elements of the power conversion device 20 other than the capacitor module 23 will be described.

[0029] In the following, the depth direction of the case of the capacitor module 23 is referred to as the Z direction. The direction perpendicular to the Z direction is referred to as the X direction, and the direction perpendicular to both the X and Z directions is referred to as the Y direction. The X, Y, and Z directions are mutually perpendicular. Unless otherwise specified, the shape viewed from the Z direction, in other words, the shape along the XY plane defined by the X and Y directions, is referred to as the planar shape. The planar view from the Z direction may sometimes be simply referred to as the planar view.

[0030] The cooler 21 cools other elements constituting the power conversion device 20, which are arranged on the cooler 21. The cooler 21 may be, for example, a heat sink. The heat sink may have fins on the back side. The cooler 21 may have a flow path through which a refrigerant flows. The refrigerant may be, for example, a phase-change refrigerant such as water or ammonia, or a phase-non-change refrigerant such as an ethylene glycol-based refrigerant. The refrigerant may be, for example, LLC. LLC is an abbreviation for long life coolant.

[0031] The cooler 21 may be part of a housing that houses the semiconductor module 22, the capacitor module 23, and the current sensor 24, or may be provided separately from the housing. The cooler 21 and the components arranged on the cooler 21 may be thermally connected via a bonding material such as solder, or may be thermally connected via a thermally conductive member. The thermally conductive member may be referred to as TIM, GF, or the like. TIM is an abbreviation for Thermal Interface Material. GF is an abbreviation for Gap Filler.

[0032] The semiconductor modules 22 constitute the upper and lower arm circuits 9, i.e., the inverter 6. The semiconductor modules 22 may also be referred to as power modules, semiconductor devices, etc. The illustrated power conversion device 20 includes three semiconductor modules 22. The multiple semiconductor modules 22 include a semiconductor module 22U that constitutes the upper and lower arm circuits 9U, a semiconductor module 22V that constitutes the upper and lower arm circuits 9V, and a semiconductor module 22W that constitutes the upper and lower arm circuits 9W.

[0033] The semiconductor modules 22 have, for example, a common structure. The illustrated semiconductor module 22 includes a main body 221 and external connection terminals protruding from the main body 221. The main body 221 includes semiconductor elements 222H and 222L, a sealing body 223, and the like.

[0034] The semiconductor elements 222H and 222L are formed by forming switching elements on semiconductor substrates made of materials such as silicon (Si) or wide-bandgap semiconductors with a wider bandgap than silicon. The switching elements have a vertical structure so that the main current flows in the thickness direction of the semiconductor substrate. Wide-bandgap semiconductors include, for example, silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), and diamond.

[0035] The illustrated semiconductor elements 222H, 222L are formed by forming the above-described n-channel MOSFET 11 and diode 12 on a semiconductor substrate made of SiC. The MOSFET 11 has a vertical structure so that a main current flows in the thickness direction of the semiconductor elements 222H, 222L (semiconductor substrate). The semiconductor elements 222H, 222L have main electrodes (not shown) on both sides in the thickness direction. The semiconductor elements 222H, 222L have a source electrode on the front surface and a drain electrode on the back surface as main electrodes. The source electrode is formed on a portion of the front surface. The drain electrode is formed on almost the entire back surface.

[0036] The main current flows between the drain electrode and the source electrode. The semiconductor elements 222H, 222L have a pad (not shown) that is a signal electrode on the surface where the source electrode is formed. The illustrated semiconductor elements 222H, 222L are arranged so that their plate thickness direction is approximately parallel to the Z direction. One semiconductor module 22 includes three semiconductor elements 222H that constitute the upper arm 9H and three semiconductor elements 222L that constitute the lower arm 9L. The three semiconductor elements 222H that constitute one arm are lined up in the X direction. Similarly, the three semiconductor elements 222L are lined up in the X direction. The semiconductor elements 222H and semiconductor elements 222L that constitute one arm are lined up in the Y direction.

[0037] The sealing body 223 seals some of the other elements that make up the semiconductor module 22. The remaining parts of the other elements are exposed to the outside of the sealing body 223. The sealing body 223 seals the semiconductor elements 222H, 222L, and parts of the external connection terminals. Other parts of the external connection terminals protrude outside the sealing body 223. The sealing body 223 is made of, for example, resin. The illustrated sealing body 223 is molded by transfer molding using epoxy resin. The sealing body 223 has a generally rectangular shape when viewed from above. The sealing body 223 forms the outer periphery of the main body 221.

[0038] The sealing body 223 may be formed by potting. The sealing body 223 is filled into the accommodation space formed by the housing (not shown) and the cooler 21, and seals the semiconductor elements 222H, 222L, etc., arranged in the accommodation space.

[0039] The external connection terminals are terminals for electrically connecting the semiconductor module 22 to an external device. The external connection terminals include a P-terminal 224P, an N-terminal 224N, and an O-terminal 224O as main terminals electrically connected to the main electrodes of the semiconductor elements 222H and 222L. The P-terminal 224P is electrically connected to the drain electrode of the semiconductor element 222H. The N-terminal 224N is electrically connected to the source electrode of the semiconductor element 222L. The O-terminal 224O is electrically connected to the connection point (midpoint) between the source electrode of the semiconductor element 222H and the drain electrode of the semiconductor element 222L.

[0040] The P terminal 224P and the N terminal 224N extend from the main body 221 toward the capacitor module 23. The illustrated semiconductor module 22 has one P terminal 224P and two N terminals 224N. The P terminal 224P and the N terminal 224N protrude to the outside from the surface of the main body 221 facing the capacitor module 23. In the X direction, the P terminal 224P is arranged between the N terminals 224N. The O terminal 224O extends from the main body 221 toward the current sensor 24. The O terminal 224O protrudes to the outside from the side surface opposite the surface facing the capacitor module 23. In addition to the terminals described above, the external connection terminals also include signal terminals (not shown).

[0041] In addition to the above-mentioned elements, the semiconductor module 22 also includes wiring members (not shown). The wiring members provide a wiring function that electrically connects the main electrodes and main terminals of the semiconductor elements 222H, 222L. The wiring members provide a heat dissipation function that dissipates heat from the semiconductor elements 222H, 222L. The wiring members may be, for example, a substrate with metal bodies arranged on both sides of an insulating base material, or may be a heat sink that is a metal member. The heat sink may be provided as part of the lead frame. The entire wiring member may be sealed with the sealing body 223, or a portion may be exposed from the main body portion 221. Exposing the wiring member can improve heat dissipation.

[0042] The semiconductor module 22 is disposed on the cooler 21. As described above, the main body 221 of the semiconductor module 22 may be fixed to the cooler 21 via a bonding material, or may be thermally connected to the cooler 21 via a heat conductive member. As shown in FIG. 2, the three semiconductor modules 22 are lined up in the X direction. The three semiconductor modules 22 are lined up in the order of semiconductor module 22U, semiconductor module 22V, and semiconductor module 22W. In addition, the side surfaces of adjacent semiconductor modules 22 face each other in the X direction with a predetermined gap therebetween.

[0043] The current sensor 24 provides the current sensor 13 described above. The current sensor 24 is configured to detect phase currents individually. The current sensor 24 may be a magnetic detection type sensor equipped with a magnetoelectric conversion element, or a resistance detection type sensor equipped with a shunt resistor. The illustrated current sensor 24 is a magnetic detection type. The current sensor 24 includes a bus bar 241 provided corresponding to each phase, and a main body 242. The bus bar 241 has its thickness in the Z direction and extends in the Y direction.

[0044] The illustrated main body 242 has a Hall element 243, which is a magnetoelectric conversion element, and a resin member, core, and substrate (not shown). For convenience, FIG. 2 shows the outer shell of the resin member as the main body 242. The main body 242 has three Hall elements 243 and three cores corresponding to the bus bars 241. The Hall elements 243 are disposed in the gaps of the corresponding cores when mounted on the substrate. The cores and bus bars 241 are held by the resin member. The bus bars 241 pass through the annular regions of the corresponding cores. The substrate is fixed to the resin member.

[0045] In the illustrated power conversion device 20, the semiconductor module 22, the capacitor module 23, and the current sensor 24 are aligned in the Y direction. The semiconductor module 22 is disposed between the capacitor module 23 and the current sensor 24 in the Y direction.

[0046] <Capacitor module> Fig. 3 is a plan view showing an example of a capacitor module. Fig. 4 is a plan view showing a configuration in which bus bars and a sealing body are omitted from Fig. 3. Fig. 5 is a perspective view showing an example of a frame body. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 3. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 3. Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 3.

[0047] The capacitor module 23 provides the above-mentioned smoothing capacitor 5. The capacitor module 23 includes a metal case 30, a capacitor element 40, a bus bar 50, a frame 60, and a sealing body 70.

[0048] The metal case 30 is formed using a metal material such as aluminum. The metal case 30 has a cylindrical shape with a bottom. The metal case 30 has a bottom wall 31 and side walls 32. The metal case 30 is disposed on the cooler 21 so that the outer surface of the bottom wall 31 faces the cooler 21 in the Z direction. The illustrated bottom wall 31 has a generally rectangular planar shape with the X direction as its longitudinal direction, and the side wall 32 has a generally rectangular ring shape in plan. The side wall 32 includes four side walls 321, 322, 323, and 324. The side wall 321 is the side wall 32 on the semiconductor module 22 side in the Y direction. The side wall 322 is the side wall 32 opposite the side wall 321 in the Y direction. The side wall 324 is the side wall 32 opposite the side wall 323 in the X direction. The side wall 32 has an upper end 33. The upper end 33 is the end opposite to the end continuing to the bottom wall 31. The metal case 30 may be configured as a part of the cooler 21 described above. In other words, the cooler 21 may also serve as the metal case 30.

[0049] The capacitor element 40 is, for example, a film capacitor element. The capacitor element 40 is formed by winding a film around an axis that is approximately parallel to the Z direction. The capacitor element 40 has a substantially rectangular shape in plan view. The capacitor element 40 has electrodes 41 on one surface and on the opposite surface. The electrodes 41 are sometimes referred to as metallikon electrodes. One of the electrodes 41 is a P-electrode 41P, and the other is an N-electrode 41N.

[0050] The one surface and the back surface, which are electrode formation surfaces, may be surfaces in the Z direction or surfaces in a direction perpendicular to the Z direction. In the exemplary capacitor element 40, the one surface and the back surface are surfaces in the Z direction. In other words, the back surface is the surface opposite the one surface in the Z direction. The back surface is the lower surface facing the bottom wall 31 in the Z direction, and the one surface is the upper surface. Capacitor element 40 has a negative N-electrode 41N on one surface and a positive P-electrode 41P on the back surface.

[0051] The capacitor module 23 may include only one capacitor element 40, or may include multiple capacitor elements 40. In a configuration including multiple capacitor elements 40, the capacitor elements 40 are aligned in at least one direction perpendicular to the Z direction. The illustrated capacitor module 23 includes four capacitor elements 40. The capacitor elements 40 are aligned in the X direction.

[0052] The busbars 50 include a P busbar 50P connected to the P electrode 41P and an N busbar 50N connected to the N electrode 41N. The P busbar 50P and the N busbar 50N each have an electrode connection portion 51, a terminal portion 52, and a linking portion 53. The electrode connection portion 51 is a connection portion of the busbar 50 with the corresponding electrode 41. The terminal portion 52 is a portion of the busbar 50 that protrudes outside the sealing body 70. The terminal portion 52 is a portion for connecting to other devices such as the semiconductor module 22. The terminal portion 52 of the busbar 50P is connected to the P terminal 224P of the semiconductor module 22 as shown in FIG. 2. Similarly, the terminal portion 52 of the N busbar 50N is connected to the N terminal 224N. The linking portion 53 is a portion of the busbar 50 that connects the electrode connection portion 51 and the terminal portion 52.

[0053] The electrode connection portions 51 and the connecting portions 53 are covered by the sealing body 70. The electrode connection portions 51 and the connecting portions 53 are disposed within the sealing body 70. The terminal portions 52 are disposed outside the sealing body 70. The illustrated P bus bar 50P and N bus bar 50N are drawn from the corresponding electrodes 41 toward the side wall 321. The P bus bar 50P and the N bus bar 50N protrude from the sealing body 70 near the side wall 321. The plate thickness direction of the electrode connection portions 51 is approximately parallel to the Z direction. The connecting portions 53 are continuous with the electrode connection portions 51 and include a portion extending in the Y direction and a portion extending in the Z direction. The connecting portions 53 are approximately L-shaped in the YZ plane. The terminal portions 52 extend from the connecting portions 53 toward the semiconductor module 22. The P bus bar 50P and the N bus bar 50N are disposed side by side so that their plate surfaces face each other over most of the entire length of the terminal portions 52. An insulating member may be disposed between the terminal portions 52 of the P bus bar 50P and the N bus bar 50N.

[0054] The frame body 60 is formed using an electrically insulating material such as resin. The illustrated frame body 60 is a resin molded body. The frame body 60 has a holding portion 61 and an extension portion 62. At least a portion of the holding portion 61 is disposed within the sealing body 70. The holding portion 61 is interposed between the metal case 30 and the capacitor element 40 so as to hold the capacitor element 40 in a predetermined position with the bus bar 50 connected to the metal case 30.

[0055] The illustrated holding portion 61 has frames 63 and holes 64 formed between the frames 63. In this manner, the holding portion 61 has the holes 64. A sealant 70 is disposed (filled) in the holes 64.

[0056] The frame 63 includes a first frame 631, a second frame 632, and an annular frame 633. The holding portion 61 is composed of multiple frames. The first frame 631 extends in the Y direction in a plan view. The first frame 631 extends from the side wall 321 toward the side wall 322. The second frame 632 extends in the X direction in a plan view. The second frame 632 extends from the side wall 323 toward the side wall 324. The illustrated frame 63 includes four first frames 631 and two second frames 632. The four first frames 631 are aligned in the X direction at a predetermined interval. The first frames 631 are arranged so as to individually overlap the four capacitor elements 40 in a plan view. The two second frames 632 are aligned in the Y direction at a predetermined interval.

[0057] The first frame 631 and the second frame 632 each have a bottom wall side frame portion 634 and a side wall side frame portion 635. The bottom wall side frame portion 634 is a portion disposed to face the bottom wall 31 of the metal case 30. The side wall side frame portion 635 is a portion connected to the bottom wall side frame portion 634 and disposed to face the side wall 32. In the illustrated frame 63, the bottom wall side frame portion 634 is disposed between each of the capacitor elements 40 and the bottom wall 31. The side wall side frame portion 635 is disposed between each of the capacitor elements 40 and the side wall 32. When the bus bar 50 is connected to the capacitor element 40, the capacitor element 40 is in contact with at least the bottom wall side frame portion 634. When the bus bar 50 is connected to the capacitor element 40, the capacitor element 40 may be in contact with a portion of the side wall side frame portion 635.

[0058] The first frame 631 has a bottom wall side frame portion 634 extending in the Y direction and a side wall side frame portion 635 that is connected to an end of the bottom wall side frame portion 634 and extends in the Z direction. The first frame 631 has side wall side frame portions 635 on both ends. The second frame 632 has a bottom wall side frame portion 634 that extends in the X direction and a side wall side frame portion 635 that is connected to an end of the bottom wall side frame portion 634 and extends in the Z direction. The second frame 632 has side wall side frame portions 635 on both ends.

[0059] In the illustrated frame 63, the first frame 631 and the second frame 632 are connected to each other. The bottom wall side frame portion 634 of the first frame 631 and the bottom wall side frame portion 634 of the second frame 632 are connected to each other. The holding portion 61 has eight connecting portions where the first frame 631 and the second frame 632 intersect and are connected.

[0060] The annular frame 633 has an annular shape in a plan view. All of the first frames 631 and second frames 632 are connected to the annular frame 633. The side wall side frame portions 635 of the first frames 631 and second frames 632 are connected to the annular frame 633. The shape of the frame 63 is maintained by the annular frame 633. The annular frame 633 has the side wall side frame portions 635.

[0061] Due to the structure of the holding portion 61 described above, a frame 63 is interposed between the opposing surfaces of all of the capacitor elements 40 and the metal case 30. In addition, holes 64 are located between the opposing surfaces of all of the capacitor elements 40 and the metal case 30. A frame 63 (bottom wall-side frame portion 634) is interposed between the opposing surfaces of all of the capacitor elements 40 and the bottom wall 31. A hole 64 is located between the opposing surfaces of all of the capacitor elements 40 and the bottom wall 31. A frame 63 (side wall-side frame portion 635) is interposed between the opposing surfaces of all of the capacitor elements 40 and the side wall 32. A hole 64 is located between the opposing surfaces of all of the capacitor elements 40 and the side wall 32.

[0062] The extension portion 62 is continuous with the holding portion 61. The extension portion 62 extends from the holding portion 61 and is disposed outside the sealing body 70. The extension portion 62 is disposed between the terminal portion 52 of the bus bar 50 and the upper end 33 of the side wall 32 of the metal case 30.

[0063] The illustrated extension portion 62 is continuous with the annular frame 633. The extension portion 62 is arranged to cross the overlapping region between the upper end 33 of the side wall 321 on the semiconductor module 22 side and the terminal portion 52 in a plan view. The extension portion 62 is arranged to encompass the entire overlapping region between the upper end 33 and the terminal portion 52 in a plan view. The extension portion 62 includes a portion that overlaps with the bottom wall 31 in a plan view, a portion that overlaps with the upper end 33, and a portion that extends to the outside of the metal case 30, i.e., a portion that does not overlap with the metal case 30.

[0064] The extension portion 62 extends in the X direction. In a plan view, the extension portion 62 extends so as to overlap the upper ends 33 of the side walls 323 and 324. The extension portion 62 includes a portion that overlaps the terminal portion 52 and portions that are provided on both sides of the portion that overlaps the terminal portion 52 and do not overlap the terminal portion 52. The illustrated extension portion 62 has a generally rectangular shape with the X direction as the longitudinal direction in a plan view. The extension portion 62 is arranged so that one longitudinal end portion overlaps the upper end 33 of the side wall 323 and the other longitudinal end portion overlaps the upper end 33 of the side wall 324. As shown in FIG. 2, the extension portion 62 extends in the X direction to a position where it overlaps with the cooler 21.

[0065] The sealing body 70 is formed using a resin material having electrical insulation properties. The sealing body 70 is configured to include a material having better thermal conductivity than the frame body 60. The material constituting the sealing body 70 may be the same resin material as the resin material constituting the frame body 60 to which a filler having excellent thermal conductivity has been added, or may be a resin material different from that of the frame body 60. The sealing body 70 is filled into the metal case 30. The sealing body 70 is formed, for example, by potting. The sealing body 70 seals the capacitor element 40, a portion of the bus bar 50, and at least a portion of the frame body 60.

[0066] The sealing body 70 is placed (filled) in the hole 64 formed in the holding portion 61. The sealing body 70 is filled in all of the holes 64. The capacitor element 40 and the bus bar 50 are thermally connected to the metal case 30 via the sealing body 70 placed in the hole 64.

[0067] <Summary of the First Embodiment> The capacitor module 23 of this embodiment includes a metal case 30, a capacitor element 40, a bus bar 50, a frame 60, and a sealing body 70. The metal case 30 has a bottom wall 31 and side walls 32 connected to the bottom wall. The capacitor element 40 is housed in the metal case 30. The bus bar 50 is electrically connected to the capacitor element 40. The frame 60 contains an electrically insulating material. The frame 60 has a holding portion 61 interposed between the metal case 30 and the capacitor element 40 to hold the capacitor element 40 with the bus bar 50 connected thereto. The sealing body 70 contains a material with better thermal conductivity than the frame 60 and seals the capacitor element 40, a portion of the bus bar 50, and at least a portion of the frame 60. The holding portion 61 has holes 64 for heat dissipation, and the capacitor element 40 and the bus bar 50 are thermally connected to the metal case 30 through the sealing body 70 disposed in the holes 64.

[0068] Because the holding portion 61 of the frame body 60 is interposed between the capacitor element 40 and the metal case 30 in a state where the bus bar 50 is connected, insulation between the capacitor element 40 and / or the bus bar 50 and the metal case 30 can be ensured. Furthermore, holes 64 are formed in the holding portion 61, and the capacitor element 40 and the bus bar 50 are thermally connected to the metal case 30 through the sealing body 70 placed in the holes 64. Because the sealing body 70 has better thermal conductivity than the frame body 60, heat dissipation can be improved even while the holding portion 61 is interposed between the capacitor element 40 and the metal case 30. As described above, heat dissipation can be improved while ensuring insulation.

[0069] The holding portion 61 may have any structure as long as it has holes 64 and can hold the capacitor element 40, to which the bus bar 50 is connected, in a predetermined position relative to the metal case 30. As illustrated, the holding portion 61 may have a frame 63 and holes 64 formed between the frame 63. By using the frame 63, the holding portion 61 having holes 64, particularly the holding portion 61 having a plurality of holes 64, can be realized with a simple configuration.

[0070] Capacitor module 23 may include only one capacitor element 40. As illustrated, it may also include multiple capacitor elements 40. By using frame 60 and sealing body 70 described above, even in a configuration including multiple capacitor elements 40, it is possible to improve heat dissipation while ensuring insulation.

[0071] As illustrated, the frame 63 may include a bottom wall-side frame portion 634 disposed between each of the capacitor elements 40 and the bottom wall 31 of the metal case 30. Because the bottom wall-side frame portion 634 is disposed between all of the capacitor elements 40 and the bottom wall 31, it is possible to improve heat dissipation to the bottom wall 31 side while ensuring insulation between all of the capacitor elements 40 and the bottom wall 31.

[0072] As illustrated, the frame 63 may include a sidewall-side frame portion 635 arranged between each of the capacitor elements 40 and the sidewall 32 of the metal case 30. Since the bottom wall-side frame portion 634 is arranged between all of the capacitor elements 40 and the sidewall 32, it is possible to improve heat dissipation to the sidewall 32 while ensuring insulation between all of the capacitor elements 40 and the sidewall 32.

[0073] As illustrated, the frame 60 may be configured to have an extension 62, and the extension 62 may be disposed between the terminal 52 of the bus bar 50 and the upper end 33 of the side wall 32 of the metal case 30. The frame 60 can ensure insulation not only in the portion covered by the sealing body 70 but also between the terminal 52 of the bus bar 50 and the metal case 30.

[0074] As illustrated, the extension portion 62 may be provided so as to cross the overlapping region between the terminal portion 52 and the upper end 33 of the side wall 32 in a plan view. This increases the spatial insulation distance between the terminal portion 52 and the side wall 32, and also increases the creepage distance along the surface of the extension portion 62 between the metal case 30 and the terminal portion 52. This improves the insulation between the terminal portion 52 of the bus bar 50 and the metal case 30.

[0075] As illustrated, the sidewall 32 may have a rectangular ring shape in plan view and include a first sidewall overlapping the terminal portion 52 in plan view, a second sidewall facing the first sidewall, and a third and fourth sidewall connected to the first sidewall. The extension portion 62 may then extend to overlap the third sidewall in plan view. In the illustrated capacitor module 23, the sidewall 321 corresponds to the first sidewall, and the sidewall 322 corresponds to the second sidewall. The sidewall 323 corresponds to the third sidewall, and the sidewall 324 corresponds to the fourth sidewall.

[0076] This increases the spatial insulation distance between terminal portion 52 and the third and fourth side walls, and also increases the creepage distance along the surface of extension portion 62 between terminal portion 52 and the third and fourth side walls. This improves the insulation not only between the first side wall but also between terminal portion 52 of bus bar 50 and the third and fourth side walls connected to the first side wall.

[0077] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and / or elements from the embodiments. The disclosure encompasses the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0078] The disclosure in the specification, drawings, etc. is not limited by the claims. The disclosure in the specification, drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being bound by the claims.

[0079] When an element or layer is referred to as being "on," "coupled," "connected," or "bonded," it may be directly on, coupled, connected, or bonded to another element or layer, and intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly coupled," "directly connected," or "directly bonded" to another element or layer, no intervening elements or layers are present. Other terms used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items. That is, reference to A and / or B means at least one of A and B.

[0080] Spatially relative terms such as "inside," "outside," "back," "below," "low," "top," "top," and the like are used herein to facilitate the description of one element or feature's relationship to other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures were turned over, elements described as "below" or "directly below" other elements or features would then be oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of top and bottom. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used in this specification would be interpreted accordingly.

[0081] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be written in a multiple dependent form, with the subsequent clause referring to the preceding clause as an alternative. Furthermore, some clauses may be written in a multiple dependent form, referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0082] <Technical philosophy 1> a metal case (30) having a bottom wall (31) and a side wall (32) continuous with the bottom wall; a capacitor element (40) housed in the metal case; a bus bar (50) electrically connected to the capacitor element; a frame (60) including an electrically insulating material, the frame having a holding portion (61) interposed between the metal case and the capacitor element so as to hold the capacitor element with the bus bar connected thereto; a seal (70) that is configured to include a material having higher thermal conductivity than the frame, and seals the capacitor element, a portion of the bus bar, and at least a portion of the frame; Equipped with The holding portion has holes (64) for heat dissipation, The capacitor element and the bus bar are thermally connected to the metal case through the sealing body disposed in the hole.

[0083] <Technical philosophy 2> The capacitor module according to Technical Idea 1, wherein the holding portion has a frame (63) and the hole formed between the frames.

[0084] <Technical philosophy 3> The capacitor module according to Technical Idea 2 includes a plurality of the capacitor elements.

[0085] <Technical philosophy 4> The capacitor module according to Technical Concept 3, wherein the frame includes a bottom wall side frame portion (634) disposed between each of the capacitor elements and the bottom wall.

[0086] <Technical philosophy 5> The capacitor module according to Technical Concept 3 or Technical Idea 4, wherein the frame includes a sidewall-side frame portion (635) arranged between each of the capacitor elements and the sidewall.

[0087] <Technical philosophy 6> The bus bar has a terminal portion (52) that protrudes outside the sealing body, The frame has an extension portion (62) extending from the holding portion and disposed outside the sealing body, The capacitor module according to any one of Technical Concepts 1 to 4, wherein the extension portion is disposed between the terminal portion and an upper end (33) of the side wall.

[0088] <Technical philosophy 7> The capacitor module according to Technical Idea 6, wherein the extension portion is provided so as to cross an overlapping region between the terminal portion and the upper end of the side wall in a plan view in the depth direction of the metal case.

[0089] <Technical philosophy 8> In the plan view, the side wall has a rectangular ring shape, The side walls include a first side wall (321) that overlaps with the terminal portion in the plan view, a second side wall (322) that faces the first side wall, and a third side wall (323) and a fourth side wall (324) that are continuous with the first side wall, The capacitor module according to Technical Idea 7, wherein the extension portion extends so as to overlap the third side wall and the third side wall in the plan view. [Explanation of symbols]

[0090] 1... drive system, 2... DC power supply, 3... motor generator, 3a... winding, 4... power conversion circuit, 5... smoothing capacitor, 6... inverter, 7... P line, 8... N line, 9, 9U, 9V, 9W... upper and lower arm circuits, 9H... upper arm, 9L... lower arm, 10... output line, 11... MOSFET, 12... diode, 13... current sensor, 20... power conversion device, 21... cooler, 22, 22U, 22V, 22W... semiconductor module, 221... main body, 222H, 222L... semiconductor element, 223... sealing body, 224N... N terminal, 224O... O terminal, 224P... P terminal, 23... capacitor module 24...current sensor, 241...bus bar, 242...main body, 243...hall element, 30...metal case, 31...bottom wall, 32, 321, 322, 323, 324...side wall, 33...upper end, 40...capacitor element, 41...electrode, 41N...N electrode, 41P...P electrode, 50...bus bar, 50N...N bus bar, 50P...P bus bar, 51...electrode connection portion, 52...terminal portion, 53...connection portion, 60...frame body, 61...holding portion, 62...extension portion, 63...frame, 631...first frame, 632...second frame, 633...annular frame, 634...bottom wall side frame portion, 635...side wall side frame portion, 64...hole, 70...sealing body

Claims

1. a metal case (30) having a bottom wall (31) and a side wall (32) continuous with the bottom wall; a capacitor element (40) housed in the metal case; a bus bar (50) electrically connected to the capacitor element; a frame (60) including an electrically insulating material, the frame having a holding portion (61) interposed between the metal case and the capacitor element so as to hold the capacitor element with the bus bar connected thereto; a sealing body (70) that is configured to include a material having higher thermal conductivity than the frame body and that seals the capacitor element, a portion of the bus bar, and at least a portion of the frame body; Equipped with The holding portion has holes (64) for heat dissipation, The capacitor element and the bus bar are thermally connected to the metal case through the sealing body disposed in the hole.

2. The capacitor module according to claim 1 , wherein the holding portion has a frame (63) and the hole formed between the frame.

3. The capacitor module according to claim 2 , comprising a plurality of the capacitor elements.

4. The capacitor module according to claim 3 , wherein the frame includes a bottom wall-side frame portion (634) disposed between each of the capacitor elements and the bottom wall.

5. The capacitor module of claim 3 , wherein the frame includes a sidewall frame portion (635) disposed between each of the capacitor elements and the sidewall.

6. The bus bar has a terminal portion (52) protruding outside the sealing body, The frame has an extension portion (62) extending from the holding portion and disposed outside the sealing body, The capacitor module according to any one of claims 1 to 4, wherein the extension portion is disposed between the terminal portion and an upper end (33) of the side wall.

7. 7. The capacitor module according to claim 6, wherein the extension portion is provided across an overlapping region between the terminal portion and an upper end of the side wall in a plan view in the depth direction of the metal case.

8. In the plan view, the side wall has a rectangular ring shape, The side walls include a first side wall (321) overlapping with the terminal portion in the plan view, a second side wall (322) facing the first side wall, and a third side wall (323) and a fourth side wall (324) continuing to the first side wall, The capacitor module according to claim 7 , wherein the extension portion extends so as to overlap the third side wall in the plan view.

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