Power conversion device

Abstract

A power conversion device (20) comprises a support member (30), a semiconductor module (40), a capacitor module (50), and a current sensor (60). The semiconductor module (40), the capacitor module (50), and the current sensor (60) are disposed on one surface of the support member (30). The semiconductor module (40) includes a semiconductor element (41) and a sealing body (42) that seals the semiconductor element (41). A bus bar (51) of the capacitor module (50) and a bus bar (61) of the current sensor (60) are electrically connected to the semiconductor element (41) inside of the sealing body (42).

Description

Power Conversion Device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-106305 filed in Japan on July 1, 2024, and the contents of the original application are incorporated by reference in their entirety.

[0002] The disclosure herein relates to power conversion devices.

[0003] Patent Document 1 discloses a power conversion device. The contents of the prior art document are incorporated by reference as explanations of technical elements in this specification.

[0004] Japanese Patent Application Laid-Open No. 2018-186686

[0005] In Patent Document 1, in an IGBT module, positive and negative terminals protruding from the resin package of the main body are connected to corresponding positive and negative output terminals of a smoothing capacitor. The output terminals of the IGBT module protruding from the resin package are connected to bus bars of a current detector. Because the terminals are connected outside the resin package, it is necessary to ensure sufficient insulation distances, such as spatial insulation distance and creepage distance. Further improvements are needed in power conversion devices in the above-mentioned respects and in other respects not mentioned.

[0006] An object of the present disclosure is to provide a power conversion device that can reduce inductance while suppressing an increase in size.

[0007] One embodiment of the disclosed power conversion device comprises: a support member having one surface; a semiconductor module having a semiconductor element and a sealing body that seals the semiconductor element, the semiconductor module being arranged on the one surface; and an electrical component having a plurality of bus bars and being arranged on the one surface, the plurality of bus bars being electrically connected to the semiconductor element inside the sealing body.

[0008] According to the disclosed power conversion device, bus bars of electrical components are electrically connected to semiconductor elements inside the sealing body of the semiconductor module. The semiconductor module does not have terminals that protrude outside the sealing body as connections for the bus bars, so there is no need to ensure an insulation distance between the protruding terminals. To ensure an insulation distance, there is no need to arrange the protruding terminals far apart. As a result, a power conversion device can be provided that can reduce inductance while suppressing an increase in size.

[0009] 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.

[0010] It is a diagram showing a power conversion circuit and a drive system. It is a plan view showing the power conversion device according to the first embodiment. It is a plan view showing a configuration in which a sealing body is omitted. It is a cross-sectional view taken along the line IV-IV in FIG. 2. It is a plan view showing a modified example.

[0011] 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.

[0012] (First Embodiment) A capacitor module of this embodiment is applied to, for example, a mobile body using a rotating electric machine as a drive source. The mobile body is, for example, an electric vehicle such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), an electric flying object such as a drone or an electric vertical take-off and landing aircraft (eVTOL), a ship, construction machinery, or 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.

[0013] 1 shows an example of a vehicle drive system 1. The drive system 1 includes a DC power supply 2, a motor generator 3, and a power conversion circuit 4.

[0014] The DC power supply 2 is a DC voltage source formed by a rechargeable secondary battery. The secondary battery is, 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, i.e., 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.

[0015] 1 shows an example of a power conversion circuit 4. The power conversion circuit 4 shown in FIG.

[0016] 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.

[0017] 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 source 2 and the motor generator 3.

[0018] The inverter 6 is configured with 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.

[0019] 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.

[0020] 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.

[0021] 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).

[0022] A freewheeling diode 12 is connected in antiparallel 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.

[0023] 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.

[0024] The power conversion circuit 4 may include a converter. The converter is a DC-DC conversion circuit configured to be able to convert DC voltage. 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.

[0025] 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.

[0026] The power conversion circuit 4 may include a drive circuit for the switching elements that constitute the inverter 6 and 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.

[0027] 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 host ECU (not shown) and signals detected by various sensors. ECU is an abbreviation for Electronic Control Unit.

[0028] 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.

[0029] <Power Converter> Fig. 2 is a plan view showing an example of a power converter. Fig. 3 is a plan view showing a configuration in which the sealing body is omitted from Fig. 2. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 2. In Fig. 4, the capacitor elements are hatched with dots for convenience in order to distinguish them from other members.

[0030] In the following, the mounting direction of the semiconductor module and capacitor module on the support member 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 orthogonal. 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.

[0031] 2 to 4 provides the above-described power conversion circuit 4. The power conversion device 20 includes a support member 30, a semiconductor module 40, a capacitor module 50, and a current sensor 60.

[0032] The support member 30 has one surface that is a mounting surface for other elements that constitute the power conversion device 20. The support member 30 may be at least a part of a housing that houses the other elements that constitute the power conversion device 20, or may be provided separately from the housing. The support member 30 may be formed using a metal material such as aluminum, or may be formed using a resin material. It may also be configured to include a metal material and a resin material. The support member 30 may be configured by a single member, or by assembling multiple members.

[0033] The support member 30 may have a function of cooling other elements that constitute the power conversion device 20 and that are arranged on the support member 30. A support member 30 that has a cooling function is sometimes called a cooler. The cooler may be, for example, a heat sink. The heat sink may have fins on the back side. The cooler 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 non-phase-change refrigerant such as an ethylene glycol-based refrigerant. The refrigerant may be, for example, LLC. LLC is an abbreviation for long life coolant.

[0034] The support member 30 and the elements (components) disposed on the support member may be thermally connected via a bonding material such as solder, or via a thermally conductive member. Thermally conductive members are sometimes referred to as TIM, GF, etc. TIM is an abbreviation for Thermal Interface Material. GF is an abbreviation for Gap Filler. The illustrated support member 30 is formed using a metal material. The support member 30 has recesses 32 and 33. A semiconductor module 40 is disposed in the recess 32. A capacitor module 50 is disposed in the recess 33. The recess 32 is recessed relative to the surrounding area of ​​the recess 32 on one surface of the support member 30. The recess 33 is recessed relative to the surrounding area of ​​the recess 32 on one surface of the support member 30. In the Z direction, the recess 33 is deeper than the recess 32.

[0035] The support member 30 has a flow path 34. The illustrated flow path 34 is provided so as to be continuous with the recess 32. The flow path 34 opens to the bottom surface of the recess 32. A refrigerant inlet pipe and a refrigerant outlet pipe (not shown) are connected to the flow path 34. A refrigerant 35 flows through the flow path 34. The flow path 34 is provided so as to overlap with at least a portion of the semiconductor module 40 in a plan view. The flow path 34 is provided so as to include, for example, a semiconductor element 41 provided in the semiconductor module 40 in a plan view.

[0036] The semiconductor modules 40 constitute the upper and lower arm circuits 9, i.e., the inverter 6. The semiconductor modules 40 may also be referred to as power modules, semiconductor devices, etc. The illustrated power conversion device 20 includes three semiconductor modules 40. The multiple semiconductor modules 40 include a semiconductor module 40U that constitutes the upper and lower arm circuits 9U, a semiconductor module 40V that constitutes the upper and lower arm circuits 9V, and a semiconductor module 40W that constitutes the upper and lower arm circuits 9W.

[0037] The semiconductor modules 40 have, for example, substantially the same structure as one another. The illustrated semiconductor module 40 includes a semiconductor element 41, a sealing body 42, a substrate 43, a housing 44, wiring members 45 and 46, and a metal member 47.

[0038] The semiconductor element 41 is formed by forming a switching element on a semiconductor substrate made of silicon (Si) or a wide bandgap semiconductor with a wider bandgap than silicon. The switching element has a vertical structure so that the main current flows in the thickness direction of the semiconductor substrate. Examples of wide bandgap semiconductors include silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), and diamond.

[0039] The illustrated semiconductor element 41 is 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 element 41 (semiconductor substrate). The semiconductor element 41 has main electrodes (not shown) on both sides of the semiconductor element 41 in the thickness direction. The semiconductor element 41 has 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.

[0040] The main current flows between the drain electrode and the source electrode. The semiconductor element 41 has a pad (not shown) that is a signal electrode on the surface where the source electrode is formed. The semiconductor elements 41 are arranged so that their thickness direction is approximately parallel to the Z direction. One semiconductor module 40 includes, as semiconductor elements 41, three semiconductor elements 41H that constitute the upper arm 9H and three semiconductor elements 41L that constitute the lower arm 9L. The three semiconductor elements 41H that constitute one arm are lined up in the X direction. Similarly, the three semiconductor elements 41L are lined up in the X direction. The semiconductor elements 41H and semiconductor elements 41L that constitute one arm are lined up in the Y direction.

[0041] The sealing body 42 seals a portion of the other elements constituting the semiconductor module 40. The remaining portions of the other elements are exposed outside the sealing body 42. The sealing body 42 is formed in a state in which the bus bar 51 of the capacitor module 50 and the bus bar 61 of the current sensor 60 are connected to the conductor pattern 432 of the substrate 43. The sealing body 42 is formed using an electrically insulating resin material such as epoxy resin. The illustrated sealing body 42 is formed by resin potting. The sealing body 42 is filled into the frame of the housing 44 and seals at least a portion of the semiconductor element 41, the substrate 43, etc.

[0042] The substrate 43 has at least an insulating base material 431 and a conductor pattern 432. The insulating base material 431 is formed using an electrically insulating material such as resin or ceramic. The conductor pattern 432 is wiring arranged on the insulating base material 431. The conductor pattern 432 includes wiring formed by patterning a surface metal body arranged on the surface of the insulating base material 431. The front surface of the insulating base material 431 is the surface facing the semiconductor element 41, and the back surface is the surface facing the support member 30.

[0043] The substrate 43 includes a P wiring 432P, an N wiring 432N, and an output wiring 432A as a conductor pattern 432 arranged on the surface of an insulating base material 431. The P wiring 432P is electrically connected to the drain electrode of the semiconductor element 41H and the P bus bar 51P of the capacitor module 50. The N wiring 432N is electrically connected to the source electrode of the semiconductor element 41L and the N bus bar 51N of the capacitor module 50. The output wiring 432A is electrically connected to the source electrode of the semiconductor element 41H, the drain electrode of the semiconductor element 41L, and the bus bar 61 of the current sensor 60.

[0044] The illustrated P wiring 432P has a generally convex shape in plan view. The P wiring 432P has a base portion extending in the X direction and an extension portion that is connected to the base portion and extends from the center of the base portion in the Y direction toward the capacitor module 50. Three semiconductor elements 41H are arranged along the extension direction of the base portion. The drain electrodes of the semiconductor elements 41H are joined to the base portion of the P wiring 432P. A P bus bar 51P is joined near the tip of the extension portion of the P wiring 432P.

[0045] The output wiring 432A has a generally rectangular shape in plan view with the longitudinal direction in the X direction. The output wiring 432A is disposed closer to the current sensor 60 than the P wiring 432P and the N wiring 432N in the Y direction. The output wiring 432A is aligned with the base of the N wiring 432N in the Y direction. The output wiring 432A is disposed at the end of the substrate 43 on the current sensor 60 side. Three semiconductor elements 41L are disposed along the longitudinal direction of the output wiring 432A. The drain electrodes of the semiconductor elements 41L are bonded to the output wiring 432A. A bus bar 61 is bonded to the output wiring 432A at a position closer to the current sensor 60 than the mounting position of the semiconductor elements 41L. The bus bar 61 is bonded to the output wiring 432A near the end of the output wiring 432A on the current sensor 60 side.

[0046] A wiring member 45 is joined to the output wiring 432A. The wiring member 45 electrically connects the semiconductor element 41 and the conductor pattern 432. The wiring member 45 is, for example, a metal plate such as a clip, a bonding wire, or the like. An example of the wiring member 45 is a clip. One end of the wiring member 45 is joined to the output wiring 432A, and the other end is joined to the source electrode of the semiconductor element 41H. The wiring member 45 extends in the Y direction in a plan view. The three wiring members 45 are aligned in the X direction. The wiring member 45 is located above the base of the N wiring 432N and is arranged to straddle the base. The wiring member 45 is joined to the output wiring 432A at a position closer to the capacitor module 50 than the mounting position of the semiconductor element 41L. The output wiring 432A is sometimes referred to as a relay wiring, etc.

[0047] The N wiring 432N has a generally U-shape in plan view. The N wiring 432N has a base extending in the X direction and a pair of extensions connected to the base and extending in the Y direction from both ends of the base toward the capacitor module 50. The base of the N wiring 432N is disposed between the base of the P wiring 432P and the output wiring 432A in the Y direction. The extensions of the N wiring 432N sandwich the P wiring 432P in the X direction. A wiring member 46 is bonded to the base. The wiring member 46 has a configuration similar to that of the wiring member 45. One end of the wiring member 46 is bonded to the source electrode of the semiconductor element 41L, and the other end is bonded to the base of the N wiring 432N. The wiring member 46 extends in the Y direction in plan view. The three wiring members 46 are aligned in the X direction. At the base, the bonding portions of the three wiring members 46 are aligned in the X direction.

[0048] An N bus bar 51N is connected (joined) near the tip of the extended portion of the N wiring 432N. The N bus bars 51N are individually joined to a pair of extended portions. The P bus bar 51P and the N bus bar 51N are joined to the substrate 43 near the end on the capacitor module 50 side in the Y direction. On the substrate 43, the joints of the P bus bar 51P and the N bus bar 51N are aligned in the X direction. A joint of one P bus bar 51P is located between the joints of two N bus bars 51N. A bus bar 61 is joined to the substrate 43 near the end on the current sensor 60 side in the Y direction.

[0049] The housing 44 has a frame shape in a plan view. The housing 44 extends in the Z direction and has a cylindrical shape. The housing 44 is, for example, a resin molded body. The illustrated housing 44 has six walls 441, 442, 443, 444, 445, and 446 that define the storage space. The wall 441 is a wall on the capacitor module 50 side, and the wall 442 is a wall on the current sensor 60 side. The wall 442 is a wall opposite the wall 441 in the Y direction. The wall 444 is a wall opposite the wall 443 in the X direction. The walls 443 and 444 are continuous with the walls 441 and 442. The four walls 441, 442, 443, and 444 form a substantially rectangular ring shape in a plan view.

[0050] The walls 445 and 446 are partition walls. The walls 445 and 446 divide the space surrounded by the four walls 441, 442, 443, and 444 into three sections. The walls 445 and 446 extend in the Y direction and are continuous with the walls 441 and 442. The walls 441, 442, 443, and 445 form a space for accommodating the elements that make up the semiconductor module 40U. The walls 441, 442, 445, and 446 form a space for accommodating the elements that make up the semiconductor module 40V. The walls 441, 442, 444, and 446 form a space for accommodating the elements that make up the semiconductor module 40W.

[0051] The housing 44 may be disposed on a metal member 47 included in the semiconductor module 40, and may define an accommodation space together with the metal member 47. The housing 44 may be disposed on one surface of the support member 30, and may define an accommodation space together with the support member 30. The exemplified housing 44 is disposed on the metal member 47, and defines an accommodation space together with the metal member 47.

[0052] The metal member 47 is located on the back surface side of the insulating base material 431. In the illustrated semiconductor module 40, the substrate 43 is disposed on the metal member 47. The metal member 47 is disposed so as to enclose the substrates 43 of the three semiconductor modules 40 (40U, 40V, 40W) in a plan view. The metal member 47 is, for example, a metal plate having a substantially rectangular shape in plan view. The outer peripheral edge of the metal member 47 is disposed on the bottom surface of the recess 32 of the support member 30. The portion of the metal member 47 surrounded by the outer peripheral edge overlaps the opening of the flow path 34 in a plan view. The metal member 47 closes the opening of the flow path 34. A liquid-tight seal is formed between the outer peripheral edge of the metal member 47 and the support member 30.

[0053] As illustrated, the metal member 47 may have fins 48. The fins 48 extend in the Z direction from the rear surface of the metal member 47 and are disposed within the flow path 34. The fins 48 are in contact with the coolant 35. The illustrated metal member 47 has a plurality of pin-shaped fins 48.

[0054] The metal member 47 may be a back metal body of the substrate 43. In other words, the metal member 47 may constitute the substrate 43 together with the insulating base material 431 and the conductor pattern 432 (front metal body). For example, the three openings of the flow path 34 may be covered by the metal members 47 provided on the three substrates 43.

[0055] The metal member 47 may be provided on the support member 30 as a cover that closes the opening of the flow path 34. For example, in a configuration in which the semiconductor module 40 does not include the metal member 47, the support member 30 may include a metal member that serves as a cover and closes the opening of the flow path 34. In a configuration in which the substrate 43 includes a back surface metal body, the support member 30 may include a metal member that serves as a cover and closes the opening of the flow path 34, separate from the back surface metal body.

[0056] The semiconductor module 40 further includes signal terminals (not shown). The signal terminals are external connection terminals that electrically connect pads of the semiconductor element 41 to a circuit board (not shown). The signal terminals may be held in, for example, a housing. The signal terminals may be inserted into the housing 44, with one end exposed to the housing space and the other end protruding from the housing 44 and extending in the opposite direction from the support member 30.

[0057] The capacitor module 50 provides the smoothing capacitor 5 described above. The capacitor module 50 includes a bus bar 51, a capacitor element 52, and a sealing body 53. The bus bar 51 is a metal plate made of a metal with good conductivity, such as Cu. The bus bar 51 is connected to the electrodes 54 of the capacitor element 52. The bus bar 51 includes a P bus bar 51P and an N bus bar 51N. The P bus bar 51P and the N bus bar 51N each have an electrode connection portion 511, a terminal portion 512, and a coupling portion 513.

[0058] The electrode connection portions 511 are connection portions of the bus bar 51 that connect to the corresponding electrodes 54. The terminal portions 512 are portions of the bus bar 51 that protrude outside the sealing body 53. The terminal portions 512 are portions for connecting to other devices such as the semiconductor module 40. The terminal portions 512 of the P bus bar 51P are connected to the P wiring 432P of the semiconductor module 40 as described above. Similarly, the terminal portions 512 of the N bus bar 51N are connected to the N wiring 432N. The coupling portions 513 are portions of the bus bar 51 that connect the electrode connection portions 511 and the terminal portions 512.

[0059] The electrode connection portion 511 and the coupling portion 513 are covered by the sealing body 53. The electrode connection portion 511 and the coupling portion 513 are disposed within the sealing body 53. The terminal portion 512 is disposed outside the sealing body 53. The illustrated P bus bar 51P and N bus bar 51N are drawn out from the corresponding electrodes 54 in the Y direction toward the semiconductor module 40. The plate thickness direction of the electrode connection portion 511 is approximately parallel to the Z direction. The coupling portion 513 is continuous with the electrode connection portion 511, and includes a portion extending in the Y direction and a portion extending in the Z direction. The coupling portion 513 is approximately L-shaped in the YZ plane.

[0060] The terminal portions 512 extend from the connecting portions 513 toward the semiconductor module 40. The terminal portions 512 extend in the Y direction in a plan view. The terminal portions 512 are arranged to straddle (cross) the wall portion 441 of the housing 44. The P bus bar 51P and the N bus bar 51N are arranged in parallel so that their plate surfaces face each other over most of the entire length of the terminal portions 512 to reduce inductance. A portion of the terminal portions 512 is covered by the sealing body 42 that constitutes the semiconductor module 40. A portion of the terminal portions 512 is embedded within the sealing body 42. A portion of the terminal portions 512 of the P bus bar 51P, including a connection portion with the P wiring 432P, is sealed by the sealing body 42. A portion of the terminal portions 512 of the N bus bar 51N, including a connection portion with the N wiring 432N, is sealed by the sealing body 42.

[0061] The capacitor element 52 is, for example, a film capacitor element. The capacitor element 52 is formed by winding a film around an axis that is approximately parallel to the Z direction. The capacitor element 52 has a substantially rectangular shape in plan view. The capacitor element 52 has electrodes 54 on one surface and on the opposite surface. The electrodes 54 are sometimes referred to as metallikon electrodes, etc. One of the electrodes 54 is a P-electrode 54P, and the other is an N-electrode 54N.

[0062] The one surface and the back surface, which are the 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 52, 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 of the cylindrical case with a bottom that houses the sealing body 53, and the one surface is the upper surface. Capacitor element 52 has a negative N-electrode 54N on one surface and a positive P-electrode 54P on the back surface.

[0063] The capacitor module 50 may include only one capacitor element 52 or multiple capacitor elements 52. In a configuration including multiple capacitor elements 52, the capacitor elements 52 are aligned in at least one direction perpendicular to the Z direction. The illustrated capacitor module 50 includes four capacitor elements 52. The capacitor elements 52 are aligned in the X direction.

[0064] The sealing body 53 is made of an electrically insulating resin material. The sealing body 53 is formed by potting, for example. The sealing body 53 seals a part of the bus bar 51. The sealing body 53 seals the capacitor element 52.

[0065] The capacitor module 50 may include a case 55. The case 55 may be formed using a metal material such as aluminum, or may be formed using a resin material. The illustrated case 55 is made of resin. The case 55 has a cylindrical shape with a bottom. The case 55 has a bottom wall and a side wall. The case 55 is disposed on the support member 30 so that the outer surface of the bottom wall faces one surface of the support member 30 in the Z direction, specifically, the bottom surface of the recess 33. The illustrated bottom wall has a generally rectangular planar shape with the X direction as the longitudinal direction, and the side wall has a generally rectangular planar ring shape.

[0066] Note that capacitor module 50 may not include case 55, and support member 30 may provide the housing space instead of case 55. In other words, support member 30 may also serve as case 55. For example, by filling recess 33 with sealant 53, part of bus bar 51 and capacitor element 52 can be sealed.

[0067] The capacitor module 50 may include an insulating member 56. The insulating member 56 is formed using an electrically insulating material such as resin. The insulating member 56 is interposed between the P bus bar 51P and the N bus bar 51N at least in the portion where the P bus bar 51P and the N bus bar 51N run parallel to each other. The insulating member 56 extends along the terminal portions 512 of the bus bars 51. The insulating member 56 extends in the Y direction in a plan view. The insulating member 56 is disposed so as to straddle (cross) the wall portion 441 of the housing 44. One end of the insulating member 56 is sealed by the sealing body 53 of the capacitor module 50. The other end of the insulating member 56 is sealed by the sealing body 42 of the semiconductor module 40.

[0068] The current sensor 60 serves as the current sensor 13 described above. The current sensor 60 is configured to detect phase currents individually. The current sensor 60 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 60 is a magnetic detection type. The current sensor 60 includes bus bars 61 provided corresponding to each phase, and a main body 62.

[0069] The illustrated main body 62 includes a Hall element 63, which is a magnetoelectric conversion element, a resin member (not shown), a core, and a substrate. For convenience, the main body 62 is shown in a simplified form in FIGS. 2 to 4. The main body 62 includes three Hall elements 63 and three cores corresponding to the bus bars 61. The Hall elements 63 are mounted on the substrate and disposed in the gaps of the corresponding cores. The cores and bus bars 61 are held in the resin member. The bus bars 61 pass through the annular regions of the corresponding cores. The substrate is fixed to the resin member.

[0070] The bus bar 61 extends in the Y direction in a plan view. The bus bar 61 is disposed so as to straddle (cross) the wall portion 442 of the housing 44. A portion of the bus bar 61, including a connection portion with the output wiring 432A, is sealed by the sealing body 42 of the semiconductor module 40.

[0071] In the illustrated power conversion device 20, the semiconductor module 40, the capacitor module 50, and the current sensor 60 are aligned in the Y direction. The semiconductor module 40 is disposed between the capacitor module 50 and the current sensor 60 in the Y direction.

[0072] Summary of First Embodiment The power conversion device 20 of this embodiment includes a support member 30, a semiconductor module 40, and electrical components. The semiconductor module 40 and the electrical components are arranged on one surface of the support member 30. The semiconductor module 40 has a semiconductor element 41 and a sealing body 42 that seals the semiconductor element 41. The electrical components have a plurality of bus bars. The bus bars of the electrical components are electrically connected to the semiconductor element 41 inside the sealing body 42. In the illustrated power conversion device 20, the capacitor module 50 and the current sensor 60 correspond to the electrical components. The bus bars 51 and 61 correspond to the bus bars.

[0073] In this way, the bus bars of the electrical components are electrically connected to the semiconductor elements 41 inside the sealing body 42 of the semiconductor module 40. The semiconductor module 40 does not have terminals that protrude outside the sealing body 42 to which the bus bars are connected. Therefore, it is not necessary to ensure an insulating distance between the protruding terminals. It is also not necessary to arrange the protruding terminals far apart to ensure an insulating distance. As a result, it is possible to reduce inductance while suppressing an increase in the physical size. Furthermore, since the terminals of the semiconductor module 40 are no longer necessary, the configuration can be simplified.

[0074] As illustrated, the semiconductor module 40 may have a substrate 43 including an insulating base material 431 and a plurality of conductor patterns 432. The plurality of bus bars and the semiconductor element 41 may be sealed by a sealant 42 while connected to the corresponding conductor patterns 432. Because the bus bars of the electrical components are directly connected to the conductor patterns 432 (wiring) of the substrate 43 without going through the terminals of the semiconductor module 40, it is possible to reduce inductance while suppressing an increase in the module size.

[0075] As illustrated, the semiconductor module 40 may have a frame-shaped housing 44. The sealing body 42 may fill the space defined by the housing 44, and the bus bar may be arranged to straddle the housing 44 in the arrangement direction of the electrical component and the semiconductor module 40. In this case, resin can be injected into the space of the housing 44 to form the sealing body 42 while the bus bar and the semiconductor element 41 are electrically connected. In other words, a configuration can be realized in which the bus bar of the electrical component is electrically connected to the semiconductor element 41 inside the sealing body 42. Furthermore, the bus bar length can be shortened, thereby reducing inductance.

[0076] As shown in the example, the placement area of ​​the semiconductor module 40 may be recessed from the surrounding area on one surface of the support member 30. Because the semiconductor module 40 having the housing 44 is placed in the recess, it is possible to prevent the physical size from increasing in the Z direction despite the configuration having the housing 44. Furthermore, because the upper end of the housing 44 is close to one surface of the support member 30, it is possible to simplify the routing of the bus bar. In other words, it is possible to shorten the bus bar length and reduce inductance.

[0077] As illustrated, the electrical component may include a capacitor module 50 having a capacitor element 52 and a bus bar 51 connected to the capacitor element 52. In a configuration including the semiconductor module 40 and the capacitor module 50, inductance can be reduced while suppressing an increase in the physical size.

[0078] As illustrated, the capacitor module 50 may have an insulating member 56 interposed between the P bus bar 51P and the N bus bar 51N in the parallel running portion. By disposing the insulating member 56, the P bus bar 51P and the N bus bar 51N can be arranged closer to each other. This enhances the effect of magnetic flux cancellation, further reducing inductance.

[0079] As shown in the example, a portion of the insulating member 56 may be sealed by the sealing body 42. In other words, the insulating member 56 may be disposed so as to extend to a position where it is sealed by the sealing body 42. This structure increases the parallel running distance between the P bus bar 51P and the N bus bar 51N, thereby further reducing inductance.

[0080] As illustrated, the electrical component may include a current sensor 60. In a configuration including a semiconductor module 40 and a current sensor 60, inductance can be reduced while suppressing an increase in physical size. As illustrated, the electrical component may include a capacitor module 50 and a current sensor 60. Inductance can be reduced between the semiconductor module 40 and the capacitor module 50 while suppressing an increase in physical size, and inductance can be reduced between the semiconductor module 40 and the current sensor 60 while suppressing an increase in physical size. Therefore, in a power conversion device 20 including a semiconductor module 40, a capacitor module 50, and a current sensor 60, the effect of reducing inductance while suppressing an increase in physical size can be further enhanced.

[0081] <Modifications> The electrical components are not limited to the capacitor module 50 and the current sensor 60 described above. For example, as shown in FIG. 5 , the power conversion device 20 may include an output terminal block 70 as an electrical component. The power conversion device 20 shown in FIG. 5 includes a support member 30, a semiconductor module 40, a capacitor module 50, and the output terminal block 70. The power conversion device 20 includes the output terminal block 70 instead of the current sensor 60. The output terminal block 70 includes a bus bar 71 and a main body 72. The output terminal block 70 electrically connects the semiconductor module 40 and the winding 3 a of the motor generator 3. The main body 72 has a function of holding the bus bar 71. The main body 72 may also have the function of the current sensor 60 described above. The main body 72 may include, for example, a magnetoelectric conversion element.

[0082] The bus bar 71 extends in the Y direction in a plan view. The bus bar 71 is disposed so as to straddle (cross) the wall portion 442 of the housing 44. A portion of the bus bar 71, including the connection portion with the output wiring 432A, is sealed by the sealing body 42 of the semiconductor module 40. Therefore, in a configuration including the semiconductor module 40 and the output terminal block 70, it is possible to reduce inductance while suppressing an increase in the physical size.

[0083] The power conversion device 20 may include only the support member 30, the semiconductor module 40, and the capacitor module 50. The power conversion device 20 may include only the support member 30, the semiconductor module 40, and the current sensor 60. The power conversion device 20 may include only the support member 30, the semiconductor module 40, and the output terminal block 70.

[0084] (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.

[0085] 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.

[0086] When an element or layer is referred to as being "on," "coupled," "connected," or "coupled," it may be directly on, coupled, connected, or coupled 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 coupled" 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, a reference to A and / or B means at least one of A and B.

[0087] 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 also be oriented in other ways (rotated 90 degrees or at other orientations), and the spatially relative descriptors used in this specification would be interpreted accordingly.

[0088] Although the semiconductor module 40 is exemplified as a 2-in-1 package that provides the upper and lower arm circuits 9 for one phase, the semiconductor module 40 is not limited to this. The semiconductor module 40 may be, for example, a 6-in-1 package that provides the upper and lower arm circuits 9 for three phases, or a 1-in-1 package that provides one arm.

[0089] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0090] <Technical Idea 1> A power conversion device comprising: a support member (30) having one surface; a semiconductor module (40) having a semiconductor element (41) and a sealing body (42) that seals the semiconductor element, the semiconductor module (40) being arranged on the one surface; and an electric component (50, 60, 70) having a plurality of bus bars (51, 61, 71) and being arranged on the one surface, wherein the plurality of bus bars are electrically connected to the semiconductor element inside the sealing body.

[0091] <Technical Idea 2> The power conversion device according to Technical Idea 1, wherein the semiconductor module has a substrate (43) including an insulating base material (431) and a plurality of conductor patterns (432) arranged on the insulating base material, and the plurality of bus bars and the semiconductor elements are sealed by the sealing body while being connected to the corresponding conductor patterns.

[0092] <Technical Idea 3> The power conversion device according to Technical Idea 1 or Technical Idea 2, wherein the semiconductor module has a frame-shaped housing (44), the sealing body is filled in a space defined by the housing, and the bus bar is arranged so as to straddle the housing in the arrangement direction of the electrical component and the semiconductor module.

[0093] <Technical Concept 4> In the power conversion device according to Technical Concept 3, an arrangement area of ​​the semiconductor module is recessed with respect to a surrounding area of ​​the arrangement area.

[0094] <Technical Concept 5> The power conversion device according to any one of Technical Concepts 1 to 4, wherein the electrical component includes a capacitor module (50) having a capacitor element (52) and the bus bar connected to the capacitor element.

[0095] <Technical Idea 6> The power conversion device according to Technical Idea 5, wherein the plurality of bus bars include a P bus bar (51P) connected to a P electrode of the capacitor element and an N bus bar (51N) connected to an N electrode of the capacitor element, and the capacitor module has an insulating member (56) interposed in a portion where the P bus bar and the N bus bar run parallel to each other.

[0096] <Technical Concept 7> The power conversion device according to Technical Concept 6, wherein a portion of the insulating member is sealed by the sealing body.

[0097] <Technical Concept 8> The power conversion device according to any one of Technical Concepts 1 to 7, wherein the electrical component includes a current sensor (60).

[0098] <Technical Concept 9> The power conversion device according to any one of Technical Concepts 1 to 7, wherein the electrical components include an output terminal block (70).

Claims

1. A power conversion device comprising: a support member (30) having one surface; a semiconductor module (40) having a semiconductor element (41) and an encapsulant (42) that encapsulates the semiconductor element, the semiconductor module (40) being arranged on the one surface; and an electrical component (50, 60, 70) having a plurality of bus bars (51, 61, 71) and being arranged on the one surface, wherein the plurality of bus bars are electrically connected to the semiconductor element inside the encapsulant.

2. The power conversion device according to claim 1, wherein the semiconductor module has a substrate (43) including an insulating substrate (431) and a plurality of conductor patterns (432) arranged on the insulating substrate, and the plurality of bus bars and the semiconductor elements are sealed by the sealing body while connected to the corresponding conductor patterns.

3. The power conversion device according to claim 2, wherein the semiconductor module has a frame-shaped housing (44), the sealing body is filled in a space defined by the housing, and the bus bar is arranged so as to straddle the housing in the arrangement direction of the electrical component and the semiconductor module.

4. The power conversion device according to claim 3, wherein, on said one surface, an area in which said semiconductor module is arranged is recessed with respect to a surrounding area of ​​said arrangement area.

5. The power conversion device according to any one of claims 1 to 4, wherein the electrical component includes a capacitor module (50) having a capacitor element (52) and the bus bar connected to the capacitor element.

6. The power conversion device according to claim 5, wherein the plurality of bus bars include a P bus bar (51P) connected to a P electrode of the capacitor element and an N bus bar (51N) connected to an N electrode of the capacitor element, and the capacitor module has an insulating member (56) interposed between the parallel-running portion of the P bus bar and the N bus bar.

7. The power conversion device according to claim 6, wherein a portion of the insulating member is sealed by the sealing body.

8. The power conversion device according to any one of claims 1 to 4, wherein the electrical component includes a current sensor (60).

9. The power conversion device according to any one of claims 1 to 4, wherein the electrical components include an output terminal block (70).

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