Power conversion device

Abstract

To provide a power conversion device that can achieve both the suppression of resonance in a control board and the cooling performance of a semiconductor device.SOLUTION: A power conversion device 4 includes a semiconductor device 90, a control board 13, and a cooler stacked on the semiconductor device to cool the semiconductor device. The power conversion device 4 includes a pressure unit 15 stacked on the semiconductor device and applying a pressing force to press the semiconductor device in the stacking direction, and a fixing screw 20. The fixing screw 20 applies a fixing force to press the control board 13 or the board support member 14 supporting the control board 13, stacked on the pressure unit 15, against the pressing unit in the stacking direction. The fixing screw 20 is provided at a position overlapping the semiconductor device 90 in the stacking direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The disclosure herein relates to power conversion devices. [Background technology]

[0002] Patent Document 1 discloses an inverter device including a shielding member, a control board supported by the shielding member, and a semiconductor device fixed to the shielding member, whereby heat from the semiconductor device is transferred to the shielding member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-35226 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed in Patent Document 1 leaves room for improvement in terms of suppressing resonance of the control board and ensuring the cooling performance of the semiconductor device.

[0005] An object of the disclosure in this specification is to provide a power conversion device that can achieve both suppression of resonance in a control board and cooling performance for a semiconductor device. [Means for solving the problem]

[0006] The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. Furthermore, the reference symbols in parentheses in the claims and this section are merely examples showing the correspondence between specific means described in the embodiments below as one aspect, and do not limit the technical scope.

[0007] One of the disclosed power conversion devices includes a semiconductor device (90) that performs power conversion, a control board (13) on which electronic components that drive the semiconductor device are mounted, a cooler (17, 18, 171) that is stacked on the semiconductor device and cools the semiconductor device, a pressure section (15) that is stacked on the semiconductor device and applies a pressing force to press the semiconductor device in the stacking direction, and a fixing member (20) that is stacked on the pressure section on the opposite side of the semiconductor device and applies a fixing force to press the control board or a board support member (14) that supports the control board against the pressure section in the stacking direction, and the fixing member is located in a position that overlaps the semiconductor device in the stacking direction.

[0008] According to this power conversion device, the semiconductor device can be effectively cooled by the cooler stacked on the semiconductor device. The power conversion device includes a stacked structure article such as a semiconductor device, a cooler, a pressure unit, and a control board or board support member. The fixing member functions to press the control board or board support member, which is stacked on the pressure unit on the opposite side of the semiconductor device, against the pressure unit in the stacking direction. Furthermore, the fixing member is located at a position overlapping the semiconductor device in the stacking direction. This configuration increases the rigidity of the control board against vibrations transmitted from the semiconductor device or the cooler. Furthermore, the control board or board support member is pressed against the pressure unit in the stacking direction by the fixing member overlapping the semiconductor device in the stacked structure article. The control board has high rigidity as a component of the stacked structure article. Therefore, the control board has high resistance to vibrations transmitted to the power conversion device from outside. Therefore, the power conversion device can achieve both suppression of resonance in the control board and cooling performance of the semiconductor device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a circuit diagram of a power conversion device according to a first embodiment. [Figure 2] FIG. 2 is a plan view showing the configuration of the power conversion device. [Figure 3] 2 is a partial cross-sectional view showing a stacked structure of a substrate, a substrate support member, a cooler, and a semiconductor device. [Figure 4] FIG. 2 is a partial cross-sectional view showing a first example, which is one of other examples of a laminate structure article. [Figure 5] FIG. 2 is a partial cross-sectional view showing a second example, which is one of other examples of a laminate structure article. [Figure 6] FIG. 10 is a partial cross-sectional view showing a third example, which is one of other examples of a laminate structure article. [Figure 7] FIG. 10 is a partial cross-sectional view showing a fourth example, which is one of other examples of a laminate structure article. [Figure 8] FIG. 10 is a partial cross-sectional view showing a fifth example, which is one of other examples of a laminate structure article. [Figure 9] FIG. 10 is a partial cross-sectional view showing a sixth example, which is another example of a laminated structure article. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicate descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other previously described embodiments may be applied to the other parts of the configuration. In addition to combinations of parts that are specifically specified as being combinable in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

[0011] First embodiment A first embodiment disclosing an example of a power conversion device will be described with reference to FIGS. 1 to 9. Application examples of the power conversion device are as follows. The power conversion device can be applied to an on-board power conversion device mounted on vehicles such as electric vehicles, hybrid vehicles, and plug-in hybrid vehicles. The power conversion device can also be mounted on flying objects such as electric vertical take-off and landing aircraft and drones, ships, construction machinery, agricultural machinery, etc. An example in which the power conversion device is applied to a vehicle will be described below.

[0012] As shown in FIG. 1, a vehicle drive system 1 includes a DC power supply 2, a motor generator 3, and a power converter 4. The DC power supply 2 is a DC voltage source configured with a chargeable and dischargeable secondary battery. The secondary battery is, for example, a lithium-ion battery, a nickel-metal hydride battery, or the like. The motor generator 3 is, for example, a three-phase AC rotating electric machine, and is an example of an electric load to which the power converter 4 supplies power. 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 converter 4 performs power conversion between the DC power supply 2 and the motor generator 3.

[0013] The power conversion device 4 includes a power conversion circuit. As shown in FIG. 1, the power conversion device 4 includes a smoothing capacitor 5 and an inverter 6, which is a power conversion circuit. The smoothing capacitor 5 mainly has the function of smoothing the DC voltage supplied from the DC power supply 2. The smoothing capacitor 5 is connected to a P line 10, which is a power supply line on the high potential side, and an N line 11, which is a power supply line on the low potential side. The smoothing capacitor 5 is an example of a capacitor in the claims.

[0014] The smoothing capacitor 5 is connected in parallel to the DC power supply 2. The P line 10 is connected to the positive terminal of the DC power supply 2. The N line 11 is connected to the negative terminal of the DC power supply 2. The positive terminal of the smoothing capacitor 5 is connected to the P line 10 between the DC power supply 2 and the inverter 6. The negative terminal of the smoothing capacitor 5 is connected to the N line 11 between the DC power supply 2 and the inverter 6. The P line 10 includes a plurality of P bus bars that connect electrical components to each other. The N line 11 includes a plurality of N bus bars that connect electrical components to each other.

[0015] The inverter 6 is a DC-AC conversion circuit. In accordance with switching control by a control circuit provided on the control circuit board, the inverter 6 converts DC voltage into three-phase AC voltage and outputs it to the motor generator 3. This operation drives the motor generator 3 to generate a predetermined torque.

[0016] The control circuit generates a drive command for operating the IGBT 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 and signals detected by various sensors. The various sensors include a current sensor 7, a rotation angle sensor, and a voltage sensor. The control circuit outputs, for example, a PWM signal as the drive command. The control circuit is equipped with a microcomputer. The rotation angle sensor detects the rotation angle of the rotor of the motor generator 3 and outputs it to the control circuit. The voltage sensor detects the voltage across the smoothing capacitor 5 and outputs it to the control circuit.

[0017] During regenerative braking of the vehicle, inverter 6 converts the three-phase AC voltage generated by motor generator 3 in response to rotational force from the wheels into DC voltage under switching control of the control circuit. The converted DC power is output to P line 10. In this way, inverter 6 performs bidirectional power conversion between DC power supply 2 and motor generator 3.

[0018] The power conversion device 4 may be configured to include a noise filter. A case in which a configuration including a noise filter is adopted is described below. The noise filter is connected to each of the P line 10 and the N line 11. The noise filter is connected in parallel to the DC power supply 2. The positive terminal of the noise filter is connected to the P line 10 between the DC power supply 2 and the smoothing capacitor 5. The negative terminal of the noise filter is connected to the N line 11 between the DC power supply 2 and the smoothing capacitor 5. The noise filter removes noise input to and output from the P line 10 and the N line 11. The noise filter may be configured to include a capacitor. The capacitor included in the noise filter has a smaller capacitance than the smoothing capacitor 5.

[0019] The inverter 6 includes upper and lower arm circuits 9 corresponding to each of the three phases. The upper and lower arm circuits 9 are sometimes referred to as legs. The upper and lower arm circuits 9 have 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 10 and the N line 11, with the upper arm 9H on the P line 10 side and the lower arm 9L on the N line 11 side.

[0020] The connection point between the upper arm 9H and the lower arm 9L is connected to the winding 3a of the corresponding phase in the motor generator 3 via an output line 8. 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 a corresponding output line 8. The V-phase upper and lower arm circuit 9V is connected to the V-phase winding 3a via a corresponding output line 8. The W-phase upper and lower arm circuit 9W is connected to the W-phase winding 3a via a corresponding output line 8. At least a portion of the output lines 8 is formed of a conductive member such as a bus bar.

[0021] The power conversion device 4 includes current sensors 7 that individually detect the currents flowing through the three-phase lines that make up the output line 8. The current sensors 7 are fixed, for example, to bus bars that form the three-phase lines. The current sensors 7 output electrical signals corresponding to the output currents of the arms to the control circuit. The current sensors 7 include resistance detection sensors or magnetic field detection sensors.

[0022] A current sensor 7 that detects current using resistance detection includes a shunt resistor and a high-speed amplifier. A resistance detection type current sensor 7 includes an electronic component having a circuit that converts the voltage drop across the shunt resistor into a current and detects the current value. A current sensor 7 that detects current using magnetic field detection includes a Hall IC, which is a current sensor component. The Hall IC detects the current value by converting the magnetic field generated around the current into a voltage using the Hall effect and measuring it. A magnetic field detection type current sensor component includes an electronic component having a Hall element and an amplifier circuit. A magnetic field detection type current sensor component may also be a current sensor that detects magnetic fields contactlessly using an MI (Magneto Impedance) element.

[0023] The inverter 6 has six arms. Each arm is equipped with a switching element. The number of switching elements constituting each arm is not particularly limited. There may be one or more. When there are more than one switching elements, the multiple switching elements connected in parallel are turned on and off at the same timing by a common gate drive signal.

[0024] In this specification, an n-channel MOSFET 91 is used as the switching element constituting each arm. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. In the upper arm 9H, the drain of the MOSFET 91 is connected to a P line 10. In the lower arm 9L, the source of the MOSFET 91 is connected to an N line 11. The source of the MOSFET 91 in the upper arm 9H and the drain of the MOSFET 91 in the lower arm 9L are connected to each other.

[0025] A freewheeling diode 92 is connected in antiparallel to each MOSFET 91. The diode 92 may be a parasitic diode of the MOSFET 91, or may be provided separately from the parasitic diode. The anode of the diode 92 is connected to the source of the corresponding MOSFET 91. The cathode of the diode 92 is connected to the drain.

[0026] The switching element is not limited to the MOSFET 91. An IGBT may be used as the switching element. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. In the case of an IGBT, a freewheeling diode is also connected in anti-parallel.

[0027] 2 shows the configuration of the power conversion device 4, and illustrates a state in which the components are housed in a housing 12. As shown in FIG. 2, the power conversion device 4 includes a control board 13, a board support member 14 that supports the control board 13, and a plurality of semiconductor devices 90, all of which are housed in the housing 12. The power conversion device 4 also includes a smoothing capacitor 5, a current sensor 7, and a cooler, all of which are housed in the housing 12. The control board 13, the board support member 14, and the semiconductor devices 90 are arranged in this order, facing vertically downward.

[0028] The control board 13 is mounted with electronic components that drive the semiconductor device 90. The control board 13 has a control circuit pattern that drives the semiconductor device 90. The control board 13 is supported by columnar support portions 14a that protrude in a columnar shape from the board support member 14. The control board 13 is fastened and fixed to the board support member 14 while placed on the columnar support portions 14a by screw members that screw into the columnar support portions 14a. The control board 13 may also be configured to be fixed to the board support member 14 by engaging with the ends of the columnar support portions 14a. The board support member 14 is a plate-like member that is fixed to the housing 12 by screw members 21 at multiple locations. The housing 12 is fixed to, for example, a part of the vehicle body.

[0029] The semiconductor device 90 provides at least one arm of the power conversion circuit. The semiconductor device 90 provides the upper and lower arm circuits 9 for one phase. Multiple semiconductor devices 90 are connected in parallel to provide the power conversion circuit. Multiple semiconductor devices 90 may also be referred to as multiple semiconductor modules. In the following, two directions that are orthogonal to each other are referred to as the X direction and the Y direction. The X direction and the Y direction indicate directions along a horizontal plane. The Z direction corresponds to the vertical direction.

[0030] The semiconductor device 90 has a flattened outer shape due to the sealing material, except for the terminals protruding from the sealing material. The semiconductor device 90 is installed so that the thickness direction, which is the smallest side dimension, is aligned with the vertical direction. The control circuit board is installed above the semiconductor device 90 so that the thickness direction of the board is aligned with the vertical direction. This configuration makes it possible to reduce the vertical length of the power conversion device 4 occupied by the semiconductor device 90 and the control circuit board.

[0031] A terminal portion 90a forming a collector terminal and an emitter terminal protrudes from one side of the flat body of the semiconductor device 90. The terminal portion 90a protrudes toward the smoothing capacitor 5 and is connected to the P line 10 and the N line 11 via the terminal coupling portion of the terminal base unit. A relay terminal protrudes from the other side of the flat body. The relay terminal is connected to the output line 8. The gate terminal of the semiconductor device 90 is connected to a control circuit board 93. The control circuit board 93 forms a control circuit on which electronic components such as an arithmetic element that controls the operation of the MOSFET 91 are mounted.

[0032] 3, the current sensor 7 is provided on the opposite side of the semiconductor device 90 from the smoothing capacitor 5. The current sensor 7 and the smoothing capacitor 5 are provided on both sides of the semiconductor device 90 located therebetween. The power conversion device 4 includes stacked structure articles such as the semiconductor device 90, a cooler, a pressurizing unit 15, a control board 13, and a board support member 14. The current sensor 7, the smoothing capacitor 5, and the semiconductor device 90 are arranged side by side in a direction perpendicular to the stacking direction of the stacked structure article.

[0033] The power conversion device 4 is equipped with a cooler that cools at least one side of the multiple semiconductor devices 90. In this configuration, the multiple semiconductor devices 90 and the cooler are stacked and installed so that they are aligned in the height direction, which is the Z direction. The semiconductor devices 90 are thin or flat, with their thickness significantly smaller than their width, and are installed with their thickness direction aligned with the stacking direction. The stacking direction is the direction in which components are stacked in a laminated structure article, and is the vertical direction. The smoothing capacitor 5, semiconductor devices 90, and current sensor 7 are installed so that they do not overlap in a plan view viewed in the stacking direction. This configuration contributes to reducing the size of the power conversion device 4 in the stacking direction.

[0034] The cooler is made of aluminum, copper, or an alloy thereof. The cooler can be manufactured by, for example, die casting. The semiconductor device 90 is in contact with the heat receiving portion of the cooler. The heat receiving portion of the cooler is formed in a flat plate shape to increase the contact area with the semiconductor device 90. A thermally conductive member such as a highly thermally conductive gel, sheet, or grease may be interposed between the heat receiving portion of the cooler and the semiconductor device 90.

[0035] As shown in FIG. 3 , the power conversion device 4 includes a first cooler 17 and a second cooler 18 that cool both sides of the plurality of semiconductor devices 90. The first cooler 17 and the second cooler 18 are made of a material with high thermal conductivity, such as metal. In this configuration, the first cooler 17, the plurality of semiconductor devices 90, and the second cooler 18 are stacked and arranged in this order in the height direction or vertical direction. The first cooler 17 and the second cooler 18 are in close contact with the plurality of semiconductor devices 90, sandwiching the plurality of semiconductor devices 90. A thermally conductive material with high thermal conductivity, such as grease or gel, may be interposed between the first cooler 17 and the plurality of semiconductor devices 90. A thermally conductive material with high thermal conductivity, such as grease or gel, may be interposed between the second cooler 18 and the plurality of semiconductor devices 90.

[0036] The first cooler 17 has an internal passage 17a through which a cooling fluid flows. The first cooler 17 absorbs heat from the semiconductor device 90 from one of the opposing surfaces of the semiconductor device 90. The second cooler 18 has an internal passage 18a through which a cooling fluid flows. The second cooler 18 absorbs heat from the semiconductor device 90 from the other opposing surface of the semiconductor device 90. The power conversion device 4 has a configuration in which heat is dissipated from both sides of the outer casing of the multiple semiconductor devices 90 that are perpendicular to the stacking direction.

[0037] Furthermore, the first cooler 17 and the second cooler 18 may not have an internal passage through which the cooling fluid flows. The first cooler 17 and the second cooler 18 may have a plurality of fins protruding from an outer surface other than the surface facing the semiconductor device 90. The internal passages 17a, 18a may be provided over a wide area even in a location that does not face the semiconductor device 90 in the stacking direction. The internal passages 17a, 18a may be passages that meander over a wide area on the back side of the control board 13. The fluid flowing through the internal passages 17a, 18a may be a phase-change refrigerant such as water or ammonia, or a phase-non-change refrigerant such as an ethylene glycol-based refrigerant.

[0038] The power conversion device 4 includes a fixing member that applies a fixing force to press the board support member 14, which supports the control board 13, against the pressure unit 15 in the stacking direction. The fixing member is, for example, a fixture that presses the board support member 14 and the pressure unit 15 together in the stacking direction to fix them together. The fixing member presses the control board 13 against the pressure unit 15 via the board support member 14 in the stacking direction to fix them together. The configuration of the fixing member is not limited as long as it is a fixture that has the function of sandwiching two members stacked in the thickness direction. For example, a fixing member having a male screw structure that can be threaded into a female screw portion, or a fixing member that can be crimped while sandwiching two members, can be used as the fixing member.

[0039] The pressure applying portion 15 has a hardness that allows it to elastically deform when subjected to an external force acting in the thickness direction, or is made of a material that allows it to elastically deform when subjected to the external force. The thickness direction is also the stacking direction. The pressure applying portion 15 is made of, for example, metal or resin. The pressure applying portion 15 can be made of a plate-like member or a plate. The pressure applying portion 15 includes a nut member 22 that is integrally formed with the pressure applying portion 15. The nut member 22 is a separate component from the pressure applying portion 15. The nut member 22 includes a female thread portion 22a formed on the inner periphery of the cylindrical body and a lid portion that closes the axial end of the cylindrical body. The nut member 22 is preferably made of metal to achieve a high fastening force with the fixing screw 20. The nut member 22 can be integrally formed with the pressure applying portion 15 by being integrally molded with the pressure applying portion 15.

[0040] 3 includes a head and a male thread portion 20a that screws into a female thread portion 22a provided on the pressure applying portion 15. The fixing screw 20 tightly contacts the pressure applying portion 15 with the substrate support member 14 by the fastening force generated by the threaded engagement between the male thread portion 20a and the female thread portion 22a. The fixing screw 20 clamps the substrate support member 14 between the head and the pressure applying portion 15, and presses the substrate support member 14 and the pressure applying portion 15 together in the stacking direction to secure them together.

[0041] The laminated structure article includes a spring member 16 interposed between the first cooler 17 and the pressure applying unit 15. The spring member 16 is a plate-like member having a thickness that allows it to elastically deform in response to an external force acting in the stacking direction, and is made of a material that is elastically deformable by the external force. The spring member 16 is made of, for example, a metal or resin material. When an external force compresses the laminated structure article in the stacking direction, the spring member 16 provides a spring reaction force that pushes back against the first cooler 17 and the pressure applying unit 15. This spring reaction force strengthens the adhesion between the first cooler 17 and the spring member 16 and between the pressure applying unit 15 and the spring member 16, thereby facilitating heat transfer between the substrate support member 14 and the coolers.

[0042] The current sensor 7 is provided so as to have a portion that overlaps horizontally with the semiconductor device 90 and the cooler. The current sensor 7 is provided at a position that overlaps with the first cooler 17 or the second cooler 18 in a direction perpendicular to the stacking direction. The horizontal direction is an example of a direction perpendicular to the stacking direction. The current sensor 7 is provided at a position where at least a portion overlaps with the control board 13 in the stacking direction. The current sensor 7 may also be configured to be provided at a position that overlaps with the control board 13 in the stacking direction. The current sensor 7 is provided over an area that includes the semiconductor device 90 and the cooler in the stacking direction of the multilayer structure article. The smoothing capacitor 5, the semiconductor device 90, and the current sensor 7 may also be configured to be provided in positions that are aligned horizontally.

[0043] The smoothing capacitor 5 includes a capacitor element, a sealing member, electrodes connected to the capacitor element, terminals, etc. The smoothing capacitor 5 includes a capacitor element and a sealing member filled in the capacitor element housing to seal the capacitor element. The sealing member seals the capacitor element in the housing space. The sealing member forms the outer shell of the smoothing capacitor 5. The outer shell of the smoothing capacitor 5 has a rectangular parallelepiped shape, excluding the terminals, etc. The sealing member is made of a thermosetting resin such as epoxy resin. The sealing member is an insulator that fills the gaps between the capacitor element and electrodes and the capacitor element housing. With this configuration, the sealing member seals the capacitor element, electrodes, etc. One end of the terminals is connected to the electrodes inside the smoothing capacitor 5, and the other end protrudes from the sealing member. The terminals are connected to the P line 10 and the N line 11 within the housing via terminal couplings of the terminal block unit.

[0044] The smoothing capacitor 5 is provided so as to have a portion that overlaps with the semiconductor device 90 and the cooler in the horizontal direction. The smoothing capacitor 5 is provided at a position that overlaps with the first cooler 17 or the second cooler 18 in a direction perpendicular to the stacking direction. The smoothing capacitor 5 is provided at a position where at least a portion of the smoothing capacitor 5 overlaps with the control board 13 in the stacking direction. The smoothing capacitor 5 may be configured to be provided at a position that overlaps with the control board 13 in the stacking direction. The smoothing capacitor 5 is provided over an area that includes the semiconductor device 90 and the cooler in the stacking direction of the multilayer structure article. The smoothing capacitor 5 and the semiconductor device 90 are connected via a bus bar. This bus bar is included in the bus bars that form the P line 10 and the N line 11. The length of this bus bar is proportional to the distance between the smoothing capacitor 5 and the semiconductor device 90 in the horizontal direction.

[0045] The smoothing capacitor 5 may be configured to be installed in a position where the direction of the minimum external length is the horizontal or lateral direction. This configuration reduces the horizontal length of the power conversion device 4 that the smoothing capacitor 5 occupies, and reduces the size of the power conversion device 4 in the direction in which the semiconductor device 90 and the smoothing capacitor 5 are aligned.

[0046] The P line 10 and the N line 11 are insulated by an insulating component. The insulating component is, for example, an input connector. Inside the input connector, terminals connected to the tips of the bus bars that form each line are provided. Terminals of a wire harness extending from the DC power supply 2 are connected to the terminals inside the input connector. As a result, each of the P line 10 and the N line 11 is electrically connected to the DC power supply 2.

[0047] The configuration of the laminated structure article may be as shown in Figs. 4 to 9. Other modified examples of the laminated structure article will be described with reference to Figs. 4 to 9. Fig. 4 shows a first modified example, which is an example of the laminated structure article. The laminated structure article shown in Fig. 4 differs from the laminated structure article shown in Fig. 3 in that it does not include a nut member 22. The laminated structure article shown in Fig. 4 includes a female thread portion 15a formed in the pressure applying portion 15. The fixing screw 20 tightly contacts the pressure applying portion 15 with the substrate support member 14 by the fastening force generated by the threaded engagement between the male thread portion 20a and the female thread portion 15a. With this threaded configuration, the fixing screw 20 clamps the substrate support member 14 between the head and the pressure applying portion 15, and presses the substrate support member 14 and the pressure applying portion 15 together in the stacking direction.

[0048] The laminated structure article shown in Fig. 5 differs from the laminated structure article shown in Fig. 4 in that it does not include spring member 16. In the laminated structure article shown in Fig. 5, pressure unit 15 and first cooler 17 are in contact with each other in the stacking direction. In this laminated structure article, the close contact between pressure unit 15 and first cooler 17 allows smooth heat transfer between first cooler 17 and substrate support member 14.

[0049] The laminated structure article shown in Fig. 6 differs from the laminated structure article shown in Fig. 3 in that it does not include a substrate support member 14. As shown in Fig. 6, the fixing member applies a fixing force that presses the control board 13 directly against the pressure unit 15 in the stacking direction. The fixing member tightly contacts the control board 13 with the pressure unit 15 by the fastening force generated by the threaded engagement between the male and female threads. With this threaded configuration, the fixing member sandwiches the control board 13 between the head and the pressure unit 15, and presses the control board 13 and the pressure unit 15 together in the stacking direction to fix them together.

[0050] The laminated structure article shown in Fig. 7 differs from the laminated structure article shown in Fig. 6 in that it does not include the first cooler 17 and the pressurizing unit 15. The laminated structure article shown in Fig. 7 only includes a cooler that cools one side of the plurality of semiconductor devices 90 opposite to the control board side.

[0051] The laminated structure article shown in Fig. 8 has a configuration in which the control board 13 is located at the lowest position compared to the other laminated structure articles shown in this specification. In other words, the laminated structure articles shown in this specification other than that shown in Fig. 8 may be configured to be installed upside down.

[0052] The laminated structure article shown in FIG. 9 differs from the laminated structure article shown in FIG. 5 in that the pressurizing unit and the cooler are configured as a single component. As shown in FIG. 9, a first cooler 171 is provided with a pressurizing unit. A female thread portion 15a is formed in the first cooler 171. The fixing member applies a fixing force that presses the control board 13 or the board support member 14 against the first cooler 17 in the stacking direction. The fixing member tightly contacts the control board 13 to the first cooler 17 by a fastening force generated by threaded engagement between the male thread portion and the female thread portion. With this threaded configuration, the fixing member sandwiches the board support member 14 between the head and the first cooler 17, and presses and fixes the board support member 14 and the first cooler 17 together in the stacking direction.

[0053] The effects of the power conversion device 4 disclosed in the specification will be described. The power conversion device 4 includes a semiconductor device 90, a control board 13, a cooler that cools the semiconductor device 90, a pressure applying unit 15, and a fixing member. The power conversion device 4 includes a stacked structure article such as the semiconductor device 90, the cooler, the pressure applying unit 15, and the control board 13 or the board support member 14. The pressure applying unit 15 is stacked on the semiconductor device 90 and applies a pressing force that presses the semiconductor device 90 in the stacking direction. The control board 13 or the board support member 14 that supports the control board 13 is stacked on the pressure applying unit 15 on the opposite side to the semiconductor device. The fixing member applies a fixing force that presses the control board 13 or the board support member 14 against the pressure applying unit 15 in the stacking direction. The fixing member is provided at a position that overlaps the semiconductor device 90 in the stacking direction.

[0054] According to this power conversion device 4, the semiconductor device can be effectively cooled by the cooler stacked on the semiconductor device. The fixing member presses the control board 13 or board support member 14, which is stacked on the pressure unit 15 on the side opposite to the semiconductor device 90, against the pressure unit 15 in the stacking direction. Furthermore, because the fixing member is provided at a position overlapping the semiconductor device 90 in the stacking direction, the rigidity of the control board 13 against vibrations transmitted from the semiconductor device 90 and the cooler can be improved.

[0055] The control board 13 or the board support member 14 is pressed against the pressure member 15 in the stacking direction by a fixing member at a position where it overlaps with the semiconductor device 90 in the stacked structure article. Therefore, the control board 13 has high rigidity as one component of the stacked structure article. This allows the control board 13 to exhibit high resistance to vibrations transmitted from the outside to the power conversion device 4, and makes it possible to suppress resonance of the control board 13. As described above, it is possible to provide a power conversion device 4 that can achieve both suppression of resonance of the control board 13 and cooling performance of the semiconductor device 90.

[0056] The cooler includes a first cooler 17 through which a cooling fluid flows and a second cooler 18 through which a cooling fluid flows. The first cooler 17 is arranged stacked on one surface side in the stacking direction relative to the semiconductor device 90. The second cooler 18 is arranged stacked on the other surface side in the stacking direction relative to the semiconductor device 90. The power conversion device 4 includes a spring member 16 interposed between the first cooler 17 and the pressurizing unit 15 and applying a spring reaction force to the first cooler 17 and the pressurizing unit 15.

[0057] This configuration provides a structure that cools both sides of semiconductor device 90 in the stacking direction. In addition, the cooling fluid flowing through the cooler has a vibration damping effect, which can suppress vibrations transmitted from semiconductor device 90 to control board 13. The reaction force of spring member 16 can improve the adhesion between control board 13 or board support member 14 and pressure member 15, and between pressure member 15 and first cooler 17. This allows for efficient heat transfer from control board 13 to first cooler 17, providing a power conversion device that improves the ability to cool electronic components on control board 13.

[0058] The fixing member has a male thread portion 20a that screws into a female thread portion 15a formed on the pressure applying portion 15. The fixing member presses the control board 13 or the board support member 14 against the pressure applying portion 15 in the stacking direction by the fastening force of the male thread portion 20a. This configuration can reduce the thickness of the pressure applying portion 15. This allows for a configuration that can reduce the thickness of the control board 13 or the board support member 14 and the pressure applying portion 15, while also suppressing vibrations transmitted from the semiconductor device 90 to the control board 13.

[0059] The power conversion device 4 includes a nut member 22 that is a separate component from the pressure applying unit 15 and is provided integrally with the pressure applying unit 15. The fixing member includes a male thread portion 20a that screws into a female thread portion 22a formed on the nut member. The fixing member presses the control board 13 or the board support member 14 against the pressure applying unit 15 in the stacking direction by the fastening force of the male thread portion 20a. With this configuration, the pressure applying unit 15 and the female thread portion are separate components, so the pressure applying unit 15 can be used in both products that include a female thread and products that do not include a female thread portion. This makes it possible to provide a highly versatile component that constitutes the pressure applying unit 15.

[0060] The nut member 22 has a lid formed at its axial end. With this configuration, the lid can increase the rigidity of the nut member 22 that forms the female thread portion 22a, thereby improving the vibration resistance of the power converter 4. In addition, the lid can catch chips generated when the male thread portion of the fixing member and the female thread portion of the nut member are screwed together. This prevents chips from being exposed to the outside, providing a power converter 4 with improved electrical insulation.

[0061] The cooler has a pressure applying part. The fixing member has a male threaded part 20a that screws into a female threaded part 15a formed on the cooler. The fixing member presses the control board 13 or the board support member 14 against the pressure applying part in the stacking direction by the fastening force of the male threaded part 20a. With this configuration, heat transfer loss can be suppressed compared to when the cooler and the pressure applying part are separate parts, and the cooling performance of the cooler can be improved.

[0062] The power conversion device 4 includes a capacitor connected to the semiconductor device and a current sensor 7 that detects a current flowing through an output line 8 that connects an electrical load and the semiconductor device. The capacitor and current sensor 7 are provided in a position where they at least partially overlap with the control board 13 in the stacking direction. The cooler is provided in a position that overlaps with the capacitor and current sensor 7 in a direction perpendicular to the stacking direction. With this configuration, the capacitor and current sensor 7 have portions that overlap with the control board 13 in the stacking direction, so the length dimension of the power conversion device 4 in the stacking direction can be reduced, allowing for miniaturization. Furthermore, because the cooler is located in a position that overlaps with the capacitor and current sensor, a power conversion device 4 can be provided that can cool the semiconductor device 90, the capacitor, and the current sensor.

[0063] Other embodiments The disclosure of this specification 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 elements shown in the embodiments, and various modifications can be made. 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 elements from the embodiments. The disclosure encompasses the substitution or combination of parts and elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is defined by the claims, and should be interpreted as including all modifications within the meaning and scope of the claims.

[0064] A power conversion device that can achieve the object disclosed in this specification may have a configuration in which the smoothing capacitor 5 and the current sensor 7 are not housed within the housing 12.

[0065] (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.

[0066] (Technical thought 1) a semiconductor device (90) that performs power conversion; a control board (13) on which electronic components for driving the semiconductor device are mounted; a cooler (17, 18, 171) arranged in a stack on the semiconductor device to cool the semiconductor device; a pressure unit (15) that is arranged in a stacked manner on the semiconductor device and applies a pressing force to the semiconductor device in the stacking direction; a fixing member (20) that applies a fixing force to press the control board or a board support member (14) supporting the control board against the pressure unit in a stacking direction, the fixing member (20) being stacked on the pressure unit on the opposite side of the semiconductor device; Equipped with The fixing member is provided at a position overlapping the semiconductor device in the stacking direction.

[0067] (Technical thought 2) The cooler includes a first cooler (17) through which a cooling fluid flows and which is stacked on one surface side of the semiconductor device in the stacking direction, and a second cooler (18) through which a cooling fluid flows and which is stacked on the other surface side of the semiconductor device in the stacking direction, The power conversion device according to Technical Idea 1 includes a spring member (16) interposed between the first cooler and the pressurizing unit to apply a spring reaction force to the first cooler and the pressurizing unit.

[0068] (Technical Thought 3) The fixing member has a male thread portion (20a) that screws into a female thread portion (15a) formed on the pressure member, The power conversion device according to Technical Idea 1 or 2, wherein the fixing member presses the control board or the board support member against the pressure member in the stacking direction by the fastening force of the male screw portion.

[0069] (Technical Thought 4) a nut member (22) that is a separate part from the pressure applying part and is provided integrally with the pressure applying part; the fixing member has a male thread portion (20a) that screws into a female thread portion (22a) formed on the nut member, The power conversion device according to Technical Idea 1 or 2, wherein the fixing member presses the control board or the board support member against the pressure member in the stacking direction by the fastening force of the male screw portion.

[0070] (Technical Thought 5) The power conversion device according to Technical Idea 4, wherein the nut member has a lid portion formed at an end portion in the axial direction.

[0071] (Technical Thought 6) The cooler includes the pressurizing unit, the fixing member has a male thread portion (20a) that screws into a female thread portion (15a) formed on the cooler, The power conversion device according to Technical Idea 1, wherein the fixing member presses the control board or the board support member against the pressure member in the stacking direction by the fastening force of the male screw portion.

[0072] (Technical Thought 7) a capacitor (5) connected to the semiconductor device; a current sensor (7) for detecting a current flowing through an output line (8) connecting an electrical load (3) and the semiconductor device; Equipped with the capacitor and the current sensor are provided at positions where at least a portion of the capacitor and the current sensor overlap with the control board in the stacking direction, The power conversion device according to any one of Technical Ideas 1 to 6, wherein the cooler is arranged in a position that overlaps with the capacitor and the current sensor in a direction perpendicular to the stacking direction. [Explanation of symbols]

[0073] 3...Motor generator (electrical load), 5...Smoothing capacitor (capacitor) 7...current sensor; 8...output line; 13...control board; 14...board support member 15...pressure portion, 15a...female thread portion, 16...spring member 17...First cooler (cooler), 18...Second cooler (cooler) 20...Fixing screw (fixing member), 20a...Male threaded portion, 22...Nut member 22a... female screw portion, 90... semiconductor device, 171... first cooler (cooler)

Claims

1. A semiconductor device (90) that performs power conversion; a control board (13) on which electronic components for driving the semiconductor device are mounted; a cooler (17, 18, 171) that is stacked on the semiconductor device and cools the semiconductor device; a pressure unit (15) that is arranged in a stacked manner on the semiconductor device and applies a pressing force to the semiconductor device in a stacking direction; a fixing member (20) that applies a fixing force to press the control board or a board support member (14) supporting the control board against the pressure unit in a stacking direction, the fixing member (20) being stacked on the pressure unit on the opposite side of the semiconductor device; Equipped with The fixing member is provided at a position overlapping the semiconductor device in the stacking direction.

2. The cooler includes a first cooler (17) through which a cooling fluid flows and which is stacked on one surface side of the semiconductor device in the stacking direction, and a second cooler (18) through which a cooling fluid flows and which is stacked on the other surface side of the semiconductor device in the stacking direction, The power conversion device according to claim 1, further comprising a spring member (16) interposed between the first cooler and the pressurizing portion and applying a spring reaction force to the first cooler and the pressurizing portion.

3. The fixing member has a male thread portion (20a) that screws into a female thread portion (15a) formed on the pressure portion, The power conversion device according to claim 2 , wherein the fixing member presses the control board or the board support member against the pressure member in the stacking direction by a fastening force from the male screw portion.

4. a nut member (22) that is a separate part from the pressure applying part and is provided integrally with the pressure applying part; The fixing member has a male thread portion (20a) that screws into a female thread portion (22a) formed on the nut member, The power conversion device according to claim 2 , wherein the fixing member presses the control board or the board support member against the pressure member in the stacking direction by a fastening force from the male screw portion.

5. The power conversion device according to claim 4 , wherein the nut member has a cover formed at an end in the axial direction.

6. The cooler includes the pressurizing unit, the fixing member has a male thread portion (20a) that screws into a female thread portion (15a) formed on the cooler, The power conversion device according to claim 1 , wherein the fixing member presses the control board or the board support member against the pressure member in the stacking direction by a fastening force from the male screw portion.

7. a capacitor (5) connected to the semiconductor device; a current sensor (7) for detecting a current flowing through an output line (8) connecting an electrical load (3) and the semiconductor device; Equipped with the capacitor and the current sensor are provided at positions where at least a portion of the capacitor and the current sensor overlap with the control board in the stacking direction, The power conversion device according to claim 1 , wherein the cooler is provided at a position overlapping the capacitor and the current sensor in a direction perpendicular to the stacking direction.

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