JP5103318B2 - Power converter for vehicle, metal base for power module and power module - Google Patents

Description

  The present invention relates to a vehicular power conversion device that is mounted on an electric vehicle or a hybrid vehicle, and that converts DC power and AC power into mutual output.

Conventionally, a power conversion device such as an inverter used in an electric vehicle or a hybrid vehicle includes a power semiconductor switching element such as an IGBT that generates a large amount of heat. For this reason, a cooling structure is adopted in which a plurality of heat radiating pins protrude from the bottom surface of the base plate of the power module on which the switching element is mounted to the cooling liquid flow path to radiate the switching element. The heat radiating pins are brazed directly to the base plate (see, for example, Patent Document 1).
JP2007-295765

  However, in such a conventional vehicular power conversion device, since a plurality of pins are brazed to the base plate of the power module, there is a problem that the productivity is low and the manufacturing cost is high. there were.

(1) The invention of claim 1 is a semiconductor circuit that converts power between DC power and AC power, a metal base that mounts the semiconductor circuit on the surface, and a rear surface of the metal base that projects from the cooling liquid. And a power module having a plurality of radiating fins that exchange heat, and is applied to a vehicle power converter that drives an in-vehicle motor with AC power output from the power module. The semiconductor circuit is configured to output three-phase AC power, and a plurality of radiating fins are integrally formed with the metal base by forging, and the hardness and thickness of the metal base prevent ratchet deformation. It is determined as follows.
(2) The invention of claim 7 includes a power module having the semiconductor circuit, the metal base, and the plurality of heat dissipating fins, and drives a vehicle-mounted motor with AC power output from the power module. Applies to The plurality of heat radiating fins are integrally formed by a metal powder injection molding method together with a metal base, and the hardness and thickness of the metal base are determined so as to prevent the occurrence of ratchet deformation .
(3) The invention of claim 14 is the metal base used in the vehicle power converter.
(4) A fifteenth aspect of the invention is a power module including the metal base of the fourteenth aspect and a semiconductor circuit used for the vehicle power converter.

  According to the present invention, since the heat dissipating fin protruding into the cooling liquid channel is integrally formed on the metal base by forging or metal powder injection molding, the cooling performance can be improved while suppressing the manufacturing cost.

  A power converter according to an embodiment of the present invention will be described below in detail with reference to the drawings. The power conversion device according to the embodiment of the present invention can be applied to a hybrid vehicle or a pure electric vehicle. As a representative example, the power conversion device according to the embodiment of the present invention is applied to a hybrid vehicle. The control configuration and the circuit configuration of the power converter will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a control block of a hybrid vehicle.

  The power conversion device according to the embodiment of the present invention is used in a vehicle-mounted power conversion device for a vehicle-mounted electrical system mounted on an automobile, in particular, a vehicle drive electrical system, and has a very severe mounting environment and operational environment. The inverter device will be described as an example. A vehicle drive inverter device is provided in a vehicle drive electrical system as a control device that controls the drive of a vehicle drive motor, and a DC power supplied from an onboard battery or an onboard power generator that constitutes an onboard power source is a predetermined AC power. Then, the AC power obtained is supplied to the vehicle drive motor to control the drive of the vehicle drive motor. Further, since the vehicle drive motor also has a function as a generator, the vehicle drive inverter device also has a function of converting the AC power generated by the vehicle drive motor into DC power according to the operation mode. Yes. The converted DC power is supplied to the on-vehicle battery.

  In FIG. 1, a hybrid electric vehicle (hereinafter referred to as “HEV”) 110 is one electric vehicle and includes two vehicle drive systems. One of them is an engine system that uses an engine 120 that is an internal combustion engine as a power source. The engine system is mainly used as a drive source for HEV. The other is an in-vehicle electric system using motor generators 192 and 194 as a power source. The in-vehicle electric system is mainly used as an HEV drive source and an HEV power generation source. The motor generators 192 and 194 are, for example, synchronous machines or induction machines, and operate as both a motor and a generator depending on the operation method.

  A front wheel axle 114 is rotatably supported at the front portion of the vehicle body. A pair of front wheels 112 are provided at both ends of the front wheel axle 114. A rear wheel axle (not shown) is rotatably supported on the rear portion of the vehicle body. A pair of rear wheels are provided at both ends of the rear wheel axle. The HEV of this embodiment employs a so-called front wheel drive system in which the main wheel driven by power is the front wheel 112 and the driven wheel to be driven is the rear wheel. You may adopt.

  A front wheel side differential gear (hereinafter referred to as “front wheel side DEF”) 116 is provided at the center of the front wheel axle 114. The front wheel axle 114 is mechanically connected to the output side of the front wheel side DEF 116. The output shaft of the transmission 118 is mechanically connected to the input side of the front wheel side DEF 116. The front wheel side DEF 116 is a differential power distribution mechanism that distributes the rotational driving force that is shifted and transmitted by the transmission 118 to the left and right front wheel axles 114. The output side of the motor generator 192 is mechanically connected to the input side of the transmission 118. The output side of the engine 120 and the output side of the motor generator 194 are mechanically connected to the input side of the motor generator 192 via the power distribution mechanism 122. Motor generators 192 and 194 and power distribution mechanism 122 are housed inside the casing of transmission 118.

  The motor generators 192 and 194 are synchronous machines having a permanent magnet on the rotor, and the AC power supplied to the armature windings of the stator is controlled by the inverter devices 140 and 142, thereby the motor generators 192 and 194. Is controlled. A battery 136 is electrically connected to the inverter devices 140 and 142, and power can be exchanged between the battery 136 and the inverter devices 140 and 142.

  In the present embodiment, two motor generator units, a first motor generator unit composed of a motor generator 192 and an inverter device 140, and a second motor generator unit composed of a motor generator 194 and an inverter device 142 are provided. ing. That is, in the case where the vehicle is driven by the power from the engine 120, when assisting the driving torque of the vehicle, the second motor generator unit is operated as the power generation unit by the power of the engine 120 to generate power. The first electric power generation unit is operated as an electric unit by the obtained electric power. Further, in the same case, when assisting the vehicle speed of the vehicle, the first motor generator unit is operated by the power of the engine 120 as a power generation unit to generate power, and the second motor generator unit is generated by the electric power obtained by the power generation. Operate as an electric unit.

  In the present embodiment, the vehicle can be driven only by the power of the motor generator 192 by operating the first motor generator unit as an electric unit by the electric power of the battery 136. Further, in the present embodiment, the battery 136 can be charged by generating power by operating the first motor generator unit or the second motor generator unit as a power generation unit by the power of the engine 120 or the power from the wheels.

  The battery 136 is also used as a power source for driving an auxiliary motor 195. The auxiliary machine is, for example, a motor that drives a compressor of an air conditioner or a motor that drives a hydraulic pump for control. DC power is supplied from the battery 136 to the inverter device 43 and converted into AC power by the inverter device 43. To the motor 195. The inverter device 43 has the same function as the inverter devices 140 and 142 and controls the phase, frequency, and power of alternating current supplied to the motor 195. For example, the motor 195 generates torque by supplying AC power having a leading phase with respect to the rotation of the rotor of the motor 195. On the other hand, by generating the delayed phase AC power, the motor 195 acts as a generator, and the motor 195 is operated in a regenerative braking state. The control function of the inverter device 43 is the same as the control function of the inverter devices 140 and 142. Since the capacity of the motor 195 is smaller than the capacity of the motor generators 192 and 194, the maximum conversion power of the inverter device 43 is smaller than the inverter devices 140 and 142, but the circuit configuration of the inverter device 43 is basically the circuit of the inverter devices 140 and 142. Same as the configuration.

  The inverter device 140, the inverter device 142, the inverter device 43, and the capacitor module 500 are in an electrical close relationship. Furthermore, there is a common point that measures against heat generation are necessary. It is also desired to make the volume of the device as small as possible. From these points, the power conversion device described in detail below includes the inverter devices 140 and 142, the inverter device 43, and the capacitor module 500 in the casing of the power conversion device. With this configuration, a small and highly reliable device can be realized.

  Further, by incorporating the inverter device 140, the inverter device 142, the inverter device 43, and the capacitor module 500 in one housing, it is effective in simplifying wiring and taking measures against noise. Further, the inductance of the connection circuit between the capacitor module 500 and the inverter device 140, the inverter device 142, and the inverter device 43 can be reduced, the spike voltage can be reduced, and heat generation can be reduced and heat radiation efficiency can be improved.

  Next, the electric circuit configuration of the inverter device 140, the inverter device 142, or the inverter device 43 will be described with reference to FIG. In the embodiment illustrated in FIGS. 1 to 2, the case where the inverter device 140, the inverter device 142, or the inverter device 43 is individually configured will be described as an example. Since the inverter device 140, the inverter device 142, or the inverter device 43 has the same configuration and performs the same function and has the same function, the inverter device 140 will be described here as a representative example.

  The power conversion device 200 according to the present embodiment includes an inverter device 140 and a capacitor module 500, and the inverter device 140 includes an inverter circuit 144 and a control unit 170. Further, the inverter circuit 144 includes a plurality of upper and lower arm series circuits 150 including an IGBT 328 (insulated gate bipolar transistor) and a diode 156 that operate as an upper arm, and an IGBT 330 and a diode 166 that operate as a lower arm (FIG. 2). In this example, three upper and lower arm series circuits 150) are connected to an AC power line (AC bus bar) 186 from the middle point (intermediate electrode 169) of each upper and lower arm series circuit 150 through an AC terminal 159 to the motor generator 192. is there. In addition, the control unit 170 includes a driver circuit 174 that drives and controls the inverter circuit 144 and a control circuit 172 that supplies a control signal to the driver circuit 174 via the signal line 176.

  The IGBTs 328 and 330 of the upper arm and the lower arm are switching power semiconductor elements, operate in response to the drive signal output from the control unit 170, and convert DC power supplied from the battery 136 into three-phase AC power. . The converted electric power is supplied to the armature winding of the motor generator 192.

  The inverter circuit 144 is configured by a three-phase bridge circuit, and a DC positive terminal 314 to which upper and lower arm series circuits 150, 150, 150 for three phases are electrically connected to the positive side and the negative side of the battery 136, respectively. And DC negative electrode terminal 316 are electrically connected in parallel.

  In the present embodiment, the use of IGBTs 328 and 330 as switching power semiconductor elements is exemplified. The IGBTs 328 and 330 include collector electrodes 153 and 163, emitter electrodes (signal emitter electrode terminals 155 and 165), and gate electrodes (gate electrode terminals 154 and 164). Diodes 156 and 166 are electrically connected between the collector electrodes 153 and 163 of the IGBTs 328 and 330 and the emitter electrode as shown. The diodes 156 and 166 have two electrodes, a cathode electrode and an anode electrode. The cathode electrode serves as the collector electrode of the IGBTs 328 and 330 so that the direction from the emitter electrode to the collector electrode of the IGBTs 328 and 330 is the forward direction. The anode electrodes are electrically connected to the emitter electrodes of the IGBTs 328 and 330, respectively. A MOSFET (metal oxide semiconductor field effect transistor) may be used as the switching power semiconductor element. In this case, the diode 156 and the diode 166 are not necessary.

  Upper and lower arm series circuit 150 is provided for three phases corresponding to each phase winding of the armature winding of motor generator 192. The three upper and lower arm series circuits 150 correspond to the U-phase, V-phase, and W-phase, respectively, and are connected to the motor generator 192 via the intermediate electrode 169 that connects the emitter electrode of the IGBT 328 and the collector electrode 163 of the IGBT 330 and the AC terminal 159. U phase, V phase, and W phase are formed. The upper and lower arm series circuits are electrically connected in parallel. The collector electrode 153 of the upper arm IGBT 328 is connected to the positive capacitor electrode of the capacitor module 500 via the positive terminal (P terminal) 157, and the emitter electrode of the lower arm IGBT 330 is connected to the capacitor module 500 via the negative terminal (N terminal) 158. Are respectively electrically connected (connected by a DC bus bar). An intermediate electrode 169 corresponding to the middle point portion of each arm (the connection portion between the emitter electrode of the IGBT 328 of the upper arm and the collector electrode of the IGBT 330 of the lower arm) is connected to the corresponding phase winding of the armature winding of the motor generator 192 by alternating current. The terminals 159 and the AC connector 188 are electrically connected.

  Capacitor module 500 is for configuring a smoothing circuit that suppresses fluctuations in DC voltage caused by the switching operation of IGBTs 328 and 330. The positive electrode side of the battery 136 is electrically connected to the positive electrode side capacitor electrode of the capacitor module 500, and the negative electrode side of the battery 136 is electrically connected to the negative electrode side capacitor electrode of the capacitor module 500 via the DC connector 138. Thus, the capacitor module 500 is connected between the collector electrode 153 of the upper arm IGBT 328 and the positive electrode side of the battery 136, and between the emitter electrode of the lower arm IGBT 330 and the negative electrode side of the battery 136. Electrically connected in parallel to the series circuit 150.

  The control unit 170 is for operating the IGBTs 328 and 330, and generates a timing signal for controlling the switching timing of the IGBTs 328 and 330 based on input information from other control devices or sensors. And a drive circuit 174 that generates a drive signal for switching the IGBTs 328 and 330 based on the timing signal output from the control circuit 172.

  The control circuit 172 includes a microcomputer (hereinafter referred to as “microcomputer”) for calculating the switching timing of the IGBTs 328 and 330. The microcomputer receives as input information a target torque value required for the motor generator 192, a current value supplied to the armature winding of the motor generator 192 from the upper and lower arm series circuit 150, and a magnetic pole of the rotor of the motor generator 192. The position has been entered. The target torque value is based on a command signal output from a host controller (not shown). The current value is detected based on the detection signal output from the current sensor 180. The magnetic pole position is detected based on a detection signal output from a rotating magnetic pole sensor (not shown) provided in the motor generator 192. In the present embodiment, the case where the current values of three phases are detected will be described as an example, but the current values for two phases may be detected.

  The microcomputer in the control circuit 172 calculates the d and q axis current command values of the motor generator 192 based on the target torque value, and the calculated d and q axis current command values and the detected d and q The voltage command values for the d and q axes are calculated based on the difference from the current value of the shaft, and the calculated voltage command values for the d and q axes are calculated based on the detected magnetic pole position. Convert to W phase voltage command value. Then, the microcomputer generates a pulse-like modulated wave based on a comparison between the fundamental wave (sine wave) and the carrier wave (triangular wave) based on the voltage command values of the U phase, V phase, and W phase, and the generated modulation wave The wave is output to the driver circuit 174 as a PWM (pulse width modulation) signal.

  When driving the lower arm, the driver circuit 174 amplifies the PWM signal, and when the driver circuit 174 drives the upper arm to the gate electrode of the corresponding IGBT 330 of the lower arm, the driver circuit 174 sets the level of the reference potential of the PWM signal. After shifting to the level of the reference potential of the upper arm, the PWM signal is amplified and output as a drive signal to the gate electrode of the corresponding IGBT 328 of the upper arm. As a result, each IGBT 328, 330 performs a switching operation based on the input drive signal.

  In addition, the control unit 170 performs abnormality detection (overcurrent, overvoltage, overtemperature, etc.) to protect the upper and lower arm series circuit 150. For this reason, sensing information is input to the control unit 170. For example, information on the current flowing through the emitter electrodes of the IGBTs 328 and 330 is input to the corresponding drive units (ICs) from the signal emitter electrode terminals 155 and 165 of each arm. Thereby, each drive part (IC) detects overcurrent, and when overcurrent is detected, the switching operation of corresponding IGBT328,330 is stopped, and corresponding IGBT328,330 is protected from overcurrent. Information on the temperature of the upper and lower arm series circuit 150 is input to the microcomputer from a temperature sensor (not shown) provided in the upper and lower arm series circuit 150. In addition, voltage information on the DC positive side of the upper and lower arm series circuit 150 is input to the microcomputer. The microcomputer performs over-temperature detection and over-voltage detection based on the information, and when an over-temperature or over-voltage is detected, stops the switching operation of all the IGBTs 328 and 330, and the upper and lower arm series circuit 150 (subtract) The semiconductor module including the circuit 150 is protected from overtemperature or overvoltage.

  The conduction and cut-off operations of the IGBTs 328 and 330 of the upper and lower arms of the inverter circuit 144 are switched in a certain order, and the current generated in the stator winding of the motor generator 192 at this switching flows through a circuit including the diodes 156 and 166.

  As shown in the figure, the upper and lower arm series circuit 150 includes a positive terminal (P terminal, positive terminal) 157, a negative terminal (N terminal, negative terminal) 158, an AC terminal 159 connected to the intermediate electrode 169 of the upper and lower arms, An arm signal terminal (signal emitter electrode terminal) 155, an upper arm gate electrode terminal 154, a lower arm signal terminal (signal emitter electrode terminal) 165, and a lower arm gate terminal electrode 164 are provided. The power conversion device 200 has a DC connector 138 on the input side and an AC connector 188 on the output side, and is connected to the battery 136 and the motor generator 192 through the connectors 138 and 188, respectively. Further, as a circuit for generating an output of each phase of the three-phase alternating current to be output to the motor generator, a power conversion device having a circuit configuration in which two upper and lower arm series circuits are connected in parallel to each phase may be used.

  3-7, 200 is a power converter, 10 is an upper case, 11 is a metal base plate, 12 is a housing, 13 is a cooling water inlet pipe, 14 is a cooling water outlet pipe, 420 is a lower cover, 16 is The lower case, 17 is an AC terminal case, 18 is an AC terminal, 19A is a cooling jacket, 19 is a cooling water passage in the cooling jacket 19A, and 20 is a control circuit board that holds the control circuit 172. Reference numeral 21 denotes a connector for connection to the outside, and reference numeral 22 denotes a drive circuit board that holds a driver circuit 174. Two power modules (semiconductor module units) 300 are provided, and an inverter circuit 144 is built in each power module. 700 is a laminated conductor plate, 800 is an O-ring, 304 is a metal base, 188 is an AC connector, 314 is a DC positive terminal, 316 is a DC negative terminal, 500 is a capacitor module, 502 is a capacitor case, 504 is a positive capacitor terminal, Reference numeral 506 denotes a negative side capacitor terminal, and 514 denotes a capacitor cell.

  FIG. 3 is an external perspective view of the overall configuration of the power conversion device according to the embodiment of the present invention. The power conversion device 200 according to this embodiment includes a casing 12 having a substantially rectangular top or bottom surface, and a cooling water inlet pipe 13 and a cooling water outlet pipe 14 provided on one of the outer circumferences on the short side of the casing 12. And an upper case 10 for closing the upper opening of the housing 12 and a lower case 16 for closing the lower opening of the housing 12. Since the shape of the bottom surface or the top surface of the housing 12 is substantially rectangular, it is easy to attach to the vehicle and is easy to produce.

  Two sets of AC terminal cases 17 used for connection to the motor generators 192 and 194 are provided on the outer periphery of the long side of the power conversion device 200. AC terminal 18 is used to electrically connect power module 300 and motor generators 192 and 194. The AC current output from the power module 300 is transmitted to the motor generators 192 and 194 via the AC terminal 18.

  The connector 21 is connected to a control circuit board 20 built in the housing 12. Various signals from the outside are transmitted to the control circuit board 20 via the connector 21. The direct current (battery) negative electrode side connection terminal portion 510 and the direct current (battery) positive electrode side connection terminal portion 512 electrically connect the battery 136 and the capacitor module 500. Here, in the present embodiment, the connector 21 is provided on one side of the outer peripheral surface on the short side of the housing 12. On the other hand, the direct current (battery) negative electrode side connection terminal portion 510 and the direct current (battery) positive electrode side connection terminal portion 512 are provided on the outer peripheral surface on the short side opposite to the surface on which the connector 21 is provided. That is, the connector 21 and the direct current (battery) negative electrode side connection terminal portion 510 are arranged apart from each other. As a result, noise that enters the housing 12 from the direct current (battery) negative electrode side connection terminal portion 510 and propagates to the connector 21 can be reduced, and the controllability of the motor by the control circuit board 20 can be improved.

  FIG. 4 is a perspective view in which the entire configuration of the power conversion device according to the embodiment of the present invention is disassembled into components.

  As shown in FIG. 4, a cooling jacket 19A in which a cooling water flow path 19 is formed is provided in the middle of the housing 12, and two sets of openings are arranged on the upper surface of the cooling jacket 19A along the flow direction. 400 and 402 are formed. Two power modules 300 are fixed to the upper surface of the cooling jacket 19A so as to close the two sets of openings 400 and 402. Each power module 300 is provided with fins 305 for heat dissipation (see FIG. 7), and the fins 305 (see FIG. 7) of each power module 300 are respectively connected to the cooling water flow path 19 from the openings 400 and 402 of the cooling jacket 19A. It protrudes inside. A structure for fixing the power module 300 to the housing 12 will be described later.

  An opening 404 for facilitating aluminum casting is formed on the lower surface of the cooling jacket 19A, and the opening 404 is closed by the lower cover 420. An auxiliary inverter 43 is attached to the lower surface of the cooling jacket 19A. The auxiliary inverter device 43 includes a circuit similar to the inverter circuit 144 shown in FIG. 2, and includes a power module including a power semiconductor element constituting the inverter circuit 144. The auxiliary inverter device 43 is fixed to the lower surface of the cooling jacket 19 </ b> A so that the heat radiating metal surface of the built-in power module faces the lower surface of the cooling water passage 19. Further, an O-ring 800 for sealing is provided between the power module 300 and the housing 12, and an O-ring 802 is also provided between the lower cover 420 and the housing 12. In this embodiment, the sealing material is an O-ring, but a resin material, a liquid seal, a packing, or the like may be used instead of the O-ring. In particular, when the liquid seal is used, the power converter 200 can be easily assembled. Can be improved.

  Further, a lower case 16 is provided below the cooling jacket 19A, and a capacitor module 500 is provided in the lower case 16. Capacitor module 500 is fixed to the inner surface of the bottom plate of lower case 16 such that the heat dissipation surface of the metal case is in contact with the inner surface of the bottom plate of lower case 16. With this structure, the power module 300 and the inverter device 43 can be efficiently cooled using the upper surface and the lower surface of the cooling jacket 19A, which leads to a reduction in the size of the entire power conversion device.

  When the cooling water from the cooling water inlet / outlet pipes 13 and 14 flows through the cooling water flow path 19, the radiation fins of the two power modules 300 provided are cooled, and the entire two power modules 300 are cooled. The The auxiliary inverter device 43 provided on the lower surface of the cooling jacket 19A is also cooled at the same time.

  Further, the casing 12 provided with the cooling water flow path 19 is cooled, so that the lower case 16 provided at the lower part of the casing 12 is cooled, and the heat of the capacitor module 500 causes the lower case 16 and the casing 12 to be cooled. The capacitor module 500 is cooled by being thermally conducted to the cooling water.

  A laminated conductor plate 700 for electrically connecting the power module 300 and the capacitor module 500 is disposed above the power module 300. The laminated conductor plate 700 is configured to be wide in the width direction of the two power modules 300 across the two power modules 300. Further, the laminated conductor plate 700 includes a positive electrode side conductor plate 702 connected to the positive electrode side terminal of the capacitor module 500, a negative electrode side conductor plate 704 connected to the negative electrode side terminal, and the positive electrode side terminal and the negative electrode side terminal. It is comprised by the insulating member arrange | positioned. As a result, the laminated area of the laminated conductor plate 700 can be increased, so that the parasitic inductance from the power module 300 to the capacitor module 500 can be reduced. In addition, since one laminated conductor plate 700 is placed on the two power modules 300, the laminated conductor plate 700, the power module 300, and the capacitor module 500 can be electrically connected. Even if it is a power converter provided, the assembly man-hour can be suppressed.

  A control circuit board 20 and a drive circuit board 22 are disposed above the laminated conductor plate 700. A driver circuit 174 shown in FIG. 2 is mounted on the drive circuit board 22, and a control circuit 172 having a CPU shown in FIG. 2 is mounted on the control circuit board 20. A metal base plate 11 is disposed between the drive circuit board 22 and the control circuit board 20. The metal base plate 11 functions as an electromagnetic shield for a circuit group mounted on both the boards 22 and 20 and also has an action of releasing and cooling the heat generated in the drive circuit board 22 and the control circuit board 20. Yes. In this way, the cooling jacket 19A is provided at the center of the housing 12, the power module 300 for driving the vehicle is disposed on one side thereof, and the power module 43 for auxiliary machines is disposed on the other side. Cooling can be efficiently performed in a small space, and the entire power conversion device can be downsized. By making the cooling jacket 19A integrally with the housing 12 by aluminum casting, the cooling jacket 19A has an effect of increasing the mechanical strength in addition to the cooling effect. Further, since the casing 12 and the cooling jacket 19A are integrally formed by aluminum casting, heat conduction is improved and cooling efficiency is improved.

  The drive circuit board 22 is provided with an inter-board connector 23 that passes through the metal base plate 11 and is connected to a circuit group of the control circuit board 20. The control circuit board 20 is provided with a connector 21 for electrical connection with the outside. The connector 21 is used to transmit a signal to and from the in-vehicle battery 136 provided outside the power converter, that is, a lithium battery module. A signal representing the state of the battery and a signal such as the state of charge of the lithium battery are sent from the lithium battery module to the control circuit board 20. A signal line 176 (not shown in FIG. 4) shown in FIG. 2 is connected to the board-to-board connector 23, and a switching timing signal of the inverter circuit is transmitted from the control circuit board 20 to the drive circuit board 22. The drive circuit board 22 is gate-driven. A signal is generated and applied to each gate electrode of the power module.

  Openings are formed in the upper end and lower end of the housing 12. These openings are closed by fixing the upper case 10 and the lower case 16 to the housing 12 with fastening parts such as screws and bolts, for example. A cooling jacket 19 </ b> A in which a cooling water channel 19 is provided is formed in the center of the casing 12 in the height direction. By covering the upper surface opening of the cooling jacket 19A with the power module 300 and covering the lower surface opening with the lower cover 420, the cooling water channel 19 is formed inside the cooling jacket 19A. A water leakage test of the cooling water passage 19 is performed during the assembly. When the water leak test is passed, the work of attaching the substrate and the capacitor module 500 from the upper and lower openings of the housing 12 can be performed next. In this way, the cooling jacket 19A is arranged in the center of the housing 12, and then a structure that allows the necessary parts to be fixed from the openings at the upper and lower ends of the housing 12 is adopted, thereby improving productivity. To do. Moreover, it becomes possible to complete the cooling water flow path 19 first and to attach other parts after the water leak test, which improves both productivity and reliability.

  FIG. 5 is a view in which a cooling water inlet pipe and an outlet pipe are attached to an aluminum casting of the casing 12 having a cooling jacket 19A. FIG. 5 (a) is a perspective view of the casing 12, and FIG. FIG. 5C is a bottom view of the housing 12. As shown in FIG. 5, a cooling jacket 19 </ b> A in which a cooling water passage 19 is formed is integrally cast in the housing 12. A cooling water inlet pipe 13 and a cooling water inlet pipe 14 for taking in cooling water are provided on one side surface of the short side of the housing 12 having a substantially rectangular shape in plan view.

  The cooling water that has flowed into the cooling water channel 19 from the cooling water inlet pipe 13 flows along the long side of the rectangle in the direction of the arrow 418, and in the vicinity of the front side of the other side of the short side of the rectangle, the arrows 421a and 421b. Then, it flows again in the direction of the arrow 422 along the long side of the rectangle, and flows out from the outlet hole (not shown) to the cooling water inlet pipe 14. Four openings 400 and 402 are opened on the upper surface of the cooling jacket 19A. One opening 400 is provided for each of the outward and return paths of the cooling water. The opening 402 is the same. The power modules 300 are fixed to the openings 400 and 402, respectively, and the heat radiation fins of the power modules 300 protrude into the cooling water flow from the respective openings. Two sets of power modules 300 arranged in the direction of the flow of the cooling water, that is, the direction along the long side of the housing 12 are fixed so as to block the opening of the cooling jacket 19A through a sealing material such as an O-ring 800, for example. Is done.

  The cooling jacket 19A is integrally formed with the casing 12 across the middle stage of the casing peripheral wall 12W. Four openings 400 and 402 are provided on the upper surface of the cooling jacket 19A, and one opening 404 is provided on the lower surface. Around each of the openings 400 and 402, a power module mounting surface 410S is provided. A portion between the openings 400 and 402 of the attachment surface 410S is referred to as a support portion 410. One power module 300 is fixed toward the inlet / outlet side of the cooling water with respect to the support portion 410, and another one power module 300 is fixed toward the return side of the cooling water with respect to the support portion 410.

  The bolt hole 412 and the bolt through hole 412A shown in FIG. 5B are used to fix the power module 300 on the cooling water inlet / outlet side to the mounting surface 410S, and the opening 400 is sealed by this fixing. The bolt hole 414 and the bolt through hole 414A are used for fixing the power module 300 on the cooling water return side to the mounting surface 410S, and the opening 402 is sealed by this fixing. By arranging the power modules 300 so as to straddle both the forward path and the return path of the cooling water flow path 19 as described above, the inverter circuit 144 can be integrated on the metal base 304 at a high density. Therefore, the power conversion device 200 can be greatly reduced in size.

  The power module 300 on the inlet / outlet side is cooled by the cold cooling water from the cooling water inlet pipe 13 and the cooling water heated near the outlet side by the heat from the heat generating components. On the other hand, the folded-back power module 300 is cooled by a slightly warmed cooling water and a cooling water that is slightly cooler than the cooling water near the outlet hole 403. As a result, the arrangement relationship between the folded cooling passage and the two power modules 300 has an advantage that the cooling efficiency of the two power modules 300 is balanced.

  The support portion 410 is used for fixing the power module 300 and is necessary for sealing the openings 400 and 402. Further, the support portion 410 has a great effect on strengthening the strength of the housing 12. The cooling water channel 19 has a folded shape as described above, and is provided with a partition wall 408 that separates the forward path of the channel and the return path of the channel, and this partition wall 408 is formed integrally with the support portion 410. The partition 408 is a member that separates the forward path of the flow path from the return path of the flow path, and has a function of increasing the mechanical strength of the housing 12. In addition, the heat of the cooling water in the return path of the flow path is transferred to the cooling water in the forward path of the flow path to make the temperature of the cooling water uniform. If the temperature difference between the inlet side and the outlet side of the cooling water is large, uneven cooling efficiency increases. Although the temperature difference to some extent is unavoidable, the partition wall 408 is formed integrally with the support portion 410, so that there is an effect of suppressing the temperature difference of the cooling water.

  As described above, since the cooling jacket 19 </ b> A is provided across the housing 12 at the middle position of the housing 12, the cooling jacket 19 </ b> A functions as a strength member of the housing 12. In addition, the support portion 410 and the partition 408 function as the cooling jacket 19 </ b> A and eventually the strength member of the housing 12.

  FIG. 5C shows the back surface of the cooling jacket 19 </ b> A, and an opening 404 is formed on the back surface corresponding to the support portion 410. This opening 404 is for improving the yield when the support portion 410 formed by casting the casing and the casing 12 are integrally formed. The formation of the opening 404 eliminates the double structure of the support portion 410 and the bottom portion of the cooling water channel 19, facilitates casting, and improves productivity.

  Further, a through hole 406 is formed on the outer side of the cooling water passage 19. Electrical components (the power module 300 and the capacitor module 500) installed on both sides of the cooling water channel 19 are connected via the through hole 406.

  Since the housing 12 can be manufactured as an integral structure with the cooling jacket 19A, it is suitable for casting production, particularly aluminum die casting production.

  FIG. 6 shows a state where the power module 300 is fixed to the upper surface opening of the jacket 19A and the lower cover 420 is fixed to the rear surface opening. On one long side of the rectangle of the housing 12, an AC power line 186 and an AC connector 188 protrude from the housing 12.

  In FIG. 6, a through hole 406 is formed inside the other long side of the rectangle of the housing 12, and a part of the laminated conductor plate 700 connected to the power module 300 through the through hole 406 can be seen. The auxiliary inverter device 43 is disposed in the vicinity of the side surface of the housing 12 to which the DC positive electrode side connection terminal portion 512 is connected. Further, a capacitor module 500 is disposed below the auxiliary inverter device 43 (on the side opposite to the side where the cooling water flow path 19 is present). The auxiliary machine positive terminal 44 and the auxiliary machine negative terminal 45 protrude downward (in the direction in which the capacitor module 500 is disposed), and are connected to the auxiliary machine positive terminal 532 and the auxiliary machine negative terminal 534 on the capacitor module 500 side, respectively. Is done. As a result, the wiring distance from the capacitor module 500 to the auxiliary device inverter 43 is shortened, so that the auxiliary device positive terminal 532 and the auxiliary device negative terminal 534 on the capacitor module 500 side through the metal casing 12. Noise that enters the control circuit board 20 can be reduced.

  In addition, the auxiliary inverter device 43 is disposed in the gap between the coolant channel 19 and the capacitor module 500, and the auxiliary inverter device 43 is approximately as high as the lower cover 420. Therefore, the auxiliary inverter device 43 can be cooled and an increase in the height of the power conversion device 200 can be suppressed.

  Moreover, as shown in FIG. 6, the cooling water inlet piping 13 and the cooling water outlet piping 14 are being fixed with the screw. In the state of FIG. 6, the water leakage inspection of the cooling water channel 19 can be performed. The auxiliary inverter device 43 is attached to the one that has passed this inspection, and the capacitor module 500 is further attached.

  FIG. 7 is a cross-sectional view of the power conversion device 200 (AA cross-section reference of FIG. 6), and the basic structure is as already described based on FIGS.

  A cooling jacket 19A (indicated by a dotted line in FIG. 7) made of aluminum die-casting integrally with the casing 12 is provided at the center in the vertical direction in the cross section of the casing 12, and is formed on the upper surface side of the cooling jacket 19A. The power module 300 (the chain line portion in FIG. 7) is installed in the opening. The left side with respect to the paper surface of FIG. 7 is the forward path 19a of the cooling water, and the right side with respect to the paper surface is the return path 19b on the return side of the water channel. As described above, the openings are respectively provided above the forward path 19a and the return path 19b, and the openings are blocked by the metal base 304 for heat dissipation of the power module 300 so as to straddle both the forward path 19a and the return path 19b. A heat radiation fin 305 provided on the base 304 protrudes from the opening in the flow of the cooling water. In addition, an auxiliary inverter device 43 is fixed to the lower surface side of the cooling water passage 19.

  One end of the plate-like AC power line 186 bent substantially at the center is connected to the AC terminal 159 of the power module 300, and the other end protrudes from the power converter 200 to form an AC connector. Positive electrode side capacitor terminal 504 and negative electrode side capacitor terminal 506 are electrically and mechanically connected to positive electrode side conductor plate 702 and negative electrode side conductor plate 704, respectively, through through-hole 406 (two-dot chain line portion in FIG. 7). The An AC connector 188, a positive-side capacitor terminal 504, and a negative-side capacitor terminal 506 are arranged in a direction substantially perpendicular to the flow direction of the cooling water in the cooling water flow path 19 provided in the housing 12. Therefore, the electrical wiring is arranged in an orderly manner, which leads to a reduction in size of the power conversion device 200. The positive electrode side conductor plate 702, the negative electrode side conductor plate 704, and the AC side power line 186 of the multilayer conductor plate 700 project outside the power module 300 to form connection terminals. Therefore, the electrical connection structure is very simple, and the size is reduced because no other connection conductor is used. This structure improves productivity and improves reliability.

  Further, the through hole 406 is isolated from the cooling water flow path 19 by a frame inside the housing 12, and the positive side conductor plate 702 and the negative side conductor plate 704, the positive side capacitor terminal 506, and the negative side capacitor terminal 504 are connected. Since the connecting portion exists in the through hole 406, the reliability is improved.

  In the cooling structure described above, the power module 300 having a large calorific value is fixed to one surface of the cooling jacket 19A, and the fins 305 of the power module 300 are protruded into the cooling water flow path 19 to efficiently cool the power module 300. To do. Next, the auxiliary inverter device 43 having a large heat radiation amount is cooled on the other surface of the cooling jacket 19A. Further, the capacitor module 500 having the next largest heat generation amount is cooled via the housing 12 and the lower case 16. Thus, since it is set as the cooling structure match | combined with much heat dissipation, while cooling efficiency and reliability improve, the power converter device 200 can be reduced more in size.

  Further, since the auxiliary inverter device 43 is fixed to the bottom surface of the cooling jacket 19A facing the capacitor module 500, when the capacitor module 500 is used as a smoothing capacitor of the auxiliary inverter device 43, the wiring distance is short. There is an effect. In addition, since the wiring distance is short, the inductance can be reduced.

  A drive circuit board 22 on which a driver circuit 174 is mounted is disposed above the power module 300. Further, a control circuit board is disposed above the drive circuit board 22 with a metal base plate 11 that enhances the effects of heat dissipation and electromagnetic shielding. 20 is arranged. The control circuit board 20 is mounted with the control circuit 172 shown in FIG. By fixing the upper case 10 to the housing 12, the power conversion device 200 according to the present embodiment is configured.

  As described above, since the drive circuit board 22 is arranged between the control circuit board 20 and the power module 300, the operation timing of the inverter circuit is transmitted from the control circuit board 20 to the drive circuit board 22, and based on that. A gate signal is generated by the drive circuit board 22 and applied to each gate of the power module 300. Since the control circuit board 20 and the drive circuit board 22 are thus arranged along the electrical connection relationship, the electrical wiring can be simplified and the power converter 200 can be downsized. The drive circuit board 22 is disposed at a distance closer to the control circuit board 20 than the power module 300 and the capacitor module 500. Therefore, the wiring distance from the drive circuit board 22 to the drive circuit board 20 is shorter than the wiring distance between other components (such as the power module 300) and the control circuit board 20. Therefore, electromagnetic noise transmitted from the DC positive electrode side connection terminal portion 512 and electromagnetic noise due to the switching operation of the IGBTs 328 and 330 can be prevented from entering the wiring from the drive circuit board 22 to the control circuit board 20.

  The power module 300 is fixed to one surface of the cooling jacket 19A and the auxiliary device inverter device 43 is fixed to the other surface, whereby the power module 300 and the auxiliary device 43 are connected with the cooling water flowing through the cooling water passage 19. Cool at the same time. In this case, the power module 300 has a greater cooling effect because the fins for heat dissipation are in direct contact with the cooling water in the cooling water passage 19. Further, the casing 12 is cooled by the cooling water flowing through the cooling water passage 19, and the lower case 16 and the metal base plate 11 fixed to the casing 12 are cooled. Since the metal case of the capacitor module 500 is fixed to the lower case 16, the capacitor module 500 is cooled with cooling water via the lower case 16 and the housing 12. Further, the control circuit board 20 and the drive circuit board 22 are cooled via the metal base plate 11. The lower case 16 is also made of a material having good thermal conductivity, receives heat generated from the capacitor module 500, conducts heat to the housing 12, and the heat transferred is dissipated by the cooling water in the cooling water passage 19. . A relatively small-capacity auxiliary inverter device 43 that is used for an in-vehicle air conditioner, an oil pump, and a pump for other purposes is installed on the lower surface of the cooling jacket 19A. The heat generated from the auxiliary inverter device 43 is radiated by the cooling water in the cooling water passage 19 through the intermediate frame of the housing 12. In this way, the cooling jacket 19A is provided in the center of the housing 12, the metal base plate 11 is provided on one side of the cooling jacket 19A, that is, the upper side, and the lower case 16 is provided on the other side, that is, the lower side, thereby configuring the power conversion device 200. It is possible to efficiently cool the parts necessary for the heat generation according to the heat generation amount. Also, the components are neatly arranged inside the power conversion device 200, and the size can be reduced.

  The heat radiator that performs the heat radiation function of the power conversion device is first the cooling water flow path 19, but the metal base plate 11 also has that function. The metal base plate 11 performs an electromagnetic shielding function, receives heat from the control circuit board 20 and the drive circuit board 22, conducts heat to the housing 12, and is radiated by the cooling water in the cooling water flow path 19.

  As described above, the power conversion device according to the present embodiment has a laminated structure in which the radiator is a three-layered structure, that is, the metal base plate 11, the cooling water channel 19 (cooling jacket 19A), and the lower case 16. Yes. These heat radiators are installed in a hierarchy adjacent to the respective heat generators (power module 300, control circuit board 20, drive circuit board 22, and capacitor module 500). In the center of the hierarchical structure, there is a cooling water flow path 19 that is a main radiator, and the metal base plate 11 and the lower case 16 are structured to transmit heat to the cooling water in the cooling water flow path 19 through the housing 12. . Three radiators (cooling water channel 19, metal base plate 11, and lower case 16) are accommodated in the casing 12, thereby improving heat dissipation and contributing to reduction in thickness and size.

  FIG. 8A is an upper perspective view of the power module 300 according to the present embodiment, and FIG. 8B is a top view of the power module 300. FIG. 9 is an exploded perspective view of a DC terminal of the power module 300 according to the present embodiment. FIG. 10 is a cross-sectional view in which the power module case 302 is partially transparent in order to make the structure of the DC bus bar easier to understand. FIG. 9A is a diagram in which one of the metal base 304 and three upper and lower arm series circuits that are components of the power module 300 is extracted. FIG. 9B is an exploded perspective view of the metal base 304, the circuit wiring pattern, and the insulating substrate 334.

  8A, 302 is a power module case, 304 is a metal base, 305 is a fin (see FIG. 10), 314a is a DC positive terminal connection, 316a is a DC negative terminal connection, and 318 is an insulating paper (FIG. 9). 320U / 320L is the control terminal of the power module, 328 is the IGBT for the upper arm, 330 is the IGBT for the lower arm, 156/166 is the diode, 334 is the insulating substrate (see FIG. 10), 334k is the insulating substrate 334 Upper circuit wiring patterns (see FIG. 10) and 334r represent solid patterns 337 (see FIG. 10) under the insulating substrate 334, respectively.

  The power module 300 mainly includes, for example, a semiconductor module portion including wiring in a power module case 302 made of a resin material, a metal base 304 made of a metal material such as Cu, Al, AlSiC, and the like, and a connection terminal (DC). Positive electrode terminal 314 and control terminal 320U). As terminals to be connected to the outside, the power module 300 includes a U, V, W phase AC terminal 159 for connection to the motor, a DC positive terminal 314 and a DC negative terminal 316 for connection to the capacitor module 500 (see FIG. 9). ).

  The IGBTs 328 and 330 of the upper and lower arms, the diodes 156 and 166, etc. are soldered on the insulating substrate 334, and the region surrounded by the power module case 302 is sealed and protected by a resin or silicon gel (not shown). The insulating substrate 334 may be a ceramic substrate or a thinner insulating sheet. As described later, since it is preferable to have excellent heat conduction, it is desirable to select and use a material having high heat conductivity such as aluminum nitride or silicon nitride.

  FIG. 8B shows an arrangement configuration showing the specific arrangement of the upper and lower arm series circuits on the insulating substrate 334 made of ceramic with good thermal conductivity fixed to the metal base 304. FIG. The IGBTs 328 and 330 and the diodes 327 and 332 shown in FIG. 8B respectively connect two chips in parallel to form an upper arm and a lower arm, and increase the current capacity that can be supplied to the upper and lower arms.

  As shown in FIG. 9, the DC terminal 313 built in the power module 300 has a laminated structure of a DC negative terminal 316 and a DC positive terminal 314 with an insulating paper 318 interposed therebetween (dotted line portion in FIG. 9). The ends of the DC negative electrode terminal 316 and the DC positive electrode terminal 314 are bent in opposite directions to form a negative electrode connecting portion 316a and a positive electrode connecting portion 314a for electrically connecting the laminated conductor plate 700 and the power module 300. ing. By providing two connection portions 314a and 316a with the multilayer conductor plate 700, the average distances from the negative electrode connection portion 316a and the positive electrode connection portion 314a to the three upper and lower arm series circuits are substantially equal. The parasitic inductance variation can be reduced.

  When the DC positive electrode terminal 314, the insulating paper 318, and the DC negative electrode terminal 316 are stacked and assembled, the negative electrode connecting portion 316a and the positive electrode connecting portion 314a are bent in opposite directions. The insulating paper 318 is bent along the negative electrode connecting portion 316a to ensure the insulating creepage distance between the positive and negative terminals. As the insulating paper 318, when heat resistance is required, a sheet in which polyimide, meta-aramid fiber, polyester having improved tracking properties, or the like is used is used. In addition, in consideration of defects such as pin fall, two sheets are stacked to increase reliability. Also, in order to prevent tearing or tearing, the corners are rounded or the sag surface at the time of punching faces the insulating paper so that the edge of the terminal does not touch the insulating paper. In this embodiment, insulating paper is used as the insulator, but as another example, the terminal may be coated with the insulator. In order to reduce the parasitic inductance, for example, in the case of a power module with a withstand voltage of 600 V, the distance between the positive electrode and the negative electrode is 0.5 mm or less, and the thickness of the insulating paper is half or less.

  The DC positive terminal 314 and the DC negative terminal 316 have connection ends 314k and 316k for connecting to the circuit wiring pattern 334k. Two connection ends 314k and 316k are provided for each phase (U, V, W phase). As a result, as will be described later, each arm of each phase can be connected to a circuit wiring pattern in which two small loop current paths are formed. Each connection end 314k, 316k protrudes in the direction of the circuit wiring pattern 334k, and its tip is bent to form a joint surface with the circuit wiring pattern 334k. The connection ends 314k and 316k and the circuit wiring pattern 334k are connected via solder or the like, or the metals are directly connected to each other by ultrasonic welding.

  The power module 300, particularly the metal base 304, expands and contracts due to the temperature cycle. Due to the expansion and contraction, the connection portion between the connection ends 314k and 316k and the circuit wiring pattern 334k may be cracked or broken. Therefore, in the power module 300 according to the present embodiment, as shown in FIG. 9, the laminated flat surface portion 319 formed by laminating the DC positive terminal 314 and the DC negative terminal 316 is provided on the side where the insulating substrate 334 is mounted. The metal base 304 is configured to be substantially parallel to the plane. As a result, the laminated flat surface portion 319 can perform a warping operation corresponding to the warping of the metal base 304 caused by the above-described expansion and contraction. Therefore, the rigidity of the connection ends 314k and 316k formed integrally with the laminated flat surface portion 319 can be reduced with respect to the warp of the metal base 304. Therefore, the stress applied in the vertical direction of the joint surface between the connection ends 314k and 316k and the circuit wiring pattern 334k can be relieved, and the joint surface can be prevented from cracking or breaking.

  In addition, the lamination plane part 319 according to the present embodiment has the width in the width direction of the lamination plane part 319 so that the metal base 304 can be bent in response to both the width direction and the depth direction of the metal base 304. The length in the depth direction is increased to 130 mm and the length in the depth direction to 10 mm. In addition, the thickness of each of the laminated flat surface portions 319 of the DC positive electrode terminal 314 and the DC negative electrode terminal 316 is set to be relatively thin as 1 mm so as to facilitate the warping operation.

  As shown in FIG. 10, an IGBT and a diode constituting an inverter circuit are mounted on one surface of the metal base 304, and a resin power module case 302 is provided on the periphery of the metal base 304. Yes. In order to efficiently dissipate heat to the cooling water flowing through the cooling water channel 19, a plurality of heat radiation fins, that is, a plurality of heat radiation pins 305 are provided on the back surface of the metal base opposite to the mounting surface of the insulating substrate 334. As shown in FIGS. 10A and 12, the metal base 304 is provided with two sets of fin groups 305G so as to correspond to the upper and lower arms, respectively. Each radiating fin group 305 </ b> G has a plurality of radiating fins 305. In the power conversion device of this embodiment, the four radiating fin groups 305G of the pair of power modules 300 protrude into the water channel from the openings 400 and 402 above the reciprocating cooling water channel 19, respectively. The metal surface around the radiating fin group 305 </ b> G of the metal base 304 is used to close the openings 400 and 402 provided in the cooling jacket 19 </ b> A via the O-ring 800.

  As shown in FIG. 13, in each radiation fin group 305G, the radiation pins 305 are arranged in a staggered manner. Compared with the case where the heat radiation pins 305 are arranged in a lattice pattern, the cooling capacity can be improved by effectively bringing the cooling water into contact with each pin while reducing the pressure loss in the cooling water flow path.

  As will be described in detail later, the fin 305 is integrally formed with the metal base 304 by forging using copper as a raw material. In this manufacturing method, the productivity of the power module 300 is improved, the thermal conductivity from the metal base 304 to the fins 305 is improved, and the heat dissipation of the IGBT and the diode can be improved. In addition, as will be described in detail later, by designing the metal base 304 made by forging copper as a raw material to have a Vickers hardness of 60 or more, the ratchet deformation of the metal base 304 caused by the temperature cycle is suppressed. In addition, the sealing performance between the metal base 304 and the housing 12 can be improved.

  An insulating substrate 334 is fixed to one surface of the metal base 304, and an upper arm IGBT 328 and an upper arm diode 156, and a lower arm IGBT 330 and a lower arm are fixed on the insulating substrate 334 by solder 337. The chip having the diode 166 is fixed.

  As shown in FIG. 11 (a), the upper and lower arm series circuit 150 includes an upper arm circuit 151, a lower arm circuit 152, a terminal 370 for connecting the upper and lower arm circuits 151 and 152, and an AC power for output. An AC terminal 159 is provided. Further, as shown in FIG. 11B, the upper arm circuit 151 includes an insulating substrate 334 on which a circuit wiring pattern 334k is formed on a metal base 304, and an IGBT 328 and a diode 156 are provided on the circuit wiring pattern 334k. Implemented and configured.

  The IGBT 328 and the diode 156 have their back side electrodes and the circuit wiring pattern 334k joined together by solder. The insulating substrate 334 forms a so-called solid pattern having no pattern on the surface (back surface) opposite to the circuit wiring pattern surface. The solid pattern on the back surface of the insulating substrate 334 and the metal base 304 are joined by solder. Similarly to the upper arm, the lower arm circuit 152 is mounted on the insulating substrate 334 disposed on the metal base 304, the circuit wiring pattern 334k wired on the insulating substrate 334, and the circuit wiring pattern 334k. IGBT 330 and diode 166 are provided.

  The electrodes on the back side of the IGBT 330 and the diode 166 are also joined to the circuit wiring pattern 334k by solder. In addition, each arm of each phase in the present embodiment is configured by connecting two sets of circuit units in which IGBT 328 and diode 156 are connected in parallel to each other in parallel. The required number of sets of circuit units is determined by the amount of current supplied to the motor 192. When a current larger than the current supplied to the motor 192 according to the present embodiment is required, three circuit units or more are connected in parallel. On the other hand, when the motor can be driven with a small current, each arm of each phase is configured by only one set of circuit units.

A current path of the power module 300 will be described with reference to FIG. A path of a current flowing through the upper arm circuit 151 of the power module 300 is shown below.
(1) One side electrode of the upper arm IGBT 328 and the upper arm diode 156 (element side) from the DC positive electrode terminal 314 (not shown) through the connection conductor portion 371U and (2) from the connection conductor portion 371U through the element side connection conductor portion 372U. (3) Connection conductor portion 373U from the other electrode of upper arm IGBT 328 and upper arm diode 156 via wire 336, (4) Connection from connection conductor portion 373U The connection conductor portion 371D flows through the connection portions 374U and 374D of the terminal 370. As described above, the upper arm is configured by connecting two sets of circuit units in which IGBT 328 and diode 156 are connected in parallel, in parallel. Therefore, in the current path of (2) above, the current is branched into two at the element side connection conductor portion 372U, and the branched current flows to the two sets of circuit portions.

A current path flowing in the lower arm circuit 152 of the power module 300 is shown below.
(1) One side electrode of the lower arm IGBT 330 and the upper arm diode 166 from the connection conductor portion 371D through the element side connection conductor portion 372D (the electrode on the side connected to the element side connection conductor portion 372D), (2) The other side electrodes of the lower arm IGBT 330 and the lower arm diode 166 flow through the connection conductor portion 373D via the wire 336, and (3) the DC negative electrode terminal 316 (not shown) flows from the connection conductor portion 373D. Since the lower arm is configured by connecting two sets of circuit units in which the IGBT 330 and the diode 166 are connected in parallel in the same manner as the upper arm, in the current path of (1) above, the current is the element side connecting conductor. It is branched into two at the section 371D, and the branched current flows to two sets of circuit sections.

  Here, the connection conductor portion 371U for connecting the IGBT 328 (and the diode 156) of the upper arm circuit and the DC positive terminal 314 (not shown) is disposed near the substantially central portion of one side of the insulating substrate 334. The IGBT 328 (and the diode 156) is mounted in the vicinity of the other side opposite to the one side of the insulating substrate 334 on which the connection conductor portion 371U is disposed. In the present embodiment, the two connecting conductor portions 373U are arranged in a row on one side of the insulating substrate 334 with the connecting conductor portion 371U described above interposed therebetween.

  Such a circuit pattern and a mounting pattern, that is, a circuit wiring pattern on the insulating substrate 334, has two wiring patterns (371U) on both sides of a substantially T-shaped wiring pattern and a substantially T-shaped vertical bar (371U). By mounting the terminals from the connection ends 371U and 373U, a transient current path at the time of switching of the IGBT 328 is an M-shaped current path as shown by an arrow 350 (broken line) in FIG. It becomes two small loop current paths (the direction of the arrow is when the lower arm is turned on). A magnetic field 350H in the direction of the arrow 350H (solid line) in FIG. 11B is generated around the two small loop current paths. The magnetic field 350H induces an induced current, so-called eddy current 340, in the metal base 304 disposed below the insulating substrate 334. The eddy current 340 generates a magnetic field 340H in a direction that cancels the magnetic field 350H, and can reduce the parasitic inductance generated in the upper arm circuit.

  The two small loop currents described above are two U-turn currents such that currents flowing on the insulating substrate 334 cancel each other. For this reason, as shown in the magnetic field 350H of FIG. 11B, a smaller loop magnetic field is generated inside the power module 300, so that the parasitic inductance can be reduced. In addition, the magnetic field loop that occurs during switching is small, and the magnetic field loop can be confined inside the power module, reducing the induced current to the case outside the power module, malfunctioning of the circuit on the control circuit board, and power conversion Electromagnetic noise to the outside of the device can also be prevented.

  The lower arm circuit also has a circuit wiring pattern and a mounting pattern similar to the upper arm circuit described above. That is, the connection conductor portion 371D for connecting the IGBT 330 (and the diode 166) of the lower arm circuit and the DC negative electrode terminal 316 (not shown) is disposed near the substantially central portion of one side of the insulating substrate 334. The IGBT 330 (and the diode 166) is mounted in the vicinity of the other side opposite to the one side of the insulating substrate 334 on which the connection conductor portion 371D is disposed. In the present embodiment, the two connecting conductor portions 373D are arranged in a line on one side of the insulating substrate 334 with the connecting conductor portion 371D described above interposed therebetween.

  By using such a circuit wiring pattern and a mounting pattern, the above-described parasitic inductance is also reduced on the lower arm circuit side. In the present embodiment, the entrance of the current path of each arm of each phase is, for example, the connection conductor part 371U sandwiched between the two connection conductor parts 373U, while the exit of the current path is the two connection conductor parts 373U. It has become. However, even if these inlets and outlets are reversed, the aforementioned small loop current path is formed in each arm of each phase. Therefore, as described above, it is possible to reduce the parasitic inductance of each arm of each phase and prevent electromagnetic noise.

  As shown in FIG. 14, a circuit wiring pattern 351 is formed on the inverter circuit mounting surface of the insulating substrate 334, and a power switching element such as an IGBT 328 is joined to the circuit wiring pattern 351 through the under-chip solder 350. Yes. A soldering pattern 352 is also formed on the back surface side of the insulating substrate 334, and the insulating substrate 334 is bonded to the metal base 304 via the bonding solder 353 with the soldering pattern 352. Heat generated in the IGBT 328 or the like is conducted to the metal base 304 and the heat dissipation pin 305 via the power switching element such as the IGBT 328, the under-chip solder 350, the circuit wiring pattern 351, the insulating substrate 334, the soldering pattern 352, and the bonding solder 353. Then, heat is radiated to the cooling water in the cooling water passage 19.

(Ratchet deformation)
Since the thermal expansion coefficient of the metal base 304 is larger than the thermal expansion coefficient of the insulating substrate 334, the elongation of the metal base 304 is larger than the elongation of the insulating substrate 334 at a high temperature as shown in FIG. When the temperature is high, the bonding solder 353 that connects the insulating substrate 334 and the metal base 304 becomes soft, so that the difference in elongation is absorbed by the shear deformation of the bonding solder 353. As a result, the metal base 304 is unlikely to warp. On the other hand, at a low temperature, the shrinkage amount of the metal base 304 is larger than the shrinkage amount of the insulating substrate 334, and the shear deformation amount of the bonding solder 353 is small. Therefore, the difference in shrinkage between the metal base 304 and the insulating substrate 334 is not absorbed and partitioned by the bonding solder 353, and the metal base 304 is curved into a shape that protrudes toward the insulating substrate 334. At this time, since a tensile force acts simultaneously with the bending moment on the metal base 304, the maximum stress is generated on the joint surface with the insulating substrate 334. If the yield stress of the metal base 304 is larger than the maximum stress, the deformation amount of the metal base 304 is within a range in which it can be elastically deformed, and can return to its original shape each time the temperature cycle is repeated. However, when the maximum stress exceeds the yield stress of the metal base 304, the metal base 304 is plastically deformed. When plastic deformation occurs, even if the metal base 304 becomes high temperature again, a bending force that returns to the original shape does not work, and the insulating substrate 334 is soldered at the position along the metal base 304 that is bent due to shear deformation. Fixed.

  As described above, the metal base 304 undergoes plastic deformation such that the insulating substrate 334 side is curved in a convex shape at low temperatures. The plastic deformation of the metal base 304 is accumulated when the temperature cycle is repeated, and the amount of deformation gradually increases. A phenomenon generated by such a mechanism is called ratchet deformation. When the ratchet phenomenon occurs due to the thermal load cycle (temperature cycle) of the metal base 304, the insulating substrate 334 may be damaged, and the power module 300 may fail. Therefore, in the power module, it is necessary to prevent such ratchet deformation.

(Ratchet deformation prevention measures)
In order to prevent ratchet deformation, it is effective not to fix the deformation of the metal base 304, in other words, not to cause plastic deformation. Therefore, it is effective to increase the hardness of the metal base 304 so as not to exceed the yield stress.

  Since HEV110 is normally used in the environment of -40-125 degreeC, the temperature cycle assumed in this embodiment assumes low temperature side minimum temperature -40 degreeC and high temperature side upper limit temperature +125 degreeC. The material of the metal base 304 of the power module 300 is copper and the thickness is 3 mm. The maximum stress when a thermal load is applied to the metal base 304 in the temperature cycle can be calculated as follows.

  The elastic stress in the state where the insulating substrate 334 is bonded to the 3 mm metal base 304 was analyzed. With a temperature change from 125 ° C. to −40 ° C., the maximum stress of the metal base 304 was 150 MPa. Assuming that the deformation of the metal base 304 becomes a neutral state at the intermediate temperature of the above temperature cycle, the maximum applied to the metal base 304 at a low temperature is provided by compressing to the high temperature side and evenly distributing the tensile stress to the low temperature side. The stress is 75 MPa.

(About metal base materials)
FIG. 16 is a graph with the horizontal axis representing yield stress and the vertical axis representing Vickers hardness. As can be seen from FIG. 16, there is a correlation between the Vickers hardness of the metal material and the yield stress. As described above, the maximum stress generated in the metal base 304 with the temperature cycle is 75 MPa. Accordingly, it can be seen from the graph of FIG. 16 that if a material having a Vickers hardness of 60 or more after forging is selected, ratchet deformation can be prevented.

  As a material for the metal base 304, a material having as high a thermal conductivity as possible is desirable. In order to improve the cooling capacity, it is preferable to use, for example, oxygen-free copper or tough pitch copper. Since the conventional metal base is usually produced by rolling, its hardness is increased by its work hardening. Therefore, ratchet deformation can be prevented as long as the material itself is evaluated. However, the heat radiating pins 305 of the metal base 304 are conventionally fixedly attached to the back surface of the metal base 304 by brazing. When brazing the heat dissipation pin 305 to the metal base 304, it is necessary to heat to about 600 to 700 ° C. If high-purity oxygen-free copper or tough pitch copper is used, the metal base 305 is annealed, and the hardness decreases to around Vickers hardness 40.

  Japanese Patent Application Laid-Open No. 2007-295765 proposes to use a copper alloy whose hardness does not easily decrease at a high temperature as a metal base material in order to prevent the ratchet deformation. Specifically, it describes a copper material to which elements such as tin, cobalt, zinc, nickel, and phosphorus are added in a total amount of about 1%. The thermal conductivity of this copper material is 300 W / m ° C. or lower, which is lower than the thermal conductivity of high-purity oxygen-free copper or tough pitch copper, and therefore the cooling capacity is lowered. Further, in the structure in which the radiating pins are brazed to the metal base, there is a problem that the thermal conductivity of the brazing material sandwiched between the radiating pins and the metal base is small and the thermal resistance of the brazing material layer is increased.

  Therefore, in the structure in which the power module 300 is directly water-cooled as in the present embodiment, the metal base 304 does not cause ratchet deformation even at a temperature cycle of −40 to 125 ° C. Achieving improved cooling performance is a challenge.

  Therefore, the present inventors have earnestly studied an optimal manufacturing method for forming the metal base 304 and the heat radiation pin 305 with a high purity copper material such as oxygen-free copper while ensuring a Vickers hardness of 60 or more. The following knowledge was obtained. That is, it has been found that if the heat dissipation pin 305 is integrally formed on the metal base 304 by forging, the Vickers hardness exceeds 60 due to work hardening during forging.

  As shown in FIG. 17, the metal base 304 and the heat dissipation pin 305 are transformed into a metal material in which the forged line 900 appears in the cut section by work hardening by forging. This phenomenon occurs due to the flow of metal crystals when forging a material with a radiating pin forging die. According to the graph shown in FIG. 16, the Vickers hardness 60 corresponds to 80 MPa as the yield stress, and it can be understood that the Vickers hardness 60 can sufficiently withstand a temperature cycle in a use environment of −40 to 125 ° C. In addition, since the metal base 304 and the heat radiation pin 305 are integrally formed of the same material, there is no brazing joint, and the thermal conductivity does not decrease. That is, it can be expected that the heat conductivity is improved by improving the thermal conductivity as compared with the prior art.

(Metal base thickness)
In order to prevent ratchet deformation, the stress generated by the temperature cycle can be reduced by increasing the thickness of the metal base 304. However, in the ratchet deformation prevention measure by the thickness of the material, the thermal fatigue life of the solder 353 that joins the insulating substrate 334 and the metal base 304 is reduced as can be seen from FIG. It will be shorter. This is because the shear stress generated by the temperature cycle increases as the metal base 304 becomes thicker. In HEV110 of this embodiment, since the temperature cycle life of −40 to 125 ° C. is 1000 times or more, it is understood that the plate thickness is 3 mm to 4 mm according to the correlation characteristics shown in FIG. Therefore, in this embodiment, the thickness of the metal base 304 is 3 mm.

  In this way, when the plate thickness is 3 mm based on the temperature cycle of the solder 353, whether or not the deformation amount of the metal base 304 due to the water pressure in the cooling water flow path is kept within an allowable value, and whether or not the Vickers hardness 60 can be satisfied. Will be described below with reference to FIGS. 30 (a) and 30 (b).

  FIG. 30A is a graph in which the horizontal axis represents the area of the metal base 304 and the vertical axis represents the plate thickness. FIG. 30B is a graph in which the horizontal axis indicates the area, the vertical axis indicates the Vickers hardness, and the plate thickness is 3 mm and 5 mm as parameters. In addition, the area of a horizontal axis is an area of the metal base 304 required in order to close the opening of a cooling water flow path. The greater the area and the higher the pressure in the cooling water flow path, the greater the stress on the metal base 304. Here, the calculation was performed assuming that the water pressure was 0.2 MPa and the allowable deformation amount of the metal base 304 was 0.5 mm.

From FIG. 30 (a), an area that can withstand a water pressure of 0.2 MPa with a plate thickness of 3 mm is approximately 20000 mm ² . According to the diagram of the plate thickness of 3 mm in FIG. 30B, it can be seen that the Vickers hardness in an area of 20000 mm ² is 60 or more.
From the above, when the metal base 304 having a thickness of 3 mm determined from the thermal fatigue condition of the solder 353 is used, if the Vickers hardness of the metal base 304 after forging satisfies 60 or more, the metal base 304 with a water pressure of 0.2 MPa is used. It can be seen that the amount of deformation can be suppressed to within 0.5 mm, and the water leakage performance is sufficient.

(Dimensions and shape of heat dissipation pin)
The shape and size of the radiating pins 305 are determined so as to ensure the cooling performance while suppressing the pressure loss of the cooling water flowing in the cooling water channel 19 within a predetermined value. The cooling performance improves as the pin height (pin length) increases and the diameter decreases. The height: diameter ratio for efficiently forming a large number of heat dissipation pins from the back surface of the metal base by forging using a copper material is limited to 1: 4. Therefore, in the present embodiment, a cylindrical heat radiation pin 305 having a diameter of about 2 mm and a height of about 8 mm is used. It should be noted that the conventional pin shape in which a heat radiating pin protrudes from one surface of the metal base 304 by brazing is also in a ratio of diameter (2 mm): height (8 mm) = 1: 4 and sufficiently satisfies the cooling performance. It is a dimension to do.

  With reference to FIGS. 31A and 31B, it will be described that the cooling performance by the pin fin having a diameter of 2 mm and a height of 8 mm is sufficiently satisfied. FIG. 31A is a graph when the horizontal axis represents the pin height, the vertical axis represents the equivalent heat transfer coefficient, and the pin diameter is 2 mm. The graph 31a is a graph when the pressure loss is set to the allowable upper limit value, and the graph 31b is a graph when the inter-pin gap is set to the allowable lower limit value. The allowable upper limit value of pressure loss is determined depending on the pump capacity of the cooling system, the cross-sectional area of the flow path, and the like. The allowable lower limit of the pin-to-pin gap is such that when pin fins are arranged in a staggered manner, the maximum size of dust that is expected to flow into the cooling water flow path is not clogged between the pins, and the pressure loss is It is determined as a value that is below the allowable value. The inter-pin gap is a gap in a direction orthogonal to the flow direction of the cooling water of the pin fins arranged in a staggered manner, and a gap in a direction oblique to the flow direction.

  When the intersection of the graphs 31a and 31b in FIG. 31A is K31, the pressure loss in the region above the graph 31a on the left side of the intersection K31 exceeds the allowable upper limit value. In the region above the graph 31b on the right side of the intersection K31, the inter-pin gap exceeds the allowable lower limit value, and the pressure loss exceeds the allowable upper limit value. Therefore, it can be seen that the equivalent heat transfer coefficient becomes the highest when the pin height at the intersection K31 of the graphs 31a and 31b, that is, 8 mm.

  When the pin height is 8 mm, the pin diameter is optimally 2 mm. This will be discussed with reference to FIG. FIG. 31B is a graph in which the horizontal axis represents the pin diameter, the vertical axis represents the equivalent heat transfer coefficient, and the pin height is 7 mm and 8 mm as parameters. In the graph 31c with a pin height of 8 mm, the equivalent heat transfer coefficient has a substantially peak value at a pin diameter of 2 mm. Therefore, it can be seen that the pin fin set to 2 mm in diameter and 8 mm in height is an ideal value (optimum value) from the viewpoint of heat conduction efficiency.

  When the metal base 304 expands and contracts due to the temperature cycle and the insulating substrate 334 is deformed, the junction between the DC positive terminal 314 and the DC negative terminal 316 that electrically connects the circuit wiring pattern 351 and the battery 136. There is a risk of cracking or breaking. However, in the power module 300 according to the present embodiment, as illustrated in FIGS. 5, 8, and 9, a planar stacked state in which the DC positive terminal 314 and the DC negative terminal 316 face the insulating substrate 334 and the metal base 304. It is configured. Therefore, the end electrodes brought into contact with the joint portions of the terminals 314 and 316 with the circuit wiring pattern 351 can follow the insulating substrate 334 and the metal base 304 which are deformed by the temperature cycle. As a result, by setting these terminals 314 and 316 thin, for example, by setting the rigidity small, the stress applied in the vertical direction of the joint surface is relieved, and the joint surface is more reliably prevented from cracking or breaking. can do.

  The detailed structure of the capacitor module 500 of the present embodiment will be described below with reference to FIGS. FIG. 19 is a perspective view showing an external configuration of the capacitor module according to this embodiment. FIG. 20 is a perspective view showing a state before filling with a filler 522 such as a resin so that the inside of the capacitor module 500 shown in FIG. 19 can be seen. FIG. 21 is a diagram showing a structure in which the capacitor cell 514 is fixed to the laminated conductor, which is a detailed structure of the capacitor module 500.

  19 to 21, 500 is a capacitor module, 502 is a capacitor case, 504 is a negative side capacitor terminal, 506 is a positive side capacitor terminal, 510 is a direct current (battery) negative side connection terminal portion, and 512 is a direct current (battery) positive electrode. Side connection terminal portions 532 are positive terminals for auxiliary machines, 534 are negative terminals for auxiliary machines, and 514 is a capacitor cell.

  As shown in FIGS. 19 and 21, a plurality of laminated conductor plates composed of a negative electrode conductor plate 505 and a positive electrode conductor plate 507, four in this embodiment, a direct current (battery) negative electrode side connection terminal portion 510 and a direct current ( Battery) It is electrically connected in parallel to the positive electrode side connection terminal portion 512. The negative electrode plate 505 and the positive electrode plate 507 are provided with a plurality of terminals 516 and terminals 518 for connecting the positive and negative electrodes of the plurality of capacitor cells 514 in parallel.

  As shown in FIG. 21, a capacitor cell 514, which is a unit structure of the power storage unit of the capacitor module 500, is formed by laminating and winding two films each having a metal such as aluminum deposited thereon and winding them. Each is constituted by a film capacitor 515 having a positive electrode and a negative electrode. The positive and negative electrodes are manufactured by spraying a conductor 508 such as tin, with the wound shaft surfaces being the positive electrode and the negative electrode, respectively.

  Further, as shown in FIG. 21, the negative electrode conductor plate 505 and the positive electrode conductor plate 507 are constituted by thin plate-like wide conductors and adopt a laminated structure in which they are laminated via insulating paper 517 to reduce parasitic inductance. Terminals 516 and 518 for connecting to the electrode 508 of the capacitor cell are provided at the end of the laminated conductor. Terminals 516 and 518 are electrically connected to electrodes 508 of two capacitor cells 514 by soldering or welding. In order to facilitate the soldering operation by the soldering apparatus or the welding operation by the welding machine, and to facilitate the inspection of the capacitor cell, that is, the electrode surface connected to the terminals 516 and 518 is outside the cell. Thus, the capacitor cells are arranged and the structure of the conductor plate is designed to constitute one capacitor cell group. By using such a capacitor cell group, the required capacitor capacity can be accommodated by increasing or decreasing the number of capacitor cell groups. As a result, a common capacitor cell can be used for a wide variety of capacitor modules, and a capacitor module suitable for mass production can be obtained. In order to reduce the parasitic inductance and to dissipate heat, it is preferable to provide a plurality of terminals 516 and 518, respectively.

  A negative electrode side capacitor terminal 504 and a positive electrode side capacitor terminal 506 for connection to the laminated conductor plate 700 are provided at one end of a negative electrode conductor plate 505 and a positive electrode conductor plate 507 which are thin plate-like wide conductors. At the other end of the negative electrode conductor 505 and the positive electrode conductor 507, a direct current negative electrode side connection terminal 510 and a direct current positive electrode side connection terminal 512 that are connected to a terminal that receives battery power are provided.

  A capacitor module 500 shown in FIG. 20 includes a total of eight capacitor cells 514 in which four capacitor cell groups each having two capacitor cells as one unit are arranged vertically. As connection terminals to the outside of the capacitor module 500, four pairs of positive and negative capacitor terminals 504 and 506 connected to the laminated conductor plate 700, DC positive and negative electrode side connection terminals 510 and 512 for receiving battery power, and an auxiliary machine inverter Auxiliary positive and negative terminals 532 and 534 for supplying power to the power module are used. Openings 509 and 511 are formed in the positive and negative capacitor terminals 504 and 506, and nuts are welded to the back sides of the openings 509 and 511 so that the DC positive and negative terminals 316 and 314 of the power module 300 can be bolted.

  The capacitor case 502 includes a terminal cover 520, determines the position of the terminal, and insulates the casing of the power converter. The capacitor case 502 is provided with a partition between the cell groups for positioning the cell groups. As a material of the capacitor case 502, a material having excellent thermal conductivity may be used, and a material having good thermal conductivity for heat dissipation may be embedded in a partition between the capacitor cell group.

  In the capacitor module 500, heat is generated when a ripple current flows during switching due to the electrical resistance of the metal thin film and the internal conductor (terminal) deposited on the film inside the capacitor cell. For the moisture resistance of the capacitor cell, the capacitor cell and the inner conductor (terminal) are impregnated (molded) with resin in the capacitor case 502. For this reason, the capacitor cell and the internal conductor are in close contact with the capacitor case 502 through the resin, and the heat generated by the capacitor cell is easily transmitted to the case. Furthermore, in this structure, since the negative electrode conductor plate 505, the positive electrode conductor plate 507, the capacitor cell 508, and the terminals 516 and 518 are directly connected, the heat generated in the capacitor cell is directly transmitted to the negative electrode and the positive electrode conductor, and the wide conductor conducts heat to the mold resin. The structure is easy to convey. For this reason, as shown in FIG. 7, heat is transferred well from the capacitor case 502 to the lower case 16, from the lower case 16 to the housing 12, and further to the cooling water flow path 19, thereby ensuring heat dissipation.

  As shown in FIG. 20, in the present embodiment, a laminated structure of a negative electrode conductor plate 505 and a positive electrode conductor plate 507 is independently arranged vertically in four rows to constitute a capacitor module. The four rows of negative electrode conductors 505 and positive electrode conductors 507 may be configured as an integral wide conductor plate, and all capacitor cells 514 may be connected to the wide conductor plate. As a result, the number of components can be reduced, productivity can be improved, and the capacitances of all capacitor cells 514 can be used substantially evenly, thereby extending the component life of the entire capacitor module 500. be able to. Furthermore, parasitic inductance can be reduced by using a wide conductor plate.

  FIG. 22A is a perspective view in which only the capacitor module 500, the laminated conductor plate 700, and the two power modules 300 are extracted from the power conversion device 200 according to the present embodiment. FIG. 22B is an exploded perspective view of the laminated conductor plate 700.

  As shown in FIG. 22A, the two power modules 300 are arranged side by side with the AC terminals 159 aligned on one side. On the side opposite to these AC terminals 159, electrical connection portions between the two power modules 300 and the capacitor module 500 are provided. Electrical connection between the two power modules 300 and the capacitor module 500 is performed by a laminated conductor plate 700 on a flat plate.

  A large number of capacitor cells 514 (not shown) are accommodated in the capacitor case 502 fixed on the lower case 16, and the positive electrode side capacitor terminal 504 and the negative electrode side capacitor terminal 506 of the capacitor module 500 are connected to one side of the capacitor case 502. It is arranged along the long side. The positive electrode connection portion and the negative electrode connection portions 504 c and 506 b at the upper ends of the positive electrode side capacitor terminal 504 and the negative electrode side capacitor terminal 506 are arranged at positions protruding from the upper surface of the capacitor cell 514.

  The laminated conductor plate 700 connected to the power module 300 is disposed so as to cover the two power modules 300. The positive-side capacitor terminal 504 and the negative-side capacitor terminal 506 form an L-shaped structure that rises from the opening surface of the capacitor case 502. The L-shaped positive-side capacitor terminal 504 and the negative-side capacitor terminal The positive electrode connecting portion 506b and the negative electrode connecting portion 504c at the upper end of 506 are in direct contact with the laminated conductor plate 700 and connected with bolts when the power converter 200 is assembled.

  As shown in FIG. 22B, this laminated conductor plate 700 is composed of a flat positive electrode side conductor plate 702 and a negative electrode side conductor plate 704, and an insulation sandwiched between the positive electrode side conductor plate 702 and the negative electrode side conductor plate 704. The sheet 706 is configured. That is, since the laminated conductor plate 700 is formed as a laminated structure, the parasitic inductance from the power module 300 to the capacitor module 500 can be reduced.

  As shown in FIGS. 22A and 8B, the plurality of upper arm control terminals 320U are arranged close to the central portion on the side A (see FIG. 8B) of the power module 300. . That is, the U-phase control pin is brought closer to the V-phase control pin, the W-phase control pin is brought closer to the V-phase control pin, and the upper arm control terminals 320U are arranged in a row near the central portion on the A side of the power module 300. . The laminated conductor plate 700 has through holes 705 for penetrating the plurality of upper arm control terminals 320U, and the positive electrode side conductor plate 702 and the negative electrode side conductor plate 704 are provided on both sides of the through hole 705. Are stacked. With these configurations, the lamination area of the negative electrode side conductor plate 704 and the positive electrode side conductor plate 702 can be increased, and further, the parasitic inductance from the power module 300 to the capacitor module 500 can be reduced.

  A boss 321 is arranged in the vicinity of the central portion on the A side of the power module 300 shown in FIG. 8B, that is, in the vicinity of the upper arm control terminal 320U. The drive circuit board 22 on which the driver circuit 174 is mounted is fixed to the boss 321, and the upper arm control terminal 320 </ b> U is passed through a hole formed in the drive circuit board 22. Thereafter, the terminal on the drive circuit board 22 and the arm control terminal 320U are joined by welding or the like. With such a configuration, the joint portion between the upper arm control terminal 320U and the terminal on the drive circuit board 22 is a short distance from the boss 321, so that vibration resistance during vehicle travel is improved.

  The drive circuit board 22 is disposed above the laminated conductor plate 700. Therefore, as shown in FIG. 22B, the laminated conductor plate 700 includes a negative-side conductor plate 704 on the drive circuit board 22 side, and a positive-side conductor plate 702 on the power module 300 side. As a result, the low voltage negative electrode conductor plate 704 and the insulating sheet 706 are present between the high voltage positive electrode conductor plate 702 and the drive circuit board 22 to prevent the drive circuit board 22 from being exposed to the high voltage. be able to.

  As shown in FIG. 22 (b), the positive conductor plate 702 is disposed over the two power modules 300, and further connects the two power modules 300 and the capacitor module 500. Similarly, the negative electrode conductor plate 704 is disposed over the two power modules 300, and further connects the two power modules 300 and the capacitor module 500. Thereby, since the laminated conductor plate 700 becomes wide, the parasitic inductance from the power module 300 to the capacitor module 500 can be reduced. In addition, since there are four connection locations of the capacitor module 500 for one power module, the parasitic inductance can be reduced. Further, by sharing the connection conductor from the two power modules 300 to the capacitor module 500 between the two power modules 300, the number of parts of the entire power conversion device 200 can be reduced, and the productivity can be improved. Can do.

  As shown in FIG. 8, the power module 300 includes a positive electrode side connection portion 314a and a negative electrode side connection portion 316a as a set, and a pair of connection portions 314a and 316a are arranged on one side of the power module 300, and the opposite side. Another set of connection portions 314a and 316a is arranged on the side of the. The laminated conductor plate 700 is disposed over the two sets of connection portions 314a and 316a, and is further connected to the connection portions 314a and 316a by bolts. As a result, the direct current supplied from the capacitor module 500 is not concentrated on the pair of connection portions 314a and 316a, that is, the direct current is distributed to the two sets of connection portions 314a and 316a. Therefore, the inductance from the power module 300 to the capacitor module 500 can be reduced.

  As described above, the capacitor module 500 has a plurality of capacitor cells 514 built therein. In this embodiment, two capacitor cells 514 constitute a capacitor cell group, and four sets of the capacitor cell groups are provided. Further, wide conductors (positive conductor plate 507 and negative conductor plate 505) corresponding to each set are provided. As shown in FIG. 20, the negative-side capacitor terminal 504 and the positive-side capacitor terminal 506 are connected to the respective wide conductors one by one. In the present embodiment, all these negative capacitor terminals 504 and positive capacitor terminals 506 are electrically connected to a set of laminated conductor plates 700. As a result, all the capacitor cells 514 are electrically connected to the two power modules 300, and the capacitances of all the capacitor cells 514 can be used substantially evenly. Can extend the service life of parts. Further, by using this set of laminated conductor plates 700, the inside of the capacitor module 500 can be divided for each capacitor cell group constituted by two capacitor cells 514, and the current capacity of the motor 192 can be increased. In addition, the number of units of the capacitor cells 514 constituting the capacitor cell group can be easily changed.

  It is desirable that the positive electrode side conductor plate 702 and the negative electrode side conductor plate 704 constituting the laminated conductor plate 700 have a gap distance as small as possible in order to reduce the parasitic inductance. For example, when the laminated conductor plate 700 has a bent structure portion for connecting the power module 300 and the capacitor module 500, a larger gap distance than that of the flat plate portion is generated in the bent structure portion. Inductance will increase.

  Therefore, the positive electrode side connection portion 314a and the negative electrode side connection portion 316a of the power module 300 according to the present embodiment, and the positive electrode side connection portion 504c and the negative electrode side connection portion 506b of the capacitor module 500 are arranged on substantially the same plane. Configure. Thereby, since the flat laminated conductor plate 700 can be used, the gap distance between the positive electrode side conductor plate 702 and the negative electrode side conductor plate 704 can be reduced, and the parasitic inductance can be reduced.

  FIG. 23A shows an enlarged view of a connection portion 380 (see FIG. 22A) between the power module 300 and the laminated conductor plate 700 shown in FIG.

  As shown in FIG. 23 (a), the negative electrode side connecting portion 316a and the positive electrode side connecting portion 314a are configured by bending the ends of the DC positive electrode terminal 314 and the DC negative electrode terminal 316 in the opposite directions. The negative electrode conductor plate 704 and the positive electrode conductor plate 702 of the laminated conductor plate 700 are connected to the part 316a and the positive electrode side connection part 314a, respectively. As a result, the current on the negative electrode side that instantaneously flows during switching of the IGBTs 328 and 330 becomes like a current path 382 shown in FIG. 23A, and therefore, the connection between the connection portion 704a of the negative electrode conductor plate and the negative electrode side connection portion 316a. A U-turn current is formed. Therefore, since the magnetic flux generated around the connection portion 704a of the negative electrode side conductor plate 704 and the magnetic flux generated around the negative electrode side connection portion 316a cancel each other, the inductance can be reduced.

  On the other hand, the current of the positive electrode conductor plate connection portion 702a passes through a current path 384 as shown in FIG. Since the negative electrode conductor plate 704 is disposed above the connection portion 702a of the positive electrode conductor plate, the current direction of the connection portion 702a of the positive electrode conductor plate and the current direction of the negative electrode conductor plate 704 are opposite to each other. The magnetic flux generated by the current will cancel out. As a result, the parasitic inductance of the connecting portion 702a of the positive conductor plate can be reduced.

  In addition, as shown in FIG. 23A, the insulating paper 318 and the insulating sheet 706 are arranged so as to have regions overlapping in the vertical direction. Furthermore, when the laminated conductor plate 700 is fixed to the negative electrode side connecting portion 316a and the positive electrode side connecting portion 314a with bolts or the like, the insulating paper 318 and the insulating sheet 706 are sandwiched between the laminated conductor plate 700 and the positive electrode side connecting portion 314a. It arrange | positions so that it may have an area | region which does not have, ie, an area | region where a compressive stress is not applied. Thereby, the insulation between the positive electrode and the negative electrode in the connection part, specifically, the insulation between the positive electrode side connection part 314a and the negative electrode conductor plate 704 can be ensured.

FIG. 23B shows an enlarged view (see FIG. 22A) of the connection portion 390 of the laminated conductor plate 700. FIG.
As shown in FIG. 23 (b), the positive electrode side connecting portion 506b and the negative electrode side connecting portion 504c of the capacitor module 500 are configured to be bent in opposite directions, and the positive electrode conductor plate of the multilayer conductor plate 700 is formed on the upper surface thereof. 702 and the negative electrode conductor plate 704 are connected to each other. As a result, the current on the negative electrode side that instantaneously flows during switching of the IGBTs 328 and 330 becomes a current path 392 shown in FIG. A U-turn current is formed with the portion 504c. Therefore, since the magnetic flux generated around the connection portion 704a of the negative electrode conductor plate 704 and the magnetic flux generated around the negative electrode side connection portion 504c cancel each other, the inductance can be reduced.

  Similarly, the current on the positive electrode side that instantaneously flows during switching of the IGBTs 328 and 330 passes through a current path 394 as shown in FIG. That is, a U-turn current is formed between the connecting portion 702 b of the positive electrode conductor plate and the positive electrode side connecting portion 506 b of the capacitor module 500. Therefore, since the magnetic flux generated around the connection portion 702b of the positive electrode side conductor plate 702 and the magnetic flux generated around the positive electrode side connection portion 506b cancel each other, the inductance can be reduced.

  Further, as shown in FIG. 23B, the insulating sheet 517 and the insulating sheet 706 are respectively arranged so as to have regions overlapping in the vertical direction. Furthermore, when the laminated conductor plate 700 is fixed to the positive electrode side connecting portion 506b and the negative electrode side connecting portion 504c of the capacitor module 500 with bolts or the like, the insulating sheet 517 and the insulating sheet 706 are connected to the laminated conductor plate 700 and the positive electrode side connecting portion 506b. It arrange | positions so that it may have the area | region which is not pinched | interposed by, ie, the area | region where a compressive stress is not added. Thereby, the insulation between the positive electrode and the negative electrode in the connection part, specifically, the insulation between the positive electrode side connection part 506b and the negative electrode conductor plate 704 can be ensured.

According to the power converter device by embodiment described above, there can exist the following effects.
(1) The heat dissipating pin 305 is manufactured integrally with the metal base 304 by forging. As a result, when the number of radiating pins is large, the number of man-hours can be reduced and the cost can be reduced rather than fixing the radiating pins 305 to the metal base 304 by brazing.
(2) If the radiating pins 305 are arranged in a staggered manner, the cooling water flowing in the cooling water flow path 19 comes into contact efficiently, and the metal base 304 can be effectively cooled. The formation area of the radiating pin group 305G can be reduced, and the power module 300 can be made compact.

(3) A plurality of heat radiating pins 305 are not provided as a group, but a pair of heat radiating pin groups 305G each including a plurality of heat radiating pins 305 are provided. Compared with the case where a plurality of heat radiation pins 305 are collectively formed in a large area, the press pressure during forging can be reduced, and the manufacturing cost can be further reduced by using a small press.
(4) By using a copper material whose Vickers hardness after forging is 60 or more, ratchet deformation caused by a temperature cycle can be suppressed, and the sealing performance between the mounting surface 410S of the cooling jacket 19A can be improved. . By suppressing ratchet deformation, it is possible to prevent damage to the insulating substrate 334 and damage to the joints with the terminals 314 and 316. Further, the sealing performance of the cooling water channel 19 is not impaired.

(5) In the power conversion device 200 having the above-described effects, the power module 300 can be constructed in a compact and low-cost manner while achieving high output by increasing the density of the inverter circuit 144. In addition, it is possible to extend the life and improve the reliability of the power module 300 and thus the power converter.

The above first embodiment will be described more specifically.
As the cooling metal base 304 of the insulating substrate 334 of the power module 300 mounted on the HEV 110, high-purity oxygen-free copper or tough pitch copper having a mixing ratio of impurity elements other than copper of less than 0.3% by weight is adopted. The heat radiation pin 305 is integrally formed by forging. The plate thickness of the metal base 304 is set to 3 mm or more and 4 mm or less, while the heat radiating pin 305 has a height of 7 mm or more and 8 mm or less and a columnar pin shape with a circular section having a diameter of 1.75 mm or more and 3 mm or less. Mold to size and shape. The metal base 304 and the heat radiating pin 305 thus manufactured can have a Vickers hardness of 60 or more and a dimension and shape that does not cause ratchet deformation, and have a thermal conductivity of 300 W / m ° C. or more and an excellent cooling capacity. Can be demonstrated. For this reason, a large chip size of 12.5 mm × 14 mm can be selected as the IGBT 328 of the power switching element mounted on the power module 300, and a predetermined cooling performance is ensured while increasing the density of the inverter circuit 144. Can do.
Note that the size of the IGBT 328 is not limited to 12.5 mm × 14 mm.

(Second Embodiment)
FIG. 24 is a diagram showing a second embodiment of the vehicular power converter according to the present invention. The second embodiment is configured in substantially the same way as the first embodiment. The same components are denoted by the same reference numerals and the characteristic portions will be described.

  When the metal base 304 and the heat dissipation pin 305 are produced by forging, carbon powder is used to improve the slip between the forging die and the metal material. For this reason, the surface of the metal base may become rough, and the surface roughness may decrease. Further, warping and undulation (hereinafter referred to as flatness) occur in the metal base due to processing accuracy after forging.

Therefore, in the second embodiment, for the purpose of improving the surface roughness and flatness, the peripheral area 902 of the heat dissipation pin group 305G provided on the back surface of the metal base 304 is milled to improve the surface roughness of the area. To do. A peripheral region 902 of the radiating pin group 305G is a surface that is in contact with the mounting surface 410S of the cooling jacket 19A and seals the openings 400 and 402 of the cooling water passage 19 with the O-ring 800. Accordingly, when the surface roughness of the region 902 is rough, the water tightness of the opening by the metal base 304 may be lowered. The surface roughness of the region 902 of the metal base 304 is improved by the milling process, and even if the radiating fin is integrally formed with the metal base by the forging method, the water tightness of the openings 400 and 402 by the metal base 304 is affected. There is no.
Although the peripheral region 902 is milled, at least the contact surface with the O-ring 800 may be milled.

  The bonding solder 353 for bonding the insulating substrate 334 to the metal base 304 is preferably melt-applied to a constant thickness in the plane direction of the element mounting surface 904 of the metal base 304. This is to prevent the generation of voids (holes) in the solder by melt-coating the solder 353. Since the solder 353 is melt-coated, the smaller the surface roughness of the element mounting surface 904, the better the bondability of the insulating substrate 334 with the solder 353. Therefore, it is preferable to mill not only the region 902 on the formation surface side of the heat radiation pin 305 but also the element mounting surface 904 to improve the surface roughness. When the surface roughness of the element mounting surface 904 roughened by carbon is reduced, the insulating substrate 334 is firmly bonded to the metal base 304 by the melt-applied solder, and the reliability of the power module is improved.

As described above, according to the second embodiment, the following operational effects can be obtained in addition to the operational effects of the first embodiment.
(1) The mounting surface region 902 of the metal base 304 is milled to improve surface roughness and flatness. Therefore, the sealing performance with respect to the metal base 304 by the O-ring 800 is improved, and leakage of the cooling water from the cooling water channel 19 can be prevented with high reliability.
(2) The device mounting surface 904 of the metal base 304 is milled to improve surface roughness and flatness. Therefore, the melt application property of the bonding solder 353 for bonding the metal base 304 to the insulating substrate 334 is improved, the bonding life of the insulating substrate 334 is extended, and the reliability and life of the power module can be improved.

(Third embodiment)
FIG. 25 is a diagram showing a third embodiment of the vehicle power converter according to the present invention. In the third embodiment, the metal base 304 and the heat radiating pins 305 are integrally molded by a metal powder injection molding method (Metal Injection Molding). In the metal powder injection molding method, a metal powder is mixed with a resin binder, injection molded, and then fired to obtain a molded product. The metal base 304 of the third embodiment is formed by injection-molding high-purity copper powder into a mold together with a resin binder and firing it. As shown in FIG. 25, carbon 901 generated by baking the resin binder remains in the metal base 304. The illustration of the heat radiation pin 305 is omitted.

  In the case of molding by normal casting, improvement in hardness due to work hardening cannot be expected, but when the metal powder injection molding method is adopted, the hardness of the metal base 304 becomes high due to the function of the residual carbon 901, and press etc. A Vickers hardness of 60 or more can be obtained without processing after the step.

  Since the metal base 304 manufactured by the metal powder injection molding method can have higher dimensional accuracy than forging, the processed surface can be manufactured with high surface accuracy without performing machining as in the second embodiment. be able to.

In the third embodiment, the following operational effects are obtained in addition to the operational effects of the first embodiment.
(1) Since the metal base 304 and the radiating pin 305 are produced by the metal powder injection molding method, the contact surface with the O-ring 800 and the bonding surface with the bonding solder 353 can be formed on a flat surface with high accuracy as it is. it can. Therefore, the sealing performance by the metal base 304 and the bonding performance of the insulating substrate 334 by bonding solder can be improved without milling, and the manufacturing cost can be reduced.

The metal base 304 and the heat radiation fin 305 according to the embodiment described above may be modified as follows.
(1) In the above embodiment, as shown in FIG. 13, the heat dissipation pins 305 are arranged in a staggered manner, but as shown in FIG. 26, the heat dissipation pins 305 may be arranged in a lattice shape. Since the heat radiating pins 305 are arranged in parallel in the direction in which the cooling water flows in the cooling water flow path 19, the cooling water can be brought into contact with the heat radiating pins 305 by making the flow resistance smaller than arranging them in a staggered manner. As a result, the cooling water circulation efficiency can be increased and the cooling capacity can be improved.

(2) As shown in FIG. 27, column-shaped heat radiation pins 306 having an elliptical cross section are arranged so that the major axis in the cross-sectional shape of the heat radiation pins 306 is parallel to the flowing direction of the cooling water in the cooling water channel 19. can do. By arranging the flat direction of the heat dissipation pin 306 having an elliptical cross section in accordance with the flow direction of the cooling water, the flow resistance of the cooling water can be further reduced. In addition, the area of the heat radiation pin 306 that contacts the cooling water can be increased. As a result, the cooling capacity can be further improved.

(3) As shown in FIG. 28, the heat radiating plate 307 may be arranged in parallel so as to be parallel to the direction in which the cooling water flows in the cooling water passage 19. Compared with the case where the radiating pins 305 and 306 are arranged in a staggered pattern or a grid pattern, the area where the cooling water is brought into contact can be increased while reducing the flow resistance. As a result, the cooling capacity can be further improved while improving the circulation efficiency of the cooling water. As with the heat dissipation pin 305, if the thickness of the heat dissipation flat plate 307 is 2 mm and the height is 8 mm, the ratio of thickness: height = 1: 4, which is a limit ratio that can be manufactured by forging. It is the optimal dimension.

(4) Although the heat dissipation pin 305 is a straight pin as shown in FIG. 17, it may be a taper pin that is tapered from the metal base 304 in the projecting direction as shown in FIG. The diameter of the base portion of the taper pin is increased, and the strength of the heat dissipation pin 308 can be improved. Further, the contact area with the cooling water can be increased. As a result, it is possible to avoid the heat dissipation pin 308 from being deformed and damaged by increasing the circulation rate of the cooling water, and the cooling capacity can be easily improved.

  The present invention is not limited to the above-described embodiment, and can be implemented in various forms within the scope of the technical idea. Therefore, it is also possible to combine each embodiment and one or a plurality of modified examples. Any combination of the modified examples is possible.

  The above description is merely an example, and the present invention is not limited to the configuration of the above embodiment.

It is a figure which shows the control block of a hybrid vehicle. It is a figure for demonstrating the electric circuit structure containing an inverter apparatus. It is an appearance perspective view of the whole composition of the power converter concerning the embodiment of the present invention. It is the perspective view which decomposed | disassembled the whole structure of the power converter device which concerns on embodiment of this invention into each component. It is the figure which attached the cooling water inlet piping and the outlet piping to the aluminum casting of the housing | casing which has a cooling water flow path, (a) is a perspective view of a housing | casing, (b) is a top view of a housing | casing, (c) is It is a bottom view of a housing | casing. It is detail drawing of the bottom view of a housing | casing. It is sectional drawing (AA sectional reference of FIG. 6) of a power converter device. (a) is the upper perspective view of the power module regarding this embodiment, (b) is a top view of a power module. It is a disassembled perspective view of the DC terminal of the power module 300 regarding this embodiment, (a) is the figure which extracted one out of the metal base and three upper-lower arm series circuits which are the components of a power module. In order to make the structure of the DC bus bar easier to understand, the power module case is a cross-sectional view partially transparent. (a) is a figure for demonstrating an upper-and-lower arm series circuit, (b) is a figure for demonstrating the electric current path of a power module. It is the perspective view which looked at the metal base which cools a power module from the back. It is a partially expanded plan view which shows the arrangement | sequence of the thermal radiation pin integrally molded to a metal base. It is a laminated structure figure which cools a power module. It is a conceptual structure figure explaining the subject in a cooling lamination structure. It is a graph which shows the correlation with the Vickers hardness of a metal material, and a yield stress. It is a partially expanded longitudinal cross-sectional view of the metal base and heat radiating pin explaining the change in the metal material by forging. It is a graph which shows the correlation with the temperature cycle lifetime explaining the dimension shape of a metal material, and the thickness of a metal base. It is a perspective view which shows the external appearance structure of a capacitor | condenser module. It is a perspective view which shows the state of the capacitor module before filling with fillers 522, such as resin. It is a figure for demonstrating the structure of a capacitor cell. (a) is the perspective view which extracted only the capacitor module, the DC side conductor plate, and the two power modules 300 in the power converter device 200 which concerns on this embodiment, (b) is the decomposition | disassembly of a DC side conductor plate. It is a perspective view. FIG. 17A is an enlarged view of a connection location between the power module and the DC side conductor plate shown in FIG. 17, and FIG. 17B is an enlarged view of a connection location 390 of the laminated conductor plate 700. It is a figure which shows 2nd Embodiment of the vehicle power converter device which concerns on this invention, and is a longitudinal cross-sectional view which shows the structure of a metal base. It is a figure which shows 3rd Embodiment of the power converter device for vehicles which concerns on this invention, and is a partially expanded sectional view which shows the structure in the metal base. It is a partially expanded plan view of an example in which the radiating pins are arranged in a grid pattern. It is a partial enlarged plan view which shows the arrangement | sequence of the thermal radiation pin of a cross-sectional ellipse. It is a figure which shows the metal base which projected the flat type radiation fin, (a) is a top view, (b) is the side view seen from the extending direction of a radiation fin, (s) is seen from the side of a radiation fin. FIG. It is a partially expanded longitudinal cross-sectional view which shows a taper-shaped heat radiation pin. (A) is a graph in which the horizontal axis represents the area of the metal base 304 and the vertical axis represents the plate thickness. (B) is a graph in which the horizontal axis represents the area, the vertical axis represents the Vickers hardness, and the plate thickness is 3 mm and 5 mm as parameters. (A) is a graph in which the horizontal axis represents the pin height, the vertical axis represents the equivalent heat transfer coefficient, and the pin diameter is 2 mm. (B) is a graph in which the horizontal axis represents the pin diameter, the vertical axis represents the equivalent heat transfer coefficient, and the pin height is 7 mm and 8 mm as parameters.

Explanation of symbols

10: Upper case 11: Radiation base plate 12: Housing 13: Cooling water inlet pipe 14: Cooling water outlet pipe 16: Lower case 19: Cooling water flow path 19A: Cooling jacket 19a: Outward path 19b: Return path 19c: Communication path 20: Control circuit board 21: Connector 22: Driving circuit board 43: Inverter device for auxiliary equipment 110: Hybrid electric vehicle 112: Front wheel 120: Engine 136: Battery 140, 142: Inverter device 144: Inverter circuit 150: Upper and lower arm series circuit 156: Upper arm diode 159: AC terminal 166: Lower arm diode 186: AC power line 192, 194: Motor generator 200: Power converter for vehicle 300: Power module 302: Power module case 304: Metal base 305, 306, 30 8: Heat radiation pin 307: Heat radiation plate 314: DC terminal 328: IGBT for upper arm 330: IGBT for lower arm
334: Insulating substrate 350: Under-chip solder 351: Circuit wiring pattern 352: Soldering pattern 353: Bonding solder 400, 402: Opening 404: Through opening 420: Cover 500: Capacitor module 502: Capacitor case 504, 506: Capacitor electrode terminal 510, 512: Connection terminal portion 514: Capacitor cell 700: Multilayer conductor plate 800, 802: O-ring 900: Forged wire 901: Residual carbon 902: Surrounding region 904: Bonding surface

Claims (15)

A semiconductor circuit that converts power between DC power and AC power, a metal base that mounts the semiconductor circuit on the surface, and a plurality of heat dissipation that protrudes from the back surface of the metal base and exchanges heat with the cooling liquid A power converter for a vehicle comprising a power module having fins and driving an in-vehicle electric motor with AC power output from the power module,
The semiconductor circuit is configured to output three-phase AC power, and the plurality of radiating fins are integrally formed with the metal base by forging ,
The vehicle power converter according to claim 1, wherein the hardness and thickness of the metal base are determined so as to prevent ratchet deformation . The vehicle power converter according to claim 1,
A cooling jacket provided with a flow path for the cooling liquid and an opening for projecting the radiation fin into the flow path;
The back surface of the metal base is provided with a sealing surface that makes the opening watertight,
The metal base is fixed to the cooling jacket with the sealing surface so that the opening is watertight,
The vehicular power converter according to claim 1, wherein the sealing surface is processed to have better flatness and surface roughness than the surface of the metal base from which the radiating fin protrudes. In the vehicle power converter according to claim 1 or 2,
A circuit mounting region is provided on a surface of the metal base, an insulating substrate is fixed to the circuit mounting region with solder, and the semiconductor circuit is fixed to the insulating substrate with solder. Power converter. The vehicle power converter according to claim 1,
A power conversion apparatus for a vehicle, wherein the metal base is provided with a pair of heat radiation fin groups including the plurality of heat radiation fins. The vehicular power converter according to claim 4,
The flow path in the cooling jacket is formed as a U-turn shape having an outward path and a return path,
The pair of radiating fin groups are arranged separately so as to exchange heat between the cooling liquid in the forward path and the return path, respectively. In the vehicle power converter according to any one of claims 1 to 5,
Before Symbol metal base vehicle power conversion device, characterized in that the copper and copper-based metal. A semiconductor circuit that converts power between DC power and AC power, a metal base that mounts the semiconductor circuit on the surface, and a plurality of heat dissipation that protrudes from the back surface of the metal base and exchanges heat with the cooling liquid A power converter for a vehicle comprising a power module having fins and driving an in-vehicle electric motor with AC power output from the power module,
The plurality of radiating fins are integrally molded together with the metal base by a metal powder injection molding method ,
The vehicle power converter according to claim 1, wherein the hardness and thickness of the metal base are determined so as to prevent ratchet deformation . The power converter for vehicles according to any one of claims 1 to 7 ,
The metal base is made of a copper material or copper powder having a Vickers hardness of 60 or more after molding, and is manufactured to have a plate thickness of 3 mm or more and 4 mm or less to prevent ratchet deformation. A vehicle power converter. The power converter for vehicles according to any one of claims 1 to 8 ,
Including a pair of the power modules,
Each of the pair of power modules is provided with the semiconductor circuit, and these semiconductor circuits are connected in parallel to each other,
Each semiconductor circuit has an upper and lower arm circuit for each phase so as to output three-phase AC power, and the upper and lower arm circuit is composed of six insulated gate bipolar switching elements. apparatus. The vehicle power converter according to claim 9 , wherein
Each of the six insulated gate bipolar switching elements has a size of 12.5 mm × 14 mm. The power converter for vehicles according to any one of claims 1 to 10 ,
The power conversion device for a vehicle, wherein the plurality of radiating fins are arranged in a staggered pattern. The power converter for vehicles according to claim 11 ,
The power dissipation device for vehicles, wherein the heat radiation fin is a cylindrical pin having a height of 7 mm to 8 mm and a diameter of 2.0 mm to 3 mm. The power converter for vehicles according to claim 11 ,
The power conversion device for a vehicle, wherein the radiating fin is a tapered pin tapered from the metal base. The metal base for power modules used for the power converter device for vehicles of any one of Claims 1 thru | or 13 . A metal base according to claim 14 ;
A power module comprising a semiconductor circuit provided on a surface of the metal base.

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