JP6782809B2 - Semiconductor module and power converter equipped with it - Google Patents

Description

The present invention relates to a semiconductor module and a power conversion device including the semiconductor module.

As a conventional technique intended to efficiently transfer heat from a semiconductor module to a cooler to improve heat dissipation, for example, the cooling structure shown in Patent Document 1 has been proposed. According to this Patent Document 1, a semiconductor module is inserted into a module insertion hole formed in a cooler, and heat is dissipated from a contact surface with the module insertion hole, and the semiconductor module has a module insertion hole. It is disclosed that the contact surface is coated with a soft metal layer and heat is dissipated to a cooler through the soft metal layer.

Further, as a conventional technique intended to achieve both cooling efficiency and assemblability of a semiconductor element used in an inverter, for example, an inverter device shown in Patent Document 2 has been proposed. According to Patent Document 2, an accommodating portion for accommodating a power card in which both sides of a semiconductor element are sandwiched between heat dissipation plates and a circulation path portion for circulating a cooling medium are formed around the power card, and the power card and the accommodating portion are formed. It is disclosed that the gap is filled with an insulating resin and the insulating resin is cured to fix the power card.

Further, for example, Patent Document 3 proposes a conventional technique of a cooling structure intended to improve the cooling capacity while reducing the burden of assembling the semiconductor module. According to Patent Document 3, a semiconductor module is housed inside, a block having heat radiating surfaces for radiating heat generated by Joule of the semiconductor is provided on the front surface and the back surface, and this block is inserted into a cooling water passage formed inside the case. Discloses that the front and back of the block face the cooling water passage.

Further, a conventional technique of a cooling structure capable of cooling both sides of a semiconductor module and also cooling a smoothing capacitor is proposed in Patent Document 4, for example. According to Patent Document 4, semiconductor modules are installed on both sides of the smoothing capacitor, and a flat refrigerant tube is curved in a zigzag shape to form a refrigerant flow path along both sides of the semiconductor module and the smoothing capacitor, resulting in liquid leakage. It is disclosed that a high heat dissipation capacity is realized.

Japanese Unexamined Patent Publication No. 2005-175163 Japanese Unexamined Patent Publication No. 2005-237141 JP-A-2006-202899 Japanese Unexamined Patent Publication No. 2001-352023

In recent years, for example, in automobiles, electrification of each in-vehicle system of a vehicle, including a vehicle drive system, has been promoted. However, in the electrification of in-vehicle systems, new additions and conventional power conversion devices that control the electric machine that drives the driven body and the electric power supplied from the in-vehicle power supply to the rotating electric machine to control the driving of the rotating electric machine. It is necessary to replace the components of the system.

For example, in an automobile, the power conversion device converts DC power supplied from an in-vehicle power source to drive a rotary electric machine into AC power, or DC for supplying AC power generated by a rotary electric machine to an in-vehicle power source. It has a function to convert it into electric power. The amount of power converted by the power converter tends to increase, but the overall size and weight of the automobile are being reduced, so that the increase in size and weight of the power converter is suppressed. In-vehicle power converters are required to be used in environments with large temperature changes compared to industrial ones, and are relatively compact and can maintain high reliability even in high temperature environments. There is a demand for a power converter capable of converting a large amount of electric power.

The power conversion device includes an inverter circuit, and power conversion between DC power and AC power is performed by the operation of the inverter circuit. In order to perform this power conversion, it is necessary for the power semiconductor constituting the inverter circuit to repeat the switching operation (switching operation) between the cutoff state and the conduction state. A large amount of heat is generated in the power semiconductor during this switching operation. The temperature of the semiconductor chip, which is the power semiconductor of the inverter circuit, rises due to the heat generated during the switching operation. Therefore, it is an important issue to suppress this temperature rise.

As the amount of power to be converted increases, the amount of heat generated by the semiconductor chip increases. As a countermeasure, it is necessary to increase the size of the semiconductor chip and the number of semiconductor chips used, resulting in an increase in the size of the power conversion device. As a method of suppressing the increase in size of such a power conversion device, it is conceivable to improve the cooling efficiency of the semiconductor chip.

Therefore, for example, Patent Documents 1 to 3 are proposals made with the intention of improving the cooling efficiency of the semiconductor chip. It is clear that improving the cooling efficiency of semiconductor chips leads to miniaturization of semiconductor chips, but it is not always possible to suppress the increase in size of the entire power converter. For example, if improvements are made to improve the cooling efficiency of the semiconductor chip, the structure of the entire power converter may become complicated as a result, and the semiconductor chip can be miniaturized, but the power converter as a whole If you look at it, it may happen that it cannot be miniaturized very much.

Therefore, in order to suppress the increase in size of the entire power converter, it is necessary to improve the cooling efficiency of the semiconductor chip in consideration of the entire power converter, and to suppress the electrical or mechanical complexity of the entire power converter as much as possible. is required. Therefore, the electrical complication is caused by, for example, the complication of the electrical wiring between the semiconductor module containing the semiconductor chip and the capacitor module, the driver board, and the AC connector. Further, the mechanical complication is caused by the complication of the mounting method of the semiconductor module on the waterway housing and the complication of the mounting method of the capacitor module.

It cannot be said that the known techniques described in Patent Documents 1 to 3 sufficiently consider the miniaturization of the entire power conversion device, and further, specific disclosure of the arrangement of the capacitor module and the cooling structure is not possible. It is enough. Further, Patent Document 4 discloses an arrangement structure that takes into consideration cooling of a smoothing capacitor in addition to cooling of a semiconductor module, but is of a method of cooling with a refrigerant tube connected to a refrigerant pipe of an external refrigeration cycle device. However, the cooling method is different from the water cooling method, and there is a lack of consideration for the arrangement related to other components such as the circuit board connected to the semiconductor module, which leaves a problem in the miniaturization of the entire device. ..

An object of the present invention is to provide a technique mainly leading to miniaturization of the entire power conversion device.

As described above, the power conversion device according to the embodiment of the present invention can mainly present the following configuration examples as means for solving a large number of problems necessary for commercialization.

A first semiconductor chip that constitutes the upper arm of the inverter circuit, a second semiconductor chip that constitutes the lower arm of the inverter circuit, and a first conductor plate that is electrically connected to one surface of the first semiconductor chip. And a second conductor plate electrically connected to the other surface of the first semiconductor chip, and electrically connected to one surface of the second semiconductor chip and electrically connected to the second conductor plate. The third conductor plate connected to the second semiconductor chip, the fourth conductor plate electrically connected to the other surface of the second semiconductor chip, and the gate electrode of the first semiconductor chip are electrically connected to each other. The first gate conductor, the second gate conductor electrically connected to the gate electrode of the second semiconductor chip, the first conductor plate via the first insulating member, and the third. Conductor plate, the first gate conductor, and the first metal plate to which the second gate conductor is fixed, and the second conductor plate and the fourth through the second insulating member. A semiconductor module including a second metal plate to which a conductor plate is fixed.

According to the present invention, it is possible to mainly improve productivity, improve reliability, miniaturize or improve cooling efficiency in a semiconductor module and a power conversion device including the semiconductor module.

It is a figure which shows the control block of a hybrid vehicle. The figure which shows the circuit configuration of the electric system for driving a vehicle which includes the inverter device including the upper and lower arm series circuit and the control part, the power conversion device which consists of the capacitor connected to the DC side of the inverter device, the battery, and the motor generator. Is. It is a figure which shows the circuit structure of the power conversion apparatus which uses the two upper and lower arm series circuits for each phase AC output to a motor generator. It is a perspective view which shows the appearance of the whole structure in the power conversion apparatus which concerns on embodiment of this invention. It is a perspective view which disassembled the whole structure of the power conversion apparatus which concerns on embodiment of this invention. It is a top view which removed the upper case in the whole structure of the power conversion apparatus which concerns on embodiment of this invention. It is an exploded view which shows the arrangement structure of the semiconductor module in the power conversion device which concerns on embodiment of this invention, and is the figure which removed the upper case, the control board, the driver board and the AC connector from the whole structure of the power conversion device shown in FIG. is there. It is a perspective view of the electric power system around the semiconductor module which attached the AC connector and the DC connector with respect to the exploded view shown in FIG. It is an exploded view of the electric power system around the semiconductor module shown in FIG. It is sectional drawing which saw the arrangement structure of the semiconductor module shown in FIG. 7 from the flow direction of cooling water. It is sectional drawing which removed the upper case from the whole structure of the power conversion apparatus which concerns on this embodiment, and was seen from the flow direction of cooling water. It is sectional drawing which saw the semiconductor module, the condenser module, and the cooling water channel which concerns on this embodiment from above. It is a perspective view which shows the appearance of the whole structure of the semiconductor module in the power conversion apparatus which concerns on embodiment of this invention. It is sectional drawing of the semiconductor module which concerns on this Embodiment, and is the figure which shows the sectional structure of line AA shown in FIG. It is a perspective view which disassembled the whole structure of the semiconductor module which concerns on this embodiment. It is a figure which shows the cross-sectional structure of the line BB shown in FIG. It is an exploded view which shows the structure of the internal arrangement of the upper and lower arm series circuit in the semiconductor module which concerns on this embodiment. It is a figure which shows the arrangement structure of the upper and lower arm series circuit arranged on the heat radiation fin (A side) in the semiconductor module which concerns on this embodiment. It is a figure which shows the bonding relationship of each component arranged on the heat radiation fin (A side) in a semiconductor module. It is a figure which shows the bonding relation of each component arranged on the heat radiation fin (B side) in a semiconductor module. It is a figure which shows the structure of the terminal connection between a semiconductor module and a capacitor module which concerns on this embodiment. It is a structural layout diagram explaining the reduction of the wiring inductance in a semiconductor module and a capacitor module which concerns on this embodiment. It is a layout drawing on the equivalent circuit explaining the reduction of the wiring inductance in the semiconductor module and the capacitor module which concerns on this embodiment. It is a figure which shows the other structural example about the arrangement of the positive electrode terminal and the negative electrode terminal of the semiconductor module which concerns on this embodiment. It is a function explanatory drawing which shows one structural example of the water channel structure and the arrangement structure of a plurality of semiconductor modules which concerns on this embodiment. It is a function explanatory drawing which shows the other structural example of the water channel structure and the arrangement structure of a plurality of semiconductor modules which concerns on this embodiment.

The power conversion device according to the embodiment of the present invention will be described in detail below with reference to the drawings. First, first, the technical problem to be improved and the technical problem in the power conversion device according to the present embodiment and this technical problem. The outline of the technology for solving the problem will be explained.

The power conversion device according to the embodiment of the present invention considers the following technical viewpoints as a product that meets the needs of the world, and one of the viewpoints is a miniaturization technology, that is, an increase in power to be converted. This is a technology that suppresses the increase in size of the power converter as much as possible. Further, another viewpoint is a technique for improving the reliability of the power converter, and yet another viewpoint is a technique for improving the productivity of the power converter. The power conversion device according to the embodiment of the present invention has been commercialized based on the above-mentioned three viewpoints and a comprehensive viewpoint of these viewpoints, and the characteristics of the power conversion device in each viewpoint are described. It is listed and outlined below.

(1) Description of Miniaturization Technology In the power conversion device according to the present embodiment, a series circuit of upper and lower arms of an inverter is housed inside a semiconductor module provided with cooling metals on both sides, and the semiconductor module is inserted into cooling water. It is fitted (adopting a slot-in structure) and has a structure in which the cooling metals on both sides are cooled with cooling water.

This structure improves the cooling efficiency and enables the miniaturization of the semiconductor module. Further, as a specific structure, an insulating member which is an insulating plate such as an insulating sheet or a ceramic plate is provided inside the cooling metals on both sides, and a series circuit of the upper and lower arms is provided between the conductor metals fixed to each insulating member. The semiconductor chips of the upper arm and the lower arm to be configured are sandwiched. With this structure, a good heat conduction path is formed between both sides of the semiconductor chips of the upper arm and the lower arm and the cooling metal, and the cooling efficiency of the semiconductor module is greatly improved.

Further, the semiconductor chip (IGBT chip and diode chip) of the upper arm of the semiconductor module and the semiconductor chip of the lower arm of the semiconductor module are arranged at different positions with respect to the flow direction of the cooling water, and the IGBT of the upper arm is arranged. By arranging the chip and the IGBT chip of the lower arm on the same horizontal plane of the cooling water flow, the vertical width occupied by the fin-shaped cooling metal for cooling the IGBT chip of the upper and lower arm series circuits becomes larger than that of the diode chip. , The IGBT chip with a larger amount of heat dissipation can be effectively cooled. That is, in order to cool the IGBT chips of the upper and lower arms, the amount of cooling water is larger than that of the diode chips, which leads to a significant improvement in cooling efficiency.

Both sides of the semiconductor chip of the upper arm and the lower arm are connected to the conductor metal (conductor plate) inside the cooling metal, and the conductor metal is fixed to the cooling metal via an insulating member. The thickness of the insulating member is thin, for example, 350 μm or less in the case of a ceramic plate, and even thinner in the case of an insulating sheet, which is 50 μm to 200 μm. Here, the insulating sheet is, for example, a thermocompression-bonded resin sheet. Since the conductor metal is provided close to the cooling metal, an eddy current due to the current flowing through the conductor metal flows through the cooling metal, and the eddy current generates heat, but these heats are efficiently transferred to the cooling water.

In addition, the eddy current reduces the inductance in the semiconductor module. Inductance reduction can reduce voltage jump due to switching operation of the semiconductor chips of the upper arm and lower arm, leading to improvement in reliability. In addition, suppressing the voltage rise makes it possible to speed up the switching operation of the semiconductor chips of the upper arm and the lower arm, shorten the time for the switching operation, and lead to a reduction in the amount of heat generated by the switching operation.

Furthermore, the capacitor module and the semiconductor module are housed in a waterway housing in substantially the same plane space, and the semiconductor modules are arranged on both sides of the capacitor module (adopting a sandwich structure) to reduce the size. .. In addition to this, by arranging a driver board for driving the semiconductor chip and a control board for controlling the semiconductor chip on the upper surface of the capacitor module, the upper surface of the capacitor module can be effectively used and miniaturized. It has been realized.

(2) Description of reliability improvement In the power conversion device according to the present embodiment, as described above, the cooling efficiency of the semiconductor module can be significantly improved, and as a result, the temperature rise of the semiconductor chip can be suppressed, and the reliability. It leads to improvement of.

A plurality of semiconductor modules have a sandwich structure in which a capacitor module is sandwiched between them. Further, by arranging the DC positive terminal and the DC negative terminal of the semiconductor module at equal intervals from the capacitor module side, these DC terminals and the capacitor module The positive terminal and the negative terminal can be connected by a DC bus bar of the same shape, and the inductance between the semiconductor module and the capacitor module can be reduced, and the internal arrangement structure of the semiconductor module can reduce the inductance of the semiconductor module. Therefore, it is possible to reduce the voltage jump due to the switching operation, which leads to the improvement of reliability. In addition, suppressing the voltage rise makes it possible to speed up the switching operation of the semiconductor chip, which leads to a reduction in the amount of heat generated by shortening the switching operation time, which in turn suppresses the temperature rise, leading to an improvement in reliability.

In this way, the structure in which the DC terminal of the semiconductor module is connected to the capacitor module and the terminal structure of the capacitor module become a simple structure, which leads to not only productivity improvement and miniaturization but also reliability improvement.

In this power converter, the cooling efficiency is significantly improved, so that engine cooling water can be used as cooling water. For this reason, the automobile does not require a dedicated cooling water system, which greatly improves the reliability of the automobile as a whole.

This power conversion device has a structure in which a semiconductor module containing a series circuit of the upper and lower arms of the inverter is inserted into the water channel through an opening provided in the cooling water channel and fixed. It is possible to separately inspect the semiconductor module and the waterway housing separately manufactured on the production line, and then perform the process of fixing the semiconductor module to the waterway housing. In this way, the semiconductor module, which is an electrical component, and the waterway housing, which is a mechanical component, can be manufactured and inspected separately, which not only improves productivity but also leads to improvement in reliability.

Further, in the semiconductor module, it is possible to fix the necessary conductors and semiconductor chips to the first and second heat-dissipating metals, respectively, and then integrate the first and second heat-dissipating metals to manufacture the semiconductor module. It is possible. It is possible to perform the process of integrating the heat-dissipating metal after confirming the manufacturing states of the first and second heat-dissipating metals, which leads not only to the improvement of productivity but also to the improvement of reliability.

In this power converter, when the collector surface of the semiconductor chip of the upper arm is fixed to the first radiation metal, the collector surface of the semiconductor chip of the lower arm is also fixed to the first radiation metal, and the upper and lower arms The collector surface and the emitter surface of the semiconductor chip are in the same direction. With such a structure, productivity is improved and reliability is improved.

Further, the semiconductor chip of the upper and lower arms and the signal terminal and the gate terminal of the upper and lower arms are fixed to the same heat-dissipating metal. Therefore, the wire bonding connection process for connecting the semiconductor chip to the signal terminal or the gate terminal can be collected on one of the heat-dissipating metals, and inspection and the like can be facilitated. This not only improves productivity but also improves reliability.

Further, by arranging the U-phase, V-phase, and W-phase semiconductor modules on each side surface of the capacitor module in the sandwich structure of the water channel housing described above, the U-turn points of the cooling water channel are reduced, so that the pressure loss of the water channel is reduced. It can be reduced, the source pressure of the cooling water can be lowered, the leakage of the cooling water is reduced, and the reliability is improved. Furthermore, by arranging the condenser module in the cooling water path formed on substantially the same plane, the condenser module can be cooled directly, and the condenser module can be cooled in addition to the semiconductor module. Is stable and helps improve the reliability of the power converter.

(3) Description of Productivity Improvement In the power conversion device according to the present embodiment, as described above, the semiconductor module and the cooling housing are manufactured separately, and then the semiconductor module is fixed to the cooling housing. It is possible to manufacture semiconductor modules on an electrical production line. This improves productivity and reliability. Further, since the capacitor module can be similarly manufactured by another manufacturing process and then fixed to the water channel housing, the productivity is improved.

In addition, the semiconductor module and the capacitor module can be fixed to the waterway housing, and then the terminals of the semiconductor module and the capacitor module can be connected, and a space for introducing the welding machine for connection can be secured. It leads to improvement of productivity. Further, in these connection steps, the terminals of the semiconductor module are fixed to the heat-dissipating metal of the semiconductor module, respectively, and the heat during terminal welding is diffused to the heat-dissipating metal, respectively, and the adverse effect on the semiconductor chip can be suppressed, resulting in this. This leads to improved productivity and reliability.

In addition, since the semiconductor chips of the upper and lower arms and the signal terminals and gate terminals of the upper and lower arms can be fixed to one of the heat-dissipating metals of the semiconductor module, wire bonding of both the upper arm and the lower arm is performed on one of the heat-dissipating metal production lines. It can be done and productivity is improved.

The power conversion device according to the present embodiment can mass-produce semiconductor modules having the same structure, and can adopt a method of using the required number of semiconductor modules based on the required specifications of the power conversion device, and planned mass production of semiconductor modules. This makes it possible to improve productivity, lower prices, and improve reliability. As described above, the power conversion device according to the embodiment of the present invention has structural features and effects from the above-mentioned three technical viewpoints. The details will be described below.

"Embodiment of the present invention"
Next, the power conversion device according to the embodiment of the present invention will be described in detail below 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, but as a typical example, a control configuration when the power conversion device according to the embodiment of the present invention is applied to a hybrid vehicle. The circuit configuration of the power conversion device will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a control block of a hybrid vehicle. FIG. 2 shows a vehicle drive electric system including a power conversion device including a series circuit of upper and lower arms and an inverter device including a control unit, a capacitor connected to the DC side of the inverter device, a battery, and a motor generator. It is a figure which shows the circuit structure.

The power conversion device according to the embodiment of the present invention is used for an in-vehicle power conversion device of an in-vehicle electric system mounted on an automobile, particularly a vehicle drive electric system, and has a very severe mounting environment and operating environment. An inverter device for use will be described as an example. The vehicle drive inverter device is provided in the vehicle drive electric system as a control device for controlling the drive of the vehicle drive electric motor, and uses the DC power supplied from the vehicle battery or the vehicle power generator that constitutes the vehicle power supply as a predetermined AC power. And the obtained AC power is supplied to the vehicle drive electric motor to control the drive of the vehicle drive electric motor. In addition, 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. There is. The converted DC power is supplied to the in-vehicle battery.

The configuration of the present embodiment can be applied to an inverter device other than the one for driving a vehicle, for example, an inverter device used as a control device for an electric braking device or an electric power steering device, but it is most desirable to apply it for driving a vehicle. It is effective. Further, the idea of the present embodiment can be applied to other in-vehicle power converters such as DC-DC power converters such as DC / DC converters and DC choppers or AC-DC power converters, but it is also applied to vehicle drive. By doing so, it exerts the most desirable effect. Furthermore, an industrial power converter used as a control device for an electric motor that drives factory equipment, or a household power converter that is used as a control device for an electric motor that drives a home photovoltaic power generation system or home electric appliances. However, as described above, the most desirable effect is exhibited by applying it for vehicle driving.

Further, a vehicle drive electric system provided with a vehicle drive inverter device to which the present embodiment is applied is driven by using an engine as an internal combustion engine and a vehicle drive electric motor as a vehicle drive source and driving one of the front and rear wheels. The case of mounting on a hybrid vehicle configured as described above will be described as an example. Further, as a hybrid vehicle, one of the front and rear wheels is driven by an engine and one of the front and rear wheels is driven by a vehicle driving electric motor, but this embodiment can be applied to any hybrid vehicle. Further, as described above, it can be applied to a pure electric vehicle such as a fuel cell vehicle, and even in a pure electric vehicle, the power conversion device described below has substantially the same operation, and substantially the same effect can be obtained.

In FIG. 1, the hybrid electric vehicle (hereinafter referred to as “HEV”) 10 is one electric vehicle and includes two vehicle driving systems. One of them is an engine system powered by an engine 20 which is an internal combustion engine. The engine system is mainly used as a drive source for an HEV. The other is an in-vehicle electric system powered by motor generators 92 and 94. The in-vehicle electric system is mainly used as a drive source for an HEV and a power generation source for the HEV. The motor generators 92 and 94 are, for example, permanent magnet synchronous motors, but since they operate as both a motor and a generator depending on the operation method, they are referred to as motor generators here.

A front wheel axle 14 is rotatably supported on the front portion of the vehicle body. A pair of front wheels 12 are provided at both ends of the front wheel axle 14. A rear wheel axle (not shown) is rotatably supported on the rear part of the vehicle body. A pair of rear wheels are provided at both ends of the rear wheel axle. The HEV of the present embodiment employs a so-called front-wheel drive system in which the main wheels driven by power are the front wheels 12 and the trailing wheels that are carried around are the rear wheels. The opposite, that is, the rear-wheel drive system is used. You may adopt it.

A front wheel side differential gear (hereinafter, referred to as “front wheel side DEF”) 16 is provided at the center of the front wheel axle 14. The front wheel axle 14 is mechanically connected to the output side of the front wheel side DEF 16. The output shaft of the transmission 18 is mechanically connected to the input side of the front wheel side DEF 16. The front wheel side DEF 16 is a differential power distribution mechanism that distributes the rotational driving force transmitted by the transmission 18 to the left and right front wheel axles 14. The output side of the motor generator 92 is mechanically connected to the input side of the transmission 18. The output side of the engine 20 and the output side of the motor generator 94 are mechanically connected to the input side of the motor generator 92 via the power distribution mechanism 22. The motor generators 92 and 94 and the power distribution mechanism 22 are housed inside the housing of the transmission 18.

The power distribution mechanism 22 is a differential mechanism composed of gears 23 to 30. Gears 25 to 28 are bevel gears. The gears 23, 24, 29, 30 are spur gears. The power of the motor generator 92 is transmitted directly to the transmission 18. The shaft of the motor generator 92 is coaxial with the gear 29. With this configuration, when the drive power is not supplied to the motor generator 92, the power transmitted to the gear 29 is directly transmitted to the input side of the transmission 18.

When the gear 23 is driven by the operation of the engine 20, the power of the engine 20 is transferred from the gear 23 to the gear 24, then from the gear 24 to the gear 26 and the gear 28, and then from the gear 26 and the gear 28 to the gear 30. Each is transmitted, and finally is transmitted to the gear 29. When the gear 25 is driven by the operation of the motor generator 94, the rotation of the motor generator 94 is transmitted from the gear 25 to the gear 26 and the gear 28, then from the gear 26 and the gear 28 to the gear 30, and finally. It is transmitted to the gear 29. As the power distribution mechanism 22, instead of the above-mentioned differential mechanism, another mechanism such as a planetary gear mechanism may be used.

The motor generators 92 and 94 are synchronous machines having a permanent magnet in the rotor, and the AC power supplied to the armature winding of the stator is controlled by the inverter devices 40 and 42 to control the motor generators 92 and 94. Drive is controlled. A battery 36 is electrically connected to the inverter devices 40 and 42, and electric power can be exchanged between the battery 36 and the inverter devices 40 and 42.

In the present embodiment, the first electric power generation unit composed of the motor generator 92 and the inverter device 40 and the second electric power generation unit composed of the motor generator 94 and the inverter device 42 are provided, and they are used properly according to the operating state. ing. That is, when the vehicle is driven by the power from the engine 20, when assisting the drive torque of the vehicle, the second electric power generation unit is used as a power generation unit and is operated by the power of the engine 20 to generate power, and the power is generated. 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 used as a power generation unit and is operated by the power of the engine 20 to generate electricity, and the second motor generator unit is generated by the electric power obtained by the power generation. Operate as an electric unit.

Further, in the present embodiment, by operating the first electric power generation unit as an electric unit by the electric power of the battery 36, the vehicle can be driven only by the power of the motor generator 92. Further, in the present embodiment, the battery 36 can be charged by operating the first motor generator unit or the second motor generator unit as a power generation unit by the power of the engine 20 or the power from the wheels to generate power.

Next, the electric circuit configurations of the inverter devices 40 and 42 will be described with reference to FIG. In the embodiment shown in FIGS. 1 to 2, the case where the inverter devices 40 and 42 are individually configured will be described as an example, but as will be described later with reference to FIGS. 7 and the like, the inverter devices 40, The 42 may be housed in one device. Since the inverter devices 40 and 42 have the same configuration, perform the same operation, and have the same functions, the inverter device 40 will be described here as an example.

The power conversion device 100 according to the present embodiment includes an inverter device 40, a capacitor 90, a DC connector 38, and an AC connector 88, and the inverter device 40 has an inverter circuit 44 and a control unit 70. Further, the inverter circuit 44 has a plurality of upper and lower arm series circuits 50 including an IGBT 52 (insulated gate type bipolar transistor) and a diode 56 that operate as an upper arm, and an IGBT 62 and a diode 66 that operate as a lower arm (FIG. 2). In the example of, three upper and lower arm series circuits 50, 50, 50), and an AC power line from the midpoint portion (intermediate electrode 69) of each upper and lower arm series circuit 50 to the motor generator 92 through the AC terminal 59 (see FIG. 3). It is a configuration that draws out 86. Further, the control unit 70 includes a driver circuit (built into the driver board) 74 that drives and controls the inverter circuit 44, and a control circuit 72 (built into the control board) that supplies a control signal to the driver circuit 74 via the signal line 76. have.

The upper arm and lower arm IGBTs 52 and 62 are power semiconductor elements for switching, operate by receiving a drive signal output from the control unit 70, and convert the DC power supplied from the battery 36 into three-phase AC power. .. This converted power is supplied to the armature winding of the motor generator 92. As described above, the three-phase AC power generated by the motor generator 92 can also be converted into DC power.

The power conversion device 100 according to the present embodiment is composed of a three-phase bridge circuit, and the three-phase upper and lower arm series circuits 50, 50, and 50 are electrically located between the positive electrode side and the negative electrode side of the battery 36, respectively. It is configured by being connected in parallel. Here, the upper and lower arm series circuit 50 is called an arm, and includes a switching power semiconductor element 52 and a diode 56 on the upper arm side, and a switching power semiconductor element 62 and a diode 66 on the lower arm side.

In this embodiment, it is exemplified that IGBTs (insulated gate bipolar transistors) 52 and 62 are used as power semiconductor elements for switching. The IGBTs 52 and 62 include collector electrodes 53 and 63, an emitter electrode, a gate electrode (gate electrode terminals 54 and 64), and a signal emitter electrode (signal emitter electrode terminals 55 and 65). Diodes 56 and 66 are electrically connected between the collector electrodes 53 and 63 of the IGBTs 52 and 62 and the emitter electrodes as shown in the figure. The diodes 56 and 66 are provided with two electrodes, a cathode electrode and an anode electrode, and the cathode electrode is attached to the collector electrode of the IGBTs 52 and 62 so that the direction from the emitter electrode of the IGBTs 52 and 62 to the collector electrode is forward. , The anode electrode is electrically connected to the emitter electrodes of the IGBTs 52 and 62, respectively.

A MOSFET (metal oxide semiconductor type field effect transistor) may be used as the switching power semiconductor element. The MOSFET includes three electrodes, a drain electrode, a source electrode, and a gate electrode. The MOSFET is provided with a parasitic diode between the source electrode and the drain electrode in the forward direction from the drain electrode to the source electrode. Therefore, unlike the IGBT, it is not necessary to separately provide a diode.

The upper and lower arm series circuit 50 is provided for three phases corresponding to each phase winding of the armature winding of the motor generator 92. The three upper and lower arm series circuits 50, 50, and 50 have U-phase, V-phase, and W-phase to the motor generator 92 via the intermediate electrode 69 connecting the emitter electrode of the IGBT 52 and the collector electrode 63 of the IGBT 62 and the AC terminal 59, respectively. Is forming. The upper and lower arm series circuits are electrically connected in parallel. The collector electrode 53 of the IGBT 52 of the upper arm is connected to the positive electrode side of the capacitor 90 via the positive electrode terminal (P terminal) 57, and the emitter electrode of the IGBT 62 of the lower arm is connected to the negative electrode of the capacitor 90 via the negative electrode terminal (N terminal) 58. Each is electrically connected to the side capacitor electrode. The intermediate electrode 69, which corresponds to the midpoint of each arm (the connection between the emitter electrode of the IGBT 52 of the upper arm and the collector electrode of the IGBT 62 of the lower arm), is an AC connector to the corresponding phase winding of the armature winding of the motor generator 92. It is electrically connected via 88. In this embodiment, as will be described in detail later, one upper / lower arm series circuit 50 composed of upper and lower arms is a main circuit component of the semiconductor module.

The capacitor 90 is for forming a smoothing circuit that suppresses fluctuations in the DC voltage caused by the switching operation of the IGBTs 52 and 62. The positive electrode side of the battery 36 is electrically connected to the positive electrode side of the capacitor 90, and the negative electrode side of the battery 36 is electrically connected to the negative electrode side capacitor electrode of the capacitor 90 via the DC connector 38. As a result, the capacitor 90 is connected between the collector electrode 53 of the upper arm IGBT 52 and the positive electrode side of the battery 36, and between the emitter electrode of the lower arm IGBT 62 and the negative electrode side of the battery 36, and the battery 36 and the upper and lower arms are connected in series. It is electrically connected in parallel to the circuit 50.

The control unit 70 is for operating the IGBTs 52 and 62, and is a control circuit 72 that generates a timing signal for controlling the switching timing of the IGBTs 52 and 62 based on input information from other control devices and sensors. It is provided with a drive circuit (built into the control board) and a drive circuit (built into the driver board) 74 that generates a drive signal for switching the IGBTs 52 and 62 based on the timing signal output from the control circuit 72.

The control circuit 72 includes a microcomputer (hereinafter, referred to as “microcomputer”) for arithmetically processing the switching timings of the IGBTs 52 and 62. As input information to the microcomputer, the target torque value required for the motor generator 92, the current value supplied from the upper and lower arm series circuit 50 to the armature winding of the motor generator 92, and the magnetic pole of the rotor of the motor generator 92. The position has been entered. The target torque value is based on a command signal output from a higher-level control device (not shown). The current value is detected based on the detection signal output from the current sensor 80. 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 92. In the present embodiment, the case of detecting the current values of three phases will be described as an example, but the current values of two phases may be detected.

The microcomputer in the control circuit 72 calculates the current command values of the d and q axes of the motor generator 92 based on the target torque value, and the calculated current command values of the d and q axes and the detected d and q The voltage command values of the d and q axes are calculated based on the difference from the current value of the axes, and the calculated voltage command values of the d and q axes are calculated as the U phase, V phase, and so on based on the detected magnetic pole positions. Converts to the W-phase voltage command value. Then, the microcomputer generates a pulse-shaped modulation wave based on the comparison between the fundamental wave (sine wave) and the carrier wave (triangle wave) based on the U-phase, V-phase, and W-phase voltage command values, and this generated modulation. The wave is output to the driver circuit 74 as a PWM (pulse width modulation) signal. Six PWM signals are output from the microcomputer to the driver circuit 74 corresponding to the upper and lower arms of each phase. As the timing signal output from the microcomputer, another signal such as a rectangular wave signal may be used.

The driver circuit 74 is composed of an integrated circuit in which a plurality of electronic circuit components are integrated into one, a so-called driver IC. In the present embodiment, a case where one IC is provided for each of the upper and lower arms of each phase (1 arm in 1 module: 1 in 1) will be described as an example, but one IC is provided corresponding to each of the arms. An IC may be provided (2in1), or one IC may be provided corresponding to all arms (6in1). The driver circuit 74 amplifies the PWM signal when driving the lower arm, and uses this as a drive signal to connect to the gate electrode of the corresponding lower arm IGBT 62, and when driving the upper arm, 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 this is output as a drive signal to the gate electrode of the corresponding upper arm IGBT 52. As a result, each of the IGBTs 52 and 62 performs a switching operation based on the input drive signal.

Further, the control unit 70 detects an abnormality (overcurrent, overvoltage, overtemperature, etc.) and protects the upper and lower arm series circuit 50. Therefore, sensing information is input to the control unit 70. For example, information on the current flowing through the emitter electrodes of the IGBTs 52 and 62 is input to the corresponding drive unit (IC) from the signal emitter electrode terminals 55 and 65 of each arm. As a result, each drive unit (IC) detects an overcurrent, and when an overcurrent is detected, stops the switching operation of the corresponding IGBTs 52 and 62 to protect the corresponding IGBTs 52 and 62 from the overcurrent. Information on the temperature of the upper and lower arm series circuit 50 is input to the microcomputer from a temperature sensor (not shown) provided in the upper and lower arm series circuit 50. Further, information on the voltage on the DC positive electrode side of the upper and lower arm series circuit 50 is input to the microcomputer.

The microcomputer performs overtemperature detection and overvoltage detection based on the information, and when overtemperature or overvoltage is detected, stops the switching operation of all the IGBTs 52 and 62, and the upper and lower arm series circuit 50 (pulled out). , The semiconductor module including this circuit 50) is protected from overtemperature or overvoltage.

In FIG. 2, the upper and lower arm series circuit 50 is a series circuit of the upper arm IGBT 52 and the upper arm diode 56 and the lower arm IGBT 62 and the lower arm diode 66, and the IGBTs 52 and 62 are switching semiconductor elements. .. The conduction and cutoff operations of the IGBTs 52 and 62 of the upper and lower arms of the inverter circuit 44 are switched in a certain order, and the current of the stator winding of the motor generator 92 at the time of this switching flows through the circuit created by the diodes 56 and 66.

As shown in the upper and lower arm series circuit 50, the positive terminal (P terminal, positive electrode terminal) 57, the negative terminal (N terminal 58, negative electrode terminal), and the AC terminal 59 from the intermediate electrode 69 of the upper and lower arms (see FIG. 3). ), Upper arm signal terminal (signal emitter electrode terminal) 55, upper arm gate (base) electrode terminal 54, lower arm signal terminal (signal emitter electrode terminal) 65, lower arm gate (base) It includes an electrode terminal 64. Further, the power conversion device 100 has a DC connector 38 on the input side and an AC connector 88 on the output side, and is connected to the battery 36 and the motor generator 92 through the connectors 38 and 88, respectively.

FIG. 3 is a diagram showing a circuit configuration of a power conversion device that uses two upper and lower arm series circuits for each phase as a circuit for generating the output of each phase of three-phase alternating current that is output to the motor generator. As the capacity of the motor generator increases, the amount of power converted by the power converter increases, and the current value flowing through the upper and lower arm DC circuits of each phase of the inverter circuit 44 increases. Although it is possible to cope with the increase in conversion power by increasing the electrical capacity of the upper and lower arms, it is preferable to increase the production amount of the inverter circuit (modularized one), and in FIG. 3, it is standardized and produced. By increasing the number of inverter circuits (modules) used, it is possible to cope with the increase in the amount of power to be converted.

More specifically, FIG. 3 shows that the inverter circuit 44 shown in FIG. 2 is composed of three upper and lower arm series circuits 50, 50, 50 and forms U-phase, V-phase, and W-phase to the motor generator 92. Is provided with two inverter circuits (inverter circuit 1 (45) and inverter circuit 2 (46)) having the same configuration as the inverter circuit 44 shown in FIG. 2, and these inverter circuits 45 and 46 are connected in parallel to be controlled. This is to deal with the increase in the capacity of the motor generator 92 of the above. That is, in the configuration shown in FIG. 3, 50U1 and 50U2 are provided corresponding to the U-phase upper and lower arm series circuit 50 shown in FIG. 2, and similarly, 50V1 and 50V2 are provided corresponding to the V phase, and the W phase is provided. Correspondingly, 50W1 and 50W2 are provided. The AC power lines 86 of the inverter circuit 1 and the inverter circuit 2 shown in FIG. 3 are structurally described as the AC bus bar 1 (391) and the AC bus bar 2 (392) in the following drawings.

Next, the outline of the overall configuration of the power conversion device according to the embodiment of the present invention will be described.

FIG. 4 is a perspective view showing the appearance of the overall configuration of the power conversion device according to the embodiment of the present invention. FIG. 5 is an exploded perspective view of the entire configuration of the power conversion device according to the embodiment of the present invention. FIG. 6 is a plan view of the overall configuration of the power conversion device according to the embodiment of the present invention with the upper case removed.

In FIGS. 4 to 6, the power conversion device according to the present embodiment illustrates that the circuit includes the inverter circuit 1 (45) and the inverter circuit 2 (46) shown in FIG.

38 is a DC connector, 88 is an AC connector 1 (a connector connected to the AC power line 86 of the inverter circuit 1 shown in FIG. 3), and 89 is an AC connector 2 (a power converter connected to the AC power line 86 of the inverter circuit 2 shown in FIG. 3). (Connector), 91 is an AC connector flange, 100 is a power converter, 112 is an upper case, 122 is an AC connector positioning unit, 124 is an upper case flange, 142 is a lower case, 144 is a waterway lid, and 145 is a module lid 1. 146 is the module lid 2, 246 is the waterway inlet, 248 is the waterway outlet, 372 is the control board (built-in control circuit), 373 is the control IC1, 374 is the control IC2, 386 is the driver board, and 387 is the driver IC. 388 represents a signal connector, 391 represents an AC bus bar 1 (AC power line 86 of the inverter circuit 1 shown in FIG. 3), and 392 represents an AC bus bar 2 (AC power line 86 of the inverter circuit 2 shown in FIG. 3).

The overall configuration of the power conversion device 100 according to the embodiment of the present invention shown in FIGS. 4 to 6 includes a DC connector 38 connected to the battery 36 (see FIG. 2) and a motor generator as an external electrical connection structure. It includes an AC connector 1 (88) and an AC connector 2 (89) for connecting to 92 (see FIG. 2), has an upper case 112 and a lower case 142 as an external structure, and further includes an upper and lower arm series circuit 50. A water channel inlet portion 246 and a water channel outlet portion 248 for cooling the semiconductor module and the condenser module are provided.

Further, the module lid 1 (145) covering the upper part of each semiconductor module including the upper and lower arm series circuits of the U1 phase, the V1 phase, and the W1 phase shown in FIG. 3 and the upper and lower sides of the U2 phase, the V2 phase, and the W2 phase, respectively. A driver board 386 and a control board 372 are laminated between the module lid 2 (146) that covers the upper part of each semiconductor module including the arm series circuit and the upper case 112 (see FIG. 5). ). The control IC 1 (373) and the control IC 2 (374) are mounted on the control board 372, and the driver IC 387 is mounted on the driver board 386. Further, an AC bus bar 1 (391) and an AC bus bar 2 (392) are arranged for three phases in the lower portion of the driver board 386. The horizontally formed water channel space including the water channel inlet portion 246 and the outlet portion 248 has a structure in which a semiconductor module including an upper and lower arm series circuit 50 and a heat radiation fin is loaded and cooled, as will be described later. ..

Next, the semiconductor module 500 in the power conversion device according to the embodiment of the present invention will be described below with reference to FIGS. 13, 14, 15, and 16. FIG. 13 is a perspective view showing the appearance of the overall configuration of the semiconductor module in the power conversion device according to the embodiment of the present invention. FIG. 14 is a cross-sectional view of the semiconductor module according to the present embodiment, and is a diagram showing a cross-sectional structure of the line AA shown in FIG. FIG. 15 is an exploded perspective view of the entire configuration of the semiconductor module according to the present embodiment. FIG. 16 is a diagram showing a cross-sectional structure of line BB shown in FIG.

In FIGS. 13 to 16, the semiconductor module 500 in the power conversion device according to the embodiment of the present invention has a heat radiation fin (A side) 522 on one side (note that the heat radiation fin has only an uneven fin-shaped portion). The whole of the heat radiation metal is not referred to), the heat radiation fin (B side) 562 on the other side, the upper and lower arm series circuit 50 sandwiched between both heat radiation fins 522 and 562, and the positive electrode terminal of the upper and lower arm series circuit. It is provided with various terminals including 532, a negative electrode terminal 572, and an AC terminal 582, a top case 512, a bottom case 516, and a side case 508. As shown in FIGS. 14 and 15, an upper and lower arm series circuit on a conductor plate fixed to the heat radiation fin (A side) 522 and the heat radiation fin (B side) 562 via an insulating sheet (the manufacturing method thereof will be described later). ) Is sandwiched between the heat radiation fins (A side) 522 and the heat radiation fins (B side) 562, the bottom case 516, the top case 512, and the side case 508 are attached, and the top case 512 is sandwiched between the heat radiation fins 522 and 562. The semiconductor module 500 is formed as an integrated structure by filling the mold resin from the side.

As shown in FIG. 13, the semiconductor module 500 has a heat radiation fin (A side) and a heat radiation fin (B side) facing (inserted) into the cooling water channel, and a series circuit of upper and lower arms is formed from the top case 512. 50 positive electrode terminal 532 (corresponding to P terminal 57 in FIGS. 2 and 3), negative electrode terminal 572 (corresponding to N terminal 58 in FIGS. 2 and 3), AC terminal 582 (corresponding to AC terminal 59 in FIG. 3), The structure is such that the signal terminal (for the upper arm) 552, the gate terminal (for the upper arm) 553, the signal terminal (for the lower arm) 556, and the gate terminal (for the lower arm) 557 project.

The external shape of the semiconductor module 500 is a substantially rectangular parallelepiped shape, and the area of the heat radiation fin (A side) 522 and the heat radiation fin (B side) 562 is large, and the surface of the heat radiation fin (B side) 562 is the front surface and the heat radiation fin (A side). ) Is the rear surface (as shown in the illustrated example of FIG. 13), the side surface having the side case 508 and the opposite side, both side surfaces, the bottom surface, and the upper surface are narrower than the above-mentioned front surface or rear surface. The basic shape of the semiconductor module is a substantially rectangular parallelepiped shape, and the heat radiation fins (B side) and (A side) are square, so cutting is easy, and the semiconductor module has a shape that does not easily roll on the production line. , Excellent in productivity. Furthermore, the ratio of the heat dissipation area to the total volume can be increased, and the cooling effect is improved.

In the present embodiment, the heat radiation fin (A side) 522 or the heat radiation fin (B side) 562 includes a metal plate for sandwiching the semiconductor chip and holding the conductor inside the semiconductor module and fins for dissipating heat. Is made of one metal. This structure is excellent in increasing heat dissipation efficiency. However, although the heat dissipation efficiency is slightly lowered, it can also be used in a structure in which a metal plate for sandwiching a semiconductor chip and holding a conductor inside a semiconductor module and a heat radiation fin are separately formed and bonded together.

Further, a positive electrode terminal 532 (corresponding to P terminal 57 in FIG. 3), a negative electrode terminal 572 (corresponding to N terminal 58 in FIG. 3), and an AC terminal 582 (corresponding to N terminal 58 in FIG. 3) and AC terminal 582 (corresponding to P terminal 57 in FIG. (Equivalent to AC terminal 59), signal terminal (for upper arm) 552, gate terminal (for upper arm) 553, signal terminal (for lower arm) 556, gate terminal (for lower arm) 557 are collected. , It is excellent in the ease of inserting the semiconductor module 500 into the water channel housing. Further, a hole 583 for ensuring insulation between these terminals is provided between the positive electrode terminal 532 and the negative electrode terminal 572. The hole 583 is formed in a mold resin 507 formed between the positive electrode terminal 532 and the negative electrode terminal 572. Then, a terminal insulating portion attached to the capacitor module provided between the positive electrode terminal and the negative electrode terminal of the capacitor module 390 is inserted into the hole 583 (see FIG. 21). Therefore, the hole 583 has both functions of insulation between terminals and positioning.

Further, as shown in FIG. 13, the outer shape of the upper surface provided with such terminals is made larger than the outer shape of the bottom side, and the terminal portion that is most easily damaged when the semiconductor module moves in a manufacturing line or the like. Can be protected. That is, since the outer shape of the top case 512 is made larger than the outer shape of the bottom case 516, in addition to the effect of excellent sealing of the cooling water channel opening described later, the water channel housing during manufacturing and transportation of the semiconductor module. It has the effect of protecting the terminals of the semiconductor module when it is attached to.

According to the arrangement of the terminals shown in FIG. 13, the positive electrode terminal 532 and the negative electrode terminal 572 each have a plate-like shape with a rectangular cross-sectional area and a comb-teeth shape at the tip thereof, and further, the heat radiation fin (B side). They are arranged on the left and right sides at equal intervals as viewed from 562, and are arranged close to one side surface of the semiconductor module. As shown in FIGS. 13 and 14, each terminal 532, 572 has a structure in which the conductor plate of the arm is first extended in the vertical direction (planting) and then extended in the horizontal direction as a structure leading to the comb-teeth shape at the tip thereof. (Bent at a right angle) to a comb-teeth shape. That is, the positive electrode terminal 532 and the negative electrode terminal 572 have bent portions, and their comb tooth shapes are arranged along the heat radiation fins 522 (A side). The terminals 532 and 572 shown in FIGS. 13 and 14 show a bent portion, but the terminals 532 and 572 shown in FIGS. 15 to 20 shown later have no bent portion and have a straight shape. However, the terminal of FIG. 13 shows a state after the steps of soldering work, internal molding, and case bonding (joining) are completed, and finally bending is performed. That is, the straight shapes of FIGS. 15 to 20 are in a state before bending. The reason for the final bending is to prevent a force from being applied to the internal semiconductor and the solder joint during the bending operation, and to bend the top case 512 first, which makes it difficult to assemble.

Although the details will be described later, since the capacitor module 390 is arranged so as to face the heat radiation fin (B side) 562, the positive electrode terminal and the negative electrode terminal of the capacitor module have the same length as the positive electrode terminal 532 and the negative electrode terminal 572 of the semiconductor module. It can be connected with the DC bus bar of, and wiring becomes easy. Further, the connection ends of the positive electrode terminal 532 and the negative electrode terminal 572 and the connection ends of the AC terminal 582 are arranged so as to be offset in the front-rear direction (direction connecting both side surfaces of the semiconductor module) of the semiconductor module. For this reason, there is a space for using equipment for connecting the connection ends of the positive electrode terminal 532 and the negative electrode terminal 572 to other parts and the connection end of the AC terminal 582 to other parts in the production line of the power conversion device. It is easy to secure and has excellent productivity.

Power converters for automobiles can cool to -30 degrees or less and nearly -40 degrees. On the other hand, the temperature may reach 100 degrees or higher, and rarely close to 150 degrees. As described above, the power conversion device mounted on the automobile has a wide operating temperature range, and it is necessary to fully consider the change in thermal expansion. It is also used in an environment where vibration is constantly applied. The semiconductor module 500 described with reference to FIGS. 13 to 16 has a structure in which a semiconductor chip is sandwiched between two heat radiating metals. In this embodiment, a metal plate having heat radiation fins having an excellent heat release function is used as an example of the heat radiation metal, and the heat radiation fins 522 (A side) and the heat radiation fins 562 (B side) are described in this embodiment. There is.

In the structure in which the semiconductor chip is sandwiched, both sides of the two heat-dissipating metals are fixed by the top case 512 and the bottom case 516. In particular, the top case 512 and the bottom case 516 have a structure in which two heat-dissipating metals are sandwiched and fixed from the outside. Specifically, the structure may be such that the protruding protrusions of the two heat-dissipating metals 522 and 562 are fitted to the fitting portion 517 of the bottom case 516, and the same fitting structure may be applied to the top case 512. Just do it. With such a structure, it is possible to prevent a large force in the direction of opening between the two heat-dissipating metals due to vibration or thermal expansion. It is possible to obtain a highly reliable power conversion device that does not break down even when mounted on an automobile for a long period of time.

Further, in the present embodiment, in addition to the two heat-dissipating metals, the top case 512 and the bottom case 516 including the side case have a structure in which they are sandwiched and fixed from the outer peripheral side, so that the reliability is further improved. To do.

The positive electrode terminal 532, the negative electrode terminal 572, the AC terminal 582, the signal terminals 552 and 556, and the gate terminals 553 and 557 of the semiconductor module are projected to the outside through the internal holes of the top case 512, which is one of the cases. The structure is such that this hole is sealed with a mold resin 507. A high-strength material is used for the top case 512, and the top case 512 is made of a material having a similar coefficient of thermal expansion, for example, a metal material in consideration of the coefficient of thermal expansion of the two heat-dissipating metals. The mold resin 507 has an action of absorbing the stress due to the change in thermal expansion of the case 512 and reducing the stress applied to the terminal described above. Therefore, the power conversion device of the present embodiment has high reliability that can be used even in a state where the temperature change range is wide as described above or in a state where vibration is constantly applied.

FIG. 17 is an exploded view showing the structure of the internal arrangement of the upper and lower arm series circuits in the semiconductor module according to the present embodiment. In FIG. 17, the semiconductor module according to the present embodiment uses a heat-dissipating metal plate, for example, a heat-dissipating fin (A side) 522 and a heat-dissipating fin (B side) 562, which are metal plates having a fin structure, as basic materials inside the semiconductor module. The insulating sheet (A side) 546 and the insulating sheet (B side) 596 are fixed by vacuum thermal crimping. Then, the conductor plate 534 on the positive electrode side and the conductor plate 535 for connecting the upper and lower arms are fixed to the insulating sheet (A side) 546 (see FIG. 19).

Further, the conductor plate 574 on the negative electrode side and the conductor plate 584 on the AC terminal side are fixed to the insulating sheet (B side) 596, and the lower arm signal terminal 556 is connected to the conductor plate 574 on the negative electrode side to connect the AC terminal. The upper arm signal terminal 552 is connected to the conductor plate 584 on the side (see FIG. 20).

The insulating sheet (A side) 546 and the insulating sheet (B side) 596 electrically connect the semiconductor chips and conductors constituting the upper and lower arm series circuit of the inverter circuit with the heat radiation fins (A side) 522 and the heat radiation fins (B side) 562. In addition to functioning as an insulating member that specifically insulates, it also functions to form a heat conduction path that conducts heat generated from a semiconductor chip or the like to radiating fins (A side) 522 and radiating fins (B side) 562. The insulating member may be a resin insulating sheet or an insulating plate, or may be a ceramic substrate. For example, in the case of a ceramic substrate, it is desirable that the thickness of the insulating member is 350 μmeter or less, and in the case of an insulating sheet, it is thinner and is preferably 50 μm to 200 μm. However, from the viewpoint of reducing inductance, it is effective that the insulating member is thin, and the resin insulating sheet is characteristically superior to the ceramic substrate.

Next, the upper arm IGBT chip 537 and the upper arm diode chip 539 are arranged in the vertical direction and fixed by soldering to the conductor plate 534 on the positive electrode side of the heat radiation fin (A side) 522. Similarly, the lower arm IGBT chip 541 and the lower arm diode chip 543 are arranged in the vertical direction and fixed by soldering to the conductor plate 535 for connecting the upper and lower arms of the heat radiation fin (A side) 522. Here, when comparing the vertical sizes of the IGBT chip and the diode chip, the size of the IGBT chip is considerably larger. Then, considering the water channel occupancy occupied by the IGBT chip and the diode chip with respect to the cooling water passing through the heat radiation fin 522, the water channel occupancy occupied by the upper arm IGBT chip 537 is higher than that of the upper arm diode chip 539. Will also be quite large. The heat dissipation of the IGBT chip, which dissipates more heat than the diode chip, is promoted, and the heat dissipation efficiency of the entire semiconductor module is improved. Such heat dissipation efficiency can be improved not only for the tip for the upper arm but also for the tips 541 and 543 for the lower arm.

Further, as will be described in detail in the description of FIGS. 18 to 20, the upper and lower arm connecting solder joints 555 connecting the emitter electrode of the upper arm and the collector electrode of the lower arm are similar to the chips 541 and 543 of the lower arm. It is formed on the conductor plate 535 of the heat radiation fin (A side) 522 (see FIGS. 18 and 19), and the joint portion 555 is connected to the AC terminal 582 (corresponding to the AC terminal 59 in FIG. 3) via the solder layer 544 and the conductor plate 584. ) Connected to form an intermediate electrode 69 (see FIG. 2) of the upper and lower arm series circuit. Further, between the gate electrode of the upper arm IGBT 537 soldered on the conductor plate of the heat radiation fin (A side) 522 and the signal conductor of the gate terminal (for the upper arm) 553, and the gate of the lower arm IGBT 541. The structure is such that the electrode and the gate conductor of the gate terminal (for the lower arm) 557 are connected by wire bonding 593, 596, respectively.

On the other hand, as shown in FIGS. 17 and 20, the insulating sheet (B side) 596 of the heat radiation fin (B side) 562 has a conductor plate 574 on the negative electrode side of the negative electrode terminal 527 and a conductor plate on the AC terminal side of the AC terminal 582. The conductor plates of 584, the signal terminal (for the upper arm) 552, and the signal terminal (for the lower arm) 556 are fixed to each other. The conductor plate 574 on the negative electrode side is provided with a solder joint portion 757 to which the emitter side of the lower arm IGBT chip 541 is connected and a solder joint portion 759 to which the anode side of the diode chip 543 of the lower arm is connected, and is a conductor on the AC terminal side. The plate 584 is provided with a solder joint portion 756 to which the emitter side of the upper arm IGBT chip 537 is connected and a solder joint portion 758 to which the anode side of the diode chip 543 of the upper arm is connected. The negative electrode terminal 572 (corresponding to the negative electrode terminal 58 shown in FIG. 2) has a conductor plate 574, solder joints 757 and 759, and solder layers 540 and 542 with respect to the lower arm IGBT chip 541 and the lower arm diode chip 543. Connected via. Further, the positive electrode terminal 532 is connected to the IGBT chip 537 of the upper arm and the diode chip 543 of the upper arm via the conductor plate 534, the solder joints 751 and 752, and the solder layers 547 and 548. Further, the AC terminal 582 is via a conductor plate 584, a solder joint portion 560 for connecting the upper and lower arms, a solder layer 544, a solder joint portion 555 for connecting the upper and lower arms, and a conductor plate 535 connected to the emitter side of the upper arm IGBT chip. It is connected and connected to the lower arm IGBT chip 541. Each conductor plate of the upper arm signal terminal 552 (corresponding to the signal terminal 55 shown in FIG. 2) and the lower arm signal terminal 556 (corresponding to the signal terminal 65 shown in FIG. 2) is an upper arm IGBT chip. It is coupled to the emitter side of each of the 537 and the lower arm IGBT chip 541. The circuit configuration of the upper and lower arm series circuit 50 shown in FIG. 2 is formed by the arrangement structure of the semiconductor modules described above.

As shown in FIG. 17, both semiconductor chips constituting the upper arm and the lower arm are arranged and fixed in the vertical direction on the heat radiation fin (A side) 522, which is one of the heat radiation fins, and further, with the gate terminal 553 for the upper arm. Since the lower arm date terminal 557 is provided on the heat radiation fin (A side) 522 and connection work such as wire bonding can be performed on one heat radiation fin (A side) 522, it is possible to concentrate in the manufacturing process, and productivity and reliability. It will improve the sex. Further, when used in an environment with large vibration such as for automobiles, the semiconductor chip to be wired and the terminal are fixed to the same heat radiation fin, so that the vibration resistance is improved.

As described above, the heat radiation fin (A side) 522 and the heat radiation fin (B side) 562 are opposed to each other as shown in FIG. 17, and the IGBT chips 537, 541 and the diode chip 539 of the heat radiation fin (A side) 522 are opposed to each other. The negative electrode terminal 572, the AC terminal 582, the upper arm signal terminal 552, and the lower arm signal terminal of the heat radiation fin (B side) 562 so that the electrodes with 543 are connected according to the circuit configuration shown in FIG. It is soldered so that it faces the conductor plates connected to 556 respectively. Further, as shown in FIG. 15, the bottom case 516, the top case 512, and the side case 508 are provided with an adhesive to the heat radiation fins (A side) 522 and the heat radiation fins (B side) 562, which have an integrated structure. It will be glued. Further, the semiconductor module 500 is formed by filling the inside with a mold resin through the holes 513 (see FIG. 15) of the top case.

Next, in the semiconductor module 500 according to the present embodiment, the method and specific structure of the upper and lower arm series circuit (for example, a 2-arm in 1 module structure) sandwiched between the two heat radiation fins 522 and 562 will be described in FIGS. The description will be extended with reference to FIG. FIG. 18 is a diagram showing an arrangement structure of the upper and lower arm series circuits arranged on the heat radiation fin (A side) in the semiconductor module according to the present embodiment. FIG. 19 is a diagram showing a bonding relationship of each component arranged on the heat radiation fin (A side) in the semiconductor module. FIG. 20 is a diagram showing a bonding relationship of each component arranged on the heat radiation fin (BA side) in the semiconductor module.

The basic process in the manufacture of the semiconductor module according to this embodiment is shown. A heat-dissipating metal plate, for example, an insulating sheet which is a high thermal conductive resin layer inside each of the heat-dissipating fins (A side) 522 and the heat-dissipating fins (B side) 562, which are metal plates having a fin structure in this embodiment, as basic materials. (A side) 546 and the insulating sheet (B side) 596 are fixed by vacuum thermal crimping, and the conductor plate 534 and the conductor plate 535 on the positive electrode side are fixed to the insulating sheet 546 (A side), and the insulating sheet 596 (B side). The conductor plate 574 on the negative electrode side and the conductor plate 584 for the AC terminal are fixed to. FIG. 19 shows the state of adhesion of the conductor plates 534 and 535 to the heat radiating fins (A side) 522 and the insulating sheet (A side) 546, and shows the conductors to the heat radiating fins (B side) 562 and the insulating sheet (B side) 596. The state of sticking of the plates 574 and 584 is shown in FIG.

Further, the gate conductor of the gate terminal (for the upper arm) 553 and the gate conductor 559 of the gate terminal (for the lower arm) 557 are fixed to the insulating sheet 546 (A side). The signal conductor of the signal terminal (for the upper arm) 552 and the signal conductor of the signal terminal (for the lower arm) 556 are fixed to the insulating sheet 596 (B side). These arrangement relationships are as shown in FIGS. 19 and 20 and 23.

Next, the solder layers 547,548, corresponding to the solder joints 751, 752, 753, 754 provided on the conductor plate 534 on the positive electrode side on the heat radiation fin (A side) 522 side and the conductor plate 535 for connecting the upper and lower arms, The IGBT chip 537 (for the upper arm), the diode chip 539 (for the upper arm), the IGBT chip 541 (for the lower arm), and the diode chip 543 (for the lower arm) are soldered with 549 and 550 interposed therebetween. At this time, the conductor plate 534 and the conductor plate 535 on the positive electrode side are provided in an insulated state from each other, and the IGBT chip and the diode chip are soldered to the respective conductor plates 534 and 535. Further, as shown in FIG. 2, a solder joint portion 555 for connecting the emitter electrode of the upper arm and the collector electrode of the lower arm is soldered to the conductor plate 535 in the same manner as the chips 541 and 543, and is used for connecting the upper and lower arms. Solder joint 555 (see FIG. 19) is abutted and connected to the conductor plate 584 for the AC terminal via the solder joint 560 (see FIG. 20) for connecting the upper and lower arms, so that the intermediate electrode 69 (see FIG. (See FIG. 2).

Next, a gate wire (upper arm) is placed between the gate electrode of the IGBT 537 of the upper arm soldered on the conductor plate 534 of the heat radiation fin (A side) 522 and the gate conductor of the gate terminal (for the upper arm) 553. (For) 593 for bonding connection (see FIG. 17). Similarly, a gate wire (lower) is placed between the gate electrode of the lower arm IGBT 541 soldered on the conductor plate 535 of the heat radiation fin (A side) 522 and the gate conductor of the gate terminal (for the lower arm) 557. Bonding connection with 597 (for arm).

As shown in FIG. 18, both semiconductor chips constituting the upper arm and the lower arm are fixed to the heat radiation fin (A side) 522, which is one of the heat radiation fins, and the gate terminal 553 for controlling a signal to these semiconductor chips. , A gate conductor connected to 557 is provided. Since the semiconductor chip for the upper and lower arms and its control line are fixed to one of the insulating members in this way, the connection work between the signal line and the semiconductor chip such as wire bonding can be concentrated in the manufacturing process, and productivity is improved. It improves reliability. Further, when used in an environment with large vibration such as for automobiles, both one semiconductor chip to be wired and the other control line are fixed to one heat radiation fin which is the same member, so that vibration resistance is improved. To do.

As shown in FIG. 19, the semiconductor chip 537 for the upper arm (bonded to the solder joint portion 751) and the semiconductor chip 541 for the lower arm (bonded to the solder joint portion 753) are oriented in the same direction, that is, respectively. The collector surface of the semiconductor chip faces the insulating sheet 546 side, which is an insulating member, and the solder joint portions 751, 753 are provided so as to face the collector side of the IGBT chips 537,541. In this way, workability is improved by aligning the directions of the semiconductor chips of the upper arm and the lower arm. This is the same for the diode chips 539 and 543.

As shown in FIG. 14, in the arrangement structure of the upper and lower arm series circuits 50 built in the semiconductor module 500 according to the present embodiment, referring to the detailed structure shown in FIG. 17, the IGBT 52 of the upper arm is the diode 56 of the upper arm. It is installed in the upper part of the above, and this installation relationship is the same for the IGBT and diode of the lower arm. The details will be described later, but the semiconductor module 500 shown in FIG. 13 is inserted into the cooling water channel from above and installed, and the semiconductor module 500 is cooled by the cooling water flowing in the cooling water channel, but the cooling water dissipates heat. It will flow through the comb-toothed portion (recess) of the fin (A side) 522 and the heat radiation fin (B side) 562.

Here, the lengths of the IGBT and the diode in the height direction are higher than the height M of the diode 56 in terms of their structural and shape features, taking the upper arm as an example. Long in the vertical direction (L> M). Then, the cooling water flowing through the comb-toothed portion of the heat radiating fin exerts a cooling effect according to the lengths L and M. In other words, the amount of cooling water corresponds to the lengths L and M, and the IGBT that wants to dissipate more heat than the diode corresponds to a larger amount of cooling water, which leads to an improvement in cooling efficiency.

Further, the semiconductor module 500 having an integrated structure shown in FIG. 13 has a shape in which the positive electrode terminal 532 and the negative electrode terminal 572, which should be connected to the positive electrode side and the negative electrode side of the capacitor 90, protrude upward, and further, these terminals. The 532 and 572 are arranged on a straight line in the direction along the cooling water channel (along the longitudinal direction of the rectangular shape in the cross section of the semiconductor module viewed from above).

On the other hand, as will be described later, a plurality of semiconductor modules are installed on both sides of the semiconductor module along the rectangular longitudinal direction (cooling water flow direction) of the upper cross section of the semiconductor module, that is, the semiconductor modules are sandwiched between them. It is a sandwich structure in which a plurality of semiconductor modules are arranged on both sides (see FIG. 11).

In such an arrangement structure of the semiconductor module and the capacitor module, the terminals on the positive electrode side and the negative electrode side of the capacitor module are arranged so as to face the positive electrode terminal 532 and the negative electrode terminal 572 of the semiconductor module shown in FIG. As a result, when connecting the semiconductor module 500 and the capacitor module 390 with a bar, it is possible to use a bar having the same shape and the same length on the positive electrode side and the negative electrode side, which improves workability and improves the switching operation of the IGBT. The accompanying inductance can be reduced.

Next, a specific configuration for improving miniaturization, cooling efficiency, and assembling property in the power conversion device according to the embodiment of the present invention will be described below with reference to FIGS. 7 to 12. FIG. 7 is an exploded view showing an arrangement configuration of semiconductor modules in the power conversion device according to the embodiment of the present invention, and the upper case, control board, driver board, and AC connector are removed from the overall configuration of the power conversion device shown in FIG. It is a figure. FIG. 8 is a perspective view of a power system around a semiconductor module in which an AC connector and a DC connector are attached to an exploded view shown in FIG. FIG. 9 is an exploded view of the power system around the semiconductor module shown in FIG. FIG. 10 is a cross-sectional view of the arrangement configuration of the semiconductor modules shown in FIG. 7 as viewed from the flow direction of the cooling water. FIG. 11 is a cross-sectional view taken from the overall configuration of the power conversion device according to the present embodiment when the upper case is removed and viewed from the flow direction of the cooling water. FIG. 12 is a cross-sectional view of the semiconductor module, the condenser module, and the cooling water channel according to the present embodiment as viewed from above.

First, the arrangement structure of the semiconductor module, the cooling water channel, the power system, and the like in the power conversion device according to the present embodiment will be described with reference to FIGS. 7 to 9. The semiconductor modules of the embodiments shown in FIGS. 7 to 9 include a semiconductor module 1 having an upper upper and lower arm series circuit composed of a U1 phase, a V1 phase, and a W1 phase as shown in FIG. 3, a U2 phase, a V2 phase, and the like. It is a structure exemplifying six semiconductor modules of two systems including a semiconductor module 2 having a lower upper and lower arm series circuit composed of a W2 phase. The semiconductor module 1 is connected to the AC connector 1 (88) through the three AC bus bars 1 (391), and similarly, the semiconductor module 2 is connected to the AC connector 2 (89) through the three AC bus bars 2 (392). Be connected. In the drawing, a semiconductor module 1 having an upper upper and lower arm series circuit composed of a U1 phase, a V1 phase, and a W1 phase as shown in FIG. 3 is built on the cooling water channel inlet 246 side (that is, the AC connector 88, 89 arrangement side). The semiconductor module 2 composed of the U2 phase, the V2 phase, and the W2 phase is arranged on the opposite side (the cooling water channel outlet portion 248 side).

Further, a DC connector 38 connected to the condenser module 390 is arranged on a side surface opposite to the side surface on which the cooling water inlet portion 246 and the outlet portion 248 are arranged. Further, an AC connector 88 and an AC connector 89 (see FIG. 3) are mounted on the AC connector mounting portion 123 with the AC connector positioning portion 122 interposed therebetween, and an AC connector portion flange 90 is provided on the upper surface thereof. A semiconductor module insertion channel 237 into which the semiconductor module 500 is inserted is formed in the lower case 142 on both sides of the capacitor module insertion portion 147 into which the capacitor module 390 (see FIG. 11) is inserted (see FIG. 10). In this way, a sandwich structure is formed in which the semiconductor modules 500 are arranged on both sides of the capacitor module 390.

A module lid 1 (145) is arranged on the upper surface of the semiconductor module 1 arranged on the AC connector side, and a module lid 2 (146) is arranged on the upper surface of the semiconductor module 2 arranged on the opposite side. A water channel lid 144 (see FIG. 9) is arranged on the upper surface of the folded water channel 227 (see FIGS. 7 and 12) in the front portion where the inlet portion 246 and the outlet portion 248 are arranged. Further, in the semiconductor module insertion channel 237 (see FIG. 10), a folded channel 236 on the back surface is formed on the opposite side of the front surface (see FIG. 7). Further, a water channel forming body 1 (490) is provided in the vicinity of the water channel inlet portion 246, and a water channel forming body 2 (491) is provided in the vicinity of the water channel outlet portion 248, and the heat radiation fin (A side) of the semiconductor module is provided. The water flow is guided so that the cooling water flows over the entire area of the heat radiating fin (B side) (see FIG. 12).

Next, a detailed arrangement structure of a semiconductor module, a cooling water channel, a power system, and the like in the power conversion device according to the present embodiment will be described with reference to FIGS. 10 to 12. The present embodiment employs a slot-in structure in which the semiconductor module 500 is inserted into the water channel 237 formed in the lower case 142 from above, and the semiconductor module 500 is the semiconductor module positioning portion 502 of the lower case 142. Is positioned and fixed to the water channel 237 by the semiconductor module fixing portion 501 of the module lids 145 and 146.

In the water channel on the side of the AC connector mounting portion 123 on which the AC connectors 88 and 89 are mounted, the semiconductor modules of the U1 phase, the V1 phase, and the W1 phase shown in FIG. 3 are formed in the rear direction of the water channel forming body 1 (490), for example. 500, 500, 500 are inserted and fixed. Similarly, the U2 phase, V2 phase, and W2 phase semiconductor modules 500, 500, and 500 shown in FIG. 3 are inserted and fixed in the water channel on the side of the water channel outlet portion 248.

According to FIG. 12, the water flow 250 from the water channel inlet 246 is guided by the water channel forming body 1 (490) to form a water stream 251 on one of the heat radiation fins of the semiconductor module 500, and at the back surface of the water channel 237. It is folded back at the water flow 252 shown in the folded water channel 236 of the above to form the water flow 253. Subsequently, the water flow is guided by the channel forming body 1 (490), passes through the folded channel 227 at the front portion, and then is guided by the channel forming body 2 (491), and is guided to the channel on the side of the channel outlet portion 248. Form a stream of water. The water flow in the water channel on the right side connected to the water channel outlet portion 248 shown in FIG. 12 forms the same water flow as the water flow on the left side described above.

As shown in FIG. 12, the present embodiment adopting a structure in which three semiconductor modules 500 are arranged on the left side of the capacitor module 390 and three semiconductor modules 500 are arranged on the right side thereof is disclosed in the prior art. The waterway inlet and the waterway outlet are arranged on the same side surface (for example, the front part), and six inverted U-shaped waterways are arranged in the direction connecting the inlet and the outlet (for example, the left-right direction). Compared to the structure in which the U-shaped canals are connected in order by the folded canals and six semiconductor modules 500 are installed in the respective inverted U-shaped canals, the U-turned folded canals are the 11 folded canals in the above-mentioned prior art. On the other hand, in the present embodiment shown in FIG. 12, there are three locations: two return channels 236 (folded channels above the left and right channels) and a return channel composed of the illustrated water stream 254 and water stream 256.

Then, considering the pressure loss of the water flow at the time of changing the direction of the water flow in the water channel, there are 11 U-turn water channels in the above-mentioned prior art, whereas in the present embodiment shown in FIG. 12, there are 3 locations. The pressure loss in the water channel can be significantly reduced. If this pressure loss is reduced, the flow speed of the water flow does not differ so much between the inlet and the outlet, and the cooling efficiency by the cooling water does not decrease so much.

Further, as shown in FIGS. 11 and 12, since the condenser module 390 has water channels formed on both the left and right sides and the front side (see water flow 255), the condenser module 390 is also cooled by the cooling water flowing through the water channels. It has a structure that

Next, according to FIG. 11 (see also FIG. 5), the upper surface of the capacitor module 390 occupies a fairly large surface in the power converter 100, and the upper surface of the capacitor module 390 is effectively utilized. The structural arrangement is also one of the features of this embodiment. That is, a driver board 386 (corresponding to the driver board 74 shown in FIG. 2) is installed on the upper surface of the capacitor module 390, and the driver IC 387 is mounted on the driver board 386. Further, a control board 372 is installed above the driver board 386 via a connecting material, and both boards 386 and 372 are electrically connected by a signal connector 388 (see FIG. 5). The control board IC 373 is mounted on the control board 372. As described above, in the present embodiment, the driver board and the control board are installed on the upper surface of the capacitor module 390 to effectively utilize the upper surface.

To explain, the semiconductor module on the left side (for U1 phase, V1 phase, and W1 phase) shown in FIG. 11 corresponds to the inverter circuit 1 (45) shown in FIG. 3, and the semiconductor module on the right side shown in FIG. (For U2 phase, V2 phase, W2 phase) corresponds to the inverter circuit 2 (46) shown in FIG. Originally, the driver board 386 is provided for each of the inverter circuit 1 (45) and the inverter circuit 2 (46), but in the present embodiment, the inverters built in the three semiconductor modules 500 on the left side of FIG. 11 are provided. By adopting a structure in which a driver board is laid between the circuit 1 (45) and the inverter circuit 2 (46) provided on the right side (see FIG. 3), the two inverter circuits 1 and 2 are separated from each other. A single driver board 386 can also be used.

Further, looking at FIG. 10, the lower case 142 functionally forms a water channel housing (water channel 237 in FIG. 10), and further forms an insertion portion 147 of the condenser module.

Therefore, since the lower case 142 functions not only as a water channel housing but also as a positioning function of the condenser module 390, the positioning of the condenser module is easy.

As can be seen from the arrangement structure of the semiconductor module 500 and the capacitor module 390 in the power conversion device shown in FIG. 7 and the arrangement structure of the positive terminal 532 and the negative terminal 572 of the semiconductor module 500 shown in FIG. 13, the heat radiation fin (B side) Since the capacitor module 390 is arranged facing the 562, the positive terminal and the negative terminal of the capacitor module 390 can be connected to the positive terminal 532 and the negative terminal 572 of the semiconductor module 500 with DC bus bars of the same length, and the connection is easy. (Two DC bus bars of the same length and the same structure are prepared, and these DC bus bars are passed between the positive terminal 532 and the positive terminal of the capacitor module, and between the negative terminal 572 and the negative terminal of the capacitor module. The capacitor module and the semiconductor module are connected by a DC bus bar of the same shape with a simple structure to form a wiring structure with low inductance.

FIG. 21 is a diagram showing a structure of terminal connection between a semiconductor module and a capacitor module according to the present embodiment. FIG. 21 illustrates one side of a sandwich structure in which a capacitor module 390 is sandwiched between semiconductor modules 500.

A DC bus bar 393 is projected from the capacitor module 390, and a positive electrode terminal 394 and a negative electrode terminal 395 of the condenser module are arranged at the end portions thereof, and a comb-shaped terminal portion is planted at the tip portion thereof. Further, between the positive electrode terminal 394 and the negative electrode terminal 395, a thin plate-shaped capacitor module terminal insulating portion 396 that ensures insulation between these terminals is attached to the DC bus bar 393. By inserting the thin plate-shaped terminal insulating portion 396 into the insertion hole 583 drilled in the upper surface of the semiconductor module, the terminal connection between the semiconductor module 500 and the capacitor module 390 can be positioned.

By this positioning, the junction between the positive electrode terminal 532 of the semiconductor module and the positive electrode terminal 394 of the capacitor module and the junction between the negative electrode terminal 572 of the semiconductor module and the negative electrode terminal 395 of the capacitor module are fixed. That is, the comb-teeth shapes of both terminals to be joined are closely related to each other, and subsequent soldering work, for example, becomes easy, and solder adhesion becomes strong (the connection terminals of the capacitor module 390 and the semiconductor module have comb-teeth shapes with each other. This makes it easier to weld and other fixed connections between the two connection terminals). As shown in the figure, the arrangement of the positive electrode terminal 532 and the negative electrode terminal 572 of the semiconductor module is juxtaposed with respect to the facing surface side of the capacitor module 390, so that the positive electrode terminal 394 and the negative electrode terminal 395 of the capacitor module have a projecting structure. Can be identical to each other.

Further, since a plurality of semiconductor modules 500 are arranged along the longitudinal direction of the fins, the structure of the DC bus bar 393 of the capacitor module for each semiconductor module can be the same.

Next, the reduction of the wiring inductance of the semiconductor module according to the present embodiment will be described with reference to FIGS. 22 and 23. FIG. 22 is a structural layout diagram for explaining the reduction of wiring inductance in the semiconductor module and the capacitor module according to the present embodiment. FIG. 23 is a layout diagram on an equivalent circuit for explaining the reduction of wiring inductance in the semiconductor module and the capacitor module according to the present embodiment. Since a transient voltage rise and large heat generation of the semiconductor chip occur during the switching operation of the upper arm or the lower arm constituting the inverter circuit, it is particularly desirable to reduce the inductance during the switching operation. Since the diode recovery current 600 is generated at the time of transient, the action of reducing the inductance will be described based on this recovery current by taking the recovery current of the lower arm diode 543 (corresponding to 66 in FIG. 2) as an example.

The recovery current of the diode 543 is the current that flows through the diode 543 despite the reverse bias, and is generally said to be caused by the carriers filled in the diode 543 in the forward state of the diode 543. Three-phase AC power is generated at the AC terminal 582 of the inverter circuit by performing the conduction operation or the cutoff operation of the upper arm or the lower arm constituting the inverter circuit in a predetermined order. When the semiconductor chip 537 operating as the upper arm is switched from the conductive state to the cutoff state, the current of the stator winding of the motor generator 92 (see FIG. 2) is maintained via the diode 543 of the lower arm. The return current flows. This return current is the forward current of the diode 543, and the inside of the diode is filled with carriers. Next, when the semiconductor chip 537 operating as the upper arm is switched from the cutoff state to the conductive state again, the recovery current due to the carrier described above flows through the diode 543 of the lower arm. In steady operation, one of the upper and lower arm series circuits is always cut off, and a short-circuit current does not flow through the upper and lower arms, but the transient current, for example, the diode recovery current, flows through the series circuit composed of the upper and lower arms. ..

When the IGBT (semiconductor element for switching) 537 that operates as the upper arm of the upper and lower arm series circuit in FIGS. 22 and 23 changes from off to on, the positive electrode terminal 532 (corresponding to 57 in FIG. 2), the IGBT 537, and the diode 543 A recovery current of the diode 543 flows through the negative electrode terminal 572 (corresponding to 58 in FIG. 2) (indicated by an arrow in the figure). At this time, the IGBT 541 is in the cutoff state. Looking at the flow of this recovery current, as shown in FIG. 22, the conductor plates are arranged in parallel in the vertical direction in the path from the chips 537 and 543 to the positive electrode terminal 532 and the negative electrode terminal 572, and the same current in the opposite directions. Flows. Then, in the space between the conductor plates, the magnetic fields generated by the mutual currents cancel each other out, and as a result, the inductance of the current path is reduced.

That is, the conductor plate 534 and the positive electrode terminal 532 on the positive electrode side and the conductor plate 574 and the negative electrode terminal 572 on the negative electrode side are in a laminated state in which they are arranged close to each other so as to reduce the inductance. FIG. 23 shows the equivalent circuit of FIG. 22, in which the conductor plate 534 on the positive electrode side and the equivalent coil 712 of the positive electrode terminal 532 act in the direction of canceling the magnetic flux with the conductor 574 on the negative electrode side and the equivalent coil 714 of the terminal 572, and the inductance increases. It will be reduced.

Further, looking at the recovery current path shown in FIG. 22, a loop-shaped path is generated following the reverse and parallel current path. When a current flows through this loop-shaped path, an eddy current 602,601 flows through the radiating fins (A side) and the radiating fins (B side), and the magnetic field canceling effect of this eddy current causes the inductance in the loop-shaped path to flow. A reducing effect occurs. In the equivalent circuit of FIG. 23, the phenomenon of generating eddy currents is equivalently represented by inductances 722, 724, and 726. Since these inductances are arranged close to the metal plate which is the heat radiation fin, the eddy current generated by the induction cancels the magnetic flux generated, and as a result, the inductance of the semiconductor module is reduced by the eddy current effect. It becomes.

As described above, by arranging the circuit configuration of the semiconductor module according to the present embodiment, the inductance can be reduced by the effect of the laminated arrangement and the effect of the eddy current. It is important to reduce the inductance during the switching operation, and in the semiconductor module of this embodiment, the series circuit of the upper arm and the lower arm is housed in the semiconductor module. Therefore, it is possible to reduce the inductance with respect to the recovery current of the diode flowing through the upper and lower arm series circuit, and the effect of reducing the inductance in the transient state is large.

If the inductance is reduced, the induced voltage generated in the semiconductor module becomes small, a low-loss circuit configuration can be obtained, and the small inductance can lead to an improvement in the switching speed. Further, when a plurality of semiconductor modules 500 composed of the above-mentioned upper and lower arm series circuits 50 are arranged in parallel and connected to each capacitor 90 in the capacitor module 95 to increase the capacity, the inductance of the semiconductor module 500 itself is reduced. As a result, the influence of the variation in inductance due to the semiconductor module 500 in the power conversion device 100 is reduced, and the operation of the inverter device is stabilized.

Further, when a large capacity of the motor generator (for example, 400 A or more) is required, the capacitor also needs to have a large capacity, and if a large number of individual capacitors 90 are connected in parallel and the DC bus bars 393 of the capacitors are arranged in parallel. The positive electrode terminal 532 and the negative electrode terminal 572 of each semiconductor module and the individual capacitor terminals are connected at equal distances, and the current flowing through each semiconductor module is evenly distributed, resulting in a well-balanced low-loss motor generator. The operation can be planned. Further, by arranging the positive electrode terminal and the negative electrode terminal of the semiconductor module in parallel, it is possible to perform a low loss operation in combination with the reduction of the inductance due to the laminating effect.

As described above, the power conversion device according to the embodiment of the present invention uses a double-sided cooling type semiconductor module to improve miniaturization, assembling property, and cooling efficiency, and has the same aspects as the overall structure. In a substantially square-shaped water channel housing provided with a water channel inlet and an outlet, a condenser module insertion part is formed in the central portion thereof, and a water channel connecting the water channel inlet and the water channel outlet is formed on both sides of the central portion. The basic structure is such that a plurality of semiconductor modules are slotted in the water channel along the longitudinal direction of the heat radiation fins of the semiconductor module. In this basic structure, an AC connector 1 and an AC connector 2 are provided on the side surface other than the side surface provided with the water channel inlet portion and the outlet portion, and a DC connector is provided on the other side surface.

Further, a driver board for the upper and lower arm series circuit built in the semiconductor module is provided on the upper surface of the capacitor module in this basic structure, and a control board is provided on the upper surface thereof to effectively utilize the space on the upper surface of the capacitor module. It has an overall structure.

Further, due to the water channel structure and the arrangement structure of the plurality of semiconductor modules shown in FIG. 12, the pressure loss of the water channel is reduced by reducing the number of U-turn portions of the water flow. Further, the sandwich structure of the condenser module and the water channel shown in FIG. 12 has a structure in which the capacitor can also be cooled by the cooling water of the water channel. Further, the arrangement structure of the positive electrode terminal and the negative electrode terminal of the semiconductor module as shown in FIG. 13 enables coupling with a DC bus bar having the same structure as the terminals corresponding to those of the capacitor module, enabling low inductance wiring. By arranging the driver board and the control board on the upper surface of the capacitor module, the upper surface of the capacitor module can be effectively used, and the driver board can be formed by a common driver board even in a power conversion device having two inverter circuits. Further, by forming the condenser module insertion portion in the water channel housing formed of the lower case, the positioning of the condenser module becomes reliable and easy.

Further, as shown in FIG. 14, the IGBT of the upper arm and the IGBT of the lower arm built in the semiconductor module are arranged with a length L along the water flow direction of the water channel, and similarly, the diodes of the upper arm and the lower arm are also arranged. Since the length M is arranged under the IGBT, there is no useless length in the height direction of the semiconductor module, which leads to miniaturization. Further, since the IGBT, which is the first cooling target, occupies the water channel (the length of the fin portion in the height direction) corresponding to L longer than M, the cooling efficiency is also improved.

Next, another configuration example of the arrangement of the positive electrode terminal and the negative electrode terminal of the semiconductor module according to the present embodiment will be described with reference to FIG. 24. First, the positive electrode terminal 532 and the negative electrode terminal 572 of the semiconductor module shown in FIG. 21 had an arrangement in which the arranged comb-tooth shapes were arranged vertically along the water flow direction of the heat radiation fins (A side) 522 (FIG. 13). See). According to FIG. 24, the comb-teeth shapes of the positive electrode terminal 532 and the negative electrode terminal 572 are configured to face each other in the lateral direction of the semiconductor module. That is, the arrangement of the comb tooth shapes of the positive electrode terminals 532 is arranged along the water flow direction on the heat radiation fin (A side) 522 side, and the arrangement of the comb tooth shapes of the negative electrode terminal 572 is arranged in the water flow direction on the heat radiation fin (B side) 562 side. It has a structure in which the comb tooth shapes face each other in the lateral direction of the semiconductor module, and only the arrangement of the positive electrode terminal 532 and the negative electrode terminal 572 is different from that of the structure shown in FIG. 21 (others). Of course, the arrangement of the terminals of is slightly different).

As shown in the figure, in order to form the comb tooth shape of each terminal, a bent portion is formed on each of the conductor plates 534 (conductor plate on the positive electrode side) and 574 (conductor plate on the negative electrode side) to form a comb tooth shape. It may be bent so as to face each other. A terminal insulation portion insertion hole 583 is provided between the conductor plates 534 and 574 of each terminal 532, 572 of the semiconductor module so as to correspond to the terminal insulation portion 396 of the capacitor module. Corresponding to the arrangement structure of the positive electrode terminal and the negative electrode terminal of the semiconductor module 500 described above, the structures of the positive electrode terminal 394 and the negative electrode terminal 395 of the capacitor module 390 are also the DC bus bar 393 and the terminals and the terminals and the terminals as compared with those shown in FIG. The arrangement with the terminal insulation part has been changed by 90 degrees. That is, the other configuration example shown in FIG. 24 can be applied only by changing the structures of the positive electrode terminals and the negative electrode terminals of the semiconductor module and the capacitor module.

Next, a configuration example of the water channel structure and the arrangement structure of the plurality of semiconductor modules according to the present embodiment will be described below with reference to FIGS. 25 and 26. FIG. 25 is a functional explanatory view showing a configuration example of a water channel structure and an arrangement structure of a plurality of semiconductor modules according to the present embodiment. FIG. 26 is a functional explanatory view showing another configuration example of the water channel structure and the arrangement structure of the plurality of semiconductor modules according to the present embodiment.

In the figure, 142 is a lower case, 226 is a front inlet waterway, 227 is a front folded waterway, 228 is a front outlet waterway, 236 is a back folded waterway, 237 is a semiconductor module insertion waterway, and 246 is a waterway inlet 248. Is a water channel outlet, 258 is a water flow, 390 is a condenser module, 490 is a water channel forming body 1, 491 is a water channel forming body 2500, and 500 is a semiconductor module.

In FIG. 25, FIG. 25A is a diagram for functionally explaining the water channel structure and the semiconductor module arrangement structure shown in FIG. 12, and the functions and operations thereof are as described in detail in the description of FIG.

FIG. 25B is a modification of the water channel structure, which aims to improve the cooling efficiency of the condenser module and reduce the pressure loss in the flow path. Explaining the modified example shown in FIG. 25 (B) in comparison with the example of FIG. 25 (A), in the case of FIG. 25 (A), the cooling water first cools the semiconductor module arranged in the vicinity of the inlet water channel 226. (Three semiconductor modules are inserted on the inlet channel 226 side), the semiconductor modules arranged in the vicinity of the outlet channel 228 are cooled later. Therefore, the temperature of the cooling water that comes into contact with the semiconductor module is uneven in the vicinity of the inlet water channel 226 and the vicinity of the outlet water channel 228, resulting in non-uniform cooling.

On the other hand, in the case of FIG. 25B, since the water channel forming body 1 (490) is provided on the back surface to form the folded water channel 236, the water channel forming body 1 (490) is arranged in the vicinity of the inlet water channel 226 and the outlet water channel 228. Since one surface (radiation fin (A side) 522 or heat dissipation fin (B side) 562 shown in FIG. 13) of the semiconductor module 500 is cooled first and the other surface is cooled last, each semiconductor module There is an advantage that the cooling of 500 is relatively uniform.

Further, in FIG. 25 (C), as in the modified example of the water channel structure, the water channel forming body 1 (490) and the water channel forming body 2 (491) are shown while providing the folded water channel 236 on the back surface as in the figure (B). The plurality of semiconductor modules 500 are divided into three units, and each of the three units is arranged on each side of the rectangular housing. For example, the three units are U-phase, V-phase, and W-phase semiconductors. By separating each module, it is possible to thermally balance each phase. That is, there is an advantage that it is possible to prevent only one predetermined phase from becoming hot.

Further, FIG. 26 shows a modified example of the water channel structure, in which the water channel is not provided at the water channel inlet portion 226 and the water channel outlet portion 228, and the water channel is formed on the back surface portion. According to FIG. 26A, it is not necessary to provide the channel forming bodies 490 and 491 over the entire length of the channel extending to the channel inlet portion and the channel outlet portion, and the cost can be reduced. Further, as compared with the water channels shown in FIGS. 26 (A) to 26 (C), the number of turns of the water channel can be reduced, and by branching the water flow, the flow velocity of the cooling water in each water channel is reduced, and the pressure loss in the water channel is reduced. It can be reduced.

Further, in the one shown in FIG. 26B, semiconductor modules are arranged for each phase and each channel side. Compared with the modified examples of FIGS. 25 (A) to 25 (C), the number of turns of the water channel can be reduced, and the flow velocity of the cooling water in each water channel is reduced by branching the water flow, so that the pressure loss in the water channel is reduced. It can be reduced.

10: Hybrid electric vehicle, 12: Front wheel, 14: Front wheel axle, 16: Front wheel side DEF, 18: Transmission, 20: Inverter, 22: Power distribution mechanism, 23, 24, 25, 26: Gear, 27, 28, 29, 30: Gear, 36: Battery, 38: DC connector, 40, 42: Inverter device, 44: Inverter circuit, 45: Inverter circuit 1, 46: Inverter circuit 2, 50: Upper and lower arm series circuit, 50U1: Inverter U-phase series circuit of circuit 1, 50U2: U-phase series circuit of inverter circuit 2, 50V1: V-phase series circuit of inverter circuit 1, 50V2: V-phase series circuit of inverter circuit 2, 50W1: W-phase series of inverter circuit 1. Circuit, 50W2: W-phase series circuit of inverter circuit 2, 52: upper arm IGBT, 53: upper arm collector electrode, 54: upper arm gate (base) electrode terminal, 55: upper arm signal emitter electrode terminal , 56: Upper arm diode, 57: Positive (P) terminal, 58: Negative (N) terminal, 59: AC terminal, 62: Lower arm IGBT, 63: Lower arm collector electrode, 64: Lower arm gate Electrode terminal, 65: Inverter electrode terminal for signal of lower arm, 66: Inverter of lower arm, 69: Intermediate electrode, 70: Control unit, 72: Control circuit (built in control board 372), 74: Driver circuit (driver board) (Built in 386), 76: Signal line, 80: Detector, 82: Signal line, 86: AC power line (output bus bar), 88: AC connector 1, 89: AC connector 2, 90: Converter (built in capacitor module 390) ), 91: AC connector part flange, 92, 94: Motor generator, 100: Power converter, 112: Upper case, 122: AC connector positioning part, 123: AC connector mounting part, 124: Upper case flange, 142: Lower case 144: Waterway lid, 145: Module lid 1, 146: Module lid 2, 147: Condenser module insertion part, 212: Waterway housing, 214: Waterway housing main body, 224: Front part of waterway housing , 226: Front inlet channel, 227: Front folded channel, 228: Front outlet channel, 236: Back folded channel, 237: Semiconductor module insertion channel, 246: Water channel inlet, 248: Channel outlet Unit, 250, 251, 252, 253: Water flow, 254, 255, 256, 257: Water flow, 372: Control board (built-in control circuit), 373: Control IC1, 374: Control IC2, 386: Driver board, 387: Driver IC, 388: Signal connector, 390: Condenser module, 391: AC bus bar 1, 392: AC bus bar 2, 490: Water channel forming body 1, 491: Water channel forming body 2, 500: Semiconductor module, 501 : Semiconductor module fixing part, 502: Semiconductor module positioning part, 507: Mold resin, 508: Side case, 512: Top case, 513: Mold resin filling part of top case, 516: Bottom case, 517: Fitting of bottom case 522: Radiation fin (A side), 532: Positive terminal, 534: Positive conductor plate, 535: Upper and lower arm connection conductor plate, 536, 538, 540, 542,544: Solder layer, 537: IGBT chip (For upper arm), 539: Diode chip (for upper arm), 541: IGBT chip (for lower arm), 543: Diode chip (for lower arm), 544: Solder layer, 546: Insulation sheet (A side), 548: Solder layer, 549: Solder layer, 550: Solder layer, 552: Signal terminal (for upper arm), 535: Gate terminal (for upper arm), 556: Signal terminal (for lower arm), 557: Gate Terminal (for lower arm), 560: Joint (for connecting upper and lower arms), 562: Heat dissipation fin (B side), 572: Negative terminal, 582: AC terminal, 593: Gate wire (for upper arm), 596: Insulation Sheet (B side), 597: Gate wire (for lower arm), 751: Solder joint (IGBT collector side), 752: Solder joint (diode cathode side), 753: Solder joint (IGBT collector side), 754 : Solder joint (diode cathode side), 756: Solder joint (IGBT emitter side), 757: Solder joint (IGBT emitter side), 758: Solder joint (diode anode side), 759: Solder joint (diode) Anode side).

Claims (11)

The first semiconductor chip that constitutes the upper arm of the inverter circuit and
The second semiconductor chip that constitutes the lower arm of the inverter circuit and
A first conductor plate electrically connected to one surface of the first semiconductor chip,
A second conductor plate electrically connected to the other surface of the first semiconductor chip,
A third conductor plate that is electrically connected to one surface of the second semiconductor chip and is also electrically connected to the second conductor plate.
A fourth conductor plate electrically connected to the other surface of the second semiconductor chip,
A first gate conductor electrically connected to the gate electrode of the first semiconductor chip,
A second gate conductor electrically connected to the gate electrode of the second semiconductor chip,
A first metal plate to which the first conductor plate, the third conductor plate, the first gate conductor, and the second gate conductor are fixed via the first insulating member.
A semiconductor module including a second conductor plate and a second metal plate to which the fourth conductor plate is fixed via a second insulating member. The semiconductor module according to claim 1.
The first metal plate and the second metal plate are semiconductor modules having fins for heat dissipation integrally. The semiconductor module according to claim 1.
The first metal plate and the second metal plate are semiconductor modules to which separate heat radiating fin members are joined. The semiconductor module according to any one of claims 1 to 3.
The first insulating member and the second insulating member are semiconductor modules which are ceramic substrates. The semiconductor module according to claim 4.
The ceramic substrate is a semiconductor module having a thickness of 350 micrometers or less. The semiconductor module according to any one of claims 1 to 3.
The first insulating member and the second insulating member are semiconductor modules which are resin insulating sheets. The semiconductor module according to claim 6.
The insulating sheet is a semiconductor module having a thickness of 50 micrometers or more and 200 micrometers or less. The semiconductor module according to any one of claims 1 to 7.
A first gate terminal that is electrically connected to the first gate conductor and is drawn out from a region sandwiched between the first metal plate and the second metal plate.
A semiconductor module including a second gate terminal that is electrically connected to the second gate conductor and is drawn out from a region sandwiched between the first metal plate and the second metal plate. The semiconductor module according to any one of claims 1 to 8.
A positive electrode terminal that is electrically connected to the first conductor plate and is drawn out from a region sandwiched between the first metal plate and the second metal plate.
A negative electrode terminal that is electrically connected to the fourth conductor plate and is drawn out from a region sandwiched between the first metal plate and the second metal plate is provided.
The first semiconductor chip is configured to include a first IGBT and a first diode.
The second semiconductor chip is configured to include a second IGBT and a second diode.
The first semiconductor chip and the second semiconductor chip have the first IGBT, the first diode, the second diode, and the second IGBT arranged at the same position as the first metal plate. Arranged so as to be each vertex of a quadrangle in the region sandwiched by the second metal plate.
The connection position between the second conductor plate and the third conductor plate is a semiconductor module formed on the side of the quadrangle opposite to the direction in which the positive electrode terminal and the negative electrode terminal are pulled out. .. The semiconductor module according to any one of claims 1 to 9.
A capacitor module that is electrically connected to the semiconductor module,
A power conversion device including a flow path forming body in which a flow path through which a refrigerant flows is formed. The power conversion device according to claim 10.
At least three semiconductor modules are provided.
The flow paths include a first flow path that flows on one side of the three semiconductor modules, a second flow path that flows on the other side of the three semiconductor modules, and the first water channel and the second water channel. It has a folded flow path that connects to and
The capacitor module is a power conversion device provided at positions facing the three semiconductor modules with the first flow path interposed therebetween.

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