Abstract:
The purpose of the present invention is to reduce the wiring inductance of a power semiconductor module. It comprises a first power semiconductor device, a second power semiconductor device, a first conductor unit which is opposed to the first power semi conductor device, a second conductor unit which is opposed to the first conductor unit across the first power semiconductor device, a third conductor unit which is opposed to the second power semiconductor device, a fourth conductor unit which is opposed to the third conductor unit across the second power semiconductor device, a first intermediate conductor unit which extends from the first conductor unit, a second intermediate conductor unit which extends from the fourth conductor unit and, a positive electrode side first terminal, and a positive electrode side second terminal which project from the first intermediate conductor unit, and a negative electrode side first terminal and a negative electrode side second terminal which project from the second intermediate conductor unit. The negative electrode side first terminal is arranged in a position adjacent to the positive electrode side first terminal. The negative electrode side second terminal is arranged in a position adjacent to the positive electrode side second terminal.

Description:
TECHNICAL FIELD 
     The present invention relates to a power semiconductor module for converting a direct current into an alternating current, and, more particularly, to a power semiconductor module for supplying the alternating current to a motor for driving a hybrid vehicle or an electric vehicle. 
     BACKGROUND ART 
     In recent years, what are required are that power converters output a large current and are formed with a small size. If the power converter is intended to output a large current, the heat generated by a power semiconductor device built in the power semiconductor module is increased. Thus, unless the heat capacity of the power semiconductor module or the power converter is large enough, it will reach the heat resistant temperature of the power semiconductor device, thus impeding miniaturization thereof. There has been developed a double sided cooling power semiconductor module which improves its cooling efficiency by cooling down the power semiconductor device from the both sides. 
     To cool down the double sided cooling power semiconductor module, both main surfaces of the power semiconductor device are sandwiched by lead frames as plate conductors, and a coolant is thermally connected with one surface of one lead frame on the opposite side of a surface opposed to the main surface of the power semiconductor device. Patent literature 1 discloses the invention of a double sided cooling power semiconductor module. In the module, the both main surfaces of the power semi conductor device included in an upper arm and a lower arm of an inverter circuit are sandwiched by the lead frames as the plate conductors. The module has upper and lower arm series circuits in which the upper and lower arms of the inverter circuit are connected in series. In the module, DC positive electrode wirings and DC negative electrode wirings extending from the conductors are parallel and opposed to each other. A resin encapsulation member is arranged therebetween, thereby reducing the wiring inductance while ensuring the insulation, and thus miniaturizing the module. 
     In enlargement of the current of the power converter, loss reduction of the power semiconductor device is a subject to be attained. To realize this, it is necessary to perform, high-speed switching of the power semiconductor devices with reduced loss. For the high speed switching, it is necessary to re strain the surge voltage generated by the wiring inductances in the wiring conductors of the inverter circuit. To reduce the wiring inductances as the root cause of the surge voltage, an effective structure is to align closely transient currents flowing in opposite directions, and is well known as a laminate structure of the DC positive electrode and the DC negative electrode. However, as the enlargement of the current of the power converter, a further reduction of the wiring inductances is required, at the terminal parts transmitting the DC power supplied to the power semiconductor module. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Unexamined Patent Application Publication 2011-77464 
     SUMMARY OF INVENTION 
     Technical Problem 
     An object of the present invention is to reduce the wiring inductance of the power semiconductor module. 
     Solution to Problem 
     To attain the above object, according to the present invention, there is provided a power semiconductor module, comprising: a first power semiconductor device for forming an upper arm of an inverter circuit; a second power semiconductor device for forming a lower arm of the inverter circuit; a first conductor unit which is opposed to the first power semiconductor device; a second conductor unit which is opposed to the first conductor unit across the first power semiconductor device; a third conductor unit which is opposed to the second power semiconductor device; a fourth conductor unit which is opposed to the third conductor unit across the second power semiconductor device; a first intermediate conductor unit which extends from the first conductor unit; a second intermediate conductor unit which extends from the fourth conductor unit and is formed to be opposed to the first intermediate conductor unit; a positive electrode side first terminal and a positive electrode side second terminal which project from the first intermediate conductor unit; and a negative electrode side first terminal and a negative electrode side second terminal which project from the second intermediate conductor unit, and wherein the negative electrode side first terminal is nearer to the positive electrode side first terminal than to the negative electrode side second terminal, and arranged in a position adjacent to the positive electrode side first terminal, and the negative electrode side second terminal is nearer to the positive electrode side second terminal than to the negative electrode side first terminal, and is arranged in a position adjacent to the positive electrode side second terminal. 
     Advantageous Effects of Invention 
     According to the present invention, the reduction of the wiring inductance can be attained. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating a control block of a hybrid vehicle. 
         FIG. 2  is a circuit diagram of an inverter device. 
         FIG. 3  is an exploded perspective view of circuit components included in a serial circuit of an upper arm and a lower arm of a power semiconductor module  300 . 
         FIG. 4  is an external perspective view after the circuit components illustrated in  FIG. 3  have been embedded. 
         FIG. 5  is a circuit configuration diagram corresponding to  FIG. 3  and  FIG. 4 . 
         FIG. 6  is an exploded perspective view of a case  304  containing an encapsulated package  302 . 
         FIG. 7  is an exploded perspective view illustrating a process for putting the encapsulated package  302  into the case  304 . 
         FIG. 8  is an external perspective view illustrating a process for fixing a lid body  308 A to a wall  308 B. 
         FIG. 9  is an external perspective view of a power semiconductor module  300 . 
         FIG. 10  is a cross sectional view of a cross section taken from a direction of an arrow of a cross section AA in  FIG. 9 . 
         FIG. 11  is an external perspective view illustrating a state in which a power board  700  and the power semiconductor module  300  are connected to each other. 
         FIG. 12  is a cross sectional view seen from a direction of an arrow of a cross section AA in  FIG. 11 . 
         FIG. 13( a )  is a perspective view illustrating a recovery current path circulating thereinside, at the time of switching operation of the power semiconductor module  300 . 
         FIG. 13( b )  is a circuit diagram illustrating the recovery current path circulating thereinside, at the time of switching operation of the power semiconductor module  300 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A power converter according to this embodiment will now specifically be described with reference to the drawings. 
     The power converter according to this embodiment is applicable to hybrid vehicles or pure electric vehicles. As a typical example, explanations will be made to a control structure and a circuit structure when applied to a hybrid vehicle. 
       FIG. 1  is a diagram illustrating a control block of a hybrid vehicle. 
     As the power converter according to this embodiment, explanations will be made to an inverter device for driving vehicles, for use in an electric system for driving vehicles, and in a very severe loading environment or operational environment, by way of example. 
     The inverter device for driving vehicles converts DC power supplied from a vehicle battery included in a vehicle power supply or a vehicle power generator into predetermined AC power, and supplies an electric motor for driving vehicles with the obtained AC power to control the driving of the electric motor for driving vehicles. The electric motor for driving vehicles also has a function as a generator. Thus, the inverter device also has a function for converting the AC power generated by the electric motor for driving vehicles into DC power in accordance with its operation mode. 
     The configuration of this embodiment is suitable as a power converter for driving vehicles, for example, vehicles or trucks. Other than the power converter for these, it is applicable to a power converter (for example, railway train, shipping or aircraft), an industrial power converter (used as a control device of an electric motor for driving the equipment system of a factory), or a power converter for household use (used as a control device of an electric motor for driving household solar power generation system or household electric appliance). 
     In  FIG. 1 , a hybrid electric vehicle  110  is an electric vehicle and includes two vehicle driving systems. One of them is an engine system having an engine  120  which is an internal combustion engine as a power source. The engine system is used mainly as a driving source for HEV. The other one is a vehicle electric system having motor generators  192  and  194  as power sources. The vehicle electric system is used mainly as a driving source for HEV and a power generation source for HEV. The motor generators  192  and  194  are, for example, any of synchronous machine or induction machine, operate as generators or as motors in accordance with an operation method, and thus will be described as motor generators. 
     A front wheel axle  114  is rotatably supported on the front part of the car body, and a pair of front wheels  112  are provided on the both ends of the front wheel axle  114 . A rear wheel axle is rotatably supported on the rear part of the car body, and a pair of rear wheels (not illustrated) are provided on the both ends of the rear wheel axle. The HEV of this embodiment adopts the front wheel drive system. However, it may adopt the other system, that is, the rear wheel drive system. 
     A front wheel side differential gear (hereinafter referred to as a front wheel side DEF)  116  is provided at the center part of the front wheel axle  114 . An output shaft of a transmission  118  is mechanically connected onto the input side of the front wheel side DEF  116 . The output side of the motor generator  192  is mechanically connected onto the input side of the transmission  118 . The output side of the engine  120  and the output side of the motor generator  194  are mechanically connected to the input side of the motor generator  192  through a power distribution mechanism  122 . The motor generators  192  and  194 , and the power distribution mechanism  122  are contained inside the casing of the transmission  118 . 
     A battery  136  is electrically connected to inverter devices  140  and  142 . Electric power can be transmitted and received mutually between the battery  136  and the inverter devices  140  and  142 . 
     This embodiment includes two units: a first electric power generating unit (composed of the motor generator  192  and the inverter device  140 ) and a second electric power generating unit (composed of the motor generator  194  and the inverter device  142 ). The two units are used respectively in accordance with the operation states. That is, in a case where the vehicle is driven by power from the engine  120 , the second electric power generating unit is operated to generate power by the power of the engine  120  as a power generating unit, when assisting the driving torque of the vehicle. Then, the first electric power generating unit is operated as a power generating unit by the power acquired by the power generation. In the same case, when assisting the vehicle speed of the vehicle, the first electric power generating unit is operated to generate power by the power of the engine  120  as a power generating unit. The second electric power generating unit is operated as a power generating unit by the power acquired by the power generation. 
     In this embodiment, the first electric power generating unit is operated as a power generating unit by the power of the battery  136 , thereby the vehicle can be driven only by the power of the motor generator  192 . Further, in this embodiment, the first electric power generating unit or the second electric power generating unit is operated as a power generating unit to generate power by the power of the engine  120  or the power from the wheels, thereby electrically charging the battery  136 . 
     The battery  136  is used al so as a power supply for driving a motor  195  for an auxiliary machine. The auxiliary machine may, for example, be a motor for driving a compressor of the air conditioner or a motor for driving a control hydraulic pump. DC power is supplied from the battery  136  to an inverter device  43 , converted into AC power at the inverter device  43 , and then supplied to the motor  195 . The inverter device  43  has the same function as that of the inverter devices  140  and  142 , and controls the AC phase, frequency, and power to be supplied to the motor  195 . For example, the inverter device supplies AC power having the leading phase with respect to the rotation of the rotor of the motor  195 , thereby causing the motor  195  to generate the torque. On the contrary, AC power having the lagging phase is generated. As a result, the motor  195  functions as a power generator, and the motor  195  operates in a regenerative braking state. The control function of this inverter device  43  is the same as the control function of the inverter device  140  or  142 . Because the capacity of the motor  195  is smaller than the capacity of the motor generator  192  or  194 , the maximum power conversion of the inverter device  43  is smaller than that of the inverter device  140  or  142 , but the circuit configuration of the inverter device  43  is substantially the same as the circuit configuration of the inverter device  140  or  142 . Explanations will now be made to the electric circuit configuration of the inverter device  140 , the inverter device  142 , or the inverter device  43 , using  FIG. 2 . In  FIG. 2 , the inverter device  140  will be explained as a representative example. 
     An inverter circuit  144  has upper and lower arm series circuits  150  in association with three phases (U phase, V phase, and W phase) corresponding to phase windings of the armature winding of the motor generator  192 . Each of the upper and lower arm series circuits  150  includes an IGBT  328  and a diode  156  operating as an upper arm and also an IGBT  330  and a diode  166  operating as a lower arm. Each of the upper and lower arm series  150  is connected to an AC power line (AC busbar)  186 , from its midpoint (intermediate electrode  169 ) to the motor generator  192  through an AC terminal  159  and an AC connector  188 . 
     A collector electrode  153  of the IGBT  328  of the upper arm is electrically connected to a capacitor electrode on the positive electrode side of a capacitor module  500  through a positive electrode terminal (P terminal)  167 , and an emitter electrode of the IGBT  330  of the lower arm is electrically connected to a capacitor electrode on the negative electrode side of the capacitor module  500  through a negative terminal (N terminal)  168 . 
     A control unit  170  has a driver circuit  174 , which controls the driving of the inverter circuit  144 , and a control circuit  172 , which supplies the driver circuit  174  with a control signal through a signal line  176 . The IGBT  328  or the IGBT  330  operates upon reception of a driving signal output from the control unit  170 , and converts the DC power supplied from the battery  136  into three-phase AC power. This converted power is supplied to the armature winding of the motor generator  192 . 
     The IGBT  328  includes the collector electrode  153 , an emitter electrode for signal  151 , and a gate electrode  154 . The IGBT  330  includes a collector electrode  163 , an emitter electrode for signal  165 , and a gate electrode  164 . The diode  156  is electrically connected parallelly to the IGBT  328 . The diode  166  is electrically connected parallelly to the IGBT  330 . As a switching power semiconductor device, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) may be used. In this case, the diode  156  or the diode  166  is not necessary. The capacitor module  500  is electrically connected to a positive electrode side capacitor terminal  506  and a negative electrode side capacitor terminal  504 , through a DC connector  138 . The inverter device  140  is connected to the positive electrode side capacitor terminal  506  through a DC positive electrode terminal  314 , and connected to the negative electrode side capacitor terminal  504  through a DC negative electrode terminal  316 . 
     The control circuit  172  includes a micro computer (hereinafter referred to as a “micom”) for processing calculation of a switching timing of the IGBTs  328  and  330 . Information input, to the “micom” includes a target torque value requested to the motor generator  192 , a current value supplied from the upper and lower arm series circuit  150  to the armature winding of the motor generator  192 , and also the position of magnetic pole of the rotor of the motor generator  192 . The target torque value is based on an instruction signal output from a non-illustrative high-rank control device. The current value has been detected based on a detection signal output from a current sensor  180  through a signal line  182 . The position of the magnetic pole has been detected based on a detection signal output from a rotating magnetic pole sensor (not illustrated) provided for the motor generator  192 . In this embodiment, explanations will be made to a case where three-phase current values are detected, by way of example. However, current values corresponding to two phases may be detected. 
     The gate electrode  154  and an emitter electrode for signal  155  in  FIG. 2  correspond to a signal connection terminal  327 U of  FIG. 3 , as will be described later, while the gate electrode  164  and the emitter electrode  165  correspond to a signal connection terminal  327 L of  FIG. 3 . A positive electrode terminal  157  is the same as a positive electrode terminal  315 D of  FIG. 3 , and a negative electrode terminal  158  is the same as a DC negative electrode  319 D of  FIG. 3 . The AC terminal  159  is the same as an AC terminal  320 D of  FIG. 3 . 
     Explanations will now be made to a power semiconductor module  300  according to the embodiment, using  FIG. 3  to  FIG. 10 .  FIG. 3  is an exploded perspective view of circuit components included in a serial circuit of an upper arm and a lower arm of the power semiconductor module  300 .  FIG. 4  is an external perspective view after the circuit components of  FIG. 3  are embedded. The IGBT  328  and the diode  156  are included in the upper arm circuit of the inverter circuit. The IGBT  330  and the diode  166  are included in the lower arm circuit.  FIG. 5  is a circuit configuration diagram corresponding to  FIG. 3  and  FIG. 4 . 
     The collector electrode of the IGBT  328  and the cathode electrode of the diode  156  are bonded to a conductor unit  315  using a metal bonding member, such as soldering, while the emitter electrode of the IGBT  328  and the anode electrode of the diode  156  are bonded with an electrode bonding unit  322  using a metal bonding member. The electrode bonding unit  322  may be incorporated together with a conductor unit  318 . The conductor unit  315  is opposed to the IGBT  328  and the diode  156 . The conductor unit  318  is opposed to the conductor unit  315  through the IGBT  328 . The collector electrode of the IGBT  330  and the cathode electrode of the diode  166  are bonded with a conductor unit  320  using a metal bonding member, while the emitter electrode of the IGBT  330  and the anode electrode of the diode  166  are bonded with the electrode bonding unit  322  using a metal bonding member. The electrode bonding unit  322  may be incorporated together with a conductor unit  319 . The conductor unit  320  is opposed to the IGBT  330  and the diode  166 . The conductor unit  319  is opposed to the conductor unit  320  through the IGBT  330 . 
     An intermediate electrode  329 A is connected to the conductor unit  318 , and projects from the conductor unit  318  toward the conductor unit  319 . An intermediate electrode  329 B is connected to the conductor unit  320 , and projects from the conductor unit  320  toward the conductor unit  315 . The intermediate electrode  329 A is opposed to the intermediate electrode  329 B, and is bonded with the intermediate electrode  329 B using a metal bonding member. The AC terminal  320 D is connected to the conductor unit  320 . 
     A first intermediate conductor unit  381  is connected to the conductor unit  315 , and connected also to a positive electrode side first terminal  315 D 1  and a positive electrode side second terminal  315 D 2 . A negative electrode side first terminal  319 D 1  is arranged on the side part of the positive electrode side first terminal  315 D 1 . A negative electrode side second terminal  319 D 2  is arranged between the positive electrode side first terminal  315 D 1  and the positive electrode side second terminal  315 D 2 . 
     A second intermediate conductor unit  382  is connected to the conductor unit  319 , and is formed to be opposed to the first intermediate conductor unit  381 . Further, the second intermediate conductor unit  382  is connected to the negative electrode side first terminal  319 D 1  and the negative electrode side second terminal  319 D 2 , using a metal bonding member. 
     As a result, the current flowing through the first intermediate conductor unit  381  flows in a direction opposite to that of the current flowing through the second intermediate conductor unit  382 , thus causing cancellation of the magnetic fluxes each other. Thus, it is possible to reduce the inductance of the first intermediate conductor unit  381  and the second intermediate conductor unit  382 . 
     In this embodiment, those adjacent terminals of the positive electrode side first terminal  315 D 1 , the positive electrode side second terminal  315 D 2 , the negative side first terminal  319 D 1 , and the negative electrode side second terminal  319 D 2  are arranged in a line at even intervals. 
     As a result, the positive electrode side first terminal  315 D 1  causes cancellation of the magnetic fluxes with the negative electrode side first terminal  319 D 1  or the negative electrode second terminal  319 D 2 , thereby reducing the inductance of the terminals. The positive electrode side second terminal  315 D 2  causes cancellation of the magnetic fluxes with the negative electrode side second terminal  319 D 2 , thereby reducing the inductance of the terminals. 
     Not limited to this embodiment, the negative electrode side first terminal  319 D 1  may be arranged nearer to the positive electrode side first terminal  315 D 1  than to the negative electrode side second terminal.  319 D 2 , and arranged in a position adjacent to the positive electrode side first terminal  315 D 1 , while the negative electrode side second terminal  319 D 2  may be arranged nearer to the positive electrode side second terminal  315 D 2  than to the negative electrode side first terminal  319 D 1 , and arranged in a position adjacent to the positive electrode side second terminal  315 D 1 . In this case, the magnetic flux is canceled out between the negative electrode side first terminal  319 D 1  and the positive electrode side first terminal  315 D 1  to reduce the inductance of the terminals. The magnetic flux is canceled out between the negative electrode side second terminal  319 D 2  and the positive electrode side second terminal  315 D 2  to reduce the inductance of the terminals. 
     The positive electrode side first terminal  315 D 1  and the positive electrode side second terminal  315 D 1  have a function for branching the current flowing through the first intermediate conductor unit  381  to avoid concentration of the current in a limited part, thereby reducing the inductance of the wiring. The negative electrode side first terminal  319 D 1  and the negative electrode side second terminal  319 D 2  also have a function for branching the current flowing through the second intermediate conductor unit  382  to avoid concentration of the current in a limited part, thereby reducing the inductance of the wiring. 
     The IGBT  328  and the IGBT  330  are included in a signal electrode on the same surface as the emitter electrode surface. The upper arm signal connection terminal  327 U is connected to the signal electrode of the IGBT  328  through wire bonding (not illustrated). The lower arm signal connection terminal  327 L is connected to the signal electrode of the IGBT  330  through wire bonding (not illustrated). 
     The signal connection terminal  327 U and the signal connection terminal  327 U project parallelly to the projecting direction of the positive electrode side first terminal  315 D 1  and the positive electrode side second terminal  315 D 2 . The conductor unit  318  is formed smaller than the conductor unit  315 , because its part opposed to the gate electrode of the IGBT  328  has been removed therefrom. Thus, the conductor unit  318  has a smaller current path than that of the conductor unit  315 . The diode  156  is arranged nearer to the conductor unit  319  or the conductor unit  320  than to the IGBT  328 , and the first intermediate conductor unit  381  is formed nearer to the diode  156  than to the IGBT  328 . As a result, the diode  156  restrains that the current path gets small. 
     Similarly, because the part opposed to the gate electrode of the IGBT  330  is removed therefrom, the unit  319  is formed smaller than the conductor unit  320 . The diode  166  is arranged nearer to the conductor unit  315  Or the conductor unit  318  than to the IGBT  330 , while the second intermediate conductor unit  382  is formed nearer to the diode  166  than to the IGBT  330 . 
       FIG. 6  is an exploded perspective view of a case  304  containing an encapsulated package  302 . A frame member  304 D forms the side wall and bottom surface of the case  304 . A base plate  307 A is fixed to the frame member  304 D, and forms the widest surface of the case  304 . A base plate  307 B is opposed to the base plate  307 A, fixed to the frame member  304 D, and forms the widest surface of the case  304 . The base plate  307 A and the base plate  307 B function as a heat dissipation wall of the case  304 . 
     The case  304  is formed from a member having electric conductivity, for example, a compound material of Cu, Cu alloy, Cu—C, and Cu—CuO, or formed from a compound material, such as Al, Al alloy, AlSiC, Al—C. The case  304  is formed using any of a joint technique by performing the welding for high waterproof performance, a forging technique, or a casting technique. 
     The base plate  307 A and the base plate  307 B form a fin  305  on their outer surface. A first opening part  309 A and a second opening part  309 C are formed in the bottom surface of the frame member  304 D. 
     A first through hole  309 B is formed near the bottom surface of the frame member  304 D. The first through hole  309 B penetrates through from the side where the base plate  307 B is arranged to the side where the base plate  307 A is arranged, in the frame member  304 D. 
     A second through hole  309 D is formed near the bottom surface of the frame member  304 D. The second through hole  309 D penetrates through from the side where the base plate  307 B is arranged to the side where the base plate  307 A is arranged, in the frame member  304 D. 
     The first opening part  309 A is linked to she space inside the first through hole  309 B. The second opening part  309 C is linked to the space inside the second through hole  309 D. A flange  311  is formed on the bottom surface of the frame member  304 D, and fixed to a flow channel forming member for forming a flow channel. 
       FIG. 7  is an exploded perspective view illustrating a process for putting the encapsulated package  302  into the case  304 . 
     The wall  308 B is arranged to surround the fin  305 , the first through hole  309 B, and the second through hole  309 D, and fixed to the frame member  304 D. An insertion section  306  is formed in the upper surface of the case  304 . 
     The circuit member of the inverter illustrated in  FIG. 4  is encapsulated by a resin encapsulation member  348  to form the encapsulated package  302 . An exposed surface  321 A is formed by causing; a part of the conductor unit  320  to be exposed from the resin encapsulation member  348 . A part of each of the conductor unit  315 , the conductor unit  318 , and the conductor unit  319  are also exposed from the resin encapsulation member  348 , thereby forming the exposed surface  321 B. 
     As the encapsulation resin  348 , a novolac-based, polyfunctional-based, or biphenyl-based epoxy resin-based resin may be used. Ceramics (SiO2, Al2O3, AlN, BN) gel, or rubber is contained therein, thereby enabling making the thermal expansion coefficient closer to that of the conductor units  315 ,  320 ,  318 , or  319 . As a result, the thermal expansion coefficient difference between the members can be reduced, and the thermal stress occurring due to a temperature increase at the use environment can remarkably be decreased. Thus, the life of the power semiconductor module can be extended. As a molding member of an auxiliary mold body  600 , a high heat resistance thermoplastic resin, such as PPS (polyphenyl sulfide) or PBT (polybutylene terephthalate), is suited. 
     The resin encapsulation member  348  encapsulates a part of each of the positive electrode side first terminal  315 D 1 , the positive electrode side second terminal  315 D 2 , the negative side first terminal.  319 D 1 , and the negative electrode side second terminal  319 D 2 . The positive electrode side first terminal  315 D 1 , the positive electrode side second terminal  315 D 2 , and negative side first terminal  319 D 1 , and the negative electrode side second terminal  319 D 2  are formed in a manner that one surfaces of the terminals get together with a virtual surface  390 , and the terminals have an equal thickness. 
     Accordingly, when the resin encapsulation member  348  is introduced to the terminals fixed in a mold, the resin encapsulation member  348  is restrained from leaking out from the mold, and the productivity of the power semiconductor module can be improved. 
     The terminal overlapping the virtual surface  390  may include the AC terminal  320 D, the signal connection terminal  327 U, or the signal connection terminal  327 L, thus enabling further improvement the productivity of the power semiconductor module. 
     The auxiliary mold body  600  has a plurality of through holes for penetration of the positive electrode side first terminal  315 D 1 , the positive electrode side second terminal  315 D 2 , the negative electrode side first terminal  319 D 1 , the negative electrode side second terminal  319 D 2 , the AC terminal  320 D, the signal connection terminal  327 L, and the signal connection terminal  327 U. 
     A plurality of partition walls  601  are connected to the auxiliary mold body  600 . The plurality of partition walls  601  are arranged between the positive electrode side first terminal  315 D 1  and the negative electrode side first terminal  319 D 1 , between the negative electrode side first terminal  319 D 1  and the positive electrode side second terminal  315 D 2 , and between the positive electrode side second terminal  315 D 2  and the negative electrode side second terminal  319 D 2 . A resin cover  602  connected to the auxiliary mold body  600  covers the signal connection terminal  327 L and the signal connection terminal  327 U. 
       FIG. 8  is an external perspective view illustrating a process for fixing a lid body  308 A to the wall  308 B. The lid body  308 A is arranged to cover the fin  305 , the first through hole  309 B, and the second through hole  309 D. As a result, as a flow channel space, there is formed a space using the lid body  308 A, the wall  308 B, the base plate  307 B, and the frame member  304 D. Specifically, a refrigerant flows from the first opening part  309 A, is branched at the first through hole  309 B, and flows through two flow channel spaces. The branched refrigerants meet at the second through hole  309 D, and flow out from the second opening part  309 C. 
       FIG. 9  is an external perspective view of the power semiconductor module  300 .  FIG. 10  is a cross sectional view of a cross section taken from a direction of an arrow of a cross section AA in  FIG. 9 . One surface of the encapsulated package  302  is joined to the base plate  307 B through an insulating member  333 . The other surface of the encapsulated package  302  is joined to the base plate  307 A through the insulating member  333 . As a result, the generation of heat of the power semiconductor devices is efficiently transferred to the fin  305 . After the encapsulated package  302  is inserted into the case  304 , a potting member  351  is filled in the case  304 . 
       FIG. 11  is an external perspective view illustrating a state where a power board  700  and the power semiconductor module  300  are connected.  FIG. 12  is a cross sectional view seen from a direction of an arrow of a cross section AA in  FIG. 11 . 
     The power board  700  is composed of a positive electrode side board  703 , a negative electrode side board  701 , and an insulating covering member  708  for encapsulating them. The positive electrode side board  703  has a first through hole  705 A for penetration of the positive electrode side first terminal  315 D 1 , the positive electrode side second terminal  315 D 2 , the negative electrode side first terminal  319 D 1 , the negative electrode side second terminal  319 D 2 , and the partition walls  601 . Similarly, the negative electrode side board  704  has a first through hole  706 A for penetration of the positive electrode side first terminal  315 D 1 , the positive electrode side second terminal  315 D 2 , the negative electrode side first terminal  319 D 1 , the electrode side second terminal  319 D 2 , and the partition walls  601 . This first through hole  706 A is formed in a position opposed to the first through hole  705 A. 
     The positive electrode side board  703  has a second through hole  705 B for penetration of the AC terminal  320 D, the signal connection terminal  327 L, and the signal connection terminal  327 U. Similarly, the negative electrode side board  704  has a second through hole (not illustrated) for penetration of the AC terminal  320 D, the signal connection terminal  327 L, or the signal connection terminal  327 U. This second through hole is formed in a position opposed to the second through hole  705 B. 
     Other than these, a through hole  705 C, a through hole  705 D, a through hole  705 E, and a through hole  705 F are formed in a manner similar to the first through hole  705 A and the second through hole  705 B. 
     A positive electrode side first terminal  701 A and a positive electrode side second terminal  701 B project from the side wall which forms the first through hole  705 A, and are bent into a vertical direction of the main surface of the positive electrode side board  703 . Similarly, a negative electrode side first terminal  702 A and a negative electrode side second terminal  702 B project from the side wall which forms the first through hole  706 A, and are bent into a vertical direction of the main surface of the negative electrode side board  704 . 
     The negative electrode side first terminal  701 A is formed to be opposed to the negative electrode side first terminal  319 D 1  on the side of the power semiconductor module  300 . The negative electrode side second terminal  701 B is formed to be opposed to the negative electrode side second terminal  319 D 2  on the side of the power semiconductor module  300 . The positive electrode side first terminal  702 A is formed to be opposed to the positive electrode first terminal  315 D 1  on the side of the power semiconductor module  300 . The positive electrode side second terminal  702 B is formed to be opposed to the positive electrode side second terminal  315 D 2  on the side of the power semiconductor module  300 . For the connection joint, welding joint (for example, TIG welding or FSW) or mechanical joint (caulking or screw fastening) may be applied. 
     That is, the negative electrode side first terminal  702 A is arranged between the positive electrode side first terminal  701 A and the positive electrode side second terminal  701 B, while the positive electrode side second terminal  701 B is arranged between the negative electrode side first terminal  702 A and the negative electrode side second terminal  702 B. 
     As a result, the negative electrode side first terminal  702 A causes cancellation of the magnetic fluxes with the positive electrode side first terminal  701 A or the positive electrode side second terminal  701 B, thus enabling reduction of the inductance. The negative electrode side second terminal  702 B causes cancellation of the magnetic fluxes with the positive electrode side second terminal  701 B, thus enabling reduction of the inductance. 
     The partition walls  601  are arranged between the positive electrode side first terminal  701 A and the negative electrode side first terminal  702 A, between the negative electrode side first terminal  702 A and the positive electrode side second terminal  701 B, and between the positive electrode side second terminal  701 B and the negative electrode side second terminal  702 B, and ensure the insulation distance between the terminals. 
     An AC busbar  800  is arranged on the upper surface of the power board  700 , connected to the AC terminal  320 D, and also connected to the current sensor  180 . 
       FIG. 13( a )  is a perspective view illustrating a recovery current path circulating thereinside, at the time of switching operation of the power semiconductor module  300 , while  FIG. 13( b )  is a circuit diagram illustrating the recovery current path circulating thereinside, at the time of switching operation of the power semiconductor module  300 . As illustrated in  FIG. 13( a ) , the power semiconductor module  300  and the power board  700  are connected with each other. Induction fields  101  of the positive electrode side first terminal  315 D 1 , the positive electrode side second terminal  315 D 2 , the negative electrode side first terminal  319 D 1 , and the negative electrode side second terminal  319 D 2  are reduced by cancellation. These fields are generated by the recovery current penetrating through the upper and lower arm series circuit at the time of switching operation. It is possible to realize the low inductance near the terminal connection parts where wiring inductances are most frequently formed. The first intermediate conductor unit  381  is formed to be opposed to the second intermediate conductor unit  382 . That is, magnetic fields generated at an inductance  362  and an inductance  363  illustrated in  FIG. 13( b )  are canceled out each other. 
     REFERENCE SIGNS LIST 
     
         
           43  Inverter Device 
           110  Hybrid Vehicle 
           112  Front Wheels 
           114  Front Wheel Axle 
           116  For Wheel Side Differential Gear 
           118  Transmission 
           120  Engine 
           122  Power Distribution Mechanism 
           136  Battery 
           138  DC Connector 
           140 ,  142  Inverter Device 
           143  Power Converter 
           144  Inverter Circuit 
           150  Upper And Lower Arm Series Circuit 
           151  Emitter Electrode For Signal 
           153  Collector Electrode 
           154  Gate Electrode 
           156  Diode 
           157  Positive Electrode Terminal 
           158  Negative Electrode Terminal 
           159  AC Terminal 
           163  Collector Terminal 
           164  Gate Electrode 
           165  Emitter Electrode For Signal 
           166  Diode 
           167  Positive Electrode Terminal (P Terminal) 
           168  Negative Electrode Terminal (N Terminal) 
           169  Intermediate Electrode 
           170  Control Unit 
           172  Control Circuit 
           174  Driver Circuit 
           176  Signal Line 
           180  Current Sensor 
           182  Signal Line 
           186  AC Pusher 
           188  AC Connector 
           192  Motor Generator 
           194  Motor Generator 
           195  Motor For Auxiliary Machine 
           300  Power Semiconductor Module 
           302  Encapsulated package 
           304  Case 
           304 D Frame Member 
           305  Fin 
           306  Insertion Section 
           307 A Base Plate 
           307 B Base Plate 
           308 A Lid Body 
           308 B Wall 
           309 A First Opening Part 
           309 B Firth Through Hole 
           309 C second Opening Part 
           309 D Second Through Hole 
           311  Flange 
           315  Conductor Unit 
           315 D 1  Positive Electrode Side First Terminal 
           315 D 2  Positive Electrode Side Second Terminal 
           316  DC Negative Electrode Terminal 
           318  Conductor Unit 
           319  Conductor Unit 
           319 D 1  Negative Electrode Side First Terminal 
           319 D 2  Negative Electrode Side Second Terminal 
           320  Conductor Unit 
           320 D AC Terminal 
           321 A Exposed Surface 
           321 B Exposed Surface 
           322  Electrode Bonding Unit 
           327 U Signal Connection Terminal 
           327 L Signal Connection Terminal 
           328  IGBT 
           329 A Intermediate Electrode 
           329 B Intermediate Electrode 
           330  IGBT 
           333  Insulating Member 
           348  Resin Encapsulation Member 
           381  First intermediate Conductor Unit 
           382  Second Intermediate Conductor Unit 
           390  Virtual Surface 
           600  Auxiliary Mold Body 
           601  Partition Wall 
           602  Resin Cover 
           700  Power Board 
           701 A Negative Electrode Side First Terminal 
           701 B Negative Electrode Side Second Terminal 
           702 A Positive Electrode Side First Terminal 
           702 B Positive Electrode Side Second Terminal 
           703  Positive Electrode Side Board 
           704  Negative Electrode Side Board 
           705 A First Through Hole 
           705 B Second Through Hole 
           705 C Through Hole 
           705 D Through Hole 
           705 E Through Hole 
           705 F Through Hole 
           706 A First Through Hole 
           708  Insulating Covering Member 
           800  AC Busbar