JP4640213B2 - Power semiconductor device and inverter bridge module using the same - Google Patents

Description

  The present invention relates to an inverter bridge module used for an inverter device and a power semiconductor device used therefor, and more particularly to reduction of wiring inductance of a bus bar connecting the power semiconductor devices.

  A motor is usually used as a drive source for an electric vehicle or the like, and the motor is controlled by an inverter device. A power semiconductor device such as an IGBT or a power MOSFET is used for a main circuit of such an inverter device. FIG. 1 of Patent Document 1 shows such a power semiconductor device, and FIG. 19 shows a configuration of a three-phase inverter bridge module in which a plurality of power semiconductor devices are connected.

Japanese Patent Laid-Open No. 2003-31765 (FIGS. 1 and 19)

  In the power semiconductor device shown in FIG. 1 of the above-mentioned patent document, two main terminals of a collector terminal and an emitter terminal are drawn out from one side surface of the housing. Six such power semiconductor devices are used and connected to each other to form a three-phase inverter bridge module as shown in FIG. In this figure, six power semiconductor devices are arranged in two rows of three, and the emitter terminal of the power semiconductor device in one row and the collector terminal of the power semiconductor device in the other row are spaced apart from each other by a predetermined distance. Facing each other. That is, the connection ends of the main terminals to be connected to the common output terminals U, V, and W face each other at a predetermined interval. The collector terminals of the power semiconductor devices in one column are arranged in a row and connected to a common power supply terminal P, and the emitter terminals of the power semiconductor devices in the other row are arranged in a row and connected to a common power supply terminal N. Has been.

  However, in the conventional three-phase inverter bridge module, not only the power supply terminals P and N but also the output terminals U, V, and W are disposed between the two power semiconductor devices arranged opposite to each other. Therefore, not only is the arrangement of the bus bars complicated, but the distance between the bus bars of the power terminals P and N must be increased, and the wiring inductance of the three-phase inverter bridge module cannot be sufficiently reduced.

  When the wiring inductance increases in this way, a surge voltage generated by a sudden current change (di / dt) during the switching operation of the inverter bridge module increases in proportion to the inductance, and the power semiconductor device due to such a surge voltage. In order to prevent the destruction of the power, it is necessary to devise a device for suppressing a rapid current change, which causes a reduction in power conversion efficiency or an increase in cost.

  The present invention has been made to solve the above-described problems, and its object is to devise the structure of the inverter bridge module and the layout of the main terminals of the power semiconductor device used therefor, thereby wiring the bus bars. An object of the present invention is to provide an inverter bridge module that reduces inductance and is small, lightweight, and low in cost.

  In order to achieve the above object, a power semiconductor device according to the present invention includes a housing having a first side surface and a second side surface facing each other, and a first part pulled out from the first side surface of the housing. 1 main terminal, a second main terminal drawn out from the first side surface of the housing, and a second main terminal drawn out from the second side surface of the housing to be electrically connected inside the first main terminal and the housing. A third main terminal connected to each other, a metal block enclosed in the housing and electrically connected to the first main terminal, and one main surface of the metal block on the metal block And having at least one power semiconductor element electrically connected to the second main terminal on the other main surface.

  In another aspect of the power semiconductor device according to the present invention, a housing having a first side surface and a second side surface facing each other, and a first main drawn out from the first side surface of the housing. A terminal, a second main terminal drawn from the first side surface of the casing, and a second side terminal of the casing, and connected integrally with the second main electrode inside the casing. A third main terminal, a metal block enclosed in the housing and electrically connected to the first main terminal, and placed on the metal block so as to be in contact with one main surface thereof. And at least one power semiconductor element having the second main terminal electrically connected to the other main surface.

  Furthermore, an inverter bridge module according to the present invention includes a first bus bar, a second bus bar juxtaposed in parallel near the first bus bar, the first bus bar, and the second bus bar. An inverter bridge module comprising at least a pair of the power semiconductor devices according to the present invention connected to each of the power bus devices, wherein the pair of power semiconductor devices are respectively connected to the first bus bar or the second bus bar. It arrange | positions so that a 1st side surface may oppose.

  Due to the configuration as described above, according to the inverter bridge module according to the present invention, the bus bar wiring constituting the main current path is simplified and the wiring inductance inherent to the inverter bridge module is reduced as compared with the conventional inverter bridge module. In addition, the system can be reduced in size and weight, and an inverter bridge module with high power conversion efficiency and low cost can be realized.

<Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a three-phase inverter bridge module according to the present invention. 2 is a plan view (a) and a front view (b) of a bus bar used in the three-phase inverter bridge module of FIG. FIG. 3 is a perspective view showing the appearance of the power semiconductor device used in the three-phase inverter bridge module of FIG. FIG. 4 is a circuit diagram of the three-phase inverter bridge module of FIG.

  In FIG. 1, a P bus bar 1 and an N bus bar 2 made of copper or a copper alloy, having a stripe shape, and having a thickness of 1.5 mm are provided at substantially the center of the upper surface of the heat sink 3. The P bus bar 1 and the N bus bar 2 are juxtaposed in parallel with an interval of 2 mm close to each other, and as shown in FIG. 2, one tab (1a or 2a) in which a bolt hole for connecting to a power source is formed. ) At opposite positions of the stripe end, and three tabs (1b or 2b) formed with bolt holes for connecting to a power semiconductor device to be described later are opposed to each other on the stripe side. Each has a position. Three power semiconductor devices 4 are connected to the three tabs 1 b of the P bus bar 1. These three power semiconductor devices are the same, but are numbered 4a, 4b, 4c in order for distinction. The three power semiconductor devices 4 are also connected to the three tabs 2b of the N bus bar 2 so as to face the power semiconductor devices 4a, 4b, and 4c described above. These three power semiconductor devices are the same as the power semiconductor devices 4a, 4b, and 4c described above, but numbers 4d, 4e, and 4f are given in order for distinction. The power semiconductor devices 4a, 4b, 4c and the power semiconductor devices 4d, 4e, 4f are fixed to the upper surface of the heat sink 3 so as to face each other at a predetermined interval.

  In the power semiconductor device 4, an IGBT and a free wheel diode are connected in reverse parallel and sealed in one epoxy resin casing 9, and the casing 9 has an upper surface and a bottom surface as shown in FIG. The first collector terminal 5 which is one of the main terminals and the first emitter terminal 6 which is also one of the main terminals are drawn out from the first side face thereof. . A second collector terminal 7 which is one of the main terminals is drawn out from the second side opposite to the first side. In the power semiconductor devices 4a, 4b, and 4c in FIG. 1, each power semiconductor device is juxtaposed so that the first side faces the P bus bar 1, and each of the first collector terminals 5 includes three P bus bars 1. In the power semiconductor devices 4d, 4e, and 4f, the power semiconductor devices are juxtaposed so that the first side faces the N bus bar 2 and is connected to the tab 1b with bolts. 6 is fixedly connected to the three tabs 2b of the N bus bar 2 with bolts. The first emitter terminal 6 of the power semiconductor device 4a and the first collector terminal 5 of the power semiconductor device 4d that are arranged to face each other with the P bus bar 1 and the N bus bar 2 interposed therebetween are the P bus bar 1 and the N bus bar 2 They are electrically connected to each other by bridging with an appropriate connecting member below. The second collector terminals 7 of the power semiconductor devices 4d, 4e, and 4f respectively constitute output terminals U, V, and W of the inverter bridge module, and are connected to a load such as a motor by a bus bar or the like. The second collector terminals 7 of the power semiconductor devices 4a, 4b, 4c are not connected anywhere in the present embodiment, and may be disconnected from the base. By connecting in this way, the inverter bridge module of FIG. 1 has a circuit configuration as shown in FIG.

  Next, the internal structure of the power semiconductor device 4 will be described. FIG. 5A is a plan view showing the internal structure of the power semiconductor device 4, and FIG. For convenience, the outline of the housing 9 is indicated by a broken line. The diode element 11 and the IGBT element 12 are placed on the metal block 10 having a thickness of 3 mm, and the back surface of the diode element 11 and the IGBT element 12 and the surface of the metal block 10 are fixed by soldering. In addition to supporting the diode element 11 and the IGBT element 12, the metal block 10 plays a role of dissipating heat generated from the diode element 11 and the IGBT element 12 to the outside and a role as an electrode. It is desirable to have a thickness, and materials with good thermal and electrical conductivity are used.

  Emitter electrodes and anode electrodes are respectively formed on the surfaces of the diode element 11 and the IGBT element 12, and the first emitter terminal 6 extending into the housing 9 and these electrodes are joined by solder. The first collector terminal 5 and the second collector terminal 7 that also extend inside the housing 9 are fixed to the metal block 10 by solder bonding or ultrasonic bonding. The auxiliary emitter terminal 13 is electrically connected to the emitter electrode on the surface of the IGBT element 12 by wire bonding using a thin aluminum wire, and the control terminal 14 is electrically connected to the gate electrode on the surface of the IGBT element 12 in the same manner. The sense terminal 15 is electrically connected to the sense emitter electrode on the surface of the IGBT element 12 in the same manner. A casing 9 is formed by molding with an epoxy resin so as to enclose the entire structure as described above. The first collector terminal 5, the second collector terminal 7, the auxiliary emitter terminal 13, the control terminal 14 and the sense terminal 15 are formed by using an ordinary patterned lead frame and cutting unnecessary portions after resin molding. Therefore, a thin copper plate having a thickness of 1 mm or less is used as the material with emphasis on workability.

  Next, the operation of the three-phase inverter bridge module according to the present embodiment will be described. The inverter bridge module is used when DC power is converted into AC power having an arbitrary frequency. A DC power source having a relatively high potential is connected to the P bus bar 1, and a DC power source having a relatively low potential is connected to the N bus bar 2, and the DC power supplied from these DC power sources is converted into three-phase AC power. The output terminals U, V, and W are supplied to a load such as a motor. Since the power semiconductor device 4a and the power semiconductor device 4d connected to the output terminal U are not conductive at the same time, when the power semiconductor device 4a is in the conductive state and the power semiconductor device 4d is in the non-conductive state The main current input from the P bus bar 1 includes the first collector terminal 5 of the power semiconductor device 4a, the metal block 10, the IGBT element 12, the first emitter terminal 6, the first collector terminal 5 of the power semiconductor device 4d, The current flows from the output terminal U to the load through the current path of the metal block 10 and the second collector terminal 7. At this time, if either or both of the power semiconductor device 4e and the power semiconductor device 4f are in a conductive state, the main current is fed back from the load to either or both of the output terminal V and the output terminal W, and the power semiconductor device 4e and The power semiconductor device 4f returns to the DC power source from the N bus bar 2 via a current path of the second collector terminal 7, the metal block 10, the IGBT element 12, and the first emitter terminal 6 of both or both of the power semiconductor devices 4f.

  Similarly, since the power semiconductor device 4b and the power semiconductor device 4e connected to the output terminal V are not in the conductive state at the same time, the power semiconductor device 4b is in the conductive state and the power semiconductor device 4e is in the non-conductive state. In some cases, the main current input from the P bus bar 1 is the first collector terminal 5 of the power semiconductor device 4b, the metal block 10, the IGBT element 12, the first emitter terminal 6, and the first collector of the power semiconductor device 4e. The current flows from the output terminal V to the load through the current path of the terminal 5, the metal block 10, and the second collector terminal 7. At this time, if either or both of the power semiconductor device 4d and the power semiconductor device 4f are in a conductive state, the main current is fed back from the load to either or both of the output terminal U and the output terminal W, and the power semiconductor device 4d and The power semiconductor device 4f returns to the DC power source from the N bus bar 2 via a current path of the second collector terminal 7, the metal block 10, the IGBT element 12, and the first emitter terminal 6 of both or both of the power semiconductor devices 4f. The same applies when the power semiconductor device 4c is in a conducting state and the power semiconductor device 4f is in a non-conducting state, and thus the description thereof is omitted.

  As can be seen from the above description of operation, in such an inverter bridge module, the current supplied from the power supply always flows through the P bus bar 1 and the N bus bar 2, and the magnitudes thereof are equal and in the reverse direction. In the inverter bridge module according to the present embodiment, the first collector terminal 5 and the first emitter terminal 6 are drawn out from the first side surface of the housing 9 of the power semiconductor device 4 which is a component, and the opposite first Since the second collector terminal 7 is drawn out from the side surface of 2, the bus bar connected to the output terminals U, V, W can be arranged at a position different from the P bus bar 1 and the N bus bar 2, and the P bus bar The distance between 1 and the N bus bar 2 can be set sufficiently small. As a result, the bus bar wiring is simplified, the entire inverter bridge module can be reduced in size and cost, and the wiring inductance of each of the P bus bar 1 and the N bus bar 2 is canceled, and the wiring inductance of the entire inverter bridge module is reduced. Since the generated surge voltage is reduced, an inverter bridge module with high power conversion efficiency and low cost can be realized.

<Modification 1>
FIG. 6 is a plan view showing the internal structure of Modification 1 of the power semiconductor device used in the inverter bridge module of FIG. The difference from the power semiconductor device of FIG. 5 is that the first collector terminal 5 and the second collector terminal 7 are joined to the diagonal position of the metal block 10. Also in this modified example, the first collector terminal 5 and the first emitter terminal 6 are drawn out from the first side surface of the housing 9 and the second side surface on the opposite side is used as in the power semiconductor device of FIG. Since the two collector terminals 7 are pulled out, it goes without saying that it contributes to simplification of the bus bar of the inverter bridge module and reduction of wiring inductance. Furthermore, since the thick copper is used for the metal block 10, the first collector terminal 5 or the second collector terminal 7 joined to the metal block 10 in the assembly process is deformed by the weight of the metal block 10. Although there was a problem that a crack occurs in the joint portion, in the present modification, the first collector terminal 5 or the second collector terminal 7 is joined to the diagonal position of the metal block 10, and the metal block 10 Since the first collector terminal 5 and the second collector terminal 7 are held in a well-balanced manner, there is no fear that excessive stress is applied to the joint portion, and the above-described problems can be solved.

<Modification 2>
FIG. 7 is a plan view showing the internal structure of Modification 2 of the power semiconductor device used in the inverter bridge module of FIG. A difference from the power semiconductor device of FIG. 5 is that a second emitter terminal 8 is provided instead of the second collector terminal 7, and the second emitter terminal 8 is integrally connected to the first emitter terminal 6. It is that. That is, the first emitter terminal 6 and the second emitter terminal 8 are made of one thin copper plate. When the power semiconductor device of FIG. 7 is applied to the inverter bridge module of FIG. 1, the roles of the output terminals U, V, and W are respectively played by the second emitter terminals 8 of the power semiconductor devices 4a, 4b, and 4c. It will be. The circuit configuration in that case is as shown in FIG. 8, which is substantially the same as the circuit configuration of FIG. Therefore, also in this modification, like the power semiconductor device of FIG. 5, the first collector terminal 5 and the first emitter terminal 6 are pulled out from the first side surface of the housing 9 and the second side surface on the opposite side. It goes without saying that the second emitter terminal 8 is led out from this, which contributes to simplification of the bus bar of the inverter bridge module and reduction of wiring inductance. Furthermore, in this modification, since the junction between the metal block 10 and the second emitter terminal 8 is not necessary, the reliability of the power semiconductor device is also improved.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to these and various modifications can be made. For example, in the above embodiment, the inverter bridge module has a three-phase bridge configuration that converts direct current to three-phase alternating current. However, a single-phase bridge configuration or a half-bridge configuration that converts direct current to single-phase alternating current may be used. it can. In the case of the single-phase bridge configuration, the configuration of the inverter bridge module is the configuration excluding the power semiconductor device 4c and the power semiconductor device 4f in FIG. 1, and in the case of the half-bridge configuration, the configuration of the inverter bridge module is further The power semiconductor device 4c and the power semiconductor device 4f are excluded. That is, it goes without saying that the effect of the present invention is exhibited as long as at least a pair of power semiconductor devices 4a and 4d sandwiching the P bus bar 1 and the N bus bar 2 are provided.

It is a perspective view showing an embodiment of a three-phase inverter bridge module according to the present invention. It is the top view (a) and front view (b) of the bus bar which are used for the three-phase inverter bridge module of FIG. It is a perspective view which shows the external appearance of the power semiconductor device currently used for the three-phase inverter bridge module of FIG. FIG. 2 is a circuit diagram of the three-phase inverter bridge module of FIG. 1. It is the top view (a) which shows the internal structure of the electric power semiconductor device of FIG. 3, and its AA sectional drawing (b). It is a top view which shows the internal structure of the modification 1 of the power semiconductor device used for the three-phase inverter bridge module of FIG. It is a top view which shows the internal structure of the modification 2 of the power semiconductor device used for the three-phase inverter bridge module of FIG. FIG. 8 is a circuit diagram when the power semiconductor device of FIG. 7 is applied to the three-phase inverter bridge module of FIG. 1.

Explanation of symbols

1 P bus bar, 2 N bus bar, 3 heat sink, 4 power semiconductor device, 5 first collector terminal, 6 first emitter terminal, 7 second collector terminal, 8 second emitter terminal, 9 housing, 10 metal Block 11 Diode element 12 IGBT element 13 Auxiliary emitter terminal 14 Control terminal 15 Sense terminal

Claims (3)

A housing having a first side surface and a second side surface facing each other;
A first main terminal drawn from the first side surface of the housing;
A second main terminal drawn from the first side surface of the housing;
A third main terminal drawn from the second side surface of the housing and electrically connected to the first main terminal inside the housing;
A metal block enclosed in the housing and electrically connected to the first main terminal;
At least one power semiconductor element placed on the metal block so as to be in contact with one main surface and electrically connected to the second main terminal on the other main surface;
A power semiconductor device comprising: A housing having a first side surface and a second side surface facing each other;
A first main terminal drawn from the first side surface of the housing;
A second main terminal drawn from the first side surface of the housing;
A third main terminal pulled out from the second side surface of the casing and integrally connected to the second main terminal inside the casing;
A metal block enclosed in the housing and electrically connected to the first main terminal;
At least one power semiconductor element placed on the metal block so as to be in contact with one main surface and electrically connected to the second main terminal on the other main surface;
A power semiconductor device comprising: A first bus bar;
A second bus bar juxtaposed in parallel adjacent to the first bus bar;
The power semiconductor device according to claim 1 or 2, wherein the power semiconductor device is connected to each of the first bus bar and the second bus bar.
An inverter bridge module comprising:
The inverter bridge module, wherein the pair of power semiconductor devices are arranged such that the first side faces the first bus bar or the second bus bar, respectively.

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