JP2008294338A - Power module, and transport machine equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power module which can be manufactured inexpensively and is high in productivity, and to provide a transport machine equipped with the same. <P>SOLUTION: The power module includes a substrate containing a plurality of power semiconductor devices, a frame for housing the substrate, a terminal formed in a different manner from the frame and electrically connected to some of the plurality of power semiconductor devices, and a fixing means for fixing the terminal on the frame. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power module, and more particularly to a power module for supplying electric power to a motor used as a drive source for transportation equipment. The present invention also relates to a transportation device provided with such a power module.

  In recent years, transportation equipment using an electric motor (hereinafter simply referred to as “motor”) as a drive source has attracted attention from the viewpoint of environmental problems and energy problems. In addition, the motor has an advantage that the operation sound generated at the time of driving is smaller than that of the internal combustion engine and an advantage that the degree of freedom of design of the outer shape is large and it can be arranged close to a place where a driving source is required. It has. For this reason, it is also possible to realize a new transportation device having characteristics not found in a transportation device using a conventional internal combustion engine. From this viewpoint, the development of a transportation device using a motor is underway.

  Transportation equipment including a motor includes a power module (also referred to as a “power semiconductor device”) for supplying electric power to the motor and controlling the number of rotations. FIG. 16 is a circuit diagram schematically showing a drive system including a conventional power module 500. As shown in FIG. 16, the power module 500 includes a plurality of power semiconductor elements (transistors) 513 and a control circuit 551 that controls the transistors 513. A control signal generated by a gate drive circuit 552 included in the control circuit 551 is applied to the gate electrode of each transistor 513. The power supplied from the battery 501 is converted into appropriate driving power by the power module 500 and supplied to the motor 502. The battery 501 is connected in parallel with a capacitor 540 for smoothing voltage fluctuation.

  FIG. 17 shows a specific structure of the power module 600 disclosed in Patent Document 1. As shown in FIG. 17, the power module 600 includes a frame (case) 620 and a substrate 610 accommodated inside the frame 620.

  The frame body 620 is formed by injection molding using a thermoplastic resin. The frame body 620 has a cylindrical shape, and the substrate 610 is disposed so as to close the lower side of the frame body 620.

  The substrate 610 includes a metal base plate 611a, an insulating layer 611b supported by the metal base plate 611a, and a power semiconductor element 613 mounted on a circuit pattern formed on the surface of the insulating layer 611b. On the circuit pattern, electronic members 615 such as diodes and resistors necessary for the circuit configuration are mounted.

The power module 600 further includes a terminal 630 for connecting the power semiconductor element 613 or the electronic member 615 to an external circuit. The terminal 630 is inserted in the frame 620 as shown in FIG. That is, the frame body 620 and the terminal 630 are integrated by insert molding. Insert molding is a technique in which an insert product is loaded into a mold, a resin is injected, the insert product is wrapped with a molten resin, and solidified to produce an integrated composite part. One end of the terminal 630 is exposed in the space inside the frame 620 and the other end is exposed to the outside. The power semiconductor element 613 or the electronic member 615 and the terminal 630 are electrically connected by a bonding wire 614. The frame 620 is filled with a thermosetting resin 601 such as an epoxy resin. The power semiconductor element 613 is covered with a resin 602 that is more flexible and elastic than the resin 601 filled in the entire frame 620.
Japanese Patent No. 3797021

  As described above, in the power module 600 disclosed in Patent Document 1, the terminal 630 is fixed to the frame 620 by integrating the frame 620 and the terminal 630 by insert molding.

  However, the mold for performing insert molding is complicated and highly accurate, and is very expensive. Therefore, when the number of manufactured products is not so large (for example, 100,000 or less), the mold amortization cost becomes high, which increases the unit price of the product. In addition, since the mold needs to be changed every time the design is changed in the development stage, the mold cost increases if the mold is expensive. Thus, when the structure which the terminal was fixed to the frame by insert molding is employ | adopted, the manufacturing cost of a power module will increase and productivity will fall.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly productive power module that can be manufactured at low cost and a transport device including the power module.

  A power module according to the present invention is formed separately from a substrate including a plurality of power semiconductor elements, a frame body that accommodates the substrate, and the frame body, and is electrically connected to any of the plurality of power semiconductor elements. Connected terminals, and fixing means for fixing the terminals to the frame.

  In a preferred embodiment, the terminal has a plate shape.

  In a preferred embodiment, the power module according to the present invention further includes a capacitor for smoothing a voltage supplied from a power source.

  In a preferred embodiment, the terminal has a connection portion for making an electrical connection with the capacitor between one end portion and the other end portion thereof.

  In a preferred embodiment, the frame includes a first space that houses the substrate and a second space that houses the capacitor.

  In a preferred embodiment, the frame includes a space for commonly housing the substrate and the capacitor.

  In a preferred embodiment, the power module according to the present invention further includes a control board including a circuit for controlling the plurality of power semiconductor elements, and the control board is accommodated in the frame.

  In a preferred embodiment, the fixing means includes at least one of a structure formed on the frame body and a structure formed on the terminal itself.

  In a preferred embodiment, the fixing means includes a groove formed on the surface of the frame.

  In a preferred embodiment, the plurality of surfaces defining the groove include reverse tapered side surfaces.

  In a preferred embodiment, the fixing means includes a protrusion formed in the groove.

  In a preferred embodiment, the fixing means includes a leaf spring formed at an end portion of the terminal.

  In a preferred embodiment, the fixing means includes a protrusion formed on the surface of the frame body and an opening formed on the terminal and fitted into the protrusion.

  In a preferred embodiment, the fixing means includes a member provided separately from the frame and the terminal.

  In a preferred embodiment, the fixing means includes an adhesive member that adheres the frame and the terminal to each other.

  In a preferred embodiment, the fixing means includes a mechanical coupling member that mechanically couples the frame and the terminal to each other.

  In a preferred embodiment, a transportation device according to the present invention includes a power module having the above-described configuration.

  In the power module according to the present invention, the terminal is formed separately from the frame, and is fixed to the frame by a fixing means. Therefore, the mold for forming the frame body does not need to be very expensive with a complicated specification used for insert molding, and may be a simple specification and relatively inexpensive. Therefore, even when the number of manufactured products is not so large, the mold amortization cost can be reduced, and an increase in the product unit price due to the mold amortization cost can be suppressed. Moreover, even if it is necessary to change the mold every time the design is changed at the development stage, the mold cost can be reduced. Thus, according to the present invention, the manufacturing cost of the power module can be reduced and the productivity can be improved. That is, the power module according to the present invention can be manufactured at low cost and has high productivity.

  The terminal is preferably plate-shaped. The plate-like terminal is suitable for supplying high power and can be easily molded. Further, when the end portion of the terminal is bonded to the substrate (for example, soldered to the substrate), the bonding area is easily increased.

  The power module according to the present invention preferably further includes a capacitor for smoothing the voltage supplied from the power source. Since the capacitor is built in the power module, the size of the device including the capacitor can be reduced. In addition, since the wiring length between the power semiconductor element and the capacitor attachment point can be shortened, the inductance of the circuit from one terminal of the capacitor to the other terminal can be reduced, which occurs when the power semiconductor element is switched. Noise (surge voltage) can be reduced. Therefore, the applied voltage is sufficiently smaller than the rated voltage of the power semiconductor element and the failure rate of the power semiconductor element is reduced, so that the reliability is improved. In addition, since the applied voltage is reduced, it is possible to use a power semiconductor element having a lower rated voltage. A power semiconductor element having a low rated voltage generally has low power loss and low cost. Therefore, the power loss of the entire power module can be reduced, and the cost can be reduced.

  When the power module has a built-in capacitor, for example, the terminal has a connecting portion for making an electrical connection with the capacitor between one end and the other end of the power module. The wiring length between the capacitor mounting points can be shortened.

  When adopting a configuration in which the frame includes a first space that accommodates the substrate and a second space that accommodates the capacitor, the size of the power module in the vertical direction (the direction perpendicular to the main surface of the substrate) (that is, the direction) (Height) can be reduced.

  Further, when the frame body adopts a configuration including a space that commonly accommodates the substrate and the capacitor, the size of the power module in the horizontal direction (direction in which the main surface of the substrate expands) can be reduced.

  The power module according to the present invention may further include a control board including a circuit for controlling a plurality of power semiconductor elements. Typically, the control board is also housed inside the frame.

  The fixing means for fixing the terminal to the frame includes, for example, at least one of a structure formed on the frame itself and a structure formed on the terminal itself.

  The structure formed in the frame itself is, for example, a groove formed on the surface of the frame. By fitting the terminal in such a groove, the terminal can be fixed to the frame. If the plurality of surfaces defining the groove include reverse tapered side surfaces or protrusions are formed in the groove, the terminal can be more firmly fixed.

  The structure formed in the terminal itself is, for example, a leaf spring formed at the end of the terminal. The terminal including the leaf spring clamps the frame body using the elastic force of the leaf spring, whereby the terminal can be fixed to the frame body.

  Also, the projections formed on the surface of the frame (the structure formed on the frame itself) are combined with the openings formed on the terminals and fitted into the projections (the structure formed on the terminals themselves). May be used. The terminal can be fixed to the frame by fitting the projection of the frame and the opening of the terminal.

  Alternatively, the fixing means may include a member provided separately from the frame and the terminal.

  The member provided separately from the frame and the terminal is, for example, an adhesive member that bonds the frame and the terminal to each other. The terminal can be fixed to the frame by bonding the frame and the terminal using an adhesive member such as an adhesive layer or an adhesive tape.

  The member provided separately from the frame and the terminal is a mechanical coupling member that mechanically couples the frame and the terminal to each other. By mechanically coupling the frame and the terminal using a mechanical coupling member such as a screw or a rivet, the terminal can be fixed to the frame.

  Since the power module according to the present invention can be manufactured at low cost and has high productivity, it is suitably used for various types of transportation equipment.

  ADVANTAGE OF THE INVENTION According to this invention, the power module with high productivity which can be manufactured at low cost, and a transport apparatus provided with the same are provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment.

  First, an outline of a drive system of a transportation device in which the power module (power semiconductor device) 100 according to the present embodiment is used will be described with reference to FIG. FIG. 1 is a circuit diagram schematically showing a drive system including the power module 100.

  The drive system shown in FIG. 1 includes a power module 100, a battery 101 that supplies power to the power module 100, and a motor 102 that is driven by the power module 100.

  The battery 101 is electrically connected to the power module 100 and is connected in parallel with the capacitor 40 for smoothing the voltage. As will be described in detail later, the capacitor 40 is mounted on the power module 100.

  The motor 102 in this embodiment is a brushless DC motor. The motor 102 is rotationally driven by applying three-phase alternating currents having phases different by 120 degrees to the three terminals of the motor 102.

  The power module 100 receives power from the battery 101 and generates drive power suitable for rotating the motor 102. As described above, since the motor 102 is driven by a three-phase alternating current, the power module 100 generates a three-phase alternating current from the direct current supplied from the battery 101. For this purpose, the power module 100 is formed with three current paths each composed of two field effect transistors (FETs) 13 connected in series. That is, the power module 100 includes six field effect transistors 13 as power semiconductor elements (semiconductor elements that perform a switching operation for controlling supply of current).

  In the present embodiment, a MOS field effect transistor (hereinafter simply referred to as “transistor”) is used as a power semiconductor element (switching element), but other transistors such as a bipolar transistor may be used. In addition to transistors, other power semiconductor elements that can apply a large current, such as diodes and thyristors, may be used. The power semiconductor element is a semiconductor switching element for driving a motor in a narrow sense.

  A control signal generated by the gate drive circuit 52 included in the control circuit 51 is applied to the gate electrode of each transistor 13, and each FET performs a switching operation based on the control signal. For example, switching is performed at a high speed at a frequency by pulse width modulation (PWM), whereby a three-phase alternating current is generated and supplied to the motor 102.

  Next, a specific configuration of the power module 100 will be described with reference to FIGS. 2 (a) and 2 (b). 2A and 2B are a cross-sectional view and a top view schematically showing the power module 100. FIG.

  As shown in FIGS. 2A and 2B, the power module 100 includes a substrate (power circuit substrate) 10 including a plurality of transistors (power semiconductor elements) 13 and a frame ( Case) 20 and a plurality of terminals 30 each electrically connected to one of the plurality of transistors 13. The power module 100 further includes a capacitor 40 that smoothes the voltage supplied from the battery 101 that is a power source, and a control board 50 that includes a circuit (control circuit) 51 that controls the transistor 13.

  The substrate 10 includes a plate member 11 having an insulating surface. In the present embodiment, the plate member 11 includes a base substrate 11a and an insulating layer 11b provided on the surface of the base substrate 11a. The base substrate 11a is made of, for example, aluminum, and the insulating layer 11b is made of, for example, an epoxy resin.

  In the power module 100, since a large amount of heat is generated by a large current flowing through the transistor 13 and the wiring, the plate member 11 is thermally conductive so that the generated heat can be dissipated outside the power module 100 via the plate member 11. It is preferable that it is excellent in property. Since the insulating layer 11b generally has low thermal conductivity, it is preferable to make the insulating layer 11b thin enough to ensure insulation and to make the base substrate 11a thick enough to ensure the strength of the substrate 10. From the viewpoint of thermal conductivity and strength as a structural material, it is preferable to use a metal substrate as the base substrate 11a. Or you may form the plate-shaped member 11 using the material excellent in both insulation and heat conductivity.

  A conductive pattern 12 is formed on the insulating layer 11b (that is, on the insulating surface of the plate-like member 11). The conductive pattern 12 is, for example, a copper foil. A transistor 13 is provided on the conductive pattern 12. The transistor 13 is soldered to the conductive pattern 12 so that its drain electrode is in contact with the conductive pattern 12.

  The frame 20 is made of a resin (for example, a thermoplastic resin such as PBT or PPS). The frame body 20 includes a first space 21 that accommodates the substrate 10 and a second space 22 that accommodates the capacitor 40. The first space 21 is a space surrounded in a cylindrical shape by the side wall portion 20a of the frame body 20, and the upper side and the lower side are open. The substrate 10 is accommodated so as to close the lower side of the first space 21. On the other hand, the second space 22 is a space surrounded in a bag shape by the side wall portion 20 a and the bottom portion 20 b of the frame body 20, and the capacitor 40 is placed on the bottom portion 20 b of the frame body 20.

  The terminal 30 is formed separately from the frame body 20. That is, in this embodiment, the terminal 30 is not inserted in the frame 20, and the structure which integrates the terminal 30 and the frame 20 by insert molding is not employ | adopted. The terminal 30 is made of a metal material such as phosphor bronze or brass.

  The terminals 30 in the present embodiment are plate-like and are bent so as to follow the surfaces of the substrate 10 and the frame body 20. The terminal 30 and the transistor 13 are electrically connected by the wire 14 and / or the conductive pattern 12. The wire 14 is made of aluminum, for example. The plurality of terminals 30 include a power terminal 30 </ b> A that is electrically connected to the battery 101, and a signal terminal 30 </ b> B that is electrically connected to the control circuit 51 of the control board 50. A hole 20c for electrical connection between the power terminal 30A and the external wiring is provided in the upper part of the frame body 20, and by screwing using a nut 23 fitted in the hole 20c, Electrical connection between the power terminal 30A and the battery 101 is performed. Of course, the method of ensuring the electrical connection between the power terminal 30A and the battery 101 is not limited to this.

  The capacitor 40 is, for example, an electrolytic capacitor. 2A and 2B illustrate a cylindrical capacitor 40. FIG. As described above, the power terminal 30A and the external wiring are connected to each other at the upper part of the frame body 20 (that is, at one end of the power terminal 30A). On the other hand, the capacitor 40 is connected to the power terminal 30A at a position closer to the substrate 10 as shown in FIG. That is, the power terminal 30 </ b> A has a connection portion 31 for making an electrical connection with the capacitor 40 between one end portion and the other end portion (a portion along the side wall portion 20 a of the frame body 20). .

  The connecting portion 31 is connected to a terminal (referred to as a “capacitor terminal”) 41 protruding from the bottom surface of the capacitor 40. The capacitor terminal 41 is provided so as to penetrate the side wall portion (more specifically, the side wall portion separating the first space 21 and the second space 22) 20a of the frame body 20, and the power terminal 30A. The connection part 31 is joined by welding or soldering. The two power terminals 30 </ b> A in the present embodiment have connection portions 31 at substantially the same height.

  A control circuit 51 for controlling the transistor 13 is formed on the control substrate 50. The control substrate 50 is accommodated in the frame body 20, and more specifically, is accommodated in the first space 21 so as to overlap the substrate 10 when viewed from above. The control board 50 is supported by protrusions provided on the frame body 20.

  The first space 21 that accommodates the substrate 10 and the control substrate 50 is filled with a resin (for example, urethane resin) 1 for the purpose of waterproofing and vibration countermeasures. Further, in order to protect the wire 14 connected to the transistor 13 from vibration or the like, the transistor 13 and the wire 14 connected to the transistor 13 are locally sealed with a different resin (for example, epoxy resin) 2.

  The terminal 30 of the power module 100 in the present embodiment is formed separately from the frame body 20 as described above, and the power module 100 includes a fixing unit that fixes the terminal 30 to the frame body 20. . Hereinafter, a specific example of the fixing means will be described.

  The fixing means is, for example, a groove 24 formed on the surface of the frame body 20 as shown in FIGS. 3 (a) and 3 (b). FIG. 3A shows a groove 24 for fixing the power terminal 30A, and FIG. 3B shows a groove 24 for fixing the signal terminal 30B. The groove 24 is formed on the inner surface of the side wall portion 20a of the frame body 20 so as to extend in the vertical direction. Each groove 24 is defined by a bottom surface 24a and two side surfaces 24b and 24c, and a plurality of surfaces defining each groove 24 includes a side surface 24c formed in an inversely tapered shape. Therefore, the width of the groove 24 is slightly narrowed from the bottom to the top of the groove 24. Here, an example is shown in which only one of the two side surfaces 24b and 24c is formed in a reverse taper shape, but both side surfaces may be formed in a reverse taper shape. The terminals 30 are fixed to the frame body 20 by fitting the power terminals 30 </ b> A and the signal terminals 30 </ b> B into the grooves 24 as shown in FIGS. 4A and 4B.

  As described above, in the power module 100 according to the present embodiment, the terminal 30 is formed separately from the frame body 20 and is fixed to the frame body 20 by fixing means (for example, the groove 24 described above). Therefore, the mold for molding the frame 20 does not have to be very expensive with complicated specifications such as those used for insert molding, and may be relatively inexpensive with simple specifications. Therefore, even when the number of manufactured products is not so large, the mold amortization cost can be reduced, and an increase in the product unit price due to the mold amortization cost can be suppressed. Moreover, even if it is necessary to change the mold every time the design is changed at the development stage, the mold cost can be reduced. Thus, by adopting a configuration like the power module 100 of the present embodiment, it is possible to reduce manufacturing costs and improve productivity. That is, the power module 100 of this embodiment can be manufactured at low cost and has high productivity.

  A plurality of surfaces defining the groove 24 shown in FIGS. 3A and 3B include a side surface 24 c formed in a reverse taper shape, and the width of the groove 24 is from the bottom to the top of the groove 24. It is becoming narrower. Therefore, the terminal 30 can be more firmly fixed.

  Further, as shown in FIGS. 5A and 5B, a protrusion 25 may be formed in the groove 24. The protrusion 25 protrudes from the two side surfaces 24b toward the center of the groove 24 in the width direction. Strong fixation can also be performed by fitting the terminal 30 into the groove 24 as shown in FIGS. 6A and 6B.

  The terminal 30 is preferably plate-shaped. The plate-like terminal 30 is suitable for supplying high power and can be easily molded. Further, when the end portion of the terminal 30 is bonded to the substrate 10 (for example, soldered to the substrate 10), the bonding area is easily increased.

  Subsequently, another specific example of the fixing means will be described.

  As the fixing means, a leaf spring 32 formed at the end of the terminal 30 as shown in FIGS. 7A and 7B may be used. The terminal 30 including the leaf spring 32 clamps the frame body 20 using the elastic force of the leaf spring 32, whereby the terminal 30 is fixed to the frame body 20. The leaf spring 32 is formed integrally with other portions of the terminal 30, for example, and by forming the terminal 30 using a highly elastic metal material, the terminal 30 including the leaf spring 32 at the end can be obtained.

  Further, as a fixing means, as shown in FIGS. 8A and 8B, a protrusion 26 formed on the surface of the frame body 20, and an opening 33 formed on the terminal 30 so as to be fitted to the protrusion 26. And may be used. The protrusions 26 of the frame body 20 and the openings 33 of the terminals 30 are fitted to each other, whereby the terminals 30 are fixed to the frame body 20. Here, two protrusions 26 and two openings 33 are provided for one terminal 30, but the number of protrusions 26 and openings 33 is not limited thereto.

  The leaf spring 32 shown in FIG. 7 and the protrusion 26 and the opening 33 shown in FIG. 8 may be used together with a groove formed on the surface of the frame body 20 (a groove that can accommodate the terminal 30). However, from the viewpoint of fixing the terminal 30 more firmly and preventing displacement, as shown in FIG. 7B and FIG. It is preferable to use it.

  The fixing means described above includes at least one of a structure (groove 24 and protrusions 25 and 26) formed on the frame 20 itself and a structure (leaf spring 32 and opening 33) formed on the terminal 30 itself. A member provided separately from the frame body 20 and the terminal 30 may be used as the fixing means.

  As such a member, for example, an adhesive member 60 that bonds the frame body 20 and the terminal 30 to each other as shown in FIG. 9 can be used. The adhesive member 60 is, for example, an adhesive layer formed by applying an adhesive to the surface of the frame 20 or the surface of the terminal 30, or an adhesive tape formed by applying an adhesive to both sides of the base material. (Adhesive sheet).

  Alternatively, a mechanical coupling member that mechanically couples the frame body 20 and the terminal 30 to each other can also be used. The mechanical coupling member is, for example, a screw 62 as shown in FIGS. 10 (a) and 10 (b), or a rivet 64 as shown in FIGS. 11 (a) and 11 (b). Here, two screws 62 and two rivets 64 are provided for one terminal 30, but the number of screws 62 and rivets 64 is not limited to this. Moreover, you may use it combining a bolt and a nut as a mechanical coupling member.

  The adhesive member 60 shown in FIG. 9 and the mechanical coupling member shown in FIGS. 10 and 11 may be used together with a groove (a groove that can accommodate the terminal 30) formed on the surface of the frame 20, Although it may be used without being combined with such a groove, from the viewpoint of fixing the terminal 30 more firmly and preventing displacement, as shown in FIGS. In addition, it is preferably used together with the groove.

  As described above, since various structures and members can be used as the fixing means, the fixing means may be appropriately selected in consideration of the advantages of the respective structures and members. When the groove 24 formed on the surface of the frame 20 as shown in FIGS. 3 and 5 is used, the terminal 30 may have a simple shape, and it is not necessary to perform special processing on the terminal 30. When the leaf spring 32 formed at the end of the terminal 30 as shown in FIG. 7 is used, the frame 20 may have a simple shape. When the projections 26 formed on the surface of the frame 20 as shown in FIG. 8 and the openings 33 formed in the terminals 30 so as to be fitted to the projections 26 are used, the terminals 30 are relatively simple. It may be shaped (since it only forms the opening 33).

  Further, when the adhesive member 60 for bonding the frame body 20 and the terminal 30 to each other as shown in FIG. 9 is used, it is not necessary to form a fixing structure on the frame body 20 and the terminal 30. Both the body 20 and the terminal 30 can have a simple shape. When the mechanical coupling member as shown in FIGS. 10 and 11 is used, the frame body 20 and the terminal 30 can have a simple shape, and there are also advantages that the coupling force is strong and the reliability is high. .

  As shown in FIGS. 1 and 2, the power module 100 in the present embodiment includes a capacitor 40. That is, the capacitor 40 is built in the power module 100.

  On the other hand, in the conventional power module shown in FIGS. 16 and 17, the capacitor is arranged outside the power module. This increases the size of the device including the capacitor. Further, since the wiring length between the power semiconductor element and the capacitor attachment point becomes long, the inductance of the circuit becomes large, and there is a problem that noise generated when the power semiconductor element is switched increases.

  In the present embodiment, since the capacitor 40 that smoothes the voltage supplied from the power supply is built in the power module 100, the device size including the capacitor 40 can be reduced. Also, the wiring length between the transistor (power semiconductor element) 13 and the capacitor 40 attachment point can be shortened (for example, connection is made at the connection portion 31 provided between one end portion and the other end portion of the terminal 30). Therefore, the inductance of the circuit from one terminal 41 of the capacitor 40 to the other terminal 41 can be reduced, and noise (surge voltage) generated when the transistor 13 is switched can be reduced. Therefore, the applied voltage is sufficiently smaller than the rated voltage of the transistor 13 and the failure rate of the transistor 13 is reduced, so that the reliability is improved. In addition, since the applied voltage is reduced, it is possible to use a power semiconductor element having a lower rated voltage. Since the power semiconductor element having a low rated voltage generally has low power loss and low cost, the power loss of the entire power module 100 can be reduced, and the cost can be further reduced.

  Note that the method of accommodating the capacitor 40 in the second space 22 is not limited to the configuration shown in FIG. An example of another configuration for accommodating the capacitor 40 is shown in FIGS. In the configuration shown in FIGS. 2A and 2B, a relatively small and long capacitor 40 is accommodated sideways (that is, the bottom surface and the top surface face the side wall portion 20a, and the side surface faces the bottom portion 20b). Has been. On the other hand, in the configuration shown in FIGS. 12A and 12B, the capacitor 40 having a relatively large diameter and short (that is, flatter) is vertically oriented (that is, the side surface faces the side wall portion 20a, and the bottom surface is the bottom portion). 20b). The side wall portion 20 a that defines the second space 22 is curved so as to follow the side surface shape of the capacitor 40. Further, the capacitor terminal 41 protruding downward is electrically connected to the connection portion 31 of the power terminal 30A via a conductive member 42 provided so as to penetrate the side wall portion 20a.

  Further, the frame body 20 does not necessarily include the first space 21 in which the substrate 10 is accommodated and the second space 22 in which the capacitor 40 is accommodated, as shown in FIGS. 13 (a) and 13 (b). In addition, a space 27 that commonly accommodates the substrate 10 and the capacitor 40 may be included. In the configuration shown in FIGS. 13A and 13B, the frame 20 does not include the second space 22 shown in FIG. 2, and the substrate 10 and the capacitor 40 are the same (single) space 27. Is housed in. Specifically, the capacitor 40 is disposed between the power circuit board 10 and the control board 50.

  As shown in FIGS. 13A and 13B, the configuration in which the frame 20 includes a space 27 that commonly accommodates the substrate 10 and the capacitor 40 is the horizontal direction of the power module 100 (the substrate 10 and the control substrate). There is an advantage that the size in the direction in which the main surface of 50 spreads can be reduced.

  On the other hand, as shown in FIGS. 2A and 2B, the configuration in which the frame body 20 includes the first space 21 in which the substrate 10 is accommodated and the second space 22 in which the capacitor 40 is accommodated, There is an advantage that the size (that is, the height) of the power module 100 in the vertical direction (direction orthogonal to the main surface of the substrate 10 or the control substrate 50) can be reduced.

  Further, the power module 100 may include a plurality of capacitors 40 as shown in FIGS. 14 (a), (b), and (c). Here, a configuration in which two capacitors 40 are accommodated in the second space 22 is illustrated. By incorporating the plurality of capacitors 40 in the power module 100, the capacitance increases, and voltage fluctuation can be suitably suppressed even when the output current is large. The two capacitor terminals 41 of each capacitor 40 are arranged along the vertical direction as shown in FIG. 14A, and are connected to a branched portion 34 extending in the horizontal direction of the power terminal 30A.

  The power module 100 according to the present embodiment is suitably used for various transportation equipment including a motor as a drive source. FIG. 15 shows an electric vehicle 430 including the power module 100 in the present embodiment.

  The electric vehicle 430 is a cart used for transporting luggage such as golf bags and personnel at a golf course. The electric vehicle 430 includes a travel drive motor 431, two rear wheels 432 driven by the motor 431, and a front wheel 434 that is steered manually or automatically. The driving force of the travel drive motor 431 is transmitted to the rear wheels 432 via a transmission (not shown). The front wheel 434 is steered by manual operation or automatic operation of the handle 435.

  A front seat 436 and a rear seat 437 are provided on the front and rear sides. A charging controller 438 and a brake motor 439 are provided below the front seat 436. A travel drive battery device 440 serving as a power source for the travel drive motor 431 is provided below the rear seat 437. The travel drive battery device 440 includes a total of six batteries 441 (only three on one side are shown) connected in series. These batteries 441 are placed on the receiving seat 442 with a gap provided.

  A travel control controller 443 is provided above the travel drive motor 431. The travel control controller 443 is connected to the travel drive battery device 440, the travel drive motor 431, the brake motor 439, and the steering motor 444, and controls them. The travel control controller 443 and the travel drive motor 431 are disposed between the two rear wheels 432.

  The power module 100 described above is installed inside the travel control controller 443, receives a direct current from the battery 441, and converts it into an alternating current. The alternating current from the power module 100 is supplied to the travel drive motor 431, the brake motor 439, and the steering motor 444.

  Although a four-wheel electric vehicle is illustrated here, a two-wheel electric vehicle such as an electric motorcycle may be used. In addition to an electric vehicle, other transportation equipment that moves a load or personnel using a motor as a drive source may be used.

  According to the present invention, a highly productive power module that can be manufactured at low cost is provided. The power module according to the present invention is suitably used for various transportation equipment using a motor as a drive source.

1 is a circuit diagram schematically showing a drive system including a power module 100 in a preferred embodiment of the present invention. (A) And (b) is sectional drawing and the top view which show the power module 100 typically. (A) And (b) is a figure which shows an example of the fixing means with which the power module 100 is provided. (A) And (b) is a figure which shows typically a mode that the terminal is being fixed by the fixing means shown to Fig.3 (a) and (b). (A) And (b) is a figure which shows an example of the fixing means with which the power module 100 is provided. (A) And (b) is a figure which shows typically a mode that the terminal is being fixed by the fixing means shown to Fig.5 (a) and (b). (A) And (b) is a figure which shows an example of the fixing means with which the power module 100 is provided. (A) And (b) is a figure which shows an example of the fixing means with which the power module 100 is provided. It is a figure which shows an example of the fixing means with which the power module 100 is provided. (A) And (b) is a figure which shows an example of the fixing means with which the power module 100 is provided. (A) And (b) is a figure which shows an example of the fixing means with which the power module 100 is provided. (A) And (b) is sectional drawing which shows the other structure of the power module 100 typically, and a top view. (A) And (b) is sectional drawing which shows the other structure of the power module 100 typically, and a top view. (A), (b) and (c) are figures which show typically other composition of power module 100, (a) is a sectional view, (b) is a top view, and (c) is a terminal for electric power. It is the figure which looked at the side wall part provided with from the inside of the 1st space. It is a side view which shows typically an example of the transport equipment provided with the power module. FIG. 6 is a circuit diagram schematically showing a drive system including a conventional power module 500. It is sectional drawing which shows the conventional power module 600 typically.

Explanation of symbols

1, 2 Resin 10 Substrate (Power circuit board)
DESCRIPTION OF SYMBOLS 11 Plate-like member 11a Base substrate 11b Insulating layer 12 Conductive pattern 13 Transistor (power semiconductor element)
14 Wire 20 Frame (case)
20a Side wall portion 20b Bottom portion 20c Hole 21 Space for accommodating substrate (first space)
22 Space for storing capacitors (second space)
23 Nut 24 Groove 24a Bottom 24b, 24c Side 25 Protrusion 26 Protrusion 27 Space for accommodating substrate and capacitor 30 Terminal 30A Power terminal 30B Signal terminal 31 Connection portion 32 Leaf spring 33 Opening portion 40 Capacitor 50 Control substrate 51 Control circuit 52 Gate drive circuit 60 Adhesive member 62 Screw 64 Rivet 100 Power module (power semiconductor device)
101 battery 102 motor 430 electric vehicle

Claims (17)

A substrate including a plurality of power semiconductor elements;
A frame for housing the substrate;
A terminal formed separately from the frame and electrically connected to any of the plurality of power semiconductor elements;
Fixing means for fixing the terminal to the frame;
Power module with   The power module according to claim 1, wherein the terminal has a plate shape.   The power module according to claim 1, further comprising a capacitor that smoothes a voltage supplied from a power source.   4. The power module according to claim 3, wherein the terminal has a connection portion for making an electrical connection with the capacitor between one end portion and the other end portion thereof. 5.   The power module according to claim 4, wherein the frame includes a first space that accommodates the substrate and a second space that accommodates the capacitor.   The power module according to claim 4, wherein the frame body includes a space that accommodates the substrate and the capacitor in common. A control board including a circuit for controlling the plurality of power semiconductor elements;
The power module according to claim 1, wherein the control board is accommodated inside the frame.   The power module according to any one of claims 1 to 7, wherein the fixing means includes at least one of a structure formed on the frame body and a structure formed on the terminal itself.   The power module according to any one of claims 1 to 8, wherein the fixing means includes a groove formed on a surface of the frame.   The power module according to claim 9, wherein the plurality of surfaces defining the groove include reverse tapered side surfaces.   The power module according to claim 9, wherein the fixing means includes a protrusion formed in the groove.   The power module according to claim 1, wherein the fixing means includes a leaf spring formed at an end portion of the terminal.   The power module according to claim 1, wherein the fixing means includes a protrusion formed on the surface of the frame body and an opening formed in the terminal and fitted into the protrusion.   The power module according to claim 1, wherein the fixing unit includes a member provided separately from the frame and the terminal.   The power module according to claim 1, wherein the fixing means includes an adhesive member that adheres the frame and the terminal to each other.   15. The power module according to claim 1, wherein the fixing means includes a mechanical coupling member that mechanically couples the frame and the terminal to each other.   A transportation device comprising the power module according to claim 1.

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