Abstract:
An object of the invention is to suppress that resistance against vibrations is reduced, while reducing the number of components. A power conversion device according to the present invention includes: a power semiconductor module that converts a DC current into an AC current; a plate conductor that transfers the DC current or the AC current; a resin sealing material that seals the plate conductor; and an electric component that is used to control the power semiconductor module, wherein the resin sealing material includes a supporting member that supports the electric component, and wherein the plate conductor is buried in a portion of the resin sealing material that is disposed to face the electric component.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a power conversion device, and particularly to a power conversion device which is used in a vehicle. 
       BACKGROUND ART 
       [0002]    There is a request for minimizing electric components mounted in a hybrid vehicle and an electric vehicle in order to minimize these vehicles and to secure spaces therein. In particular, a power conversion device which controls a driving motor for the hybrid vehicle and the electric vehicle is requested to be minimized. On the other hand, resistance against vibrations caused from variations in a road status while running and from the engine or the motor is also requested for the power conversion device used in the hybrid vehicle and the electric vehicle. 
         [0003]    PTL 1 (JP 2010-35347 A) discloses a technique of supporting a driver board and a control board using a metal base. 
         [0004]    However, there is a request for a technique of suppressing a reduction of resistance against vibration while reducing the number of components for the miniaturization. 
       CITATION LIST 
     Patent Literature 
       [0005]    PTL 1: JP 2010-35347 A 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    An object of the invention is to suppress a reduction of resistance against vibration while reducing the number of components. 
       Solution to Problem 
       [0007]    In order to solve the problem, a power conversion device according to the present invention includes: a power semiconductor module that converts a DC current into an AC current; a plate conductor that transfers the DC current or the AC current; a resin sealing material that seals the plate conductor; and an electric component that is used to control the power semiconductor module, wherein the resin sealing material includes a supporting member that supports the electric component, and wherein the plate conductor is buried in a portion of the resin sealing material that is disposed to face the electric component. 
       Advantageous Effects of Invention 
       [0008]    According to the invention, it is possible to suppress a reduction of resistance against vibrations while reducing the number of components. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0009]      FIG. 1  is a perspective view illustrating the entire configuration of a main circuit unit  900  of a power conversion device. 
           [0010]      FIG. 2  is an exploded perspective view of the main circuit unit  900  of the power conversion device. 
           [0011]      FIG. 3  is a cross-sectional perspective view illustrating the vicinity of a connecting portion of a signal terminal when viewed in a direction of arrow in plane A illustrated in  FIG. 1 . 
           [0012]      FIG. 4  is a cross-sectional view of a layout of a current sensor when viewed from a direction of arrow in plane B illustrated in  FIG. 1 . 
           [0013]      FIG. 5  is a partially enlarged view of a power terminal  101  and signal terminals  102   a  and  102   b  of a power semiconductor module  100   a  of range C of  FIG. 2 . 
           [0014]      FIG. 6  is a perspective view illustrating the entire configuration of a mold bus bar  500 . 
           [0015]      FIG. 7  is an exploded perspective view of the mold bus bar  500 . 
           [0016]      FIG. 8  is a cross-sectional view partially illustrating the mold bus bar  500  when viewed from a direction of arrow of plane A of  FIG. 6 . 
           [0017]      FIG. 9  is a cross-sectional view partially illustrating the mold bus bar  500  when viewed from a direction of arrow of plane B of  FIG. 6 . 
           [0018]      FIG. 10  is a cross-sectional view partially illustrating the mold bus bar  500  when viewed from a direction of arrow of plane D of  FIG. 6 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0019]    Hereinafter, embodiments of the invention will be descried using the drawings. The following descriptions will be given about a specific example of the content of the invention. However, the invention is not limited to these descriptions, and various changes and modifications may be made by a person skilled in the art within a scope of technical ideas disclosed in this specification. In addition, the components having the same function will be denoted by the same symbols in the drawings for the description of the invention, and the redundant description will be omitted. 
         [0020]      FIG. 1  is a perspective view illustrating the entire configuration of a main circuit unit  900  of a power conversion device. Herein, the main circuit unit  900  is a circuit unit which receives DC power from a battery mounted in a vehicle and outputs AC power to a motor for driving the vehicle.  FIG. 2  is an exploded perspective view of the main circuit unit  900  of the power conversion device.  FIG. 3  is a cross-sectional perspective view of the vicinity of a connecting portion between signal terminals  102   a  and  102   b  and a driver circuit board  300   a  when viewed from a direction of arrow of plane A illustrated in  FIG. 1 .  FIG. 4  is a cross-sectional view of the vicinity of a current sensor  400  when viewed from a direction of arrow of plane B illustrated in  FIG. 1 .  FIG. 5  is a partially enlarged view of a power terminal  101  and the signal terminals  102   a  and  102   b  of a power semiconductor module  100   a  in range C of  FIG. 2 . 
         [0021]    The power semiconductor modules  100   a  to  100   f  illustrated in  FIG. 2  include inverter circuits which convert DC power into AC power. In this embodiment, one power semiconductor module  100   a  forms an upper and lower arm circuit to output one phase current among the inverter circuits which output three-phase AC currents. For example, the power semiconductor module  100   a  is a U-phase upper and lower arm circuit, a power semiconductor module  100   b  is a V-phase upper and lower arm circuit, and a power semiconductor module  100   c  is a W-phase upper and lower arm circuit. Then, the power semiconductor modules  100   a  to  100   c  form a first inverter circuit. Similarly, a power semiconductor module  100   d  is a U-phase upper and lower arm circuit, a power semiconductor module  100   e  is a V-phase upper and lower arm circuit, and a power semiconductor module  100   f  is a W-phase upper and lower arm circuit. Then, the power semiconductor modules  100   d  to  100   f  form a second inverter circuit. In other words, in this embodiment, one power conversion device  1  is provided with two inverter circuits. These two inverter circuits each may drive separate motors, or may drive one motor. 
         [0022]    A capacitor module  200  illustrated in  FIGS. 1 and 2  smooths the DC power which is supplied to the first inverter circuit and the second inverter circuit. Noise filtering capacitors  201   a  and  201   b  remove noises which are transferred from the battery. 
         [0023]    The driver circuit board  300   a  illustrated in  FIGS. 1 and 2  are disposed at a position to face the power semiconductor modules  101   a  to  100   c . Similarly, a driver circuit board  300   b  is disposed at a position to face the power semiconductor modules  101   d  to  100   f . In addition, the driver circuit board  300   a  and the driver circuit board  300   b  are formed such that parts thereof face to the capacitor module  200 . 
         [0024]    A mold bus bar  500  illustrated in  FIGS. 1 and 2  transfers the DC power and the AC power to the first inverter circuit and the second inverter circuit which will be described below using  FIG. 6  and the subsequent drawings. The mold bus bar  500  is disposed between a region where the driver circuit board  300   a  and the driver circuit board  300   b  are disposed, an a region where the power semiconductor modules  100   a  to  100   f  and the capacitor module  200  are disposed. In addition, the mold bus bar  500  electrically connects the power semiconductor modules  100   a  to  100   f  and the capacitor module  200 , and supports the driver circuit board  300   a  and the driver circuit board  300   b , and a current sensor  400   a  and a current sensor  400   b.    
         [0025]    In addition, as illustrated in  FIGS. 2 and 3 , the mold bus bar  500  is formed with a first through hole  514  through which the power terminal  101 , the signal terminal  102   a , and the signal terminal  102   b  are passed. In a connecting portion  301   a , the signal terminal  102   a  is connected to the driver circuit board  300   a . Similarly, in a connecting portion  301   b , the signal terminal  102   b  is connected to the driver circuit board  300   a . In this embodiment, the power terminal  101  is disposed between the signal terminal  102   a  and the signal terminal  102   b . Then, part of the signal terminal  102   a  is covered by a terminal protecting portion  104   a , and part of the signal terminal  102   b  is covered by a terminal protecting portion  104   b . The terminal protecting portion  104   a  and the terminal protecting portion  104   b  are formed from a place where the power semiconductor module  100   a  is disposed up to a place where the driver circuit board  300   a  is disposed through the first through hole  514 . With this configuration, the mold bus bar  500 , the signal terminal  102   a , and the signal terminal  102   b  can come into contact with each other at the time of assembling with high reliability. 
         [0026]    In addition, since the thickness of the terminal protecting portion  104   a  and the terminal protecting portion  104   b  is made thicker than that of the power terminal  101 , the contact between the mold bus bar  500  and the power terminal  101  is suppressed at the time of assembling, and thus the reliability can be improved. The terminal protecting portion  104   a  and the terminal protecting portion  104   b  is configured by an insulating resin material. Further, the signal terminal  102   a  and the signal terminal  102   b  are disposed with the power terminal  101  interposed therebetween, and the power terminal  101  may be protected by the terminal protecting portion  104   a  and the terminal protecting portion  104   b.    
         [0027]    The current sensor  400   a  illustrated in  FIGS. 2 and 4  detects an AC current flowing to AC bus bars  503   a  to  503   c , and the current sensor  400   b  detects an AC current flowing to AC bus bars  503   d  to  503   f . The current sensor  400   a  and the current sensor  400   b  form through holes  403  through which the AC bus bars  503   a  to  503   f  pass.  FIG. 6  is a perspective view illustrating the entire configuration of the mold bus bar  500 .  FIG. 7  is an exploded perspective view of the mold bus bar  500 .  FIG. 8  is a cross-sectional view partially illustrating the mold bus bar  500  when viewed from a direction of arrow of plane A of  FIG. 6 .  FIG. 9  is a cross-sectional view partially illustrating the mold bus bar  500  when viewed from a direction of arrow of plane B of  FIG. 6 .  FIG. 10  is a cross-sectional view partially illustrating the mold bus bar  500  when viewed from a direction of arrow of plane D of  FIG. 6 . 
         [0028]    As illustrated in  FIG. 7 , the mold bus bar  500  is configured by a negative conductor plate  501 , a positive conductor plate  502 , the AC bus bars  503   a  to  503   f , and a resin sealing material  507 . The negative conductor plate  501 , the positive conductor plate  502 , and the AC bus bars  503   a  to  503   f  each are a plate conductor which is configured by side surfaces and main surfaces having an area larger than that of the side surface. The negative conductor plate  501 , the positive conductor plate  502 , and the AC bus bars  503   a  to  503   f  are formed such that the main surface of the negative conductor plate  501 , the main surface of the positive conductor plate  502 , and part of the main surface of the AC bus bars  503   a  to  503   f  face to the same direction. 
         [0029]    As illustrated in  FIGS. 6 and 7 , the resin sealing material  507  seals the negative conductor plate  501 , the positive conductor plate  502 , and the AC bus bars  503   a  to  503   f  such that the main surface of the negative conductor plate  501 , the main surface of the positive conductor plate  502 , and part of the main surface of the AC bus bars  503   a  to  503   f  are covered. In this embodiment, the AC bus bars  503   a  to  503   f  are sealed and integrated by the resin sealing material  507  together with the negative conductor plate  501  and the positive conductor plate  502  so as to form power wirings into one component (assembly). Therefore, an assembly performance can be improved. The negative conductor plate  501  in this embodiment is configured such that the main surface of the negative conductor plate  501  is disposed to face the main surface of the positive conductor plate  502 , and a stacked structure is formed with respect to the positive conductor plate  502 . The resin sealing material  507  is provided between the negative conductor plate  501  and the positive conductor plate  502 , and the negative conductor plate  501  is electrically insulated from the positive conductor plate  502 . 
         [0030]    In addition, a negative power source terminal  501   a  is connected to the negative conductor plate  501  as illustrated in  FIGS. 6 and 7 , bent to form an angle with respect to the main surface of the negative conductor plate  501 , and protrudes from the main surface of the resin sealing material  507 . A positive power source terminal  502   a  is connected to the positive conductor plate  502 , bent to form an angle with respect to the main surface of the positive conductor plate  502 , and protrudes from the main surface of the resin sealing material  507 . The negative power source terminal  501   a  and the positive power source terminal  502   a  are disposed on one side of the resin sealing material  507 . In addition, a terminal  501   b  linked to the negative conductor plate  501  as illustrated in  FIGS. 6 and 7  is connected to the noise filtering capacitor  201   b . A terminal  502   b  linked to the positive conductor plate  502  is connected to the noise filtering capacitor  201   a.    
         [0031]    A ground bus bar  506  illustrated in  FIGS. 6 and 7  connects the noise filtering capacitors  201   a  and  201   b  illustrated in  FIG. 2  and a ground potential node (not illustrated). A ground terminal  506   a  protrudes from the side surface of the resin sealing material  507 , and connected to the ground potential node. A terminal  506   b  is bent to form an angle with respect to the ground terminal  506   a , protrudes from the main surface of the resin sealing material  507 , and is connected to the noise filtering capacitor  201   b . A terminal  506   c  is bent to form an angle with respect to the ground terminal  506   a , and disposed to face the terminal  506   b . In addition, the terminal  506   c  protrudes from the main surface of the resin sealing material  507 , and connected to the noise filtering capacitor  201   a.    
         [0032]    The ground bus bar  506  is disposed such that a distance of the electrical path between the ground bus bar  506  and the negative power source terminal  501   a  is substantially equal to the distance of the electrical path between the ground bus bar  506  and the positive power source terminal  502   a . For example, the ground bus bar  506  is disposed between the negative power source terminal  501   a  and the positive power source terminal  502   a . Therefore, the distances of the electrical paths of the ground bus bar  506 , the negative power source terminal  501   a , and the positive power source terminal  502   a  can be made short and substantially equal, so that it is possible to improve a noise suppression effect. 
         [0033]    In addition, the ground bus bar  506  is disposed such that the negative power source terminal  501   a  is interposed by the terminal  506   b  on a side near the ground bus bar  506  and the terminal  501   b  on a side near the negative conductor plate  501 , and the positive power source terminal  502   a  is interposed by the terminal  506   c  on a side near the ground bus bar  506  and the terminal  502   b  on a side near the positive conductor plate  502 . Therefore, the distances of the electrical paths from the noise filtering capacitor  201   a  to the negative power source terminal  501   a  and the positive power source terminal  502   a  can be made short and substantially equal, so that the noise suppression effect can be improved. 
         [0034]    Further, since the ground bus bar  506  configured in a plate shape is sealed by the resin sealing material  507 , the distances of the electrical paths from the ground bus bar  506  to the negative power source terminal  501   a  and the positive power source terminal  502   a  can be accurately set, so that the noise suppression effect can be improved. 
         [0035]    A supporting member  508  illustrated in  FIGS. 6 and 7  protrudes from the main surface of the resin sealing material  507 , and supports the driver circuit boards  300   a  and  300   b  as illustrated in  FIG. 1 . The supporting member  508  in this embodiment is made of the same resin material as that of the resin sealing material  507 , and integrally formed with the resin sealing material  507 . Further, the supporting member  508  may be made of a resin material different from that of the resin sealing material  507 , and connected to the resin sealing material  507  by a fixing member. 
         [0036]    As illustrated in  FIG. 8 , each of a plurality of supporting bosses  508   a  is buried in each of the plurality of supporting members  508 . As illustrated in  FIG. 1 , the driver boards  300   a  and  300   b  are supported and fixed by the plurality of supporting bosses  508   a . The supporting boss  508   a  is buried while protruding from an end surface  508   b  of the supporting member  508 . With this configuration, it is possible to prevent that the supporting member  508  made of a resin and the drive board  300   a  are worn out and fatigued to be broken due to vibrations of the vehicle. Further, end surfaces  508   c  of the plurality of supporting bosses  508   a  become flush with each other, and form a board mounting surface  509 . 
         [0037]    In addition, as illustrated in  FIGS. 1 and 8 , the negative conductor plate  501  or the positive conductor plate  502  are disposed such that the main surface of the negative conductor plate  501  or the main surface of the positive conductor plate  502  faces the main surfaces of the driver boards  300   a  and  300   b , and is buried in the resin sealing material  507 . Therefore, even in a case where a resin material is used as a sealing material of the mold bus bar  500  and a resin material is used as a material of the supporting member  508 , the negative conductor plate  501  or the positive conductor plate  502  can improve the strength of the mold bus bar  500 , and improve resistance against vibrations. 
         [0038]    Further, the supporting member  508  is disposed in a space between the main surface of the negative conductor plate  501  or the main surface of the positive conductor plate  502  and the main surfaces of the driver boards  300   a  and  300   b , so that the resistance against vibrations can be improved still more. 
         [0039]    In addition, the positive conductor plate  502  includes a stacking portion  530  with respect to the negative conductor plate  501  in a portion where the respective circuit components of the driver circuit boards  300   a  and  300   b  face circuit mounting surfaces  305   a  and  305   b . Even in a case where a resin material is used as the sealing material of the mold bus bar  500  and a resin material is used as a material of the supporting member  508 , the strength of the mold bus bar  500  can be improved by the stacking portion  530 , and the resistance against vibrations can be improved. 
         [0040]    As illustrated in  FIGS. 9 and 2 , the mold bus bar  500  is formed by the first through hole  514  through which the power terminal  101  of the power semiconductor module  100   a  passes, and a second through hole  515  through which the power terminal  101  of the power semiconductor module  100   b  passes. Then, the stacking portion  530  of the positive conductor plate  502  and the negative conductor plate  501  extends up to a region between the first through hole  514  and the second through hole  515 . 
         [0041]    In addition, the stacking portion  530  of the portion is sealed by the resin sealing material  507 . In a case where the power semiconductor module  100   a  and the power semiconductor module  100   b  are miniaturized and shortened in distance therebetween so as to achieve a miniaturization of the power conversion device, the distance between the first through hole  514  and the second through hole  506  is shortened and the strength of the mold bus bar  500  may be lowered. However, since the stacking portion  530  extends up to a region between the first through hole  514  and the second through hole  515 , the strength of the mold bus bar  500  can be improved, and the resistance against vibration can be improved. 
         [0042]    As illustrated in  FIGS. 10 and 6 , each of the plurality of supporting bosses  511  is buried in each of the plurality of supporting members  540 . As illustrated in  FIG. 1 , the current sensors  400   a  and  400   b  are supported and fixed by the plurality of supporting bosses  511 . The supporting boss  511  is buried while protruding from an end surface  540   a  of the supporting member  540 . With this configuration, it is possible to prevent that the supporting member  540  made of a resin and the current sensor  400   a  are worn out and fatigued to be broken due to vibrations of the vehicle. Further, end surfaces  511   a  of the plurality of supporting bosses  511  become flush with each other, and form a sensor mounting surface  512 . 
         [0043]    In addition, as illustrated in  FIGS. 10 and 7 , each of the main surfaces of the AC bus bars  503   a  to  503   f  faces the current sensor  400   a  or the current sensor  400   b , and is buried in the resin sealing material  507 . Therefore, even in a case where the sealing material of the mold bus bar  500  is made of a resin material and the supporting member  540  is made of a resin material, the AC bus bars  503   a  to  503   f  can improve the strength of the mold bus bar  500 , and improve the resistance against vibration. 
         [0044]    Further, the supporting member  540  is disposed in a space between the main surface of any one of the AC bus bars  503   a  to  503   f  and the current sensor  400   a  or the current sensor  400   b , so that the resistance against vibrations can be improved still more. 
         [0045]    Further, in this embodiment, the electric components supported by the supporting member of the mold bus bar  500  has been described as the driver boards  300   a  and  300   b  and the current sensors  400   a  and  400   b , and may be a control board to transfer a control signal to the driver boards  300   a  and  300   b , the noise filtering capacitors  201   a    201   b , or a discharge resistor to discharge electric charges remaining in the capacitor module  200 . 
         [0046]    In addition, as illustrated in  FIGS. 10 and 6 , the mold bus bar  500  is provided with a first surface  550  which includes a supporting member  508  to support the driver boards  300   a  and  300   b  and a second surface  560  which includes the supporting member  540  to support the current sensors  400   a  and  400   b . The second surface  560  and the first surface  550  are disposed to form an angle. Specifically, the second surface  560  is disposed to form an angle of 90 degrees with respect to the first surface  550 . Then, in a bent portion connecting the second surface  560  and the first surface  550 , the AC bus bars  503   a  to  503   f  is buried in the resin sealing material  507 . 
         [0047]    Therefore, the bent portion can improve the strength of the mold bus bar  500 , and the resistance against vibrations can be improved. In addition, the mold bus bar  500  is formed along the shape of a flow path forming body (not illustrated) for cooling the power semiconductor modules  100   a  to  100   f , so that a cooling performance of the mold bus bar  500  can be improved. 
       REFERENCE SIGNS LIST 
       [0048]      100   a  to  100   f  . . . power semiconductor module,  101  . . . power terminal,  102   a  . . . signal terminal,  102   b  . . . signal terminal,  104   a  . . . terminal protecting portion,  104   b  . . . terminal protecting portion,  200  . . . capacitor module,  201   a  . . . noise filtering capacitor,  201   b  . . . noise filtering capacitor,  300   a  . . . driver circuit board,  300   b  . . . driver circuit board,  301   a  . . . connecting portion,  301   b  . . . connecting portion,  305   a  . . . circuit mounting surface,  305   b  . . . circuit mounting surface,  400   a  . . . current sensor,  400   b  . . . current sensor,  403  . . . through hole,  500  . . . mold bus bar,  501  . . . negative conductor plate,  501   a  . . . negative power source terminal,  501   a  . . . terminal,  502  . . . positive conductor plate,  502   a  . . . positive power source terminal,  502   b  . . . terminal,  503   a  to  503   f  . . . AC bus bar,  506  . . . ground bus bar,  506   a  . . . ground terminal,  506   b  . . . terminal,  506   c  . . . terminal,  507  . . . resin sealing material,  508  . . . supporting member,  508   a  . . . supporting boss,  508   b  . . . end surface,  509  . . . board mounting surface,  511  . . . supporting boss,  511   a  . . . end surface,  512  . . . sensor mounting surface,  514  . . . first through hole,  515  . . . second through hole,  522  . . . DC terminal,  530  . . . stacking portion,  540  . . . supporting member,  540   a  . . . end surface,  900  . . . main circuit unit