Abstract:
Problem 
     To obtain a drive unit integrated rotating electrical machine that makes it easier to connect power circuits and achieves not only excellent vibration resistance but also excellent heat releasing properties. 
     Means for Solution 
     A drive unit integrated rotating electrical machine has a motor, a drive unit driving the motor under control and provided with power switching elements and conductors passing a current to the power switching elements, and a heat sink cooling the drive unit, which are combined into one unit. The drive unit integrated rotating electrical machine is characterized in that: the power switching elements are molded and formed into mold modules in a state in which terminals thereof are exposed; the conductors are insert-molded in a frame in a state in which terminals thereof are exposed; and the exposed terminals of the mold modules are connected to the exposed terminals of the insert-molded conductors and the mold modules are firmly fixed to the heat sink.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Application No. PCT/JP2011/061652filed May 20, 2011, the contents of all of which are incorporated herein by reference in their entirety. 
     TECHNICAL FIELD 
     The present invention relates to a drive unit integrated rotating electrical machine employed in an electric power steering device or the like. 
     BACKGROUND ART 
     A drive unit integrated rotating electrical machine in the related art employed in an electric power steering device or the like uses a ceramic board as a drive board in a drive unit part (see, for example, PTL 1). Further, drive semiconductor switching elements (for example, MOS-FETs) are mounted by bare chip mounting on the ceramic board, which is the drive board (see, for example, PTL 1 and PTL 2). 
     CITATION LIST 
     Patent Literature 
     PTL 1: JP-A-2010-12819 (page 1 and FIG. 2) 
     SUMMARY OF INVENTION 
     Technical Problem 
     The drive unit integrated rotating electrical machine in the related art described in PTL 1 uses a ceramic board as the drive board and drive semiconductor switching elements are generally mounted on the ceramic board by bare chip mounting. 
     The drive unit integrated rotating electrical machine is formed as follows. That is, the semiconductor switching elements are mounted on a ceramic board and this ceramic board is installed to a heat sink, for example, by soldering. Then, after a frame assembly (assembled body) (hereinafter, referred to as the frame ASSY), which is provided with terminals to feed power to the semiconductor switching elements and a control terminal portion of the semiconductor switching elements, is attached to the heat sink, the semiconductor switching elements are connected to the frame ASSY one by one using, for example, aluminum wires. 
     Hence, there is a problem that productivity is poor. 
     Further, the ceramic board is fixed to the heat sink, for example, by soldering, and cracking occurs in the solder over temperature cycles in use. Hence, there is a problem that thermal resistance between the ceramic substrate and the heat sink becomes larger. 
     Furthermore, there is a problem that the ceramic board comes off from the heat sink because of environmentally-induced vibrations. 
     The present invention solves the problems as above and has an object to obtain a drive unit integrated rotating electrical machine that makes it easier to connect drive semiconductor switching elements and a frame ASSY provided with power feeding terminals and also achieves excellent vibration resistance. 
     Solution to Problem 
     A drive unit integrated rotating electrical machine according to the invention omits a drive board and instead has a rotating electrical machine, a drive unit driving the rotating electrical machine under control and provided with power switching elements and conductors passing a current to the power switching elements, and a heat sink cooling the drive unit, which are combined into one unit. The power switching elements are molded and formed into mold modules with terminals thereof being exposed. The conductors are insert-molded in a frame with terminals thereof being exposed. The exposed terminals of the mold modules are connected to the exposed terminals of the insert-molded conductors and the mold modules are firmly fixed to the heat sink. 
     Advantageous Effects of Invention 
     According to the invention, it becomes possible to obtain a drive unit integrated rotating electrical machine that makes it easier to connect mold modules in which power switching elements are molded with the terminals thereof being exposed and respective terminals of a frame in which conductors passing a current to the power switching elements are insert-molded and also enhances vibration resistance. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross section including a speed reducer and showing a drive unit integrated rotating electrical machine according to a first embodiment of the invention. 
         FIG. 2  is an axial cross section showing the drive unit integrated rotating electrical machine according to the first embodiment of the invention. 
         FIG. 3  is a top view omitting a housing and a control board of a drive unit part and showing the drive unit integrated rotating electrical machine according to the first embodiment of the invention. 
         FIG. 4  is a partial cross section of a heat sink, a mold module, and a frame ASSY on section A-A of  FIG. 3  to show the drive unit integrated rotating electrical machine according to the first embodiment of the invention. 
         FIG. 5  is a partial cross section of a heat sink, a mold module, and a frame ASSY on section A-A of  FIG. 3  to show a drive unit integrated rotating electrical machine according to a second embodiment of the invention. 
         FIG. 6  is a perspective view of a mold module back surface to show the drive unit integrated rotating electrical machine according to the second embodiment of the invention. 
         FIG. 7  is a partial cross section of a heat sink, a mold module, and a frame ASSY on section A-A of  FIG. 3  to show a drive unit integrated rotating electrical machine according to a third embodiment of the invention. 
         FIG. 8  is a side view showing a drive unit integrated rotating electrical machine according to a fourth embodiment of the invention. 
         FIG. 9  is a partial cross section of a heat sink, a mold module, and a frame ASSY on section A-A of  FIG. 3  to show a drive unit integrated rotating electrical machine according to a fifth embodiment of the invention. 
         FIG. 10  is a circuit diagram of the drive unit integrated rotating electrical machine according to the first embodiment of the invention. 
         FIG. 11  is a developed view omitting a housing and a control board of a drive unit part and showing the drive unit integrated rotating electrical machine according to the first embodiment of the invention. 
         FIG. 12  is a perspective view omitting a housing and a control board of a drive unit part and showing the drive unit integrated rotating electrical machine according to the first embodiment of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
     Hereinafter, a first embodiment of the invention will be described using  FIG. 1  to  FIG. 3  and  FIG. 10  to  FIG. 12 .  FIG. 1  is a cross section showing a drive unit integrated rotating electrical machine according to the first embodiment of the invention and a speed reducer.  FIG. 2  is an axial cross section showing the drive unit integrated rotating electrical machine of the invention.  FIG. 3  is a cross section of a drive unit part showing the drive unit integrated rotating electrical machine of the invention.  FIG. 4  is a partial cross section of a heat sink, a mold module, and a frame ASSY on section A-A of  FIG. 3  to show the drive unit integrated rotating electrical machine of the invention. A drive unit  8  uses a mold module for a power switching element FETps, a motor relay FETry, and a power-supply relay RyM in each phase, that is, a phase U, a phase V, and a phase W.  FIG. 4  shows a cross section of the phase V as a representative and omits cross sections of the other phases. It should be appreciated, however, that the other phases are of the same configuration as the phase V. 
     Referring to  FIG. 1  to  FIG. 4 , a rotating electrical machine  2  is a permanent magnet synchronous motor and a three-phase stator winding  5  is wound around a stator core  3  formed of a lamination of magnetic steel sheets via a resin insulator  4 . Wirings of the respective phases are wye- or delta connected by a winding terminal  7  stored in a resin terminal holder  6 . 
     A motor terminal  9  to establish an electrical connection with the drive unit  8  is attached to the winding terminal  7 . 
     The stator core  3  is press-fit in an iron frame  10  and forms a stator  11  of the motor. 
     There is a bottom portion at one end of the frame  10  and a rear bearing box portion  14  in which to store a rear bearing  13  supporting one end of a rotor  12  is formed at a center of the bottom portion. 
     A magnet  16  generating a magnetic field is attached along an outer peripheral portion of a shaft  15  of the rotor  12 . 
     The other end of the frame  10  is open and provided with a mating portion  18  to couple the frame  10  to a housing  17  of the drive unit  8 . 
     The housing  17  is formed of a die cast molded article made of aluminum alloy and joined to a heat sink  19  of the drive unit  8  at one end. 
     The heat sink  19  is formed of a die cast molded article made of aluminum alloy. A front bearing box portion  21  in which to store a front bearing  20  supporting one end of the rotor is formed at a center of the heat sink. 
     The housing  17  and the heat sink  19  together form a drive unit storing portion  22 . 
     An attachment mating portion  24  to attach the heat sink  19  to a speed reducer  23  is provided at the other end of the heat sink  19 . 
     A resolver, which is a rotation sensor  25 , is attached to the heat sink  19  at the center on the front side. 
     A boss  26 , which is a coupling to couple the shaft  15  to the speed reducer  23 , is attached to the shaft  15  at an end on the front side. 
     The drive unit  8  has a control board  29  made of glass epoxy on which a micro-computer  27  and an FET drive circuit  28  are mounted and mold modules (semiconductor packages)  30  molded from resin and on which power elements (semiconductor switching elements), such as power MOSFETs, are mounted. A frame ASSY  40  is provided between the control board  29  and the mold modules  30 . Battery potential copper terminals B (hereinafter, referred to as the terminals B)  41  to supply power to the mold modules  30  and ground potential terminals G (hereinafter, referred to as the terminal G)  42  are insert-molded with resin and formed integrally with the frame ASSY  40 . The frame ASSY  40  is fixed to the heat sink  19  with frame ASSY fixing screws  48 . 
     Each mold module  30  is pressed parallel to and against an mold module attachment surface of the heat sink  19  uniformly across the entire surface as the center portion of the mold module  30  is pressed by an elastic material  46  attached to the frame ASSY  40  and is therefore attached in close contact with an inner wall of the heat sink  19  via resin  35 . Hence, it is configured in such a manner that heat generated in the power elements in the mold modules  30  is transferred to the heat sink  19 . 
     Also, the mold module  30  is provided with a terminal (hereinafter, referred to as the terminal MB)  31  of battery potential in the mold module  30  to feed power to the internal power MOSFET, a terminal (hereinafter, referred to as the terminal MG)  32  of ground potential in the mold module  30 , mold module signal terminals  34  to control the power MOSFET, and a mold module motor terminal  33  to feed power from the mold module  30  to the motor. 
     The mold module signal terminals  34  are connected to the control board  29  and the mold module motor terminal  33  is connected to the motor terminal  9 . 
     After the mold modules  30  are installed to the heat sink  19  using the frame ASSY  40 , the terminals MB  31  and the terminals MG  32  are joined, respectively, to the terminals B  41  and the terminals G  42  of the frame ASSY  40 , respectively, by welds  71  and  72 . 
     The heat sink  19  stores therein a capacitor  45  absorbing ripples of a current flown to the rotating electrical machine  2  and is connected to the mold modules  30  via the terminals B  41  and the terminals G  42  of the frame ASSY  40 . The heat sink  19  also stores an unillustrated coil absorbing noises and is connected to a connector portion  50  via the terminals B  41  of the frame ASSY  40 . 
     The housing  17  is provided with a housing radially protruding portion  51 . A housing axially opening portion  52 , which is a connector attachment portion, is provided at an axial end of the housing radially protruding portion  51 . The connector portion  50  is attached to the housing axially opening portion  52  and the connector portion  50  is provided with a power-supply connector  53  and a signal connector  54 . 
     The heat sink  19  is provided with a heat sink radially protruding portion  55  at an opposing position to the housing radially protruding portion  51  and with a heat sink opening portion  60  at an axial end of the heat sink radially protruding portion  55 . 
     Power-supply terminals  43  and signal terminals  44  extending from the frame ASSY  40  protrude axially from the heat sink opening portion  60 . 
     The power-supply terminals  43  and the signal terminals  44  are connected to the respective corresponding terminals, that is, the power-supply connector terminal  53  and the signal connector terminal  54  extending from the connector portion  50  to the housing axially opening portion  52 , by welding or the like at positions at which the power-supply terminals  43  and the signal terminals  44  protrude axially from the heat sink opening portion  60 . 
     A cover  65  is provided to the heat sink opening portion  60 . The cover  65  covers a connector connection portion  66  including connection portions between the power-supply terminals  43  and the power-supply connector terminals  63  and connection portions between the signal terminals  44  and signal connector terminals  64 . Airtight and waterproof sealing by seal resin is applied to a contact surface of the cover  65  and the heat sink  19  when a need arises. 
     In  FIG. 10 , alpha-numeral  8 CB denotes a power-supply connector portion which connects the drive circuit  8  and a battery B and is provided to the drive circuit  8 . 
     In the drive-unit integrated rotating electrical machine configured in this manner, the mold modules  30  are pressed at the center portions of the mold modules  33  by the elastic materials  46  attached to the frame ASSY  40 , so that the terminals MB  31  and the terminals MG  32  are joined, respectively, to the terminals B  41  and the terminals G  42  of the frame ASSY  40 , respectively, by the welds  71  and  72  in a state in which the mold modules  30  are pressed uniformly, parallel to and against the attachment surface of heat sink. Further, because the mold modules  30  are firmly fixed to the heat sink  19  with the resin  35 , heat generated in the mold modules  30  can be transferred to the heat sink  19  homogeneously and more excellent vibration resistance can be achieved. Furthermore, because connection by welding is easier than by wire bonding in the related art, excellent productivity can be achieved. 
     In addition, the drive unit integrated rotating electrical machine includes the drive unit  8  formed of the heat sink  19  on which the power circuits are mounted and the housing  17  containing internal components, and the rotating electrical machine  2  formed of the stator  11  and the rotor  12 , which are combined into one unit sequentially from the attachment side of the speed reducer  23  substantially coaxially with the rotation shaft of the rotor  12 . Hereinafter, a rotating electrical machine configured in this manner is referred to as the drive unit integrated rotating electrical machine. According to this configuration, the mold modules  30  receive vibrations from the rotating electrical machine in the coaxial integral structure. However, the mold modules  30  are pressed against the heat sink  19  by the frame ASSY  40 , and the heat sink  19  is attached to the speed reducer  23 , which is a fixed point. Hence, the mold modules  30  are advantageous in vibration resistance. In addition, because the heat sink  19  on which are mounted the mold modules  30  is attached to the speed reducer  23 , heat generated in the mold modules  30  is readily transferred to the speed reducer  23 . Hence, excellent heat releasing properties can be achieved. 
     Second Embodiment 
     A second embodiment of the invention will now be described using  FIG. 5 .  FIG. 5  is a partial cross section of the heat sink  19 , the mold module  30 , and the frame ASSY  40  on the section A-A of  FIG. 3  to show a drive unit coaxially integrated rotating electrical machine according to the second embodiment of the invention. The drive unit  8  uses a mold module for a power switching element FETps, a motor relay FETry, and a power-supply relay RyM in each phase, that is, a phase U, a phase V, and a phase W.  FIG. 5  shows a cross section of the phase V as a representative and omits cross sections of the other phases. It should be appreciated, however, that the other phases are of the same configuration as the phase V.  FIG. 6  is a perspective view of the mold module  30  of  FIG. 5  showing a surface mounted onto the heat sink  19 . In comparison with the counterpart of the first embodiment above, the drive unit coaxially integrated rotating electrical machine of the second embodiment is different in the configuration of a part described in the following. 
     Mold module back surface protruding portions  36  are provided to the attachment surface to the heat sink  19  of each mold module  30  mounted on the top surface of the heat sink  19 . The terminal MB  31 , the terminal MG  32 , and the mold module motor terminal  33  of the mold module are exposed to the attachment surface to the heat sink  19  of the mold module  30 . 
     Also, frame ASSY protruding portions  47  of substantially a spherical shape are provided to the frame ASSY  40 . The frame ASSY  40  is attached to the heat sink  19  in a state in which the frame ASSY protruding portions  47  are in contact with the mold modules  30 . 
     In a state in which the frame ASSY protruding portions  47  of the frame ASSY  40  are in contact with the mold modules  30 , the frame ASSY  40  and the heat sink  19  have a clearance in between. When the frame ASSY  40  is fixed to the heat sink  19  with the frame ASSY fixing screws  48 , the frame ASSY  40  undergoes deflection and the frame ASSY  40  and the heat sink  19  come into contact with each other. In this instance, the mold modules  30  are pressed against the heat sink  19  by the frame ASSY protruding portions  47  of the frame ASSY  40 . 
     Resin  35  is present between the mold modules  30  and the heat sink  19  so as to transfer heat of the mold modules  30  to the heat sink  19 . The resin  35  is hardening resin. 
     Also, an insulating layer is provided to the heat sink  19  on the surface on which the mold modules  30  are mounted. 
     Also, the resin  35  is applied in an amount large enough to overflow to the outer peripheral portion of the mold module  30  from the surface abutted on the heat sink  19 . 
     In the drive unit coaxially integrated rotating electrical machine configured in this manner, the mold modules  30  are fixed to the heat sink  19  with the resin  35  by providing the mold module back surface protruding portions  36  so as to produce a clearance of a uniform thickness between the mold modules  30  and the heat sink  19 . It thus becomes possible to release heat generated in a plurality of switching elements in each mold module  30  to the heat sink  19  homogeneously. 
     In a case where the clearance has a non-uniform thickness, heat is released inhomogeneously from a plurality of the switching elements in the mold module  30  and temperatures of the switching elements become equal. In order to prevent overheating of the mold module  30 , heat generation of the switching elements is lowered by suppressing a current flowing through the switching elements when any one of the switching elements reaches a maximum temperature so as to protect the switching element reaching the maximum temperature from breaking. Hence, a current is suppressed even when the other switching elements have a margin of temperature from the maximum temperature. 
     When the clearance is made uniform, variances in temperature among the respective switching elements can be lessened by making thermal resistances from the respective switching elements to the heat sink  19  equal. It thus becomes possible to enhance an output and extend an operating time of the drive unit coaxially integrated rotating electrical machine. 
     Further, because temperatures of the respective switching elements can be equal, it becomes possible to enhance reliability of the switching elements. 
     Further, the attachment surface to the heat sink  19  of the mold module  30  is provided with the protrusions of a uniform height made of resin from which the mold module is molded. Hence, a clearance can be secured between the mold module and the heat sink. Also, because it is no longer necessary to control the clearance to be uniform at the end of the facility, the machinability can be enhanced. 
     Also, the mold modules  30  are attached to the heat sink  19  as substantially the center portions of the mold modules  30  are pressed by point contact using the protrusions of substantially a spherical shape provided to the frame ASSY  40 . It thus becomes possible to press the mold modules  30  against the heat sink  19  via the protrusions of the mold modules  30  in such a manner that a clearance between the heat sink  19  and the mold modules  30  becomes uniform while preventing the mold modules  30  from tilting with respect to the attachment surface of the heat sink  19 . In comparison with a case where the elastic members are provided between the mold modules  30  and the frame ASSY  40 , the elastic members can be omitted and the machinability can be enhanced. In addition, because the mold modules  30  are pressed by the frame ASSY  40 , vibration resistance can be enhanced further. 
     The respective electrodes of the terminal MB  31 , the terminal MG  32 , and the mold module motor terminal  33  of the mold module  30  are exposed to the heat sink attachment surface of the mold module  30  and are therefore in direct contact with the resin  35 . It thus becomes possible to lower thermal resistances between the respective switching elements and the heat sink  19 . This capability is advantageous in heat releasing properties. 
     Also, the resin  35  between the mold modules  30  and the heat sink  19  is hardening resin herein. In a case where conductive foreign matter is mixed with the resin, a product becomes defective when a short circuit occurs between the electrode from which the foreign matter is exposed and the heat sink  19 . However, by checking the occurrence of a short circuit after the resin is hardened, defective products can be removed during the fabrication process. Also, because an adhesive is hardened and the foreign matter is fixed therein, should the foreign matter be mixed with the resin, a short circuit does not occur once the products are determined as being non-defective products by a check after the resin is hardened. Hence, reliability can be enhanced. 
     In addition, because the mold modules  30  are fixed to the heat sink  19  more firmly by the hardening of the resin, vibration resistance can be enhanced, too. 
     Further, the insulating layer (for example, alumite) is provided to the heat sink  19  on the surface on which the mold modules  30  are mounted. Owing to this configuration, should the mixing of air bubbles give rise to a void in a layer of the resin  35  between the mold modules  30  and the heat sink  19 , the presence of the insulating layer can ensure electrical insulation between the mold modules  30  and the heat sink  19 . Hence, reliability can be enhanced further. 
     Further, the resin  35  is applied in an amount large enough to overflow from the outer periphery of the attachment surface to the heat sink  19  of the mold module  30 . Accordingly, the resin  35  can be applied to the entire attachment surface to the heat sink  19  of the mold module  30  in a reliable manner. In addition, because the resin  35  overflows from the outer peripheral portion of the mold module  30 , it becomes possible to confirm that the resin is applied to the entire surface in a reliable manner. The products can be therefore manufactured in a stable manner. 
     Third Embodiment 
     A third embodiment of the invention will now be described using  FIG. 7 .  FIG. 7  is a partial cross section of the heat sink, the mold module, and the frame ASSY on the section A-A of  FIG. 3  and shows a drive unit coaxially integrated rotating electrical machine according to the third embodiment of the invention. The drive unit  8  uses a mold module for a power switching element FETps, a motor relay FETry, and a power supply relay RyM in each phase, that is, a phase U, a phase V, and a phase W.  FIG. 7  shows a cross section of the phase V as a representative and omits cross sections of the other phases. It should be appreciated, however, that the other phases are of the same configuration as the phase V. In comparison with the counterparts of the first and second embodiments above, the drive unit coaxially integrated rotating electrical machine of the third embodiment is different in the configuration of a part described in the following. 
     In the third embodiment, mold module back surface protruding portions like those in the second embodiment above are not provided to the attachment surface to the heat sink  19  of the mold module  30  and the resin  35  between the mold module  30  and the heat sink  19  include fillers  37  therein. 
     The fillers  37  are furnished with a function of enhancing heat transfer. In addition, owing to the fillers  37 , the clearance between the mold modules  30  and the heat sink  19  can be provided as a uniform clearance according to sizes of the fillers  37 . 
     The fillers  37  include the ones of a small size and the ones of a large size and the fillers of the maximum size are distributed homogeneously within in the resin  35 . The clearance can be provided substantially uniformly by the fillers  37 . It thus becomes possible to release heat generated in a plurality of the switching elements in the mold module  30  to the heat sink  19  homogeneously. 
     Also, variances in temperature among the respective switching elements can be lessened by making thermal resistances from the respective switching elements to the heat sink  19  equal. It thus becomes possible to enhance an output and extend an operating time of the drive unit coaxially integrated rotating electrical machine. 
     The other advantages are the same as those of the second embodiment above. 
     Fourth Embodiment 
     A fourth embodiment of the invention will now be described using  FIG. 8 .  FIG. 8  is a side view showing a drive unit coaxially integrated rotating electrical machine according to the fourth embodiment of the invention. In comparison with the counterparts of the first to third embodiments above, the drive unit coaxially integrated rotating electrical machine of the fourth embodiment is different in configuration in a part described in the following. 
     In the fourth embodiment, the drive unit coaxially integrated rotating electrical machine is formed to have a coaxial integral structure having a motor part and a drive unit part combined sequentially in this order from the side of the speed reducer  23 . 
     In the drive unit coaxially integrated rotating electrical machine configured in this manner, the mold modules  30  are attached at positions farther from the attachment portion of the speed reducer  23  in the coaxial integral structure. This configuration is disadvantageous in terms of vibrations. However, the mold modules  30  are attached to the heat sink  19  with resin and, moreover, pressed by the frame ASSY  40 . Hence, excellent vibration resistance can be achieved. 
     Fifth Embodiment 
     A fifth embodiment of the invention will now be described using  FIG. 9 .  FIG. 9  is a partial cross section of the heat sink, the mold module, and the frame ASSY on the section A-A of  FIG. 3  and shows a drive unit coaxially integrated rotating electrical machine according to the fifth embodiment of the invention. The drive unit  8  uses a mold module for a power switching element FETps, a motor relay FETry, and a power supply relay RyM in each phase, that is, a phase U, a phase V, and a phase W.  FIG. 9  shows a cross section of the phase V as a representative and omits cross sections of the other phases. It should be appreciated, however, that the other phases are of the same configuration as the phase V. In comparison with the counterparts of the first to third embodiments above, the drive unit coaxially integrated rotating electrical machine of the fifth embodiment is different in the configuration of a part described in the following. 
     In the fifth embodiment, mold module back surface protruding portions like those in the second embodiment above are not provided to the attachment surface to the heat sink  19  of the mold module  30  and an insulating plate  38  (for example, a ceramic plate) of a uniform thickness is provided between the mold modules  30  and the heat sink  19 . 
     The terminal MB  31 , the terminal MG  32 , and the mold module motor terminal  33  of the mold module  30  are exposed to the attachment surface to the heat sink  19  of the mold module  30 . 
     Heat conductive grease  39  is interposed between the mold module  30  and the insulating plate  38  and between the insulating plate  38  and the heat sink  19 . 
     Owing to the insulating plate  38  of a uniform thickness, heat generated in a plurality of switching elements in the mold module  30  can be released homogeneously to the heat sink  19 . 
     Also, variances in temperature among the respective switching elements can be lessened by making thermal resistances from the respective switching elements, which are power elements, such as FETs, to the heat sink  19  equal. It thus becomes possible to enhance an output and extend an operating time of the drive unit coaxially integrated rotating electrical machine. 
     Further, because the mold modules  30  and the heat sink  19  can be electrically isolated in a reliable manner by the insulating plate  38 , insulation properties can be enhanced. 
     The above has described that the heat conductive grease  39  is provided to the both surfaces of the insulating plate. It should be appreciated, however, that resin is used instead. 
     The mold modules of the first to fifth embodiments have been described as the mold modules  30 , each of which includes the power switching element FETps and the motor relay FETry to feed power to the motor in the form of a mold module. It should be appreciated, however, that the the mold modules are not limited to the mold modules  30 . Advantages same as those described above can be obtained even in a case where the mold module is a mold module which includes the power-supply relay RyM that interrupts power feeding to the mold module at the occurrence of a failure or during a non-operating time in the form of a mold module. 
     The first to fifth embodiments above have described a coaxially integrated rotating electrical machine. However, the same can be said in a case where the drive unit is provided separately or attached to the side surface of the rotating electrical machine. 
     According to the first to fifth embodiments above, a plurality of mold modules are used in the coaxially integrated rotating electrical machine. In a case where the mold modules are arranged concentrically with the motor rotation shaft, the respective mold modules can be pressed more uniformly by the frame ASSY. Hence, this configuration is more advantageous in terms of vibration resistance. 
     In  FIG. 1  to  FIG. 6 , the same reference numerals denote the same or equivalent portions. 
     As can be obvious from the description above and the drawings described above,  FIG. 1  to  FIG. 12  and the first to fifth embodiments have technical characteristics as follows. 
     Characteristic 1 
     A drive unit integrated rotating electrical machine includes a motor and a drive unit driving the motor under control and having a case structure formed of a metal heat sink and a housing, which are combined into one unit. The drive unit integrated rotating electrical machine is characterized as follows. That is, the drive unit of the drive unit integrated rotating electrical machine has power circuit components, and the power circuit components are a plurality of power switching elements FETps forming abridge circuit and motor relay switching elements FETry performing ON and OFF control of motor currents supplied to the motor from the respective power switching elements. The power circuit components are mounted on terminals, which are conductive members. The power circuit components and the terminals are molded into one unit with mold resin. The resulting mold modules have the terminals partially exposed to the outside of the mold resin for the purpose of connection. The mold modules are disposed between a frame ASSY in which power-supply terminals are insert-molded and the heat sink. In the drive unit configured in this manner, the mold modules are connected and coupled to the connection terminals of the frame ASSY and disposed on the heat sink. 
     Characteristic 2 
     The drive unit integrated rotating electrical machine described in Characteristic 1 is characterized in that the mold modules are firmly fixed to the heat sink with resin. 
     Characteristic 3 
     The drive unit integrated rotating electrical machine described in Characteristic 2 is characterized in that the mold modules and the heat sink have a clearance in between. 
     Characteristic 4 
     The drive unit integrated rotating electrical machine described in Characteristic 3 is characterized in that the mold modules are pressed by the frame. 
     Characteristic 5 
     The drive unit integrated rotating electrical machine described in Characteristic 4 is characterized in that protruding portions are provided by molding to heat sink attachment surfaces of the mold modules. 
     Characteristic 6 
     The drive unit integrated rotating electrical machine described in Characteristic 4 is characterized in that the resin includes fillers therein. 
     Characteristic 7 
     The drive unit integrated rotating electrical machine described in any one of Characteristics 4 to 6 is characterized in that elastic members are provided between the mold modules and the frame ASSY. 
     Characteristic 8 
     The drive unit integrated rotating electrical machine described in any one of Characteristics 4 to 6 is characterized in that protruding portions are provided to mold module pressing portions of the frame ASSY. 
     Characteristic 9 
     The drive unit integrated rotating electrical machine described in any one of Characteristics 3 to 8 is characterized in that electrodes are exposed on a side of a heat sink attachment surfaces of the mold modules. 
     Characteristic 10 
     The drive unit integrated rotating electrical machine described in Characteristic 9 is characterized in that the resin is hardening resin. 
     Characteristic 11 
     The drive unit integrated rotating electrical machine described in Characteristic 9 is characterized in that an insulating layer is provided to a mold module attachment surface of the heat sink. 
     Characteristic 12 
     The drive unit integrated rotating electrical machine described in Characteristic 1 is characterized in that an insulating plate is provided between the mold modules and the heat sink. 
     Characteristic 13 
     The drive unit integrated rotating electrical machine described in any one of Characteristics 2 to 4, 9, and 10 is characterized in that the resin is applied in an amount large enough to overflow from outer peripheries of the mold modules. 
     Characteristic 14 
     The drive unit integrated rotating electrical machine described in any one of Characteristics 1 to 13 is characterized in that a motor part and a drive unit part are combined sequentially from a speed reducer attachment side so as to form a coaxial integral structure. 
     Characteristic 15 
     The drive unit integrated rotating electrical machine described in any one of Characteristics 1 to 13 is characterized in that a drive unit part and a motor part are combined sequentially from a speed reducer attachment side so as to form a coaxial integral structure.