JP2009060746A - Connector unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connector unit capable of reducing size, improving and realizing electric and thermal connection liability. <P>SOLUTION: This is the connector unit 5 which can be connected to an electric rotating machine, and includes a terminal for a DC power supply extending outward, a terminal for a three-phase AC power source extending toward an internal area of a housing of the electric rotating machine, and a power conversion part 10 which converts DC-three phase AC. A power conversion part provided in the connector unit has a thermal stress relaxing conductive member having a thermal expansion coefficient which is a middle value of a thermal expansion ratio of a semiconductor tip and the thermal expansion ratio of a wiring member between the semiconductor tip and the wiring member. Besides, the power converting part 10 provided in the connector unit has a thermal stress relaxing heat transfer member having a thermal expansion coefficient which is the middle value of the thermal expansion coefficient of the wiring member and the heat sink thermal expansion coefficient between the wiring member and a heat sink 21. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a connector unit that connects a rotating electrical machine for a vehicle and a cable that supplies electric power.

Background Electric vehicles and hybrid electric vehicles (HEVs) are attracting attention against the background of soaring fossil fuels and regulations on CO ₂ emissions to prevent global warming. First, a motor and a power converter used for HEV driving will be described. FIG. 20 is a block circuit diagram showing an example of a conventional HEV electrical system. As shown in the figure, an engine 501, an engine radiator 502, a vehicle driving motor 503, and a power source for generating a three-phase AC power source for driving the motor 503 are included in a conventional HEV vehicle body 500. A generation unit 510 is provided. The power generation unit 510 includes an inverter 505 that supplies three-phase AC power for driving the motor 503, a battery 506 that supplies DC power to the inverter 505, and a converter 507 that converts the voltage of the DC power. Are arranged.

In the power generation unit 510 illustrated in FIG. 20, the power stored in the battery 506 is converted into a desired voltage by the converter 507, and DC power is supplied to the inverter 505. The inverter 505 is configured by a part of a power conversion unit incorporating a power device such as an IGBT, and the inverter 505 generates a three-phase AC power source from the DC power source. As described above, the three-phase AC power generated by the power generator 510 is connected to the motor 508 by the connector 511 via the three-phase AC power line 508 and sent. Then, the motor 503 is rotated by the three-phase AC power source, and the engine 501 is driven. Converter 507, inverter 505, and battery 506 are housed in individual cases and are electrically connected by external wiring. For example, Patent Document 1 discloses a structure in which a power control unit and a motor are separated from each other. In the structure of this document, the battery 506 is disposed independently of the power generation unit 510.
As described above, electric wiring is often used in an automobile equipped with a motor. The electrical wiring is usually made by a wire harness called assembly wiring, but the specific gravity of copper used as a raw material is high, and this manufacturing cost tends to increase, and it is required to reduce this.

As another example of the arrangement structure of the power conversion unit, an inverter-integrated electric compressor of a refrigeration cycle apparatus for a vehicle air conditioner integrated with a motor for the purpose of downsizing the apparatus is disclosed (Patent Document 2). A power conversion unit including a control circuit and an inverter circuit is stored in a storage box, and the entire storage box is externally attached to the motor housing. The resin-molded power semiconductor device is directly fixed to the pedestal surface on the outer periphery of the motor housing via an insulating sheet. Low-pressure refrigerant gas discharged from the evaporator is introduced into the storage box, and the interior of the storage box including the power conversion unit is cooled. Further, a DC power source is sent from the battery via a DC power source line, and is connected to a terminal of the power conversion unit by a connector. As a result, an inverter-integrated motor for a vehicle that can be reduced in size can be obtained.
JP 2006-74331 A JP 2003-324903 A

However, in the system integrated with the electric motor including the control unit (Patent Document 2), the entire electric motor integrated with the control unit and the power conversion unit exceeds a predetermined size, which hinders mounting on a vehicle or the like. However, there are many cases where the space utilization efficiency is lowered.
Furthermore, as the capacity of the power conversion unit increases, the size is reduced, and the processing speed increases, the amount of heat generated from the semiconductor device also increases, resulting in differences in the thermal expansion coefficient of each member of the heat dissipation path. The problem of generating large thermal stress is becoming serious. The thermal stress causes warping and peeling in the heat dissipation path, and interrupts the heat dissipation path.
As described above, even if the power conversion unit can be integrated with the electric motor and downsized, if the thermal stress cannot be reduced, the electrical and thermal connection reliability in the power conversion unit is lowered, and the electric capacity is small. It can only be used in the system.
Therefore, it is important to reduce the mounting stress on the vehicle and the thermal stress while suppressing the manufacturing cost of the motor-equipped automobile including the wiring cost described above.

  An object of this invention is to provide the connector unit provided with the power converter part which can implement | achieve size reduction and the improvement of electrical and thermal connection reliability, restraining manufacturing cost.

  The connector unit of the present invention includes a DC power supply terminal, a three-phase AC power supply terminal, and a power conversion unit for performing power conversion between DC power and AC power, and a connector connectable to a housing of a rotating electrical machine The power conversion unit includes a semiconductor chip and a wiring member connected to the semiconductor chip via a thermal stress relaxation conductive member, and the thermal expansion coefficient of the thermal stress relaxation conductive member is the semiconductor A thermal stress relaxation conductive member having an intermediate value between the thermal expansion coefficient of the chip and the thermal expansion coefficient of the wiring member is provided.

  Since a thermal stress relaxation conductive member having a thermal expansion coefficient that is intermediate between the thermal expansion coefficient of the semiconductor chip and the thermal expansion coefficient of the wiring member is interposed in the power conversion unit, the thermal expansion difference between the semiconductor chip and the wiring member , The thermal stress due to this difference in thermal expansion is relaxed, and warping and peeling can be prevented. In particular, since the power converter is built into the connector unit, it tends to become hotter due to the thermal effects of the motor and engine. A highly reliable connector unit can be provided. Here, the rotating electric machine means both a motor and a generator.

  A material that mainly constitutes the semiconductor chip (referred to as a material dominant in the thermal expansion coefficient among the constituent materials) is a first material, and a material that mainly constitutes the wiring member (a thermal expansion coefficient among the constituent materials) The material mainly constituting the thermal stress relaxation conductive member is preferably the first material or the second material. This makes it easy to bring the thermal expansion coefficient of the thermal stress relaxation conductive member closer to an intermediate value between the thermal expansion coefficient of the semiconductor chip and the thermal expansion coefficient of the wiring member. In addition, the semiconductor chip and the wiring member may contain other materials in addition to the main constituent material (referred to as a material dominant to the thermal expansion coefficient). The dominant material here refers to a material having the greatest influence in determining the thermal expansion coefficient of the material itself.

  In this case, the content of the material mainly constituting the thermal stress relaxation conductive member is preferably 30 to 80% by volume of the entire thermal stress relaxation conductive member. Thereby, a thermal expansion coefficient can be adjusted in the range which does not impair the electroconductivity of a thermal-stress relaxation electrically-conductive member.

  The thermal stress relaxation conductive member has a different thermal expansion coefficient between a first region that faces the semiconductor chip and a second region that faces the wiring member, and the thermal expansion coefficient of the first region is Since the expansion and contraction due to the thermal expansion is alleviated by being an intermediate value between the thermal expansion coefficient of the semiconductor chip and the thermal expansion coefficient of the second region, the heat caused by the difference in thermal expansion between the semiconductor chip and the wiring member Stress can be relaxed. That is, the thermal stress can be further relaxed by inclining the thermal expansion coefficient difference in the thickness direction in the thermal stress relaxation conductive member (which may be stepwise, linear, curvilinear, or the like).

The material other than the material mainly constituting the thermal stress relaxation conductive member is made of Si, Al ₂ O ₃ , SiC, Si ₃ N ₄ , SiO ₂ , AlN, W, Mo, or Fe ₃₂ Ni ₅ Co (Invar alloy). It is preferable that it is composed of at least one material selected from the group consisting of: This is because the thermal expansion coefficient can be adjusted to a value between the thermal expansion coefficients of the semiconductor chip and the wiring member while having conductivity. Thereby, the thermal stress resulting from the difference in thermal expansion coefficient between the semiconductor chip and the wiring member can be further relaxed, and the bonding reliability can be improved.

  Since the thermal stress relaxation conductive member is composed of the first material and the second material, it becomes easy to control the thermal expansion coefficient, and heat caused by the difference in thermal expansion coefficient between the semiconductor chip and the wiring member. The stress can be further relaxed, and the bonding reliability can be improved.

  The thermal stress relaxation conductive member has different thermal expansion coefficients in the first region and the second region, and the thermal expansion coefficient of the first region is the thermal expansion coefficient of the semiconductor chip and the thermal expansion of the second region. The intermediate value of the coefficient makes it possible to further alleviate the thermal stress caused by the difference in the thermal expansion coefficient between the semiconductor chip and the wiring member, so that the reliability of the joint becomes higher.

  Since the thermal stress relaxation conductive member is formed by a thermal spraying method, even if it is difficult to form a composite material, the thermal stress relaxation conductive member can be easily combined by a relatively low temperature treatment. Realize. Moreover, since it forms at low temperature, the thermal stress between the members of the power conversion part formed is reduced. Therefore, a connector unit having a power conversion unit with high bonding reliability by reducing thermal stress can be obtained.

  Furthermore, by providing a heat sink connected to the wiring member via an insulating resin layer, the structure of the power conversion unit is simplified, and a connector unit having a power conversion unit with greatly reduced component costs is provided. it can. The heat sink may also serve as all or part of the case of the connector unit.

  The connector unit of the present invention includes a DC power supply terminal, a three-phase AC power supply terminal, and a power conversion unit for performing power conversion between DC power and AC power, and can be connected to a housing of a rotating electrical machine. The power conversion unit includes a semiconductor chip, a wiring member connected to the semiconductor chip, and a heat sink connected to the wiring member via a thermal stress relaxation heat transfer member, The thermal expansion coefficient of the thermal stress relaxation heat transfer member is provided with a thermal stress relaxation heat transfer member that is an intermediate value between the thermal expansion coefficient of the wiring member and the thermal expansion coefficient of the heat sink.

  A thermal stress relaxation conductive member having a thermal expansion coefficient that is intermediate between the thermal expansion coefficient of the wiring member and the thermal expansion coefficient of the wiring member is interposed in the power conversion unit, so that the thermal expansion difference between the wiring member and the heat sink is small. Thus, the thermal stress resulting from this difference in thermal expansion is relaxed, and warping and peeling can be prevented. In particular, since the power converter is built into the connector unit, it tends to become hotter due to the thermal effects of the motor and engine. A highly reliable connector unit can be provided.

  The material mainly constituting the wiring member (referred to as a material dominant in the thermal expansion coefficient among the constituent materials) is the third material, and the material mainly constituting the heat sink (in the thermal expansion coefficient among the constituent materials). When the fourth material is a dominant material), the material mainly constituting the thermal stress relaxation heat transfer member is preferably the third material or the fourth material. Thereby, it becomes easy to control the thermal expansion coefficient of the thermal stress relaxation heat transfer member to an intermediate value between the thermal expansion coefficient of the wiring member and the thermal expansion coefficient of the heat sink. In addition, the wiring member and the heat sink may contain other materials in addition to the main constituent material (referred to as a material dominant to the thermal expansion coefficient). The dominant material here refers to a material having the greatest influence in determining the thermal expansion coefficient of the material itself.

  Within the thermal stress relaxation heat transfer member, the first region which is the side facing the wiring member and the second region which is the side facing the heat sink have different thermal expansion coefficients, and the thermal expansion coefficient of the first region Is an intermediate value between the thermal expansion coefficient of the wiring member and the thermal expansion coefficient of the second region, so that expansion and contraction due to thermal expansion is alleviated, so that heat caused by the thermal expansion difference between the wiring member and the heat sink is reduced. Stress can be relaxed. That is, the thermal stress can be further relaxed by inclining the thermal expansion coefficient difference in the thickness direction in the thermal stress relaxation conductive member (which may be stepwise, linear, or curvilinear).

  Since the thermal stress relaxation heat transfer member is composed of the third material and the fourth material, it is easy to control the thermal expansion coefficient, which results from the difference in thermal expansion coefficient between the wiring member and the heat sink. Thermal stress can be further reduced, and bonding reliability can be increased.

  In the thermal stress relaxation heat transfer member, the first region and the second region have different thermal expansion coefficients, and the thermal expansion coefficient of the first region is the thermal expansion coefficient of the wiring member and the heat of the second region. By being an intermediate value of the expansion coefficient, it becomes possible to further relax the thermal stress caused by the difference in thermal expansion coefficient between the wiring member and the heat sink, so that the reliability of the joint becomes higher.

  The wiring member is preferably made of Cu or a Cu alloy, and the heat sink is preferably made of Al or an Al alloy. Thereby, the thermal stress resulting from the thermal expansion coefficient difference of a wiring member and a heat sink can be reduced more, and joining reliability can be improved.

  Since the thermal stress relaxation heat transfer member is formed by a thermal spraying method, even if it is difficult to form a composite material, the thermal stress relaxation heat transfer member is easily combined by relatively low temperature processing. The member is realized. Moreover, since it forms at low temperature, the thermal stress between the members of the power conversion part formed is reduced. Therefore, a connector unit having a power conversion unit with high bonding reliability by reducing thermal stress can be obtained.

  Further, by further including an insulating resin layer between the wiring member and the thermal stress relaxation heat transfer member, the connector having the power conversion unit in which the structure of the power conversion unit is simplified and the component cost is greatly reduced. Units can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the connector unit which can implement | achieve both size reduction and an improvement of electrical and thermal connection reliability can be provided by integrating a power converter and a connector.

(Embodiment 1)
-Electrical system configuration-
1 is a block diagram schematically showing a configuration of an electric system inside a vehicle body of a hybrid vehicle according to Embodiment 1. FIG. In the figure, members mainly related to the present invention are displayed. As shown in the figure, in a vehicle body 9 of a hybrid vehicle, an engine 1, an engine radiator 2, a motor 3 attached to the engine, and an inverter that generates a three-phase AC power source for driving the motor 3 , A battery 6 for supplying DC power to an inverter in the connector unit 5, and a converter 7 for converting the voltage of the DC power supply are arranged. Here, in the present embodiment, the connector unit 5 incorporating the inverter is coupled to the motor housing of the motor 3, and the connector unit 5 and the converter 7 are connected by the DC power supply wiring 8. Yes.

  In the present embodiment, electric power stored in the battery 6 is converted into a desired voltage by the converter 7, and DC power is supplied to the inverter in the connector unit 5. As will be described later, a power conversion unit incorporating a power device such as an IGBT is arranged in the inverter, and a three-phase AC power source is generated from the DC power source in the power conversion unit. Then, the motor 3 is rotated by the three-phase AC power source to drive the vehicle.

  In the present embodiment, the battery 6 and the converter 7 are arranged in the trunk, and the connector unit 5 is arranged in the engine room. Therefore, the connector unit 5 is connected from the converter 7 via a pair of DC power supply wires 8. DC power is supplied to the inverter inside. Therefore, integrating the power converter with the connector unit eliminates the need for long three-phase AC power supply wiring, reduces the amount of thick wiring used to supply large power, and reduces component costs. it can.

  FIG. 2 is an electric circuit diagram showing a circuit configuration from the battery 6 to the motor 3. In the figure, illustration of members such as a converter and a capacitor is omitted. As will be described later, the connector unit 5 is provided with a socket 28 to which the DC power supply wiring 8 is connected. The connector unit 5 has DC power supply wiring members 23 a and 23 b extending from the socket 28. DC power is supplied.

  Although not shown in FIG. 1, the motor control unit 80 shown in FIG. 2 is arranged in the body 9 of the hybrid vehicle, and a control signal wiring 81 extends from the motor control unit 80. . On the other hand, the connector unit 5 is provided with a socket 29 to which a control signal wiring 81 is connected, and a control signal is supplied into the connector unit 5 through a control signal wiring 83 extending from the socket 29. .

  As shown in FIG. 2, in the connector unit 5, a power conversion unit 10 including a total of six switching circuits including IGBTs and diodes arranged in parallel is arranged. In the connector unit 5, a device driving circuit 16 for controlling the operation of each switching circuit in the connector unit is disposed. The device drive circuit 16 receives an input signal from the control signal wiring 83 extending from the socket 29, and outputs a control signal to each switching circuit via the control signal wiring 17.

  In the connector unit, each switching circuit is supplied with DC power via DC power supply wiring members 23a and 23b, and the switching circuit is driven in accordance with a control signal from the device driving circuit 16 to provide three-phase (U-phase). , V phase, W phase) power signal is generated, and this power signal is output to the motor 3 from the three-phase AC power supply wiring members 23u, 23v, 23w.

  The motor 3 is driven by three-phase (U-phase, V-phase, W-phase) AC, and the stator of the motor 3 is provided with bus bars 63u, 63v, 63w connected to the coil 3a. . Each bus bar 63u, 63v, 63w is connected to the three-phase AC power supply wirings 23u, 23v, 23w of the connector unit 5, respectively, and the motor 3 according to the three-phase AC power input to the bus bars 63u, 63v, 63w. The inner rotor rotates, and thereby the motor 3 is driven.

-Connector unit and motor housing connection structure-
FIG. 3 is a perspective view showing a part of the motor 3 in a broken state. FIG. 4 is a cross-sectional view of a part of the motor and the connector unit. However, the rotor is not shown in FIG. As shown in FIGS. 3 and 4, the motor housing body 60 is provided with a stator 61 and a rotor 65 that is rotationally driven in accordance with a current flowing through the coil of the stator 61. The stator 61 includes a core portion 62 formed by assembling a split core around which a coil is wound in a ring shape, and a ring portion 64 for fastening and fixing the split core assembled in a ring shape. And along the ring part 64 and the inner peripheral part of the core part 62, the three-phase bus-bars 63 and 66 connected to the coil wound around each division | segmentation core are arrange | positioned.
Each bus bar 63, 66 is connected to each coil wound around each divided core. However, in FIGS. 3 and 4, the connection structure between each bus bar 63, 66 and each coil is not shown. Yes. In FIG. 4, the bus bar 63 on the outer peripheral side is enlarged and displayed without the insulating coating layer.

  The motor housing body 60 is provided with an opening 60 a, and the connector unit 5 is fixed to the edge 60 b of the side tube 60 c surrounding the opening 60 a by the mounting screw 31. The outer peripheral bus bar 63 (63u, 63v, 63w) includes ring portions 63u1, 63v1, 63w1, and motor side terminals 63u2, 63v2, protruding from the ring portions 63u1, 63v1, 63w1 so as to be close to the opening 60a, 63w2.

  On the other hand, as will be described later, the connector unit 5 includes DC power supply terminals 23a2 and 23b2 protruding toward the outside of the motor housing, and three-phase AC power supply terminals 23u2 and 23v2 protruding toward the inside of the motor housing. 23w2 is provided. In the present embodiment, when the connector unit 5 is mounted on the motor housing body 60, the three-phase AC power terminals 23u2, 23v2, 23w2 of the connector unit 5 and the motor side terminals 63u2, 63v2, of the stator 61, 63w2 is fixed with a bolt or the like in a direct contact state.

-Connector unit structure-
Next, the structure of the connector unit 5 will be described. FIG. 5 is a perspective view of the connector unit 5 as viewed from the main surface side, and FIG. 6 is a perspective view of the connector unit 5 as viewed from the back surface side, and FIG. The reversed state is displayed.

  As shown in FIG. 5, each member of the connector unit 5 is mounted on the heat sink 21. A printed wiring board 33 on which a device drive circuit or the like is mounted is provided on the top, and all members except for external terminals are sealed with epoxy resin or the like (not shown) on the printed wiring board 33. Yes. The printed wiring board 33 is provided with a first opening 33a, a slit 33b, and a second opening 33c. In the first opening 33a, an IGBT chip 11a in which an IGBT as a power device is formed and a diode chip 11b in which a diode as a power device is formed are arranged. A control signal wiring 83 is disposed in the second opening 33c. In addition, three-phase AC power supply terminals 23u2, 23v2, and 23w2 project through the slit portion 33b.

  On the other hand, as shown in FIG. 6, when viewed from the back side of the heat sink 21, the heat sink 21 has a flat plate portion 21a and a fin portion formed with a large number of fins (not shown) protruding outward from the flat plate portion 21a. 21b and first and second openings 21c and 21d surrounded by sockets 28 and 29, respectively. Then, DC power supply terminals 23a2 and 23b2 are arranged in the first opening 21c, and a terminal part of the control signal wiring 83 is arranged in the second opening 21d.

Next, the structure of each member laminated on the heat sink of the connector unit 5 will be described. FIG. 7 is a perspective view showing the layers other than the wiring member on the heat sink 21 as seen through. FIG. 8 is a perspective view showing the layers on the heat sink 21 separately.
As shown in FIGS. 7 and 8, an insulating resin layer 26, a wiring member 23, and an insulating layer 35 are stacked in order from the bottom between the heat sink 21 and the printed wiring board 33. The wiring member 23 includes DC power supply wiring members 23a and 23b that supply DC power, and three-phase AC power supply wiring members 23u, 23v, and 23w that supply three-phase AC power.

The DC power supply wiring members 23a and 23b have flat plate portions 23a1 and 23b1 extending in the horizontal direction, and DC power supply terminals 23a2 and 23b2 which are bent from the flat plate portions 23a1 and 23b1 and extend downward in the drawing. Yes. That is, the DC power supply metal wires 23a and 23b have a substantially L-shaped cross-sectional shape.
Further, the three-phase AC power supply wiring members 23u, 23v, 23w are formed by three-phase extending upward in the drawing by being bent from the flat plate portions 23u1, 23v1, 23w1 extending in the horizontal direction and the flat plate portions 23u1, 23v1, 23w1. It has AC power supply terminals 23u2, 23v2, and 23w2. That is, the three-phase AC power supply metal wires 23u, 23v, and 23w have a substantially L-shaped cross-sectional shape.

The above-described flat plate portions 23a2, 23b2, 23u1, 23v1, and 23w1 constitute the wiring member of the present invention.
In the present embodiment, the flat plate portions 23a1 and 23b1 which are the first portions of the wiring members are the same metal plates as the DC power supply terminals 23a2 and 23b2, respectively (in this embodiment, a Cu plate or a Cu alloy plate). ). Further, the flat plate portions 23u1, 23v1, 23w1, which are the second part of the wiring member, are respectively the same metal plates as the three-phase AC power supply terminals 23u2, 23v2, 23w2 (in this embodiment, a Cu plate or a Cu alloy plate). ).

The DC power supply terminals 23a2 and 23b2 extend into the socket 28 through the first opening 26a of the insulating resin layer 26 and the first opening 21c of the flat plate portion 21a of the heat sink 21 (see FIG. 6). . Further, the three-phase alternating current power supply terminals 23u2, 23v2, and 23w2 are inserted through the slit portion 35b of the insulating layer 35 and the slit portion 33b of the printed wiring board 33 and protrude above the printed wiring board 33 (see FIG. 5). ). Further, the end portion of the control signal wiring 83 is bent downward and extends into the socket 29 through the second opening portion 26 b of the insulating resin layer 26 and the second opening portion 21 d of the flat plate portion 21 a of the heat sink 21. ing.
In the present embodiment, the DC power supply terminals 23a2 and 23b2 extend from the main surface side to the back surface side through the first opening portion 21c of the flat plate portion 21a of the heat sink 21, but the first opening portion of the heat sink 21 Instead of 21c, a side groove in which the end face of the flat plate portion 21a is cut out may be formed so that the DC power supply terminals 23a2 and 23b2 pass through the side groove and reach the back surface side.

-Structure of power converter-
9 is a cross-sectional view of the connector unit according to Embodiment 1 taken along the line IV-IV shown in FIG. FIG. 10 is an enlarged cross-sectional view of the main part of the connector unit according to the first embodiment.
Hereinafter, the structure of the connector unit including the power conversion unit will be described with reference to FIGS. 9 and 10.

  The power conversion unit 10 includes a semiconductor chip 11 that displays the IGBT chip 11a and the diode chip 11b together, and a wiring member (23a2, 23b2, 23u1) for electrically connecting a semiconductor element in the semiconductor chip 11 and an external member. 23v1, 23w1). In the cross section shown in FIG. 9 among the wiring members, the flat plate portions 23a1 and 23a2 of the DC power supply wiring members 23a and 23b and the flat plate portion 23w1 of the three-phase AC power supply wiring member 23w appear. In addition, the solder layer 14 including Pb-free solder that joins the flat plate portions 23a1, 23a2, and 23w1 of the wiring member and the semiconductor chip 11, and thermal stress relaxation conductivity formed on the flat plate portions 23a1 and 23w1 of the wiring member. A member 41, a heat sink 21 for releasing heat generated in the solder layer and the semiconductor chip 11, an insulating resin layer 26 for fixing the flat plate portions 23a1, 23a2, and 23w1 of the wiring member to the heat sink 21, and a semiconductor Chip 11. According to FIG. 10 (not shown in FIG. 9), the top surface and the bottom surface of the semiconductor chip 11 are respectively provided with a top surface electrode 12 and a back surface electrode 13 connected to the active region of the IGBT and the diode. The electrode 13 is joined to the wiring member in a conductive state by the solder layer 14.

  Further, the upper surface electrode of the semiconductor chip 11 (the upper surface electrode of the IGBT chip or the upper surface electrode of the diode chip) and each flat plate portion of the wiring member (23w2 and 23b1 in the cross section shown in FIG. 9) are the large current wiring 18. Are electrically connected. Further, in the semiconductor chip 11, the upper surface electrode of the IGBT chip and the upper surface electrode of the diode chip are also electrically connected by the large current wiring 18.

  The heat sink 21 includes a flat plate portion 21a and a fin portion 21b protruding from the back surface side of the flat plate portion 21a. The flat plate portion 21 a is attached to the edge portion 60 b of the side tube 60 c of the opening 60 a of the motor housing main body 60 by the mounting screw 31. The flat plate portion 21 a of the heat sink 21 functions as a support member that supports the wiring member and the semiconductor chip 11. The heat sink 21 functions as a heat dissipation structure and also functions as a part of the motor housing. That is, the motor housing is configured by the motor housing body 60 a and the heat sink 21.

  In the present embodiment, the heat sink 21 is naturally air-cooled. However, a container 50 (see the broken line) surrounding the fin portion 21b may be separately provided to forcibly circulate air or liquid for forced cooling. Good. However, the fin part 21b is not necessarily required, and other heat radiating members may be provided instead of the fin part 21b.

  A socket 28 is provided in the first opening 21 a of the heat sink 21, and a DC power supply terminal 23 a 2 bent from the flat plate portion 23 a 1 of the DC power supply wiring member 23 a extends to the socket 28. Although not shown in the cross section shown in FIG. 9, the DC power supply terminal 23b2 bent substantially at a right angle from the flat plate portion 23b1 of one DC power supply wiring member 23b also extends to the socket 28 (FIGS. 7 and 8). reference). That is, each DC power supply terminal 23 a 2, 23 b 2 extends to the external space of the motor housing body 60.

  Further, in a cross section other than the cross section shown in FIG. 9, the three-phase AC power supply terminal 23 w 2 bent substantially at a right angle from the flat plate portion 23 w 1 of the three-phase AC power supply wiring member 23 w extends into the internal space of the motor housing body 60. Yes. The three-phase AC power supply terminal 23w2 is fixed by the attachment member 37 in a state of being in direct contact with the motor side terminal 63w2. Although not shown in FIG. 9, the three-phase AC power supply terminals 23u2 and 23v2 bent substantially at right angles from the flat plate portions 23u1 and 23v1 of the other three-phase AC power supply wiring members 23u and 23v have the same configuration. ing. Note that the three-phase AC power terminals 23u2, 23v2, 23w2 and the motor side terminals 63u2, 63v2, 63w2 may be covered with an insulating resin together with the mounting member 37.

  Further, a printed wiring board 33 is laminated above the wiring member via an insulating layer 35, and the device driving circuit 16 is disposed on the printed wiring board 33. A signal wiring 17 for supplying a control signal is electrically connected between a signal wiring (not shown) extending on the printed wiring board 33 and a control electrode (not shown) of the semiconductor chip 11. It is connected to the.

  Although not shown in FIG. 9, on the upper surface side of the heat sink 21, the semiconductor chip 11, the control signal wiring 17, the high current wiring 18, the printed wiring board 33, the insulating layer 35, the wiring member, the solder layer 14, Members such as the insulating resin layer 26 are sealed with a resin such as an epoxy resin except for their terminals.

  In the present embodiment, sintered aluminum (sintered Al) is used as the material of the heat sink 21. However, it is not limited to this. For example, using other metals such as Al, Al alloy, Cu, and Cu alloy, ceramics such as AlN, SiN, BN, SiC, and WC, or composite materials such as Al—SiC, Cu—W, and Cu—Mo. Also good.

  In the present embodiment, Cu or Cu alloy is used as the material of the wiring member 23 (23a, 23b, 23u, 23v, 23w), but is not limited to this. For example, you may use Al, Al alloy, and composite materials, such as Al-SiC, Cu-W, and Cu-Mo.

  In the present embodiment, wiring members (each flat plate portion 23a1, 23b1, 23u1, 23v1, 23w1) and terminals to external devices (DC power supply terminals 23a2, 23b2 and three-phase AC power supply terminals 23u2, 23v2, 23w2) Are configured by a single metal plate (in this embodiment, a Cu plate or a Cu alloy plate), but a wiring member and a terminal may be provided separately, and both may be connected by an Al wire or the like. Good.

  As described above, the power conversion unit 10 of the present embodiment includes the solder layer 14 made of Pb-free solder and the insulating resin layer 26. In general, Pb-free solder includes the following. For example, Sn (liquid phase point 232 ° C.), Sn-3.5% Ag (liquid phase point 221 ° C.), Sn-3.0% Ag (liquid phase point 222 ° C.), Sn-3.5% Ag-0 .55% Cu (liquid phase point 220 ° C.), Sn-3.0% Ag-0.5% Cu (liquid phase point 220 ° C.), Sn-1.5% Ag-0.85% Cu-2.0 Bi (Liquid phase point 223 ° C.), Sn-2.5% Ag-0.5% Cu-1.0 Bi (liquid phase point 219 ° C.), Sn-5.8 Bi (liquid phase point 138 ° C.), Sn-0. 55% Cu (liquid phase point 226 ° C.), Sn-0.55% Cu—others (liquid phase point 226 ° C.), Sn-0.55% Cu-0.3% Ag (liquid phase point 226 ° C.), Sn -5.0% Cu (liquidus point 358 ° C), Sn-3.0% Cu-0.3% Ag (liquidus point 312 ° C), Sn-3.5% Ag-0.5% Bi-3 .0In (Liquid phase point 16 ° C.), Sn-3.5% Ag-0.5% Bi-4.0In (liquid phase point 211 ° C.), Sn-3.5% Ag-0.5% Bi-8.0In (liquid phase point) 208 ° C.), Sn-8.0% Zn-3.0% Bi (liquid phase point 197 ° C.), and the like. In this embodiment, a low melting point Pb-free solder having a liquidus point of 250 ° C. or lower, for example, Sn-3.0% Ag-0.5% Cu (liquidus point 220 ° C.) is used. It is not limited to. However, high melting point Pb-free solder (liquid phase point is Sn-5.0% Cu (liquid phase point 358 ° C.), Sn-3.0% Cu-0.3% Ag (liquid phase point 312 ° C.), etc.) Excluding those exceeding 250 ° C).

  In the present embodiment, an epoxy resin containing a metal or ceramic filler is used for the insulating resin layer 26. Although the usable temperature of the epoxy resin varies depending on the type, it is easy to select a temperature exceeding 250 ° C. In this embodiment, a temperature higher than the liquid phase point of Pb-free solder is used. Therefore, in the process of assembling the power conversion unit, it is possible to perform a reflow process of Pb-free solder after the insulating resin layer 26 is formed. For example, an epoxy resin filled with alumina, silica, aluminum, aluminum nitride, or the like can be used, and the thermal conductivity is preferably 3.0 (W / m · K) or more, and 5.0 ( W / m · K) or more is more preferable.

  The thickness of the insulating resin layer 26 is preferably 0.4 mm or less, and more preferably 0.2 mm or less. The thermal resistance of the insulating resin layer 26 is determined depending on the thermal conductivity and thickness, but the thermal resistance decreases as the thickness decreases. Therefore, heat dissipation performance will become high because thickness is 0.4 mm or less.

  Moreover, since the printed wiring board 33 which mounts the device drive circuit 16 which is a control circuit for controlling the operation | movement of a power device is integrated in the power converter 10, compactization of the member inside a vehicle can be achieved. .

  Further, the flat plate portions 23a1, 23b1 of the DC power supply wires 23a, 23b and the DC power supply terminals 23a2, 23b2 of the wiring members are formed of a common metal plate, thereby reducing the component cost and the connector unit 5. Can be reduced in size.

  Further, among the wiring members, the flat plate portions 23u1, 23v1, 23w1 of the three-phase AC power supply wiring members 23u, 23v, 23w and the three-phase AC power supply terminals 23u2, 23v2, 23w2 are formed of a common metal plate. As a result, it is possible to reduce the component cost and the size of the connector unit 5.

  In this embodiment, since one solder layer 14 and the insulating resin layer 26 made of a resin adhesive are used in place of the two solder layers that have been conventionally used, depending on the process before and after the process. It is not necessary to use a low melting point Pb-free solder and a high melting point Pb free solder, and only a low melting point Pb free solder is required. Currently, Pb-free solder having a relatively high Cu composition ratio (for example, Sn-5.0% Cu having a liquidus point of 300 ° C. or higher, Sn-3.0% Cu-0.3% Ag) is also used as Pb-free solder Although being developed, it is difficult to obtain a high melting point Pb-free solder having reliable connection reliability. On the other hand, as the low melting point Pb-free solder, for example, a solder having a high connection reliability such as Sn-3.0% Ag-0.5% Cu (JEITA recommended alloy) having a liquidus point of 220 ° C. is obtained. . As the resin adhesive, an epoxy resin having a usable temperature exceeding 250 ° C. can easily be obtained that can withstand a higher temperature than the liquid phase point of the low melting point Pb-free solder. Therefore, according to the present embodiment, the solder layer 14 can be made Pb-free, and connection reliability can be ensured while ensuring the connection reliability.

Here, the thermal stress relaxation conductive member will be described with reference to FIG. The wiring member 23 a is made of Cu, which is a first material, and is a wiring member that serves as a foundation for the thermal stress relaxation conductive member 41. The thermal stress relaxation conductive member 41 includes the first material (Cu) and a second material (Si, Al ₂ O ₃ , SiC, Si ₃ N ₄ , which has a smaller thermal expansion coefficient than the first material, SiO ₂ , AlN, W, Mo, Fe ₃₂ Ni ₅ Co (Invar alloy), etc.), and is formed using a cold spray method. As will be described later, the thermal stress relaxation conductive member 28a formed by the cold spray method is formed at a relatively low temperature (several hundred degrees Celsius). In addition, it has been confirmed that the film formed using the cold spray method is dense. In the cold spray method, the deposition efficiency of the film is large, and the manufacturing cost is low. The thickness of the semiconductor chip 11 is 0.3 mm to 0.5 mm, the thickness of the thermal stress relaxation conductive member is about 0.5 mm, the thickness of the solder layer 14 is about 0.1 mm, and the wiring member 23a1 The thickness is about 0.4 mm, the thickness of the insulating resin layer 26 is about 0.2 mm, the thickness of the flat plate portion 21a of the heat sink 21 is about 5 mm, and the length of the fin portion 21b in the vertical direction is about 15 mm. The pitch of the fin portions 21b is about 1.5 mm, and the lateral thickness of the fin portions 21b is about 1.5 mm.

  FIG. 11 is a cross-sectional view for explaining the outline of the cold spray method. The cold spray apparatus 100A includes a mixer (hopper) 107 that mixes two kinds of materials (particles) introduced from two raw material supply pipes 108A and 108B, a heater 102 that heats compressed air, and a gun for spraying the particles. 103 and pipes 104 and 105 for supplying compressed air. A substrate is installed at a position about 5 to 30 mm away from the gun 103. Instead of compressed air, a compressed gas such as helium or nitrogen may be used.

The first material (Cu) and the second material (Si, Al ₂ O ₃ , SiC, Si ₃ N ₄ , SiO ₂ , AlN, W, Mo are respectively supplied to the mixer 107 from the two raw material supply pipes 108A and 108B. And Fe ₃₂ Ni ₅ Co (invar alloy), etc. (particle size 10 to 40 μm) are introduced, mixed in the mixer 107 and then sent to the gun 103 by compressed air fed from the pipe 104. It is done. On the other hand, the compressed air sent from the pipe 105 is heated to 300 to 500 ° C. by the heater 102 and sent to the gun 103. Then, in a state where the heated compressed air and each particle group are mixed with each other by the gun 103, the jet is injected in a supersonic flow. Each particle collides with the substrate at a high speed of 500 m / s or more, the particles are plastically deformed by the kinetic energy of the particles, and are joined in an entangled state to form the thermal stress relaxation conductive member 41. The gun 103 is repeatedly swept along the substrate. The diameter of each particle is 0.1 μm to 50 μm, preferably 10 μm to 50 μm.
As a substrate for depositing the thermal stress relaxation conductive member 41, a Cu plate that becomes the wiring member 23a is used. After that, the thermal stress relaxation conductive member 41 is patterned together with the Cu plate, and then an adhesive that becomes the insulating resin layer 26 is used. The thermal stress relaxation conductive member 41 and the wiring member 23a are formed by being attached to the heat sink 21. In the structure shown in FIG. 9, a region of the thermal stress relaxation conductive member 41 in which the solder layer is not required is deleted by selective etching or the like, but the thermal stress relaxation conductive member 41 in this region is removed. You may leave it as it is. Further, the thermal stress relaxation conductive member 41 may be formed on the Cu plate using a metal mask, and the etching process may be omitted.

Alternatively, the wiring member 23a may be formed in advance on the heat sink 21 via the insulating resin layer 26, and the thermal stress relaxation conductive member 41 may be formed on the wiring member 23a by direct thermal spraying.
In addition, the wiring member 23a is previously formed on the heat sink 21 via the insulating resin layer 26, while the thermal stress relaxation conductive member 41 is formed on a suitable substrate by a thermal spraying method. The member 41 may be peeled off and the wiring member 23a may be joined using solder or brazing material.

  According to the present embodiment, the thermal expansion coefficient of the thermal stress relaxation conductive member 41 is a value between the thermal expansion coefficients of the semiconductor chip 11 and the wiring member 23a. Therefore, it is possible to suppress the occurrence of cracks in the solder layer 14 due to the thermal stress caused by the difference in thermal expansion coefficient between the semiconductor chip 11 and the wiring member 23. And the reliability of the junction part between members (between the wiring member 23a and the thermal stress relaxation conductive member 41 and between the thermal stress relaxation conductive member 41 and the semiconductor chip 11) can be maintained high.

In particular, by adopting a cold spray method in the process of forming the thermal stress relaxation conductive member 41, the thermal stress relaxation conductive member can be formed at a relatively low temperature. In the cold spray method, compressed air heated to 300 to 400 ° C. by the heater 102 is used. However, since it is rapidly cooled by the expansion of air, when it collides with the heat sink 21, it becomes a low temperature of room temperature to 100 ° C. Because. Accordingly, it is possible to suppress warping caused by the difference in thermal expansion coefficient between the wiring member 23a and the thermal stress relaxation conductive member 41 after processing. A film formed using a thermal spraying method such as the cold spray method has been confirmed to be dense. In particular, the cold spray method has a high film deposition efficiency and a low manufacturing cost.
Further, when a plurality of materials are combined, a difference in specific gravity, a difference in melting point, or the like becomes an obstacle, and in most cases, the range that can be combined is limited. On the other hand, as in the present embodiment, the thermal stress relaxation conductive member 28 including the first material and the second material can be easily formed in an almost arbitrary composition range by using the thermal spraying method. .

  Further, in the present embodiment, when the cold spray shown in FIG. 11 is performed, there is little supply of the second material from the raw material supply pipe 108B during the first sweep, and the lower end of the thermal stress relaxation conductive member 41 is reduced. The composition ratio of the second material in the part is about 20% by volume. Then, as the number of sweeps proceeds, such as the second time, the third time,..., The ratio of the second material supplied from the raw material supply pipe 108B increases. At the time of the final sweep, the second material from the raw material supply pipe 108A is increased. To increase the composition ratio of the second material at the upper end of the thermal stress relaxation conductive member 41 to about 70% by volume.

  By such a thermal spraying method, the composition distribution of the thermal stress relaxation conductive member 41 is realized such that the composition ratio of the first material increases as it is closer to the semiconductor chip 11 and the composition ratio of the second material increases as it is closer to the wiring member 23a. . Thus, the thermal stress relaxation conductive member 41 has a composition distribution in which the composition ratio of the first material is larger as it is closer to the semiconductor chip 11 and the composition ratio of the second material is larger as it is closer to the wiring member 23a. As a result, both the thermal expansion coefficient difference between the thermal stress relaxation conductive member 41 and the semiconductor chip 11 and the thermal expansion coefficient difference at the interface between the thermal stress relaxation conductive member 41 and the wiring member 23a can be reduced. The thermal stress applied to the solder layer 14 can be reduced, and the occurrence of cracks in the solder layer 14 can be reliably suppressed. Moreover, the reliability of joining between members extending from the wiring member 23a to the semiconductor chip 11 can be enhanced.

  In the present embodiment, the average composition ratio of the first material in the thermal stress relaxation conductive member 41 is 30 to 80% by volume. If the volume is 30% or less, the network between the Cu powders becomes weak, the bonding force decreases, and the strength of the thermal stress relaxation conductive member 41 may not be ensured. In order to ensure electrical continuity, it is preferable that the local maximum composition ratio of the first material is 30 deposition% or more. In the first sweep, the composition ratio of the second material at the lower end portion of the thermal stress relaxation conductive member 41 is 0% without supplying the second material from the raw material supply pipe 108B. Also good. However, it is preferable to keep the average composition ratio of the second material in the entire thermal stress relaxation conductive member 41 in the range of 30 to 80%.

  The composition distribution in the thermal stress relaxation conductive member 41 does not necessarily have to be as in the present embodiment. For example, even if the composition ratio of Cu and the second material is a uniform composition of 1: 1, if the thermal expansion coefficient of the second material is smaller than the thermal expansion coefficient (17 ppm / K) of Cu, The heat caused by the difference between the thermal expansion coefficient and the thermal expansion coefficient applied to the solder layer 14 is a value between the thermal expansion coefficient and the thermal expansion coefficient (3 to 6 ppm / K) of each material constituting the semiconductor chip 11 such as Si or SiC. Stress can be relaxed.

The first material is Cu or Cu alloy, the second material is Si, Al ₂ O ₃ , SiC, Si ₃ N ₄ , SiO ₂ , AlN, W, Mo, Fe ₃₂ Ni ₅ Co (Invar alloy), etc. As a result, the following remarkable effects can be exhibited.

FIG. 15 shows the amount of addition (Vol%) when a second material (Al ₂ O ₃ , SiC, SiO ₂ , AlN, W, Mo, Fe ₃₂ Ni ₅ Co (Invar alloy)) is added to Cu. It is a graph which shows the change of a thermal expansion coefficient. As shown in FIG. 15, the thermal expansion coefficient of the thermal stress relaxation conductive member 41 decreases as the amount of the second material added increases. When the addition amount of the second material is 20% or more, the thermal expansion coefficient of the thermal stress relaxation conductive member 41 is 15 ppm / K or less.

FIG. 16 shows the amount of addition (Vol%) when a second material (Al ₂ O ₃ , SiC, SiO ₂ , AlN, W, Mo, Fe ₃₂ Ni ₅ Co (Invar alloy)) is added to Cu. It is a graph which shows the change of thermal conductivity. As shown in FIG. 16, the thermal conductivity decreases as the addition amount of the second material increases. However, if the addition amount of the second material is 70% or less, the thermal conductivity is 100 W / m · K. A sufficiently large value can be obtained as described above.
FIG. 17 is a table showing various characteristics of the first and second materials.

  In particular, it is preferable that the thermal expansion coefficient of the thermal stress relaxation conductive member 41 is 10 ppm / K or less because the difference in thermal expansion coefficient from the semiconductor chip 11 can be further reduced.

  On the other hand, when the wiring member 23a is made of Cu, Cu alloy, Al, or Al alloy, the electrical resistance and the thermal conductivity can be particularly reduced, so that the conductive function and the heat dissipation function as the wiring member are particularly enhanced. Therefore, according to the present embodiment, it is possible to maintain high reliability of joining between members by reducing thermal stress while particularly improving the overall performance of the power conversion unit 10. However, the constituent material of the wiring member 23a of the present invention is not necessarily limited to Cu, Cu alloy, Al, or Al alloy.

  Further, the thermal stress relaxation conductive member 41 only needs to include a region located directly below the semiconductor chip 11 and does not need to be widely formed on the wiring member 23a.

  Furthermore, as another thermal spraying method for forming the wiring member 23a, an HVAF (High Velocity Aero Fuel) method can be used. FIG. 12 is a cross-sectional view for explaining the outline of the HVAF method. The HVAF apparatus 100B sprays particles by a mixer (hopper) 107 that mixes two kinds of materials (particles) introduced from two raw material supply pipes 108A and 108B, a heater 102 that heats compressed air and combustible gas, and particles. For this purpose, a pipe 104 and 105 for supplying compressed air, and a gas pipe 106 for supplying a combustible gas (such as propane gas). A substrate is installed at a position about 5 to 30 mm away from the gun 103.

The first material (Cu) and the second material (Al ₂ O ₃ , SiC, SiO ₂ , AlN, W, Mo, Fe ₃₂ Ni ₅ Co (from the two raw material supply pipes 108A and 108B) are supplied to the mixer 107, respectively. When each particle group (particle size: 10 to 40 μm) of Invar alloy) is introduced, it is mixed in the mixer 107 and then sent to the gun 103 by compressed air sent from the pipe 104. On the other hand, the compressed air and the combustible gas sent from the pipe 105 and the gas pipe 106 are accelerated by the ignition plug 109 and sent to the gun 103. Then, in a state where the combustion gas, compressed air, and each particle group are mixed with each other by the gun 103, the gun 103 and the flame are injected in supersonic flow. Each particle collided with the substrate at approximately the same temperature (300 to 500 ° C.) and higher speed (600 to 800 m / s) as in the cold spray method, and the particles were entangled by plastic deformation due to the kinetic energy of the particles. The thermal stress relaxation conductive member 41 is formed by being coupled in a state. The particle size of the particles is 10 to 40 μm.

  In the case of using the HVOF (High Velocity Oxygen Fuel) method, an apparatus as shown in FIG. 4 is used except that oxygen is supplied from the supply pipes 104 and 105. In that case, a frame speed of 2000 m / s or more and a particle speed of 750 m / s are achieved.

FIG. 13 is a cross-sectional view for explaining the outline of the AD (Aerosol Deposition) method. A work holder 112, a substrate 113, a metal mask 115, and a nozzle 116 are disposed in a film forming chamber 111 provided with a vacuum pump. The aerosol generation chamber 118 is supplied with a particle group of the first material (Cu) from the raw material supply pipe 119A, and from the raw material supply pipe 119B to the second material (Al ₂ O ₃ , SiC, SiO ₂ , AlN, A group of particles of W, Mo, Fe ₃₂ Ni ₅ Co (Invar alloy)) is supplied, and the particles are mixed in the aerosol chamber 118. Each particle rides on a gas flow supplied from a compressed gas cylinder such as air, He, Ar, or nitrogen, is carried from the connecting pipe 117 to the nozzle 116, and is ejected at a high speed. Then, the thermal stress relaxation conductive member 41 including the first material and the second material is deposited on the substrate 113. When the film formation is completed, the thermal stress relaxation conductive member 41 is peeled off from the substrate 113 and bonded to the wiring member 23a, thereby forming the structure shown in FIG.

  In this method, as in the cold spray method, the film is formed at a low temperature of about room temperature. The particle speed is 200 to 400 m / s, and the particle diameter is 0.03 μm to 0.1 μm, so that finer particles can be used.

  Comparing the thickness of the composite material film to be formed, it is several tens μm to several mm in the cold spray method, HVAF method, and HVOF method, but several μm to several tens μm in the AD method. In the power conversion unit of the present invention, it is important to have a thickness of several tens of μm or more that can relieve stress, and it is preferable to use a cold spray method, an HVAF method, or an HVOF method.

(Modification)
FIG. 14 is a diagram for explaining a modification of the manufacturing method of the first embodiment. In the first embodiment, the first material particle group and the second material particle group are mixed, and then each particle is ejected from one nozzle. The particle group is sprayed. That is, as shown in FIG. 14, a particle group of the first material (Cu) is ejected from the nozzle A, and the second material (Si, Al ₂ O ₃ , SiC, Si ₃ N ₄ , SiO ₂ is ejected from the nozzle B. , AlN, W, Mo, Fe ₃₂ Ni ₅ Co (Invar alloy), etc.) are ejected to deposit a thermal stress relaxation conductive member 41 including the first material and the second material on the substrate. To go. The nozzles A and B are nozzles used in the cold spray method, the HVAF method, the HVOF method, or the AD method.

According to the present embodiment, a power converter that functions as an inverter for converting DC power into three-phase AC power between DC power terminals 23a2, 23b2 and three-phase AC power terminals 23u2, 23v2, 23w2. 10 is provided so that a part of the connector unit 5 (in this embodiment, the heat sink 21 as a heat dissipation structure) can be connected to the motor housing body 60. For this reason, the DC power supply wiring is replaced with the three-phase AC power supply wiring between the battery 6, the converter 7 and the power conversion unit 10 that generate the DC power supply, as compared with the conventional inverter and the connector separated from each other. Therefore, the cost of parts can be reduced by reducing the amount of high-power wiring used.
In addition, in the power conversion unit integrated with the connector, the connector is connected to the motor by producing and providing a thermal stress relaxation conductive member that reduces thermal stress between the semiconductor chip and the wiring member by a thermal spraying method. A connector unit having high electrical and thermal connection reliability even in an actual usage environment can be provided at a relatively low cost.

(Embodiment 2)
18 is a cross-sectional view of the power conversion unit according to the second embodiment, taken along the line IV-IV shown in FIG. FIG. 19 is an enlarged cross-sectional view illustrating a main part of the power conversion unit according to the first embodiment. In the figure, members having the same configurations as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  In the present embodiment, the thermal stress relaxation heat transfer member 42 formed on the heat sink 21 is formed, and the wiring members 23a1, 23b1, 23w1 are installed on the insulating resin layer 26 thereon.

  Here, the thermal stress relaxation heat transfer member will be described with reference to FIG. In the present embodiment, the thermal stress relaxation heat transfer member 42 includes the first material (Cu or Cu alloy) and the second material (Al or Al alloy), and the above-described cold spray method is used. It is formed using.

  In the present embodiment, the thermal stress relaxation heat transfer member 42 has a composition ratio of the first material (Cu or Cu alloy A) of approximately 100% at the lower end, and from the lower end toward the upper end. The composition ratio of the second material (l or Al alloy) gradually increases, and the composition ratio of the second material is almost 100% at the upper end.

  The composition distribution in the thermal stress relaxation heat transfer member 42 does not necessarily have to be as in the present embodiment. For example, even if the composition ratio of Cu and Al is 1: 1, the coefficient of thermal expansion is an intermediate value between the coefficient of thermal expansion of Cu (17 ppm / K) and the coefficient of expansion of Al (23 ppm / K). Therefore, the thermal stress resulting from the difference in thermal expansion coefficient between the wiring member 23a1 and the heat sink 21 can be relaxed.

  That is, in the present embodiment, the thermal expansion coefficient of the thermal stress relaxation heat transfer member 28 including the first material (Cu or Cu alloy) and the second material (Al or Al alloy) is made of the first material. This is an intermediate value of the thermal expansion coefficient between the wiring member 23a1 and the heat sink 21 made of the second material. Therefore, the thermal stress caused by the difference in thermal expansion coefficient between the wiring member 23a1 and the heat sink 21 can be relaxed, and between the members (between the heat sink 21 and the thermal spray thermal stress relaxation heat transfer member 28 and the thermal stress relaxation heat transfer member). 42-between the insulating resin layer 26 and the wiring member 23), the reliability of the joint portion can be maintained high.

However, the thermal stress relaxation heat transfer member 42 is not necessarily formed of two materials, and may be formed by thermal spraying of a plurality of materials. By including a plurality of materials, the thermal expansion coefficient can be easily adjusted.
Further, the thermal stress relaxation heat transfer member 42 does not necessarily include the main component of the heat sink 21 and the main component of the wiring member 23a1, and an average thermal expansion coefficient can be obtained by mixing a plurality of materials. Any value between the thermal expansion coefficients of the heat sink 21 and the wiring member 23a1 may be used. This is because the thermal stress due to the difference in thermal expansion coefficient can be reduced.

The first material is preferably one material selected from the main component (Cu in the present embodiment) of the wiring member 23a1 and the main component (Al in the present embodiment) of the heat sink 21. In that case, it becomes easy to fire the thermal expansion coefficient relatively easily. For example, when the first material is Cu (the main component of the wiring member 23a1), thermal stress relaxation is achieved by thermal spraying a group of Cu particles and a group of other materials having a thermal expansion coefficient larger than that of Cu. It is easy to adjust the thermal expansion coefficient of the heat transfer member 42 to an intermediate value between the heat sink 21 and the wiring member 23a1. When the first material is Al (the main component of the heat sink 21), a group of Al particles and a group of particles having a smaller thermal expansion coefficient than Al, such as SiO ₂ and Al ₂ O ₃ , are used. By thermal spraying, it is easy to adjust the thermal expansion coefficient of the thermal stress relaxation heat transfer member 42 to an intermediate value between the heat sink 21 and the wiring member 23a1.

  When the first material is Cu (the main component of the wiring member 23a1), the closer to the wiring member 23a1, the larger the Cu composition ratio of the thermal stress relaxation heat transfer member 42, so that the thermal stress relaxation transfer is increased. The difference in thermal expansion coefficient between the thermal member 42 and the wiring member 23a1 can be reduced, and the thermal stress can be reduced. When the first material is Al (the main component of the heat sink 21), the thermal stress relaxation heat transfer member is increased by increasing the Al composition ratio of the thermal stress relaxation heat transfer member 42 closer to the heat sink 21. The difference in thermal expansion coefficient between 42 and the heat sink 21 can be reduced, and the thermal stress can be reduced.

  In particular, the thermal stress relaxation heat transfer member 42 has a composition distribution in which the composition ratio of the first material is larger as it is closer to the wiring member 23 a 1 and the composition ratio of the second material is larger as it is closer to the heat sink 21. As a result, the difference in thermal expansion coefficient between the wiring member 23a1 and the heat sink 21 can be almost absorbed, so that the reliability of the joint is particularly improved.

  By applying the present invention to a combination of the first material being Cu or Cu alloy and the second material being Al or Al alloy, the following remarkable effects can be exhibited.

When alloying by mixing general molten metals, the maximum solid solubility of Al in Cu is around 10% (aluminum bronze), and it is difficult to obtain a practical alloy even if more Al is added. However, by using a thermal spraying method, the thermal spray thermal stress relaxation heat transfer member 28 can be easily formed in an almost arbitrary composition range.
Since the heat sink 21 is made of Al or an Al alloy, fins with fine pitch can be easily formed by die casting or extrusion, so that the heat dissipation function of the heat sink is particularly enhanced. On the other hand, when the wiring member 23a1 is made of Cu or a Cu alloy, the electrical resistance can be particularly reduced, so that the conductive function as the wiring member is particularly enhanced. Therefore, according to the present embodiment, the overall function of the heat sink 21 and the wiring member 23a1 can be particularly enhanced, and the reliability of bonding between the members can be maintained high by reducing the thermal stress.
However, the thermal stress relaxation heat transfer member of the present invention does not necessarily need to be composed of a composite material of Al or Al alloy and Cu or Cu alloy.

  Further, as described above, the thermal stress relaxation heat transfer member 42 can be similarly formed by the HVAF method, the HVOF method, and the AD method, and the power conversion unit with high reliability of bonding between the members is integrated by reducing the thermal stress. Connector units can be provided.

(Other embodiments)
In the above embodiment, a structure in which a part of the connector unit is connected to the motor housing has been disclosed. Can be applied. That is, the present invention can also be applied to a rotating electrical machine and a housing of the rotating electrical machine.

  The semiconductor element disposed in the power conversion unit of the present invention may be a power device using a wide band gap semiconductor (SiC, GaN, etc.) or a power device using Si.

  In the said embodiment, although the power conversion part was an inverter which combined IGBT and a diode, the inverter using MOSFET may be sufficient as the power conversion part of this invention.

  In the said embodiment, although the heat radiating structure was comprised only by the heat sink 21, the heat radiating structure may have a heat sink and another member. A member other than the heat sink or a member other than the heat dissipation structure may be coupled to the housing of the rotating electrical machine.

  The structure of the embodiment of the present invention disclosed above is merely an example, and the scope of the present invention is not limited to the scope of these descriptions. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  The connector unit, the housing of the rotating electrical machine, and the rotating electrical machine of the present invention can be used for a motor such as a hybrid vehicle, an electric vehicle, a compressor of a refrigeration apparatus, or a generator.

1 is a block diagram schematically showing a configuration of an electric system inside a vehicle body of a hybrid vehicle according to Embodiment 1. FIG. FIG. 3 is an electric circuit diagram showing a circuit configuration from the battery to the motor in the first embodiment. It is a perspective view which fractures | ruptures and shows a part of motor. It is sectional drawing of a part of motor and a connector unit. It is the perspective view which looked at the connector unit from the main surface side. It is the perspective view which looked at the connector unit from the back side. It is a perspective view seeing through each layer other than the wiring member on a heat sink. It is a perspective view which isolate | separates and displays each layer on a heat sink. It is sectional drawing in the IV-IV line shown in FIG. 7 of the connector unit which concerns on Embodiment 1. FIG. 3 is an enlarged cross-sectional view of a main part of the connector unit according to Embodiment 1. FIG. It is a figure explaining the outline of the cold spray method. It is a figure explaining the outline of HVAF method (HVOF method). It is a figure explaining the outline of AD method. It is a figure which shows the modification of embodiment. It is a graph which shows the change of the thermal expansion coefficient with respect to addition amount (volume%) when adding a 2nd material to Cu. It is a graph which shows the change of the heat conductivity with respect to addition amount (volume%) when the 2nd material is added to Cu. It is a figure which shows the various characteristics of a 1st and 2nd material by a table | surface. It is sectional drawing in the IV-IV line shown in FIG. 7 of the connector unit which concerns on Embodiment 2. FIG. 6 is an enlarged cross-sectional view of a main part of a connector unit according to Embodiment 2. FIG. It is a block circuit diagram which shows the example of the electric system diagram of the conventional hybrid vehicle.

Explanation of symbols

1 Engine 2 Radiator 3 Motor 5 Connector Unit 6 Battery 7 Converter 8 DC Power Supply Wiring 8
DESCRIPTION OF SYMBOLS 10 Power conversion part 11a IGBT chip 11b Diode chip 12 Upper surface electrode 13 Lower surface electrode 14 Solder layer 16 Device drive circuit 17 Control signal wiring 18 High current wiring 21 Heat sink 21a Flat plate part 21b Fin part 21c 1st opening part 21d 2nd opening Part 23 Wiring member 23a DC power supply wiring member 23b DC power supply wiring member 23a1 Flat plate part 23b1 Flat plate part 23a2 DC power supply terminal 23b2 DC power supply terminal 23u Three-phase AC power supply wiring member 23v Three-phase AC power supply wiring member 23w Three Phase AC power supply wiring member 23u1 Flat plate portion 23v1 Flat plate portion 23w1 Flat plate portion 23u2 Three-phase AC power supply terminal 23v2 Three-phase AC power supply terminal 23w2 Three-phase AC power supply terminal 26 Insulating resin layer 26a First opening portion 26b Second opening portion 28 socket 29 socket G 31 Mounting screw 33 Printed wiring board 33a First opening 33b Slit 33c Second opening 35 Insulating layer 35a First opening 35b Slit 35c Second opening 37 Mounting member 41 Thermal stress relaxation conductive member 42 Thermal stress relaxation Heat transfer member 50 Container 60 Motor housing body 60a Opening 60b Side tube 60c Edge 63u Bus bar 63v Bus bar 63w Bus bar 63u1 Ring portion 63v1 Ring portion 63w1 Ring portion 63u2 Motor side terminal 63v2 Motor side terminal 63w2 Motor side terminal 80 Motor control unit 80 Motor control unit 80 Control signal wiring 83 Control signal wiring 100A Cold spray device 102 Heater 103 Gun 104 Piping 105 Piping 107 Mixer 108A Raw material supply pipe 108B Raw material supply pipe 109 Spark plug 110 AD equipment DESCRIPTION OF SYMBOLS 111 Deposition chamber 112 Work holder 113 Substrate 115 Metal mask 116 Nozzle 117 Communication piping 118 Aerosolization chamber 119A Raw material supply pipe 119B Raw material supply pipe 500 Car body 501 Engine 502 Engine radiator 503 Motor 505 Inverter 506 Battery 507 Converter 508 Three-phase AC power supply Line 510 Power generation unit 511 connector

Claims (17)

A DC power supply terminal;
A three-phase AC power supply terminal;
A power conversion unit for performing power conversion between DC power and AC power, and a connector unit connectable to a housing of a rotating electrical machine,
The power converter is
A semiconductor chip;
A wiring member connected to the semiconductor chip via a thermal stress relaxation conductive member,
The thermal expansion coefficient of the thermal stress relaxation conductive member is an intermediate value between the thermal expansion coefficient of the semiconductor chip and the thermal expansion coefficient of the wiring member. The connector unit according to claim 1,
A material that mainly constitutes the semiconductor chip (refers to a material that is dominant in the coefficient of thermal expansion among the constituent materials) is a first material,
When the material mainly constituting the wiring member (referred to as the material dominant in the thermal expansion coefficient among the constituent materials) is the second material,
The connector unit, wherein a material mainly constituting the thermal stress relaxation conductive member is a first material or a second material. The connector unit according to claim 2,
Content of the material which mainly comprises the said thermal stress relaxation electrically-conductive member is a connector unit which is 30-80 volume% of the said whole thermal stress relaxation electrically-conductive member. The connector unit according to claim 2 or claim 3,
The thermal stress relaxation conductive member is
The first region that faces the semiconductor chip and the second region that faces the wiring member have different thermal expansion coefficients, and the thermal expansion coefficient of the first region is different from the thermal expansion coefficient of the semiconductor chip. A connector unit that is an intermediate value of the thermal expansion coefficient of the second region. The connector unit according to any one of claims 2 to 4,
The material other than the material mainly constituting the thermal stress relaxation conductive member is made of Si, Al ₂ O ₃ , SiC, Si ₃ N ₄ , SiO ₂ , AlN, W, Mo, or Fe ₃₂ Ni ₅ Co (Invar alloy). A connector unit comprising at least one material selected from the group consisting of: The connector unit according to claim 2,
The thermal stress relaxation conductive member is a connector unit made of the first material and the second material. The connector unit according to claim 6,
The thermal stress relaxation conductive member is
The first region and the second region have different thermal expansion coefficients, and the thermal expansion coefficient of the first region is an intermediate value between the thermal expansion coefficient of the semiconductor chip and the thermal expansion coefficient of the second region. Connector unit. The connector unit according to any one of claims 1 to 7,
The connector unit, wherein the thermal stress relaxation conductive member is formed by a thermal spraying method. The connector unit according to any one of claims 1 to 8,
Further, a connector unit in which a heat sink is connected to the wiring member via an insulating resin layer. A DC power supply terminal;
A three-phase AC power supply terminal;
A power conversion unit for performing power conversion between DC power and AC power, and a connector unit connectable to a housing of a rotating electrical machine,
The power converter is
A semiconductor chip;
A wiring member connected to the semiconductor chip;
A heat sink connected to the wiring member via a thermal stress relaxation heat transfer member;
The thermal expansion coefficient of the thermal stress relaxation heat transfer member is an intermediate value between the thermal expansion coefficient of the wiring member and the thermal expansion coefficient of the heat sink. The connector unit according to claim 10,
A material mainly constituting the wiring member (referred to as a material dominant in the thermal expansion coefficient among the constituent materials) is a third material,
When the material that mainly constitutes the heat sink (referred to as the material dominant in the thermal expansion coefficient among the constituent materials) is the fourth material,
The connector unit, wherein a material mainly constituting the thermal stress relaxation heat transfer member is a third material or a fourth material. The connector unit according to claim 11,
The thermal stress relaxation heat transfer member is
The first region which is the side facing the wiring member and the second region which is the side facing the heat sink have different thermal expansion coefficients, and the thermal expansion coefficient of the first region is different from the thermal expansion coefficient of the wiring member. A connector unit that is an intermediate value of the thermal expansion coefficients of the two regions. The connector unit according to claim 11,
The thermal stress relaxation heat transfer member is a connector unit composed of the third material and the fourth material. The connector unit according to claim 13,
The thermal stress relaxation heat transfer member is
The first region and the second region have different thermal expansion coefficients, and the thermal expansion coefficient of the first region is an intermediate value between the thermal expansion coefficient of the wiring member and the thermal expansion coefficient of the second region. Connector unit. The connector unit according to any one of claims 11 to 14,
The wiring member is made of Cu or Cu alloy,
The heat sink is a connector unit made of Al or Al alloy. The connector unit according to any one of claims 10 to 15,
The thermal stress relaxation heat transfer member is a connector unit formed by a thermal spraying method. The connector unit according to any one of claims 10 to 16, wherein
A connector unit further comprising an insulating resin layer between the wiring member and the thermal stress relaxation heat transfer member.

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