JP5211544B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device that uses a semiconductor element to constitute a power conversion circuit of an electric vehicle.

  Conventionally, the switching element connected between the high potential side of the DC power source and the motor and the switching element connected between the low potential side and the motor are mounted on different base plates, and these two base plates are mounted. There is known an apparatus in which an inverter circuit is configured by including the same in the same module (see, for example, Patent Document 1). In the apparatus described in Patent Document 1, since a pair of base plates are arranged side by side in one module, the entire module is configured in a substantially rectangular shape.

Japanese Patent No. 3641807

  However, if the module is configured in a substantially rectangular shape as in the apparatus described in Patent Document 1, for example, when a plurality of modules are arranged in a circular area in accordance with the shape of a cylindrical motor, useless space increases. The whole apparatus becomes large.

A semiconductor device according to the present invention includes a high potential side switching element connected between a high potential side of a power source and a motor, and a low potential side switching element connected between a low potential side of the power source and the motor. A first substrate having a substantially rectangular shape on which the high-potential side switching element is mounted and a second substrate having a substantially rectangular shape on which the low-potential side switching element is mounted. In the module, the first substrate and the second substrate are arranged so that adjacent one sides of each substrate are opposed to each other, and each substrate is shifted along the one side. disposed, said module is characterized that you have provided more than once in a circular area.
In addition, the semiconductor device according to the present invention is configured so that one corner of the other substrate is in contact with one side of one of the first substrate and the second substrate. There is disposed inclined, the module is characterized that you have provided more than once in a circular area.

  ADVANTAGE OF THE INVENTION According to this invention, the useless space at the time of arrange | positioning a several semiconductor module to the circumferential direction decreases, and a semiconductor module can be efficiently arrange | positioned in a circular area | region.

-First embodiment-
A first embodiment in which a semiconductor device according to the present invention is configured as a motor-driven power conversion device will be described below with reference to FIGS.
FIG. 1 is a diagram showing the semiconductor device according to the first embodiment, and particularly shows a part of a circuit diagram of a three-phase inverter mounted on an electric vehicle. In the figure, P and N are DC input wirings, and U, V and W are AC output wirings. In FIG. 1, direct current from the direct current power source 110 is converted into alternating current using semiconductor switching elements 101 to 106 such as IGBTs and diodes 201 to 206, and output to the three-phase alternating current motor 120. Note that the switching elements 101 to 106 are not limited to IGBTs, and can be configured by transistors, MOSFETs, or the like. A smoothing capacitor 111, a discharge resistor 112, a line bypass capacitor 113, and the like are connected between the DC wirings P and N.

  The high potential side (high side) of the power supply 110 is connected to the motor 120 via the wiring 151, the switching elements 101 to 103, and the wiring 153. The low potential side (low side) of the power supply 110 is connected to the motor 120 via the wiring 152, the switching elements 104 to 106 and the wiring 153.

  That is, the collectors (drains) of the high-side switching elements 101 to 103 are connected to the wiring 151, and the emitters (sources) of the low-side switching elements 104 to 106 are connected to the wiring 152. The emitter of the switching element 101 and the collector of the switching element 104 are connected to the inverter output (U-phase) wiring 153, respectively. The emitter of the switching element 102 and the collector of the switching element 105 are connected to the V-phase wiring 153, respectively. The emitter of switching element 103 and the collector of switching element 106 are each connected to wiring 153 for W phase. The gates of the switching elements 101 to 106 are connected to a signal input / output terminal 14 (see FIG. 2). Diodes 201 to 206 are connected in antiparallel between the collectors and emitters of the switching elements 101 to 106, respectively.

  In the present embodiment, a pair of high-side and low-side switching elements (for example, 101, 104) and a pair of diodes (for example, 201, 204) are integrated into a module for each phase of AC output to constitute a semiconductor module. FIG. 2 is a plan view of the semiconductor module 1 (U-phase module) corresponding to the U-phase circuit. The semiconductor module 1 is configured as a rhombus housing in plan view. The configurations of the V-phase module and the W-phase module are the same as those in FIG.

  In the semiconductor module 1, the switching element 101 and the diode 201 are each mounted on the conductive high side substrate 2, and the switching element 104 and the diode 204 are each mounted on the conductive low side substrate 3. That is, the electrodes on the back surface of the switching element 101 and the diode 201 are bonded to the upper surface of the substrate 2 via a conductive bonding material such as solder. The electrodes on the back surface of the switching element 104 and the diode 204 are connected to the upper surface of the substrate 3. Each electrode is surface bonded. A heat sink (not shown) is provided below the substrates 2 and 3, and the substrates 2 and 3 are fixed to the heat sink with an insulator interposed therebetween.

  From each side edge of the semiconductor module 1, a P-pole terminal 11 connected to the wiring 151, an N-pole terminal 12 connected to the wiring 152, an output terminal 13 connected to the wiring 153, and a signal input / output Terminals 14 are provided in a protruding manner. These terminals 11 to 14, the substrates 2 and 3, the switching elements 101 and 104, and the diodes 201 and 204 are connected to each other in the semiconductor module 1 by bonding wires or the like, so that the circuit of FIG. 1 is configured.

  The semiconductor module 1 is filled with a sealing material such as an epoxy resin for the purpose of preventing a short circuit between the collector and emitter of the semiconductor chip and protecting the bonding wire. A through hole 15 for module attachment is opened at the center of the semiconductor module 1, and the semiconductor module 1 can be attached by a bolt or the like through the through hole 15. The terminals 11 to 13 are so-called bus bars, and can be configured integrally with the substrates 2 and 3. The attachment positions of the terminals 11 to 14 are not limited to the illustrated positions.

  A characteristic configuration of the present embodiment will be described. As shown in FIG. 2, in the present embodiment, adjacent rectangular sides 2a and 3a of substantially rectangular substrates 2 and 3 having the same shape are opposed to each other, and the substrates 2 and 2a are arranged along the sides 2a and 3a. 3 are offset from each other. The semiconductor module 1 configured in this manner is attached to the side surface of the casing of the substantially cylindrical motor 120, for example. An example of mounting the semiconductor module 1 is shown in FIG. In FIG. 3, the U-phase module 1U, the V-phase module 1V, and the W-phase module 1W are radially arranged in the circumferential direction. Each module 1 is housed inside a sector having a central angle of 120 ° obtained by dividing a circular region by the number of phases 3.

  When the semiconductor modules 1 with the substrates 2 and 3 offset in this manner are arranged in the circumferential direction, the entire module can be accommodated inside a circle 4 indicated by a dotted line in the figure, and the entire power conversion device can be reduced in size. . On the other hand, when the semiconductor module 100 is configured by simply arranging the substrates 2 and 3 side by side as shown in FIG. 4, if the semiconductor module 100 is arranged in the circumferential direction, a wasteful space is increased, and the entire outer diameter is increased. Therefore, it is difficult to downsize the entire apparatus.

FIG. 5 is a diagram showing details of the semiconductor module 1 shown in FIG. The lengths of the substrates 2 and 3 in the longitudinal direction are a, the length in the short direction is b, the offset length is c, and the corners of the substrates 2 and 3 are d21 to d24 and d31 to d34, respectively. The corner portion d21 of the substrate 2 is disposed along the center O of the motor 120. At this time, the lengths L1 to L3 from the center O to the ends d23, d33, and d34 of the semiconductor module 1 are respectively expressed by the following equations (I) to (III).
L1 = √ (a ² + b ² ) (I)
L2 = √ ((ac) ² + (2b) ² ) (II)
L3 = √ (c ² + (2b) ² ) (III)

  In the above equation, L1 is determined only by the sizes of the substrates 2 and 3, whereas L2 and L3 are determined using the offset length c as a parameter. Therefore, by determining the offset length c so that L2 and L3 are shorter than L1, the outer diameter of the entire apparatus can be reduced, and downsizing is possible. In this case, L2> L3 when c <a/2, L2=L3 when c=a/2, and L2<L3 when c> a / 2.

  Here, in order to fit the semiconductor module 1 inside the 120 ° sector, it is necessary to set c = b / √3 from c / b = tan 30 °. Using this relationship, the aspect ratio of the substrates 2 and 3 can be determined. For example, the aspect ratio for setting L1 = L2 is a: b = 5: √3. As a result, the aspect ratio of the substrates 2 and 3 for downsizing the apparatus can be obtained.

  As described above, in the first embodiment, since the substrates 2 and 3 are offset from each other to configure the outer shape and contour of the semiconductor module 1, a plurality of semiconductor modules 1 can be efficiently arranged in a circular region. The entire apparatus can be reduced in size. Since the sizes a and b and the offset length c of the substrates 2 and 3 are set so that each module 1 falls within a fan-shaped range with a central angle of 120 °, the shape of the semiconductor module 1 can be easily optimized. When three modules 1 are arranged in the circumferential direction, the design is easy because the offset length c of the substrates 2 and 3 is determined so as to satisfy c = b / √3.

-Second Embodiment-
A second embodiment of the semiconductor device according to the present invention will be described with reference to FIGS.
In the first embodiment, the semiconductor modules 1 are configured by offsetting the substrates 2 and 3 from each other. However, in the second embodiment, the semiconductor substrate 1 is arranged by tilting the other substrate 3 with respect to one substrate 2. Module 1 is configured. In the following description, differences from the first embodiment will be mainly described.

  FIG. 6 is a view showing an example of attachment of the semiconductor module 1 according to the second embodiment, and FIG. 7 is a view showing details of the semiconductor module 1. The plan view of the semiconductor module 1 is the same as that shown in FIG. As shown in FIG. 7, in the second embodiment, the corner portion d <b> 32 of the substrate 3 is provided in contact with the longitudinal side of the substrate 2, and the substrate 3 is tilted with respect to the substrate 2. At this time, both end portions d22 and d23 of the short side of the substrate 2 and both end portions d33 and d34 of the long side of the substrate 3 are positioned on the same circle 4 centered on O. The arrangement of the substrate 2 and the substrate 3 may be reversed.

In this case, the triangle connecting the points d24, d32, and d31 in FIG. 7 is an isosceles triangle having an apex angle of 120 °, and the inclination angle of the substrate 3 with respect to the substrate 2 is 30 °. By reducing the isosceles triangle, the apparatus can be downsized. Here, the length L4 of the points d24 to d23 is a and is determined by the size of the substrates 2 and 3. On the other hand, the length L5 of the points d24 to d33 is expressed by the following formula (IV).
L2 = √ ((a / 2√3 + b) ² + (a / 2) ² ) (IV)
Therefore, the substrates 2 and 3 may be arranged so as to satisfy L5 ≦ L4. For example, if L4 = L5, a: b = √3: 1 is obtained, whereby the aspect ratio of the substrates 2 and 3 can be reduced. Can be requested.

  As described above, in the second embodiment, since the substrate 3 is arranged to be inclined with respect to the substrate 2, a plurality of semiconductor modules 1 can be efficiently arranged in a circular region, and the entire apparatus is reduced in size. be able to. The semiconductor module 1 is configured such that the short-side ends d22 and d23 of the substrate 2 and the long-side ends d33 and d34 of the substrate 3 are located on the same circle, and the entire apparatus is placed inside the circle 4. Therefore, the shape of the module 1 can be easily optimized. When three modules 1 are arranged in the circumferential direction, the substrates 2 and 3 may be arranged so that the angle formed by the substrate 3 with respect to the substrate 2 is 30 °, so that the design is easy.

  The example in which the module 1 of the three-phase inverter is arranged on the side surface of the cylindrical motor 120 has been described above, but it may be other than three-phase. An example is shown in FIGS. 8 and 9 are examples of a nine-phase inverter, and nine semiconductor modules 1 are arranged in the circumferential direction on the side surface of the motor 120. 8 is obtained by offsetting the substrates 2 and 3, and corresponds to FIG. FIG. 9 shows the substrate 3 inclined with respect to the substrate 2, and corresponds to FIG. In the present embodiment, the modules 1 are configured by offsetting or tilting the substrates 2 and 3, so that each module 1 can be efficiently arranged in a circular region even when the inverter is multiphased. .

  In this case, in the example shown in FIG. 9, the end portions 1 c and 1 d of other modules 1 adjacent in the circumferential direction are arranged in the sector-shaped minimum region including all of the single semiconductor module 1. The module 1 can be arranged with high density while avoiding interference with the module 1. In FIG. 7, since three modules 1 are arranged in the circumferential direction and the number of divisions in the circumferential direction is 3, the substrate 3 is inclined by 30 ° with respect to the substrate 2. For the number N, the substrate 3 may be inclined at an inclination angle θ that satisfies θ = (180-360 / N) / 2 or θ = (360 / N) / 2.

  In the above embodiment (FIGS. 3 and 5), the semiconductor modules 1 are configured by offsetting the substrates 2 and 3, and each module 1 is arranged in a fan-shaped region having a central angle of 120 °. As long as the module 1 is accommodated in a fan-shaped region divided in the circumferential direction by the number of phases of the inverter circuit, the central angle of the fan may be other than 120 °. In this case, it is preferable to set the offset length c so as to satisfy c = b · | tan ((360 / N) −90) |, where N is the number of divisions in the circumferential direction.

  In the above embodiment, the substrate 2 on which the high-potential side switching element 101 is mounted and the substrate 3 on which the low-potential side switching element 104 is mounted have the same shape. Module 1 may be arranged. Accordingly, in FIG. 7, the end portions d22, d23, d33, and d34 of the substrates 3 and 4 are arranged on the same circle, but they need not necessarily be on the same circle. The diodes 201 to 206 in the module 1 may be parasitic diodes instead of flywheel diodes, and the circuit configuration of the semiconductor device is not limited to that shown in FIG. In other words, the present invention is not limited to the semiconductor device of the embodiment as long as the features and functions of the present invention can be realized.

1 is a circuit diagram of a semiconductor device according to a first embodiment of the present invention. The top view of the semiconductor module which concerns on 1st Embodiment. The figure which shows the example of attachment of the semiconductor module of FIG. The figure which shows the example of attachment of the other semiconductor module compared with FIG. The figure which shows the detail of FIG. The figure which shows the example of attachment of the semiconductor module which concerns on 2nd Embodiment. The figure which shows the detail of FIG. The figure which shows the modification of FIG. The figure which shows the modification of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor module 2, 3 Board | substrates 101-106 Switching element 201-206 Diode c Offset length (theta) Inclination angle

Claims (8)

A high potential side switching element connected between the high potential side of the power source and the motor;
A low potential side switching element connected between the low potential side of the power source and the motor;
A first substrate having a substantially rectangular shape on which the high-potential side switching element is mounted;
In a semiconductor device comprising an inverter circuit including at least the second substrate having a substantially rectangular shape on which the low potential side switching element is mounted in the same module,
In the module, the first substrate and the second substrate are arranged so that adjacent one sides of each substrate face each other, and the substrates shift along the one side. Arranged ,
The module semiconductor device characterized that you have provided more than once in a circular area. The semiconductor device according to claim 1,
The module is provided in a number corresponding to at least the number of phases of the inverter circuit,
Each module, a semiconductor device, wherein a total each of which is housed in the circular area of the region of the substantially fan-shaped divided circumferentially or number of phases of the inverter circuit. The semiconductor device according to claim 2,
The first substrate and the second substrate have the same dimensions, and the one side is a side in the longitudinal direction of each substrate,
When the shift amount of the substrate is C, the number of divisions in the circumferential direction of the circular region is N, and the length of the side in the short direction of each substrate is X,
C = X · | tan ((360 / N) −90) |
Each of the substrates is provided so as to satisfy the above. A high potential side switching element connected between the high potential side of the power source and the motor;
A low potential side switching element connected between the low potential side of the power source and the motor;
A first substrate having a substantially rectangular shape on which the high-potential side switching element is mounted;
In a semiconductor device comprising an inverter circuit including at least the second substrate having a substantially rectangular shape on which the low potential side switching element is mounted in the same module,
In the module, the other substrate is inclined with respect to one substrate so that one corner of the other substrate is in contact with one side of either the first substrate or the second substrate. Arranged ,
The module semiconductor device characterized that you have provided more than once in a circular area. The semiconductor device according to claim 4,
The module is provided in a number corresponding to at least the number of phases of the inverter circuit,
Each module, while being housed respectively in said circular area was divided in the circumferential direction substantially fan-shaped area,
A semiconductor device, characterized in that an end portion of another module adjacent in the circumferential direction is arranged in a minimum fan-shaped region that accommodates all of one module. The semiconductor device according to claim 5,
When the inclination angle of the other substrate with respect to the one substrate is θ and the number of divisions in the circumferential direction of the circular region is N,
θ = (180-360 / N) / 2
A semiconductor device, wherein each substrate is arranged so as to satisfy The semiconductor device according to claim 5,
When the inclination angle of the other substrate with respect to the one substrate is θ and the number of divisions in the circumferential direction of the circular region is N,
θ = (360 / N) / 2
A semiconductor device, wherein each substrate is arranged so as to satisfy The semiconductor device according to any one of claims 5 to 7,
The first substrate and the second substrate have the same dimensions, and the one side is a longitudinal side of the one substrate,
Both ends of the short side of the one substrate in each module and both ends of the long side not including the one end of the other substrate are positioned on the same circle. A semiconductor device, wherein each substrate is provided.

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