Power conversion device

Abstract

To provide a power converter capable of reducing inductance.SOLUTION: A power converter includes: a substrate on which DC wiring and AC wiring are formed; and multiple circuit bodies that are electrically connected in parallel, each having a first terminal and a second terminal each connected to the DC wiring or the AC wiring. The first terminal and the second terminal are adjacent to each other projecting in a same direction in the circuit body, and the multiple circuit bodies are arranged so that the first terminal and the second terminal of each circuit body are aligned alternately on the substrate.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a power conversion device.

Background Art

[0002] In the following Patent Document 1, a configuration is disclosed in which upper and lower arm circuits constituting inverter circuit wiring are symmetrically arranged, and positive / negative terminals are alternately arranged and output.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Based on the conventional configuration, an object of the present invention is to provide a power conversion device that realizes further reduction in inductance while considering the insufficient inductance equalization of each mounted chip.

Means for Solving the Problems

[0005] According to the first aspect of the present invention The power conversion device includes a substrate on which a DC wiring and an AC wiring are formed, and a plurality of circuit bodies that are electrically connected in parallel and each have a first terminal and a second terminal connected to the DC wiring or the AC wiring. The first terminal and the second terminal are adjacent to each other in the circuit body and protrude in the same direction, and the plurality of circuit bodies are arranged such that the first terminals and the second terminals of each are alternately arranged on the substrate. , the plurality of circuit bodies include a first circuit body group composed of two or more circuit bodies that are electrically connected in parallel to form an upper arm, and a second circuit body group composed of two or more circuit bodies that are electrically connected in parallel to form a lower arm. The first circuit body group and the second circuit body group are arranged opposite to each other on the substrate with the DC wiring and the AC wiring interposed therebetween . The power conversion device according to the second aspect of the present invention includes a substrate on which DC wiring and AC wiring are formed, and a plurality of circuit bodies that are electrically connected in parallel and each have a first terminal and a second terminal connected to the DC wiring or the AC wiring. The first terminal and the second terminal are adjacent to each other in the circuit body and protrude in the same direction. The plurality of circuit bodies are arranged such that the first terminals and the second terminals of each are alternately arranged on the substrate. The plurality of circuit bodies are arranged such that the arrangement direction of the first terminal and the second terminal is perpendicular or parallel to the longitudinal direction of the DC wiring The power conversion device according to the third aspect of the present invention includes a substrate on which DC wiring and AC wiring are formed, a plurality of circuit bodies that are electrically connected in parallel and each have a first terminal and a second terminal connected to the DC wiring or the AC wiring, and a plurality of smoothing capacitors having long sides and short sides and electrically connected to the DC wiring. The first terminal and the second terminal are adjacent to each other in the circuit body and protrude in the same direction. The plurality of circuit bodies are arranged such that the first terminals and the second terminals of each are alternately arranged on the substrate. The plurality of smoothing capacitors are arranged such that the long sides are arranged parallel or perpendicular to the longitudinal direction of the DC wiring

Effects of the Invention

[0006] According to the present invention, a power conversion device with reduced inductance can be provided.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

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Figure 16

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and for the sake of clarity of explanation, appropriate omissions and simplifications are made. The present invention can also be implemented in various other forms. Unless otherwise limited, each component may be singular or plural.

[0009] The positions, sizes, shapes, ranges, etc. of the respective components shown in the drawings may not represent the actual positions, sizes, shapes, ranges, etc. in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings.

[0010] (Overall Configuration of an Embodiment of the Present Invention and the Apparatus) FIG. 1 is an external perspective view of the inverter.

[0011] The inside of the inverter housing 1 is sealed by the lid body 2, and a cooling water passage and inverter component parts described later are built in the housing 1. An AC connector 3 and a DC connector 4 project from the inverter housing 1, and a signal connector 5 is output from the lid body 2.

[0012] FIG. 2 is an overall perspective view of the inverter after the lid body is released. FIG. 3 is a cut perspective view of the A-A cut line in FIG. 2 as viewed from the R direction. FIG. 4 is a cross-sectional view of the A-A section in FIG. 2.

[0013] In the inverter housing 1, a motor control board 6, a gate drive board 7, a smoothing capacitor 8, an EMC filter 9, a cooling water passage 10, and a main circuit unit 11 (the area surrounded by the dotted line in FIG. 4) are arranged. The motor control board 6 is mounted above the housing 1 so as to cover the gate drive board 7, the cooling water passage 10, and the main circuit unit 11. A signal connector 5 is mounted on the motor control board 6 and projects to the outside through the lid body 2 as described above.

[0014] A board bonding pin 12 is mounted on the gate drive board 7 (see FIG. 4). The board bonding pin 12 is electrically connected to a board bonding through hole 22 (see FIG. 6) of the main circuit unit 11 by a bonding material such as solder. The main circuit unit 11 is fixed with the cooling water passage 10 sandwiching it in the vertical direction of the paper surface.

[0015] FIG. 5 is an exploded perspective view of the cooling unit and the main circuit unit in FIG. 4.

[0016] The main circuit unit 11 has power semiconductor elements mounted on a plurality of lead packages and main circuit wirings for each part. By being sandwiched and fixed by the cooling water channel 10, each element and each circuit wiring are cooled.

[0017] FIG. 6 is a perspective view of the main circuit unit of FIG. 5.

[0018] The main circuit unit 11 mounts a plurality of transfer molded circuit bodies 50 (chip molded packages) on the main circuit printed board 13. In the main circuit unit 11, a total of 12 circuit bodies 50 are provided, two for each of the upper arm and the lower arm for each phase of the three-phase AC power output by the inverter. However, the number of circuit bodies 50 provided in the main circuit unit 11 is not limited to this, and the main circuit unit 11 can be configured using any number of circuit bodies 50.

[0019] On the main circuit printed board 13, a DC connection part 20 and an AC connection part 21 are formed, and an AC bus bar and a DC bus bar connected to the AC connector 3 and the DC connector 4 described in FIG. 2 above are electrically joined by being screwed and fastened respectively. Further, on the main circuit unit 11, a board bonding through hole 22 and a capacitor bonding through hole 23 are formed, and are electrically connected to the gate drive board 7, the smoothing capacitor 8, etc. described above through a bonding material such as solder. Note that the gate drive board 7 is electrically connected to the control signal terminal 36 of the circuit body 50 described later, and the smoothing capacitor 8 is electrically connected to the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15 described later.

[0020] FIG. 7 is a partially enlarged view of the semiconductor module part of FIG. 6 according to an embodiment of the present invention, FIG. 8 is a cross-sectional view taken along line A’-A’ of FIG. 7, FIG. 9(a) is an enlarged view of the circuit body of FIG. 7, and FIG. 9(b) is an electrical circuit diagram.

[0021] The circuit body 50 of the main circuit unit 11 includes a SiC-MOS element, a first terminal 30, a second terminal 31, and a control signal terminal 36. The circuit body 50 is arranged on the main circuit printed board 13, and on its upper and lower sides, a DC positive electrode wiring pattern 14 (back) and a DC negative electrode wiring pattern 15 (front), which are DC bus bars, and an AC wiring pattern 16, which is an AC bus bar, are formed.

[0022] The DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15 overlap each other in the thickness direction of the main circuit printed board 13 in the upper region of FIG. 7. In this region, the front side (front side) of FIG. 7 is the DC negative electrode wiring pattern 15, and the back side (front side) of the paper is the DC positive electrode wiring pattern 14. On the other hand, in the region sandwiched between the circuit bodies 50 in the lower part of FIG. 7, the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15 are arranged side by side in the plane direction of the main circuit printed board 13 and overlap with the AC wiring pattern 16. In this region, the AC wiring pattern 16 is formed wider than the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15 on the main circuit printed board 13. Also, the parts of the AC wiring pattern 16 that do not overlap with the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15 are formed on the front and back surfaces of the main circuit printed board 13, and their respective currents are opposed.

[0023] As shown in Fig. 9(a), the circuit body 50 has a side surface where the control signal terminal 36 protrudes externally, and a side surface where the first terminal 30 and the second terminal 31 are arranged adjacent to each other and protrude externally in the same direction, and is sealed with the mold resin 35. As shown in Fig. 9(b), the first terminal 30 and the second terminal 31 respectively correspond to the drain terminal and the source terminal of an N-channel type SiC-MOS element. In the case of the circuit body 50 of the upper arm, the first terminal 30 is connected to the DC positive electrode wiring pattern 14, and the second terminal 31 is connected to the AC wiring pattern 16. On the other hand, in the case of the circuit body 50 of the lower arm, the first terminal 30 is connected to the AC wiring pattern 16, and the second terminal 31 is connected to the DC negative electrode wiring pattern. Note that the electrical circuit diagram of the circuit body 50 shown in Fig. 9(b) is an example and is not limited thereto. For example, the first terminal 30 and the second terminal 31 may be interchanged, or a P-channel type SiC-MOS element may be used instead of the N-channel type SiC-MOS element.

[0024] As shown in Fig. 7, in the main circuit unit 11, with the DC positive electrode wiring pattern 14, the DC negative electrode wiring pattern 15, and the AC wiring pattern 16 interposed therebetween, a pair of circuit bodies 50 are arranged opposite to each other on both sides of these wiring patterns on the main circuit printed board 13. Also, each pair of circuit bodies 50 are arranged in such a direction that their respective first terminals 30 and second terminals 31 are alternately arranged on the wiring pattern side. And the two circuit bodies 50 arranged on the left side of Fig. 7 are electrically connected in parallel to form the upper arm by connecting their respective first terminals 30 and second terminals 31 to the DC positive electrode wiring pattern 14 and the AC wiring pattern 16 respectively. On the other hand, the two circuit bodies 50 arranged on the right side of Fig. 7 are electrically connected in parallel to form the lower arm by connecting their respective first terminals 30 and second terminals 31 to the AC wiring pattern 16 and the DC negative electrode wiring pattern 15 respectively. By the main circuit unit 11 having three such combinations of the circuit bodies 50, an inverter that converts DC power into three-phase AC power is configured. Note that the arrangement direction (the vertical direction in Fig. 7) of the first terminal 30 and the second terminal 31 of each circuit body 50 is perpendicular to the longitudinal direction (the left-right direction in Fig. 7) of the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15.

[0025] As a result, between the first terminal 30 and the second terminal 31 of each circuit body 50, and between adjacent circuit bodies 50, that is, between the first terminal 30 of one circuit body 50 and the second terminal 31 of the other circuit body 50, the directions of the currents flowing through them are opposite to each other, and their magnetic fields can cancel each other out. Therefore, combined with the laminated structure of the aforementioned DC positive wiring pattern 14 and DC negative wiring pattern 15 on the main circuit printed circuit board 13, the inductance can be reduced due to the magnetic field cancellation effect.

[0026] FIG. 10 is an assembled view of the main circuit unit of FIG. 6. FIG. 11 is an exploded view of the circuit body.

[0027] The circuit bodies 50 for each of the upper and lower arms are inserted into the through holes 27 formed in the main circuit printed circuit board 13, thereby being connected to the DC positive wiring pattern 14 and the DC negative wiring pattern 15, resulting in the structure of a card-type inverter. Also, the snubber capacitor 40 is installed on the substrate 13 between the inserted circuit bodies 50.

[0028] The circuit body 50 has a SiC-MOS element 41 between a first lead frame 32 having a control signal terminal 36 and a first terminal 30, and a second lead frame 33 having a second terminal 31 and pedestal electrodes 34, and the whole is sealed by transfer molding. The pedestal electrodes 34 are for electrically connecting the surface electrodes of the SiC-MOS element 41 while the second lead frame 33 maintains an insulating distance from the first lead frame 32.

[0029] When the circuit body 50 is inserted into the through hole 27, the heat dissipation surface of the circuit body 50 is exposed from the back surface of the through hole 27. As a result, the SiC-MOS element 41 dissipates heat from both-sided electrodes through the lead frames 32 and 33.

[0030] FIG. 12 is an electrical circuit diagram of the main circuit unit. Note that FIG. 12 shows the electrical circuit diagram of the upper and lower arm circuits for one phase out of the three-phase upper and lower arm circuits of the main circuit unit 11.

[0031] A transient current 65 generated during switching flows through the electrical circuit of the main circuit unit 11. Conventionally, by utilizing the circuit body 50 in a small-piece package and omitting the joints by integrating the substrate and the main circuit wiring, mass production of the inverter has been made possible. However, in order to improve the switching speed by connecting the circuit bodies 50 in parallel, further inductance reduction is required for current balance of the transient current 65, surge voltage reduction, and loss reduction.

[0032] Therefore, in the present invention, as described above, the first terminals 30 and the second terminals 31 of the two circuit bodies 50 connected in parallel to each of the upper and lower arms are alternately arranged, and the first terminals 30 and the second terminals 31 of each circuit body 50 of the upper arm and the first terminals 30 and the second terminals 31 of each circuit body 50 of the lower arm are arranged to face each other with the DC positive electrode wiring pattern 14, the DC negative electrode wiring pattern 15, and the AC wiring pattern 16 interposed therebetween. Thereby, the inductance of the drain / source terminal portion where the inductance is maximized in the circuit body 50 can be reduced. According to the experimental results, it has been found that conventionally it was 5 nH per circuit body (1 PKG), but by implementing the embodiment of the present invention, it can be reduced to 2 nH per circuit body (1 PKG).

[0033] In the embodiment described above, an example in which the upper and lower arms of the inverter are respectively constituted by two circuit bodies 50 connected in parallel has been described. However, the number of circuit bodies 50 connected in parallel is not limited to two, and it is possible to further increase the number. Even in that case, by adopting the same circuit arrangement as in FIG. 7, the drain / source terminals of each circuit body 50 are arranged to face each other between the upper arm and the lower arm, and the drain / source terminals of the circuit bodies 50 connected in parallel in each of the upper and lower arms are arranged to be alternately aligned, so that each can be connected to the corresponding wiring pattern. As a result, while taking advantage of the benefit of increasing the number of parallel circuit bodies 50 which are SiC small chips, since the layout is such that the switching transient currents flow in opposite directions, the wiring inductance can be reduced as the number of parallel elements increases.

[0034] (Modification Example 1) FIG. 13 is a diagram showing a first modification example of the present invention, and corresponds to FIG. 7.

[0035] Different from the arrangement of the circuit body 50 shown in FIG. 7, in the arrangement of the circuit body 50 of the first modification example shown in FIG. 13, the arrangement direction of the first terminal 30 and the second terminal 31 of each circuit body 50 is parallel to the left-right direction of FIG. 13, that is, the longitudinal direction of the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15 (the left-right direction of FIG. 13). Even with such an arrangement, the effect of reducing the wiring inductance as described above can be obtained.

[0036] (Modification Example 2) FIG. 14 is a diagram showing a second modification example of the present invention, and corresponds to FIG. 6.

[0037] In the foregoing embodiment, as can be seen from FIGS. 2 and 3, the plurality of smoothing capacitors 8 are arranged side by side such that the long sides of each smoothing capacitor 8 are perpendicular to the longitudinal direction of the main circuit unit 11 (the longitudinal direction of the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15). On the other hand, in the second modification shown in FIG. 14, the plurality of smoothing capacitors 8 are arranged side by side such that the long sides of each smoothing capacitor 8 are parallel to the longitudinal direction of the main circuit unit 11. By doing so, the vertical dimension of FIG. 14 can be made smaller than that of FIG. 6, so that the inverter can be further miniaturized.

[0038] (Modification 3) FIG. 15 is a diagram showing a third modification of the present invention and corresponds to FIG. 7.

[0039] In the main circuit unit 11, a snubber capacitor 40 is disposed between the circuit body 50 on the upper arm circuit side and the circuit body 50 on the lower arm circuit side. The snubber capacitor 40 is connected to the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15.

[0040] (Modification 4) FIG. 16 is a diagram showing a fourth modification of the present invention and corresponds to FIG. 7.

[0041] The embodiment of the present invention can also be applied to the boost converter 101. In the boost converter 101, the boost circuit unit 103 has the same configuration as the main circuit unit 11 in the foregoing embodiment. The boost converter 101 is constituted by the boost circuit unit 103, a smoothing capacitor element 8 electrically connected to the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15, and a boost reactor 102 electrically connected to the AC wiring pattern 16.

[0042] In FIG. 16, the smoothing capacitor element 8 and the boost reactor 102 are omitted and only one of each is shown. Actually, a plurality of these are provided side by side in the longitudinal direction of the boost circuit unit 103. At this time, as shown in FIGS. 2 and 3, the long sides of each smoothing capacitor 8 may be arranged side by side in a direction perpendicular to the longitudinal direction of the boost circuit unit 103 (the longitudinal direction of the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15). Alternatively, as described with reference to FIG. 14, the long sides of each smoothing capacitor 8 may be arranged side by side in a direction parallel to the longitudinal direction of the boost circuit unit 103 (the longitudinal direction of the DC positive electrode wiring pattern 14 and the DC negative electrode wiring pattern 15). The same applies to the boost reactor 102. Thereby, also in the boost converter 101, the same effect as the inductance reduction of the inverter shown in the embodiment of the present invention can be obtained.

[0043] According to one embodiment of the present invention described above, the following operational effects are achieved.

[0044] (1) The power conversion device includes a substrate 13 on which DC wiring and AC wiring are formed, and a plurality of circuit bodies 50 that are electrically connected in parallel and each have a first terminal 30 and a second terminal 31 connected to the DC wiring or the AC wiring. The first terminal 30 and the second terminal 31 are adjacent to each other in the circuit body 50 and protrude in the same direction, and the plurality of circuit bodies 50 are arranged such that the first terminals 30 and the second terminals 31 of each are alternately arranged on the substrate 13. By doing so, a power conversion device with reduced inductance can be provided.

[0045] (2) The power conversion device has a first circuit body group composed of a plurality of circuit bodies 50 that are electrically connected in parallel to form an upper arm, and a second circuit body group composed of a plurality of circuit bodies 50 that are electrically connected in parallel to form a lower arm. The first circuit body group and the second circuit body group are arranged opposite to each other on the substrate 13 with the DC wiring and the AC wiring interposed therebetween. By doing so, it is possible to reduce the inductance due to the magnetic field cancellation effect.

[0046] (3) In the power conversion device, the plurality of circuit bodies 50 are arranged such that the arrangement direction of the first terminal 30 and the second terminal 31 is perpendicular to the longitudinal direction of the DC wiring. By doing so, the dimension in the left - right direction of the substrate 13 can be reduced.

[0047] (4) In the power conversion device, the plurality of circuit bodies 50 are arranged such that the arrangement direction of the first terminal 30 and the second terminal 31 is parallel to the longitudinal direction of the DC wiring. By doing so, the dimension in the up - down direction of the substrate 13 can be reduced.

[0048] (5) The power conversion device has a long side and a short side, and includes a plurality of smoothing capacitors 8 electrically connected to the DC wiring. The plurality of smoothing capacitors 8 are arranged side by side such that the long side is perpendicular or parallel to the longitudinal direction of the DC wiring. By doing so, the dimensions in the left - right direction and the up - down direction can be reduced.

[0049] (6) The power conversion device includes a snubber capacitor 40 arranged between the first circuit body group and the second circuit body group, and the DC wiring is connected to the snubber capacitor 40. By doing so, it contributes to the reduction of inductance.

[0050] (7) Provided is a boost converter 101 including the power conversion device, further including a smoothing capacitor 8 electrically connected to the DC wiring and a boost reactor 102 electrically connected to the AC wiring. By doing so, a boost converter 101 with reduced inductance can be provided.

[0051] Note that the present invention is not limited to the above - described embodiments, and various modifications and combinations with other configurations can be made without departing from the gist thereof. Also, the present invention is not limited to those having all the configurations described in the above - described embodiments, and those in which a part of the configuration is deleted are also included.

Description of Reference Numerals

[0052] 1 Inverter housing 2 Cover 3 AC connector 4 DC connector 5 Signal connector 6 Motor control board 7 Gate drive board 8 Smoothing capacitor 9 EMC filter 10 Cooling water path 11 Main circuit unit 12 Board bonding pin 13 Main circuit printed board 14 DC positive wiring pattern 15 DC negative wiring pattern 16 AC wiring pattern 20 DC connection part 21 AC connection part 30 First terminal 31 Second terminal 32 First lead frame 33 Second lead frame 34 Pedestal electrode 35 Mold resin 36 Control signal terminal 40 Snubber capacitor (ceracon) 41 SiC-MOS element 50 Circuit body (small chip mold PKG) 65 Transient current 101 Boost converter 102 Boost reactor 103 Boost circuit unit

Claims

1. A substrate on which a DC wiring and an AC wiring are formed, and a plurality of circuit bodies that are electrically connected in parallel and each have a first terminal and a second terminal connected to the DC wiring or the AC wiring, wherein the first terminal and the second terminal are adjacent to each other in the circuit body and protrude in the same direction, the plurality of circuit bodies are arranged such that the first terminals and the second terminals thereof are alternately arranged on the substrate, the plurality of circuit bodies include a first circuit body group composed of two or more circuit bodies that are electrically connected in parallel to form an upper arm, and a second circuit body group composed of two or more circuit bodies that are electrically connected in parallel to form a lower arm, the first circuit body group and the second circuit body group are arranged to face each other on the substrate with the DC wiring and the AC wiring therebetween A power conversion device.

2. The power conversion device according to claim 1, further comprising a snubber capacitor disposed between the first circuit body group and the second circuit body group, wherein the snubber capacitor is connected to the DC wiring A power conversion device.

3. A substrate on which a DC wiring and an AC wiring are formed, and a plurality of circuit bodies that are electrically connected in parallel and each have a first terminal and a second terminal connected to the DC wiring or the AC wiring, wherein the first terminal and the second terminal are adjacent to each other in the circuit body and protrude in the same direction, the plurality of circuit bodies are arranged such that the first terminals and the second terminals thereof are alternately arranged on the substrate, the plurality of circuit bodies are arranged such that the arrangement direction of the first terminal and the second terminal is perpendicular or parallel to the longitudinal direction of the DC wiring A power conversion device.

4. A substrate on which a DC wiring and an AC wiring are formed, and a plurality of circuit bodies that are electrically connected in parallel and each have a first terminal and a second terminal connected to the DC wiring or the AC wiring, a plurality of smoothing capacitors having long sides and short sides and electrically connected to the DC wiring, wherein the first terminal and the second terminal are adjacent to each other in the circuit body and protrude in the same direction, the plurality of circuit bodies are arranged such that the first terminals and the second terminals thereof are alternately arranged on the substrate, the plurality of smoothing capacitors are arranged such that the long sides are arranged side by side in a direction perpendicular or parallel to the longitudinal direction of the DC wiring Power conversion device.

5. The power conversion device according to any one of claims 1 to 3, a smoothing capacitor electrically connected to the DC wiring, and a smoothing reactor electrically connected to the AC wiring. Boost converter.

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