Inverter

Abstract

To realize miniaturization of an inverter.SOLUTION: An inverter includes a first substrate, a second substrate, a support member, a plurality of capacitors, and a plurality of power elements. A plurality of electrodes are mounted on the mounting surface of the first substrate. The second substrate is disposed such that its main surface faces the mounting surface of the first substrate. The support member is a support member that supports the second substrate, and includes a first bus bar and a second bus bar that are disposed in parallel to the mounting surface. The plurality of capacitors are disposed between the first bus bar and the second bus bar on the mounting surface. The plurality of power elements are arranged in a row so as to sandwich the first bus bar between the mounting surface and the plurality of capacitors.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inverter. [Background technology]

[0002] Conventionally, inverters have been known in which multiple boards on which various electronic components are mounted are stacked. For this type of inverter, a configuration has been proposed in which a control board on which a control circuit is mounted, a capacitor board on which capacitors are mounted, and a power board on which power elements are mounted are stacked (see, for example, Patent Document 1).

[0003] In addition, in the power board shown in Patent Document 1, multiple electrodes are arranged in a row, and bus bars extending in a direction different from the arrangement direction of the electrodes are arranged at the position of each electrode. In Patent Document 1, multiple power elements are arranged between each bus bar in the extension direction of the bus bars. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-023181 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional technologies have room for further improvement in terms of inverter miniaturization. For example, with the technology described in Patent Document 1, when configuring a low-output inverter by reducing the number of power elements, the board area can be reduced by the amount of the reduced power elements. However, because a space for fasteners must be secured within the busbar area where the busbars are arranged on the board, securing a certain area or more for the busbar area excluding the fastener area results in a larger busbar area, which may make it impossible to reduce the board area.

[0006] The present invention has been made in view of the above, and has an object to provide an inverter that can be made smaller. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the inverter of the present invention includes a first substrate, a second substrate, a support member, a plurality of capacitors, and a plurality of power elements. The first substrate has a plurality of electrodes mounted on a mounting surface. The second substrate is disposed with its main surface facing the mounting surface of the first substrate. The support member supports the second substrate and has a first bus bar and a second bus bar disposed in parallel on the mounting surface. The plurality of capacitors are disposed between the first bus bar and the second bus bar on the mounting surface. The plurality of power elements are disposed in a row on the mounting surface with the first bus bar sandwiched between the plurality of capacitors. [Effects of the Invention]

[0008] According to the present invention, by arranging a first bus bar in parallel between a row of capacitors and a row of power elements on the same board, it is possible to electrically connect multiple capacitors and multiple power elements with a single set of bus bars (first bus bar and second bus bar). This reduces the number of bus bars, and the area required for fasteners can be reduced accordingly. Therefore, the area of ​​the first board can be reduced, allowing the inverter to be made smaller. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an exploded perspective view of an inverter according to a first embodiment. [Figure 2] FIG. 2 is a top view of the inverter according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the inverter according to the first embodiment. [Figure 4]FIG. 4 is an exploded perspective view of the inverter according to the second embodiment. [Figure 5] FIG. 5 is an exploded perspective view of an inverter according to a first modified example. [Figure 6] FIG. 6 is a cross-sectional view of an inverter according to a first modification. [Figure 7] FIG. 7 is an exploded perspective view of an inverter according to a second modification. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An inverter according to an embodiment will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

[0011] In the following, a case where the first substrate (power substrate 3) is a resin substrate will be described as a first embodiment, and a case where the first substrate is a metal substrate will be described as a second embodiment.

[0012] First, a first embodiment will be described with reference to Figs. 1 to 3. Fig. 1 is an exploded perspective view of an inverter 1 according to the first embodiment. Fig. 2 is a top view of the inverter 1 according to the first embodiment. Fig. 3 is a cross-sectional view of the inverter 1 according to the first embodiment. Note that Fig. 3 shows a cross section taken along line AA in Fig. 2.

[0013] As shown in Fig. 1, the inverter 1 according to the first embodiment includes a control board 2, a power board 3, and a heat sink 4. The inverter 1 is arranged in the order of the control board 2, the power board 3, and the heat sink 4 from the top down. The power board 3 is an example of a first board, and the control board 2 is an example of a second board.

[0014] The control board 2 is a resin board on which a control circuit that controls the inverter 1 is mounted. The control board 2 is disposed with its main surface facing the mounting surface 3a of the power board 3. The control board 2 also has a plurality of through holes 2a and 2b into which fasteners (not shown) are inserted to collectively fix the control board 2, the power board 3, and the heat sink 4.

[0015] The power board 3 is a board on which electronic components related to current conversion are mounted. In the first embodiment, the power board 3 is configured as a resin board. Various electronic components are mounted on a mounting surface 3a of the power board 3, which is the main surface facing the control board 2. Specifically, the power board 3 has a plurality of electrodes 31, a plurality of power elements 32, a first bus bar 33, a second bus bar 34, and a plurality of capacitors 35 mounted on the mounting surface 3a. Furthermore, the power board 3 configured as a resin board is a multi-layer board on which wiring layers that electrically connect the various electronic components are stacked.

[0016] The electrodes 31 are mounted in a row, with a plurality of input electrodes 31a that receive DC current from the outside and a plurality of output electrodes 31b that output AC current to the outside (motor). Specifically, the input electrodes 31a and the output electrodes 31b are arranged on the side of the power elements 32 with respect to the first bus bar 33. The input electrodes 31a include positive and negative electrodes, and are arranged at one end and the other end of the row of the electrodes 31. The output electrodes 31b include phase electrodes corresponding to each phase of the three-phase AC current (U phase, V phase, W phase), and are arranged between the positive and negative input electrodes 31a.

[0017] The power elements 32 are switching elements made of semiconductors such as transistors. The power elements 32 are arranged in a row on the electrodes 31 side of the first bus bar 33. Specifically, the power elements 32 are composed of a plurality of first power elements 32a on the positive side and a plurality of second power elements 32b on the negative side, with the first power elements 32a and the second power elements 32b arranged on both sides of each output electrode 31b. This allows the first power elements 32a and the second power elements 32b to be connected to each output electrode 31b over the shortest distance. Furthermore, arranging the power elements 32 and the electrodes 31 in the same row saves space and reduces the area of ​​the power board 3. This allows the inverter 1 to be made smaller.

[0018] The first bus bar 33 is a rod-shaped metal member that electrically connects the positive input electrode 31a, the first power element 32a, and the plurality of capacitors 35. The first bus bar 33 is disposed between the row of the plurality of power elements 32 and the row of the plurality of capacitors 35. The top surface of the first bus bar 33 (the surface facing the control board 2) is provided with a plurality of through holes 33a into which fasteners (not shown) are inserted.

[0019] The second bus bar 34 is a rod-shaped metal member that electrically connects the negative input electrode 31a, the second power element 32b, and the plurality of capacitors 35. The second bus bar 34 is arranged in parallel with the first bus bar 33 on the side of the plurality of capacitors 35 with respect to the first bus bar 33. The second bus bar 34 is also arranged in a position where the plurality of capacitors 35 is sandwiched between the second bus bar 34 and the first bus bar 33. The top surface of the second bus bar 34 (the surface facing the control board 2) is provided with a plurality of through holes 34a into which fasteners (not shown) are inserted.

[0020] The plurality of capacitors 35 are smoothing capacitors that smooth current input from the outside. The plurality of capacitors 35 are arranged in a row between the first bus bar 33 and the second bus bar 34. In other words, the plurality of capacitors 35 are arranged in a row so that the first bus bar 33 is sandwiched between the plurality of power elements 32. By arranging the plurality of capacitors 35 in a row between the first bus bar 33 and the second bus bar 34 in this way, even if the capacitors 35 tilt, they are supported by the first bus bar 33 and the second bus bar 34, and therefore, they can be prevented from falling off the power board 3. Furthermore, although the plurality of capacitors 35 are arranged in a row in the example shown in FIG. 1 , the plurality of capacitors 35 may also be arranged closely together, for example, in a staggered arrangement. This also prevents the plurality of capacitors 35 from falling off the power board 3.

[0021] The heat sink 4 is a heat dissipation member disposed opposite the rear side of the mounting surface 3a of the power board 3. The heat sink 4 dissipates heat generated in the power board 3. The heat sink 4 is provided with a plurality of fastening holes 4a and 4b into which fasteners (not shown) are inserted to collectively fasten the control board 2, the power board 3, and the heat sink 4. The heat sink 4 is also provided with fixing holes 4c into which the electrodes 31 are fixed.

[0022] 2, the through hole 2a of the control board 2, the through hole 33a of the first bus bar 33, and the fastening hole 4a of the heat sink 4 are positioned to overlap in a top view, and a fastener (not shown) is inserted therethrough. The through hole 2b of the control board 2, the through hole 34a of the second bus bar 34, and the fastening hole 4b of the heat sink 4 are positioned to overlap in a top view, and a fastener (not shown) is inserted therethrough. This allows the inverter 1 to fix the control board 2, power board 3, and heat sink 4 together using a fastener (not shown).

[0023] As shown in the cross-sectional view of FIG. 3 , the control board 2 is supported by the first bus bar 33 and the second bus bar 34. Specifically, the control board 2 is supported by the first bus bar 33 via the first insulating member 37 and the second bus bar 34 via the second insulating member 36. That is, the first bus bar 33 and the first insulating member 37, and the second bus bar 34 and the second insulating member 36 are support members that support the control board 2. As shown in FIG. 3 , the first bus bar 33 and the first insulating member 37, and the second bus bar 34 and the second insulating member 36 are configured to be taller than the capacitors 35. This allows multiple capacitors 35 to be arranged between the control board 2 and the power board 3.

[0024] In this way, in the inverter 1 according to the first embodiment, the first bus bar 33 is arranged in parallel between the row of capacitors 35 and the row of power elements 32 arranged on the same board, so that the capacitors 35 and the power elements 32 can be electrically connected using one set of bus bars. This reduces the number of bus bars, and the number of fastening holes (through holes 33a, 34a) is reduced accordingly, allowing the area of ​​the power board 3 to be reduced. Furthermore, by mounting the capacitors 35 and the power elements 32 on the power board 3, a two-layer configuration consisting of the control board 2 and the power board 3 can be achieved, allowing the height of the inverter 1 to be reduced compared to a conventional three-layer configuration (control board, capacitor board, and power board). This allows the inverter 1 to be made smaller.

[0025] In addition, in the present disclosure, a multilayer board made of a resin material can be used for the power board 3 of the low-output inverter 1, and stacking wiring layers eliminates the need to stack a conventional capacitor on a separate board, thereby achieving miniaturization. Also, in the present disclosure, the use of large first bus bar 33 and second bus bar 34 can suppress heat generation in the power elements 32 and capacitors 35.

[0026] Next, a second embodiment will be described. In the following, configurations different from the first embodiment will be mainly described, and descriptions of configurations that are the same as those in the first embodiment may be omitted. Figure 4 is an exploded perspective view of the inverter 1 according to the second embodiment.

[0027] As described above, in the inverter 1 according to the second embodiment, the power board 3 is formed of a metal board. In the second embodiment, since the power board 3 is a metal board, it is not possible to use multilayer wiring as in the first embodiment, and therefore it is necessary to connect the intersections of the wires via bus bars. Specifically, since the first bus bar 33 is disposed between the second power element 32b and the second bus bar 34, any attempt to pass the wires through will result in the wires intersecting the first bus bar 33.

[0028] 4, the first bus bar 33 has a through hole 33b that penetrates between the second bus bar 34 side and the multiple power elements 32 side. The second bus bar 34 has a main bar 34b1 that is parallel to the first bus bar 33 and an extension bar 34b2 that extends from the main bar 34b1 through the through hole 33b toward the multiple power elements 32 side. The main bar 34b1 and the extension bar 34b2 may be integrally formed, or may be formed by connecting separate bus bar members. Inside the through hole 33b, the first bus bar 33 and the extension bar 34b2 are electrically insulated from each other by an insulating member provided between them.

[0029] This allows the second bus bar 34 (extension bar 34b2) and the second power element 32b to be connected by wiring. As a result, in the inverter 1 according to the second embodiment, by arranging the first bus bar 33 in parallel between a row of capacitors 35 and a row of power elements 32 arranged on the same board, the capacitors 35 and the power elements 32 can be electrically connected using a single set of bus bars. This reduces the number of bus bars, and the number of fastening holes (through holes 33a, 34a) is reduced accordingly, thereby reducing the area of ​​the power board 3. Furthermore, by mounting the capacitors 35 and the power elements 32 on the power board 3, a two-layer structure consisting of the control board 2 and the power board 3 can be achieved, thereby reducing the height of the inverter 1 compared to a conventional three-layer structure (control board, capacitor board, and power board). This allows the inverter 1 to be made smaller.

[0030] Furthermore, in the inverter 1 according to the second embodiment, by employing a metal substrate for the power substrate 3, high output can be achieved.

[0031] Next, modified examples of the inverter 1 according to the present disclosure will be described with reference to FIGS. 5 to 7. FIG. 5 is an exploded perspective view of the inverter 1 according to a first modified example. FIG. 6 is a cross-sectional view of the inverter 1 according to the first modified example. Note that the first modified example is applicable to both the first and second embodiments described above. In the following, configurations different from the first and second embodiments will be mainly described, and descriptions of configurations that are the same as the first and second embodiments may be omitted.

[0032] As shown in FIG. 5, the first modified example differs from the first and second embodiments described above in the shape of the bus bars (first bus bar 33 and second bus bar 34) and the shape of the heat sink 4.

[0033] Specifically, the first bus bar 33 has a protrusion 332 (hereinafter referred to as the first protrusion 332) that protrudes from the mounting surface 3a. Specifically, the first bus bar 33 has a main body 331 provided at a position overlapping the mounting surface 3a in a top view, a first protrusion 332 that protrudes from the main body 331, and a connecting portion 333 that connects the main body 331 and the first protrusion 332. The first protrusion 332 is provided with a through hole 332a into which a fastener 100 (described later) is inserted. The first protrusion 332 and the connecting portion 333 are provided at both ends of the first bus bar 33 in the extension direction. Note that the first protrusion 332 and the connecting portion 333 may be provided at only one end of the first bus bar 33 in the extension direction.

[0034] The second bus bar 34 also has a protrusion 342 (hereinafter referred to as the first protrusion 342) that protrudes from the mounting surface 3a. Specifically, the second bus bar 34 has a main body 341 provided at a position overlapping the mounting surface 3a in a top view, a first protrusion 342 that protrudes from the main body 341, and a connecting portion 343 that connects the main body 341 and the first protrusion 342. The first protrusion 342 has a through hole 342a into which a fastener 100 (described later) is inserted. The first protrusion 342 and the connecting portion 343 are provided at both ends of the second bus bar 34 in the extension direction. Note that the first protrusion 342 and the connecting portion 343 may be provided at only one end of the second bus bar 34 in the extension direction.

[0035] The heat sink 4 has protrusions 41 (hereinafter referred to as second protrusions 41) that protrude from the mounting surface 3a at positions that overlap the first protrusions 332, 342 in a top view. The second protrusions 41 are provided on both ends of the heat sink 4 and are stepped portions that are thicker than the central portion. The second protrusions 41 are provided with fastening holes 41a, 41b into which fasteners 100, which will be described later, are inserted. Specifically, the fastening hole 41a is provided at a position that overlaps the through hole 332a of the first protrusion 332 in a top view. The fastening hole 41b is provided at a position that overlaps the through hole 342a of the first protrusion 342 in a top view.

[0036] As shown in Fig. 6, the first protrusion 332 and the second protrusion 41 are fixed by inserting a fastener 100 into the through hole 332a and the fastening hole 41a. Specifically, the first protrusion 332 and the second protrusion 41 are fixed to each other via the insulating member 120. Note that while Fig. 6 illustrates the fixing configuration of the first protrusion 332 and the second protrusion 41, the first protrusion 342 and the second protrusion 41 are fixed in a similar manner, and therefore a description thereof will be omitted.

[0037] This allows the heat generated in the first bus bar 33 (second bus bar 34) to be transferred directly to the heat sink 4 without passing through the power board 3, and dissipated.

[0038] Furthermore, the connecting portion 333 is configured with a shape that is less rigid than the main body portion 331 and the first protruding portion 332. For example, the connecting portion 333 is configured to be thinner than the main body portion 331 and the first protruding portion 332. In other words, the connecting portion 333 is more easily deformed than the main body portion 331 and the first protruding portion 332. Therefore, for example, if stress occurs when fastening the fastener 100 due to tolerances that occur in the first protruding portion 332 or the second protruding portion 332, the connecting portion 333 can absorb the stress by deforming. Note that the shape with lower rigidity is not limited to a shape that is thin, and may be another shape such as a hollowed-out shape.

[0039] Next, a second modified example will be described with reference to Fig. 7. Fig. 7 is an exploded perspective view of the inverter 1 according to the second modified example. The second modified example is applicable to both the first and second embodiments described above. In the following, configurations different from the first and second embodiments will be mainly described, and descriptions of configurations that are the same as the first and second embodiments may be omitted.

[0040] As shown in FIG. 7, the second modified example differs from the first and second embodiments described above in the shapes of the first bus bar 33 and the second bus bar 34.

[0041] Specifically, the first bus bar 33 has a main body portion 334 that is parallel to the row of the plurality of capacitors 35, and a connecting member 335 (hereinafter referred to as the first connecting member 335) that connects one end of each of the first bus bar 33 and the second bus bar 34 via an insulating member (not shown). The main body portion 334 and the first connecting member 335 are integrally formed. In other words, the first bus bar 33 is formed in an L-shape when viewed from above by the main body portion 334 and the first connecting member 335.

[0042] The second bus bar 34 has a main body portion 344 that is parallel to the row of the plurality of capacitors 35, and a connecting member 345 (hereinafter, second connecting member 345) that connects the other ends of the first bus bar 33 and the second bus bar 34 via an insulating member (not shown). The main body portion 344 and the second connecting member 345 are integrally formed. In other words, the second bus bar 34 is formed in an L-shape when viewed from above by the main body portion 344 and the second connecting member 345.

[0043] Furthermore, the plurality of capacitors 35 are arranged surrounded by the main body 334, the first connecting member 335, the main body 344, and the second connecting member 345. This allows the capacitors 35 to be supported by the first bus bar 33 and the second bus bar 34, and therefore prevents the capacitors 35 from tilting and becoming detached from the power board 3 due to vibrations caused by, for example, vehicle travel.

[0044] As described above, the inverter 1 according to the embodiment includes a first substrate (power substrate 3), a second substrate (control substrate 2), a support member, a plurality of capacitors 35, and a plurality of power elements 32. The first substrate has a plurality of electrodes 31 mounted on a mounting surface 3a. The second substrate is disposed with its main surface facing the mounting surface 3a of the first substrate. The support member supports the second substrate and has a first bus bar 33 and a second bus bar 34 disposed in parallel on the mounting surface 3a. The plurality of capacitors 35 are disposed in a row between the first bus bar 33 and the second bus bar 34 on the mounting surface 3a. The plurality of power elements 32 are disposed in a row on the mounting surface 3a with the first bus bar 33 sandwiched between them.

[0045] According to the present disclosure, the inverter 1 can electrically connect a plurality of capacitors 35 and a plurality of power elements 32 using a single set of bus bars (first bus bar 33 and second bus bar 34) by arranging the first bus bar 33 in parallel between a row of capacitors 35 and a row of power elements 32 arranged on the same board. This allows the number of bus bars to be reduced, and the number of fastening holes (through holes 33a, 34a) is reduced accordingly, thereby reducing the area of ​​the power board 3. Furthermore, by mounting the capacitors 35 and the power elements 32 on the power board 3, a two-layer configuration consisting of the control board 2 and the power board 3 can be achieved, thereby reducing the height of the inverter 1 compared to a conventional three-layer configuration (control board, capacitor board, and power board). This allows the inverter 1 to be made smaller.

[0046] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0047] 1 inverter 2 Control board 2a, 2b through hole 3 Power Board 3a Mounting surface 4 Heatsink 4a, 4b fastening hole 4c fixing hole 31 electrode 31a Input electrode 31b Output electrode 32 Power elements 32a First power element 32b Second power element 33 First bus bar 33a, 33b, 34a through hole 34 Second bus bar 34b1 Main body bar 34b2 Extension bar 35 capacitor 36 Second insulating member 37 First insulating member 41 Second protrusion 41a, 41b fastening hole 100 Fasteners 120 Insulating material 331, 341, 334, 344 Main body 332 1st protrusion 332a, 342a through hole 333, 343 connection part 335 First connecting member 342 1st protrusion 345 Second connecting member

Claims

1. a first substrate having a plurality of electrodes mounted on a mounting surface; a second substrate disposed such that a main surface of the second substrate faces the mounting surface of the first substrate; a support member for supporting the second substrate, the support member having a first bus bar and a second bus bar arranged in parallel on the mounting surface; a plurality of capacitors arranged between the first bus bar and the second bus bar on the mounting surface; a plurality of power elements arranged in a line on the mounting surface so as to sandwich the first bus bar between the plurality of power elements and the plurality of capacitors; An inverter comprising:

2. the first substrate is a metal substrate, The first bus bar is a through hole penetrating the second bus bar side and the plurality of power elements side; The second bus bar is a main body bar arranged in parallel with the first bus bar; an extension bar extending from the main bar through the through hole toward the plurality of power elements; The inverter according to claim 1 .

3. the plurality of electrodes are mounted such that input electrodes and output electrodes are mounted in a row on the side of the first bus bar facing the plurality of power elements, the input electrodes are disposed at opposite ends of the column; the output electrodes are a plurality of phase electrodes corresponding to the three phases, and are arranged between the input electrodes; Each of the plurality of power elements disposed at both ends of each of the plurality of phase electrodes The inverter according to claim 1 .

4. At least one of the first bus bar and the second bus bar, the first substrate, and the second substrate are Each of the plates has a through hole at a position where the plates overlap when viewed from above, and a fastener is inserted into the through hole to fix the plates. The inverter according to claim 1 .

5. a heat sink fixed to a side opposite to the mounting surface of the first substrate; The heat sink is A fastening hole is provided at a position overlapping the through hole in a top view, and the fastener is inserted into the fastening hole to be fixed. The inverter according to claim 4 .

6. At least one of the first bus bar and the second bus bar is a first protrusion protruding from the mounting surface in a top view; The heat sink is a second protruding portion protruding from the mounting surface at a position overlapping the first protruding portion in a top view; The first protrusion and the second protrusion are They are fixed to each other via an insulating member. The inverter according to claim 5 .

7. At least one of the first bus bar and the second bus bar is a main body portion provided at a position overlapping the mounting surface in a top view; and a connecting portion connecting the main body portion and the first protrusion, The connecting portion is The shape has lower rigidity than the main body portion and the first protrusion portion. The inverter according to claim 6 .

8. a first connecting member that connects one end of each of the first bus bar and the second bus bar to each other via an insulating member; a second connecting member that connects the other end portions of the first bus bar and the second bus bar to each other via an insulating member; Furthermore, The plurality of capacitors include: The first bus bar, the second bus bar, the first connecting member, and the second connecting member are arranged so as to be surrounded by the first bus bar, the second bus bar, the first connecting member, and the second connecting member. The inverter according to claim 1 .

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