Power conversion device

Abstract

To provide a power conversion device capable of preventing the temperature rise of circuit components.SOLUTION: A power conversion device includes; a case (30) having side walls (31) and a bottom wall (32); a plurality of first heat dissipation plates (41), a plurality of second heat dissipation plates (42), a plurality of circuit components (10), and a sealing material (50), disposed in the case; and a printed wiring board (60) electrically connected to the plurality of circuit components and attached to the case. The normal of the inner wall surface of the bottom wall is along a first direction (DR1). Each of the plurality of first heat dissipation plates extends along a second direction (DR2) perpendicular to the first direction, and is spaced apart in a third direction (DR3) perpendicular to both the first direction and the second direction. Each of the plurality of second heat dissipation plates extends along the third direction, and is spaced apart in a second direction (DR2).SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2016-66666 (Patent Document 1) describes a capacitor. The capacitor described in Patent Document 1 has a case, a capacitor element, an electrode plate, a mold resin, and a lid body. The capacitor element and the electrode plate are housed in the case. The lead terminal of the capacitor element is electrically connected to the electrode plate. The mold resin is filled in the case. Thereby, the capacitor element and the electrode plate are sealed in the case. The lid body is attached to the opening of the case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the capacitor described in Patent Document 1, the heat generated in the capacitor element is transmitted to the lid body through the lead terminal and the electrode plate, and is radiated from the protrusion of the lid body. Therefore, the capacitor described in Patent Document 1 has a large thermal resistance, and the temperature rise of the capacitor element becomes large.

[0005] The present disclosure has been made in view of the problems of the prior art as described above. More specifically, the present disclosure provides a power conversion device capable of suppressing the temperature rise of circuit components.

Means for Solving the Problems

[0006] The power conversion device of the present disclosure includes a case having a side wall and a bottom wall, a plurality of first heat dissipation plates, a plurality of second heat dissipation plates, a plurality of circuit components, and a sealing material disposed in the case, and a printed wiring board electrically connected to the plurality of circuit components and attached to the case. The normal line of the inner wall surface of the bottom wall is along the first direction. Each of the plurality of first heat dissipation plates extends along a second direction orthogonal to the first direction and is arranged at intervals in a third direction orthogonal to the first direction and the second direction. Each of the plurality of second heat dissipation plates extends along the third direction and is arranged at intervals in the second direction. Each of the plurality of circuit components is disposed in a space defined by two adjacent ones of the plurality of first heat dissipation plates, two adjacent ones of the plurality of second heat dissipation plates, and the bottom wall. The sealing material is filled in the space. Each of the plurality of circuit components has an element body having an electrode surface, a lead wire connected to the electrode surface, and an exterior case housing the element body. Each of the plurality of circuit components is arranged such that the electrode surface faces one of the plurality of first heat dissipation plates.

Advantages of the Invention

[0007] According to the power conversion device of the present disclosure, it is possible to suppress the temperature rise of the circuit components.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Details of the embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and duplicate descriptions will not be repeated.

[0010] Embodiment 1. The power conversion device according to Embodiment 1 will be described. The power conversion device according to Embodiment 1 is designated as the power conversion device 100.

[0011] (Configuration of the power conversion device 100) The configuration of the power conversion device 100 will be described below.

[0012] FIG. 1 is a circuit diagram of a power conversion device 100. As shown in FIG. 1, the power conversion device 100 includes a peripheral circuit 110 and a switching circuit 120.

[0013] The peripheral circuit 110 has a plurality of circuit components 10. In the example shown in FIG. 1, the plurality of circuit components 10 are a capacitor 10a, an inductor 10b, a contactor 10c, a discharge resistor 10d, and a charging resistor 10e. The capacitor 10a, the inductor 10b, and the contactor 10c are connected in series. The inductor 10b is disposed between the capacitor 10a and the contactor 10c. The discharge resistor 10d and the charging resistor 10e are connected in parallel to the capacitor 10a and the contactor 10c, respectively. The peripheral circuit 110 is connected to a DC supply circuit 130.

[0014] The switching circuit 120 is, for example, a three-phase inverter circuit. The switching circuit 120 has a plurality of circuit components 20. In the example shown in FIG. 1, the plurality of circuit components 20 are transistors 20a to 20f and diodes 20g to 20l.

[0015] The drain of the transistor 20a is electrically connected to one electrode of the capacitor 10a. The source of the transistor 20a is electrically connected to the drain of the transistor 20b. The source of the transistor 20b is electrically connected to the other electrode of the capacitor 10a.

[0016] The anode of the diode 20g is electrically connected to the source of the transistor 20a. The cathode of the diode 20g is electrically connected to the drain of the transistor 20a. The anode of the diode 20h is electrically connected to the source of the transistor 20b. The cathode of the diode 20h is electrically connected to the drain of the transistor 20b.

[0017] Note that the transistor 20c, transistor 20d, diode 20i, and diode 20j are each connected in the same manner as the transistor 20a, transistor 20b, diode 20g, and diode 20h. Also, the transistor 20e, transistor 20f, diode 20k, and diode 20l are each connected in the same manner as the transistor 20a, transistor 20b, diode 20g, and diode 20h. Although not shown in the figure, the gates of the transistors 20a to 20f are connected to a control circuit.

[0018] The switching circuit 120 is connected to the motor 140. The motor 140 is, for example, a three-phase motor. The motor 140 has an input line 141, an input line 142, and an input line 143. The input line 141 is electrically connected to the source of the transistor 20a and the drain of the transistor 20b. The input line 142 is electrically connected to the source of the transistor 20c and the drain of the transistor 20d. The input line 143 is electrically connected to the source of the transistor 20e and the drain of the transistor 20f.

[0019] FIG. 2 is a perspective view of the power conversion device 100. FIG. 3 is an exploded perspective view of the power conversion device 100. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2. FIG. 5 is a plan view of the case 30 included in the power conversion device 100. FIG. 6 is a bottom view of the printed wiring board 60 included in the power conversion device 100. FIG. 7 is a side view of the first heat sink 41 included in the power conversion device 100. FIG. 8 is a side view of the second heat sink 42 included in the power conversion device 100. As shown in FIGS. 2 to 8, the power conversion device 100 includes a plurality of circuit components 10, a case 30, a plurality of first heat sinks 41 and a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60.

[0020] The case 30 has a side wall 31 and a bottom wall 32. The direction along the normal line of the inner wall surface of the bottom wall 32 is defined as the first direction DR1. The direction orthogonal to the first direction DR1 is defined as the second direction DR2. The direction orthogonal to the first direction DR1 and the second direction DR2 is defined as the third direction DR3.

[0021] The side wall 31 is, for example, rectangular in plan view. The side wall 31 has a first side wall portion 31a and a second side wall portion 31b, and a third side wall portion 31c and a fourth side wall portion 31d. The first side wall portion 31a and the second side wall portion 31b face each other with a space therebetween in the second direction DR2. The third side wall portion 31c and the fourth side wall portion 31d face each other with a space therebetween in the third direction DR3. The arithmetic mean roughness on the inner wall surface of the side wall 31 is preferably 6.3 μm or more. The bottom wall 32 is continuous with the lower end of the side wall 31.

[0022] The case 30 is formed of a rigid material. The case 30 is formed of, for example, a metal material. The case 30 is formed of copper (Cu), a copper alloy, aluminum (Al), an aluminum alloy, iron (Fe), an iron alloy, or the like. The case 30 may be formed of a resin material.

[0023] A plurality of first grooves 31aa are formed on the inner wall surface of the first side wall portion 31a. The plurality of first grooves 31aa are arranged with a space therebetween in the third direction DR3. The first groove 31aa extends along the first direction DR1. Both ends of the first groove 31aa in the third direction DR3 reach the upper end and the lower end of the first side wall portion 31a, respectively.

[0024] A plurality of second grooves 31ba are formed on the inner wall surface of the second side wall portion 31b. The plurality of second grooves 31ba are arranged with a space therebetween in the third direction DR3. The second groove 31ba extends along the first direction DR1. Both ends of the second groove 31ba in the third direction DR3 reach the upper end and the lower end of the second side wall portion 31b, respectively. The second groove 31ba faces the first groove 31aa in the second direction DR2.

[0025] The first heat dissipation plate 41 and the second heat dissipation plate 42 are arranged in the case 30. More specifically, the first heat dissipation plate 41 and the second heat dissipation plate 42 are arranged in the space defined by the side wall 31 and the bottom wall 32. The first heat dissipation plate 41 and the second heat dissipation plate 42 are formed of a material with high thermal conductivity. The first heat dissipation plate 41 and the second heat dissipation plate 42 are formed of, for example, copper, copper alloy, aluminum, aluminum alloy, iron, iron alloy, etc. The first heat dissipation plate 41 and the second heat dissipation plate 42 may be formed of the same material or different materials. The arithmetic mean roughness on the side surfaces of the first heat dissipation plate 41 and the second heat dissipation plate 42 is preferably 6.3 μm or more.

[0026] In plan view, the first heat dissipation plate 41 extends along the second direction DR2. A plurality of the first heat dissipation plates 41 are arranged at intervals in the third direction DR3. The first heat dissipation plate 41 has a first end 41a and a second end 41b in the second direction DR2. The second end 41b is the end on the opposite side of the first end 41a. The first heat dissipation plate 41 is attached to the case 30 by inserting the first end 41a and the second end 41b into the first groove 31aa and the second groove 31ba, respectively. The first heat dissipation plate 41 faces the electrode surface 11a.

[0027] In the first direction DR1, the first heat dissipation plate 41 has a third end 41c and a fourth end 41d. The third end 41c is on the side of the bottom wall 32. The third end 41c is thermally connected to the bottom wall 32 via a heat dissipation auxiliary material 51 described later. The fourth end 41d is the end on the opposite side of the third end 41c. A plurality of first insertion ports 41e are formed in the first heat dissipation plate 41. The first insertion port 41e penetrates the first heat dissipation plate 41 along the thickness direction. The first insertion port 41e extends from the fourth end 41d toward the third end 41c side. The number of the first insertion ports 41e is equal to or more than the number of the second heat dissipation plates 42.

[0028] The second heat dissipation plate 42 extends along the third direction DR3 in a plan view. A plurality of second heat dissipation plates 42 are arranged side by side at intervals in the second direction DR2. The second heat dissipation plate 42 has a fifth end 42a and a sixth end 42b in the first direction DR1. The fifth end 42a is on the side of the bottom wall 32. The sixth end 42b is the end on the opposite side of the fifth end 42a.

[0029] A plurality of second insertion ports 42c are formed in the second heat dissipation plate 42. The second insertion ports 42c penetrate the second heat dissipation plate 42 along the thickness direction. The second insertion ports 42c extend from the fifth end 42a toward the sixth end 42b side. Note that the number of the second insertion ports 42c is equal to or greater than the number of the first heat dissipation plates 41. The second heat dissipation plate 42 is attached to the first heat dissipation plate 41 by inserting the second insertion ports 42c into the first insertion ports 41e. The first heat dissipation plate 41 and the second heat dissipation plate 42 are assembled in a grid shape in a plan view.

[0030] Although not shown, a plurality of grooves may be formed on the inner wall surface of the third side wall portion 31c, extending along the first direction DR1 and arranged at intervals in the second direction DR2. Also, a plurality of grooves may be formed on the inner wall surface of the fourth side wall portion 31d, extending along the first direction DR1 and arranged at intervals in the second direction DR2. The second heat dissipation plate 42 may be attached to the case 30 by inserting both ends of the second heat dissipation plate 42 in the third direction DR3 into the grooves formed on the inner wall surface of the third side wall portion 31c and the grooves formed on the inner wall surface of the fourth side wall portion 31d, respectively.

[0031] The second heat dissipation plate 42 has a seventh end 42e and an eighth end 42f in the third direction DR3. The eighth end 42f is the end on the opposite side of the seventh end 42e. It is preferable that the seventh end 42e and the eighth end 42f are separated from the inner wall surfaces of the third side wall portion 31c and the fourth side wall portion 31d, respectively. From another perspective, it is preferable that a molding material 52 is arranged between the seventh end 42e and the inner wall surface of the third side wall portion 31c and between the eighth end 42f and the inner wall surface of the fourth side wall portion 31d.

[0032] In addition, when the electrode surface 11a faces the second heat sink 42 instead of the first heat sink 41, grooves into which the seventh end 42e is inserted may be formed on the inner wall surface of the third side wall portion 31c and grooves into which the eighth end 42f is inserted may be formed on the inner wall surface of the fourth side wall portion 31d, instead of the first groove 31aa and the second groove 31ba.

[0033] In the example shown in FIGS. 2 to 8, the circuit component 10 is a capacitor 10a. The capacitor 10a is disposed in a space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32.

[0034] The capacitor 10a is, for example, a film capacitor. The circuit component 10 has an element body and lead wires. When the circuit component 10 is the capacitor 10a, the element body is a capacitor element body 11 and the lead wires are lead wires 12. The capacitor 10a further has an exterior case 13 and a sealing resin 14.

[0035] The capacitor element body 11 is configured, for example, by winding a metal film and a dielectric film disposed on the metal film. Both end faces of the capacitor element body 11 are electrode surfaces 11a. The lead wire 12 is electrically connected to the electrode surface 11a. The lead wire 12 serves to conduct an external current to the capacitor element body 11. The lead wire 12 is formed of a conductive material such as a metal material.

[0036] The capacitor element body 11 has two electrode surfaces 11a. The two electrode surfaces 11a face two different first heat sinks 41 via a molding material 52, respectively.

[0037] The exterior case 13 is formed of an insulating material. The exterior case 13 is formed of, for example, a resin material. The capacitor element body 11 and the lead wire 12 are housed inside the exterior case 13. However, a part of the lead wire 12 protrudes from the upper surface of the exterior case 13. The encapsulating resin 14 is filled inside the exterior case 13.

[0038] A plurality of capacitors 10a are arranged side by side so as to form a first row and a second row. The first row and the second row are along the second direction DR2. The electrode surface 11a of the capacitor 10a belonging to the first row preferably faces the electrode surface 11a of the capacitor 10a belonging to the second row. A first heat sink 41 is disposed between the first row and the second row. That is, the electrode surface 11a of the capacitor 10a belonging to the first row faces the electrode surface 11a of the capacitor 10a belonging to the second row via the first heat sink 41.

[0039] The encapsulant 50 is filled inside the case 30. More specifically, the encapsulant 50 is filled in the space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32. The encapsulant 50 has a heat dissipation auxiliary material 51 and a molding material 52.

[0040] The heat dissipation auxiliary material 51 is, for example, a resin material such as silicone resin, epoxy resin, or urethane resin, grease, gel, or an insulating sheet. The heat dissipation auxiliary material 51 may contain a heat conduction filler. The heat conduction filler is formed of, for example, ceramics or a metal material. The heat conductivity of the heat dissipation auxiliary material 51 is, for example, 1 W / m·K or more and several tens of W / m·K or less. The heat dissipation auxiliary material 51 is applied on the bottom wall 32. More specifically, the heat dissipation auxiliary material 51 is applied on the inner wall surface of the bottom wall 32. Although not shown, the heat dissipation auxiliary material 51 may also be applied on the first groove 31aa and the second groove 31ba.

[0041] The mold material 52 is, for example, a resin material with high thermal conductivity. The mold material 52 is, for example, an epoxy resin, a silicone resin, or a urethane resin containing a heat conduction filler. The thermal conductivity of the mold material 52 is, for example, 0.1 W / m·K or more and 20 W / m·K or less. The Young's modulus of the mold material 52 is, for example, 1 MPa or more and 50 GPa or less. The mold material 52 may be the same material as the heat dissipation auxiliary material 51. For example, the heat dissipation auxiliary material 51 and the mold material 52 may be an adhesive.

[0042] The mold material 52 is disposed on the heat dissipation auxiliary material 51. The mold material 52 is in contact with the bottom surface, side surfaces, and top surface of the exterior case 13. That is, the mold material 52 surrounds the capacitor 10a. Note that the lead wire 12 protrudes from the mold material 52. The mold material 52 is also in contact with the inner wall surface of the side wall 31, the side surfaces of the first heat dissipation plate 41, and the side surfaces of the second heat dissipation plate 42.

[0043] The printed wiring board 60 has a first surface 60a and a second surface 60b. The first surface 60a faces the case 30 side. The second surface 60b is the opposite surface of the first surface 60a. The capacitor 10a is electrically connected to the printed wiring board 60. More specifically, the capacitor 10a is connected to the printed wiring board 60 by inserting the lead wire 12 into a through hole (not shown) formed in the printed wiring board 60 and soldering it. Thereby, the wiring of the peripheral circuit 110 shown in FIG. 1 is realized. Note that the capacitor 10a and the printed wiring board 60 may be connected using a conductive adhesive.

[0044] Also, the printed wiring board 60 has external connection terminals 60c. The external connection terminals 60c are composed of lands and are connected to the switching circuit 120 shown in FIG. 1 by coming into contact and conducting electricity with a bus bar (not shown). The printed wiring board 60 is attached to the upper end of the side wall 31.

[0045] FIG. 9 is a schematic side view when a plurality of power conversion devices 100 are connected. One of the plurality of power conversion devices 100 is defined as power conversion device 101, and another one of the plurality of power conversion devices 100 is defined as power conversion device 102. As shown in FIG. 9, the power conversion device 101 and the power conversion device 102 are connected by a connection member 61. The connection member 61 is connected to the external connection terminal 60c of the printed wiring board 60 included in the power conversion device 101 at one end, and is connected to the external connection terminal 60c of the printed wiring board 60 included in the power conversion device 102 at the other end. The connection member 61 is, for example, a rolled material formed of a metal material.

[0046] Note that in FIG. 9, the number of the three power conversion devices 100 is three, but the number of the connected power conversion devices 100 can be increased or decreased. Further, in FIG. 9, an example of connecting a plurality of power conversion devices 100 along the first direction DR1 is shown, but the plurality of power conversion devices 100 may be connected along the second direction DR2 or the third direction DR3.

[0047] <Modification Example 1 of Power Conversion Device 100> FIG. 10 is a plan view of a case 30 included in the modification example 1 of the power conversion device 100. As shown in FIG. 10, a plurality of grooves 31e may be formed on the outer wall surface of the side wall 31. The grooves 31e extend, for example, along the first direction DR1. In this case, since the surface area of the outer wall surface of the side wall 31 increases and the thermal resistance between the case 30 and the outside air is reduced, the temperature rise of the capacitor 10a can be further suppressed.

[0048] <Modification Example 2 of Power Conversion Device 100> FIG. 11 is a cross-sectional view in the modification example 2 of the power conversion device 100. FIG. 11 shows a cross section at a position corresponding to IV-IV in FIG. 2. As shown in FIG. 11, the sealing material 50 may have a silicone gel 53 instead of the mold material 52. The silicone gel 53 preferably has a low viscosity and high insulation.

[0049] Since the silicone gel 53 has high adhesion to the capacitor 10a, the first heat dissipation plate 41, and the second heat dissipation plate 42, it is not necessary to consider the creepage along the boundaries between the capacitor 10a, the first heat dissipation plate 41, and the second heat dissipation plate 42 in the insulation evaluation. Therefore, in this case, an insulation area for securing the creepage distance becomes unnecessary, and miniaturization around the capacitor 10a becomes possible. Also, in this case, it becomes possible to efficiently transfer the heat generated by the capacitor 10a to the case 30. Furthermore, the silicone gel 53 is a material with a high penetration, that is, a soft material. Therefore, in this case, the reliability when a heat cycle or a power cycle is applied to the power conversion device 100 can be improved. Note that since the capacitor 10a is also fixed in position by being attached to the case 30 of the printed wiring board 60, even if the penetration of the silicone gel 53 is high, there is no problem in fixing the position of the capacitor 10a.

[0050] (Assembly method of power conversion device 100) The assembly method of the power conversion device 100 will be described below.

[0051] In assembling the power conversion device 100, first, a case 30, a plurality of first heat dissipation plates 41, a plurality of second heat dissipation plates 42, and a printed wiring board 60 to which a plurality of capacitors 10a are connected are prepared. Second, a heat dissipation auxiliary material 51 is applied onto the inner wall surface of the bottom wall 32. At this time, the heat dissipation auxiliary material 51 may also be applied onto the first groove 31aa and the second groove 31ba. Third, the first heat dissipation plate 41 is attached to the case 30. The attachment of the first heat dissipation plate 41 is performed by inserting the first end 41a and the second end 41b into the first groove 31aa and the second groove 31ba, respectively.

[0052] Fourthly, the second heat sink 42 is attached to the first heat sink 41. The attachment of the second heat sink 42 is performed by inserting the second insertion port 42c into the first insertion port 41e. Fifthly, the molding material 52 is injected into the case 30. Sixthly, the printed wiring board 60 is attached to the upper end of the side wall 31. Thereby, the capacitor 10a is disposed in a space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32, and is surrounded by the molding material 52. Seventhly, the molding material 52 is cured. Thus, the assembly of the power conversion device 100 is completed.

[0053] <Modification Example 1 of the Assembly Method of the Power Conversion Device 100> When the heat dissipation auxiliary material 51 and the molding material 52 are made of the same material, in the assembly of the power conversion device 100, the sealing material 50 may be injected into the case 30 before the first heat sink 41 is attached to the case 30. In this case, since the assembly procedure is reduced, the time required for assembly can be reduced.

[0054] <Modification Example 2 of the Assembly Method of the Power Conversion Device 100> In the assembly of the power conversion device 100, the application of the heat dissipation auxiliary material 51 may be performed after the attachment of the first heat sink 41 to the case 30 and the attachment of the second heat sink 42 to the first heat sink 41, and before the injection of the molding material 52. In this case, the first heat sink 41 will contact the bottom wall 32 without the heat dissipation auxiliary material 51 in between.

[0055] <Modification Example 3 of the Assembly Method of the Power Conversion Device 100> When the heat dissipation auxiliary material 51 and the molding material 52 are made of the same material, in the assembly of the power conversion device 100, the sealing material 50 may be injected after the printed wiring board 60 is attached to the case 30. The injection of the sealing material 50 is performed from an injection port previously formed in the printed wiring board 60. In this case, since the assembly procedure is reduced, the time required for assembly can be reduced.

[0056] (Effect of the Power Conversion Device 100) The effects of the power conversion device 100 will be described below.

[0057] When the power conversion device 100 operates, when an alternating current flows through the capacitor 10a, power consumption occurs due to the resistance component of the capacitor 10a, and heat is generated in the capacitor 10a. The heat generation of the capacitor 10a mainly occurs in the capacitor element body 11, the electrode surface 11a, and the lead wire 12.

[0058] In the power conversion device 100, a plurality of capacitors 10a are densely arranged. Therefore, if the heat generation of the capacitors 10a interferes with each other and the temperature of the capacitors 10a rises excessively, there is a risk of deterioration, destruction, and shortening of the life of the capacitors 10a.

[0059] However, in the power conversion device 100, the capacitor 10a is thermally connected to the case 30 by the sealing material 50, the first heat dissipation plate 41, and the second heat dissipation plate 42. Therefore, according to the power conversion device 100, the heat generated by the capacitor 10a is dissipated from the case 30 to the outside air, and the temperature rise of the capacitor 10a is suppressed. When the temperature rise of the capacitor 10a is suppressed, the life of the capacitor 10a is prolonged. For example, when the temperature of the capacitor 10a drops by 10°C, the life of the capacitor 10a becomes about twice as long.

[0060] In addition, when the circuit component 10 is the inductor 10b, when the temperature of the inductor 10b drops by 10°C, the life of the enamel coating of the inductor 10b becomes about twice as long. Also, when the circuit component 10 is the discharge resistor 10d or the charge resistor 10e, due to the relationship of temperature dilation, the rank of the power category of the discharge resistor 10d or the charge resistor 10e can be lowered, and the number of series or parallel of the discharge resistor 10d or the charge resistor 10e can be reduced.

[0061] In the power conversion device 100, the heat generated by the capacitor 10a is transmitted to the first heat sink 41 through the molding material 52. The heat transmitted to the first heat sink 41 is transmitted from the first end 41a and the second end 41b to the side wall 31, and from the third end 41c to the bottom wall 32 through the heat dissipation auxiliary material 51. Therefore, in the power conversion device 100, the area of the heat transfer path from the capacitor 10a to the case 30 is large, and the thermal resistance from the capacitor 10a to the case 30 is reduced, so the temperature rise of the capacitor 10a is suppressed.

[0062] Since current concentrates on the electrode surface 11a, in order to suppress the temperature rise of the capacitor 10a, cooling of the electrode surface 11a is important. In the power conversion device 100, since the two electrode surfaces 11a of the capacitor 10a face two different first heat sinks 41 through the molding material 52, the temperature rise of the capacitor 10a can be further suppressed.

[0063] In the power conversion device 100, the first insertion port 41e is formed at the fourth end 41d. That is, the first insertion port 41e is not formed at the third end 41c. Therefore, the heat transfer area between the first heat sink 41 and the bottom wall 32 becomes large, and the thermal resistance between the first heat sink 41 and the bottom wall 32 becomes small, so the temperature rise of the capacitor 10a can be further suppressed.

[0064] In addition to the first heat sink 41, the power conversion device 100 has a second heat sink 42 that is thermally connected to the first heat sink 41. Therefore, in the power conversion device 100, the heat transmitted from the capacitor 10a to the first heat sink 41 through the molding material 52 is also transmitted to the case 30 through the second heat sink 42, and the temperature rise of the capacitor 10a is further suppressed.

[0065] In the power conversion device 100, since the first heat sink 41 extends along the second direction DR2 and the plurality of capacitors 10a are arranged side by side along the second direction DR2, the temperature difference between the plurality of capacitors 10a arranged side by side along the second direction DR2 becomes small. Similarly, in the power conversion device 100, since the second heat sink 42 extends along the third direction DR3 and the plurality of capacitors 10a are arranged side by side along the third direction DR3, the temperature difference between the plurality of capacitors 10a arranged side by side along the second direction DR2 becomes small.

[0066] The temperature rise of the capacitor 10a varies depending on the position where it is arranged. More specifically, the capacitor 10a arranged near the center of the power conversion device 100 is more likely to have its temperature rise than the capacitor 10a arranged near the outer periphery of the power conversion device 100 because it is affected by the heat generation of the capacitors 10a arranged around it. The temperature derating is determined by the capacitor 10a with the highest temperature. As described above, in the power conversion device 100, the first heat sink 41 and the second heat sink 42 equalize the temperature among the plurality of capacitors 10a, so that the power conversion device 100 can be used more effectively. Also, in the power conversion device 100, as a result of the temperature being equalized among the plurality of capacitors 10a, the number of series-connected or parallel-connected capacitors 10a can be reduced.

[0067] In the power conversion device 100, either the first heat sink 41 or the second heat sink 42 is arranged between two adjacent capacitors 10a. Therefore, the first heat sink 41 and the second heat sink 42 function as a fire wall. That is, even if a discharge spark and impact occur due to the failure of a certain capacitor 10a, it is suppressed that the spark and the impact reach other capacitors 10a by the first heat sink 41 and the second heat sink 42. When the circuit component 10 is the inductor 10b, since the leakage magnetic flux from the inductor 10b to the surroundings is shielded by the first heat sink 41 and the second heat sink 42, it becomes possible to improve the accuracy of the sensor components (for example, current sensors using the Hall effect) arranged around.

[0068] In the power conversion device 100, since the encapsulant 50 is filled in the case 30, the vibration resistance of the capacitor 10a is improved. When the arithmetic mean roughness on the inner wall surface of the side wall 31, the side surface of the first heat sink 41, and the side surface of the second heat sink 42 is 6.3 μm or more, the adhesiveness with the encapsulant 50 is improved, so the mechanical strength of the power conversion device 100 is improved.

[0069] In the power conversion device 100, by increasing or decreasing the number of the first heat sinks 41 and the number of the second heat sinks, the number or size of the compartments formed in a grid shape by two adjacent first heat sinks 41 and two adjacent second heat sinks 42 can be increased or decreased according to the number or size of the capacitors 10a. Also, in the power conversion device 100, the thickness, type, material, etc. of the first heat sink 41 and the second heat sink 42 can be arbitrarily selected. Furthermore, in the power conversion device 100, by performing bending or embossing on the first heat sink 41 and the second heat sink 42, it is possible to ensure the strength of the first heat sink 41 and the second heat sink 42 and change the shape of the grid-shaped compartments. Thus, in the power conversion device 100, various specifications can be realized flexibly and at low cost.

[0070] The temperature of the capacitor 10a tends to rise at the electrode surface 11a where the current concentrates. In the power conversion device 100, since the electrode surface 11a faces the first heat sink 41 (or the second heat sink 42), the heat generated at the electrode surface 11a is easily transmitted to the case 30 through the first heat sink 41 (or the second heat sink 42), and the temperature rise of the capacitor 10a can be further suppressed.

[0071] When the seventh end 42e is away from the inner wall surface of the third side wall portion 31c and the eighth end 42f is away from the inner wall surface of the fourth side wall portion 31d, the mold material 52 is easily filled between the seventh end 42e and the third side wall portion 31c and between the eighth end 42f and the fourth side wall portion 31d. The manufacturing efficiency of the power conversion device 100 is improved, and the heat generated in the capacitor 10a is easily transmitted to the case 30 through the mold material 52.

[0072] Since the second heat sink 42 is positioned by intersecting with the first heat sink 41, when the seventh end 42e and the eighth end 42f come into contact with the inner wall surfaces of the third side wall portion 31c and the fourth side wall portion 31d, respectively, if the dimensional tolerances of the first insertion port 41e and the second insertion port 42c are not strictly controlled, the second heat sink 42 may bend and break. On the other hand, when the seventh end 42e is separated from the inner wall surface of the third side wall portion 31c and the eighth end 42f is separated from the inner wall surface of the fourth side wall portion 31d, even if the management of the dimensional tolerances of the first insertion port 41e and the second insertion port 42c is relaxed, damage to the second heat sink 42 as described above can be suppressed.

[0073] Embodiment 2. The power conversion device according to Embodiment 2 will be described. The power conversion device according to Embodiment 2 is referred to as the power conversion device 100A. Here, the points different from the power conversion device 100 will be mainly described, and overlapping descriptions will not be repeated.

[0074] (Configuration of the power conversion device 100A) The configuration of the power conversion device 100A will be described below.

[0075] The power conversion device 100A includes a plurality of circuit components 10, a case 30, a plurality of first heat sinks 41 and a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this regard, the configuration of the power conversion device 100A is common to the configuration of the power conversion device 100.

[0076] FIG. 12 is a plan view of the case 30 included in the power conversion device 100A. FIG. 13 is an enlarged cross-sectional view of the power conversion device 100A in the vicinity of the third groove 32a. FIG. 13 shows an enlarged cross-section orthogonal to the second direction DR2. FIG. 14 is an enlarged cross-sectional view of the power conversion device 100A in the vicinity of the fourth groove 32b. FIG. 14 shows an enlarged cross-section orthogonal to the third direction DR3. As shown in FIGS. 12 to 14, in the power conversion device 100A, a plurality of third grooves 32a and a plurality of fourth grooves 32b are formed on the inner wall surface of the bottom wall 32.

[0077] The third groove 32a extends along the second direction DR2. The plurality of third grooves 32a are arranged at intervals in the third direction DR3. The third end 41c side of the first heat sink 41 is inserted into the third groove 32a. The fourth groove 32b extends along the third direction DR3. The plurality of fourth grooves 32b are arranged at intervals in the second direction DR2. The fifth end 42a side of the second heat sink 42 is inserted into the fourth groove 32b. Although not shown, the third groove 32a and the fourth groove 32b may or may not be filled with the sealing material 50. In this regard, the configuration of the power conversion device 100A is different from the configuration of the power conversion device 100.

[0078] (Effect of the power conversion device 100A) The effect of the power conversion device 100A will be described below.

[0079] In the power conversion device 100A, since the first heat sink 41 is inserted into the third groove 32a and the second heat sink 42 is inserted into the fourth groove 32b, the heat transfer area between the first heat sink 41 and the second heat sink 42 and the bottom wall 32 increases, and the thermal resistance between the first heat sink 41 and the second heat sink 42 and the bottom wall 32 decreases. As a result, according to the power conversion device 100A, the temperature rise of the capacitor 10a can be further suppressed.

[0080] Also, in the power conversion device 100A, since the first heat sink 41 is inserted into the third groove 32a and the second heat sink 42 is inserted into the fourth groove 32b, the assemblability and positioning accuracy of the first heat sink 41 and the second heat sink 42 are improved. As a result of the improved positioning accuracy of the first heat sink 41 and the second heat sink 42, the distance between the first heat sink 41 and the second heat sink 42 and the capacitor 10a can be accurately set, and the thickness of the sealing material 50 can be reduced to reduce the thermal resistance between the capacitor 10a and the first heat sink 41 and the second heat sink 42.

[0081] Furthermore, in the power conversion device 100A, since the first heat sink 41 and the second heat sink 42 are fixed to the bottom wall 32, the sealing material 50 can be surely filled in the space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32.

[0082] Embodiment 3. The power conversion device according to Embodiment 3 will be described. The power conversion device according to Embodiment 3 is referred to as a power conversion device 100B. Here, the points different from the power conversion device 100A will be mainly described, and overlapping descriptions will not be repeated.

[0083] The power conversion device 100B includes a plurality of circuit components 10, a case 30, a plurality of first heat sinks 41 and a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this regard, the configuration of the power conversion device 100B is common to the configuration of the power conversion device 100A.

[0084] FIG. 15 is an enlarged cross-sectional view of the power conversion device 100B in the vicinity of the third groove 32a. FIG. 15 shows an enlarged cross-section orthogonal to the second direction DR2. FIG. 16 is an enlarged cross-sectional view of the power conversion device 100B in the vicinity of the fourth groove 32b. FIG. 16 shows an enlarged cross-section orthogonal to the third direction DR3. As shown in FIGS. 15 and 16, in the power conversion device 100B, the first heat sink 41 is metal-bonded to the third groove 32a on the third end 41c side. In the power conversion device 100B, the second heat sink 42 is metal-bonded to the fourth groove 32b on the fifth end 42a side.

[0085] Note that the first heat sink 41 does not have to be metallically joined to the third groove 32a at all parts inserted into the third groove 32a, and the second heat sink 42 does not have to be metallically joined to the fourth groove 32b at all parts inserted into the fourth groove 32b. The metallic joining between the first heat sink 41 and the third groove 32a and the metallic joining between the second heat sink 42 and the fourth groove 32b are performed by, for example, a brazing material 33. The metallic joining between the first heat sink 41 and the third groove 32a and the metallic joining between the second heat sink 42 and the fourth groove 32b may be performed by welding. In this regard, the configuration of the power conversion device 100B is different from the configuration of the power conversion device 100A.

[0086] (Effect of the power conversion device 100B) The effect of the power conversion device 100B will be described below.

[0087] In the power conversion device 100B, since the first heat sink 41 is metallically joined to the third groove 32a and the second heat sink 42 is metallically joined to the fourth groove 32b, the thermal resistance between the first heat sink 41 and the second heat sink 42 and the bottom wall 32 is reduced. As a result, according to the power conversion device 100B, the temperature rise of the capacitor 10a can be further suppressed.

[0088] Further, in the power conversion device 100B, since the first heat sink 41 is metallically joined to the third groove 32a and the second heat sink 42 is metallically joined to the fourth groove 32b, the assemblability and positioning accuracy of the first heat sink 41 and the second heat sink 42 are improved. As a result of the improvement in the positioning accuracy of the first heat sink 41 and the second heat sink 42, the distance between the first heat sink 41 and the second heat sink 42 and the capacitor 10a can be accurately set, and the thickness of the sealing material 50 can be reduced to reduce the thermal resistance between the capacitor 10a and the first heat sink 41 and the second heat sink 42.

[0089] Furthermore, in the power conversion device 100B, since the first heat sink 41 and the second heat sink 42 are fixed to the bottom wall 32, the sealing material 50 can be more reliably filled in the space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32.

[0090] (Modification Example 1 of Power Conversion Device 100B) FIG. 17 is a plan view of the case 30 included in the modification example 1 of the power conversion device 100B. As shown in FIG. 17, in the power conversion device 100B, the third groove 32a may be widened at a portion where it intersects with the fourth groove 32b, and the fourth groove 32b may be widened at a portion where it intersects with the third groove 32a. Further, although not shown, in the power conversion device 100B, the third groove 32a may be widened at an end portion in the second direction DR2, and the fourth groove 32b may be widened at an end portion in the third direction DR3. In this case, the widened portions of the third groove 32a and the fourth groove 32b serve as brazing material reservoirs, and it is possible to suppress the brazing material 33 from overflowing from the third groove 32a and the fourth groove 32b and causing a joint failure.

[0091] (Modification Example 2 of Power Conversion Device 100B) FIG. 18 is an enlarged cross-sectional view of the modification example 2 of the power conversion device 100B in the vicinity of the first groove 31aa. FIG. 19 is an enlarged cross-sectional view of the modification example 2 of the power conversion device 100B in the vicinity of the second groove 31ba. FIGS. 18 and 19 show enlarged cross-sections orthogonal to the first direction DR1. As shown in FIGS. 18 and 19, in the power conversion device 100B, the first heat sink 41 may be metallically joined to the first groove 31aa on the first end 41a side and may be metallically joined to the second groove 31ba on the second end 41b side.

[0092] The metallic joining between the first heat sink 41 and the first groove 31aa and the second groove 31ba is performed by, for example, a brazing material 33. The metallic joining between the first heat sink 41 and the first groove 31aa and the second groove 31ba may be performed by welding. In this case, since the thermal resistance between the first heat sink 41 and the side wall 31 is reduced, the temperature rise of the capacitor 10a can be further suppressed.

[0093] Embodiment 4. The power conversion device according to Embodiment 4 will be described. The power conversion device according to Embodiment 4 is designated as power conversion device 100C. Here, the differences from the power conversion device 100A will mainly be described, and redundant explanations will not be repeated.

[0094] The power conversion device 100C includes a plurality of circuit components 10, a case 30, a plurality of first heat dissipation plates 41 and a plurality of second heat dissipation plates 42, a sealing material 50, and a printed wiring board 60. In this regard, the configuration of the power conversion device 100C is common to the configuration of the power conversion device 100A.

[0095] FIG. 20 is an enlarged cross-sectional view of the power conversion device 100C in the vicinity of the third groove 32a. FIG. 20 shows an enlarged cross-section orthogonal to the second direction DR2. FIG. 21 is an enlarged cross-sectional view of the power conversion device 100C in the vicinity of the fourth groove 32b. FIG. 21 shows an enlarged cross-section orthogonal to the third direction DR3. As shown in FIGS. 20 and 21, in the power conversion device 100C, the first heat dissipation plate 41 is metal-bonded to the third groove 32a by caulking on the third end 41c side. In the power conversion device 100C, the second heat dissipation plate 42 is metal-bonded to the fourth groove 32b by caulking on the fifth end 42a side.

[0096] More specifically, in the power conversion device 100C, caulking grooves 32ca and caulking grooves 32cb are formed on the inner wall surface of the bottom wall 32. The caulking grooves 32ca and caulking grooves 32cb extend along the second direction DR2. The third groove 32a is disposed between the caulking grooves 32ca and caulking grooves 32cb in the third direction DR3. Also, in the power conversion device 100C, caulking grooves 32da and caulking grooves 32db are formed on the inner wall surface of the bottom wall 32. The caulking grooves 32da and caulking grooves 32db extend along the third direction DR3. The fourth groove 32b is disposed between the caulking grooves 32da and caulking grooves 32db in the second direction DR2.

[0097] When the first heat sink 41 is caulked into the third groove 32a, a press tool is inserted into the caulking groove 32ca and the caulking groove 32cb. As a result, the portions of the bottom wall 32 between the caulking groove 32ca and the third groove 32a and the portions of the bottom wall 32 between the caulking groove 32cb and the third groove 32a are plastically deformed toward the first heat sink 41 side, and the first heat sink 41 is caulked into the third groove 32a. Similarly, by inserting a press tool into the caulking groove 32da and the caulking groove 32db, the second heat sink 42 is caulked into the fourth groove 32b. Note that the first heat sink 41 does not have to be caulked into all the portions of the third groove 32a where it is inserted, and the second heat sink 42 does not have to be caulked into all the portions of the fourth groove 32b where it is inserted. In this regard, the configuration of the power conversion device 100C is different from the configuration of the power conversion device 100A.

[0098] (Effect of the power conversion device 100C) The effect of the power conversion device 100C will be described below.

[0099] In the power conversion device 100C, due to caulking, the first heat sink 41 is metallically joined to the third groove 32a and the second heat sink 42 is metallically joined to the fourth groove 32b, so the thermal resistance between the first heat sink 41 and the second heat sink 42 and the bottom wall 32 is reduced. As a result, according to the power conversion device 100C, the temperature rise of the capacitor 10a can be further suppressed.

[0100] Also, in the power conversion device 100C, due to caulking, the first heat sink 41 is metallically joined to the third groove 32a and the second heat sink 42 is metallically joined to the fourth groove 32b, so the assemblability and positioning accuracy of the first heat sink 41 and the second heat sink 42 are improved. As a result of the improved positioning accuracy of the first heat sink 41 and the second heat sink 42, the distance between the first heat sink 41 and the second heat sink 42 and the capacitor 10a can be accurately set, and the thickness of the sealing material 50 can be reduced to reduce the thermal resistance between the capacitor 10a and the first heat sink 41 and the second heat sink 42.

[0101] Furthermore, in the power conversion device 100C, since the first heat sink 41 and the second heat sink 42 are fixed to the bottom wall 32, the sealing material 50 can be surely filled in the space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32.

[0102] (Modification Example 1 of Power Conversion Device 100C) FIG. 22 is an enlarged cross-sectional view of the power conversion device 100C in the vicinity of the bottom wall 32. FIG. 22 shows an enlarged cross-section orthogonal to the second direction DR2. As shown in FIG. 22, in the power conversion device 100C, a plurality of fifth grooves 32e may be formed on the outer wall surface of the bottom wall 32. The fifth grooves 32e extend along the second direction DR2. The plurality of fifth grooves 32e are arranged at intervals in the third direction DR3. Note that the fifth grooves 32e may extend along the third direction DR3. In this case, the plurality of fifth grooves 32e are arranged at intervals in the second direction DR2.

[0103] In the power conversion device 100C, caulking grooves 32ea and caulking grooves 32eb may be further formed on the outer wall surface of the bottom wall 32. The caulking grooves 32ea and caulking grooves 32eb extend along the second direction DR2. The fifth groove 32e is arranged between the caulking groove 32ea and the caulking groove 32eb. Note that when the fifth groove 32e extends along the third direction DR3, the caulking groove 32ea and the caulking groove 32eb extend along the third direction DR3.

[0104] The power conversion device 100C may include a plurality of plate members 34. The plate member 34 is inserted into the fifth groove 32e and caulked to the fifth groove 32e. The caulking of the plate member 34 into the fifth groove 32e is performed by inserting a press tool into the caulking groove 32ea and the caulking groove 32eb. Since the plate member 34 caulked into the fifth groove 32e functions as a cooling fin, the heat dissipation from the case 30 to the outside air is improved, and the temperature rise of the capacitor 10a can be further suppressed.

[0105] (Modification Example 2 of Power Conversion Device 100C) FIG. 23 is an enlarged cross-sectional view of Modification 2 of the power conversion device 100C in the vicinity of the first groove 31aa. FIG. 24 is an enlarged cross-sectional view of Modification 2 of the power conversion device 100C in the vicinity of the second groove 31ba. FIGS. 23 and 24 show enlarged cross-sections orthogonal to the first direction DR1. As shown in FIGS. 23 and 24, in the power conversion device 100C, the first heat sink 41 may be metallically joined to the first groove 31aa on the first end 41a side by caulking, or may be metallically joined to the second groove 31ba on the second end 41b side.

[0106] In the power conversion device 100C, caulking grooves 31ab and 31ac may be formed on the inner wall surface of the first side wall portion 31a. In the power conversion device 100C, caulking grooves 31bb and 31bc may be formed on the inner wall surface of the second side wall portion 31b. The caulking grooves 31ab, 31ac, 31bb, and 31bc extend along the first direction DR1. The first groove 31aa is disposed between the caulking grooves 31ab and 31ac, and the second groove 31ba is disposed between the caulking grooves 31bb and 31bc.

[0107] The first heat sink 41 is caulked into the first groove 31aa by inserting a caulking tool into the caulking grooves 31ab and 31ac, and is caulked into the second groove 31ba by inserting a caulking tool into the caulking grooves 31bb and 31bc. In this case, since the thermal resistance between the first heat sink 41 and the side wall 31 is reduced, the temperature rise of the capacitor 10a can be further suppressed.

[0108] Embodiment 5. The power conversion device according to Embodiment 5 will be described. The power conversion device according to Embodiment 5 is referred to as a power conversion device 100D. Here, the points different from the power conversion device 100 will be mainly described, and repeated descriptions will not be repeated.

[0109] (Configuration of Power Conversion Device 100D) The configuration of the power conversion device 100D will be described below.

[0110] The power conversion device 100D includes a plurality of circuit components 10, a case 30, a plurality of first heat dissipation plates 41 and a plurality of second heat dissipation plates 42, a sealing material 50, and a printed wiring board 60. In this regard, the configuration of the power conversion device 100D is common to the configuration of the power conversion device 100.

[0111] FIG. 25 is a cross-sectional view of the power conversion device 100D. FIG. 25 shows a cross-section at a position corresponding to IV-IV of FIG. 2. As shown in FIG. 25, in the power conversion device 100D, the capacitor 10a does not have an exterior case 13 and a sealing resin 14. The power conversion device 100D further includes an insulating net 70. The insulating net 70 is a net-shaped member formed of an insulating resin material. The insulating net 70 is formed of, for example, an epoxy resin, a silicone resin, a urethane resin, etc. The insulating net 70 may be formed of a rubber material having flexibility and stretchability.

[0112] The insulating net 70 is disposed in a space defined by two adjacent first heat dissipation plates 41, two adjacent second heat dissipation plates 42, and the bottom wall 32 so as to surround the capacitor 10a. That is, the insulating net 70 is located between the capacitor 10a and the first heat dissipation plate 41, the second heat dissipation plate 42, and the bottom wall 32. In the example shown in FIG. 25, the insulating net 70 and the capacitor 10a are not in contact, but the insulating net 70 may be in contact with the capacitor 10a. It is sufficient that the capacitor 10a is not in contact with the first heat dissipation plate 41, the second heat dissipation plate 42, and the bottom wall 32 due to the insulating net 70.

[0113] In the power conversion device 100D, the sealing material 50 may not include a heat dissipation auxiliary material 51 and a molding material 52. In the power conversion device 100D, the sealing material 50 may be formed by potting an arbitrary resin material. In these regards, the configuration of the power conversion device 100D is different from the configuration of the power conversion device 100.

[0114] (Effect of the power conversion device 100D) The effects of the power conversion device 100D will be described below.

[0115] In the power conversion device 100D, since the capacitor 10a does not have the exterior case 13 and the encapsulating resin 14, the number of windings of the metal film and the dielectric film in the capacitor 10a can be increased, and the capacitance per capacitor 10a can be increased. Also, in the power conversion device 100D, since the capacitor 10a does not have the exterior case 13 and the encapsulating resin 14, the cost of the capacitor 10a can be reduced.

[0116] Note that in the power conversion device 100D, since the insulating net 70 is disposed between the capacitor 10a and the first heat sink 41, the second heat sink 42, and the bottom wall 32, the insulation between the capacitor 10a and the first heat sink 41, the second heat sink 42, and the bottom wall 32 can be ensured even without the exterior case 13 and the encapsulating resin 14. In the power conversion device 100D, since a resin material having a higher thermal conductivity than the encapsulating resin 14 can be used as the encapsulant 50, the heat generated by the capacitor 10a can be efficiently transferred to the case 30.

[0117] (Modification Examples 1, 2, and 3 of the Power Conversion Device 100D) FIG. 26 is a cross-sectional view of Modification Example 1 of the power conversion device 100D. FIG. 26 shows a cross-section at a position corresponding to IV-IV in FIG. 2. As shown in FIG. 26, in the power conversion device 100D, insulating paper 71 may be used instead of the insulating net 70. The insulating paper 71 is disposed in the space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32 so as to surround the capacitor 10a.

[0118] FIG. 27 is a cross-sectional view of Modification 2 of the power conversion device 100D. FIG. 27 shows a cross-section at a position corresponding to IV-IV in FIG. 2. As shown in FIG. 27, in the power conversion device 100D, a heat conduction insulating sheet 72 may be used instead of the insulating net 70. The heat conduction insulating sheet 72 is disposed in a space defined by two adjacent first heat radiating plates 41, two adjacent second heat radiating plates 42, and the bottom wall 32.

[0119] FIG. 28 is a cross-sectional view of Modification 3 of the power conversion device 100D. FIG. 28 shows a cross-section at a position corresponding to IV-IV in FIG. 2. As shown in FIG. 28, in the power conversion device 100D, a spacer 73 may be used instead of the insulating net 70. The spacer 73 is disposed between the capacitor 10a and the first heat radiating plate 41, between the capacitor 10a and the second heat radiating plate 42, and between the capacitor 10a and the bottom wall 32. The spacer 73 is formed of, for example, a resin material.

[0120] Also in these cases, since the contact between the capacitor 10a and the first heat radiating plate 41, the second heat radiating plate 42, and the bottom wall 32 is prevented by the insulating paper 71, the heat conduction insulating sheet 72, or the spacer 73, the insulation between the first heat radiating plate 41, the second heat radiating plate 42, and the bottom wall 32 can be ensured.

[0121] (Modification 4 of the power conversion device 100D) FIG. 29 is a cross-sectional view of Modification 4 of the power conversion device 100D. FIG. 29 shows a cross-section at a position corresponding to IV-IV in FIG. 2. As shown in FIG. 29, in the power conversion device 100D, the sealing material 50 may be silicone gel 53. The silicone gel 53 preferably has a low viscosity and high insulation.

[0122] Since the silicone gel 53 has high adhesion to the capacitor 10a, the first heat sink 41, and the second heat sink 42, in the evaluation of insulation performance, it is not necessary to consider the creepage along the boundaries between the capacitor 10a, the first heat sink 41, and the second heat sink 42. Therefore, in this case, an insulation area for securing the creepage distance is not required, and miniaturization around the capacitor 10a becomes possible. In particular, in the power conversion device 100D using the insulation net 70, by using the silicone gel 53, high insulation performance, that is, high creepage breakdown voltage and through-insulation breakdown voltage can be ensured.

[0123] Also, in this case, the heat generated by the capacitor 10a can be efficiently transmitted to the case 30. Furthermore, the silicone gel 53 has a high penetration, that is, it is a soft material. Therefore, in this case, the reliability when a heat cycle or a power cycle is applied to the power conversion device 100 can be improved. Note that since the capacitor 10a is also fixed in position by being attached to the case 30 of the printed wiring board 60, even if the penetration of the silicone gel 53 is high, there is no problem in fixing the position of the capacitor 10a.

[0124] Embodiment 6. The power conversion device according to Embodiment 6 will be described. The power conversion device according to Embodiment 6 is designated as the power conversion device 100E. Here, the points different from the power conversion device 100 will be mainly described, and repeated descriptions will not be repeated.

[0125] (Configuration of the power conversion device 100E) The configuration of the power conversion device 100E will be described below.

[0126] The power conversion device 100E includes a plurality of circuit components 10, a case 30, a plurality of first heat sinks 41 and a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this regard, the configuration of the power conversion device 100E is common to the configuration of the power conversion device 100.

[0127] FIG. 30 is a side view of the first heat sink 41 included in the power conversion device 100E. As shown in FIG. 30, in the power conversion device 100E, a plurality of through holes 41f are formed in the first heat sink 41. The through holes 41f penetrate the first heat sink 41 along the thickness direction. The plurality of through holes 41f are arranged at intervals in the second direction DR2. The through holes 41f are arranged between two adjacent first insertion ports 41e. In the power conversion device 100E, the width of the first insertion port 41e in the second direction DR2 is larger than the thickness of the second heat sink 42. More specifically, in the power conversion device 100E, the width of the first insertion port 41e in the second direction DR2 may be 0.1 mm or more larger than the thickness of the second heat sink 42, and preferably 0.5 mm or more larger than the thickness of the second heat sink 42.

[0128] FIG. 31 is a side view of the second heat sink 42 included in the power conversion device 100E. As shown in FIG. 31, in the power conversion device 100E, a plurality of through holes 42d are formed in the second heat sink 42. The through holes 42d penetrate the second heat sink 42 along the thickness direction. The plurality of through holes 42d are arranged at intervals in the third direction DR3. The through holes 42d are arranged between two adjacent second insertion ports 42c. In the power conversion device 100E, the width of the second insertion port 42c in the third direction DR3 is larger than the thickness of the first heat sink 41. More specifically, in the power conversion device 100E, the width of the second insertion port 42c in the third direction DR3 may be 0.1 mm or more larger than the thickness of the first heat sink 41, and preferably 0.5 mm or more larger than the thickness of the first heat sink 41.

[0129] Note that in the power conversion device 100E, it is sufficient if at least one of the following conditions is satisfied: a through hole 41f is formed in the first heat sink 41; a through hole 42d is formed in the second heat sink 42; the width of the first insertion port 41e in the second direction DR2 is sufficiently larger than the thickness of the second heat sink 42; and the width of the second insertion port 42c in the third direction DR3 is sufficiently larger than the thickness of the first heat sink 41. Regarding these points, the configuration of the power conversion device 100E is different from that of the power conversion device 100.

[0130] The effects of the power conversion device 100E will be described below. In the power conversion device 100E, a through hole 41f is formed in the first heat sink 41, and a through hole 42d is formed in the second heat sink 42. Therefore, the sealing material 50 is easily injected through the through hole 41f and the through hole 42d into the space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32. As a result, voids are less likely to occur in the sealing material 50 in the space defined by two adjacent first heat sinks 41, two adjacent second heat sinks 42, and the bottom wall 32. When there are no voids in the sealing material 50, the thermal resistance of the sealing material 50 is reduced. Therefore, in the power conversion device 100E, the temperature rise of the capacitor 10a can be further suppressed.

[0131] In the power conversion device 100E, the sealing material 50 also exists in the through hole 41f and the through hole 42d. Therefore, in the power conversion device 100E, the adhesion between the first heat sink 41 and the second heat sink 42 and the sealing material 50 can be further improved. Further, in the power conversion device 100E, as a result of forming the through hole 41f and the through hole 42d, the amount of material used to form the first heat sink 41 and the second heat sink 42 is reduced, so that the manufacturing cost and weight of the first heat sink 41 and the second heat sink 42 can be reduced.

[0132] In the power conversion device 100E, the width of the first insertion port 41e in the second direction DR2 is sufficiently larger than the thickness of the second heat sink 42, and the width of the second insertion port 42c in the third direction DR3 is sufficiently larger than the thickness of the first heat sink 41. Therefore, the second heat sink 42 can be easily attached to the first heat sink 41. Therefore, according to the power conversion device 100E, the assemblability can be improved.

[0133] Embodiment 7. The power conversion device according to Embodiment 7 will be described. The power conversion device according to Embodiment 7 is designated as power conversion device 100F. Here, the points different from the power conversion device 100 will be mainly described, and repeated descriptions will not be repeated.

[0134] (Configuration of Power Conversion Device 100F) The configuration of the power conversion device 100F will be described below.

[0135] The power conversion device 100F includes a plurality of circuit components 10, a case 30, a plurality of first heat sinks 41 and a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this regard, the configuration of the power conversion device 100F is common to the configuration of the power conversion device 100.

[0136] FIG. 32 is an exploded perspective view of the printed wiring board 60 included in the power conversion device 100F. As shown in FIG. 32, in the power conversion device 100F, the printed wiring board 60 has a plurality of stacked layers. In the example shown in FIG. 32, the printed wiring board 60 has a four-layer structure and includes a first layer 60d, a second layer 60e, a third layer 60f, and a fourth layer 60g. However, in the power conversion device 100F, the printed wiring board 60 is not limited to the case of having a four-layer structure. The first layer 60d, the second layer 60e, the third layer 60f, and the fourth layer 60g are stacked in this order from the first surface 60a toward the second surface 60b side.

[0137] In the power conversion device 100F, each of the plurality of layers constituting the printed wiring board 60 has a wiring pattern. In the example shown in FIG. 32, the wiring patterns of the first layer 60d, the second layer 60e, the third layer 60f, and the fourth layer 60g are the wiring pattern 60h, the wiring pattern 60i, the wiring pattern 60j, and the wiring pattern 60k, respectively. Different potentials are applied to the wiring pattern 60h and the wiring pattern 60j from the wiring pattern 60i and the wiring pattern 60j. For example, when a positive potential is applied to the wiring pattern 60h and the wiring pattern 60j, a negative potential is applied to the wiring pattern 60i and the wiring pattern 60j. Note that between adjacent wiring patterns in the thickness direction of the printed wiring board 60, they are insulated from each other. The wiring pattern 60h is preferably disposed near a portion where the side wall 31 and the printed wiring board 60 are in contact. In these respects, the configuration of the power conversion device 100F is different from the configuration of the power conversion device 100.

[0138] (Effect of Power Conversion Device 100F) The effect of the power conversion device 100F will be described below.

[0139] In the power conversion device 100F, since wiring patterns of different potentials are alternately laminated, a stray capacitance is generated between the layers. As a result, since the capacitance of the required capacitor 10a can be supplemented by the stray capacitance of the printed wiring board 60, the number of series or parallel capacitors 10a can be reduced. Further, in the power conversion device 100F, since wiring patterns of different potentials are arranged in parallel, the inductance between the wiring patterns can be reduced. As a result, the surge voltage due to the switching of the switching circuit 120 can be reduced.

[0140] When an alternating current flows through the printed wiring board 60 when the power conversion device 100F operates, power consumption occurs due to the resistance component of the printed wiring board 60, and the printed wiring board 60 generates heat. In the example shown in FIG. 32, the wiring pattern 60h, the wiring pattern 60i, the wiring pattern 60j, and the wiring pattern 60k generate heat. When the wiring pattern 60h is disposed near a portion where the side wall 31 and the printed wiring board 60 are in contact, it is possible to suppress the temperature rise of the wiring pattern 60h.

[0141] Embodiment 8. The power conversion device according to Embodiment 8 will be described. The power conversion device according to Embodiment 8 is referred to as a power conversion device 100G. Here, the points different from the power conversion device 100 will be mainly described, and overlapping descriptions will not be repeated.

[0142] (Configuration of Power Conversion Device 100G) The configuration of the power conversion device 100G will be described below.

[0143] The power conversion device 100G includes a plurality of circuit components 10, a case 30, a plurality of first heat dissipation plates 41 and a plurality of second heat dissipation plates 42, a sealing material 50, and a printed wiring board 60. In this regard, the configuration of the power conversion device 100G is common to the configuration of the power conversion device 100.

[0144] FIG. 33 is a bottom view of the printed wiring board 60 included in the power conversion device 100G. FIG. 34 is a schematic cross-sectional view taken along line XXXIV-XXXIV of FIG. 33. FIG. 35 is a schematic cross-sectional view taken along line XXXV-XXXV of FIG. 33. As shown in FIGS. 33 to 35, in the power conversion device 100G, the first heat dissipation plate 41 and the second heat dissipation plate 42 are connected to the printed wiring board 60. The connection of the first heat dissipation plate 41 and the second heat dissipation plate 42 to the printed wiring board 60 is performed, for example, by soldering. In this regard, the configuration of the power conversion device 100G is different from the configuration of the power conversion device 100.

[0145] (Assembly Method of Power Conversion Device 100G) The method for assembling the power conversion device 100G will be described below.

[0146] In the assembly of the power conversion device 100G, first, the case 30, a plurality of first heat sinks 41, a plurality of second heat sinks 42, and the printed wiring board 60 to which the plurality of capacitors 10a are connected are prepared. Second, the sealing material 50 is injected into the case 30. Third, the printed wiring board 60 to which the plurality of first heat sinks 41, the plurality of second heat sinks 42, and the plurality of capacitors 10a are connected is attached to the case 30. Fourth, the sealing material 50 is cured. Thus, the assembly of the power conversion device 100G is completed.

[0147] (Effect of the power conversion device 100G) The effect of the power conversion device 100G will be described below.

[0148] In the power conversion device 100G, since the first heat sink 41 and the second heat sink 42 are pre-connected to the printed wiring board 60, the assemblability of the first heat sink 41 and the second heat sink 42 to the case 30 is improved. Further, in the power conversion device 100G, since the positioning accuracy of the capacitor 10a, the first heat sink 41, and the second heat sink 42 is improved, the thickness of the sealing material 50 can be reduced to reduce the thermal resistance between the capacitor 10a and the first heat sink 41 and the second heat sink 42.

[0149] Furthermore, in the power conversion device 100G, since the first heat sink 41 and the second heat sink 42 are connected to the printed wiring board 60, the heat generated by the printed wiring board 60 is radiated from the case 30 through the first heat sink 41 and the second heat sink 42, so that the temperature rise of the printed wiring board 60 is suppressed and the heat equalization of the entire power conversion device 100G is possible.

[0150] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The basic scope of the present disclosure is indicated by the claims rather than the above embodiments, and it is intended that all modifications within the meaning and scope equivalent to the claims be included.

Description of reference numerals

[0151] Power conversion devices 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 101, 102, circuit component 10, capacitor 10a, inductor 10b, contactor 10c, discharge resistor 10d, charging resistor 10e, capacitor element body 11, electrode surface 11a, lead wire 12, exterior case 13, sealing resin 14, circuit component 20, transistors 20a, 20b, 20c, 20d, 20e, 20f, diodes 20g, 20h, 20i, 20j, 20k, 20l, case 30, side wall 31, first side wall portion 31a, first groove 31aa, caulking grooves 31ab, 31ac, second side wall portion 31b, second groove 31ba, caulking grooves 31bb, 31bc, third side wall portion 31c, fourth side wall portion 31d, groove 31e, bottom wall 32, third groove 32a, fourth groove 32b, caulking grooves 32ca, 32cb, caulking grooves 32da, 32db, fifth groove 32e, caulking grooves 32ea, 32eb, brazing material 33, plate member 34, first heat sink 41, first end 41a, second end 41b, third end 41c, fourth end 41d, first insertion port 41e, through hole 41f, second heat sink 42, fifth end 42a, sixth end 42b, second insertion port 42c, through hole 42d, seventh end 42e, eighth end 42f, sealing material 50, heat dissipation auxiliary material 51, molding material 52, silicone gel 53, printed wiring board 60, first surface 60a, second surface 60b, external connection terminal 60c, first layer 60d, second layer 60e, third layer 60f, fourth layer 60g, wiring patterns 60h, 60i, 60j, 60k, connection member 61, insulating net 70, insulating paper 71, heat conductive insulating sheet 72, spacer 73, peripheral circuit 110, switching circuit 120, DC supply circuit 130, motor 140, input wires 141, 142, 143, first direction DR1, second direction DR2, third direction DR3.

Claims

1. a case having a side wall and a bottom wall; a plurality of first heat sinks, a plurality of second heat sinks, a plurality of circuit components, and a sealing material disposed within the case; a printed wiring board electrically connected to the plurality of circuit components and attached to the case; A normal line of the inner wall surface of the bottom wall is along a first direction, Each of the plurality of first heat dissipation plates extends along a second direction perpendicular to the first direction, and is arranged at intervals in a third direction perpendicular to the first direction and the second direction, Each of the plurality of second heat dissipation plates extends along the third direction and is arranged at intervals in the second direction, each of the plurality of circuit components is disposed within a space defined by adjacent two of the plurality of first heat sinks, adjacent two of the plurality of second heat sinks, and the bottom wall; The sealing material is filled in the space, Each of the plurality of circuit components includes an element body having an electrode surface, a lead wire connected to the electrode surface, and an exterior case housing the element body, A power conversion device, wherein each of the plurality of circuit components is arranged such that the electrode surface faces one of the plurality of first heat sinks.

2. the printed wiring board has a first surface facing the case and a second surface opposite the first surface; 2. The power conversion device according to claim 1, wherein the printed wiring board has a first wiring pattern on the first surface, and a second wiring pattern laminated with the first wiring pattern and applied with a potential different from that of the first wiring pattern.

3. the plurality of circuit components include a plurality of first circuit components arranged along the second direction to form a first row, and a plurality of second circuit components arranged along the second direction to form a second row, the electrode surface of each of the first circuit components faces the electrode surface of each of the second circuit components, The power conversion device according to claim 1 , wherein one of the plurality of first heat sinks is disposed between the first row and the second row.

4. The power conversion device according to claim 1 , wherein at least one of the plurality of first heat sinks and the plurality of second heat sinks is connected to the printed wiring board.

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