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 technology]

[0002] Japanese Patent Laid-Open Publication No. 2016-66666 (Patent Document 1) describes a capacitor. The capacitor described in Patent Document 1 has a case, a capacitor element, electrode plates, a molded resin, and a lid. The capacitor element and the electrode plates are housed in the case. The lead terminals of the capacitor element are electrically connected to the electrode plates. The molded resin is filled in the case. This seals the capacitor element and the electrode plates within the case. The lid is attached to the opening of the case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-66666 Summary of the Invention [Problem to be solved by the invention]

[0004] In the capacitor described in Patent Document 1, heat generated in the capacitor element is transferred to the lid through the lead terminals and electrode plates and dissipated from the protrusions on the lid. As a result, the capacitor described in Patent Document 1 has high thermal resistance, resulting in a large temperature rise in the capacitor element.

[0005] The present disclosure has been made in view of the above-described problems of the conventional technology. More specifically, the present disclosure provides a power conversion device capable of suppressing a temperature rise of circuit components. [Means for solving the problem]

[0006] The power conversion device of the present disclosure includes a case having side walls 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, and a printed wiring board electrically connected to the plurality of circuit components and attached to the case. The normal to the inner wall surface of the bottom wall is along a first direction. Each of the plurality of first heat sinks extends along a second direction perpendicular to the first direction and is spaced apart in a third direction perpendicular to the first and second directions, and each of the plurality of second heat sinks extends along the third direction and is spaced apart in the second direction. Each of the plurality of circuit components is disposed in 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 fills the space. Each of the plurality of circuit components has an element body having an electrode surface, lead wires connected to the electrode surface, and an exterior case housing the element body. Each of the plurality of circuit components is arranged so that the electrode surface faces one of the plurality of first heat sinks. [Effects of the Invention]

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

[0008] [Figure 1] 1 is a circuit diagram of a power conversion device 100. FIG. [Figure 2] FIG. 1 is a perspective view of a power conversion device 100. [Figure 3] FIG. 2 is an exploded perspective view of the power conversion device 100. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] 2 is a plan view of a case 30 of the power conversion device 100. FIG. [Figure 6] 2 is a bottom view of a printed wiring board 60 included in the power conversion device 100. FIG. [Figure 7] 2 is a side view of a first heat sink 41 included in the power conversion device 100. FIG. [Figure 8]4 is a side view of a second heat sink 42 included in the power converter 100. FIG. [Figure 9] FIG. 2 is a schematic side view showing a state in which a plurality of power conversion devices 100 are connected together. [Figure 10] 1 is a plan view of a case 30 of a first modification of the power conversion device 100. FIG. [Figure 11] FIG. 10 is a cross-sectional view of a second modified example of the power conversion device 100. [Figure 12] 2 is a plan view of a case 30 of the power conversion device 100A. FIG. [Figure 13] 10 is an enlarged cross-sectional view of the power converter 100A in the vicinity of a third groove 32a. FIG. [Figure 14] 10 is an enlarged cross-sectional view of the power converter 100A in the vicinity of a fourth groove 32b. FIG. [Figure 15] 10 is an enlarged cross-sectional view of the power converter 100B in the vicinity of a third groove 32a. FIG. [Figure 16] 10 is an enlarged cross-sectional view of the power converter 100B in the vicinity of a fourth groove 32b. FIG. [Figure 17] 10 is a plan view of a case 30 included in a first modification of the power conversion device 100B. FIG. [Figure 18] FIG. 10 is an enlarged cross-sectional view of a second modification of the power converter 100B in the vicinity of a first groove 31aa. [Figure 19] FIG. 10 is an enlarged cross-sectional view of a second modification of the power converter 100B in the vicinity of a second groove 31ba. [Figure 20] 10 is an enlarged cross-sectional view of the power converter 100C in the vicinity of a third groove 32a. FIG. [Figure 21] 10 is an enlarged cross-sectional view of the power converter 100C in the vicinity of a fourth groove 32b. FIG. [Figure 22] 3 is an enlarged cross-sectional view of the power converter 100C in the vicinity of the bottom wall 32. FIG. [Figure 23] FIG. 10 is an enlarged cross-sectional view of a second modification of the power converter 100C in the vicinity of a first groove 31aa. [Figure 24] FIG. 10 is an enlarged cross-sectional view of a second modification of the power converter 100C in the vicinity of a second groove 31ba. [Figure 25]FIG. 10 is a cross-sectional view of a power conversion device 100D. [Figure 26] FIG. 10 is a cross-sectional view of a first modified example of the power conversion device 100D. [Figure 27] FIG. 10 is a cross-sectional view of a second modification of the power conversion device 100D. [Figure 28] FIG. 10 is a cross-sectional view of a third modified example of the power conversion device 100D. [Figure 29] FIG. 10 is a cross-sectional view of a fourth modified example of the power conversion device 100D. [Figure 30] 10 is a side view of a first heat sink 41 included in the power converter 100E. FIG. [Figure 31] 10 is a side view of a second heat sink 42 included in the power converter 100E. FIG. [Figure 32] 1 is an exploded perspective view of a printed wiring board 60 included in a power conversion device 100F. [Figure 33] 10 is a bottom view of a printed wiring board 60 included in the power conversion device 100G. FIG. [Figure 34] FIG. 34 is a schematic cross-sectional view taken along line XXXIV-XXXIV in FIG. 33. [Figure 35] FIG. 34 is a schematic cross-sectional view taken along line XXXV-XXXV in FIG. 33. DETAILED DESCRIPTION OF THE INVENTION

[0009] The 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 designated by the same reference numerals, and redundant description will not be repeated.

[0010] Embodiment 1 A description will be given of a power conversion device according to embodiment 1. The power conversion device according to embodiment 1 is referred to as a power conversion device 100.

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

[0012] 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 charge 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 charge 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 transistor 20a is electrically connected to one electrode of capacitor 10a. The source of transistor 20a is electrically connected to the drain of transistor 20b. The source of transistor 20b is electrically connected to the other electrode of capacitor 10a.

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

[0017] The transistors 20c, 20d, diodes 20i, and 20j are connected in the same manner as the transistors 20a, 20b, diodes 20g, and 20h, respectively. The transistors 20e, 20f, diodes 20k, and 20l are connected in the same manner as the transistors 20a, 20b, diodes 20g, and 20h, respectively. Although not shown, the gates of the transistors 20a to 20f are connected to a control circuit.

[0018] The switching circuit 120 is connected to a 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 in FIG. 2. FIG. 5 is a plan view of a case 30 included in the power conversion device 100. FIG. 6 is a bottom view of a printed wiring board 60 included in the power conversion device 100. FIG. 7 is a side view of a first heat sink 41 included in the power conversion device 100. FIG. 8 is a side view of a 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 sealant 50, and a printed wiring board 60.

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

[0021] The side wall 31 has, for example, a rectangular shape in a plan view. The side wall 31 has a first side wall portion 31a, a second side wall portion 31b, 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 gap in the second direction DR2. The third side wall portion 31c and the fourth side wall portion 31d face each other with a gap in the third direction DR3. The arithmetic mean roughness of 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 made of a rigid material. For example, the case 30 is made of a metal material. The case 30 is made of copper (Cu), a copper alloy, aluminum (Al), an aluminum alloy, iron (Fe), an iron alloy, or the like. The case 30 may also be made 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 at intervals in the third direction DR3. The first grooves 31aa extend along the first direction DR1. Both ends of each first groove 31aa in the third direction DR3 reach the upper and lower ends 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 at intervals in the third direction DR3. The second grooves 31ba extend along the first direction DR1. Both ends of the second groove 31ba in the third direction DR3 reach the upper and lower ends of the second side wall portion 31b, respectively. The second grooves 31ba face the first grooves 31aa in the second direction DR2.

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

[0026] The first heat sink 41 extends along the second direction DR2 in a plan view. The multiple first heat sinks 41 are arranged at intervals in the third direction DR3. Each first heat sink 41 has a first end 41a and a second end 41b in the second direction DR2. The second end 41b is the end opposite the first end 41a. The first heat sink 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 sink 41 faces the electrode surface 11a.

[0027] The first heat dissipation plate 41 has a third end 41c and a fourth end 41d in the first direction DR1. The third end 41c is located on the bottom wall 32 side. The third end 41c is thermally connected to the bottom wall 32 via a heat dissipation auxiliary material 51, which will be described later. The fourth end 41d is the end opposite the third end 41c. A plurality of first plug-ins 41e are formed in the first heat dissipation plate 41. The first plug-in holes 41e penetrate the first heat dissipation plate 41 along the thickness direction. The first plug-in holes 41e extend from the fourth end 41d toward the third end 41c. The number of first plug-in holes 41e is equal to or greater than the number of second heat dissipation plates 42.

[0028] The second heat dissipation plates 42 extend along the third direction DR3 in a plan view. The multiple second heat dissipation plates 42 are arranged at intervals in the second direction DR2. The second heat dissipation plates 42 have a fifth end 42a and a sixth end 42b in the first direction DR1. The fifth end 42a is on the bottom wall 32 side. The sixth end 42b is the end opposite the fifth end 42a.

[0029] A plurality of second sockets 42c are formed in the second heat dissipation plate 42. The second sockets 42c penetrate the second heat dissipation plate 42 in the thickness direction. The second sockets 42c extend from the fifth end 42a toward the sixth end 42b. The number of second sockets 42c is equal to or greater than the number of first heat dissipation plates 41. The second heat dissipation plate 42 is attached to the first heat dissipation plate 41 by inserting the second sockets 42c into the first sockets 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 extending along the first direction DR1 and spaced apart in the second direction DR2 may be formed on the inner wall surface of the third side wall 31c. Furthermore, a plurality of grooves extending along the first direction DR1 and spaced apart in the second direction DR2 may be formed on the inner wall surface of the fourth side wall 31d. The second heat sink 42 may be attached to the case 30 by inserting both ends of the second heat sink 42 in the third direction DR3 into the grooves formed in the inner wall surface of the third side wall 31c and the grooves formed in the inner wall surface of the fourth side wall 31d.

[0031] The second heat sink 42 has a seventh end 42e and an eighth end 42f in the third direction DR3. The eighth end 42f is the end opposite the seventh end 42e. The seventh end 42e and the eighth end 42f are preferably spaced apart from the inner wall surface of the third side wall 31c and the inner wall surface of the fourth side wall 31d, respectively. From another perspective, it is preferable that a molding material 52 be disposed between the seventh end 42e and the inner wall surface of the third side wall 31c and between the eighth end 42f and the inner wall surface of the fourth side wall 31d.

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

[0033] 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 a 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 formed, for example, by winding a metal film and a dielectric film disposed on the metal film. Both end surfaces of the capacitor element body 11 form electrode surfaces 11a. Lead wires 12 are electrically connected to the electrode surfaces 11a. The lead wires 12 serve to pass external current to the capacitor element body 11. The lead wires 12 are made of a conductive material such as a metal material.

[0036] Capacitor element body 11 has two electrode surfaces 11a, which face two different first heat sinks 41 with molding material 52 interposed therebetween.

[0037] The exterior case 13 is made of an insulating material. The exterior case 13 is made of, for example, a resin material. The capacitor element body 11 and the lead wires 12 are housed inside the exterior case 13. However, a portion of the lead wires 12 protrudes from the top surface of the exterior case 13. The interior of the exterior case 13 is filled with a sealing resin 14.

[0038] The capacitors 10a are arranged in a first row and a second row. The first row and the second row extend along the second direction DR2. The electrode surfaces 11a of the capacitors 10a in the first row preferably face the electrode surfaces 11a of the capacitors 10a in the second row. A first heat sink 41 is disposed between the first and second rows. That is, the electrode surfaces 11a of the capacitors 10a in the first row face the electrode surfaces 11a of the capacitors 10a in the second row via the first heat sink 41.

[0039] The sealing material 50 is filled inside the case 30. More specifically, the sealing material 50 is filled in a space defined by two adjacent first heat dissipation plates 41, two adjacent second heat dissipation plates 42, and the bottom wall 32. The sealing material 50 includes 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 thermally conductive filler. The thermally conductive filler is made of, for example, a ceramic or metal material. The thermal 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 to the bottom wall 32. More specifically, the heat dissipation auxiliary material 51 is applied to the inner wall surface of the bottom wall 32. Although not shown, the heat dissipation auxiliary material 51 may also be applied to the first groove 31aa and the second groove 31ba.

[0041] The molding material 52 is, for example, a resin material with high thermal conductivity. The molding material 52 is, for example, an epoxy resin, a silicone resin, or a urethane resin containing a thermally conductive filler. The thermal conductivity of the molding 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 molding material 52 is, for example, 1 MPa or more and 50 GPa or less. The molding material 52 may be made of the same material as the heat dissipation auxiliary material 51. For example, the heat dissipation auxiliary material 51 and the molding material 52 may be an adhesive.

[0042] The molding material 52 is disposed on the heat dissipation auxiliary material 51. The molding material 52 is in contact with the bottom, side, and top surfaces of the exterior case 13. That is, the molding material 52 surrounds the capacitor 10a. The lead wires 12 protrude from the molding material 52. The molding material 52 is also in contact with the inner wall surfaces of the side walls 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. The second surface 60b is the surface opposite to the first surface 60a. The capacitor 10a is electrically connected to the printed wiring board 60. More specifically, the lead wires 12 are inserted into through holes (not shown) formed in the printed wiring board 60 and soldered to connect the capacitor 10a to the printed wiring board 60. This achieves the wiring of the peripheral circuit 110 shown in FIG. 1. The capacitor 10a and the printed wiring board 60 may be connected using a conductive adhesive.

[0044] The printed wiring board 60 also has external connection terminals 60c. The external connection terminals 60c are formed by lands, and are connected to the switching circuit 120 shown in Fig. 1 by contacting a bus bar (not shown) and being energized. 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 connecting a plurality of power conversion devices 100. One of the plurality of power conversion devices 100 is designated as power conversion device 101, and the other of the plurality of power conversion devices 100 is designated as power conversion device 102. As shown in FIG. 9, the power conversion devices 101 and 102 are connected by a connection member 61. One end of the connection member 61 is connected to an external connection terminal 60c of a printed wiring board 60 included in the power conversion device 101, and the other end is connected to an external connection terminal 60c of a printed wiring board 60 included in the power conversion device 102. The connection member 61 is, for example, a rolled material formed from a metal material.

[0046] 9, the number of the three power electronics devices 100 is three, but the number of the connected power electronics devices 100 can be increased or decreased. Also, while FIG. 9 shows an example in which the plurality of power electronics devices 100 are connected along the first direction DR1, the plurality of power electronics devices 100 may be connected along the second direction DR2 or the third direction DR3.

[0047] <First Modification of Power Converter 100> 10 is a plan view of the case 30 of the first modification of the power conversion device 100. As shown in FIG. 10, a plurality of grooves 31e may be formed in the outer wall surface of the side wall 31. The grooves 31e extend, for example, along the first direction DR1. In this case, the surface area of ​​the outer wall surface of the side wall 31 is increased, and the thermal resistance between the case 30 and the outside air is reduced, thereby further suppressing the temperature rise of the capacitor 10a.

[0048] <Modification 2 of the power conversion device 100> Fig. 11 is a cross-sectional view of the power conversion device 100 in Modification 2. Fig. 11 shows a cross section taken along a line 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 molding material 52. The silicone gel 53 preferably has low viscosity and high insulating properties.

[0049] Because the silicone gel 53 has high adhesion to the capacitor 10a, the first heat sink 41, and the second heat sink 42, there is no need to consider creepage at the boundaries between the capacitor 10a, the first heat sink 41, and the second heat sink 42 when evaluating insulation. Therefore, an insulating area to ensure creepage distance is not required, enabling miniaturization around the capacitor 10a. Furthermore, heat generated by the capacitor 10a can be efficiently transferred to the case 30. Furthermore, the silicone gel 53 has a high penetration, i.e., is a soft material. Therefore, reliability of the power conversion device 100 can be improved when subjected to heat cycles or power cycles. The capacitor 10a is also fixed in position by attaching the printed wiring board 60 to the case 30, so the high penetration of the silicone gel 53 does not interfere with the positioning of the capacitor 10a.

[0050] (Method of assembling the power conversion device 100) A method for assembling the power converter 100 will be described below.

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

[0052] Fourth, the second heat sink 42 is attached to the first heat sink 41. The second heat sink 42 is attached by inserting the second socket 42c into the first socket 41e. Fifth, the molding material 52 is poured into the case 30. Sixth, the printed wiring board 60 is attached to the upper end of the side wall 31. As a result, the capacitor 10a is placed in the space defined by the two adjacent first heat sinks 41, the two adjacent second heat sinks 42, and the bottom wall 32, and is surrounded by the molding material 52. Seventh, the molding material 52 is hardened. With the above steps, the assembly of the power conversion device 100 is completed.

[0053] <First Modification of the Method of Assembling the Power Converter 100> If the heat dissipation auxiliary material 51 and the molding material 52 are made of the same material, the sealing material 50 may be injected into the case 30 before the first heat sink 41 is attached to the case 30 during the assembly of the power conversion device 100. In this case, the number of assembly steps is reduced, and therefore the time required for assembly can be reduced.

[0054] <Modification 2 of the method for assembling the power conversion device 100> In assembling the power conversion device 100, the application of the heat dissipation auxiliary material 51 may be performed after the first heat dissipation plate 41 is attached to the case 30 and the second heat dissipation plate 42 is attached to the first heat dissipation plate 41, but before the injection of the molding material 52. In this case, the first heat dissipation plate 41 comes into contact with the bottom wall 32 without the heat dissipation auxiliary material 51 therebetween.

[0055] <Third Modification of the Method of Assembling the Power Converter 100> If the heat dissipation auxiliary material 51 and the molding material 52 are made of the same material, in assembling 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 sealing material 50 is injected through an injection port that is pre-formed in the printed wiring board 60. In this case, the number of assembly steps is reduced, and therefore the time required for assembly can be reduced.

[0056] (Effects of the power conversion device 100) The effects of the power conversion device 100 will be described below.

[0057] When an AC current flows through the capacitor 10a during operation of the power conversion device 100, power is consumed due to the resistance component of the capacitor 10a, and the capacitor 10a generates heat. The heat generated by the capacitor 10a is generated mainly 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 arranged close together. Therefore, if the heat generated by the capacitors 10a interferes with each other and the temperature of the capacitors 10a rises excessively, there is a risk that the characteristics of the capacitors 10a will deteriorate, the capacitors 10a will be destroyed, or the lifespan of the capacitors 10a will be shortened.

[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 sink 41, and the second heat sink 42. Therefore, in the power conversion device 100, the heat generated by the capacitor 10a is dissipated to the outside air from the case 30, 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 extended. For example, when the temperature of the capacitor 10a decreases by 10°C, the life of the capacitor 10a is approximately doubled.

[0060] If the circuit component 10 is an inductor 10b, a 10°C decrease in the temperature of the inductor 10b approximately doubles the life of the enamel coating of the inductor 10b. If the circuit component 10 is a discharge resistor 10d or a charge resistor 10e, the power category of the discharge resistor 10d or the charge resistor 10e can be lowered due to temperature derating, and the number of series or parallel connections of the discharge resistors 10d or the charge resistors 10e can be reduced.

[0061] In the power conversion device 100, heat generated by the capacitor 10a is transferred to the first heat sink 41 via the molding material 52. The heat transferred to the first heat sink 41 is transferred 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 via 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, thereby suppressing a temperature rise in the capacitor 10a.

[0062] Because current concentrates on electrode surface 11a, cooling electrode surface 11a is important to suppress a temperature rise in capacitor 10a. In power conversion device 100, the two electrode surfaces 11a of capacitor 10a face two different first heat sinks 41 via molding material 52, which further suppresses a temperature rise in capacitor 10a.

[0063] In power conversion device 100, first socket 41e is formed at fourth end 41d. That is, first socket 41e is not formed at third end 41c. This increases the heat transfer area between first heat sink 41 and bottom wall 32, reducing the thermal resistance between first heat sink 41 and bottom wall 32, thereby further suppressing the temperature rise of capacitor 10a.

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

[0065] In the power conversion device 100, the first heat sink 41 extends along the second direction DR2 and the plurality of capacitors 10a are lined up along the second direction DR2, so that the temperature difference between the plurality of capacitors 10a lined up along the second direction DR2 is small. Similarly, in the power conversion device 100, the second heat sink 42 extends along the third direction DR3 and the plurality of capacitors 10a are lined up along the third direction DR3, so that the temperature difference between the plurality of capacitors 10a lined up along the second direction DR2 is small.

[0066] The temperature rise of the capacitors 10a varies depending on their placement positions. More specifically, the capacitors 10a placed near the center of the power converter 100 are affected by the heat generated by the capacitors 10a placed around them, and are therefore more likely to rise in temperature than the capacitors 10a placed near the periphery of the power converter 100. The temperature derating is determined by the capacitor 10a with the highest temperature. As described above, in the power converter 100, the first heat sink 41 and the second heat sink 42 equalize the temperature among the multiple capacitors 10a, allowing the power converter 100 to be used more effectively. Furthermore, in the power converter 100, the temperature equalization among the multiple capacitors 10a allows the number of capacitors 10a connected in series or in parallel to be reduced.

[0067] In the power conversion device 100, either a first heat sink 41 or a second heat sink 42 is disposed between two adjacent capacitors 10a. Therefore, the first heat sink 41 and the second heat sink 42 function as a firewall. That is, even if a failure in one capacitor 10a causes a spark and shock due to discharge, the first heat sink 41 and the second heat sink 42 prevent the spark and shock from reaching the other capacitors 10a. When the circuit component 10 is an inductor 10b, leakage magnetic flux from the inductor 10b to the surroundings is blocked by the first heat sink 41 and the second heat sink 42, which improves the accuracy of sensor components (e.g., current sensors using the Hall effect) disposed nearby.

[0068] In the power converter 100, the vibration resistance of the capacitor 10a is improved because the sealant 50 is filled inside the case 30. When the arithmetic mean roughness of 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 adhesion with the sealant 50 is improved, and the mechanical strength of the power converter 100 is improved.

[0069] In the power converter 100, by increasing or decreasing the number of first heat sinks 41 and the number of second heat sinks, the number or size of the sections formed by two adjacent first heat sinks 41 and two adjacent second heat sinks 42 in a grid pattern can be increased or decreased to match the number or size of the capacitors 10a. Furthermore, in the power converter 100, the thickness, type, material, etc. of the first heat sinks 41 and the second heat sinks 42 can be selected as desired. Furthermore, in the power converter 100, bending or concave-convex press processing can be performed on the first heat sinks 41 and the second heat sinks 42 to ensure the strength of the first heat sinks 41 and the second heat sinks 42 and change the shape of the grid-shaped sections. In this way, the power converter 100 can flexibly realize a variety of specifications at low cost.

[0070] The temperature of capacitor 10a tends to rise at electrode surface 11a where current is concentrated. In power conversion device 100, electrode surface 11a faces first heat sink 41 (or second heat sink 42), so heat generated at electrode surface 11a is easily transferred to case 30 via first heat sink 41 (or second heat sink 42), which further suppresses the temperature rise of capacitor 10a.

[0071] When the seventh end 42e is spaced apart from the inner wall surface of the third side wall portion 31c and the eighth end 42f is spaced apart from the inner wall surface of the fourth side wall portion 31d, the molding material 52 is more likely to be 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, improving the manufacturing efficiency of the power conversion device 100 and making it easier for heat generated in the capacitor 10a to be transferred to the case 30 via the molding material 52.

[0072] Because the second heat sink 42 is positioned by intersecting with the first heat sink 41, if the seventh end 42e and the eighth end 42f come into contact with the inner wall surface of the third side wall 31c and the inner wall surface of the fourth side wall 31d, respectively, the second heat sink 42 may bend and break unless the dimensional tolerances of the first socket 41e and the second socket 42c are strictly controlled. On the other hand, if the seventh end 42e is spaced apart from the inner wall surface of the third side wall 31c and the eighth end 42f is spaced apart from the inner wall surface of the fourth side wall 31d, damage to the second heat sink 42 as described above can be suppressed even if the dimensional tolerances of the first socket 41e and the second socket 42c are relaxed.

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

[0074] (Configuration of 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, a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this respect, 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 of the power converter 100A. FIG. 13 is an enlarged cross-sectional view of the power converter 100A in the vicinity of the third groove 32a. FIG. 13 shows an enlarged cross-section perpendicular to the second direction DR2. FIG. 14 is an enlarged cross-sectional view of the power converter 100A in the vicinity of the fourth groove 32b. FIG. 14 shows an enlarged cross-section perpendicular to the third direction DR3. As shown in FIGS. 12 to 14, in the power converter 100A, a plurality of third grooves 32a and a plurality of fourth grooves 32b are formed in the inner wall surface of the bottom wall 32.

[0077] The third groove 32a extends along the second direction DR2. The multiple third grooves 32a are arranged at intervals in the third direction DR3. The third end 41c side of the first heat dissipation plate 41 is inserted into the third groove 32a. The fourth groove 32b extends along the third direction DR3. The multiple fourth grooves 32b are arranged at intervals in the second direction DR2. The fifth end 42a side of the second heat dissipation plate 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 a sealant 50. In these respects, the configuration of the power conversion device 100A differs from the configuration of the power conversion device 100.

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

[0079] In the power conversion device 100A, 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, so that 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, the power conversion device 100A can further suppress the temperature rise of the capacitor 10a.

[0080] Furthermore, in the power conversion device 100A, 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, which improves the ease of assembly and positioning accuracy of the first heat sink 41 and the second heat sink 42. As a result of improving 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 set with high accuracy, 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, the first heat sink 41 and the second heat sink 42 are fixed to the bottom wall 32, so that the sealing material 50 can be more reliably filled into the space defined by the two adjacent first heat sinks 41, the two adjacent second heat sinks 42, and the bottom wall 32.

[0082] Embodiment 3 A power conversion device according to embodiment 3 will be described. The power conversion device according to embodiment 3 is referred to as power conversion device 100B. Here, differences from 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, a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this respect, 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 converter 100B in the vicinity of the third groove 32a. FIG. 15 shows an enlarged cross-section perpendicular to the second direction DR2. FIG. 16 is an enlarged cross-sectional view of the power converter 100B in the vicinity of the fourth groove 32b. FIG. 16 shows an enlarged cross-section perpendicular to the third direction DR3. As shown in FIGS. 15 and 16, in the power converter 100B, the first heat sink 41 is metal-bonded to the third groove 32a at the third end 41c. In the power converter 100B, the second heat sink 42 is metal-bonded to the fourth groove 32b at the fifth end 42a.

[0085] The first heat sink 41 does not have to be metal-bonded to the third groove 32a at the entire portion inserted into the third groove 32a, and the second heat sink 42 does not have to be metal-bonded to the fourth groove 32b at the entire portion inserted into the fourth groove 32b. The metal bonding between the first heat sink 41 and the third groove 32a and the metal bonding between the second heat sink 42 and the fourth groove 32b are performed using, for example, brazing material 33. The metal bonding between the first heat sink 41 and the third groove 32a and the metal bonding between the second heat sink 42 and the fourth groove 32b may also be performed by welding. In these respects, the configuration of the power conversion device 100B differs from the configuration of the power conversion device 100A.

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

[0087] In the power conversion device 100B, the first heat sink 41 is metal-bonded to the third groove 32a and the second heat sink 42 is metal-bonded to the fourth groove 32b, thereby reducing the thermal resistance between the first heat sink 41 and the second heat sink 42 and the bottom wall 32. As a result, the power conversion device 100B can further suppress the temperature rise of the capacitor 10a.

[0088] Furthermore, in the power conversion device 100B, the first heat sink 41 is metal-bonded to the third groove 32a and the second heat sink 42 is metal-bonded to the fourth groove 32b, improving the ease of assembly and positioning accuracy of the first heat sink 41 and the second heat sink 42. As a result of improving 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 set with high accuracy, 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, the first heat sink 41 and the second heat sink 42 are fixed to the bottom wall 32, so that the sealing material 50 can be more reliably filled into the space defined by the two adjacent first heat sinks 41, the two adjacent second heat sinks 42, and the bottom wall 32.

[0090] (Modification 1 of power conversion device 100B) 17 is a plan view of the case 30 of the power converter 100B according to the first modification. As shown in FIG. 17, in the power converter 100B, the third grooves 32a may be widened at the portions where they intersect with the fourth grooves 32b, and the fourth grooves 32b may be widened at the portions where they intersect with the third grooves 32a. Although not shown, in the power converter 100B, the third grooves 32a may be widened at the ends in the second direction DR2, and the fourth grooves 32b may be widened at the ends in the third direction DR3. In this case, the widened portions of the third grooves 32a and the fourth grooves 32b serve as brazing filler metal reservoirs, preventing the brazing filler metal 33 from overflowing from the third grooves 32a and the fourth grooves 32b and causing poor bonding.

[0091] (Modification 2 of power conversion device 100B) Fig. 18 is an enlarged cross-sectional view of the power converter 100B according to Modification 2 in the vicinity of the first groove 31aa. Fig. 19 is an enlarged cross-sectional view of the power converter 100B according to Modification 2 in the vicinity of the second groove 31ba. Figs. 18 and 19 show enlarged cross sections perpendicular to the first direction DR1. As shown in Figs. 18 and 19, in the power converter 100B, the first heat sink 41 may be metal-bonded to the first groove 31aa at the first end 41a side, and may be metal-bonded to the second groove 31ba at the second end 41b side.

[0092] The metal bonding between the first heat sink 41 and the first groove 31aa and the second groove 31ba is performed, for example, by using a brazing material 33. The metal bonding between the first heat sink 41 and the first groove 31aa and the second groove 31ba may also be performed by welding. In this case, the thermal resistance between the first heat sink 41 and the sidewall 31 is reduced, thereby further suppressing the temperature rise of the capacitor 10a.

[0093] Embodiment 4 A power conversion device according to embodiment 4 will be described. The power conversion device according to embodiment 4 is referred to as power conversion device 100C. Here, differences from power conversion device 100A will be mainly described, and overlapping descriptions 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 sinks 41, a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this respect, 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 converter 100C in the vicinity of the third groove 32a. FIG. 20 shows an enlarged cross-section perpendicular to the second direction DR2. FIG. 21 is an enlarged cross-sectional view of the power converter 100C in the vicinity of the fourth groove 32b. FIG. 21 shows an enlarged cross-section perpendicular to the third direction DR3. As shown in FIGS. 20 and 21, in the power converter 100C, the first heat sink 41 is metal-joined to the third groove 32a by crimping at the third end 41c side. In the power converter 100C, the second heat sink 42 is metal-joined to the fourth groove 32b by crimping at the fifth end 42a side.

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

[0097] When the first heat dissipation plate 41 is crimped into the third groove 32a, a press tool is inserted into the crimping grooves 32ca and 32cb. This causes the portions of the bottom wall 32 between the crimping grooves 32ca and 32a and the portions of the bottom wall 32 between the crimping grooves 32cb and 32a to plastically deform toward the first heat dissipation plate 41, crimping the first heat dissipation plate 41 into the third groove 32a. Similarly, by inserting a press tool into the crimping grooves 32da and 32db, the second heat dissipation plate 42 is crimped into the fourth groove 32b. The entire portion of the first heat dissipation plate 41 inserted into the third groove 32a need not be crimped into the third groove 32a, and the entire portion of the second heat dissipation plate 42 inserted into the fourth groove 32b need not be crimped into the fourth groove 32b. In these respects, the configuration of the power conversion device 100C differs from the configuration of the power conversion device 100A.

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

[0099] In the power converter 100C, the first heat sink 41 is metal-joined to the third groove 32a and the second heat sink 42 is metal-joined to the fourth groove 32b by crimping, thereby reducing the thermal resistance between the first heat sink 41 and the bottom wall 32 and between the second heat sink 42 and the bottom wall 32. As a result, the power converter 100C can further suppress the temperature rise of the capacitor 10a.

[0100] Furthermore, in the power conversion device 100C, the first heat sink 41 is metal-joined to the third groove 32a and the second heat sink 42 is metal-joined to the fourth groove 32b by crimping, improving the ease of assembly and positioning accuracy of the first heat sink 41 and the second heat sink 42. As a result of improving 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 set with high accuracy, 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, the first heat sink 41 and the second heat sink 42 are fixed to the bottom wall 32, so that the sealing material 50 can be more reliably filled into the space defined by the two adjacent first heat sinks 41, the two adjacent second heat sinks 42, and the bottom wall 32.

[0102] (Variation 1 of power conversion device 100C) FIG. 22 is an enlarged cross-sectional view of the power converter 100C near the bottom wall 32. FIG. 22 shows an enlarged cross-section perpendicular to the second direction DR2. As shown in FIG. 22, in the power converter 100C, a plurality of fifth grooves 32e may be formed in 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, a crimping groove 32ea and a crimping groove 32eb may be further formed on the outer wall surface of the bottom wall 32. The crimping groove 32ea and the crimping groove 32eb extend along the second direction DR2. The fifth groove 32e is disposed between the crimping groove 32ea and the crimping groove 32eb. When the fifth groove 32e extends along the third direction DR3, the crimping groove 32ea and the crimping groove 32eb also extend along the third direction DR3.

[0104] The power conversion device 100C may have a plurality of plate members 34. The plate members 34 are inserted into the fifth groove 32e and crimped into the fifth groove 32e. The plate members 34 are crimped into the fifth groove 32e by inserting a press tool into the crimping grooves 32ea and 32eb. The plate members 34 crimped into the fifth groove 32e function as cooling fins, improving heat dissipation from the case 30 to the outside air and further suppressing a temperature rise in the capacitor 10a.

[0105] (Modification 2 of power conversion device 100C) Fig. 23 is an enlarged cross-sectional view of the power converter 100C according to Modification 2 in the vicinity of the first groove 31aa. Fig. 24 is an enlarged cross-sectional view of the power converter 100C according to Modification 2 in the vicinity of the second groove 31ba. Figs. 23 and 24 show enlarged cross sections perpendicular to the first direction DR1. As shown in Figs. 23 and 24, in the power converter 100C, the first heat sink 41 may be metal-joined to the first groove 31aa at the first end 41a side by crimping, and may be metal-joined to the second groove 31ba at the second end 41b side by crimping.

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

[0107] The first heat sink 41 is crimped into the first groove 31aa by inserting a press tool into the crimping grooves 31ab and 31ac, and into the second groove 31ba by inserting a press tool into the crimping grooves 31bb and 31bc. In this case, the thermal resistance between the first heat sink 41 and the sidewall 31 is reduced, further suppressing the temperature rise of the capacitor 10a.

[0108] Embodiment 5. A power conversion device according to embodiment 5 will be described. The power conversion device according to embodiment 5 is referred to as power conversion device 100D. Here, differences from power conversion device 100 will be mainly described, and overlapping 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 sinks 41, a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this respect, 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 taken along a line corresponding to line IV-IV in FIG. 2. As shown in FIG. 25, in the power conversion device 100D, the capacitor 10a does not have an outer case 13 or a sealing resin 14. The power conversion device 100D further includes an insulating net 70. The insulating net 70 is a net-shaped member made of an insulating resin material. The insulating net 70 is made of, for example, an epoxy resin, a silicone resin, a urethane resin, or the like. The insulating net 70 may also be made of a flexible and stretchable rubber material.

[0112] The insulating net 70 is disposed in a 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. That is, the insulating net 70 is positioned between the capacitor 10a and the first heat sinks 41, the second heat sinks 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 with each other, but the insulating net 70 may be in contact with the capacitor 10a. It is sufficient that the insulating net 70 prevents the capacitor 10a from contacting the first heat sinks 41, the second heat sinks 42, and the bottom wall 32.

[0113] In the power conversion device 100D, the sealing material 50 does not have to include the heat dissipation auxiliary material 51 and the molding material 52. In the power conversion device 100D, the sealing material 50 may be formed by potting any resin material. In these respects, the configuration of the power conversion device 100D differs from the configuration of the power conversion device 100.

[0114] (Effects 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, the capacitor 10a does not have an exterior case 13 or a sealing resin 14, so the number of turns of the metal film and the dielectric film in the capacitor 10a can be increased, which increases the capacitance per capacitor 10a. Furthermore, in the power conversion device 100D, the capacitor 10a does not have an exterior case 13 or a sealing resin 14, so the cost of the capacitor 10a can be reduced.

[0116] 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, 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 sealing resin 14. In the power conversion device 100D, since a resin material with a higher thermal conductivity than the sealing resin 14 can be used as the sealing material 50, the heat generated by the capacitor 10a can be efficiently transferred to the case 30.

[0117] (Modifications 1, 2, and 3 of Power Converter 100D) Fig. 26 is a cross-sectional view of Modification 1 of the power conversion device 100D. Fig. 26 shows a cross section taken along a line 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 arranged 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.

[0118] Fig. 27 is a cross-sectional view of Modification 2 of the power conversion device 100D. Fig. 27 shows a cross section taken along a line IV-IV in Fig. 2. As shown in Fig. 27, in the power conversion device 100D, a thermally conductive insulating sheet 72 may be used instead of the insulating net 70. The thermally conductive insulating sheet 72 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.

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

[0120] In these cases, contact between the capacitor 10a and the first heat sink 41, the second heat sink 42, and the bottom wall 32 is prevented by the insulating paper 71, the thermally conductive insulating sheet 72, or the spacer 73, so that insulation between the first heat sink 41, the second heat sink 42, and the bottom wall 32 can be ensured.

[0121] (Fourth Modification of Power Converter 100D) Fig. 29 is a cross-sectional view of a fourth modification of the power conversion device 100D. Fig. 29 shows a cross section taken along a line IV-IV in Fig. 2. As shown in Fig. 29, in the power conversion device 100D, the sealing material 50 may be a silicone gel 53. The silicone gel 53 preferably has low viscosity and high insulating properties.

[0122] Because silicone gel 53 has high adhesion to capacitor 10a, first heat sink 41, and second heat sink 42, it is not necessary to consider creepage at the boundaries between capacitor 10a, first heat sink 41, and second heat sink 42 when evaluating insulation. Therefore, in this case, an insulating area to ensure creepage distance is not required, making it possible to reduce the size of the area around capacitor 10a. In particular, in power conversion device 100D that uses insulating net 70, use of silicone gel 53 can ensure high insulation, i.e., high creepage dielectric strength and through dielectric strength.

[0123] In this case, heat generated by capacitor 10a can be efficiently transferred to case 30. Furthermore, silicone gel 53 has a high penetration, i.e., it is a soft material. Therefore, in this case, reliability can be improved when power conversion device 100 is subjected to heat cycles or power cycles. Note that, because capacitor 10a is also fixed in position by attaching printed wiring board 60 to case 30, the high penetration of silicone gel 53 does not hinder the positional fixation of capacitor 10a.

[0124] Embodiment 6 A power conversion device according to embodiment 6 will be described. The power conversion device according to embodiment 6 is referred to as power conversion device 100E. Here, differences from power conversion device 100 will be mainly described, and overlapping descriptions will not be repeated.

[0125] (Configuration of 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, a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this respect, 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 dissipation plate 41 included in the power converter 100E. As shown in FIG. 30, in the power converter 100E, a plurality of through holes 41f are formed in the first heat dissipation plate 41. The through holes 41f penetrate the first heat dissipation plate 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 sockets 41e. In the power converter 100E, the width of the first socket 41e in the second direction DR2 is greater than the thickness of the second heat dissipation plate 42. More specifically, in the power converter 100E, it is sufficient that the width of the first socket 41e in the second direction DR2 is greater than the thickness of the second heat dissipation plate 42 by 0.1 mm or more, and preferably is greater than the thickness of the second heat dissipation plate 42 by 0.5 mm or more.

[0128] FIG. 31 is a side view of the second heat dissipation plate 42 included in the power converter 100E. As shown in FIG. 31, in the power converter 100E, a plurality of through holes 42d are formed in the second heat dissipation plate 42. The through holes 42d penetrate the second heat dissipation plate 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 sockets 42c. In the power converter 100E, the width of the second socket 42c in the third direction DR3 is greater than the thickness of the first heat dissipation plate 41. More specifically, in the power converter 100E, it is sufficient that the width of the second socket 42c in the third direction DR3 is greater than the thickness of the first heat dissipation plate 41 by 0.1 mm or more, and preferably is greater than the thickness of the first heat dissipation plate 41 by 0.5 mm or more.

[0129] The power conversion device 100E only needs to satisfy at least one of the following: a through-hole 41f is formed in the first heat dissipation plate 41; a through-hole 42d is formed in the second heat dissipation plate 42; the width of the first socket 41e in the second direction DR2 is sufficiently larger than the thickness of the second heat dissipation plate 42; and the width of the second socket 42c in the third direction DR3 is sufficiently larger than the thickness of the first heat dissipation plate 41. In these respects, the configuration of the power conversion device 100E differs from the configuration of the power conversion device 100.

[0130] The effects of the power conversion device 100E will be described below. In the power converter 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. The absence of voids in the sealing material 50 reduces the thermal resistance of the sealing material 50. Therefore, in the power converter 100E, the temperature rise of the capacitor 10a can be further suppressed.

[0131] In the power converter 100E, the sealant 50 is also present in the through holes 41f and 42d. Therefore, in the power converter 100E, it is possible to further improve the adhesion between the sealant 50 and the first heat sink 41 and the second heat sink 42. Furthermore, in the power converter 100E, the formation of the through holes 41f and 42d reduces the amount of material used to form the first heat sink 41 and the second heat sink 42, thereby reducing the manufacturing cost and weight of the first heat sink 41 and the second heat sink 42.

[0132] In the power converter 100E, the width of the first socket 41e in the second direction DR2 is sufficiently larger than the thickness of the second heat sink 42, and the width of the second socket 42c in the third direction DR3 is sufficiently larger than the thickness of the first heat sink 41, so that the second heat sink 42 can be easily attached to the first heat sink 41. Therefore, the power converter 100E can improve the ease of assembly.

[0133] Embodiment 7 A power conversion device according to embodiment 7 will be described. The power conversion device according to embodiment 7 is referred to as power conversion device 100F. Here, differences from power conversion device 100 will be mainly described, and overlapping 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, a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this respect, 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, the printed wiring board 60 of the power conversion device 100F has a plurality of stacked layers. In the example shown in FIG. 32, the printed wiring board 60 has a four-layer structure including a first layer 60d, a second layer 60e, a third layer 60f, and a fourth layer 60g. However, the power conversion device 100F is not limited to a four-layer structure in which the printed wiring board 60 has 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.

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

[0138] (Effects of the power conversion device 100F) The effects of the power conversion device 100F will be described below.

[0139] In the power conversion device 100F, wiring patterns of different potentials are alternately stacked, which generates stray capacitance between the layers. As a result, the required capacitance of the capacitor 10a can be compensated for by the stray capacitance of the printed wiring board 60, which reduces the number of capacitors 10a connected in series or in parallel. Furthermore, in the power conversion device 100F, wiring patterns of different potentials are arranged in parallel, which reduces the inductance between the wiring patterns. As a result, the surge voltage caused by switching of the switching circuit 120 can be reduced.

[0140] When an AC current flows through the printed wiring board 60 during operation of the power conversion device 100F, 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 patterns 60h, 60i, 60j, and 60k generate heat. If the wiring pattern 60h is disposed near the portion where the side wall 31 and the printed wiring board 60 contact each other, it is possible to suppress a rise in the temperature of the wiring pattern 60h.

[0141] Embodiment 8 A power conversion device according to the eighth embodiment will be described. The power conversion device according to the eighth embodiment is referred to as a power conversion device 100G. Here, differences 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 sinks 41, a plurality of second heat sinks 42, a sealing material 50, and a printed wiring board 60. In this respect, 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 in FIG. 33. FIG. 35 is a schematic cross-sectional view taken along line XXXV-XXXV in FIG. 33. As shown in FIGS. 33 to 35, in the power conversion device 100G, the first heat sink 41 and the second heat sink 42 are connected to the printed wiring board 60. The first heat sink 41 and the second heat sink 42 are connected to the printed wiring board 60 by, for example, soldering. In these respects, the configuration of the power conversion device 100G differs from the configuration of the power conversion device 100.

[0145] (How to assemble the power conversion device 100G) A method for assembling the power conversion device 100G will be described below.

[0146] In assembling the power conversion device 100G, first, the case 30 and 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 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 hardened. With the above steps, the assembly of the power conversion device 100G is completed.

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

[0148] In power conversion device 100G, first heat sink 41 and second heat sink 42 are connected to printed wiring board 60 in advance, which improves the ease of assembling first heat sink 41 and second heat sink 42 to case 30. Furthermore, in power conversion device 100G, the positioning accuracy of capacitor 10a, first heat sink 41, and second heat sink 42 is improved, which makes it possible to reduce the thickness of sealing material 50 and reduce the thermal resistance between capacitor 10a and first heat sink 41 and second heat sink 42.

[0149] Furthermore, in the power conversion device 100G, the first heat sink 41 and the second heat sink 42 are connected to the printed wiring board 60, and therefore the heat generated by the printed wiring board 60 is dissipated from the case 30 via the first heat sink 41 and the second heat sink 42, thereby suppressing the temperature rise of the printed wiring board 60 and enabling uniform heating of the entire power conversion device 100G.

[0150] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The basic scope of the present disclosure is defined by the claims, not the above-described embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

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

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 to an inner wall surface of the bottom wall extends 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 in 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 that houses 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 to which a potential different from that of the first wiring pattern is applied.

3. the plurality of circuit components include a plurality of first circuit components arranged in a first row along the second direction, and a plurality of second circuit components arranged in a second row along the second direction; the electrode surface of each of the plurality of first circuit components faces the electrode surface of each of the plurality of 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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