Electric power conversion device

Abstract

To provide an electric power conversion device capable of avoiding complicating manufacturing processes while improving performance.SOLUTION: An electric power conversion device comprise a capacitor, a power module, a seal part sealing the gap between the capacitor and power module, a cooler, a first connection part led out of the capacitor, a second connection part led out of the power module and connected to the first connection part, and a potting material fixing the connection between the first connection part and second connection part. The power module has a base plate arranged on a cooling surface of the cooler, a semiconductor chip on the base plate, a first chamber housing the semiconductor chip, and a casing which has a second chamber where the first connection part and second connection part are arranged and an opening part open to the capacitor side and the opposite side from the cooling surface is formed, and in which a potting chamber filled with the potting material is formed, wherein the seal part has a cut part formed at a different position from the opening part.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent Document 1 discloses a power conversion device. This power conversion device includes a switching element, a capacitor, a cooler that cools the switching element and the capacitor by arranging them on the same plane, a first connection part drawn from the switching element, and a second connection part drawn from the switching element and connected to the first connection part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-188998 A Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, in order to realize an electrified society, there is a demand for miniaturization and high output of power converters. In this regard, natural cooling is generally used to cool the two connections mentioned above. However, there are cases where natural cooling is not enough to cool the connections. In addition, when the two connection parts are fastened with screws, it is necessary to secure an insulation distance between the connection part and the cooler so that the screws used for fastening do not interfere with the cooler. For this reason, the connection part cannot be brought close to the cooling surface of the cooler for cooling. In addition, there is also the issue that the connection part becomes long and the equivalent series inductance (ESL) increases. While solving the above problems, it is also necessary to avoid complicating the manufacturing process.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a power conversion device that can improve performance while avoiding complication of the manufacturing process. [Means for solving the problem]

[0006] In order to solve the above problems, a power conversion device according to the present disclosure includes a capacitor, a power module arranged in parallel with the capacitor, a seal portion that seals a gap between the capacitor and the power module, a cooler having a cooling surface that cools the capacitor and the power module, a conductive first connection portion drawn from the capacitor to the power module side, a conductive second connection portion drawn from the power module to the capacitor side and connected to the first connection portion, and a potting material that fixes the connection between the first connection portion and the second connection portion, wherein the power module has a base plate arranged on the cooling surface, a semiconductor chip attached to the base plate, and a casing having a first chamber in which the semiconductor chip is housed, and a second chamber in which the first connection portion and the second connection portion are arranged and in which an opening portion that opens to the capacitor side and the opposite side to the cooling surface is formed, and in which a potting chamber in which the potting material is filled is formed, and a notch portion is formed in the seal portion at a position overlapping with the opening portion. Effect of the Invention

[0007] According to the power conversion device of the present disclosure, it is possible to improve performance while avoiding complication of the manufacturing process. [Brief description of the drawings]

[0008] [Figure 1] 1 is a plan view of a power conversion device according to a first embodiment of the present disclosure. [Diagram 2] 1 is a partial cross-sectional view of a power conversion device according to a first embodiment of the present disclosure. [Diagram 3] 1 is a plan view showing an internal structure of a power module according to a first embodiment of the present disclosure and a main part of a power conversion device. [Figure 4] FIG. 2 is a front view of a seal portion according to the first embodiment of the present disclosure. [Diagram 5]FIG. 11 is a plan view of a power conversion device according to a second embodiment of the present disclosure. [Figure 6] FIG. 6 is a partial cross-sectional view of a power conversion device according to a second embodiment of the present disclosure. [Figure 7] FIG. 11 is a plan view of a power conversion device according to a third embodiment of the present disclosure. [Figure 8] FIG. 11 is a partial cross-sectional view of a power conversion device according to a fourth embodiment of the present disclosure. [Figure 9] 13 is a side view of a first connecting portion and a second connecting portion according to a modified example of the present disclosure. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First Embodiment (Configuration of power conversion device) Hereinafter, a power conversion device 1 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 4. FIG. As shown in Figures 1 and 2, the power conversion device 1 includes a cooler 10, a capacitor 20 (smoothing capacitor), a power module 30, a heat transfer sheet 2, a first connection portion 60, a second connection portion 70, and a potting material 3.

[0010] (cooler) The cooler 10 has a unit case 11. Inside the unit case 11, a flow path 12 through which cooling water W flows is provided. The unit case 11 has a cooling surface 13 on which a condenser 20, which will be described later, and a power module 30 are disposed. The cooling surface 13 cools the condenser 20 and the power module 30. More specifically, the condenser 20 and the power module 30 are cooled by transferring heat from the condenser 20 and the power module 30 to the cooling water W flowing inside the cooler 10. In addition, an insertion hole 14 communicating with the flow path 12 is provided in the cooling surface 13.

[0011] The cooling surface 13 is formed in a flat shape. In the following description, a direction perpendicular to the cooling surface 13 will be referred to as a first direction D1, a direction parallel to the cooling surface 13 and perpendicular to the first direction D1 will be referred to as a second direction D2, and another direction parallel to the cooling surface 13 and perpendicular to the first direction D1 and the second direction D2 will be referred to as a third direction D3.

[0012] (Capacitor) The condenser 20 is disposed on the cooling surface 13. The condenser 20 extends in the second direction D2. The condenser 20 is formed in a rectangular shape when viewed from the first direction D1, and four corners are fixed to the cooling surface 13 by screws 21. The fixing method of the condenser 20 is not limited to four-point fixing, and can be changed as appropriate. For example, the condenser 20 may be fixed to the cooling surface 13 by five-point fixing depending on the size of the condenser 20. The condenser 20 is indirectly cooled by the cooler 10 via the cooling surface 13 (indirect water cooling method). The lower surface 20a of the condenser 20 on the cooling surface 13 side is provided with a groove portion 22 recessed in the first direction D1 to a depth of about 1 mm. The groove portion 22 is formed in a U-shape when viewed from below in the first direction D1. The groove portion 22 has an opening 23 that opens toward the power module 30 side in the second direction D2. The area of ​​the lower surface 20 a of the condenser 20 other than the groove portion 22 is in contact with the cooling surface 13 .

[0013] (Power Module) The power module 30 is arranged in parallel with the capacitor 20. In this embodiment, a plurality of power modules 30 (three in the illustrated example) are provided. Each power module 30 is arranged in a position adjacent to the capacitor 20 in the second direction D2. The three power modules 30 are arranged side by side in the third direction D3. As shown in FIG. 3, as shown in FIGS. 2 and 3, the power module 30 has a base plate 31, an insulating plate 32, a metal plate 33, a semiconductor chip 34, wire bonding 35, a casing 40, and fins 36. In the illustrated example, part of the configuration of the power module 30 (such as a bus bar) is omitted to simplify the explanation.

[0014] (Base plate) The base plate 31 is disposed on the cooling surface 13 so as to cover the insertion hole 14. A gap between the base plate 31 and the cooling surface 13 is sealed so that the cooling water W flowing inside the unit case 11 does not leak out. Electronic components such as a semiconductor chip 34 are mounted on the surface of the base plate 31 opposite the cooling surface 13 in the first direction D1. The base plate 31 is a conductive member formed of, for example, a metal material. The base plate 31 is formed in a rectangular shape when viewed from the first direction D1, and its four corners are fixed by screws 37.

[0015] An insulating plate 32 is provided on the base plate 31. The insulating plate 32 is a thin plate-like member made of, for example, ceramic. Furthermore, a metal plate 33 is provided on the insulating plate 32. The metal plate 33 is a thin plate-like member made of, for example, copper. The metal plate 33 is divided into a plurality of pieces. Note that in the illustrated example, the thicknesses of the metal plate 33 and the insulating plate 32 are made thicker than in reality, but in reality, the metal plate 33 and the insulating plate 32 are formed to a thickness on the order of several hundred μm, which is considerably thinner than the base plate 31.

[0016] (Semiconductor chips) The semiconductor chip 34 is provided on the metal plate 33. That is, the semiconductor chip 34 is attached to the base plate 31 via the metal plate 33 and the insulating plate 32.

[0017] The semiconductor chip 34 and the metal plates 33, and adjacent metal plates 33, are electrically connected by wire bonding 35. Furthermore, the wire bonding 35 connects the metal plates 33 to a second connection portion 70, which will be described later. This electrically connects the semiconductor chip 34 and the second connection portion 70.

[0018] (Casing) The casing 40 is provided so as to cover the base plate 31 from the side opposite to the cooler 10 in the first direction D1. The casing 40 has a potting chamber 41 in which the potting material 3 is filled. The potting chamber 41 has a first chamber 42 and a second chamber 43. The first chamber 42 houses the semiconductor chip 34. The second chamber 43 is provided at a position adjacent to the first chamber 42 in the second direction D2 and communicates with the first chamber 42. At least a part of a first connection part 60 and a second connection part 70 described later is disposed in the second chamber 43. The second chamber 43 has an opening 44 that opens toward the condenser 20 in the second direction D2 and toward the opposite side to the cooling surface 13 in the first direction D1.

[0019] (Potting material) The potting material 3 is filled into the potting chamber 41 through this opening 44. The potting material 3 is filled into both the first chamber 42 and the second chamber 43. Therefore, the potting material 3 of this embodiment covers not only the first connection portion 60 and the second connection portion 70, but also the semiconductor chip 34.

[0020] (fin) A plurality of fins 36 are provided on the surface of the base plate 31 on the cooling surface 13 side, and are arranged in the second direction D2. Each fin 36 extends in the third direction D3. The plurality of fins 36 are inserted into the flow passage 12 through the insertion holes 14. The fins 36 increase the contact area with the cooling water W flowing through the flow passage 12, thereby improving the cooling performance. Thus, in this embodiment, the fins 36 are exposed to the cooling water W, and the power module 30 is directly cooled by the cooling water W (direct water cooling method).

[0021] (Heat transfer sheet) The heat transfer sheet 2 has a heat transfer section 2a sandwiched between the condenser 20 and the cooler 10 in a first direction D1, and a seal section 50 sandwiched between the condenser 20 and the power module 30 in a second direction D2. The heat transfer sheet 2 is made of a thermal interface material (TIM). Before being installed in the power conversion device 1, the heat transfer sheet 2 is formed to be slightly thicker than the depth of the groove section 22 of the condenser 20.

[0022] (Heat transfer section) The heat transfer portion 2a is provided between the condenser 20 and the cooling surface 13. When the condenser 20 is attached to the cooling surface 13, the heat transfer portion 2a is disposed in the groove portion 22 of the condenser 20, and the heat transfer portion 2a is crushed in the first direction D1 by the lower surface 20a of the condenser 20 and the cooling surface 13. The groove portion 22 becomes the path of the heat transfer portion 2a, and the heat transfer portion 2a is crushed so as to extend in the second direction D2. As a result, the heat transfer portion 2a is tightly attached to the region of the lower surface 20a of the condenser 20 where the groove portion 22 is formed and to the cooling surface 13 without any gaps. The heat transfer portion 2a is in close contact with the condenser 20 and the cooler 10, thereby improving the thermal conductivity between the condenser 20 and the cooler 10 and promoting the cooling of the condenser 20.

[0023] (Sealing part) As shown in FIG. 4, the seal portion 50 is disposed between the condenser 20 and the power module 30. The seal portion 50 is connected to the heat transfer portion 2a at the opening 23 of the groove portion 22. The seal portion 50 seals the gap between the condenser 20 and the power module 30. The seal portion 50 extends in the third direction D3 so as to straddle the multiple power modules 30. The seal portion 50 has a notch portion 51 formed at a position overlapping with the opening portion 44. The notch portion 51 penetrates the seal portion 50 in the second direction D2. The notch portion 51 is formed in a U-shape that opens on the opposite side to the cooler 10 in the first direction D1 as viewed from the second direction D2. One notch portion 51 is formed for each condenser 20. The notch portion 51 is configured to communicate with the opening portion 44 of the casing 40 in the second direction D2. The dimension of the cutout portion 51 in the third direction D3 is equal to the dimension of the adjacent opening portion 44 in the third direction D3. In addition, the bottom of the cutout portion 51 is located above the base plate 31 (on the opposite side to the cooling surface 13 across the base plate 31 in the first direction D1).

[0024] The seal portion 50 of this embodiment is a part of one heat transfer sheet 2 formed of a thermal interface material (TIM) like the heat transfer portion 2a. That is, the seal portion 50 is formed of the same thermal interface material (TIM) as the heat transfer portion 2a. The seal portion 50 extends in the first direction D1 and the third direction D3. The seal portion 50 has elasticity, so it can expand and contract in the opposing direction (second direction D2) between the condenser 20 and the power module 30. The seal portion 50 is formed in advance to be slightly thicker in the second direction D2 than the gap between the condenser 20 and the power module 30, and is compressed from both sides in the second direction D2 by the condenser 20 and the power module 30, thereby shrinking in the second direction D2 and coming into close contact with the surfaces of the condenser 20, the power module 30, and the cooling surface 13. In this way, the seal portion 50 seals the gap between the condenser 20 and the power module 30.

[0025] (First connection part) The first connection portion 60 is a conductive member drawn from the capacitor 20 to the power module 30 side. The first connection portion 60 is a so-called bus bar. The first connection portion 60 extends in the second direction D2 and is inserted into the opening 44 of the second chamber 43. An end portion of the first connection portion 60 on the power module 30 side is disposed in the second chamber 43.

[0026] (Second connection part) The second connection portion 70 is a conductive member drawn from the power module 30 to the capacitor 20 side. The second connection portion 70 is a so-called bus bar. At least the end of the second connection portion 70 on the capacitor 20 side is disposed in the second chamber 43. The second connection portion 70 is connected to the first connection portion 60 in a state where it is overlapped with the first connection portion 60 from the cooler 10 side in the first direction D1. The second connection portion 70 is fixed to the first connection portion 60 by welding.

[0027] The second connection portion 70 has a chip-side end portion 71 accommodated in the first chamber 42 and a main body portion 72 extending from the chip-side end portion 71 in the second direction D2. The chip-side end portion 71 is disposed at a position floating in the first direction D1 from the metal plate 33 and is connected to the metal plate 33 by wire bonding 35. The main body portion 72 extends from the chip-side end portion 71 toward the capacitor 20 in the second direction D2 and is connected to the first connection portion 60 in the second chamber 43. In this embodiment, the main body portion 72 extends linearly in the second direction D2. Furthermore, the main body portion 72 and the chip-side end portion 71 are disposed on the same plane along the base plate 31, and the second connection portion 70 as a whole is formed linearly in the second direction D2 side view.

[0028] (Potting material) The potting material 3 is filled into the potting chamber 41 and the cutout portion 51, and buries the first connection portion 60 and the second connection portion 70. In this embodiment, in addition to the first connection portion 60 and the second connection portion 70, electronic components housed in the casing 40, such as the semiconductor chip 34, are also buries. As a result, the connection between the first connection portion 60 and the second connection portion 70 is fixed by the potting material 3.

[0029] After the first connection portion 60 and the second connection portion 70 are connected by welding or the like, the potting material 3 is poured into the potting chamber 41 through the opening 44 to fill the potting chamber 41. At this time, the potting material 3 enters between the first connection portion 60 and the base plate 31, and between the second connection portion 70 and the base plate 31. Thereafter, the potting material 3 is cooled for a predetermined time, whereby the potting material 3 solidifies and is fixed in the power module 30.

[0030] (Action and effect) The power conversion device 1 having the above-mentioned configuration comprises a capacitor 20, a power module 30 arranged in parallel with the capacitor 20, a sealing portion 50 that seals the gap between the capacitor 20 and the power module 30, a cooler 10 having a cooling surface 13 that cools the capacitor 20 and the power module 30, a conductive first connection portion 60 extended from the condenser 20 to the power module 30 side, a conductive second connection portion 70 extended from the power module 30 to the capacitor 20 side and connected to the first connection portion 60, and a potting material 3 that fixes the connection between the first connection portion 60 and the second connection portion 70. The power module 30 has a base plate 31 arranged on the cooling surface 13, a semiconductor chip 34 attached to the base plate 31, and a casing 40 having a first chamber 42 in which the semiconductor chip 34 is housed, a second chamber 43 in which a first connection portion 60 and a second connection portion 70 are arranged and in which an opening 44 is formed that opens to the capacitor 20 side and to the opposite side to the cooling surface 13, and in which a potting chamber 41 in which a potting material 3 is filled is formed. A notch portion 51 is formed in the sealing portion 50 at a position overlapping with the opening 44.

[0031] Since the potting material 3 covers the first connection portion 60 and the second connection portion 70, insulation between the first connection portion 60 and the second connection portion 70 and surrounding members (such as the base plate 31 and the casing 40) is ensured. In addition, since the potting material 3 promotes heat transfer from the first connection portion 60 and the second connection portion 70 to the cooler 10, the cooling performance can be improved. Furthermore, since the potting material 3 fixes the first connection portion 60 and the second connection portion 70, the first connection portion 60 and the second connection portion 70 can be connected by a simple method such as welding without fastening the first connection portion 60 and the second connection portion 70 with a screw. Therefore, since there is no need to consider interference between the fastening screw and the base plate 31, the first connection portion 60 and the second connection portion 70 can be brought close to the base plate 31. Therefore, the distance between the first connection portion 60 and the second connection portion 70 and the cooling surface 13 is shortened, and the cooling performance is improved. In addition, it is possible to prevent the first connection portion 60 and the second connection portion 70 from becoming long in the direction perpendicular to the cooling surface 13 (first direction D1). In this embodiment, both the first connection portion 60 and the second connection portion 70 are formed in a shape that extends linearly in the opposing direction (second direction D2) of the capacitor 20 and the power module 30. In this way, the first connecting portion 60 and the second connecting portion 70 can be shortened, thereby reducing the equivalent series inductance (ESL). An increase in ESL is a cause of increased surges and noise, but by reducing the ESL with the above configuration, surges and noise can be reduced. Furthermore, since the seal portion 50 prevents leakage of the potting material 3, there is no need to introduce a new process for preventing leakage of the potting material 3. Since the seal portion 50 has the cutout portion 51, the first connection portion 60 can be pulled out without being hindered. Therefore, according to the power conversion device 1 of this embodiment, it is possible to improve performance while avoiding complication of the manufacturing process.

[0032] In addition, in this embodiment, the power conversion device 1 further includes a heat transfer portion 2a provided between the capacitor 20 and the cooling surface 13 and formed from a thermal interface material, and the sealing portion 50 is formed from the same thermal interface material as the heat transfer portion 2a.

[0033] This improves the thermal conductivity between the capacitor 20 and the cooler 10, and also improves the thermoelectric efficiency between the first connection portion 60, the second connection portion 70, and the cooler 10. In addition, the seal portion 50 and the heat transfer portion 2a can be formed from the same material. For example, in this embodiment, the seal portion 50 and the heat transfer portion 2a are made of a single heat transfer sheet 2, which improves manufacturing efficiency and reduces manufacturing costs.

[0034] In this embodiment, the main body 72 and the chip-side end 71 are disposed on the same plane along the base plate 31, and the second connection portion 70 as a whole is formed in a straight line when viewed from the side in the second direction D2, but this is not limited to the above. The shape of the second connection portion 70 can be changed as appropriate. The second connection portion 70 may be formed so that the end portion on the chip-side end 71 side is slightly spaced from the base plate 31 in the first direction D1, and then extends in a straight line toward the capacitor 20 in the second direction D2.

[0035] <Second embodiment> Hereinafter, a power conversion device 101 according to a second embodiment of the present disclosure will be described with reference to Fig. 5 and Fig. 6. Among the configurations of the second embodiment, configurations common to the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate. 5, the power converter 101 of this embodiment includes a cooler 110 and a plurality of (three in the illustrated example) power modules 130. The cooler 110 is provided with a cooling surface 13.

[0036] As shown in FIG. 6, in the region of the cooling surface 13 between the condenser 20 and the power module 130, a step surface 115 with which the power module 130 abuts is provided. The step surface 115 extends linearly in the third direction D3, which is perpendicular to the opposing direction (second direction D2) between the capacitor 20 and the power module 130 and is aligned with the capacitor 20. The multiple power modules 130 abut against the step surface 115 from the second direction D2.

[0037] Moreover, the fixing holes 131a for fastening provided in the base plate 131 of the power module 130 are formed to have a larger diameter than the screws 37 to be inserted into the fixing holes 131a.

[0038] (Action and effect) In the power conversion device 101 configured as described above, a plurality of power modules 130 are provided, and a step surface 115 against which the power module 130 abuts is provided in a region of the cooling surface 13 between the condenser 20 and the power module 130. The step surface 115 extends linearly along the condenser 20 in a direction (third direction D3) perpendicular to the opposing direction (second direction D2) between the condenser 20 and the power module 130.

[0039] As a result, by abutting the multiple power modules 130 against the step surface 115, the surfaces of the multiple power modules 130 facing the capacitor 20 can be arranged on the same plane. This prevents variation in the distance between the power modules 130 and the capacitor 20, and ensures that the gap between the capacitor 20 and the power module 130 is sealed by the seal portion 50. Furthermore, the fixing holes 131a of the base plate 131 are formed to have a larger diameter than the screws 37 inserted into the fixing holes 131a. Therefore, it is not necessary to shift the power modules 130 in order to align the fixing holes 131a with the cooling surface 13, and the step surface 115 can easily align the positions of the multiple power modules 130.

[0040] <Third embodiment> Hereinafter, a power conversion device 201 according to a third embodiment of the present disclosure will be described with reference to Fig. 7. Among the configurations of the third embodiment, configurations common to the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate. As shown in FIG. 7, a power converter 201 of this embodiment includes a plurality of power modules 30 (three in the illustrated example) and a seal portion 250. The seal portion 250 has a thickness that allows it to expand and contract in the opposing direction (second direction D2) between the capacitor 20 and the power module 30. The seal portion 250 is compressed from both sides in the second direction D2 by the capacitor 20 and the multiple power modules 30, and the thickness in the second direction D2 changes depending on the gap between the capacitor 20 and each power module 30. The seal portion 250 is in close contact with the condenser 20 and the power module 30 at any position in the third direction D3.

[0041] (Action and effect) In the power converter 201 configured as described above, a plurality of power modules 30 are provided, and the seal portion 250 has a thickness that allows it to expand and contract in the opposing direction between the capacitor 20 and the power modules 30 (the second direction D2).

[0042] As a result, by pressing the multiple power modules 30 against the seal portion 250, the seal portion 250 expands and contracts in the thickness direction, and can absorb the variation in the distance between the power modules 30 and the capacitor 20. Therefore, even if the three power modules 30 are slightly misaligned in the second direction D2 and the side surfaces of the three power modules 30 facing the capacitor 20 are not flush with each other on the same plane as in Fig. 7, if the thickness of the seal portion 250 is made longer in the second direction D2 than the gap between the power module 30 farthest from the capacitor 20 among the three power modules 30 and the capacitor 20, the thickness of the seal portion 250 is naturally adjusted according to the gap between the capacitor 20 and each power module 30, and the gap between the power module 30 and the capacitor 20 can be reliably sealed by the seal portion 250.

[0043] <Fourth embodiment> Hereinafter, a power conversion device 301 according to a fourth embodiment of the present disclosure will be described with reference to Fig. 8. Among the configurations of the fourth embodiment, configurations common to the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate. 8, the power converter 301 of the present embodiment includes a second connection portion 370 and an insulating sheet 4. At least a portion of the second connection portion 370 that is connected to the first connection portion 60 approaches the base plate 31 and extends along the base plate 31. In the present embodiment, the main body portion 372 of the second connection portion 370 extends linearly toward the capacitor 20 in the second direction D2, with the end portion on the chip-side end portion 71 side extending toward the base plate 31, and then approaching the base plate 31.

[0044] Furthermore, an insulating sheet 4 is provided between the main body 372 of the second connection portion 370 and the base plate 31. The insulating sheet 4 is in close contact with the second connection portion 370 and the base plate 31 to ensure insulation between the second connection portion 370 and the base plate 31. Furthermore, the insulating sheet 4 supports the second connection portion 370. The insulating sheet 4 is formed of, for example, a resin material.

[0045] (Action and effect) In the power converter 301 configured as described above, at least the portion of the second connection portion 370 that is connected to the first connection portion 60 is close to the base plate 31 and extends along the base plate 31 .

[0046] This can further reduce the ESL by affecting the loop current flowing through the power module 30. Furthermore, the heat of the first connection portion 60 and the second connection portion 370 can be easily transferred to the cooler 10, and the cooling capacity can be further improved.

[0047] In this embodiment, an insulating sheet 4 is provided between the second connection portion 370 and the base plate 31.

[0048] This makes it possible to bring the second connection portion 370 and the base plate 31 as close as possible, while ensuring insulation between the second connection portion 370 and the base plate 31 by the insulating sheet 4. This further improves the effect of reducing ESL.

[0049] Note that the insulating sheet 4 may not be provided between the second connection portion 370 and the base plate 31, and the potting material 3 may be located between the second connection portion 370 and the base plate 31, as in the first embodiment. However, providing the insulating sheet 4 is advantageous in that it can bring the second connection portion 370 and the base plate 31 closer to each other while reliably ensuring insulation between the second connection portion 370 and the base plate 31.

[0050] (Other embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the gist of the present disclosure are also included. In the above embodiment, the seal parts 50, 250 are integral with the heat transfer part 2a and are formed from the same thermal interface material (one heat transfer sheet 2), but this is not limited to the above. The seal parts 50, 250 may be formed separately from the heat transfer part 2a and from a different material. In addition, the material constituting the seal parts 50, 250 is not limited to the thermal interface material. The seal parts 50, 250 may be formed from other resin materials as long as they can seal the gap between the capacitor 20 and the power modules 30, 130. In addition, the seal parts 50, 250 do not have to be formed in a sheet shape in advance.

[0051] In the above embodiment, a case has been described in which three power modules 30, 130 are provided for one capacitor 20, but this is not limiting. The number of power modules 30, 130 can be changed as appropriate, and for example, only one power module 30, 130 may be provided for one capacitor 20.

[0052] In the above embodiment, the potting material 3 is filled in both the first chamber 42 and the second chamber 43, but this is not limited to the above. The first chamber 42 and the second chamber 43 may be separated, and the potting material 3 may be filled only in the second chamber 43.

[0053] In the above embodiment, the second connection portion 70, 370 is welded to the first connection portion 60 in a state where it is overlapped in the first direction D1, but this is not limited thereto. As shown in Fig. 9, the second connection portion 70, 370 and the first connection portion 60 may be welded in a state where they are in contact with each other in the second direction D2.

[0054] In the above embodiment, the second connection portion 70, 370 is fixed to the first connection portion 60 by welding, but this is not limited thereto. The second connection portion 70, 370 may be fastened to the first connection portion 60 by a screw. However, fixing the first connection portion 60 and the second connection portion 70, 370 by welding is advantageous in that there is no need to consider interference with the screw and the size can be reduced.

[0055] In the above embodiment, the first connection portion 60 and the second connection portion 70, 370 are described as bus bars, but the first connection portion 60 and the second connection portion 70, 370 are not limited to bus bars as long as they are conductive and capable of conducting electricity.

[0056] <Additional Notes> The power electronics devices 1, 101, 201, and 301 described in the respective embodiments can be understood, for example, as follows.

[0057] (1) A power conversion device 1, 101, 201, 301 according to a first aspect includes a capacitor 20, a power module 30, 130 arranged in parallel with the capacitor 20, a seal part 50, 250 for sealing a gap between the capacitor 20 and the power module 30, 130, a cooler 10, 110 having a cooling surface 13 for cooling the capacitor 20 and the power module 30, 130, a conductive first connection part 60 drawn from the condenser 20 to the power module 30, 130 side, a conductive second connection part 70, 370 drawn from the power module 30, 130 to the capacitor 20 side and connected to the first connection part 60, and a conductive second connection part 70, 370 drawn from the power module 30, 130 to the capacitor 20 side and connected to the first connection part 60. and a potting material 3 that fixes the connection between the capacitor 20 and the sealing portion 70, 370, and the power module 30, 130 has a base plate 31, 131 arranged on the cooling surface 13, a semiconductor chip 34 attached to the base plate 31, 131, and a casing 40 having a first chamber 42 in which the semiconductor chip 34 is housed, and a second chamber 43 in which the first connection portion 60 and the second connection portion 70, 370 are arranged and in which an opening 44 that opens to the capacitor 20 side and the opposite side to the cooling surface 13 is formed, and in which a potting chamber 41 in which the potting material 3 is filled is formed, and a notch portion 51 is formed in the sealing portion 50, 250 at a position overlapping with the opening 44.

[0058] Since the potting material 3 covers the first connection portion 60 and the second connection portions 70, 370, insulation between the first connection portion 60 and the second connection portions 70, 370 and the surrounding components (such as the base plates 31, 131 and the casing 40) is ensured. Furthermore, since the potting material 3 fixes the first connection portion 60 and the second connection portion 70, 370, the first connection portion 60 and the second connection portion 70, 370 can be connected by a simple method such as welding without fastening the first connection portion 60 and the second connection portion 70, 370 with a screw. Therefore, since there is no need to consider interference between the fastening screw and the base plate 31, 131, the first connection portion 60 and the second connection portion 70, 370 can be brought close to the base plate 31, 131. Therefore, the distance between the first connection portion 60 and the second connection portion 70, 370 and the cooling surface 13 is reduced, and the cooling performance is further improved. In addition, it is possible to prevent the first connection portion 60 and the second connection portion 70, 370 from becoming long in the direction perpendicular to the cooling surface 13, and the ESL can be reduced. Furthermore, since the seal parts 50, 250 prevent leakage of the potting material 3, there is no need to introduce a new process for preventing leakage of the potting material 3. Since the seal parts 50, 250 are provided with the notch parts 51, the first connection part 60 is not prevented from being pulled out.

[0059] (2) The power conversion device 1, 101, 201, 301 of the second aspect is the power conversion device 1, 101, 201, 301 of the first aspect, and further includes a heat transfer portion 2a provided between the condenser 20 and the cooling surface 13 and formed from a thermal interface material, and the sealing portion 50, 250 may be formed from the same thermal interface material as the heat transfer portion 2a.

[0060] This improves the thermal conductivity between the capacitor 20 and the coolers 10, 110, and also improves the thermoelectric efficiency between the first connecting portion 60 and the second connecting portion 70, 370 and the coolers 10, 110. In addition, since the seal portions 50, 250 and the heat transfer portion 2a can be formed from the same material, it is possible to improve the manufacturing efficiency and reduce the manufacturing cost.

[0061] (3) The power conversion device 101 of the third aspect is the power conversion device 101 of the first or second aspect, wherein a plurality of the power modules 130 are provided, and a step surface 115 against which the power module 130 abuts is provided in the area of ​​the cooling surface 13 between the condenser 20 and the power module 130, and the step surface 115 may extend linearly in a direction perpendicular to the opposing direction between the condenser 20 and the power module 130 and along the condenser 20.

[0062] As a result, the surfaces of the power modules 130 facing the capacitor 20 can be arranged on the same plane by abutting the power modules against the step surface 115. This makes it possible to prevent variation in the distance between the power modules 130 and the capacitor 20, and ensures that the gap between the capacitor 20 and the power module 130 is sealed by the seal portion 50.

[0063] (4) The power conversion device 201 of the fourth aspect is the power conversion device 201 of the first or second aspect, wherein a plurality of the power modules 30 are provided, and the sealing portion 250 may have a thickness sufficient to enable expansion and contraction in the opposing direction between the capacitor 20 and the power modules 30.

[0064] With this arrangement, by pressing a plurality of power modules 30 against the seal portion 250, the seal portion 250 expands and contracts, and can absorb variations in the distance between the power modules 30 and the capacitors 20. Therefore, the gaps between the power modules 30 and the capacitors 20 can be reliably sealed by the seal portion 250.

[0065] (5) A fifth aspect of the power conversion device 301 is a power conversion device 301 of any one of the first to fourth aspects, and at least a portion of the second connection portion 370 that is connected to the first connection portion 60 may be close to the base plate 31 and extend along the base plate 31.

[0066] This can further reduce the ESL by affecting the loop current flowing through the power module 30. Furthermore, the heat of the first connection portion 60 and the second connection portion 370 can be easily transferred to the cooler 10, and the cooling capacity can be further improved. [Explanation of symbols]

[0067] 1...power conversion device 2...heat transfer sheet 2a...heat transfer portion 3...potting material 10...cooler 11...unit case 12...flow path 13...cooling surface 14...insertion hole 20...capacitor 20a...lower surface 21...screw 22...groove 23...opening 30...power module 31...base plate 32...insulating plate 33...metal plate 34...semiconductor chip 35...wire bonding 36...fin 37...screw 40...casing 41...potting chamber 42...first chamber 43...second chamber 44...opening 50...seal portion 51...notch portion 60...first connection portion 70...second connection portion 71...chip side end portion 72...main body portion D1...first direction D2...second direction D3...third direction W...cooling water 101...power conversion device 110...cooler 115...step surface 130...power module 131...base plate 131a...fixing hole 201...power conversion device 250...sealing part 301: Power conversion device 370: Second connection portion 372: Main body portion 4: Insulating sheet

Claims

1. A capacitor; A power module arranged in parallel with the capacitor; a seal portion that seals a gap between the capacitor and the power module; a cooler having a cooling surface for cooling the condenser and the power module; a conductive first connection portion extended from the capacitor to the power module side; a conductive second connection portion that is drawn from the power module to the capacitor side and is connected to the first connection portion; a potting material that fixes the connection between the first connection portion and the second connection portion; Equipped with The power module comprises: a base plate disposed on the cooling surface; a semiconductor chip attached to the base plate; a casing including a first chamber in which the semiconductor chip is housed, and a second chamber in which the first connection portion and the second connection portion are disposed and in which openings are formed that open to the capacitor side and to the side opposite to the cooling surface, and in which a potting chamber is formed in which the potting material is filled; having The sealing portion has a notch formed at a position overlapping with the opening.

2. a heat transfer portion provided between the capacitor and the cooling surface and formed of a thermal interface material; The power converter according to claim 1 , wherein the seal portion is formed from the same thermal interface material as the heat transfer portion.

3. The power module is provided in plurality, a step surface with which the power module comes into contact is provided in a region of the cooling surface between the capacitor and the power module, The power conversion device according to claim 1 , wherein the step surface extends linearly along the capacitor in a direction perpendicular to a direction in which the capacitor and the power module face each other.

4. The power module is provided in plurality, The power conversion device according to claim 1 or 2, wherein the seal portion has a thickness sufficient to enable expansion and contraction in a direction in which the capacitor and the power module face each other.

5. 3 . The power conversion device according to claim 1 , wherein at least a portion of the second connection portion that is connected to the first connection portion is close to the base plate and extends along the base plate.

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